Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1998 Isla de Vieques Isla de Culebra St. Thomas St. John I P U E R T O R I C O St. Croix I Prepared in cooperation with the Commonwealth of U.S. Department of the Interior Puerto Rico, the Government of the U.S. Virgin Islands, U.S. Geological Survey and with other agencies U.S. Department of the Interior U.S. Geological Survey Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1998 By Pedro L. Díaz, Zaida Aquino, Carlos Figueroa-Alamo, Ricardo J. Vachier, and Ana V. Sánchez Water-Data Report PR-98-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other agencies U.S. DEPARTMENT OF THE INTERIOR BRUCE BABBITT, Secretary U.S. GEOLOGICAL SURVEY Charles G. Groat, Director For additional information on the water resources investigation programs in Puerto Rico and the U.S. Virgin Islands write to: Chief, Caribbean District, Water Resources Division U.S. Geological Survey GSA Center, 651 Federal Drive Suite 400-15 Guaynabo, Puerto Rico 00965 Telephone: (787) 749-4346 1999 III PREFACE This annual hydrologic data report of Puerto Rico and the U.S. Virgin Islands is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey’s surface- and ground-water data-collection networks in each state, Puerto Rico, the U.S. Virgin Islands, and the other Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by state, local, and Federal agencies, and the private sector for developing and managing our Nation’s land and water resources. The report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey, Water Resources Division, who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and assembled the report. In addition to the authors, who had primary responsibility for assuring that the information contained herein is accurate, complete, and adheres to the U.S. Geological Survey policy and established guidelines, the Caribbean District would like to acknowledge Heriberto Torres-Sierra, Surface-Water Specialist, for his dedication and long hours of hard work. With the help of the Hydrologic Studies Section, he determined peak discharges for the Hurricane Georges floods. The following personnel contributed significantly to the collection, processing and tabulations of the data: José M. Agis George Arroyo Gregory Cherry Iris M. Concepción Israel Cruz Angel G. Ferrer Robert Fitzhugh Wilfredo García Hector Guardiola Evelyn S. Guevara Senén Guzmán-Ríos Felipe Hernández Sandra Lagares José Merced Carlos Narvaez Victoria Nuñez Rafael Peña-Cortez Ronald T. Richards Carlos C. Rodríguez Julio A. Rodríguez Miguel Rodríguez Rafael M. Rodríguez José René Sánchez Luis Santiago-Rivera Carlos Santos Luis Soler Angel Torres James Torres José A. Torres Ahmed Valencia Luis Vega Ruth I. Guzmán typed the text of the report. Francisco Maldonado prepared the illustrations. This report was prepared in cooperation with agencies of the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other federal agencies under the general supervision of Rafael W. Rodríguez, District Chief, Caribbean District, San Juan, Puerto Rico. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE July 28 , 1999 3. REPORT TYPE AND DATES COVERED Annual - October 1, 1997 to September 30, 1998 4. TITLE AND SUBTITLE Water Resources Data for Puerto Rico and the U.S. Virgin Islands Water Year 1998 5. FUNDING NUMBERS 6. AUTHOR(S) Pedro L. Díaz, Zaida Aquino, Carlos Figueroa-Alamo, Ricardo J. Vachier, Ana V. Sánchez 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 8. PERFORMING ORGANIZATION REPORT NUMBER USGS-WDR-PR-98-1 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 10. AGENCY REPORT NUMBER SPONSORING / MONITORING USGS-WDR-PR-98-1 11. SUPPLEMENTARY NOTES Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies. 12a. DISTRIBUTION / AVAILABILITY STATEMENT NO RESTRICTION ON DISTRIBUTIONS 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 words) Water resources data for surface-water, quality-of-water, and ground-water records for the 1998 water year for Puerto Rico and the U.S. Virgin Islands consists of records of discharge, water quality of streams, and water levels of wells. This report contains discharge records for 76 streamflow-gaging stations; daily sediment records for 27 streamflow stations; 99 partial-record or mis­ cellaneous streamflow stations; stage records for 17 reservoirs; water-quality records for 16 streamflow-gaging stations, 42 un- gaged streamsites, 11 lake sites, 2 lagoons, and 1 bay; and water-level records for 97 observation wells. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating local and federal agencies in Puerto Rico and the U.S. Virgin Islands. 14. SUBJECT TERMS *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data sediments, Streamflow, Water analysis, Water levels, Lakes 15. NUMBER OF PAGES 646 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION OF THIS PAGE Unclassified 19. SECURITY CLASSIFICATION OF ABSTRACT 20. LIMITATION OF ABSTRACT NS N 7540-01-280-5500 Standard Form 298 (Rev. 2-89) Prescribed by A NSI S td 239-18 298-102 V CONTENTS Page Preface ....................................................................................................................................................................................... iii List of surface-water and water-quality stations, in downstream order, for which records are published in this volume .......................................................................................................vii List of ground-water wells, by basin, for which records are published in this volume ......................................................................................................................................................xi List of discontinued surface-water discharge or stage-only stations ........................................................................................xiv Introduction..................................................................................................................................................................................1 Cooperation..................................................................................................................................................................................2 Summary of hydrologic conditions..............................................................................................................................................3 Rainfall ..................................................................................................................................................................................3 Surface water .........................................................................................................................................................................3 Ground water .........................................................................................................................................................................6 Water quality .........................................................................................................................................................................9 Special networks and programs ................................................................................................................................................. 10 Explanation of records ............................................................................................................................................................... 10 Station identification numbers............................................................................................................................................. 11 Downstream order system............................................................................................................................................. 11 Latitude-longitude system............................................................................................................................................. 11 Records of stage and water discharge ................................................................................................................................. 19 Data collection and computation................................................................................................................................... 19 Data Presentation .......................................................................................................................................................... 20 Station manuscript .................................................................................................................................................. 20 Data table of daily mean values.............................................................................................................................. 21 Statistics of monthly mean data .............................................................................................................................. 22 Summary statistics .................................................................................................................................................. 22 Identifying estimated daily discharge ........................................................................................................................... 23 Accuracy of the records ................................................................................................................................................23 Records of surface-water quality......................................................................................................................................... 24 Classification of records................................................................................................................................................24 Arrangement of records ................................................................................................................................................24 On-site measurements and sample collection ............................................................................................................... 24 Water temperature......................................................................................................................................................................25 Sediment........................................................................................................................................................................ 25 Laboratory measurements ............................................................................................................................................. 25 Data presentation...........................................................................................................................................................26 Remark codes ................................................................................................................................................................ 27 Records of ground-water levels........................................................................................................................................... 27 Data collection and computation................................................................................................................................... 27 Data presentation...........................................................................................................................................................28 Records of ground-water quality ......................................................................................................................................... 28 Data collection and computation................................................................................................................................... 29 Data presentation...........................................................................................................................................................29 Access to U.S. Geological Survey Water Data.......................................................................................................................... 29 Definition of terms ..................................................................................................................................................................... 30 Publications on Techniques of Water-Resources Investigations ............................................................................................... 40 Surface- and quality-of-water records for Puerto Rico..............................................................................................................45 Discharge at partial-record stations in Puerto Rico ................................................................................................................. 453 Water-quality at partial-record stations in Puerto Rico ........................................................................................................... 471 Ground-water records for Puerto Rico..................................................................................................................................... 483 Surface-water records for U.S. Virgin Islands......................................................................................................................... 605 Ground-water records for U.S. Virgin Islands ........................................................................................................................ 615 Index ........................................................................................................................................................................................ 623 VI ILLUSTRATIONS Page Figure 1. Graphs showing monthly-mean discharge of selected streams in Puerto Rico ....................................................... 4 2. Graphs showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands....................... 8 3. Map showing location of maximum concentration of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico ...................................................................................................... 12 4. Map showing location of maximum concentration of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico ...................................................................................................... 13 5. Map showing location of surface-water stations in Puerto Rico ........................................................................... 14 6. Map showing location of water-quality stations in Puerto Rico............................................................................ 15 7. Map showing location of ground-water stations in Puerto Rico ........................................................................... 16 8. Map showing location of surface-water stations in the U.S. Virgin Islands ......................................................... 17 9. Map showing location of ground-water stations in the U.S. Virgin Islands.......................................................... 18 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude) .............................. 19 11. Map showing the Río Guajataca basin ................................................................................................................. 47 12. Map showing the Río Camuy basin ...................................................................................................................... 57 13. Map showing the Río Grande de Arecibo basin ................................................................................................... 61 14. Map showing the Río Grande de Manatí basin................................................................................................... 105 15. Map showing the Río Cibuco basin .................................................................................................................... 129 16. Map showing the Río de la Plata basin ............................................................................................................... 139 17. Map showing the Río Hondo to Río Puerto Nuevo basins ................................................................................. 163 18. Map showing the Río Grande de Loíza basin ..................................................................................................... 205 19. Map showing northeastern river basins -- Río Herrera to Río Antón Ruíz basins ............................................. 303 20. Map showing southeastern river basins -- Río Humacao to Quebrada Aguas Verdes ....................................... 341 21. Map showing south coast river basins -- Río Salinas to Río Jacaguas basins .................................................... 361 22. Map showing south coast river basins -- Río Inabón to Río Loco basins .......................................................... 383 23. Map showing the Río Guanajibo basin ............................................................................................................... 417 24. Map showing the Río Yagüez and Río Grande de Añasco basins...................................................................... 433 25. Map showing the Río Culebrinas basin .............................................................................................................. 445 26. Map showing location of low-flow partial-record stations in Comerío, Puerto Rico......................................... 455 27. Map showing location of low-flow partial-record stations in Caguas, Puerto Rico ........................................... 461 28. Map showing location of low-flow partial-record stations in Carolina, Puerto Rico ......................................... 467 TABLES Page Table 1. Island-wide monthly rainfall for the water year 1998 and annual averages for the 30-year reference period, 1961-90 ........................................................................................................................ 3 2. Summary of peak stages and discharges prior to and during September 21-22, 1998, at selected U.S. Geological Survey streamflow gaging stations in Puerto Rico ................................................. 5 3. Highest ground-water level recorded during water year 1998 and previous highest ground-water levels at selected wells in Puerto Rico ........................................................................................... 7 4. Lowest ground-water levels recorded during water year 1998 and previous lowest ground-water levels at selected wells in Puerto Rico ........................................................................................... 7 5. Surface-water quality stations in Puerto Rico with highest concentration of selected constituents during water year 1998 ..................................................................................................................... 9 6. Factors for conversion of chemical constituents in milligrams per liter to milli­ equivalents per liter............................................................................................................................................. 34 VII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME (Letter after station name designates type of data: (d) discharge, (c) chemical, (b) biological, (s) sediment, (p) pesticide, (e) elevation, gage heights) Station number Page RIO GUAJATACA BASIN Río Guajataca at Lares (d,c,b)....................................................................................................... 50010500 48 Lago Guajataca at Damsite near Quebradillas (e) ........................................................................ 50010800 52 Canal Principal de Diversiones at Lago Guajataca (c,b) .............................................................. 50011000 53 Río Guajataca above mouth near Quebradillas (c,b) .................................................................... 50011400 55 RIO CAMUY BASIN Río Camuy near Bayaney (d)........................................................................................................ 50014800 58 RIO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e) ............................................................................................. 50020100 62 Río Grande de Arecibo near Adjuntas (c,b).................................................................................. 50020500 63 Río Grande de Arecibo below Utuado (d,s).................................................................................. 50024950 65 Río Grande de Arecibo near Utuado (c,b) .................................................................................... 50025000 71 Río Saliente at Coabey near Jayuya (d) ................................................................................ 50025155 73 Río Caonillas at Paso Palma (d,s) ................................................................................................. 50026025 75 Río Caonillas above Lago Caonillas near Jayuya (c,b) ................................................................ 50026050 81 Lago Caonillas at Damsite near Utuado (e) .......................................................................... 50026140 83 Río Grande de Arecibo below Lago Dos Bocas near Florida (c,b) .............................................. 50027250 84 Río Grande de Arecibo above Arecibo (d,s)................................................................................. 50027750 86 Río Tanamá near Utuado (d,c,b,s) ........................................................................................ 50028000 92 Río Tanamá at Charco Hondo (d) ........................................................................................ 50028400 99 Río Grande de Arecibo at Central Cambalache (d,c,b) ................................................................ 50029000 101 RIO GRANDE DE MANATI BASIN Río Orocovis at Orocovis (d)................................................................................................ 50030460 106 Río Orocovis near Orocovis (c,b) ......................................................................................... 50030700 108 Río Grande de Manatí near Morovis (d,c,b) ................................................................................. 50031200 110 Lago El Guineo at Damsite near Villalba (e)........................................................................ 50032290 114 Lago de Matrullas at Damsite near Orocovis (e) .................................................................. 50032590 115 Río Bauta near Orocovis (d) ................................................................................................. 50034000 116 Río Grande de Manatí at Ciales (d) .............................................................................................. 50035000 118 Río Grande de Manatí at Highway 149 at Ciales (c,b) ................................................................. 50035500 120 Río Cialitos at Highway 649 at Ciales (c,b) ......................................................................... 50035950 121 Río Grande de Manatí at Highway 2 near Manatí (d,c,b,p).......................................................... 50038100 123 LAGUNA TORTUGUERO BASIN Laguna Tortuguero Outlet near Vega Baja (c,b) .......................................................................... 50038200 127 RIO CIBUCO BASIN Río Cibuco below Corozal (d,c,b) ................................................................................................ 50038320 130 Río Cibuco at Vega Baja (d,c,b) ................................................................................................... 50039500 134 RIO DE LA PLATA BASIN Lago Carite at Gate Tower near Cayey (e) ................................................................................... 50039990 140 Río de la Plata at Proyecto La Plata (c,b) ..................................................................................... 50043000 141 Río de la Plata at Comerio (d,s) .................................................................................................... 50043800 143 Río de la Plata near Comerio (c,b)................................................................................................ 50044000 149 Río Guadiana near Naranjito (c,b) ........................................................................................ 50044850 151 Lago La Plata at Damsite near Toa Alta (e) ................................................................................. 50045000 153 Río de la Plata below La Plata Dam (d,s) ..................................................................................... 50045010 154 Río de la Plata at Highway 2 near Toa Alta (d,c,b,s,p)................................................................. 50046000 159 RIO HONDO BASIN Río Hondo at Flood Channel near Cataño (c,b)............................................................................ 50047530 164 VIII SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO DE BAYAMON BASIN Río de Bayamón at Arenas (d)...................................................................................................... 50047535 166 Río Sabana at Vista Monte (d).............................................................................................. 50047540 168 Lago de Cidra at Damsite near Cidra (e) ...................................................................................... 50047550 170 Río de Bayamón below Cidra Dam (d,s) ...................................................................................... 50047560 171 Río de Bayamón near Aguas Buenas (c,b) ................................................................................... 50047600 177 Río de Bayamón near Bayamón (d).............................................................................................. 50047850 179 Río Guaynabo near Bayamón (c,b)....................................................................................... 50047990 181 Río de Bayamón at Flood Channel at Bayamón (c,b,p) ............................................................... 50048510 183 RIO PUERTO NUEVO BASIN Río Piedras: Lago Las Curías at Damsite near Río Piedras (e) ......................................................................... 50048680 185 Río Piedras at El Señorial(d,s) ...................................................................................................... 50048770 186 Río Piedras near Río Piedras (c,b,p) ............................................................................................. 50048800 197 Río Piedras at Hato Rey (d,c,b) .................................................................................................... 50049100 199 Laguna San José: Laguna San José No. 2 at San Juan (c,b) ...................................................................................... 50049820 203 Bahía de San Juan: Bahía de San Juan No. 5 at San Juan (c,b).................................................................................... 50049920 204 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b) ........................................................................................... 50050300 206 RIO GRANDE DE LOIZA BASIN Río Grande de Loíza at Quebrada Arenas (d)............................................................................... 50050900 208 Quebrada Blanca at El Jagual (d,s) ....................................................................................... 50051150 210 Quebrada Salvatierra near San Lorenzo (d,s) ....................................................................... 50051180 216 Río Cayaguás at Cerro Gordo (d) ......................................................................................... 50051310 222 Río Grande de Loíza at Highway 183 near San Lorenzo (d,s) ..................................................... 50051800 224 Río Turabo above Borinquen (d,s)........................................................................................ 50053025 230 Río Grande de Loíza at Caguas (d,c,b,s) ...................................................................................... 50055000 236 Río Caguitas near Aguas Buenas (d,s).................................................................................. 50055100 243 Río Caguitas at Villa Blanca at Caguas (d,s)........................................................................ 50055225 249 Río Caguitas at Highway 30 at Caguas (c,b) ........................................................................ 50055250 255 Río Bairoa at Bairoa (d,s) ..................................................................................................... 50055390 257 Río Bairoa near Caguas (c,b) ................................................................................................ 50055400 263 Río Gurabo: Río Gurabo below El Mangó (d,s)........................................................................................ 50055750 265 Río Valenciano near Juncos (d,s)..................................................................................... 50056400 271 Río Gurabo at Gurabo (d,s)................................................................................................... 50057000 277 Río Gurabo near Gurabo (c,b) .............................................................................................. 50057025 283 Río Cañas at Río Cañas (d,s) ................................................................................................ 50058350 285 Lago Loíza at Damsite near Trujillo Alto (c,b,e).......................................................................... 50059000 291 Río Grande de Loíza below Damsite (d,s).................................................................................... 50059050 293 Río Grande de Loíza below Trujillo Alto (c,b)............................................................................. 50059100 299 Río Canóvanas near Campo Rico (d).................................................................................... 50061800 301 RIO ESPIRITU SANTO BASIN Quebrada Sonadora near El Verde........................................................................................ 50063440 304 Río Espíritu Santo near Río Grande (d,c,b) .................................................................................. 50063800 306 Río Grande near El Verde (d) ............................................................................................... 50064200 310 RIO MAMEYES BASIN Río Mameyes near Sabana (d,s).................................................................................................... 50065500 312 Río Mameyes at Mameyes (d) ...................................................................................................... 50066000 317 IX SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO SABANA BASIN Río Sabana at Sabana (d) .............................................................................................................. 50067000 321 RIO FAJARDO BASIN Río Fajardo above Fajardo (d,s).................................................................................................... 50070500 323 Río Fajardo near Fajardo (d,c,b,p,s) ............................................................................................. 50071000 329 Río Fajardo below Fajardo (c,b) ................................................................................................... 50072500 335 RIO BLANCO BASIN Quebrada Guabá near Naguabo (d)............................................................................................... 50074950 337 Río Icacos near Naguabo (d)......................................................................................................... 50075000 339 RIO HUMACAO BASIN Río Humacao at Las Piedras (d) ................................................................................................... 50081000 342 Río Humacao at Highway 3 at Humacao (c,b) ............................................................................. 50082000 344 RIO GUAYANES BASIN Río Guayanés at Yabucoa (c,b,p) ................................................................................................. 50083500 346 Río Guayanés above mouth at Playa de Guayanés (c,b) .............................................................. 50086500 348 RIO MAUNABO BASIN Río Maunabo at Lizas (d) ............................................................................................................. 50090500 350 Río Maunabo at Maunabo (c,b) .................................................................................................... 50091000 352 RIO CHICO BASIN Río Chico at Providencia (c,b)...................................................................................................... 50091800 354 RIO GRANDE DE PATILLAS BASIN Río Grande de Patillas near Patillas (d,c,b) .................................................................................. 50092000 356 Lago Patillas at Damsite near Patillas (e) ..................................................................................... 50093045 359 RIO SALINAS BASIN Río Lapas near Rabo del Buey (d)................................................................................................ 50100200 362 Río Majada at La Plena (d) ........................................................................................................... 50100450 364 RIO COAMO BASIN Río Coamo at Coamo (d) .............................................................................................................. 50106100 366 Río Coamo near Coamo (c,b) ....................................................................................................... 50106500 368 RIO DESCALABRADO BASIN Río Descalabrado near Los Llanos (d).......................................................................................... 50108000 370 RIO JACAGUAS BASIN Río Toa Vaca above Lago Toa Vaca (d,s)............................................................................ 50110900 372 Lago Toa Vaca at Damsite near Villaba (e).................................................................................. 50111210 378 Lago Guayabal at Damsite near Juana Díaz (e)............................................................................ 50111300 380 Río Jacaguas at Juana Díaz (d) ..................................................................................................... 50111500 381 IO INABON BASIN Río Inabón at Real Abajo (d) ........................................................................................................ 50112500 384 RIO BUCANA BASIN Río Bucaná: Río Cerrillos above Lago Cerrillos near Ponce (d)....................................................................... 50113800 386 Lago Cerrillos at Damsite near Ponce (e) ..................................................................................... 50113950 388 Río Cerrillos near Ponce (d,c,b).................................................................................................... 50114000 389 Río Bucaná at Highway 14 Bridge near Ponce (d) ....................................................................... 50114390 393 X SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO PORTUGUES BASIN Río Portugués at Tibes (d,s).......................................................................................................... 50114900 395 Río Portugués near Ponce (c,b)................................................................................................... ..50115000 401 Río Potugués at Highway 14 near Ponce (d) ................................................................................ 50115900 403 Río Portugués at Ponce (c,b,p)...................................................................................................... 50116200 407 RIO GUAYANILLA BASIN Río Guayanilla near Guayanilla (d) .............................................................................................. 50124200 409 Río Guayanilla at Central Rufina (c,b,p) ...................................................................................... 50124700 411 RIO YAUCO BASIN Lago Lucchetti at Damsite near Yauco (e) ................................................................................... 50125780 413 RIO LOCO BASIN Lago Loco at Damsite near Yauco (e) .......................................................................................... 50128900 414 Río Loco at Guánica (c,b,p) .......................................................................................................... 50129700 415 RIO GUANAJIBO BASIN Río Guanajibo at Highway 119 at San Germán (d) ...................................................................... 50131990 418 Río Guanajibo near San Germán (c,b) .......................................................................................... 50133600 420 Río Rosario near Hormigueros (d,c,b,s) ............................................................................... 50136400 422 Río Guanajibo near Hormigueros (d,c,b,p)................................................................................... 50138000 429 RIO YAGUEZ BASIN Río Yagüez near Mayagüez (c,b).................................................................................................. 50138800 434 RIO GRANDE DE AÑASCO BASIN Lago Guayo at Damsite near Castañer (e) ............................................................................ 50141500 436 Río Grande de Añasco near Lares (c,b) ........................................................................................ 50143000 437 Río Grande de Añasco near San Sebastián (d,c,b)........................................................................ 50144000 439 Río Grande de Añasco near Añasco (c,b,p) .................................................................................. 50146000 443 RIO CULEBRINAS BASIN Río Culebrinas near San Sebastián (c,b)....................................................................................... 50147600 446 Río Culebrinas at Highway 404 near Moca (d) ............................................................................ 50147800 448 Río Culebrinas near Aguada (c,b,p).............................................................................................. 50149100 450 Discharge at partial-record stations and miscellaneous sites low-flow partial-record stations.................................................................................................................... 456 Analyses of samples collected of water-quality partial-record stations and miscellaneous sites.................................................................................................................... 472 ST. THOMAS, U.S. VIRGIN ISLANDS Bonne Resolution Gut at Bonne Resolution (d) ........................................................................... 50252000 606 Turpentine Run at Mount Zion (d)................................................................................................ 50274000 608 ST. JOHN, U.S. VIRGIN ISLANDS Guinea Gut at Bethany (d) ............................................................................................................ 50295000 610 ST. CROIX, U.S. VIRGIN ISLANDS Jolly Hill Gut at Jolly Hill (d) ....................................................................................................... 50345000 612 XI GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RIO GUAJATACA BASIN Well 182925067031100 Local number OT-1.....................................................................................................................................484 Well 182422067015100 Local number 165 .......................................................................................................................................486 Well 182647066552400 Local number 202 .......................................................................................................................................487 RIO CAMUY BASIN Well 182723066511200 Local number Z-4........................................................................................................................................488 Well 182431066463400 Local number CA-4.....................................................................................................................................490 RIO GRANDE DE ARECIBO BASIN Well 182756066454700 Local number BARR-1 ...............................................................................................................................492 Well 182737066370900 Local number 204 .......................................................................................................................................493 Well 182616066364100 Local number EN-1.....................................................................................................................................494 Well 182626066345100 Local number TI-1 ......................................................................................................................................495 Well 182603066333601 Local number FA-2 .....................................................................................................................................496 Well 182209066340600 Local number FL-1 .....................................................................................................................................498 RIO GRANDE DE MANATI BASIN Well 182757066325600 Local number 206 .......................................................................................................................................499 Well 182710066303700 Local number 207 .......................................................................................................................................500 Well 182549066304300 Local number 166 .......................................................................................................................................501 Well 182506066280200 Local number HI-2......................................................................................................................................502 Well 182308066260400 Local number 210 .......................................................................................................................................503 Well 182548066265700 Local number CS-7 .....................................................................................................................................504 RIO CIBUCO BASIN Well 182614066261500 Local number PA-2 .....................................................................................................................................505 Well 182712066251700 Local number TO-3.....................................................................................................................................506 Well 182615066235300 Local number 211 .......................................................................................................................................507 Well 182647066201700 Local number 70 .........................................................................................................................................508 Well 182515066194000 Local number 212 .......................................................................................................................................509 Well 182330066185700 Local number 213 .......................................................................................................................................510 RIO DE LA PLATA BASIN Well 182804066173500 Local number DA-1 ....................................................................................................................................511 Well 182526066165001 Local number SR-2 .....................................................................................................................................512 Well 182548066164401 Local number MA-2....................................................................................................................................513 Well 182620066163400 Local number HG-1 ....................................................................................................................................514 Well 182620066163403 Local number HG-4 ....................................................................................................................................517 Well 182657066162700 Local number SA-1 .....................................................................................................................................518 Well 182657066162701 Local number SA-3 .....................................................................................................................................519 Well 182654066150600 Local number TB-1 .....................................................................................................................................520 Well 182530066135400 Local number 216 .......................................................................................................................................521 Well 182655066142400 Local number 217 .......................................................................................................................................522 XII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED RIO HONDO TO RIO PUERTO NUEVO BASINS Well 182441066082600 Local number 219 .......................................................................................................................................523 Well 182531066075900 Local number 652 .......................................................................................................................................524 Well 182511066045401 Local number PN-2 .....................................................................................................................................526 Well 182435066052700 Local number PN-5 .....................................................................................................................................527 Well 182445066043401 Local number PN-6 .....................................................................................................................................528 Well 182443066041502 Local number PN-8c ...................................................................................................................................529 Well 182417066042700 Local number PN-10 ...................................................................................................................................530 Well 182349066032600 Local number PN-13 ...................................................................................................................................531 Well 182406066034700 Local number PN-19 ...................................................................................................................................532 RIO GRANDE DE LOIZA BASIN Well 181352066025300 Local number CJ-TW19A...........................................................................................................................533 Well 181311066022500 Local number CJ-TW11..............................................................................................................................534 Well 181446066013400 Local number CJ-TW20..............................................................................................................................536 Well 181539066014500 Local number CJ-TW15..............................................................................................................................538 Well 181550065593200 Local number 50 .........................................................................................................................................540 Well 182515065594100 Local number 222 .......................................................................................................................................541 Well 181540065580300 Local number CJ-TW18..............................................................................................................................542 Well 181513065554600 Local number CJ-TW3B .............................................................................................................................544 RIO HERRERA TO RIO ANTON RUIZ BASINS Well 182344065490801 Local number RE-2A ..................................................................................................................................545 Well 182223065455900 Local number RM-02..................................................................................................................................547 Well 181230065444900 Local number ARR-1..................................................................................................................................548 Well 182138065431800 Local number RS-02 ...................................................................................................................................549 Well 182131065421100 Local number RP-04 ...................................................................................................................................550 Well 181823065401900 Local number RF-04 ...................................................................................................................................551 Well 181917065382701 Local number RF-12 ...................................................................................................................................552 RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS Well 180358065503600 Local number YDO-1 .................................................................................................................................553 Well 180415065513900 Local number 96 .........................................................................................................................................554 Well 175855066023100 Local number FID-2....................................................................................................................................555 Well 175855066050500 Local number ALG-1..................................................................................................................................557 Well 175728066072200 Local number BAR-1..................................................................................................................................559 Well 175719066085500 Local number P-13......................................................................................................................................561 Well 175858066100200 Local number 6 ...........................................................................................................................................562 Well 180002066132200 Local number HW-TW-01..........................................................................................................................563 Well 180001066122002 Local number HW-TW-03C .......................................................................................................................564 Well 175947066130601 Local number HW-TW-5B .........................................................................................................................565 Well 175957066123400 Local number HW-TW-13..........................................................................................................................566 XIII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED RIO SALINAS TO RIO JACAGUAS BASINS Well 175809066133100 Local number CQ-1.....................................................................................................................................567 Well 180206066135500 Local number RM-5 ....................................................................................................................................568 Well 180104066152300 Local number RM-10..................................................................................................................................569 Well 175910066155500 Local number SA-D ...................................................................................................................................570 Well 175708066163000 Local number EC-1 .....................................................................................................................................572 Well 175903066165000 Local number PG-07 ...................................................................................................................................574 Well 175943066224800 Local number PS-07....................................................................................................................................575 Well 175829066232200 Local number 87 .........................................................................................................................................576 Well 180020066261500 Local number CA-1.....................................................................................................................................577 Well 180048066301800 Local number FA-1 .....................................................................................................................................579 RIO INABON TO RIO LOCO BASINS Well 175950066354200 Local number 141 .......................................................................................................................................581 Well 175934066364800 Local number CO-3.....................................................................................................................................582 Well 180045066381600 Local number AN-1 ....................................................................................................................................585 Well 180156066434000 Local number LV-1.....................................................................................................................................586 Well 180133066503300 Local number 132 .......................................................................................................................................588 RIO GUANAJIBO BASIN Well 180132067033800 Local number 143 .......................................................................................................................................589 Well 180542067084000 Local number CR-1.....................................................................................................................................590 Well 180628067084300 Local number CR-TW9A............................................................................................................................593 Well 180628067084301 Local number CR-TW9B ............................................................................................................................594 RIO YAGUEZ TO RIO GRANDE DE AÑASCO BASINS Well 181232067083700 Local number CI-1 ......................................................................................................................................597 RIO CULEBRINAS BASIN Well 181911067140500 Local number C-4........................................................................................................................................599 Well 182017067143300 Local number R-4 .......................................................................................................................................601 Well 182442067091700 Local number 200 .......................................................................................................................................604 ST. CROIX, U.S. VIRGIN ISLANDS Well 174225064472000 Local number 2 ...........................................................................................................................................616 Well 174243064475100 Local number 3 ...........................................................................................................................................617 Well 174316064480800 Local number 13 .........................................................................................................................................618 ST. THOMAS, U.S. VIRGIN ISLANDS Well 182038064550300 Local number 6 ...........................................................................................................................................619 Well 182038064580000 Local number 8 ...........................................................................................................................................620 ST. JOHN, U.S. VIRGIN ISLANDS Well 181956064464500 Local number 11 .........................................................................................................................................621 -- -- -- -- XIV WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 DISCONTINUED STREAMFLOW STATIONS The following continuous-record streamflow stations in Puerto Rico and the U.S. Virgin Islands have been discontinued or converted to partial-record stations. Daily streamflow or stage records were collected for the period of record shown for each station. Station number Station name Drainage area (mi2) Period of record 50007000 Quebrada de los Cedros near Isabela 6.91 1970 50010600 Río Guajataca above Lago de Guajataca 1984-89 50011000 Canal Diversion Lago Guajataca 1970 50011200 Río Guajataca below Lago Guajataca 1969-70,1984-87 50011400 Río Guajataca above mouth near Quebradillas 1969-70,1984-89 50013000 Río Camuy near Lares 7.62 1969-71 50014000 Río Criminales near Lares 4.68 1969-70 50014600 Río Camuy at Tres Pueblos Sinkhole -- 1990-96 50015700 Río Camuy near Hatillo -- 1984-96 50016000 Río Camuy near Camuy -- 1969-73 50021000 Río Pellejas at Central Pellejas 5.46 1968-70 50021050 Río Pellejas below Central Pellejas 7.89 1972-75 50021500 Río Pellejas near Utuado 9.55 1969-71 50023000 Río Viví near Central Pellejas 5.66 1969-75 50027200 Río Grande de Arecibo blw. Lago dos Bocas 169 1970-71 50029000 Río Grande de Arecibo at Central Cambalache 200 1969-83 50031500 Río Sana Muerto near Orocovis 3.68 1965-70 50035200 Río Grande de Manatí at Hwy 145 at Ciales 132 1972 50035950 Río Cialitos at Hwy 649 at Ciales 17 1970-82 50038360 Río Mavilla near Corozal 9.51 1969-70 50038600 Río Unibón near Morovis 5.29 1969-70 50038700 Río Morovis at Morovis 1.26 1968 50038900 Río Indio at Vega Baja -- 1963,66,71 50039600 Río Cibuco at Central San Vicente -- 1969-72 50043200 Río Usabon near Barranquitas 9.15 1968-69,71 50043400 Río Aibonito Tributary near Aibonito 1.13 1968-71 50044600 Río Guadiana near Naranjito 1.73 1971 50044650 Quebrada del Toro near Naranjito 0.54 1971 50044800 Quebrada Anones near Naranjito 2.32 1971 50045700 Río Lajas at Toa Alta 8.65 1966-75 50047820 Río de Bayamón at Hwy 174 near Bayamón 31.90 1966 50048000 Río de Bayamón at Bayamón 71.90 1963-67 50049000 Río Piedras at Río Piedras 12.5 1971-82, 1987-93 50049310 Quebrada Josefina at Piñero Avenue 3.84 1988-91 50053050 Río Turabo at Borinquen 7.89 1984-90 50054000 Quebrada de las Quebradillas near Caguas 6.25 1969-71,73 50055170 Río Cagüitas near Caguas 8.27 1992-97 50055650 Quebrada Caimito near Juncos 0.82 1984-87 50056000 Río Valenciano near Las Piedras 6.85 1971 50056900 Quebrada Mamey near Gurabo 2.30 1984-92 XV WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50058300 Quebrada Arena near Caguas -- 1971 50059000 Río Piedras at Río Piedras 12.5 1971-82, 1987-93 50061300 Río Canovanillas near Loíza 14.40 1968-73 50062500 Río Herrera near Colonia Dolores 2.75 1968-72 50063300 Río Espíritu Santo near El Verde 2.23 1968-73 50063500 Quebrada Toronja at El Verde 0.064 1983-96 50065700 Río Mameyes at Hwy 191 at Mameyes 11.80 1967-85 50072000 Río Fajardo at Fajardo 21.60 1960-63 50073200 Río Daguao at Daguao 2.26 1966-82 50073400 Quebrada Palma at Daguao 4.84 1972-77 50074000 Río Santiago at Naguabo 4.99 1966-82 50075500 Río Blanco at Florida 11.00 1966-82 50076000 Río Blanco near Florida 12.30 1983-85 50077000 Río Blanco at Río Blanco 17.60 1973-77 50077400 Río Blanco at Colonia La Fe 18.80 1967-70 50078500 Río Anton Ruíz at Central Pasto Viejo 4.33 1968 50081500 Río Humacao near Humacao 9.23 1973 50082000 Río Humacao at Hwy 3 at Humacao 17.30 1983-85 50082200 Río Humacao near La Suiza 19.90 1965-66, 1969-71 50082800 Río Guayanés near Colonia Laura 4.69 1969-82 50083500 Río Guayanés near Yabucoa 17.20 1969-71 50084000 Río Limones near Yabucoa 7.89 1969-71 50085100 Río Guayanés at Central Roig 26.60 1965-66, 1968,70 50086100 Río del Ingenio at Comunas 5.50 1965-66, 1968-69 50086500 Río Guayanés at Playa Guayanés 34.00 1965-66, 1968-71 50087200 Caño Santiago near Central Roig 6.04 1965-71 50091000 Río Maunabo at Maunabo 12.40 1965,67, 1969-82 50091200 Río Maunabo near Maunabo 12.70 1971-72 50091400 Río Jacaboa near Lamboglia 4.13 1965-73 50091700 Río Chico at Patillas 6.82 1965, 1969-72 50091800 Río Chico at Providencia 50094200 Río Grande de Patillas at Patillas 50094300 Río Grande de Patillas at Providencia 50094400 Río Nigua at Pitahaya 50095200 Río Guamaní at Guayama 4.90 1965, 1967-69, 1971 27.90 1967, 1969, 1971 29.00 1971 5.86 1965, 1969, 1970-71, 1973 8.22 1969-71 50095500 Río Guamaní near Guayama 50099000 Quebrada Aguas Verdes near Salinas 50106500 Río Coamo near Coamo 50106900 Río Coamo below Lago Coamo near Coamo 50107200 Río Coamo at mouth near Santa Isabel 12.30 1969-70 0.39 1989 46.00 1967-68, 1984-85, 1986 65.40 1967-68 69.30 1967-68 50108200 Río Descalabrado at Las Ollas 13.90 1965, 1967-71 50108500 Río Descalabrado near Santa Isabel 18.10 1966-67 50111200 Río Toa Vaca near Villalba 21.40 1966-70 50111700 Río Jacaguas near Juana Díaz 53.20 1966-68 50111750 Río Jacaguas below Quebrada Guanábana 56.30 1989 XVI WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50112100 Río Jacaguas near Arús 59.60 1966-67 50112600 Río Inabón at Coto Laurel -- 1967-71 50113100 Río Guayo near Coto Laurel 11.80 1965, 1968-71 50113500 Río Inabón near Arús 30.20 1964-65 50114400 Río Bucaná near Ponce 25.60 1965-81 50114700 Río Bucaná near Playa de Ponce 28.40 1964-67 50115000 Río Portugués near Ponce 8.82 1964-97 50116500 Río Portugués at Highway 2 Bypass at Ponce 20.50 1964-65 50119000 Río Matilde at Ponce 19.40 1965-66 50121000 Río Tallaboa at Peñuelas 24.20 1959-82 50122000 Río Tallaboa at Tallaboa 31.50 1959-63 50124000 Río Guayanilla nr Guayanilla 18.50 1961-69 50124500 Río Guayanilla at Guayanilla 20.80 1971-82 50125900 Río Duey above Diversion near Yauco 8.93 1977-80 50126150 Río Yauco above Diversion Monserrate near Yauco 27.20 1978-85 50128000 Río Yauco near Yauco 45.50 1962-64, 1977-85 50129000 Río Loco near Yauco 8.50 1963-67 50129500 Río Loco near Guánica 21.00 1963-69 50129900 Laguna Cartagena near Boquerón -- 1984-86 50130320 Quebrada Mamey at Joyuda 0.38 1986-88 50136000 Río Rosario at Rosario 16.40 1975-86 50141000 Río Yahuecas near Adjuntas 15.40 1980-85 50145000 Río Grande de Añasco at El Espino 108.00 1959-66, 1961-63 50147000 Río Culebrinas at San Sebastian 16.70 1960-82 50214500 Quebrada Resaca near Monte Resaca, Culebra 0.23 1991-93 50215000 Drainage Canal at Culebra Airport, Culebra 0.08 1991-93 50231000 Quebrada Confresí Tributary near Isabel II, Vieques 0.28 1991-93 50232000 Quebrada La Mina near Esperanza, Vieques 0.68 1991-96 50233000 Quebrada Pilón at Colonia Puerto Real, Vieques 0.67 1991-96 50276000 Turpentine Run at Mariendal 2.97 1963-69, 1978-86 50292600 Lameshur Bay Gut at Lameshur, St. John 0.38 1992-94 50294000 Fish Bay Gut at Fish Bay, St. John 1.48 1992-94 50295500 Cruz Bay Gut at Cruz Bay, St. John, V 0.09 1992-93 50332000 River Gut at River 1.42 1991-93 50333500 River Gut near Golden Grove 5.40 1990-93 50333700 River Gut at Hwy 66 at Fairplanes 5.89 1990-96 50334500 Bethehem Gut at Hwy 66 at Fairplanes 4.11 1990-96 50337500 Gut 4.5 at Cane Valley 0.2 1991-93 50348000 Salt River at Canaan 0.36 1991-93 50349000 Gut 10 near Altona 0.13 1991-93 1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 INTRODUCTION The Water Resources Division of the U.S. Geological Survey, in cooperation with local and federal agencies obtains a large amount of data pertaining to the water resources of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the area. To make these data readily available to interested parties outside the U.S. Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 1998." This report includes records on both surface and ground water. Specifically, it contains: (1) discharge records for 76 streamflow gaging stations, daily sediment records for 27 streamflow stations, 99 partial-record or miscellaneous streamflow stations, stage records for 17 reservoirs, and (2) water-quality records for 16 streamflow-gaging stations, and for 42 ungaged stream sites, 11 lake sites, 2 lagoons, and 1 bay, and (3) water-level records for 97 observation wells. Water-resources data for Puerto Rico for calendar years 1958-67 were released in a series of reports entitled "Water Records of Puerto Rico." Water-resources data for the U.S. Virgin Islands for the calendar years 1962-69 were released in a report entitled "Water Records of U.S. Virgin Islands." Included were records of streamflow, ground-water levels, and water-quality data for both surface and ground water. Beginning with the 1968 calendar year, surface-water records for Puerto Rico were released separately on an annual basis. Ground-water level records and water-quality data for surface and ground water were released in companion reports covering periods of several years. Data for the 1973-74 reports were published under separate covers. Water-resources data reports for 1975­ 76, 1977, 1978, 1979-80, 1981-82, 1983, 1984, 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, and 1997 water years consist of one volume each and contain data for streamflow, water quality, and ground water. Publications similar to this report are published annually by the U.S. Geological Survey for all States. These official Survey reports have an identification number consisting of the two-letter State abbreviation, the last two digits of the water year, and the volume number. For example, this volume is identified as "U.S. Geological Survey Water-Data Report PR-98-1." These water-data reports are for sale in paper copy or in microfiche by the National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia, 22161. Additional information, including current prices, for ordering specific reports may be obtained from the District Chief at the address given on back of the title page or by telephone (787) 749-4346. 2 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 COOPERATION The U.S. Geological Survey has had cooperative agreements with organizations of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands for the systematic collections of water resources data since 1958. Organizations that supplied data are acknowledged in the station descriptions. Organizations that assisted in collecting data through cooperative agreements with the U.S. Geological Survey are: Puerto Rico Environmental Quality Board Puerto Rico Aqueduct and Sewer Authority Puerto Rico Department of Agriculture Puerto Rico Industrial Development Company Puerto Rico Department of Housing Puerto Rico Highway Authority Puerto Rico Department of Natural and Environmental Resources Puerto Rico Department of Health Puerto Rico Electric Power Authority Puerto Rico Solid Waste Management Authority Puerto Rico Legislature Puerto Rico Civil Defense U.S. Virgin Islands Department of Planning and Natural Resources Funds were also provided by the U.S. Army, Corps of Engineers, for the collection of records at six gaging stations published in this report. _________________________________________________ _________________________________________________ _________________________________________________ 3 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 SUMMARY OF HYDROLOGIC CONDITIONS Rainfall Rainfall throughout Puerto Rico during water year 1998 (October 1997 to September 1998) averaged about 117 percent above normal. Rainfall was above normal during the months of October, January, February, March, July, August, and September (table 1). Significant above-normal rainfall conditions were recorded during September as rainfall averaged 225 percent above normal, mostly due to the passage of Hurricane Georges over Puerto Rico during September 21-22, 1998. As much as 25 inches of rain fell on some of the island’s interior municipios during a 24-hour period. Severe floods and landslides resulted from the intensive rainfall and serious damages to homes, businesses, and infrastructure were reported. During the months of November, December, April, May, and June, rainfall was deficient with averages that ranged from 28 to 97 percent of normal. Rainfall, during the 1998 water year, averaged 102 percent of normal in northern Puerto Rico, 126 percent of normal in southern Puerto Rico, 123 percent of normal in western Puerto Rico, and 121 percent of normal in eastern Puerto Rico. Monthly average rainfall islandwide for the 1998 water year and for the 30-year period (1961-1990) used to define normal rainfall, as reported by the National Oceanic and Atmospheric Administration are listed in table 1. Table 1. Islandwide monthly rainfall for the water year 1998 and annual averages for the 30-year reference period, 1961-1990 1998 Water Year 30-year normal Month (inches) (inches) October 9.52 8.29 November 4.68 6.55 December 1.23 4.38 January 4.16 2.86 February 4.08 2.52 March 3.59 3.02 April 4.32 4.46 May 6.46 6.96 June 4.66 4.99 July 5.39 5.08 August 9.52 6.89 September 16.04 7.14 TOTAL 73.65 63.14 Surface Water Streamflow in Puerto Rico during most of the 1998 water year was, in general, above normal in southern and eastern Puerto Rico, but below normal in the northern and western regions, based on the four index stations. A comparison of the monthly- mean flows during the 1998 water year with the long-term minimum, median and maximum of the monthly mean flows, for the period of record at the index stations on the Río Grande de Manatí (north), the Río Fajardo (east), the Río Inabón (south), and the Río Grande de Añasco (west) is shown in figure 1. During December, below normal flows were recorded at the four index stations. At the Río Grande de Manatí and Río Grande de Añasco index stations these below normal flows established new historical minimum monthly-mean flows. Excessive flows occurred at the four index stations during September due to intensive rainfall produced by the passage of Hurricane Georges over Puerto Rico. Historical maximum monthly-mean flows for September, were recorded at the Río Grande de Manatí and Río Grande de Añasco. In the northern area, the Río Grande de Manatí index station recorded flows below the long-term monthly median during October to January, March, April, and July. Monthly mean flows during these months ranged from 22 to 82 percent of the long- term median of the monthly mean flows. Monthly mean flow during February, May, June, August, and September was above normal, and ranged from 121 to 1,100 percent of normal. Historical minimum and maximum monthly mean flows were recorded at this index station during December and September, respectively. In the eastern area, the index station on the Río Fajardo, recorded monthly mean flows above the long-term median during eleven of the twelve months of the 1998 water year. At this station, only the December mean flow was slightly below the long-term monthly median. The flow in December was 96 percent of normal. The rest of the year, monthly mean flows ranged from 124 to 220 percent of the long-term median. 4 NORTH EAST RÍO GRANDE DE MANATÍ AT HWY 2 RÍO FAJARDO NEAR FAJARDO (50038100) (50071000) 10,000 1998 MONTHLY MEAN 1964-97 MEDIAN OF MONTHLY-MEAN 1,000 1,000 100 100 1998 MONTHLY MEAN 1964-97 MEDIAN OF MONTHLY-MEAN MONTHLY-MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10 10 1 O N D J F M A M J J A S 1997 1998 SOUTH RÍO INABÓN AT REAL ABAJO (50112500) 1 O N D J F M A M J J A S 1997 1998 WEST RÍO GRANDE DE AÑASCO NEAR SAN SEBASTIÁN (50144000) 1,000 1998 MONTHLY MEAN 1964-97 MEDIAN OF MONTHLY-MEAN 100 10 10 1 1 O N D J F M A M J J A S O N D J F M A M J J A S 1997 1998 1997 1998 Unshaded area indicates range between highest and lowest monthly-mean discharges for the period of record to water year 1998. 10,000 1,000 1998 MONTHLY MEAN 1964-97 MEDIAN OF MONTHLY-MEAN 100 MONTHLY-MEAN DISCHARGE, IN CUBIC FEET PER SECOND Figure 1. Monthly-mean discharge of selected streams in Puerto Rico. 5 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 In the southern area, the Río Inabón index station recorded monthly mean flows below the long-term median during October to January. During these months, the monthly mean flows ranged from 42 to 88 percent of normal. During April, a new historical minimum monthly mean flow was recorded. The rest of the year, the monthly mean flows were above the long-term monthly median, and ranged from 145 to 510 percent of normal. In the western area, the index station on the Río Grande de Añasco, recorded monthly mean flows below the long-term median during the first seven months of the 1998 water year. A below normal monthly mean flow was also recorded during June. During these months, the monthly mean flows ranged from 41 to 89 percent of the long-term median. Historical minimum monthly mean flows were recorded during November and December at this index station. Mean monthly flows were above normal during May and from July to September. Monthly mean flows during these months ranged from 226 to 560 percent of the long-term median. A historical maximum monthly mean flow was recorded during September. The most important hydrologic event that happened during the 1998 water year was the flooding caused by the intense rainfall generated by the passage of Hurricane Georges over Puerto Rico. The eye of Hurricane Georges made landfall near the municipios of Humacao and Yabucoa on the east coast of Puerto Rico and moved over the mountainous central region of the Island during September 21-22. Hurricane Georges produced heavy rains over Puerto Rico, especially in the mountainous interior. This heavy rain produced moderate to severe floods through the island. Almost all of the island’s 78 municipios were affected by the floods. The most severe flooding occurred within the basins of the north and west areas: the Río Grande de Arecibo, the Río Grande de Manatí, the Río de la Plata, the Río Grande de Añasco, and the Río Culebrinas. Floodwaters inundated urban areas and communities, washing away and damaging homes, businesses, vehicles, bridges, and roads. Fortunately, there were no deaths directly associated with the passage of the hurricane over Puerto Rico. Damage to the island infrastructure was enormous. The U.S. Geological Survey data network was highly affected with many stations destroyed or severely damaged. Historical maximum peak stages and discharges were recorded during this event in several streamflow gaging stations. Peak stages and discharges at selected streamflow gaging stations in Puerto Rico are listed in table 2. Table 2. Summary of peak stages and discharges prior to and during September 21-22, 1998, at selected U.S. Geological Survey streamflow gaging stations in Puerto Rico [mi2, square miles; ft3/s, cubic feet per second; mm/dd/yy, month/day/year] Previous maximum discharge Flood of September 22, 1998 Station number and name Drainage area (mi2) Period of record Date mm/dd/yy Peak stage (feet) Maximum discharge (ft3/s) Peak stage (feet) Peak discharge (ft3/s) 50034000 16.7 1970-1982 9/10/1996 25.14 25,900 25.93 28,200 Río Bauta near Orocovis 1989-1998 50050900 6.0 1978-1998 9/10/1996 25.93 44,000 26.37 45,000 Río Grande de Loíza at Quebrada Arenas 50061800 9.84 1967-1998 9/13/1982 13.10 15,000 15.90 17,300 Río Canóvanas near Campo Rico 50064200 7.31 1967-1998 9/16/1975 15.50 17,400 19.30 22,000 Río Grande near El Verde 50074950 0.05 1992-1998 9/10/1996 10.74 102 10.78 104 Quebrada Guaba near Naguabo 50106100 3.5 1987-1998 1/8/1992 25.67 51,600 25.94 52,700 Río Coamo at Coamo 50113800 15.4 1989-1998 9/10/1996 10.62 10,600 12.42 16,200 Río Cerillos above Lago Cerrillos near Ponce 50124200 18.9 1981-1998 9/12/1982 20.40 14,700 21.88 18,700 Río Guayanilla near Guayanilla 50131990 34.6 1991-1998 1/6/1992 13.23 6,610 19.53 24,900 Río Guanajibo at Hwy 119 at San Germán 94.3 1963-1998 9/16/1975 33.90 140,000 34.50 163,000 Río Grande de Añasco near San Sebastián 50144000 6 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Ground Water Ground-water levels in most aquifers in Puerto Rico and the U.S. Virgin Islands followed seasonal fluctuations associated with rainfall patterns during water year 1998. Generally, late into the water year, the ground-water levels increased in response to above-normal rainfall from July through November, especially during the passage of Hurricane Georges, on September 21-22, 1998, which caused flooding throughout most of the coastal plains. Ground-water levels generally declined during the months of April, May, and July through August in response, primarily, to ground-water withdrawals for public and industrial use in the north coast, and irrigation in the south coast. Record-low and record-high water levels were recorded at several wells in Puerto Rico during water year 1998 (tables 3 and 4). Ground-water levels in the North Coast Limestone aquifer system of Puerto Rico fluctuated from October to August in response to seasonal rainfall patterns and sustained ground-water withdrawals. This trend was altered by the rainfall produced by Hurricane Georges in late September, which caused water levels to rise significantly at the Sabana Hoyos index well, where the ground-water levels rose 1.20 ft (fig. 2). In the South Coastal Plain aquifer system of Puerto Rico, the ground-water levels remained relatively stable from October to August, in response to above-normal rainfall runoff which may have neutralized the drawdown trend from sustained ground­ water withdrawals for agricultural, public, and industrial use. A significant rise was recorded during September, when Hurricane Georges affected the area and ground-water levels rose 2.50 ft at the Alomar index well (fig. 2). In the U.S. Virgin Islands (St. Croix, St. Thomas, and St. John) ground-water levels rose significantly from mid-October to early December as heavy rainfall was recorded in the area. The ground-water levels generally declined from early December to mid-September in response to below-normal rainfall and sustained ground-level withdrawals. The declining trend was reversed by above-normal rainfall produced by the passage of Hurricane Georges by the area. At the Guinea Gut well, the ground-water levels rose about 15.50 ft (fig. 2). _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ _____________________________________________________________________________________________________ 7 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Table 3. Highest ground-water levels recorded during 1998 water year and previous high ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm/dd/yy, month/day/year; ft-blsd, feet below land-surface datum; mm/yy, month/year] Well name or Local number number Location Previous 1998 highest Highest Period of water water record level Date level Date (mm/yy) (ft-blsd) (mm/dd/yy) (ft-blsd) (mm/dd/yy) Florida #01 FL-1 PR 08/96 to 09/98 139.90 09/20/96 137.91 09/22/98 La Esperanza 2 PN-2 PR 07/89 to 09/98 8.01 12/30/92 7.71 09/23/98 12/31/92 CJ-TW-19A CJ-TW-19A PR 06/92 to 09/98 22.60 09/14/96 22.07 09/25/98 09/26/98 09/27/98 Jardín Botánico #3 PN-19 PR 06/91 to 09/98 3.06 09/11/96 2.84 09/22/98 09/23/98 Yabucoa 7 96 PR 04/78 to 09/98 13.10 12/02/87 9.67 09/30/98 HW-TW-5B HW-TW-5B PR 04/88 to 09/98 7.89 05/26/92 5.93 09/22/98 Albergue de Niños Ponce AN-1 PR 03/92 to 09/98 35.29 06/22/92 28.57 09/27/98 Aguadilla Cement 200 PR 10/85 to 09/98 2.24 08/25/88 1.61 09/22/98 Table 4. Lowest ground-water levels recorded during 1998 water year and previous low ground-water levels at selected wells in Puerto Rico [PR, Puerto Rico; mm/dd/yy, month/day/year; ft-blsd, feet below land-surface datum; mm/yy, month/year] Well name or Local number number Location Previous 1998 lowest lowest Period of water water record level Date level Date (mm/yy) (ft-blsd) (mm/dd/yy) (ft-blsd) (mm/dd/yy) Encantada 1 EN-1 PR 08/96 to 09/98 313.74 07/05/98 313.84 04/03/98 07/06/97 Palo Alto 2 PA-2 PR 05/96 to 09/98 240.04 08/12/96 240.14 08/18/98 to 08/15/96 Phillips 13 P-13 PR 09/91 to 09/98 28.88 09/22/95 31.22 08/24/98 HW-TW-13 HW-TW-13 PR 04/88 to 09/98 48.10 11/06/92 48.12 09/03/98 11/07/92 Vivoni Col. Amistad 143 PR 10/85 to 09/98 40.70 09/26/97 40.85 10/08/97 10/09/97 CR-TW-9A CR-TW-9A PR 05/96 to 09/98 7.22 08/14/97 8.53 03/21/98 Figure 2. Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. 8 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 October November December January February March April May June July August September 1998 40 42 44 46 30.5 28.5 29.0 29.5 30.0 WELL 70, SABANA HOYOS, PUERTO RICO WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WELL 87, ALOMAR WELL, PUERTO RICO October November December January February March April May June July August September 1998 5 10 15 20 25 WELL 11, GUINEA GUT, ST. JOHN U.S. VIRGIN ISLANDS October November December January February March April May June July August September 1998 Figure 2. Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. 9 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Water Quality In the water year 1998 the U.S. Geological Survey, in cooperation with several local government agencies, collected water-quality data at 73 surface-water stations in Puerto Rico. The water-quality data collected at these stations included the major chemical constituents, such as calcium, magnesium, sodium, chloride and sulfate. The data also included constituents listed in table 5. The highest concentration for each of these constituents detected during water year 1998 and the station where it was detected are summarized in table 5. Table 5. Surface-water quality stations in Puerto Rico with highest concentration of selected constituents during water year 1998 [All constituent concentrations are in milligrams per liter; MBAS, Methylene blue active substance] ________________________________________________________________________________ Station number Station name Constituent Concentration ________________________________________________________________________________ 50144000 Río Grande de Añasco near San Sebastián Sulfide 1.2 50047530 Río Hondo at Flood Channel Boron 1.9 50147600 Río Culebrinas near San Sebastián Manganese 1.1 50025000 Río Grande de Arecibo near Utuado Iron 8.4 50055400 Río Bairoa near Caguas Zinc 0.60 * * Cyanide <0.01 50049100 Río Piedras at Hato Rey Phenols 0.04 50055400 Río Bairoa near Caguas MBAS 0.91 ________________________________________________________________________________ * Cyanide concentrations at all water-quality stations were below the detection limit (<0.010). The presence of high concentrations of fecal coliform (fig. 3) and fecal streptococcal (fig. 4) bacteria continued to be the principal surface-water quality problem in Puerto Rico during water year 1998. The highest concentrations observed during this year occurred in stations located in the San Juan Metropolitan area which has the highest population concentration in Puerto Rico. The main sources of contamination in surface-water systems in Puerto Rico are discharges of liquid wastes from industrial and municipal sources. The highest concentration of fecal coliform and fecal streptococcal bacterial in surface waters in Puerto Rico generally occurred in streams draining densely populated and industrialized areas. Suspended-sediment concentration were monitored at 27 stations in Puerto Rico during water year 1998 as part of the cooperative program between the U.S. Geological Survey and various local and federal agencies. High suspended-sediment concentrations are a common problem in many streams in Puerto Rico. Most of the streams with high suspended-sediment concentrations were related to land use, especially urban development, agriculture, and activities where soil movement was involved. The high suspended-sediment concentrations affect the quality of drinking water sources and the storage capacities of reservoirs used for water supply. 10 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 SPECIAL NETWORKS AND PROGRAMS Hydrologic Bench-Mark Network is a network of 57 sites in small drainage basins around the country whose purpose is to provide consistent data on the hydrology, including water quality, and related factors in representative undeveloped watersheds nationwide, and to provide analyses on a continuing basis to compare and contrast conditions observed in basins more obviously affected by the activities of man. National Stream Quality Accounting Network (NASQAN) is a nationwide data-collection network designed by the U.S. Geological Survey to meet many of the information needs of government agencies and other groups involved in natural or regional water-quality planning and management. The 500 or so sites on NASQAN are generally located at the downstream ends of hydrologic accounting units designated by the U.S. Geological Survey Office of Water Data Coordination in consultation with the Water Resources Council. The objectives of NASQAN are (1) to obtain information on the quality and quantity of water moving within and from the United States through a systematic and uniform process of data collection, summarization, analysis, and reporting such that the data may be used for, (2) description of the areal variability of water quality in the Nation's rivers through analysis of data from this and other programs, (3) detection of changes or trends with time in the pattern of occurrence of water- quality characteristics, and (4) providing a nationally consistent data base useful for water-quality assessment and hydrologic research. The National Trends Network (NTN) is a 150-station network for sampling atmospheric deposition in the United States. The purpose of the network is to determine the variability, both in location and in time, of the composition of atmospheric deposition, which includes snow, rain, dust particles, aerosols, and gases. The core from which the NTN was built was the already- existing deposition-monitoring network of the National Atmospheric Deposition Program (NADP). The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey is a long-term program with goals to describe the status and trends of water-quality conditions for a large, diverse, and geographically distributed part of the Nation's ground- and surface-water resources, and to identify, describe, and explain the major natural and human factors that affect these observed conditions and trends. Assessment activities have begun in more than one-third of the study units and ultimately will be conducted in 60 study units (major watersheds and aquifer systems) that represent a wide range of environmental settings nationwide and that account for a large percentage of the Nation's water use. A wide array of chemical constituents will be measured in ground water, surface water, streambed sediments, and fish tissues. The coordinated application of comparative hydrologic studies at a wide range of spatial and temporal scales will provide information for decision making by water-resources managers and a foundation for aggregation and comparison of findings to address water-quality issues of regional and national interest. Radiochemical Programs is a network of regularly sampled water-quality stations where samples are collected to be analyzed for radioisotopes. The streams that are sampled represent major drainage basins in the conterminous United States. Tritium Network is a network of stations which has been established to provide baseline information on the occurrence of tritium in the Nation's surface waters. In addition to the surface-water stations in the network, tritium data are also obtained at a number of precipitation stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. EXPLANATION OF RECORDS The surface- and ground-water records published in this report are for the 1998 water year that began October 1, 1997 and ended September 30, 1998. A calendar of the water year is provided on the inside of the front cover. The records contain streamflow data, water-quality data for surface and ground water, and ground-water-level data. The locations of the stations and wells where the data were collected are shown in figures 3 to 9. The following sections of the introductory text are presented to provide users with a more detailed explanation of how the hydrologic data published in this report were collected, analyzed, computed, and arranged for presentation. 11 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Station Identification Numbers Each data station, whether stream site or well, in this report is assigned a unique identification number. This number is unique in that it applies specifically to a given station and to no other. The number usually is assigned when a station is first established and is retained for that station indefinitely. The systems used by the U.S. Geological Survey to assign identification numbers for surface-water stations and for ground-water well sites differ, but both are based on geographic location. The "downstream order" system is used for regular surface-water stations and the "latitude-longitude" system is used for wells. Downstream Order System Since October 1, 1950, the order of listing hydrologic-station records in Survey reports is in a downstream direction along the main stream. All stations on a tributary entering upstream from a main-stream station are listed before that station. A station on a tributary that enters between two main-stream stations is listed between them. A similar order is followed in listing stations in first rank, second rank, and other ranks of tributaries. As an added means of identification, each hydrologic station and partial-record station has been assigned a station number. These are in the same downstream order used in this report. In assigning station numbers, no distinction is made between partial-record stations and other stations; therefore, the station number for a partial-record station indicates downstream order position in a list made up of both types of stations that may be established; hence, the numbers are not consecutive. The complete 8-digit number for each station such as 50028000, which appears just to the left of the station name, includes the 2-digit part number "50" plus the 6-digit downstream order number "028000." Latitude-Longitude System The 8-digit downstream order station numbers are not assigned to wells and miscellaneous sites where only random water-quality samples or discharge measurements are taken. The well and miscellaneous site numbering system of the U.S. Geological Survey is based on the grid system of latitude and longitude. The system provides the geographic location of the well or miscellaneous site and a unique number for each site. The number consists of 15 digits. The first 6 digits denote the degrees, minutes, and seconds of latitude, the next 7 digits denote degrees, minutes, and seconds of longitude, and the last 2 digits (assigned sequentially) identify the wells or other sites within a 1­ second grid. The numbers shown in the grid correspond to the local numbers assigned to each well as visited in the field. An example is well 16 (fig. 10). 12 Laguna Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 66°00' 65°30' 0 0 10 Tortuguero Río Culebrinas Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 15' 45' FECAL COLIFORM Figure 3. Location of maximum concentration of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico. < 1,000 1,000 - 10,000 10,000 - 100,000 100,000 - 1,000,000 EXPLANATION 10 20 KILOMETERS 20 MILES Laguna Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo 67°15' 18°30' 15' 18°00' 17°45' 67°00' 45' 30' 66°00' 65°30' 0 0 10 Tortuguero Río Culebrinas Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA 15' 45' FECAL STREPTOCOCCI Figure 4. Location of maximum concentration of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico. < 1,000 1,000 - 10,000 10,000 - 100,000 100,000 - 1,000,000 EXPLANATION 10 20 KILOMETERS 20 MILES 13 14 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' 18°30' 15' 18°00' 17°45' Laguna Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo 093045 053025 0905 0 0 10 0710 0618 0570 0550 0551 047850 044830 047550 0438 0430 032590 032290 1002 1061 1080 025155 1242 0201 1289 1415 0108 125780 1364 1380 100450 0920 039990 093045 038320 0395 0381 027750 0284 0290 0280 0148 0105 1478 1440 0157 0350 0312 0340 0590 059050 048770 048680 0491 0460 045010 0450 0564 0810 051310 0509 053025 0655 0670 0660 063440 074950 0750 0705 0638 131990 026140 026025 024950 047560 047540 047535 0642 0518 0905 055750 055225 055390 058350 0610 030460 Tortuguero Río Culebrinas Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA CONTINUOUS STREAMFLOW STATION AND NUMBER LAKE-ELEVATION STATION AND NUMBER SEDIMENT STATION AND NUMBER EXPLANATION 10 20 KILOMETERS 20 MILES 111210 113950 1115 1113 114390 1138 1149 1159 1125 051150 051180 1140 1109 Figure 5. Location of surface-water stations in Puerto Rico. 15 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' 18°30' 15' 18°00' 17°45' Laguna Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo 0550 0910 0918 0725 0710 0820 0865 0835 0910 0918 0920 0399 0430 0312 0307 1065 1247 1336 1364 1388 1440 1491 1430 1476 010790 010720 1460 1380 1297 0250 027090 027250 026050 0355 0381 0290 0280 0105 0205 020050 035950 0440 0444 0460 0382 0395 044850 038320 044950 039950 0550 0476 047537 047549 0575 0554 0588 0590 0591 0503 0491 0488 047990 047530 048510 049820 049920 057025 055250 0638 0 0 10 Tortuguero Río Culebrinas Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA CHEMICAL STATION AND NUMBER (Quaterly) BIOLOGICAL STATION AND NUMBER (Quaterly) SEDIMENT STATION AND NUMBER EXPLANATION 1140 1162 1150 0114 0110 025110 10 20 KILOMETERS 20 MILES Figure 6. Location of water-quality stations in Puerto Rico. 16 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' 18°30' 15' 18°00' 17°45' Laguna Río Guajataca Río Camuy Río Grande de Arecibo Río Grande de Manatí Río Cibuco Río de la Plata Río Hondo Río de Bayamón Bahía de San Juan Río Piedras Laguna San José Laguna La Torrecilla Quebrada Blasina Río Grande de Loíza Río Herrera Río Espíritu Santo Río Mameyes Río Sabana Río Juan Martín Río Loco Río Yauco Río Guayanilla Río Tallaboa Río Matilde Río Portugués Río Bucaná Río Inabón Río Jacaguas Río Cañas Río Descalabrado Río Coamo Río Jueyes Río Salinas Río Seco Río Guamaní Río Nigua Río Grande de Patillas Río Chico Río Jacaboa Río Maunabo YDO-1 222 RE-2A RS-02 RP-04 RF-12 RF-04 ARR-1 RM-02 SA-1 SA-3 HG-1 MA-2 SR-2 DA-1 212 213 204 207 166 HI-2 CS-7 210 206 219 652 217 216 TB-1 70 PN-2 PN-5 PN-6 PN-8C PN-13 PN-19 PN-10 96 YDO-1 6 CQ-1 EC-1 SA-D CA-1 PS-07 PG-07 ALG-1 BAR-1 P-13 RM-5 RM-10 87 132 143 200 R-4 C-4 165 202 Z-4 BARR-1 CA-4 EN-1 TI-1 FL-1 50 141 CA-1 CO-3 AN-1 CR-1 CI-1 0 0 10 Tortuguero Río Culebrinas Río Guayabo Río Grande Río Grande de Añasco Río Yagüez Río Guanajibo Río Fajardo Río Daguao Quebrada Palma Río Santiago Río Blanco Río Antón Ruíz Río Humacao Río Guayanés ATLANTIC OCEAN CARIBBEAN SEA WELL AND NUMBER EXPLANATION 211 PA-2 TO-3 FID-2 HW-TW-1 HW-TW-5B HW-TW-30 HW-TW-13 OT-1 FA-2 FA-1 LV-1 CJ-TW 19A CJ-TW 11 CJ-TW 15 CJ-TW 20 CJ-TW 3B CJ-TW 18 TW 9A TW 9B 10 20 KILOMETERS 20 MILES Figure 7. Location of ground-water stations in Puerto Rico. + 18°22 00   64°42 00   64°47 00   18°22 00   18°19 00   65°00 00   65°55 00   17°45 00   17°41 00   18°19 00   64°48 00   64°40 30   Bonne Resolution Jolly Hill Gut Salt River Cob Gut Guinea Bay Gut Gut Gut Battery Fish T u r p en tine Run Westend Saltpond ST. CROIX EXPLANATION Green Cay CHRISTIANSTED FREDERIKSTED C A R I B B E A N S E A C A R I B B E A N S E A Buck Island ST. JOHN C A R I B B E A N S E A A T L A N T I C O C E A N Flannagan Island Coral Bay Whistling Cay Congo Cay Lovango Cay Windward Passage Pillsbury Sound Durloe Cays Leduck Island S a b b a t n Cha n e l CRUZ BAY ST. THOMAS Sula Cay Capella Islands Little St. James I Dog Island Great St. James I Shark Island Mingo Cay Grass Cay CHARLOTTE AMALIE A T L A N T I C O C E A N C A R I B B E A N S E A Cricket Rock Cockroach Island Dutchcap Cay Salt Cay West Cay Kalkun Cay Savana Island Turtledove Cay Saba Island Flat Cays Outer Brass Island Hans Lollik Island Little Hans Lollik Island Water Island 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 17 Figure 8. Location of surface-water stations in the U.S. Virgin Islands. SURFACE-WATER STATION AND NUMBER EXPLANATION 3450 3450 2950 2520 2740 + 18°22 00   64°42 00   64°47 00   18°22 00   18°19 00   65°00 00   65°55 00   17°45 00   17°41 00   18°19 00   64°48 00   64°40 30   Bonne Resolution 18 Jolly Hill Gut Salt River Cob Gut Guinea Bay Gut Gut Gut Battery Fish T u r p en tine Run Westend Saltpond ST. CROIX Figure 9. Location of ground-water stations in the U.S. Virgin Islands. WELL AND WELL NUMBER EXPLANATION 2 Green Cay CHRISTIANSTED FREDERIKSTED C A R I B B E A N S E A C A R I B B E A N S E A Buck Island ST. JOHN C A R I B B E A N S E A A T L A N T I C O C E A N Flannagan Island Coral Bay Whistling Cay Congo Cay Lovango Cay Windward Passage Pillsbury Sound Durloe Cays Leduck Island S a b b a t n Cha n e l CRUZ BAY ST. THOMAS Sula Cay Capella Islands Little St. James I Dog Island Great St. James I Shark Island Mingo Cay Grass Cay CHARLOTTE AMALIE A T L A N T I C O C E A N C A R I B B E A N S E A Cricket Rock Cockroach Island Dutchcap Cay Salt Cay West Cay Kalkun Cay Savana Island Turtledove Cay Saba Island Flat Cays Outer Brass Island Hans Lollik Island Little Hans Lollik Island Water Island 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 1 2 MILES 1 2 KILOMETERS 0 0 2 3 13 11 8 6 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 27 74 16 134 132 131 COORDINATES FOR WELLS 27 (180150066474900) AND 74 (180135066471000) COORDINATES FOR WELLS 132 (180133066503300) AND 134 (180120066503200) COORDINATES FOR WELLS 131 (180058066502700) COORDINATES FOR WELLS 16 (175922066495800) Figure 10. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude). Records of Stage and Water Discharge Records of stage and water discharge may be complete or partial. Complete records of discharge are those obtained using a continuous stage-recording device through which either instantaneous or mean daily discharges may be computed for any time, or any period of time, during the period of record. Complete records of lake or reservoir content, similarly, are those for which stage or content may be computed or estimated with reasonable accuracy for any time, or period of time. They may be obtained using a continuous stage-recording device, but need not be. Because daily mean discharges and end-of-day contents commonly are published for such stations, they are referred to as "daily stations." By contrast, partial records are obtained through discrete measurements without using a continuous stage-recording device and pertain only to a few flow characteristics, or perhaps only one. The nature of the partial record is indicated by table titles such as "Low-flow partial records." Records of miscellaneous discharge measurements or of measurements from special studies, such as low-flow seepage studies, may be considered as partial records, but they are presented separately in this type of report. Location of all complete-record stations for which data are given in this report are shown in figures 5 and 8. Data Collection and Computation The data obtained at a complete-record gaging station on a stream or canal consists of a continuous record of stage, individual measurements of discharge throughout a range of stages, and notations regarding factors that may affect the relationships between stage and discharge. These data, together with supplemental information, such as weather records, are used to compute daily discharges. The data obtained at a complete-record gaging station on a lake or reservoir consist of a record of stage and of notations regarding factors that may affect the relationship between stage and lake content. These data are used with stage-area and stage-capacity curves or tables to compute water-surface areas and lake storage. Continuous records of stage are obtained with analog recorders that trace continuous graphs of stage or with digital recorders that punch stage values on paper tapes at selected time intervals or electronic satellite data collector platforms that receive stage values at selected time intervals. Measurements of discharge are made with current meters using methods adapted by the Geological Survey as a result of experience accumulated since 1880. These methods are described in standard textbooks, in Water- Supply Paper 2175, and in U.S. Geological Survey Techniques of Water-Resources Investigations, Book 3, Chapter A6. 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 In computing discharge records, results of individual measurements are plotted against the corresponding stages, and stage-discharge relation curves are then constructed. From these curves, rating tables indicating the approximate discharge for any stage within the range of the measurements are prepared. If it is necessary to define extremes of discharge outside the range of the current-meter measurements, the curves are extended using: (1) logarithmic plotting; (2) velocity-area studies; (3) results of indirect measurements of peak discharge, such as slope-area or contracted-opening measurements, and computations of flow-over-dams or weirs; or (4) step-backwater techniques. Daily mean discharges are computed by applying the daily mean stages (gage heights) to the stage-discharge curves or tables. If the stage-discharge relation is subject to change because of frequent or continual change in the physical features that form the control, the daily mean discharge is determined by the shifting-control method, in which correction factors based on the individual discharge measurements and notes of the personnel making the measurements are applied to the gage heights before the discharges are determined from the curves or tables. This shifting-control method also is used if the stage-discharge relation is changed temporarily because of aquatic growth or debris on the control. At some stations the stage-discharge relation is affected by changing stage; at these stations the rate of change in stage is used as a factor in computing discharge. In computing records of lake or reservoir contents, it is necessary to have available from surveys, curves or tables defining the relationship of stage and contents. The application of stage to the stage-content curves or tables gives the contents from which daily, monthly or yearly changes then are determined. If the stage-content relationship changes because of deposition of sediment in a lake or reservoir, periodic surveys may be necessary to redefine it. Even when this is done, as time between the last survey increases, the contents computed may increase in error. Discharges over lake or reservoir spillways are computed from stage- discharge relationships much as other stream discharges are computed. For some gaging stations there are periods when no gage-height record is obtained, or the recorded gage height is so faulty that it cannot be used to compute daily discharge or contents. This happens when the recorder stops or otherwise fails to operate properly, intakes are plugged, the float is loose in the well, or for various other reasons. For such periods, the daily discharges are estimated from the recorded range in stage, previous or following record, discharge measurements, weather records, and comparison with other station records from the same or nearby basins. Likewise, daily contents may be estimated from operator's logs, previous or following record, inflow-outflow studies, and other information. Information explaining how estimated daily- discharge values are identified in station records is included in the next two sections, "Data Presentation" (REMARKS paragraph) and "Identifying Estimated Daily Discharge." Data Presentation Steamflow data in this report are presented in a new format that is considerably different from the format in data reports prior to the 1992 water year. The major changes are that statistical characteristics of discharge now appear in tabular summaries following the water-year data table and less information is provided in the text or station manuscript above the table. These changes represent the results of a pilot program to reformat the annual water-data report to meet current user needs and data preferences. The records published for each continuous-record surface-water discharge station (gaging station) now consist of four parts, the manuscript or station description; the data table of daily mean values of discharge for the current water year with summary data; a tabular statistical summary of monthly mean flow data for a designated period, by water year; and a summary statistics table that includes statistical data of annual, daily, and instantaneous flows as well as data pertaining to annual runoff, 7-day low-flow minimum, and flow duration. Station manuscript The manuscript provides, under various headings, descriptive information, such as station location; period of record; historical extremes outside the period of record; record accuracy; and other remarks pertinent to station operation and regulation. The following information, as appropriate, is provided with each continuous record of discharge or lake content. Comments to follow clarify information presented under the various headings of the stations descriptions. LOCATION.--Information on locations is obtained from the most accurate maps available. The location of the gage with respect to the cultural and physical features in the vicinity and with respect to the reference place mentioned in the station name is given. 21 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 DRAINAGE AREA.--Drainage areas are measured using the most accurate maps available. Drainage areas are updated as better maps become available. PERIOD OF RECORD.--This indicates the period for which there are published records for the station or for an equivalent station. An equivalent station is one that was in operation at a time that the present station was not, and whose location was such that records from it can reasonable be considered equivalent with records from the present station. REVISED RECORDS.--Because of new information, published records occasionally are found to be incorrect, and revisions are printed in later reports. Listed under this heading are all the reports in which revisions have been published for the station and the water years to which the revisions apply. If a revision did not include daily, monthly, or annual figures of discharge, that fact is noted after the year dates as follows: "(M)" means that only the instantaneous maximum discharge was revised; "(m)" that only the instantaneous minimum was revised; and "(P)" that only peak discharges were revised. If the drainage area has been revised, the report in which the most recently revised figure was first published is given. GAGE.--The type of gage in current use, the datum of the current gage, and a condensed history of the types, locations, and datums of previous gages are given under this heading. REMARKS.--All periods of estimated daily-discharge record will either be identified by date in this paragraph of the station description for water-discharge stations or flagged in the daily-discharge table. (See next section, "Identifying Estimated Daily Discharge.") If a remarks statement is used to identify estimated record, the paragraph will begin with this information presented as the first entry. The paragraph is also used to present information relative to the accuracy of the records, to special methods of computations, to conditions that affect natural flow at the station and, possibly, to other pertinent items. For reservoir stations, information is given on the dam forming the reservoir, the capacity, outlet works and spillway, and purpose and use of the reservoir. COOPERATION.--Records provided by a cooperating organization or obtained for the Geological Survey by a cooperating organization are identified here. EXTREMES OUTSIDE PERIOD OF RECORD.--Included here is information concerning major floods or unusually low flows that occurred outside the stated period of record. The information may or may not have been obtained by the U.S. Geological Survey. REVISIONS.--If a critical error in published records is discovered, a revision is included in the first report published following discovery of the error. Although rare, occasionally the records of a discontinued gaging station may need revision. Because, for these stations, there would be no current or, possibly, future station manuscript published to document the revision in a "Revised Records" entry, users of data for these stations who obtained the record from previously published data reports may wish to contact the District office to determine if the published records were ever revised after the station was discontinued. Of course, if the data were obtained by computer retrieval, the data would be current and there would be no need to check because any published revision of data is always accompanied by revision of the corresponding data in computer storage. Manuscript information for lake or reservoir stations differs from that for stream stations in the nature of the "Remarks" and in the inclusion of a skeleton stage-capacity table when daily contents are given. Data table of daily mean value The daily table of discharge records for stream gaging stations gives mean discharge for each day of the water year. In the monthly summary for the table, the line headed "TOTAL" gives the sum of the daily figures for each month; the line headed "MEAN" gives the average flow in cubic feet per second for the month; and the lines headed "MAX" and "MIN" give the maximum and minimum daily mean discharges, respectively, for each month. Discharge for the month also is usually expressed in cubic feet per second per square mile (line headed "CFSM"); or in inches (line headed "IN"); or in acre-feet (line headed "AC-FT"). Figures for cubic feet per second per square mile and runoff in inches or in acre-feet may be omitted if there is extensive regulations or diversion or if the drainage area includes large noncontributing areas. 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Statistics of monthly mean data A tabular summary of the mean (line headed "MEAN"), maximum (line headed "MAX"), and minimum (line headed "MIN") of monthly mean flows for each month for a designated period is provided below the mean values table. The water years of the first occurrence of the maximum and minimum monthly flow are provided immediately below those figures. The designated period will be expressed as "FOR WATER YEARS ____-____, BY WATER YEAR (WY)," and will list the first and last water years of the range of years selected from the PERIOD OF RECORD paragraph in the station manuscript. It will consist of all of the station records within the specified water years, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. Summary statistics A table titled "SUMMARY STATISTICS" follows the statistics of monthly mean data tabulation. This table consists of four columns, with the first column containing the line headings of the statistics being reported. The table provides a statistical summary of yearly, daily, and instantaneous flows, not only for the current water year but also for the previous calendar year and for a designated period, as appropriate. The designated period selected, "WATER YEARS ____-____," will consist of all of the station records within the specified water years, inclusive, including complete months of record for partial water years, if any, and may coincide with the period of record for the station. The water years for which the statistics are computed will be consecutive, unless a break in the station record is indicated in the manuscript. All of the calculations for the statistical characteristics designated ANNUAL (see line headings below), except for the "ANNUAL 7-DAY MINIMUM" statistic, are calculated for the designated period using complete water years. The other statistical characteristics may be calculated using partial water years. The date or water year, as appropriate, of the first occurrence of each statistic reporting extreme values of discharge is provided adjacent to the statistic. Repeated occurrences may be noted in the REMARKS paragraph of the manuscript or in footnotes. Because the designated period may not be the same as the station period of record published in the manuscript, occasionally the dates of occurrence listed for the daily and instantaneous extremes in the designated-period column may not be within the selected water years listed in the heading. When this occurs, it will be noted in the REMARKS paragraph or in footnotes. Selected streamflow duration curve statistics and runoff data are also given. Runoff data may be omitted if there is extensive regulation or diversion of flow in the drainage basin. The following summary statistics data, as appropriate, are provided with each continuous record of discharge. Comments to follow clarify information presented under the various line headings of the summary statistics table. ANNUAL TOTAL.--The sum of the daily mean values of discharge for the year. At some stations the annual total discharge is adjusted for reservoir storage or diversion. The adjusted figures are identified by a symbol and corresponding footnotes. ANNUAL MEAN.--The arithmetic mean of the individual daily mean discharges for the year noted or for the designated period. At some stations the yearly mean discharge is adjusted for reservoir storage or diversion. The adjusted figures are identified by a symbol and corresponding footnotes. HIGHEST ANNUAL MEAN.--The maximum annual mean discharge occurring for the designated period. LOWEST ANNUAL MEAN.--The minimum annual mean discharge occurring for the designated period. HIGHEST DAILY MEAN.--The maximum daily mean discharge for the year or for the designated period. LOWEST DAILY MEAN.--The minimum daily mean discharge for the year or for the designated period. ANNUAL 7-DAY MINIMUM.--The lowest mean discharge for 7 consecutive days for a calendar year or a water year. Note that most low-flow frequency analyses of annual 7-day minimum flows use a climatic year (April 1 - March 31). The date shown in the summary statistics table is the initial date of the 7-day period. (This value should not be confused with the 7-day 10-year low-flow statistics). 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 INSTANTANEOUS PEAK FLOW.--The maximum instantaneous discharge occurring for the water year or for the designated period. Note that secondary instantaneous peak discharges above a selected base discharge are stored in District computer files for stations meeting certain criteria. Those discharge values may be obtained by writing to the District Office. (See address on back of the title page of this report.) INSTANTANEOUS PEAK STAGE.--The maximum instantaneous stage occurring for the water year or for the designated period. If the dates of occurrence for the instantaneous peak flow and instantaneous peak stage differ, the REMARKS paragraph in the manuscript or a footnote may be used to provide further information. INSTANTANEOUS LOW FLOW.--The minimum instantaneous discharge occurring for the water year or for the designated period. ANNUAL RUNOFF.--Indicates the total quantity of water in runoff for a drainage area for the year. Data reports may use any of the following units of measurements in presenting annual runoff data: Acre-foot (AC-FT) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet or about 326,000 gallons or 1,233 cubic meters. Cubic feet per second per square mile (CFSM) is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. Inches (INCHES) indicates the depth to which the drainage area would be covered if all of the runoff for given time period were uniformly distributed on it. 10 PERCENT EXCEEDS.--The discharge that is exceeded 10 percent of the time for the designated period. 50 PERCENT EXCEEDS.--The discharge that is exceeded 50 percent of the time for the designated period. 90 PERCENT EXCEEDS.--The discharge that is exceeded 90 percent of the time for the designated period. Data collected at partial-record stations follow the information for continuous-record sites. Data for partial-record discharge stations are presented in a table of discharge measurements at low-flow partial-record stations. These measurements are generally made in times of drought to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellaneous sites. Identifying Estimated Daily Discharge Estimated daily-discharge values published in the water-discharge tables are identified by flagging individual daily values with the letter symbol "e" and printing a table footnote, "e Estimated." Accuracy of the Records The accuracy of streamflow records depends primarily on: (1) The stability of the stage-discharge relation or, if the control is unstable, the frequency of discharge measurements; and (2) the accuracy of measurements of stage, measurements of discharge, and interpretation of records. The accuracy attributed to the records is indicated under "REMARKS." "Excellent" means that about 95 percent of the daily discharges are within 5 percent of the true; "good," within 10 percent; and "fair," within 15 percent. Records that do not meet the criteria mentioned, are rated "poor." Different accuracies may be attributed to different parts of a given record. Daily mean discharges in this report are given to the nearest hundredth of a cubic foot per second for values less than 1 ft3/s; to the nearest tenth between 1.0 and 10 ft3/s; to whole numbers between 10 and 1,000 ft3/s; and to 3 significant figures for more than 1,000 ft3/s. The number of significant figures used is based solely on the magnitude of the discharge value. The same rounding rules apply to discharges listed for partial-record stations and miscellaneous sites. 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Information used in the preparation of the records in this publication, such as discharge-measurement notes, gage-height records, temperature measurements, and rating tables are on file in the Caribbean District office. Also, most of the daily mean discharges are in computer-readable form and have been analyzed statistically. Information on the availability of the unpublished information or on the results of statistical analyses of the published records may be obtained from the District office. Records of Surface-Water Quality Records of surface-water quality ordinarily are obtained at or near stream gaging stations because interpretation of records of surface-water quality nearly always requires corresponding discharge data. Records of surface-water quality in this report may involve a variety of types of data and measurement frequencies. Classification of Records Water-quality data for surface-water sites are grouped into one of three classifications. A continuing-record station is a site where data are collected on a regularly scheduled basis. Frequency may be once or more times daily, weekly, monthly, or quarterly. A partial-record station is a site where limited water-quality data are collected systematically over a period of years. Frequency of sampling is usually less than quarterly. A miscellaneous sampling site is a location other than a continuing or partial- record station, where random samples are collected to give better areal coverage to define water-quality conditions in the river basin. A careful distinction needs to be made between "continuing records" as used in this report and "continuous recordings," which refers to a continuous graph or a series of discrete values punched at short intervals on a paper tape. Some records of water quality, such as temperature and specific conductance, may be obtained through continuous recordings; however, because of costs, most data are obtained only monthly or less frequently. Locations of stations for which records on the quality of surface water appear in this report are shown in figure 6. Arrangement of Records Water-quality records collected at a surface-water daily record station are published immediately following that record, regardless of the frequency of sample collection. Station number and name are the same for both records. Where a surface-water daily record station is not available or where the water quality differs significantly from that at the nearby surface-water station, the continuing water-quality record is published with its own station number and name in the regular downstream-order sequence. Water-quality data for partial-record stations and for miscellaneous sampling sites appear in separate tables following the table of discharge measurement at miscellaneous sites. On-site Measurements and Sample Collection In obtaining water-quality data, a major concern needs to be assuring that the data obtained represent the in situ quality of the water. To assure this, certain measurements, such as water temperature, pH, and dissolved oxygen, need to be made onsite when the samples are taken. To assure that measurements made in the laboratory also represent the in situ water, carefully prescribed procedures need to be followed in collecting the samples, in treating the samples to prevent changes in quality pending analysis, and in shipping the samples to the laboratory. Procedures for onsite measurements and for collecting, treating, and shipping samples are given in publications on "Techniques of Water-Resources Investigations," Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. Detailed information on collecting, treating, and shipping samples may be obtained from the Geological Survey District office. One sample can define adequately the water quality at a given time if the mixture of solutes throughout the stream cross section is homogeneous. However, the concentration of solutes at different locations in the cross section may vary widely with different rates of water discharge, depending on the source of material and the turbulence and mixing of the stream. Some streams must be sampled through several vertical sections to obtain a representative sample needed for an accurate mean concentration and for use in calculating load. All samples obtained for the National Stream Quality Accounting Network (see definitions) are obtained from at least several verticals. Whether samples are obtained from the centroid of flow or from several verticals, depends on flow conditions and other factors which must be evaluated by the collector. 25 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Chemical-quality data published in this report are considered to be the most representative values available for the stations listed. The values reported represent water-quality conditions at the time of sampling as much as possible, consistent with available sampling techniques and methods of analysis. In the rare case where an apparent inconsistency exists between a reported pH value and the relative abundance of carbon dioxide species (carbonate and bicarbonate), the inconsistency is the result of a slight uptake of carbon dioxide from the air by the sample between measurement of pH in the field and determination of carbonate and bicarbonate in the laboratory. For chemical-quality stations equipped with digital monitors, the records consist of daily maximum, minimum, and mean values for each constituent measured and are based upon hourly punches beginning at 0100 hours and ending at 2400 hours for the day of record. More detailed records, when available, (hourly values) may be obtained from the U.S.G.S. District office whose address is given on the back of the title page of this report. Water Temperature Water temperatures are measured at most of the water-quality stations. In addition, water temperatures are taken at time of discharge measurements for water-discharge stations. For stations where water temperatures are taken manually once or twice daily, the water temperatures are taken at about the same time each day. Large streams have a small diurnal temperature change; shallow streams may have a daily range of several degrees and may follow closely the changes in air temperature. Some streams may be affected by waste-heat discharges. At stations where recording instruments are used, either mean temperatures or maximum and minimum temperatures for each day are published. Water temperatures measured at the time of water-discharge measurements are on file in the District office. Sediment Suspended-sediment concentrations are determined from samples collected by using depth-integrating and pumping sediment samplers. Samples usually are obtained at several verticals in the cross section, or a single sample may be obtained at a fixed point and a coefficient applied to determine the mean concentration in the cross sections. During periods of rapidly changing flow or rapidly changing concentration, samples may have been collected more frequently (twice daily or hourly). The published sediment discharges for days of rapidly changing flow or concentration were computed by the subdivided-day method (time-discharge weighted average). Therefore, for those days when the published sediment discharge value differs from the value computed as the product of discharge times mean concentration times 0.0027, the reader can assume that the sediment discharge for that day was computed by the subdivided-day method. For periods when no samples were collected, daily discharges of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, suspended-sediment loads for other periods of similar discharge, and computed by the subdivided-day method using the transport curves. At other stations, suspended-sediment samples were collected periodically at many verticals in the stream cross section. Although data collected periodically may represent conditions only at the time of observations, such data are useful in establishing seasonal relations between quality and streamflow and in predicting long-term sediment-discharge characteristics of the stream. In addition to the records of suspended-sediment discharge, records of the periodic measurements of the particle-size distribution of the suspended sediment are included for some stations. Laboratory Measurements Sediment samples, samples for biochemical-oxygen demand (BOD), samples for indicator bacteria, and daily samples for specific conductance are analyzed locally. All other samples are analyzed in the Geological Survey laboratories in Denver, Co. or Ocala, Fla. Methods used in analyzing sediment samples and computing sediment records are given in TWRI, Book 5, Chap. C1. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Data Presentation For continuing-record stations, information pertinent to the history of station operation is provided in descriptive headings preceding the tabular data. These descriptive headings give details regarding location, drainage area, period of record, type of data available, instrumentation, general remarks, cooperation, and extremes for parameters currently measured daily. Tables of chemical, physical, biological, radiochemical data, and so forth, obtained at a frequency less than daily are presented first, and tables of "daily values" of specific conductance, pH, water temperature, dissolved oxygen, and suspended sediment then follow in sequence, when these parameters are studied. In the descriptive headings, if the location is identical to that of the discharge gaging station, neither the LOCATION nor the DRAINAGE AREA statements are repeated. The following information, as appropriate, is provided with each continuous- record station. Comments that follow clarify information presented under the various headings of the station description. LOCATION.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. DRAINAGE AREA.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. PERIOD OF RECORD.--This indicates the periods for which there are published water-quality records for the station. The periods are shown separately for records of parameters measured daily or continuously and those measured less than daily. For those measured daily or continuously, periods of record are given for the parameters individually. INSTRUMENTATION.--Information on instrumentation is given only if a water-quality monitor temperature record, sediment pumping sampler, or other sampling device is in operation at a station. REMARKS.--Remarks provide added information pertinent to the collection, analysis, or computation of the records. COOPERATION.--Records provided by a cooperating organization or obtained for the Geological Survey by a cooperating organization are identified here. EXTREMES.--Maximums and minimums are given only for parameters measured daily or more frequently. None are given for parameters measured weekly or less frequently, because the true maximums or minimums may not have been sampled. Extremes, when given, are provided for both the period of record and for the current water year. REVISIONS.--If errors in published water-quality records are discovered after publication, appropriate updates are made to the Water-Quality File in the U.S. Geological Survey's computerized data system, WATSTORE, and subsequently by monthly transfer of update transactions to the U.S. Environmental Protection Agency's STORET system. Because the usual volume of updates makes it impractical to document individual changes in the State data-report series or elsewhere, potential users of U.S. Geological Survey water-quality data are encouraged to obtain all required data from the appropriate computer file to insure the most recent updates. The surface-water-quality records for partial-record stations and miscellaneous sampling sites are published in separate tables following the table of discharge measurements at miscellaneous sites. No descriptive statements are given for these records. Each station is published with its own station number and name in the regular downstream-order sequence. 27 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Remark Codes The following remark codes may appear with the water-quality data in this report: PRINTED OUTPUT REMARK E Estimated value > Actual value is known to be greater than the value shown < Actual value is known to be less than the value shown K Results based on colony count outside the acceptance range (non-ideal colony count) L Biological organism count less than 0.5 percent (organism may be observed rather than counted) D Biological organism count equal to or greater than 15 percent (dominant) & Biological organism estimated as dominant Records of Ground-Water Levels Only ground-water level data from a basic network of observation wells are published herein. This basic network contains observation wells so located that the most significant data are obtained from the fewest wells in the most important aquifers. Data Collection and Computation Measurements of water levels are made in many types of wells under varying conditions, but the methods of measurement are standardized to the extent possible. The equipment and measuring techniques used at each observation well ensure that measurements at each well are of consistent accuracy and reliability. Each well is identified by means of (1) a 15-digit number that is based on latitude and longitude and (2) a local number that is provided for local needs. See figure 9. Water-level records are obtained from direct measurements with a steel tape or from the graph or punched tape of a water- stage recorder. The water-level measurements in this report are given in feet with reference to land-surface datum (lsd). Land- surface datum is a datum plane that is approximately at land surface at each well. If known, the elevation of the land-surface datum is given in the well description. The height of the measuring point (MP) above or below land-surface datum is given in each well description. Water levels in wells equipped with recording gages are reported for every day and as an instantaneous observation at noon. Water levels are reported to as many significant figures as can be justified by the local conditions. For example, in a measurement of a depth to water of several hundred feet, the error of determining the absolute value of the total depth to water may be a few tenths of a foot, whereas the error in determining the net change of water level between successive measurements may be only a hundredth of a few hundredths of a foot. For lesser depths to water, the accuracy is greater. Accordingly, most measurements reported to a hundredth of a foot, but some are given to a tenth of a foot or a larger unit. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Data Presentation Each well record consists of three parts, the station description, the data table of water levels observed during the water year and a graph of the water levels for the current water year and other selected period. The description of the well is presented first through use of descriptive headings preceding the tabular data. The comments to follow clarify information presented under the various headings of the well description. LOCATION.--This paragraph follows the well-identification number and reports the latitude and longitude (given in degrees, minutes, and seconds); a landline location designation; the hydrologic-unit number; the distance and direction from a geographic point of reference; and the owner's name. AQUIFER.--This entry designates by name (if a name exists) and geologic age the aquifer(s) open to the well. WELL CHARACTERISTICS.--This entry describes the well in terms of depth, diameter, casing depth and/or screened interval, method of construction, use, and additional information such as casing breaks, collapsed screen, and other changes since construction. INSTRUMENTATION.--This paragraph provides information on both the frequency of measurement and the collection method used, allowing the user to better evaluate the reported water-level extremes by knowing whether they are based on weekly, monthly, or some other frequency of measurement. DATUM.--This entry describes both the measuring point and the land-surface elevation at the well. The measuring point is described physically (such as top of collar, notch in top of casing, plug in pump base and so on), and in relation to land surface (such as 1.3 ft above land-surface datum). The elevation of the land-surface datum is described in feet above (or below) sea level; it is reported with a precision depending on the method of determination. REMARKS.--This entry describes factors that may influence the water level in a well or the measurement of the water level. It should identify wells that also are water-quality observation wells, and may be used to acknowledge the assistance of local (non-Survey) observers. PERIOD OF RECORD.--This entry indicates the period for which there are published records for the well. It reports the month and year of the start of publication of water-level records by the U.S. Geological Survey and the words "to current year" if the records are to be continued into the following year. Periods for which water-level records are available, but are not published by the Geological Survey, may be noted. EXTREMES FOR PERIOD OF RECORD.--This entry contains the highest and lowest water levels of the period of published record, with respect to land-surface datum, and the dates of their occurrence. A table of water levels follows the station description for each well. Water levels are reported in feet below land-surface datum and all taped measurements of water level are listed. For wells equipped with recorders, daily values tables are published for the instantaneous water-level observation at noon. The highest and lowest water levels of the water year and their dates of occurrence are shown on a line below the table. Because all values are not published for wells with recorders, the extremes may be values that are not listed in the table. Missing records are indicated by dashes in place of the water level. A hydrograph for a selected period of record follows each water-level table. Records of Ground-Water Quality Records of ground-water quality in this type of report differ from other types of records in that for most sampling sites they consist of only one set of measurements for the water year. The quality of ground water ordinarily changes only slowly; therefore, for most general purposes one annual sampling, or only a few samples taken at infrequent intervals during the year, is sufficient. Frequent measurement of the same constituents is not necessary unless one is concerned with a particular problem, such as monitoring for trends in nitrate concentration. In the special cases where the quality of ground water may change more rapidly, more frequent measurements are made to identify the nature of the changes. 29 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Data Collection and Computation The records of ground-water quality in this report were obtained mostly as a part of special studies in specific areas. Consequently, a number of chemical analyses are presented for some counties but none are presented for others. As a result, the records for this year, by themselves, do not provide a balanced view of ground-water quality Statewide. Such a view can be attained only by considering records for this year in context with similar records obtained for these and other counties in earlier years. Most methods for collecting and analyzing water samples are described in the "U.S. Geological Survey Techniques of Water-Resources Investigations" manuals listed on a following page. The values reported in this type of report represent water- quality conditions at the time of sampling as much as possible, consistent with available sampling techniques and methods of analysis. All samples are obtained by trained personnel. The wells sampled are pumped long enough to assure that the water collected comes directly from the aquifer and has not stood for a long time in the well casing where it would have been exposed to the atmosphere and to the material, possibly metal, comprising the casings. Data Presentation The records of ground-water quality, when available, are published in a section titled QUALITY OF GROUND WATER immediately following the ground-water level records. Data for quality of ground water are listed alphabetically by County, and are identified by well number. The prime identification number for wells sampled is the 15-digit number derived from the latitude- longitude locations. No descriptive statements are given for ground-water-quality records; however, the well number, depth of well, date of sampling, and other pertinent data are given in the table containing the chemical analyses of the ground water. The REMARK codes listed for surface-water-quality records are also applicable to ground-water-quality records. ACCESS TO U.S. GEOLOGICAL SURVEY WATER DATA The U.S. Geological Survey provides near real-time stage and discharge data for many of the gaging stations equipped with the necessary telemetry and historic daily-mean and peak-flow discharge data for most current or discontinued gaging stations through the world wide web (WWW). These data may be accessed at http://water.usgs.gov Some water-quality and ground-water data also are available through the WWW. In addition, data can be provided in various machine-readable formats on magnetic tape or 3-1/2 inch floppy disk. Information about the availability of specific types of data or products, and user charges, can be obtained locally from each of the Water Resources Division District Offices (see address on the back of the title page). 30 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 DEFINITION OF TERMS Terms related to streamflow, water-quality, and other hydrologic data as used in this report, are defined below. See also the table for converting inch- pound units to the International System of units (SI) on the inside of the back cover. Acre-foot (AC-FT, acre-ft) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equal to about 326,000 gallons or 1,233 cubic meters. Adenosine triphosphate (ATP) is an organic, phosphate-rich, compound important in the transfer of energy in organisms. Its central role in living cells makes it an excellent indicator of the presence of living material in water. A measure of ATP therefore provides a sensitive and rapid estimate of biomass. ATP is reported in micrograms per liter of the original water sample. Algae growth potential (AGP) is the maximum algal dry weight biomass that can be produced in a natural water sample under standardized laboratory conditions. The growth potential is the algal biomass present a stationary phase and is expressed as milligrams dry weight of algae produced per liter of sample. Aquifer is a geologic formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. Artesian means confined and is used to describe a well in which the water level stands above the top of the aquifer, tapped by the well. A flowing artesian well is one in which the water level is above the land surface. Bacteria are microscopic unicellular organisms, typically spherical, rodlike, or spiral and threadlike in shape, often clumped into colonies. Some bacteria cause disease, while others perform an essential role in nature in the recycling of materials; for example, by decomposing organic matter into a form available for reuse by plants. Total coliform bacteria are a particular group of bacteria that are used as indicators of possible sewage pollution. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod-shaped bacteria which ferment lactose with gas formation within 48 hours at 35˚C. In the laboratory these bacteria are defined as all the organisms which produce colonies with a golden-green metallic sheen within 24 hours when incubated at 35˚C + 1.0˚C on M-Endo medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. 31 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Fecal coliform bacteria are bacteria that are present in the intestines or feces of warm-blooded animals. They are often used as indicators of the sanitary quality of the water. In the laboratory they are defined as all organisms which produce blue colonies within 24 hours when incubated at 44.5˚C + 0.2˚C on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Fecal streptococcal bacteria are bacteria found also in intestines of warm-blooded animals. Their presence in water is considered to verify fecal pollution. They are characterized as Gram-positive, cocci bacteria which are capable of growth in brain-heart infusion broth. In the laboratory they are defined as all the organisms which produce red or pink colonies within 48 hours at 35˚C + 1.0˚C on KF-streptococcus medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Bed material is the unconsolidated material of which a streambed, lake, pond, reservoir, or estuary bottom is composed. Biochemical oxygen demand (BOD) is a measure of the quantity of dissolved oxygen, in milligrams per liter, necessary for the decomposition of organic matter by microorganisms, such as bacteria. Biomass is the amount of living matter present at any given time, expressed as the mass per unit area or volume of habitat. Ash mass is the mass or amount of residue present after the residue from the dry mass determination has been ashed in a muffle furnace at a temperature of 500˚C for 1 hour. The ash mass values of zooplankton and phytoplankton are expressed in grams per cubic meter (g/m3), and periphyton and benthic organisms in grams per square meter (g/m2). Dry mass refers to the mass of residue present after drying in an oven at 105˚C for zooplankton and periphyton, until the mass remains unchanged. This mass represents the total organic matter, ash and sediment, in the sample. Dry- mass values are expressed in the same units as ash mass. Organic mass or volatile mass of the living substance is the difference between the dry mass and the ash mass and represents the actual matter. The organic mass is expressed in the same units as for ash and dry mass. Wet mass is the mass of living matter plus contained water. Bottom material: See Bed material. Cells/volume refers to the number of cells of any organism which is counted by using a microscope and grid or counting cell. Many planktonic organisms are multicelled and are counted according to the number of contained cells per sample, usually milliliters (mL) or liters (L). Chemical oxygen demand (COD) is a measure of the chemically oxidizable material in the water, and furnishes an approximation of the amount of organic and reducing material present. The determined value may correlate with natural water color or with carbonaceous organic pollution from sewage or industrial wastes. Chlorophyll refers to the green pigments of plants. Chlorophyll a and b are the two most common green pigments in plants. Color unit is produced by one milligram per liter of platinum in the form of the chloroplatinate ion. Color is expressed in units of the platinum-cobalt scale. Contents is the volume of water in a reservoir or lake. Unless otherwise indicated, volume is computed on the basis of a level pool and does not include bank storage. 32 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Control designates a feature downstream from the gage that determines the stage-discharge relation at the gage. This feature may be a natural constriction of the channel, an artificial structure, or a uniform cross section over a long reach of the channel. Control structure as used in this report is a structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of salt water. Cubic foot per second (ft3/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point during 1 second and is equivalent to 7.48 gallons per second or 448.8 gallons per minute or 0.02832 cubic meters per second. Cubic foot per second-day (ft3/s/day) is the volume of water represented by a flow of 1 cubic foot per second for 24 hours. It is equivalent to 86,400 cubic feet, approximately 1.9835 acre-feet, about 646,000 gallons, or 2,445 cubic meters. Cubic feet per second per square mile (CFSM) is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming that the runoff is distributed uniformly in time and area. Discharge is the volume of water (or more broadly, volume of fluid plus suspended sediment), that passes a given point within a given period of time. Instantaneous discharge is the discharge at a particular instant of time. Mean discharge (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. Annual 7-day minimum is the lowest mean discharge for 7 consecutive days for a calendar year or a water year. Note that most low-flow frequency analyses of annual 7-day minimum flows use a climatic year (April 1 - March 31). The date shown in the summary statistics table is the initial date of the 7-day period. (This value should not be confused with the 7-day 10-year low-flow statistic.) Dissolved refers to that material in a representative water sample which passes through a 0.45 um membrane filter. This is a convenient operational definition used by Federal agencies that collect water data. Determinations of "dissolved" constituents are made on subsamples of the filtrate. Dissolved-solids concentration of water is determined either analytically by the "residue-on-evaporation" method, or mathematically by totaling the concentrations of individual constituents reported in a comprehensive chemical analysis. During the analytical determination of dissolved solids, the bicarbonate (generally a major dissolved component of water) is converted to carbonate. Therefore, in the mathematical calculations of dissolved-solids concentration, the bicarbonate value, in milligrams per liter, is multiplied by 0.492 to reflect the change. Diversity index is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: ___ s d = -Σ ni log2 ni n n Where ni is the number of individuals per taxon, n is the total number of individuals, and s is the total number of taxa in the sample of the community. Diversity index values range from zero, when all the organisms in the sample are the same, to some positive number, when some or all of the organisms in the sample are different. Drainage area of a stream at a specified location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the stream above the specified point. Figures of drainage area given herein include all closed basins, or noncontribution areas, within the area unless otherwise noted. 33 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Drainage basin is a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. Gage height (gh) is the water-surface elevation referred to some arbitrary gage datum. Gage height is often used interchangeably with the more general term "stage," although gage height is more appropriate when used with a reading on a gage. Gaging station is a particular site on a stream, canal, lake, or reservoir where systematic observations of hydrologic data are obtained. Ground-water station is a well at which observations of ground-water level are made, either continuously by recorder, or periodically by hand. In addition, various chemical or physical parameters may be obtained, usually on a periodic basis. Hardness of water is a physical-chemical characteristic that is commonly recognized by the increased quantity of soap required to produce lather. It is attributable to the presence of alkaline earths (principally calcium and magnesium) and is expressed as equivalent calcium carbonate (CaCO3). Hydrologic Bench-Mark Network is a network in small drainage basins around the country whose purpose is to provide consistent data on the hydrology, including water quality, and related factors in representative undeveloped watersheds nationwide, and to provide analyses on a continuing basis to compare and contrast conditions observed in basins more obviously affected by the activities of man. Hydrologic unit is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as delineated by the Office of Water Data Coordination on the State Hydrologic Unit Maps; each hydrologic unit is identified by an eight-digit number. Land-surface datum (LSD) is a datum plane that is approximately at land surface at each ground-water observation well. Measuring point (MP) is an arbitrary permanent reference point from which the distance to the water surface in a well is measured to obtain the water level. Metamorphic stage refers to the stage of development that an organism exhibits during its transformation from an immature form to an adult form. This developmental process exists for most insects, and the degree of difference from the immature stage to the adult form varies from relatively slight to pronounced, with many intermediates. Examples of metamorphic stages of insects are egg-larva-adult or egg-nymph-adult. Methylene blue active substances (MBAS) are apparent detergents. The determination depends on the formation of a blue color when methylene blue dye reacts with synthetic anionic detergent compounds. Micrograms per gram (µg/g) is a unit expressing the concentration of a chemical element as the mass (micrograms) of the element per unit mass (gram) of material analyzed. Micrograms per liter (µG/L, ug/L) is a unit expressing the concentration of chemical constituents in solution as mass (micrograms) of solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram per liter. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical constituents in solution. Milligrams per liter represent the mass of solute per unit volume (liter) of water. Concentration of suspended sediment also is expressed in mg/L, and is based on the mass of sediment per liter of water-sediment mixture. Conversion of chemical concentrations in Mg/L to milliequivalents per liter can be done by using the factors in table 6. _____________________________________________________________________________________________________ ____________________________________________________________________________________________________ 34 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Table 6. Factors for conversion of chemical constituents in milligrams per liter to milliequivalents per liter Ion Multiply by Ion Multiply by Aluminum (Al+3)* ................ 0.11119 Iodide (I-1 .............................. 0.00788 Ammonia as NH4+1 .............. .05544 Iron (Fe+3) ............................. .05372 Barium (Ba+2) ....................... .01456 Lead (Pb+2) ........................... .00965 Bicarbonate (HCO3-1)........... .01639 Lithium (Li+1) ....................... .14411 Bromide (Br-1)....................... .01251 Magnesium (Mg+2) ............... .08226 Calcium (Ca+2)...................... .04990 Manganese (Mn+2)*.............. .03640 Carbonate (CO3-2)................. .03333 Nickel (Ni+2) ......................... .03406 Chloride (Cl-1)....................... .02821 Nitrate (N03-1)....................... .01613 Chromium (Cr+6)* ................ .11539 Nitrite (NO2-1) ...................... .02174 Cobalt (Co+2)* ...................... .03394 Phosphate (PO4-3) ................. .03159 Copper (Cu+2)* ..................... .03148 Potassium (K+1) .................... .02557 Cyanide (CN-1)...................... .03844 Sodium (NA+1) ..................... .04350 Fluoride (F-1)......................... .05264 Strontium (Sr+2) .................... .02283 Hydrogen (H+1)..................... .99209 Sulfate (SO4-2) ...................... .02082 Hydroxide (OH-1).................. .05880 Zinc (Zn+2)*.......................... .03060 *Constituent reported in micrograms per liter; multiply by factor and divide results by 1,000. National Stream Quality Accounting Network (NASQAN) is a nationwide data-collection network designed by the U.S. Geological Survey to meet many of the information needs of government agencies and other groups involved in natural or regional water-quality planning and management. The 500 or so sites in NASQAN are generally located at the downstream ends of hydrologic accounting units designated by the U.S. Geological Survey office of Water Data Coordination in consultation with the Water Resources Council. The objectives of NASQAN are (1) to obtain information on the quality and quantity of water moving within and from the United States through a systematic and uniform process of data collection, summarization, analysis, and reporting such that the data may be used for, (2) description of the areal variability of water quality in the Nation's rivers through analysis of description of the areal variability of water quality in the Nation's rivers through analysis of data from this and other programs, (3) detection of changes or trends with time in the pattern of occurrence of water-quality characteristics, and (4) providing a nationally consistent data base useful for water-quality assessment and hydrologic research. National Trends Network (NTN) is a network for sampling atmospheric deposition in the United States. The purpose of the network is to determine the variability, both in location and in time, of the composition of atmospheric deposition, which includes snow, rain, dust particles, aerosols, and gases. The core from which the NTN was built was the already-existing deposition- monitoring network of the National Atmospheric Deposition Program (NADP). Organism is any living entity. Organism count/area refers to the number of organisms collected and enumerated in a sample and adjusted to the number per unit area habitat, usually square meters (m2), acres, or hectare. Periphyton, benthic organisms, and macrophytes are expressed in these terms. Organism count/volume refers to the number of organisms collected and enumerated in a sample and adjusted to the number per sample volume, usually milliliters (mL) or liters (L). Numbers of planktonic organisms can be expressed in these terms. Total organism count is the total number of organisms collected and enumerated in any particular sample. Parameter Code is a 5-digit number used in the U.S. Geological Survey computerized data system, WATSTORE, to uniquely identify a specific constituent. The codes used in WATSTORE are the same as those used in the U.S. Environmental Protection Agency data system, STORET. The Environmental Protection Agency assigns and approves all requests for new codes. Partial-record station is a particular site where limited streamflow and/or water-quality data are collected systematically over a period of years for use in hydrologic analyses. 35 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Particle-size is the diameter, in millimeters (mm), of a particle determined by either sieve or sedimentation methods. Sedimentation methods (pipet, bottom-withdrawal tube, visual-accumulation tube) determine fall diameter of particles in either distilled water (chemically dispersed) or in native water (the river water at the time and point of sampling). Particle-size classification used in this report agrees with recommendations made by the American Geophysical Union Subcommittee on Sediment Terminology. The classification is as follows: Classification Size (mm) Method of analysis Clay...... 0.00024 - 0.004 Sedimentation Silt ...... .004 - .062 Sedimentation Sand...... .062 - 2.0 Sedimentation or sieve Gravel.... 2.0 - 64.0 Sieve The particle-size distributions given in this report are not necessarily representative of all particles in transport in the stream. Most of the organic matter is removed and the sample is subjected to mechanical and chemical dispersion before analysis in distilled water. Chemical dispersion is not used for native water analysis. Percent composition is a unit for expressing the ratio of a particular part of a sample or population to the total sample or population, in terms of types, numbers, mass or volume. Periphyton is the assemblage of microorganisms attached to and living upon submerged solid surfaces. While primarily consisting of algae, they also include bacteria, fungi, protozoa, rotifers, and other small organisms. Pesticides are chemical compounds used to control undesirable organisms. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. Picocurie (PC, pCi) is one trillionth (1 X 10-12) of the amount of ratioactivity represented by a curie (Ci). A curie is the amount of radioactivity that yields 3.7 x 1010 radioactive disintegrations per second. A picocurie yields 2.22 disintegrations per minute (dpm). Plankton is the community of suspended, floating, or weakly swimming organisms that live in the open water of lakes and rivers. Phytoplankton is the plant part of the plankton. They are usually microscopic and their movement is subject to the water currents. Phytoplankton growth is dependent upon solar radiation and nutrient substances. Because they are able to incorporate as well as release materials to the surrounding water, the phytoplankton have a profound effect upon the quality of the water. They are the primary food producers in the aquatic environment, and are commonly known as algae. Blue-green algae are a group of phytoplankton organisms having a blue pigment, in addition to the green pigment called chlorophyll. Blue-green algae often cause nuisance conditions in water. Diatoms are the unicellular or colonial algae having a siliceous shell. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. Green algae have chlorophyll pigments similar in color to those of higher green plants. Some forms produce algae mats or floating "moss" in lakes. Their concentrations are expressed as number of cells per milliliter (cells/mL) of sample. Zooplankton is the animal part of the plankton. Zooplankton are capable of extensive movements within the water column and are often large enough to be seen with the unaided eye. Zooplankton are secondary consumers feeding upon bacteria, phytoplankton, and detritus. Because they are the grazers in the aquatic environment, the zooplankton are a vital part of the aquatic food web. The zooplankton community is dominated by small crustaceans and rotifers. 36 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Primary productivity is a measure of the rate at which new organic matter is formed and accumulated through photosynthetic and chemosynthetic activity of producer organisms (chiefly, green plants). The rate of primary production is estimated by measuring the amount of oxygen released (oxygen method) or the amount of carbon assimilated by the plants (carbon method). Milligrams of carbon per area or volume per unit time [mg C/(m2.time)] for periphyton and macrophytes and [mg C/(m3.time)] for phytoplankton are units for expressing primary productivity. They define the amount of carbon dioxide consumed as measured by radioactive carbon (carbon 14). The carbon 14 method is of greater sensitivity than the oxygen light and dark bottle method, and is preferred for use in unenriched waters. Unit time may be either hour or day, depending on the incubation period. Milligrams of oxygen per area or volume per unit time [mg0 / (m2.time)] for periphyton and macrophytes and [mg0 /(m3.time)] for phytoplankton are the units for expressing primary productivity. They define production and respiration rates as estimated from changes in the measured dissolved-oxygen concentration. The oxygen light and dark bottle method is preferred if the rate of primary production is sufficient for accurate measurements to be made within 24 hours. Unit time may be either the hour or day, depending on the incubation period. Polychlorinated biphenyls (PCBs) are industrial chemicals that are mixtures of chlorinated biphenyl compounds having various percentages of chlorine. They are similar in structure to organochlorine insecticides. Radiochemical program is a network of regularly sampled water-quality stations where samples are collected to be analyzed for radioisotypes. The streams that are sampled represent major drainage basins in the conterminous United States. Recoverable from bottom material is the amount of a given constituent that is in solution after a representative sample of bottom material has been digested by a method (usually using an acid or mixture of acids) that results in dissolution of readily soluble substances. Complete dissolution of all bottom material is not achieved by the digestion treatment and thus the determination represents less than the total amount (that is, less than 95 percent) of the constituent in the sample. To achieve comparability of analytical data, equivalent digestion procedures would be required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Return period is the average time interval between occurrences of a hydrological event of a given or greater magnitude, usually expressed in years. May also be called recurrence interval. Runoff in inches (IN, in) shows the depth to which the drainage area would be covered if all the runoff for a given time period were uniformly distributed on it. Sediment is solid material that originates mostly from disintegrated rocks and is transported by, suspended in, or deposited from water; it includes chemical and biochemical precipitates and decomposed organic material, such as humus. The quantity, characteristics, and cause of the occurrence of sediment in streams are influenced by environmental factors. Some major factors are degree of slope, length of slope, soil characteristics, land usage, and quantity and intensity of precipitation. Bed load is the sediment that is transported in a stream by rolling, sliding, or skipping along the bed and very close to it. In this report, bed load is considered to consist of particles in transit within 0.25 ft of the streambed. Bed load discharge (tons per day) is the quantity of bed load measured by dry weight that moves past a section as bed load in a given time. Suspended sediment is the sediment that at any given time is maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. 37 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Suspended-sediment concentration is the velocity-weighted concentration of suspended sediment in the sampled zone (from the water surface to a point approximately 0.3 ft above the bed) expressed as milligrams of dry sediment per liter of water-sediment mixture (mg/L). Mean concentration is the time-weighted concentration of suspended sediment passing a stream section during a 24-hour day. Suspended-sediment discharge (tons/day) is the rate at which dry mass of sediment passes a section of a stream or is the quantity of sediment, as measured by dry mass or volume, that passes a section in a given time. It is calculated in units of tons per day as follows: concentrations (mg/L) x discharge (ft3/s) x 0.0027. Suspended-sediment load is a general term that refers to material in suspension. It is not synonymous with either discharge or concentration. Total sediment discharge (tons/day) is the sum of the suspended-sediment discharge and the bed-load discharge. It is the total quantity of sediment, as measured by dry mass or volume, that passes a section during a given time. Total-sediment load or total load is a term which refers to the total sediment (bed load plus suspended-sediment load) that is in transport. It is not synonymous with total-sediment discharge. 7-day 10-year low flow (7Q10) is the discharge at the 10-year recurrence interval taken from a frequency curve of annual values of the lowest mean discharge for 7 consecutive days (the 7-day low flow). Sodium-adsorption-ratio (SAR) is the expression of relative activity of sodium ions in exchange reactions within soil and is an index of sodium or alkali hazard to the soil. Waters range in respect to sodium hazard from those which can be used for irrigation on almost all soils to those which are generally unsatisfactory for irrigation. Solute is any substance that is dissolved in water. Specific conductance is a measure of the ability of a water to conduct an electric current. It is expressed in microsiemens per centimeter at 25˚C. Specific conductance is related to the type and concentration of ions in solution and can be used for approximating the dissolved-solids content of the water. Commonly, the concentration of dissolved solids (in milligrams per liter) is about 65 percent of the specific conductance (in micromhos). This relation is not constant from stream to stream, and it may vary in the same source with changes in the composition of the water. Stage-discharge relation is the relation between gage height (stage) and volume of water per unit of time, flowing in a channel. Streamflow is the discharge that occurs in a natural channel. Although the term "discharge" can be applied to the flow of a canal, the word "streamflow" uniquely describes the discharge in a surface stream course. The term "streamflow" is more general than "runoff" as streamflow may be applied to discharge whether or not it is affected by diversion or regulation. Substrate is the physical surface upon which an organism lives. Natural substrate refers to any naturally occurring emersed or submersed solid surface, such as a rock or tree, upon which an organism lives. Artificial substrate is a device which is purposely placed in a stream or lake for colonization of organisms. The artificial substrate simplifies the community structure by standardizing the substrate from which each sample is taken. Examples of artificial substrates are basket samplers (made of wire cages filled with clean streamside rocks) and multiplate samplers (made of hardboard) for benthic organism collection, and plexiglass strips for periphyton. 38 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Surface area of a lake is that area outlined on the latest U.S.G.S. topographic map as the boundary of the lake and measured by a planimeter in acres. In localities not covered by topographic maps, the areas are computed from the best maps available at the time planimetered. All areas shown are those for the stage when the planimetered map was made. Surficial bed material is that part (0.1 to 0.2 ft) of the bed material that is sampled using U.S. Series Bed-Material Samplers. Suspended (as used in tables of chemical analyses) refers to the amount (concentration) of the total concentration in a water- sediment mixture. It is associated with the material retained on a 0.45-micrometer filter. Suspended, recoverable is the amount of a given constituent that is in solution after the part of a representative water-suspended sediment sample that is retained on a 0.45 um membrane filter has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all the particulate matter is not achieved by the digestion treatment and thus the determination represents something less than the "total" amount (that is, less than 95 percent) of the constituent present in the sample. To achieve comparability of analytical data, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures are likely to produce different analytical results. Determinations of "suspended, recoverable" constituents are made either by analyzing portions of the material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total recoverable concentrations of the constituent. Suspended, total is the total amount of a given constituent in the part of representative water-suspended sediment sample that is retained on a 0.45 um membrane filter. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. A knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to determine when the results should be reported as "suspended, total." Determinations of "suspended, total" constituents are made either by analyzing portions of the material collected on the filter or, more commonly, by difference, based on determinations of (1) dissolved and (2) total concentrations of the constituent. Taxonomy is the division of biology concerned with the classification and naming of organisms. The classification of organisms is based upon a hierarchial scheme beginning with Kingdom and ending with Species at the base. The higher the classification level, the fewer features the organisms have in common. For example, the taxonomy of a particular mayfly, Hexagenia limbata, is the following: Kingdom.....................Animal Phylum........................Arthopoda Class...........................Insecta Order...........................Ephemeroptera Family.........................Ephemeridae Genus..........................Hexagenia Species........................Hexagenia limbata Thermograph is an instrument that continuously records variations of temperature on a chart. The more general term "temperature recorder" is used in the table heading and refers to any instrument that records temperature whether on a chart, a tape, or any other medium. Time-weighted average is computed by multiplying the number of days in the sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the total number of days. A time- weighted average represents the composition of water that would be contained in a vessel or reservoir that had received equal quantities of water from the stream each day for the year. Tons per acre-foot indicates the dry mass of dissolved solids in 1 acre-foot of water. It is computed by multiplying the concentration of the constituent, in milligrams per liter by 0.00136. 39 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1998 Tons per day (T/DAY) is the quantity of a substance in solution or suspension that passes a stream section during a 24-hour period. Total is the total amount of a given constituent in a representative water-suspended sediment sample, regardless of the constituent's physical or chemical form. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent present in both the dissolved and suspended phases of the sample. A knowledge of the expected form of the constituent in the sample, as well as the analytical methodology used, is required to judge when the results should be reported as "total." (Note that the word "total" does double duty here, indicating both that the sample consists of a water-suspended sediment mixture and that the analytical method determined all of the constituent in the sample.) Total discharge is the total quantity of any individual constituent, as measured by dry mass or volume, that passes through a stream cross-section per unit of time. This term needs to be qualified, such as "total sediment discharge," "total chloride discharge," and so on. Total, recoverable is the amount of a given constituent that is in solution after a representative water-suspended sediment sample has been digested by a method (usually using a dilute acid solution) that results in dissolution of only readily soluble substances. Complete dissolution of all particulate matter is not achieved by the digestion treatment, and thus the determination represents something less than the "total" amount (that is, less than 95 percent) of the constituent present in the dissolved and suspended phases of the sample. To achieve comparability of analytical data, equivalent digestion procedures are required of all laboratories performing such analyses, because different digestion procedures are likely to produce different analytical results. Tritium Network is a network of stations which has been established to provide baseline information on the occurrence of tritium in the Nation's surface waters. In addition to the surface-water stations in the network, tritium data are also obtained at a number of precipitations stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. Water year in U.S. Geological Survey reports dealing with surface water supply is the 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends and which includes 9 of the 12 months. Thus, the year ending September 30, 1980, is called the "1980 water year." WDR is used as an abbreviation for "Water-Data Report" in the REVISED RECORDS paragraph to refer to State annual hydrologic-data reports (WRD was used as an abbreviation for "Water-Resources Data" in reports published prior to 1976). Weighted average is used in this report to indicate discharge-weighted average. It is computed by multiplying the discharge for a sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the sum of the discharges. A discharge- weighted average approximates the composition of water that would be found in a reservoir containing all the water passing a given location during the water year after thorough mixing in the reservoir. WSP is used as an abbreviation for "Water-Supply Paper" in references to previously published reports. 40 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS The U.S. Geological Survey publishes a series of manuals describing procedures for planning and conducting specialized work in water- resources investigations. The material is grouped under major subject headings called books and is further divided into sections and chapters. For example, Section A of Book 3 (Applications of Hydraulics) pertains to surface water. The chapter, the unit of publication, is limited to a narrow field of subject matter. This format permits flexibility in revision and publication as the need arises. The reports listed below are for sale by the U.S. Geological Survey, Branch of Information Services, Box 25286, Federal Center, Denver, Colorado 80225 (authorized agent of the Superintendent of Documents, Government Printing Office). Prepayment is required. Remittance should be sent by check or money order payable to the U.S. Geological Survey. Prices are not included because they are subject to change. Current prices can be obtained by writing to the above address. When ordering or inquiring about prices for any of these publications, please give the title, book number, chapter number, and “U.S. Geological Survey Techniques of Water-Resources Investigations.” Book 1. Collection of Water Data by Direct Measurement Section D. Water Quality 1-D1. Water temperature—influential factors, field measurement, and data presentation, by H. H. Stevens, Jr., J.F. Ficke, and G. F. Smoot: USGS–TWRI Book 1, Chapter D1. 1975. 65 pages. 1-D2. Guidelines for collection and field analysis of ground-water samples for selected unstable constituents, by W.W. Wood: USGS– TWRI Book 1, Chapter D2. 1976. 24 pages. Book 2. Collection of Environmental Data Section D. Surface Geophysical Methods 2-D1. Application of surface geophysics to ground-water investigations, by A.A. R. Zohdy, G.P. Eaton, and D.R. Mabey: USGS–TWRI Book 2, Chapter D1. 1974. 116 pages. 2-D2. Application of seismic-refraction techniques to hydrologic studies, by F.P. Haeni: USGS–TWRI Book 2, Chapter D2. 1988. 86 pages. Section E. Subsurface Geophysical Methods 2-E1. Application of borehole geophysics to water-resources investigations, by W.S. Keys and L.M. MacCary: USGS–TWRI Book 2, Chapter E1. 1971. 126 pages. 2-E2. Borehole geophysics applied to ground-water investigations, by W.S. Keys: USGS–TWRI Book 2, Chapter E2. 1990. 150 pages. Section F. Drilling and Sampling Methods 2-F1. Application of drilling, coring, and sampling techniques to test holes and wells, by Eugene Shuter and W.E. Teasdale: USGS– TWRI Book 2, Chapter F1. 1989. 97 pages. Book 3. Applications of Hydraulics Section A. Surface-Water Techniques 3-A1. General field and office procedures for indirect discharge measurements, by M.A. Benson and Tate Dalrymple: USGS–TWRI Book 3, Chapter A1. 1967. 30 pages. 3-A2. Measurement of peak discharge by the slope-area method, by Tate Dalrymple and M.A. Benson: USGS–TWRI Book 3, Chapter A2. 1967. 12 pages. 3-A3. Measurement of peak discharge at culverts by indirect methods, by G.L. Bodhaine: USGS–TWRI Book 3, Chapter A3. 1968. 60 pages. 3-A4. Measurement of peak discharge at width contractions by indirect methods, by H.F. Matthai: USGS-TWRI Book 3, Chapter A4. 1967. 44 pages. 3-A5. Measurement of peak discharge at dams by indirect methods, by Harry Hulsing: USGS–TWRI Book 3. Chapter A5. 1967. 29 pages. 3-A6. General procedure for gaging streams, by R.W. Carter and Jacob Davidian: USGS–TWRI Book 3, Chapter A6. 1968. 13 pages. 3-A7. Stage measurement at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI Book 3, Chapter A7. 1968. 28 pages. 3-A8. Discharge measurements at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI Book 3, Chapter A8. 1969. 65 pages. 3-A9. Measurement of time of travel in streams by dye tracing, by F.A. Kilpatrick and J.F. Wilson, Jr.: USGS–TWRI Book 3, Chapter A9. 1989. 27 pages. 41 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS--Continued 3-Al0. Discharge ratings at gaging stations, by E.J. Kennedy: USGS–TWRI Book 3, Chapter A10. 1984. 59 pages. 3-A11. Measurement of discharge by the moving-boat method, by G.F. Smoot and C.E. Novak: USGS–TWRI Book 3, Chapter A11. 1969. 22 pages. 3-A12. Fluorometric procedures for dye tracing, Revised, by J.F. Wilson, Jr., E.D. Cobb, and F.A. Kilpatrick: USGS–TWRI Book 3, Chapter A12. 1986. 34 pages. 3-A13. Computation of continuous records of streamflow, by E.J. Kennedy: USGS–TWRI Book 3, Chapter A13. 1983. 53 pages. 3-A14. Use of flumes in measuring discharge, by F.A. Kilpatrick and V.R. Schneider: USGS–TWRI Book 3, Chapter A14. 1983. 46 pages. 3-A15. Computation of water-surface profiles in open channels, by Jacob Davidian: USGS–TWRI Book 3, Chapter A15. 1984. 48 pages. 3-A16. Measurement of discharge using tracers, by F.A. Kilpatrick and E.D. Cobb: USGS–TWRI Book 3, Chapter A16. 1985. 52 pages. 3-A17. Acoustic velocity meter systems, by Antonius Laenen: USGS–TWRI Book 3, Chapter A17. 1985. 38 pages. 3-A18. Determination of stream reaeration coefficients by use of tracers, by F.A. Kilpatrick, R.E. Rathbun, Nobuhiro Yotsukura, G.W. Parker, and L.L. DeLong: USGS–TWRI Book 3, Chapter A18. 1989. 52 pages. 3-A19. Levels at streamflow gaging stations, by E.J. Kennedy: USGS–TWRI Book 3, Chapter A19. 1990. 31 pages. 3-A20. Simulation of soluable waste transport and buildup in surface waters using tracers, by F.A. Kilpatrick: USGS–TWRI Book 3, Chapter A20. 1993. 38 pages. 3-A21 Stream-gaging cableways, by C. Russell Wagner: USGS–TWRI Book 3, Chapter A21. 1995. 56 pages. Section B. Ground-Water Techniques 3-B1. Aquifer-test design, observation, and data analysis, by R.W. Stallman: USGS–TWRI Book 3, Chapter B1. 1971. 26 pages. 3-B2. Introduction to ground-water hydraulics, a programed text for self-instruction, by G.D. Bennett: USGS–TWRI Book 3, Chapter B2. 1976. 172 pages. 3-B3. Type curves for selected problems of flow to wells in confined aquifers, by J.E. Reed: USGS–TWRI Book 3, Chapter B3. 1980. 106 pages. 3-B4. Regression modeling of ground-water flow, by R.L. Cooley and R.L. Naff: USGS–TWRI Book 3, Chapter B4. 1990. 232 pages. 3-B4. Supplement 1. Regression modeling of ground-water flow --Modifications to the computer code for nonlinear regression solution of steady-state ground-water flow problems, by R.L. Cooley: USGS–TWRI Book 3, Chapter B4. 1993. 8 pages. 3-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems—An introduction, by O.L. Franke, T.E. Reilly, and G.D. Bennett: USGS–TWRI Book 3, Chapter B5. 1987. 15 pages. 3-B6. The principle of superposition and its application in ground-water hydraulics, by T.E. Reilly, O.L. Franke, and G.D. Bennett: USGS–TWRI Book 3, Chapter B6. 1987. 28 pages. 3-B7. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow, by E.J. Wexler: USGS–TWRI Book 3, Chapter B7. 1992. 190 pages. Section C. Sedimentation and Erosion Techniques 3-C1. Fluvial sediment concepts, by H.P. Guy: USGS–TWRI Book 3, Chapter C1. 1970. 55 pages. 3-C2. Field methods for measurement of fluvial sediment, by H.P. Guy and V.W. Norman: USGS–TWRI Book 3, Chapter C2. 1970. 59 pages. 3-C3. Computation of fluvial-sediment discharge, by George Porterfield: USGS–TWRI Book 3, Chapter C3. 1972. 66 pages. Book 4. Hydrologic Analysis and Interpretation Section A. Statistical Analysis 4-A1. Some statistical tools in hydrology, by H.C. Riggs: USGS–TWRI Book 4, Chapter A1. 1968. 39 pages. 4-A2. Frequency curves, by H.C. Riggs: USGS–TWRI Book 4, Chapter A2. 1968. 15 pages. Section B. Surface Water 4-B1. Low-flow investigations, by H.C. Riggs: USGS–TWRI Book 4, Chapter B1. 1972. 18 pages. 4-B2. Storage analyses for water supply, by H.C. Riggs and C.H. Hardison: USGS–TWRI Book 4, Chapter B2. 1973. 20 pages. 4-B3. Regional analyses of streamflow characteristics, by H.C. Riggs: USGS–TWRI Book 4, Chapter B3. 1973. 15 pages. 42 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS--Continued Section D. Interrelated Phases of the Hydrologic Cycle 4-D1. Computation of rate and volume of stream depletion by wells, by C.T. Jenkins: USGS–TWRI Book 4, Chapter D1. 1970. 17 pages. Book 5. Laboratory Analysis Section A. Water Analysis 5-A1. Methods for determination of inorganic substances in water and fluvial sediments, by M.J. Fishman and L.C. Friedman, editors: USGS–TWRI Book 5, Chapter A1. 1989. 545 pages. 5-A2. Determination of minor elements in water by emission spectroscopy, by P.R. Barnett and E.C. Mallory, Jr.: USGS–TWRI Book 5, Chapter A2. 1971. 31 pages. 5-A3. Methods for the determination of organic substances in water and fluvial sediments, edited by R.L. Wershaw, M.J. Fishman, R.R. Grabbe, and L.E. Lowe: USGS–TWRI Book 5, Chapter A3. 1987. 80 pages. 5-A4. Methods for collection and analysis of aquatic biological and microbiological samples, by L.J. Britton and P.E. Greeson, editors: USGS–TWRI Book 5, Chapter A4. 1989. 363 pages. 5-A5. Methods for determination of radioactive substances in water and fluvial sediments, by L.L. Thatcher, V.J. Janzer, and K.W. Edwards: USGS–TWRI Book 5, Chapter A5. 1977. 95 pages. 5-A6. Quality assurance practices for the chemical and biological analyses of water and fluvial sediments, by L.C. Friedman and D.E. Erdmann: USGS–TWRI Book 5, Chapter A6. 1982. 181 pages. Section C. Sediment Analysis 5-C1. Laboratory theory and methods for sediment analysis, by H.P. Guy: USGS–TWRI Book 5, Chapter C1. 1969. 58 pages. Book 6. Modeling Techniques Section A. Ground Water 6-A1. A modular three-dimensional finite-difference ground-water flow model, by M.G. McDonald and A.W. Harbaugh: USGS–TWRI Book 6, Chapter A1. 1988. 586 pages. 6-A2. Documentation of a computer program to simulate aquifer-system compaction using the modular finite-difference ground-water flow model, by S.A. Leake and D.E. Prudic: USGS–TWRI Book 6, Chapter A2. 1991. 68 pages. 6-A3. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 1: Model Description and User’s Manual, by L.J. Torak: USGS–TWRI Book 6, Chapter A3. 1993. 136 pages. 6-A4. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 2: Derivation of finite- element equations and comparisons with analytical solutions, by R.L. Cooley: USGS–TWRI Book 6, Chapter A4. 1992. 108 pages. 6-A5. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 3: Design philosophy and programming details, by L.J. Torak: USGS–TWRI Book 6, Chapter A5, 1993. 243 pages. 6-A6. A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction, by Eric D. Swain and Eliezer J. Wexler. 1996. 125 pages. Book 7. Automated Data Processing and Computations Section C. Computer Programs 7-C1. Finite difference model for aquifer simulation in two dimensions with results of numerical experiments, by P.C. Trescott, G.F. Pinder, and S.P. Larson: USGS–TWRI Book 7, Chapter C1. 1976. 116 pages. 7-C2. Computer model of two-dimensional solute transport and dispersion in ground water, by L.F. Konikow and J.D. Bredehoeft: USGS–TWRI Book 7, Chapter C2. 1978. 90 pages. 7-C3. A model for simulation of flow in singular and interconnected channels, by R.W. Schaffranek, R.A. Baltzer, and D.E. Goldberg: USGS–TWRI Book 7, Chapter C3. 1981. 110 pages. Book 8. Instrumentation Section A. Instruments for Measurement of Water Level 8-A1. Methods of measuring water levels in deep wells, by M.S. Garber and F.C. Koopman: USGS–TWRI Book 8, Chapter A1. 1968. 23 pages. 8-A2. Installation and service manual for U.S. Geological Survey manometers, by J.D. Craig: USGS–TWRI Book 8, Chapter A2. 1983. 57 pages. 43 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS--Continued Section B. Instruments for Measurement of Discharge 8-B2. Calibration and maintenance of vertical-axis type current meters, by G.F. Smoot and C.E. Novak: USGS–TWRI Book 8, Chapter B2. 1968. 15 pages. Book 9. Handbooks for Water-Resources Investigations Section A. National Field Manual for the Collection of Water-Quality Data 9-A6. National Field Manual for the Collection of Water-Quality Data: Field Measurements, edited by F.D. Wilde and D.B. Radtke: USGS–TWRI Book 9, Chapter A6. 1998. Variously paginated. 9-A7. National Field Manual for the Collection of Water-Quality Data: Biological Indicators, by D.N. Myers and F.D. Wilde: USGS– TWRI Book 9, Chapter A7. 1997. 49 pages. 9-A8. National Field Manual for the Collection of Water-Quality Data: Bottom-material samples, by D.B. Radtke: USGS–TWRI Book 9, Chapter A8. 1998. 48 pages. 9-A9. National Field Manual for the Collection of Water-Quality Data: Safety in Field Activities, by S.L. Lane and R.G. Fay: USGS– TWRI Book 9, Chapter A9. 1998. 60 pages. 44 THIS PAGE WAS LEFT BLANK INTENTIONALLY 45 Surface and Quality-of-Water Records for Puerto Rico 46 THIS PAGE WAS LEFT BLANK INTENTIONALLY   66°53 38 67°10 38   47 18°30 18°15 Canal Principal de los Cedros de Diversión Quebrada Río Río Guajataca Guajataca 0108 0105 0105 165 AGUADILLA ISABELA QUEBRADILLAS CAMUY OCEAN SAN SEBASTIÁN MOCA LARES 202 165 0108 010790 010720 0105 0 0 1 1 2 2 3 3 4 4 Lago de Guajataca QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER CHANNEL FLOW DIRECTION ATLANTIC Basin area PUERTO RICO 0114 OT-1 0110 5 MILES 5 KILOMETERS Figure 11. Río Guajataca basin. 48 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR LOCATION.--Lat 18°18'01", long 66°52'24", Hydrologic Unit 21010001 at bridge on Highway 111, 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) east of Lares. DRAINAGE AREA.--3.16 mi2 (8.18 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to February 1962 (annual low-flow measurements only), January 1963 to April 1969 (monthly measurements only), May 1969 to December 1970 (February to May 1971 and March 1974 to November 1989, monthly measurements only), December 1989 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 935 ft (285 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Small diversion above station for sewage treatment plant; effluent re-enters stream below station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 18 3.4 2.7 2.6 1.8 1.3 1.1 .98 2.8 1.2 1.8 5.9 2 11 2.4 2.3 2.2 1.7 1.2 1.2 .98 2.5 1.3 1.6 71 3 6.0 2.3 1.6 2.3 1.7 1.1 .73 .92 5.7 4.0 1.7 25 4 3.7 2.2 1.6 2.2 4.0 1.0 .61 .69 2.4 2.9 2.4 16 5 3.6 2.0 1.5 2.4 7.4 1.1 .59 .68 20 2.1 2.0 12 6 6.5 2.4 1.3 2.5 2.6 1.1 .55 5.0 4.6 3.5 1.5 32 7 15 1.7 1.3 3.8 2.0 1.7 .77 3.3 1.8 3.3 4.7 20 8 6.5 1.7 1.4 2.6 5.4 1.1 .80 1.7 1.6 5.2 3.0 12 9 3.9 1.7 1.5 2.2 3.0 .91 .75 1.7 2.4 2.2 30 9.6 10 2.9 1.9 1.6 2.2 1.6 .84 .74 1.2 2.6 2.2 11 7.8 11 6.8 1.8 2.1 5.5 12 49 2.4 1.4 3.5 13 20 2.6 1.5 2.5 14 39 4.9 1.4 2.6 15 49 3.2 1.4 2.0 1.5 .85 .66 1.1 2.6 2.0 11 7.2 1.6 .85 .76 .98 2.3 13 3.5 77 1.6 .80 .66 .97 19 21 2.0 18 1.8 2.3 .62 .80 7.1 8.8 1.9 11 1.8 2.3 .57 1.6 4.3 9.8 1.9 8.3 16 27 1.8 1.4 1.8 17 27 1.4 1.7 6.2 18 18 1.3 3.0 8.2 19 12 1.4 2.9 4.9 20 9.2 1.6 3.1 3.0 1.8 1.5 .81 1.1 81 24 2.1 17 1.7 .92 .74 15 9.7 22 19 15 1.6 1.1 .73 8.3 19 11 3.8 41 1.5 .77 8.5 10 7.4 5.4 2.2 13 1.8 .73 4.9 36 3.9 4.3 1.9 8.2 21 6.8 1.2 2.3 2.2 22 6.1 1.1 4.3 2.0 23 5.3 1.6 5.8 2.1 24 5.5 1.2 4.2 2.0 25 4.2 1.2 3.4 2.0 1.6 .68 1.1 26 3.6 3.3 11 43 1.2 .61 1.1 17 2.8 2.3 4.2 505 1.1 .64 .93 9.9 2.2 2.3 2.3 91 1.0 .79 .87 3.7 2.0 2.3 7.2 57 1.1 .80 .82 2.1 1.9 2.0 17 44 26 3.9 2.2 2.8 2.7 27 4.4 3.6 2.3 1.6 28 3.7 2.2 2.3 1.6 29 3.8 9.8 2.2 2.1 30 3.5 4.4 3.7 2.1 31 3.1 --- 2.7 1.7 1.2 .73 .94 2.6 1.8 1.8 3.6 37 .95 .78 1.0 2.4 3.5 1.8 3.1 32 1.3 .73 .83 2.0 1.9 1.8 50 36 --- .76 .72 2.3 1.4 1.5 12 44 --- 2.4 .82 4.4 1.4 1.4 15 39 --- .81 --- 2.9 --- 7.6 16 --­ TOTAL 384.4 72.6 72.7 87.3 MEAN 12.4 2.42 2.35 2.82 MAX 49 9.8 5.8 8.2 MIN 2.9 1.1 1.3 1.6 AC-FT 762 144 144 173 CFSM 3.92 .77 .74 .89 IN. 4.53 .85 .86 1.03 57.35 33.20 35.92 168.30 225.2 177.3 250.4 1355.0 2.05 1.07 1.20 5.43 7.51 5.72 8.08 45.2 7.4 2.4 8.5 36 81 24 50 505 .95 .61 .55 .68 1.4 1.2 1.5 5.9 114 66 71 334 447 352 497 2690 .65 .34 .38 1.72 2.38 1.81 2.56 14.3 .68 .39 .42 1.98 2.65 2.09 2.95 15.95 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 1998, BY WATER YEAR (WY) MEAN 16.4 8.03 3.69 3.36 MAX 33.7 16.7 7.31 8.91 (WY) 1991 1971 1971 1997 MIN 8.52 2.42 1.35 .66 (WY) 1995 1998 1991 1991 2.65 2.13 3.18 8.85 7.26 4.26 6.29 14.9 7.21 6.38 7.63 20.2 16.4 9.85 11.1 45.2 1996 1971 1993 1995 1995 1969 1996 1998 .93 .92 1.09 2.37 1.70 1.73 3.34 5.95 1992 1994 1994 1997 1997 1997 1970 1993 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1969 - 1998 ANNUAL TOTAL 1583.27 ANNUAL MEAN 4.34 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 88 LOWEST DAILY MEAN .50 ANNUAL SEVEN-DAY MINIMUM .56 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 3140 ANNUAL RUNOFF (CFSM) 1.37 ANNUAL RUNOFF (INCHES) 18.64 10 PERCENT EXCEEDS 9.3 50 PERCENT EXCEEDS 2.1 90 PERCENT EXCEEDS .95 2919.67 8.00 6.58 9.08 1996 4.13 1994 Sep 24 505 Sep 22 505 Sep 22 1998 May 17 .55 Apr 6 .47 Jan 13 1991 May 13 .68 Apr 9 .51 Jan 9 1991 3880 Sep 22 5300 Oct 7 1990 19.20 Sep 22 21.30 Oct 7 1990 5790 4770 2.53 2.08 34.37 28.31 18 15 2.3 3.3 .84 .96 49 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR 50 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18’01", long 66°52'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anón, and 0.4 mi (0.6 km) northeast of Lares plaza. DRAINAGE AREA.--3.16 mi 2 (8.18 km2). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS­ PH OXYGEN, OXYGEN COLI­ CHARGE, SPE­ WATER DIS­ DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON­ FIELD TEMPER- TUR­ OXYGEN, (PER­ ICAL 0.45 FECAL, FEET DUCT- (STAND­ ATURE BID­ DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 20... 1310 7.9 227 8.0 24.0 2.2 7.3 90 <10 40000 K1200 FEB 23... 1245 1.6 255 7.7 21.5 1.5 7.5 88 <10 K1500 580 MAY 21... 1155 6.1 229 7.5 23.5 14 7.6 92 <10 3400 7000 AUG 31... 1315 5.7 278 7.4 24.5 6.9 7.5 93 <10 2400 2400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS­ (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 20... 87 25 5.7 10 .5 2.5 82 <.5 7.2 12 FEB 23... -- -- -- -- -- -- 97 -- -- -­ MAY 21... 84 25 5.1 9.6 .5 4.3 66 -- 16 12 AUG 31... 110 35 5.9 11 .5 2.9 110 <1.0 13 11 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 20... .11 29 141 3.02 2 .570 .190 .760 1.70 .40 FEB 23... -- -- -- -- 3 -- <.010 .830 .030 .22 MAY 21... <.10 20 132 2.16 20 2.18 .019 2.20 .060 .22 AUG 31... <.10 25 170 2.60 9 -- <.010 1.50 .030 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 20... 2.1 2.9 13 .340 <1 <100 10 <1 <1 <10 FEB 23... .25 1.1 4.8 .030 -- -- -- -- -- -­ MAY 21... .28 2.5 11 .030 <1 <100 <10 <1 <1 <10 AUG 31... <.20 -- -- .080 -- -- -- -- -- -­ -- -- -- -- -- -- 51 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV­ RECOV- RECOV- NIUM, RECOV- RECOV­ CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 20... 200 <1 26 <.10 <1 <1 <10 <.010 <1 <.02 FEB 23... -­ -­ -­ -­ -­ -­ -­ MAY 21... 450 <1 59 <.10 <1 <1 <10 <.010 <1 .03 AUG 31... -­ -­ -­ -­ -­ -­ -­ --- --- --- --- --- --- --- --- --- 52 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR LOCATION.--Lat 18°24'02", long 66°55'25", Hydrologic Unit 21010002, on right bank, in a concrete intake tower at Damsite, 5.2 mi (8.4 km) southeast from Quebradillas plaza, 0.5 mi (0.8 km) northeast from Iglesia San Antonio de Padua and 2.8 mi (4.5 km) from Escuela Segunda Unidad Baldorioty de Castro. DRAINAGE AREA.--24.6 mi2 (63.71 km2) ELEVATION RECORDS PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guajataca was completed in 1928. The dam is a semihydraulic earthfill structure about 123 ft (37 m) high, a top width of 31 ft (9.5 m) at crest elevation of 664 ft (202.5 m), a base width of 623 ft (190 m), a crest length of 1,036 ft (316 m) and has a maximum storage capacity of 49,200 acre-feet (60.6 hm3). The Guajataca Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and provides water for the municipalities of Aguadilla, Isabela, Moca, Aguada and Quebradillas although its primary purpose is for agricultural irrigation for the flatlands of the area. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 648.3 ft (197.60 m), Sept. 23, 1998; minimum elevation, 608.07 ft (185.34 m), May 17, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 648.3 ft (197.60 m), Sept. 23; minimum elevation, 608.07 ft (185.34 m), May 17. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 593 0 625 15,295 600 2,405 650 36,403 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 614.32 625.22 624.56 620.40 616.57 611.36 611.87 608.92 621.82 629.34 634.67 641.96 2 615.67 625.10 624.44 620.20 616.39 611.20 611.77 608.75 621.83 629.21 634.57 642.71 3 616.31 625.00 624.33 620.02 616.21 611.02 A 608.66 621.85 629.10 634.51 642.55 4 616.30 624.87 624.19 619.84 616.19 610.88 611.52 608.59 621.81 629.00 634.45 642.17 5 616.73 624.72 624.03 619.64 616.14 612.30 611.39 608.46 621.87 628.94 634.48 641.82 6 617.17 624.58 623.89 619.49 615.99 612.71 611.25 608.61 622.15 628.96 634.41 642.59 7 618.88 624.43 623.73 619.30 615.81 613.05 611.11 608.92 622.12 628.84 634.32 642.73 8 619.69 624.28 623.59 619.13 615.73 613.21 610.96 608.89 622.01 628.87 634.22 642.43 9 619.78 624.15 623.46 618.94 615.59 613.16 610.73 608.79 621.88 628.81 634.42 642.11 10 619.76 624.00 623.32 618.79 615.42 613.06 610.57 608.68 621.72 628.74 634.40 641.74 11 619.71 623.95 623.18 618.67 615.20 612.96 610.41 608.54 623.04 629.07 634.97 641.71 12 621.46 623.99 623.02 618.55 615.00 612.83 610.26 608.43 624.77 629.77 636.20 642.16 13 622.28 623.88 622.88 618.39 614.80 612.70 610.10 608.26 626.57 632.58 636.63 643.36 14 623.95 623.75 622.72 618.17 614.60 612.57 609.92 608.18 627.86 633.51 636.65 643.00 15 625.20 623.84 622.57 617.97 614.39 612.46 609.78 608.18 628.46 634.08 636.59 642.42 16 626.16 623.78 622.41 617.76 614.17 612.37 609.76 608.14 629.20 634.80 636.60 641.98 17 626.45 623.64 622.26 617.86 613.97 612.24 609.62 608.53 629.46 635.27 636.57 641.86 18 626.52 623.44 622.13 618.13 613.73 612.10 609.48 608.81 629.78 635.36 636.49 642.28 19 626.51 623.28 621.99 618.33 613.51 611.95 609.65 609.16 629.97 635.36 636.38 642.03 20 626.48 623.12 621.84 618.29 613.29 611.78 609.74 612.97 630.00 635.34 636.27 641.38 21 626.43 622.95 621.69 618.15 613.05 611.66 609.73 614.81 629.99 635.27 636.40 641.26 22 626.36 622.78 621.78 617.99 612.81 611.53 609.63 616.76 629.94 635.19 636.38 647.94 23 626.27 622.61 621.71 617.85 612.58 611.39 609.48 619.88 629.87 635.19 636.29 648.27 24 626.16 622.44 621.59 617.70 612.36 611.27 609.60 620.97 629.78 635.23 636.34 647.97 25 626.06 622.39 621.44 617.58 612.16 611.13 609.75 621.25 629.72 635.16 636.84 647.53 26 625.94 623.44 621.28 617.40 611.92 610.99 609.66 621.65 629.65 635.06 636.95 647.04 27 625.81 624.01 621.12 617.25 611.69 610.87 609.53 621.77 629.71 635.03 636.99 646.51 28 625.69 624.35 620.97 617.20 611.51 610.75 609.40 621.76 629.69 634.93 639.35 645.99 29 625.56 624.47 620.78 617.05 611.79 609.24 621.71 629.56 634.86 640.27 645.63 30 625.42 624.62 620.72 616.89 611.96 609.08 621.64 629.45 634.76 640.72 645.86 31 625.29 620.57 616.74 611.95 621.58 634.72 641.63 MAX 626.52 625.22 624.56 620.40 616.57 613.21 621.77 630.00 635.36 641.63 648.27 MIN 614.32 622.39 620.57 616.74 611.51 610.75 608.14 621.72 628.74 634.22 641.26 A No gage-height record 53 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'02", long 66°55'27", off Highway 476 at Lago Guajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 23... 0715 E65 324 8.1 25.5 1.2 1.2 15 <10 200 66 MAR 13... 1400 40 313 8.0 26.0 .65 9.1 115 <10 <10 <10 JUN 02... 1615 65 317 6.8 26.5 .83 2.8 36 <10 K120 K110 AUG 31... 1530 65 327 7.4 25.5 1.1 1.7 21 <10 240 260 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 23... 150 54 3.6 5.1 .2 2.0 140 <.5 9.0 7.8 MAR 13... -- -- -- -- -- -- 140 -- -- -­ JUN 02... 140 49 3.8 6.0 .2 2.4 140 -- 11 8.9 AUG 31... 150 53 3.5 5.6 .2 2.1 160 <1.0 8.1 6.9 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 23... <.10 6.1 171 E30.0 <1 .156 .054 .210 .660 .25 MAR 13... -- -- -- -- 3 -- <.010 .040 .040 .52 JUN 02... .11 6.3 171 30.1 1 .116 .014 .130 .740 .36 AUG 31... <.10 6.4 181 31.9 3 -- <.010 <.020 .240 .38 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 23... .91 1.1 5.0 <.020 20 <100 20 <1 <1 <10 MAR 13... .56 .60 2.7 .040 -- -- -- -- -- -­ JUN 02... 1.1 1.2 5.4 <.020 2 <100 30 <1 <1 <10 AUG 31... .62 -- -- .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 54 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... 150 2 220 <.10 <1 <1 20 <.010 <1 <.02 MAR 13... JUN 02... 170 2 230 <.10 <1 <1 20 <.010 <1 .02 AUG 31... 55 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°28'31", long 66°57'46", Hydrologic Unit 21010002, on left bank at ford 1.7 mi (2.7 km) upstream from bridge on highway 2, 1.6 mi (2.6 km) west of Quebradillas plaza, 2.1 mi (3.4 km) upstream from Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago Guajataca. DRAINAGE AREA.--Indeterminate PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 1200 20 466 7.8 25.5 .97 7.0 85 <10 210 1000 MAR 13... 1215 8.7 611 7.8 24.5 .85 4.8 57 <10 K60 K45 JUN 04... 1215 29 409 8.1 25.5 8.6 7.4 90 <10 600 200 SEP 11... 1400 100 378 7.6 26.0 4.9 7.3 112 <10 3900 320 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 200 71 6.3 14 .4 1.4 190 <.5 8.5 25 MAR 13... -- -- -- -- -- -- 230 -- -- -­ JUN 04... 180 65 4.9 10 .3 1.7 180 -- 8.3 16 SEP 11... 180 64 3.8 6.3 .2 1.6 180 <1.0 7.4 9.2 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 6.7 246 13.3 <1 -- <.010 1.50 .010 -­ MAR 13... -- -- -- -- 2 2.59 .010 2.60 .040 .22 JUN 04... <.10 6.3 220 17.1 7 -- <.010 1.10 .010 .21 SEP 11... <.10 6.6 207 56.2 3 .575 .015 .590 .030 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... <.20 -- -- <.020 <1 <100 30 <1 1 <10 MAR 13... .26 2.9 13 .030 -- -- -- -- -- -­ JUN 04... .22 1.3 5.8 <.020 <1 <100 30 <1 1 <10 SEP 11... <.20 -- -- <.020 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 56 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 240 <1 30 <.10 <1 <1 <10 <.010 <1 <.02 MAR 13... JUN 04... 200 <1 25 <.10 <1 <1 <10 <.010 <1 <.02 SEP 11... 57   66°45 66°53 38 18°30 18°15 Río Río Río Piedras Río Caño Camuy River Underground A n g e l e s C r i m i n a l e s 0148 CA-4 QUEBRADILLAS CAMUY ARECIBO OCEAN LARES UTUADO 0148 0 0 1 1 2 2 3 3 4 4 CA-4 Z-4 Tiburones CAÑO TIBURONES FLOW DIRECTION EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER HATILLO ATLANTIC Basin area PUERTO RICO 5 MILES 5 KILOMETERS Figure 12. Río Camuy basin. --- --- --- --- --- --- --- 58 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR LOCATION.--Lat 18°23'48", long 66°49'04", Hydrologic Unit 21010002, on left bank at Highway 488, 1.4 mi (2.2 km) southeast of school at Santiago, 0.9 mi (1.4 km) northwest from Escuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upstream from mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--May 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 341 ft (104 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 82 58 54 e29 27 25 37 26 e60 57 112 259 2 182 59 49 e29 26 25 29 25 e52 55 62 426 3 183 56 43 e29 26 24 e27 25 e89 53 56 347 4 75 55 41 e27 28 23 e26 28 82 55 56 203 5 97 53 41 e28 63 50 25 27 238 52 64 142 6 97 53 41 e29 44 65 25 101 198 51 53 247 7 186 52 39 e47 30 43 25 137 106 106 74 304 8 217 52 39 e35 29 38 26 54 74 59 82 196 9 95 50 38 e27 41 29 24 64 60 85 205 138 10 71 49 39 e27 31 27 23 44 59 55 177 116 11 65 49 37 e26 29 26 23 33 117 63 482 102 12 309 58 36 e27 29 25 23 30 242 55 615 239 13 313 60 36 e49 28 26 23 29 414 56 296 272 14 385 52 35 e35 27 26 23 39 227 84 136 160 15 329 51 35 e27 27 42 22 31 123 101 103 109 16 378 55 35 e26 27 35 59 31 261 460 118 130 17 229 50 34 33 27 27 42 28 275 324 125 181 18 177 47 33 76 26 27 28 72 194 149 100 298 19 134 45 32 52 25 25 146 152 155 94 84 257 20 116 43 32 50 25 24 153 603 94 81 77 141 21 103 43 32 36 25 24 77 571 79 73 138 255 22 92 42 32 33 25 24 54 257 75 66 120 9010 23 85 41 34 31 25 23 39 e130 65 63 84 3140 24 79 41 41 30 24 23 44 e94 59 87 82 1140 25 75 40 33 30 24 22 61 e79 67 65 276 835 26 72 44 32 31 27 23 38 e73 70 58 131 580 27 68 67 e32 29 26 23 33 e65 184 89 114 e540 28 66 70 e32 28 25 23 31 e62 122 65 687 e520 29 64 66 e32 27 40 28 e61 72 58 463 e900 30 61 102 e30 27 88 27 87 62 55 197 e600 31 59 e31 27 66 78 127 436 TOTAL 4544 1603 1130 1037 816 1011 1241 3136 3975 2901 5805 21787 MEAN 147 53.4 36.5 33.5 29.1 32.6 41.4 101 133 93.6 187 726 MAX 385 102 54 76 63 88 153 603 414 460 687 9010 MIN 59 40 30 26 24 22 22 25 52 51 53 102 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 1998, BY WATER YEAR (WY) MEAN 197 113 66.5 57.2 50.0 46.8 86.6 167 110 75.2 97.9 201 MAX 427 244 97.4 163 96.4 66.0 202 624 235 109 187 726 (WY) 1986 1986 1988 1997 1996 1992 1986 1986 1995 1989 1998 1998 MIN 81.6 53.4 36.5 33.1 29.1 23.7 28.0 43.2 42.7 38.8 47.9 61.8 (WY) 1988 1998 1998 1991 1998 1994 1994 1989 1997 1994 1993 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1984 - 1998 ANNUAL TOTAL 26693 48986 ANNUAL MEAN 73.1 134 106 HIGHEST ANNUAL MEAN 179 1986 LOWEST ANNUAL MEAN 61.5 1994 HIGHEST DAILY MEAN 600 Jan 22 9010 Sep 22 9010 Sep 22 1998 LOWEST DAILY MEAN 29 Jun 10 22 Mar 25 16 Mar 18 1994 ANNUAL SEVEN-DAY MINIMUM 32 Dec 25 23 Mar 22 17 Mar 16 1994 INSTANTANEOUS PEAK FLOW 11600 Sep 22 11600 Sep 22 1998 INSTANTANEOUS PEAK STAGE 21.69 Sep 22 21.69 Sep 22 1998 INSTANTANEOUS LOW FLOW 22 Mar 25 15 Mar 22 1994 10 PERCENT EXCEEDS 124 256 204 50 PERCENT EXCEEDS 52 55 66 90 PERCENT EXCEEDS 34 26 33 e Estimated 59 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 60 THIS PAGE WAS LEFT BLANK INTENTIONALLY 61 Río Río Río Río Río Río Río Río Jauca Río Río Río Cidra Río Río Río Río Río Caricaboa Saliente G r a n d e Grande G r a n d e de de de J a y u y a Arecibo Arecibo Río Río Lago Caonillas Lago Pellejas Lago Adjunt as Lago V iví Lago Garzas Lago Jordan Lago Dos Bocas Caño T iburones Tanamá Limón Limón La Venta Yunes C a o n i l l a s C a o n il las Viví T unnel Tunnel Tunnel Tunnel Tunnel Viví Vacas Pellejas 0280 CAÑO TIBURONES FLOW DIRECTION TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER 0280 0205 FL-1 0201 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER HATILLO ARECIBO BARCELONETA Basin area PUERTO RICO A TLANTIC OCEAN ADJUNTAS JAYUYA UTUADO FLORIDA 0 0 1 1 2 2 3 3 4 4 5 MILES 5 KILOMETERS 025155 0284 027750 0290 027250 027090 025110 026140 0250 024950 026050 026025 0280 0205 204 EN-1 BARR-1 TI-1 FA-2 FL-1 020050 0201 Figure 13. Río Grande de Arecibo basin. 62 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR LOCATION.--Lat 18°08'20", long 66°44'29", Hydrologic Unit 21010002, in power gate tower of Garzas Dam on Río Vacas, 1.7 mi (2.7 km) upstream from Río Garzas, and 2.2 mi (3.5 km) southwest of Adjuntas. DRAINAGE AREA.--6.02 mi2 (15.6 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to May 1989, March 1993 to current year. GAGE.--Water-stage recorder. Datum of gage is 2,400.00 ft (731.520 m) above mean sea level. Prior to May 25, 1988 at datum 2,376.80 ft (724.449 m), May 25 to July 13, 1988 at datum 2,338.08 ft (712.647 m), July 14, 1988 to May 25, 1989 at datum 2,337.82 ft (712.560 m), above mean sea level. REMARKS.--Lake is formed by earthfill dam completed in 1943. Outflow from lake controlled by vertical-lift sluice gate and fixed-crest concrete spillway. Spillway elevation, 2,415.00 ft (736.09 m),Lake is used for irrigation and power production. Operated by P.R. Electric Power Authorithy. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,418.28 ft (737.092 m), Sept. 22, 1998; minimum elevation, 2,364.79 ft (720.788 m), Aug. 23, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,418.28 ft (737.092 m), Sept. 22; minimum elevation, 2,403.38 ft (732.550 m), Feb. 10. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,364 660 2,415 4,082 2,382 1,500 2,418 4,411 2,394 2,250 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 A 2407.94 2407.87 2409.77 2406.42 2407.73 2408.09 2410.19 2414.73 2414.71 2414.84 2414.86 2 A 2407.67 2408.07 2409.89 2406.50 2407.66 2408.51 2410.15 2414.74 2414.83 2414.85 2414.90 3 A 2407.39 2408.31 2410.03 2406.56 2407.61 2408.59 2410.11 2414.75 2414.80 2414.73 2414.97 4 A 2407.16 2408.25 2410.14 2405.30 2407.53 2408.60 2410.20 2414.78 2414.77 2414.68 2414.91 5 A 2407.05 2408.33 2410.25 2403.69 2407.47 2408.59 2410.31 2414.78 A 2414.62 2414.92 6 A 2407.06 2408.39 2410.26 2403.60 2407.43 2408.57 2410.54 2414.76 2414.70 A 2414.96 7 A 2407.12 2408.46 2410.36 2403.62 2407.37 2409.56 2410.67 2414.74 2414.73 2414.80 2414.92 8 A 2407.17 2408.53 2410.48 2403.42 2407.29 2409.74 2411.70 2414.78 2414.72 2414.83 2414.90 9 A 2406.47 2408.59 2410.58 2403.40 2407.21 2409.80 2411.93 2414.79 2414.72 2414.87 2414.89 10 A 2405.95 2408.67 2410.68 2403.43 2407.13 2409.82 A 2414.79 2414.86 2414.73 2414.88 11 A 2405.69 2408.77 2410.83 2403.46 2407.05 2409.89 2412.10 2414.67 2414.75 2414.68 2414.93 12 A 2405.73 2408.87 2410.91 2403.51 2407.00 2410.13 2412.20 2414.66 2414.72 2414.54 2414.88 13 A 2405.85 2408.95 2410.99 2408.48 2406.92 2410.23 A 2414.66 2414.71 2414.40 2414.89 14 A 2406.01 2409.01 2411.11 2408.48 2406.87 2410.27 2413.60 2414.66 2414.70 2414.50 2414.87 15 A 2405.57 2409.11 2410.94 2408.46 2406.89 2410.29 2414.20 2414.69 2414.70 2414.73 2414.87 16 A 2405.61 2409.19 2410.99 2408.40 2406.88 2410.30 2414.40 2414.72 2414.72 2414.77 A 17 A 2405.71 2409.27 2411.09 2408.35 2406.84 2410.29 2414.49 2414.89 2414.83 2414.49 A 18 A 2405.83 2409.28 2411.16 2408.30 2406.77 2410.36 2414.56 2414.79 2414.78 2414.49 A 19 A 2405.97 2408.59 2411.26 2408.24 2406.70 2410.44 2414.61 2414.74 2414.76 2414.52 2414.20 20 A 2406.10 2408.66 2411.36 2408.20 2406.66 2410.46 2414.70 2414.73 2414.80 2414.77 2411.60 21 A 2406.24 2408.69 2411.38 2408.14 2406.59 2410.46 2414.94 2414.74 2414.73 2414.83 2416.72 22 A 2406.39 2408.76 2406.02 2408.08 2406.52 2410.45 2414.77 2414.74 2414.71 2414.86 2415.45 23 A 2406.57 2408.87 2406.07 2408.00 2406.43 2410.43 2414.81 2414.81 2414.90 2414.81 2415.10 24 A 2406.71 2408.95 2406.10 2407.96 2406.35 2410.39 2414.81 2414.82 2414.79 2416.11 2415.06 25 A 2406.87 2409.05 2406.14 2407.92 2406.34 2410.37 2414.75 2414.76 2414.77 2414.92 2415.04 26 A 2406.97 2409.15 2406.18 2407.91 2406.26 2410.34 2414.75 2414.70 2414.77 2414.88 2415.04 27 A 2407.13 2409.25 2406.24 2407.85 2406.20 2410.32 2414.73 2414.68 2414.81 2414.86 2414.98 28 A 2407.31 2409.35 2406.26 2407.79 2406.12 2410.29 2414.77 2414.67 2414.77 2414.69 2414.98 29 2408.79 2407.47 2409.45 2406.28 --- 2406.10 2410.25 2414.73 2414.70 2414.76 2414.84 2414.97 30 2408.47 2407.65 2409.55 2406.32 --- 2406.41 2410.21 2414.73 2414.71 2414.75 2414.86 2414.97 31 2408.20 --- 2409.65 2406.36 --- 2406.43 --- 2414.72 --- 2414.74 2414.86 --­ MAX --- 2407.94 2409.65 2411.38 2408.48 2407.73 2410.46 --- 2414.89 --- --- --­ MIN --- 2405.57 2407.87 2406.02 2403.40 2406.10 2408.09 --- 2414.66 --- --- --­ A No gage-height record 63 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°10'54", long 66°44'12", at Highway 135 bridge, 1.0 mi (1.6 km) upstream from Lago Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas plaza. DRAINAGE AREA.--12.7 mi2 (32.9 km2) this does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 29... 0900 18 328 8.4 21.5 1.0 8.4 100 <10 K890 450 MAR 11... 0800 8.5 381 7.6 19.0 .30 7.9 89 <10 K1200 470 JUN 17... 1100 23 328 7.9 24.0 .35 8.4 105 <10 K750 480 SEP 08... 1455 136 240 7.4 25.5 2.2 7.3 94 <10 K680 520 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 29... 150 34 15 17 .6 2.7 120 <.5 17 24 MAR 11... -- -- -- -- -- -- 120 -- -- -­ JUN 17... 110 28 9.1 21 .9 1.8 110 -- 8.5 30 SEP 08... 82 22 6.7 10 .5 1.8 89 <1.0 8.4 12 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 29... .20 24 206 10.0 3 -- <.010 1.30 .020 -­ MAR 11... -- -- -- -- <1 1.26 .040 1.30 .050 .29 JUN 17... <.10 28 192 12.0 <1 .982 .018 1.00 .020 -­ SEP 08... <.10 27 142 52.2 5 .985 .015 1.00 .040 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 29... <.20 -- -- .080 <1 <100 20 <1 <1 <10 MAR 11... .34 1.6 7.3 .120 -- -- -- -- -- -­ JUN 17... <.20 -- -- .080 <1 <100 30 <1 <1 <10 SEP 08... <.20 -- -- .050 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 64 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 29... 80 <1 31 <.10 <1 <1 <10 <.010 <1 .03 MAR 11... JUN 17... 60 <1 18 <.10 <1 <1 <10 <.010 1 <.02 SEP 08... --- --- --- --- --- --- --- 65 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR LOCATION.--Lat 18°18'07", long 66°42'15", Hydrologic Unit 21010001, 2.4 mi (3.9 km) north of Utuado Plaza, 3.4 mi (5.5 km) southwest from Dos Bocas Dam, 3.5 mi (5.6 km) northwest from Caonillas Dam. DRAINAGE AREA.--65.62 mi2 (170 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1996 to current year. GAGE.--Water-stage recorder. Elevation of gage is 295.28 ft (90 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 123 65 71 39 e32 27 59 46 66 61 189 252 2 69 63 63 39 e32 27 156 39 67 65 302 400 3 56 63 67 39 30 27 e126 39 64 85 292 355 4 53 63 64 38 55 28 e51 37 72 72 283 573 5 51 63 65 38 217 28 47 38 250 67 229 405 6 50 62 64 e44 58 31 45 99 126 105 310 601 7 345 61 63 e60 34 68 117 60 79 88 e534 495 8 224 59 60 47 55 36 159 190 69 70 561 366 9 153 74 59 38 74 29 56 173 71 67 567 379 10 81 193 57 39 46 31 44 76 70 82 513 285 11 110 149 55 39 47 28 44 63 94 89 827 325 12 572 118 54 44 52 29 51 66 66 71 670 353 13 386 108 53 65 49 29 63 72 60 68 611 262 14 450 91 52 45 50 31 50 79 58 96 434 227 15 323 96 51 38 54 53 43 262 55 131 310 215 16 210 119 50 37 45 30 49 117 90 444 345 255 17 316 96 49 41 40 43 67 67 176 433 280 333 18 323 90 48 41 38 33 65 152 217 499 216 541 19 220 85 48 44 35 24 e148 211 105 434 207 e401 20 174 81 55 39 32 22 62 216 76 310 207 e305 21 148 77 48 41 29 24 41 915 73 289 246 589 22 130 75 46 34 28 22 54 454 73 215 244 e7600 23 116 70 61 33 27 22 68 333 67 207 247 e1500 24 105 69 48 34 27 22 54 222 70 345 281 e980 25 95 67 44 e36 27 22 51 167 104 213 956 e700 26 89 e63 44 e36 35 24 51 125 76 168 599 e580 27 80 71 43 32 28 23 50 101 72 175 551 e520 28 76 65 42 31 28 24 58 86 65 166 356 e500 29 71 102 40 31 73 52 83 61 158 295 e860 30 69 85 39 31 77 49 89 60 155 253 e560 31 66 39 30 61 74 263 282 TOTAL 5334 2543 1642 1223 1304 1048 2030 4751 2652 5691 12197 21717 MEAN 172 84.8 53.0 39.5 46.6 33.8 67.7 153 88.4 184 393 724 MAX 572 193 71 65 217 77 159 915 250 499 956 7600 MIN 50 59 39 30 27 22 41 37 55 61 189 215 AC-FT 10580 5040 3260 2430 2590 2080 4030 9420 5260 11290 24190 43080 CFSM 2.62 1.29 .81 .60 .71 .52 1.03 2.34 1.35 2.80 6.00 11.0 IN. 3.02 1.44 .93 .69 .74 .59 1.15 2.69 1.50 3.23 6.91 12.31 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 1998, BY WATER YEAR (WY) MEAN 198 163 85.6 79.6 65.0 50.9 56.9 105 83.1 102 188 445 MAX 224 242 118 120 83.5 68.0 67.7 153 120 184 393 724 (WY) 1997 1997 1997 1997 1997 1997 1998 1998 1996 1998 1998 1998 MIN 172 84.8 53.0 39.5 46.6 33.8 46.2 50.8 40.8 36.6 77.0 87.3 (WY) 1998 1998 1998 1998 1998 1998 1997 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1996 - 1998 ANNUAL TOTAL 28001 62132 ANNUAL MEAN 76.7 170 135 HIGHEST ANNUAL MEAN 170 1998 LOWEST ANNUAL MEAN 99.6 1997 HIGHEST DAILY MEAN 572 Oct 12 7600 Sep 22 7600 Sep 22 1998 LOWEST DAILY MEAN 23 Aug 7 22 Mar 20 22 Mar 20 1998 ANNUAL SEVEN-DAY MINIMUM 28 Aug 1 23 Mar 19 23 Mar 19 1998 INSTANTANEOUS PEAK FLOW 33000 Sep 22 33000 Sep 22 1998 INSTANTANEOUS PEAK STAGE 21.28 Sep 22 21.28 Sep 22 1998 INSTANTANEOUS LOW FLOW 20 Mar 24 20 Mar 24 1998 ANNUAL RUNOFF (AC-FT) 55540 123200 97740 ANNUAL RUNOFF (CFSM) 1.17 2.59 2.06 ANNUAL RUNOFF (INCHES) 15.87 35.22 27.94 10 PERCENT EXCEEDS 117 392 295 50 PERCENT EXCEEDS 61 69 71 90 PERCENT EXCEEDS 34 32 36 e Estimated 66 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 67 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- April, 1996 to current water year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April, 1996 to current water year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 10,600 mg/L September 10, 1996; Minimum daily mean, 3 mg/L August 6, 1996. SEDIMENT LOADS: Maximum daily mean, 768,000 tons (e698,000 tonnes) September 22,1998; Minimum daily mean, 0.50 ton (0.45 tonne) August 6, 1996. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,830 mg/L October 12, 1997; Minimum daily mean, 6 mg/L May 2, 1998. SEDIMENT LOADS: Maximum daily mean, e768,000 tons (e698,000 tonne) September 22, 1998; Minimum daily mean, 0.68 tons (0.61 tonne). SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 123 1370 1160 65 33 5.8 71 79 15 2 69 318 61 63 33 5.6 63 44 7.5 3 56 156 24 63 33 5.7 67 48 8.7 4 53 144 20 63 35 5.9 64 56 9.8 5 51 147 20 63 42 7.2 65 59 10 6 50 151 20 62 51 8.6 64 58 10 7 345 2880 10100 61 49 8.1 63 58 9.7 8 224 1450 898 59 44 7.0 60 56 9.2 9 153 590 279 74 84 30 59 43 6.8 10 81 242 53 193 1240 713 57 30 4.7 11 110 493 174 149 1280 745 55 40 6.0 12 572 3810 15900 118 877 398 54 57 8.3 13 386 1600 1810 108 303 92 53 36 5.2 14 450 313 395 91 195 48 52 20 2.9 15 323 275 252 96 151 39 51 20 2.7 16 210 618 1020 119 122 39 50 24 3.2 17 316 3020 4570 96 125 32 49 29 3.9 18 323 2830 2600 90 136 33 48 35 4.6 19 220 518 323 85 147 34 48 42 5.3 20 174 177 84 81 151 33 55 40 5.9 21 148 139 56 77 75 16 48 37 4.8 22 130 109 38 75 33 6.7 46 33 4.1 23 116 96 30 70 36 6.7 61 316 91 24 105 130 37 69 45 8.4 48 316 41 25 95 173 44 67 56 10 44 250 29 26 89 168 40 e63 48 e11 44 215 25 27 80 150 33 71 37 7.0 43 187 22 28 76 109 22 65 33 5.8 42 139 16 29 71 74 14 102 608 410 40 99 11 30 69 50 9.3 85 191 44 39 80 8.5 31 66 35 6.2 39 68 7.1 TOTAL 5334 40092.5 2543 2815.5 1642 398.9 --- --- --- --- --- --- --- --- --- --- --- --- 68 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 39 58 6.1 e32 183 e15 27 94 6.9 2 39 52 5.4 e32 174 e14 27 114 8.2 3 39 87 9.0 30 165 13 27 115 8.4 4 38 148 15 55 1600 969 28 110 8.2 5 38 95 9.8 217 2630 2410 28 106 8.0 6 e44 56 e6.5 58 303 58 31 107 10 7 e60 166 e26 34 134 12 68 249 56 8 47 185 23 55 190 40 36 93 9.4 9 38 189 20 74 282 67 29 64 5.0 10 39 207 22 46 75 9.4 31 52 4.4 11 39 227 24 47 58 7.4 28 32 2.4 12 44 261 32 52 57 7.9 29 20 1.6 13 65 421 75 49 40 5.3 29 19 1.5 14 45 361 44 50 39 5.3 31 29 2.7 15 38 323 33 54 35 5.2 53 215 57 16 37 293 29 45 31 3.7 30 60 4.9 17 41 275 31 40 23 2.5 43 111 17 18 41 194 21 38 18 1.8 33 165 15 19 44 151 18 35 22 2.0 24 115 7.4 20 39 149 16 32 32 2.8 22 111 6.7 21 41 143 16 29 47 3.7 24 120 7.9 22 34 120 11 28 68 5.1 22 131 7.8 23 33 122 11 27 84 6.1 22 141 8.5 24 34 132 12 27 95 6.8 22 149 8.7 25 e36 142 e13 27 78 5.7 22 156 9.2 26 e36 153 e14 35 66 6.5 24 163 11 27 32 159 14 28 61 4.7 23 170 11 28 31 165 14 28 76 5.7 24 163 10 29 31 180 15 73 1690 712 30 31 196 16 77 1110 261 31 30 193 16 61 387 66 TOTAL 1223 617.8 1304 3695.6 1048 1353.8 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 59 488 169 46 2 156 1020 469 39 3 e126 614 e231 39 4 e51 153 e22 37 5 47 84 11 38 7 .87 66 24 4.3 6 .68 67 21 3.9 7 .75 64 21 3.6 11 1.1 72 120 34 15 1.5 250 2180 2930 6 45 64 7.9 7 117 654 588 8 159 1020 479 9 56 156 25 10 44 61 7.2 99 826 580 126 428 186 60 168 32 79 102 22 190 1120 1700 69 92 17 173 583 321 71 199 42 76 99 21 70 119 23 11 44 33 3.9 12 51 29 4.0 13 63 144 26 14 50 73 9.9 15 43 47 5.5 63 28 4.8 94 472 291 66 19 3.4 66 163 30 72 15 2.9 60 47 7.7 79 18 4.5 58 38 5.9 262 1270 1310 55 35 5.2 16 49 36 4.7 17 67 506 162 18 65 298 114 19 e148 596 e197 20 62 235 43 117 175 61 90 957 560 67 75 14 176 1120 1210 152 819 984 217 1810 1640 211 1260 997 105 333 109 216 1420 1110 76 54 11 21 41 64 7.4 22 54 281 78 23 68 156 31 24 54 67 9.8 25 51 52 7.0 915 3490 23900 73 45 8.8 454 786 1110 73 37 7.3 333 221 199 67 32 5.7 222 183 111 70 28 5.4 167 109 50 104 622 337 26 51 40 5.5 27 50 31 4.2 28 58 29 4.5 29 52 27 3.7 30 49 14 1.9 31 --- --- --- 125 62 21 76 214 46 101 35 9.8 72 94 18 86 21 4.9 65 80 14 83 14 3.2 61 90 15 89 424 139 60 98 16 74 104 21 --- --- --­ TOTAL 2030 --- 2732.1 4751 --- 32719.40 2652 --- 7608.8 --- --- --- --- --- --- 69 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 61 54 8.8 189 127 65 252 198 137 2 65 28 4.9 302 993 1300 400 1440 2620 3 85 43 9.7 292 679 531 355 2600 2810 4 72 73 14 283 498 574 573 2360 4540 5 67 82 15 229 78 49 405 460 534 6 105 826 441 310 2120 4060 601 2670 6760 7 88 196 53 e534 2440 e4710 495 239 321 8 70 47 8.9 561 2340 4400 366 225 222 9 67 44 7.9 567 1130 1860 379 1240 1700 10 82 44 9.7 513 1830 3760 285 148 115 11 89 39 9.4 827 3230 12300 325 606 1020 12 71 35 6.7 670 695 1310 353 812 1140 13 68 38 6.9 611 144 242 262 179 127 14 96 413 187 434 81 96 227 148 91 15 131 1230 556 310 57 48 215 124 72 16 444 2050 4150 345 1580 2280 255 601 682 17 433 443 522 280 749 765 333 1540 2360 18 499 347 543 216 78 45 541 2650 4980 19 434 272 319 207 73 41 e401 90 e102 20 310 215 181 207 71 40 e305 73 e60 21 289 142 112 246 771 585 589 1370 11200 22 215 96 56 244 215 140 e7600 1470 e768000 23 207 115 70 247 139 93 e1500 986 e82500 24 345 632 619 281 301 495 e980 663 e27200 25 213 201 121 956 1260 5330 e700 2670 e7000 26 168 72 33 599 155 253 e580 2360 e4540 27 175 51 24 551 328 624 e520 1830 e3760 28 166 47 21 356 1590 1720 e500 1820 e3500 29 158 56 24 295 210 168 e860 3230 e12300 30 155 63 26 253 120 82 e560 2340 e4400 31 263 1050 1610 282 370 363 TOTAL 5691 9769.9 12197 48329 21717 954793 YEAR 62132 1104926.30 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 01... 1945 247 6190 4130 95 NOV 29... 1700 346 13000 12100 98 DEC 23... 1850 113 1780 543 89 MAR 29... 1635 165 5500 2450 94 APR 17... 1555 170 1970 904 96 MAY 20... 1715 350 5690 5380 75 SEP 02... 1645 786 3660 7770 79 70 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 01... 1715 499 9460 12700 27 37 50 07... 1845 766 13400 27700 30 42 58 NOV 11... 1745 361 8370 8160 34 45 62 FEB 04... 2215 215 12500 7260 20 27 38 MAY 06... 1745 322 5160 4490 36 48 61 SEP 02... 1500 934 6880 17400 30 40 54 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 01... 63 74 79 90 96 98 99 07... 72 86 90 97 99 100 100 NOV 11... 78 90 94 99 100 100 100 FEB 04... 55 75 82 92 100 100 100 MAY 06... 73 83 87 97 99 100 100 SEP 02... 69 81 86 96 99 100 100 71 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'11", long 66°41'59", at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km) downstream from Río de Caguana, and 2.5 mi (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 mi2 (170.9 km2) this excludes 6.0 mi2 (15.5 km2) upstream from Lago Garzas to Río Guayanes in the Río Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 29... 1130 80 292 8.0 27.5 6.3 7.9 99 <10 K1600 810 MAR 11... 0945 34 316 7.9 21.5 2.9 8.6 104 <10 20000 K1100 JUN 18... 1245 240 173 7.8 26.5 130 7.2 90 <10 30000 28000 SEP 02... 1040 215 257 7.5 26.5 7.1 7.7 97 <10 3000 950 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 29... 81 19 7.9 34 2 3.7 93 <.5 15 33 MAR 11... -- -- -- -- -- -- 97 -- -- -­ JUN 18... 64 17 5.1 8.2 .4 2.6 54 -- 14 8.2 SEP 02... 84 21 7.6 10 .5 2.1 82 <1.0 8.7 12 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 29... <.10 25 192 41.5 9 1.23 .075 1.30 .020 .23 MAR 11... -- -- -- -- 6 1.28 .015 1.30 .030 .20 JUN 18... <.10 18 106 68.5 176 1.17 .033 1.20 .100 .54 SEP 02... <.10 24 139 80.7 74 1.27 .028 1.30 .060 .22 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 29... .25 1.5 6.9 .220 <1 <100 20 <1 1 15 MAR 11... .23 1.5 6.8 .080 -- -- -- -- -- -­ JUN 18... .64 1.8 8.1 .250 <1 <100 20 <1 3 29 SEP 02... .28 1.6 7.0 .080 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 72 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 29... 1700 5 110 <.10 <1 <1 20 <.010 <1 .06 MAR 11... JUN 18... 8400 3 250 <.10 <1 <1 20 <.010 <1 <.02 SEP 02... --- --- --- --- --- --- --- 73 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR LOCATION.--Lat 18°12'48", long 66°33'49", Hydrologic Unit 21010002, 2.0 mi (3.2 km) southeast of Jayuya, 1.4 mi (2.2 km) northeast of Hacienda Gripiñas. DRAINAGE AREA.--9.25 mi2 (23.96 km2). PERIOD OF RECORD.--October 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,706 ft (520 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 9.9 9.2 4.0 4.9 6.5 24 14 25 12 11 27 2 16 9.6 9.5 4.1 4.9 6.3 22 14 36 12 13 267 3 16 9.1 8.6 3.9 4.9 7.3 22 13 30 13 13 354 4 11 9.1 7.4 3.6 126 8.2 20 13 41 14 10 356 5 9.4 8.7 7.0 3.6 259 6.6 15 12 222 12 9.5 138 6 8.7 8.0 6.6 3.7 28 13 13 15 82 29 21 161 7 38 7.5 6.0 4.5 16 55 340 17 45 24 51 103 8 45 7.1 5.8 4.1 57 27 105 139 35 16 110 71 9 32 29 5.7 3.7 48 12 43 55 32 14 60 92 10 25 54 5.6 3.9 22 9.5 28 27 28 16 39 58 11 18 17 5.4 5.8 16 8.3 27 21 25 15 62 230 12 30 17 5.1 4.8 14 7.7 72 17 23 13 62 116 13 101 14 5.1 7.8 12 7.2 60 17 22 13 40 148 14 306 12 4.9 7.3 12 17 37 244 20 81 28 89 15 285 33 4.9 4.5 15 68 28 158 19 49 22 60 16 150 22 4.6 4.0 11 30 28 59 44 32 30 56 17 199 14 4.7 3.7 10 16 36 39 69 26 29 52 18 173 12 5.1 9.6 9.4 12 56 32 39 22 25 108 19 73 11 5.6 18 8.7 10 53 31 25 19 23 76 20 46 11 4.6 11 8.3 16 88 226 21 17 19 55 21 34 10 5.1 7.2 8.1 18 63 269 20 16 43 e2420 22 27 9.8 4.7 6.5 7.8 15 39 124 26 13 87 e1050 23 23 9.0 4.4 5.9 7.3 16 32 68 19 14 55 e270 24 19 9.0 4.2 5.6 7.6 12 30 50 17 16 462 e150 25 17 8.8 4.1 5.8 7.7 12 27 40 17 14 629 e110 26 15 9.8 4.1 5.8 9.3 12 23 35 16 12 93 e98 27 14 9.6 3.9 5.4 7.5 11 21 31 15 16 95 e90 28 13 8.2 3.8 5.1 6.8 12 19 28 14 13 58 e86 29 12 29 3.9 5.1 13 17 25 13 12 43 e145 30 11 17 4.0 5.1 48 15 45 13 11 33 e98 31 10 4.0 5.1 39 31 11 34 TOTAL 1791.1 435.2 167.6 178.2 749.2 551.6 1403 1909 1053 597 2309.5 7134 MEAN 57.8 14.5 5.41 5.75 26.8 17.8 46.8 61.6 35.1 19.3 74.5 238 MAX 306 54 9.5 18 259 68 340 269 222 81 629 2420 MIN 8.7 7.1 3.8 3.6 4.9 6.3 13 12 13 11 9.5 27 AC-FT 3550 863 332 353 1490 1090 2780 3790 2090 1180 4580 14150 CFSM 6.25 1.57 .58 .62 2.89 1.92 5.06 6.66 3.79 2.08 8.05 25.7 IN. 7.20 1.75 .67 .72 3.01 2.22 5.64 7.68 4.23 2.40 9.29 28.69 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1998, BY WATER YEAR (WY) MEAN 40.7 23.3 12.3 18.2 17.1 11.5 23.3 40.6 23.3 17.0 28.7 105 MAX 72.0 40.0 22.7 48.1 44.4 17.8 46.8 98.6 35.4 50.9 74.5 365 (WY) 1996 1991 1993 1992 1996 1998 1998 1995 1994 1996 1998 1996 MIN 11.6 10.0 5.41 4.13 4.67 4.79 5.95 5.35 5.30 2.83 9.82 10.8 (WY) 1992 1994 1998 1995 1994 1994 1994 1990 1997 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1989 - 1998 ANNUAL TOTAL 6112.2 18278.4 ANNUAL MEAN 16.7 50.1 30.0 HIGHEST ANNUAL MEAN 64.0 1996 LOWEST ANNUAL MEAN 10.9 1994 HIGHEST DAILY MEAN 306 Oct 14 2420 Sep 21 4700 Sep 10 1996 LOWEST DAILY MEAN 3.1 Aug 7 3.6 Jan 4 2.3 Jul 27 1994 ANNUAL SEVEN-DAY MINIMUM 3.5 Jul 5 3.8 Dec 31 2.5 Jul 23 1994 INSTANTANEOUS PEAK FLOW 14200 Sep 21 14500 Sep 10 1996 INSTANTANEOUS PEAK STAGE 19.16 Sep 21 19.29 Sep 10 1996 INSTANTANEOUS LOW FLOW 3.6 Jan 4 2.1 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 12120 36260 21760 ANNUAL RUNOFF (CFSM) 1.81 5.41 3.25 ANNUAL RUNOFF (INCHES) 24.58 73.51 44.11 10 PERCENT EXCEEDS 30 99 54 50 PERCENT EXCEEDS 8.8 17 13 90 PERCENT EXCEEDS 4.0 5.1 4.5 e Estimated 74 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 75 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR LOCATION.--Lat 18°13'53", long 66°38'14", Hydrologic Unit 21010001, 3.5 mi (5.6 km) south of Lago Caonillas Dam, 4.8 mi (7.72 km) southeast of Utuado Plaza and 2.78 mi (4.47 km) east of Lago Viví Dam. DRAINAGE AREA.--37.94 mi2 (98.26 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 984 ft (300 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 40 39 40 15 2 36 38 35 15 3 28 36 32 15 4 24 36 28 14 5 22 35 25 14 14 18 117 48 67 40 63 119 14 17 127 47 e69.0 40 67 490 14 17 e87 43 e78.0 46 59 527 57 21 e60 40 e77.0 43 43 544 448 18 42 39 e165 40 41 340 6 21 33 24 15 7 100 31 23 21 8 122 29 22 23 9 93 58 21 16 10 60 112 21 15 79 37 36 53 e150 e56.0 e63.0 366 42 169 458 65 e94 e55.0 e194 282 89 104 249 284 e82.0 e45.0 e186 220 126 44 127 183 e77.0 e43.0 e168 212 57 32 93 90 e75.0 e47.0 e206 173 11 48 52 20 22 12 77 69 20 39 13 146 56 19 e33 14 421 41 19 e43 15 332 45 19 e25 45 27 80 68 e70.0 e47.0 e211 300 38 25 132 57 e67.0 e45.0 e227 249 28 23 135 52 e68.0 e45.0 158 280 29 29 99 339 e64.0 e62.0 114 218 36 71 80 371 e63.0 e167 95 167 16 250 68 17 e19 17 583 43 18 e17 18 370 38 18 e18 19 189 35 21 e32 20 131 33 20 24 26 74 80 154 e71.0 161 148 155 24 44 104 112 e183 99 131 227 22 32 128 131 e108 89 106 218 22 26 e141 107 e75.0 83 92 184 21 26 140 305 60 e70 78 142 21 103 32 20 20 22 86 31 20 18 23 74 29 19 16 24 65 28 18 16 25 59 31 17 16 21 39 142 390 58 e60 106 e1420 20 28 131 e252 66 50 177 e13000 19 30 107 e146 52 47 149 e1370 18 25 84 e106 49 e60 360 e663 20 23 83 e90 56 e51 e498 e528 26 54 36 17 16 27 49 34 16 15 28 47 28 16 14 29 45 72 16 14 30 43 79 15 14 31 41 --- 15 14 39 26 72 e81 50 43 e233 450 24 23 67 e76 46 69 e247 401 20 24 65 e73 44 49 191 455 --- 30 54 69 43 45 147 387 --- 106 49 79 41 42 124 353 --- 102 --- 83 --- 87 153 --­ TOTAL 3759 1327 651 608 MEAN 121 44.2 21.0 19.6 MAX 583 112 40 43 MIN 21 28 15 14 AC-FT 7460 2630 1290 1210 CFSM 3.20 1.17 .55 .52 IN. 3.69 1.30 .64 .60 1412 1310 3369 4033 2268.0 1926.0 4835.0 24440 50.4 42.3 112 130 75.6 62.1 156 815 448 169 458 390 183 167 498 13000 14 17 36 39 41 40 41 119 2800 2600 6680 8000 4500 3820 9590 48480 1.33 1.11 2.96 3.43 1.99 1.64 4.11 21.5 1.38 1.28 3.30 3.95 2.22 1.89 4.74 23.96 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 1998, BY WATER YEAR (WY) MEAN 119 82.5 48.6 53.1 MAX 162 114 78.2 89.8 (WY) 1996 1997 1997 1997 MIN 72.9 44.2 21.0 19.6 (WY) 1997 1998 1998 1998 59.8 39.8 62.2 95.2 57.7 64.9 88.9 413 86.0 51.3 112 130 81.4 117 156 815 1996 1996 1998 1998 1996 1996 1998 1998 41.9 25.7 17.0 29.1 16.1 15.5 47.9 33.2 1997 1997 1997 1997 1997 1997 1996 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1996 - 1998 ANNUAL TOTAL 15818 ANNUAL MEAN 43.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 583 LOWEST DAILY MEAN 10 ANNUAL SEVEN-DAY MINIMUM 11 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 31380 ANNUAL RUNOFF (CFSM) 1.14 ANNUAL RUNOFF (INCHES) 15.51 10 PERCENT EXCEEDS 76 50 PERCENT EXCEEDS 28 90 PERCENT EXCEEDS 13 49938.0 137 98.4 137 1998 49.9 1997 Oct 17 13000 Sep 22 13000 Sep 22 1998 Jul 4 14 Jan 4 10 Jul 4 1997 Jul 1 14 Jan 28 11 Jul 1 1997 36000 Sep 22 36000 Sep 22 1998 31.15 Sep 22 31.15 Sep 22 1998 13 Jan 31 9.5 Jul 6 1997 99050 71260 3.61 2.59 48.96 35.22 239 164 54 47 18 17 e Estimated 76 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 77 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- October, 1995 to current water year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October, 1995 to current water year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e952,000 tons (e864,000 tonnes) September 22, 1998; Minimum daily mean, 0.04 ton (0.03 tonne) December 29-30, 1998. EXTREMES FOR CURRENT YEAR 1998. SEDIMENT CONCENTRATION: Maximum daily mean, 24,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e952,000 tons (e864,000 tonnes) September 22, 1998 ; Minimum daily mean, 0.04 ton (0.03 tonne) December 29-30, 1997 . SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 40 73 14 39 1 .13 40 96 11 2 36 88 9.6 38 1 .15 35 41 3.8 3 28 26 1.9 36 2 .23 32 30 2.7 4 24 29 1.9 36 4 .39 28 23 1.7 5 22 36 2.1 35 5 .44 25 18 1.2 6 21 34 1.9 33 4 .34 24 14 .92 7 100 1170 774 31 3 .26 23 11 .67 8 122 1190 271 29 3 .24 22 8 .49 9 93 250 76 58 5 84 21 5 .26 10 60 50 8.3 112 13 225 21 2 .13 11 48 21 2.8 52 49 7.5 20 2 .11 12 77 199 94 69 241 113 20 2 .12 13 146 685 391 56 155 26 19 5 .27 14 421 677 904 41 22 2.5 19 10 .52 15 332 434 426 45 69 18 19 10 .52 16 250 400 270 68 112 28 17 9 .43 17 583 3850 17600 43 19 2.2 18 4 .17 18 370 4750 5540 38 8 .79 18 1 .06 19 189 366 205 35 6 .61 21 1 .06 20 131 32 12 33 8 .73 20 1 .06 21 103 22 6.2 32 17 1.4 20 1 .08 22 86 18 4.2 31 26 2.2 20 2 .10 23 74 15 3.0 29 12 .94 19 1 .07 24 65 12 2.2 28 5 .40 18 1 .06 25 59 9 1.4 31 22 3.5 17 3 .12 26 54 7 .99 36 29 3.3 17 5 .22 27 49 10 1.3 34 12 1.1 16 2 .11 28 47 16 2.0 28 11 .83 16 1 .05 29 45 13 1.6 72 899 526 16 1 .04 30 43 8 .94 79 410 117 15 1 .04 31 41 3 .33 15 1 .06 TOTAL 3759 26629.66 1327 1167.18 651 26.14 --- --- --- --- --- --- --- --- --- 78 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 15 2 .08 14 2 15 2 .08 14 3 15 2 .08 14 4 14 2 .08 57 5 14 2 .08 448 3 .09 18 4 .22 3 .11 17 2 .11 2 .09 17 4 .17 176 502 21 6 .33 555 1800 18 7 .35 6 15 2 .08 7 21 19 1.7 8 23 27 1.8 9 16 4 .19 10 15 3 .11 79 35 8.3 37 127 38 42 8 .92 169 1840 2070 89 703 469 104 1250 439 126 675 303 44 112 14 57 67 11 32 40 3.5 11 22 33 8.3 45 12 39 71 10 38 13 e33 33 e3.2 28 14 e43 101 e13 29 15 e25 26 e1.8 36 52 6.4 27 12 .89 42 4.3 25 4 .28 18 1.4 23 3 .21 8 .63 29 36 5.1 10 .94 71 484 110 16 e19 21 e1.1 17 e17 21 e.98 18 e18 20 e.98 19 e32 66 e6.7 20 24 45 3.0 26 11 .80 74 126 36 24 5 .35 44 122 16 22 2 .14 32 31 2.8 22 2 .12 26 10 .72 21 2 .12 26 6 .40 21 20 32 1.7 22 18 10 .49 23 16 3 .15 24 16 3 .13 25 16 3 .13 21 3 .16 39 60 7.2 20 4 .19 28 7 .52 19 3 .14 30 5 .43 18 2 .10 25 5 .32 20 2 .11 23 4 .28 26 16 3 .13 27 15 3 .12 28 14 3 .11 29 14 3 .11 30 14 2 .09 31 14 2 .08 39 89 10 26 4 .26 24 30 2.0 23 3 .17 20 10 .52 24 2 .14 --- --- --- 30 3 22 --- --- --- 106 6 205 --- --- --- 102 14 159 TOTAL 608 --- 56.58 1412 --- 3122.93 1310 --- 3133.40 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 117 762 751 48 5 .62 67 7 1.4 2 127 729 280 47 2 .30 e69.0 7 e1.3 3 e87 112 e30 43 2 .23 e78.0 10 e2.1 4 e60 50 e8.2 40 2 .22 e77.0 53 e16 5 42 42 4.8 39 2 .26 e165 527 e925 6 36 38 3.7 53 110 31 e150 470 e288 7 458 724 5800 65 85 19 e94 31 e7.7 8 249 129 101 284 1090 2140 e82.0 26 e5.7 9 127 20 7.2 183 578 377 e77.0 22 e4.6 10 93 11 2.7 90 29 7.3 e75.0 19 e3.8 11 80 7 1.5 68 13 2.3 e70.0 16 e3.0 12 132 171 279 57 8 1.3 e67.0 14 e2.5 13 135 249 109 52 17 2.4 e68.0 12 e2.2 14 99 28 7.6 339 1470 7100 e64.0 11 e2.0 15 80 26 5.8 371 815 1600 e63.0 11 e1.8 16 80 10 2.2 154 60 26 e71.0 75 e31 17 104 253 117 112 17 5.1 e183 1490 e1280 18 128 708 325 131 353 203 e108 152 e56 19 e141 890 e401 107 595 172 e75.0 32 e6.5 20 140 979 412 305 2020 4090 60 16 2.6 21 142 167 99 390 3050 3570 58 7 1.1 22 131 321 176 e252 717 e574 66 5 .94 23 107 405 125 e146 47 e19 52 4 .60 24 84 73 17 e106 26 e7.6 49 5 .65 25 83 36 8.0 e90 20 e4.9 56 6 .87 26 72 21 4.1 e81 18 e4.0 50 5 .71 27 67 12 2.2 e76 16 e3.3 46 5 .60 28 65 9 1.5 e73 12 e2.4 44 4 .52 29 54 10 1.5 69 10 1.9 43 5 .57 30 49 10 1.3 79 81 27 41 11 1.2 31 83 24 6.0 TOTAL 3369 9084.3 4033 19998.13 2268.0 2650.96 --- --- --- --- --- --- 79 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 40 18 1.9 63 203 37 119 82 29 2 40 8 .91 67 237 71 490 3390 11100 3 46 4 .53 59 164 29 527 5350 11400 4 43 5 .53 43 33 3.8 544 4260 12300 5 40 5 .54 41 29 3.1 340 3390 3410 6 e56.0 446 e112 e63.0 37 e6.3 366 2690 5560 7 e55.0 66 e11 e194 755 e893 282 230 33 8 e45.0 21 e2.6 e186 505 e431 220 229 31 9 e43.0 23 e2.7 e168 634 e344 212 226 619 10 e47.0 26 e3.3 e206 814 e1100 173 190 57 11 e47.0 26 e3.3 e211 854 e857 300 287 2140 12 e45.0 26 e3.1 e227 841 e619 249 33 33 13 e45.0 25 e3.1 158 287 134 280 287 2100 14 e62.0 160 e99 114 149 46 218 27 30 15 e167 446 e296 95 161 41 167 26 10 16 161 376 253 148 1200 933 155 25 10 17 99 72 20 131 81 33 227 755 e900 18 89 21 5.1 106 32 9.1 218 1200 933 19 83 18 4.0 92 29 7.2 184 97 57 20 e70 16 e3.1 78 27 5.6 142 26 10 21 e60 13 e2.2 106 69 164 e1420 4920 e110000 22 50 13 1.7 177 219 675 e13000 24800 e952000 23 47 22 2.8 149 71 386 e1370 12200 e47200 24 e60 30 e4.8 360 949 6430 e663 6000 e19100 25 e51 21 e2.9 e498 211 e698 e528 5300 e10900 26 43 14 1.7 e233 53 e33 450 2690 7060 27 69 11 52 e247 347 e352 401 1000 5190 28 49 9 1.3 191 97 57 455 1500 8180 29 45 11 1.4 147 26 10 387 900 4760 30 42 13 1.5 124 33 11 353 878 3710 31 87 430 298 153 443 296 TOTAL 1926.0 1196.01 4835.0 14715.1 24440 1218862 YEAR 49938.0 1300642.39 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) NOV 30... 1030 69 260 48 63 FEB 05... 0245 1210 908 2970 73 08... 1800 117 1610 509 58 JUL 06... 1800 88 4110 977 91 AUG 31... 1845 299 2010 1620 94 80 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 07... 1730 270 5110 3730 43 56 71 NOV 12... 1630 41 2270 251 38 48 61 FEB 04... 2400 1890 5610 28600 42 53 67 MAR 07... 1630 76 4320 886 19 26 36 07... 1900 536 6750 9770 37 48 61 JUL 31... 1915 288 3260 2540 42 54 69 AUG 16... 1830 340 5380 4940 33 47 61 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 07... 83 88 90 94 96 98 99 NOV 12... 73 81 87 96 99 100 100 FEB 04... 78 84 86 91 96 100 100 MAR 07... 45 53 54 97 99 100 100 07... 74 85 89 97 99 100 100 JUL 31... 82 91 94 98 100 100 100 AUG 16... 75 88 90 97 99 100 100 81 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°13'26", long 66°38'22", 300 ft (91 m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, 3.3 mi (5.3 km) northwest of Jayuya plaza. DRAINAGE AREA.--40.4 mi2 (104.6 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 28... 1340 51 214 8.1 28.0 23 7.4 97 <10 K130 K100 MAR 10... 1245 37 236 7.9 25.0 1.5 8.1 100 <10 4100 210 JUN 17... 1445 114 159 7.4 26.0 110 7.3 93 <10 K120000 70000 SEP 08... 1155 E300 168 7.3 25.5 120 7.8 101 <10 K1500 570 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 63 16 6.3 9.9 .5 3.1 66 <.5 10 8.2 MAR 10... -- -- -- -- -- -- 74 -- -- -­ JUN 17... 58 15 5.0 8.0 .5 1.7 51 -- 10 10 SEP 08... 60 16 5.0 9.0 .5 1.9 54 <1.0 12 9.2 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... <.10 22 109 15.0 174 -- <.010 .680 .020 -­ MAR 10... -- -- -- -- <1 -- <.010 1.20 .030 -­ JUN 17... <.10 19 100 30.7 270 .862 .018 .880 .040 1.2 SEP 08... <.10 25 111 E90.0 8 1.09 .014 1.10 .050 .66 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... <.20 -- -- .060 <1 <100 10 <1 <1 <10 MAR 10... <.20 -- -- .080 -- -- -- -- -- -­ JUN 17... 1.2 2.1 9.2 .400 <1 <100 30 <1 9 34 SEP 08... .71 1.8 8.0 .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 82 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 130 <1 16 <.10 <1 <1 <10 <.010 <1 .04 MAR 10... JUN 17... 5600 4 250 <.10 <1 <1 <10 <.010 <1 <.02 SEP 08... --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 83 RIO GRANDE DE ARECIBO BASIN 50026140 LAGO CAONILLAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 18°16'43", long 66°39'24", Hydrologic Unit 21010001, at Lago Caonillas Dam on Río Caonillas, 2.9 mi (4.7 km) northeast of Plaza de Utuado, 0.3 mi (0.6 km) west from Iglesia Santa María del Monte Carmelo, and 1.8 mi (3.0 km) northwest from Hacienda Carbonell. DRAINAGE AREA.--48.4 mi2 (125.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1991 to current year. Prior to October 1994, published as Lago Caonillas at Caonillas. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Caonillas was completed in 1948. The dam is a concrete gravity structure with a total length of 815 ft (248 m),a maximum height of 235 ft (72 m), and a maximum base width of 195 ft (59 m). Non-overflow sections on each abutment have a total length of 603 ft (184 m). The dam is the main unit of Caonillas Hydroelectric Project, and provides 49,000 acre-feet (60 hm3) of usable storage for power generation at Caonillas Power Plant No. 1 located 2.5 mi (4.0 km) downstream from the dam. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 841.29 ft (256.42 m), Sept. 22, 1998; minimun elevation, 737.92 ft (224.92 m), Aug. 8, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 841.29 ft (256.42 m), Sept. 22; minimum elevation, 766.57 ft (233.65 m), Oct. 5. . Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 705 0 800 27,982 750 8,421 830 46,161 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 768.16 784.66 786.24 785.63 785.57 A 788.67 799.11 815.66 A 821.04 823.54 2 768.22 784.68 786.32 785.61 785.54 A 789.16 799.19 815.82 A 820.68 825.57 3 768.20 784.70 786.39 785.63 784.56 A 789.47 799.26 816.02 A 820.28 826.38 4 768.20 784.65 786.44 785.63 784.85 A 789.61 799.18 816.19 A 820.08 825.11 5 767.90 784.67 786.43 785.66 788.02 A 789.76 799.23 817.76 A 819.61 824.38 6 767.83 784.29 786.45 785.68 787.12 788.30 789.76 799.46 818.37 A 819.42 825.46 7 769.06 784.30 786.45 785.36 786.76 789.15 792.90 799.62 818.49 A 820.19 825.65 8 769.82 784.01 786.47 785.37 787.17 789.49 793.99 801.34 818.66 A 820.97 825.43 9 769.76 784.18 786.48 785.33 787.75 789.59 794.39 802.13 818.74 A 821.50 823.32 10 769.81 784.66 786.35 785.32 787.93 789.62 794.65 802.40 818.78 A 822.13 824.37 11 769.82 784.87 786.36 785.32 788.03 789.67 794.84 802.58 818.93 A 823.29 824.42 12 770.35 785.28 786.36 785.44 788.12 789.09 795.26 802.71 818.51 A 824.08 824.39 13 771.15 785.44 786.37 785.53 788.17 787.90 795.51 802.83 818.53 822.74 824.38 824.56 14 774.72 785.56 786.38 785.61 788.24 787.85 795.40 804.59 818.67 822.54 824.22 824.50 15 775.52 785.66 786.37 785.62 788.32 788.10 795.50 806.51 818.46 822.93 823.97 824.06 16 776.98 785.52 786.36 785.62 788.37 787.48 795.66 807.05 818.65 823.28 824.42 824.16 17 782.73 785.26 786.35 785.61 788.40 787.62 796.05 807.39 819.35 823.43 824.38 824.37 18 785.35 785.34 786.35 785.69 788.42 787.61 796.23 807.22 819.73 823.66 824.22 824.12 19 786.05 785.23 786.36 785.74 A 787.66 796.66 807.71 819.52 823.68 823.92 823.77 20 787.56 785.30 786.15 785.88 A 787.69 797.17 809.28 818.92 823.91 823.62 822.61 21 787.35 785.34 785.99 785.90 A 787.79 797.70 811.98 819.48 823.69 823.56 830.08 22 787.54 785.38 786.05 785.89 A 787.85 797.92 813.24 819.65 823.32 823.72 830.98 23 787.16 785.31 786.06 785.88 A 787.90 798.30 813.82 819.80 823.41 824.01 827.71 24 787.32 785.35 785.85 785.86 A 787.73 798.55 814.21 819.98 823.08 824.52 827.15 25 787.31 785.28 785.84 785.84 A 787.77 798.80 814.31 820.22 823.17 826.79 826.87 26 787.04 785.37 785.82 785.82 A 787.79 798.98 814.57 820.37 822.78 826.29 826.76 27 786.01 785.44 785.82 785.75 A 787.82 799.15 814.78 820.52 822.78 826.17 826.67 28 785.03 785.48 785.78 785.72 A 787.85 799.26 814.95 820.66 822.42 825.81 827.06 29 785.08 785.79 785.75 785.68 787.94 799.28 815.12 A 822.10 825.41 826.83 30 785.12 786.14 785.62 785.65 788.37 799.09 815.31 A 821.57 824.93 826.68 31 785.08 785.60 785.61 788.19 815.52 821.41 824.35 MAX 787.56 786.14 786.48 785.90 799.28 815.52 826.79 830.98 MIN 767.83 784.01 785.60 785.32 788.67 799.11 819.42 822.61 A No gage-height record 84 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'50", long 66°40'02", at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6 km) west of Florida plaza. DRAINAGE AREA.--169 mi2 (436 km2) does not include 6.0 mi2 (15.6 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 28... 0930 E2000 213 7.6 26.5 1.8 4.0 49 <10 K40 K50 MAR 10... 1015 30 256 7.9 25.0 .80 5.5 67 <10 4400 <10 JUN 23... 0900 26 210 7.7 26.5 5.7 4.6 57 <10 270 K140 SEP 04... 0905 E1800 176 6.9 26.0 68 5.1 62 <10 2600 5600 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 80 23 5.8 9.4 .5 2.1 71 <.5 11 9.2 MAR 10... -- -- -- -- -- -- 90 -- -- -­ JUN 23... 80 22 5.9 9.2 .4 2.4 74 -- 13 10 SEP 04... 66 18 5.0 8.1 .4 2.6 62 <1.0 11 8.9 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... <.10 21 123 E664 9 -- <.010 .810 .010 .30 MAR 10... -- -- -- -- <1 .251 .029 .280 .110 .27 JUN 23... <.10 18 125 8.93 6 -- <.010 .490 .050 -­ SEP 04... <.10 20 110 E535 62 .703 .017 .720 .080 .43 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... .31 1.1 5.0 .060 <1 <100 20 <1 <1 <10 MAR 10... .38 .66 2.9 .050 -- -- -- -- -- -­ JUN 23... <.20 -- -- <.020 <1 <100 <10 <1 <1 <10 SEP 04... .51 1.2 5.4 .050 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 85 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 620 <1 85 <.10 <1 <1 <10 <.010 <1 .05 MAR 10... JUN 23... 580 <1 70 <.10 <1 <1 <10 <.010 <1 <.02 SEP 04... 86 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR LOCATION.--Lat 18°25'22", long 66°41'58", Hydrologic Unit 21010002, 0.5 mi (0.8 km) upstream from Río Tanamá, 3.6 mi (5.8 km) south of Arecibo and 4.9 mi (7.9 km) above mouth, and 10.4 mi (16.7 km) downstream from Lago Dos Bocas. DRAINAGE AREA.--174 mi2 (451 km2), approximately,of which an undetermined amount does not contribute directly to surface runoff. PERIOD OF RECORD.--April 1982 to current year. GAGE.--Water-stage recorder. Elevation of gage is 30 ft (9 m), from topographic map. REMARKS.--Records fair. Flow regulated by Lago Dos Bocas Dam 10.4 mi (16.7 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 149 102 109 115 2 77 155 172 134 3 355 166 255 150 4 136 243 355 67 5 111 220 301 54 156 24 162 127 467 e52 168 526 79 27 92 101 273 e44 138 426 262 30 39 41 102 45 271 381 182 251 41 85 107 39 327 e222 101 366 36 50 350 35 325 351 6 147 229 114 52 7 213 159 148 69 8 187 83 162 172 9 98 156 161 55 10 250 57 181 58 460 71 34 69 418 48 301 e370 248 40 41 120 252 55 452 e410 164 37 232 84 322 160 306 e390 146 27 77 191 224 248 335 484 54 24 121 104 201 368 524 691 11 182 48 110 45 12 253 122 89 114 13 1290 191 74 107 14 659 120 124 48 15 646 59 88 116 49 22 51 269 295 135 644 263 46 24 33 395 655 203 987 226 43 24 142 146 573 294 646 410 43 23 240 45 236 220 557 483 41 25 83 37 315 92 547 468 16 475 128 167 198 17 420 349 155 113 18 694 221 142 48 19 398 111 86 44 20 351 274 73 38 78 25 156 30 294 297 391 663 299 22 128 124 92 296 409 426 108 27 158 315 89 146 454 420 60 27 139 166 169 311 267 667 248 28 224 693 117 270 266 748 21 386 93 154 47 22 307 58 153 68 23 343 58 127 99 24 335 182 196 210 25 275 116 84 107 361 27 194 1340 98 326 471 765 212 26 244 982 371 472 466 e7290 104 26 240 419 292 400 261 2680 70 26 301 341 84 416 444 1600 35 85 196 182 64 245 807 1080 26 259 122 67 42 27 350 58 63 138 28 381 55 101 85 29 400 93 68 286 30 191 62 81 387 31 182 --- 96 119 123 41 176 305 56 96 735 834 41 65 43 304 344 95 737 638 27 37 168 121 95 101 633 530 --- 121 61 204 90 204 666 738 --- 107 160 92 e96 320 620 753 --- 159 --- 68 --- 366 378 --­ TOTAL 10500 4090 4256 3385 MEAN 339 136 137 109 MAX 1290 349 355 387 MIN 77 48 63 38 AC-FT 20830 8110 8440 6710 CFSM 1.95 .78 .79 .63 IN. 2.24 .87 .91 .72 3840 1864 4012 7550 7141 6399 14533 25933 137 60.1 134 244 238 206 469 864 460 366 301 1340 655 472 987 7290 27 22 33 30 56 35 138 222 7620 3700 7960 14980 14160 12690 28830 51440 .79 .35 .77 1.40 1.37 1.19 2.69 4.97 .82 .40 .86 1.61 1.53 1.37 3.11 5.54 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1982 - 1998, BY WATER YEAR (WY) MEAN 584 500 277 240 MAX 1984 1413 570 437 (WY) 1986 1986 1988 1988 MIN 171 123 72.4 83.5 (WY) 1995 1995 1995 1995 223 208 329 547 333 243 259 527 428 351 617 2000 683 374 474 1479 1988 1985 1986 1986 1987 1987 1988 1996 61.3 60.1 65.7 178 69.3 62.7 82.8 99.9 1995 1998 1995 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1982 - 1998 ANNUAL TOTAL 77375 ANNUAL MEAN 212 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2730 LOWEST DAILY MEAN 29 ANNUAL SEVEN-DAY MINIMUM 39 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 153500 ANNUAL RUNOFF (CFSM) 1.22 ANNUAL RUNOFF (INCHES) 16.54 10 PERCENT EXCEEDS 360 50 PERCENT EXCEEDS 181 90 PERCENT EXCEEDS 56 93503 256 355 729 1986 132 1994 Jan 22 7290 Sep 22 14800 May 18 1985 Jun 21 22 Mar 11 16 Apr 14 1994 Jun 24 24 Mar 11 22 Mar 30 1994 Not determined Sep 22 45800 May 18 1985 15.87 Sep 22 18.22 May 18 1985 185500 257400 1.47 2.04 19.99 27.74 500 733 159 232 41 54 e Estimated 87 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 88 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1982 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October, 1995 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1995. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,510 mg/L September 22, 1998; Minimum daily mean, 2 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e84,900 tons (77,000 tonnes) September 22, 1998; Minimum daily mean, 0.14 ton (0.013 tonne) March 24, 1998. EXTREMES FOR CURRENT YEAR 1998. SEDIMENT CONCENTRATION: Maximum daily mean, 3,510 mg/L September 22, 1998; Minimum daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e84,900 tons (77,000 tonnes) September 22, 1998; Minimum daily mean, 0.14 ton (0.013 tonne) March 24, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 149 37 19 2 77 17 3.8 3 355 68 82 4 136 35 16 5 111 29 13 102 31 8.9 109 20 10 155 36 21 172 21 12 166 30 22 255 46 39 243 55 44 355 58 64 220 44 35 301 63 58 6 147 24 16 7 213 31 38 8 187 33 32 9 98 18 5.6 10 250 41 49 229 46 38 114 32 10 159 53 27 148 42 19 83 23 5.3 162 45 24 156 50 24 161 39 21 57 39 6.0 181 45 25 11 182 36 23 48 12 253 41 47 122 13 1290 88 315 191 14 659 75 147 120 15 646 78 137 59 31 4.1 110 40 12 36 19 89 50 12 40 25 74 30 6.1 34 13 124 33 12 20 3.6 88 17 4.0 16 475 54 71 128 17 420 79 116 349 18 694 126 249 221 19 398 74 98 111 20 351 62 65 274 36 16 167 31 19 60 74 155 29 16 44 31 142 24 12 28 10 86 12 2.7 63 54 73 11 2.1 21 386 56 64 93 22 307 53 48 58 23 343 61 65 58 24 335 61 64 182 25 275 53 47 116 27 7.5 154 38 19 16 2.5 153 41 19 12 2.4 127 34 13 36 21 196 47 27 25 10 84 26 5.9 26 259 53 44 122 27 350 64 72 58 28 381 74 91 55 29 400 53 69 93 30 191 49 34 62 31 182 47 27 --- 21 9.7 67 22 4.0 10 1.5 63 20 3.4 9 1.4 101 29 8.6 14 4.3 68 19 3.5 10 1.6 81 22 7.2 --- --- 96 30 8.8 TOTAL 10500 --- 2167.4 4090 --- 542.8 4256 --- 499.3 --- --- --- --- --- --- --- --- --- --- --- --- 89 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 115 33 12 156 25 17 24 5 .35 2 134 37 16 79 21 5.1 27 10 .76 3 150 39 20 262 37 68 30 18 1.4 4 67 20 3.6 182 25 30 251 22 21 5 54 18 2.7 101 8 2.3 366 19 23 6 52 18 2.5 460 57 111 71 4 .79 7 69 20 4.7 248 53 45 40 3 .36 8 172 28 22 164 43 26 37 4 .35 9 55 9 1.3 146 37 22 27 4 .28 10 58 8 1.2 54 18 2.6 24 5 .31 11 45 7 .84 49 16 2.1 22 10 .58 12 114 24 14 46 15 1.8 24 19 1.3 13 107 17 7.4 43 13 1.5 24 27 1.8 14 48 5 .70 43 12 1.4 23 16 1.0 15 116 21 11 41 11 1.2 25 9 .62 16 198 41 30 78 18 6.1 25 7 .45 17 113 31 13 299 42 44 22 8 .47 18 48 16 2.1 108 17 5.1 27 9 .67 19 44 15 1.8 60 17 2.8 27 7 .52 20 38 14 1.5 248 53 45 28 6 .41 21 47 15 2.7 361 20 23 27 4 .31 22 68 21 4.3 212 9 5.5 26 3 .22 23 99 25 11 104 8 2.2 26 2 .17 24 210 45 32 70 7 1.4 26 2 .14 25 107 30 11 35 7 .66 85 11 3.9 26 42 15 1.8 123 12 6.2 41 3 .34 27 138 27 20 41 7 .77 65 2 .45 28 85 25 6.6 27 7 .52 37 2 .22 29 286 49 82 121 31 14 30 387 67 98 107 21 7.2 31 119 19 9.1 159 28 24 TOTAL 3385 446.84 3840 480.25 1864 107.37 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 162 28 19 127 2 92 17 5.9 101 3 39 10 1.1 41 4 41 10 1.1 85 5 36 9 .92 50 8 3.3 467 58 110 9 2.5 273 46 43 7 .73 102 30 9.3 7 2.3 107 29 12 8 1.1 350 81 125 6 34 9 .84 7 41 31 3.3 8 232 26 20 9 77 10 2.4 10 121 22 16 69 9 5.0 418 86 116 120 42 18 252 55 59 84 28 11 322 66 73 191 40 27 224 57 51 104 23 8.6 201 52 36 11 51 37 5.4 12 33 20 1.8 13 142 27 21 14 240 31 49 15 83 12 4.0 269 45 80 295 75 86 395 50 84 655 121 300 146 47 24 573 102 184 45 16 1.9 236 106 70 37 13 1.3 315 87 88 16 156 40 18 30 17 128 36 16 124 18 158 34 24 315 19 139 34 19 166 20 224 36 37 693 11 .98 294 68 70 79 26 92 12 3.4 85 99 89 18 4.8 38 24 169 34 23 127 277 117 28 10 21 194 33 32 1340 22 244 40 45 982 23 240 13 10 419 24 301 10 13 341 25 196 7 5.2 182 127 516 98 18 5.6 265 691 371 44 79 254 292 292 48 53 214 214 84 8 1.8 64 55 64 5 .89 26 176 8 4.9 27 43 6 .67 28 168 7 4.0 29 61 8 1.3 30 160 7 5.4 31 --- --- --- 305 118 105 56 5 .68 304 62 65 344 45 77 121 38 17 95 14 5.4 204 79 58 90 12 4.4 92 44 12 e96 10 e1.2 68 23 4.1 --- --- --­ TOTAL 4012 --- 387.23 7550 --- 2726.81 7141 --- 1702.47 --- --- --- --- --- --- 90 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 e52 9 e.89 168 6 3.0 526 94 144 2 e44 8 e.71 138 4 1.5 426 69 90 3 45 8 .91 271 12 17 381 61 65 4 39 7 .73 327 37 47 e222 47 e33 5 35 6 .60 325 34 34 351 50 50 6 48 8 1.3 301 22 27 e370 86 e65 7 55 9 1.3 452 36 61 e410 95 e95 8 160 18 17 306 70 57 e390 104 e65 9 248 31 33 335 51 48 484 77 120 10 368 38 50 524 71 117 691 115 218 11 135 9 3.7 644 103 213 263 60 52 12 203 17 16 987 174 466 226 44 31 13 294 23 29 646 123 223 410 78 95 14 220 22 24 557 95 153 483 90 126 15 92 9 2.2 547 97 154 468 86 121 16 297 51 47 391 79 91 663 70 127 17 296 19 24 409 80 95 426 68 85 18 146 13 11 454 83 109 420 75 93 19 311 40 44 267 60 46 667 108 202 20 270 36 33 266 62 47 748 108 218 21 326 40 44 471 58 86 765 121 251 22 472 41 66 466 62 87 e7290 3510 e84900 23 400 50 69 261 60 47 2680 725 5710 24 416 37 59 444 77 103 1600 244 1060 25 245 10 10 807 133 294 1080 183 534 26 96 5 1.3 735 123 244 834 145 328 27 95 4 1.1 737 111 220 638 123 212 28 101 5 1.4 633 113 198 530 102 146 29 204 29 28 666 122 220 738 124 257 30 320 30 40 620 111 199 753 149 310 31 366 51 57 378 68 81 TOTAL 6399 717.14 14533 3788.5 25933 95803 YEAR 93503 109369.11 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 13... 0230 2120 124 710 88 FEB 06... 2015 898 113 274 97 17... 1600 702 114 216 86 MAR 04... 1815 620 85 142 92 JUN 02... 1726 635 103 177 84 AUG 07... 2100 845 78 178 95 13... 0640 466 146 184 100 91 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENTED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) SEP 22... 0356 5750 7150 111000 47 65 81 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) SEP 22... 87 92 94 97 99 100 100 --- --- --- --- --- --- --- 92 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR LOCATION.--Lat 18°18'02", long 66°46'58", Hydrologic Unit 21010001, on downstream side of left abutment of bridge on Highway 111, 1.2 mi (1.9 km) upstream from natural tunnel, 1.5 mi (2.4 km) northeast of Angeles, and 5.8 mi (9.3 km) northwest of Utuado. DRAINAGE AREA.--18.4 mi2 (47.7 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1944 to June 1958 (daily stage and two to four measurements per month by Puerto Rico Water Resources Authority), November 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 938.32 ft (286.000 m) above mean sea level. Datum of gage was increased by 3.00 ft (0.914 m) on Oct. 1978. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 53 46 23 15 10 15 e17 e14 33 36 34 e83 2 41 45 22 15 11 15 20 e15 36 37 33 e100 3 31 44 22 15 11 14 16 e16 35 36 34 e95 4 28 42 22 14 16 14 14 e26 37 36 33 e92 5 26 41 21 14 68 15 18 e40 168 36 34 78 6 28 40 20 16 24 16 13 e78 e190 43 34 82 7 106 40 20 24 21 19 e23 e88 e50 37 34 67 8 45 38 19 18 25 16 e31 e60 e40 33 34 59 9 31 37 19 14 31 14 e17 s53 e36 33 66 60 10 28 39 19 14 21 14 e16 29 e34 e50 121 51 11 44 60 18 13 20 13 e15 23 e140 e40 182 45 12 191 48 18 14 20 13 e14 21 e230 32 111 89 13 101 48 18 25 19 13 e13 20 e96 31 75 65 14 140 41 17 20 18 17 e19 19 e86 e60 64 56 15 109 67 17 15 22 24 e23 21 e47 84 57 51 16 95 42 17 14 19 19 e23 20 e49 89 57 63 17 136 35 17 14 18 28 e19 22 e76 51 66 57 18 108 32 17 16 17 25 e28 27 79 52 55 87 19 82 31 17 19 17 14 e50 124 52 41 51 60 20 73 30 17 14 16 13 e60 128 47 34 49 49 21 66 30 17 14 16 13 e27 380 e43 33 80 155 22 64 29 16 16 16 12 e24 117 36 33 58 3310 23 62 28 17 13 15 11 e23 73 36 34 52 375 24 59 29 19 12 16 12 e20 55 36 36 69 220 25 56 29 16 13 16 10 e19 47 52 34 129 152 26 54 33 16 11 20 11 e18 45 38 33 68 128 27 52 25 16 11 16 11 e17 40 47 32 91 113 28 50 24 16 11 15 11 e17 37 36 32 e187 106 29 49 25 16 11 44 e16 36 36 31 e95 184 30 47 24 15 10 86 e15 45 36 30 e86 120 31 46 16 10 e36 36 31 e90 TOTAL 2101 1122 560 455 554 588 645 1755 1957 1250 2229 6252 MEAN 67.8 37.4 18.1 14.7 19.8 19.0 21.5 56.6 65.2 40.3 71.9 208 MAX 191 67 23 25 68 86 60 380 230 89 187 3310 MIN 26 24 15 10 10 10 13 14 33 30 33 45 AC-FT 4170 2230 1110 902 1100 1170 1280 3480 3880 2480 4420 12400 CFSM 3.68 2.03 .98 .80 1.08 1.03 1.17 3.08 3.55 2.19 3.91 11.3 IN. 4.25 2.27 1.13 .92 1.12 1.19 1.30 3.55 3.96 2.53 4.51 12.64 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 1998, BY WATER YEAR (WY) MEAN 79.8 67.1 41.9 29.6 26.0 24.8 35.6 56.8 42.6 35.8 46.2 77.7 MAX 195 159 121 71.0 50.8 71.2 143 193 116 65.7 110 208 (WY) 1990 1969 1966 1997 1996 1972 1969 1963 1979 1981 1979 1998 MIN 25.4 25.1 18.1 14.7 13.3 11.0 9.70 12.4 15.6 9.18 15.9 25.0 (WY) 1963 1995 1998 1998 1965 1984 1984 1977 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1960 - 1998 ANNUAL TOTAL 13416 19468 ANNUAL MEAN 36.8 53.3 47.0 HIGHEST ANNUAL MEAN 71.1 1969 LOWEST ANNUAL MEAN 20.7 1994 HIGHEST DAILY MEAN 251 Jan 22 3310 Sep 22 3310 Sep 22 1998 LOWEST DAILY MEAN 14 May 20 10 Jan 30 5.4 Aug 4 1994 ANNUAL SEVEN-DAY MINIMUM 15 May 15 11 Jan 26 6.4 Jul 29 1994 INSTANTANEOUS PEAK FLOW 25500 Sep 22 25500 Sep 22 1998 INSTANTANEOUS PEAK STAGE 21.24 Sep 22 21.24 Sep 22 1998 INSTANTANEOUS LOW FLOW 9.1 Mar 25 5.4 Aug 4 1994 ANNUAL RUNOFF (AC-FT) 26610 38610 34080 ANNUAL RUNOFF (CFSM) 2.00 2.90 2.56 ANNUAL RUNOFF (INCHES) 27.12 39.36 34.73 10 PERCENT EXCEEDS 62 91 83 50 PERCENT EXCEEDS 29 32 33 90 PERCENT EXCEEDS 16 14 16 e Estimated 93 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 94 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED SEDIMENT DISCHARGE: January 1968 to current year. INSTRUMENTATION.--US D-49 SEDIMENT SAMPLER SINCE OCTOBER 1968.SEDIMENT PUMPING SAMPLER SINCE 1990 EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean,20,400 mg/L November 27, 1968; minimum daily mean,<1 mg/L during water year 1985. SEDIMENT LOADS: Maximum daily,240,000 tons (218,000 tonnes) Sept. 22,1998, minimum daily, <0.01 ton ( <0.01tonne) several days during many years. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATIONS: Maximum daily mean,2,950 mg/L September 22, 1998; minimum daily mean,4 mg/L several days. SEDIMENT LOADS: Maximum daily, 240,000 tons (218,000 tonnes) September 22,1998; minimum daily,0.17 ton (0.15 tonne) several days. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 23... 0935 62 164 7.8 23.0 2.0 8.2 98 <10 240 620 FEB 23... 1525 15 174 7.5 25.5 1.4 8.3 105 <10 K30 230 JUN 02... 1100 30 168 8.2 25.5 3.0 8.8 111 <10 K30 K120 SEP 04... 1300 87 148 6.8 24.7 52 7.8 94 <10 K11000 20000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 23... 74 21 5.5 7.3 .4 1.9 52 <.5 10 8.4 FEB 23... -- -- -- -- -- -- 61 -- -- -­ JUN 02... 62 15 5.8 8.4 .5 2.3 57 -- 12 8.5 SEP 04... 53 14 4.8 6.8 .4 2.5 49 <1.0 8.0 7.3 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 23... <.10 25 111 18.5 <1 -- <.010 1.10 .010 -­ FEB 23... -- -- -- -- 1 -- <.010 .620 .010 -­ JUN 02... <.10 24 111 8.90 <1 -- <.010 .680 <.010 -­ SEP 04... <.10 23 96 22.3 64 1.08 .018 1.10 .040 .47 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 23... <.20 -- -- <.020 <1 <100 <10 <1 <1 <10 FEB 23... <.20 -- -- <.020 -- -- -- -- -- -­ JUN 02... .23 .91 4.0 <.020 <1 <100 20 <1 <1 <10 SEP 04... .51 1.6 7.1 .040 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 95 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... 380 <1 30 <.10 <1 <1 <10 <.010 <1 <.02 FEB 23... JUN 02... 220 <1 18 <.10 <1 <1 <10 <.010 <1 <.02 SEP 04... SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 53 183 56 46 2 41 108 12 45 3 31 72 6.1 44 4 28 57 4.2 42 5 26 50 3.6 41 31 3.8 23 38 2.4 28 3.3 22 36 2.1 23 2.7 22 34 2.0 19 2.1 22 32 1.9 15 1.7 21 31 1.7 6 28 58 4.9 7 106 683 704 8 45 140 19 9 31 64 5.4 10 28 58 4.3 40 11 1.2 20 27 1.5 40 8 .84 20 22 1.2 38 6 .65 19 18 .95 37 7 .68 19 15 .77 39 7 .78 19 13 .63 11 44 151 30 60 12 191 928 1350 48 13 101 476 134 48 14 140 971 427 41 15 109 421 137 67 169 48 18 10 .51 159 22 18 9 .41 166 24 18 7 .33 52 6.3 17 7 .32 431 141 17 10 .47 16 95 492 128 42 17 136 1220 992 35 18 108 260 85 32 19 82 95 21 31 20 73 53 11 30 112 14 17 16 .72 26 2.5 17 20 .92 23 1.9 17 15 .68 21 1.8 17 11 .48 20 1.6 17 8 .37 21 66 33 5.9 22 64 23 3.9 23 62 9 1.5 24 59 9 1.5 25 56 11 1.7 30 17 1.3 17 8 .36 29 13 1.0 16 8 .35 28 12 .89 17 9 .44 29 14 1.1 19 36 1.9 29 16 1.3 16 29 1.3 26 54 15 2.1 27 52 16 2.3 28 50 11 1.6 29 49 8 1.0 30 47 15 1.9 31 46 33 4.1 33 77 8.8 16 26 1.1 25 45 3.1 16 22 .95 24 41 2.6 16 19 .78 25 41 2.7 16 15 .63 24 40 2.6 15 10 .43 --- --- --- 16 7 .30 TOTAL 2101 --- 4162.0 1122 --- 306.24 560 --- 28.90 --- --- --- --- --- --- --- --- --- --- --- --- 96 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 15 5 .21 10 9 .23 15 4 .17 2 15 5 .22 11 8 .23 15 4 .17 3 15 6 .23 11 7 .20 14 7 .28 4 14 6 .25 16 13 1.3 14 12 .46 5 14 8 .32 68 345 90 15 18 .74 6 16 11 .44 24 79 5.3 16 16 .70 7 24 39 3.7 21 53 3.0 19 13 .68 8 18 31 1.6 25 64 5.9 16 11 .49 9 14 13 .50 31 115 11 14 10 .37 10 14 7 .28 21 36 2.1 14 8 .31 11 13 7 .26 20 15 .79 13 7 .26 12 14 8 .29 20 8 .43 13 8 .27 13 25 63 4.5 19 6 .31 13 8 .28 14 20 75 4.1 18 6 .28 17 16 .84 15 15 71 2.8 22 5 .29 24 46 3.1 16 14 68 2.5 19 5 .25 19 32 1.7 17 14 63 2.4 18 5 .23 28 65 11 18 16 59 2.5 17 4 .21 25 60 5.5 19 19 50 2.7 17 4 .19 14 17 .64 20 14 26 1.0 16 4 .18 13 16 .57 21 14 18 .69 16 4 .18 13 14 .48 22 16 17 .78 16 4 .19 12 12 .37 23 13 8 .27 15 5 .19 11 10 .31 24 12 8 .27 16 5 .22 12 9 .29 25 13 8 .29 16 5 .22 10 9 .24 26 11 10 .30 20 5 .28 11 8 .24 27 11 11 .35 16 5 .21 11 9 .27 28 11 13 .36 15 5 .19 11 11 .31 29 11 12 .34 44 203 76 30 10 11 .30 86 522 203 31 10 9 .25 e36 119 e14 TOTAL 455 35.00 554 124.10 588 324.04 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 e17 28 e1.3 e14 2 20 35 2.1 e15 3 16 19 .82 e16 4 14 15 .55 e26 5 18 16 .80 e40 7 e.28 33 53 4.7 7 e.18 36 68 7.3 7 e.16 35 62 5.9 7 e2.9 37 106 12 7 e1.5 168 1080 1690 6 13 17 .62 7 e23 16 e1.2 8 e31 15 e11 9 e17 15 e1.3 10 e16 14 e.22 e78 6 e79 e190 318 e2080 e88 6 e86 e50 106 e6.6 e60 1060 e55 e40 35 e1.5 s53 214 e55 e36 86 e7.3 29 35 2.9 e34 89 e5.9 11 e15 14 e.17 12 e14 14 e.55 13 e13 13 e.62 14 e19 13 e.48 15 e23 12 e1.2 23 18 1.2 e140 903 e129 21 16 .91 e230 251 e2080 20 13 .70 e96 183 e453 19 9 .48 e86 134 e203 21 7 .38 e47 97 e3.4 16 e23 12 e1.2 17 e19 12 e.48 18 e28 11 e2.9 19 e50 11 e6.6 20 e60 11 e15 20 5 .28 e49 71 e3.4 22 26 1.9 e76 310 e15 27 108 11 79 481 172 124 1660 1060 52 156 23 128 987 522 47 51 6.5 21 e27 10 e2.9 380 22 e24 10 e3.1 117 23 e23 10 e1.2 73 24 e20 9 e2.1 55 25 e19 9 e1.7 47 1070 1780 e43 19 e2.0 221 80 36 14 1.4 76 15 36 12 1.1 44 6.6 36 10 .97 27 3.4 52 159 43 26 e18 9 e1.3 27 e17 8 e1.3 28 e17 8 e1.3 29 e16 8 e.49 30 e15 8 e.18 31 --- --- --- 45 19 2.3 38 86 9.1 40 14 1.5 47 137 29 37 10 1.0 36 60 5.8 36 10 .96 36 28 2.7 45 87 14 36 16 1.5 36 61 6.0 --- --- --­ TOTAL 645 --- 64.68 1755 --- 3792.53 1957 --- 7006.07 --- --- --- --- --- --- 97 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 36 15 1.4 34 20 1.8 e83 179 e40 2 37 31 3.8 33 30 2.7 e100 563 e205 3 36 57 5.6 34 69 6.2 e95 421 e108 4 36 28 2.6 33 159 14 e92 490 e128 5 36 17 1.7 34 277 25 78 501 107 6 43 497 90 34 237 22 82 231 49 7 37 91 9.0 34 195 18 67 84 15 8 33 68 6.2 34 141 13 59 37 6.0 9 33 54 4.8 66 741 378 60 141 27 10 e50 87 e29 121 665 786 51 63 8.8 11 e40 91 e17 182 1980 2080 45 25 3.0 12 32 35 3.0 111 551 173 89 345 224 13 31 32 2.7 75 155 32 65 129 23 14 e60 62 e35 64 56 9.7 56 37 5.6 15 84 1200 876 57 40 6.1 51 33 4.5 16 89 564 239 57 30 4.6 63 117 26 17 51 194 29 66 140 35 57 128 22 18 52 848 320 55 82 12 87 361 120 19 41 131 17 51 41 5.7 60 106 18 20 34 62 5.8 49 22 2.9 49 34 4.5 21 33 36 3.3 80 294 67 155 1710 3930 22 33 33 2.9 58 55 8.8 3310 2950 240000 23 34 30 2.7 52 18 2.5 375 2610 3080 24 36 28 2.7 69 182 80 220 156 99.8 25 34 25 2.3 129 1610 811 152 50 21 26 33 23 2.1 68 50 9.6 128 42 15 27 32 21 1.8 91 796 453 113 36 11 28 32 17 1.5 e187 2200 e3450 106 35 10 29 31 14 1.2 e95 449 e116 184 991 1130 30 30 13 1.0 e86 323 e75 120 166 56 31 31 16 1.3 e90 232 e56 TOTAL 1250 1721.4 2229 8756.6 6252 249497.2 YEAR 19468 275818.96 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 18... 0715 113 187 57 76 MAY 07... 1035 3.1 188 1.6 94 08... 1841 314 2510 2130 93 19... 1635 359 3510 3400 93 20... 2145 372 1600 1610 83 JUN 11... 1825 453 1980 2420 92 JUL 06... 1758 128 2220 767 76 AUG 10... 1754 535 2450 3540 93 SEP 02... 1722 236 1920 1220 86 98 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) MAY 08... 1631 1530 7660 31600 33 43 57 21... 1615 625 3850 6500 32 44 58 JUN 11... 1640 1620 12000 52400 38 49 60 SEP 02... 1730 356 1650 1590 27 38 55 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) MAY 08... 69 79 82 92 98 99 100 21... 71 82 85 92 96 99 100 JUN 11... 69 77 79 89 96 99 100 SEP 02... 65 81 83 94 98 100 100 99 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18°24'52", long 66°42'52", Hydrologic Unit 21010002 on right bank near to an abandoned power house at Charco Hondo,1.5 mi (2.4 km) upstream from mouth, and 4 mi (6 km) south of Arecibo. DRAINAGE AREA.--57.6 mi2 (149.2 km2). PERIOD OF RECORD.--April 1969 to June 1971, October 1981 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 60 ft (18 m), from topographic map. REMARKS.--Records poor. Diversion 0.8 mi (1.3 km) upstream for municipal supply of Arecibo. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 91 71 49 38 2 125 71 46 39 3 105 68 45 39 4 79 68 44 38 5 77 66 44 38 32 30 45 30 66 52 134 229 32 30 40 28 50 50 71 198 32 29 e35 29 64 57 82 197 32 29 31 30 75 54 66 174 88 34 35 34 150 49 103 160 6 77 65 43 39 7 125 63 e42 43 8 152 64 e42 51 9 89 61 42 37 10 79 62 e42 36 48 33 30 83 172 86 64 161 37 41 28 164 88 104 156 205 36 36 63 125 71 60 146 176 51 31 37 120 64 53 206 152 38 29 32 55 69 64 257 122 11 90 71 43 36 12 148 81 42 36 13 291 61 41 46 14 665 58 41 49 15 367 69 41 39 35 27 30 43 231 100 328 102 35 27 29 38 214 56 349 144 33 27 29 36 128 53 228 159 33 28 28 36 112 77 161 132 36 36 27 34 81 117 137 101 16 237 80 41 36 17 171 54 40 36 18 205 52 41 44 19 146 50 41 45 20 126 48 40 39 34 38 46 35 86 249 145 105 33 33 45 34 133 292 152 113 32 45 37 e40 151 166 116 205 36 27 66 e72 122 120 94 189 31 25 123 e221 79 94 86 124 21 112 e47 40 39 22 104 47 43 39 23 97 46 44 36 24 92 46 47 35 25 87 e46 42 35 31 25 67 e254 70 80 157 488 30 24 46 e527 72 69 144 e6400 30 23 49 167 63 76 96 e1500 29 24 42 126 58 125 88 e350 30 24 39 83 65 89 272 e280 26 84 e52 41 35 27 81 51 41 35 28 78 46 40 33 29 76 48 40 33 30 74 63 e86 33 31 72 --- 39 33 34 24 35 96 86 63 124 e240 32 24 35 110 80 69 140 e220 32 24 34 70 98 71 434 e210 --- 39 33 57 61 58 330 e360 --- 180 30 64 55 61 175 e240 --- 90 --- 92 --- 130 175 --­ TOTAL 4402 1775 1353 1190 MEAN 142 59.2 43.6 38.4 MAX 665 81 86 51 MIN 72 46 39 33 AC-FT 8730 3520 2680 2360 CFSM 6.40 2.67 1.97 1.73 IN. 7.38 2.97 2.27 1.99 1012 1136 1246 2933 2914 2844 5216 13436 36.1 36.6 41.5 94.6 97.1 91.7 168 448 88 180 123 527 231 292 434 6400 29 23 27 28 50 49 64 101 2010 2250 2470 5820 5780 5640 10350 26650 1.63 1.65 1.87 4.26 4.38 4.13 7.58 20.2 1.70 1.90 2.09 4.91 4.88 4.77 8.74 22.51 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 1998, BY WATER YEAR (WY) MEAN 162 131 78.4 59.5 MAX 335 260 219 167 (WY) 1990 1982 1982 1997 MIN 72.1 50.4 36.4 22.3 (WY) 1983 1995 1989 1989 50.1 42.6 65.6 126 88.7 65.3 81.0 141 106 70.0 141 371 196 120 168 448 1996 1971 1986 1986 1995 1969 1998 1998 16.8 16.6 25.9 15.8 23.3 22.0 35.1 44.9 1989 1988 1989 1989 1989 1989 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1969 - 1998 ANNUAL TOTAL 28311 ANNUAL MEAN 77.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 665 LOWEST DAILY MEAN 33 ANNUAL SEVEN-DAY MINIMUM 34 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 56150 ANNUAL RUNOFF (CFSM) 3.49 ANNUAL RUNOFF (INCHES) 47.44 10 PERCENT EXCEEDS 127 50 PERCENT EXCEEDS 61 90 PERCENT EXCEEDS 38 39457 108 89.1 124 1986 46.9 1994 Oct 14 6400 Sep 22 6400 Sep 22 1998 May 1 23 Mar 23 4.2 May 28 1989 May 14 24 Mar 22 5.4 May 22 1989 Not determined Sep 22 Not determined Sep 22 1998 24.56 Sep 22 24.56 Sep 22 1998 78260 64510 4.87 4.01 66.12 54.50 184 176 58 65 31 29 e Estimated 100 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 101 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 13.9 mi (22.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Río Tanamá, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2). PERIOD OF RECORD.--January 1963 to January 1965 (monthly measurements only), February 1965 to April 1969 (occasional measurements only), May 1969 to September 1983, October 1996 to September 1997. GAGE.--Water-stage recorder. Datum of gage is 3.73 ft (1.14 m) above mean sea level. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas dam, 13.9 mi (22.4 km) upstream. The mean daily discharge for September 22, 1998 is not available ,because there not rating definition above 13.0 ft; gage-height peak for September 21, 1998 was 17.0 ft. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 272 151 119 132 209 82 291 223 639 e110 303 927 2 187 241 183 160 140 82 172 181 453 e109 205 1020 3 462 218 286 196 307 80 85 102 236 127 445 1380 4 247 353 435 91 306 326 75 159 240 117 494 983 5 160 316 392 78 209 590 71 114 525 108 499 1280 6 237 328 136 73 564 175 65 118 625 122 434 1340 7 273 273 172 96 355 108 72 308 454 181 e729 1510 8 353 140 185 265 247 107 339 196 481 272 516 1400 9 172 249 198 96 239 91 158 363 392 415 578 868 10 334 119 199 95 96 83 197 241 340 612 875 1280 11 276 114 122 79 85 79 112 362 439 292 1120 516 12 379 201 86 164 78 74 74 593 941 362 1940 430 13 1840 297 70 169 78 69 220 290 862 475 1050 720 14 966 216 116 106 e76 61 327 118 435 428 855 847 15 912 118 82 138 e70 69 168 101 465 231 832 825 16 742 231 170 289 e121 78 266 91 495 522 584 1150 17 607 456 159 214 e494 69 227 240 255 566 590 756 18 975 302 135 105 e187 90 255 463 255 323 748 739 19 599 164 80 104 e135 72 233 334 342 567 427 1180 20 531 336 62 90 e407 63 379 960 239 499 355 1310 21 557 146 149 87 513 60 355 1940 199 577 778 1360 22 451 90 149 126 385 59 363 2330 494 825 792 23 498 84 115 145 205 64 393 786 457 719 435 9390 24 495 214 206 299 149 61 435 618 187 731 704 5500 25 383 143 87 172 91 123 285 394 154 483 1510 3630 26 384 160 74 85 224 68 314 442 174 192 1310 2780 27 477 90 69 187 113 91 106 514 470 185 1320 e2190 28 529 80 113 151 88 56 259 259 248 194 1120 1870 29 554 104 87 335 197 133 341 193 341 1140 2600 30 325 93 90 541 266 257 222 e171 516 1130 2800 31 271 131 199 280 214 615 636 TOTAL 15448 6027 4657 5067 6171 3773 6686 13617 11860 11816 24454 MEAN 498 201 150 163 220 122 223 439 395 381 789 MAX 1840 456 435 541 564 590 435 2330 941 825 1940 MIN 160 80 62 73 70 56 65 91 154 108 205 AC-FT 30640 11950 9240 10050 12240 7480 13260 27010 23520 23440 48500 CFSM 2.49 1.00 .75 .82 1.10 .61 1.11 2.20 1.98 1.91 3.94 IN. 2.87 1.12 .87 .94 1.15 .70 1.24 2.53 2.21 2.20 4.55 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 1998, BY WATER YEAR (WY) MEAN 792 720 515 353 297 315 377 556 454 381 442 704 MAX 1577 1388 1327 651 425 627 641 1192 1220 854 1269 1866 (WY) 1971 1978 1982 1997 1997 1972 1983 1980 1979 1979 1979 1979 MIN 404 201 150 155 152 122 196 188 139 189 218 271 (WY) 1983 1998 1998 1973 1974 1998 1975 1977 1977 1997 1974 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR WATER YEARS 1969 - 1998 ANNUAL TOTAL 114972 ANNUAL MEAN 315 501 HIGHEST ANNUAL MEAN 691 1979 LOWEST ANNUAL MEAN 290 1974 HIGHEST DAILY MEAN 4120 Jan 22 15900 Aug 31 1979 LOWEST DAILY MEAN 56 Mar 28 56 Mar 28 1998 ANNUAL SEVEN-DAY MINIMUM 93 Dec 25 67 Mar 18 1998 INSTANTANEOUS PEAK FLOW Not determined INSTANTANEOUS PEAK STAGE 19.28 INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 228000 ANNUAL RUNOFF (CFSM) 1.57 ANNUAL RUNOFF (INCHES) 21.38 10 PERCENT EXCEEDS 518 50 PERCENT EXCEEDS 272 90 PERCENT EXCEEDS 100 Sep 22 Not determined Sep 22 1998 Sep 22 19.28 Sep 22 1998 50 Feb 26 1974 363100 2.51 34.05 962 351 133 e Estimated 102 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 103 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 8.3 mi (13.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Rio Tanama , and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2), approximately. PERIOD OF RECORD.--Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 06... 1030 194 254 7.5 25.5 7.6 7.5 90 <10 210 K160 FEB 27... 0945 101 281 7.7 24.0 3.4 7.9 93 <10 500 270 JUN 23... 1120 214 273 8.0 28.0 10 6.8 86 <10 390 240 SEP 14... 1230 E500 254 7.4 26.5 27 7.1 88 <5 3000 2500 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 06... 96 28 7.0 11 .5 1.7 98 <.5 6.1 11 FEB 27... -- -- -- -- -- -- 110 -- -- -­ JUN 23... 110 34 5.6 8.8 .4 2.1 100 -- 14 10 SEP 14... 110 35 4.9 8.0 .3 2.0 100 <1.0 11 9.3 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 06... <.10 29 148 77.5 1 .704 .016 .720 .020 -­ FEB 27... -- -- -- -- 5 .426 .014 .440 .030 -­ JUN 23... <.10 15 150 87.0 11 -- <.010 .630 .040 -­ SEP 14... <.10 16 146 E197 3 .844 .016 .860 .030 .21 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 06... <.20 -- -- .030 <1 <100 20 <1 <1 <10 FEB 27... <.20 -- -- <.020 -- -- -- -- -- -­ JUN 23... <.20 -- -- .060 <1 <100 30 <1 <1 <10 SEP 14... .24 1.1 4.9 .060 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 104 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 06... 210 <1 35 <.10 <1 <1 <10 <.010 <1 .12 FEB 27... JUN 23... 180 <1 30 <.10 <1 <1 <10 <.010 <1 <.02 SEP 14... 105 de de Río Río Río Río Río Río Río Río Lago de Matrullas Lago Guineo Caño Grande Grande Cialitos Toro Negro Manatí Manatí Matrullas Sana Muertos Bauta Orocovis Laguna 0340 0307 210 032290 OCEAN OROCOVIS VILLALBA CIALES MOROVIS COROZAL FLORIDA 0 0 1 1 2 2 3 3 4 4 030460 0307 0312 0350 035950 0355 0381 0382 0340 HI-2 210 CS-7 206 207 166 032290 032590 T iburones T ortuguero QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER SURFACE-WATER STATION AND NUMBER CAÑO TIBURONES FLOW DIRECTION TUNNEL FLOW DIRECTION DRAINAGE BASIN BOUNDARY TOWN OR CITY BARCELONETA MANATÍ VEGA BAJA VEGA ALTA A TLANTIC JAYUYA BARRANQUITAS Basin area PUERTO RICO 5 MILES 5 KILOMETERS Figure 14. Río Grande de Manatí basin. 106 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR LOCATION.--Lat 18°13'25", long 66°23'34", Hydrologic Unit 21010001, on right bank, 0.4 mi (0.6 km) south of junction of Highways 155 and 156 in Orocovis, 2.1 mi (3.38 km) upstream from Río Botijas, and 250 ft (76 m) upstream from bridge on Highway 599. DRAINAGE AREA.--5.03 mi2 (13.03 km2). PERIOD OF RECORD.--April 1981 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 500 ft (152 m), from topographic map. REMARKS.--Records poor. Low flow affected by diversions for water supply. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.1 .88 .56 e.41 .35 e.59 .89 .61 3.9 1.2 1.3 1.5 2 2.2 .77 .56 e.38 .33 e.56 .76 .73 3.8 1.3 1.1 67 3 1.7 .82 .80 e.41 .35 e.54 .64 .70 3.4 1.5 1.0 49 4 3.0 .94 1.2 e.50 23 e.57 .68 .55 3.7 1.7 1.0 30 5 3.2 .83 .67 e1.1 162 e.80 .81 .42 3.3 1.9 1.2 11 6 2.1 .85 .51 e11 7 11 .82 .49 e4.3 8 10 .76 .45 e2.5 e22 .98 .60 .58 2.7 2.5 4.9 11 e2.9 1.0 1.1 .65 2.3 3.0 11 55 e37 1.0 1.2 40 2.5 3.0 2.5 29 9 4.3 .78 .48 e2.0 e30 1.0 .74 14 2.5 2.1 2.0 11 10 1.3 5.5 .47 e3.0 e2.9 .84 .68 3.1 2.5 1.7 1.8 6.4 11 2.7 .97 .47 e1.2 12 3.3 .85 .50 e1.4 13 4.1 .78 e.46 e2.5 14 98 .77 e.48 e2.9 15 51 .75 e.45 e1.1 e1.2 .70 .89 1.5 2.2 1.7 1.6 8.4 e.82 .58 128 .62 7.4 1.7 2.0 5.2 e.60 .55 34 10 3.7 1.7 1.5 5.4 e.69 .60 6.1 219 2.0 1.8 1.2 10 e1.1 .68 2.3 110 1.5 1.9 1.2 7.9 16 28 .75 e.48 e.85 17 60 .77 e.46 e.70 18 30 .76 e.47 e.63 19 9.7 .76 e.48 e.57 20 4.1 .78 e.61 e.56 e.79 .68 1.7 21 1.5 1.5 1.7 4.7 e.70 .60 1.0 10 1.9 1.4 1.8 3.6 e.71 .71 1.4 56 1.7 1.5 1.6 4.5 e.67 .79 2.3 31 1.5 1.4 1.5 4.3 e.66 .74 1.7 23 1.3 1.8 1.2 5.8 21 2.2 .77 e.58 e.51 22 1.4 .71 e.49 e.48 23 1.3 .74 e.48 e.46 24 1.2 1.1 e.48 e.43 25 1.5 .62 e.45 e.42 e.65 .70 2.4 99 1.3 1.9 5.9 e575 e.65 .60 4.0 53 2.2 1.8 16 e1130 e.81 .70 6.1 18 1.0 1.4 11 e158 e.58 .61 1.9 12 1.4 1.4 50 e71 e.56 .65 1.3 10 1.0 1.2 124 e48 26 1.2 .65 e.55 e.41 e.67 .49 1.1 9.2 .91 1.3 10 e37 27 .85 .66 e.45 e.44 e.60 .70 .86 9.2 .85 1.8 3.1 e31 28 .87 .61 e.44 .41 e.67 .63 .64 6.5 .96 1.4 1.9 e28 29 .84 .61 e.46 .56 --- 5.5 .56 5.4 1.1 1.1 1.6 e48 30 .83 .57 e.45 .44 --- 2.0 .62 4.7 1.2 1.5 1.2 e33 31 .85 --- e.44 .33 --- 1.2 --- 4.6 --- 1.2 1.4 --­ TOTAL 343.84 27.93 16.32 42.90 MEAN 11.1 .93 .53 1.38 MAX 98 5.5 1.2 11 MIN .83 .57 .44 .33 AC-FT 682 55 32 85 CFSM 2.21 .19 .10 .28 IN. 2.54 .21 .12 .32 293.96 28.29 206.97 775.06 67.22 52.3 269.2 2489.7 10.5 .91 6.90 25.0 2.24 1.69 8.68 83.0 162 5.5 128 219 7.4 3.0 124 1130 .33 .49 .56 .42 .85 1.1 1.0 1.5 583 56 411 1540 133 104 534 4940 2.09 .18 1.37 4.97 .45 .34 1.73 16.5 2.17 .21 1.53 5.73 .50 .39 1.99 18.41 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 1998, BY WATER YEAR (WY) MEAN 15.8 6.37 4.74 6.08 MAX 58.0 15.2 15.8 34.3 (WY) 1990 1991 1982 1992 MIN 1.95 .93 .53 .77 (WY) 1994 1998 1998 1995 4.15 1.73 5.38 14.9 4.20 3.40 4.08 24.8 15.7 3.07 21.0 45.9 15.2 9.07 12.3 83.0 1996 1996 1993 1995 1992 1996 1989 1998 .96 .90 .93 .86 .88 .88 1.03 .88 1995 1994 1995 1997 1994 1994 1982 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1981 - 1998 ANNUAL TOTAL 1043.62 ANNUAL MEAN 2.86 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 98 LOWEST DAILY MEAN .23 ANNUAL SEVEN-DAY MINIMUM .40 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 2070 ANNUAL RUNOFF (CFSM) .57 ANNUAL RUNOFF (INCHES) 7.72 10 PERCENT EXCEEDS 3.8 50 PERCENT EXCEEDS 1.1 90 PERCENT EXCEEDS .48 4613.69 12.6 7.89 12.6 1998 1.49 1994 Oct 14 1130 Sep 22 1570 Sep 10 1996 Jul 10 .33 Jan 31 .20 Oct 4 1992 Jun 16 .40 Jan 28 .33 Oct 11 1992 6930 Sep 21 8890 Sep 10 1996 16.06 Sep 21 17.38 Sep 10 1996 9150 5710 2.51 1.57 34.12 21.30 22 12 1.2 1.9 .49 .78 e Estimated 107 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR--Continued O N D J F M A M J J A S 0.1 10,000 0.2 0.5 1 2 5 10 20 50 100 200 500 1,000 2,000 5,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 108 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'20", long 66°22'58", at flat low bridge about 300 ft (91 m) northwest of Highway 568, 1.0 mi (1.6 km) north of Orocovis plaza. DRAINAGE AREA.--10.1 mi2 (26.2 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 15... 1430 44 225 7.4 23.5 27 7.6 95 <10 6000 33000 FEB 19... 0930 5.9 356 7.9 20.5 1.6 8.1 94 <10 320 K170 JUN 16... 1030 8.0 313 8.1 26.0 4.0 7.4 97 <10 290 360 SEP 01... 0815 5.8 333 7.9 24.5 1.1 7.5 95 <10 K620 400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 15... 82 19 8.3 10 .5 1.9 66 <.5 13 17 FEB 19... -- -- -- -- -- -- 140 -- -- -­ JUN 16... 130 31 12 13 .5 2.2 130 -- 8.3 15 SEP 01... 140 35 12 14 .5 8.3 140 <1.0 8.4 17 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 15... .10 26 134 16.0 31 .650 .110 .750 .260 .34 FEB 19... -- -- -- -- <1 .680 .050 .730 .110 -­ JUN 16... <.10 33 193 4.18 2 -- <.010 .920 .020 -­ SEP 01... .11 33 213 3.32 3 -- <.010 .750 .020 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 15... .59 1.3 6.0 .230 <1 <100 20 <1 3 <10 FEB 19... <.20 -- -- .110 -- -- -- -- -- -­ JUN 16... <.20 -- -- .120 <1 <100 20 <1 <1 <10 SEP 01... <.20 -- -- .120 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 109 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 15... 1500 <1 73 <.10 <1 <1 10 <.010 <1 <.02 FEB 19... JUN 16... 210 <1 18 <.10 <1 <1 <10 <.010 <1 <.02 SEP 01... --- --- --- --- --- --- --- 110 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR LOCATION.--Lat 18°17'45", long 66°24'47", Hydrologic Unit 21010001, on right bank , 0.1 mi (0.2 km) downstream from Quebrada Perchas, 0.8 mi (1.3 km) upstream from Río Sana Muerto, and 2.2 mi (3.5 km) south of Morovis. DRAINAGE AREA.--55.2 mi2 (143.0 km2). PERIOD OF RECORD.--January 1965 to current year. GAGE.--Water-stage recorder and concrete control. Elevation of gage is 440 ft (134 m), from topographic map. Feb. 2, 1966 to Apr. 27, 1967, staff gage read twice daily. REMARKS.--Records poor. Public water-supply pumpage, about 300 ft (91 m) above the station, influences low-flow discharges. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10 e16 13 9.4 6.1 12 e37 e17 48 24 16 e17 2 10 e15 14 10 6.2 11 22 e16 44 25 16 e77 3 31 e15 14 11 8.6 12 e17 e16 96 58 16 e89 4 13 e15 13 9.7 41 12 e13 e17 63 46 16 e73 5 10 e15 13 11 633 11 13 e16 51 31 16 e43 6 8.9 e16 13 38 131 12 12 e22 41 32 18 e38 7 86 e15 13 e39 54 12 11 e14 37 34 33 e55 8 129 e14 11 e15 105 13 16 e21 36 25 e25 e51 9 138 e14 10 e12 264 11 12 e27 35 25 e21 e34 10 47 e20 11 e10 93 11 9.8 e20 37 25 e18 e29 11 25 44 11 e15 52 10 9.2 33 30 26 e19 33 12 47 35 10 e35 36 9.6 157 23 28 22 e18 56 13 69 19 10 e15 28 9.8 166 20 43 22 e17 39 14 235 16 10 e28 22 9.4 76 1070 33 20 e16 40 15 e160 15 9.8 e25 27 9.8 37 780 27 23 e16 37 16 e130 15 9.8 e15 21 10 81 170 27 20 e17 26 17 e160 17 9.6 e10 17 e7.4 40 122 53 20 e17 22 18 e220 16 10 e9.0 18 e6.9 44 79 e58 21 e19 24 19 e110 16 13 e23 15 e8.4 e154 183 e39 21 e18 32 20 e70 15 10 e22 15 9.4 76 220 34 21 e20 28 21 e45 14 9.7 e15 15 20 56 254 33 48 e24 1530 22 e35 13 9.7 e17 14 14 36 224 45 23 e25 7010 23 e30 13 9.8 e13 13 11 35 132 37 19 e22 540 24 e25 14 10 e10 12 11 38 99 37 20 e89 254 25 e23 14 10 e9.0 11 8.1 25 77 35 19 e27 216 26 e21 13 9.5 e8.0 14 8.5 29 68 31 18 e21 184 27 e20 14 9.7 e7.0 14 7.8 34 84 29 57 e21 175 28 e18 13 9.2 6.6 14 9.2 e28 67 27 27 e19 179 29 e18 12 8.7 6.3 10 e21 55 26 20 28 436 30 e16 13 8.7 6.2 e120 e18 58 25 19 23 302 31 e16 8.8 6.9 e150 73 19 19 TOTAL 1975.9 496 332.0 467.1 1699.9 577.3 1323.0 4077 1185 830 690 11669 MEAN 63.7 16.5 10.7 15.1 60.7 18.6 44.1 132 39.5 26.8 22.3 389 MAX 235 44 14 39 633 150 166 1070 96 58 89 7010 MIN 8.9 12 8.7 6.2 6.1 6.9 9.2 14 25 18 16 17 AC-FT 3920 984 659 926 3370 1150 2620 8090 2350 1650 1370 23150 CFSM 1.15 .30 .19 .27 1.10 .34 .80 2.38 .72 .49 .40 7.05 IN. 1.33 .33 .22 .31 1.15 .39 .89 2.75 .80 .56 .46 7.86 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1965 - 1998, BY WATER YEAR (WY) MEAN 149 139 105 80.1 63.4 63.1 105 157 59.6 44.7 52.9 109 MAX 1037 491 522 228 179 226 412 915 173 157 435 432 (WY) 1971 1971 1966 1997 1969 1972 1969 1985 1987 1979 1979 1996 MIN 24.0 11.4 8.65 10.4 15.3 12.7 8.80 15.7 6.75 5.54 9.70 6.87 (WY) 1978 1995 1995 1995 1994 1984 1995 1994 1994 1994 1984 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1965 - 1998 ANNUAL TOTAL 18105.5 25322.2 ANNUAL MEAN 49.6 69.4 93.8 HIGHEST ANNUAL MEAN 248 1971 LOWEST ANNUAL MEAN 24.2 1994 HIGHEST DAILY MEAN 2100 Jan 22 7010 Sep 22 17100 May 18 1985 LOWEST DAILY MEAN 7.2 Sep 18 6.1 Feb 1 3.5 May 1 1995 ANNUAL SEVEN-DAY MINIMUM 7.7 Sep 15 6.5 Jan 27 4.0 Jul 22 1994 INSTANTANEOUS PEAK FLOW 32700 Sep 21 48000 May 18 1985 INSTANTANEOUS PEAK STAGE 15.65 Sep 21 17.89 May 18 1985 ANNUAL RUNOFF (AC-FT) 35910 50230 67960 ANNUAL RUNOFF (CFSM) .90 1.26 1.70 ANNUAL RUNOFF (INCHES) 12.20 17.06 23.09 10 PERCENT EXCEEDS 88 101 169 50 PERCENT EXCEEDS 23 20 47 90 PERCENT EXCEEDS 9.7 9.8 20 e Estimated 111 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 112 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 15... 1030 149 240 8.0 25.0 58 8.5 105 <10 6000 5500 FEB 19... 1115 14 321 7.9 24.5 3.8 7.9 97 <10 K130 K72 JUN 16... 1330 27 284 8.4 31.0 .45 8.7 120 <10 <10 <10 SEP 01... 1010 18 290 7.8 28.5 1.3 7.9 104 <10 K27 K100 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 15... 88 22 8.4 11 .5 2.9 66 <.5 14 19 FEB 19... -- -- -- -- -- -- 120 -- -- -­ JUN 16... 110 27 12 13 .5 2.9 110 -- 8.6 16 SEP 01... 120 28 11 14 .5 2.6 110 <1.0 10 17 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 15... .12 24 141 56.7 58 .390 .060 .460 .170 .20 FEB 19... -- -- -- -- <1 -- <.010 .580 <.010 -­ JUN 16... .13 17 162 11.7 <1 -- <.010 .220 .020 -­ SEP 01... .13 26 175 8.31 2 -- <.010 .510 .030 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 15... .37 .83 3.7 .060 <1 <100 20 <1 5 <10 FEB 19... <.20 -- -- .040 -- -- -- -- -- -­ JUN 16... <.20 -- -- .020 <1 <100 20 <1 <1 <10 SEP 01... <.20 -- -- .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 113 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 15... 2300 <1 110 <.10 <1 <1 10 <.010 <1 <.02 FEB 19... JUN 16... 70 <1 17 <.10 <1 <1 <10 <.010 <1 <.02 SEP 01... 114 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR LOCATION.--Lat 18°09'41", long 66°31'36", Hydrologic Unit 21010001, at damsite on Río Toro Negro, 3.0 mi (4.8 km) northwest from Villalba plaza and 1.9 mi (3.1 km) northeast of Cerro Maravillas. The reservoir itself fixes the territorial limits between the Municipality of Ciales and Orocovis. DRAINAGE AREA.--1.64 mi2 (4.25 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago El Guineo at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago El Guineo was completed in 1931. It provides a maximum storage of approximately 2,180 ac-ft (2.688 hm3) for power and irrigation. Waters are discharged through an outlet power tunnel into the Río Toro Negro and coveyed to the head water works of Toro Negro Hydroelectric Plant No.2, for energy generation at Toro Negro Hydroelectric plant No.1, and are discharged into the Guayabal Reservoir to be later used for irrigation at South Coast Irrigation System. The dam is rockfill with a vertical concrete corewall, rock toes, and riprap facing of upstream slope, with a total length of 565 ft (172 m), a maximum structural height of 125 ft (38 m) to top of corewall. At a maximum reservoir water surface elevation the uncontrolled morning-glory tunnel spillway crest has an elevation of 2,960 ft (902 m) above mean sea level and a design capacity of 7,000 ft3/s. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,964.40 ft (903.55 m), Sept. 22, 1998; minimun elevation, 2,919.79 ft (899.95 m), May 27, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,964.40 ft (903.55 m), Sept. 22; minimun elevation, 2,939.48 ft (895.95 m), Oct. 1. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,872 0 2,919 361 2,925 491 2,943 1,029 2,950 1,308 2,961 1,852 2,966 2,180 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2939.70 2949.92 2953.22 2952.61 2952.64 2955.12 2959.46 2960.68 2960.71 2960.66 2960.64 A 2 2939.85 2950.07 2953.32 2952.66 2952.69 2955.19 2959.58 2960.68 2960.71 2960.70 2960.71 A 3 2939.98 2950.22 2953.27 2952.71 2952.55 2955.36 A 2960.68 2960.71 2960.71 2960.54 A 4 2940.07 2950.15 2953.23 2952.77 2952.97 2955.43 2959.80 2960.68 2960.74 2960.71 2960.35 2959.60 5 2940.11 2950.08 2953.32 2952.81 2953.66 2955.49 2959.97 2960.68 2960.81 2960.69 2960.16 2959.39 6 2940.18 2949.48 2953.39 2952.86 2953.18 2955.56 2960.06 2960.70 2960.72 2960.74 A 2959.91 7 2941.08 2949.41 2953.47 2952.95 2953.29 2955.71 A 2960.70 2960.70 2960.69 2960.70 2960.51 8 2941.33 2949.54 2953.55 2952.89 2953.95 2955.79 A 2960.79 2960.71 2960.69 2960.78 2959.77 9 2941.52 2950.20 2953.53 2952.75 2953.67 2955.84 2960.71 2960.70 2960.71 2960.49 2960.74 2958.42 10 2941.69 2950.49 2953.60 2952.79 2953.48 2955.89 2960.70 2960.69 2960.58 2960.41 2960.63 2957.06 11 2941.87 2950.65 2953.58 2952.94 2953.60 2955.94 2960.82 2960.69 2960.40 2960.49 2960.67 2955.84 12 2942.25 2950.79 2953.64 2953.02 2953.69 2956.00 2960.80 2960.70 2960.36 2960.56 2960.63 2955.36 13 2944.01 2950.91 2953.71 2952.67 2953.76 2956.04 2960.72 2960.77 2960.52 2960.54 2960.56 2955.32 14 2946.56 2950.83 2953.79 2952.71 2953.97 2956.46 2960.71 2960.96 2960.66 2960.91 2960.59 2954.13 15 2947.48 2951.74 2953.82 2952.64 2954.08 2957.01 2960.70 2960.76 2960.50 2960.68 2960.69 2953.87 16 2947.30 2951.93 2953.45 2952.68 2954.18 2957.16 2960.70 2960.72 2960.40 2960.83 2960.72 2953.99 17 2953.36 2952.08 2952.86 2952.72 2954.26 2957.24 2960.69 2960.71 2960.67 2960.82 2960.64 2953.87 18 2954.38 2952.03 2952.50 2953.03 2954.33 2957.30 2960.73 2960.71 A 2960.81 2960.57 2952.98 19 2954.94 2952.16 2952.26 2953.18 2954.39 2957.37 2960.70 2960.70 2960.50 2960.79 2960.43 2951.64 20 2954.37 2952.10 2952.05 2953.25 2954.47 2957.56 2960.84 2960.85 2960.69 2960.77 2960.28 2951.07 21 2953.74 2952.22 2952.15 2953.31 2954.54 2957.68 2960.71 2960.78 2960.73 2960.72 2960.37 2962.62 22 2953.05 2952.34 2952.21 2952.63 2954.61 2957.81 2960.69 2960.72 2960.55 2960.72 2960.75 A 23 2952.25 2952.45 2952.28 2952.67 2954.65 2957.92 2960.75 2960.71 2960.61 2960.55 2960.70 A 24 2951.45 2952.55 2952.25 2952.74 2954.78 2958.00 2960.83 2960.71 2960.69 2960.49 A A 25 2951.68 2952.50 2952.31 2952.79 2954.87 2958.16 2960.72 2960.71 2960.69 2960.61 A A 26 2951.88 2952.64 2952.37 2952.69 2954.93 2958.26 2960.70 2960.72 2960.69 2960.68 A 2962.30 27 2951.37 2952.74 2952.44 2952.53 2954.99 2958.40 2960.70 2960.71 2960.69 2960.69 A A 28 2950.50 2952.84 2952.50 2952.57 2955.05 2958.49 2960.70 2960.71 2960.69 2960.69 A 2958.28 29 2949.60 2953.01 2952.55 2952.61 --- 2958.68 2960.68 2960.70 2960.69 2960.59 A 2957.08 30 2949.61 2953.12 2952.55 2952.57 --- 2959.12 2960.68 2960.72 2960.67 2960.48 A 2955.78 31 2949.76 --- 2952.56 2952.60 --- 2959.32 --- 2960.70 --- 2960.45 A --­ MAX 2954.94 2953.12 2953.82 2953.31 2955.05 2959.32 --- 2960.96 --- 2960.91 --- --­ MIN 2939.70 2949.41 2952.05 2952.53 2952.55 2955.12 --- 2960.68 --- 2960.41 --- --­ A No gage-height record 115 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR LOCATION.--Lat 18°12'46", long 66°28'50", Hydrologic Unit 21010001, in shelter house at damsite, and 5.8 mi (9.3 km) southwest of Orocovis. DRAINAGE AREA.--4.46 mi2 (11.55 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago de Matrullas at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Matrullas was completed in 1934. The dam is an earthfill structure about 120 ft (37 m) height, a top width of 30 ft (9 m) and a length of 710 ft (216 m), and has a maximum storage capacity of about 4,274 ac-ft (5.220 hm3) at top of dam elevation. The Matrullas Dam is owned by the Puerto Rico Electric Power Authority and is part of the Toro Negro Hydroelectric Project; a project developed by the P.R.E.P.A. for the primary purpose of generating electric power. Discharges from the Power Plants are collected by the Jacaguas River which flows into Guayabal Dam, at which dam they are regulated for irrigation of lands served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,419.90 ft (737.58 m), Sept. 10, 1996; minimum elevation, 2,375.55 ft (724.06 m), Sept. 24, 25, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation,2,419.60 ft (737.49 m), Sept. 22; minimum elevation,2,409.24 ft (734.34 m), Oct.1. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 2,338 2 2,399 1,845 2,360 302 2,420 3,331 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2409.64 2414.70 2413.64 2413.28 2413.34 2413.85 2410.38 2414.72 2415.25 2414.93 2415.16 2413.93 2 2409.90 2414.84 2413.53 2413.35 2413.40 2413.64 2410.50 2414.89 2415.25 2414.82 2415.25 2415.40 3 2410.03 2414.73 2413.34 2413.41 2413.16 2413.46 A 2415.06 2415.20 2414.63 2415.17 2415.28 4 2410.14 2414.59 2413.14 2413.48 2414.16 2413.24 2410.51 2414.92 2415.37 2414.84 2415.05 2415.28 5 2410.25 2414.47 2412.94 2413.55 2415.26 2413.02 2410.66 2414.79 2415.44 2415.02 2414.89 2415.27 6 2410.34 2414.26 2413.02 2413.61 2415.10 2412.83 2410.44 2414.73 2415.33 2415.01 A 2415.45 7 2410.40 2414.10 2413.11 2413.68 2415.22 2413.10 2412.48 2414.64 2415.32 2415.19 2415.33 2415.38 8 2410.64 2414.23 2412.89 2413.46 2415.50 2413.22 2412.56 2414.99 2415.23 2415.26 2415.34 2415.08 9 2410.69 2414.44 2412.67 2413.30 2415.19 2413.00 2412.78 2415.22 2415.20 2415.09 2415.33 2414.69 10 2410.70 2414.42 2412.45 2413.37 2415.05 2412.77 2412.95 2415.27 2415.17 2415.00 2415.17 2414.25 11 2410.89 2414.57 2412.30 2413.43 2414.91 2412.52 2413.28 2415.17 2415.16 2415.15 2415.29 2414.05 12 2411.11 2414.41 2412.11 2413.51 2414.67 2412.30 2414.44 2415.19 2415.27 2415.25 2415.23 2413.85 13 2412.30 2414.24 2412.20 2413.44 2414.49 2412.06 2414.62 2415.10 2415.31 2415.08 2415.14 2413.94 14 2414.33 2414.05 2412.29 2413.23 2414.67 2412.15 2414.61 2413.56 2415.30 2415.15 2415.05 2413.79 15 2414.90 2414.19 2412.07 2412.99 2414.80 2412.25 2414.53 2413.94 2415.18 2415.13 2415.18 2413.67 16 2415.10 2414.31 2412.07 2412.76 2414.91 2412.01 2414.56 2414.27 2415.16 2415.03 2415.26 2413.77 17 2415.51 2414.13 2412.17 2412.83 2414.78 2411.78 2414.76 2414.12 2415.23 2414.91 2415.12 2413.85 18 A 2413.96 2412.31 2413.33 2414.58 2411.53 2415.19 2413.88 A 2415.08 2415.33 2414.88 19 A 2414.06 2412.41 2413.47 2414.42 2411.29 2415.32 2414.46 2415.11 2415.22 2415.14 2414.56 20 2415.16 2413.87 2412.49 2413.56 2414.22 2411.09 2415.36 2414.36 2415.27 2415.27 2415.09 2414.38 21 2415.06 2413.79 2412.57 2413.64 2414.30 2411.18 2415.19 2414.03 2415.30 2415.08 2415.28 2418.56 22 2415.01 2413.89 2412.67 2413.33 2414.39 2411.28 2415.15 2414.89 2415.16 2414.99 2415.40 2416.21 23 2414.96 2414.00 2412.65 2413.40 2414.17 2411.36 2415.10 2415.08 2415.28 2414.87 2415.31 2415.76 24 2414.85 2413.79 2412.72 2413.47 2413.95 2411.11 2415.04 2415.36 2415.28 2415.03 A 2415.64 25 2415.05 2413.60 2412.79 2413.54 2413.77 2410.88 2415.22 2415.36 2415.28 2415.16 2415.28 2415.56 26 2415.21 2413.41 2412.87 2413.30 2413.60 2410.63 2415.25 2415.34 2415.13 2415.25 2415.13 2415.52 27 2415.06 2413.50 2412.94 2413.06 2413.68 2410.41 2415.09 2415.31 2415.26 2415.26 2414.94 2415.49 28 2414.91 2413.59 2413.02 2413.11 2413.76 2410.50 2414.98 2415.30 2415.27 2415.25 2414.73 2415.58 29 2414.76 2413.71 2413.09 2413.17 --- 2410.65 2414.84 2415.28 2415.12 2415.25 2414.57 2415.46 30 2414.65 2413.82 2413.15 2413.23 --- 2410.75 2414.83 2415.34 2415.03 2415.25 2414.43 2415.44 31 2414.54 --- 2413.21 2413.28 --- 2410.59 --- 2415.32 --- 2415.04 2414.20 --­ MAX --- 2414.84 2413.64 2413.68 2415.50 2413.85 --- 2415.36 --- 2415.27 --- 2418.56 MIN --- 2413.41 2412.07 2412.76 2413.16 2410.41 --- 2413.56 --- 2414.63 --- 2413.67 A No gage-height record --- --- --- --- --- --- --- 116 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR LOCATION.--Lat 18°14'10", long 66°27'18", Hydrologic Unit 21010001, on left bank, at bridge on Highway 157 (12.1 km), and 4.2 mi (6.8 km) west of Orocovis. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--February 1959 to April 1966 (annual low-flow measurements only), February to September 1969 (occasional measurements only), October 1969 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 772.82 ft (235.556 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 46 12 7.6 6.2 5.9 8.3 15 10 23 14 9.5 19 2 35 12 8.5 6.3 5.9 7.9 21 9.1 23 14 8.5 189 3 25 11 8.4 6.1 5.9 8.2 37 8.7 23 15 8.6 195 4 22 11 7.6 6.2 62 8.7 16 8.3 28 16 7.9 213 5 20 12 7.6 6.8 403 8.2 12 7.9 68 16 7.9 75 6 19 11 7.6 6.5 73 8.0 11 8.3 38 16 8.2 80 7 67 10 7.2 6.6 33 8.7 79 12 27 16 31 102 8 107 10 7.2 6.7 174 8.6 74 106 23 15 20 72 9 74 10 7.2 6.1 174 7.4 31 70 22 14 20 47 10 36 21 7.2 5.9 50 6.8 20 26 21 14 17 37 11 53 13 7.1 5.9 31 6.5 15 16 20 14 13 38 12 91 12 7.3 5.9 24 6.5 392 11 25 13 15 38 13 94 11 7.2 8.5 18 6.5 147 54 24 12 11 46 14 517 10 7.2 13 16 6.2 53 351 20 14 9.0 58 15 268 10 7.2 7.2 17 6.2 32 339 19 17 7.9 60 16 133 9.6 7.1 6.5 13 5.9 31 109 18 15 10 43 17 118 9.6 8.2 6.2 12 5.6 30 62 23 13 13 36 18 145 9.4 7.7 46 11 5.6 98 218 21 12 17 195 19 58 9.1 7.4 33 9.9 5.5 97 215 18 12 17 114 20 35 8.7 6.7 9.7 9.1 5.8 38 184 17 12 22 55 21 26 8.7 6.5 8.7 9.0 7.9 41 434 17 14 36 e1820 22 21 8.7 11 7.7 8.3 6.2 34 191 19 11 99 e10000 23 19 8.7 11 6.7 7.7 6.4 41 73 17 11 90 e1400 24 17 8.3 7.4 6.5 7.3 5.9 32 50 17 11 156 e290 25 16 8.3 6.6 6.5 7.7 5.8 24 41 17 11 386 e200 26 15 8.3 6.5 6.5 13 6.1 20 36 17 9.5 70 e150 27 14 8.1 6.1 6.4 9.6 5.6 17 34 16 14 43 e120 28 14 7.9 6.2 6.2 8.7 5.6 14 30 15 11 34 e100 29 13 8.1 6.5 6.2 14 12 28 15 11 27 e240 30 13 8.5 6.4 6.2 48 10 27 15 10 23 e280 31 12 6.1 6.1 30 25 9.9 20 TOTAL 2143 306.0 229.5 279.0 1219.0 282.6 1494 2794.3 666 407.4 1257.5 16312 MEAN 69.1 10.2 7.40 9.00 43.5 9.12 49.8 90.1 22.2 13.1 40.6 544 MAX 517 21 11 46 403 48 392 434 68 17 386 10000 MIN 12 7.9 6.1 5.9 5.9 5.5 10 7.9 15 9.5 7.9 19 AC-FT 4250 607 455 553 2420 561 2960 5540 1320 808 2490 32350 CFSM 4.14 .61 .44 .54 2.61 .55 2.98 5.40 1.33 .79 2.43 32.6 IN. 4.77 .68 .51 .62 2.72 .63 3.33 6.22 1.48 .91 2.80 36.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 1998, BY WATER YEAR (WY) MEAN 83.8 50.7 27.0 20.7 16.3 14.8 27.2 50.6 18.8 15.9 21.0 120 MAX 392 205 108 83.4 43.5 59.9 80.2 179 78.6 104 152 1104 (WY) 1971 1971 1971 1992 1998 1972 1980 1981 1979 1979 1979 1996 MIN 14.6 7.12 4.29 3.66 5.70 4.18 4.92 4.24 3.59 3.22 3.97 3.55 (WY) 1994 1995 1995 1995 1994 1994 1995 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1969 - 1998 ANNUAL TOTAL 7009.4 27390.3 ANNUAL MEAN 19.2 75.0 38.9 HIGHEST ANNUAL MEAN 117 1996 LOWEST ANNUAL MEAN 6.56 1994 HIGHEST DAILY MEAN 517 Oct 14 10000 Sep 22 19500 Sep 10 1996 LOWEST DAILY MEAN 3.6 Jul 18 5.5 Mar 19 2.8 Jul 23 1994 ANNUAL SEVEN-DAY MINIMUM 4.2 Jul 22 5.8 Mar 14 2.8 Jul 23 1994 INSTANTANEOUS PEAK FLOW 28200 Sep 22 28200 Sep 22 1998 INSTANTANEOUS PEAK STAGE 25.93 Sep 22 25.93 Sep 22 1998 INSTANTANEOUS LOW FLOW 5.0 Mar 19 2.6 Jul 26 1994 ANNUAL RUNOFF (AC-FT) 13900 54330 28190 ANNUAL RUNOFF (CFSM) 1.15 4.49 2.33 ANNUAL RUNOFF (INCHES) 15.61 61.01 31.66 10 PERCENT EXCEEDS 32 104 64 50 PERCENT EXCEEDS 9.5 14 13 90 PERCENT EXCEEDS 5.3 6.5 5.4 e Estimated 117 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR--Continued O N D J F M A M J J A S 1 100,000 2 5 10 20 50 100 200 500 1,000 2,000 5,000 10,000 20,000 50,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR --- --- --- --- --- --- --- 118 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR LOCATION.--Lat 18°19'26", long 66°27'36", Hydrologic Unit 21010001, on left bank, 1.6 mi (2.6 km) upstream from Hwy 145 bridge, 0.8 mi (1.3 km) downstream from Quebrada Saliente, 0.9 mi (1.4 km) upstream from Quebrada Cojo Valés, and 1.2 mi (1.9 km) southeast of Ciales. DRAINAGE AREA.--128 mi2 (332 km2), excludes 6.0 mi2 (15.5 km2), the runoff from which is diverted through El Guineo and Matrullas reservoirs. PERIOD OF RECORD.--September 1946 to September 1953, May 1956 to December 1957 (unpublished, available in files of Caribbean District Office and in the National Water Data Storage and Retrieval System, Washington, D.C.); February 1959 to September 1960 (monthly discharge measurements only); October 1960 to current year. Equivalent record from January 1971 to December 1972 published as 50035200 Río Grande de Manatí at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 mi2 (342 km2). GAGE.--Water-stage recorder. Elevation of gage is 140 ft (43 m), from topographic map. Prior to Apr. 1, 1962, staff gage, read twice daily, at site 100 ft (30 m) upstream at same datum. January 1971 to December 1972 at site 1.6 mi (2.6 km) downstream at different datum. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights of major floods, pointed out by local residents are as follows: August 1899, 50 ft (15 m), September 1928, 36 ft (11 m), and September 1932, 34 ft (10 m) at site 1.6 mi (2.6 km) upstream. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 68 48 51 e31 e25 e45 e130 e71 127 56 e52 60 2 173 49 47 e34 e25 e43 e86 e63 161 57 e40 543 3 99 46 53 e36 e28 e44 e72 e60 174 105 e38 635 4 63 49 47 e39 e56 e45 e72 e56 163 e100 e36 505 5 47 50 44 e37 e1060 e43 e58 e55 293 e71 e37 269 6 41 50 42 e59 e291 e43 e50 57 267 e67 e58 231 7 169 45 41 e182 e146 e46 e48 58 153 e77 e245 361 8 440 43 37 e84 e190 e51 e410 68 138 e64 298 332 9 442 44 32 e57 e498 e44 e130 77 123 e61 249 194 10 150 121 e34 e46 e191 e42 e82 66 119 e67 166 158 11 95 149 e36 e235 e118 e41 e68 63 115 e65 90 115 12 330 137 e37 e94 e87 e40 e300 63 96 e61 117 186 13 308 75 e37 e89 e75 e41 e460 62 138 e52 79 132 14 1180 58 e37 e324 e63 e41 e200 e205 115 e54 55 137 15 581 55 e35 e117 e73 e42 e135 e1510 103 e58 54 139 16 479 68 e34 e63 e62 e42 e140 e321 94 e60 52 95 17 669 60 e34 e47 e55 e38 e540 e258 152 e55 64 112 18 808 61 e34 e49 e56 e37 e220 e254 213 e56 64 282 19 324 55 e38 e268 e49 e37 e367 e411 127 e58 104 336 20 204 53 e39 e93 e51 e39 e320 e549 103 e54 82 182 21 136 53 e35 e57 e49 e64 e332 e556 118 e86 135 e3290 22 101 51 e40 e95 e46 e50 e279 e804 160 63 231 e10100 23 85 49 e44 e48 e46 e43 e233 e454 103 49 259 e1090 24 74 49 e38 e35 e44 e43 e203 e311 99 52 174 e593 25 67 49 e33 e33 e43 e39 e168 e236 106 51 1710 e492 26 65 55 e31 e35 e48 e37 e142 e188 85 46 299 e451 27 58 53 e32 e31 e49 e38 e127 200 65 109 155 e426 28 54 47 e31 e28 e49 e38 e103 157 63 74 156 e446 29 52 45 e32 e26 e40 e87 138 65 56 103 e861 30 51 61 e32 e25 e120 e80 154 60 53 79 e688 31 51 e33 e25 e350 174 e66 84 TOTAL 7464 1828 1170 2422 3573 1706 5642 7699 3898 2003 5365 23441 MEAN 241 60.9 37.7 78.1 128 55.0 188 248 130 64.6 173 781 MAX 1180 149 53 324 1060 350 540 1510 293 109 1710 10100 MIN 41 43 31 25 25 37 48 55 60 46 36 60 AC-FT 14800 3630 2320 4800 7090 3380 11190 15270 7730 3970 10640 46500 CFSM 1.88 .48 .29 .61 1.00 .43 1.47 1.94 1.02 .50 1.35 6.10 IN. 2.17 .53 .34 .70 1.04 .50 1.64 2.24 1.13 .58 1.56 6.81 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1946 - 1998, BY WATER YEAR (WY) MEAN 421 335 252 192 167 135 254 411 151 104 149 309 MAX 2422 1006 1296 679 1394 477 1174 2293 458 438 1212 1295 (WY) 1971 1971 1966 1952 1950 1969 1969 1985 1979 1979 1979 1996 MIN 91.9 34.7 29.7 26.2 41.6 29.7 28.5 29.6 17.8 14.1 27.0 23.9 (WY) 1994 1995 1995 1995 1957 1994 1984 1994 1994 1994 1994 1994 119 RIO GRANDE DE MANATI BASIN DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 50035000 RIO GRANDE DE MANATI AT CIALES, PR--Continued SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1946 - 1998 ANNUAL TOTAL 47478 ANNUAL MEAN 130 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 4200 LOWEST DAILY MEAN 22 ANNUAL SEVEN-DAY MINIMUM 28 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 94170 ANNUAL RUNOFF (CFSM) 1.02 ANNUAL RUNOFF (INCHES) 13.80 10 PERCENT EXCEEDS 206 50 PERCENT EXCEEDS 61 90 PERCENT EXCEEDS 35 66211 181 241 520 1971 47.3 1994 Jan 22 10100 Sep 22 42700 May 18 1985 Aug 7 25 Jan 30 8.5 Jul 28 1994 Jul 24 26 Jan 28 9.5 Jul 24 1994 78900 Sep 21 128000 Sep 10 1996 22.38 Sep 21 25.20 Sep 10 1996 21 Feb 4 8.5 Jul 27 1994 131300 174600 1.42 1.88 19.24 25.58 334 435 66 112 37 50 e Estimated 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR -- 120 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'46", long 66°28'06", at bridge on Highway 149, about 800 ft (244 m) upstream from confluence with Río Cialitos, 0.5 mi (0.8 km) north of Ciales plaza. DRAINAGE AREA.--136 mi2 (352 km2) this excludes the 6 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas, flow from which is diverted to Río Jacaguas. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP- HARD­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI NESS CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, TOTAL FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER AS SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) (00900) NOV 04... 0935 69 247 8.0 26.0 1.9 7.3 89 <10 210 K73 81 MAR 05... 1220 52 262 8.2 27.5 2.1 8.5 107 <10 200 K70 MAY 28... 1250 192 228 8.3 27.5 1.3 8.1 98 <10 240 K50 86 AUG 19... 1315 159 216 7.8 28.0 11 7.8 100 <10 K1300 410 85 ANC SOLIDS, MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI­ DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS­ DATE (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) NOV 04... 19 7.9 35 2 3.7 93 <.5 15 33 <.10 28 190 MAR 05... -- -- -- -- -- 100 -- -- -- -- -- -­ MAY 28... 22 7.5 11 .5 2.2 89 -- 8.4 12 <.10 24 140 AUG 19... 22 7.1 10 .5 1.9 69 <1.0 8.1 11 <.10 23 124 RESIDUE NITRO­ SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + PHOS- TOTAL TOTAL WATER SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC PHORUS ARSENIC RECOV- RECOV- UNFLTRD (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS P) AS AS) AS BA) AS B) AS CD) (70302) (00530) (00620) (00615) (00630) (00610) (00625) (00665) (01002) (01007) (01022) (01027) NOV 04... 35.4 8 -- <.010 .150 .010 <.20 .060 <1 <100 20 <1 MAR 05... -- 1 -- <.010 .050 .030 <.20 .060 -- -- -- -­ MAY 28... 72.8 1 .390 .010 .400 .020 <.20 <.020 <1 <100 30 <1 AUG 19... 53.2 13 .180 .010 .190 .030 <.20 .060 -- -- -- -­ CHRO- MANGA- MIUM, COPPER, IRON, LEAD, NESE, MERCURY TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) (01034) (01042) (01045) (01051) (01055) (71900) (01147) METHY­ SILVER, ZINC, LENE TOTAL TOTAL BLUE RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (MG/L TOTAL STANCE AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01077) (01092) (00720) (32730) (38260) NOV 04... <1 <10 190 <1 40 <.10 <1 <1 <10 <.010 <1 .04 MAR 05... -- -- -- -- -- -- -- -- -- -- -- -­ MAY 28... <1 <10 80 <1 30 <.10 <1 <1 <10 <.010 <1 .08 AUG 19... -- -- -- -- -- -- -- -- -- -- -- -­ 121 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'18", long 66°28'28", 100 ft (30 m) upstream from bridge on Highway 649, 0.7 mi (1.1 km) upstream from mouth, and about 0.4 mi (0.6 km) west of Ciales plaza. DRAINAGE AREA.--17.0 mi2 (44.0 km2). PERIOD OF RECORD.--Water years 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, INST. CIFIC WHOLE SOLVED CHEM- FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) NOV 04... 1105 12 227 8.1 24.0 3.2 8.4 99 <10 2000 MAR 03... 1300 4.6 256 7.8 23.0 2.2 8.3 97 <10 420 MAY 28... 1110 15 220 8.3 26.0 4.0 8.0 98 <10 430 AUG 19... 1205 20 228 7.9 26.5 13 7.8 98 <10 K930 STREP- HARD- MAGNE- TOCOCCI NESS CALCIUM SIUM, SODIUM, FECAL, TOTAL DIS- DIS- DIS- (COLS. (MG/L SOLVED SOLVED SOLVED DATE PER AS (MG/L (MG/L (MG/L 100 ML) CACO3) AS CA) AS MG) AS NA) (31679) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER AD- SIUM, UNFLTRD SULFATE SORP- DIS- FET SULFIDE DIS­ TION SOLVED FIELD TOTAL SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L AS K) CACO3 AS S) AS SO4) (00931) (00935) (00410) (00745) (00945) NOV 04... 500 89 21 8.9 31 1 3.2 95 <.5 14 MAR 03... 380 -- -- -- -- -- -- 110 -- -­ MAY 28... 310 84 24 5.8 10 .5 1.9 90 -- 6.4 AUG 19... 2000 88 25 6.0 9.6 .4 2.0 87 <1.0 6.4 SOLIDS, RESIDUE CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO­ RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) (00940) (00950) (00955) (70301) (70302) (00530) (00615) (00630) (00610) (00605) NOV 04... 27 <.10 28 190 6.20 8 <.010 .400 .020 -­ MAR 03... -- -- -- -- -- 2 <.010 .250 .020 -­ MAY 28... 11 <.10 26 140 5.79 8 <.010 .410 .030 -­ AUG 19... 10 <.10 26 138 7.56 13 <.010 .620 .030 .24 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 04... <.20 -- -- .060 <1 <100 10 <1 <1 <10 MAR 03... <.20 -- -- .040 -- -- -- -- -- -­ MAY 28... <.20 -- -- .050 <1 <100 30 <1 <1 <10 AUG 19... .27 .89 3.9 .060 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 122 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 04... 160 <1 14 <.10 <1 <1 <10 <.010 <1 .03 MAR 03... MAY 28... 140 <1 18 <.10 <1 <1 <10 <.010 2 <.02 AUG 19... 123 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR LOCATION.--Lat 18°25'52", long 66°31'37", Hydrologic Unit 21010002, at bridge on Highway 2, and 2.3 mi (3.7 km) west of Manatí. DRAINAGE AREA.--197 mi2 (510 km2), approximately, of which about 38 mi2 (98 km2) is partly or entirely noncontributing, excludes 6.0 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1963-68 (annual maximum discharge only), February 1970 to current year. REVISED RECORDS.--WRD PR-86-1: 1970-71 (M), 1975, 1979, 1982-85 (P). GAGE.--Water-stage recorder. Elevation of gage is 14 ft (4 m), from topographic map. Prior to 1968 crest-stage gage at same site and datum 3.57 ft (1.09 m) lower. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Possible water extraction about 500 ft (152.4 m) upstream of gage by unknown source affecting low flow. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights to gage datum of major floods, pointed out by local residents, are as follows: Sept. 13, 1928, 36.6 ft (11.16 m), Sept. 27, 1932, 36.3 ft (11.06 m), and Aug. 4, 1945, 34.3 ft (10.45 m). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 155 86 e76 48 2 219 84 e65 51 3 171 84 65 52 4 138 82 66 55 5 123 84 61 e56 48 72 172 94 276 97 77 129 49 68 114 89 251 92 69 570 47 65 95 90 288 95 68 1720 53 64 94 94 271 191 80 914 5180 66 76 88 251 114 68 518 6 94 86 59 e51 7 82 80 58 e110 8 391 80 57 98 9 711 76 55 75 10 258 113 54 62 599 67 67 94 546 101 e66 310 273 65 64 101 272 104 79 569 179 97 532 139 225 104 412 573 1050 88 172 1010 213 91 270 317 353 68 109 256 196 90 226 252 11 182 143 53 63 12 231 273 53 163 13 646 137 53 88 14 1410 105 52 165 15 847 90 52 151 213 61 88 172 170 88 148 201 170 57 369 154 156 87 137 246 140 56 612 115 192 80 177 267 122 55 265 e333 206 81 116 266 118 55 175 e9510 164 223 91 236 16 656 90 50 92 17 484 94 51 74 18 1490 93 49 65 19 476 87 51 138 20 298 80 55 129 117 103 251 1050 146 129 85 202 104 81 715 e658 141 106 158 178 95 62 289 e421 251 115 117 166 89 55 502 1530 173 99 149 594 87 52 425 1570 142 99 127 238 21 219 79 53 86 22 173 73 50 93 23 149 71 56 82 24 133 69 60 63 25 120 67 53 59 84 55 400 2240 136 105 164 235 80 65 387 2590 147 112 258 80400 75 58 243 821 148 85 371 12000 73 52 211 544 120 83 218 2380 71 52 193 392 124 89 2500 1540 26 114 68 51 61 27 109 e73 50 57 28 105 e67 50 53 29 96 65 50 50 30 93 67 50 51 31 90 --- 51 47 75 49 155 331 153 80 676 1160 80 50 150 301 124 103 299 950 75 50 137 263 110 142 257 774 --- 53 114 242 107 96 251 1830 --- 153 99 541 105 82 172 2240 --- 462 --- 495 --- 79 141 --­ TOTAL 10463 2746 1709 2488 MEAN 338 91.5 55.1 80.3 MAX 1490 273 76 165 MIN 82 65 49 47 AC-FT 20750 5450 3390 4930 CFSM 1.71 .46 .28 .41 IN. 1.98 .52 .32 .47 9699 2456 7275 26328 5804 3242 8027 111975 346 79.2 243 849 193 105 259 3733 5180 462 715 9510 546 223 2500 80400 47 49 64 88 105 79 66 129 19240 4870 14430 52220 11510 6430 15920 222100 1.76 .40 1.23 4.31 .98 .53 1.31 18.9 1.83 .46 1.37 4.97 1.10 .61 1.52 21.14 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1970 - 1998, BY WATER YEAR (WY) MEAN 708 522 351 263 207 182 349 661 228 153 212 620 MAX 2958 1803 1498 879 444 521 1037 3178 747 577 1644 3733 (WY) 1971 1971 1971 1997 1988 1972 1993 1985 1987 1979 1979 1998 MIN 154 71.0 55.1 59.1 72.0 56.2 49.9 93.7 63.8 53.0 67.9 67.4 (WY) 1995 1995 1998 1995 1994 1994 1995 1989 1994 1994 1984 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR ANNUAL TOTAL 73217 ANNUAL MEAN 201 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 6880 Jan 22 LOWEST DAILY MEAN 49 Dec 18 ANNUAL SEVEN-DAY MINIMUM 51 Dec 25 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 145200 ANNUAL RUNOFF (CFSM) 1.02 ANNUAL RUNOFF (INCHES) 13.83 10 PERCENT EXCEEDS 296 50 PERCENT EXCEEDS 98 90 PERCENT EXCEEDS 55 FOR 1998 WATER YEAR WATER YEARS 1970 - 1998 192212 527 370 756 1971 96.5 1994 80400 Sep 22 80400 Sep 22 1998 47 Jan 31 31 Jan 24 1995 49 Jan 28 33 Jul 23 1994 136000 Sep 22 Not determined Sep 10 1996 34.90 Sep 22 36.39 Sep 10 1996 28 Jan 23 1995 381300 268100 2.67 1.88 36.30 25.52 569 632 109 164 53 81 e Estimated 124 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR--Continued O N D J F M A M J J A S 10 100,000 20 50 100 200 500 1,000 2,000 5,000 10,000 20,000 50,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 125 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR. WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 27... 1030 108 307 7.6 28.0 4.9 6.3 80 <10 K8100 340 FEB 25... 1150 71 351 7.8 27.5 5.7 7.8 98 <10 4000 790 JUN 24... 1015 120 296 7.8 29.0 3.9 7.1 92 <10 410 K82 AUG 28... 1135 284 223 7.3 29.0 19 6.5 84 <10 K270 K540 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 27... 130 38 7.5 11 .4 1.9 120 <.5 9.7 13 FEB 25... -- -- -- -- -- -- 150 -- -- -­ JUN 24... 120 37 7.6 11 .4 2.0 130 -- 8.5 13 AUG 28... 88 25 5.9 9.3 .4 2.0 83 <1.0 7.9 11 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 27... .10 21 174 50.5 17 .809 .021 .830 .050 .50 FEB 25... -- -- -- -- 7 .588 .012 .600 .030 .52 JUN 24... .11 15 172 55.6 13 -- <.010 .550 .040 -­ AUG 28... <.10 22 133 102 29 1.07 .030 1.10 .150 .23 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... .55 1.4 6.1 .170 <1 <100 20 <1 1 <10 FEB 25... .55 1.1 5.1 .050 -- -- -- -- -- -­ JUN 24... <.20 -- -- .070 1 <100 30 <1 1 <10 AUG 28... .38 1.5 6.6 .080 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 126 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR.--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 840 <1 83 <.10 <1 <1 <10 <.010 <1 .03 FEB 25... JUN 24... 530 <1 59 <.10 <1 <1 <10 <.010 <1 <.02 AUG 28... 127 LAGUNA TORTUGUERO BASIN 50038200 LAGUNA TORTUGUERO OUTLET NEAR VEGA BAJA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18028'29", long 66026'50", at bridge on Highway 686, 4.2 mi (6.8 km) northeast of Manatí, and 4.4 mi (7.1 km) northwest of Vega Baja plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1964-66, 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI- ANC SPE- WATER DIS- DEMAND, FORM, STREP- WATER CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI UNFLTRD CON- FIELD TEMPER- OXYGEN, (PER- ICAL 0.45 FECAL, FET DUCT- (STAND- ATURE DIS- CENT (HIGH UM-MF (COLS. FIELD DATE TIME ANCE ARD WATER SOLVED SATUR- LEVEL) (COLS./ PER MG/L AS (US/CM) UNITS) (DEG C) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3 (00095) (00400) (00010) (00300) (00301) (00340) (31616) (31679) (00410) OCT 14... 1400 1100 8.0 29.5 5.6 74 40 310 2700 110 FEB 17... 1520 1120 7.6 28.0 7.1 90 20 K150 K64 110 MAY 20... 1045 1170 7.7 30.0 6.6 88 20 470 100 110 AUG 27... 1150 1250 7.8 30.5 5.7 76 20 460 180 100 RESIDUE NITRO­ TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO­ SULFIDE DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, TOTAL SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS S) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) (00745) (00530) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) OCT 14... .7 1 .390 .010 .400 .230 .67 .90 1.3 5.8 FEB 17... -- 1 -- <.010 .260 .160 .94 1.1 1.4 6.0 MAY 20... -- 2 .365 .015 .380 .250 .95 1.2 1.6 7.0 AUG 27... <1.0 3 .348 .010 .360 .340 .86 1.2 1.6 6.9 MANGA- METHY­ BORON, COPPER, IRON, NESE, ZINC, LENE PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL BLUE PHORUS RECOV- RECOV- RECOV- RECOV- RECOV- CYANIDE ACTIVE TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS P) AS B) AS CU) AS FE) AS MN) AS ZN) AS CN) (UG/L) (MG/L) (00665) (01022) (01042) (01045) (01055) (01092) (00720) (32730) (38260) OCT 14... <.020 80 <10 80 <10 <10 <.01 <1 .11 FEB 17... <.020 -- -- -- -- -- -- -- -­ MAY 20... <.020 60 <10 50 <10 <10 <.01 2 .10 AUG 27... <.020 -- -- -- -- -- -- -- -­ 128 THIS PAGE WAS LEFT BLANK INTENTIONALLY 129 Río Río Río Río Río Río Dos Corozal Bocas Cibuco Río Río Río Río Río de los Negros Mavilla Mavilla Indio Cibuco Cibuco Morovis MOROVIS Laguna T ortuguero Unibón 038320 038320 213 VEGA BAJA VEGA DORADO BAJA A TLANTIC OCEAN OROCOVIS CIALES COROZAL COMERÍO 0 0 1 1 2 2 3 3 4 4 0395 0382 038320 70 212 213 QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER MANATÍ ALTA TOA ALTA Basin area PUERTO RICO TOA NARANJITO 5 MILES 5 KILOMETERS 211 TO-3 PA-2 Figure 15. Río Cibuco basin. 130 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR LOCATION.--Lat l8°21'13", long 66°20'07", Hydrologic Unit 21010001, on right bank, 150 ft (46 m) downstream from junction with Río Corozal, and 1.4 mi (2.3 km) northwest of Corozal. DRAINAGE AREA.--15.1 mi2 (39.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 1969 to current year. GAGE.--Water-stage recorder. Elevation of gage is 195 ft (59 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Daily discharge affected by sewage treatment plant about 0.6 mi (1.0 km) upstream from station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.8 5.4 e2.2 e3.0 e2.6 e3.6 9.5 e5.8 10 5.3 7.0 6.7 2 7.5 4.6 e2.1 e3.8 e3.2 e3.4 5.2 11 22 7.0 6.1 9.6 3 6.7 e5.0 e2.1 e3.2 3.2 e3.5 e3.7 35 58 16 6.0 8.8 4 9.1 4.9 e2.0 e3.7 e168 e3.5 e3.0 10 23 13 6.4 7.9 5 11 e5.8 e2.1 e3.5 424 e3.4 e2.6 6.7 14 7.9 6.3 e11 6 7.3 e4.8 e2.1 e12 7 13 4.3 e2.1 e44 8 22 3.8 e2.1 e12 9 10 3.5 e1.9 e6.0 10 8.6 4.6 e1.9 e5.8 40 e4.9 2.5 7.4 12 12 e8.7 11 16 e4.2 3.3 7.8 14 9.9 35 8.2 27 e3.4 4.8 e11 10 6.8 13 6.4 36 2.7 2.9 e9.5 15 7.4 21 5.7 e16 e3.3 e2.2 7.1 12 7.7 9.1 5.2 11 9.6 e35 e1.8 e53 12 e62 e15 e1.9 e11 13 e29 e5.0 e2.3 e108 14 41 e4.1 e1.8 e42 15 15 e3.8 e1.7 e8.1 e10 e3.2 2.5 6.5 9.6 7.7 7.7 5.0 e9.2 e3.4 34 4.8 8.9 5.9 7.8 5.2 e7.2 e3.1 e42 3.9 45 6.8 8.5 e6.1 e23 e3.4 e7.6 126 15 6.2 7.4 5.3 e18 e3.2 e5.5 141 11 9.1 6.2 4.7 16 15 e3.8 e1.6 e5.1 17 21 3.3 e1.6 e4.3 18 12 e5.5 e1.8 e3.7 19 9.3 11 e2.2 e3.7 20 8.4 e4.2 e2.1 e3.1 e8.3 e3.2 e297 8.9 8.0 5.7 6.3 4.4 e6.4 e3.0 e105 85 26 7.8 13 4.3 e5.8 e3.5 e39 28 e16 13 8.2 5.4 e5.3 e3.1 e16 319 9.8 8.4 9.3 e6.8 e5.2 7.4 18 108 6.9 31 10 5.3 21 7.3 3.5 1.8 e3.1 22 6.8 2.9 e1.8 e3.5 23 6.0 2.3 e2.0 e3.0 24 5.8 2.6 e2.0 e3.0 25 5.9 e2.5 e1.9 e3.1 e4.5 e7.8 e13 43 28 13 e27 150 e4.4 e3.6 e26 29 12 8.1 9.9 e1200 e4.5 e2.9 12 23 8.9 9.7 7.9 e139 e4.0 e2.4 8.8 19 7.7 9.6 54 e46 e4.0 2.0 7.6 16 11 7.0 39 27 26 5.8 4.9 e2.1 e3.3 27 5.2 e3.7 e1.7 e3.7 28 5.1 e3.1 e1.8 e3.0 29 5.1 e3.2 e1.7 e3.3 30 4.9 e2.8 e1.7 e3.2 31 4.8 --- e2.2 e2.9 e4.8 e1.8 7.3 14 9.8 7.4 12 20 e4.4 1.7 16 13 8.1 47 19 20 e4.1 e1.6 9.4 12 7.3 17 65 19 --- e36 7.2 13 7.0 11 18 85 --- e48 e6.6 11 6.3 8.5 8.8 e48 --- 90 --- 8.9 --- 8.1 6.9 --­ TOTAL 389.0 168.9 60.1 374.1 MEAN 12.5 5.63 1.94 12.1 MAX 62 35 2.3 108 MIN 4.8 2.3 1.6 2.9 AC-FT 772 335 119 742 CFSM .83 .37 .13 .80 IN. .96 .42 .15 .92 869.1 270.2 720.2 1144.3 452.3 341.0 470.5 1887.0 31.0 8.72 24.0 36.9 15.1 11.0 15.2 62.9 424 90 297 319 58 47 65 1200 2.6 1.6 2.2 3.9 6.3 5.3 6.0 4.3 1720 536 1430 2270 897 676 933 3740 2.06 .58 1.59 2.44 1.00 .73 1.01 4.17 2.14 .67 1.77 2.82 1.11 .84 1.16 4.65 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 1998, BY WATER YEAR (WY) MEAN 40.1 46.3 34.3 24.9 MAX 135 155 169 69.6 (WY) 1991 1971 1971 1992 MIN 8.05 5.63 1.94 6.93 (WY) 1979 1998 1998 1995 21.5 21.0 32.3 43.9 14.6 11.8 16.5 33.6 51.3 65.1 111 157 44.4 34.6 50.8 191 1988 1981 1973 1986 1987 1979 1979 1996 7.75 4.36 3.32 3.20 1.63 2.19 3.44 3.88 1994 1984 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1969 - 1998 ANNUAL TOTAL 5383.8 ANNUAL MEAN 14.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 380 LOWEST DAILY MEAN 1.6 ANNUAL SEVEN-DAY MINIMUM 1.8 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 10680 ANNUAL RUNOFF (CFSM) .98 ANNUAL RUNOFF (INCHES) 13.26 10 PERCENT EXCEEDS 30 50 PERCENT EXCEEDS 7.5 90 PERCENT EXCEEDS 2.7 7146.7 19.6 28.5 56.5 1971 7.47 1994 Jan 22 1200 Sep 22 3070 Sep 10 1996 Dec 16 1.6 Dec 16 .91 Jul 17 1994 Dec 11 1.8 Dec 11 1.2 Jun 21 1994 3910 Sep 22 20400 Nov 9 1995 12.61 Sep 22 22.35 Nov 9 1995 14180 20640 1.30 1.89 17.61 25.64 35 50 7.0 13 2.3 5.0 e Estimated 131 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 132 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-76, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 16... 1025 13 439 7.6 26.0 3.0 6.4 79 <10 30000 K19000 FEB 17... 1150 7.2 447 8.1 25.5 1.2 6.2 76 <10 K60 K100 JUN 15... 1200 12 388 7.8 27.5 4.1 7.6 97 <10 K1700 K1700 AUG 18... 1140 7.8 381 8.0 28.0 5.1 7.5 97 <10 3000 800 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 16... 160 41 15 20 .7 3.6 150 <.5 20 31 FEB 17... -- -- -- -- -- -- 150 -- -- -­ JUN 15... 150 37 13 19 .7 3.9 130 -- 16 25 AUG 18... 140 36 12 20 .7 3.9 130 <1.0 14 27 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 16... .11 31 251 9.00 5 1.00 .010 1.00 .020 .20 FEB 17... -- -- -- -- 2 2.03 .067 2.10 .100 .30 JUN 15... .15 26 218 7.11 4 1.99 .013 2.00 .020 -­ AUG 18... .24 30 221 4.66 10 2.18 .018 2.20 .050 .36 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 16... .20 1.1 5.0 .070 <1 <100 30 <1 4 <10 FEB 17... .40 2.5 11 .330 -- -- -- -- -- -­ JUN 15... <.20 -- -- .210 <1 <100 40 <1 <1 15 AUG 18... .41 2.6 12 .350 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 133 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 16... 300 <1 72 <.10 <1 <1 <10 <.010 <1 .09 FEB 17... JUN 15... 200 <1 43 <.10 <1 <1 <10 <.010 1 <.02 AUG 18... --- --- --- --- --- --- --- 134 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR LOCATION.--Lat 18°26'53", long 66°22'29", Hydrologic Unit 21010002, on left bank, at bridge on Hwy 2, 0.6 mi (1.0 km) downstream from Río Indio, and 0.8 mi (1.3 km) east of Vega Baja. DRAINAGE AREA.--99.1 mi2 (256.7 km2), of which 25.4 mi2 (65.8 km2), does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is 7.79 ft (2.374 m) above mean sea level. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of Dec. 11, 1965 reached a stage of 26.2 ft (7.99 m), datum unknown, discharge about 28,000 ft3/s (793 m3/s). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30 21 16 15 15 23 101 21 36 26 25 32 2 30 22 15 16 16 22 39 21 60 25 23 32 3 28 20 15 18 16 21 29 36 217 34 22 74 4 64 22 14 15 18 20 24 53 233 102 22 36 5 127 24 14 17 1300 23 22 30 120 43 23 36 6 62 24 13 34 225 24 22 29 60 33 25 34 7 39 21 13 179 89 24 22 46 48 53 36 74 8 51 20 13 90 54 22 36 42 44 36 126 133 9 102 18 13 35 138 21 30 107 51 32 55 40 10 36 18 13 23 68 19 24 47 77 30 49 31 11 38 19 13 102 49 18 22 36 42 33 32 27 12 92 100 13 314 43 17 23 32 37 29 29 27 13 258 31 13 102 38 18 109 29 130 26 28 25 14 123 24 13 427 37 17 46 42 160 26 26 31 15 76 20 13 107 90 17 30 644 72 24 24 25 16 55 30 12 53 45 18 591 204 47 30 23 24 17 100 26 12 40 36 16 497 179 51 25 25 22 18 64 23 13 32 32 16 122 292 124 40 39 21 19 45 38 13 28 30 19 52 531 74 61 30 27 20 38 37 12 27 26 18 72 592 44 116 35 25 21 33 114 13 24 26 39 60 167 43 162 111 29 22 30 27 12 24 25 28 49 127 95 47 57 3560 23 28 20 12 22 24 18 64 76 46 34 35 1370 24 26 18 12 20 23 16 31 64 38 48 48 348 25 25 17 12 19 23 14 25 54 35 34 252 206 26 24 18 12 19 25 13 25 67 40 27 66 149 27 23 23 12 18 26 13 37 47 34 83 47 150 28 21 19 12 18 25 15 37 40 31 60 115 107 29 20 17 12 17 25 26 46 30 36 139 105 30 21 17 12 16 82 22 60 29 30 49 307 31 21 12 16 333 66 27 36 TOTAL 1730 848 399 1887 2562 989 2289 3827 2148 1412 1652 7107 MEAN 55.8 28.3 12.9 60.9 91.5 31.9 76.3 123 71.6 45.5 53.3 237 MAX 258 114 16 427 1300 333 591 644 233 162 252 3560 MIN 20 17 12 15 15 13 22 21 29 24 22 21 AC-FT 3430 1680 791 3740 5080 1960 4540 7590 4260 2800 3280 14100 CFSM .56 .29 .13 .61 .92 .32 .77 1.25 .72 .46 .54 2.39 IN. .65 .32 .15 .71 .96 .37 .86 1.44 .81 .53 .62 2.67 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 1998, BY WATER YEAR (WY) MEAN 151 187 165 101 88.9 81.6 147 187 70.4 51.1 77.7 144 MAX 559 523 1316 339 190 339 667 655 239 162 461 690 (WY) 1986 1980 1982 1997 1988 1990 1987 1985 1987 1979 1979 1996 MIN 45.9 28.3 12.9 30.2 27.3 20.5 16.2 24.7 12.5 14.0 21.2 26.7 (WY) 1974 1998 1998 1995 1994 1994 1984 1977 1994 1994 1978 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1973 - 1998 ANNUAL TOTAL 26576 26850 ANNUAL MEAN 72.8 73.6 120 HIGHEST ANNUAL MEAN 236 1982 LOWEST ANNUAL MEAN 38.5 1994 HIGHEST DAILY MEAN 2270 Jan 22 3560 Sep 22 14600 Dec 13 1981 LOWEST DAILY MEAN 12 Dec 16 12 Dec 16 7.2 May 3 1995 ANNUAL SEVEN-DAY MINIMUM 12 Dec 22 12 Dec 22 8.1 Apr 28 1995 INSTANTANEOUS PEAK FLOW 7650 Sep 22 34000 Apr 12 1987 INSTANTANEOUS PEAK STAGE 16.66 Sep 22 19.10 Apr 12 1987 INSTANTANEOUS LOW FLOW 12 Dec 16 7.2 May 2 1995 ANNUAL RUNOFF (AC-FT) 52710 53260 86610 ANNUAL RUNOFF (CFSM) .73 .74 1.21 ANNUAL RUNOFF (INCHES) 9.98 10.08 16.39 10 PERCENT EXCEEDS 136 123 223 50 PERCENT EXCEEDS 34 30 57 90 PERCENT EXCEEDS 18 15 22 135 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 136 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 14... 1145 79 422 7.8 25.5 20 4.5 55 13 4000 2200 FEB 18... 0830 31 482 7.9 24.5 5.9 6.2 74 <10 2000 K1200 MAY 20... 1330 335 340 7.5 26.0 92 6.5 80 24 K18000 7800 AUG 27... 1525 41 416 7.7 28.0 15 6.0 76 <10 K1600 4800 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 14... 170 57 7.7 14 .5 4.3 150 <.5 22 21 FEB 18... -- -- -- -- -- -- 180 -- -- -­ MAY 20... 140 43 6.7 10 .4 4.9 120 -- 19 16 AUG 27... 160 51 8.9 16 .5 4.2 160 <1.0 15 22 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 14... .15 17 233 49.8 22 3.00 .170 3.20 .730 .92 FEB 18... -- -- -- -- 5 1.77 .032 1.80 .040 .25 MAY 20... .13 14 187 170 228 2.36 .040 2.40 .170 1.2 AUG 27... .11 19 231 25.3 18 1.28 .019 1.30 .060 .55 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 14... 1.6 4.8 21 1.00 <1 <100 40 <1 2 <10 FEB 18... .29 2.1 9.3 .150 -- -- -- -- -- -­ MAY 20... 1.4 3.8 17 .340 <1 <100 20 <1 16 29 AUG 27... .61 1.9 8.5 .320 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 137 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 14... 590 <1 35 <.10 <1 <1 <10 <.010 <1 .03 FEB 18... MAY 20... 6900 4 350 <.10 <1 <1 30 <.010 2 .05 AUG 27... 138 THIS PAGE WAS LEFT BLANK INTENTIONALLY 139 Río Río Caño de Martín Peña Río Río Río Río Río Río Río de Río Río Lajas Río Río Río de de de la la la Plata Plata Plata Lago Represa Laguna Bahía de San Juan Bu ra ca nes bo Arroyata C u e s ta Arriba Cañas G u a d i a n a Hondo Usabón Aibonito Matón Guavate Lago Carite 0450 216 045010 0460 0460 VEGA DORADO BAJA OCEAN COROZAL COMERÍO CIDRA AGUAS BUENAS 0 0 1 1 2 2 3 3 4 4 0460 0450 045010 044950 044830 044850 0444 0438 0430 0399 039950 039990 0440 217 216 TB-1 SA-1, DA-1 SR-2 SA-3 MA-2 de la Plat a de Comerío San José TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER ALTA TOA ALTA TOA CATAÑO SAN JUAN A TLANTIC AIBONITO BARRANQUITAS CAYEY NARANJITO 5 MILES Basin area PUERTO RICO 5 KILOMETERS HG-1, HG-4 Figure 16. Río de la Plata basin. 140 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR LOCATION.--Lat 18°03'46", long 66°05'58", Hydrologic Unit 21010005, on top of a concrete tower at diversion tunnel on Carite Reservoir, 0.7 mi (1.1 km) northwest from Escuela Carite Chino, 1.2 mi (1.9 km) northeast from Central Hidroeléctrica de Carite Num. 1 and 1.8 mi (2.9 km) northeast from Escuela Segunda Unidad. DRAINAGE AREA.--8.20 mi2 (21.24 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1989 to current year. Prior to October 1994, published as Lago Carite at Gate Tower. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Carite Dam was completed in 1913. The operation of the reservoir is controlled by the utilization of water to meet the demands for domestic, industrial and agricultural purposes in the Guayama Area. The dam is an earthfill with crest elevation of 1,806 ft (550 m) above mean sea level, with a structural height of 104 ft (32 m) and a length of 500 ft (152 m). The dam has a capacity of approximately 11,310 acre-feet (13.9 hm3). The Dam is operated by the Puerto Rico Electric and Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,789.62 ft (545.48 m), Sep. 21, 1998; minimum elevation, 1,761.22 ft (536.81 m), May 28, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation 1,789.62 ft (545.48 m), Sep. 21; minimum elevation, 1,769.39 ft (539.10 m), Oct. 1. Capacity Table (based on Data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,746 0 1,775 6,194 1,760 2,471 1,780 7,704 1,769 4,561 1,790 11,048 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1769.39 1781.43 1781.27 1779.67 1781.38 1781.31 1781.59 1781.52 1781.57 1781.17 1780.01 1781.53 2 1769.48 1781.41 1781.24 1779.68 1781.35 1781.31 1781.62 1781.51 1781.52 1781.12 1779.92 1781.62 3 1769.48 1781.42 1781.16 1779.77 1781.34 1781.34 1781.59 1781.51 1781.49 1781.13 1779.84 1781.67 4 1769.50 1781.41 1781.11 1779.88 1781.39 1781.34 1781.55 1781.55 1781.47 1781.19 1779.76 1781.62 5 1769.49 1781.40 1781.07 1779.98 1782.13 1781.32 1781.54 1781.54 1781.50 1781.18 1779.67 1781.56 6 1769.48 1781.39 1781.00 1780.71 1781.79 1781.29 1781.50 1781.49 1781.45 1781.15 A 1781.64 7 1769.45 1781.37 1780.95 1781.06 1781.64 1781.66 1781.64 1781.46 1781.49 1781.09 1779.53 1781.70 8 1769.50 1781.37 1780.88 1781.27 1781.64 1781.65 1781.58 1781.50 1781.47 1781.09 1779.63 1781.71 9 1769.49 1781.70 1780.83 1781.41 1781.57 1781.56 1781.52 1781.59 1781.46 1781.04 1779.66 1781.69 10 1769.47 1782.19 1780.76 1781.52 1781.48 1781.51 1781.50 1781.52 1781.47 1780.99 1779.58 1781.53 11 1769.66 1781.78 1780.71 1781.52 1781.51 1781.48 1781.70 1781.50 1781.39 1780.95 1779.50 1781.55 12 1769.70 1781.63 1780.65 1781.51 1781.51 1781.45 1781.79 1781.49 1781.42 1780.93 1779.53 1781.51 13 1774.24 1781.57 1780.59 1781.54 1781.46 1781.42 1781.67 1781.96 1781.36 1780.87 1779.48 1781.54 14 1781.23 1781.52 1780.53 1781.51 1781.61 1781.42 1781.62 1781.82 1781.34 1780.83 1779.38 1781.52 15 1782.30 1781.50 1780.47 1781.50 1781.58 1781.42 1781.58 1781.74 1781.33 1780.77 1779.34 1781.59 16 1781.99 1781.49 1780.42 1781.47 1781.53 1781.40 1781.58 1781.68 1781.38 1780.73 1779.29 1781.54 17 1781.94 1781.49 1780.40 1781.47 1781.51 1781.38 1781.57 1781.61 1781.36 1780.64 1779.28 1781.48 18 1781.79 1781.47 1780.32 1781.46 1781.48 1781.36 1781.56 1781.54 1781.28 1780.61 1779.24 1781.46 19 1781.69 1781.45 1780.24 1781.42 1781.46 1781.36 1781.55 1781.52 1781.32 1780.56 1779.23 1781.50 20 1781.64 1781.44 1780.22 1781.41 1781.45 1781.65 1781.56 1781.47 1781.31 1780.71 1779.15 1781.47 21 1781.58 1781.46 1780.18 1781.39 1781.43 1781.67 1781.56 1781.45 1781.46 1780.64 1779.23 1789.62 22 1781.56 1781.48 1780.14 1781.38 1781.42 1781.73 1781.54 1781.42 1781.48 1780.58 1780.75 A 23 1781.53 1781.52 1780.09 1781.37 1781.41 1781.63 1781.51 1781.44 1781.43 1780.50 1780.84 A 24 1781.50 1781.52 1780.00 1781.40 1781.39 1781.56 1781.51 1781.44 1781.38 1780.47 1784.06 A 25 1781.50 1781.49 1779.95 1781.45 1781.39 1781.55 1781.50 1781.42 1781.37 1780.42 1782.60 A 26 1781.48 1781.46 1779.86 1781.44 1781.38 1781.51 1781.50 1781.77 1781.34 1780.34 1782.06 A 27 1781.45 1781.41 1779.81 1781.42 1781.36 1781.56 1781.54 1781.75 1781.31 1780.34 1781.81 A 28 1781.45 1781.36 1779.74 1781.42 1781.34 1781.54 1781.55 1781.62 1781.26 1780.32 1781.68 A 29 1781.45 1781.33 1779.67 1781.42 --- 1781.53 1781.55 1781.57 1781.22 1780.25 1781.71 A 30 1781.42 1781.32 1779.65 1781.41 --- 1781.78 1781.53 1781.68 1781.21 1780.17 1781.63 A 31 1781.42 --- 1779.64 1781.40 --- 1781.69 --- 1781.63 --- 1780.09 1781.58 --­ MAX 1782.30 1782.19 1781.27 1781.54 1782.13 1781.78 1781.79 1781.96 1781.57 1781.19 --- --­ MIN 1769.39 1781.32 1779.64 1779.67 1781.34 1781.29 1781.50 1781.42 1781.21 1780.09 --- --­ A No gage-height record 141 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 30... 0800 35 427 8.0 26.0 6.2 7.0 88 <10 320 290 FEB 26... 0840 19 494 7.8 24.5 .40 7.0 87 <10 210 K130 MAY 19... 1155 57 309 7.4 30.0 3.8 7.6 104 <10 3400 K82 AUG 20... 1220 14 387 8.2 30.0 4.1 10.4 143 <10 K40 K20 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 30... 150 37 15 33 1 2.9 150 <.5 24 33 FEB 26... -- -- -- -- -- -- 170 -- -- -­ MAY 19... 100 25 9.3 22 1 2.3 100 -- 12 23 AUG 20... 130 27 16 12 .5 2.4 130 <1.0 11 11 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 30... .10 26 261 24.6 7 1.59 .014 1.60 .020 .26 FEB 26... -- -- -- -- 2 1.20 .010 1.20 .030 .26 MAY 19... .22 21 174 27.0 5 1.57 .035 1.60 .040 .29 AUG 20... .10 22 179 6.77 8 1.38 .024 1.40 .070 .35 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 30... .28 1.9 8.3 .200 <1 <100 50 <1 <1 <10 FEB 26... .30 1.5 6.5 .080 -- -- -- -- -- -­ MAY 19... .33 1.9 8.5 .170 <1 <100 30 <1 <1 <10 AUG 20... .42 1.8 8.1 .150 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 142 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 30... 110 <1 16 <.10 <1 <1 <10 <.010 <1 .05 FEB 26... MAY 19... 500 <1 29 <.10 <1 <1 <10 <.010 2 .04 AUG 20... --- --- --- --- --- --- --- 143 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR LOCATION.--Lat 18°13'23", long 66°13'30", Hydrologic Unit 21010005, on right bank 50 ft (15 m) upstream from bridge off Highway 167 in the Town of Comerío, 0.4 mi (0.6 km) southwest of Comerío High School, and 0.2 mi (0.3 km) northeast of Plaza de Comerío. DRAINAGE AREA.--109 mi2 (282 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 604.2 ft (184.160 m) above mean sea level. REMARKS.--Records fair. Filtration plant more or less 1,000 feet upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 58 56 31 26 29 88 34 66 17 13 79 2 12 59 50 28 27 28 58 35 56 15 13 190 3 26 57 47 30 26 28 54 51 44 18 12 397 4 16 57 46 35 33 36 44 35 43 22 11 424 5 17 56 45 44 4590 31 35 36 39 43 12 182 6 16 56 43 210 444 31 31 37 41 25 11 112 7 16 53 42 168 152 33 32 32 45 21 16 148 8 195 50 40 135 563 60 62 228 36 17 28 161 9 109 51 40 97 634 53 49 160 33 15 52 125 10 28 2340 40 134 141 39 38 84 35 13 34 110 11 20 339 40 80 90 32 34 50 34 13 30 87 12 50 150 40 62 68 28 188 38 31 13 20 68 13 117 105 38 107 58 26 135 34 29 12 17 58 14 6890 88 37 141 52 26 78 179 33 12 16 74 15 2390 76 37 77 76 26 58 407 26 12 14 73 16 1030 69 36 55 65 27 59 115 24 15 13 102 17 775 68 38 47 53 23 65 85 25 16 16 66 18 672 69 40 42 49 21 58 64 31 16 21 57 19 244 65 36 39 44 23 50 109 30 18 26 60 20 153 62 34 37 42 29 44 73 21 32 23 68 21 122 61 42 36 39 142 62 179 20 116 25 4830 22 105 66 44 33 36 66 61 159 45 36 634 26900 23 92 72 37 32 35 71 48 68 52 20 421 2410 24 82 74 35 32 34 55 42 53 30 16 1040 652 25 77 69 34 31 33 42 39 43 20 16 4270 353 26 73 59 33 32 32 35 39 42 18 16 991 260 27 69 55 32 34 31 33 37 125 19 16 312 319 28 66 54 32 32 30 39 36 109 18 21 180 426 29 64 53 34 30 53 38 68 16 18 135 411 30 63 55 32 29 292 36 56 19 16 113 270 31 60 33 27 392 71 14 81 TOTAL 13663 4546 1213 1947 7503 1849 1698 2859 979 670 8600 39472 MEAN 441 152 39.1 62.8 268 59.6 56.6 92.2 32.6 21.6 277 1316 MAX 6890 2340 56 210 4590 392 188 407 66 116 4270 26900 MIN 12 50 32 27 26 21 31 32 16 12 11 57 AC-FT 27100 9020 2410 3860 14880 3670 3370 5670 1940 1330 17060 78290 CFSM 4.06 1.40 .36 .58 2.47 .55 .52 .85 .30 .20 2.56 12.1 IN. 4.68 1.56 .42 .67 2.57 .63 .58 .98 .34 .23 2.95 13.53 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1998, BY WATER YEAR (WY) MEAN 219 102 52.7 136 100 43.7 53.7 90.2 73.0 89.5 96.0 476 MAX 866 166 112 732 268 75.7 162 263 213 291 277 1433 (WY) 1991 1993 1993 1992 1998 1989 1993 1992 1996 1993 1998 1996 MIN 40.6 19.0 17.1 21.3 24.4 20.6 22.3 19.7 13.2 10.4 12.7 26.2 (WY) 1992 1995 1995 1995 1990 1993 1991 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1989 - 1998 ANNUAL TOTAL 32239 84999 ANNUAL MEAN 88.3 233 126 HIGHEST ANNUAL MEAN 239 1996 LOWEST ANNUAL MEAN 35.3 1994 HIGHEST DAILY MEAN 6890 Oct 14 26900 Sep 22 32400 Sep 10 1996 LOWEST DAILY MEAN 11 Sep 5 11 Aug 4 5.8 Jun 25 1994 ANNUAL SEVEN-DAY MINIMUM 12 Sep 1 12 Jul 31 7.3 Jul 31 1994 INSTANTANEOUS PEAK FLOW 82600 Sep 21 127000 Jan 5 1992 INSTANTANEOUS PEAK STAGE 24.83 Sep 21 29.22 Jan 5 1992 ANNUAL RUNOFF (AC-FT) 63950 168600 91420 ANNUAL RUNOFF (CFSM) .81 2.15 1.16 ANNUAL RUNOFF (INCHES) 11.05 29.14 15.80 10 PERCENT EXCEEDS 89 192 161 50 PERCENT EXCEEDS 37 43 36 90 PERCENT EXCEEDS 15 17 15 144 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 145 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to current year. INSTRUMENTATION.-- USD-77 sediment sampler since 1989. Automatic sediment sampler since 1989. REMARKS.--Sediment samples were collected by a local observer on a week basis. During high flow events sediment samples were collected by local observer. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 8,800 mg/L Jan. 05, 1992; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 950,000 tons (862,000 tonnes) Jan. 05, 1992; Minimum daily mean, 0.04 tons (0.04 tonne) November 28, 1994. EXTREMES FOR WATER YEARS 1998.-- SEDIMENT CONCENTRATION: Maximun daily mean, 6,060 mg/L September 22, 1998 ; Minimun daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximun daily mean, 583,000 tons (530,000 tonnes) September 22, 1998; Minimun daily mean, 0.07 tons (0.06tonne) August 6, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 14 8 .29 58 10 1.5 56 6 .98 2 12 8 .27 59 8 1.3 50 6 .86 3 26 8 .55 57 7 1.1 47 8 .97 4 16 8 .35 57 7 1.0 46 9 1.2 5 17 8 .36 56 6 .95 45 11 1.3 6 16 8 .34 56 7 1.1 43 10 1.2 7 16 8 .34 53 13 1.9 42 10 1.1 8 195 110 211 50 20 2.8 40 10 1.0 9 109 79 32 51 20 2.8 40 9 .98 10 28 31 2.3 2340 1090 10800 40 9 .94 11 20 31 1.7 339 215 210 40 8 .89 12 50 49 8.4 150 64 28 40 8 .83 13 117 89 38 105 17 4.9 38 7 .68 14 6890 2480 83700 88 16 3.9 37 6 .57 15 2390 1050 7470 76 17 3.4 37 5 .50 16 1030 536 1700 69 16 2.9 36 5 .48 17 775 384 1450 68 12 2.2 38 5 .51 18 672 388 854 69 9 1.6 40 5 .55 19 244 148 101 65 8 1.3 36 6 .61 20 153 73 31 62 9 1.6 34 8 .72 21 122 37 12 61 12 2.0 42 10 1.1 22 105 18 5.1 66 14 2.4 44 15 1.8 23 92 9 2.2 72 10 1.9 37 23 2.3 24 82 8 1.8 74 7 1.4 35 29 2.7 25 77 8 1.7 69 5 1.0 34 17 1.6 26 73 11 2.1 59 6 1.0 33 10 .87 27 69 15 2.7 55 8 1.1 32 7 .62 28 66 18 3.2 54 9 1.3 32 8 .72 29 64 16 2.7 53 8 1.1 34 9 .86 30 63 14 2.3 55 7 1.1 32 11 .93 31 60 12 1.9 33 11 .99 TOTAL 13663 95639.60 4546 11088.55 1213 31.36 --- --- --- --- --- --- --- --- --- --- --- --- 146 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 31 8 .71 26 13 .90 29 4 .34 2 28 6 .49 27 14 1.0 28 6 .42 3 30 5 .41 26 16 1.1 28 7 .56 4 35 5 .47 33 17 1.8 36 8 .83 5 44 5 .60 4590 1610 31600 31 7 .59 6 210 534 847 444 268 369 31 6 .48 7 168 578 296 152 104 44 33 5 .46 8 135 105 40 563 218 1180 60 34 7.9 9 97 59 15 634 445 990 53 26 3.8 10 134 83 33 141 84 33 39 9 .93 11 80 62 14 90 35 8.8 32 9 .79 12 62 44 7.3 68 19 3.5 28 10 .75 13 107 102 31 58 25 4.0 26 11 .76 14 141 103 41 52 36 5.1 26 11 .76 15 77 57 12 76 38 7.8 26 10 .73 16 55 38 5.7 65 20 3.6 27 10 .73 17 47 37 4.7 53 10 1.5 23 10 .63 18 42 38 4.4 49 6 .82 21 10 .57 19 39 36 3.8 44 6 .76 23 10 .62 20 37 26 2.5 42 7 .75 29 10 .79 21 36 18 1.7 39 7 .73 142 80 38 22 33 13 1.2 36 7 .64 66 45 8.2 23 32 12 1.0 35 6 .59 71 25 4.7 24 32 11 .94 34 6 .56 55 15 2.3 25 31 11 .93 33 7 .60 42 15 1.7 26 32 15 1.3 32 7 .64 35 15 1.4 27 34 21 2.0 31 7 .61 33 15 1.3 28 32 26 2.2 30 5 .43 39 15 1.6 29 30 19 1.6 53 30 11 30 29 14 1.1 292 567 801 31 27 12 .83 392 697 1270 TOTAL 1947 1374.88 7503 34262.23 1849 2164.64 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 88 76 18 34 2 58 63 9.9 35 3 54 54 7.7 51 4 44 50 6.1 35 5 35 47 4.5 36 11 .95 66 50 8.9 11 1.1 56 55 8.9 12 1.7 44 61 7.2 12 1.2 43 48 5.5 13 1.2 39 40 4.2 6 31 52 4.3 37 7 32 77 6.7 32 8 62 64 11 228 9 49 52 6.9 160 10 38 51 5.2 84 13 1.3 41 35 3.9 13 1.1 45 29 3.5 239 565 36 29 2.8 358 226 33 32 2.9 22 5.2 35 35 3.3 11 34 50 4.7 50 12 188 137 85 38 13 135 119 44 34 14 78 80 17 179 15 58 55 8.8 407 2 .31 34 39 3.5 2 .21 31 43 3.5 2 .18 29 40 3.1 137 193 33 22 2.0 282 411 26 12 .83 16 59 42 6.6 115 17 65 31 5.5 85 18 58 24 3.8 64 19 50 20 2.6 109 20 44 16 1.9 73 139 44 24 17 1.1 101 23 25 32 2.2 94 16 31 51 4.2 86 26 30 49 4.0 63 13 21 46 2.6 21 62 13 2.3 179 22 61 14 2.3 159 23 48 15 1.9 68 24 42 15 1.7 53 25 39 12 1.3 43 129 73 20 36 1.9 116 57 45 26 4.0 56 10 52 26 3.9 47 6.8 30 10 .79 47 5.3 20 10 .53 26 39 9 .95 27 37 9 .89 28 36 9 .88 29 38 9 .93 30 36 10 .94 31 --- --- --- 42 45 5.0 18 10 .51 125 62 24 19 12 .60 109 75 23 18 14 .68 68 46 8.5 16 18 .79 56 42 6.4 19 20 1.0 71 50 10 --- --- --­ TOTAL 1698 --- 274.29 2859 --- 1760.45 979 --- 92.83 --- --- --- --- --- --- 147 RIO DE LA PLATA BASIN 50043800 Río DE LA PLATA AT COMERIO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 17 17 .78 13 3 .12 79 40 8.6 2 15 15 .59 13 3 .10 190 98 140 3 18 17 .88 12 3 .09 397 225 245 4 22 20 1.2 11 3 .08 424 230 280 5 43 25 3.2 12 2 .08 182 83 44 6 25 9 .65 11 2 .07 112 22 6.7 7 21 28 1.6 16 2 .09 148 20 8.0 8 17 26 1.2 28 21 1.8 161 20 8.7 9 15 23 .93 52 42 6.9 125 19 6.4 10 13 21 .76 34 34 3.1 110 14 4.3 11 13 19 .64 30 27 2.2 87 10 2.5 12 13 18 .61 20 22 1.2 68 8 1.5 13 12 20 .64 17 18 .87 58 8 1.2 14 12 22 .69 16 17 .72 74 7 1.5 15 12 23 .76 14 16 .61 73 12 3.8 16 15 21 .87 13 15 .52 102 48 15 17 16 19 .79 16 15 .63 66 8 1.4 18 16 17 .72 21 17 1.1 57 5 .77 19 18 16 .76 26 19 1.4 60 5 .81 20 32 25 2.9 23 10 .62 68 5 .88 21 116 205 91 25 5 .34 4830 1400 222000 22 36 26 2.6 634 510 1560 26900 6060 583000 23 20 9 .53 421 329 524 2410 657 5710 24 16 4 .18 1040 388 5200 652 234 430 25 16 3 .13 4270 902 13300 353 140 134 26 16 2 .10 991 526 1550 260 122 86 27 16 2 .09 312 142 129 319 145 246 28 21 3 .15 180 45 22 426 255 355 29 18 3 .16 135 42 15 411 258 434 30 16 4 .16 113 41 13 270 178 133 31 14 4 .14 81 41 8.9 TOTAL 670 116.41 8600 22344.54 39472 813309.06 YEAR 84999 982458.84 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) NOV 10... 0700 4970 2500 33500 96 JAN 13... 0930 125 173 58 98 FEB 05... 1215 6920 2520 47100 83 MAR 31... 0630 461 792 986 56 APR 03... 0800 46 54 6.7 90 MAY 14... 0745 106 378 108 98 JUN 02... 0715 52 35 4.9 85 148 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) NOV 10... 0700 4970 2500 33500 48 60 73 MAR 31... 0630 461 792 986 21 26 32 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 10... 85 93 96 99 100 100 100 MAR 31... 39 49 56 73 86 96 99 149 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'33", long 66°12'28", at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerío plaza. DRAINAGE AREA.--139 mi2 (360 km2), excludes 8.2 mi2 (21.1 km2) upstream from Carite Reservoir, the flow of which is diverted to Rio Guamani. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 05... 0845 47 428 8.0 25.5 11 7.4 91 <10 K780 240 MAR 02... 1355 29 447 8.5 24.5 2.2 7.2 88 <10 240 210 JUN 01... 1350 72 363 8.2 30.0 4.5 8.4 114 <10 K840 K150 AUG 17... 1130 22 382 8.2 30.0 10 8.4 114 <10 K36 490 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 05... 160 52 6.3 18 .6 .90 150 <.5 30 10 MAR 02... -- -- -- -- -- -- 150 -- -- -­ JUN 01... 110 27 11 23 1 2.8 120 -- 12 25 AUG 17... 120 29 12 26 1 4.2 140 <1.0 15 28 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 05... .20 23 230 29.2 53 -- <.010 .910 .030 .19 MAR 02... -- -- -- -- 2 -- <.010 .370 .040 .17 JUN 01... .12 23 196 37.8 8 .936 .014 .950 .040 .30 AUG 17... .15 29 228 13.6 18 -- <.010 .190 .030 .31 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 05... .22 1.1 5.0 .140 <1 <100 10 <1 <1 <10 MAR 02... .21 .58 2.6 .050 -- -- -- -- -- -­ JUN 01... .34 1.3 5.7 .090 <1 <100 50 <1 <1 <10 AUG 17... .34 .53 2.3 .090 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 150 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 05... 50 <1 15 <.10 <1 8 <10 <.010 <1 .05 MAR 02... JUN 01... 230 <1 20 <.10 <1 <1 <10 <.010 <1 .04 AUG 17... 151 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'39", long 66°13'28", at steel-cross-bridge 0.8 mi (1.3 km) northwest of Highway 164, 1.2 mi (1.9 km) upstream from mouth and about 2.0 mi (3.2 km) northeast of Naranjito plaza. DRAINAGE AREA.--4.0 mi2 (10.3 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 05... 1200 3.5 441 8.1 28.5 2.7 7.6 96 <10 230 520 MAR 03... 0940 3.0 464 8.1 24.5 .34 6.0 72 <10 260 200 MAY 29... 1015 6.1 406 8.1 27.5 .53 8.3 106 <10 560 670 AUG 18... 1500 4.0 444 7.8 28.0 2.9 6.3 81 <10 K840 700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 05... 140 43 7.0 11 .4 1.3 150 <.5 7.8 8.7 MAR 03... -- -- -- -- -- -- 150 -- -- -­ MAY 29... 160 36 17 20 .7 2.8 140 -- 22 26 AUG 18... 170 40 17 21 .7 3.2 150 <1.0 29 28 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 05... <.10 20 189 2.04 -- -- <.010 2.00 .020 -­ MAR 03... -- -- -- -- 1 -- <.010 2.20 .030 .24 MAY 29... <.10 24 232 3.80 3 .828 .012 .840 .020 .25 AUG 18... .12 27 254 2.75 1 1.59 .012 1.60 .020 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 05... <.20 -- -- .220 2 <100 30 <1 <1 <10 MAR 03... .27 2.5 11 .130 -- -- -- -- -- -­ MAY 29... .27 1.1 4.9 .120 2 <100 50 <1 <1 <10 AUG 18... <.20 -- -- .160 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 152 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 05... 60 <1 51 <.10 <1 <1 <10 <.010 <1 .06 MAR 03... MAY 29... 300 <1 32 <.10 <1 <1 <10 <.010 <1 <.02 AUG 18... --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 153 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR LOCATION.--Lat 18°20'40", long 66°14'10", Hydrologic Unit 21010005, 2.9 mi (4.7 km) at northeast of Plaza de Naranjito, 2.7 mi (4.3 km) West of Road 167, km 15.3, Buena Vista, Bayamón, 5.2 mi (8.4 km) east of Plaza de Corozal. DRAINAGE AREA.--181 mi2 (469 km2). ELEVATION RECORDS PERIOD OF RECORD.--February 1989 to current year. Prior to October 1994, published as Lago La Plata at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago La Plata first construction phase was completed in 1974 and the second construction phase to provide the spillway with bascule gates was completed in October 1989. The maximum storage is 37,000 ac-ft (45.6 hm3) and its purpose is the supply of water for domestic and industrial use. La Plata Dam is a concrete gravity structure located across the Río de la Plata, the dam has an overall length of 774 ft (236 m) and a maximum height of about 131 ft (40 m). The dam spillway is provided with 6 bascule gates. The spillway crest has a total clear length of 690 ft (210 m), an elevation of 155 ft (47 m). The Dam is owned and operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 170.90 ft (52.09 m), Sept. 10, 1996; minimum elevation, 107.95 ft (32.90 m), Feb. 21, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 168.13 ft (51.24 m), Nov. 10; minimum elevation, 126.88 ft (38.67 m), Oct. 8. Capacity Table (based on data from Puerto Rico Aqueduct and Sewer Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 98.43 2,760 164.05 28,550 131.24 11,360 170.61 33,160 154.60 22,720 175.52 37,040 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 128.79 164.67 164.74 157.62 155.48 164.95 164.00 163.34 165.06 160.09 152.83 164.96 2 128.38 164.52 164.57 157.35 155.18 164.74 163.99 163.10 165.28 159.87 152.48 164.96 3 127.96 164.36 164.40 A 154.87 164.54 163.90 162.94 165.38 159.64 152.12 165.43 4 127.55 164.18 164.20 156.86 156.36 164.33 163.79 162.72 165.41 159.41 151.76 165.31 5 127.44 164.01 164.01 156.69 160.46 164.16 163.63 162.48 165.30 159.22 151.39 165.36 6 127.35 163.83 163.80 157.19 162.11 163.98 163.44 162.28 165.12 159.25 A 165.50 7 127.06 163.64 163.59 158.35 162.54 163.80 163.32 162.06 164.96 159.03 151.30 165.63 8 127.47 163.43 163.37 158.69 164.87 163.68 163.31 162.52 164.78 158.76 151.23 165.13 9 128.51 163.21 163.16 158.76 166.85 163.59 163.22 162.95 164.70 158.48 151.18 165.23 10 128.37 166.39 162.94 158.93 167.22 163.42 163.09 162.94 164.52 158.23 151.05 165.25 11 128.11 166.80 162.54 158.95 167.31 163.22 162.89 162.79 164.32 157.93 150.83 165.19 12 128.08 167.11 162.52 158.83 167.29 163.00 163.36 162.57 164.11 157.62 150.59 165.08 13 128.63 166.70 162.28 159.18 167.22 162.78 163.70 162.34 163.92 157.30 150.28 164.92 14 166.00 166.69 162.08 159.66 167.23 162.65 163.73 163.49 163.73 156.95 149.96 164.79 15 166.62 166.66 161.83 159.69 167.25 162.43 163.70 165.09 163.50 156.63 149.64 164.56 16 166.02 166.58 161.60 159.56 167.23 162.21 165.19 165.32 163.26 156.30 149.28 164.45 17 166.48 166.46 161.37 159.39 167.13 161.99 165.28 165.43 163.13 156.01 149.04 164.33 18 165.85 166.40 161.15 159.20 167.02 161.75 165.22 165.38 A 155.72 148.73 164.17 19 166.14 166.31 160.91 158.99 166.88 161.52 165.11 165.53 162.78 155.41 148.41 164.01 20 165.97 166.16 160.66 158.77 166.74 161.45 165.01 165.55 162.53 155.38 148.15 162.71 21 166.15 166.03 160.42 158.53 166.55 161.72 164.94 165.75 162.40 155.63 148.05 166.23 22 166.16 165.91 160.23 158.26 166.36 161.68 164.91 165.99 162.24 155.48 149.38 160.38 23 165.75 165.82 159.99 157.98 166.17 161.60 164.81 165.93 162.14 155.25 151.12 162.92 24 165.68 165.75 159.72 157.71 165.98 161.48 164.64 165.79 161.95 155.00 A 164.46 25 165.60 165.68 159.48 157.43 165.78 161.34 164.48 165.60 161.72 154.68 163.94 164.95 26 165.49 A 159.22 157.16 165.60 161.13 164.28 165.43 161.45 154.40 165.08 164.32 27 165.35 165.39 158.94 156.89 165.41 160.92 164.17 165.44 161.18 154.28 164.72 164.95 28 165.24 165.23 158.67 156.61 165.19 160.74 163.97 165.53 160.92 154.03 165.24 164.82 29 165.10 165.06 A 156.34 160.92 163.77 165.45 160.65 153.77 165.17 164.25 30 164.97 164.89 158.12 156.06 162.37 163.57 165.30 160.36 153.47 165.13 164.18 31 164.81 157.86 155.78 163.87 165.15 153.15 165.06 MAX 166.62 167.31 164.95 165.28 165.99 160.09 166.23 MIN 127.06 154.87 160.74 162.89 162.06 153.15 160.38 A No gage-height record --- --- --- --- --- --- --- 154 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR LOCATION.--Lat 18°20'45", long 66°14'17", Hydrologic Unit 21010005, 2.8 mi (4.5 km) west of Road 167, km 15.3, Buena Vista, Bayamón, 5.0 mi (8.0 km) east of Plaza de Corozal, 3.0 mi (4.8 km) northeast of Plaza de Naranjito. DRAINAGE AREA.--173 m2 (448 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage 164 ft (30 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.0 7.2 2.0 .00 .18 .04 1.0 1.8 4.1 1.6 1.4 2.8 2 2.0 7.3 2.0 .00 .39 .04 1.6 2.0 4.7 1.3 1.3 8.2 3 1.6 5.6 2.1 .00 .43 .16 1.6 2.1 3.8 1.7 1.2 195 4 1.6 5.5 1.9 .00 2.2 .42 1.7 2.0 2.0 1.7 .96 427 5 1.6 6.0 1.8 .00 6570 .28 2.4 1.3 2.4 1.6 .22 136 6 2.0 6.0 1.7 .05 .55 .23 1.6 1.1 2.5 2.5 .01 3.0 7 2.2 5.9 1.1 .12 .09 .24 2.3 1.1 2.6 1.8 1.1 2.9 8 2.2 5.4 .82 .03 .02 .31 3.2 1.6 2.5 1.6 .68 300 9 2.2 5.0 .73 .01 170 .32 2.9 2.0 2.5 1.6 .03 3.5 10 2.0 1820 .90 .01 .01 .84 2.7 2.0 2.6 1.5 .00 2.6 11 2.0 293 1.2 .02 .00 .91 2.5 1.7 2.0 1.5 .00 2.8 12 2.4 4.8 1.2 .06 .91 1.3 3.8 1.3 2.1 1.6 .00 2.5 13 2.5 144 1.0 .08 .10 1.3 5.2 1.2 2.2 1.8 .02 2.5 14 853 3.1 .91 .13 .00 1.2 4.8 2.0 2.3 2.0 .00 2.4 15 e11 3.0 .60 .08 .00 .89 2.2 2.0 1.8 2.5 .00 48 16 e2.0 3.1 .24 .46 .00 .83 89 2.2 2.2 2.4 .00 42 17 e134 3.0 .27 .55 .00 1.2 2.4 2.5 3.0 2.8 .04 1.8 18 e.11 3.6 .58 .55 .00 1.2 1.8 2.6 2.1 2.8 .01 1.9 19 e.05 4.3 .42 .57 .00 1.8 1.8 2.4 2.0 2.4 .00 1.9 20 e2.8 4.4 .28 .63 .00 1.2 1.9 .64 2.2 2.6 .00 399 21 e11 4.5 .25 .66 .00 1.1 2.0 .60 2.3 2.3 .01 3930 22 10 2.8 .18 .66 .00 1.1 1.9 .72 1.8 2.3 .00 e75700 23 85 2.4 .12 .66 .00 1.1 2.0 .87 1.7 2.7 .00 e25300 24 8.5 2.0 .13 .66 .00 .97 2.2 .94 1.6 2.7 .25 e777 25 7.0 2.2 .25 .66 .02 1.1 2.1 .97 1.8 2.1 2880 e646 26 7.2 2.4 .27 .65 .04 1.8 2.2 1.5 2.0 1.4 1100 e688 27 7.1 3.2 .27 .60 .23 1.2 2.0 1.5 2.0 2.0 642 e69 28 7.2 4.2 .29 .72 .04 1.1 1.4 2.0 1.7 1.4 330 e937 29 6.8 2.2 .02 .81 1.2 1.4 2.2 1.5 1.1 141 e1160 30 6.8 2.0 .00 .85 1.3 1.4 2.8 1.8 1.3 46 e729 31 7.0 .00 .70 1.8 4.8 1.4 3.7 TOTAL 1192.86 2368.1 23.53 10.98 6745.21 28.48 155.0 54.44 69.8 60.0 5149.93 111521.8 MEAN 38.5 78.9 .76 .35 241 .92 5.17 1.76 2.33 1.94 166 3717 MAX 853 1820 2.1 .85 6570 1.8 89 4.8 4.7 2.8 2880 75700 MIN .05 2.0 .00 .00 .00 .04 1.0 .60 1.5 1.1 .00 1.8 AC-FT 2370 4700 47 22 13380 56 307 108 138 119 10210 221200 CFSM .22 .46 .00 .00 1.39 .01 .03 .01 .01 .01 .96 21.5 IN. .26 .51 .01 .00 1.45 .01 .03 .01 .02 .01 1.11 24.01 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1998, BY WATER YEAR (WY) MEAN 171 75.2 35.5 216 59.6 15.9 31.4 109 38.4 64.9 43.4 1386 MAX 1107 225 161 1581 241 83.2 231 494 220 384 166 8046 (WY) 1991 1993 1993 1992 1998 1990 1993 1993 1993 1993 1998 1996 MIN .048 .004 .000 .19 .14 .022 .011 .000 .002 .037 .020 .001 (WY) 1992 1995 1995 1990 1995 1995 1995 1994 1994 1994 1989 1991 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1989 - 1998 ANNUAL TOTAL 4251.13 127380.13 ANNUAL MEAN 11.6 349 190 HIGHEST ANNUAL MEAN 714 1996 LOWEST ANNUAL MEAN 8.62 1997 HIGHEST DAILY MEAN 1820 Nov 10 75700 Sep 22 141000 Sep 10 1996 LOWEST DAILY MEAN .00 Jun 29 .00 Dec 30 .00 Jul 14 1989 ANNUAL SEVEN-DAY MINIMUM .00 Jun 28 .00 Dec 30 .00 Jul 14 1989 INSTANTANEOUS PEAK FLOW 122000 Sep 22 197000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 34.16 Sep 22 42.26 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 8430 252700 137300 ANNUAL RUNOFF (CFSM) .067 2.02 1.10 ANNUAL RUNOFF (INCHES) .92 27.42 14.90 10 PERCENT EXCEEDS 5.7 8.3 152 50 PERCENT EXCEEDS .97 1.8 1.2 90 PERCENT EXCEEDS .16 .02 .00 e Estimated 155 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 10,000 1,000 100 10 1 0.1 0.01 0.001 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 156 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to current year. INSTRUMENTATION.-- Automatic sediment sampler since 1989. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,390 mg/L September 10, 1996; Minimum daily mean, 0 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,810,000 tons (1,640,000 tonnes) September 10, 1996; Minimum daily mean, 0.0 ton several days 1999. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 524,000 tons (475,000 tonnes) September 22, 1998; Minimum daily mean, 0 ton several days. SEDIMENT LOADS: Maximum daily mean, 2,470 mg/L September 22, 1998; Minimum daily mean, 0 mg/L several days . SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2.0 10 .05 7.2 19 .37 2.0 2 .01 2 2.0 10 .05 7.3 18 .35 2.0 2 .01 3 1.6 10 .04 5.6 16 .25 2.1 2 .01 4 1.6 10 .04 5.5 15 .23 1.9 2 .01 5 1.6 10 .04 6.0 13 .21 1.8 3 .01 6 2.0 10 .05 6.0 3 .05 1.7 3 .01 7 2.2 10 .06 5.9 2 .03 1.1 3 .01 8 2.2 10 .06 5.4 2 .03 .82 4 .01 9 2.2 10 .06 5.0 2 .03 .73 4 .01 10 2.0 10 .05 1820 49 372 .90 4 .01 11 2.0 8 .04 293 21 32 1.2 3 .01 12 2.4 6 .04 4.8 11 .15 1.2 3 .01 13 2.5 6 .04 144 16 18 1.0 3 .01 14 853 31 119 3.1 8 .07 .91 3 .01 15 e11 12 e45 3.0 7 .05 .60 2 <.01 16 e2.0 10 e.05 3.1 5 .05 .24 2 <.01 17 e134 22 e11 3.0 5 .04 .27 2 <.01 18 e.11 10 e.01 3.6 4 .04 .58 2 <.01 19 e.05 10 e.01 4.3 3 .04 .42 2 <.01 20 e2.8 11 e.08 4.4 3 .03 .28 2 <.01 21 e11 11 e.32 4.5 2 .03 .25 2 <.01 22 10 11 .30 2.8 2 .01 .18 1 <.01 23 85 31 18 2.4 1 .01 .12 1 <.01 24 8.5 3 .08 2.0 1 .01 .13 1 <.01 25 7.0 2 .04 2.2 1 .01 .25 1 <.01 26 7.2 2 .04 2.4 1 .01 .27 1 <.01 27 7.1 6 .11 3.2 1 .01 .27 1 <.01 28 7.2 18 .36 4.2 1 .01 .29 1 <.01 29 6.8 20 .38 2.2 1 .01 .02 1 <.01 30 6.8 20 .37 2.0 2 .01 .00 0 .00 31 7.0 19 .37 .00 0 .00 TOTAL 1192.86 196.14 2368.1 424.14 23.53 0.29 --- --- --- --- --- --- --- --- --- 157 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 .00 0 .00 .18 1 <.01 .04 1 <.01 2 .00 0 .00 .39 1 <.01 .04 1 <.01 3 .00 0 .00 .43 1 <.01 .16 1 <.01 4 .00 0 .00 2.2 2 .07 .42 1 <.01 5 .00 0 .00 6570 223 10100 .28 1 <.01 6 .05 1 <.01 .55 3 <.01 .23 1 <.01 7 .12 1 <.01 .09 2 <.01 .24 1 <.01 8 .03 2 <.01 .02 1 <.01 .31 1 <.01 9 .01 2 <.01 170 32 35 .32 1 <.01 10 .01 2 <.01 .01 1 <.01 .84 1 <.01 11 .02 2 <.01 .00 1 .00 .91 1 <.01 12 .06 2 <.01 .91 1 <.01 1.3 1 <.01 13 .08 2 <.01 .10 1 <.01 1.3 1 <.01 14 .13 2 <.01 .00 1 .00 1.2 1 <.01 15 .08 2 <.01 .00 0 .00 .89 1 <.01 16 .46 2 <.01 .00 0 .00 .83 1 <.01 17 .55 2 <.01 .00 0 .00 1.2 1 <.01 18 .55 2 <.01 .00 0 .00 1.2 1 <.01 19 .57 2 <.01 .00 0 .00 1.8 1 <.01 20 .63 2 <.01 .00 0 .00 1.2 1 <.01 21 .66 2 <.01 .00 0 .00 1.1 1 <.01 22 .66 1 <.01 .00 1 .00 1.1 1 <.01 23 .66 1 <.01 .00 0 .00 1.1 1 <.01 24 .66 1 <.01 .00 1 .00 .97 1 <.01 25 .66 1 <.01 .02 1 <.01 1.1 1 <.01 26 .65 1 <.01 .04 1 <.01 1.8 1 <.01 27 .60 1 <.01 .23 1 <.01 1.2 1 <.01 28 .72 1 <.01 .04 1 <.01 1.1 1 <.01 29 .81 1 <.01 --- --- --- 1.2 1 <.01 30 .85 1 <.01 --- --- --- 1.3 1 <.01 31 .70 1 <.01 --- --- --- 1.8 1 <.01 TOTAL 10.98 --- 0.26 6745.21 --- 10135.20 28.48 --- 0.31 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 1.0 1 <.01 1.8 6 .03 4.1 2 .03 2 1.6 1 <.01 2.0 6 .03 4.7 3 .03 3 1.6 1 <.01 2.1 6 .04 3.8 3 .03 4 1.7 2 .01 2.0 6 .04 2.0 3 .01 5 2.4 3 .02 1.3 7 .02 2.4 3 .02 6 1.6 5 .02 1.1 7 .02 2.5 3 .02 7 2.3 9 .06 1.1 6 .02 2.6 3 .02 8 3.2 13 .12 1.6 6 .03 2.5 3 .02 9 2.9 13 .10 2.0 5 .03 2.5 3 .02 10 2.7 13 .09 2.0 5 .03 2.6 3 .02 11 2.5 12 .08 1.7 5 .02 2.0 3 .02 12 3.8 12 .12 1.3 4 .01 2.1 3 .02 13 5.2 11 .16 1.2 4 .01 2.2 3 .02 14 4.8 11 .14 2.0 4 .02 2.3 3 .02 15 2.2 10 .06 2.0 3 .02 1.8 3 .01 16 89 17 6.2 2.2 3 .02 2.2 3 .02 17 2.4 9 .06 2.5 3 .02 3.0 3 .02 18 1.8 8 .04 2.6 3 .02 2.1 3 .01 19 1.8 7 .03 2.4 2 .01 2.0 3 .01 20 1.9 6 .03 .64 2 <.01 2.2 3 .01 21 2.0 5 .03 .60 2 <.01 2.3 3 .02 22 1.9 5 .02 .72 2 <.01 1.8 3 .01 23 2.0 4 .02 .87 2 <.01 1.7 2 .01 24 2.2 4 .02 .94 2 <.01 1.6 2 .01 25 2.1 4 .03 .97 2 .01 1.8 2 .01 26 2.2 5 .03 1.5 2 .01 2.0 2 .01 27 2.0 5 .03 1.5 2 .01 2.0 2 .01 28 1.4 5 .02 2.0 2 .01 1.7 2 .01 29 1.4 5 .02 2.2 2 .01 1.5 2 .01 30 1.4 5 .02 2.8 2 .02 1.8 2 .01 31 4.8 2 .03 TOTAL 155.0 7.61 54.44 0.59 69.8 0.49 --- --- --- --- --- --- --- --- 158 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 1.6 2 .01 1.4 6 .02 2.8 9 .07 2 1.3 2 .01 1.3 6 .02 8.2 10 .40 3 1.7 2 .01 1.2 6 .02 22 14 4 1.7 2 .01 .96 6 .01 419 17 32 5 1.6 2 .01 .22 6 <.01 133 12 4.6 6 2.5 2 .01 .01 6 <.01 .46 10 .08 7 1.8 2 .01 1.1 6 .02 .42 9 .07 8 1.6 2 .01 .68 6 .01 296 10 117 9 1.6 2 .01 .03 6 <.01 .70 13 .12 10 1.5 2 .01 .00 0 .00 .29 12 .08 11 1.5 2 .01 .00 0 .00 .37 11 .08 12 1.6 2 .01 .00 6 .00 .28 10 .07 13 1.8 2 .01 .02 6 <.01 .28 9 .06 14 2.0 2 .01 .00 0 .00 .24 9 .05 15 2.5 2 .01 .00 0 .00 47 14 3.2 16 2.4 2 .01 .00 0 .00 40 19 2.4 17 2.8 2 .02 .04 6 <.01 .05 10 .05 18 2.8 3 .02 .01 6 <.01 .06 6 .03 19 2.4 3 .02 .00 6 .00 .04 5 .03 20 2.6 3 .02 .00 6 .00 398 9 35 21 2.3 4 .02 .01 6 <.01 3930 106 8050 22 2.3 4 .03 .00 6 .00 e75700 2470 e524000 23 2.7 4 .03 .00 0 .00 e25300 749 e175000 24 2.7 5 .04 .25 6 <.01 e777 41 e362 25 2.1 6 .03 2880 51 606 e646 35 e301 26 1.4 6 .02 1100 11 587 e688 29 e320 27 2.0 7 .04 642 11 291 e69 15 e6.2 28 1.4 7 .03 330 10 133 e937 29 e491 29 1.1 7 .02 141 10 45 e1160 37 e587 30 1.3 7 .02 46 10 10 e729 32 e382 31 1.4 6 .03 3.7 10 .10 TOTAL 60.0 0.55 5149.93 1672.28 709708.59 e Estimated < Actual value is known to be less than the value shown WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) NOV 03... 1100 5.5 80 1.2 50 APR 16... 1843 370 24 24 67 SEP 03... 1146 123 26 8.6 78 04... 1931 1180 32 102 73 20... 2315 3840 54 560 56 21... 0644 3830 27 279 81 23... 1315 24800 704 47200 99 --- --- --- --- --- --- --- 159 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR LOCATION.--Lat 18°24'41", long 66°15'39", Hydrologic Unit 21010005, on left bank, at downstream side of bridge on Highway 2, 1.3 mi ( 2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), excludes 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. Area at site used prior to September 25, 1984, 200 mi2 (518 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. Prior to October 1984, published as Río de la Plata at Toa Alta, PR; October 1984 to September 1988 published as 50046900. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 9.15 ft (2.789 m), above mean sea level. Prior to October, 1984, at site about 1.0 mi (1.6 km) upstream at mean sea level datum. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. Flow affected by water extraction for La Virgencita water treatment plant by Puerto Rico Aqueduct and Sewer Authority of about 3.99 ft3/s (0.11 m3/s). Located about 1,000 ft upstream from station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations of major floods, as pointed out by local residents are as follows: Sept. 13, 1928, 120,000 ft3/s (3,400 m3/s), gage height, 37.4 ft (11.40 m); June 16, 1943, 82,000 ft3/s (2,322 m3/s), gage height, 34.4 ft (10.48 m), at site 1.0 mi upstream and different datum. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 39 29 26 25 22 24 37 19 21 34 22 69 2 41 35 24 23 22 23 29 20 24 34 20 63 3 33 42 24 26 21 22 24 20 27 30 18 172 4 142 45 24 22 38 22 21 21 25 e70 14 272 5 165 44 24 22 9370 23 21 21 21 34 13 482 6 95 31 25 60 670 23 19 20 23 55 e14 102 7 51 32 25 157 100 23 22 23 21 73 e62 72 8 40 28 25 39 68 23 55 26 38 28 110 252 9 49 27 24 33 279 22 27 22 46 24 33 255 10 35 1510 24 30 64 25 24 18 46 27 76 57 11 58 911 23 37 51 23 22 18 26 25 52 43 12 246 62 23 43 50 21 29 19 26 21 22 40 13 206 183 22 105 47 22 42 19 29 20 19 40 14 675 69 22 86 50 28 28 34 29 20 16 28 15 3110 67 21 33 52 28 23 91 25 21 16 27 16 3460 52 21 28 39 23 575 47 45 23 16 80 17 858 33 20 24 33 30 172 63 57 33 19 44 18 1750 32 20 24 30 26 45 77 289 66 35 30 19 425 54 19 24 28 26 41 31 89 53 31 28 20 213 29 19 22 26 23 41 26 35 65 19 25 21 182 176 19 24 27 25 55 24 35 66 36 2660 22 62 39 19 23 25 23 37 22 44 26 25 47100 23 140 30 18 21 25 21 33 87 34 19 23 7990 24 79 33 19 22 24 20 32 52 29 46 82 594 25 38 28 21 23 23 21 39 28 30 24 3710 914 26 39 28 23 23 22 21 46 24 31 20 e1010 692 27 39 28 25 22 24 21 42 22 31 29 1420 295 28 37 27 25 22 23 20 e26 22 33 24 1120 886 29 33 28 25 23 54 e19 22 34 19 627 717 30 32 26 23 23 37 e19 21 34 20 174 805 31 31 25 20 216 21 22 95 TOTAL 12403 3758 697 1109 11253 959 1645 980 1277 1071 8949 64834 MEAN 400 125 22.5 35.8 402 30.9 54.8 31.6 42.6 34.5 289 2161 MAX 3460 1510 26 157 9370 216 575 91 289 73 3710 47100 MIN 31 26 18 20 21 20 19 18 21 19 13 25 AC-FT 24600 7450 1380 2200 22320 1900 3260 1940 2530 2120 17750 128600 CFSM 2.00 .63 .11 .18 2.01 .15 .27 .16 .21 .17 1.44 10.8 IN. 2.31 .70 .13 .21 2.10 .18 .31 .18 .24 .20 1.67 12.07 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 1998, BY WATER YEAR (WY) MEAN 456 415 308 183 133 96.7 178 332 157 143 243 444 MAX 4813 2015 1352 929 409 468 723 1939 847 690 1677 3173 (WY) 1971 1985 1971 1992 1989 1969 1987 1985 1970 1961 1979 1996 MIN 18.8 18.4 14.8 16.9 16.0 8.31 5.07 7.63 11.4 13.2 16.5 19.2 (WY) 1995 1995 1995 1984 1983 1986 1984 1984 1977 1994 1976 1991 160 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR--Continued SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1960 - 1998 ANNUAL TOTAL 37439 ANNUAL MEAN 103 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 3460 LOWEST DAILY MEAN 11 ANNUAL SEVEN-DAY MINIMUM 12 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 74260 ANNUAL RUNOFF (CFSM) .51 ANNUAL RUNOFF (INCHES) 6.97 10 PERCENT EXCEEDS 149 50 PERCENT EXCEEDS 32 90 PERCENT EXCEEDS 20 108935 298 255 824 1971 31.5 1994 Oct 16 47100 Sep 22 68100 Sep 10 1996 Sep 6 13 Aug 5 2.7 Apr 17 1984 Sep 5 18 Jul 31 2.9 Apr 15 1984 104000 Sep 22 Not determined Sep 10 1996 26.14 Sep 22 27.33 Sep 10 1996 216100 185000 1.49 1.28 20.28 17.36 192 473 29 81 20 18 e Estimated O N D J F M A M J J A S 10 100,000 20 50 100 200 500 1,000 2,000 5,000 10,000 20,000 50,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 161 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'41", long 66°15'39", at Highway 2, 1.3 mi (2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), exclude 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamani. PERIOD OF RECORD.--Water years 1958 to current year WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 27... 1340 37 467 7.6 29.5 1.3 5.4 70 <10 K1500 860 FEB 18... 1135 31 514 7.7 27.0 2.2 10.6 132 11 2100 <10 JUN 15... 1500 25 501 7.7 31.5 .46 7.0 95 <10 K730 K20 SEP 03... 1205 60 494 7.9 30.0 3.8 2.2 29 13 2100 540 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 27... 180 53 11 23 .8 3.2 170 <.5 17 32 FEB 18... -- -- -- -- -- -- 190 -- -- -­ JUN 15... 180 56 11 26 .8 3.1 180 -- 17 40 SEP 03... 190 56 12 23 .7 3.9 190 <1.0 16 34 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 27... .11 19 260 26.2 5 1.14 .062 1.20 .070 .49 FEB 18... -- -- -- -- 2 .414 .076 .490 .020 .68 JUN 15... .15 16 276 18.3 1 .592 .028 .620 .060 .69 SEP 03... .11 20 279 45.0 8 .510 .120 .630 .420 .68 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... .56 1.8 7.8 .100 1 <100 60 <1 <1 <10 FEB 18... .70 1.2 5.3 .060 -- -- -- -- -- -­ JUN 15... .75 1.4 6.1 .080 1 <100 40 <1 <1 12 SEP 03... 1.1 1.7 7.7 .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 162 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HWY 2 NR TOA ALTA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 150 <1 140 <.10 <1 <1 <10 <.010 <1 .10 FEB 18... JUN 15... 130 <1 76 <.10 <1 <1 <10 <.010 3 .03 SEP 03... 163 047560 0476 047850 219 047550 Río Río Río Río Río Pu e r t o N u e vo Piedras Piedras Río Río Guaynabo Q u e b r a d a Quebrada Margarita S Antón de B a y a m ó n Hondo Canal del Río de Bayamón Minillas Lago Lago Laguna Laguna Bahía de San Juan DORADO BAJA OCEAN COMERIO CIDRA AGUAS BUENAS 0 0 1 1 2 2 3 3 4 4 047560 0476 047850 047990 048510 047530 049920 049820 0491 219 652 PN-2 PN-5 PN-6 PN-10 PN-13 PN-19 PN-8C 048770 0488 047550 047549 048680 047537 Basin area PUERTO RICO QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER an de Cidra Las Curias Represa de Río Piedras San José Martín Peña TOA ALTA TOA CATAÑO SAN JUAN ATLANTIC NARANJITO BAYAMÓN GUAYNABO TRUJILLO ALTO 5 MILES 5 KILOMETERS Figure 17. Río Hondo to Río Puerto Nuevo basins. 164 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATANO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°26'13", long 66°09'36", at Río Hondo Channel, 800 ft (245 m) below junction with Río Hondo, 0.9 mi (1.5 km) downstream from bridge on de Diego Expressway and 1.1 mi (1.8 km) above mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI­ SPE- WATER DIS- DEMAND, FORM, STREP­ CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 07... 1000 27000 7.2 28.0 5.8 3.7 47 110 4600 390 MAR 09... 0845 14100 7.4 24.5 5.4 3.0 36 57 K1700 820 JUN 10... 1215 1530 7.3 31.0 6.9 3.1 42 <10 500000 14000 SEP 15... 1345 441 8.2 31.0 4.7 6.0 80 <10 E3000 K11400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 07... 2800 200 570 4690 38 69 160 <.5 1200 9200 MAR 09... -- -- -- -- -- -- 110 -- -- -­ JUN 10... 97 27 7.3 13 .6 3.1 90 -- 17 14 SEP 15... 130 31 12 27 1 3.2 150 <1.0 16 27 SOLIDS, RESIDUE NITRO­ FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) NOV 07... .45 5.6 16100 89 .068 .042 .110 1.10 .50 1.6 MAR 09... -- -- -- 14 .436 .064 .500 .660 .30 .96 JUN 10... .10 19 156 7 .223 .047 .270 .390 .91 1.3 SEP 15... .10 26 232 4 -- .014 <.020 .060 .78 .84 CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) NOV 07... 1.7 7.6 .230 2 <100 1900 <5 2 33 610 MAR 09... 1.5 6.5 .110 -- -- -- -- -- -- -­ JUN 10... 1.6 6.9 .260 <1 <100 860 <5 <1 20 440 SEP 15... -- -- .090 -- -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 165 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATANO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 07... 81 260 <.10 <1 <1 20 <.010 <1 .24 MAR 09... JUN 10... 60 220 .10 <1 1 <10 <.010 <1 .02 SEP 15... --- --- --- --- --- --- --- 166 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR LOCATION.--Lat 18°10'11", long 66°07'18", Hydrologic Unit 21010005, at left bank, 2.61 mi (4.20 km) southeast of plaza de Cidra, 0.56 mi (0.90 km) southwest from Escuela Segunda Unidad de Bayamón, and 2.70 mi (4.34 km) northeast from Central Cayey. DRAINAGE AREA.--0.45 mi2 (1.16 km2). PERIOD OF RECORD.--July 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,378 ft (420 m), from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .08 .10 .08 .03 e.05 .10 .76 .05 .11 .04 .03 .09 2 .14 .09 .09 .05 e.05 .09 .58 .05 .09 .04 .19 .77 3 .10 .09 .08 .05 e.04 .10 .36 .09 .09 .05 .04 .49 4 .09 .09 .08 .07 e.55 .09 .28 .09 .09 .22 .03 4.4 5 .08 .09 .07 .08 e49 .09 .24 .06 .09 .06 .02 .41 6 .08 .10 .07 1.8 e1.4 .10 .14 .05 .07 .04 .09 .22 7 .15 .09 .06 2.3 e.61 .25 .16 .05 .06 .04 .10 .16 8 .11 .09 .06 .81 e7.0 .18 .16 1.6 .05 .04 .15 .19 9 .12 .09 .05 .44 e2.3 .08 .11 .32 .06 .04 .16 .23 10 .16 4.1 .05 .33 e.64 .09 .11 .14 .06 .03 .05 .23 11 .12 .57 .04 .21 .51 .11 .15 .08 .05 .03 .05 .11 12 .10 .23 .05 1.1 .46 .12 .29 .06 .28 .03 .05 .08 13 10 .16 .04 2.8 .37 .14 .22 .06 .18 .03 .04 .12 14 25 .12 .05 1.3 .56 .27 .12 .07 .07 .03 .03 .13 15 4.0 .10 .04 .35 .52 .23 .11 .08 .06 .04 .02 2.0 16 1.7 .12 .04 .21 .36 .17 .11 .08 .07 .04 .02 .37 17 8.0 .11 .04 .16 .43 .14 .82 .07 .31 .04 .03 .12 18 1.7 .10 .04 .05 .31 .10 .24 .06 .21 .07 .07 .08 19 .43 .11 .04 .04 .20 .09 .20 .17 .08 .07 .04 .09 20 .19 .09 .04 .03 .18 1.9 .28 .06 .05 1.1 .03 .11 21 .14 .36 .05 .03 .17 .90 .11 .06 .10 .29 .23 81 22 .12 .63 .04 .03 .14 .64 .09 .06 .31 .07 4.1 97 23 .10 .58 .03 .04 .15 .33 .07 .05 .09 .04 .50 4.0 24 .11 .54 .03 e.04 .11 .21 .07 .06 .08 .05 18 .79 25 .13 .22 .03 e.04 .09 .25 .09 .05 .07 .03 10 .43 26 .11 .14 .03 e.04 .13 .16 .14 .57 .06 .02 1.8 .37 27 .10 .11 .03 e.04 .13 .56 .19 1.3 .06 .10 .56 .33 28 .10 .09 .03 e.04 .13 .43 .17 .53 .06 .09 .38 .22 29 .10 .08 .03 e.04 7.7 .08 .29 .06 .04 .24 .18 30 .10 .08 .04 e.04 3.6 .06 .29 .05 .03 .14 .16 31 .10 .03 e.04 1.0 .18 .02 .11 TOTAL 53.56 9.47 1.48 12.63 66.59 20.22 6.51 6.73 3.07 2.86 37.30 194.88 MEAN 1.73 .32 .048 .41 2.38 .65 .22 .22 .10 .092 1.20 6.50 MAX 25 4.1 .09 2.8 49 7.7 .82 1.6 .31 1.1 18 97 MIN .08 .08 .03 .03 .04 .08 .06 .05 .05 .02 .02 .08 AC-FT 106 19 2.9 25 132 40 13 13 6.1 5.7 74 387 CFSM 3.84 .70 .11 .91 5.28 1.45 .48 .48 .23 .21 2.67 14.4 IN. 4.43 .78 .12 1.04 5.50 1.67 .54 .56 .25 .24 3.08 16.11 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 1998, BY WATER YEAR (WY) MEAN .67 .66 .29 .55 .81 .27 .22 .62 .75 1.00 1.01 3.06 MAX 1.73 1.30 .63 .63 2.38 .65 .45 2.02 1.79 2.12 1.87 6.50 (WY) 1998 1993 1993 1996 1998 1998 1993 1993 1996 1993 1996 1998 MIN .30 .32 .048 .41 .16 .097 .095 .10 .10 .092 .46 .20 (WY) 1997 1998 1998 1998 1993 1993 1997 1997 1998 1998 1992 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1992 - 1998 ANNUAL TOTAL 147.05 415.30 ANNUAL MEAN .40 1.14 .86 HIGHEST ANNUAL MEAN 1.16 1996 LOWEST ANNUAL MEAN .31 1997 HIGHEST DAILY MEAN 25 Oct 14 97 Sep 22 141 Sep 10 1996 LOWEST DAILY MEAN .02 Jul 3 .02 Jul 26 .02 Jul 3 1997 ANNUAL SEVEN-DAY MINIMUM .03 Jun 28 .03 Dec 23 .03 Jun 28 1997 INSTANTANEOUS PEAK FLOW 1150 Sep 21 1150 Sep 21 1998 INSTANTANEOUS PEAK STAGE 7.89 Sep 21 7.89 Sep 21 1998 INSTANTANEOUS LOW FLOW .02 Jul 31 .02 Jul 15 1997 ANNUAL RUNOFF (AC-FT) 292 824 626 ANNUAL RUNOFF (CFSM) .90 2.53 1.92 ANNUAL RUNOFF (INCHES) 12.16 34.33 26.11 10 PERCENT EXCEEDS .51 .78 1.0 50 PERCENT EXCEEDS .11 .10 .16 90 PERCENT EXCEEDS .04 .04 .06 e Estimated 167 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 168 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR LOCATION.--Lat 18°10'28", long 66°08'38", Hydrologic Unit 21010005, at left bank, 1.2 mi (1.9 km) southeast of Plaza de Cidra, 1.2 mi (1.9 km) southwest from Escuela Segunda Unidad de Bayamón, and 0.4 mi (0.6 km) upstream from Lago de Cidra. DRAINAGE AREA.--0.80 mi2 (2.07 km2). PERIOD OF RECORD.--August 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,345 ft (410 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .18 .50 .31 e.30 .28 .34 .70 .31 .29 .18 .21 .49 2 .20 .50 .31 e.31 .27 .34 .55 .30 .28 .18 .23 2.5 3 .17 .56 .31 e.30 .24 .36 .44 .42 .27 .18 .21 2.0 4 .16 .49 .29 e.31 1.1 .37 .40 .36 .28 .32 .22 4.3 5 .16 .61 .32 e.32 67 .36 .39 .32 .28 .20 .22 1.2 6 .16 .47 .29 e.62 2.6 .34 .38 .31 .25 .18 .36 .86 7 .45 .46 .29 e1.0 1.3 .43 3.1 .32 .25 .18 .38 .75 8 .25 .46 .29 e.39 9.8 .37 .61 2.4 .24 .16 .33 .76 9 .19 .61 .28 e.32 3.3 .29 .41 1.1 .30 .15 .38 .62 10 .19 10 .29 e.31 1.3 .31 .37 .62 .24 .14 .28 .60 11 .30 .87 .29 e.30 .93 .34 .55 .54 .23 .12 .26 .50 12 .22 .65 .30 e.30 .77 .36 .67 .47 .64 .10 .34 .45 13 13 .56 .32 e.45 .68 .36 .50 .56 .43 .09 .25 .43 14 54 .51 .32 e.44 .87 .43 .45 .61 .29 .09 .24 .41 15 11 .47 .32 e.33 .75 .35 .45 .48 .26 .25 .41 .88 16 4.5 .46 .33 e.30 .67 .34 .59 .43 .26 .17 .24 .45 17 37 .46 .36 .29 .71 .30 .82 .41 .36 .16 .31 .41 18 6.5 .48 .32 .27 .60 .34 .64 .53 .28 1.2 .85 .40 19 2.2 .45 .31 .26 .56 .29 .58 .46 .28 .24 .35 .41 20 1.5 .46 .33 .26 .53 2.0 .52 .42 .25 5.5 .47 .48 21 1.1 .54 .36 .26 .52 .59 .42 .38 .47 .84 1.7 138 22 .94 .86 .34 .26 .48 .43 .41 .37 .43 .37 9.7 219 23 .83 .97 e.31 .26 .47 .36 .39 .43 .27 .76 1.3 20 24 .70 .96 e.31 .26 .48 .35 .35 .37 .25 .53 23 5.4 25 .66 .50 e.30 .29 .44 .38 .34 .38 .23 .27 17 3.2 26 .62 .47 e.30 .26 .42 .32 .49 1.2 .23 .23 6.5 3.4 27 .55 .39 e.30 .24 .34 .55 .42 1.6 .22 .96 2.4 5.2 28 .53 .35 e.30 .24 .49 .35 .38 .47 .22 .82 1.9 3.1 29 .51 .33 e.30 .24 3.9 .33 .53 .22 .29 1.1 2.1 30 .49 .33 e.30 .22 14 .32 .38 .20 .25 .76 1.7 31 .49 e.30 .24 1.6 .32 .22 .54 TOTAL 139.75 25.73 9.60 10.15 97.90 31.45 16.97 17.80 8.70 15.33 72.44 420.00 MEAN 4.51 .86 .31 .33 3.50 1.01 .57 .57 .29 .49 2.34 14.0 MAX 54 10 .36 1.0 67 14 3.1 2.4 .64 5.5 23 219 MIN .16 .33 .28 .22 .24 .29 .32 .30 .20 .09 .21 .40 AC-FT 277 51 19 20 194 62 34 35 17 30 144 833 CFSM 5.64 1.07 .39 .41 4.37 1.27 .71 .72 .36 .62 2.92 17.5 IN. 6.50 1.20 .45 .47 4.55 1.46 .79 .83 .40 .71 3.37 19.53 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 1998, BY WATER YEAR (WY) MEAN 1.72 1.13 .69 .73 1.38 .56 .66 .93 .66 1.49 1.47 6.63 MAX 4.51 1.56 1.11 1.01 3.50 1.01 1.23 2.26 1.21 3.02 2.34 16.7 (WY) 1998 1993 1993 1997 1998 1998 1993 1993 1996 1993 1998 1996 MIN .76 .86 .31 .33 .33 .15 .37 .42 .25 .29 .48 .25 (WY) 1997 1998 1998 1998 1993 1993 1996 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1992 - 1998 ANNUAL TOTAL 322.70 865.82 ANNUAL MEAN .88 2.37 1.61 HIGHEST ANNUAL MEAN 2.37 1998 LOWEST ANNUAL MEAN .63 1997 HIGHEST DAILY MEAN 54 Oct 14 219 Sep 22 401 Sep 10 1996 LOWEST DAILY MEAN .16 Oct 4 .09 Jul 13 .09 Jul 13 1998 ANNUAL SEVEN-DAY MINIMUM .17 Sep 30 .12 Jul 8 .12 Jun 6 1993 INSTANTANEOUS PEAK FLOW 2060 Sep 21 2380 Sep 10 1996 INSTANTANEOUS PEAK STAGE 11.24 Sep 21 12.02 Sep 10 1996 INSTANTANEOUS LOW FLOW .08 Jul 14 .08 Jul 14 1998 ANNUAL RUNOFF (AC-FT) 640 1720 1160 ANNUAL RUNOFF (CFSM) 1.11 2.97 2.01 ANNUAL RUNOFF (INCHES) 15.01 40.26 27.29 10 PERCENT EXCEEDS 1.0 1.8 1.4 50 PERCENT EXCEEDS .43 .38 .47 90 PERCENT EXCEEDS .19 .23 .20 e Estimated 169 RIO DE BAYAMON BASIN 50047540 RIO SABANA AT VISTA MONTE, PR--Continued O N D J F M A M J J A S 0.01 1,000 0.02 0.05 0.1 0.2 0.5 1 2 5 10 20 50 100 200 500 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 170 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR LOCATION.--Lat 18°11'57", long 66°08'29", Hydrologic Unit 21010005, at Lago de Cidra Dam on Río de Bayamón, 1.9 mi (3.0 km) northeast of Plaza de Cidra and 1.8 mi (2.9 km) northwest of Escuela Segunda Unidad de Bayamón. DRAINAGE AREA.--8.26 mi2 (21.39 km2). ELEVATION RECORDS PERIOD OF RECORD.--January 1988 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago de Cidra was completed in 1946. The maximum storage is 5,300 ac-ft (6.53 hm3) and provides supplemental water to metropolitan San Juan. The dam is a concrete gravity and earthfill structure approximately 541 ft (165 m) long between abutments with a maximum structural height of about 78.7 ft (24.0 m). The spillway portion of the dam, length 131 ft (40 m) and crest elevation 1,322 ft (403 m), is an ungated ogee crest located 131 ft (40 m) from the right abutment. This dam is owned by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,328.09 ft (404.80 m), Sep. 10, 1996; minimum elevation 1,295.86 ft (394.98 m), April 22,1995. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,325.07 ft (403.88 m), Sep.22; minimum elevation, 1,304.37 ft (397.57 m), Aug. 20,21. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,295 860 1,305 1,970 1,309 2,610 1,312 3,100 1,319 4,400 1,322 5,200 1,328 6,920 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1313.57 1320.53 1318.23 1313.50 1312.50 1316.66 1317.01 1315.86 1312.62 1306.88 1306.95 1309.12 2 1313.62 1320.45 1318.13 1313.37 1312.30 1316.56 1317.01 1315.72 1312.45 1306.75 1306.87 1309.26 3 1313.64 1320.39 1318.01 A 1312.10 1316.48 1317.01 1315.61 1312.29 1306.71 1306.80 1309.13 4 1313.64 A 1317.91 1313.15 1312.23 1316.44 1317.01 1315.44 1312.00 1306.73 1306.68 1309.28 5 1313.65 A 1317.77 1313.01 1316.89 1316.47 1317.02 1315.31 1311.75 1306.71 1306.51 1309.06 6 1313.61 A 1317.61 A 1316.86 1316.38 1317.00 1315.19 1311.51 1306.71 A 1308.85 7 1313.64 1320.08 1317.44 1313.88 1316.72 1316.39 1317.31 1315.11 1311.16 1306.61 1306.42 1308.64 8 1313.67 1319.98 1317.28 1313.91 1317.58 1316.33 1317.30 1315.33 1310.91 1306.60 1306.30 1308.60 9 1313.69 1319.90 1317.16 1313.96 1317.52 1316.27 1317.27 1315.29 1310.49 1306.60 1306.18 1308.58 10 1313.71 1320.46 1316.92 1313.92 1317.47 1316.17 1317.22 1315.19 1310.28 1306.48 1306.03 1308.47 11 1313.82 A 1316.78 1313.90 1317.56 1316.02 1317.24 1315.08 1309.98 1306.35 1305.93 1308.33 12 1313.80 A 1316.62 1313.93 1317.52 1315.95 1317.24 1315.00 1309.79 1306.20 1305.84 1308.17 13 1315.58 A 1316.45 1314.01 1317.46 1315.90 1317.20 1314.89 1309.50 1306.11 1305.64 1308.05 14 1319.51 A 1316.27 1313.90 1317.56 1315.84 1317.16 A 1309.19 1305.90 1305.42 1307.95 15 1319.92 A 1316.08 1313.78 1317.44 1315.76 1317.11 A 1308.88 1305.74 1305.22 1308.12 16 1319.99 A 1315.90 1313.67 1317.37 1315.67 1317.11 A 1308.64 1305.66 1305.01 1307.99 17 1321.57 A 1315.77 1313.55 1317.32 1315.57 1317.10 A 1308.48 1305.63 1304.83 1307.80 18 1321.61 A 1315.63 1313.43 1317.24 1315.45 1317.06 1314.51 A 1305.82 1304.70 1307.56 19 1321.56 1319.57 1315.49 1313.31 1317.20 1315.34 1316.99 A 1308.13 1305.76 1304.52 1307.31 20 1321.46 1319.46 1315.35 1313.28 1317.16 1315.72 1316.91 1314.31 1307.94 1306.59 1304.37 1306.97 21 1321.38 1319.36 1315.23 1313.26 1317.13 1315.71 1316.81 1314.19 1307.76 1306.60 1304.52 1319.66 22 1321.31 1319.28 1315.07 1313.23 1317.09 1315.66 1316.69 1314.08 1307.56 1306.64 1305.66 1323.43 23 1321.20 1319.15 1314.91 1313.20 1317.05 1315.61 1316.60 1313.98 1307.44 1306.68 1305.64 1322.65 24 1321.12 1319.08 1314.75 1313.16 1316.96 1315.53 1316.51 1313.89 1307.48 1306.71 1308.30 1322.52 25 1321.04 1318.99 1314.59 1313.15 1316.89 1315.47 1316.35 1313.65 1307.31 1306.74 1309.51 1322.49 26 1320.96 1318.90 1314.43 1313.12 1316.86 1315.40 1316.37 1313.60 1307.37 1306.76 1309.81 1322.54 27 1320.87 1318.76 1314.29 1313.05 1316.79 1315.39 1316.28 1313.53 1307.27 1306.95 1309.76 1322.47 28 1320.80 1318.63 1314.13 1312.98 1316.74 1315.33 1316.21 1313.33 1307.12 1307.03 1309.78 1322.37 29 1320.73 1318.49 1314.00 1312.89 --- 1315.86 1316.12 1313.14 1307.05 1307.03 1309.67 1322.26 30 1320.66 1318.35 1313.80 1312.86 --- 1316.92 1316.00 1312.94 1306.88 1307.03 1309.58 1322.07 31 1320.59 --- 1313.65 1312.72 --- 1316.99 --- 1312.78 --- 1307.00 1309.39 --­ MAX 1321.61 --- 1318.23 --- 1317.58 1316.99 1317.31 --- --- 1307.03 --- 1323.43 MIN 1313.57 --- 1313.65 --- 1312.10 1315.33 1316.00 --- --- 1305.63 --- 1306.97 A No gage-height record --- --- --- --- --- --- --- 171 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR LOCATION.--Lat 18°12'04", long 66°08'26", Hydrologic Unit 21010005, 0.2 mi (0.3 km) downstream of Lago Cidra Dam on right bank, 2.1 mi (3.4 km) northwest of Plaza de Cidra. DRAINAGE AREA.--8.31 mi2 (21.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,279 ft (390 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.6 9.6 15 17 e32 25 18 e25 24 11 10 30 2 8.0 10 14 18 e28 25 19 27 23 11 9.4 32 3 8.2 10 14 18 e24 25 e17 27 23 11 10 25 4 8.7 10 15 18 e20 26 e16 25 27 10 14 22 5 8.3 10 18 17 e15 25 16 23 32 9.9 17 21 6 8.1 11 20 18 e16 26 e17 23 32 e9.8 e17 20 7 8.3 11 21 16 e20 28 16 21 30 10 17 20 8 8.2 14 20 13 e27 30 14 21 31 11 17 19 9 8.0 17 15 13 e13 29 e13 19 26 10 16 18 10 8.2 17 16 12 e15 29 e13 20 24 10 13 23 11 8.1 15 17 13 e14 29 e17 21 24 10 13 26 12 7.9 17 19 19 e20 23 e14 21 25 11 14 25 13 11 17 21 25 e24 23 e13 19 24 11 20 25 14 12 15 21 26 e27 26 e13 18 26 10 20 21 15 5.7 15 20 22 31 26 e15 17 23 11 20 22 16 5.7 15 21 24 30 27 e15 18 19 10 20 24 17 10 15 18 23 31 22 e15 18 19 13 19 27 18 16 15 18 18 29 27 e16 21 19 16 20 34 19 15 15 17 18 26 28 e16 25 19 16 19 34 20 16 15 18 17 25 26 e14 24 19 17 19 37 21 13 16 18 17 26 27 e16 20 19 16 14 105 22 12 22 18 18 25 28 e19 19 18 13 14 2050 23 12 26 18 19 25 28 e19 17 14 10 13 234 24 12 20 18 19 25 28 19 23 11 10 16 35 25 13 16 17 18 24 29 19 31 11 10 8.9 20 26 13 17 17 18 25 27 e27 32 11 9.7 6.4 21 27 11 18 17 17 24 26 e23 33 11 11 14 28 28 10 19 18 18 25 25 e25 31 11 10 7.5 26 29 9.8 20 17 22 28 e24 29 11 10 16 32 30 9.3 19 17 16 26 e23 26 11 10 24 33 31 9.8 18 24 19 25 10 25 TOTAL 313.9 466.6 551 571 666 816 521 719 617 348.4 483.2 3089 MEAN 10.1 15.6 17.8 18.4 23.8 26.3 17.4 23.2 20.6 11.2 15.6 103 MAX 16 26 21 26 32 30 27 33 32 17 25 2050 MIN 5.7 9.6 14 12 13 19 13 17 11 9.7 6.4 18 AC-FT 623 926 1090 1130 1320 1620 1030 1430 1220 691 958 6130 CFSM 1.22 1.87 2.14 2.21 2.86 3.16 2.09 2.79 2.47 1.35 1.87 12.4 IN. 1.40 2.09 2.46 2.55 2.98 3.65 2.33 3.21 2.76 1.56 2.16 13.81 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 1998, BY WATER YEAR (WY) MEAN 14.0 21.9 15.6 18.4 18.4 17.5 13.7 11.2 11.3 14.2 13.7 49.6 MAX 22.7 41.2 30.4 59.6 36.5 26.3 24.5 23.2 20.6 39.6 29.2 233 (WY) 1997 1992 1992 1992 1991 1998 1996 1998 1998 1993 1996 1996 MIN 3.74 8.85 4.36 5.45 7.24 11.4 5.72 4.13 3.47 1.56 1.18 1.64 (WY) 1995 1995 1994 1995 1994 1994 1997 1993 1994 1994 1995 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1991 - 1998 ANNUAL TOTAL 3776.3 9162.1 ANNUAL MEAN 10.3 25.1 18.2 HIGHEST ANNUAL MEAN 36.1 1996 LOWEST ANNUAL MEAN 5.93 1994 HIGHEST DAILY MEAN 27 Feb 15 2050 Sep 22 5420 Sep 10 1996 LOWEST DAILY MEAN 2.7 May 13 5.7 Oct 15 .60 Aug 6 1992 ANNUAL SEVEN-DAY MINIMUM 3.5 May 11 8.1 Oct 6 .80 May 1 1995 INSTANTANEOUS PEAK FLOW 4210 Sep 22 15000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 19.83 Sep 22 27.34 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 7490 18170 13180 ANNUAL RUNOFF (CFSM) 1.24 3.02 2.19 ANNUAL RUNOFF (INCHES) 16.88 40.97 29.70 10 PERCENT EXCEEDS 18 28 27 50 PERCENT EXCEEDS 8.5 18 12 90 PERCENT EXCEEDS 4.2 10 2.8 e Estimated 172 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 173 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1991 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: November 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by a local observerand automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,670 mg/L Jan. 05, 1992; Minimum daily mean,3 mg/L November 27, 1993 and June 27-28, 1997. SEDIMENT LOADS: Maximum daily mean, 27,700 tons (25,100 tonnes) September 10, 1996; Minimum daily mean, 0.02 ton (0.02 tonne) November 21, 1993. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 801 mg/L September 21, 1998; Minimum daily mean, 4 mg/L October 3, 1997. SEDIMENT LOADS: Maximum daily mean, 3,810 tons (3,460 tonnes) September 22, 1998; Minimum daily mean, 0.09 tons (0.08 tonne) October 3, 1997. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 7.6 33 .67 9.6 49 1.3 15 36 1.4 2 8.0 11 .24 10 52 1.4 14 33 1.2 3 8.2 4 .09 10 50 1.4 14 31 1.1 4 8.7 6 .13 10 47 1.3 15 30 1.2 5 8.3 8 .18 10 45 1.2 18 30 1.4 6 8.1 11 .24 11 42 1.3 20 30 1.6 7 8.3 15 .34 11 36 1.0 21 31 1.7 8 8.2 21 .49 14 76 3.2 20 31 1.7 9 8.0 20 .45 17 104 4.7 15 32 1.3 10 8.2 18 .42 17 100 4.5 16 31 1.3 11 8.1 17 .37 15 96 3.8 17 30 1.4 12 7.9 23 .50 17 84 3.9 19 29 1.5 13 11 81 2.1 17 72 3.4 21 27 1.5 14 12 54 2.6 15 62 2.6 21 20 1.1 15 5.7 34 .53 15 58 2.4 20 14 .79 16 5.7 25 .38 15 57 2.3 21 13 .75 17 10 68 2.9 15 56 2.2 18 14 .65 18 16 193 8.4 15 57 2.3 18 14 .68 19 15 182 7.3 15 58 2.3 17 15 .73 20 16 160 6.7 15 59 2.3 18 17 .85 21 13 141 4.8 16 57 2.5 18 20 .95 22 12 137 4.3 22 55 3.3 18 22 1.1 23 12 134 4.5 26 53 3.8 18 25 1.2 24 12 144 4.7 20 51 2.7 18 28 1.3 25 13 133 4.6 16 49 2.2 17 27 1.2 26 13 116 4.2 17 47 2.2 17 25 1.1 27 11 100 3.0 18 45 2.3 17 22 1.0 28 10 78 2.2 19 43 2.2 18 20 .96 29 9.8 59 1.6 20 41 2.1 17 17 .78 30 9.3 45 1.1 19 38 1.9 17 14 .65 31 9.8 45 1.2 18 11 .53 TOTAL 313.9 71.23 466.6 74.0 551 34.62 --- --- --- --- --- --- --- --- --- --- --- --- 174 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 17 10 .44 e32 16 e2.7 25 15 1.0 2 18 12 .57 e28 18 e2.1 25 17 1.1 3 18 16 .77 e24 22 e1.9 25 18 1.2 4 18 21 1.0 e20 35 e1.3 26 19 1.3 5 17 22 .98 e15 61 e1.3 25 18 1.2 6 18 21 1.1 e16 107 e1.3 26 16 1.2 7 16 21 .94 e20 170 e1.3 28 15 1.1 8 13 25 .89 e27 168 e2.0 30 15 1.2 9 13 32 1.1 e13 157 e1.1 29 15 1.2 10 12 40 1.3 e15 146 e1.3 29 15 1.2 11 13 39 1.4 e14 128 e1.2 29 15 1.2 12 19 36 1.8 e20 97 e1.3 23 14 .85 13 25 34 2.3 e24 69 e1.6 23 13 .83 14 26 31 2.2 e27 47 e2.0 26 16 1.1 15 22 29 1.7 31 46 3.9 26 19 1.4 16 24 26 1.7 30 45 3.7 27 24 1.8 17 23 25 1.7 31 46 3.8 22 29 1.7 18 18 22 1.1 29 50 4.0 27 36 2.6 19 18 20 .99 26 57 3.9 28 44 3.3 20 17 18 .78 25 64 4.4 26 75 5.3 21 17 17 .75 26 70 4.9 27 67 4.9 22 18 18 .85 25 52 3.5 28 40 3.0 23 19 17 .83 25 33 2.3 28 24 1.8 24 19 15 .78 25 19 1.3 28 15 1.1 25 18 14 .69 24 11 .71 29 15 1.2 26 18 16 .80 25 7 .46 27 19 1.4 27 17 19 .88 24 8 .54 26 23 1.6 28 18 22 1.1 25 11 .78 25 34 2.4 29 22 20 1.2 28 53 4.0 30 16 17 .72 26 120 10 31 24 15 .95 19 64 3.3 TOTAL 571 34.31 666 60.59 816 66.48 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 18 51 2.4 e25 2 19 40 2.0 27 3 e17 33 e1.3 27 4 e16 25 e1.3 25 5 16 23 1.0 23 20 e1.9 24 35 2.2 23 1.7 23 43 2.7 23 1.7 23 53 3.3 24 1.6 27 62 4.5 23 1.4 32 39 3.4 6 e17 33 e1.3 23 7 16 51 2.2 21 8 14 77 2.9 21 9 e13 80 e1.1 19 10 e13 75 e1.1 20 20 1.3 32 22 1.9 18 1.0 30 25 2.0 16 .90 31 32 2.6 16 .81 26 28 2.0 15 .84 24 21 1.4 11 e17 69 e1.2 12 e14 61 e1.2 13 e13 53 e.80 14 e13 44 e1.1 15 e15 41 e1.1 21 15 .84 24 17 1.1 21 15 .86 25 17 1.1 19 15 .77 24 18 1.2 18 15 .72 26 18 1.2 17 17 .78 23 17 1.1 16 e15 38 e1.3 18 17 e15 40 e1.3 18 18 e16 44 e1.3 21 19 e16 52 e1.3 25 20 e14 62 e1.2 24 19 .94 19 17 .89 19 .91 19 17 .90 18 1.0 19 18 .91 17 1.1 19 18 .92 11 .74 19 19 .95 21 e16 66 e1.3 20 22 e19 76 e1.3 19 23 e19 77 e1.3 17 24 19 60 e1.3 23 25 19 42 e1.3 31 7 .38 19 18 .92 10 .53 18 17 .83 20 .91 14 13 .51 22 1.3 11 10 .30 20 1.7 11 11 .33 26 e27 31 e2.0 27 e23 21 e2.0 28 e25 16 e2.0 29 e24 13 e1.9 30 e23 16 e1.9 31 --- --- --- 32 19 1.6 11 15 .45 33 18 1.7 11 18 .56 31 18 1.5 11 17 .49 29 20 1.6 11 16 .44 26 23 1.7 11 18 .51 25 28 1.9 --- --- --­ TOTAL 521 --- 44.70 719 --- 36.63 617 --- 41.61 --- --- --- --- --- --- 175 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 11 21 .62 10 19 .50 30 82 6.7 2 11 24 .72 9.4 21 .54 32 58 5.0 3 11 20 .60 10 26 .73 25 39 2.6 4 10 15 .43 14 31 1.2 22 32 1.9 5 9.9 13 .35 17 27 1.2 21 29 1.7 6 e9.8 12 e.32 e17 22 1.0 20 29 1.6 7 10 11 .31 17 19 .88 20 30 1.6 8 11 14 .42 17 17 .77 19 31 1.6 9 10 17 .47 16 15 .66 18 27 1.3 10 10 20 .53 13 14 .49 23 24 1.5 11 10 22 .62 13 12 .43 26 32 2.2 12 11 19 .58 14 12 .44 25 44 3.0 13 11 15 .44 20 12 .65 25 46 3.1 14 10 13 .37 20 11 .59 21 46 2.5 15 11 12 .35 20 10 .56 22 45 2.7 16 10 12 .34 20 11 .61 24 36 2.4 17 13 11 .38 19 13 .68 27 28 2.0 18 16 10 .43 20 14 .76 34 21 1.9 19 16 9 .40 19 14 .71 34 16 1.5 20 17 72 3.8 19 12 .62 37 12 1.2 21 16 36 1.5 14 11 .42 105 801 1150 22 13 22 .78 14 103 3.8 2050 787 3810 23 10 18 .50 13 64 2.2 234 344 231 24 10 21 .58 16 46 2.8 35 241 23 25 10 26 .74 8.9 49 1.2 20 183 10 26 9.7 27 .72 6.4 72 1.3 21 145 8.4 27 11 35 1.2 14 109 4.3 28 170 13 28 10 28 .78 7.5 120 2.4 26 229 16 29 10 25 .68 16 123 5.3 32 304 26 30 10 22 .59 24 109 7.1 33 340 30 31 10 20 .55 25 95 6.5 TOTAL 348.4 21.10 483.2 51.34 3089 5365.4 YEAR 9162.1 5902.01 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 18... 1415 15 204 8.3 98 NOV 08... 1515 16 108 4.7 96 FEB 21... 1630 29 74 5.8 97 MAR 30... 1625 24 285 18 28 APR 23... 1100 16 85 3.7 87 JUL 20... 1200 18 233 11 98 AUG 29... 0850 8.0 127 2.7 95 SEP 21... 2230 558 3080 4640 97 22... 0730 3150 667 5670 97 176 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA , PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. SED. SED. MENT, SUSP. SUSP. SUSP. SEDI- DIS- FALL FALL FALL MENT, CHARGE, DIAM. DIAM. DIAM. SUS- SUS- % FINER % FINER % FINER PENDED PENDED THAN THAN THAN (MG/L) (T/DAY) .002 MM .004 MM .008 MM (80154) (80155) (70326) (70327) (70328) SEP 22... 0315 2280 1130 6960 39 56 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) SEP 22... 77 82 90 96 99 100 100 71 177 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'39", long 66°08'39", at bridge on Highway 156, and 2.9 mi (4.7 km) west of Aguas Buenas plaza. DRAINAGE AREA.--18.5 mi2 (47.9 km2). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 30... 1000 13 274 8.1 24.0 1.5 7.5 91 11 200 780 FEB 26... 1045 24 244 7.7 23.5 8.8 7.9 96 <10 210 450 MAY 19... 1435 26 260 7.4 27.5 2.5 7.6 100 <10 470 K110 AUG 20... 1430 27 270 8.1 29.0 8.6 7.8 105 <10 K710 K1700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 30... 39 8.6 4.3 13 .9 .90 98 <.5 6.6 16 FEB 26... -- -- -- -- -- -- 87 -- -- -­ MAY 19... 91 22 9.0 16 .7 2.7 96 -- 7.5 18 AUG 20... 130 32 10 17 .7 4.6 98 <1.0 15 25 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 30... .10 23 131 4.60 4 -- <.010 .750 <.010 -­ FEB 26... -- -- -- -- 3 -- <.010 .680 .020 .19 MAY 19... .13 21 153 10.7 4 .530 .010 .540 .020 .25 AUG 20... .10 22 193 14.1 9 -- <.010 .560 .040 .26 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 30... .26 1.0 4.5 .050 <1 <100 30 <1 <1 <10 FEB 26... .21 .89 3.9 <.020 -- -- -- -- -- -­ MAY 19... .27 .81 3.6 <.020 <1 <100 20 <1 <1 <10 AUG 20... .30 .86 3.8 .050 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 178 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 30... 590 <1 52 <.10 <1 <1 <10 <.010 <1 .03 FEB 26... MAY 19... 430 2 50 <.10 <1 <1 <10 <.010 <1 <.02 AUG 20... 179 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR LOCATION.--Lat 18°20'08", long 66°08'13", Hydrologic Unit 21010005, on left bank, at rock quarry near Highway 174, 1.3 mi (2.1 km) south of colonia Santa Rosa and 4.7 mi (7.6 km) south of Bayamón. DRAINAGE AREA.--41.8 mi2 (108.3 km2). PERIOD OF RECORD.--September 1964 to October 1970, June 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98 ft (30 m), from topographic map. REMARKS.--Records fair. Diversion to the Guaynabo water treatment plant, for municipal supply, made upstream from station (at Represa de San Juan). Flow is regulated by storage and release of water at Lago de Cidra (capacity 5,220 acre-ft), 10.5 mi (16.9 km) upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 77 e5.1 e4.9 e2.7 2 38 e5.2 e4.5 e2.5 3 16 e5.1 e4.2 e2.6 4 14 e5.1 e4.1 e3.1 5 200 e4.9 e4.0 e4.0 e4.2 7.2 10 7.9 6.2 5.3 9.0 12 e4.4 7.0 8.7 7.2 6.2 6.8 8.2 12 e4.3 6.9 8.0 7.7 6.4 11 7.7 17 e5.4 6.7 7.5 7.8 7.9 9.1 7.4 13 e700 8.1 7.3 7.8 9.9 6.7 6.6 12 6 209 e4.9 e3.8 e38 7 71 e4.7 e3.7 e27 8 109 e4.5 e3.5 e22 9 74 e4.5 e3.5 e16 10 35 e200 e3.5 e22 e80 8.9 6.9 7.6 8.5 63 7.7 14 e25 8.4 8.2 7.6 6.9 16 73 11 e90 9.1 11 28 6.9 7.8 44 12 e100 7.0 7.3 16 12 6.7 19 11 e24 6.6 6.6 10 8.1 7.3 18 8.8 11 179 e36 e3.5 e13 12 e155 e15 e3.5 e10 13 e300 e9.6 e3.4 e17 14 e900 e7.8 e3.3 e23 15 35 e6.8 e3.3 e13 e14 6.4 6.6 8.4 6.5 6.5 15 8.2 e11 6.3 10 7.8 6.0 6.2 16 8.1 e9.4 6.2 11 7.7 5.7 5.7 15 8.3 e8.6 10 8.1 87 6.4 5.5 13 8.1 e12 8.3 8.1 34 6.2 5.6 13 8.8 16 e20 e6.2 e3.2 e9.0 17 e16 e6.1 e3.4 e7.6 18 e14 e6.1 e3.5 e6.8 19 e13 e5.8 e3.2 e6.3 20 e12 e5.5 e3.0 e6.0 e10 6.9 104 12 6.2 6.9 13 10 e9.0 7.0 22 11 61 8.0 24 8.9 e8.6 7.5 11 8.7 23 7.6 28 8.5 8.5 6.6 9.6 8.4 8.1 8.8 22 7.9 8.5 10 9.1 7.8 7.1 62 17 8.2 21 e11 e5.4 e3.7 e5.8 22 e9.4 e5.8 e3.8 e5.3 23 e8.2 e6.4 e3.3 e5.2 24 e7.4 e6.6 e3.1 e5.2 25 e6.8 e6.2 e3.0 e5.0 8.4 33 8.5 8.2 16 71 87 547 7.7 8.0 8.7 7.7 12 9.6 53 e3640 7.6 6.9 9.5 7.4 7.9 31 38 603 7.5 6.6 7.5 7.9 7.8 29 369 183 7.4 7.3 9.7 8.4 12 15 469 87 26 e6.6 e5.2 e2.9 e5.2 27 e6.2 e4.8 e2.8 e5.3 28 e5.8 e4.7 e2.8 e5.2 29 e5.6 e4.7 e3.0 e4.9 30 e5.6 e4.8 e2.8 e4.7 31 e5.3 --- e2.9 e4.4 7.8 7.2 8.9 7.1 6.6 12 38 69 8.2 6.8 8.5 7.4 6.0 19 123 108 8.0 7.8 8.3 7.2 5.9 14 299 67 --- 94 7.8 7.1 5.7 11 41 226 --- 154 7.9 6.8 5.5 10 18 156 --- 46 --- 6.4 --- 10 13 --­ TOTAL 2564.9 403.5 107.1 307.8 MEAN 82.7 13.4 3.45 9.93 MAX 900 200 4.9 38 MIN 5.3 4.5 2.8 2.5 AC-FT 5090 800 212 611 CFSM 1.98 .32 .08 .24 IN. 2.28 .36 .10 .27 1199.5 528.7 366.3 382.0 300.6 494.1 1924.6 5893.8 42.8 17.1 12.2 12.3 10.0 15.9 62.1 196 700 154 104 87 61 71 469 3640 4.2 6.2 6.6 6.4 5.5 5.3 6.6 7.9 2380 1050 727 758 596 980 3820 11690 1.02 .41 .29 .29 .24 .38 1.49 4.70 1.07 .47 .33 .34 .27 .44 1.71 5.25 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 1998, BY WATER YEAR (WY) MEAN 33.5 42.0 38.8 34.7 MAX 129 174 263 159 (WY) 1991 1970 1966 1969 MIN 4.30 7.91 3.45 5.30 (WY) 1969 1965 1998 1968 23.2 17.7 20.5 37.9 18.4 21.1 41.7 67.9 75.3 52.9 72.7 131 60.8 46.6 137 360 1989 1990 1971 1966 1970 1970 1970 1996 4.75 3.58 5.36 4.85 3.68 4.01 7.47 6.02 1965 1965 1965 1994 1994 1994 1994 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1964 - 1998 ANNUAL TOTAL 8132.4 ANNUAL MEAN 22.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 900 LOWEST DAILY MEAN 2.8 ANNUAL SEVEN-DAY MINIMUM 2.9 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 16130 ANNUAL RUNOFF (CFSM) .53 ANNUAL RUNOFF (INCHES) 7.24 10 PERCENT EXCEEDS 31 50 PERCENT EXCEEDS 9.8 90 PERCENT EXCEEDS 4.8 14472.9 39.7 33.2 59.7 1966 10.9 1994 Oct 14 3640 Sep 22 8640 Sep 10 1996 Dec 27 2.5 Jan 2 2.2 Apr 19 1965 Dec 25 2.8 Dec 28 2.4 Apr 14 1965 17000 Sep 22 65000 Sep 10 1996 19.36 Sep 22 29.07 Sep 10 1996 28710 24040 .95 .79 12.88 10.79 65 55 8.0 13 4.4 4.9 e Estimated 180 RIO DE BAYAMON BASIN 50047850 RIO BAYAMON NR BAYAMON, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 181 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'32", long 66°07'59", at bridge on Highway 833, 0.2 mi (0.3 km) upstream from Río de Bayamón, and 2.3 mi (3.7 km) southeast of Bayamón plaza. DRAINAGE AREA.--73.2 mi2 (189.6 km2). PERIOD OF RECORD.--Water years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI­ SPE- WATER DIS- DEMAND, FORM, STREP­ CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 30... 0930 517 7.1 27.0 4.0 4.2 52 <10 5700 690 FEB 19... 0830 481 7.3 25.0 6.5 3.5 42 <10 2900 K1800 JUN 01... 0800 471 7.1 27.5 3.5 2.2 28 10 42000 4600 AUG 24... 0730 496 6.8 27.5 4.0 1.8 23 17 56000 51000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 30... 200 70 5.1 9.7 .3 3.3 192 <.5 7.7 16 FEB 19... -- -- -- -- -- -- 200 -- -- -­ JUN 01... 170 46 13 30 1 3.4 180 -- 11 35 AUG 24... 160 42 14 30 1 4.0 210 <1.0 17 34 SOLIDS, RESIDUE NITRO­ FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) OCT 30... <.10 7.9 232 4 .802 .098 .900 .160 .36 .52 FEB 19... -- -- -- 27 .780 .150 .930 .240 .53 .77 JUN 01... .18 28 275 12 .610 .130 .740 .200 .31 .51 AUG 24... .16 28 294 11 .260 .050 .310 1.20 .60 1.8 CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) OCT 30... 1.4 6.3 .190 2 <100 40 <1 <1 <10 250 FEB 19... 1.7 7.5 .230 -- -- -- -- -- -- -­ JUN 01... 1.3 5.5 .240 2 <100 70 <1 <1 <10 370 AUG 24... 2.1 9.3 .330 -- -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 182 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 30... <1 220 <.10 <1 <1 <10 <.010 <1 .04 FEB 19... JUN 01... <1 260 <.10 <1 <1 10 <.010 <1 .09 AUG 24... 183 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'29", long 66°09'04", at bridge on Highway 890, 1.0 mi (1.6 km) downstream from bridge on Highway 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 mi2 (186.2 km2). PERIOD OF RECORD.--Water years 1974 to current year. REMARKS.--Prior to 1979 sampling site was 0.8 mile (1.3 km) downstream but was changed because of flood channel construction. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 30... 1200 20 492 7.4 29.5 3.8 8.9 116 <10 5100 230 FEB 19... 1030 20 462 7.2 25.0 7.6 7.5 89 <10 K18000 K1800 JUN 01... 1130 23 467 7.2 29.0 13 7.2 93 <10 K6400 60 AUG 24... 0915 33 429 6.8 28.5 9.6 5.9 75 11 36000 4800 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 30... 190 46 15 18 .6 2.3 195 <.5 45 20 FEB 19... -- -- -- -- -- -- 190 -- -- -­ JUN 01... 180 46 15 27 .9 2.6 180 -- 13 31 AUG 24... 140 36 13 27 1 2.8 180 <1.0 14 28 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 30... <.10 20 285 15.4 40 .260 .020 .280 .100 .28 FEB 19... -- -- -- -- 6 .324 .036 .360 .160 .31 JUN 01... <.10 28 269 17.0 25 .230 .030 .260 .070 .35 AUG 24... .18 27 255 21.6 23 .350 .100 .450 .410 .49 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 30... .38 .66 2.9 .070 1 <100 40 <1 <1 <10 FEB 19... .47 .83 3.7 .080 -- -- -- -- -- -­ JUN 01... .42 .68 3.0 .080 <1 <100 40 <1 1 <10 AUG 24... .90 1.4 6.0 .150 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 184 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 30... 330 <1 300 <.10 <1 <1 <10 <.010 <1 .03 FEB 19... JUN 01... 860 3 230 <.10 <1 <1 <10 <.010 <1 .04 AUG 24... --- --- --- --- --- --- --- --- --- --- --- --- --- 185 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR LOCATION.--Lat 18°24'23", long 66°03'05", Hydrologic Unit 21010005 at Lago Las Curias Dam on Río Piedras, 4.15 mi (6.67 km) south of University of Puerto Rico Tower, 1.6 mi (2.57 km) northwest from Escuela José F. Díaz and 0.8 mi (1.28 km) north of Escuela Cupey Alto. DRAINAGE AREA.--0.97 mi2 (2.51 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1997 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Las Curias was completed in 1946. The reservoir has a capacity of 1,135 ac-ft (1.40 hm3) at spillway crest elevation 315.78 ft (96.25 m) for water supply. The dam is earthfill and has a crest elevation of 327.3 ft (99.75 m). Masonry parapet walls continous from abutment on each side of the 25 ft (7.62 m) wide crest. The dam is about 82.0 ft (25.0 m) high and 984.2 ft (300.0 m) long. The morning-glory inlet conduit spillway is located along the left abutment of the dam and has an uncontrolled capacity of about 5,000 ft3/s (141.6 m3/s) at reservoir elevation 321.5 ft (98.0 m). This dam is operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 317.01 ft (96.62 m),Aug. 11, 1998; minimum elevation, 314.15 ft (95.75 m), Sept. 30, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 317.01 ft (96.62 m), Aug. 11; minimum elevation, 314.15 ft (95.75 m), Sept. 30. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 284.7 154 314.3 1,078 298.2 462 317.5 1,232 307.1 770 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 315.87 315.80 315.79 315.57 315.68 315.71 315.82 315.75 315.74 315.67 315.82 314.99 2 315.95 315.79 315.78 315.59 315.67 315.70 315.81 315.74 315.72 315.66 315.79 315.53 3 315.85 315.80 315.77 315.60 315.66 315.70 315.80 315.73 315.71 315.72 315.78 315.56 4 315.84 315.81 315.76 315.60 A 315.69 315.78 315.73 315.69 315.84 315.77 315.59 5 315.84 315.81 315.75 315.60 319.21 315.71 315.77 315.70 315.87 315.81 315.78 315.61 6 315.85 315.81 315.75 315.72 A 315.71 315.75 315.69 315.83 315.81 A 316.04 7 315.85 315.80 315.74 315.81 A 315.73 315.76 315.68 315.81 315.80 315.89 315.93 8 315.95 315.79 315.73 315.80 A 315.71 315.75 315.68 315.80 315.79 315.86 315.91 9 315.87 315.78 315.72 315.79 A 315.69 315.73 315.66 315.88 315.78 315.84 315.91 10 315.85 315.80 315.73 315.80 A 315.68 315.72 315.65 315.83 315.79 315.90 315.90 11 315.85 315.80 315.73 315.79 A 315.67 315.71 315.62 315.80 315.77 315.99 315.91 12 315.91 315.81 315.71 315.78 A 315.66 315.86 315.60 315.80 315.76 315.90 315.93 13 316.21 315.80 315.70 315.90 A 315.65 315.83 315.59 315.78 315.74 315.87 315.93 14 315.89 315.80 315.69 315.83 A 315.72 315.81 315.74 315.76 315.75 315.85 315.91 15 315.87 315.85 A 315.82 A 315.71 315.85 315.74 315.74 315.76 315.84 315.92 16 315.86 315.83 A 315.81 A 315.70 315.88 315.73 315.76 315.92 315.83 315.92 17 315.86 315.82 A 315.81 A 315.69 315.84 315.73 315.83 315.89 315.83 315.96 18 315.86 315.83 A 315.87 A 315.68 315.83 315.73 315.83 315.88 315.91 315.82 19 315.85 315.82 A 315.84 A 315.67 315.82 315.74 315.80 315.86 315.85 315.52 20 315.85 315.81 A 315.84 A 315.66 315.87 315.74 315.78 315.92 315.87 315.23 21 315.84 315.83 A 315.83 A 315.65 315.86 315.75 315.78 315.86 315.75 316.60 22 315.84 315.81 A 315.81 A 315.63 315.84 315.75 315.77 315.85 315.47 316.09 23 315.82 315.80 A 315.80 A 315.62 315.82 315.80 315.75 315.86 315.16 315.82 24 315.82 315.82 A 315.79 315.74 315.60 315.80 315.79 315.74 315.86 315.54 315.60 25 315.82 315.81 A 315.78 315.74 315.59 315.82 315.78 315.75 315.85 315.67 315.36 26 315.81 315.81 A 315.77 315.74 315.57 315.81 315.82 315.74 315.84 315.38 315.13 27 315.80 315.80 A 315.76 315.73 315.56 315.82 315.80 315.73 315.84 315.70 314.87 28 315.80 315.80 A 315.74 315.72 315.56 315.80 315.81 315.72 315.84 315.96 314.62 29 315.79 315.80 315.59 315.73 315.80 315.80 315.80 315.70 315.84 315.69 314.39 30 315.80 315.80 315.57 315.69 315.81 315.78 315.78 315.69 315.84 315.41 314.15 31 315.80 315.57 315.69 315.83 315.77 315.83 315.12 MAX 316.21 315.85 315.90 315.83 315.88 315.82 315.88 315.92 316.60 MIN 315.79 315.78 315.57 315.56 315.71 315.59 315.69 315.66 314.15 A No gage-height record 186 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR LOCATION.--Lat 18°21'51", long 66°03'56", Hydrologic Unit 21010005, on right bank, in the Riberas of Señorial Housing area, 0.6 mi (1.0 km) west of Highway 176 and 2.7 mi (4.3 km) southwest of Río Piedras Plaza. DRAINAGE AREA.--7.49 mi2 (19.40 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORDS.--March 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 98.4 ft (30.0 m), from topographic map. REMARKS.--Records poor. Low flow is affected by discharges from water treatment plant of PRASA and others dispersed pollution points directly to the river. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 e17 15 14 2 13 e12 14 25 3 14 e34 11 17 68 12 8.0 6.6 e11 e7.3 e7.8 13 23 13 10 6.7 e7.1 e6.9 e7.4 16 15 17 8.4 15 e6.9 e6.9 e7.3 14 4 9.1 e18 13 13 16 16 7.9 7.2 e6.9 e6.9 e7.3 13 5 9.1 e75 10 16 15 23 7.7 6.7 e6.8 e8.0 e6.9 12 6 13 e22 11 12 7 e43 e11 10 11 8 e25 19 10 11 9 e22 15 11 9.7 10 e49 18 13 9.1 12 13 7.3 6.5 e6.6 e9.7 e6.9 12 13 14 7.1 6.7 e6.9 e12 e7.1 11 14 16 7.2 6.5 e6.9 e19 e16 11 26 13 6.9 6.6 e7.0 e11 e10 10 15 12 6.9 6.5 e7.1 e9.9 e16 10 11 e27 14 17 23 12 e17 30 12 10 13 e60 122 12 8.7 14 e54 25 11 8.9 15 e23 26 10 8.6 17 11 6.9 6.4 e13 e12 e10 9.9 29 13 7.0 6.6 e7.1 e7.3 e15 11 20 12 6.9 7.5 e6.7 e5.3 e32 26 15 11 6.7 6.5 e6.2 e5.1 e44 33 13 11 6.6 6.4 e6.3 e7.2 e18 16 16 e22 27 12 8.6 17 e18 37 10 8.5 18 e17 31 9.9 11 19 e16 24 10 10 20 e12 23 10 9.4 14 11 6.7 8.5 e6.1 e11 e25 13 12 11 6.9 6.3 e5.9 e5.6 e26 12 11 31 6.9 6.0 e5.9 e12 e22 12 14 11 6.6 5.8 e7.6 e11 e17 11 e13 9.3 7.1 75 e5.7 e49 e18 10 21 e27 22 15 70 22 e15 102 11 81 23 e19 20 12 63 24 e13 21 37 55 25 e16 13 13 24 e21 10 7.1 e82 e5.8 e15 e68 12 22 11 7.0 e17 e5.9 e6.6 e130 13 12 8.4 6.5 e8.8 e9.9 e5.0 28 24 21 8.6 6.6 e19 e12 e4.6 55 22 20 8.7 6.5 e20 e6.8 e7.2 26 15 26 e70 10 108 16 27 e38 15 36 12 28 e199 13 52 15 29 e83 10 74 14 30 e33 36 50 12 31 e35 --- 19 15 19 10 6.5 e8.7 e6.1 e6.9 18 37 12 8.3 7.0 e8.8 e6.2 e4.6 18 18 11 9.2 6.4 e8.1 e6.3 e8.2 15 17 --- 30 6.5 e7.1 e7.9 e4.8 15 45 --- 9.9 6.5 e6.9 e19 e27 13 18 --- 8.6 --- e6.9 --- e12 23 --­ TOTAL 1025.2 862 658.9 621.5 MEAN 33.1 28.7 21.3 20.0 MAX 199 122 108 81 MIN 9.1 10 9.9 8.5 AC-FT 2030 1710 1310 1230 CFSM 4.42 3.84 2.84 2.68 IN. 5.09 4.28 3.27 3.09 513 403.0 212.3 403.3 229.6 325.0 728.7 496.9 18.3 13.0 7.08 13.0 7.65 10.5 23.5 16.6 68 31 10 82 19 49 130 45 11 8.3 6.4 5.8 5.7 4.6 6.9 9.9 1020 799 421 800 455 645 1450 986 2.45 1.74 .94 1.74 1.02 1.40 3.14 2.21 2.55 2.00 1.05 2.00 1.14 1.61 3.62 2.47 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 1997, BY WATER YEAR (WY) MEAN 24.4 21.6 14.9 14.8 MAX 57.3 59.8 40.5 24.4 (WY) 1991 1993 1993 1992 MIN 8.48 5.93 4.32 6.95 (WY) 1992 1996 1996 1995 12.8 11.0 11.9 15.1 11.6 14.7 21.7 27.6 23.6 19.5 23.9 47.2 24.8 38.0 66.9 71.8 1991 1990 1993 1992 1989 1993 1992 1996 2.70 1.85 2.83 3.38 2.66 4.22 6.60 6.90 1996 1996 1995 1994 1994 1994 1990 1991 SUMMARY STATISTICS FOR 1996 CALENDAR YEAR FOR 1997 WATER YEAR WATER YEARS 1988 - 1997 ANNUAL TOTAL 6443.02 ANNUAL MEAN 17.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1650 LOWEST DAILY MEAN .92 ANNUAL SEVEN-DAY MINIMUM .97 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 12780 ANNUAL RUNOFF (CFSM) 2.35 ANNUAL RUNOFF (INCHES) 32.00 10 PERCENT EXCEEDS 34 50 PERCENT EXCEEDS 3.5 90 PERCENT EXCEEDS 1.3 6479.4 17.8 16.6 24.1 1993 7.76 1994 Sep 10 199 Oct 28 1650 Sep 10 1996 Jul 4 4.6 Jul 24 .84 Aug 13 1995 Jun 30 5.9 Jul 23 .97 Jun 30 1996 2170 Nov 22 5390 Sep 10 1996 11.48 Nov 22 15.46 Sep 10 1996 12850 12030 2.37 2.22 32.18 30.12 33 34 12 7.5 6.6 2.4 e Estimated 187 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1996 1997 WATER YEAR 188 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 46 11 11 7.6 2 56 9.2 11 7.4 3 23 9.9 11 9.8 4 17 9.1 11 7.9 5 18 11 10 8.5 3.0 4.5 5.2 4.3 3.5 3.8 5.1 e8.3 3.1 4.5 4.8 4.1 3.3 4.4 4.8 23 3.1 5.1 4.3 4.4 3.4 13 4.8 7.5 58 4.5 4.3 4.7 3.4 20 4.8 6.6 72 18 4.6 4.3 24 4.6 6.2 7.0 6 22 9.6 10 28 7 18 9.9 10 33 8 69 10 10 5.8 9 24 11 10 5.4 10 18 12 10 5.0 9.4 4.3 4.4 4.1 5.3 4.1 e8.0 201 7.7 8.9 5.7 4.2 4.6 7.8 e39 30 29 4.5 5.9 5.0 6.1 3.6 e11 14 13 4.0 4.5 4.2 28 4.1 e15 14 6.4 3.8 4.3 3.9 9.3 9.3 e37 11 11 28 11 9.9 4.5 12 25 11 8.7 4.9 13 52 12 8.9 30 14 123 11 8.7 13 15 19 32 8.5 5.6 6.6 3.7 4.4 3.9 4.3 4.1 e84 10 5.8 3.7 36 3.8 7.4 3.6 e31 11 5.3 3.7 9.6 3.7 3.8 3.6 e10 16 18 36 4.4 26 3.5 11 8.7 9.9 8.9 5.1 9.5 7.0 3.6 8.2 7.4 12 16 16 16 8.1 4.9 17 14 9.7 8.1 4.6 18 13 16 7.6 17 19 12 12 7.2 6.7 20 11 11 7.1 4.9 6.4 4.2 60 3.7 9.6 75 6.3 14 5.6 4.2 12 6.9 19 21 e6.0 20 5.2 5.8 6.1 4.4 11 22 e60 22 5.6 4.1 5.5 6.7 4.9 6.6 e15 16 5.0 3.8 12 6.0 4.4 22 e10 16 21 11 22 8.0 4.7 22 11 13 6.7 4.2 23 10 12 6.6 3.9 24 10 14 6.5 3.8 25 11 12 6.1 3.7 4.8 3.9 7.7 6.3 8.4 10 e28 e714 4.7 3.9 5.4 4.0 5.4 7.6 e11 e1030 4.7 3.9 5.2 29 5.0 8.2 e7.0 e49 4.2 3.9 5.0 4.9 4.7 17 e61 22 4.2 3.9 10 4.3 7.7 5.3 e50 17 26 11 13 6.3 3.7 27 10 11 6.7 3.7 28 10 11 6.3 3.6 29 9.6 11 6.5 3.5 30 9.5 11 6.2 3.5 31 9.7 --- 6.7 3.4 4.4 3.7 5.5 9.1 4.3 5.5 e7.5 47 4.5 3.8 7.9 7.1 4.6 9.8 e30 22 4.5 4.5 5.1 8.8 4.6 8.1 e55 15 --- 36 4.8 4.3 4.3 6.2 e18 25 --- 10 4.7 3.7 3.9 7.1 e9.3 13 --- 10 --- 3.5 --- 7.2 e8.4 --­ TOTAL 736.8 374.4 259.4 256.2 MEAN 23.8 12.5 8.37 8.26 MAX 123 32 11 33 MIN 9.5 9.1 6.1 3.4 AC-FT 1460 743 515 508 CFSM 3.17 1.67 1.12 1.10 IN. 3.66 1.86 1.29 1.27 313.1 223.9 268.8 200.3 215.3 343.8 659.3 2423.3 11.2 7.22 8.96 6.46 7.18 11.1 21.3 80.8 72 36 60 29 28 75 84 1030 3.0 3.7 4.3 3.5 3.3 3.6 4.8 6.6 621 444 533 397 427 682 1310 4810 1.49 .96 1.20 .86 .96 1.48 2.84 10.8 1.56 1.11 1.34 .99 1.07 1.71 3.27 12.04 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 1998, BY WATER YEAR (WY) MEAN 24.3 20.7 14.2 14.1 MAX 57.3 59.8 40.5 24.4 (WY) 1991 1993 1993 1992 MIN 8.48 5.93 4.32 6.95 (WY) 1992 1996 1996 1995 12.6 10.6 11.6 14.3 11.2 14.3 21.7 32.5 23.6 19.5 23.9 47.2 24.8 38.0 66.9 80.8 1991 1990 1993 1992 1989 1993 1992 1998 2.70 1.85 2.83 3.38 2.66 4.22 6.60 6.90 1996 1996 1995 1994 1994 1994 1990 1991 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1988 - 1998 ANNUAL TOTAL 5303.9 ANNUAL MEAN 14.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 130 LOWEST DAILY MEAN 4.6 ANNUAL SEVEN-DAY MINIMUM 5.9 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 10520 ANNUAL RUNOFF (CFSM) 1.94 ANNUAL RUNOFF (INCHES) 26.34 10 PERCENT EXCEEDS 24 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 6.5 6274.6 17.2 16.7 24.1 1993 7.76 1994 Aug 22 1030 Sep 22 1650 Sep 10 1996 Jul 24 3.0 Feb 1 .84 Aug 13 1995 Jul 23 3.3 Jan 28 .97 Jun 30 1996 4700 Sep 21 5390 Sep 10 1996 14.75 Sep 21 15.46 Sep 10 1996 12450 12070 2.30 2.22 31.16 30.23 27 33 7.7 7.5 3.9 2.5 e Estimated 189 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 190 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1988 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 1988 to September 30, 1998. INSTRUMENTATION.-- Automatic sediment sampler since 1988. REMARKS.-- During high flow sediment samples were collected by automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,600 mg/L Sep. 18, 1989; Minimum daily mean, 2 mg/L November 18, 1988. SEDIMENT LOADS: Maximum daily mean, e165,000tons (e150,000tonnes) September 22, 1998; Minimum daily mean, 0.02 ton (0.02 tonne) June 9, 1994. EXTREMES FOR WATER YEARS 1997-1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,870 mg/L May 20, 1997; Minimum daily mean, 9 mg/L January 16-17, 1997. SEDIMENT LOADS: Maximum daily mean, 2,140 tons (1,940 tonnes) November 22, 1996; Minimum daily mean, 0.21 ton (0.19 tonne) January 16-17, 1997. SEDIMENT CONCENTRATION: Maximum daily mean, 3,420 mg/L July 16, 1998; Minimum daily mean, 6 mg/L February 3, 1998. SEDIMENT LOADS: Maximum daily mean, 165,000 tons (150,000 tonnes) September 22, 1998; Minimum daily mean, 0.05 ton (0.04 tonne) February 3, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 14 130 5.2 e17 38 e9.4 15 158 9.0 2 13 115 4.3 e12 37 e4.3 14 124 5.0 3 14 124 8.2 e34 36 e66 11 86 2.6 4 9.1 480 1.7 e18 35 e15 13 114 4.5 5 9.1 69 1.7 e75 34 e187 10 77 2.1 6 13 115 5.5 e22 33 e18 11 79 2.3 7 e43 75 e72 e11 32 e4.0 10 81 2.3 8 e25 73 e26 19 30 1.5 10 83 2.3 9 e22 71 e18 15 27 1.1 11 85 2.5 10 e49 500 e91 18 179 24 13 126 7.6 11 e27 67 e32 14 141 6.1 17 181 9.8 12 e17 66 e6.1 30 513 93 12 109 3.7 13 e60 900 e176 122 1090 1710 12 91 2.8 14 e54 569 e146 25 291 20 11 82 2.4 15 e23 60 e20 26 318 27 10 73 2.0 16 e22 59 e18 27 423 48 12 54 2.1 17 e18 57 e15 37 516 69 10 17 .46 18 e17 56 e9.4 31 415 37 9.9 16 .43 19 e16 54 e5.2 24 134 8.5 10 15 .41 20 e12 53 e4.3 23 42 2.6 10 14 .41 21 e27 51 e27 22 36 2.2 15 100 4.8 22 e15 50 e5.8 102 912 2140 11 75 2.2 23 e19 49 e15 20 203 12 12 107 3.8 24 e13 47 e4.8 21 237 15 37 485 101 25 e16 46 e5.2 13 113 4.2 13 127 4.4 26 e70 750 e197 10 72 2.0 108 1090 1480 27 e38 460 e69 15 141 8.9 36 445 64 28 e199 985 e1760 13 108 4.4 52 569 146 29 e83 41 e197 10 63 1.7 74 753 187 30 e33 40 e64 36 466 75 50 730 208 31 e35 39 e69 19 168 8.6 TOTAL 1025.2 3079.4 862 4616.9 658.9 2274.51 --- --- --- --- --- --- --- --- --- --- --- --- 191 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 14 118 4.6 68 899 529 12 20 .63 2 25 300 24 23 284 20 13 54 2.2 3 17 198 11 15 137 5.5 17 121 6.8 4 13 107 3.7 16 172 9.9 16 118 5.9 5 16 170 10 15 139 6.0 23 235 19 6 12 96 3.0 12 99 3.2 13 23 .77 7 11 84 2.6 13 113 4.2 14 87 4.1 8 11 79 2.2 14 138 6.5 16 125 7.1 9 9.7 74 2.0 26 339 45 13 54 2.0 10 9.1 70 1.7 15 121 4.8 12 24 .74 11 23 298 72 17 194 13 11 19 .57 12 10 89 2.5 29 358 44 13 16 .52 13 8.7 49 1.2 20 116 7.1 12 13 .43 14 8.9 27 .65 15 69 3.2 11 13 .36 15 8.6 15 .35 13 12 .41 11 12 .35 16 8.6 9 .22 14 25 1.7 11 12 .33 17 8.5 9 .21 12 10 .34 11 11 .34 18 11 63 4.4 11 10 .29 31 319 119 19 10 98 2.8 14 10 .38 11 12 .35 20 9.4 66 1.7 e13 11 e.39 9.3 11 .27 21 70 1030 276 e21 168 e13 10 10 .31 22 81 826 198 22 248 19 11 12 .34 23 63 911 201 12 35 1.2 8.4 17 .38 24 55 666 104 21 232 16 8.6 27 .63 25 24 257 18 20 176 12 8.7 44 1.0 26 16 136 5.8 19 146 11 10 89 2.6 27 12 110 3.7 12 23 .76 8.3 67 1.5 28 15 131 5.6 11 20 .62 9.2 111 3.2 29 14 138 5.8 30 997 302 30 12 105 3.5 9.9 106 2.9 31 15 153 8.6 8.6 87 2.0 TOTAL 621.5 980.83 513 778.49 403.0 488.62 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 8.0 71 1.5 6.6 21 .38 e11 14 e7.0 2 10 140 7.0 6.7 21 .38 e7.1 15 e.99 3 8.4 133 3.1 15 185 25 e6.9 15 e.99 4 7.9 57 1.2 7.2 27 .51 e6.9 15 e.99 5 7.7 54 1.1 6.7 26 .47 e6.8 15 e.99 6 7.3 53 1.0 6.5 25 .45 e6.6 16 e.99 7 7.1 51 .99 6.7 25 .44 e6.9 17 e.99 8 7.2 50 .96 6.5 24 .42 e6.9 18 e.99 9 6.9 46 .86 6.6 23 .42 e7.0 19 e.99 10 6.9 41 .77 6.5 23 .40 e7.1 20 e.99 11 6.9 37 .68 12 7.0 33 .63 13 6.9 29 .55 14 6.7 26 .48 15 6.6 23 .42 6.4 22 .38 e13 21 e2.0 6.6 22 .38 e7.1 23 e.99 7.5 35 .97 e6.7 24 e.99 6.5 28 .49 e6.2 24 e.99 6.4 24 .41 e6.3 24 e.99 16 6.7 21 .38 17 6.9 21 .39 18 6.9 21 .39 19 6.6 21 .38 20 7.1 21 .40 8.5 92 3.6 e6.1 24 e.99 6.3 24 .41 e5.9 24 e.37 6.0 23 .37 e5.9 24 e.37 5.8 21 .33 e7.6 25 e1.1 75 1870 1530 e5.7 29 e.37 21 7.1 21 .41 22 7.0 21 .39 23 6.5 21 .37 24 6.6 21 .38 25 6.5 21 .37 e82 2580 e197 e5.8 35 e.37 e17 171 e25 e5.9 41 e.37 e8.8 35 e2.0 e9.9 49 e2.9 e19 340 e11 e12 58 e2.0 e20 335 e12 e6.8 69 e.86 26 6.5 21 .37 27 7.0 21 .40 28 6.4 21 .36 29 6.5 21 .37 30 6.5 21 .37 31 --- --- --- e8.7 81 e2.0 e6.1 82 e.86 e8.8 78 e2.0 e6.2 88 e.86 e8.1 78 e3.1 e6.3 86 e.86 e7.1 40 e.99 e7.9 36 e.97 e6.9 15 e.99 e19 200 e25 e6.9 14 e.99 --- --- --­ TOTAL 212.3 --- 26.97 403.3 --- 1823.28 229.6 --- 60.12 --- --- --- --- --- --- 192 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 e7.3 51 e.99 e7.8 50 e.99 13 45 1.6 2 e6.9 46 e.99 e7.4 48 e.99 16 164 11 3 e6.9 43 e.99 e7.3 51 e.99 14 47 1.7 4 e6.9 44 e.99 e7.3 47 e.99 13 39 1.4 5 e8.0 45 e3.1 e6.9 43 e.99 12 47 1.5 6 e9.7 46 e.27 e6.9 49 e.99 12 57 1.8 7 e12 55 e7.0 e7.1 50 e.99 11 69 2.1 8 e19 59 e25 e16 160 e11 11 84 2.6 9 e11 60 e7.0 e10 70 e2.1 10 75 2.1 10 e9.9 32 e7.0 e16 150 e11 10 74 2.0 11 e12 58 e7.0 e10 65 e2.1 9.9 73 2.0 12 e7.3 51 e.97 e15 130 e2.0 11 109 3.7 13 e5.3 35 e.37 e32 750 e56 26 318 40 14 e5.1 30 e.37 e44 900 e380 33 423 56 15 e7.2 27 e.97 e18 181 e2.9 16 135 5.9 16 e11 60 e7.0 e25 351 e28 13 85 2.9 17 e5.6 40 e.37 e26 348 e28 12 58 1.9 18 e12 41 e7.0 e22 351 e28 12 41 1.3 19 e11 57 e7.0 e17 150 e11 11 36 1.0 20 e49 44 e380 e18 145 e11 10 32 .89 21 e15 33 e2.0 e68 925 e201 12 122 4.4 22 e6.6 25 e.97 e130 1000 e1700 13 128 5.4 23 e5.0 19 e.97 28 308 23 24 1150 344 24 e4.6 16 e.97 55 1530 524 22 351 34 25 e7.2 19 e.99 26 149 12 15 131 5.2 26 e6.9 24 e.99 18 59 2.9 37 842 341 27 e4.6 30 e.37 18 134 7.8 18 181 8.6 28 e8.2 38 e3.1 15 49 2.0 17 171 8.1 29 e4.8 48 e.37 15 49 2.0 45 900 382 30 e27 200 e23 13 49 1.8 18 194 9.6 31 e12 125 e1.8 23 194 23 TOTAL 325.0 499.91 728.7 3079.53 496.9 1285.69 YEAR 6479.4 18994.25 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) NOV 13... 0400 167 1800 812 92 22... 1420 365 10100 9950 55 DEC 26... 1945 304 5500 4510 84 29... 1315 188 1040 528 83 JAN 24... 1129 44 299 36 99 FEB 01... 1145 170 6590 3030 68 01... 1248 446 6180 7440 83 MAR 29... 1240 259 11100 7760 96 MAY 20... 1831 211 6390 3640 92 JUN 27... 1157 6.1 56 .92 97 JUL 30... 2141 70 3870 731 91 AUG 14... 1516 130 6350 2230 95 SEP 26... 1016 178 6090 2930 93 29... 1400 100 8120 2190 94 193 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) NOV 12... 1155 125 5830 1970 39 46 55 22... 1500 1380 11600 43100 25 30 33 DEC 26... 2030 996 10100 27200 18 25 34 MAR 18... 1423 168 5560 2520 30 38 43 MAY 20... 1516 274 9470 7000 22 39 49 JUN 30... 1415 205 5310 2940 23 31 49 JUL 30... 1713 79 5250 1120 35 45 58 SEP 23... 1811 186 43100 21700 6 9 12 WATER-QUALITY DATA, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 12... 67 78 97 99 100 100 100 22... 41 48 59 72 85 96 99 DEC 26... 45 57 72 83 90 95 98 MAR 18... 60 75 86 94 98 99 100 MAY 20... 65 78 91 97 99 99 100 JUN 30... 65 79 94 96 98 100 100 JUL 30... 72 83 97 99 100 100 100 SEP 23... 19 29 58 75 91 98 100 --- --- --- --- --- --- 194 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 46 2050 1580 11 57 3.7 11 28 .81 2 56 992 445 9.2 10 .24 11 27 .77 3 23 434 28 9.9 26 .88 11 26 .74 4 17 242 11 9.1 10 .23 11 25 .71 5 18 265 15 11 51 2.0 10 24 .67 6 22 379 31 9.6 10 .26 10 23 .62 7 18 273 14 9.9 10 .27 10 22 .60 8 69 1400 1350 10 10 .27 10 21 .57 9 24 495 33 11 10 .29 10 20 .55 10 18 259 12 12 97 3.5 10 20 .55 11 28 534 109 11 24 .70 9.9 47 1.5 12 25 451 46 11 20 .61 8.7 18 .42 13 52 706 923 12 20 .61 8.9 17 .40 14 123 874 856 11 19 .56 8.7 15 .36 15 19 52 2.8 32 717 305 8.5 15 .33 16 16 19 .85 16 166 12 8.1 14 .30 17 14 18 .71 9.7 20 .51 8.1 13 .28 18 13 18 .60 16 114 14 7.6 12 .25 19 12 17 .52 12 23 .71 7.2 12 .23 20 11 16 .47 11 20 .59 7.1 12 .23 21 11 15 .44 22 271 31 8.0 12 .26 22 11 14 .41 13 34 1.2 6.7 12 .22 23 10 14 .38 12 34 1.1 6.6 12 .21 24 10 13 .36 14 112 5.7 6.5 12 .21 25 11 12 .35 12 34 1.1 6.1 12 .20 26 11 12 .33 13 61 2.5 6.3 12 .20 27 10 11 .31 11 33 1.0 6.7 12 .22 28 10 11 .29 11 32 .93 6.3 12 .20 29 9.6 11 .28 11 31 .91 6.5 12 .21 30 9.5 10 .27 11 29 .85 6.2 12 .20 31 9.7 10 .27 6.7 12 .22 TOTAL 736.8 5462.64 374.4 393.22 259.4 13.24 SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) JANUARY MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) FEBRUARY MARCH 1 7.6 12 .25 3.0 7 .06 4.5 43 .52 2 7.4 12 .24 3.1 7 .06 4.5 40 .49 3 9.8 70 2.5 3.1 6 .05 5.1 37 .51 4 7.9 56 1.7 58 1770 3250 4.5 32 .39 5 8.5 70 2.4 72 1970 1350 18 244 85 6 28 583 114 9.4 108 2.8 4.3 39 .46 7 33 759 151 7.7 83 1.7 8.9 130 8.6 8 5.8 37 .61 29 948 382 4.5 48 .60 9 5.4 24 .35 13 176 7.4 4.0 23 .25 10 5.0 23 .31 6.4 42 .74 3.8 23 .24 11 4.5 22 .27 12 4.9 27 .39 13 30 607 121 14 13 158 7.4 15 5.6 15 .23 6.6 39 .69 3.7 23 .23 5.8 41 .64 3.7 23 .23 5.3 43 .61 3.7 23 .23 18 302 26 36 880 458 8.9 130 3.4 5.1 63 .90 16 4.9 11 .15 17 4.6 11 .13 18 17 328 83 19 6.7 48 .98 20 4.9 12 .16 6.4 103 1.8 4.2 36 .41 5.6 96 1.5 4.2 35 .39 5.2 90 1.3 5.8 71 2.3 5.6 84 1.3 4.1 48 .64 5.0 79 1.1 3.8 22 .23 21 4.7 11 .14 22 4.2 11 .12 23 3.9 10 .11 24 3.8 10 .10 25 3.7 9 .09 4.8 74 .96 3.9 17 .18 4.7 69 .87 3.9 12 .13 4.7 64 .81 3.9 9 .09 4.2 60 .68 3.9 7 .08 4.2 56 .63 3.9 7 .08 26 3.7 9 .09 27 3.7 9 .09 28 3.6 8 .08 29 3.5 8 .08 30 3.5 8 .07 31 3.4 7 .07 4.4 53 .62 3.7 7 .08 4.5 49 .59 3.8 8 .08 4.5 46 .56 4.5 8 .09 --- --- --- 36 1230 618 --- --- --- 10 138 9.7 --- --- --- 10 144 4.9 TOTAL 256.2 --- 488.11 313.1 --- 5038.87 223.9 --- 1194.03 195 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 5.2 70 .99 4.3 28 .33 3.5 39 .37 2 4.8 61 .80 4.1 23 .26 3.3 37 .34 3 4.3 56 .64 4.4 19 .22 3.4 36 .33 4 4.3 51 .58 4.7 15 .19 3.4 34 .32 5 4.6 46 .56 4.3 12 .14 24 499 181 6 4.4 42 .50 4.1 10 .12 5.3 59 .90 7 5.7 62 1.4 4.2 10 .11 4.6 38 .47 8 5.9 91 1.5 5.0 10 .13 6.1 65 1.8 9 4.5 79 .97 4.2 10 .11 28 551 212 10 4.3 76 .89 3.9 9 .10 9.3 137 4.9 11 4.4 73 .87 12 36 545 273 13 9.6 117 4.7 14 4.4 41 .48 15 9.5 117 35 3.9 9 .10 4.3 40 .47 3.8 9 .09 7.4 98 3.7 3.7 9 .09 3.8 35 .36 26 509 165 3.5 33 .31 7.0 74 1.9 3.6 33 .32 16 60 1280 533 17 12 150 5.6 18 6.1 65 1.1 19 5.5 59 .87 20 12 159 15 3.7 32 .32 9.6 156 16 6.9 84 5.5 19 376 106 4.4 43 .72 11 138 5.1 6.7 82 2.9 4.9 47 .63 6.0 68 2.4 4.4 43 .51 21 7.7 86 2.9 22 5.4 53 .77 23 5.2 49 .69 24 5.0 46 .63 25 10 133 7.4 6.3 71 3.3 8.4 102 3.9 4.0 33 .37 5.4 56 .82 29 492 140 5.0 50 .67 4.9 58 .77 4.7 45 .56 4.3 49 .58 7.7 141 5.9 26 5.5 56 .83 27 7.9 97 2.9 28 5.1 53 .73 29 4.8 43 .56 30 4.7 35 .45 31 --- --- --- 9.1 124 9.9 4.3 44 .52 7.1 84 3.3 4.6 36 .45 8.8 132 14 4.6 35 .43 4.3 44 .51 4.3 34 .40 3.7 42 .42 3.9 33 .36 3.5 41 .39 --- --- --­ TOTAL 268.8 --- 896.31 200.3 --- 354.27 215.3 --- 549.84 SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 3.8 33 .34 5.1 48 .66 e8.3 14 e7.4 2 4.4 32 .38 4.8 3 13 248 57 4.8 4 20 440 153 4.8 46 .59 23 13 145 44 .57 7.5 15 1.5 42 .55 6.6 16 1.0 5 4.6 137 1.7 6.2 69 1.7 7.0 18 1.1 6 4.1 91 1.0 e8.0 62 e2.7 201 20 5230 7 7.8 96 4.1 e39 65 e273 30 22 53 8 3.6 39 .38 e11 68 e27 14 24 7.6 9 4.1 35 .39 e15 71 e57 14 27 9.4 10 9.3 122 8.5 e37 74 e273 11 30 3.6 11 4.1 45 .52 12 3.6 34 .34 13 3.6 34 .33 14 11 199 27 15 8.2 106 7.4 e84 3400 e4220 10 33 3.2 e31 80 e212 11 37 4.8 e10 83 e57 16 40 14 8.7 77 1.8 9.9 45 2.8 7.4 70 1.4 12 50 4.8 16 75 3420 4220 6.3 17 21 387 34 e6.0 18 22 479 100 e60 19 6.6 78 1.4 e15 20 22 348 34 e10 64 1.1 14 55 12 58 e1.6 20 61 32 1900 e1350 22 69 29 48 e57 16 92 9.2 44 e5.1 16 126 9.6 21 10 146 4.1 22 7.6 83 1.7 23 8.2 107 3.2 24 17 259 26 25 5.3 52 .75 e28 40 e212 e714 171 e162000 e11 36 e5.1 e1030 233 e165000 e7.0 33 e1.7 e49 318 167 e61 1900 e1350 22 339 20 e50 1200 e533 17 282 13 26 5.5 64 1.1 e7.5 27 9.8 166 7.8 e30 28 8.1 99 2.7 e55 29 6.2 67 1.6 e18 30 7.1 74 1.7 e9.3 31 7.2 85 2.0 e8.4 25 e2.0 47 916 421 23 e212 22 343 22 1200 e533 15 205 8.2 19 e106 25 433 74 17 e8.5 13 205 2.6 15 e8.5 --- --- --­ TOTAL 343.8 --- 4704.43 659.3 --- 9515.57 2423.3 --- 333308.8 YEAR 6274.6 361919.33 e Estimated 196 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 02... 1728 390 7250 7630 72 02... 1828 165 3110 1390 82 08... 1811 205 4930 2730 53 14... 0501 149 886 356 81 NOV 15... 1638 144 8330 3240 94 MAR 29... 1834 162 10800 4720 97 MAY 14... 2014 173 7590 3550 99 JUL 16... 1425 306 18000 1490 93 SEP 18... 1123 12 67 2.2 97 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 01... 1636 228 14900 9170 19 24 32 NOV 15... 1553 382 11800 12200 16 22 30 JAN 18... 1600 188 5730 2910 28 38 50 FEB 08... 1841 170 4900 2250 21 31 43 MAR 14... 1200 240 3840 2490 35 45 60 JUN 09... 1651 251 3670 2490 30 45 63 JUL 16... 1554 414 40100 44800 13 17 23 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 01... 42 55 62 79 94 99 100 NOV 15... 36 39 43 48 95 99 100 JAN 18... 67 84 91 96 98 100 100 FEB 08... 56 66 71 80 95 100 100 MAR 14... 74 80 83 92 97 99 100 JUN 09... 79 92 95 99 100 100 100 JUL 16... 32 45 51 65 82 96 99 197 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'15", long 66°03'40", at bridge on Winston Churchill Avenue in the El Señorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Río Piedras plaza. DRAINAGE AREA.--8.17 mi2 (20.9 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 05... 1240 8.0 409 7.4 28.0 7.1 5.6 72 <10 K62000 22000 MAR 02... 1130 4.8 475 7.4 25.5 2.4 5.4 66 13 K660000 45000 JUN 08... 0815 3.9 444 7.2 26.0 8.0 6.1 75 <10 22000 5400 SEP 03... 1215 13 413 6.9 29.5 6.6 6.6 86 11 K100000 30000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 05... 150 57 6.4 12 .6 3.5 156 <.5 12 12 MAR 02... -- -- -- -- -- -- 190 -- -- -­ JUN 08... 150 40 13 28 1 2.8 180 -- 13 35 SEP 03... 150 38 13 24 .9 3.1 140 <1.0 20 30 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 05... .10 25 218 4.71 15 .640 .110 .750 .420 .52 MAR 02... -- -- -- -- 2 .510 .220 .730 1.70 .20 JUN 08... .15 30 270 2.86 16 .590 .100 .690 .350 .25 SEP 03... .14 26 239 8.27 18 .881 .039 .920 .350 .63 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 05... .94 1.7 7.5 .180 1 <100 40 <1 <1 20 MAR 02... 1.9 2.6 12 .310 -- -- -- -- -- -­ JUN 08... .60 1.3 5.7 .140 <5 <100 60 <1 <1 <10 SEP 03... .98 1.9 8.4 .140 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 198 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 05... 430 2 150 <.10 <1 <1 10 <.010 2 .07 MAR 02... JUN 08... 410 1 200 <.10 <1 <1 <10 <.010 <1 .04 SEP 03... 199 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR LOCATION.--Lat 18°24'34", long 66°04'10", Hydrologic Unit 21010005, at bridge on Avenida Piñeiro near Expreso Las Américas (Luis A. Ferré), and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.4 mi2 (39.9 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1970 to December 1987 (discharge measurements only), 1972 to December 1982 (maximum discharge only), January 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 16 ft (5 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Mean daily discharge affected by sewage discharges (approximately 2.0 ft3/s (0.06 m3/s)), 20 ft (6 m) upstream from gaging station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 95 e40 e27 e10 6.9 2 295 e30 e27 e21 6.9 3 81 e34 e27 e21 6.6 4 39 e31 e27 11 206 5 18 e75 e29 49 609 e12 e11 e7.0 11 e14 e16 e30 e10 e8.7 e9.3 10 e18 e15 e173 28 e6.7 e11 9.3 e49 e15 e23 21 e7.0 e13 8.9 e62 e15 e35 109 e8.0 e10 123 e20 e13 82 6 18 34 27 147 75 46 e8.0 e8.5 e28 e18 e18 543 7 9.3 27 24 307 8 e311 26 21 33 9 35 26 20 33 10 13 67 21 24 53 78 e12 e9.5 11 e35 e30 156 149 25 e13 e16 53 e17 e21 140 75 20 e8.0 e9.5 148 e42 e11 86 38 16 e7.2 e7.0 52 e41 e57 70 11 212 22 22 23 12 50 22 21 20 13 101 22 21 91 14 513 19 20 25 15 27 153 20 12 45 14 e7.1 e7.0 20 e20 e255 65 37 14 e204 e6.1 56 e17 e129 71 28 15 e28 e5.6 19 e16 e38 98 e73 105 e7.7 e195 17 e223 e23 114 e43 55 e26 90 16 e220 e18 104 16 25 77 19 11 17 29 26 26 10 18 e30 82 20 28 19 e28 41 17 13 20 e25 21 17 10 31 11 e219 36 33 e202 e15 93 29 11 e37 119 40 e78 e13 112 25 15 e15 12 45 e97 e96 442 23 24 e12 e21 19 e15 e47 191 27 16 e34 e39 15 e126 e16 190 21 e23 293 19 10 22 e24 35 20 9.8 23 e25 22 30 9.1 24 e26 26 18 9.1 25 e33 21 17 9.7 e20 12 e20 e12 e28 e33 e53 926 16 11 e11 e8.5 e18 e19 e36 2140 12 12 e10 e52 e15 e25 e28 322 9.8 12 e9.3 e12 e15 e51 e203 e213 e8.0 17 e35 e34 e27 e17 e255 e186 26 e29 25 18 8.6 27 e27 e17 17 8.3 28 e28 e17 e16 8.9 29 e33 e39 e15 9.5 30 e37 e31 e19 7.9 31 e37 --- e20 7.2 e14 16 e27 e103 e14 e17 e28 e286 e16 17 e46 e31 e16 e29 e73 e208 e15 17 e9.8 63 e16 e25 e166 e180 --- 210 e12 e14 e16 e19 e29 e247 --- e29 e7.9 e12 e14 e21 e17 e205 --- e29 --- 43 --- e22 e14 --­ TOTAL 2276.3 1401 662 997.1 MEAN 73.4 46.7 21.4 32.2 MAX 513 293 30 307 MIN 9.3 17 15 7.2 AC-FT 4520 2780 1310 1980 CFSM 4.83 3.07 1.40 2.12 IN. 5.57 3.43 1.62 2.44 1697.2 1027 867.4 1016.0 913.2 1608 1763 7731 60.6 33.1 28.9 32.8 30.4 51.9 56.9 258 609 210 219 195 148 223 255 2140 6.6 10 6.7 5.6 8.9 14 11 23 3370 2040 1720 2020 1810 3190 3500 15330 3.99 2.18 1.90 2.16 2.00 3.41 3.74 17.0 4.15 2.51 2.12 2.49 2.23 3.94 4.31 18.92 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1972 - 1998, BY WATER YEAR (WY) MEAN 67.0 73.8 47.4 45.6 MAX 134 235 168 97.4 (WY) 1991 1993 1993 1993 MIN 16.6 23.9 18.8 12.9 (WY) 1992 1991 1992 1973 43.9 37.4 54.1 44.7 41.2 49.3 57.1 103 86.9 78.5 150 97.5 81.9 97.4 84.2 261 1995 1972 1972 1992 1995 1993 1988 1996 10.8 11.5 13.6 4.12 20.0 12.8 20.2 26.3 1992 1994 1995 1972 1994 1994 1993 1972 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1972 - 1998 ANNUAL TOTAL 17493.6 ANNUAL MEAN 47.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 518 LOWEST DAILY MEAN 9.3 ANNUAL SEVEN-DAY MINIMUM 12 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 34700 ANNUAL RUNOFF (CFSM) 3.15 ANNUAL RUNOFF (INCHES) 42.81 10 PERCENT EXCEEDS 110 50 PERCENT EXCEEDS 25 90 PERCENT EXCEEDS 12 21959.2 60.2 54.7 84.0 1993 28.7 1994 Jul 20 2140 Sep 22 4550 Sep 10 1996 Mar 27 5.6 May 13 1.2 Jun 28 1972 Jun 4 7.7 Jan 28 1.2 Jul 5 1972 5700 Sep 21 10500 Sep 10 1996 17.58 Sep 21 22.11 Sep 10 1996 43560 39630 3.96 3.60 53.74 48.90 151 122 24 22 9.6 9.6 e Estimated 200 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 201 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'34", long 66°04'10", at bridge on Avenida Piñero at Expreso Las Américas, and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.4 mi2 (39.9 km2). PERIOD OF RECORD.--Water years 1971 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 05... 1515 25 309 7.4 28.0 18 4.5 57 10 58000 67000 MAR 02... 1315 9.9 476 7.5 26.0 1.0 4.6 57 13 K780000 25000 JUN 08... 1220 54 257 7.0 28.5 35 5.7 73 10 230000 65000 SEP 03... 1040 25 365 7.2 29.0 22 6.2 80 12 350000 210000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 05... 140 41 8.1 15 .6 5.2 110 <.5 25 22 MAR 02... -- -- -- -- -- -- 180 -- -- -­ JUN 08... 39 8.6 4.3 13 .9 .90 98 -- 6.6 16 SEP 03... 130 37 9.0 21 .8 3.1 130 <1.0 14 24 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 05... .10 16 198 13.4 74 .654 .096 .750 .940 .66 MAR 02... -- -- -- -- 7 .810 .160 .970 1.60 .10 JUN 08... .10 16 198 13.4 74 .561 .059 .620 .460 .84 SEP 03... .15 22 208 13.9 46 .758 .082 .840 .780 .72 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 05... 1.6 2.3 10 .280 1 <100 40 <1 1 <10 MAR 02... 1.7 2.7 12 .320 -- -- -- -- -- -­ JUN 08... 1.3 1.9 8.5 .250 1 <100 50 <1 2 <10 SEP 03... 1.5 2.3 10 .200 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 202 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 05... 760 2 180 <.10 <1 1 20 <.010 <1 .17 MAR 02... JUN 08... 2100 5 150 <.10 <1 2 30 <.010 4 .13 SEP 03... 203 RIO PUERTO NUEVO BASIN 50049820 LAGUNA SAN JOSE NO. 2 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18025'46", long 66002'10", 0.2 mi (0.3 km) east of Caño de Martín Peña, and 650 ft (200 m) south of Isla Guachinango. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, COLI- ANC RESIDUE SPE- WATER TRANS- DIS- FORM, STREP- WATER TOTAL CIFIC WHOLE PAR- SOLVED FECAL, TOCOCCI UNFLTRD AT 105 CON- FIELD TEMPER- ENCY OXYGEN, (PER- 0.45 FECAL, FET DEG. C, DUCT- (STAND- ATURE (SECCHI DIS- CENT UM-MF (COLS. FIELD SUS­ DATE TIME ANCE ARD WATER DISK) SOLVED SATUR- (COLS./ PER MG/L AS PENDED (US/CM) UNITS) (DEG C) (IN) (MG/L) ATION) 100 ML) 100 ML) CACO3 (MG/L) (00095) (00400) (00010) (00077) (00300) (00301) (31616) (31679) (00410) (00530) NOV 12... 0945 22600 7.1 29.5 47.0 2.0 26 5500 550 93 10 MAR 09... 1000 18500 7.5 25.5 33.0 4.0 48 23000 800 90 22 JUN 12... 0930 19500 8.0 30.5 26.0 5.6 74 58000 860 84 8 SEP 15... 1030 16300 8.1 30.1 21.0 4.5 60 2000 K54 75 26 NITRO­ NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- CARBON, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ORGANIC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS C) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (00680) NOV 12... -- <.010 <.020 .680 .92 1.6 -- -- .310 6.5 MAR 09... .010 .030 .040 2.00 .30 2.3 2.3 10 .160 5.3 JUN 12... .010 .090 .100 .820 1.1 1.9 2.0 8.9 .180 7.1 SEP 15... -- .010 <.020 .160 1.3 1.5 -- -- .210 3.7 204 RIO PUERTO NUEVO BASIN 50049920 BAHIA DE SAN JUAN NO. 5 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION--Lat 18026'37", long 66005'11", 0.4 mi (0.6 km) west of Puente de la Constitución, and 0.5 mi (0.8 km) south from U.S. Naval Reservation. DRAINAGE--Indeterminate. PERIOD OF RECORD--Water years 1974 to present. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, COLI- ANC RESIDUE SPE- WATER TRANS- DIS- FORM, STREP- WATER TOTAL CIFIC WHOLE PAR- SOLVED FECAL, TOCOCCI UNFLTRD AT 105 CON- FIELD TEMPER- ENCY OXYGEN, (PER- 0.45 FECAL, FET DEG. C, DUCT- (STAND- ATURE (SECCHI DIS- CENT UM-MF (COLS. FIELD SUS­ DATE TIME ANCE ARD WATER DISK) SOLVED SATUR- (COLS./ PER MG/L AS PENDED (US/CM) UNITS) (DEG C) (IN) (MG/L) ATION) 100 ML) 100 ML) CACO3 (MG/L) (00095) (00400) (00010) (00077) (00300) (00301) (31616) (31679) (00410) (00530) NOV 12... 1130 49500 7.3 29.0 16.0 4.0 52 K6700 2000 150 37 MAR 09... 1145 40800 7.4 27.0 24.0 2.5 31 K64000 5500 130 31 JUN 12... 1130 33000 7.6 30.0 15.0 2.9 38 280000 36000 140 13 SEP 15... 1200 17300 7.6 29.0 14.0 .3 4 600000 K140000 140 26 NITRO­ NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- CARBON, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS ORGANIC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS C) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) (00665) (00680) NOV 12... -- .014 <.020 1.80 .80 2.6 -- -- .410 4.6 MAR 09... .022 .028 .050 2.00 .10 2.1 2.2 9.5 .300 8.6 JUN 12... .100 .070 .170 1.30 .70 2.0 2.2 9.6 .920 5.9 SEP 15... .054 .060 .110 2.9 .60 3.5 3.6 16 .510 2.5 205 R í o Río Río Río Río Río Río Río Río Río Río Río Río Grande Grande Gurabo Grande C a y a g u á s de de Cañas Lago Loíza Laguna San José Bahía de San Juan Laguna Laguna de Piñones Quebrada de las Qu b ra d a Quebradilla s Qubrada Qubrada Qubrada Q u e b ra d a Arenas Bairoa Turabo Gurabo Turabo Caguitas Loíza Loíza Canóvanas Canóvanilla s Maracuto P a st r a n a Blasina Caño de Martín Peña Valenciano 0610 059050 0590 0503 222 OCEAN CAROLINA LOÍZA HUMACAO SAN LORENZO LAS PIEDRAS TRUJILLO JUNCOS CAGUAS GURABO AGUAS BUENAS 0 0 1 1 2 2 3 3 4 4 0509 051310 053025 051800 0564 055750 0570 057025 0550 0618 0610 059050 058350 0551 0554 055390 055225 055250 0575 0588 0591 0590 0503 222 50 La T orrecilla QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER CATAÑO SAN JUAN A TLANTIC RÍO GRANDE ALTO CANÓVANAS Basin area PUERTO RICO 5 MILES 5 KILOMETERS 051150 051180 CJ-TW-19A CJ-TW-15 CJ-TW-18 CJ-TW-3B CJ-TW-11 CJ-TW-20 Figure 18. Río Grande de Loíza basin. 206 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°23'27", long 65°58'28", at bridge on Highway 3, 1.4 mi (2.3 km) south of Valle Arriba Heights housing area, and 1.2 mi (1.9 km) west-southwest of Carolina plaza. DRAINAGE AREA.--2.96 mi2 (7.67 km2). PERIOD OF RECORD.--Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 28... 0945 4.2 520 7.4 26.5 1.5 6.7 82 <10 K6900 3400 MAR 25... 1030 3.8 461 7.1 26.5 1.2 3.0 37 23 K170000 22000 JUN 09... 1105 5.5 435 7.2 27.5 2.3 4.6 58 10 24000 45000 SEP 08... 1025 11 470 7.0 28.0 62 2.8 36 13 600000 700000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 190 60 9.1 29 .9 3.3 205 <.5 10 42 MAR 25... -- -- -- -- -- -- 210 -- -- -­ JUN 09... 140 46 5.2 15 .5 .73 170 -- 26 7.8 SEP 08... 140 44 7.8 26 .9 4.2 210 <1.0 12 35 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... .29 29 306 3.49 <1 .470 .170 .640 1.90 .20 MAR 25... -- -- -- -- 8 .200 .010 .210 .020 .20 JUN 09... .30 25 236 3.53 -- .610 .210 .820 .600 .50 SEP 08... .11 22 277 8.51 134 .580 .100 .680 7.10 .90 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... 2.1 2.7 12 .400 1 <100 60 <1 <1 <10 MAR 25... .02 .24 1.1 .020 -- -- -- -- -- -­ JUN 09... 1.1 1.9 8.5 .260 1 <100 30 <1 <1 <10 SEP 08... 8.0 8.7 38 .850 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 207 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 480 <1 290 <.10 <1 <1 <10 <.010 <1 .09 MAR 25... JUN 09... 80 <1 <10 <.10 <1 <1 10 <.010 <1 <.01 SEP 08... 208 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 18°07'10", long 65°59'22", Hydrologic Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) upstream from confluence with Río Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 mi2 (15.54 km2). PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder. Elevation of gage is 640 ft (195 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22 18 19 23 2 62 17 17 15 3 26 18 17 28 4 22 17 16 55 5 20 16 16 44 15 12 27 14 16 8.7 10 18 14 12 42 14 16 10 9.7 24 14 e15 24 15 14 12 9.6 36 15 13 19 16 13 28 9.3 33 368 12 46 15 15 25 9.0 19 6 19 15 16 476 7 18 14 15 200 8 21 14 15 102 9 18 26 15 70 10 18 472 15 115 30 12 21 16 20 12 e27 122 19 551 20 14 19 21 11 60 22 75 19 26 16 16 22 105 23 28 16 17 15 15 32 135 16 21 15 14 14 11 23 45 11 33 31 15 35 12 73 25 17 43 13 460 22 15 35 14 e769 21 15 29 15 e207 23 14 25 16 18 20 12 e14 9.8 14 26 16 17 77 12 e20 9.5 14 21 15 16 18 21 e25 9.5 12 67 67 19 14 34 e15 9.6 11 42 27 17 13 31 e14 9.1 10 69 16 e90 21 21 23 17 e51 21 30 22 18 41 19 16 21 19 34 20 15 19 20 30 20 15 19 18 15 37 23 e15 11 11 25 21 14 51 17 24 10 106 20 17 14 83 15 19 15 20 19 16 16 52 14 16 17 15 18 15 237 128 14 14 54 18 e21 21 27 26 21 18 22 25 25 15 18 23 24 26 14 17 24 23 22 13 19 25 22 20 13 21 15 42 31 14 14 27 24 e4360 14 29 24 13 31 13 111 e4690 14 22 21 13 14 12 27 157 13 19 19 14 12 27 593 77 13 27 19 12 12 14 433 47 26 21 35 13 21 27 20 24 13 18 28 19 20 13 17 29 18 19 13 17 30 18 22 13 16 31 18 --- 13 16 13 22 18 56 11 11 108 41 13 28 19 48 11 14 39 139 12 24 20 14 12 23 28 45 --- 116 16 25 11 12 33 32 --- 153 15 51 9.5 12 23 29 --- 45 --- 27 --- 11 21 --­ TOTAL 2269 1089 488 1597 MEAN 73.2 36.3 15.7 51.5 MAX 769 472 30 476 MIN 18 14 13 15 AC-FT 4500 2160 968 3170 CFSM 12.2 6.05 2.62 8.59 IN. 14.07 6.75 3.03 9.90 871 1661 944 641 471.5 489.2 1833.6 10542 31.1 53.6 31.5 20.7 15.7 15.8 59.1 351 368 551 128 56 31 54 593 4690 12 12 13 12 9.5 8.7 9.0 18 1730 3290 1870 1270 935 970 3640 20910 5.18 8.93 5.24 3.45 2.62 2.63 9.86 58.6 5.40 10.30 5.85 3.97 2.92 3.03 11.37 65.36 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1978 - 1998, BY WATER YEAR (WY) MEAN 41.2 44.0 24.5 20.9 MAX 123 122 55.2 56.1 (WY) 1986 1988 1988 1992 MIN 13.1 8.34 6.65 8.16 (WY) 1990 1990 1990 1990 19.5 15.7 14.6 29.8 37.6 36.5 35.1 61.4 38.0 53.6 31.5 77.5 122 92.3 90.0 351 1982 1998 1998 1985 1979 1993 1979 1998 6.36 5.07 4.64 9.56 11.3 12.5 9.30 11.8 1979 1979 1979 1988 1985 1986 1991 1981 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1978 - 1998 ANNUAL TOTAL 10236.1 ANNUAL MEAN 28.0 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 769 LOWEST DAILY MEAN 6.6 ANNUAL SEVEN-DAY MINIMUM 6.9 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 20300 ANNUAL RUNOFF (CFSM) 4.67 ANNUAL RUNOFF (INCHES) 63.46 10 PERCENT EXCEEDS 40 50 PERCENT EXCEEDS 16 90 PERCENT EXCEEDS 8.3 22896.3 62.7 31.7 62.7 1998 14.5 1990 Oct 14 4690 Sep 22 4690 Sep 22 1998 May 6 8.7 Jul 1 3.1 May 7 1979 Apr 30 9.8 Jul 11 3.6 May 1 1979 45000 Sep 21 45000 Sep 21 1998 26.37 Sep 21 26.37 Sep 21 1998 7.9 Jul 1 2.8 May 5 1979 45410 23000 10.5 5.29 141.96 71.90 64 51 19 15 12 7.2 e Estimated 209 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 210 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR LOCATION.--Lat 18°09'40", long 65°58'58", Hydrologic Unit 2l0l0005, 0.1 mi (0.2 km) upstream from bridge on Highway 181, and 2.8 mi (4.5 km) southwest of San Lorenzo. DRAINAGE AREA.--3.25 mi2 (8.42 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 459 ft (140 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.2 3.8 3.2 2.4 2.7 2.7 4.1 2.5 2.5 1.8 1.4 1.9 2 22 3.1 3.1 2.7 2.7 2.7 12 2.4 2.3 1.8 1.4 4.5 3 6.7 3.0 3.0 2.7 2.7 3.1 5.5 3.0 2.2 2.3 1.5 3.7 4 4.4 2.8 2.9 2.8 4.7 3.0 4.1 e3.2 2.2 5.3 1.4 3.5 5 3.5 2.8 2.9 2.8 44 2.8 3.8 e2.8 3.6 2.8 1.3 1.8 6 2.9 2.8 2.9 29 8.5 2.7 3.3 e2.3 3.3 1.9 1.3 2.3 7 2.4 2.6 2.9 39 5.4 e164 3.4 e2.2 2.3 1.7 1.3 4.1 8 3.4 2.5 2.8 15 12 18 3.3 15 2.5 1.7 4.1 22 9 2.8 3.8 2.8 14 8.1 e11 3.1 4.8 2.3 1.6 4.2 11 10 3.2 29 2.8 14 4.1 e6.7 3.0 3.0 2.2 1.6 2.7 10 11 4.7 4.7 2.7 7.2 3.1 e4.9 3.6 2.5 2.0 1.6 6.7 3.2 12 11 3.6 2.8 5.7 2.6 e4.3 12 2.3 3.4 1.5 2.2 2.0 13 56 3.4 2.8 10 2.5 e4.0 4.6 5.2 2.3 1.5 1.7 4.0 14 e126 3.1 2.8 6.8 13 e4.9 3.7 7.6 2.1 1.6 1.5 2.0 15 22 3.0 2.8 4.6 6.8 4.3 3.4 e7.7 2.0 1.6 1.4 38 16 16 2.9 2.8 4.1 4.5 e4.1 8.3 e4.1 2.5 1.8 1.5 12 17 15 3.1 3.3 3.9 4.3 3.8 9.5 3.2 2.3 1.8 3.6 5.5 18 12 2.9 2.8 3.6 3.7 3.9 14 e2.9 2.1 4.5 2.3 3.5 19 8.4 3.0 2.7 3.3 3.4 4.4 e7.1 e2.9 2.5 2.8 1.7 e3.2 20 6.4 2.8 2.7 3.1 3.3 34 13 e3.4 2.1 22 2.0 e3.0 21 5.9 3.9 3.2 2.9 3.1 9.7 7.1 e2.5 2.7 6.0 3.2 e182 22 6.2 5.4 2.6 3.0 2.9 5.7 5.2 2.4 5.4 2.1 21 214 23 5.3 7.2 2.6 2.9 2.9 4.4 4.2 2.5 2.2 1.6 6.2 24 24 4.6 5.8 2.5 3.1 2.7 4.2 3.7 2.5 2.0 1.8 63 16 25 4.9 4.1 2.6 3.5 2.7 4.5 3.5 2.2 2.1 1.6 63 13 26 4.0 4.4 2.5 3.3 2.7 4.0 3.5 2.6 2.0 1.4 23 9.5 27 4.1 3.7 2.5 3.0 2.4 7.3 3.2 6.8 2.0 1.4 13 8.3 28 3.8 3.5 2.5 2.9 2.9 4.6 3.4 2.8 2.1 2.3 7.4 7.1 29 3.5 3.3 2.4 2.8 6.9 2.9 3.2 1.9 1.6 5.1 6.3 30 3.4 3.4 2.5 2.7 6.0 2.7 6.5 1.8 1.5 3.1 5.8 31 3.3 2.5 2.7 4.6 3.0 1.5 2.3 TOTAL 381.0 133.4 85.9 209.5 164.4 351.2 164.2 120.0 72.9 86.0 255.5 627.2 MEAN 12.3 4.45 2.77 6.76 5.87 11.3 5.47 3.87 2.43 2.77 8.24 20.9 MAX 126 29 3.3 39 44 164 14 15 5.4 22 63 214 MIN 2.4 2.5 2.4 2.4 2.4 2.7 2.7 2.2 1.8 1.4 1.3 1.8 AC-FT 756 265 170 416 326 697 326 238 145 171 507 1240 CFSM 3.78 1.37 .85 2.08 1.81 3.49 1.68 1.19 .75 .85 2.54 6.43 IN. 4.36 1.53 .98 2.40 1.88 4.02 1.88 1.37 .83 .98 2.92 7.18 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 1998, BY WATER YEAR (WY) MEAN 10.2 14.2 6.52 4.95 4.31 4.46 2.54 6.51 5.97 6.06 7.23 10.5 MAX 47.8 36.9 30.1 9.94 8.21 20.7 5.47 31.5 21.3 15.0 20.2 27.7 (WY) 1986 1985 1988 1992 1989 1989 1998 1985 1987 1993 1988 1996 MIN 2.75 2.49 1.49 1.74 1.32 1.64 .75 .62 2.12 2.02 1.95 1.36 (WY) 1993 1990 1990 1995 1985 1993 1994 1994 1994 1986 1994 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1984 - 1998 ANNUAL TOTAL 1971.5 2651.2 ANNUAL MEAN 5.40 7.26 6.96 HIGHEST ANNUAL MEAN 12.3 1988 LOWEST ANNUAL MEAN 2.50 1990 HIGHEST DAILY MEAN 126 Oct 14 214 Sep 22 457 Dec 7 1987 LOWEST DAILY MEAN 1.1 Jul 3 1.3 Aug 5 .33 May 20 1994 ANNUAL SEVEN-DAY MINIMUM 1.3 Jul 9 1.4 Aug 1 .37 Apr 26 1994 INSTANTANEOUS PEAK FLOW 2970 Sep 21 7610 Sep 10 1996 INSTANTANEOUS PEAK STAGE 10.38 Sep 21 14.64 Sep 10 1996 INSTANTANEOUS LOW FLOW 1.2 Aug 4 .30 May 21 1994 ANNUAL RUNOFF (AC-FT) 3910 5260 5040 ANNUAL RUNOFF (CFSM) 1.66 2.23 2.14 ANNUAL RUNOFF (INCHES) 22.57 30.35 29.10 10 PERCENT EXCEEDS 11 12 12 50 PERCENT EXCEEDS 3.1 3.2 2.7 90 PERCENT EXCEEDS 1.8 1.9 1.1 e Estimated 211 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 212 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1985 to 1986 and water year 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1984 to September 1986 and from October 1989 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1989. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,300 mg/L Oct. 06, 1985; Minimum daily mean, <1 mg/L several days in 1996. SEDIMENT LOADS: Maximum daily mean, 4,940 tons (4,480 tonnes) May 17, 1985; Minimum daily mean, <0.01 ton (<0.01 tonne) several years. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,100 mg/L Ocober 14, 1997; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,480 tons (2,250 tonnes) September 21, 1998; Minimum daily mean, <0.01 ton (<0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 3.2 4 .04 3.8 6 .06 3.2 9 .08 2 22 80 6.9 3.1 7 .06 3.1 9 .07 3 6.7 18 .35 3.0 8 .06 3.0 9 .07 4 4.4 8 .10 2.8 6 .04 2.9 6 .05 5 3.5 4 .04 2.8 4 .03 2.9 4 .04 6 2.9 3 .02 2.8 4 .03 2.9 6 .05 7 2.4 3 .02 2.6 3 .02 2.9 10 .08 8 3.4 9 .13 2.5 3 .02 2.8 16 .12 9 2.8 4 .03 3.8 14 .97 2.8 15 .12 10 3.2 12 .19 29 631 131 2.8 14 .10 11 4.7 6 .30 4.7 11 .13 2.7 12 .09 12 11 18 2.2 3.6 7 .07 2.8 10 .08 13 56 203 157 3.4 8 .07 2.8 7 .05 14 e126 1100 e1130 3.1 9 .08 2.8 4 .03 15 22 182 11 3.0 10 .08 2.8 2 .02 16 16 49 2.2 2.9 10 .08 2.8 2 .01 17 15 44 1.9 3.1 11 .09 3.3 2 .02 18 12 43 1.4 2.9 10 .08 2.8 1 .01 19 8.4 32 e.74 3.0 9 .07 2.7 1 .01 20 6.4 23 e.40 2.8 8 .06 2.7 1 .01 21 5.9 10 e.15 3.9 12 .14 3.2 2 .02 22 6.2 5 .08 5.4 14 .23 2.6 3 .02 23 5.3 9 .12 7.2 22 .58 2.6 3 .02 24 4.6 13 .17 5.8 13 .24 2.5 2 .01 25 4.9 8 .11 4.1 17 .19 2.6 2 .02 26 4.0 4 .04 4.4 15 .18 2.5 3 .02 27 4.1 2 .03 3.7 14 .14 2.5 4 .03 28 3.8 3 .03 3.5 13 .12 2.5 6 .04 29 3.5 3 .03 3.3 11 .10 2.4 8 .06 30 3.4 4 .04 3.4 10 .09 2.5 9 .06 31 3.3 5 .04 2.5 9 .06 TOTAL 381.0 1315.80 133.4 135.11 85.9 1.47 --- --- --- --- --- --- --- --- --- 213 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 2.4 10 .06 2.7 3 .02 2.7 2 .01 2 2.7 11 .08 2.7 3 .02 2.7 3 .02 3 2.7 11 .08 2.7 5 .04 3.1 3 .02 4 2.8 10 .08 4.7 10 .38 3.0 2 .02 5 2.8 10 .08 44 216 42 2.8 1 .01 6 29 267 54 8.5 7 39 182 25 5.4 8 15 48 2.1 12 9 14 74 3.5 8.1 10 14 50 2.3 4.1 25 .60 2.7 1 .01 15 .22 e164 918 e2390 37 3.8 18 64 3.5 20 .63 e11 35 e.97 3 .04 e6.7 10 e.18 11 7.2 15 .29 12 5.7 8 .13 13 10 32 2.8 14 6.8 17 .37 15 4.6 11 .14 3.1 2 .02 e4.9 2 e.02 2.6 3 .02 e4.3 1 e.01 2.5 5 .04 e4.0 2 e.02 13 64 6.4 e4.9 2 e.03 6.8 16 .32 4.3 2 .02 16 4.1 15 .17 17 3.9 13 .13 18 3.6 10 .10 19 3.3 8 .07 20 3.1 4 .04 4.5 6 .08 e4.1 2 e.02 4.3 8 .09 3.8 2 .02 3.7 12 .12 3.9 3 .03 3.4 10 .09 4.4 8 .10 3.3 7 .06 34 248 75 21 2.9 2 .02 22 3.0 5 .04 23 2.9 10 .08 24 3.1 11 .09 25 3.5 9 .09 3.1 4 .03 9.7 29 .85 2.9 2 .01 5.7 10 .16 2.9 1 .01 4.4 6 .07 2.7 1 .01 4.2 5 .06 2.7 2 .01 4.5 9 .12 26 3.3 8 .07 27 3.0 5 .04 28 2.9 2 .02 29 2.8 3 .02 30 2.7 4 .03 31 2.7 4 .03 2.7 2 .01 4.0 5 .06 2.4 1 .01 7.3 9 .28 2.9 1 .01 4.6 2 .12 --- --- --- 6.9 9 .49 --- --- --- 6.0 16 .29 --- --- --- 4.6 10 .13 TOTAL 209.5 --- 92.05 164.4 --- 55.09 351.2 --- 2472.64 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 4.1 1 .02 2.5 1 .01 2.5 3 .02 2 12 49 5.5 2.4 2 .01 2.3 2 .01 3 5.5 12 .19 3.0 5 .05 2.2 1 .01 4 4.1 5 .05 e3.2 6 e.05 2.2 1 .01 5 3.8 2 .02 e2.8 3 e.02 3.6 7 .14 6 3.3 1 .01 e2.3 2 e.01 3.3 7 .07 7 3.4 3 .03 e2.2 1 e.01 2.3 4 .03 8 3.3 7 .06 15 245 87 2.5 5 .04 9 3.1 6 .05 4.8 18 .23 2.3 2 .01 10 3.0 4 .03 3.0 14 .11 2.2 1 .01 11 3.6 2 .02 2.5 11 .07 2.0 1 <.01 12 12 32 1.5 2.3 9 .06 3.4 3 .03 13 4.6 8 .10 5.2 15 .31 2.3 1 .01 14 3.7 7 .07 7.6 36 2.2 2.1 1 .01 15 3.4 7 .06 e7.7 14 e.42 2.0 1 .01 16 8.3 30 1.5 e4.1 3 e.03 2.5 4 .03 17 9.5 22 .83 3.2 3 .03 2.3 2 .01 18 14 260 53 e2.9 3 e.02 2.1 1 .01 19 e7.1 18 e.38 e2.9 3 e.02 2.5 4 .03 20 13 59 5.8 e3.4 7 e.08 2.1 3 .02 21 7.1 16 .34 e2.5 3 e.02 2.7 6 .04 22 5.2 3 .05 2.4 1 .01 5.4 13 .25 23 4.2 2 .02 2.5 2 .01 2.2 4 .02 24 3.7 1 .01 2.5 4 .02 2.0 3 .02 25 3.5 2 .01 2.2 6 .04 2.1 2 .01 26 3.5 3 .03 2.6 6 .04 2.0 1 .01 27 3.2 4 .04 6.8 21 .54 2.0 1 <.01 28 3.4 2 .02 2.8 3 .03 2.1 1 .01 29 2.9 1 .01 3.2 1 .01 1.9 1 <.01 30 2.7 1 .01 6.5 19 .57 1.8 1 .01 31 3.0 6 .05 TOTAL 164.2 69.76 120.0 92.08 72.9 0.91 --- --- --- --- --- --- 214 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 1.8 2 .01 1.4 2 .01 1.9 2 .01 2 1.8 1 .01 1.4 1 <.01 4.5 8 .29 3 2.3 3 .02 1.5 1 <.01 3.7 7 .08 4 5.3 4 .22 1.4 1 <.01 3.5 5 .06 5 2.8 3 .05 1.3 1 <.01 1.8 2 .01 6 1.9 2 .01 1.3 1 <.01 2.3 3 .03 7 1.7 5 .02 1.3 1 <.01 4.1 4 .06 8 1.7 12 .05 4.1 2 .24 22 80 6.9 9 1.6 14 .06 4.2 6 .12 11 22 1.1 10 1.6 15 .06 2.7 5 .04 10 29 1.1 11 1.6 11 .05 6.7 18 .55 3.2 8 .07 12 1.5 7 .03 2.2 3 .02 2.0 5 .03 13 1.5 5 .02 1.7 2 .01 4.0 11 .21 14 1.6 3 .01 1.5 2 .01 2.0 3 .02 15 1.6 2 .01 1.4 2 .01 38 384 136 16 1.8 1 .01 1.5 3 .01 12 12 .47 17 1.8 1 <.01 3.6 8 .09 5.5 3 .04 18 4.5 14 .38 2.3 3 .02 3.5 2 .02 19 2.8 7 .05 1.7 1 .01 e3.2 2 .02 20 22 78 9.2 2.0 1 <.01 e3.0 2 .02 21 6.0 15 .32 3.2 3 .03 e182 982 2480 22 2.1 4 .02 21 100 12 214 1040 968 23 1.6 3 .01 6.2 14 .30 24 69 5.4 24 1.8 4 .02 63 745 279 16 13 .53 25 1.6 3 .01 63 313 88 13 4 .14 26 1.4 2 .01 23 38 3.0 9.5 9 .22 27 1.4 1 <.01 13 7 .24 8.3 12 .26 28 2.3 3 .03 7.4 3 .05 7.1 13 .24 29 1.6 1 .01 5.1 2 .03 6.3 7 .12 30 1.5 1 .01 3.1 2 .02 5.8 3 .05 31 1.5 2 .01 2.3 2 .01 TOTAL 86.0 10.74 255.5 383.89 627.2 3601.50 YEAR 2651.2 8231.04 e Estimated < Actual value is known to be less than the value shown WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 10... 1515 10 86 2.3 97 NOV 10... 1100 12 93 3.0 95 JAN 07... 1715 20 161 8.7 92 MAR 07... 1840 632 4320 7370 82 AUG 24... 1615 53 282 40 96 24... 2350 132 3900 1390 80 SEP 22... 0340 393 1850 1960 73 215 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) MAR 07... 1710 1440 4370 17000 24 30 41 AUG 24... 1351 205 8350 4620 26 32 41 SEP 21... 2150 576 5000 7780 32 43 59 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) MAR 07... 52 62 69 81 91 98 100 AUG 24... 50 56 60 78 87 91 94 SEP 21... 71 75 79 90 97 100 100 --- --- --- --- --- --- --- 216 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR LOCATION.--Lat 18°10'24", long 65°58'38", Hydrologic Unit 2l0l0005, on left downstream side of bridge on Highway 181, 0.2 mi (0.3 km) upstream from Río Grande de Loíza, and 1.5 mi (2.4 km) southwest of San Lorenzo. DRAINAGE AREA.--3.74 mi2 (9.69 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 330 ft (100 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e2.0 2.7 1.9 1.6 1.1 1.4 1.5 1.2 1.4 1.1 .62 2.4 2 e14 2.2 1.8 1.9 1.0 1.4 2.8 1.2 1.4 1.1 .60 3.1 3 e3.8 2.1 1.8 1.8 .95 1.5 3.1 1.5 1.4 1.1 .60 3.1 4 e2.8 2.1 1.7 1.9 9.7 1.6 1.6 1.5 1.3 2.1 .58 2.8 5 e2.3 2.1 1.7 2.4 101 1.7 1.5 1.4 1.4 2.1 .56 2.3 6 e1.8 2.1 1.6 67 5.0 1.8 1.4 1.3 1.8 1.2 e.57 2.5 7 e1.4 2.0 1.6 66 3.2 329 1.4 1.3 1.3 1.2 e1.0 2.6 8 2.0 2.0 1.6 8.5 44 7.4 1.4 12 1.3 1.1 1.2 8.3 9 1.8 e8.1 1.5 4.9 11 2.8 1.3 2.6 1.3 1.0 1.1 4.3 10 2.0 e7.4 1.5 4.3 3.1 2.2 1.2 1.7 1.2 1.0 .91 4.3 11 2.0 3.0 1.5 3.6 2.4 1.9 1.2 1.5 1.2 .99 .94 2.6 12 3.0 2.5 1.5 2.9 2.1 1.7 2.2 1.4 1.5 1.0 .85 2.4 13 e336 2.5 1.6 7.4 1.9 1.7 1.4 1.6 1.5 .91 .75 4.2 14 e97 2.3 1.7 5.2 11 1.7 1.3 2.7 1.3 .87 .69 2.9 15 13 2.4 1.6 3.1 4.2 1.6 1.3 2.6 1.2 .90 .69 7.3 16 8.0 2.3 1.6 2.6 2.6 1.6 2.0 1.6 1.5 1.2 .86 3.3 17 e8.2 2.5 2.1 2.3 2.4 1.6 2.3 1.5 1.2 1.2 1.1 3.0 18 6.4 2.3 1.7 2.1 2.2 1.7 2.0 1.9 e1.3 1.4 .96 3.1 19 4.3 2.2 1.8 1.9 2.0 2.1 e1.7 1.8 e1.4 1.4 .81 3.4 20 3.5 2.1 1.6 1.8 1.9 14 4.3 1.6 1.3 30 .84 4.9 21 3.1 2.2 1.9 1.7 1.8 3.4 2.4 1.4 1.7 2.1 1.2 434 22 2.8 3.3 1.7 1.6 1.7 2.2 2.1 1.3 2.0 1.0 5.3 810 23 2.7 3.6 2.1 1.6 1.6 1.8 1.5 1.4 1.4 .75 1.3 100 24 2.6 2.6 1.9 1.6 1.6 1.6 1.4 1.4 1.2 .85 105 19 25 2.8 2.2 1.8 1.6 1.6 1.7 1.4 1.2 1.2 .72 91 4.6 26 2.5 3.4 1.7 1.6 1.6 1.5 1.4 1.3 1.2 .68 11 5.5 27 2.3 2.6 1.7 1.4 1.5 1.9 1.4 3.5 1.1 .66 4.6 6.7 28 2.3 2.1 1.6 1.3 1.5 1.7 1.6 1.6 1.2 .82 3.4 7.7 29 2.2 2.0 1.6 1.3 4.8 1.4 1.6 1.1 .71 3.0 11 30 2.1 2.0 e1.6 1.2 2.2 1.3 1.9 1.1 .65 2.7 10 31 2.2 1.7 1.1 1.6 1.7 .63 2.5 TOTAL 542.9 82.9 52.7 209.2 225.65 404.8 52.8 62.2 40.4 62.44 247.23 1481.3 MEAN 17.5 2.76 1.70 6.75 8.06 13.1 1.76 2.01 1.35 2.01 7.98 49.4 MAX 336 8.1 2.1 67 101 329 4.3 12 2.0 30 105 810 MIN 1.4 2.0 1.5 1.1 .95 1.4 1.2 1.2 1.1 .63 .56 2.3 AC-FT 1080 164 105 415 448 803 105 123 80 124 490 2940 CFSM 4.68 .74 .45 1.80 2.15 3.49 .47 .54 .36 .54 2.13 13.2 IN. 5.40 .82 .52 2.08 2.24 4.03 .53 .62 .40 .62 2.46 14.73 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 1998, BY WATER YEAR (WY) MEAN 9.31 11.4 4.87 5.05 3.64 3.69 2.37 5.92 6.18 5.43 6.32 18.0 MAX 36.2 33.4 22.8 23.4 10.3 17.4 6.60 35.8 17.5 20.5 14.5 76.5 (WY) 1986 1988 1988 1992 1984 1989 1985 1985 1996 1993 1996 1996 MIN 2.31 2.72 1.17 1.16 1.23 1.15 .66 .86 .92 1.45 1.51 1.88 (WY) 1987 1990 1990 1990 1990 1992 1995 1995 1997 1994 1994 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1984 - 1998 ANNUAL TOTAL 1610.92 3464.52 ANNUAL MEAN 4.41 9.49 6.86 HIGHEST ANNUAL MEAN 12.4 1996 LOWEST ANNUAL MEAN 3.19 1990 HIGHEST DAILY MEAN 336 Oct 13 810 Sep 22 1750 Sep 10 1996 LOWEST DAILY MEAN .48 Jul 2 .56 Aug 5 .29 Sep 12 1990 ANNUAL SEVEN-DAY MINIMUM .51 Jun 28 .59 Jul 31 .41 May 19 1990 INSTANTANEOUS PEAK FLOW 4930 Sep 21 15000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 14.88 Sep 21 20.87 Sep 10 1996 INSTANTANEOUS LOW FLOW .26 May 30 1990 ANNUAL RUNOFF (AC-FT) 3200 6870 4970 ANNUAL RUNOFF (CFSM) 1.18 2.54 1.83 ANNUAL RUNOFF (INCHES) 16.02 34.46 24.93 10 PERCENT EXCEEDS 5.7 5.9 9.6 50 PERCENT EXCEEDS 1.9 1.7 2.0 90 PERCENT EXCEEDS .85 1.1 .93 e Estimated 217 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 218 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 and water years 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1984 to September 1986 and from October 1989 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1989. REMARKS.-- Sediment samples were collected by local observer on a weekly basis.During high flow sediment samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,300 mg/L Oct. 06, 1985; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 33,000 tons (29,900 tonnes) Sep. 10, 1996; Minimum daily mean, <0.01 ton (<0.01 tonne) several years. EXTREMES FOR CURRENT YEAR 1998.- SEDIMENT CONCENTRATION: Maximum daily mean, 1,590 september 22, 1998; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 6,110 tons (5,540 tonnes) September 21, 1998; Minimum daily mean, <0.01 (<0.01) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e2.0 4 e.02 2.7 5 .03 1.9 4 .02 2 e14 50 e1.7 2.2 4 .03 1.8 3 .01 3 e3.8 9 e.12 2.1 4 .02 1.8 2 .01 4 e2.8 8 e.06 2.1 4 .03 1.7 3 .01 5 e2.3 7 e.04 2.1 5 .03 1.7 5 .02 6 e1.8 6 e.03 2.1 8 .05 1.6 6 .03 7 e1.4 5 e.02 2.0 11 .06 1.6 7 .03 8 2.0 4 .02 2.0 11 .06 1.6 8 .04 9 1.8 4 .02 e8.1 45 e3.3 1.5 10 .04 10 2.0 4 .02 e7.4 90 e3.1 1.5 10 .04 11 2.0 6 .03 3.0 7 .06 1.5 5 .02 12 3.0 8 .07 2.5 5 .03 1.5 2 .01 13 e336 687 e2320 2.5 8 .05 1.6 2 .01 14 e97 1280 e708 2.3 12 .07 1.7 2 .01 15 13 50 1.7 2.4 11 .07 1.6 2 .01 16 8.0 24 .54 2.3 9 .05 1.6 7 .03 17 e8.2 18 e.43 2.5 7 .05 2.1 23 .13 18 6.4 17 .29 2.3 5 .03 1.7 24 .11 19 4.3 11 .13 2.2 4 .02 1.8 19 .09 20 3.5 7 .07 2.1 7 .04 1.6 11 .05 21 3.1 4 .03 2.2 14 .08 1.9 6 .03 22 2.8 2 .02 3.3 10 .09 1.7 3 .02 23 2.7 5 .03 3.6 6 .06 2.1 4 .02 24 2.6 7 .05 2.6 5 .03 1.9 5 .02 25 2.8 4 .03 2.2 8 .05 1.8 4 .02 26 2.5 2 .01 3.4 13 .13 1.7 3 .01 27 2.3 1 .01 2.6 10 .07 1.7 5 .02 28 2.3 1 .01 2.1 7 .04 1.6 8 .04 29 2.2 2 .01 2.0 6 .03 1.6 12 .05 30 2.1 3 .02 2.0 5 .03 e1.6 8 e.04 31 2.2 5 .03 1.7 5 .02 TOTAL 542.9 3033.56 82.9 7.79 52.7 1.01 --- --- --- --- --- --- --- --- --- 219 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 1.6 3 .01 1.1 2 <.01 1.4 2 .01 2 1.9 2 .01 1.0 1 <.01 1.4 2 .01 3 1.8 5 .02 .95 2 .01 1.5 3 .01 4 1.9 11 .06 9.7 118 61 1.6 6 .03 5 2.4 24 .15 101 1210 656 1.7 3 .01 6 67 466 350 5.0 41 .60 1.8 1 .01 7 66 777 233 3.2 22 .19 329 1540 5390 8 8.5 110 2.8 44 363 211 7.4 121 4.2 9 4.9 26 .34 11 176 11 2.8 9 .07 10 4.3 12 .14 3.1 8 .07 2.2 3 .02 11 3.6 7 .07 12 2.9 4 .04 13 7.4 64 4.6 14 5.2 66 1.2 15 3.1 7 .06 2.4 4 .02 1.9 2 .01 2.1 2 .01 1.7 2 .01 1.9 2 .01 1.7 1 <.01 11 84 6.7 1.7 1 .01 4.2 29 .40 1.6 2 .01 16 2.6 2 .02 17 2.3 3 .02 18 2.1 5 .03 19 1.9 8 .04 20 1.8 4 .02 2.6 4 .03 1.6 3 .01 2.4 2 .01 1.6 2 .01 2.2 1 .01 1.7 1 <.01 2.0 1 <.01 2.1 2 .01 1.9 1 <.01 14 353 35 21 1.7 2 .01 22 1.6 2 .01 23 1.6 3 .01 24 1.6 5 .02 25 1.6 8 .03 1.8 1 <.01 3.4 36 .35 1.7 1 <.01 2.2 11 .06 1.6 1 <.01 1.8 3 .01 1.6 1 <.01 1.6 1 .01 1.6 1 <.01 1.7 1 <.01 26 1.6 12 .05 27 1.4 5 .02 28 1.3 1 <.01 29 1.3 2 .01 30 1.2 3 .01 31 1.1 3 .01 1.6 1 <.01 1.5 2 .01 1.5 1 <.01 1.9 3 .01 1.5 1 <.01 1.7 3 .01 --- --- --- 4.8 183 11 --- --- --- 2.2 23 .14 --- --- --- 1.6 6 .03 TOTAL 209.2 --- 592.82 225.65 --- 947.18 404.8 --- 5441.10 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 1.5 2 .01 1.2 7 .02 1.4 4 .02 2 2.8 14 .19 1.2 6 .02 1.4 3 .01 3 3.1 18 .16 1.5 4 .02 1.4 2 .01 4 1.6 12 .05 1.5 3 .01 1.3 5 .02 5 1.5 13 .05 1.4 3 .01 1.4 11 .04 6 1.4 12 .05 1.3 5 .02 1.8 9 .04 7 1.4 8 .03 1.3 5 .02 1.3 5 .02 8 1.4 4 .01 12 323 78 1.3 3 .01 9 1.3 2 .01 2.6 36 .26 1.3 5 .02 10 1.2 2 .01 1.7 23 .11 1.2 7 .02 11 1.2 2 .01 1.5 15 .06 1.2 6 .02 12 2.2 30 .19 1.4 8 .03 1.5 4 .02 13 1.4 22 .09 1.6 5 .02 1.5 4 .01 14 1.3 11 .04 2.7 42 1.1 1.3 3 .01 15 1.3 6 .02 2.6 58 .54 1.2 3 .01 16 2.0 23 .21 1.6 8 .04 1.5 3 .01 17 2.3 19 .17 1.5 6 .02 1.2 3 .01 18 2.0 10 .08 1.9 16 .12 e1.3 5 e.02 19 e1.7 10 e.05 1.8 32 .16 e1.4 9 e.03 20 4.3 135 5.5 1.6 18 .08 1.3 8 .03 21 2.4 24 .16 1.4 13 .05 1.7 6 .03 22 2.1 13 .08 1.3 11 .04 2.0 5 .03 23 1.5 8 .03 1.4 12 .04 1.4 5 .02 24 1.4 5 .02 1.4 14 .05 1.2 5 .02 25 1.4 4 .01 1.2 16 .05 1.2 6 .02 26 1.4 3 .01 1.3 12 .04 1.2 8 .02 27 1.4 3 .01 3.5 38 .54 1.1 7 .02 28 1.6 2 .01 1.6 15 .06 1.2 7 .02 29 1.4 2 .01 1.6 18 .08 1.1 6 .02 30 1.3 4 .01 1.9 13 .06 1.1 6 .02 31 1.7 7 .03 TOTAL 52.8 7.28 62.2 81.70 40.4 0.60 --- --- --- --- --- --- 220 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 1.1 7 .02 .62 14 .02 2.4 6 .04 2 1.1 8 .02 .60 9 .01 3.1 20 .25 3 1.1 11 .03 .60 6 .01 3.1 17 .14 4 2.1 33 .18 .58 4 .01 2.8 13 .10 5 2.1 49 .30 .56 2 <.01 2.3 15 .10 6 1.2 19 .06 e.57 5 e.01 2.5 20 .14 7 1.2 13 .04 e1.0 9 e.03 2.6 26 .18 8 1.1 11 .03 1.2 11 .04 8.3 278 17 9 1.0 8 .02 1.1 12 .04 4.3 84 1.8 10 1.0 5 .01 .91 13 .03 4.3 41 .52 11 .99 5 .01 .94 8 .02 2.6 13 .09 12 1.0 5 .01 .85 5 .01 2.4 10 .06 13 .91 6 .01 .75 4 .01 4.2 66 1.1 14 .87 6 .01 .69 4 .01 2.9 31 .24 15 .90 6 .01 .69 4 .01 7.3 579 33 16 1.2 7 .02 .86 7 .01 3.3 22 .19 17 1.2 7 .02 1.1 9 .03 3.0 13 .11 18 1.4 7 .03 .96 7 .02 3.1 10 .08 19 1.4 7 .03 .81 5 .01 3.4 9 .09 20 30 424 75 .84 5 .01 4.9 31 .56 21 2.1 38 .23 1.2 5 .02 434 1260 6110 22 1.0 18 .05 5.3 194 15 810 1590 6050 23 .75 8 .02 1.3 12 .05 100 105 43 24 .85 7 .02 105 955 734 19 18 .95 25 .72 8 .01 91 869 453 4.6 12 .15 26 .68 9 .02 11 128 6.4 5.5 9 .14 27 .66 9 .02 4.6 23 .28 6.7 9 .16 28 .82 5 .01 3.4 12 .11 7.7 9 .18 29 .71 3 <.01 3.0 8 .06 11 8 .25 30 .65 6 .01 2.7 6 .04 10 8 .23 31 .63 16 .03 2.5 4 .03 TOTAL 62.44 76.29 247.23 1209.34 1481.3 12260.85 YEAR 3464.52 23659.52 e Estimated < Actual value is known to be less than the value shown WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) JAN 07... 1510 173 913 426 97 07... 1700 52 327 46 98 13... 2100 31 449 38 98 MAR 07... 1830 1070 3090 8930 83 20... 1600 14 350 13 99 29... 1700 36 1820 177 98 JUL 20... 1515 43 2710 315 100 AUG 22... 0437 44 3770 448 100 25... 2250 66 549 98 92 SEP 21... 2310 2670 4140 29800 67 22... 0455 572 1300 2010 85 221 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) JAN 07... 1426 378 2370 2420 33 42 54 MAR 07... 1545 968 4760 12400 21 29 36 AUG 24... 1600 53 665 95 54 69 80 SEP 15... 0829 21 245 14 26 40 60 21... 1910 586 4040 6390 38 50 64 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) JAN 07... 66 78 85 94 99 100 100 MAR 07... 46 59 71 85 94 98 100 AUG 24... 88 97 98 100 100 100 100 SEP 15... 77 86 91 98 99 100 100 21... 76 83 87 94 97 98 100 --- --- --- --- --- --- --- 222 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18°09'13", long 65°57'24", Hydrologic Unit 21010005, at downstream side of bridge on Highway 912, at Barrio Cerro Gordo, 2.8 mi (4.5 km) south of San Lorenzo. DRAINAGE AREA.--10.2 mi2 (26.4 km2). PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 490 ft (150 m), from topographic map. Prior to Oct. 1, 1983, at site 2,000 ft (610 m) downstream at different datum. REMARKS.--Records poor. Sand removal at a commercial level is practiced at times during the year. This takes place about one hundred feet downstream from the low water control. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 37 46 e37 74 e29 e21 e37 e21 e26 14 22 38 2 216 28 e34 57 e26 e21 e41 e22 e22 17 18 48 3 62 41 e34 65 e25 e24 e37 e25 e20 22 15 68 4 65 34 e32 107 e29 e23 e30 e26 20 60 15 54 5 34 e37 e33 84 e620 e21 e35 e24 22 66 31 36 6 28 e34 e32 591 e64 e21 e30 e23 25 20 e133 69 7 30 e30 e31 e517 e54 e960 e28 e22 22 37 31 161 8 33 e28 e30 e213 e120 e66 e28 e56 37 23 22 332 9 43 e54 e31 158 e82 e33 e26 e39 30 43 45 165 10 37 e400 e30 321 e41 e27 e24 e27 28 21 36 e135 11 81 e43 e30 95 e31 e24 e25 e23 22 16 43 82 12 140 e35 e32 52 e27 e23 e56 e22 52 14 31 66 13 406 e34 33 70 e26 e22 e30 e32 69 18 26 97 14 1750 e31 29 71 e130 e24 e26 e37 25 21 24 122 15 223 e32 37 46 e52 e25 e24 e43 28 14 26 502 16 134 e31 44 e40 e35 e22 e35 e31 30 16 29 e68 17 93 e32 68 e32 e33 e21 e42 e26 48 14 331 e52 18 60 e30 42 e36 e29 e20 e47 e23 34 35 82 e50 19 50 e30 34 36 e28 e22 e36 e22 30 25 32 e52 20 47 e29 33 28 e26 e110 e66 e21 23 144 53 e50 21 51 e54 69 25 e25 e50 e50 e19 27 73 88 e2900 22 41 e60 55 36 e23 e35 e38 e19 61 23 250 e4100 23 38 e64 48 31 e22 e29 e30 e23 24 16 75 e140 24 37 e49 47 36 e21 e26 e28 e21 19 58 742 e94 25 38 e41 43 e40 e21 e30 e27 e18 21 22 e860 e80 26 36 e58 38 e36 e21 e29 e26 86 20 20 e90 e70 27 29 e49 30 30 e19 e34 e27 117 21 39 e90 e78 28 31 e40 31 31 e22 e31 e30 21 21 65 e78 e70 29 35 e38 32 44 e50 e25 24 15 29 e84 e62 30 39 e40 42 48 e86 e22 141 15 27 e70 e56 31 37 30 34 e58 26 22 e41 TOTAL 3981 1552 1171 3084 1681 1988 1006 1080 857 1034 3513 9897 MEAN 128 51.7 37.8 99.5 60.0 64.1 33.5 34.8 28.6 33.4 113 330 MAX 1750 400 69 591 620 960 66 141 69 144 860 4100 MIN 28 28 29 25 19 20 22 18 15 14 15 36 AC-FT 7900 3080 2320 6120 3330 3940 2000 2140 1700 2050 6970 19630 CFSM 12.6 5.07 3.70 9.75 5.89 6.29 3.29 3.42 2.80 3.27 11.1 32.3 IN. 14.52 5.66 4.27 11.25 6.13 7.25 3.67 3.94 3.13 3.77 12.81 36.09 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1977 - 1998, BY WATER YEAR (WY) MEAN 62.3 68.3 44.2 33.3 30.8 24.2 21.0 42.9 44.6 43.5 51.9 81.1 MAX 176 196 163 99.5 74.1 64.1 46.0 155 140 118 202 330 (WY) 1986 1988 1988 1998 1997 1998 1985 1985 1979 1979 1979 1998 MIN 14.4 19.2 12.5 14.6 11.0 11.3 10.7 9.68 10.9 15.4 14.5 16.9 (WY) 1992 1982 1992 1990 1992 1992 1980 1990 1994 1994 1991 1980 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1977 - 1998 ANNUAL TOTAL 18902.5 30844 ANNUAL MEAN 51.8 84.5 45.7 HIGHEST ANNUAL MEAN 89.7 1979 LOWEST ANNUAL MEAN 18.6 1990 HIGHEST DAILY MEAN 1750 Oct 14 4100 Sep 22 5120 Sep 10 1996 LOWEST DAILY MEAN 8.4 May 6 14 Jul 1 7.1 Feb 4 1981 ANNUAL SEVEN-DAY MINIMUM 10 May 3 16 Jul 11 8.5 Jun 19 1994 INSTANTANEOUS PEAK FLOW 12700 Sep 21 13200 Aug 31 1979 INSTANTANEOUS PEAK STAGE 23.26 Sep 21 9.44 Aug 31 1979 ANNUAL RUNOFF (AC-FT) 37490 61180 33100 ANNUAL RUNOFF (CFSM) 5.08 8.28 4.48 ANNUAL RUNOFF (INCHES) 68.94 112.49 60.87 10 PERCENT EXCEEDS 95 96 70 50 PERCENT EXCEEDS 29 34 25 90 PERCENT EXCEEDS 12 21 13 e Estimated 223 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 224 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR LOCATION.--Lat 18°11'09", long 65°57'42", Hydrologic Unit 21010005, at upstream side of bridge on Highway 183 by-pass, 0.4 mi (0.6 km) south from Plaza de San Lorenzo, 1.4 mi (2.2 km), southwest from Escuela Rafael Colón García and 2.0 mi (3.2 km) northwest from Escuela Segunda Unidad de Carlos Zayas. DRAINAGE AREA.--25.0 mi2 (64.8 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 262 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated discharges, which are poor. Water purification plant located about 0.2 mi (0.3 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 84 93 72 71 e78 57 121 55 61 39 36 77 2 195 86 66 69 e74 54 136 56 54 39 34 79 3 96 87 64 67 e71 63 124 64 53 42 33 107 4 91 88 62 114 e84 61 101 67 54 108 31 103 5 80 86 63 94 e1600 54 118 62 54 89 31 73 6 73 81 61 711 e220 55 101 59 69 46 e61 116 7 68 79 58 695 e130 1460 92 55 56 51 50 151 8 71 79 58 332 e400 236 93 141 57 48 73 265 9 74 101 60 287 e300 116 86 98 58 48 86 197 10 70 647 57 386 e120 96 81 71 54 42 70 149 11 111 129 57 187 e90 83 83 58 47 38 62 94 12 162 106 61 162 e82 79 187 56 68 35 47 82 13 954 104 59 169 70 75 101 79 84 33 43 124 14 3120 94 58 169 151 85 86 93 53 41 36 122 15 376 94 57 129 126 88 81 108 47 35 36 337 16 249 93 57 123 85 75 117 78 53 40 36 126 17 217 95 89 114 83 72 140 67 77 36 175 98 18 173 90 60 109 78 70 155 60 e61 58 74 92 19 139 89 57 104 72 77 e119 57 61 62 49 96 20 124 87 54 103 71 380 217 55 51 215 55 e94 21 117 105 77 98 69 165 131 51 55 110 81 e3700 22 111 113 60 96 65 118 93 50 91 54 211 e5020 23 108 101 58 98 63 98 76 57 52 46 95 603 24 102 93 54 99 60 89 72 53 47 63 903 401 25 104 79 52 104 58 103 69 46 45 52 1160 336 26 97 110 50 104 61 99 67 99 46 43 330 296 27 93 94 50 94 60 114 68 132 46 46 144 332 28 91 76 50 90 59 103 75 61 50 64 111 302 29 90 72 49 92 182 64 72 43 48 119 261 30 87 76 53 e83 289 57 125 40 43 93 240 31 88 52 e80 200 86 41 83 TOTAL 7615 3327 1835 5233 4480 4896 3111 2271 1687 1755 4448 14073 MEAN 246 111 59.2 169 160 158 104 73.3 56.2 56.6 143 469 MAX 3120 647 89 711 1600 1460 217 141 91 215 1160 5020 MIN 68 72 49 67 58 54 57 46 40 33 31 73 AC-FT 15100 6600 3640 10380 8890 9710 6170 4500 3350 3480 8820 27910 CFSM 9.83 4.44 2.37 6.75 6.40 6.32 4.15 2.93 2.25 2.26 5.74 18.8 IN. 11.33 4.95 2.73 7.79 6.67 7.29 4.63 3.38 2.51 2.61 6.62 20.94 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 1998, BY WATER YEAR (WY) MEAN 137 129 85.5 109 82.1 61.9 43.9 64.5 109 96.3 112 230 MAX 266 223 110 192 160 158 104 186 290 208 196 631 (WY) 1991 1992 1993 1992 1998 1998 1998 1992 1992 1993 1996 1996 MIN 77.6 69.2 59.2 50.1 21.0 17.4 16.8 25.2 42.3 42.3 39.3 59.7 (WY) 1993 1996 1998 1995 1992 1992 1992 1995 1994 1994 1994 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1990 - 1998 ANNUAL TOTAL 33576 54731 ANNUAL MEAN 92.0 150 108 HIGHEST ANNUAL MEAN 154 1996 LOWEST ANNUAL MEAN 67.8 1994 HIGHEST DAILY MEAN 3120 Oct 14 5020 Sep 22 10000 Sep 10 1996 LOWEST DAILY MEAN 21 Jul 3 31 Aug 4 6.3 Apr 29 1992 ANNUAL SEVEN-DAY MINIMUM 24 Jun 28 36 Jul 30 7.4 Apr 25 1992 INSTANTANEOUS PEAK FLOW 36600 Sep 21 56800 Sep 10 1996 INSTANTANEOUS PEAK STAGE 30.14 Sep 21 35.62 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 66600 108600 78520 ANNUAL RUNOFF (CFSM) 3.68 6.00 4.34 ANNUAL RUNOFF (INCHES) 49.96 81.44 58.90 10 PERCENT EXCEEDS 133 213 176 50 PERCENT EXCEEDS 63 81 63 90 PERCENT EXCEEDS 34 48 26 e Estimated 225 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 226 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: February 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by a local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,080 mg/L November 10, 1997; Minimum daily mean, 5 mg/L Several days. SEDIMENT LOADS: Maximum daily mean, 80,600 tons (73,100 tonnes) September 10, 1996; Minimum daily mean, 0.20 ton (0.18 tonne) May 05, 1992. EXTREMES FOR CURRENT YEAR 1998-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,080 mg/l November 10, 1997; Minimum daily mean, 11 mg/l March 11,1998. SEDIMENT LOADS: Maximum daily mean, 56,000 tons (50,800 tonnes) September 21, 1998; Minimum daily mean, 1.8 tons (1.6 tonnes) April 30, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 84 102 23 93 39 9.7 72 49 9.6 2 195 564 459 86 39 9.1 66 72 13 3 96 121 31 87 42 10 64 94 16 4 91 121 30 88 64 15 62 83 14 5 80 124 27 86 82 19 63 68 12 6 73 125 25 81 43 9.5 61 42 6.9 7 68 113 21 79 23 4.8 58 23 3.6 8 71 105 20 79 21 4.5 58 16 2.5 9 74 107 21 101 64 23 60 30 4.9 10 70 110 21 647 3080 11100 57 50 7.7 11 111 314 184 129 281 99 57 34 5.2 12 162 536 407 106 142 41 61 21 3.5 13 954 1390 20000 104 97 27 59 23 3.7 14 3120 2760 49200 94 74 19 58 28 4.4 15 376 165 169 94 83 21 57 36 5.5 16 249 74 50 93 100 25 57 62 9.6 17 217 188 128 95 114 29 89 92 25 18 173 273 129 90 109 26 60 52 8.5 19 139 205 77 89 102 25 57 51 7.8 20 124 151 51 87 101 24 54 50 7.2 21 117 108 34 105 153 46 77 49 10 22 111 83 25 113 155 48 60 48 7.8 23 108 86 25 101 139 38 58 43 6.7 24 102 93 26 93 122 31 54 38 5.5 25 104 103 29 79 121 26 52 34 4.8 26 97 113 30 110 168 50 50 32 4.3 27 93 117 30 94 67 18 50 34 4.5 28 91 92 23 76 25 5.0 50 36 4.9 29 90 70 17 72 28 5.5 49 38 5.0 30 87 52 12 76 37 7.6 53 38 5.5 31 88 40 9.5 52 37 5.2 TOTAL 7615 71333.5 3327 11815.7 1835 234.8 --- --- --- --- --- --- --- --- --- --- --- --- 227 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 71 83 18 e78 70 e17 57 18 2.8 2 69 92 17 e74 66 e18 54 20 2.9 3 67 89 16 e71 52 e15 63 30 5.2 4 114 159 50 e84 32 e16 61 51 8.4 5 94 142 37 e1600 173 e15100 54 87 13 6 711 1350 6300 e220 888 e230 55 123 18 7 695 923 2030 e130 660 e53 1460 2070 25200 8 332 459 448 e400 278 e594 236 340 260 9 287 299 240 e300 121 e321 116 109 35 10 386 514 661 e120 82 e53 96 35 9.2 11 187 163 85 e90 69 e24 83 11 2.6 12 162 125 58 e82 98 e13 79 16 3.4 13 169 280 110 70 121 23 75 34 6.8 14 169 176 87 151 181 119 85 33 7.6 15 129 56 20 126 153 57 88 27 6.4 16 123 26 8.7 85 42 9.6 75 23 4.6 17 114 32 9.9 83 39 8.7 72 33 6.4 18 109 43 13 78 53 11 70 54 10 19 104 56 16 72 82 16 77 83 17 20 103 50 14 71 122 23 380 538 1070 21 98 41 11 69 130 24 165 270 128 22 96 34 8.8 65 129 23 118 100 32 23 98 29 7.6 63 113 19 98 37 9.8 24 99 36 9.5 60 56 9.1 89 30 7.1 25 104 49 14 58 27 4.3 103 29 8.1 26 104 67 19 61 20 3.3 99 29 7.8 27 94 74 19 60 18 2.9 114 108 35 28 90 77 19 59 18 2.8 103 144 40 29 92 78 19 182 200 196 30 e83 77 e14 289 318 601 31 e80 74 e18 200 241 160 TOTAL 5233 10397.5 4480 16809.7 4896 27914.1 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 121 58 19 55 2 136 107 53 56 3 124 103 37 64 4 101 54 15 67 5 118 106 40 62 13 2.0 61 58 9.6 21 3.1 54 31 4.6 36 6.3 53 21 3.0 59 11 54 39 5.8 56 9.3 54 83 12 6 101 87 24 7 92 60 15 8 93 46 12 9 86 36 8.3 10 81 28 6.1 59 84 13 69 83 15 55 67 9.9 56 68 10 141 431 456 57 59 9.2 98 163 44 58 88 14 71 92 18 54 134 19 11 83 22 4.9 12 187 463 340 13 101 72 20 14 86 43 10 15 81 33 7.2 58 59 9.2 47 97 12 56 63 9.6 68 77 18 79 120 26 84 80 27 93 167 42 53 61 8.8 108 214 61 47 36 4.5 16 117 90 40 78 17 140 182 75 67 18 155 394 282 60 19 e119 181 e54 57 20 217 251 220 55 162 34 53 58 8.4 108 20 77 89 20 73 12 e61 79 e9.6 58 8.8 61 116 19 47 7.0 51 111 15 21 131 235 65 22 93 108 28 23 76 53 11 24 72 33 6.4 25 69 29 5.4 51 35 4.9 55 100 15 50 27 3.6 91 125 32 57 33 5.1 52 75 11 53 45 6.3 47 50 6.4 46 58 7.2 45 46 5.7 26 67 30 5.4 27 68 29 5.3 28 75 19 3.7 29 64 12 2.0 30 57 12 1.8 31 --- --- --- 99 92 40 46 46 5.7 132 190 78 46 41 5.1 61 99 16 50 36 4.8 72 83 17 43 31 3.7 125 100 63 40 35 3.8 86 96 68 --- --- --­ TOTAL 3111 --- 1416.5 2271 --- 1111.3 1687 --- 337.7 --- --- --- --- --- --- 228 RIO GRANDE DE LOIZA BASIN 50051800 Río GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 39 42 4.4 36 36 3.5 77 85 18 2 39 48 5.0 34 46 4.2 79 109 24 3 42 58 6.8 33 56 4.9 107 122 43 4 108 96 46 31 50 4.2 103 123 35 5 89 82 32 31 59 4.9 73 95 19 6 46 55 6.9 e61 61 e9.6 116 342 200 7 51 41 5.6 50 90 12 151 117 61 8 48 34 4.5 73 127 36 265 518 644 9 48 27 3.6 86 136 32 197 463 407 10 42 22 2.5 70 68 13 149 220 96 11 38 25 2.6 62 81 14 94 82 21 12 35 31 2.9 47 118 15 82 70 16 13 33 38 3.4 43 103 12 124 143 68 14 41 47 5.2 36 78 7.5 122 100 35 15 35 58 5.5 36 61 5.9 337 455 860 16 40 71 7.7 36 55 5.2 126 137 48 17 36 77 7.5 175 97 241 98 110 29 18 58 77 18 74 160 32 92 112 28 19 62 90 15 49 156 21 96 114 29 20 215 470 458 55 196 29 e94 117 26 21 110 665 199 81 225 49 e3700 1270 e56000 22 54 552 80 211 146 82 e5020 2300 e49100 23 46 367 46 95 145 39 603 122 225 24 63 227 38 903 1800 10800 401 48 52 25 52 124 18 1160 977 5020 336 34 31 26 43 65 7.5 330 438 477 296 51 41 27 46 42 5.3 144 215 84 332 193 272 28 64 79 16 111 177 53 302 141 127 29 48 55 7.3 119 142 54 261 49 35 30 43 36 4.2 93 113 29 240 48 32 31 41 31 3.4 83 69 16 TOTAL 1755 1067.8 4448 17209.9 14073 108622 YEAR 54731 268270.5 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) NOV 10... 1050 398 2540 2730 98 JAN 07... 1630 495 728 973 87 MAR 07... 1500 2180 7900 46500 58 07... 1900 3600 6010 58400 70 AUG 24... 1530 894 2450 5910 88 SEP 21... 2015 5920 2300 36800 73 22... 0815 8840 3340 79700 62 229 RIO GRANDE DE LOIZA BASIN 50051800 Río GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) SEP 22... 0100 13200 5600 200000 19 26 37 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) SEP 22... 47 59 67 80 92 99 100 230 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR LOCATION.--Lat 18°09'35", long 66°02'26", Hydrologic Unit 21010005, on left bank at Highway 765, 1.2 mi (1.9 km) south of Villa Borinquen, 8.1 mi (13.0 km) upstream from Río Grande de Loíza. DRAINAGE AREA.--7.14 mi2 (18.49 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 492 ft (150 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 e17 e15 e11 2 24 e15 e14 e13 3 14 e14 13 e13 4 13 e13 13 e14 5 12 e13 13 e13 11 e12 21 14 15 9.3 9.9 12 11 e12 48 14 14 8.8 9.2 13 11 12 e32 17 14 14 9.8 21 20 e12 e23 16 13 33 9.4 25 149 e12 21 15 14 13 9.1 13 6 12 e13 13 e110 7 12 e12 13 e150 8 15 e11 12 e60 9 14 e17 12 e56 10 13 e120 12 e56 30 12 19 14 16 11 11 14 20 81 18 14 13 11 19 15 29 57 18 38 13 11 36 48 26 29 17 23 13 10 23 30 e18 24 17 18 12 10 18 20 11 21 e21 12 e26 12 39 e17 13 e22 13 274 e16 12 30 14 486 e15 12 27 15 113 e14 12 19 e13 21 18 16 11 9.8 13 14 e12 21 32 15 16 9.6 12 12 e11 21 19 23 15 9.6 11 31 e56 22 17 24 11 9.3 10 16 e28 21 16 23 11 9.6 13 95 16 75 e13 e13 18 17 85 e14 e15 17 18 60 e13 e13 15 19 39 e14 e12 13 20 31 e13 12 13 e15 20 18 19 12 10 11 27 e14 20 19 16 13 9.5 36 19 16 19 17 21 e11 12 15 22 15 19 17 16 11 12 12 19 14 82 31 15 11 34 12 23 21 28 e19 14 13 22 25 e25 13 13 23 24 e33 12 12 24 22 e25 12 13 25 21 e19 e12 14 14 42 19 14 11 17 21 e827 14 29 17 14 16 12 109 e1190 13 23 17 14 11 11 21 166 e13 20 17 14 10 12 197 94 e13 21 17 14 10 11 189 70 26 20 e20 e12 13 27 e19 e17 e12 12 28 e17 e16 e12 12 29 e18 e15 e11 11 30 e16 e16 e12 11 31 e15 --- e12 11 e13 20 17 32 10 10 72 57 12 28 17 43 10 11 26 57 12 21 18 18 11 12 20 48 --- 35 15 18 10 11 17 62 --- 38 15 21 9.9 10 15 43 --- 29 --- 16 --- 10 13 --­ TOTAL 1589 600 390 831 MEAN 51.3 20.0 12.6 26.8 MAX 486 120 15 150 MIN 12 11 11 11 MED 21 16 12 13 AC-FT 3150 1190 774 1650 CFSM 7.18 2.80 1.76 3.75 IN. 8.28 3.13 2.03 4.33 623 835 607 589 367.9 383.5 999.4 3103 22.3 26.9 20.2 19.0 12.3 12.4 32.2 103 149 82 48 43 16 34 197 1190 11 12 15 14 9.9 8.8 9.1 12 14 21 18 16 12 11 15 26 1240 1660 1200 1170 730 761 1980 6150 3.12 3.77 2.83 2.66 1.72 1.73 4.52 14.5 3.25 4.35 3.16 3.07 1.92 2.00 5.21 16.17 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 1998, BY WATER YEAR (WY) MEAN 27.3 23.2 17.0 23.0 MAX 51.3 37.9 23.1 47.5 (WY) 1998 1992 1991 1992 MIN 10.3 18.6 10.6 7.85 (WY) 1994 1996 1994 1990 17.7 13.6 10.0 15.1 25.4 22.5 22.8 50.4 25.0 26.9 20.2 31.9 67.9 54.6 41.4 123 1997 1998 1998 1993 1996 1993 1996 1996 8.93 7.35 6.18 6.11 9.59 8.42 6.98 14.1 1990 1993 1990 1994 1991 1995 1994 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1990 - 1998 ANNUAL TOTAL 7243.8 ANNUAL MEAN 19.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 486 LOWEST DAILY MEAN 6.3 ANNUAL SEVEN-DAY MINIMUM 6.8 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 14370 ANNUAL RUNOFF (CFSM) 2.78 ANNUAL RUNOFF (INCHES) 37.74 10 PERCENT EXCEEDS 28 50 PERCENT EXCEEDS 13 90 PERCENT EXCEEDS 8.1 10917.8 29.9 23.2 38.1 1996 12.1 1994 Oct 14 1190 Sep 22 1940 Sep 10 1996 Jul 4 8.8 Jul 2 3.3 Aug 17 1994 Jun 28 9.6 Jul 11 3.8 Aug 11 1994 13100 Sep 21 15200 Sep 10 1996 21.62 Sep 21 22.60 Sep 10 1996 8.3 Jul 1 2.6 Jul 17 1997 21660 16790 4.19 3.25 56.88 44.09 40 35 15 12 11 6.1 e Estimated 231 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 232 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 9,230 mg/L September 10, 1996; Minimum daily mean, 1 mg/L Several years. SEDIMENT LOADS: Maximum daily mean, 80,900 tons (73,400 tonnes) September 10, 1996; Minimum daily mean, 0.01 ton (0.01 tonne) Several days. EXTREMES FOR CURRENT YEAR 1998. SEDIMENT CONCENTRATION: Maximum daily mean, e50,900 tons (46,200 tonnes) September 21, 1998; Minimum daily mean, 0.06 ton (0.05 tonne), July 19, 1998. SEDIMENT LOADS: Maximum daily mean, e5,790 mg/L September 22, 1998; Minimum daily mean, 2 severals days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 12 62 2.0 e17 2 e.09 e15 9 e.33 2 24 83 6.6 e15 2 e.09 e14 9 e.32 3 14 21 .81 e14 2 e.09 13 8 .29 4 13 15 .51 e13 2 e.09 13 7 .24 5 12 13 .44 e13 2 e.09 13 5 .19 6 12 12 .37 e13 3 e.09 13 4 .15 7 12 11 .33 e12 3 e.09 13 5 .16 8 15 28 2.2 e11 3 e.09 12 6 .20 9 14 45 1.7 e17 3 e.19 12 8 .25 10 13 27 .99 e120 3 e113 12 9 .29 11 21 61 6.5 e21 3 e.15 12 10 .34 12 39 86 36 e17 3 e.19 13 11 .39 13 274 982 5140 e16 4 e.19 12 8 .25 14 486 1180 4470 e15 4 e.09 12 4 .14 15 113 304 112 e14 4 e.09 12 2 .08 16 75 156 34 e13 4 e.09 e13 2 e.06 17 85 364 143 e14 4 e.09 e15 4 e.57 18 60 73 14 e13 5 e.09 e13 10 e.57 19 39 13 1.4 e14 5 e.09 e12 17 e.57 20 31 11 .93 e13 5 e.09 12 16 .55 21 28 9 .68 e19 5 e.19 14 16 .60 22 25 6 .40 e25 6 e.40 13 12 .43 23 24 4 .22 e33 6 e.93 12 9 .30 24 22 2 .13 e25 6 e.40 12 6 .21 25 21 3 .15 e19 7 e.24 e12 5 e.15 26 20 4 .19 e20 7 e.24 e12 5 e.15 27 e19 5 e.24 e17 7 e.33 e12 7 e.15 28 e17 4 e.19 e16 8 e.33 e12 9 e.15 29 e18 3 e.14 e15 8 e.33 e11 13 e.15 30 e16 2 e.09 e16 8 e.31 e12 17 e.15 31 e15 2 e.09 e12 24 e.15 TOTAL 1589 9976.30 600 118.77 390 8.53 --- --- --- --- --- --- --- --- --- 233 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e11 33 e.15 11 2 e13 46 e.57 11 3 e13 64 e.57 11 4 e14 89 e.60 20 5 e13 123 e.57 149 5 .16 e12 12 e.38 5 .14 e12 9 e.28 6 .17 12 6 .20 17 28 e12 4 e.13 80 392 e12 4 e.11 6 e110 170 e112 30 7 e150 163 e112 20 8 e60 193 e14 29 9 e56 169 e35 26 10 e56 79 e35 e18 81 7.1 12 3 .10 17 .96 81 9 178 69 18 57 53 41 56 5.1 29 55 4.4 4 e.17 24 16 1.0 11 e26 56 e4.4 12 e22 53 e.20 13 30 92 13 14 27 60 5.2 15 19 12 .62 e13 3 e.14 21 11 .63 e12 3 e.13 21 8 .44 e11 3 e.12 21 6 .31 e56 4 e41 22 4 .25 e28 5 e5.0 21 5 .31 16 18 6 .31 17 17 4 .16 18 15 5 .19 19 13 8 .27 20 13 11 .40 e15 8 e.36 20 7 .40 e14 8 e.36 20 9 .50 16 6 .26 19 10 .52 15 7 .27 19 10 .52 14 8 .30 82 281 110 21 13 10 .36 22 13 9 .31 23 12 8 .27 24 13 7 .23 25 14 6 .23 14 9 .33 42 16 1.9 14 10 .37 29 13 1.0 13 10 .37 23 13 .80 e13 8 e.27 20 12 .66 e13 6 e.20 21 9 .54 26 13 7 .25 27 12 9 .27 28 12 10 .30 29 11 8 .26 30 11 7 .21 31 11 6 .18 e13 4 e.16 20 7 .37 12 6 .20 28 5 .39 12 9 .29 21 5 .29 --- --- --- 35 14 23 --- --- --- 38 100 15 --- --- --- 29 54 4.6 TOTAL 831 --- 338.08 623 --- 501.93 835 --- 388.03 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 21 23 1.3 14 8 .31 15 14 .55 2 48 116 35 14 7 .26 14 8 .32 3 e32 55 e4.7 17 8 .38 14 7 .27 4 e23 34 e2.1 16 10 .41 13 10 .38 5 21 21 1.2 15 11 .44 14 11 .41 6 19 13 .68 14 7 .28 16 29 1.3 7 18 8 .41 14 7 .24 13 13 .44 8 18 6 .26 38 102 24 13 9 .30 9 17 5 .23 23 72 4.5 13 10 .34 10 17 5 .22 18 23 1.1 12 12 .40 11 18 12 .82 16 8 .32 11 14 .41 12 32 85 9.3 15 5 .21 16 26 1.9 13 19 12 .60 23 11 6.8 15 17 .73 14 17 9 .40 24 42 4.1 11 12 .36 15 16 8 .36 23 50 3.3 11 10 .30 16 18 18 .93 19 25 1.3 12 13 .51 17 19 47 2.6 16 21 .92 13 20 .71 18 17 19 .86 21 14 5.2 e11 18 .52 19 17 18 .88 16 10 .41 11 10 .31 20 31 104 16 15 13 .52 11 5 .16 21 19 21 1.1 14 17 .67 11 5 .15 22 17 18 .83 14 9 .32 16 32 1.7 23 17 16 .71 14 4 .16 11 11 .33 24 17 13 .60 14 4 .15 10 8 .21 25 17 11 .49 14 4 .15 10 10 .28 26 17 9 .42 32 114 15 10 16 .44 27 17 11 .50 43 126 28 10 22 .63 28 18 12 .61 18 17 .79 11 16 .47 29 15 14 .57 18 29 3.1 10 11 .31 30 15 11 .44 21 42 2.5 9.9 14 .38 31 16 22 .99 TOTAL 607 85.12 589 106.83 367.9 15.52 --- --- --- --- --- --- 234 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 9.3 20 .51 9.9 24 .63 12 8 .27 2 8.8 21 .50 9.2 14 .36 13 18 1.6 3 14 37 2.3 9.8 8 .20 21 68 4.3 4 33 120 18 9.4 9 .22 25 122 7.3 5 13 31 1.1 9.1 22 .56 13 80 2.8 6 11 15 .45 11 33 .94 14 31 1.4 7 11 8 .23 19 31 6.7 15 19 .80 8 11 10 .31 36 141 46 48 108 54 9 10 16 .44 23 81 5.0 30 9 .76 10 10 19 .53 18 34 1.7 20 8 .44 11 9.8 23 .60 13 15 .53 14 8 .29 12 9.6 17 .45 12 10 .33 12 7 .24 13 9.6 12 .31 11 8 .25 31 8 34 14 9.3 9 .22 10 8 .22 16 9 .37 15 9.6 11 .28 13 33 1.7 95 338 319 16 10 13 .36 11 29 1.0 27 11 .77 17 9.5 6 .16 36 17 43 19 10 .54 18 12 2 .07 15 17 .66 22 33 2.9 19 12 2 .06 12 14 .46 19 22 1.1 20 34 106 17 12 13 .42 23 50 4.2 21 17 43 2.3 21 15 4.4 e827 3390 e50900 22 12 21 .65 109 21 473 e1190 5790 e35600 23 11 18 .51 21 26 4.3 166 25 11 24 12 13 .44 197 38 1540 94 20 5.1 25 11 10 .31 189 385 644 70 11 2.1 26 10 11 .30 72 163 48 57 6 1.0 27 11 11 .33 26 28 2.0 57 33 7.7 28 12 13 .43 20 16 .86 48 9 1.2 29 11 15 .42 17 10 .46 62 11 2.0 30 10 18 .49 15 9 .36 43 9 1.1 31 10 21 .58 13 9 .31 TOTAL 383.5 50.64 999.4 2828.57 3103 86968.28 YEAR 10917.8 101386.60 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 14... 0445 792 1410 1510 87 15... 1230 108 100 29 98 AUG 20... 1214 13 165 5.8 98 SEP 03... 1520 23 83 5.2 97 235 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 14... 0030 1590 5050 21700 18 26 35 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 14... 45 55 62 72 84 95 100 --- --- --- --- --- --- --- 236 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR LOCATION.--Lat 18°14'33", long 66°00'34", Hydrologic Unit 21010005, on right bank 250 ft (76 m) upstream from bridge on Highway 189, 1.2 mi (1.9 km) downstream from Río Turabo, and 1.8 mi (2.9 km) east of Plaza de Caguas. DRAINAGE AREA.--89.8 mi2 (232.6 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1959 (low-flow measurement only), February to November 1959 (monthly measurements only), December 1959 to current year. GAGE.--Water-stage recorder. Datum of gage is 143.28 ft (43.672 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 98 127 98 67 79 78 171 83 78 42 49 154 2 337 120 92 89 73 74 204 85 68 43 46 157 3 140 111 85 78 71 79 217 92 67 44 42 261 4 113 115 84 135 84 78 139 100 68 143 41 271 5 88 105 80 125 2390 132 147 95 81 120 37 161 6 75 103 79 1780 334 85 139 86 103 63 e51 188 7 66 94 75 1600 195 2250 139 84 73 58 e155 319 8 66 89 73 513 597 661 143 293 71 61 97 628 9 104 92 72 e395 449 204 116 197 74 56 180 368 10 91 1280 74 e583 174 146 107 109 74 54 115 345 11 188 178 69 250 135 132 105 79 59 45 82 197 12 371 139 70 217 123 116 275 70 95 45 72 168 13 752 124 76 243 105 110 145 79 125 40 59 232 14 6490 117 71 299 248 112 112 128 73 43 51 283 15 1070 116 70 177 280 120 102 157 62 41 54 733 16 640 117 69 153 143 104 140 105 66 45 59 314 17 747 110 120 143 128 88 201 84 116 49 241 221 18 527 103 88 129 116 86 203 77 e76 61 140 190 19 323 107 78 119 107 87 e178 80 e75 97 74 204 20 258 101 67 114 98 749 305 70 61 418 73 192 21 213 106 96 112 98 349 253 69 73 241 137 e3490 22 206 179 86 106 91 168 169 61 124 85 536 e8930 23 190 161 74 104 85 134 115 64 74 64 210 1150 24 179 129 73 107 82 113 107 71 60 83 1630 575 25 175 120 66 114 73 131 102 60 58 81 2430 462 26 163 171 64 119 79 124 100 131 55 59 720 399 27 147 165 62 102 84 148 105 251 53 61 339 374 28 144 112 60 98 78 135 109 94 59 98 258 456 29 131 100 58 86 374 e99 87 54 76 269 337 30 125 104 62 85 464 87 180 49 54 202 292 31 121 60 80 409 114 54 165 TOTAL 14338 4795 2351 8322 6599 8040 4534 3335 2224 2524 8614 22051 MEAN 463 160 75.8 268 236 259 151 108 74.1 81.4 278 735 MAX 6490 1280 120 1780 2390 2250 305 293 125 418 2430 8930 MIN 66 89 58 67 71 74 87 60 49 40 37 154 AC-FT 28440 9510 4660 16510 13090 15950 8990 6610 4410 5010 17090 43740 CFSM 5.15 1.78 .84 2.99 2.62 2.89 1.68 1.20 .83 .91 3.09 8.19 IN. 5.94 1.99 .97 3.45 2.73 3.33 1.88 1.38 .92 1.05 3.57 9.13 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 1998, BY WATER YEAR (WY) MEAN 358 311 217 148 113 95.5 91.3 223 243 225 266 328 MAX 1910 1131 714 559 291 306 355 863 1283 660 949 1438 (WY) 1971 1988 1988 1992 1984 1989 1978 1985 1979 1961 1979 1960 MIN 44.2 64.9 33.6 45.3 35.6 23.2 30.6 33.7 34.1 21.8 51.4 37.4 (WY) 1968 1968 1968 1968 1968 1968 1995 1974 1975 1974 1994 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1960 - 1998 ANNUAL TOTAL 55612 87727 ANNUAL MEAN 152 240 216 HIGHEST ANNUAL MEAN 526 1979 LOWEST ANNUAL MEAN 82.3 1967 HIGHEST DAILY MEAN 6490 Oct 14 8930 Sep 22 25300 Sep 6 1960 LOWEST DAILY MEAN 23 Jul 4 37 Aug 5 11 Apr 8 1968 ANNUAL SEVEN-DAY MINIMUM 28 Jun 29 44 Jul 11 11 Apr 8 1968 INSTANTANEOUS PEAK FLOW 49000 Sep 21 83000 Sep 10 1996 INSTANTANEOUS PEAK STAGE 25.64 Sep 21 32.32 Sep 10 1996 INSTANTANEOUS LOW FLOW 35 Aug 6 17 Aug 18 1994 ANNUAL RUNOFF (AC-FT) 110300 174000 156500 ANNUAL RUNOFF (CFSM) 1.70 2.68 2.41 ANNUAL RUNOFF (INCHES) 23.04 36.34 32.68 10 PERCENT EXCEEDS 229 372 360 50 PERCENT EXCEEDS 88 107 106 90 PERCENT EXCEEDS 43 60 40 e Estimated 237 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 238 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1959 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1995. INSTRUMENTATION.-- USD-49 sediment sampler since October 1983. Sediment pumping sampler since 1984. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean,14,500 mg/L Nov. 27, 1987; Minimum daily mean, 8 mg/L January 23, 1992. SEDIMENT LOADS: Maximum daily mean, 396,000 tons ( 359,000 tonnes) September 10, 1996; Minimum daily mean, 0.65 tons (0.59 tonnes) May 25,1995. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, e6,300 mg/L September 22, 1998 ; minimum daily mean, 13 mg/L January 2,3, 1998. SEDIMENT LOADS: Maximum daily mean, e254,000 tons (e230,000 tonnes) September 22, 1998; minimum daily 2.7 ton ( 2.4 tonnes) December 27, 28, 1997. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 15... 1000 1010 152 6.6 25.5 80 7.4 90 16 31000 22000 MAR 10... 0935 161 238 7.0 25.0 17 7.2 87 <10 K16000 2000 JUN 02... 0900 70 271 6.8 29.5 14 6.7 88 <10 3400 K170 SEP 04... 0830 489 202 6.3 27.5 290 6.6 84 <10 31000 49000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 15... 42 11 3.9 12 .8 2.1 39 <.5 8.9 13 MAR 10... -- -- -- -- -- -- 82 -- -- -­ JUN 02... 71 18 6.2 20 1 2.1 78 -- 13 17 SEP 04... 59 14 5.9 17 1 2.2 79 <1.0 8.4 14 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 15... .10 23 96 263 124 .470 .010 .480 .020 .41 MAR 10... -- -- -- -- 10 .880 .020 .900 .100 .14 JUN 02... .12 30 154 29.0 25 .314 .016 .330 .070 .25 SEP 04... .11 26 135 178 700 .320 .060 .380 .290 1.0 -- -- -- -- -- -- -- -- -- -- -- -- 239 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- CHRO­ GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 15... .43 .91 4.0 .070 <1 <100 30 <1 1 13 MAR 10... .24 1.1 5.0 .090 JUN 02... .32 .65 2.9 .060 <1 <100 30 <1 <1 <10 SEP 04... 1.3 1.7 7.4 .260 MANGA- IRON, LEAD, NESE, MERCURY TOTAL TOTAL TOTAL TOTAL SELE- RECOV- RECOV- RECOV- RECOV- NIUM, ERABLE ERABLE ERABLE ERABLE TOTAL DATE (UG/L (UG/L (UG/L (UG/L (UG/L AS FE) AS PB) AS MN) AS HG) AS SE) (01045) (01051) (01055) (71900) (01147) METHY­ SILVER, ZINC, LENE TOTAL TOTAL BLUE RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (MG/L TOTAL STANCE AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01077) (01092) (00720) (32730) (38260) OCT 15... 3600 2 290 <.10 <1 <1 30 <.010 <1 .07 MAR 10... -- -- -- -- -- -- -- -- -- -­ JUN 02... 740 <1 150 <.10 <1 <1 10 <.010 <1 .18 SEP 04... -- -- -- -- -- -- -- -- -- -­ SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 98 79 22 127 2 337 112 305 120 3 140 78 32 111 4 113 72 24 115 5 88 133 31 105 40 14 98 32 8.4 33 11 92 54 13 27 8.2 85 100 23 24 7.3 84 101 23 33 9.4 80 83 18 6 75 217 44 103 7 66 167 30 94 8 66 104 18 89 9 104 72 20 92 10 91 53 13 1280 51 14 79 59 13 37 9.3 75 41 8.3 24 5.8 73 28 5.6 27 6.9 72 26 5.0 1140 9060 74 26 5.2 11 188 154 94 178 12 371 227 288 139 13 752 501 7110 124 14 6490 2650 123000 117 15 1070 303 887 116 142 75 69 44 8.1 64 24 70 80 15 40 13 76 76 16 35 11 71 59 11 33 10 70 46 8.8 16 640 134 238 117 17 747 277 1010 110 18 527 203 359 103 19 323 26 23 107 20 258 21 14 101 32 10 69 43 8.1 30 9.0 120 58 20 31 8.6 88 30 7.3 36 10 78 22 4.6 77 21 67 20 3.6 21 213 28 16 106 22 206 44 24 179 23 190 42 21 161 24 179 34 16 129 25 175 27 13 120 69 21 96 19 5.0 127 61 86 19 4.4 108 49 74 19 3.7 73 26 73 18 3.6 87 28 66 18 3.1 26 163 22 9.6 27 147 18 7.1 28 144 19 7.6 29 131 23 8.1 30 125 31 10 31 121 42 14 171 84 60 64 17 2.9 165 104 48 62 17 2.7 112 47 14 60 17 2.7 100 35 9.5 58 23 3.6 104 33 9.2 62 31 5.1 --- --- --- 60 22 3.6 TOTAL 14338 --- 133708.4 4795 --- 9663.2 2351 --- 265.4 --- --- --- --- --- --- --- --- --- --- --- --- 240 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 67 15 2.7 79 55 12 78 49 10 2 89 13 3.2 73 50 10 74 50 10 3 78 13 2.6 71 48 9.2 79 76 16 4 135 62 27 84 49 13 78 36 7.7 5 125 59 20 2390 1360 12600 132 84 54 6 1780 940 10700 334 155 163 85 173 40 7 1600 657 3140 195 73 38 2250 1920 39400 8 513 494 794 597 231 1190 661 309 806 9 e395 263 e286 449 353 655 204 52 30 10 e583 344 e600 174 256 118 146 30 12 11 250 102 72 135 234 86 132 27 9.7 12 217 62 44 123 115 39 116 25 7.9 13 243 181 127 105 48 14 110 25 7.4 14 299 183 171 248 52 202 112 30 9.3 15 177 96 46 280 89 167 120 36 12 16 153 87 36 143 94 37 104 43 12 17 143 100 38 128 50 17 88 43 10 18 129 110 38 116 26 8.3 86 41 9.6 19 119 71 23 107 30 8.7 87 41 9.5 20 114 44 13 98 43 11 749 367 1770 21 112 42 13 98 39 10 349 356 398 22 106 66 19 91 30 7.4 168 83 39 23 104 66 19 85 27 6.1 134 24 8.7 24 107 58 17 82 42 9.2 113 38 11 25 114 51 16 73 60 12 131 71 25 26 119 49 16 79 58 12 124 59 20 27 102 61 17 84 55 12 148 39 16 28 98 77 20 78 52 11 135 33 12 29 86 74 17 374 188 425 30 85 66 15 464 363 869 31 80 60 13 409 328 577 TOTAL 8322 16365.5 6599 15477.9 8040 44643.8 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 171 67 32 83 2 204 53 100 85 3 217 84 96 92 4 139 100 38 100 5 147 105 44 95 34 7.7 78 53 11 35 8.1 68 37 6.9 37 9.2 67 28 5.0 39 11 68 40 7.6 40 10 81 45 13 6 139 87 34 86 7 139 94 38 84 8 143 157 61 293 9 116 121 38 197 10 107 100 29 109 40 9.4 103 97 27 36 8.0 73 90 18 273 656 71 80 15 187 113 74 57 11 76 23 74 41 8.2 11 105 86 24 12 275 109 169 13 145 75 31 14 112 41 12 15 102 30 8.3 79 50 11 59 40 6.3 70 37 7.0 95 161 18 79 40 8.8 125 113 31 128 77 32 73 53 10 157 83 51 62 38 6.4 16 140 41 45 105 17 201 87 83 84 18 203 186 101 77 19 e178 134 e71 80 20 305 121 159 70 79 22 66 36 6.3 66 15 116 80 30 56 12 e76 56 e76 56 12 e75 51 e75 40 7.6 61 46 7.6 21 253 163 121 69 22 169 169 79 61 23 115 125 39 64 24 107 97 28 71 25 102 75 21 60 39 7.3 73 49 9.8 41 6.8 124 60 30 41 7.2 74 56 11 41 7.8 60 43 7.0 40 6.5 58 38 5.9 26 100 59 16 27 105 47 13 28 109 41 12 29 e99 37 9.8 30 87 35 8.2 31 --- --- --- 131 68 37 55 42 6.3 251 211 161 53 46 6.5 94 67 17 59 42 6.7 87 51 13 54 40 5.9 180 78 69 49 53 7.0 114 81 25 --- --- --­ TOTAL 4534 --- 1560.3 3335 --- 1391.4 2224 --- 485.4 --- --- --- --- --- --- 241 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 42 71 8.1 49 86 11 154 75 31 2 43 75 8.7 46 67 8.3 157 94 42 3 44 58 6.9 42 54 6.1 261 187 133 4 143 38 46 41 60 6.7 271 171 128 5 120 52 28 37 70 7.0 161 148 49 6 63 95 16 e51 72 e5.9 188 167 75 7 58 93 14 e155 77 e62 319 188 199 8 61 82 13 97 82 19 628 419 1080 9 56 77 12 180 87 68 368 314 282 10 54 74 11 115 71 22 345 208 215 11 45 78 9.5 82 77 17 197 131 70 12 45 84 10 72 90 17 168 120 54 13 40 87 9.3 59 87 14 232 163 118 14 43 74 8.6 51 82 11 283 158 128 15 41 64 7.1 54 94 14 733 197 1650 16 45 71 8.6 59 111 18 314 124 114 17 49 71 9.5 241 240 331 221 71 42 18 61 35 8.5 140 126 50 190 74 38 19 97 44 18 74 103 21 204 78 43 20 418 437 1200 73 89 18 192 82 42 21 241 236 179 137 111 45 e3490 1830 e98200 22 85 106 25 536 565 1290 e8930 6300 e254000 23 64 60 10 210 146 94 1150 199 743 24 83 53 12 1630 780 8180 575 80 125 25 81 52 11 2430 1010 10200 462 47 59 26 59 52 8.2 720 188 368 399 41 44 27 61 51 8.5 339 132 121 374 55 67 28 98 66 18 258 96 67 456 251 349 29 76 69 14 269 162 124 337 150 137 30 54 57 8.3 202 124 68 292 96 75 31 54 71 10 165 80 36 TOTAL 2524 1756.8 8614 21320.0 22051 358332 YEAR 87727 604970.1 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 17... 2215 1230 991 3290 98 NOV 10... 0800 2200 1490 8850 99 JAN 06... 1330 5740 2780 43100 96 07... 0630 2820 866 6600 99 FEB 05... 0300 1500 1590 6440 99 05... 1500 2660 1410 10100 96 09... 0045 1340 1390 5030 100 MAR 20... 1745 1710 1110 5100 100 AUG 25... 1255 1990 376 2000 99 SEP 21... 2115 20800 9070 510000 97 242 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) FEB 05... 0730 6550 3830 67700 37 52 68 05... 1125 2780 1640 12300 45 59 73 SEP 08... 1215 841 818 1860 55 68 80 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) FEB 05... 84 93 96 99 100 100 100 05... 84 92 97 100 100 100 100 SEP 08... 87 96 98 99 100 100 100 243 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGÜITAS NEAR AGUAS BUENAS, PR LOCATION.--Lat 18°14'48", long 66°05'37", Hydrologic Unit 21010005, on right bank 450 ft (137 m) upstream from bridge on Highway 777, 1.0 mi (1.6 km) southeast from Aguas Buenas, 3.9 mi (6.3 km) northwest from Caguas, and 2.1 mi (3.4 km) southwest from Las Carolinas. DRAINAGE AREA.--5.30 mi2 (13.72 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.7 5.4 4.4 3.4 2.4 2.3 3.9 2.7 2.7 4.4 6.2 7.2 2 2.6 4.3 4.3 3.6 2.3 2.1 3.3 2.6 2.9 7.9 6.5 10 3 2.0 4.7 4.2 3.5 2.3 2.2 3.0 3.1 3.1 9.0 5.6 11 4 1.7 4.7 4.4 3.6 12 2.2 2.8 2.9 5.8 6.2 5.6 14 5 1.7 4.5 4.4 4.2 73 12 3.0 2.8 4.0 4.7 5.6 11 6 3.0 4.7 4.4 14 8.3 6.4 3.5 2.6 3.6 6.5 e6.4 11 7 3.1 4.0 4.4 27 4.8 17 5.4 2.7 3.3 6.3 e10 9.5 8 2.5 4.1 4.4 7.3 39 9.4 4.2 4.0 3.2 4.4 9.1 18 9 2.3 4.4 4.4 4.2 22 4.8 3.3 3.8 4.2 4.0 9.3 11 10 2.1 7.5 4.4 4.0 8.1 3.9 3.2 3.3 4.0 4.0 7.0 9.5 11 2.5 4.8 4.4 3.4 12 5.2 4.4 4.2 3.4 13 22 4.4 4.1 6.7 14 200 4.3 4.0 6.4 15 19 4.6 4.0 3.1 6.0 3.6 3.9 3.3 3.1 3.9 6.2 8.1 4.6 3.4 5.1 3.3 7.8 3.9 6.4 7.4 4.1 3.4 5.1 3.4 6.3 4.1 5.7 7.0 8.2 3.7 3.9 5.9 4.3 4.2 5.0 7.0 5.5 3.4 3.9 4.1 3.0 4.5 5.5 9.0 16 17 5.7 3.9 2.8 17 18 6.2 4.1 2.9 18 13 5.4 4.3 2.8 19 8.7 5.0 4.1 3.1 20 6.9 4.4 4.2 3.3 4.5 3.3 8.6 2.7 2.7 5.1 5.3 7.3 3.7 3.1 4.7 2.6 8.2 4.5 7.1 6.8 3.5 3.1 3.6 2.7 4.7 11 11 7.4 3.2 2.8 3.5 4.1 3.1 5.7 7.4 8.2 3.1 20 4.8 5.6 2.9 30 10 8.1 21 6.1 4.4 5.4 3.8 22 5.5 4.5 4.2 3.2 23 5.2 4.8 4.0 3.0 24 5.0 4.7 3.9 2.8 25 5.0 4.7 3.7 3.6 3.0 9.4 4.2 3.3 5.5 7.4 18 262 2.6 4.1 3.6 2.7 5.9 5.1 28 663 2.6 3.4 3.3 2.8 3.3 7.0 14 43 2.7 2.7 3.1 2.6 12 5.8 71 22 2.4 2.7 3.1 2.8 6.5 5.6 46 17 26 4.8 5.9 3.5 3.1 27 4.3 5.4 3.4 2.8 28 4.0 4.4 3.4 2.7 29 4.0 5.2 3.4 2.6 30 4.1 4.9 3.4 2.4 31 4.1 --- 3.4 2.4 2.5 2.3 3.1 4.3 5.4 4.2 14 22 2.4 3.7 3.4 5.3 4.9 9.2 25 19 2.4 2.4 2.9 3.0 4.5 12 13 19 --- 23 2.7 3.2 4.3 7.5 9.4 17 --- 10 2.6 2.8 4.1 6.3 7.8 14 --- 5.2 --- 2.8 --- 6.3 7.0 --­ TOTAL 388.1 146.4 126.7 145.1 MEAN 12.5 4.88 4.09 4.68 MAX 200 7.5 5.4 27 MIN 1.7 4.0 3.4 2.4 AC-FT 770 290 251 288 CFSM 2.36 .92 .77 .88 IN. 2.72 1.03 .89 1.02 241.2 181.0 114.7 103.8 139.3 210.7 394.1 1286.5 8.61 5.84 3.82 3.35 4.64 6.80 12.7 42.9 73 23 8.6 5.9 12 30 71 663 2.3 2.1 2.6 2.6 2.7 3.9 5.0 6.8 478 359 228 206 276 418 782 2550 1.63 1.10 .72 .63 .88 1.28 2.40 8.09 1.69 1.27 .81 .73 .98 1.48 2.77 9.03 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 1998, BY WATER YEAR (WY) MEAN 8.50 6.92 6.13 8.05 MAX 20.9 12.3 13.4 16.7 (WY) 1991 1993 1993 1992 MIN 3.17 2.66 2.34 2.48 (WY) 1996 1995 1995 1995 5.23 4.70 4.50 5.13 4.27 6.02 6.83 16.2 8.61 8.87 13.1 18.0 8.05 18.6 12.7 52.9 1998 1990 1993 1993 1993 1993 1998 1996 2.96 2.09 1.84 2.00 1.84 1.86 1.85 2.43 1995 1996 1995 1997 1997 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1990 - 1998 ANNUAL TOTAL 1631.4 ANNUAL MEAN 4.47 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 200 LOWEST DAILY MEAN 1.0 ANNUAL SEVEN-DAY MINIMUM 1.3 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 3240 ANNUAL RUNOFF (CFSM) .84 ANNUAL RUNOFF (INCHES) 11.45 10 PERCENT EXCEEDS 6.1 50 PERCENT EXCEEDS 2.6 90 PERCENT EXCEEDS 1.6 3477.6 9.53 7.04 11.1 1993 4.31 1997 Oct 14 663 Sep 22 1260 Sep 10 1996 Aug 1 1.7 Oct 4 1.0 Aug 1 1997 Sep 5 2.3 Feb 26 1.2 Apr 30 1996 2860 Sep 22 4490 Sep 10 1996 18.06 Sep 22 21.22 Sep 10 1996 1.2 Oct 1 .82 Jul 29 1997 6900 5100 1.80 1.33 24.41 18.04 12 9.5 4.4 4.2 2.7 1.9 e Estimated 244 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGÜITAS NEAR AGUAS BUENAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 245 RIO GRANDE DE LOIZA BASIN 50055100 Río CAGÜITAS NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: February 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by hydrologic technician and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,300 mg/L September 10, 1996; Minimum daily mean, 1 mg/L severals days during 1997-98. SEDIMENT LOADS: Maximum daily mean, 24,500 tons (22,200 tonnes) September 10, 1996; Minimum daily mean, 0.01 ton (0.01 tonnes)severals days during 1997-98 . . EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,000 mg/L September 22, 1998; Minimum daily mean, 1 mg/L January 4-5, 1998. SEDIMENT LOADS: Maximum daily mean, 8,080 tons (7,340 tonnes) September 22, 1998; Minimum daily mean, 0.01 ton (0.01 tonnes) January 4-5, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2.7 15 .11 5.4 11 .16 4.4 8 .09 2 2.6 18 .13 4.3 12 .14 4.3 10 .11 3 2.0 20 .11 4.7 9 .11 4.2 12 .14 4 1.7 18 .08 4.7 6 .08 4.4 10 .12 5 1.7 16 .07 4.5 4 .05 4.4 8 .09 6 3.0 33 .81 4.7 4 .05 4.4 6 .07 7 3.1 17 .14 4.0 4 .04 4.4 5 .06 8 2.5 19 .13 4.1 4 .04 4.4 4 .05 9 2.3 26 .16 4.4 4 .05 4.4 4 .05 10 2.1 36 .20 7.5 40 1.9 4.4 4 .05 11 2.5 48 .33 4.8 38 .49 4.4 4 .05 12 5.2 50 .70 4.4 31 .37 4.2 4 .05 13 22 1390 1320 4.4 24 .29 4.1 4 .05 14 200 2500 4930 4.3 19 .22 4.0 5 .05 15 19 88 4.6 4.6 14 .17 4.0 5 .05 16 17 77 3.5 5.7 29 .64 3.9 5 .05 17 18 290 19 6.2 14 .23 4.1 6 .06 18 13 41 1.5 5.4 16 .24 4.3 6 .07 19 8.7 27 .63 5.0 20 .27 4.1 7 .07 20 6.9 17 .32 4.4 24 .29 4.2 7 .08 21 6.1 11 .19 4.4 18 .22 5.4 8 .11 22 5.5 9 .14 4.5 12 .15 4.2 10 .11 23 5.2 13 .18 4.8 8 .11 4.0 12 .13 24 5.0 19 .25 4.7 6 .08 3.9 15 .16 25 5.0 22 .29 4.7 6 .08 3.7 11 .11 26 4.8 14 .18 5.9 23 .61 3.5 7 .07 27 4.3 9 .10 5.4 9 .13 3.4 5 .04 28 4.0 8 .08 4.4 8 .09 3.4 4 .04 29 4.0 7 .08 5.2 7 .10 3.4 5 .05 30 4.1 7 .08 4.9 6 .08 3.4 6 .05 31 4.1 9 .10 3.4 7 .06 TOTAL 388.1 6284.19 146.4 7.48 126.7 2.34 --- --- --- --- --- --- --- --- --- --- --- --- 246 RIO GRANDE DE LOIZA BASIN 50055100 Río CAGÜITAS NEAR AGUAS BUENAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 3.4 5 .04 2.4 11 .07 2.3 4 .03 2 3.6 3 .03 2.3 13 .08 2.1 4 .02 3 3.5 2 .02 2.3 14 .09 2.2 3 .02 4 3.6 1 .01 12 309 128 2.2 3 .02 5 4.2 1 .01 73 1770 756 12 479 63 6 14 163 11 8.3 19 .43 6.4 86 1.6 7 27 339 27 4.8 17 .22 17 243 22 8 7.3 91 2.0 39 1120 506 9.4 285 8.7 9 4.2 26 .30 22 379 29 4.8 38 .50 10 4.0 17 .18 8.1 90 2.0 3.9 19 .20 11 3.4 16 .15 6.0 57 .93 3.6 11 .11 12 3.4 16 .15 4.6 43 .54 3.4 12 .11 13 6.7 62 3.0 4.1 37 .41 3.4 14 .13 14 6.4 78 1.7 8.2 70 2.2 3.7 16 .16 15 3.1 25 .21 5.5 58 .94 3.4 12 .12 16 2.8 12 .09 4.5 28 .33 3.3 9 .08 17 2.9 7 .05 3.7 16 .16 3.1 7 .06 18 2.8 8 .06 3.5 10 .09 3.1 7 .06 19 3.1 10 .09 3.2 7 .06 2.8 7 .05 20 3.3 11 .10 3.1 5 .05 20 594 74 21 3.8 6 .06 3.0 4 .03 9.4 234 6.6 22 3.2 5 .05 2.6 4 .03 4.1 53 .60 23 3.0 5 .04 2.6 5 .04 3.4 19 .17 24 2.8 4 .03 2.7 6 .04 2.7 11 .08 25 3.6 19 .21 2.4 6 .04 2.7 11 .08 26 3.1 18 .15 2.5 7 .05 2.3 10 .06 27 2.8 8 .06 2.4 6 .04 3.7 30 .50 28 2.7 4 .03 2.4 5 .03 2.4 21 .13 29 2.6 5 .04 23 494 132 30 2.4 7 .05 10 171 5.2 31 2.4 9 .06 5.2 65 .94 TOTAL 145.1 46.97 241.2 1427.90 181.0 317.33 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 3.9 37 .39 2.7 4 .03 2.7 16 .12 2 3.3 23 .20 2.6 4 .03 2.9 11 .08 3 3.0 15 .12 3.1 5 .05 3.1 4 .03 4 2.8 10 .08 2.9 8 .06 5.8 45 1.8 5 3.0 8 .06 2.8 9 .06 4.0 9 .10 6 3.5 9 .09 2.6 5 .04 3.6 8 .08 7 5.4 39 1.1 2.7 4 .03 3.3 11 .10 8 4.2 48 .58 4.0 7 .07 3.2 15 .13 9 3.3 23 .20 3.8 7 .07 4.2 14 .16 10 3.2 16 .14 3.3 7 .06 4.0 13 .14 11 3.9 11 .12 12 5.1 23 .45 13 5.1 26 .40 14 3.9 11 .12 15 3.9 10 .11 3.3 7 .06 3.1 11 .09 3.3 6 .05 7.8 84 2.3 3.4 6 .05 6.3 45 1.1 5.9 41 1.6 4.3 13 .15 4.1 44 .49 3.0 12 .10 16 8.6 49 1.9 17 4.7 3 .04 18 3.6 4 .04 19 3.5 6 .06 20 4.8 11 .14 2.7 29 .21 2.7 11 .08 2.6 22 .16 8.2 92 3.6 2.7 19 .14 4.7 36 .48 4.1 44 .89 3.1 20 .17 5.6 62 1.1 2.9 12 .09 21 4.2 13 .15 22 3.6 16 .15 23 3.3 17 .15 24 3.1 14 .12 25 3.1 11 .09 3.3 25 .23 5.5 32 .82 2.7 14 .11 5.9 48 .94 2.8 11 .09 3.3 17 .15 2.6 9 .06 12 501 62 2.8 7 .05 6.5 19 .34 26 3.1 9 .08 27 3.4 7 .06 28 2.9 5 .04 29 2.7 4 .03 30 2.6 4 .03 31 --- --- --- 4.3 6 .07 5.4 17 .25 5.3 59 .95 4.9 16 .21 3.0 48 .39 4.5 15 .19 3.2 33 .29 4.3 14 .16 2.8 23 .18 4.1 9 .10 2.8 19 .15 --- --- --­ TOTAL 114.7 --- 7.24 103.8 --- 7.82 139.3 --- 76.06 --- --- --- --- --- --- 247 RIO GRANDE DE LOIZA BASIN 50055100 Río CAGÜITAS NEAR AGUAS BUENAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 4.4 7 .08 6.2 27 .45 7.2 29 .57 2 7.9 90 5.0 6.5 20 .34 10 88 3.3 3 9.0 108 4.4 5.6 14 .22 11 152 4.6 4 6.2 50 .87 5.6 11 .16 14 304 20 5 4.7 35 .44 5.6 10 .15 11 162 5.7 6 6.5 58 1.6 e6.4 10 e.18 11 130 4.0 7 6.3 13 .22 e10 102 e5.9 9.5 116 3.0 8 4.4 12 .15 9.1 108 3.3 18 432 36 9 4.0 15 .16 9.3 29 .73 11 98 3.1 10 4.0 17 .18 7.0 28 .53 9.5 27 .70 11 3.9 18 .19 6.2 26 .43 8.1 24 .53 12 3.9 14 .15 6.4 22 .37 7.4 25 .49 13 4.1 10 .10 5.7 19 .30 7.0 24 .45 14 4.2 7 .07 5.0 20 .26 7.0 17 .33 15 4.5 4 .05 5.5 20 .30 9.0 14 .34 16 5.1 3 .04 5.3 20 .28 7.3 16 .31 17 4.5 3 .04 7.1 20 .39 6.8 18 .32 18 11 27 1.5 11 190 11 7.4 17 .34 19 5.7 10 .15 7.4 107 2.2 8.2 16 .36 20 30 1750 380 10 147 4.9 8.1 16 .34 21 7.4 214 5.0 18 142 6.8 262 1710 6610 22 5.1 45 .60 28 193 15 663 4000 8080 23 7.0 52 1.2 14 175 6.8 43 655 95 24 5.8 19 .29 71 739 229 22 43 2.7 25 5.6 17 .25 46 331 50 17 16 .77 26 4.2 17 .19 14 58 2.4 22 151 22 27 9.2 106 4.9 25 1470 190 19 298 16 28 12 162 5.9 13 248 9.4 19 290 18 29 7.5 88 1.8 9.4 38 .97 17 178 8.5 30 6.3 59 1.0 7.8 32 .69 14 206 7.9 31 6.3 40 .67 7.0 31 .59 TOTAL 210.7 417.19 394.1 544.04 1286.5 14945.65 YEAR 3477.6 24084.21 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) MAR 29... 2045 46 1300 161 96 30... 0626 11 237 7.0 99 JUL 20... 1530 35 3120 295 98 21... 1630 4.4 181 2.2 98 AUG 18... 1638 24 865 56 99 24... 1400 191 1160 598 98 27... 1645 81 2350 514 95 SEP 03... 0620 9.6 852 22 99 22... 0330 1660 3460 15500 74 248 RIO GRANDE DE LOIZA BASIN 50055100 Río CAGÜITAS NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) JAN 07... 0530 94 1110 282 71 81 90 MAR 20... 1815 75 3060 620 55 69 82 JUL 20... 1830 130 10400 3650 51 63 76 SEP 21... 1915 268 5290 3830 37 52 69 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) JAN 07... 95 97 97 98 100 100 100 MAR 20... 92 95 97 99 100 100 100 JUL 20... 86 93 95 98 99 100 100 SEP 21... 80 84 90 96 99 100 100 249 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR LOCATION.--Lat 18°14'55", long 66°01'40", Hydrologic Unit 21010005, on left bank, at C. 4 street Villa Blanca housing area at Caguas, 1.8 mi (2.9 km) upstream from Río Grande de Loíza, and 0.95 mi (1.53 km) northeast from Caguas Plaza. DRAINAGE AREA.--11.71 mi2 (30.33 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Low-flow affected by pluvial discharges above 50 ft (15.24 m), upstream from station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e16 24 14 7.7 2 e54 16 13 9.7 3 e23 26 12 10 4 e18 e19 12 12 5 e14 e16 10 15 6.0 9.3 e16 7.1 7.1 6.2 6.3 43 6.0 8.6 e19 7.2 7.5 6.1 5.0 95 6.0 14 e20 12 7.7 40 4.5 53 99 9.4 e12 11 99 22 4.2 145 663 186 e13 6.9 53 9.1 4.7 32 6 e12 e15 9.7 313 7 e11 e14 9.5 282 8 e16 e13 9.8 57 9 12 e14 12 49 10 10 e190 9.9 17 60 37 e12 7.3 15 20 e30 47 26 428 e11 5.9 6.4 12 e137 26 291 141 e12 62 5.5 5.9 103 123 234 37 e10 7.2 8.2 4.8 53 58 47 26 e9.4 5.8 7.5 4.6 16 27 11 62 e18 8.3 12 12 64 e15 7.7 50 13 159 e13 8.0 90 14 698 e12 8.8 53 15 158 44 10 19 29 18 e9.2 5.5 7.2 5.8 10 17 24 16 e25 6.3 113 4.5 7.9 16 19 16 e12 6.5 38 4.7 5.9 63 168 22 e10 45 5.8 5.3 5.7 19 56 15 e9.1 11 5.3 8.9 5.3 88 16 121 16 11 13 17 197 12 14 10 18 116 12 10 9.5 19 54 12 9.3 8.9 20 43 13 11 8.5 21 11 e14 6.8 7.1 7.8 5.0 26 19 9.0 e18 87 246 8.7 61 23 15 e8.9 11 11 28 163 86 21 12 e8.8 11 6.9 9.7 25 13 29 12 e68 28 14 8.0 420 53 54 21 31 14 31 7.9 22 25 17 10 7.3 23 21 16 9.6 6.7 24 20 14 10 7.3 25 20 14 9.1 10 11 e27 12 27 54 107 109 e1210 11 e15 e10 7.0 36 17 337 e3970 10 e13 e9.0 6.3 9.3 13 94 880 10 e11 e8.2 7.1 81 15 866 567 11 e14 e8.2 6.0 15 10 821 469 26 22 42 9.6 8.3 27 18 17 9.2 8.0 28 15 14 9.1 7.6 29 14 14 9.3 7.1 30 13 14 8.4 6.8 31 18 --- 8.3 6.5 13 e12 e9.0 28 9.6 7.1 e149 433 11 e14 e10 30 8.0 92 195 321 10 e13 e8.6 8.6 7.4 103 94 386 --- e36 8.1 7.6 6.6 10 39 233 --- e42 8.6 9.7 7.0 5.5 28 123 --- e36 --- 9.0 --- 5.0 24 --­ TOTAL 2075 690 333.6 1129.8 MEAN 66.9 23.0 10.8 36.4 MAX 698 190 31 313 MIN 10 12 7.7 6.5 MED 21 15 9.8 10 AC-FT 4120 1370 662 2240 CFSM 5.72 1.96 .92 3.11 IN. 6.59 2.19 1.06 3.59 1900.0 1322.0 373.4 478.7 918.9 1169.0 3372.5 9597 67.9 42.6 12.4 15.4 30.6 37.7 109 320 663 428 28 87 246 420 866 3970 6.0 8.6 8.1 5.5 5.3 4.5 4.2 16 17 15 11 7.3 8.1 9.1 30 61 3770 2620 741 950 1820 2320 6690 19040 5.79 3.64 1.06 1.32 2.62 3.22 9.29 27.3 6.04 4.20 1.19 1.52 2.92 3.71 10.71 30.49 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 1998, BY WATER YEAR (WY) MEAN 30.8 32.4 20.6 37.8 MAX 66.9 56.8 58.4 120 (WY) 1998 1993 1993 1992 MIN 18.7 12.2 8.87 14.2 (WY) 1996 1995 1995 1995 24.9 18.3 16.0 23.1 23.6 30.7 42.5 115 67.9 42.6 39.8 59.8 45.6 74.6 109 364 1998 1998 1993 1993 1996 1993 1998 1996 10.8 7.54 5.49 3.35 2.86 4.13 3.82 8.82 1992 1994 1994 1994 1994 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1991 - 1998 ANNUAL TOTAL 9765.6 ANNUAL MEAN 26.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 698 LOWEST DAILY MEAN 7.7 ANNUAL SEVEN-DAY MINIMUM 9.0 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 19370 ANNUAL RUNOFF (CFSM) 2.28 ANNUAL RUNOFF (INCHES) 31.02 10 PERCENT EXCEEDS 43 50 PERCENT EXCEEDS 18 90 PERCENT EXCEEDS 10 23359.9 64.0 36.7 64.0 1998 11.9 1994 Oct 14 3970 Sep 22 8600 Sep 10 1996 Dec 12 4.2 Aug 4 1.3 Jun 8 1994 Dec 25 5.0 Jul 30 1.4 Jun 8 1994 11200 Sep 22 25000 Sep 10 1996 18.87 Sep 22 23.89 Sep 10 1996 46330 26550 5.47 3.13 74.21 42.53 118 47 13 15 6.7 6.0 e Estimated 250 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 251 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1991 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 1990 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1991. REMARKS.-- Sediment samples collected by local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,940 mg/L September 22, 1998; Minimum daily mean, 3 mg/L August 2, 1997. SEDIMENT LOADS: Maximum daily mean, e110,000 tons (e99,900 tonnes) September 22,1998; Minimum daily mean, e0.03 ton (e0.02 tonne) June 15, 1994. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,940 mg/L September 22, 1998; Minimum daily mean, 8 mg/L August 15, 1998. SEDIMENT LOADS: Maximum daily mean, e110,000 tons (e99,900 tonnes) September 22, 1998; Minimum daily mean, 0.21 tons (0.19 tonne), August 2,3 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e16 60 e1.1 24 41 4.3 14 27 1.1 2 e54 62 e18 16 24 1.0 13 23 .76 3 e23 63 e2.2 26 55 6.3 12 19 .61 4 e18 63 e1.6 e19 50 e1.6 12 17 .55 5 e14 58 e1.1 e16 32 e1.1 10 17 .47 6 e12 51 e.82 e15 24 e1.7 9.7 16 .43 7 e11 46 e.59 e14 19 e1.1 9.5 19 .48 8 e16 54 e1.1 e13 16 e.96 9.8 21 .57 9 12 27 .91 e14 19 e1.1 12 24 .75 10 10 23 .62 e190 25 e512 9.9 21 .56 11 62 74 38 e18 31 e1.6 8.3 17 .38 12 64 103 38 e15 30 e1.7 7.7 14 .29 13 159 259 627 e13 27 e.96 8.0 12 .25 14 698 773 2860 e12 24 e.82 8.8 14 .32 15 158 144 62 44 37 7.3 10 17 .47 16 121 47 17 16 35 1.5 11 19 .61 17 197 643 901 12 28 .93 14 31 1.3 18 116 170 79 12 26 .86 10 23 .62 19 54 24 3.5 12 24 .80 9.3 21 .53 20 43 24 2.8 13 22 .76 11 21 .78 21 31 24 2.0 14 21 .81 31 28 4.6 22 25 23 1.6 17 23 1.2 10 19 .51 23 21 20 1.2 16 29 1.3 9.6 19 .50 24 20 18 .95 14 17 .68 10 20 .56 25 20 17 .91 14 27 1.1 9.1 18 .45 26 22 18 1.1 42 50 17 9.6 16 .43 27 18 21 1.0 17 28 1.4 9.2 15 .37 28 15 21 .84 14 20 .77 9.1 13 .33 29 14 20 .78 14 26 .95 9.3 12 .30 30 13 19 .67 14 31 1.1 8.4 11 .25 31 18 34 2.2 8.3 12 .27 TOTAL 2075 4669.59 690 574.70 333.6 20.40 --- --- --- --- --- --- --- --- --- --- --- --- 252 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 7.7 13 .26 6.0 20 .32 9.3 12 .29 2 9.7 13 .35 6.0 26 .42 8.6 13 .31 3 10 14 .39 6.0 33 .53 14 15 .60 4 12 23 1.2 99 119 316 9.4 19 .49 5 15 64 1.9 663 1480 4000 186 949 1870 6 313 366 557 60 134 26 37 130 10 7 282 264 210 26 36 2.7 428 681 2050 8 57 153 29 291 613 1860 141 213 137 9 49 60 9.5 234 386 356 37 49 5.0 10 17 35 1.7 47 75 9.9 26 26 1.9 11 12 25 .80 29 27 2.1 18 14 .74 12 50 52 20 24 27 1.7 16 11 .49 13 90 81 32 19 29 1.5 16 10 .44 14 53 75 12 168 114 94 22 28 2.5 15 19 47 2.4 56 42 7.4 15 36 1.4 16 13 33 1.2 21 29 1.7 11 29 .90 17 10 25 .69 19 22 1.1 9.0 26 .63 18 9.5 20 .50 15 18 .70 e8.9 24 e.48 19 8.9 16 .38 12 15 .47 e8.8 38 e.48 20 8.5 14 .32 12 12 .39 e68 59 e36 21 7.9 17 .35 11 11 .33 e27 86 e4.2 22 7.3 18 .35 11 13 .40 e15 65 e1.7 23 6.7 18 .32 10 18 .49 e13 39 e.96 24 7.3 19 .37 10 18 .51 e11 29 e.59 25 10 19 .53 11 18 .53 e14 39 e1.1 26 8.3 15 .34 13 18 .62 e12 54 e.82 27 8.0 15 .32 11 15 .46 e14 75 e1.1 28 7.6 15 .31 10 13 .36 e13 105 e.96 29 7.1 15 .29 e36 145 e6.8 30 6.8 15 .27 e42 183 e8.4 31 6.5 16 .28 e36 89 e6.8 TOTAL 1129.8 885.32 1900.0 6686.63 1322.0 4153.08 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 e16 33 e1.1 7.1 2 e19 14 e1.6 7.2 3 e20 15 e1.6 12 4 e12 18 e.82 11 5 e13 22 e.96 6.9 19 .37 7.1 20 .39 18 .36 7.5 20 .40 24 1.3 7.7 19 .39 25 .92 99 48 51 19 .35 53 54 24 6 e12 22 e.82 7 e11 22 e.59 8 e12 22 e.82 9 e10 22 e.62 10 e9.4 22 e.61 7.3 21 .45 15 21 1.4 5.9 19 .31 6.4 13 .22 62 53 25 5.5 16 .23 7.2 21 .41 8.2 18 .67 5.8 18 .29 7.5 21 .43 11 e9.2 22 e.47 12 e25 22 e3.0 13 e12 22 e.82 14 e10 21 e.62 15 e9.1 17 e.49 5.5 22 .33 7.2 23 .45 6.3 22 .38 113 59 34 6.5 23 .40 38 35 5.8 45 43 18 5.8 20 .31 11 34 .82 5.3 18 .25 16 e14 14 e1.1 17 e18 11 e1.6 18 11 11 .31 19 11 10 .30 20 28 23 3.6 6.8 16 .29 7.1 16 .30 87 57 56 246 271 579 11 35 .88 28 34 3.0 6.9 20 .38 9.7 30 .77 14 22 2.8 8.0 30 .65 21 12 24 .92 22 e10 36 e.62 23 e9.0 27 e.53 24 e8.2 21 e.43 25 e8.2 17 e.43 27 37 4.8 54 70 23 7.0 29 .55 36 45 6.2 6.3 27 .46 9.3 31 .79 7.1 18 .36 81 74 39 6.0 19 .35 15 88 3.8 26 e9.0 14 e.53 27 e10 16 e.62 28 e8.6 22 e.55 29 8.1 23 .50 30 8.6 21 .49 31 --- --- --- 28 59 8.8 9.6 60 1.5 30 41 8.6 8.0 42 .91 8.6 23 .55 7.4 34 .69 7.6 22 .45 6.6 28 .50 9.7 24 .77 7.0 21 .40 9.0 19 .62 --- --- --­ TOTAL 373.4 --- 27.47 478.7 --- 136.35 918.9 --- 780.45 --- --- --- --- --- --- 253 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 6.2 17 .28 6.3 22 .41 43 43 6.9 2 6.1 18 .33 5.0 15 .21 95 53 19 3 40 56 7.9 4.5 14 .21 53 61 10 4 22 32 2.2 4.2 19 .22 145 96 64 5 9.1 22 .60 4.7 17 .22 32 37 3.2 6 20 25 3.3 e30 25 e4.5 47 42 6.7 7 12 28 .97 e137 49 e70 26 37 2.6 8 5.9 22 .35 103 71 33 123 105 61 9 4.8 24 .31 53 69 11 58 74 13 10 4.6 21 .26 16 33 1.5 27 47 3.7 11 5.8 19 .29 10 18 .50 17 37 1.8 12 4.5 21 .25 7.9 14 .29 16 37 1.6 13 4.7 25 .32 5.9 11 .18 63 50 12 14 5.3 23 .34 5.7 10 .15 19 31 2.2 15 8.9 19 .72 5.3 8 .12 88 98 46 16 7.8 63 1.3 5.0 10 .13 26 42 3.0 17 8.7 47 1.1 61 41 24 23 22 1.3 18 163 63 47 86 75 52 21 38 2.2 19 25 49 3.7 13 24 1.9 29 59 6.3 20 420 800 1990 53 49 16 54 78 38 21 107 165 110 109 83 34 e1210 4590 e61300 22 17 42 2.2 337 195 276 e3970 5940 e110000 23 13 39 1.4 94 128 36 880 52 134 24 15 36 1.6 866 1490 6650 567 35 53 25 10 28 .86 821 512 1490 469 33 42 26 7.1 20 .39 e149 70 e31 433 56 81 27 92 102 45 195 123 123 321 92 111 28 103 99 51 94 89 24 386 199 539 29 10 58 1.5 39 50 5.2 233 43 30 30 5.5 47 .68 28 41 3.1 123 24 8.0 31 5.0 31 .42 24 35 2.3 TOTAL 1169.0 2276.57 3372.5 8891.14 9597 172602.5 YEAR 23359.9 201704.20 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 11... 1550 113 117 36 97 JAN 07... 0645 461 146 182 96 FEB 05... 0515 1430 2020 7800 96 05... 1115 581 1080 1690 98 MAR 05... 1945 254 385 264 99 21... 1635 27 98 7.1 98 AUG 25... 1200 809 324 708 99 SEP 21... 1900 1670 11000 49600 99 22... 0645 3520 9610 91300 99 254 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 17... 1800 813 2930 6430 38 54 75 JAN 06... 1545 279 524 395 74 89 99 FEB 05... 0030 1150 4600 14300 51 68 87 SEP 22... 0200 9820 17700 469000 24 38 63 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 17... 90 96 97 99 100 100 100 JAN 06... 99 99 99 99 100 100 100 FEB 05... 95 97 97 99 100 100 100 SEP 22... 86 96 97 99 99 100 100 255 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGÜITAS AT HIGHWAY 30 AT CAGUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'11", long 66°01'26", at Highway 30 bridge, and 0.8 mi (1.3 km) east of Caguas plaza. DRAINAGE AREA.--14.1 mi2 (36.5 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 21... 0830 14 563 7.2 26.0 5.2 4.2 52 <10 44000 3000 FEB 20... 0800 10 551 7.1 24.0 2.0 4.9 58 <10 24000 K1400 MAY 26... 0825 12 432 7.0 28.0 62 3.0 38 19 58000 42000 AUG 17... 0915 5.8 583 6.8 28.7 4.7 2.8 36 <10 35000 K1500 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 21... 210 54 17 30 .9 3.4 200 <1.0 48 40 FEB 20... -- -- -- -- -- -- 180 -- -- -­ MAY 26... 130 35 11 30 1 3.5 140 -- 26 32 AUG 17... 200 52 16 36 1 3.5 190 <1.0 50 44 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 21... .17 37 350 13.6 5 .450 .010 .460 .020 .20 FEB 20... -- -- -- -- 2 .350 .220 .570 2.00 .40 MAY 26... .10 27 249 7.87 16 .067 .033 .100 2.90 .40 AUG 17... .15 41 357 5.61 14 .043 .037 .080 2.90 .00 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 256 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGÜITAS AT HIGHWAY 30 AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- CHRO­ GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 21... .24 .68 3.0 .030 <1 <100 30 <1 3 <10 FEB 20... 2.4 3.0 13 .350 MAY 26... 3.3 3.4 15 .390 2 <100 50 <1 1 <10 AUG 17... 2.9 3.0 13 .580 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 21... 2300 1 100 <.10 <1 <1 10 <.010 <1 .03 FEB 20... MAY 26... 750 2 890 <.10 <1 <1 10 <.010 2 .46 AUG 17... 257 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR LOCATION.--Lat 18°15'32", long 66°02'24", Hydrologic Unit 21010005, on left bank, in the Bairoa Housing Area, 1.6 mi (2.6 km) northwest of Plaza de Caguas, 4.1 mi (6.6 km) east of Plaza de Aguas Buenas, and 0.9 mi (1.4 km) northwest of Escuela Pepita Garriga. DRAINAGE AREA.--5.08 mi2 (13.15 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Mean daily discharge affected by domestic discharge from school nearby station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e4.3 e4.9 e3.0 e3.0 2 e4.8 e3.9 e2.9 e3.2 3 e3.6 e4.6 e2.7 e3.0 4 e3.6 e4.6 e2.8 e3.1 5 e3.6 e4.3 e2.7 e3.4 e3.5 4.1 3.3 3.6 3.7 2.9 2.9 3.5 e3.4 4.0 3.5 4.3 3.4 11 3.1 5.4 e3.4 4.7 3.3 4.8 3.5 5.9 2.8 6.0 e15 4.2 3.2 4.6 8.6 4.1 2.7 14 e60 6.1 3.2 4.2 3.5 3.3 2.9 9.5 6 e4.6 e4.1 e2.7 e14 7 e4.8 e3.9 e2.8 e24 8 e3.9 e3.8 e2.9 e10 9 e3.6 e3.8 e2.8 e6.0 10 e3.3 e5.4 e2.8 e5.6 6.2 4.8 3.1 4.1 3.4 15 e3.2 5.3 5.0 19 4.2 4.2 3.2 5.3 15 3.6 30 7.1 4.1 6.0 3.1 3.5 31 9.2 13 4.8 3.3 4.9 3.0 3.3 5.6 4.3 6.4 4.3 3.2 4.2 3.0 3.3 3.3 3.6 11 e4.0 e3.8 e2.8 e5.0 12 e5.2 e3.9 e2.7 e5.0 13 e30 e3.8 e2.6 e10 14 e180 e3.7 e2.6 e9.0 15 e17 e3.8 e2.6 e4.5 5.6 4.0 3.2 3.6 3.5 3.5 2.8 3.4 5.1 4.1 3.6 3.6 4.3 2.9 3.7 3.3 4.8 4.1 4.6 3.6 5.1 3.1 3.1 3.8 10 4.2 3.3 14 4.0 2.6 2.9 3.5 6.5 4.4 3.7 6.1 3.7 3.0 3.0 4.5 16 e15 e3.7 e2.6 e4.1 17 e16 e3.7 e2.8 e4.3 18 e11 e3.6 e2.7 e4.2 19 e7.8 e3.6 e2.8 e4.6 20 e6.2 e3.4 e3.8 e4.9 4.8 4.4 8.4 3.4 4.7 3.2 3.0 3.6 4.7 4.0 4.2 6.6 e5.6 3.0 4.3 3.6 4.5 4.1 3.6 3.3 e4.0 14 11 3.2 4.3 4.1 3.5 3.1 e3.0 3.8 3.8 3.4 4.1 8.7 3.8 6.7 e2.8 25 3.8 5.2 21 e5.4 e3.3 e5.0 e5.6 22 e4.9 e3.2 e4.0 e5.0 23 e4.6 e3.0 e3.8 e4.5 24 e4.4 e3.0 e3.6 e4.2 25 e4.5 e3.1 e3.4 e5.4 4.4 5.6 4.6 4.4 e4.1 5.0 12 139 4.2 4.2 3.8 3.1 e4.2 3.2 14 532 4.5 3.8 3.9 3.1 3.2 13 4.9 e35 4.2 4.0 3.6 3.5 19 4.3 80 e17 4.3 6.3 3.6 3.2 4.4 2.9 60 e14 26 e4.3 e4.2 e3.3 e4.6 27 e3.8 e3.1 e3.2 e4.1 28 e3.6 e2.8 e3.2 e4.0 29 e3.6 e3.1 e3.2 e3.8 30 e3.7 e3.1 e3.2 e3.5 31 e3.6 --- e3.2 e3.5 4.4 4.3 3.7 5.5 3.0 2.8 7.7 e17 4.3 5.0 4.2 4.6 3.0 11 36 e15 4.2 4.5 3.7 3.8 3.3 5.8 9.7 e15 --- 28 3.6 3.9 3.0 3.0 5.4 e13 --- 5.8 3.6 4.0 2.7 2.7 4.3 e11 --- 3.5 --- 4.0 --- 2.9 3.8 --­ TOTAL 378.7 112.2 95.2 179.1 MEAN 12.2 3.74 3.07 5.78 MAX 180 5.4 5.0 24 MIN 3.3 2.8 2.6 3.0 AC-FT 751 223 189 355 CFSM 2.40 .74 .60 1.14 IN. 2.77 .82 .70 1.31 234.8 184.2 114.6 142.0 129.0 178.3 351.7 909.9 8.39 5.94 3.82 4.58 4.30 5.75 11.3 30.3 60 28 8.4 14 19 25 80 532 3.4 3.5 3.1 3.1 2.7 2.6 2.7 3.2 466 365 227 282 256 354 698 1800 1.65 1.17 .75 .90 .85 1.13 2.23 5.97 1.72 1.35 .84 1.04 .94 1.31 2.58 6.66 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 1998, BY WATER YEAR (WY) MEAN 9.94 9.27 8.12 8.68 MAX 25.3 22.2 19.7 14.7 (WY) 1991 1993 1993 1996 MIN 4.30 3.74 3.07 4.12 (WY) 1992 1998 1998 1995 5.97 4.51 4.79 5.86 5.16 7.77 9.10 21.6 8.81 5.94 9.23 12.5 8.64 16.5 17.7 76.9 1997 1998 1996 1993 1993 1991 1996 1996 3.42 2.87 2.61 2.91 2.72 4.35 4.09 4.50 1994 1994 1992 1994 1995 1994 1991 1991 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1991 - 1998 ANNUAL TOTAL 2526.0 ANNUAL MEAN 6.92 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 180 LOWEST DAILY MEAN 2.6 ANNUAL SEVEN-DAY MINIMUM 2.7 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 5010 ANNUAL RUNOFF (CFSM) 1.36 ANNUAL RUNOFF (INCHES) 18.50 10 PERCENT EXCEEDS 9.8 50 PERCENT EXCEEDS 4.7 90 PERCENT EXCEEDS 3.3 3009.7 8.25 8.39 14.5 1996 4.52 1994 Oct 14 532 Sep 22 1700 Sep 10 1996 Dec 13 2.6 Dec 13 1.3 Jul 2 1995 Dec 12 2.7 Dec 12 1.6 Jun 30 1995 1610 Sep 22 6190 Sep 10 1996 12.39 Sep 22 18.16 Sep 10 1996 5970 6080 1.62 1.65 22.04 22.45 11 12 4.0 4.5 3.0 2.8 e Estimated 258 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 259 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1991 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1991. REMARKS:-- Sediment samples were collected by a local observer on a weekly. During high flows events sediment samples were collected and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,040 mg/L September 10, 1996; Minimum daily mean, 1 mg/L severals days 1998. SEDIMENT LOADS: Maximum daily mean, 37,900 tons (34,300 tonnes) September 10, 1996; Minimum daily mean, 0.02 ton (0.01 tonne) Several years. EXTREME FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean,1,610 mg/L September 22, 1998; Minimum daily mean, 1 several days. SEDIMENT LOADS: Maximum daily mean, 2,970 tons (2,700 tonnes) September 22, 1998; Minimum daily mean, 0.02 ton (0.01 tonne) March 18-19, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e4.3 40 e.16 e4.9 13 e.19 e3.0 13 e.09 2 e4.8 15 e.18 e3.9 14 e.13 e2.9 13 e.07 3 e3.6 2 e.11 e4.6 14 e.17 e2.7 10 e.06 4 e3.6 2 e.08 e4.6 14 e.17 e2.8 11 e.07 5 e3.6 4 e.08 e4.3 8 e.16 e2.7 13 e.06 6 e4.6 8 e.18 e4.1 4 e.15 e2.7 8 e.06 7 e4.8 14 e.18 e3.9 2 e.13 e2.8 4 e.07 8 e3.9 22 e.13 e3.8 3 e.11 e2.9 2 e.07 9 e3.6 18 e.08 e3.8 8 e.11 e2.8 2 e.07 10 e3.3 12 e.10 e5.4 12 e.28 e2.8 1 e.07 11 e4.0 11 e.14 e3.8 14 e.11 e2.8 1 e.06 12 e5.2 10 e.28 e3.9 7 e.13 e2.7 2 e.06 13 e30 10 e57 e3.8 3 e.11 e2.6 2 e.06 14 e180 16 e1000 e3.7 2 e.11 e2.6 2 e.06 15 e17 29 e20 e3.8 3 e.11 e2.6 2 e.06 16 e15 24 e9.0 e3.7 3 e.11 e2.6 3 e.06 17 e16 14 e15 e3.7 4 e.11 e2.8 4 e.07 18 e11 9 e2.9 e3.6 6 e.08 e2.7 6 e.06 19 e7.8 5 e.58 e3.6 10 e.08 e2.8 8 e.07 20 e6.2 3 e.31 e3.4 5 e.09 e3.8 7 e.11 21 e5.4 5 e.28 e3.3 1 e.10 e5.0 4 e.25 22 e4.9 8 e.19 e3.2 2 e.10 e4.0 3 e.14 23 e4.6 12 e.17 e3.0 6 e.09 e3.8 5 e.11 24 e4.4 15 e.16 e3.0 16 e.09 e3.6 8 e.08 25 e4.5 15 e.17 e3.1 29 e.10 e3.4 15 e.09 26 e4.3 13 e.16 e4.2 43 e.16 e3.3 23 e.10 27 e3.8 12 e.11 e3.1 13 e.10 e3.2 8 e.10 28 e3.6 12 e.08 e2.8 2 e.07 e3.2 3 e.10 29 e3.6 12 e.08 e3.1 2 e.10 e3.2 2 e.10 30 e3.7 12 e.11 e3.1 5 e.10 e3.2 2 e.10 31 e3.6 13 e.08 e3.2 6 e.10 TOTAL 378.7 1108.08 112.2 3.65 95.2 2.63 --- --- --- --- --- --- --- --- --- --- --- --- 260 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e3.0 16 e.09 e3.5 5 e.10 4.1 7 .08 2 e3.2 15 e.10 e3.4 5 e.09 4.0 5 .05 3 e3.0 11 e.09 e3.4 3 e.09 4.7 3 .04 4 e3.1 8 e.10 e15 2 e9.0 4.2 2 .03 5 e3.4 7 e.09 e60 19 e82 6.1 14 .38 6 e14 10 e4.3 6.2 13 .24 4.8 10 .13 7 e24 17 e33 5.0 12 .17 19 88 20 8 e10 19 e2.5 30 66 44 7.1 28 .60 9 e6.0 18 e.30 13 68 3.0 4.8 17 .22 10 e5.6 12 e.28 6.4 27 .47 4.3 13 .14 11 e5.0 7 e.25 5.6 16 .25 4.0 9 .10 12 e5.0 5 e.25 5.1 5 .07 4.1 7 .08 13 e10 10 e2.5 4.8 3 .04 4.1 5 .06 14 e9.0 21 e1.7 10 34 1.6 4.2 4 .05 15 e4.5 22 e.17 6.5 25 .47 4.4 4 .04 16 e4.1 19 e.15 4.8 15 .20 4.4 3 .04 17 e4.3 35 e.16 4.7 11 .14 4.0 3 .03 18 e4.2 58 e.16 4.5 8 .10 4.1 2 .02 19 e4.6 19 e.17 4.3 6 .07 4.1 2 .02 20 e4.9 5 e.19 4.1 4 .05 8.7 27 1.1 21 e5.6 11 e.28 4.4 6 .07 5.6 19 .31 22 e5.0 3 e.25 4.2 9 .10 4.2 8 .09 23 e4.5 3 e.17 4.5 11 .14 3.8 4 .04 24 e4.2 3 e.16 4.2 7 .08 4.0 11 .13 25 e5.4 5 e.28 4.3 6 .08 6.3 17 .33 26 e4.6 6 e.17 4.4 14 .16 4.3 4 .05 27 e4.1 6 e.15 4.3 11 .13 5.0 8 .12 28 e4.0 7 e.14 4.2 9 .10 4.5 6 .07 29 e3.8 6 e.11 28 144 40 30 e3.5 5 e.10 5.8 70 1.2 31 e3.5 5 e.10 3.5 24 .23 TOTAL 179.1 48.46 234.8 143.01 184.2 65.78 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 3.3 15 .13 3.6 12 .12 3.7 11 .11 2 3.5 10 .09 4.3 14 .17 3.4 7 .07 3 3.3 7 .06 4.8 15 .25 3.5 4 .04 4 3.2 7 .06 4.6 9 .11 8.6 23 1.9 5 3.2 7 .06 4.2 5 .06 3.5 9 .08 6 3.1 8 .07 4.1 4 .05 3.4 10 .09 7 4.2 13 .22 4.2 4 .04 3.2 14 .12 8 4.1 14 .16 6.0 17 .36 3.1 17 .14 9 3.3 11 .10 4.9 17 .23 3.0 14 .11 10 3.2 9 .08 4.2 8 .09 3.0 11 .09 11 3.2 11 .09 12 3.6 13 .13 13 4.6 16 .23 14 3.3 8 .07 15 3.7 10 .17 3.6 4 .04 3.5 9 .09 3.6 4 .04 4.3 7 .09 3.6 5 .05 5.1 8 .12 14 34 4.6 4.0 10 .11 6.1 83 .49 3.7 16 .16 16 8.4 17 .87 17 4.2 14 .16 18 3.6 10 .10 19 3.5 8 .08 20 3.8 12 .12 3.4 52 .11 4.7 104 1.4 6.6 33 1.9 e5.6 401 e.28 3.3 20 .10 e4.0 245 e.14 3.1 13 .09 e3.0 41 e.09 6.7 23 1.4 e2.8 21 e.07 21 4.6 15 .28 22 3.8 12 .13 23 3.9 8 .09 24 3.6 5 .05 25 3.6 5 .05 4.4 26 .32 e4.1 17 e.15 3.1 16 .14 e4.2 13 e.16 3.1 10 .09 3.2 13 .11 3.5 6 .06 19 82 18 3.2 4 .03 4.4 25 .30 26 3.7 4 .04 27 4.2 15 .17 28 3.7 11 .11 29 3.6 8 .08 30 3.6 9 .09 31 --- --- --- 5.5 19 .40 3.0 17 .13 4.6 7 .09 3.0 13 .11 3.8 8 .09 3.3 17 .15 3.9 15 .16 3.0 22 .18 4.0 14 .15 2.7 19 .14 4.0 13 .14 --- --- --­ TOTAL 114.6 --- 4.14 142.0 --- 11.97 129.0 --- 24.73 --- --- --- --- --- --- 261 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 2.9 16 .13 2.9 9 .07 3.5 11 .10 2 11 11 4.7 3.1 11 .10 5.4 18 .39 3 5.9 10 .40 2.8 5 .04 6.0 20 .41 4 4.1 10 .17 2.7 4 .03 14 222 11 5 3.3 9 .11 2.9 3 .03 9.5 25 1.4 6 15 104 22 e3.2 3 e.10 5.3 19 .28 7 5.3 29 .45 15 30 3.3 3.6 14 .13 8 3.5 20 .19 31 26 70 9.2 58 2.7 9 3.3 15 .13 5.6 17 .33 4.3 20 .24 10 3.3 11 .10 3.3 12 .10 3.6 15 .15 11 3.5 11 .13 2.8 10 .08 3.4 11 .10 12 2.9 10 .08 3.7 9 .09 3.3 7 .06 13 3.1 9 .08 3.1 7 .06 3.8 14 .16 14 2.6 11 .08 2.9 5 .04 3.5 7 .07 15 3.0 12 .10 3.0 6 .05 4.5 14 .19 16 3.2 15 .14 3.0 7 .06 3.6 10 .10 17 3.0 24 .19 4.3 24 .41 3.6 10 .09 18 14 52 3.9 11 42 3.5 3.2 10 .09 19 3.8 20 .21 3.8 16 .18 3.4 15 .12 20 25 127 26 3.8 13 .17 5.2 41 .55 21 5.0 36 .52 12 53 2.1 139 348 794 22 3.2 19 .16 14 19 3.1 532 1610 2970 23 13 55 4.7 4.9 13 .25 e35 311 e150 24 4.3 23 .30 80 445 229 e17 53 e20 25 2.9 10 .08 60 308 82 e14 24 e4.3 26 2.8 10 .09 7.7 27 .57 e17 16 e20 27 11 43 2.6 36 387 150 e15 11 e9.0 28 5.8 23 .40 9.7 146 4.0 e15 8 e9.0 29 3.0 14 .11 5.4 65 .95 e13 7 e6.0 30 2.7 12 .09 4.3 27 .31 e11 6 e2.9 31 2.9 10 .08 3.8 12 .13 TOTAL 178.3 68.42 351.7 551.15 909.9 4003.53 YEAR 3009.7 6035.55 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) AUG 18... 1520 24... 2055 25... 1045 27... 1955 SEP 21... 1830 22... 0300 102 206 57 97 170 947 435 99 64 493 85 99 63 1390 236 99 91 274 67 98 1180 2920 9300 74 262 RIO GRANDE DE LOIZA BASIN 50055390 RIO BAIROA AT BAIROA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) AUG 24... 1640 252 2340 1590 56 71 85 SEP 21... 2210 653 1790 3160 50 63 74 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) AUG 24... 93 97 97 99 99 100 100 SEP 21... 84 91 93 98 100 100 100 263 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'28", long 66°02'13", at bridge on Highway 1, about 2.5 mi (4.0 km) upstream from Río Grande de Loíza, and 1.4 mi (2.3 km) north of Caguas plaza. DRAINAGE AREA.--5.4 mi2 (14.0 km2). PERIOD OF RECORD.--Water years 1958, 1962-66, 1973-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 21... 1115 5.4 469 7.2 26.0 1.6 4.9 61 22 18000 500 FEB 20... 0935 5.0 461 7.2 24.0 1.0 3.8 45 <10 26000 2400 MAY 26... 1100 3.2 449 7.2 28.5 2.3 2.2 28 17 67000 28000 AUG 20... 0755 4.4 389 6.9 26.0 3.8 3.5 44 <10 12000 6400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 21... 180 49 13 30 1 3.4 180 <1.0 17 39 FEB 20... -- -- -- -- -- -- 160 -- -- -­ MAY 26... 150 36 14 28 1 5.1 160 -- 14 38 AUG 20... 140 34 13 22 .8 4.8 130 <1.0 13 29 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 21... .10 33 274 3.99 5 .440 .030 .470 .110 .89 FEB 20... -- -- -- -- 3 1.46 .340 1.80 .570 .40 MAY 26... .15 28 260 2.27 11 .074 .036 .110 2.00 .50 AUG 20... .14 28 222 2.61 9 1.75 .150 1.90 .220 .40 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 264 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- CHRO­ GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL ORGANIC GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (00625) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) OCT 21... 1.0 1.5 6.5 .290 <1 <100 30 5 3 30 FEB 20... .97 2.8 12 .350 MAY 26... 2.5 2.6 12 .430 3 <100 70 <1 <1 12 AUG 20... .62 2.5 11 .440 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 21... 700 12 230 .10 <1 <1 60 <.010 2 .06 FEB 20... MAY 26... 200 <1 230 <.10 <1 <1 20 <.010 2 .91 AUG 20... 265 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR LOCATION.--Lat 18°14'02", long 65°53'07", Hydrologic Unit 21010005, on left bank, 2.43 mi (3.91 km) northeast of Plaza de Juncos, 1.3 mi (2.1 km) southeast of Escuela La Placita and 0.35 mi (0.56 km ) southwest of El Mango. DRAINAGE AREA.--22.3 mi2 (57.8 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Low-flow is affected by sewage discharges from a water treatment plant, 0.60 mi (0.96 m) upstream from gaging station since 1990. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 12 22 6.8 2 359 11 15 8.9 3 58 10 12 10 4 17 9.3 11 13 5 12 9.5 10 18 6.9 6.9 7.6 5.0 25 4.8 7.1 17 7.0 6.8 11 4.9 12 4.7 6.6 104 6.6 7.1 13 5.1 9.9 6.0 6.0 90 6.6 6.7 8.1 10 8.7 45 5.8 31 254 6.3 7.0 9.4 8.1 16 5.8 17 6 8.8 10 9.6 227 29 6.3 6.8 6.2 8.6 7.7 6.1 55 7 7.0 9.1 9.2 430 8 47 9.1 8.6 64 9 18 17 8.3 69 10 8.3 408 8.2 78 16 7.4 6.6 5.7 11 16 35 54 51 8.0 6.4 21 25 10 21 68 132 6.0 6.2 26 16 7.1 36 52 22 5.5 6.0 15 12 6.4 25 19 11 9.9 29 7.6 133 12 79 16 7.3 39 13 319 15 7.6 29 14 1680 12 6.9 24 15 95 13 7.9 16 15 4.9 6.5 8.7 8.5 6.1 9.9 12 15 5.0 7.5 6.9 48 11 9.5 9.6 13 5.1 9.9 8.5 58 5.9 7.6 13 24 5.4 8.1 22 13 5.6 6.5 77 31 7.4 7.2 14 9.1 19 6.0 128 16 74 12 7.8 14 17 61 12 12 12 18 38 12 15 11 19 30 16 11 11 20 24 11 8.2 11 15 7.8 18 15 9.4 80 30 56 14 6.0 15 20 11 19 152 19 11 5.2 8.6 9.8 17 25 29 90 10 4.5 7.4 7.1 23 59 71 108 9.6 6.0 6.9 6.5 9.8 234 76 26 21 21 11 12 10 22 19 13 10 9.4 23 16 11 34 8.5 24 15 11 16 8.3 25 14 10 9.7 7.8 9.0 7.6 7.0 12 29 83 136 2250 8.6 7.8 8.3 9.4 26 32 159 e2260 8.1 7.1 6.5 13 9.8 42 34 e93 8.0 5.5 5.8 11 7.5 115 914 e46 7.8 6.1 6.7 8.9 6.9 32 792 e35 26 14 462 8.4 7.6 27 13 43 8.0 7.5 28 12 20 7.7 7.1 29 11 21 7.2 7.1 30 11 32 6.6 7.0 31 11 --- 6.8 6.9 7.7 5.5 6.4 30 7.1 13 325 e37 7.3 7.0 6.1 99 5.8 11 125 e27 7.0 7.5 6.0 16 5.4 40 56 e34 --- 13 5.7 13 5.2 18 230 e34 --- 15 5.2 74 5.3 9.9 48 e31 --- 16 --- 84 --- 8.1 26 --­ TOTAL 3115.0 1287.0 331.6 1311.9 MEAN 100 42.9 10.7 42.3 MAX 1680 462 34 430 MIN 7.0 9.1 6.6 6.8 AC-FT 6180 2550 658 2600 CFSM 4.51 1.92 .48 1.90 IN. 5.20 2.15 .55 2.19 752.2 222.4 237.5 597.1 451.1 992.3 3396.9 5892.6 26.9 7.17 7.92 19.3 15.0 32.0 110 196 254 16 18 99 58 234 914 2260 6.6 4.5 5.2 4.9 5.2 4.7 5.8 9.6 1490 441 471 1180 895 1970 6740 11690 1.20 .32 .36 .86 .67 1.44 4.91 8.81 1.25 .37 .40 1.00 .75 1.66 5.67 9.83 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 1998, BY WATER YEAR (WY) MEAN 50.8 63.8 27.4 39.3 MAX 161 109 59.0 103 (WY) 1991 1992 1991 1996 MIN 4.01 13.6 10.7 6.34 (WY) 1993 1996 1998 1995 31.6 11.4 8.54 25.9 45.2 47.0 44.0 90.4 66.7 18.1 11.0 123 117 147 110 196 1995 1991 1993 1992 1992 1993 1998 1998 10.4 5.63 5.29 4.83 14.7 6.74 10.2 21.4 1993 1993 1995 1990 1991 1994 1993 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1990 - 1998 ANNUAL TOTAL 11223.9 ANNUAL MEAN 30.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1680 LOWEST DAILY MEAN 4.1 ANNUAL SEVEN-DAY MINIMUM 4.5 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 22260 ANNUAL RUNOFF (CFSM) 1.38 ANNUAL RUNOFF (INCHES) 18.72 10 PERCENT EXCEEDS 44 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 5.6 18587.6 50.9 41.6 52.3 1992 22.0 1994 Oct 14 2260 Sep 22 4040 Sep 10 1996 May 4 4.5 Mar 19 1.1 Oct 27 1992 Apr 30 5.3 Jun 27 1.4 Oct 22 1992 15400 Sep 21 19100 Sep 10 1996 22.72 Sep 21 24.12 Sep 10 1996 36870 30160 2.28 1.87 31.01 25.36 76 69 11 11 6.1 4.6 e Estimated 266 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 267 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR--Continued PERIOD OF RECORDS.-- Water Year 1990 to current year. WATER-QUALITY RECORDS PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: March 1990 to current year. INSTRUMENTATION.--USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,400 mg/L September 22, 1998; Minimum daily mean, 2 mg/L May 5,1997. SEDIMENT LOADS: Maximum daily mean, 51,000 tons (46,300 tonnes) September 21, 1998; Minimum daily mean, 0.05 ton (0.3 tonne) several days. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,400 mg/L September 22, 1998; Minimum daily mean, 5 mg/L April 25, 1998. SEDIMENT LOADS: Maximum daily mean, 51,000 tons (46,300 tonnes) September 21, 1998; Minimum daily mean, 0.10 ton (0.09 tonne) April 25, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 13 32 1.2 12 44 1.5 22 60 3.7 2 359 512 1260 11 53 1.6 15 57 2.3 3 58 200 42 10 59 1.6 12 57 1.9 4 17 63 2.9 9.3 65 1.6 11 72 2.1 5 12 63 2.0 9.5 76 2.0 10 88 2.4 6 8.8 62 1.5 10 88 2.5 9.6 80 2.1 7 7.0 62 1.2 9.1 70 1.7 9.2 70 1.7 8 47 170 57 9.1 45 1.1 8.6 61 1.4 9 18 64 3.6 17 56 2.8 8.3 58 1.3 10 8.3 27 .61 408 642 2710 8.2 55 1.2 11 9.9 36 1.2 29 79 6.6 7.6 53 1.1 12 79 198 139 16 58 2.5 7.3 51 1.0 13 319 275 1810 15 56 2.3 7.6 50 1.0 14 1680 1540 19700 12 32 1.1 6.9 49 .91 15 95 72 18 13 27 1.1 7.9 49 1.0 16 74 105 21 12 32 1.1 7.8 55 1.1 17 61 166 32 12 21 .69 12 60 1.9 18 38 245 25 12 13 .43 15 55 2.2 19 30 173 14 16 76 3.3 11 49 1.5 20 24 127 8.1 11 88 2.7 8.2 51 1.1 21 21 94 5.3 11 91 2.6 12 54 1.8 22 19 86 4.4 13 74 2.6 10 55 1.5 23 16 81 3.6 11 58 1.7 34 111 17 24 15 59 2.4 11 46 1.3 16 59 2.9 25 14 43 1.6 10 34 .96 9.7 30 .78 26 14 38 1.4 462 812 2320 8.4 27 .61 27 13 34 1.2 43 121 15 8.0 27 .58 28 12 26 .85 20 66 3.7 7.7 27 .55 29 11 19 .57 21 62 4.4 7.2 27 .51 30 11 15 .43 32 84 7.3 6.6 26 .43 31 11 24 .69 6.8 26 .48 TOTAL 3115.0 23162.75 1287.0 5107.78 331.6 60.05 --- --- --- --- --- --- --- --- --- --- --- --- 268 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 6.8 26 .48 6.9 43 .80 6.9 7 .13 2 8.9 26 .63 7.0 38 .71 6.8 7 .13 3 10 35 1.0 6.6 30 .54 7.1 9 .18 4 13 46 1.7 6.6 23 .41 6.7 13 .24 5 18 58 3.0 254 385 595 6.3 13 .23 6 227 522 693 29 44 3.4 6.3 12 .20 7 430 853 2420 16 52 2.3 7.4 14 .34 8 64 173 36 51 103 112 8.0 45 .98 9 69 152 52 132 354 287 6.0 41 .66 10 78 184 81 22 47 2.8 5.5 39 .58 11 133 166 144 15 44 1.9 4.9 37 .49 12 39 27 3.3 15 46 1.8 5.0 35 .48 13 29 18 1.7 13 50 1.7 5.1 33 .46 14 24 9 .56 24 81 8.5 5.4 31 .45 15 16 11 .46 31 92 8.9 7.4 29 .58 16 14 10 .38 15 47 1.9 7.8 26 .54 17 12 9 .31 14 49 1.9 6.0 19 .31 18 11 9 .26 11 58 1.7 5.2 14 .20 19 11 8 .24 10 51 1.4 4.5 11 .13 20 11 8 .24 9.6 40 1.0 6.0 8 .13 21 10 9 .24 9.0 31 .75 7.6 6 .13 22 9.4 9 .24 8.6 28 .65 7.8 7 .14 23 8.5 10 .23 8.1 27 .59 7.1 8 .15 24 8.3 11 .24 8.0 31 .68 5.5 8 .11 25 7.8 12 .25 7.8 38 .79 6.1 7 .12 26 7.6 13 .27 7.7 32 .66 5.5 8 .12 27 7.5 20 .41 7.3 23 .46 7.0 10 .19 28 7.1 35 .68 7.0 10 .19 7.5 12 .23 29 7.1 43 .82 13 12 .40 30 7.0 45 .86 15 25 2.6 31 6.9 47 .88 16 52 2.8 TOTAL 1311.9 3445.38 752.2 1040.43 222.4 14.43 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 7.6 17 .35 5.0 2 11 21 .84 4.9 3 13 29 1.0 5.1 17 .23 25 78 5.7 16 .22 12 36 1.2 15 .20 9.9 30 .80 4 8.1 18 .39 10 16 1.0 8.7 28 .65 5 7.0 18 .34 9.4 20 .79 8.1 26 .57 6 6.8 20 .36 6.2 22 .37 8.6 24 .56 7 6.6 15 .26 5.7 20 .31 11 28 1.1 8 6.4 10 .18 21 74 13 25 41 4.9 9 6.2 8 .14 26 93 8.1 16 44 1.9 10 6.0 7 .12 15 67 1.9 12 35 1.1 11 6.5 6 .11 12 7.5 5 .11 13 9.9 12 .37 14 8.1 10 .21 15 7.2 7 .13 8.7 60 .67 8.5 27 .63 6.9 54 .43 48 111 35 8.5 48 .72 58 192 43 22 43 4.1 13 49 1.7 14 38 1.7 9.1 46 1.1 16 18 45 4.7 17 15 52 2.3 18 8.6 28 .64 19 7.4 23 .47 20 6.9 20 .37 15 34 1.9 9.4 44 1.1 20 31 3.3 11 41 1.3 9.8 27 .84 17 46 2.2 7.1 25 .47 23 56 4.2 6.5 24 .42 9.8 25 .66 21 7.0 19 .35 22 8.3 18 .40 23 6.5 13 .22 24 5.8 8 .13 25 6.7 6 .10 12 31 1.0 29 74 11 9.4 13 .33 26 100 7.4 13 10 1.5 9.8 60 1.6 11 10 1.1 7.5 36 .74 8.9 10 .70 6.9 30 .56 26 6.4 8 .13 27 6.1 12 .19 28 6.0 13 .20 29 5.7 12 .19 30 5.2 14 .20 31 --- --- --- 30 61 18 7.1 28 .55 99 328 144 5.8 27 .42 16 52 2.3 5.4 25 .37 13 38 1.3 5.2 26 .37 74 188 61 5.3 28 .40 84 241 72 --- --- --­ TOTAL 237.5 --- 15.50 597.1 --- 343.90 451.1 --- 132.78 --- --- --- --- --- --- 269 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 4.8 29 .38 7.1 10 .19 17 63 3.0 2 4.7 28 .35 6.6 10 .18 104 279 160 3 6.0 25 .40 6.0 10 .16 90 227 60 4 45 161 25 5.8 10 .16 31 108 9.2 5 16 64 3.0 5.8 11 .17 17 66 3.2 6 7.7 33 .70 6.1 12 .20 55 153 44 7 16 41 2.3 35 85 32 54 168 24 8 10 18 .56 21 102 7.5 68 112 20 9 7.1 9 .18 36 101 15 52 75 11 10 6.4 8 .14 25 87 7.5 19 55 2.8 11 6.1 9 .14 9.9 32 .87 12 45 1.5 12 11 42 1.3 9.5 30 .76 9.6 37 .96 13 5.9 28 .45 7.6 27 .55 13 41 2.1 14 5.6 16 .24 6.5 25 .43 77 185 72 15 19 36 7.3 6.0 22 .36 128 296 131 16 80 186 45 30 68 24 56 85 13 17 19 30 2.0 152 415 306 19 53 2.8 18 25 41 6.2 29 85 8.9 90 277 184 19 59 160 27 71 203 136 108 170 54 20 234 568 677 76 224 59 26 85 6.1 21 83 186 56 136 159 63 2250 1850 51000 22 32 70 18 159 355 166 e2260 2400 e32000 23 42 113 18 34 156 17 e93 250 e64 24 115 161 96 914 1220 6990 e46 167 e21 25 32 11 .95 792 1430 3970 e35 112 e11 26 13 11 .39 325 656 924 e37 90 e9.1 27 11 11 .34 125 353 136 e27 89 e8.1 28 40 93 12 56 196 32 e34 88 e8.1 29 18 27 1.6 230 643 681 e34 87 e8.0 30 9.9 10 .27 48 158 21 e31 87 e7.4 31 8.1 10 .22 26 99 7.2 TOTAL 992.3 1003.41 3396.9 13607.13 5892.6 83941.36 YEAR 18587.6 131874.90 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 11... 1315 9.0 96 2.3 95 NOV 10... 0743 324 427 374 99 26... 0658 1260 1120 3810 96 DEC 10... 1200 82 51 11 92 JAN 21... 1800 10 78 2.1 71 AUG 21... 1448 176 123 58 99 22... 0731 258 488 340 99 SEP 18... 1832 217 298 175 98 19... 0511 140 11900 4500 100 270 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. SED. SED. MENT, SUSP. SUSP. SUSP. SEDI- DIS- FALL FALL FALL MENT, CHARGE, DIAM. DIAM. DIAM. SUS- SUS- % FINER % FINER % FINER PENDED PENDED THAN THAN THAN (MG/L) (T/DAY) .002 MM .004 MM .008 MM (80154) (80155) (70326) (70327) (70328) NOV 10... 0230 484 1470 1920 68 79 91 MAY 27... 0515 333 1530 1380 57 71 83 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 10... 95 96 99 100 100 100 100 MAY 27... 91 97 98 100 100 100 100 271 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR LOCATION.--Lat 18°12'58", long 65°55'34", Hydrologic Unit 21010005, on left bank at Highway 919, 0.5 mi (0.8 km) upstream from Quebrada Don Víctor, 1.7 mi (2.7 km) upstream from Río Gurabo and 1.0 mi (1.6 km) south of Juncos. DRAINAGE AREA.--16.4 mi2 (42.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1971 to current year. GAGE.--Water-stage recorder. Elevation of gage is 320 ft (98 m), from topographic map. REMARKS.--Records poor. Minor diversion from public water supply tank, 0.5 mi (0.80 km) upstream, during low flow. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges (no stages were recorded) of major floods are as follows: Sept. 6, 1960, 37,100 ft3/s (1,050 m3/s), Oct. 9, 1970, 18,200 ft3/s (515 m3/s). DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 41 e18 e35 21 2 263 e17 e29 46 3 32 e15 e19 34 4 19 e14 e17 35 5 14 e15 e16 39 13 11 24 8.7 27 7.8 8.6 18 13 10 21 8.8 15 8.2 7.7 24 12 12 15 9.1 13 8.4 7.7 51 18 11 12 25 11 77 7.2 54 234 9.8 13 19 14 21 6.8 20 6 12 e15 e15 580 7 10 e14 e14 739 8 11 e14 e14 137 9 12 e30 e13 186 10 12 e680 12 100 42 9.5 e12 8.2 19 10 e7.7 198 28 220 e11 7.4 9.9 18 8.4 58 147 69 e11 14 24 10 9.0 355 92 21 e11 18 13 13 51 80 39 14 e10 11 10 8.3 38 46 11 23 e35 12 79 12 54 e25 12 41 13 493 e24 12 43 14 2480 e19 13 46 15 151 e20 12 30 31 13 e11 8.2 8.4 7.1 12 26 29 12 e13 8.2 23 10 16 21 25 11 e17 13 13 7.2 12 78 99 19 e14 15 9.6 11 8.3 75 70 17 e12 7.3 8.2 14 8.6 157 16 113 e19 15 27 17 e77 e19 30 24 18 e56 e19 31 23 19 e42 e25 17 21 20 e33 e17 16 20 36 10 e42 7.8 14 23 9.6 82 29 10 36 7.5 11 12 37 49 21 8.7 14 6.4 e34 57 16 76 17 9.1 9.8 6.0 40 39 11 e92 15 14 12 7.4 12 298 37 53 21 e29 e17 30 19 22 e26 e20 17 20 23 e23 e17 37 21 24 e21 e17 24 20 25 e20 e16 19 20 15 11 36 7.9 32 67 90 e1410 13 11 34 5.8 43 21 107 e4680 14 9.0 15 9.7 11 17 20 e351 12 8.3 13 20 9.3 28 856 e115 11 21 12 9.4 34 19 752 e82 26 e18 e720 18 17 27 e18 e100 17 17 28 e17 e31 17 16 29 e16 e33 18 16 30 e16 e50 21 17 31 e14 --- 22 13 11 12 14 25 25 13 141 e76 11 24 13 90 10 15 72 e64 11 18 16 14 9.8 30 41 e59 --- 64 10 20 9.2 13 123 e54 --- 197 9.3 546 8.4 11 27 e49 --- 73 --- 73 --- 10 20 --­ TOTAL 4166 2075 594 2467 MEAN 134 69.2 19.2 79.6 MAX 2480 720 37 739 MIN 10 14 12 13 AC-FT 8260 4120 1180 4890 CFSM 8.19 4.22 1.17 4.85 IN. 9.45 4.71 1.35 5.60 1108 959.4 493.1 1036.8 520.8 904.0 2568.6 8553 39.6 30.9 16.4 33.4 17.4 29.2 82.9 285 234 220 42 546 43 298 856 4680 11 8.3 9.3 5.8 8.2 7.1 6.8 18 2200 1900 978 2060 1030 1790 5090 16960 2.41 1.89 1.00 2.04 1.06 1.78 5.05 17.4 2.51 2.18 1.12 2.35 1.18 2.05 5.83 19.40 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1971 - 1998, BY WATER YEAR (WY) MEAN 73.9 86.3 51.4 26.6 MAX 293 461 550 79.6 (WY) 1986 1988 1988 1998 MIN 19.9 16.8 11.0 11.4 (WY) 1993 1996 1990 1976 20.2 19.0 15.2 46.8 50.3 47.1 62.5 90.8 47.9 39.7 41.7 268 188 163 231 285 1984 1973 1985 1985 1979 1981 1979 1998 7.21 7.01 5.17 5.02 4.95 4.61 4.71 10.8 1974 1977 1995 1990 1994 1994 1994 1987 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1971 - 1998 ANNUAL TOTAL 14767.8 ANNUAL MEAN 40.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2480 LOWEST DAILY MEAN 3.9 ANNUAL SEVEN-DAY MINIMUM 4.6 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 29290 ANNUAL RUNOFF (CFSM) 2.47 ANNUAL RUNOFF (INCHES) 33.50 10 PERCENT EXCEEDS 49 50 PERCENT EXCEEDS 15 90 PERCENT EXCEEDS 6.5 25445.7 69.7 49.4 121 1988 17.1 1990 Oct 14 4680 Sep 22 9100 Dec 8 1987 Jun 18 5.8 May 22 1.4 Jul 15 1994 Jun 29 7.0 May 16 1.7 Jul 10 1994 15100 Sep 21 40000 Dec 8 1987 18.22 Sep 21 25.63 Dec 8 1987 50470 35770 4.25 3.01 57.72 40.91 85 72 18 18 9.1 7.0 e Estimated 272 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 273 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1983 to 1986 and water year 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to current year. INSTRUMENTATION.-- Automatic sediment sampler since 1984. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis. During high flow event sediment samples were collected by a local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 8,340 mg/L September 10, 1996; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 263,000 tons (238,000 tonnes) September 10,1996; Minimum daily mean, 0.01 ton (0.01 tonne) several days. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,310 mg/L September 21, 1998; Minimum daily mean, 6 mg/L March 19-21, 1998. SEDIMENT LOADS: Maximum daily mean, 65,400 tons (59,400 tonnes) October 14, 1997; Minimum daily mean, 0.15 tons (0.14 tonne) March 19, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 41 199 39 e18 208 e4.4 e35 36 e14 2 263 492 915 e17 40 e3.6 e29 47 e14 3 32 59 5.7 e15 12 e3.4 e19 62 e5.1 4 19 15 .81 e14 18 e3.2 e17 75 e3.6 5 14 10 .38 e15 29 e3.4 e16 73 e3.5 6 12 9 .29 e15 47 e3.4 e15 69 e3.4 7 10 8 .22 e14 75 e3.2 e14 52 e3.2 8 11 17 .54 e14 113 e3.2 e14 50 e3.2 9 12 76 2.2 e30 112 e15 e13 66 e2.2 10 12 68 2.4 e680 101 e5780 12 51 1.7 11 23 100 11 e35 96 e19 12 39 1.3 12 54 235 80 e25 100 e8.5 12 28 .90 13 493 2400 17200 e24 106 e8.2 12 22 .74 14 2480 4380 65400 e19 112 e5.1 13 20 .72 15 151 523 221 e20 124 e5.8 12 18 .61 16 113 300 90 e19 139 e5.1 15 25 1.2 17 e77 598 e94 e19 156 e5.1 30 95 16 18 e56 473 e80 e19 153 e5.1 31 139 18 19 e42 149 e31 e25 102 e8.5 17 108 5.1 20 e33 47 e16 e17 67 e3.6 16 92 5.6 21 e29 18 e14 e17 55 e3.6 30 160 15 22 e26 14 e8.8 e20 48 e5.8 17 66 3.1 23 e23 12 e7.9 e17 53 e3.6 37 167 26 24 e21 9 e6.8 e17 60 e3.6 24 137 8.6 25 e20 8 e5.8 e16 57 e3.5 19 78 4.0 26 e18 9 e4.4 e720 53 e7100 18 64 3.2 27 e18 9 e4.4 e100 49 e151 17 53 2.5 28 e17 10 e3.6 e31 44 e16 17 48 2.1 29 e16 16 e3.5 e33 40 e16 18 54 2.6 30 e16 217 e3.5 e50 36 e59 21 63 3.7 31 e14 861 e3.2 22 78 4.7 TOTAL 4166 84255.44 2075 13258.9 594 179.57 --- --- --- --- --- --- --- --- --- --- --- --- 274 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 21 99 5.6 13 65 2.3 11 80 2.3 2 46 133 35 13 51 1.8 10 76 2.1 3 34 130 13 12 59 2.0 12 72 2.2 4 35 62 5.7 18 101 16 11 68 2.0 5 39 48 5.1 234 3870 3290 9.8 65 1.7 6 580 3580 7320 42 268 31 9.5 61 1.6 7 739 3320 10500 28 188 14 220 1700 4690 8 137 602 243 147 1630 2230 69 590 150 9 186 710 640 92 345 117 21 87 5.3 10 100 495 151 39 154 16 14 33 1.3 11 79 358 83 31 118 10 13 37 1.3 12 41 218 24 29 94 7.4 12 45 1.5 13 43 193 30 25 84 5.6 11 53 1.6 14 46 175 33 99 1400 973 19 105 7.0 15 30 94 7.7 70 380 83 17 172 8.2 16 27 35 2.5 36 142 14 10 90 2.5 17 24 35 2.3 29 89 7.0 10 51 1.4 18 23 37 2.3 21 103 5.8 8.7 17 .41 19 21 39 2.2 17 118 5.5 9.1 6 .15 20 20 39 2.1 15 126 5.3 14 6 .23 21 19 34 1.8 15 130 5.1 11 6 .19 22 20 31 1.6 13 120 4.2 11 7 .21 23 21 37 2.1 14 110 4.1 9.0 8 .20 24 20 47 2.5 12 104 3.4 8.3 9 .21 25 20 59 3.1 11 99 2.9 21 106 7.9 26 17 75 3.4 11 94 2.9 12 78 2.5 27 17 87 3.9 11 89 2.7 24 89 12 28 16 80 3.5 11 84 2.6 18 164 5.5 29 16 77 3.2 64 1670 1120 30 17 111 6.0 197 690 778 31 13 92 3.2 73 362 89 TOTAL 2467 19141.8 1108 6864.6 959.4 6898.50 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 24 107 7.1 8.7 2 21 86 5.3 8.8 3 15 90 3.4 9.1 4 12 82 2.1 25 5 13 74 2.9 19 66 1.6 27 82 6.6 65 1.6 15 26 1.1 64 1.6 13 34 1.2 76 12 11 52 1.6 1240 69 14 81 4.0 6 e12 68 e1.7 7 e11 281 e2.1 8 e11 74 e2.1 9 e11 16 e2.1 10 e10 13 e1.7 8.2 534 12 19 77 5.5 7.4 227 4.5 9.9 22 .61 14 157 7.6 24 69 11 18 194 10 13 31 1.1 11 146 4.2 10 19 .54 11 e11 12 e2.1 12 e13 12 e2.6 13 e17 12 e3.6 14 e14 17 e3.2 15 e12 55 e2.1 8.2 88 1.9 8.4 15 .33 8.2 53 1.2 23 122 11 13 72 4.0 13 23 .89 15 77 3.8 9.6 22 .57 7.3 34 .68 8.2 38 .86 16 e42 234 e31 17 36 306 35 18 14 125 4.9 19 9.8 136 1.6 20 12 186 3.6 7.8 35 .73 14 60 3.0 7.5 35 .70 11 53 2.1 6.4 35 .61 e34 96 e18 6.0 36 .58 40 454 71 7.4 36 .93 12 113 3.7 21 36 935 429 22 34 195 21 23 15 82 3.3 24 13 77 2.7 25 12 71 2.3 7.9 36 1.0 32 87 29 5.8 29 .46 43 82 36 9.7 35 1.8 11 76 2.2 20 41 6.4 9.3 67 1.7 9.4 48 1.4 34 196 67 26 14 69 3.2 27 13 44 1.5 28 16 68 3.9 29 10 68 1.9 30 9.3 67 1.7 31 --- --- --- 25 106 14 25 566 45 90 605 173 10 236 6.6 14 438 17 9.8 155 4.1 20 377 20 9.2 105 2.6 546 1620 4240 8.4 76 1.7 73 292 61 --- --- --­ TOTAL 493.1 --- 590.7 1036.8 --- 4675.29 520.8 --- 340.60 --- --- --- --- --- --- --- 275 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 7.8 70 1.5 8.6 37 .86 18 44 2.2 2 8.2 65 1.4 7.7 19 .40 24 92 11 3 8.4 61 1.4 7.7 13 .26 51 276 39 4 77 328 97 7.2 19 .38 54 451 71 5 21 117 8.1 6.8 31 .56 20 200 11 6 10 131 1.7 e7.7 41 e.82 198 1110 1690 7 18 145 6.3 8.4 50 1.1 58 310 59 8 10 162 1.6 9.0 52 1.3 355 2800 6010 9 13 180 3.1 51 315 136 80 559 103 10 8.3 200 1.1 38 276 57 46 245 33 11 7.1 223 .81 12 39 1.2 26 63 4.6 12 10 248 1.8 16 72 3.8 21 38 2.2 13 7.2 276 .83 12 80 2.7 78 339 149 14 11 307 2.3 8.3 30 .68 75 371 84 15 14 342 6.7 8.6 14 .31 157 807 788 16 23 90 7.9 9.6 13 .32 82 246 53 17 12 78 2.1 37 172 31 49 131 17 18 57 86 94 16 154 4.1 76 352 90 19 39 95 24 11 147 1.8 e92 142 e145 20 298 1600 2620 37 140 29 53 50 7.1 21 67 152 44 90 134 145 e1410 5310 e31000 22 21 65 3.7 107 430 230 e4680 2300 e42100 23 17 51 2.4 20 126 7.1 e351 88 e119 24 28 91 14 856 2430 11800 e115 21 e5.5 25 19 84 5.5 752 1130 3700 e82 20 e4.5 26 13 78 2.5 141 770 383 e76 19 e3.7 27 15 72 3.7 72 260 78 e64 17 e2.9 28 30 66 16 41 208 25 e59 14 e2.2 29 13 61 2.7 123 166 333 e54 12 e1.8 30 11 56 1.9 27 133 11 e49 e1.7 31 10 52 1.7 20 107 5.8 TOTAL 904.0 2981.74 2568.6 16991.49 8553 82610.4 YEAR 25445.7 238789.03 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) OCT 02... 0900 926 1300 3250 95 17... 1650 77 1110 231 98 JAN 06... 1345 695 1240 2330 91 09... 1835 287 1190 922 86 FEB 05... 0330 323 9550 8330 85 05... 1245 375 1200 1220 68 08... 2215 643 2940 5100 57 14... 1745 367 8830 8750 87 MAY 30... 0600 2620 3820 27000 84 AUG 22... 0445 466 1430 1800 94 SEP 22... 0830 4530 4430 54200 80 276 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SESPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 13... 2100 302 12700 10400 34 43 55 FEB 05... 0700 437 6560 7740 39 49 63 MAR 07... 2115 519 2680 3760 52 64 79 29... 1700 233 7720 4860 14 18 26 SEP 21... 2200 5770 8930 139000 11 17 25 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 13... 68 78 86 94 99 100 100 FEB 05... 75 82 83 86 99 100 100 MAR 07... 89 95 96 98 99 100 100 29... 38 54 71 87 99 100 100 SEP 21... 32 44 56 76 91 98 99 --- --- --- --- --- --- --- 277 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR LOCATION.--Lat 18°15'30", long 65°58'05", Hydrologic Unit 21010005, on left bank, at bridge on Highway 181, 0.3 mi (0.5 km) east of Gurabo, and 4.5 mi (7.6 km) upstream from Río Grande de Loíza. DRAINAGE AREA.--60.2 mi2 (155.9 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1958 (occasional low-flow measurements only), January to September 1959 (monthly measurements only), October 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 131.58 ft (40.106 m) above mean sea level. Prior to Oct. 1, 1989 datum 5.0 ft (1.5 m) higher. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Low flow affected by diversions for water supply about, 400 ft (121 m) upstream from station by PRASA. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 41 e23 25 19 31 29 34 15 e93 24 38 53 2 514 e22 24 25 30 28 32 15 e36 23 39 90 3 102 e21 24 25 30 29 35 16 e28 23 36 122 4 46 e22 23 26 34 29 26 23 e25 82 35 89 5 34 e23 23 34 e361 35 23 29 e23 64 33 57 6 29 e28 23 e395 82 30 25 19 e24 36 35 171 7 25 e27 23 604 52 67 24 16 e27 36 123 118 8 36 e30 22 e154 e109 76 23 30 e42 46 106 262 9 49 e47 22 124 e165 35 20 56 e46 48 63 123 10 45 e424 22 130 65 30 20 37 e30 46 93 69 11 90 e39 21 e173 51 27 19 22 e23 43 47 52 12 169 e32 20 75 47 26 34 18 e38 48 47 46 13 349 e26 20 72 45 25 26 17 e155 43 45 56 14 7580 33 21 76 86 26 24 32 e43 43 38 109 15 e199 47 21 51 96 33 21 23 e29 47 36 209 16 e130 29 22 45 52 32 30 24 e28 92 36 116 17 e149 25 31 42 49 27 63 26 e35 67 150 74 18 e70 24 33 40 44 25 28 20 e49 62 83 100 19 e46 23 29 38 41 24 28 16 e62 95 61 162 20 e36 22 22 37 39 25 38 14 e40 e405 113 81 21 e31 22 32 36 37 29 69 18 e38 178 179 e1930 22 e29 22 25 35 35 26 53 16 e90 64 202 3520 23 e27 20 48 35 35 26 21 15 e43 73 84 356 24 e26 20 40 35 33 23 18 21 e36 115 e1040 211 25 e25 20 24 35 32 26 18 15 32 68 e1520 171 26 e24 e347 22 35 33 27 18 e19 51 52 552 158 27 e23 78 20 33 31 28 18 e139 30 50 148 146 28 e22 28 20 34 30 31 17 29 28 67 96 134 29 e21 25 19 33 61 18 26 26 59 319 123 30 e20 34 18 33 82 15 e122 25 44 84 117 31 e19 18 30 87 e157 40 61 TOTAL 10006 1583 757 2559 1775 1104 838 1045 1275 2183 5542 9025 MEAN 323 52.8 24.4 82.5 63.4 35.6 27.9 33.7 42.5 70.4 179 301 MAX 7580 424 48 604 361 87 69 157 155 405 1520 3520 MIN 19 20 18 19 30 23 15 14 23 23 33 46 AC-FT 19850 3140 1500 5080 3520 2190 1660 2070 2530 4330 10990 17900 CFSM 5.36 .88 .41 1.37 1.05 .59 .46 .56 .71 1.17 2.97 5.00 IN. 6.18 .98 .47 1.58 1.10 .68 .52 .65 .79 1.35 3.42 5.58 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 1998, BY WATER YEAR (WY) MEAN 214 207 144 62.1 47.6 38.6 41.0 138 127 113 163 237 MAX 1414 1045 863 204 131 97.5 108 746 468 376 610 1225 (WY) 1971 1988 1988 1992 1989 1985 1978 1985 1970 1993 1979 1960 MIN 16.0 23.7 10.7 16.4 12.6 11.2 13.1 12.7 16.8 20.7 24.8 8.76 (WY) 1968 1996 1968 1968 1968 1965 1995 1990 1972 1994 1967 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1960 - 1998 ANNUAL TOTAL 24916.4 37692 ANNUAL MEAN 68.3 103 128 HIGHEST ANNUAL MEAN 286 1979 LOWEST ANNUAL MEAN 42.2 1967 HIGHEST DAILY MEAN 7580 Oct 14 7580 Oct 14 26200 Sep 10 1996 LOWEST DAILY MEAN 9.1 Apr 26 14 May 20 3.7 May 27 1996 ANNUAL SEVEN-DAY MINIMUM 9.9 May 1 16 Apr 27 5.2 May 25 1996 INSTANTANEOUS PEAK FLOW 41500 Sep 21 62100 Sep 10 1996 INSTANTANEOUS PEAK STAGE 28.85 Sep 21 31.44 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 49420 74760 92760 ANNUAL RUNOFF (CFSM) 1.13 1.72 2.13 ANNUAL RUNOFF (INCHES) 15.40 23.29 28.90 10 PERCENT EXCEEDS 77 147 200 50 PERCENT EXCEEDS 24 35 47 90 PERCENT EXCEEDS 12 20 16 e Estimated 278 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 279 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water year 1985 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to current year. INSTRUMENTATION.-- USDH-48 and USD-77 sediment sampler, since 1984. Automatic sediment sampler, since 1984. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 9,220 mg/L Nov 27, 1987; Minimum daily mean, 3 mg/L August 09, 1994. SEDIMENT LOADS: Maximum daily mean, 686,000 tons (622,340 tonnes) Nov 27, 1987;Minimum daily mean, 0.08 tons (0.07 tonne) August 09, 1994. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,510 mg/L November 26, 1997 ; minimum daily mean, 5 mg/L December 5, 1997. SEDIMENT LOADS: Maximum daily mean, 32,300 tons (29,300 tonnes) October 14, 1997; minimum daily, 0.30 ton (0.27 tonne) December 21, 1997. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 41 67 7.3 e23 20 e1.3 25 31 2.1 2 514 353 977 e22 18 e1.1 24 21 1.3 3 102 164 29 e21 17 e.97 24 13 .85 4 46 87 10 e22 15 e.92 23 10 .60 5 34 41 3.8 e23 16 e1.0 23 7 .47 6 29 20 1.5 e28 18 e1.3 23 7 .43 7 25 12 .84 e27 19 e1.4 23 7 .43 8 36 20 3.7 e30 29 e2.9 22 7 .42 9 49 45 6.6 e47 34 e4.7 22 7 .44 10 45 19 2.3 e424 273 e542 22 8 .48 11 90 59 20 e39 117 e13 21 10 .57 12 169 157 106 e32 88 e4.2 20 13 .70 13 349 508 1630 e26 68 e4.6 20 11 .57 14 7580 990 32300 33 51 4.5 21 7 .41 15 e199 183 e105 47 51 8.6 21 5 .30 16 e130 116 e41 29 49 3.8 22 6 .37 17 e149 111 e54 25 43 2.9 31 13 1.0 18 e70 77 e15 24 37 2.4 33 17 1.9 19 e46 44 e5.5 23 33 2.1 29 22 1.8 20 e36 28 e2.7 22 34 2.0 22 11 .69 21 e31 22 e1.8 22 16 .91 32 35 3.1 22 e29 19 e1.5 22 15 .86 25 40 2.7 23 e27 21 e1.6 20 18 1.0 48 49 9.1 24 e26 24 e1.7 20 23 1.2 40 68 7.5 25 e25 16 e1.1 20 25 1.3 24 55 3.6 26 e24 10 e.65 e347 1510 e1700 22 44 2.5 27 e23 7 e.42 78 94 26 20 32 1.7 28 e22 11 e.63 28 48 3.6 20 23 1.2 29 e21 19 e1.1 25 36 2.4 19 20 1.1 30 e20 21 e1.1 34 39 3.8 18 19 .93 31 e19 22 e1.1 18 17 .85 TOTAL 10006 35333.94 1583 2346.76 757 50.11 --- --- --- --- --- --- --- --- --- --- --- --- 280 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 19 15 .80 31 14 1.2 29 7 .56 2 25 16 1.1 30 19 1.5 28 7 .53 3 25 18 1.2 30 12 .96 29 7 .58 4 26 19 1.4 34 21 3.3 29 8 .62 5 34 21 1.9 e361 253 e192 35 26 3.2 6 e395 244 e471 82 126 28 30 34 2.8 7 604 438 1080 52 72 10 67 67 26 8 e154 133 e58 e109 80 e63 76 75 19 9 124 133 42 e165 147 e67 35 36 3.4 10 130 219 41 65 59 10 30 25 2.1 11 e173 223 e76 51 34 4.8 27 17 1.3 12 75 152 31 47 22 2.7 26 12 .85 13 72 79 16 45 14 1.7 25 9 .64 14 76 75 16 86 59 26 26 10 .69 15 51 42 5.8 96 95 27 33 10 .86 16 45 24 2.9 52 50 7.1 32 9 .80 17 42 15 1.7 49 29 3.9 27 9 .66 18 40 12 1.3 44 18 2.1 25 9 .61 19 38 14 1.5 41 24 2.6 24 9 .61 20 37 17 1.7 39 37 3.9 25 10 .66 21 36 18 1.8 37 25 2.5 29 9 .74 22 35 18 1.7 35 13 1.2 26 9 .60 23 35 18 1.7 35 8 .72 26 9 .61 24 35 18 1.7 33 9 .77 23 12 .76 25 35 18 1.7 32 10 .82 26 18 1.3 26 35 17 1.5 33 8 .74 27 17 1.3 27 33 11 1.0 31 7 .61 28 18 1.4 28 34 8 .69 30 7 .57 31 31 2.6 29 33 7 .63 61 56 13 30 33 7 .65 82 87 26 31 30 10 .80 87 97 26 TOTAL 2559 1866.17 1775 466.69 1104 140.78 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 34 69 6.3 15 2 32 45 3.8 15 3 35 24 2.3 16 4 26 16 1.1 23 5 23 13 .82 29 10 .40 e93 54 e18 11 .44 e36 26 e2.5 13 .54 e28 25 e1.9 24 1.7 e25 23 e1.6 32 2.5 e23 22 e1.3 6 25 12 .77 7 24 14 .89 8 23 17 1.0 9 20 12 .66 10 20 8 .42 19 19 .95 e24 21 e1.3 16 17 .76 e27 19 e1.4 30 32 3.6 e42 18 e2.1 56 58 9.4 e46 17 e2.1 37 49 5.1 e30 16 e1.3 11 19 12 .61 12 34 32 2.9 13 26 19 1.3 14 24 15 .93 15 21 13 .74 22 39 2.3 e23 16 e1.1 18 36 1.8 e38 26 e3.4 17 32 1.5 e155 128 e63 32 37 3.3 e43 43 e5.2 23 30 1.9 e29 24 e1.9 16 30 26 3.0 24 17 63 67 11 26 18 28 38 3.0 20 19 28 36 2.7 16 20 38 46 4.9 14 25 1.7 e28 29 e2.2 31 2.2 e35 37 e3.5 34 1.8 e49 56 e7.6 29 1.3 e62 106 e20 25 .96 e40 54 e6.1 21 69 65 22 18 22 53 66 11 16 23 21 47 2.7 15 24 18 42 2.0 21 25 18 33 1.6 15 22 1.0 e38 42 e5.5 19 .81 e90 99 e25 18 .72 e43 60 e7.0 25 1.4 e36 69 e6.6 15 .63 32 66 5.7 26 18 25 1.2 27 18 20 .95 28 17 18 .87 29 18 17 .82 30 15 13 .53 31 --- --- --- e19 49 e2.2 51 59 8.8 e139 264 e53 30 26 2.1 29 82 2.8 28 22 1.6 26 31 2.3 26 20 1.4 e122 102 e48 25 18 1.2 e157 133 e66 --- --- --­ TOTAL 838 --- 92.81 1045 --- 223.01 1275 --- 212.4 --- --- --- --- --- --- 281 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 24 18 1.1 38 19 2.0 53 51 7.3 2 23 22 1.4 39 30 3.4 90 99 29 3 23 26 1.6 36 43 4.1 122 287 36 4 82 77 22 35 29 2.7 89 209 51 5 64 77 14 33 20 1.8 57 89 14 6 36 44 4.4 35 19 1.8 171 157 150 7 36 40 3.9 123 88 74 118 139 49 8 46 26 3.2 106 97 29 262 257 289 9 48 20 2.6 63 66 11 123 129 48 10 46 18 2.2 93 85 24 69 56 11 11 43 19 2.2 47 43 5.5 52 36 5.1 12 48 22 2.8 47 32 4.0 46 25 3.1 13 43 24 2.8 45 28 3.4 56 40 9.0 14 43 26 3.0 38 26 2.7 109 148 45 15 47 31 4.0 36 27 2.7 209 172 135 16 92 87 22 36 29 2.8 116 133 43 17 67 67 12 150 118 73 74 105 21 18 62 62 11 83 84 20 100 99 40 19 95 127 33 61 65 13 162 138 64 20 e405 752 e1820 113 108 34 81 87 19 21 178 309 206 179 191 107 e1930 679 e12000 22 64 66 11 202 160 104 3520 1030 10500 23 73 55 11 84 82 19 356 421 435 24 115 110 39 e1040 466 e2580 211 102 60 25 68 65 12 e1520 714 e3630 171 25 11 26 52 47 6.6 552 401 883 158 17 7.1 27 50 34 4.5 148 145 61 146 15 6.0 28 67 51 10 96 126 33 134 13 4.8 29 59 62 10 319 231 357 123 9 2.9 30 44 49 5.9 84 116 27 117 6 1.8 31 40 30 3.3 61 73 12 TOTAL 2183 2288.5 5542 8127.9 9025 24097.1 YEAR 37692 75246.17 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 13... 1500 155 221 92 98 14... 0400 31300 1660 140000 96 14... 1115 2320 709 4440 96 17... 1845 504 210 286 98 NOV 26... 0945 454 1170 1430 90 26... 1500 380 393 403 99 26... 1915 392 2070 2190 88 MAY 27... 1445 110 432 128 98 JUL 20... 1700 992 3140 8410 98 21... 0100 516 928 1290 98 282 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 12... 2100 516 465 648 45 53 63 14... 1040 3240 1240 10800 49 59 68 NOV 26... 0600 888 5500 13200 39 48 59 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 12... 72 80 85 95 99 100 100 14... 77 84 87 95 99 100 100 NOV 26... 70 80 84 94 98 99 100 -- 283 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'56", long 65°59'04", at bridge on Highway 941, 1.2 mi (1.9 km) west-northwest from gaging station 50057000, and 1.0 mi (1.6 km) northwest of Gurabo plaza. DRAINAGE AREA.--62.8 mi2 (162.7 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 15... 1150 200 6.6 26.0 88 5.7 69 23 46000 K14000 FEB 18... 0855 19 341 7.1 26.0 10 4.4 55 <10 2000 380 MAY 26... 0945 6.9 391 7.0 30.0 10 5.3 70 <10 2100 K120 AUG 17... 0745 90 399 6.5 29.0 25 4.2 55 <10 4900 K1900 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 15... 58 14 5.8 14 .8 3.5 56 <0.5 11 15 FEB 18... -- -- -- -- -- -- 130 -- -- -­ MAY 26... 120 27 13 32 1 3.9 130 -- 15 35 AUG 17... 130 29 13 28 1 5.0 140 <1.0 16 31 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 15... .12 20 116 -- 108 .770 .060 .830 .130 .35 FEB 18... -- -- -- -- 7 1.03 .068 1.10 .200 .47 MAY 26... .17 32 236 4.40 22 .691 .059 .750 .050 .82 AUG 17... .14 34 240 58.4 46 .758 .062 .820 .190 .68 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 15... .48 1.3 5.8 .040 <1 <100 30 <1 3 <10 FEB 18... .67 1.8 7.8 .220 -- -- -- -- -- -­ MAY 26... .87 1.6 7.2 .130 1 <100 50 <1 <1 <10 AUG 17... .87 1.7 7.5 .620 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 284 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 15... 4300 2 350 <.10 <1 <1 30 <.010 <1 .05 FEB 18... MAY 26... 530 <1 520 <.10 <1 <1 <10 <.010 <1 .04 AUG 17... 285 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT RIO CAÑAS, PR LOCATION.--Lat 18°17'41", long 66°02'44", Hydrologic Unit 21010005, at right bank, off road 798, upstream side of bridge on Highway 52, 0.5 mi (0.8 km ) northeast from Escuela Segunda Unidad de Francisco Valdés, and 0.8 mi (1.3 km) north of La Barra. DRAINAGE AREA.--7.53 mi2 (19.50 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.2 6.6 9.5 11 4.1 5.2 3.7 2.6 3.7 e3.0 4.0 5.8 2 12 6.6 9.5 7.0 4.2 4.9 3.6 2.5 3.8 e3.8 3.9 7.1 3 4.3 6.5 9.3 7.0 4.1 5.3 3.4 2.6 3.7 e6.2 3.9 7.3 4 3.2 6.7 10 7.1 60 5.3 3.4 2.5 4.6 e5.0 3.7 9.8 5 3.0 6.7 9.7 7.7 79 5.7 3.3 2.4 10 e3.7 3.7 7.5 6 20 6.2 9.5 29 8.9 5.1 3.3 2.3 4.1 e27 e4.4 8.8 7 5.3 5.8 9.8 29 8.3 8.1 5.0 2.2 3.7 e9.5 51 6.4 8 7.2 5.3 9.4 10 33 6.2 4.0 4.4 3.6 e4.3 7.5 7.3 9 4.3 5.2 9.2 9.9 16 4.9 3.3 3.0 7.4 e3.6 4.5 5.3 10 3.5 7.1 8.8 9.2 9.4 4.8 3.2 2.7 4.1 e3.9 4.1 4.8 11 6.2 5.3 8.5 8.7 12 30 5.6 8.2 8.1 13 42 4.9 8.1 21 14 227 4.8 8.4 13 15 20 75 9.2 7.2 8.8 4.6 3.2 2.6 3.6 e3.5 3.9 4.4 7.9 4.5 5.9 2.5 3.4 e3.3 3.9 4.3 7.2 4.3 4.7 2.4 3.4 e3.1 3.7 5.3 15 11 3.8 41 3.3 e2.8 3.6 4.2 10 4.4 3.9 6.8 3.3 e2.8 3.6 7.1 16 18 17 8.9 7.2 17 15 10 8.7 8.5 18 14 9.7 8.0 6.5 19 13 11 8.0 5.9 20 11 9.9 8.0 5.3 7.7 3.7 12 4.5 3.1 e3.6 3.4 4.7 7.2 4.1 4.0 4.3 55 e4.3 7.8 4.5 6.2 4.0 3.6 4.2 9.8 e3.9 35 5.5 5.9 3.6 3.3 4.4 6.3 e4.6 5.8 4.5 5.6 3.8 3.3 4.3 5.8 e28 5.0 5.7 21 9.1 9.9 8.6 5.3 22 8.1 10 7.7 5.2 23 7.6 10 7.4 4.9 24 7.3 9.7 7.2 4.9 25 9.4 9.5 7.0 5.0 5.5 4.2 3.2 4.2 13 e11 12 264 5.5 3.5 3.1 4.1 e6.8 5.4 10 1060 5.3 3.4 3.0 4.0 e4.4 9.4 5.4 172 5.3 3.5 2.8 4.5 e4.4 7.9 51 86 5.2 3.8 2.9 4.3 e6.8 4.9 52 77 26 8.0 11 7.0 4.7 27 7.5 10 7.0 4.5 28 7.2 10 7.2 4.3 29 6.7 9.9 7.7 4.1 30 7.0 9.5 7.4 4.0 31 6.6 --- 7.9 4.1 5.5 3.4 3.0 4.2 e3.7 4.4 7.2 115 5.3 3.4 3.4 4.3 e3.4 5.5 21 83 5.2 3.6 3.0 4.3 e3.5 7.9 166 57 --- 16 2.7 4.1 e3.3 4.6 15 57 --- 5.1 2.7 4.2 e3.4 4.4 8.0 49 --- 4.9 --- 3.9 --- 4.3 e6.5 --­ TOTAL 550.7 315.4 260.8 269.3 MEAN 17.8 10.5 8.41 8.69 MAX 227 75 10 29 MIN 3.0 4.8 7.0 4.0 AC-FT 1090 626 517 534 CFSM 2.36 1.40 1.12 1.15 IN. 2.72 1.56 1.29 1.33 351.3 158.3 113.7 150.3 198.4 199.6 520.5 2140.3 12.5 5.11 3.79 4.85 6.61 6.44 16.8 71.3 79 16 12 41 55 28 166 1060 4.1 3.4 2.7 2.2 3.1 2.8 3.4 4.2 697 314 226 298 394 396 1030 4250 1.67 .68 .50 .64 .88 .86 2.23 9.47 1.74 .78 .56 .74 .98 .99 2.57 10.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 1998, BY WATER YEAR (WY) MEAN 15.4 13.6 11.3 11.3 MAX 39.4 36.2 29.9 24.5 (WY) 1991 1993 1993 1992 MIN 4.60 7.18 5.55 4.48 (WY) 1992 1991 1994 1994 10.3 5.24 5.37 8.26 7.49 8.42 15.7 27.8 18.8 7.97 11.1 19.5 20.0 24.9 36.8 81.6 1995 1997 1993 1992 1993 1993 1996 1996 4.29 2.48 3.24 2.50 1.78 3.40 4.36 4.25 1994 1994 1995 1994 1994 1990 1990 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1990 - 1998 ANNUAL TOTAL 3335.6 ANNUAL MEAN 9.14 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 382 LOWEST DAILY MEAN 2.3 ANNUAL SEVEN-DAY MINIMUM 2.5 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 6620 ANNUAL RUNOFF (CFSM) 1.21 ANNUAL RUNOFF (INCHES) 16.48 10 PERCENT EXCEEDS 12 50 PERCENT EXCEEDS 6.4 90 PERCENT EXCEEDS 3.1 5228.6 14.3 12.2 17.7 1996 5.77 1994 Aug 22 1060 Sep 22 1670 Sep 10 1996 Jun 28 2.2 May 7 1.1 Jun 8 1994 Jun 12 2.4 May 1 1.2 Jun 8 1994 2490 Sep 22 7500 Sep 10 1996 18.19 Sep 22 24.60 Sep 10 1996 2.2 May 6 1.0 Jun 21 1994 10370 8820 1.90 1.62 25.83 21.97 15 18 5.5 5.1 3.3 2.7 e Estimated 286 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT RIO CAÑAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 287 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT CAÑAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1990 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1994 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1990. REMARKS:-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 12,9000 mg/L September 10, 1996; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 95,000 tons (86,200 tonnes) September 10, 1996; Minimum daily mean, 0.01 ton (0.01 tonne) January 08, 1995. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,560 mg/L September 22, 1998; Minimum daily mean, 2 mg/L December 26, 1997. SEDIMENT LOADS: Maximum daily mean, 12,000 tons (10,900 tonnes) September 22, 1998;Minimum daily mean, 0.02 ton (0.02 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 7.2 203 17 6.6 36 .63 9.5 34 .87 2 12 238 20 6.6 29 .51 9.5 17 .43 3 4.3 47 .56 6.5 23 .41 9.3 7 .19 4 3.2 26 .23 6.7 19 .34 10 6 .17 5 3.0 19 .16 6.7 17 .30 9.7 7 .18 6 20 957 408 6.2 15 .26 9.5 6 .14 7 5.3 39 .58 5.8 14 .22 9.8 4 .11 8 7.2 296 24 5.3 17 .24 9.4 3 .08 9 4.3 28 .33 5.2 41 .57 9.2 3 .07 10 3.5 13 .13 7.1 58 1.2 8.8 3 .07 11 6.2 47 1.3 5.3 19 .28 8.5 5 .12 12 30 519 283 5.6 48 .81 8.2 10 .22 13 42 400 725 4.9 71 .95 8.1 9 .20 14 227 1690 3260 4.8 48 .62 8.4 6 .14 15 20 102 5.8 75 2230 2050 9.2 4 .11 16 18 54 2.6 17 341 43 8.9 6 .14 17 15 52 2.1 10 91 2.5 8.7 8 .19 18 14 54 2.1 9.7 70 1.8 8.0 6 .14 19 13 57 2.0 11 127 4.5 8.0 4 .10 20 11 60 1.8 9.9 36 .97 8.0 4 .09 21 9.1 47 1.2 9.9 28 .76 8.6 5 .11 22 8.1 33 .72 10 31 .87 7.7 6 .11 23 7.6 18 .38 10 33 .93 7.4 6 .12 24 7.3 10 .19 9.7 34 .88 7.2 7 .13 25 9.4 56 2.4 9.5 26 .65 7.0 4 .07 26 8.0 68 1.5 11 18 .51 7.0 2 .04 27 7.5 36 .71 10 14 .37 7.0 3 .06 28 7.2 10 .19 10 47 1.4 7.2 5 .10 29 6.7 13 .23 9.9 73 1.9 7.7 9 .19 30 7.0 22 .41 9.5 50 1.3 7.4 16 .32 31 6.6 36 .65 7.9 17 .35 TOTAL 550.7 4765.27 315.4 2119.68 260.8 5.36 --- --- --- --- --- --- --- --- --- 288 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT CAÑAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 11 80 3.1 4.1 5 .05 5.2 8 .11 2 7.0 67 1.3 4.2 5 .06 4.9 8 .10 3 7.0 38 .72 4.1 4 .04 5.3 5 .08 4 7.1 24 .47 60 1140 2270 5.3 3 .05 5 7.7 16 .33 79 1600 1130 5.7 6 .78 6 29 551 105 8.9 7 29 905 98 8.3 8 10 97 2.8 33 44 1.1 5.1 10 .14 23 .53 8.1 40 3.2 489 165 6.2 46 .83 9 9.9 30 3.2 16 168 9.0 4.9 13 .18 10 9.2 10 .25 9.4 28 .72 4.8 5 .06 11 8.7 10 .23 12 8.1 10 .22 13 21 88 30 14 13 90 3.8 15 7.2 17 .34 8.8 9 .20 4.6 4 .05 7.9 12 .25 4.5 4 .05 7.2 25 .49 4.3 4 .05 15 25 13 11 193 29 10 19 .53 4.4 26 .32 16 7.2 10 .20 17 8.5 169 11 18 6.5 24 .42 19 5.9 14 .22 20 5.3 10 .14 7.7 16 .34 3.7 11 .11 7.2 10 .19 4.1 9 .09 6.2 6 .09 4.0 8 .09 5.9 4 .06 3.6 8 .08 5.6 3 .05 3.8 9 .09 21 5.3 9 .13 22 5.2 4 .05 23 4.9 5 .06 24 4.9 8 .10 25 5.0 12 .17 5.5 3 .05 4.2 9 .10 5.5 3 .04 3.5 9 .09 5.3 3 .04 3.4 9 .08 5.3 3 .04 3.5 9 .08 5.2 3 .05 3.8 8 .08 26 4.7 20 .25 27 4.5 29 .35 28 4.3 38 .44 29 4.1 16 .18 30 4.0 4 .05 31 4.1 4 .04 5.5 5 .07 3.4 8 .07 5.3 6 .09 3.4 7 .06 5.2 7 .10 3.6 6 .06 --- --- --- 16 27 28 --- --- --- 5.1 53 .75 --- --- --- 4.9 20 .56 TOTAL 269.3 --- 263.56 351.3 --- 3592.18 158.3 --- 65.39 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 3.7 11 .10 2.6 3 .02 3.7 3 .03 2 3.6 9 .09 2.5 5 .03 3.8 6 .06 3 3.4 8 .08 2.6 9 .06 3.7 10 .10 4 3.4 8 .07 2.5 13 .09 4.6 28 .45 5 3.3 7 .07 2.4 7 .05 10 268 33 6 3.3 7 .06 2.3 4 .02 4.1 48 .54 7 5.0 25 1.1 2.2 3 .02 3.7 19 .19 8 4.0 22 .26 4.4 285 2.0 3.6 9 .08 9 3.3 13 .11 3.0 16 .13 7.4 17 2.4 10 3.2 12 .10 2.7 7 .05 4.1 28 .31 11 3.2 11 .09 2.6 3 .02 3.6 25 .24 12 5.9 33 2.6 2.5 3 .02 3.4 23 .22 13 4.7 32 .44 2.4 4 .03 3.4 23 .21 14 3.8 10 .10 41 1510 1320 3.3 22 .20 15 3.9 10 .21 6.8 103 2.2 3.3 22 .19 16 12 104 10 4.5 54 .65 3.1 21 .18 17 4.0 30 .33 4.3 45 .52 55 1450 1040 18 3.6 19 .19 4.2 37 .42 9.8 112 3.2 19 3.3 12 .11 4.4 34 .44 6.3 43 .74 20 3.3 15 .13 4.3 19 .23 5.8 33 .51 21 3.2 19 .16 4.2 12 .13 13 50 9.6 22 3.1 17 .14 4.1 11 .12 e6.8 48 e.95 23 3.0 11 .09 4.0 11 .12 e4.4 15 e.18 24 2.8 7 .05 4.5 22 .33 e4.4 13 e.19 25 2.9 7 .05 4.3 40 .46 e6.8 25 e.72 26 3.0 7 .06 4.2 22 .25 e3.7 10 e.10 27 3.4 8 .07 4.3 14 .16 e3.4 9 e.08 28 3.0 6 .05 4.3 9 .10 e3.5 6 e.06 29 2.7 5 .04 4.1 6 .06 e3.3 4 e.04 30 2.7 4 .03 4.2 4 .05 e3.4 5 e.04 31 3.9 4 .04 TOTAL 113.7 16.98 150.3 1328.82 198.4 1094.81 --- --- --- --- --- --- 289 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT CAÑAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 e3.0 6 e.05 4.0 5 .06 5.8 21 .32 2 e3.8 4 e.04 3.9 5 .05 7.1 67 1.9 3 e6.2 3 e.05 3.9 5 .05 7.3 76 1.4 4 e5.0 4 e.05 3.7 4 .04 9.8 150 2.7 5 e3.7 5 e5.0 3.7 3 .03 7.5 123 1.4 6 e27 341 e83 e4.4 3 e.04 8.8 79 3.1 7 e9.5 120 e4.1 51 731 574 6.4 55 .98 8 e4.3 25 e.29 7.5 74 2.1 7.3 69 1.5 9 e3.6 26 e.25 4.5 29 .37 5.3 24 .34 10 e3.9 29 e.30 4.1 7 .08 4.8 8 .10 11 e3.5 32 e.30 3.9 7 .07 4.4 8 .10 12 e3.3 35 e.31 3.9 7 .08 4.3 11 .13 13 e3.1 36 e.30 3.7 8 .08 5.3 32 .66 14 e2.8 31 e.23 3.6 9 .09 4.2 13 .15 15 e2.8 25 e.19 3.6 9 .09 7.1 53 2.0 16 e3.6 23 e.23 3.4 9 .08 4.7 23 .29 17 e4.3 22 e.26 7.8 16 3.0 4.5 16 .19 18 e3.9 21 e.22 35 509 351 5.5 19 .77 19 e4.6 20 e.26 5.8 31 .56 4.5 28 .39 20 e28 137 e169 5.0 24 .45 5.7 43 .88 21 e11 106 e6.3 12 182 6.5 264 1120 4190 22 5.4 28 .41 10 81 4.6 1060 3560 12000 23 9.4 580 3.6 5.4 264 .65 172 1070 611 24 7.9 192 1.8 51 862 279 86 143 34 25 4.9 34 .45 52 904 286 77 20 4.2 26 4.4 31 .36 7.2 39 .83 115 1330 1390 27 5.5 25 .68 21 295 51 83 936 279 28 7.9 69 2.3 166 1750 3480 57 34 5.2 29 4.6 26 .33 15 177 7.6 57 312 63 30 4.4 14 .16 8.0 56 1.2 49 24 3.2 31 4.3 8 .09 e6.5 24 .42 TOTAL 199.6 280.91 520.5 5050.12 2140.3 18598.90 YEAR 5228.6 37181.98 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) FEB 05... 0318 261 5770 4070 82 JUL 23... 1530 18 1500 73 98 AUG 28... 1810 180 4280 2080 88 SEP 22... 0200 1640 3820 16900 72 290 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT CAÑAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 06... 1630 240 12700 8230 24 37 52 12... 1415 370 9270 9260 35 45 57 FEB 04... 2248 666 10200 18300 26 34 45 MAY 14... 2049 170 10100 4640 43 56 72 JUN 17... 1858 265 7420 5310 39 50 63 AUG 28... 1600 1460 9720 38300 38 48 61 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 06... 65 80 87 96 99 100 100 12... 68 77 79 88 96 99 100 FEB 04... 56 64 68 79 88 95 99 MAY 14... 85 93 97 99 100 100 100 JUN 17... 76 86 90 96 99 100 100 AUG 28... 72 81 83 91 96 99 100 --- --- --- --- --- --- --- --- --- --- --- --- --- 291 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR LOCATION.--Lat 18°19'49", long 66°01'00", Hydrologic Unit 21010005, at pumpsite at damsite, and 1.9 mi (3.1 km) south of Trujillo Alto plaza. DRANAIGE AREA.--208 mi2 (539 km2). ELEVATION RECORDS PERIOD OF RECORD.--December 1987 to current year. Prior to October 1994, published as Lago Loíza at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lake is formed by Loíza Dam, a concrete structure completed in 1954. Useable capacity of impoundment is 30,000 acre-ft (37.0 hm3). Out flow from lake is controlled by five slide gates in powerplant and pump intake structure, four sluicegates, and concrete spillway with eight radial gates. Lake is used for municipal water supply and intermittent power generation. Gage-height satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 147.42 ft (44.93 m), Sept. 18, 1989; minimum elevation, 108.52 ft (33.08 m), July 18, 1994. EXTREMES FOR CURRENT YEAR.--Maximum elevation 136.59 ft (41.63 m), Oct. 13; minimum elevation, 124.12 ft (37.83 m), Sept. 22. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents in acre-feet Elevation, in feet Contents in acre-feet 98.4 5,000 111.5 8,900 120.4 13,000 128.6 18,000 137.8 26,000 147.6 35,000 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 134.70 134.21 134.75 130.82 133.04 133.83 134.94 134.08 134.70 127.64 131.54 132.23 2 134.41 134.20 134.70 130.76 132.81 133.67 134.67 133.92 134.61 127.37 131.33 131.60 3 134.82 134.16 134.59 130.71 132.62 133.54 A 133.80 134.51 127.14 131.08 132.34 4 134.89 134.13 134.46 130.80 133.35 133.43 134.53 133.75 126.68 127.54 130.81 132.13 5 134.86 134.12 134.35 130.95 134.78 133.96 134.52 133.68 126.62 127.71 130.54 132.41 6 134.80 134.09 134.23 134.52 134.81 133.92 134.49 133.54 126.73 127.81 A 131.66 7 134.71 134.02 134.10 134.86 134.94 134.69 134.59 133.42 126.60 127.54 132.34 132.62 8 134.79 133.94 133.96 134.77 134.98 134.97 134.61 134.12 126.48 127.28 132.54 132.52 9 134.79 133.90 133.81 134.51 134.97 134.80 134.53 134.50 126.50 127.04 132.90 132.27 10 134.71 134.32 133.67 134.51 134.89 134.82 134.43 134.53 126.37 126.82 132.72 132.05 11 134.54 134.52 133.51 134.80 134.65 134.80 134.34 134.41 126.17 126.54 132.80 132.27 12 134.57 134.50 133.36 134.72 134.70 134.77 134.84 134.22 126.26 126.23 132.72 132.47 13 136.34 134.48 133.20 134.36 134.69 134.70 134.75 134.07 126.76 125.91 132.58 132.04 14 134.64 134.38 133.07 134.61 134.55 134.72 134.71 134.52 126.63 125.59 132.38 132.55 15 134.55 134.86 132.91 134.75 134.92 134.73 134.66 134.67 126.39 125.31 132.19 132.79 16 134.93 134.27 132.79 134.83 134.79 134.68 134.84 134.62 126.17 125.62 132.00 132.41 17 134.10 134.27 132.82 134.88 134.87 134.60 134.84 134.63 128.66 125.87 132.91 131.78 18 134.64 134.28 132.76 134.90 134.86 134.50 135.03 134.51 128.84 126.51 132.60 132.18 19 134.47 134.23 132.66 134.84 134.81 134.40 134.79 134.36 128.85 127.06 132.58 131.91 20 134.77 134.21 132.51 134.74 134.76 134.45 134.73 134.23 128.70 130.19 132.85 132.29 21 134.46 134.18 132.49 134.69 134.72 134.82 134.79 134.12 128.89 131.49 132.42 125.52 22 134.51 134.40 132.39 134.60 134.62 134.91 134.90 133.92 129.21 131.51 132.39 130.16 23 134.48 134.62 132.36 134.45 134.52 134.90 134.87 133.73 129.14 131.62 132.53 131.84 24 134.45 134.64 132.31 134.31 134.42 134.82 134.79 133.58 129.16 131.93 132.34 132.69 25 134.39 134.63 132.14 134.18 134.29 134.81 134.73 133.38 129.02 131.94 132.81 132.85 26 134.31 134.20 131.96 134.04 134.20 134.79 134.66 133.45 128.89 131.79 132.89 132.75 27 134.19 134.59 131.76 133.88 134.08 134.86 134.59 134.34 128.65 131.89 132.13 132.48 28 134.16 134.64 131.56 133.71 133.97 134.87 134.51 134.31 128.45 132.12 131.98 132.37 29 134.17 134.66 A 133.60 134.87 134.39 134.26 128.21 132.12 132.37 131.97 30 134.18 134.72 131.13 133.46 134.92 134.24 134.91 127.94 131.96 132.78 132.52 31 134.17 130.95 133.25 134.81 134.70 131.76 132.43 MAX 136.34 134.86 134.90 134.98 134.97 134.91 134.70 132.12 132.85 MIN 134.10 133.90 130.71 132.62 133.43 133.38 126.17 125.31 125.52 A No gage-height record 292 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18019'49", long 66001'00", at pumphouse at damsite, and 1.9 mi (3.1 km) south of Tru­ jillo Alto plaza. DRAINAGE AREA.--208 mi2 (539 km2). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI- ANC SPE- WATER DIS- DEMAND, FORM, STREP- WATER CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI UNFLTRD CON- FIELD TEMPER- OXYGEN, (PER- ICAL 0.45 FECAL, FET DUCT- (STAND- ATURE DIS- CENT (HIGH UM-MF (COLS. FIELD DATE TIME ANCE ARD WATER SOLVED SATUR- LEVEL) (COLS./ PER MG/L AS (US/CM) UNITS) (DEG C) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3 (00095) (00400) (00010) (00300) (00301) (00340) (31616) (31679) (00410) NOV 03... 1130 266 7.2 28.0 6.0 76 <10 46 500 80 FEB 18... 1045 204 6.6 25.5 1.1 14 10 110 84 62 JUN 10... 0915 298 7.3 28.1 4.8 61 20 60 21 98 AUG 20... 0905 292 6.3 29.5 .22 3 10 56 43 100 RESIDUE NITRO­ TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO­ SULFIDE DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, TOTAL SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS S) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) (00745) (00530) (00620) (00615) (00630) (00610) (00605) (00625) (00600) (71887) NOV 03... <.5 3 .348 .032 .380 .020 .26 .28 .66 2.9 FEB 18... -- 44 .300 .110 .410 .060 .44 .50 .91 4.0 JUN 10... <.5 7 -- <.010 <.020 .200 .52 .72 -- -­ AUG 20... -- 46 -- <.010 .040 .220 .56 .78 .82 3.6 MANGA- METHY­ BORON, COPPER, IRON, NESE, ZINC, LENE PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL BLUE PHORUS RECOV- RECOV- RECOV- RECOV- RECOV- CYANIDE ACTIVE TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS P) AS B) AS CU) AS FE) AS MN) AS ZN) AS CN) (UG/L) (MG/L) (00665) (01022) (01042) (01045) (01055) (01092) (00720) (32730) (38260) NOV 03... .020 30 10 100 70 350 <.01 <1 .08 FEB 18... .200 -- -- -- -- -- -- -- -­ JUN 10... .120 60 <10 2100 410 20 <.01 <1 <.02 AUG 20... .210 -- -- -- -- -- -- -- -­ 293 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE, PR LOCATION.--Lat 18°20'33", long 66°00'20", Hydrologic Unit 21010005, on left bank of Highway 175, 1.1 mi (1.8 km) downstream of Lago Loíza Dam. DRAINAGE AREA.--209 mi2 (541 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1986 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 32 ft (10 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Loíza Dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.5 7.8 42 e5.1 3.5 4.9 9.2 e5.8 11 1.3 1.4 238 2 833 8.0 44 e5.8 3.6 4.8 121 e5.5 5.3 1.3 1.3 377 3 4.0 8.4 45 e7.1 3.4 4.8 e43 e5.2 5.6 1.9 1.2 137 4 3.5 8.2 45 e8.2 8.9 4.9 e52 e5.1 e3330 4.1 1.8 443 5 3.5 8.1 46 e9.6 2460 7.3 7.8 e5.6 43 2.8 3.0 1.2 6 3.4 8.0 46 e1070 184 5.5 7.7 e5.4 5.8 4.8 2.1 716 7 3.3 7.6 46 e2120 18 3230 9.1 e5.1 3.9 1.9 4.2 11 8 5.1 7.8 46 526 613 426 8.5 e5.5 4.4 2.1 188 1150 9 3.7 7.8 45 448 589 105 7.8 e5.2 6.5 3.0 1.6 564 10 3.5 1890 45 435 89 6.9 7.7 e5.1 5.9 1.6 162 412 11 141 39 45 233 12 284 39 44 153 13 288 38 44 339 14 33500 38 42 120 15 747 39 39 22 87 7.1 7.5 e5.0 3.4 1.4 38 1.2 10 7.0 11 e5.0 3.3 1.3 1.7 1.4 6.7 6.6 41 e4.8 2.8 1.3 .99 255 218 6.3 7.5 e21 2.8 1.6 .54 178 109 6.0 7.0 6.6 1.6 2.0 .92 933 16 369 187 41 14 17 870 30 45 13 18 135 7.7 e42 15 19 160 7.4 e29 14 20 23 7.4 e19 12 63 6.0 15 5.1 1.2 4.5 1.1 600 4.9 6.1 65 13 1.2 3.5 1.1 451 4.7 5.8 8.2 5.7 e3.2 2.7 367 1.9 4.6 5.5 e76 5.2 e1.3 2.3 .86 440 4.3 285 110 5.2 1.1 5.3 1.0 1.2 21 127 7.6 e12 13 22 49 7.2 e8.7 12 23 50 6.7 e9.5 12 24 52 6.1 e9.0 13 25 52 6.2 e9.0 12 3.9 85 92 7.7 1.4 6.1 588 10700 3.7 4.2 50 5.3 1.6 2.3 967 65900 3.9 4.2 6.3 5.7 1.7 2.4 159 2500 4.3 4.2 5.7 5.1 1.2 4.0 5380 1070 4.5 4.1 5.2 5.0 1.2 3.7 8260 853 26 52 848 e9.0 11 27 52 70 e9.3 3.7 28 31 41 e8.5 3.4 29 9.1 43 e8.5 3.5 30 8.8 42 e8.0 3.4 31 8.1 --- e4.4 3.4 4.8 4.0 4.7 5.3 1.2 3.7 1530 753 4.7 4.1 4.6 5.3 1.2 4.0 998 768 4.8 4.4 4.8 5.7 1.2 4.0 850 866 --- 313 e5.1 5.3 1.2 1.8 488 e670 --- 290 e5.3 473 1.3 1.7 .92 174 --- 304 --- 345 --- 1.5 120 --­ TOTAL 37878.5 3472.0 935.9 5660.2 MEAN 1222 116 30.2 183 MAX 33500 1890 46 2120 MIN 3.3 6.1 4.4 3.4 AC-FT 75130 6890 1860 11230 CFSM 5.85 .55 .14 .87 IN. 6.74 .62 .17 1.01 4519.2 5162.7 805.7 998.5 3456.5 85.9 20120.73 91165.9 161 167 26.9 32.2 115 2.77 649 3039 2460 3230 121 473 3330 6.1 8260 65900 3.4 4.0 4.6 4.8 1.1 1.3 .54 1.2 8960 10240 1600 1980 6860 170 39910 180800 .77 .80 .13 .15 .55 .01 3.11 14.5 .80 .92 .14 .18 .62 .02 3.58 16.23 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1987 - 1998, BY WATER YEAR (WY) MEAN 313 461 312 154 MAX 1222 2732 2603 733 (WY) 1998 1988 1988 1992 MIN 44.7 37.6 17.2 2.49 (WY) 1992 1996 1994 1995 76.8 55.0 29.1 80.8 166 147 236 919 242 299 112 367 784 672 718 4255 1989 1989 1987 1992 1987 1993 1988 1996 4.52 5.19 1.20 1.03 1.96 1.62 2.21 29.7 1990 1997 1995 1995 1994 1994 1994 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1987 - 1998 ANNUAL TOTAL 50355.9 ANNUAL MEAN 138 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 33500 LOWEST DAILY MEAN 1.8 ANNUAL SEVEN-DAY MINIMUM 2.3 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 99880 ANNUAL RUNOFF (CFSM) .66 ANNUAL RUNOFF (INCHES) 8.96 10 PERCENT EXCEEDS 47 50 PERCENT EXCEEDS 5.2 90 PERCENT EXCEEDS 3.1 174261.73 477 247 652 1988 37.8 1994 Oct 14 65900 Sep 22 110000 Sep 10 1996 Jul 15 .54 Aug 14 .42 May 13 1995 Jun 29 1.2 Jun 24 .49 Aug 11 1994 196000 Oct 14 223000 Sep 10 1996 47.01 Oct 14 49.31 Sep 10 1996 345600 179100 2.28 1.18 31.02 16.07 479 375 7.7 7.9 1.6 2.3 e Estimated 294 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 10,000 1,000 100 10 1 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 295 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE LOIZA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water year 1987 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 1986 to current year. INSTRUMENTATION.-- Automatic sediment sampler, since 1987. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,290 mg/L September 10, 1996; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 1,500,000 tons (1,360,000 tonnes) September10, 1996; Minimum daily mean, <0.01 tons (<0.01 tonne) several years. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,350 mg/L September 22, 1998; minimum daily mean, 7 mg/L October 9-10, 1997. SEDIMENT LOADS: Maximum daily mean, 1,030,000 tons (935,000 tonnes) September 22, 1998; minimum daily mean, 0.03 ton (0.02 tonne) June 20, 1998. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 7.5 28 .56 7.8 101 2.1 42 137 15 2 833 195 1220 8.0 99 2.1 44 150 18 3 4.0 71 .78 8.4 96 2.2 45 160 19 4 3.5 49 .46 8.2 94 2.1 45 156 19 5 3.5 31 .29 8.1 92 2.0 46 150 18 6 3.4 19 .17 8.0 90 1.9 46 144 18 7 3.3 12 .11 7.6 88 1.8 46 139 17 8 5.1 8 .11 7.8 85 1.8 46 134 16 9 3.7 7 .07 7.8 83 1.8 45 129 16 10 3.5 7 .06 1890 128 936 45 124 15 11 141 55 167 39 170 18 45 120 14 12 284 172 482 39 191 20 44 115 14 13 288 126 814 38 215 22 44 111 13 14 33500 736 106000 38 222 23 42 107 12 15 747 572 1530 39 159 17 39 103 11 16 369 334 397 187 161 107 41 99 11 17 870 296 949 30 154 12 45 95 12 18 135 227 94 7.7 152 3.2 e42 92 e10 19 160 190 111 7.4 151 3.0 e29 91 e7.2 20 23 221 14 7.4 150 3.0 e19 91 e4.8 21 127 189 87 7.6 149 3.1 e12 90 e3.0 22 49 179 24 7.2 148 2.9 e8.7 90 e2.2 23 50 127 17 6.7 147 2.6 e9.5 89 e2.3 24 52 124 17 6.1 143 2.4 e9.0 89 e2.2 25 52 120 17 6.2 125 2.1 e9.0 88 e2.2 26 52 117 16 848 95 221 e9.0 88 e2.1 27 52 114 16 70 97 16 e9.3 87 e2.2 28 31 111 9.3 41 106 12 e8.5 87 e2.0 29 9.1 109 2.7 43 116 13 e8.5 86 e2.0 30 8.8 106 2.5 42 126 14 e8.0 85 e1.8 31 8.1 104 2.3 e4.4 85 e1.0 TOTAL 37878.5 111991.41 3472.0 1471.1 935.9 303.0 --- --- --- --- --- --- --- --- --- --- --- --- 296 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE LOIZA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 e5.1 84 e1.2 3.5 71 .67 4.9 28 .37 2 e5.8 84 e1.3 3.6 68 .66 4.8 25 .33 3 e7.1 83 e1.6 3.4 64 .58 4.8 24 .32 4 e8.2 83 e1.8 8.9 67 3.3 4.9 30 .39 5 e9.6 82 e2.1 2460 149 917 7.3 38 .78 6 e1070 69 e275 184 162 139 5.5 49 .72 7 e2120 229 e1550 18 128 6.1 3230 173 2830 8 526 246 395 613 151 593 426 228 716 9 448 228 287 589 195 486 105 556 198 10 435 174 224 89 193 50 6.9 411 7.6 11 233 156 114 87 126 47 7.1 340 6.5 12 153 140 71 10 106 2.9 7.0 287 5.4 13 339 142 269 6.7 97 1.8 6.6 242 4.3 14 120 139 77 218 103 112 6.3 204 3.5 15 22 174 10 109 121 47 6.0 173 2.8 16 14 159 6.1 63 96 20 6.0 146 2.4 17 13 152 5.4 4.9 92 1.2 6.1 123 2.0 18 15 144 5.9 4.7 83 1.0 5.8 104 1.6 19 14 137 5.3 4.6 75 .92 5.5 87 1.3 20 12 130 4.4 4.3 68 .79 285 127 294 21 13 124 4.3 3.9 62 .65 85 148 61 22 12 118 3.9 3.7 56 .56 4.2 176 2.0 23 12 112 3.6 3.9 50 .53 4.2 166 1.9 24 13 107 3.6 4.3 46 .53 4.2 154 1.7 25 12 101 3.4 4.5 41 .51 4.1 134 1.5 26 11 96 2.9 4.8 37 .48 4.0 116 1.3 27 3.7 92 .92 4.7 34 .43 4.1 100 1.1 28 3.4 87 .81 4.8 31 .40 4.4 86 1.0 29 3.5 83 .79 313 110 209 30 3.4 79 .71 290 120 137 31 3.4 75 .68 304 105 109 TOTAL 5660.2 3332.71 4519.2 2435.01 5162.7 4604.81 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 9.2 84 2.1 e5.8 2 121 98 47 e5.5 3 e43 85 e10 e5.2 4 e52 56 e17 e5.1 19 e.29 11 84 2.6 16 e.24 5.3 77 1.1 14 e.20 5.6 73 1.1 12 e.17 e3330 160 e5740 5 7.8 68 1.4 e5.6 10 e.16 43 71 8.4 6 7.7 84 1.7 e5.4 9 e.13 5.8 53 .84 7 9.1 103 2.6 e5.1 9 e.12 3.9 40 .42 8 8.5 123 2.8 e5.5 9 e.13 4.4 30 .36 9 7.8 117 2.5 e5.2 9 e.12 6.5 23 .40 10 7.7 107 2.2 e5.1 8 e.12 5.9 17 .27 11 7.5 97 2.0 e5.0 12 11 89 2.7 e5.0 13 41 94 11 e4.8 14 7.5 95 1.9 e21 15 7.0 90 1.7 6.6 8 e.11 3.4 13 .12 8 e.11 3.3 10 .09 8 e.11 2.8 10 .08 33 e6.2 2.8 10 .08 80 1.4 1.6 10 .04 16 15 86 3.5 5.1 17 65 94 18 13 18 8.2 87 1.9 5.7 19 e76 95 e22 5.2 20 110 88 34 5.2 73 1.0 1.2 10 .04 96 4.0 1.2 10 .04 133 2.1 e3.2 11 e.08 120 1.7 e1.3 11 e.04 109 1.5 1.1 11 .03 21 92 93 27 22 50 91 13 23 6.3 69 1.2 24 5.7 53 .83 25 5.2 45 .63 7.7 100 2.1 1.4 11 .04 5.3 95 1.4 1.6 11 .05 5.7 91 1.4 1.7 11 .05 5.1 87 1.2 1.2 11 .04 5.0 83 1.1 1.2 11 .04 26 4.7 39 .50 27 4.6 34 .42 28 4.8 29 .38 29 e5.1 25 e.35 30 e5.3 22 e.31 31 --- --- --- 5.3 80 1.1 1.2 11 .04 5.3 76 1.1 1.2 11 .04 5.7 73 1.1 1.2 11 .04 5.3 70 1.0 1.2 12 .04 473 140 561 1.3 12 .04 345 88 117 --- --- --­ TOTAL 805.7 --- 232.62 998.5 --- 709.41 3456.5 --- 5756.55 --- --- --- --- --- 297 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE LOIZA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 1.3 12 .04 1.4 12 .04 238 97 103 2 1.3 12 .04 1.3 11 .04 377 161 325 3 1.9 12 .06 1.2 11 .04 137 63 51 4 4.1 12 .13 1.8 11 .05 443 61 134 5 2.8 12 .09 3.0 11 .09 1.2 49 .16 6 4.8 12 .16 2.1 10 .06 716 77 257 7 1.9 12 .06 4.2 10 .12 11 80 2.3 8 2.1 12 .07 188 28 57 1150 105 491 9 3.0 13 .10 1.6 58 .26 564 86 236 10 1.6 13 .05 162 80 109 412 86 165 11 1.4 13 .05 38 96 21 1.2 81 .27 12 1.3 13 .05 1.7 59 .26 1.4 63 .24 13 1.3 13 .05 .99 56 .15 255 58 111 14 1.6 13 .06 .54 54 .08 178 79 46 15 2.0 13 .07 .92 51 .13 933 83 368 16 4.5 13 .16 1.1 49 .14 600 91 244 17 3.5 13 .13 1.1 47 .14 451 70 181 18 2.7 13 .10 367 65 148 1.9 18 .09 19 2.3 14 .09 .86 54 .13 440 270 1430 20 5.3 14 .20 1.0 50 .14 1.2 77 .25 21 6.1 14 .23 588 72 183 10700 1830 138000 22 2.3 14 .09 967 431 3430 65900 3350 1030000 23 2.4 14 .09 159 69 163 2500 699 4670 24 4.0 14 .15 5380 239 7180 1070 653 1860 25 3.7 13 .13 8260 490 12100 853 610 1420 26 3.7 13 .13 1530 207 1520 753 570 1160 27 4.0 13 .14 998 93 354 768 533 1110 28 4.0 13 .14 850 98 289 866 498 1140 29 1.8 12 .06 488 71 152 e670 465 e815 30 1.7 12 .05 .92 49 .12 174 446 210 31 1.5 12 .05 120 57 133 TOTAL 85.9 3.02 20120.73 25840.99 91165.9 --- 1184530.31 YEAR 174261.73 1341210.94 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 02... 1747 2170 843 492 99 02... 2032 1420 1020 3910 99 12... 1742 1730 890 4160 99 15... 1045 71 539 103 99 15... 1957 1660 515 2310 100 17... 2132 2400 454 2940 85 NOV 10... 0907 4270 120 1380 92 JAN 09... 2207 1720 228 1060 100 FEB 05... 1708 1830 191 944 99 15... 1103 1750 204 964 100 MAR 10... 0847 6.5 412 7.2 100 20... 2258 1720 351 1630 97 AUG 25... 1458 3380 546 4980 98 26... 1028 3210 372 3220 99 SEP 02... 1510 233 1120 704 100 19... 0746 3510 1580 15000 100 298 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE LOIZA, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 14... 0207 134000 1190 430000 63 76 88 15... 1544 1780 957 4600 17 22 32 FEB 05... 0315 1620 897 3900 55 67 77 MAR 07... 2148 3020 851 6940 62 74 85 SEP 21... 2031 10600 2480 71000 73 88 95 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 14... 90 93 93 95 97 99 100 15... 49 76 89 96 97 99 100 FEB 05... 84 91 94 97 99 100 100 MAR 07... 91 95 95 97 97 98 98 SEP 21... 96 98 99 100 100 100 100 299 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°21'35", long 66°00'15", 100 ft (30 m) downstream of Highway 181 bridge, 0.4 mi (0.6 km) northwest of Trujillo Alto plaza, and 2.2 mi (3.5 km) northeast of Lago Loíza Reservoir. DRAINAGE AREA.--213 mi2 (552 km2). PERIOD OF RECORD.--Water year 1981 to current year. REMARKS: Flow controlled by Lago Loiza reservoir. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 05... 1030 17 318 7.6 27.5 49 7.5 97 <10 K80 420 MAR 10... 1130 9.3 250 7.0 26.0 150 5.4 66 15 K840 2100 JUN 02... 1115 9.5 373 7.2 31.0 2.0 7.9 106 <10 560 30 SEP 08... 0835 E4340 315 6.8 28.0 51 5.5 70 <10 5700 2200 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 05... 70 17 6.4 7.2 .4 2.2 115 <.5 8.2 11 MAR 10... -- -- -- -- -- -- 94 -- -- -­ JUN 02... 120 30 11 27 1 2.6 131 -- 16 27 SEP 08... 100 26 9.9 20 .8 2.8 130 <1.0 13 19 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 05... <.10 17 134 6.15 52 .926 .014 .940 .040 .37 MAR 10... -- -- -- -- 116 1.16 .039 1.20 .190 .59 JUN 02... .14 28 220 5.65 6 .326 .014 .340 .030 .33 SEP 08... .13 24 192 E2250 84 .873 .017 .890 .080 .61 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 05... .41 1.4 6.0 .110 <1 <100 40 <1 <1 <10 MAR 10... .78 2.0 8.8 .240 -- -- -- -- -- -­ JUN 02... .36 .70 3.1 .060 1 <100 50 <1 <1 <10 SEP 08... .69 1.6 7.0 .180 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 300 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 05... 630 <1 43 <.10 <1 <1 <10 <.010 <1 .05 MAR 10... JUN 02... 180 <1 60 <.10 <1 <1 <10 <.010 <1 .24 SEP 08... 301 RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR LOCATION.--Lat 18°19'08", long 65°53'21", Hydrologic Unit 21010005, at upstream side of bridge, on paved secondary road, 0.4 mi (0.6 km) northeast of junction of Highways 185 and 186, 1.5 mi (2.4 km) south of Campo Rico, and 4.4 mi (7.1 km) south of Loíza. DRAINAGE AREA.--9.84 mi2 (25.48 km2). PERIOD OF RECORD.--March 1967 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 225 ft (68 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 9.0 15 8.3 2 37 8.7 12 9.5 3 29 8.4 10 13 4 16 8.4 9.6 14 5 14 8.6 9.8 12 14 8.2 9.0 5.5 7.0 3.3 4.8 18 9.2 7.8 28 5.4 6.6 3.2 4.4 76 9.0 7.8 14 5.9 6.4 3.5 4.1 51 13 7.8 8.3 11 9.7 4.5 3.8 32 314 7.4 6.8 8.5 6.6 4.9 3.5 30 6 12 8.5 9.3 39 7 12 8.3 9.2 197 8 14 7.9 8.8 22 9 21 8.0 8.7 25 10 14 136 9.1 25 20 8.0 6.2 6.3 6.6 3.5 4.4 22 13 7.5 6.2 5.9 6.2 5.5 39 30 34 9.2 7.8 118 8.5 4.9 33 28 36 7.5 6.2 33 14 4.0 19 23 14 7.0 5.7 21 11 3.2 13 19 11 46 15 8.9 30 12 32 11 8.4 15 13 174 9.8 8.3 34 14 666 9.1 8.4 32 15 31 8.9 8.5 16 12 6.8 5.8 10 7.1 3.0 6.8 16 15 6.5 7.4 7.9 14 3.0 5.4 14 11 6.2 18 7.1 30 2.6 5.2 17 13 6.7 8.1 10 9.0 3.1 4.3 27 16 8.4 6.3 9.3 6.6 5.2 4.9 74 16 28 12 8.2 13 17 23 10 11 12 18 16 13 11 11 19 15 17 9.0 11 20 13 11 8.3 11 11 9.0 65 8.1 6.4 5.5 40 29 10 7.4 18 7.9 8.1 4.0 53 18 9.5 6.9 10 7.8 12 4.8 16 17 9.3 6.6 15 7.4 7.5 7.9 16 19 8.7 7.8 12 6.6 6.0 12 20 18 21 13 14 11 10 22 12 12 9.7 9.8 23 12 11 8.1 9.7 24 11 11 8.9 9.5 25 10 9.7 7.9 9.3 8.3 10 9.4 11 6.1 11 104 2060 7.7 8.8 8.3 7.2 9.1 5.3 41 1600 7.5 8.4 7.2 6.4 6.4 5.7 19 127 7.3 7.3 6.7 6.3 5.5 50 554 e70 7.5 7.1 6.9 6.4 4.9 13 536 e55 26 10 138 7.0 8.9 27 9.8 27 6.7 9.2 28 9.5 15 6.7 8.9 29 9.5 13 6.7 8.5 30 9.1 16 6.4 8.3 31 9.0 --- 6.9 10 11 6.8 6.8 6.5 4.8 7.1 108 44 9.1 7.2 7.6 9.3 4.2 11 39 38 8.7 7.7 6.5 6.9 3.8 15 30 34 --- 11 6.0 7.7 3.5 15 63 31 --- 34 5.7 9.4 3.3 7.2 26 29 --- 23 --- 10 --- 5.4 20 --­ TOTAL 1340.9 595.3 277.5 651.9 MEAN 43.3 19.8 8.95 21.0 MAX 666 138 15 197 MIN 9.0 7.9 6.4 8.3 AC-FT 2660 1180 550 1290 CFSM 4.40 2.02 .91 2.14 IN. 5.07 2.25 1.05 2.46 658.8 281.8 334.9 389.7 240.9 237.3 1840.6 4666 23.5 9.09 11.2 12.6 8.03 7.65 59.4 156 314 34 65 118 30 50 554 2060 7.3 6.2 5.7 5.4 3.3 2.6 3.5 14 1310 559 664 773 478 471 3650 9260 2.39 .92 1.13 1.28 .82 .78 6.03 15.8 2.49 1.07 1.27 1.47 .91 .90 6.96 17.64 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 1998, BY WATER YEAR (WY) MEAN 40.7 44.1 31.9 25.1 MAX 273 125 116 62.4 (WY) 1971 1985 1971 1969 MIN 6.74 6.66 5.82 6.66 (WY) 1968 1981 1968 1977 19.8 13.9 14.9 27.2 17.6 18.7 26.5 41.8 48.4 36.2 53.2 93.2 63.7 63.7 137 196 1988 1969 1971 1969 1970 1979 1979 1996 4.04 3.54 4.36 4.28 2.80 3.72 5.69 5.20 1977 1977 1994 1974 1974 1974 1991 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1967 - 1998 ANNUAL TOTAL 7266.6 ANNUAL MEAN 19.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 666 LOWEST DAILY MEAN 3.8 ANNUAL SEVEN-DAY MINIMUM 4.0 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 14410 ANNUAL RUNOFF (CFSM) 2.02 ANNUAL RUNOFF (INCHES) 27.47 10 PERCENT EXCEEDS 30 50 PERCENT EXCEEDS 13 90 PERCENT EXCEEDS 6.7 11515.6 31.5 27.1 58.0 1971 10.5 1994 Oct 14 2060 Sep 21 4230 Sep 10 1996 Jun 22 2.6 Jul 13 .80 Jul 24 1977 Jun 28 3.4 Jul 8 1.5 Jul 18 1977 17300 Sep 21 17300 Sep 21 1998 15.90 Sep 21 15.90 Sep 21 1998 2.4 Jul 14 .80 Jul 24 1977 22840 19650 3.21 2.76 43.53 37.45 34 43 9.4 12 5.5 5.2 e Estimated 302 RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 303 Río Río Río Río Río Demajagua Quebrada Ceiba Q u e b r a d a Juan Martín Fajardo Sabana Mameyes Río Río Río Río Río Río Río Río Río Río Río Santo Espíritu Herrera Grande Quebrada Cubuy Blanco Antón Ruíz Santiago Palma Daguao Fajardo Fajardo Pi t a h a y a Icacos 0750 0705 ARR-1 0725 A TLANTIC OCEAN LOÍZA LUQUILLO CEIBA NAGUABO HUMACAO LAS PIEDRAS 0 0 1 1 2 2 3 3 4 4 0750 0705 07495 0638 RE-2A RM-2 RS-02 RP-04 RF-04 ARR-1 RF-12 0655 0670 0660 063440 0642 0710 0725 QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER RÍO GRANDE Basin area PUERTO RICO FAJARDO CANÓVANAS 5 MILES 5 KILOMETERS Figure 19. Northeastern river basins -- Río Herrera to Río Antón Ruíz basins. --- --- --- --- --- --- --- 304 RIO ESPIRITU SANTO BASIN 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR LOCATION.--Lat 18°19'24", long 65°49'03", Hydrologic Unit 21010005, in Caribbean National Forest, at El Yunque, 0.6 mi (1.0 km) upstream from Río Espíritu Santo, 0.2 mi (0.3 km) upstream from Highway 186, and about 1.2 mi (1.9 km) south of El Verde. DRAINAGE AREA.--1.01 mi2 (2.62 km2). PERIOD OF RECORD.--March 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,230 ft (375 m), from topographic map. REMARKS.--Records poor. CORRECTIONS.--The maximum discharge for the water year 1996 is 963.0 ft3/s (27.2 m3/s), Apr. 4, 1996, gage-height, 8.09 ft (2.46 m). The previously published figure was not the maximum. The maximum discharge for the period of record is 2,230 ft3/s (63.1 m3/s), Dec. 7, 1987, gage-height, 9.42 ft (2.87 m). The previously published figure in the report for 1997 was not the maximum for the period of record. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e2.2 4.1 e2.0 5.3 1.0 .34 3.9 1.6 1.7 e1.5 e1.8 e3.8 2 e15 1.4 1.5 3.9 .93 .33 11 1.4 1.4 e1.7 e1.8 e21 3 e2.6 1.2 1.3 24 .72 .33 3.0 3.3 1.2 e4.0 e2.1 e9.4 4 e2.0 2.2 1.3 17 12 .30 2.1 9.6 1.2 e6.8 e2.2 e7.0 5 e2.0 2.2 1.3 12 e16 .25 e1.8 2.1 1.1 e2.5 e2.1 e10 6 e1.6 2.6 1.2 62 e1.3 .61 e1.5 1.3 1.5 e1.8 e4.3 e12 7 e1.5 1.4 1.2 e90 e.52 e200 e1.8 1.2 1.2 e4.2 e17 e39 8 e1.7 1.1 1.1 e4.9 e1.1 e11 e3.1 9.6 1.5 e5.4 e9.0 e11 9 e2.1 18 1.1 e3.7 e3.2 e3.8 e1.9 2.2 e16 e9.2 e8.2 e8.6 10 e1.5 e20 1.1 e3.8 e.60 e1.8 e1.6 1.1 e4.0 e2.2 e3.1 e4.5 11 e4.3 e2.3 1.2 e2.1 e.42 e1.6 e1.4 1.0 e1.8 e2.1 e2.3 e3.5 12 e3.8 e1.4 1.1 e1.5 e1.4 e1.6 e3.4 .93 e39 e1.6 e2.9 e3.1 13 e10 e1.3 1.1 e4.4 e.42 e1.5 e6.0 7.2 e5.4 e1.7 e2.8 e14 14 e29 e1.2 1.1 e5.2 e.60 e2.1 e2.7 9.1 e2.4 e1.9 e1.7 e10 15 e3.8 e2.7 1.2 e1.9 e1.4 e3.0 e2.8 9.5 e1.8 e4.2 e3.1 e54 16 e2.3 e4.4 1.0 e1.4 e.42 e2.7 e50 4.4 e4.3 e4.6 e11 e8.0 17 e1.9 e3.8 1.8 e1.2 e.42 e2.1 e6.0 1.7 e2.1 e3.7 e17 e5.2 18 e1.5 e4.1 1.5 e1.2 e.42 e2.2 e6.6 1.2 e6.0 e3.7 e8.2 e6.0 19 e1.5 e4.2 1.2 e1.2 e.38 e1.5 e41 1.1 e2.1 e11 e24 e9.5 20 e1.3 e3.5 1.3 e1.1 e.38 19 e8.0 1.2 e1.6 e18 e12 e7.0 21 e1.4 e5.4 3.7 e1.0 e.38 4.6 e5.4 1.4 e2.7 e6.0 e32 e240 22 e1.3 e2.9 1.3 e1.0 e.38 3.1 3.8 1.0 e3.4 e2.3 e12 e160 23 e1.3 e1.8 1.0 e1.0 e.38 2.5 3.1 .95 e1.9 e10 e5.8 e15 24 e1.4 e2.7 .97 e1.0 e.34 1.7 2.6 1.1 e1.8 e27 e83 e8.0 25 e1.4 e1.5 .87 e1.0 e.39 2.5 2.5 1.8 e1.8 e4.2 e54 e6.0 26 e1.5 e21 .81 e1.0 .41 4.6 2.4 15 e1.6 e2.8 e17 e5.2 27 e1.3 e4.1 .83 e.88 .40 7.9 7.3 9.8 e1.6 e4.7 e12 e4.5 28 e1.1 e2.8 .82 e.88 .45 4.2 3.9 6.6 e1.9 e5.8 e13 e3.9 29 e1.0 e2.3 .69 e.80 3.4 2.1 17 e1.5 e2.9 e14 e3.6 30 e1.1 e3.0 .61 e.75 9.2 1.7 16 e1.4 e2.4 e5.0 e3.3 31 e1.3 .84 .80 4.5 3.7 e2.7 e4.4 TOTAL 105.7 130.6 38.04 257.91 46.76 304.26 194.4 145.08 116.9 162.6 388.8 696.1 MEAN 3.41 4.35 1.23 8.32 1.67 9.81 6.48 4.68 3.90 5.25 12.5 23.2 MAX 29 21 3.7 90 16 200 50 17 39 27 83 240 MIN 1.0 1.1 .61 .75 .34 .25 1.4 .93 1.1 1.5 1.7 3.1 AC-FT 210 259 75 512 93 603 386 288 232 323 771 1380 CFSM 3.38 4.31 1.21 8.24 1.65 9.72 6.42 4.63 3.86 5.19 12.4 23.0 IN. 3.89 4.81 1.40 9.50 1.72 11.21 7.16 5.34 4.31 5.99 14.32 25.64 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 1998, BY WATER YEAR (WY) MEAN 5.42 9.32 7.46 7.02 5.88 5.01 4.66 7.38 5.80 6.37 7.03 7.93 MAX 16.8 19.8 20.9 11.1 11.9 14.3 9.76 14.3 13.7 12.7 14.2 23.2 (WY) 1986 1985 1988 1996 1988 1990 1987 1992 1987 1983 1988 1998 MIN .22 2.47 .92 3.42 1.56 1.53 .90 2.51 .98 2.33 .50 2.45 (WY) 1993 1991 1990 1985 1992 1993 1997 1996 1985 1991 1993 1986 305 RIO ESPIRITU SANTO BASIN DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR--Continued SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1983 - 1998 ANNUAL TOTAL 1472.42 ANNUAL MEAN 4.03 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 46 LOWEST DAILY MEAN .31 ANNUAL SEVEN-DAY MINIMUM .32 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 2920 ANNUAL RUNOFF (CFSM) 3.99 ANNUAL RUNOFF (INCHES) 54.23 10 PERCENT EXCEEDS 10 50 PERCENT EXCEEDS 1.7 90 PERCENT EXCEEDS .73 2587.15 7.09 6.55 9.32 1988 3.91 1994 Jan 22 240 Sep 21 346 Sep 10 1996 May 3 .25 Mar 5 .00 Aug 14 1993 Apr 30 .34 Feb 27 .01 Mar 31 1994 614 Sep 21 2230 Dec 7 1987 7.39 Sep 21 9.42 Dec 7 1987 .22 Mar 5 .00 Aug 13 1993 5130 4750 7.02 6.49 95.29 88.14 13 16 2.2 2.5 .88 .47 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 306 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR LOCATION.--Lat 18°21'37", long 65°48'49", Hydrologic Unit 21010005, on downstream side of bridge on Highway 966, 0.1 mi (0.2 km) upstream from Quebrada Jiménez, and 1.9 mi (3.1 km), southeast of Río Grande. DRAINAGE AREA.--8.62 mi2 (22.33 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to April 1963 (annual low-flow and occasional measurements only), August 1966 to current year. GAGE.--Water-stage recorder. Elevation of gage is 40 ft (12 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 36 44 55 77 13 13 30 18 29 15 18 38 2 237 26 44 48 12 12 66 15 21 17 18 214 3 43 17 39 112 12 12 33 30 17 29 20 98 4 32 22 36 91 14 12 29 98 15 67 22 70 5 32 28 36 80 282 20 24 33 13 27 21 99 6 26 33 33 271 40 20 21 20 15 18 e43 114 7 25 25 30 468 15 1270 24 17 16 40 e172 393 8 28 18 28 79 33 e143 42 89 19 52 90 112 9 34 67 27 59 57 50 27 50 164 92 81 88 10 25 279 27 61 17 e23 22 19 51 22 34 50 11 71 37 27 36 12 e21 19 15 18 21 23 36 12 62 22 24 25 25 e21 42 14 390 16 29 31 13 174 21 24 71 12 e20 82 26 97 17 28 142 14 456 19 23 84 17 e29 37 119 24 19 17 101 15 45 58 23 30 25 e40 38 83 18 41 25 534 16 38 123 26 21 12 e36 677 56 43 46 102 88 17 31 106 40 18 12 28 82 30 21 37 166 53 18 25 115 44 18 12 29 90 17 60 37 82 60 19 25 118 37 18 11 20 558 18 23 99 232 e97 20 21 98 31 17 11 88 120 15 16 176 121 e70 21 22 152 79 16 11 33 48 40 25 65 323 e2380 22 21 76 37 16 11 23 39 24 34 23 144 e1680 23 21 51 31 16 11 22 29 24 19 79 59 e151 24 22 76 33 16 e9.7 22 28 21 18 274 840 80 25 22 42 30 16 e11 24 25 30 18 48 550 61 26 23 588 28 16 12 29 25 127 16 28 167 53 27 21 113 28 14 12 38 58 131 16 43 124 46 28 17 76 28 14 13 27 37 66 19 57 135 40 29 16 63 26 13 27 23 129 15 29 139 37 30 17 85 26 12 57 19 199 14 24 51 33 31 21 26 12 34 67 27 45 TOTAL 1689 2598 1026 1845 734.7 2243 2394 1640 1264 1585 3921 7049 MEAN 54.5 86.6 33.1 59.5 26.2 72.4 79.8 52.9 42.1 51.1 126 235 MAX 456 588 79 468 282 1270 677 199 390 274 840 2380 MIN 16 17 23 12 9.7 12 19 14 13 15 17 31 AC-FT 3350 5150 2040 3660 1460 4450 4750 3250 2510 3140 7780 13980 CFSM 6.32 10.0 3.84 6.90 3.04 8.39 9.26 6.14 4.89 5.93 14.7 27.3 IN. 7.29 11.21 4.43 7.96 3.17 9.68 10.33 7.08 5.45 6.84 16.92 30.42 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 1998, BY WATER YEAR (WY) MEAN 59.6 85.7 71.0 55.2 50.4 39.6 44.3 65.7 45.7 52.1 62.4 64.9 MAX 202 196 179 119 117 153 119 185 120 114 126 235 (WY) 1971 1985 1971 1969 1982 1990 1981 1979 1970 1983 1998 1998 MIN 12.3 29.1 16.8 18.5 10.8 9.53 6.27 14.9 10.0 11.1 18.5 17.7 (WY) 1969 1982 1994 1977 1983 1996 1984 1973 1975 1975 1994 1971 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1966 - 1998 ANNUAL TOTAL 22521 27988.7 ANNUAL MEAN 61.7 76.7 58.2 HIGHEST ANNUAL MEAN 98.6 1979 LOWEST ANNUAL MEAN 21.6 1994 HIGHEST DAILY MEAN 923 Aug 22 2380 Sep 21 2600 Dec 7 1987 LOWEST DAILY MEAN 11 Jun 9 9.7 Feb 24 3.6 Apr 2 1996 ANNUAL SEVEN-DAY MINIMUM 12 Jun 6 11 Feb 19 4.4 Jun 30 1975 INSTANTANEOUS PEAK FLOW 13500 Sep 21 21200 Aug 13 1990 INSTANTANEOUS PEAK STAGE 12.87 Sep 21 16.62 Aug 13 1990 ANNUAL RUNOFF (AC-FT) 44670 55520 42140 ANNUAL RUNOFF (CFSM) 7.16 8.90 6.75 ANNUAL RUNOFF (INCHES) 97.19 120.79 91.69 10 PERCENT EXCEEDS 114 130 123 50 PERCENT EXCEEDS 34 30 26 90 PERCENT EXCEEDS 17 15 10 e Estimated 307 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 308 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958, 1961-66, 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 28... 1300 17 115 7.4 27.0 .40 7.3 92 <10 310 360 MAR 25... 0845 24 115 6.8 24.5 2.1 8.2 98 <10 4800 2700 JUN 09... 0910 17 89 6.7 26.0 2.0 8.0 98 <10 340 310 AUG 24... 1400 506 31 6.2 24.5 71 8.1 97 15 5800 K14000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 28... 39 8.6 4.3 8.4 .6 .73 40 <.5 1.8 10 MAR 25... -- -- -- -- -- -- 44 -- -- -­ JUN 09... 27 5.9 3.0 7.0 .6 .43 33 -- 1.7 8.5 AUG 24... 8 1.8 .92 3.2 .5 .46 82 <1.0 1.4 4.2 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 28... <.10 22 80 3.61 <1 -- <.010 .060 .020 -­ MAR 25... -- -- -- -- <1 -- <.010 .020 .020 .41 JUN 09... <.10 18 64 3.01 3 -- <.010 .060 .010 -­ AUG 24... <.10 5.0 66 90.3 146 .060 .010 .070 .060 1.4 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 28... <.20 -- -- .030 <1 <100 20 <1 <1 <10 MAR 25... .43 .43 1.9 .030 -- -- -- -- -- -­ JUN 09... <.20 -- -- <.020 <1 <100 30 2 <1 <10 AUG 24... 1.5 1.6 6.9 .110 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 309 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 28... 90 <1 10 <.10 <1 <1 <10 .010 <1 .06 MAR 25... JUN 09... 310 <1 <10 .16 <1 <1 <10 <.010 3 <.02 AUG 24... 310 RIO ESPIRITU SANTO BASIN 50064200 RIO GRANDE NEAR EL VERDE, PR LOCATION.--Lat 18°20'42", long 65°50'30", Hydrologic Unit 21010005, on left bank 250 ft (7.6 m) upstream side of bridge at Hwy 960, 0.05 mi (0.08 km) southwest of junction of Highways 956 and 960, 1.1 mi (1.8 km) west of El Verde, and 2.7 mi (4.3 km) south of Río Grande. DRAINAGE AREA.--7.31 mi2 (18.93 km2). PERIOD OF RECORD.--May 1967 to December 1970, January 1972 to September 1982, August 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17 e18 e18 e78 2 120 e11 e14 e45 3 37 e7.0 e13 e110 4 20 e9.3 e12 e90 5 16 e11 e12 e80 18 7.1 16 9.7 23 8.5 12 e30 13 7.1 54 9.2 14 8.3 9.8 e143 12 6.7 e18 11 12 12 9.1 e95 19 6.5 e12 47 11 23 8.6 e61 313 7.5 9.3 20 11 17 8.7 e61 6 13 e13 e11 e300 7 13 e9.1 e9.4 e470 8 13 e7.0 e8.2 e80 9 19 e29 e7.6 e60 10 12 e119 e6.4 e64 29 9.0 8.2 10 20 11 e22 e43 15 212 8.9 9.2 18 41 e94 e60 45 55 13 98 12 21 60 e58 57 16 8.0 44 64 26 55 e45 17 11 7.3 18 40 15 38 e36 11 25 e15 e6.0 e35 12 33 e6.8 e5.5 e26 13 146 e6.1 e5.4 e72 14 455 e5.5 e5.5 e86 15 46 13 e5.6 e30 14 10 7.9 13 14 12 16 e28 34 10 15 12 150 9.6 18 e25 14 9.5 56 21 79 8.9 17 e59 16 13 14 65 20 8.7 11 e72 24 19 19 30 14 24 14 219 16 48 33 e5.3 e21 17 34 31 e18 e19 18 21 50 e20 e19 19 17 45 e17 e19 20 15 25 e14 e18 12 17 361 36 17 25 47 60 11 14 49 24 18 16 113 35 10 10 31 15 39 19 43 e34 9.8 10 49 13 15 52 116 67 9.4 49 23 11 12 91 71 e49 21 12 66 e36 e17 22 11 25 e17 e17 23 9.7 e17 e14 e17 24 8.7 e25 e15 17 25 e8.0 e14 e13 16 9.9 28 16 20 18 48 221 1440 9.0 22 14 11 28 15 114 833 8.7 15 13 9.7 13 32 43 119 7.2 9.8 11 11 11 201 563 79 7.1 10 12 13 10 42 e492 66 26 e7.3 e275 e12 16 27 e6.5 e37 e11 15 28 e6.5 e24 e11 14 29 e6.4 e20 e10 13 30 e6.8 e28 e9.9 12 31 e7.9 --- e9.8 12 9.1 13 13 37 9.9 19 e144 62 8.1 26 22 69 9.5 42 e71 50 7.4 17 16 22 12 60 e58 44 --- 17 12 53 9.8 31 e90 41 --- 98 10 44 9.1 16 e43 37 --- 45 --- 52 --- 18 e32 --­ TOTAL 1210.8 994.8 372.6 1888 MEAN 39.1 33.2 12.0 60.9 MAX 455 275 36 470 MIN 6.4 5.5 5.3 12 AC-FT 2400 1970 739 3740 CFSM 5.34 4.54 1.64 8.33 IN. 6.16 5.06 1.90 9.61 758.7 800.2 918.6 857.8 733.3 973.0 2654.2 4051 27.1 25.8 30.6 27.7 24.4 31.4 85.6 135 313 212 361 98 150 201 563 1440 7.1 6.5 7.3 9.2 9.1 8.3 8.6 25 1500 1590 1820 1700 1450 1930 5260 8040 3.71 3.53 4.19 3.79 3.34 4.29 11.7 18.5 3.86 4.07 4.67 4.37 3.73 4.95 13.51 20.62 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 1998, BY WATER YEAR (WY) MEAN 54.9 66.2 45.4 43.8 MAX 392 172 140 151 (WY) 1971 1970 1971 1969 MIN 8.45 14.3 12.0 10.1 (WY) 1969 1981 1998 1977 30.8 20.9 27.0 49.5 30.5 36.5 44.6 52.4 76.4 54.4 119 203 86.5 109 90.0 153 1969 1969 1978 1969 1968 1969 1968 1975 5.80 4.50 6.29 10.2 6.22 8.66 7.39 12.4 1977 1977 1995 1974 1975 1994 1991 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1967 - 1998 ANNUAL TOTAL 10408.8 ANNUAL MEAN 28.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 455 LOWEST DAILY MEAN 3.6 ANNUAL SEVEN-DAY MINIMUM 4.0 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 20650 ANNUAL RUNOFF (CFSM) 3.90 ANNUAL RUNOFF (INCHES) 52.97 10 PERCENT EXCEEDS 57 50 PERCENT EXCEEDS 16 90 PERCENT EXCEEDS 5.8 16213.0 44.4 40.3 87.1 1969 17.3 1994 Oct 14 1440 Sep 21 3470 May 21 1969 May 5 5.3 Dec 16 2.2 Aug 15 1991 Apr 30 5.7 Dec 10 2.5 Aug 10 1991 22000 Sep 21 22000 Sep 21 1998 19.30 Sep 21 19.30 Sep 21 1998 1.6 Mar 13 1977 32160 29190 6.08 5.51 82.51 74.90 79 78 17 17 8.6 6.6 e Estimated 311 RIO ESPIRITU SANTO BASIN 50064200 RIO GRANDE NEAR EL VERDE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 312 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR LOCATION.--Lat 18°19'46", long 65°45'04", Hydrologic Unit 21010005, on left bank, at bridge on Highway 988, 1.4 mi (2.3 km) west of Sabana, 2.0 mi (3.2 km ) downstream from Río de la Mina, and 3.2 mi (5.1 km) southeast of Mameyes. DRAINAGE AREA.--6.88 mi2 (17.82 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1967 to December 1973, June 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 275 ft (84 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28 33 38 63 18 20 47 26 69 22 e24 39 2 e380 16 30 52 19 18 96 23 49 22 e25 129 3 e58 15 27 79 17 18 38 57 39 30 e32 59 4 e42 22 25 83 19 17 29 93 35 110 e30 44 5 e33 23 24 68 334 18 29 39 32 34 e31 55 6 e26 36 21 233 42 34 25 31 36 32 e70 65 7 e23 17 20 392 31 260 40 28 29 59 e166 284 8 76 42 18 77 48 64 50 113 40 69 104 105 9 68 116 18 62 49 23 26 50 106 88 103 84 10 34 270 18 83 29 18 23 31 48 38 47 49 11 192 35 18 42 29 16 24 27 32 29 33 39 12 85 25 16 29 34 15 65 26 332 26 38 39 13 264 24 15 63 26 15 64 56 113 23 35 139 14 490 22 15 47 38 69 34 177 51 28 28 69 15 77 47 14 25 34 32 29 108 42 59 28 225 16 58 107 14 22 26 21 377 67 71 47 78 70 17 45 84 24 21 27 22 81 45 39 35 97 49 18 66 107 21 19 25 23 110 36 e62 27 54 55 19 41 73 15 19 24 17 128 43 e45 75 65 63 20 32 61 21 19 23 96 126 42 34 82 54 58 21 28 87 45 18 23 35 67 40 41 37 151 1480 22 25 49 21 17 22 40 46 32 41 20 83 699 23 23 38 17 17 21 28 39 29 31 29 45 126 24 21 64 14 18 20 20 35 28 29 123 415 82 25 20 40 13 18 19 31 33 30 26 30 277 65 26 19 526 12 18 19 32 31 125 25 22 112 56 27 17 80 16 18 20 46 51 91 28 26 82 46 28 16 53 13 18 20 32 42 56 38 34 59 40 29 15 61 11 18 54 29 194 26 25 52 39 30 16 58 11 18 107 26 297 23 28 41 35 31 16 15 18 48 106 32 37 TOTAL 2334 2231 600 1694 1056 1289 1840 2146 1612 1341 2496 4387 MEAN 75.3 74.4 19.4 54.6 37.7 41.6 61.3 69.2 53.7 43.3 80.5 146 MAX 490 526 45 392 334 260 377 297 332 123 415 1480 MIN 15 15 11 17 17 15 23 23 23 20 24 35 AC-FT 4630 4430 1190 3360 2090 2560 3650 4260 3200 2660 4950 8700 CFSM 10.9 10.8 2.81 7.94 5.48 6.04 8.91 10.1 7.81 6.29 11.7 21.3 IN. 12.62 12.06 3.24 9.16 5.71 6.97 9.95 11.60 8.72 7.25 13.50 23.72 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 1998, BY WATER YEAR (WY) MEAN 64.0 80.0 56.9 54.3 42.1 37.5 40.9 64.5 54.8 49.4 53.8 64.1 MAX 240 191 164 105 68.0 79.7 83.1 147 112 93.4 81.4 166 (WY) 1971 1985 1971 1969 1988 1990 1973 1970 1970 1969 1988 1989 MIN 20.3 36.3 16.6 25.0 21.7 18.1 14.5 18.7 12.4 20.3 20.4 26.6 (WY) 1969 1974 1990 1985 1968 1968 1984 1973 1985 1994 1994 1986 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1967 - 1998 ANNUAL TOTAL 17732 23026 ANNUAL MEAN 48.6 63.1 55.8 HIGHEST ANNUAL MEAN 78.0 1971 LOWEST ANNUAL MEAN 33.1 1994 HIGHEST DAILY MEAN 526 Nov 26 1480 Sep 21 2780 Sep 18 1989 LOWEST DAILY MEAN 11 Dec 29 11 Dec 29 6.9 Apr 20 1970 ANNUAL SEVEN-DAY MINIMUM 13 Dec 24 13 Dec 24 9.4 Jun 12 1985 INSTANTANEOUS PEAK FLOW 12600 Sep 21 20500 Sep 18 1989 INSTANTANEOUS PEAK STAGE 11.03 Sep 21 13.19 Sep 18 1989 INSTANTANEOUS LOW FLOW 10 Dec 30 5.1 Apr 8 1970 ANNUAL RUNOFF (AC-FT) 35170 45670 40430 ANNUAL RUNOFF (CFSM) 7.06 9.17 8.11 ANNUAL RUNOFF (INCHES) 95.88 124.50 110.20 10 PERCENT EXCEEDS 80 109 100 50 PERCENT EXCEEDS 34 35 33 90 PERCENT EXCEEDS 18 18 16 e Estimated 313 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 314 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1992 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1992 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler, since 1993. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 484 mg/L September 10, 1996; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 5,390 tons (4,890 tonnes) September 21, 1998; Minimum daily mean, 0.03 tons (0.02 tonne) October 05, 1994. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean,463 mg/L March 7,1998; Minimum daily mean, 1 mg/L severals days . SEDIMENT LOADS: Maximum daily mean, 5,390 tons (4,890 tonnes) September 21, 1998; Minimum daily mean, 0.05 tons (0.04 tonne) October 27-28, 1997. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 28 2 .16 33 5 1.2 38 70 7.2 2 e380 139 e412 16 6 .20 30 43 3.6 3 e58 17 e.38 15 7 .17 27 26 1.9 4 e42 6 e1.7 22 9 .44 25 20 1.4 5 e33 1 e.90 23 12 .43 24 17 1.1 6 e26 1 e.54 36 15 1.3 21 13 .78 7 e23 1 e.29 17 19 .24 20 11 .60 8 76 27 19 42 25 4.9 18 11 .53 9 68 52 7.9 116 48 29 18 11 .50 10 34 4 .39 270 226 523 18 10 .49 11 192 104 232 35 12 1.1 18 10 .49 12 85 62 14 25 4 .27 16 9 .38 13 264 80 223 24 1 .09 15 8 .35 14 490 57 257 22 1 .06 15 13 .54 15 77 3 .61 47 18 5.1 14 11 .42 16 58 2 .38 107 41 15 14 8 .29 17 45 3 .34 84 23 9.4 24 8 .49 18 66 30 8.5 107 22 24 21 7 .45 19 41 16 1.8 73 22 5.3 15 7 .16 20 32 13 1.1 61 35 7.8 21 7 1.1 21 28 7 .56 87 15 8.5 45 6 3.0 22 25 4 .28 49 9 1.2 21 18 1.0 23 23 2 .14 38 2 .24 17 23 1.1 24 21 2 .11 64 34 7.9 14 21 .82 25 20 2 .10 40 15 1.9 13 19 .70 26 19 1 .08 526 136 514 12 18 .58 27 17 1 .05 80 37 8.1 16 16 .69 28 16 1 .05 53 23 3.3 13 10 .35 29 15 1 .06 61 47 12 11 6 .19 30 16 2 .07 58 96 15 11 4 .12 31 16 2 .08 15 4 .18 TOTAL 2334 1183.57 2231 1201.14 600 31.50 --- --- --- --- --- --- --- --- --- --- --- --- 315 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 63 36 19 18 4 .18 20 8 .41 2 52 26 3.4 19 6 .32 18 7 .34 3 79 27 9.9 17 5 .23 18 6 .31 4 83 28 9.6 19 8 5.4 17 6 .27 5 68 29 4.9 334 233 508 18 6 .31 6 233 296 270 42 12 1.5 34 8 1.4 7 392 129 357 31 3 .24 260 463 2780 8 77 47 10 48 14 5.2 64 25 5.8 9 62 18 4.1 49 43 2.7 23 7 .43 10 83 40 11 29 29 .71 18 4 .18 11 42 19 1.6 29 20 .76 16 3 .14 12 29 15 .70 34 14 1.1 15 4 .15 13 63 12 7.4 26 10 .56 15 4 .17 14 47 10 2.5 38 11 1.5 69 6 9.5 15 25 8 .57 34 12 1.1 32 7 1.0 16 22 7 .44 26 7 .52 21 4 .26 17 21 6 .36 27 5 .34 22 2 .13 18 19 5 .29 25 3 .20 23 2 .10 19 19 5 .25 24 2 .14 17 1 .06 20 19 4 .21 23 3 .18 96 6 16 21 18 4 .19 23 4 .25 35 7 1.2 22 17 4 .19 22 6 .33 40 7 1.8 23 17 3 .15 21 8 .44 28 8 .67 24 18 3 .15 20 11 .58 20 8 .32 25 18 3 .14 19 11 .58 31 9 .90 26 18 3 .13 19 10 .53 32 9 1.2 27 18 2 .12 20 9 .49 46 10 2.2 28 18 2 .11 20 8 .44 32 11 .92 29 18 2 .10 54 21 5.0 30 18 2 .10 107 23 26 31 18 3 .13 48 13 1.9 TOTAL 1694 714.73 1056 534.52 1289 2859.07 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 47 20 2.3 26 2 96 18 14 23 3 38 14 1.4 57 4 29 11 .87 93 5 29 9 .70 39 12 .86 69 46 4.9 10 .61 49 21 2.2 29 7.4 39 10 1.1 34 13 35 8 .75 12 1.3 32 8 .70 6 25 7 .49 7 40 15 4.3 8 50 36 3.0 9 26 24 .55 10 23 15 .42 31 10 .86 36 8 .77 28 9 .65 29 8 .63 113 10 49 40 9 1.6 50 16 2.5 106 49 41 31 26 .81 48 21 2.9 11 24 10 .47 12 65 28 8.1 13 64 35 5.9 14 34 7 .60 15 29 6 .58 27 40 .62 32 10 .86 26 64 .56 332 162 370 56 102 11 113 62 24 177 70 145 51 13 1.9 108 78 14 42 4 .51 16 377 243 512 67 17 81 34 8.0 45 18 110 22 30 36 19 128 57 52 43 20 126 51 19 42 45 4.9 71 25 6.2 26 1.8 39 15 1.6 15 1.1 e62 13 4.1 8 1.2 e45 12 1.8 7 1.3 34 11 1.0 21 67 21 4.1 22 46 8 .95 23 39 3 .29 24 35 2 .15 25 33 1 .10 40 3 .33 41 11 1.8 32 2 .21 41 10 1.5 29 5 .41 31 6 .51 28 12 .88 29 3 .22 30 11 .79 26 4 .28 26 31 3 .28 27 51 11 1.8 28 42 12 1.4 29 29 18 1.5 30 26 15 1.1 31 --- --- --- 125 15 27 25 6 .38 91 22 16 28 8 .57 56 30 4.1 38 8 1.4 194 84 84 26 3 .20 297 216 138 23 2 .10 106 100 12 --- --- --­ TOTAL 1840 --- 676.35 2146 --- 542.19 1612 --- 475.48 --- --- --- --- --- --- 316 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 22 1 .08 e24 17 e.37 39 14 1.7 2 22 1 .07 e25 22 e.46 129 27 25 3 30 4 .63 e32 26 e.85 59 8 1.5 4 110 28 34 e30 33 e.75 44 2 .26 5 34 23 1.0 e31 38 e.80 55 16 2.9 6 32 19 1.6 e70 44 e6.2 65 22 4.2 7 59 15 4.1 e166 43 e41 284 127 263 8 69 12 9.5 104 53 18 105 34 13 9 88 40 14 103 46 15 84 31 7.4 10 38 12 1.2 47 22 2.8 49 18 2.4 11 29 8 .65 33 18 1.7 39 14 1.5 12 26 6 .41 38 15 1.5 39 16 2.5 13 23 4 .26 35 13 1.2 139 52 33 14 28 7 .63 28 11 .79 69 35 4.7 15 59 31 7.3 28 9 .67 225 120 144 16 47 12 2.6 78 14 13 70 20 4.1 17 35 11 1.2 97 35 14 49 6 .80 18 27 11 .67 54 19 2.9 55 16 3.4 19 75 30 9.1 65 29 8.5 63 19 4.0 20 82 33 13 54 20 3.0 58 22 3.2 21 37 9 1.1 151 17 38 1480 309 5390 22 20 1 .07 83 29 8.8 699 180 580 23 29 5 1.3 45 18 2.2 126 53 18 24 123 53 24 415 128 312 82 32 7.2 25 30 13 1.0 277 44 56 65 23 4.0 26 22 8 .46 112 42 14 56 20 2.9 27 26 5 .33 82 24 7.1 46 17 1.9 28 34 8 .82 59 22 3.3 40 15 1.4 29 25 10 .54 52 20 2.5 39 13 1.3 30 28 12 .67 41 18 1.5 35 11 1.0 31 32 15 .90 37 13 1.4 TOTAL 1341 133.19 2496 580.29 4387 6530.26 YEAR 23026 15462.29 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 13... 2153 1840 722 3590 81 14... 0043 2050 288 1590 72 NOV 26... 0420 4210 1080 12300 87 26... 0510 1750 357 1690 91 APR 16... 1140 1320 972 3460 86 AUG 17... 1418 340 106 97 96 --- --- --- --- --- --- 317 RIO MAMEYES BASIN 50066000 RIO MAMEYES AT MAMEYES, PR LOCATION.--Lat 18°22'27", long 65°45'50", Hydrologic Unit 21010005, on right bank, at bridge on Highway 3, 3.1 mi (5.0 km), southwest from Luquillo,0.4 mi (0.6 km ) downstream from Quebrada Anón, and 2.9 mi (4.7 km) east from Escuela Juán González. DRAINAGE AREA.--13.4 mi2 (34.7 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1997 to current year. GAGE.--Water-stage recorder. Elevation of gage is 16.4 ft (5.0m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Discharges above 5,000 ft3/s (141.6 m3/s), are based on a rating curve extension and are rated poor. Low flow affected by water supply intake about 1,000 ft (305 m), upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e27 53 2 24 44 3 28 30 4 52 39 5 36 23 6 29 19 7 30 19 8 29 18 9 26 57 10 119 29 11 39 16 12 32 19 13 37 67 14 25 170 15 25 223 16 57 52 17 64 35 18 71 63 19 32 37 20 26 29 21 24 45 22 591 95 23 74 79 24 e37 90 69 25 43 84 267 26 57 41 700 27 39 39 82 28 33 33 55 29 27 27 54 30 e62 25 45 31 e45 38 TOTAL 1874 2533 MEAN 60.5 84.4 MAX 591 700 MIN 24 16 AC-FT 3720 5020 e Estimated 318 RIO MAMEYES BASIN 50066000 RIO MAMEYES AT MAMEYES, PR--Continued O N D J F M A M J J A S 10 1,000 20 30 40 50 70 100 200 300 400 500 700 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1996 1997 WATER YEAR --- --- --- --- --- --- --- 319 RIO MAMEYES BASIN 50066000 RIO MAMEYES AT MAMEYES, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29 33 42 58 26 20 54 35 204 25 29 49 2 560 20 33 37 28 20 131 31 97 25 23 205 3 60 17 29 64 24 19 46 67 71 39 21 94 4 45 23 26 64 27 19 32 131 60 198 19 62 5 34 27 25 57 557 66 30 50 54 30 19 82 6 29 38 23 380 55 66 27 35 59 e16 65 99 7 26 23 21 669 34 869 34 33 48 e52 190 560 8 100 43 20 106 51 161 72 172 59 85 146 207 9 97 140 19 73 79 50 29 80 144 174 149 159 10 29 476 19 94 30 36 25 40 88 33 63 74 11 443 48 20 50 26 30 25 33 49 23 34 55 12 114 29 18 35 34 29 67 30 500 16 36 47 13 568 28 16 73 25 27 108 43 200 14 37 224 14 1100 24 16 82 32 94 43 311 68 16 26 123 15 87 47 15 35 48 57 35 169 50 45 30 446 16 61 141 14 31 30 32 809 102 188 41 96 127 17 48 115 20 30 30 34 131 50 52 32 160 83 18 63 138 17 29 28 40 155 37 101 24 88 75 19 43 117 13 28 25 25 235 43 64 97 109 113 20 33 80 11 27 27 120 230 36 43 139 114 83 21 29 121 45 27 26 58 119 41 50 72 261 2660 22 27 53 17 27 24 50 71 30 58 32 148 1830 23 26 40 15 27 22 45 57 27 37 37 71 228 24 23 83 12 28 21 31 50 25 34 246 e500 126 25 21 41 9.5 31 19 44 47 26 33 62 e350 94 26 21 1000 8.1 28 19 37 45 164 32 37 205 85 27 19 122 9.6 28 19 59 66 138 34 39 155 70 28 17 65 8.2 29 20 51 56 61 48 49 93 59 29 16 63 7.7 28 106 41 615 33 35 98 56 30 17 66 13 27 143 35 1130 28 32 57 50 31 18 8.9 25 61 219 37 58 TOTAL 3803 3261 571.0 2327 1386 2499 2905 4004 2586 1802 3450 8225 MEAN 123 109 18.4 75.1 49.5 80.6 96.8 129 86.2 58.1 111 274 MAX 1100 1000 45 669 557 869 809 1130 500 246 500 2660 MIN 16 17 7.7 25 19 19 25 25 28 14 19 47 AC-FT 7540 6470 1130 4620 2750 4960 5760 7940 5130 3570 6840 16310 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 1998, BY WATER YEAR (WY) MEAN 123 109 18.4 75.1 49.5 80.6 96.8 129 86.2 58.1 85.9 179 MAX 123 109 18.4 75.1 49.5 80.6 96.8 129 86.2 58.1 111 274 (WY) 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 MIN 123 109 18.4 75.1 49.5 80.6 96.8 129 86.2 58.1 60.5 84.4 (WY) 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1997 1997 SUMMARY STATISTICS FOR 1998 WATER YEAR WATER YEARS 1997 - 1998 ANNUAL TOTAL 36819.0 ANNUAL MEAN 101 101 HIGHEST ANNUAL MEAN 101 1998 LOWEST ANNUAL MEAN 101 1998 HIGHEST DAILY MEAN 2660 Sep 21 2660 Sep 21 1998 LOWEST DAILY MEAN 7.7 Dec 29 7.7 Dec 29 1997 ANNUAL SEVEN-DAY MINIMUM 9.3 Dec 25 9.3 Dec 25 1997 INSTANTANEOUS PEAK FLOW 18400 Sep 21 18400 Sep 21 1998 INSTANTANEOUS PEAK STAGE 14.18 Sep 21 14.18 Sep 21 1998 ANNUAL RUNOFF (AC-FT) 73030 73080 10 PERCENT EXCEEDS 180 170 50 PERCENT EXCEEDS 44 43 90 PERCENT EXCEEDS 19 20 e Estimated 320 RIO MAMEYES BASIN 50066000 RIO MAMEYES AT MAMEYES, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 321 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR LOCATION.--Lat 18°19'52", long 65°43'52", Hydrologic Unit 21010005, on right bank along Highway 988, 0.3 mi (0.5 km) north of junction of Highways 988 and 983 in Sabana, and 3.3 mi (5.3 km) south of Luquillo. DRAINAGE AREA.--3.96 mi2 (10.26 km2). PERIOD OF RECORD.--October 1979 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Low-flow affected by Puerto Rico Aqueduct and Sewer Authority Water Intake 1.0 mi (1.6 km) upstream, and purification plant 0.2 mi (0.32 km). Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e61 11 12 11 6.5 2 e328 7.2 11 12 6.8 3 e28 6.8 10 10 6.3 4 e17 12 9.6 17 13 5 e13 8.9 9.2 18 226 6.6 9.3 5.6 50 7.9 4.8 9.8 6.0 13 5.5 26 8.3 4.2 47 6.0 6.8 6.7 20 12 3.8 21 5.6 5.3 12 17 77 3.7 12 11 8.5 6.3 15 15 3.3 16 6 e10 11 8.4 120 7 e9.7 6.9 7.9 194 8 22 30 7.1 29 9 26 81 7.3 19 10 28 178 7.2 25 16 16 6.1 5.2 17 9.6 6.5 13 13 71 15 6.3 13 13 16 108 26 14 16 48 14 17 17 35 22 5.5 6.0 11 65 25 12 46 11 4.4 4.9 5.4 22 e11 6.1 18 11 56 18 7.1 16 12 53 11 5.8 14 13 242 9.5 5.9 20 14 339 7.7 6.0 20 15 37 14 5.4 12 9.8 4.1 6.7 4.6 13 e9.7 5.0 14 9.8 e4.2 19 4.9 99 e21 4.3 13 9.1 e4.2 22 6.7 58 e11 5.4 41 11 20 8.0 160 21 e8.4 5.5 26 10 9.8 6.1 67 17 e18 5.0 65 16 28 64 5.2 11 17 23 26 6.9 10 18 26 31 5.0 10 19 19 24 4.3 9.9 20 16 17 4.2 9.6 8.8 5.3 246 31 40 e11 5.4 26 9.9 8.4 27 12 17 e12 24 15 8.5 9.4 22 9.0 e24 e10 9.5 13 7.0 4.3 13 8.9 19 e25 7.0 20 6.9 22 27 8.4 14 e16 7.5 15 21 14 24 12 9.4 22 13 14 6.6 8.3 23 12 12 5.0 8.3 24 11 38 3.8 8.4 25 10 15 3.4 8.4 6.0 10 20 9.4 16 e12 24 472 5.8 6.2 9.4 9.4 15 e8.6 14 296 5.5 7.6 8.4 7.2 12 e8.7 7.1 25 e5.4 6.2 8.0 6.3 12 e24 244 18 e4.9 4.9 7.0 6.2 11 e9.3 128 16 26 9.5 421 3.0 8.0 27 9.0 36 3.6 7.6 28 8.4 22 3.2 7.2 29 7.8 17 3.0 6.8 30 7.6 16 2.8 7.0 31 7.1 --- 3.7 6.7 e4.9 4.8 6.9 60 10 e6.8 28 14 5.3 7.8 9.0 29 9.9 e8.6 23 13 5.1 6.3 8.2 27 10 e8.6 16 12 --- 49 6.0 136 8.4 6.2 22 12 --- 20 5.5 401 8.7 5.3 12 9.1 --- 11 --- 53 --- 5.3 11 --­ TOTAL 1491.1 1190.0 195.6 673.6 MEAN 48.1 39.7 6.31 21.7 MAX 339 421 12 194 MIN 7.1 6.8 2.8 6.7 AC-FT 2960 2360 388 1340 CFSM 12.1 10.0 1.59 5.49 IN. 14.01 11.18 1.84 6.33 480.3 371.6 576.1 1169.0 694.0 441.3 685.1 1460.9 17.2 12.0 19.2 37.7 23.1 14.2 22.1 48.7 226 71 246 401 99 77 244 472 4.9 4.1 4.9 4.6 8.4 5.3 3.3 9.1 953 737 1140 2320 1380 875 1360 2900 4.33 3.03 4.85 9.52 5.84 3.59 5.58 12.3 4.51 3.49 5.41 10.98 6.52 4.15 6.44 13.72 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1980 - 1998, BY WATER YEAR (WY) MEAN 23.8 32.9 24.1 15.9 MAX 66.4 79.7 64.1 48.5 (WY) 1986 1988 1982 1996 MIN 6.48 8.15 3.92 6.12 (WY) 1983 1981 1990 1986 13.2 11.4 11.7 31.6 20.6 16.6 18.1 25.2 23.2 36.0 33.5 63.9 50.6 36.0 39.9 74.2 1997 1987 1990 1982 1987 1996 1995 1996 2.94 2.71 2.20 4.65 3.64 5.84 3.09 7.23 1983 1994 1984 1994 1997 1986 1994 1987 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1980 - 1998 ANNUAL TOTAL 7427.5 ANNUAL MEAN 20.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 421 LOWEST DAILY MEAN 1.6 ANNUAL SEVEN-DAY MINIMUM 2.0 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 14730 ANNUAL RUNOFF (CFSM) 5.14 ANNUAL RUNOFF (INCHES) 69.77 10 PERCENT EXCEEDS 33 50 PERCENT EXCEEDS 9.2 90 PERCENT EXCEEDS 3.4 9428.6 25.8 20.5 31.9 1996 7.85 1994 Nov 26 472 Sep 21 1100 Sep 10 1996 Jul 1 2.8 Dec 30 .96 Apr 10 1983 Jun 29 3.2 Dec 25 1.0 Apr 6 1983 4580 Sep 21 9600 Jan 5 1992 15.86 Sep 21 19.74 Jan 5 1992 .86 Apr 17 1983 18700 14820 6.52 5.17 88.57 70.19 43 38 11 8.9 5.3 2.8 e Estimated 322 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 323 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR LOCATION.--Lat 18°16'21", long 65°43'18", Hydrologic Unit 21010005, on right bank, 4.1 mi (6.6 km) from Plaza de Naguabo, 0.5 mi (0.8 km) northeast from Escuela Sonadora, 1.5 mi (2.4 km) southwest of Colonia Paraíso, and 2.5 mi (4.0 km) north from Escuela Segunda Unidad Mariana. DRAINAGE AREA.--3.69 mi2 (9.56 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Oct. 1, 1995 to Nov. 8, 1995 (estimated discharge). Nov. 9, 1995 to current year. GAGE.--Water-stage recorder. Datum of gage is 328 ft (100 m) above mean sea level, from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 12 22 45 10 10 19 19 32 18 14 31 2 90 10 20 36 10 9.9 18 18 26 19 13 67 3 12 9.9 18 42 9.2 10 16 22 24 20 13 35 4 12 12 17 41 18 9.9 15 24 23 37 12 30 5 12 14 16 40 63 9.9 18 17 23 20 12 33 6 14 17 15 88 17 14 16 15 25 19 e17 30 7 15 11 14 111 16 13 17 14 23 24 21 64 8 46 33 14 53 22 12 19 26 24 23 17 43 9 21 36 14 60 18 10 16 15 37 22 22 33 10 17 85 14 70 15 10 16 12 25 21 14 28 11 28 16 14 40 15 9.9 17 12 22 18 13 27 12 22 14 13 34 15 10 23 e11 75 17 13 27 13 91 12 13 49 14 10 21 15 40 16 14 40 14 115 12 14 37 14 18 18 23 30 20 14 31 15 23 14 13 28 14 14 18 e32 28 25 15 78 16 19 27 14 25 13 11 64 e26 34 21 20 34 17 16 26 19 23 13 10 26 e13 27 20 23 29 18 24 32 16 22 13 10 34 e12 e31 18 20 33 19 14 19 15 20 12 10 26 e12 23 24 24 38 20 12 16 e16 19 11 19 28 e23 22 20 24 31 21 11 19 e28 18 11 13 25 e35 26 18 37 e270 22 11 17 19 17 11 15 22 e21 22 17 29 139 23 10 16 22 16 11 13 22 21 20 18 25 55 24 9.9 25 19 15 10 12 22 20 20 42 128 46 25 9.9 23 19 14 10 13 21 20 20 19 93 42 26 9.6 144 19 13 10 15 21 47 19 17 e57 39 27 9.7 32 21 12 10 15 25 38 19 16 50 36 28 9.6 25 20 12 10 15 23 26 21 15 37 34 29 9.5 23 20 11 15 20 42 19 15 35 33 30 9.7 25 20 11 29 19 70 18 14 33 32 31 9.8 22 10 18 34 15 31 TOTAL 724.7 776.9 540 1032 415.2 403.6 665 735 798 628 890 1488 MEAN 23.4 25.9 17.4 33.3 14.8 13.0 22.2 23.7 26.6 20.3 28.7 49.6 MAX 115 144 28 111 63 29 64 70 75 42 128 270 MIN 9.5 9.9 13 10 9.2 9.9 15 11 18 14 12 27 AC-FT 1440 1540 1070 2050 824 801 1320 1460 1580 1250 1770 2950 CFSM 6.34 7.02 4.72 9.02 4.02 3.53 6.01 6.43 7.21 5.49 7.78 13.4 IN. 7.31 7.83 5.44 10.40 4.19 4.07 6.70 7.41 8.04 6.33 8.97 15.00 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 1998, BY WATER YEAR (WY) MEAN 22.4 33.5 24.0 40.5 22.1 13.4 15.4 22.3 29.7 25.9 29.5 67.3 MAX 23.4 54.6 28.4 49.9 33.6 14.5 22.2 30.2 50.3 42.4 41.1 121 (WY) 1998 1997 1996 1996 1997 1997 1998 1996 1996 1996 1996 1996 MIN 20.4 20.1 17.4 33.3 14.8 12.6 10.1 12.9 12.2 15.1 18.7 31.9 (WY) 1997 1996 1998 1998 1998 1996 1997 1997 1997 1997 1997 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1996 - 1998 ANNUAL TOTAL 7688.6 9096.4 ANNUAL MEAN 21.1 24.9 28.8 HIGHEST ANNUAL MEAN 37.5 1996 LOWEST ANNUAL MEAN 23.9 1997 HIGHEST DAILY MEAN 430 Sep 26 270 Sep 21 1700 Sep 10 1996 LOWEST DAILY MEAN 7.0 Apr 21 9.2 Feb 3 7.0 Apr 21 1997 ANNUAL SEVEN-DAY MINIMUM 7.2 Apr 20 9.7 Oct 25 7.2 Apr 20 1997 INSTANTANEOUS PEAK FLOW 3160 Sep 21 5110 Sep 10 1996 INSTANTANEOUS PEAK STAGE 8.78 Sep 21 10.72 Sep 10 1996 INSTANTANEOUS LOW FLOW 8.8 Feb 4 7.0 Dec 7 1995 ANNUAL RUNOFF (AC-FT) 15250 18040 20860 ANNUAL RUNOFF (CFSM) 5.71 6.75 7.80 ANNUAL RUNOFF (INCHES) 77.51 91.70 106.03 10 PERCENT EXCEEDS 29 40 47 50 PERCENT EXCEEDS 15 19 17 90 PERCENT EXCEEDS 8.4 11 9.8 e Estimated 324 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 325 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1996 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1995 to current year . INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1995. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,020 mg/L September 21, 1998; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e5,320 tons (e4,803 tonnes) September 21, 1998; Minimum daily mean, 0.01 tons (0.01 tonnes)several years. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,020 mg/L September 21, 1998; minimum daily mean, 1 mg/L several days . SEDIMENT LOADS : Maximum daily mean, e5,320 tons (e4,803 tonnes) September 21, 1998; minimum daily mean .03 ton (.02 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 12 1 .04 12 2 .05 22 1 .06 2 90 222 246 10 1 .03 20 2 .10 3 12 3 .09 9.9 1 .03 18 4 .20 4 12 3 .10 12 2 .07 17 4 .19 5 12 5 .15 14 3 .08 16 3 .14 6 14 5 .18 17 7 .16 15 2 .09 7 15 2 .09 11 3 .09 14 1 .05 8 46 61 59 33 23 7.7 14 1 .04 9 21 9 .57 36 18 3.7 14 1 .04 10 17 5 .25 85 102 92 14 1 .04 11 28 19 5.6 16 3 .13 14 2 .06 12 22 12 1.0 14 2 .07 13 2 .07 13 91 98 72 12 2 .07 13 2 .08 14 115 212 248 12 1 .04 14 3 .10 15 23 2 .15 14 2 .13 13 3 .10 16 19 2 .09 27 4 .74 14 2 .09 17 16 1 .05 26 10 1.0 19 2 .10 18 24 9 .77 32 19 3.4 16 1 .06 19 14 5 .19 19 9 .55 15 1 .05 20 12 1 .04 16 2 .06 e16 2 e.13 21 11 1 .03 19 1 .06 e28 11 e1.0 22 11 1 .04 17 1 .05 19 1 .06 23 10 3 .07 16 1 .05 22 4 .27 24 9.9 4 .11 25 4 .41 19 1 .06 25 9.9 3 .07 23 5 .62 19 1 .05 26 9.6 2 .04 144 106 77 19 1 .05 27 9.7 1 .03 32 1 .12 21 4 .24 28 9.6 1 .03 25 1 .07 20 3 .15 29 9.5 1 .03 23 1 .06 20 1 .06 30 9.7 2 .04 25 1 .42 20 2 .08 31 9.8 2 .05 22 3 .16 TOTAL 724.7 634.90 776.9 188.96 540 3.97 --- --- --- --- --- --- --- --- --- --- --- --- 326 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 45 35 11 10 2 .06 10 2 .04 2 36 8 .96 10 3 .07 9.9 1 .03 3 42 9 1.6 9.2 8 .20 10 1 .03 4 41 8 1.2 18 72 108 9.9 1 .03 5 40 2 .18 63 115 72 9.9 1 .04 6 88 78 29 17 3 .12 14 4 .20 7 111 68 36 16 2 .10 13 2 .07 8 53 17 2.5 22 7 .86 12 2 .05 9 60 34 6.2 18 4 .24 10 2 .06 10 70 39 8.1 15 2 .06 10 2 .05 11 40 10 1.1 15 1 .05 9.9 2 .05 12 34 3 .29 15 2 .06 10 2 .05 13 49 16 2.7 14 2 .07 10 2 .05 14 37 3 .40 14 2 .09 18 5 .38 15 28 2 .11 14 1 .08 14 4 .18 16 25 1 .08 13 1 .04 11 1 .04 17 23 1 .09 13 2 .05 10 1 .03 18 22 4 .23 13 2 .06 10 1 .03 19 20 8 .41 12 1 .04 10 1 .03 20 19 5 .24 11 1 .04 19 7 .49 21 18 3 .14 11 2 .05 13 3 .10 22 17 2 .11 11 3 .08 15 4 .19 23 16 2 .09 11 3 .09 13 4 .12 24 15 3 .13 10 2 .05 12 2 .06 25 14 5 .19 10 1 .04 13 1 .04 26 13 5 .20 10 3 .08 15 1 .04 27 12 2 .08 10 5 .14 15 2 .11 28 12 1 .04 10 3 .08 15 2 .08 29 11 2 .05 15 2 .08 30 11 2 .06 29 15 2.5 31 10 3 .08 18 4 .22 TOTAL 1032 103.56 415.2 182.90 403.6 5.47 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 19 4 .18 19 2 18 4 .18 18 3 16 4 .19 22 4 15 3 .11 24 5 18 2 .21 17 1 .05 32 15 1.5 1 .05 26 19 1.3 4 .28 24 12 .79 9 .64 23 3 .20 4 .18 23 1 .06 6 16 2 .09 7 17 5 .34 8 19 16 .86 9 16 4 .17 10 16 1 .05 15 1 .04 25 1 .07 14 1 .04 23 1 .06 26 13 2.7 24 1 .06 15 4 .16 37 13 2.7 12 3 .09 25 3 .23 11 17 1 .05 12 23 8 .58 13 21 3 .17 14 18 1 .06 15 18 1 .07 12 2 .06 22 2 .12 e11 2 e.07 75 162 99 15 5 .37 40 13 2.0 23 15 2.5 30 3 .24 e32 29 e8.3 28 3 .22 16 64 53 13 17 26 5 .35 18 34 16 2.3 19 26 6 .40 20 28 6 .54 e26 10 e1.1 34 5 .48 e13 2 e.07 27 1 .08 e12 1 e.05 e31 1 e.81 e12 4 e.13 23 1 .06 e23 14 e1.9 22 1 .06 21 25 3 .22 22 22 2 .14 23 22 2 .10 24 22 1 .06 25 21 1 .08 e35 17 e1.7 26 4 .34 e21 7 e.39 22 2 .14 21 4 .24 20 1 .07 20 3 .15 20 1 .05 20 2 .11 20 1 .05 26 21 2 .10 27 25 4 .24 28 23 2 .12 29 20 1 .06 30 19 1 .05 31 --- --- --- 47 44 9.1 19 1 .05 38 13 3.0 19 1 .05 26 3 .24 21 1 .06 42 22 6.2 19 1 .05 70 59 16 18 1 .05 34 11 1.0 --- --- --­ TOTAL 665 --- 21.07 735 --- 56.91 798 --- 110.95 --- --- --- --- --- --- 327 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 18 1 .05 14 2 .06 31 9 .80 2 19 2 .11 13 1 .04 67 45 11 3 20 4 .20 13 1 .04 35 11 1.1 4 37 17 2.9 12 1 .03 30 4 .34 5 20 4 .22 12 1 .03 33 5 .89 6 19 2 .11 e17 4 e.19 30 7 .65 7 24 8 .58 21 11 1.1 64 62 23 8 23 7 .43 17 3 .15 43 25 3.8 9 22 2 .30 22 2 .14 33 10 .93 10 21 6 .34 14 2 .07 28 5 .41 11 18 4 .17 13 1 .05 27 4 .26 12 17 2 .08 13 1 .04 27 7 .50 13 16 1 .05 14 1 .04 40 16 2.3 14 20 3 .24 14 1 .04 31 6 .51 15 25 8 .55 15 1 .04 78 50 28 16 21 4 .28 20 2 .27 34 14 1.3 17 20 4 .23 23 6 .45 29 11 .86 18 18 2 .11 20 6 .31 33 12 1.2 19 24 1 .09 24 9 .77 38 18 2.1 20 20 2 .13 24 6 .41 31 7 .60 21 18 2 .12 37 18 2.5 e270 1020 e5320 22 17 2 .09 29 5 .38 139 139 89 23 18 6 .30 25 2 .14 55 6 .85 24 42 23 4.2 128 142 107 46 4 .46 25 19 12 .61 93 28 22 42 3 .34 26 17 10 .46 e57 9 e1.3 39 3 .32 27 16 6 .27 50 8 1.1 36 3 .29 28 15 1 .05 37 7 .70 34 3 .28 29 15 1 .04 35 7 .70 33 3 .27 30 14 2 .06 33 8 .68 32 3 .26 31 15 2 .08 31 8 .67 TOTAL 628 13.45 890 141.44 1488 5492.62 YEAR 9096.4 6956.20 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 16... 0101 515 949 1320 66 NOV 10... 0315 190 258 132 90 26... 0434 347 424 397 85 26... 1330 164 68 30 74 JAN 07... 0129 395 618 659 90 07... 0700 127 25 8.6 92 FEB 05... 0044 224 950 575 82 MAY 29... 2315 162 185 81 91 SEP 15... 1315 190 322 165 92 328 RIO FAJARDO BASIN 50070500 RIO FAJARDO ABOVE FAJARDO, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) FEB 04... 2359 876 4270 10100 20 25 36 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) FEB 04... 46 59 67 88 97 98 99 --- --- --- --- --- --- --- 329 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR LOCATION.--Lat 18°17'56", long 65°41'42", Hydrologic Unit 21010005, on left bank off Highway 976, 0.1 mi (0.2 km) upstream from Highway 977 bridge, 0.3 mi (0.5 km) downstream from Quebrada Peñón, 1.1 mi (1.8 km) northeast of Colonia Paraíso, and 3.3 mi (5.3 km) southwest of Fajardo. DRAINAGE AREA.--14.9 mi2 (38.6 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1960-61 (occasional low and peak-flow measurements only), March 1961 to current year. GAGE.--Water-stage recorder. Datum of gage is 137.60 ft (41.940 m) above mean sea level. Due to flood damage, gage datum has had changes as follows: Mar. 24, 1961 to May 5, 1969, 138.95 ft (42.352 m); May 6, 1969 to Mar. 16, 1972, 135.05 ft (41.163 m); Mar. 17, 1972 to Mar 25, 1975, 138.60 ft (42.245 m). REMARKS.--Records fair except those for estimated daily discharges, which are poor. Low-flow affected by diversions for water supply about 1,312.3 ft (400 m) upstream from gaging station (estimated mean daily discharges is 9.0 ft3/s (0.255 m3/s). Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 27 109 197 12 15 78 19 114 15 18 28 2 575 21 91 42 14 14 51 16 54 17 14 378 3 37 18 88 50 12 13 34 32 36 21 13 99 4 22 24 82 37 24 13 26 57 28 243 12 37 5 15 32 74 35 707 12 161 24 23 43 11 41 6 14 43 69 521 68 47 44 17 30 25 e46 36 7 13 23 66 775 39 341 45 20 21 65 e74 315 8 152 199 63 97 208 41 67 152 20 56 40 162 9 58 515 62 214 152 21 28 51 129 47 94 80 10 18 868 59 356 44 17 26 21 41 42 29 39 11 71 50 56 52 33 15 26 16 17 23 17 28 12 66 29 50 38 33 13 78 14 421 43 15 23 13 688 20 49 75 27 12 86 29 240 20 17 112 14 1250 16 49 58 27 145 31 208 61 26 15 60 15 236 23 49 32 31 74 27 253 51 99 15 491 16 144 144 45 26 23 35 659 137 168 67 36 114 17 91 95 75 24 23 17 89 36 51 53 65 48 18 147 163 50 22 24 15 165 25 e101 41 29 64 19 71 58 45 22 21 12 54 26 e46 101 45 192 20 49 23 42 21 19 97 64 48 36 54 46 58 21 42 26 111 20 18 29 61 55 81 41 143 e762 22 38 21 69 18 17 33 30 22 55 26 50 e452 23 37 17 67 18 16 23 26 21 31 36 28 e109 24 32 65 54 18 15 15 26 20 29 329 833 e92 25 30 19 43 17 13 15 21 20 27 56 493 e84 26 30 1700 41 15 13 25 22 189 23 31 102 e80 27 27 349 47 15 13 32 36 238 21 24 219 e73 28 22 171 41 14 13 26 31 55 31 22 61 e69 29 22 126 35 13 44 21 198 21 20 58 63 30 21 156 33 13 262 20 674 17 19 34 57 31 20 34 14 101 134 22 37 TOTAL 4051 5041 1848 2869 1659 1574 2133 2827 2024 1727 2709 4246 MEAN 131 168 59.6 92.5 59.3 50.8 71.1 91.2 67.5 55.7 87.4 142 MAX 1250 1700 111 775 707 341 659 674 421 329 833 762 MIN 13 16 33 13 12 12 20 14 17 15 11 23 AC-FT 8040 10000 3670 5690 3290 3120 4230 5610 4010 3430 5370 8420 CFSM 8.77 11.3 4.00 6.21 3.98 3.41 4.77 6.12 4.53 3.74 5.86 9.50 IN. 10.11 12.59 4.61 7.16 4.14 3.93 5.33 7.06 5.05 4.31 6.76 10.60 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1961 - 1998, BY WATER YEAR (WY) MEAN 92.1 106 79.1 49.0 39.3 35.4 44.1 90.0 59.4 50.7 56.8 89.3 MAX 260 295 237 150 80.4 109 129 399 166 132 159 421 (WY) 1971 1975 1976 1996 1982 1987 1963 1979 1962 1969 1979 1989 MIN 19.1 26.0 14.9 15.4 10.8 9.70 4.02 17.7 10.0 11.4 9.70 18.9 (WY) 1969 1994 1990 1977 1983 1977 1984 1973 1985 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1961 - 1998 ANNUAL TOTAL 23004.6 32708 ANNUAL MEAN 63.0 89.6 66.4 HIGHEST ANNUAL MEAN 140 1979 LOWEST ANNUAL MEAN 19.0 1994 HIGHEST DAILY MEAN 1700 Nov 26 1700 Nov 26 8800 Sep 18 1989 LOWEST DAILY MEAN 6.5 Jul 7 11 Aug 5 1.0 May 6 1984 ANNUAL SEVEN-DAY MINIMUM 7.2 Jul 1 13 Jan 28 1.5 Apr 18 1984 INSTANTANEOUS PEAK FLOW 8480 Sep 21 21700 Sep 18 1989 INSTANTANEOUS PEAK STAGE 10.99 Sep 21 20.00 Sep 18 1989 INSTANTANEOUS LOW FLOW .86 May 3 1984 ANNUAL RUNOFF (AC-FT) 45630 64880 48080 ANNUAL RUNOFF (CFSM) 4.23 6.01 4.45 ANNUAL RUNOFF (INCHES) 57.43 81.66 60.52 10 PERCENT EXCEEDS 124 194 129 50 PERCENT EXCEEDS 27 38 32 90 PERCENT EXCEEDS 12 15 11 e Estimated 330 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 331 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1982 to September 1986 and October 1995 to current year. INSTRUMENTATION.--Automatic sediment sampler since October 1983. EXTREMES FOR PERIOD OF RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,210 mg/L October 6, 1985; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 22,100 tons (20,000 tonnes) October 6, 1985; Minimum daily mean, 0.01 tons (0.01 tonnes) May 06, 1996. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 354 mg/L November 10, 1997; minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e2,110 tons (e1,910 tonnes) September 21, 1998; minimum daily 0.04 tons (0.03 tonnes) February 26 and March 4, 1998. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, INST. CIFIC WHOLE SOLVED CHEM- FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) OCT 27... 1000 31 127 7.3 27.0 .57 7.5 93 <10 210 MAR 30... 0915 22 117 6.6 24.0 3.0 8.8 106 <10 K1800 JUN 03... 0930 37 104 6.9 26.0 2.1 8.0 99 <10 40 AUG 25... 1010 278 60 6.2 24.5 21 8.0 96 <10 2400 STREP- HARD- MAGNE- TOCOCCI NESS CALCIUM SIUM, SODIUM, FECAL, TOTAL DIS- DIS- DIS- (COLS. (MG/L SOLVED SOLVED SOLVED DATE PER AS (MG/L (MG/L (MG/L 100 ML) CACO3) AS CA) AS MG) AS NA) (31679) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER AD- SIUM, UNFLTRD SULFATE SORP- DIS- FET SULFIDE DIS­ TION SOLVED FIELD TOTAL SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L AS K) CACO3 AS S) AS SO4) (00931) (00935) (00410) (00745) (00945) OCT 27... 860 34 7.5 3.7 12 .9 1.1 39 <.5 3.3 MAR 30... 40 -- -- -- -- -- -- 44 -- -­ JUN 03... 70 27 5.8 3.0 9.5 .8 .95 34 -- 3.1 AUG 25... 4900 14 3.0 1.5 5.7 .7 1.3 13 <1.0 2.7 SOLIDS, RESIDUE CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO­ RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) (00940) (00950) (00955) (70301) (70302) (00530) (00615) (00630) (00610) (00605) OCT 27... 13 <.10 25 89 7.46 <1 <.010 .080 <.010 -­ MAR 30... -- -- -- -- -- <1 <.010 .180 .020 <.02 JUN 03... 11 <.10 24 78 7.68 3 <.010 .170 <.010 -­ AUG 25... 7.5 <.10 12 41 31.0 18 <.010 .230 .060 .35 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... .33 .41 1.8 .040 <1 <100 20 <1 <1 <10 MAR 30... <.20 .33 1.5 <.020 -- -- -- -- -- -­ JUN 03... <.20 -- -- <.020 <1 <100 30 <1 <1 <10 AUG 25... .41 .64 2.8 .050 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 332 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 220 <1 12 <.10 <1 <1 <10 <.010 3 .04 MAR 30... JUN 03... 170 <1 10 <.10 <1 <1 <10 <.010 <1 <.02 AUG 25... SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 13 7 .24 27 2 575 228 1020 21 3 37 13 1.6 18 4 22 4 .22 24 5 15 8 .33 32 17 1.2 109 6 1.8 16 .92 91 6 1.5 15 .74 88 6 1.5 15 1.0 82 7 1.5 16 1.4 74 7 1.4 6 14 12 .44 7 13 15 .54 8 152 64 80 9 58 26 4.6 10 18 18 .85 43 21 2.5 69 7 1.3 23 17 1.0 66 7 1.3 199 75 103 63 7 1.2 515 128 214 62 7 1.2 868 354 1800 59 8 1.2 11 71 31 21 50 12 66 28 9.1 29 13 688 173 738 20 14 1250 189 1660 16 15 236 5 3.2 23 22 3.2 56 8 1.2 11 .92 50 8 1.1 6 .32 49 8 1.1 6 .25 49 8 1.1 17 1.9 49 9 1.1 16 144 5 1.9 17 91 3 .82 18 147 29 17 19 71 33 6.7 20 49 9 1.2 144 49 35 45 9 2.0 95 20 8.9 75 9 5.3 163 35 52 50 9 2.4 58 17 4.3 45 10 2.0 23 6 .35 42 10 1.8 21 42 11 1.2 26 22 38 21 2.1 21 23 37 19 1.9 17 24 32 16 1.4 65 25 30 15 1.2 19 8 .62 111 10 12 5 .27 69 10 4.5 6 .26 67 10 4.8 25 6.1 54 11 2.8 16 .86 43 11 1.8 26 30 15 1.2 27 27 15 1.1 28 22 16 .96 29 22 17 .97 30 21 17 .96 31 20 18 .95 1700 155 737 41 11 1.7 349 54 59 47 11 2.2 171 10 4.7 41 12 1.6 126 6 2.0 35 12 1.2 156 12 6.0 33 12 1.1 --- --- --- 34 13 1.2 TOTAL 4051 --- 3581.68 5041 --- 3049.71 1848 --- 67.9 --- --- --- --- --- --- --- --- --- --- --- --- 333 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 197 58 99 12 9 .29 15 3 .11 2 42 30 5.3 14 12 .44 14 4 .14 3 50 26 6.9 12 8 .26 13 2 .08 4 37 20 2.4 24 6 3.5 13 1 .04 5 35 11 1.2 707 289 1040 12 1 .05 6 521 134 372 68 9 2.0 47 24 4.5 7 775 223 671 39 3 .32 341 122 247 8 97 21 6.8 208 38 93 41 6 .84 9 214 59 65 152 67 45 21 2 .12 10 356 80 111 44 4 .47 17 2 .09 11 52 10 1.7 33 2 .18 15 2 .09 12 38 6 .62 33 2 .18 13 2 .08 13 75 20 7.1 27 2 .14 12 3 .09 14 58 23 4.5 27 3 .21 145 46 38 15 32 14 1.2 31 4 .36 74 32 7.5 16 26 7 .49 23 3 .21 35 7 .83 17 24 4 .24 23 4 .27 17 4 .18 18 22 6 .35 24 6 .41 15 4 .16 19 22 11 .63 21 5 .26 12 4 .13 20 21 8 .43 19 3 .15 97 37 19 21 20 4 .20 18 2 .08 29 11 .89 22 18 3 .15 17 1 .05 33 11 1.4 23 18 3 .16 16 1 .06 23 16 1.0 24 18 6 .28 15 2 .07 15 8 .31 25 17 11 .51 13 2 .05 15 8 .33 26 15 9 .39 13 1 .04 25 15 1.3 27 15 6 .26 13 1 .05 32 13 1.2 28 14 4 .17 13 2 .07 26 7 .54 29 13 3 .12 44 20 3.6 30 13 4 .14 262 101 164 31 14 6 .22 101 57 20 TOTAL 2869 1360.46 1659 1188.12 1574 513.60 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 78 13 3.5 19 2 51 14 2.3 16 3 34 17 1.6 32 4 26 12 .87 57 5 161 59 63 24 15 .76 114 23 12 12 .52 54 5 .75 13 1.5 36 4 .41 23 5.0 28 4 .30 19 1.3 23 4 .25 6 44 16 2.1 7 45 13 3.8 8 67 33 7.7 9 28 9 .66 10 26 8 .57 17 7 .33 30 12 1.0 20 5 .26 21 11 .64 152 36 38 20 9 .48 51 13 2.7 129 38 35 21 6 .33 41 23 3.1 11 26 10 .69 12 78 28 7.4 13 86 19 7.0 14 31 11 .94 15 27 21 1.5 16 6 .26 17 6 .28 14 5 .21 421 170 445 29 11 1.4 240 71 76 208 74 87 61 19 3.3 253 69 102 51 9 1.2 16 659 128 297 137 17 89 12 3.8 36 18 165 47 52 25 19 54 11 1.8 26 20 64 32 6.3 48 51 34 168 56 38 10 1.0 51 9 1.4 6 .42 e101 34 e10 4 .31 e46 12 e1.7 14 4.9 36 6 .60 21 61 16 4.0 22 30 5 .44 23 26 6 .41 24 26 6 .45 25 21 7 .39 55 31 5.2 81 17 6.9 22 12 .72 55 20 3.2 21 5 .29 31 7 .63 20 8 .42 29 4 .35 20 16 .84 27 3 .24 26 22 6 .35 27 36 5 .45 28 31 5 .40 29 21 6 .33 30 20 9 .50 31 --- --- --- 189 235 283 23 3 .21 238 57 108 21 4 .23 55 13 2.9 31 10 .94 198 104 77 21 4 .25 674 96 185 17 3 .12 134 36 13 --- --- --­ TOTAL 2133 --- 472.25 2827 --- 958.57 2024 --- 644.48 --- --- --- --- --- --- 334 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 15 2 .09 18 5 .26 28 17 1.3 2 17 4 .18 14 6 .24 378 112 176 3 21 6 .36 13 10 .35 99 28 11 4 243 81 124 12 15 .49 37 6 .62 5 43 7 .96 11 10 .29 41 10 1.7 6 25 2 .13 e46 22 e1.7 36 20 2.0 7 65 12 3.2 e74 45 e7.2 315 109 178 8 56 25 5.1 40 11 1.4 162 65 43 9 47 12 1.7 94 11 9.4 80 15 3.2 10 42 10 1.4 29 12 .99 39 16 1.7 11 23 3 .18 17 8 .34 28 13 .95 12 43 14 3.1 15 7 .28 23 11 .71 13 20 8 .51 17 4 .20 112 36 22 14 26 5 .95 15 2 .10 60 34 6.6 15 99 7 10 15 2 .10 491 132 362 16 67 10 5.1 36 13 2.3 114 66 22 17 53 14 3.2 65 27 7.2 48 28 3.8 18 41 17 1.8 29 8 .75 64 30 7.5 19 101 20 10 45 12 4.7 192 68 54 20 54 22 3.0 46 11 1.7 58 22 3.6 21 41 8 1.0 143 50 33 e762 293 e2110 22 26 4 .35 50 6 .74 e452 139 e239 23 36 15 1.8 28 4 .26 e109 36 e11 24 329 88 114 833 337 1650 e92 31 e11 25 56 4 .72 493 156 138 e84 29 e3.2 26 31 3 .27 102 34 11 e80 27 e3.2 27 24 5 .34 219 69 84 e73 26 e1.4 28 22 6 .34 61 11 2.1 e69 24 e3.8 29 20 4 .25 58 17 3.1 63 22 3.8 30 19 4 .21 34 6 .52 57 21 3.2 31 22 4 .26 37 9 .85 TOTAL 1727 294.50 2709 1963.56 4246 3291.28 YEAR 32708 17386.11 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- SEDI- SED. CHARGE, MENT, SUSP. INST. SEDI- DIS- SIEVE CUBIC MENT, CHARGE, DIAM. FEET SUS- SUS- % FINER DATE TIME PER PENDED PENDED THAN SECOND (MG/L) (T/DAY) .062 MM (00061) (80154) (80155) (70331) NOV 09... 0930 840 177 401 100 26... 1340 1940 231 1210 95 MAY 08... 1545 71 98 19 96 29... 1915 490 181 239 99 30... 1845 598 60 97 98 AUG 24... 1718 3880 1230 12900 88 335 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°19'35", long 65°38'47", 1.2 mi (1.9 km) southwest of Playa de Fajardo, and 0.5 mi (0.8 km) east of Fajardo plaza. DRAINAGE AREA.--23.4 mi2 (60.6 km2). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 27... 1235 21 154 7.4 29.0 .60 8.8 114 <10 470 200 MAR 30... 1045 31 129 6.8 25.5 36 8.4 102 <10 2400 2200 JUN 03... 1100 50 125 7.0 28.5 3.6 8.6 111 <10 340 80 AUG 25... 1200 304 73 7.1 26.5 52 7.3 91 <10 6000 5700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 27... 42 9.2 4.6 14 .9 1.3 46 <.5 4.9 16 MAR 30... -- -- -- -- -- -- 48 -- -- -­ JUN 03... 33 7.1 3.8 11 .8 1.2 39 -- 4.0 13 AUG 25... 16 3.5 1.8 6.9 .7 1.6 45 <1.0 3.6 8.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 27... <.10 19 96 5.40 <1 -- <.010 .060 .020 -­ MAR 30... -- -- -- -- 17 -- -- -- -- -­ JUN 03... <.10 22 85 11.6 2 -- <.010 .180 .010 -­ AUG 25... <.10 13 66 53.9 40 .219 .011 .230 .060 .41 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 27... <.20 -- -- .040 <1 <100 20 <1 <1 <10 MAR 30... -- -- -- -- -- -- -- -- -- -­ JUN 03... <.20 -- -- <.020 <1 <100 30 <1 <1 <10 AUG 25... .47 .70 3.1 .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 336 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 27... 220 <1 40 <.10 <1 <1 <10 <.010 3 <.02 MAR 30... JUN 03... 230 <1 39 <.10 <1 <1 <10 <.010 <1 <.02 AUG 25... --- --- --- --- --- --- --- 337 RIO BLANCO BASIN 50074950 QUEBRADA GUABA NEAR NAGUABO, PR LOCATION.--Lat 18°17'02", long 65°47'20", Hydrologic Unit 21010005, on right bank, off Highway 191 at El Yunque Caribbean National Forest, 4.8 mi (7.7 km) southeast of Campamento Eliza Colberg, 1.3 mi (2.1 km) southeast of Mt. Britton, 2.0 mi (3.2 km) northwest of Pico del Este and 7.3 mi (11.7 km) southeast of Río Grande Plaza. DRAINAGE AREA.--0.05 mi2 (0.13 km2). PERIOD OF RECORD.--June 1992 to current year. GAGE.--Water-stage recorder. Elevation of gage is 2,100 ft (640 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .35 e.55 .48 .92 .35 .13 .18 .12 .31 .18 .23 .43 2 2.3 e.41 .45 .61 .32 .11 .35 .13 .27 .18 .21 1.1 3 .57 e.44 .41 .91 .28 .10 .13 .25 .28 .22 .21 .42 4 .44 e.50 .37 .70 1.3 .09 .11 .51 .24 .32 .20 .37 5 .43 e.56 .39 .60 1.7 .09 .11 .17 .24 .20 .20 .38 6 .34 e.62 .35 1.6 .37 .10 .08 .16 .27 .26 e.45 .43 7 .34 e.37 .34 3.4 .30 .29 .14 .18 .19 .35 e.68 1.0 8 1.7 e.84 .34 .85 .45 .20 .14 .80 .20 .28 .40 .44 9 .54 e1.0 .33 .95 .34 .12 .09 .32 .55 .32 .55 .40 10 .41 e2.5 .27 1.1 .27 .10 .08 .19 .22 .24 .30 .35 11 1.3 e.40 .25 .63 .30 .09 .10 .17 .15 .22 .24 .33 12 .80 e.30 .27 .52 .27 .09 .40 .17 1.4 .21 .28 .39 13 4.4 .28 .27 .64 .24 .09 .23 .79 .30 .19 .25 1.0 14 4.0 .26 .27 .58 .21 .25 .12 .91 .22 .36 .22 .54 15 e.80 .28 .23 .57 .18 .18 .11 .70 .20 .63 .22 1.4 16 e.76 .45 .23 .49 .16 .12 1.9 .46 .23 .34 .32 .48 17 e.70 .46 .30 .46 .14 .10 .21 .40 .26 .32 .26 .41 18 e.78 .67 .40 .46 .14 .10 .25 .30 e.35 .29 .23 .46 19 e.70 .40 .29 .41 .11 .10 .39 .28 .25 .44 .85 .45 20 e.68 .31 .34 .41 .11 .47 .23 e.42 .24 .35 .34 .50 21 e.67 .57 .41 .38 .11 .16 .14 e.25 .29 .30 .77 14 22 e.65 .35 .27 .35 .10 .18 .12 e.22 .25 .25 .38 6.0 23 e.60 .30 .52 .31 .10 .13 .11 e.24 .23 .33 .28 .86 24 e.54 .38 .39 .31 .08 .10 .10 e.25 .22 1.6 2.9 .68 25 e.45 .31 .35 .30 .09 .15 .12 e.31 .21 .37 1.5 .65 26 e.43 3.3 .30 .28 .10 .20 .13 .92 .20 .32 .52 .62 27 e.40 .50 .28 .30 .12 .30 .22 .50 .22 .31 .48 .64 28 e.40 .41 .25 .29 .13 .16 .18 .29 .22 .29 .41 .61 29 e.38 .47 .22 .29 .12 .14 .78 .19 .27 .45 .51 30 e.40 .61 .22 .33 .23 .15 .67 .18 .27 .41 .53 31 e.39 .37 .40 .16 .48 .32 .38 TOTAL 27.65 18.80 10.16 20.35 8.37 4.81 6.76 12.34 8.58 10.53 15.12 36.38 MEAN .89 .63 .33 .66 .30 .16 .23 .40 .29 .34 .49 1.21 MAX 4.4 3.3 .52 3.4 1.7 .47 1.9 .92 1.4 1.6 2.9 14 MIN .34 .26 .22 .28 .08 .09 .08 .12 .15 .18 .20 .33 AC-FT 55 37 20 40 17 9.5 13 24 17 21 30 72 CFSM 7.43 5.22 2.73 5.47 2.49 1.29 1.88 3.32 2.38 2.83 4.06 10.1 IN. 8.57 5.83 3.15 6.31 2.59 1.49 2.10 3.83 2.66 3.26 4.69 11.28 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 1998, BY WATER YEAR (WY) MEAN .42 .51 .39 .50 .41 .26 .27 .39 .37 .50 .39 .67 MAX .89 .76 .61 .67 .60 .30 .33 .61 .50 1.18 .56 1.42 (WY) 1998 1993 1993 1997 1994 1995 1994 1993 1996 1992 1992 1996 MIN .25 .32 .22 .28 .30 .16 .21 .32 .29 .22 .19 .34 (WY) 1993 1995 1994 1994 1998 1998 1995 1996 1998 1994 1993 1993 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1992 - 1998 ANNUAL TOTAL 162.95 179.85 ANNUAL MEAN .45 .49 .42 HIGHEST ANNUAL MEAN .49 1998 LOWEST ANNUAL MEAN .32 1994 HIGHEST DAILY MEAN 5.3 Jun 2 14 Sep 21 23 Sep 10 1996 LOWEST DAILY MEAN .08 May 5 .08 Feb 24 .08 May 5 1997 ANNUAL SEVEN-DAY MINIMUM .09 Apr 30 .10 Feb 20 .09 Apr 30 1997 INSTANTANEOUS PEAK FLOW 104 Sep 21 104 Sep 21 1998 INSTANTANEOUS PEAK STAGE 10.78 Sep 21 10.78 Sep 21 1998 INSTANTANEOUS LOW FLOW .05 May 1 1997 ANNUAL RUNOFF (AC-FT) 323 357 301 ANNUAL RUNOFF (CFSM) 3.72 4.11 3.47 ANNUAL RUNOFF (INCHES) 50.51 55.75 47.11 10 PERCENT EXCEEDS .70 .79 .71 50 PERCENT EXCEEDS .34 .32 .29 90 PERCENT EXCEEDS .16 .12 .15 e Estimated 338 RIO BLANCO BASIN 50074950 QUEBRADA GUABA NEAR NAGUABO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 1997 1998 WATER YEAR 339 RIO BLANCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR LOCATION.--Lat 18°16'38", long 65°47'09", Hydrologic Unit 21010005, in Caribbean National Forest, at Highway 191, at El Yunque, 1.6 mi (2.6 km) upstream from confluence with Río Cubuy, 2.8 mi (4.5 km) north of Florida, and 5.3 mi (8.5 km) northwest of Naguabo Plaza. DRAINAGE AREA.--1.26 mi2 (3.26 km2). PERIOD OF RECORD.--July 1945 to March 1953 (operated by Puerto Rico Water Resources Authority), annual maximum, water years 1953-62, annual low-flow measurements 1962-66, October 1979 to current year. GAGE.--Water-stage recorder, crest-stage gage and sharp-crested weir. Elevation of gage is 2,020 ft (616 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.4 11 11 32 5.7 2 81 6.1 9.0 17 5.7 3 11 6.7 8.0 28 5.7 4.7 10 5.8 12 4.5 6.0 14 4.6 21 5.5 8.9 4.3 5.6 54 4.6 7.6 11 7.7 6.0 5.2 15 4 8.0 8.8 6.8 25 20 4.5 5.7 21 6.9 21 5.0 11 5 6.6 9.9 6.4 18 92 4.4 5.1 7.1 6.7 9.0 5.0 14 6 5.8 12 5.7 65 8.8 5.1 4.5 6.0 10 15 19 e26 7 6.1 5.5 5.7 131 8 70 17 5.1 23 9 21 23 5.1 26 10 10 87 5.1 39 6.6 27 7.2 5.7 6.9 22 36 e103 16 9.0 6.8 33 9.8 17 25 e32 9.7 5.8 4.5 11 32 19 34 e44 6.2 5.7 4.2 8.7 10 11 13 e22 11 41 7.4 4.8 15 12 16 6.0 4.5 14 13 132 5.8 4.7 22 14 152 5.7 4.8 17 15 16 7.8 4.5 11 8.8 5.4 4.1 7.5 6.7 6.6 8.7 e12 8.6 5.4 21 8.2 85 5.0 11 13 6.5 5.9 10 29 22 4.7 9.3 52 9.6 17 4.6 31 10 14 7.1 32 7.2 10 5.1 23 7.3 28 6.6 70 16 15 23 4.6 9.5 17 12 26 7.7 9.0 18 18 35 11 8.5 19 12 15 4.1 8.8 20 11 10 8.4 8.2 6.4 6.7 92 12 12 21 20 e17 6.3 6.0 11 9.4 7.9 16 18 11 6.0 5.9 18 6.9 14 14 9.6 17 5.7 5.7 32 7.4 6.9 24 31 e15 5.7 30 15 17 6.0 21 15 18 21 11 27 15 8.0 22 10 11 4.9 8.0 23 8.5 7.9 9.8 7.3 24 7.2 16 4.8 7.2 25 7.2 11 4.3 7.2 5.7 8.2 7.2 9.4 12 13 39 254 5.4 8.9 6.1 6.5 8.6 11 17 158 5.1 5.4 7.2 7.1 6.0 14 6.5 24 5.1 4.5 5.8 7.5 5.8 72 117 16 4.9 7.4 5.9 9.4 6.0 12 e72 15 26 7.0 139 4.0 7.0 27 6.4 14 4.2 6.6 28 6.4 11 4.4 6.4 29 6.0 16 4.5 6.4 30 6.2 18 4.5 5.9 31 6.0 --- 8.5 6.0 4.8 9.4 5.8 42 6.4 8.3 e25 14 4.5 11 14 19 7.4 7.7 23 12 4.6 5.9 10 6.6 7.8 7.8 14 11 --- 4.5 6.5 36 5.1 6.4 14 10 --- 22 6.1 40 4.7 6.3 12 10 --- 7.8 --- 25 --- 10 10 --­ TOTAL 732.8 599.6 195.9 603.0 MEAN 23.6 20.0 6.32 19.5 MAX 152 139 15 131 MIN 5.8 5.5 4.0 5.9 AC-FT 1450 1190 389 1200 CFSM 18.8 15.9 5.02 15.4 IN. 21.64 17.70 5.78 17.80 287.3 268.4 364.0 474.7 358.5 451.6 639.6 1116 10.3 8.66 12.1 15.3 11.9 14.6 20.6 37.2 92 30 92 42 85 72 117 254 4.5 4.4 4.1 5.5 4.7 4.3 5.0 10 570 532 722 942 711 896 1270 2210 8.14 6.87 9.63 12.2 9.48 11.6 16.4 29.5 8.48 7.92 10.75 14.01 10.58 13.33 18.88 32.95 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1945 - 1998, BY WATER YEAR (WY) MEAN 15.6 19.1 15.2 14.2 MAX 32.1 46.9 31.3 28.4 (WY) 1986 1951 1988 1996 MIN 4.78 8.03 4.99 6.65 (WY) 1993 1948 1990 1994 14.3 10.5 12.1 16.4 12.7 13.8 14.9 18.7 44.0 26.2 34.4 26.6 23.7 39.0 24.5 51.7 1950 1949 1950 1948 1996 1952 1945 1996 4.86 3.90 4.77 6.84 5.19 7.21 5.91 7.03 1983 1951 1984 1994 1985 1994 1993 1986 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1945 - 1998 ANNUAL TOTAL 6106.0 ANNUAL MEAN 16.7 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 172 LOWEST DAILY MEAN 2.7 ANNUAL SEVEN-DAY MINIMUM 3.2 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 12110 ANNUAL RUNOFF (CFSM) 13.3 ANNUAL RUNOFF (INCHES) 180.27 10 PERCENT EXCEEDS 31 50 PERCENT EXCEEDS 10 90 PERCENT EXCEEDS 4.8 6091.4 16.7 14.8 21.1 1952 8.00 1994 Jun 2 254 Sep 21 737 Sep 10 1996 Jul 11 4.0 Dec 26 1.5 Mar 22 1946 Jul 6 4.4 Dec 24 2.0 Apr 7 1946 2180 Sep 21 2860 Apr 21 1983 8.14 Sep 21 8.96 Apr 21 1983 3.5 Apr 10 2.5 Jul 6 1997 12080 10700 13.2 11.7 179.84 159.31 31 29 9.0 8.4 5.0 4.6 e Estimated 340 RIO BLANCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR Río Caño de S a n ti a g o Río Río Río Apeadero Ja ca b o a Río Río Río Río Río Río G r a n d e de Río Río Río Río del Aguas Verde Lago Carite Quebrada Quebrada Q ue b r a da Patillas Patillas d e C a n a l G u a ya n é s Guayanés Candelero Humacao Humacao Mariana L im o n e s Maunabo R ío Nigua Guamaní Tunnel C a n a l d e G u a m an í E s t e Canal de Guamaní Oeste Lago Melania Lago Patillas C i m a r r ón Ingenio Seco Melania CHANNELS 093050 0920 0920 CARIBBEAN SEA HUMACAO MAUNABO ARROYO LAS PIEDRAS 0 0 1 1 2 2 3 3 4 4 6 0918 0910 0905 0810 0835 0865 093050 0920 P-13 BAR-1 ALG-1 FID-2 YDO-1 96 0820 FLOW DIRECTION TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER HW-TW-01 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER YABUCOA PATILLAS GUAYAMA CAYEY Basin area PUERTO RICO 5 MILES 5 KILOMETERS HW-TW-01 HW-TW-053 HW-TW-03C HW-TW-13 341 Figure 20. Southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins. 342 RIO HUMACAO BASIN 50081000 RIO HUMACAO AT LAS PIEDRAS, PR LOCATION.--Lat 18°10'27", long 65°52'11", Hydrologic unit 21010005, on left bank at downstream side of bridge on Highway 921, 0.6 mi (1.0 km) southeast of junction with Highway 30, 0.8 mi (1.3 km) downstream from Quebrada Blanca and 0.8 mi (1.3 km) south of Las Piedras. DRAINAGE AREA.--6.65 mi2 (17.22 km2). PERIOD OF RECORD.--September 1958 to December 1967 (monthly discharge measurements), July 1974 to September 1977, October 1987 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (79 m), from topographic map. Prior to July 1974, crest-stage gage at different datum. July 1974 to September 1977 at site 90 ft (27 m) upstream at present datum. REMARKS.--Records fair except those for estimated daily discharges, and above 1,000 ft3/s (28.3 m3/s), which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17 20 20 15 2 112 19 17 20 3 24 19 16 16 4 21 18 16 20 5 19 18 16 15 18 13 14 9.8 11 10 9.6 19 18 13 13 9.5 12 9.6 9.2 20 18 14 12 11 9.9 11 9.2 28 19 13 12 13 10 27 9.1 22 168 13 13 12 10 21 9.1 19 6 18 18 16 166 7 18 18 15 211 8 17 19 15 54 9 17 26 15 71 10 17 170 14 85 23 13 12 11 10 12 9.0 93 18 27 12 11 9.7 13 9.2 29 19 18 12 12 12 12 9.2 118 19 13 11 12 12 23 15 38 18 12 10 11 11 12 12 e31 11 17 25 14 32 12 40 22 15 38 13 104 28 14 29 14 567 21 14 27 15 50 20 14 24 17 12 10 10 11 11 12 22 e16 12 13 11 16 12 12 e20 e16 12 10 12 14 11 11 68 e18 14 9.6 11 11 14 11 56 e17 13 9.4 9.8 10 14 12 72 16 33 21 15 23 17 27 20 17 22 18 25 19 18 22 19 24 20 14 21 20 23 20 14 21 e17 12 13 10 11 11 13 42 e17 12 11 9.5 11 13 50 31 e17 11 9.5 9.8 e31 16 21 32 e16 12 11 9.6 e21 16 14 36 e16 13 18 14 13 89 23 37 21 22 23 15 21 22 21 28 14 21 23 21 20 14 20 24 21 21 15 20 25 22 19 13 20 e16 13 12 11 15 26 20 e316 e15 12 11 10 19 14 34 591 e15 12 10 16 12 12 16 90 e14 11 9.9 12 11 16 228 e63 e14 13 9.6 9.7 19 12 e235 e54 26 20 146 13 20 27 20 28 12 19 28 19 21 12 19 29 19 20 12 19 30 19 20 13 19 31 19 --- 12 19 e14 12 10 11 14 11 e59 52 14 13 10 17 12 13 28 50 14 12 17 10 12 18 21 49 --- 13 11 12 11 12 51 45 --- 33 10 157 10 11 22 43 --- 24 --- 17 --- 11 20 --­ TOTAL 1413 907 454 1149 MEAN 45.6 30.2 14.6 37.1 MAX 567 170 20 211 MIN 17 18 12 15 AC-FT 2800 1800 901 2280 CFSM 6.85 4.55 2.20 5.57 IN. 7.90 5.07 2.54 6.43 621 440 346.0 501.7 391.6 513.6 1013.6 2186 22.2 14.2 11.5 16.2 13.1 16.6 32.7 72.9 168 33 18 157 31 89 235 591 14 11 9.4 9.5 9.7 9.6 9.0 19 1230 873 686 995 777 1020 2010 4340 3.34 2.13 1.73 2.43 1.96 2.49 4.92 11.0 3.47 2.46 1.94 2.81 2.19 2.87 5.67 12.23 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1974 - 1998, BY WATER YEAR (WY) MEAN 29.7 36.4 28.9 20.2 MAX 74.9 126 112 37.1 (WY) 1975 1988 1988 1998 MIN 12.8 13.4 11.5 10.5 (WY) 1995 1996 1992 1995 16.2 11.8 9.75 14.1 17.2 19.5 20.9 38.9 22.2 16.4 15.1 42.2 41.1 38.1 34.7 121 1997 1989 1997 1992 1996 1993 1996 1996 11.0 8.87 5.88 7.26 5.91 7.95 9.45 10.0 1977 1996 1977 1990 1977 1990 1974 1990 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1974 - 1998 ANNUAL TOTAL 7598.6 ANNUAL MEAN 20.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 567 LOWEST DAILY MEAN 6.3 ANNUAL SEVEN-DAY MINIMUM 7.0 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 15070 ANNUAL RUNOFF (CFSM) 3.13 ANNUAL RUNOFF (INCHES) 42.51 10 PERCENT EXCEEDS 25 50 PERCENT EXCEEDS 15 90 PERCENT EXCEEDS 9.1 9936.5 27.2 22.1 37.6 1988 12.1 1990 Oct 14 591 Sep 22 2010 Sep 10 1996 Jul 15 9.0 Aug 6 2.2 Jul 15 1974 Jun 29 9.1 Aug 2 2.8 Jul 19 1974 2180 Oct 14 20800 Sep 6 1960 6.57 Oct 14 34.40 Sep 6 1960 19710 16020 4.09 3.32 55.58 45.18 39 32 16 13 10 7.3 e Estimated 343 RIO HUMACAO BASIN 50081000 RIO HUMACAO AT LAS PIEDRAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 344 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°08'49", long 65°49'37", at bridge on Highway 3, 300 ft (91 m) downstream from Quebrada Mariana, and 0.4 mi (0.6 km) south of Humacao. DRAINAGE AREA.--17.3 mi2 (44.8 km2). PERIOD OF RECORD.--Water years 1958-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 06... 1150 26 321 6.9 28.5 73 7.0 90 <10 4500 3800 MAR 09... 1120 22 300 7.1 27.0 19 7.6 95 <10 420 520 MAY 18... 1120 10 379 7.0 29.0 3.1 7.0 91 <10 K6100 270 AUG 18... 1020 23 237 6.6 27.7 59 6.7 85 <10 K15000 2400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 06... 100 29 8.0 9.2 .4 2.5 106 <.5 18 10 MAR 09... -- -- -- -- -- -- 110 -- -- -­ MAY 18... 110 33 7.9 30 1 1.8 120 -- 12 42 AUG 18... 67 19 5.1 18 1 3.3 79 <1.0 8.3 26 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 06... <.10 28 162 11.4 42 .584 .026 .610 .080 .13 MAR 09... -- -- -- -- 38 .700 .010 .710 .060 .19 MAY 18... .18 41 240 6.54 <1 .328 .012 .340 .010 -­ AUG 18... <.10 29 155 9.80 62 .494 .026 .520 .100 .40 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 06... .21 .82 3.6 1.70 <1 <100 60 <1 <1 <10 MAR 09... .25 .96 4.2 .070 -- -- -- -- -- -­ MAY 18... <.20 -- -- .050 <1 <100 40 <1 <1 <10 AUG 18... .50 1.0 4.5 .080 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 345 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 06... 390 <1 58 <.10 <1 <1 <10 <.010 <1 .03 MAR 09... MAY 18... 320 <1 58 <.10 <1 <1 <10 <.010 <1 .02 AUG 18... 346 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'33", long 65°54'03", at bridge on Highway 182, 1.4 mi (2.2 km) west-northwest of Yabucoa plaza. DRAINAGE AREA.--17.2 mi2 (44.6 km2). PERIOD OF RECORD.--Water years 1958-62, 1968-70, 1980 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, INST. CIFIC WHOLE SOLVED CHEM- FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) NOV 06... 1010 39 187 6.8 24.5 4.9 7.2 86 10 2800 MAR 06... 0930 30 190 7.0 23.5 4.7 7.4 87 <10 4000 MAY 18... 0925 22 189 7.0 26.0 9.0 6.9 84 <10 K860 AUG 28... 1045 63 157 6.6 26.0 14 6.5 81 <10 2200 STREP- HARD- MAGNE- TOCOCCI NESS CALCIUM SIUM, SODIUM, FECAL, TOTAL DIS- DIS- DIS- (COLS. (MG/L SOLVED SOLVED SOLVED DATE PER AS (MG/L (MG/L (MG/L 100 ML) CACO3) AS CA) AS MG) AS NA) (31679) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER AD- SIUM, UNFLTRD SULFATE SORP- DIS- FET SULFIDE DIS­ TION SOLVED FIELD TOTAL SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L AS K) CACO3 AS S) AS SO4) (00931) (00935) (00410) (00745) (00945) NOV 06... K1500 88 26 5.7 9.5 .4 2.3 80 <.5 8.0 MAR 06... K16000 -- -- -- -- -- -- 77 -- -­ MAY 18... 790 58 15 5.1 16 .9 1.6 75 -- 5.0 AUG 28... 7100 47 12 4.1 13 .8 1.8 56 <1.0 4.0 SOLIDS, RESIDUE CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO­ RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) (00940) (00950) (00955) (70301) (70302) (00530) (00615) (00630) (00610) (00605) NOV 06... 12 <.10 25 151 16.0 14 <.010 .440 .040 .22 MAR 06... -- -- -- -- -- 4 <.010 .440 .030 -­ MAY 18... 14 .16 35 136 7.98 18 <.010 .310 <.010 -­ AUG 28... 12 <.10 32 113 19.4 28 <.010 .460 .020 .23 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 06... .26 .70 3.1 .080 <1 <100 30 <1 <1 12 MAR 06... <.20 -- -- .050 -- -- -- -- -- -­ MAY 18... .25 .56 2.5 .030 <1 <100 30 <1 <1 <10 AUG 28... .25 .71 3.1 .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 347 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 06... 3000 <1 150 <.10 <1 <1 10 <.010 <1 .03 MAR 06... MAY 18... 1100 <1 83 <.10 <1 <1 <10 <.010 <1 <.02 AUG 28... 348 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'45", long 65°49'42", at old railroad crossing, 0.2 mi (0.3 km) from mouth, 0.4 mi (0.6 km) west of Playa de Guayanes, and 3.5 mi (5.6 km) northeast of Yabucoa plaza. DRAINAGE AREA.--34.0 mi2 (88.1 km2). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI­ SPE- WATER DIS- DEMAND, FORM, STREP­ CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 13... 1215 471 7.4 28.0 4.3 7.2 92 <10 5100 2400 MAR 06... 1040 200 7.2 24.5 4.9 7.1 85 <10 K900 810 MAY 19... 1115 253 6.8 29.5 15 4.0 52 <10 4300 430 AUG 18... 0845 225 6.4 26.5 21 3.9 48 <10 3000 5200 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 13... 170 48 13 30 1 3.7 187 <.5 12 35 MAR 06... -- -- -- -- -- -- 72 -- -- -­ MAY 19... 110 17 5.9 25 1 2.9 97 -- 5.8 23 AUG 18... 54 13 5.0 21 1 4.8 82 <1.0 6.2 22 SOLIDS, RESIDUE NITRO­ FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) NOV 13... .17 27 280 6 .700 .130 .830 .240 .42 .66 MAR 06... -- -- -- <1 -- <.010 .470 .020 -- <.20 MAY 19... .16 31 217 14 .222 .018 .240 .060 .38 .44 AUG 18... .14 3.1 126 40 .247 .013 .260 .060 .72 .78 CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) NOV 13... 1.5 6.6 .270 2 <100 40 <1 <1 <10 340 MAR 06... -- -- .040 -- -- -- -- -- -- -­ MAY 19... .68 3.0 .140 <1 <100 40 <1 <1 <10 1300 AUG 18... 1.0 4.6 .130 -- -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 349 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 13... <1 230 <.10 <1 <1 <10 <.010 <1 .12 MAR 06... MAY 19... <1 140 <.10 <1 <1 <10 <.010 <1 <.02 AUG 18... 350 RIO MAUNABO BASIN 50090500 RIO MAUNABO AT LIZAS, PR LOCATION.--Lat 18°01'38", long 65°56'24", Hydrologic Unit 21010005, on right bank, off Highway 759 at Lizas, about 1.0 mi (1.6km) downstream from Quebrada Coroco, and about 3.0 mi (4.8 km) northwest of Maunabo. DRAINAGE AREA.--5.38 mi2 (13.93 km2). PERIOD OF RECORD.--February 1971 to January 1985, February 1991 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 25 29 30 2 212 22 21 20 3 31 22 18 28 4 24 20 18 30 5 20 19 18 35 15 12 8.8 11 11 6.6 7.7 16 14 11 9.2 11 10 6.9 6.9 17 14 12 9.4 12 11 8.5 6.5 18 13 11 9.6 11 11 21 6.2 15 40 10 18 10 11 9.8 6.1 14 6 18 20 17 220 7 16 20 16 240 8 15 20 16 70 9 15 39 17 51 10 14 72 17 66 19 10 11 15 21 7.7 e14 24 16 45 12 12 47 27 e6.9 27 25 30 11 13 21 12 6.2 37 33 14 9.5 12 20 9.9 7.6 45 18 11 9.3 11 26 7.9 7.2 22 11 14 24 16 33 12 24 20 17 29 13 57 21 18 31 14 532 20 18 26 15 163 23 17 23 15 10 9.9 11 14 7.5 6.7 16 14 9.8 35 11 21 6.6 15 14 14 9.7 12 12 16 6.8 7.8 38 30 12 10 12 13 12 6.7 27 24 11 10 12 11 10 7.1 38 16 63 25 20 22 17 41 23 30 22 18 34 21 22 20 19 29 39 20 20 20 26 29 19 20 16 9.4 29 12 22 20 7.5 21 15 8.8 16 12 16 11 15 17 15 8.4 11 12 e17 13 8.5 24 14 9.8 15 12 e14 21 7.7 17 14 40 30 12 13 14 11 17 21 24 28 30 19 22 22 33 20 19 23 20 41 27 20 24 20 36 21 20 25 19 23 19 e25 14 17 12 11 12 13 11 289 13 13 11 11 19 8.4 40 670 13 9.9 11 12 9.9 7.5 12 73 12 8.3 11 14 9.0 9.4 302 47 12 11 13 11 10 11 315 37 26 19 38 18 21 27 19 28 20 18 28 19 22 19 17 29 19 44 19 19 30 19 102 19 16 31 20 --- 22 15 12 9.8 13 87 8.6 7.9 122 32 12 10 12 73 8.2 35 36 65 12 10 12 14 8.3 28 24 34 --- 9.5 11 10 7.7 12 27 28 --- 9.5 11 30 7.1 9.6 19 26 --- 10 --- 27 --- 11 17 --­ TOTAL 1580 919 618 1245 MEAN 51.0 30.6 19.9 40.2 MAX 532 102 30 240 MIN 12 19 16 15 AC-FT 3130 1820 1230 2470 CFSM 9.47 5.69 3.71 7.46 IN. 10.92 6.35 4.27 8.61 478 412.9 402.7 536 445.8 392.0 1093.3 1765 17.1 13.3 13.4 17.3 14.9 12.6 35.3 58.8 40 45 35 87 47 35 315 670 12 8.3 8.8 10 7.1 6.6 6.1 14 948 819 799 1060 884 778 2170 3500 3.17 2.48 2.50 3.21 2.76 2.35 6.56 10.9 3.31 2.85 2.78 3.71 3.08 2.71 7.56 12.20 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1971 - 1998, BY WATER YEAR (WY) MEAN 27.9 31.1 17.8 14.4 MAX 52.6 88.9 35.2 40.2 (WY) 1979 1978 1978 1998 MIN 10.4 7.46 8.74 7.79 (WY) 1994 1982 1994 1981 12.8 9.96 7.49 13.0 17.8 17.4 23.2 30.0 24.5 18.9 13.4 25.1 47.1 40.2 131 94.6 1982 1976 1998 1979 1979 1993 1979 1996 6.10 4.32 3.92 5.13 4.40 3.70 6.18 7.99 1979 1979 1979 1974 1974 1974 1974 1980 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1971 - 1998 ANNUAL TOTAL 6449.8 ANNUAL MEAN 17.7 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 532 LOWEST DAILY MEAN 3.3 ANNUAL SEVEN-DAY MINIMUM 3.7 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 12790 ANNUAL RUNOFF (CFSM) 3.28 ANNUAL RUNOFF (INCHES) 44.60 10 PERCENT EXCEEDS 29 50 PERCENT EXCEEDS 10 90 PERCENT EXCEEDS 5.2 9887.7 27.1 18.7 36.7 1979 10.8 1994 Oct 14 670 Sep 22 2480 Aug 31 1979 Jul 4 6.1 Aug 5 2.2 Jul 16 1974 Jul 2 7.5 Aug 2 2.8 Jul 11 1974 2550 Sep 21 9950 Sep 20 1994 10.47 Sep 21 17.46 Sep 20 1994 19610 13520 5.04 3.47 68.37 47.13 37 33 16 11 8.9 5.3 e Estimated 351 RIO MAUNABO BASIN 50090500 RIO MAUNABO AT LIZAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 352 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'24", long 65°54'19", at bridge on Highway 3, 0.4 mi (0.6 km) southwest of Maunabo plaza, and 1.3 mi (2.1 km) upstream from mouth. DRAINAGE AREA.--12.4 mi2 (32.1 km2). PERIOD OF RECORD.--Water years 1958-66, 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 13... 1030 48 475 7.2 27.5 25 6.6 84 <10 4200 3300 MAR 09... 0925 15 248 7.2 24.0 4.0 7.3 87 <10 3900 2100 MAY 19... 0940 9.3 263 7.0 28.0 13 7.6 97 <10 K1500 9200 AUG 28... 0900 41 223 6.6 26.5 6.4 7.0 87 <10 K1900 5400 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 13... 170 58 6.1 19 .6 .90 178 <.5 46 8.0 MAR 09... -- -- -- -- -- -- 92 -- -- -­ MAY 19... 110 20 7.6 22 1 1.3 97 -- 8.7 21 AUG 28... 65 16 6.1 18 1 1.4 75 <1.0 9.1 19 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 13... .20 24 258 33.0 23 .570 .190 .760 1.70 .40 MAR 09... -- -- -- -- 11 -- <.010 .630 .020 -­ MAY 19... .15 37 217 5.45 6 -- <.010 .190 .030 -­ AUG 28... <.10 34 149 16.5 17 -- <.010 .780 .020 .19 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 13... 2.1 2.9 13 .340 2 <100 40 <1 <1 <10 MAR 09... <.20 -- -- .040 -- -- -- -- -- -­ MAY 19... <.20 -- -- .040 <1 <100 10 <1 <1 <10 AUG 28... .21 .99 4.4 .060 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 353 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 13... 350 <1 230 <.10 <1 <1 <10 <.010 <1 .16 MAR 09... MAY 19... 390 <1 38 <.10 <1 <1 10 <.010 1 <.02 AUG 28... 354 RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR WATER-QUALITY RECORDS LOCATION.--Lat 17°59'16", long 66°00'18", at flat low bridge 200 ft (61 m) south of Highway 3, 0.5 mi (0.8 km) above mouth, and 1.5 mi (2.4 km) southeast of Patillas plaza. DRAINAGE AREA.--4.9 mi2 (12.8 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 16... 1200 46 263 6.7 27.0 27 5.1 64 11 8200 K15000 MAR 05... 0915 1.5 448 7.2 26.5 3.0 5.9 73 36 20 64 MAY 21... 0915 .68 415 6.8 31.0 .60 6.6 89 <10 930 320 AUG 19... 0915 .78 445 6.2 31.0 2.0 5.0 67 32 2000 3700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 16... 70 16 7.3 23 1 1.5 69 .7 14 27 MAR 05... -- -- -- -- -- -- 110 -- -- -­ MAY 21... 42 9.6 4.3 12 .8 .60 46 -- 8.1 11 AUG 19... 63 15 5.9 55 3 10 56 <1.0 26 56 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 16... .14 31 161 20.1 32 1.20 .050 1.30 .200 .62 MAR 05... -- -- -- -- 5 3.90 .400 4.30 4.00 -­ MAY 21... <.10 21 95 .17 7 9.11 .390 9.50 .270 2.7 AUG 19... .16 25 227 .48 10 8.28 .220 8.50 .150 2.2 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 16... .83 2.1 9.4 1.80 <1 <100 40 <1 <1 <10 MAR 05... 3.8 8.1 36 2.10 -- -- -- -- -- -­ MAY 21... 3.0 13 55 3.10 <1 <100 110 <1 <1 <10 AUG 19... 2.3 11 48 3.40 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 355 RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 16... 2900 2 140 <.10 <1 <1 30 <.010 <1 .02 MAR 05... MAY 21... 110 <1 12 <.10 <1 <1 20 <.010 <1 .07 AUG 19... --- --- --- --- --- --- --- 356 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR LOCATION.--Lat 18°02'04", long 66°01'58", Hydrologic Unit 21010004, on left bank, off Highway 184, 1.2 mi (1.9 km) upstream from Lago Patillas Dam and 2.2 mi (3.5 km) northwest of Patillas. DRAINAGE AREA.--18.3 mi2 (47.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to October 1965 (annual low-flow and occasional measurements only), January 1966 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 235 ft (72 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29 39 37 e32 28 22 38 27 35 20 25 25 2 99 35 34 e42 26 22 44 27 32 20 24 28 3 61 34 33 e37 25 25 43 26 30 21 24 43 4 52 34 32 e64 26 24 33 31 27 35 24 40 5 37 32 31 e60 233 22 49 26 26 33 24 30 6 31 31 31 e400 66 21 39 26 40 22 e31 69 7 27 30 30 e360 41 353 47 23 35 23 e27 111 8 28 33 30 145 39 144 42 22 31 21 32 72 9 28 49 29 95 44 43 34 25 33 21 43 83 10 26 436 29 113 33 33 32 27 31 19 38 67 11 37 73 28 66 30 29 51 19 26 18 27 48 12 38 51 30 56 28 28 157 19 33 19 36 43 13 487 43 29 49 27 27 61 61 37 19 30 87 14 1320 40 29 45 52 28 45 52 26 19 26 63 15 544 38 28 38 49 29 39 64 24 20 24 76 16 256 40 28 36 34 27 42 49 43 23 26 56 17 143 39 35 34 34 25 47 34 39 20 67 e49 18 107 35 29 32 31 25 51 29 e29 25 31 e42 19 81 37 29 30 28 26 46 26 e28 32 25 e48 20 68 37 29 30 27 129 56 25 26 53 25 e49 21 60 38 35 29 27 58 42 24 34 52 26 e2390 22 54 44 30 29 26 54 39 23 49 31 190 e4500 23 50 56 29 28 25 44 35 23 33 24 33 e2000 24 46 53 28 31 24 35 33 25 29 30 705 e600 25 44 44 27 40 24 39 34 25 30 28 751 e500 26 42 41 27 42 24 36 32 145 30 25 175 e400 27 40 40 29 32 22 42 33 160 28 33 59 e370 28 38 36 28 30 22 40 31 51 26 39 39 e460 29 37 35 27 36 47 29 38 25 31 36 e330 30 37 45 29 29 51 27 46 22 28 30 e290 31 35 29 27 58 62 27 28 TOTAL 3982 1618 928 2117 1095 1586 1331 1260 937 831 2681 12969 MEAN 128 53.9 29.9 68.3 39.1 51.2 44.4 40.6 31.2 26.8 86.5 432 MAX 1320 436 37 400 233 353 157 160 49 53 751 4500 MIN 26 30 27 27 22 21 27 19 22 18 24 25 AC-FT 7900 3210 1840 4200 2170 3150 2640 2500 1860 1650 5320 25720 CFSM 7.02 2.95 1.64 3.73 2.14 2.80 2.42 2.22 1.71 1.46 4.73 23.6 IN. 8.09 3.29 1.89 4.30 2.23 3.22 2.71 2.56 1.90 1.69 5.45 26.36 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 1998, BY WATER YEAR (WY) MEAN 96.9 87.9 49.5 35.3 29.0 25.3 22.4 50.2 63.3 63.3 70.0 98.1 MAX 593 393 152 125 94.6 51.2 44.4 172 200 164 231 432 (WY) 1971 1978 1971 1992 1982 1998 1998 1969 1979 1979 1979 1998 MIN 14.4 16.1 8.63 14.0 7.09 6.74 9.98 10.3 13.1 14.1 17.2 12.1 (WY) 1968 1968 1968 1973 1973 1968 1968 1974 1974 1974 1994 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1966 - 1998 ANNUAL TOTAL 15685 31335 ANNUAL MEAN 43.0 85.8 57.1 HIGHEST ANNUAL MEAN 117 1979 LOWEST ANNUAL MEAN 19.8 1994 HIGHEST DAILY MEAN 1320 Oct 14 4500 Sep 22 4780 Sep 16 1975 LOWEST DAILY MEAN 10 Jul 1 18 Jul 11 4.8 May 9 1968 ANNUAL SEVEN-DAY MINIMUM 12 Jun 27 19 Jul 9 5.0 Apr 10 1968 INSTANTANEOUS PEAK FLOW Not determined Sep 21 30900 Jan 5 1992 INSTANTANEOUS PEAK STAGE 24.36 Sep 21 unknown Jan 5 1992 INSTANTANEOUS LOW FLOW 18 Jul 11 4.6 May 13 1968 ANNUAL RUNOFF (AC-FT) 31110 62150 41400 ANNUAL RUNOFF (CFSM) 2.35 4.69 3.12 ANNUAL RUNOFF (INCHES) 31.88 63.70 42.43 10 PERCENT EXCEEDS 60 85 96 50 PERCENT EXCEEDS 28 33 28 90 PERCENT EXCEEDS 14 24 12 e Estimated 357 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR -- 358 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP- HARD­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI NESS CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, TOTAL FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER AS SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) (00900) OCT 16... 1000 258 136 6.4 24.5 10 8.1 97 <10 K17000 4600 36 MAR 05... 1045 22 180 7.2 24.0 .32 7.4 88 <10 230 310 MAY 21... 1045 25 160 7.1 28.0 1.0 7.6 98 <10 K160 K140 49 AUG 19... 1030 25 147 6.4 27.5 29 7.7 97 <10 K1000 670 43 ANC SOLIDS, MAGNE- SODIUM POTAS- WATER CHLO- FLUO- SILICA, SUM OF CALCIUM SIUM, SODIUM, AD- SIUM, UNFLTRD SULFATE RIDE, RIDE, DIS- CONSTI­ DIS- DIS- DIS- SORP- DIS- FET SULFIDE DIS- DIS- DIS- SOLVED TUENTS, SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED SOLVED (MG/L DIS­ DATE (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L (MG/L AS SOLVED AS CA) AS MG) AS NA) AS K) CACO3 AS S) AS SO4) AS CL) AS F) SIO2) (MG/L) (00915) (00925) (00930) (00931) (00935) (00410) (00745) (00945) (00940) (00950) (00955) (70301) OCT 16... 8.0 3.8 12 .8 .66 31 <.5 9.0 14 <.10 24 90 MAR 05... -- -- -- -- -- 69 -- -- -- -- -- -­ MAY 21... 11 4.9 13 .8 .72 52 -- 9.6 12 <.10 22 104 AUG 19... 10 4.4 12 .8 .58 44 <1.0 9.4 13 <.10 23 98 RESIDUE NITRO­ SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- GEN,AM- BARIUM, BORON, CADMIUM DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + PHOS- TOTAL TOTAL WATER SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC PHORUS ARSENIC RECOV- RECOV- UNFLTRD (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL DATE PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS P) AS AS) AS BA) AS B) AS CD) (70302) (00530) (00615) (00630) (00610) (00605) (00625) (00665) (01002) (01007) (01022) (01027) OCT 16... 63.0 11 <.010 .090 .010 <.20 <.20 .020 <1 <100 40 <1 MAR 05... -- <1 <.010 .100 .030 -- <.20 .020 -- -- -- -­ MAY 21... 7.01 1 <.010 .050 .010 -- <.20 <.020 <1 <100 10 <1 AUG 19... 6.59 59 <.010 .110 .020 -- <.20 .040 -- -- -- -­ CHRO- MANGA- MIUM, COPPER, IRON, LEAD, NESE, MERCURY TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SELE- RECOV- RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, ERABLE ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS CR) AS CU) AS FE) AS PB) AS MN) AS HG) AS SE) (01034) (01042) (01045) (01051) (01055) (71900) (01147) METHY­ SILVER, ZINC, LENE TOTAL TOTAL BLUE RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (MG/L TOTAL STANCE AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01077) (01092) (00720) (32730) (38260) OCT 16... <1 <10 640 <1 43 <.10 <1 <1 20 <.010 <1 <.02 MAR 05... -- -- -- -- -- -- -- -- -- -- -- -­ MAY 21... <1 <10 60 <1 <10 <.10 <1 <1 <10 <.010 2 <.02 AUG 19... -- -- -- -- -- -- -- -- -- -- -- -­ --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 359 RIO PATILLAS BASIN 50093045 LAGO PATILLAS AT DAMSITE NEAR PATILLAS, PR LOCATION.--Lat 18°01'15", long 66°01'19", Hydrologic Unit 21010004, on right bank, in a concrete tower at Damsite, 1.05 mi (1.69 km) northeast from Patillas plaza, 0.45 mi (0.72 km) northeast from Escuela Segunda Unidad de Real and 2.30 mi (3.70 km) from Escuela Segunda Unidad de Jesús María Rodríguez. DRAINAGE AREA.--25.2 mi2 (65.3 km2). ELEVATION RECORDS PERIOD OF RECORD.--March 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Patillas was completed in 1914. The dam is a semihydraulic earthfill structure about 147 ft (45 m) height, a top width of 15 ft (4.6 m), maximum pool elevation of 230 ft (70.1 m), a base width of 625 ft (190 m), a crest lenght of 1,067 ft (325 m) and has maximum pool storage of 17,073 ac-ft (21.05 hm3). The Patillas Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and its primary purpose is for irrigation of lands served by the Patillas irrigation canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 225.92 ft (68.86 m), Sept. 10, 1996; minimum elevation, 211.19 ft (64.37 m), May 29, 1995, July 19, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximun elevation, 225.49 ft (68.73 m), Sept. 21; minimum elevation, 216.97 ft (66.13 m), Sept. 21. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 143 0 200 7,752 190 5,492 225 15,005 230 16,773 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 A 221.75 221.52 221.13 221.47 221.31 221.71 221.25 221.81 A 221.42 221.13 2 221.20 221.69 221.16 221.14 221.43 221.25 221.84 221.18 221.68 A 221.30 221.41 3 221.03 221.61 221.03 221.36 221.43 A 221.89 221.13 221.66 A 221.19 221.80 4 221.01 221.52 221.00 221.80 221.46 A 221.81 221.17 221.67 A 221.09 221.84 5 220.90 221.45 220.99 221.95 221.55 A 221.88 221.16 221.69 A 221.00 221.57 6 220.92 221.46 220.99 222.09 221.22 A 221.83 221.19 221.88 221.63 221.02 221.76 7 220.95 221.44 221.00 222.06 221.40 A 221.92 221.19 221.90 A 220.97 221.62 8 221.00 221.58 221.01 221.56 221.63 A 221.82 221.20 221.74 221.59 220.96 221.77 9 221.06 221.80 220.99 221.30 221.83 221.05 221.69 221.26 221.64 221.51 221.08 221.86 10 221.09 222.01 220.98 A 221.85 221.19 221.54 221.34 221.55 221.42 221.12 221.55 11 221.14 221.79 220.96 A 221.82 221.24 221.69 221.34 221.51 221.33 221.08 221.82 12 221.29 221.42 220.96 A 221.78 221.23 221.57 221.35 221.61 221.21 221.20 221.94 13 222.14 221.31 220.98 A 221.74 221.22 221.29 221.69 221.72 A 221.18 221.62 14 222.26 221.47 220.97 221.44 222.06 221.29 221.39 221.90 221.72 221.05 221.11 221.03 15 222.27 221.65 220.97 221.62 221.79 221.31 221.47 221.97 221.71 221.03 221.03 221.64 16 221.27 221.83 221.04 221.77 221.47 221.30 221.61 221.83 221.99 221.02 220.97 221.92 17 221.83 221.93 221.13 221.86 221.18 221.26 221.77 221.59 221.85 221.00 221.29 221.92 18 221.94 221.89 221.13 221.87 221.28 221.27 221.91 221.50 221.62 221.05 221.33 221.97 19 221.69 221.89 221.12 221.83 221.33 221.29 221.87 221.50 221.56 221.13 221.32 221.81 20 221.38 221.81 221.13 221.78 221.38 222.11 A 221.50 221.58 221.44 221.30 220.11 21 221.20 221.77 221.20 221.71 221.43 221.35 221.70 221.49 221.69 221.62 221.34 222.64 22 221.22 221.87 221.20 221.66 221.45 221.05 221.67 221.47 221.91 221.58 220.79 221.45 23 221.47 221.87 221.24 221.60 221.46 220.93 221.64 221.47 221.87 221.51 220.70 222.19 24 221.63 221.68 221.22 221.58 221.47 220.96 221.59 221.48 221.77 221.56 222.17 221.83 25 221.79 221.62 221.19 221.64 221.48 221.15 221.58 221.46 221.71 221.55 221.98 221.66 26 221.89 221.81 221.18 221.71 221.44 221.27 221.55 221.75 221.62 221.47 221.73 222.01 27 221.89 221.91 221.17 221.67 221.38 221.47 221.51 221.42 221.58 221.62 221.76 222.00 28 221.86 221.89 221.15 221.61 221.35 221.64 221.46 221.22 221.56 221.75 221.33 221.31 29 221.81 221.89 221.09 221.66 221.83 221.39 221.35 221.52 221.70 220.99 221.85 30 221.76 221.85 221.09 221.60 222.00 221.33 221.67 221.46 221.62 220.75 222.01 31 221.72 221.06 221.53 221.80 221.94 221.54 220.91 MAX 222.01 221.52 222.06 221.97 221.99 222.17 222.64 MIN 221.31 220.96 221.18 221.13 221.46 220.70 220.11 A No gage-height record 360 THIS PAGE WAS LEFT BLANK INTENTIONALLY Río Río Jájome Río Río Río Río Jacaguas Río Río Río Toa Va c a Jacaguas Coamo Río R í o Coamo Cuyón Jueyes Cañas Salinas D e s c a l a bra d o (Nigua) Majada Río Río Lapa Q ue b r a d a Patillas Canal de Canal de Guamaní Oeste de Díaz J u a n a C an a l Lago V aca Lago Guayabal Lago Coamo Carmen 1061 RM-5 1065 CHANNELS CARIBBEAN SEA SALINAS ISABEL JUANA DÍAZ VILLALBA COAMO 0 0 1 1 2 2 3 3 4 4 1061 100450 1002 RM-5 RM-10 PG-07 EC-1 SA-D CQ-1 1080 1065 CA-1 PS-07 87 T o a 1109 FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER 1113 EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER SANTA AIBONITO BARRANQUITAS CAYEY Basin area PUERTO RICO 5 MILES 5 KILOMETERS 1109 1115 1113 111210 FA-1 361 Figure 21. South coast river basins -- Río Salinas to Río Jacaguas basins. 362 RIO SALINAS BASIN 50100200 RIO LAPAS NEAR RABO DEL BUEY, PR LOCATION.--Lat 18°03'36", long 66°14'28", Hydrologic Unit 21010004, on left bank, at bridge on Highway 1, Km 9.7, 1.5 mi (2.4 km) north of Rabo del Buey, and 4.4 mi (7.1 km) northeast of Salinas Plaza. DRAINAGE AREA.--9.92 mi2 (25.69 km2). PERIOD OF RECORD.--1953-63 (annual low-flow measurements only), September 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 m), from topographic map. REMARKS.--Records poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .01 2.8 4.5 2.0 .13 e.96 e1.8 e1.4 e1.4 e.56 e.28 e6.8 2 .02 2.4 4.2 2.0 .11 e.90 e13 e1.2 e1.1 e.56 e.31 e10 3 .43 2.2 4.1 2.4 .10 e1.1 e3.0 e1.3 e.76 e.70 e.29 e38 4 .00 2.1 3.7 2.7 .10 e1.4 e1.2 e1.3 e.70 e1.1 e.29 e56 5 .00 2.3 3.7 2.4 201 e1.3 e.96 e1.1 e.72 e1.4 e.29 e22 6 .00 2.5 3.5 2.9 15 e1.1 e.84 e1.1 e.98 e.94 e.56 e16 7 .00 2.5 3.6 2.9 5.5 e1.0 e21 e1.1 e1.1 e.92 e2.0 e16 8 .61 2.5 3.5 2.9 5.0 e.90 e11 e1.0 e.86 e.84 e2.3 e14 9 .00 49 3.5 2.4 7.0 e.80 e2.2 e2.8 e.84 e1.0 e2.2 e12 10 .00 e353 2.7 2.3 3.9 e.76 e1.2 e2.0 e1.0 e.84 e1.0 e9.8 11 .00 34 2.8 2.0 2.6 e.76 e2.2 e1.6 e.94 e.82 e.78 e6.8 12 .00 22 2.6 1.8 13 631 14 2.6 1.9 14 791 11 2.5 2.0 15 122 8.4 2.5 1.8 2.3 e.68 e20 e2.0 e.90 e.70 e.60 e5.8 2.0 e.68 e12 e3.0 e1.2 e.54 e.58 e5.8 2.1 e.68 e1.4 e7.4 e1.4 e.60 e.45 e5.0 2.1 e.64 e1.1 e4.1 e1.3 e.52 e.38 e5.0 16 44 8.6 2.5 1.6 17 20 8.2 2.7 1.7 18 24 7.5 2.7 1.9 19 14 6.8 2.6 2.0 20 11 6.7 2.6 1.7 1.8 e.64 e.95 e3.1 e1.5 e.60 e.38 e4.7 e1.9 e.64 e1.0 e2.8 e1.1 e.54 e.50 e3.3 e1.7 e.56 e1.1 e3.8 e.78 e.52 e.72 e3.6 e1.5 e.46 e1.2 e3.6 e.90 e.88 e.56 e4.6 e1.4 e.76 e1.3 e1.8 e1.1 e.62 e.47 e2.6 21 9.0 6.5 3.3 1.6 22 7.4 6.1 2.7 1.3 23 6.6 5.8 2.6 1.1 24 6.3 5.3 2.4 .92 25 5.8 5.4 2.2 .96 e1.3 e1.0 e2.5 e.92 e1.0 e.68 e.58 e540 e1.2 e.76 e2.8 e.82 e3.4 e.45 e16 e560 e1.1 e.80 e4.7 e.78 e.90 e.32 e5.2 e120 e1.0 e.46 e4.3 e.78 e.60 e.40 e82 e66 e.98 e.41 e2.7 e.76 e.54 e.33 e160 e42 26 5.3 5.1 2.0 .69 27 5.0 5.0 2.2 .42 28 4.8 4.7 2.1 .31 29 4.6 4.6 2.2 .24 30 4.1 4.4 2.0 .20 31 3.4 --- 2.0 .15 e.98 e.42 e2.6 e2.1 e.56 e.28 e42 e36 e.98 e.46 e2.2 e4.2 e.60 e.27 e20 e32 e.98 e.88 e2.0 e1.5 e.56 e.44 e12 e30 --- e.70 e1.7 e1.0 e.56 e.60 e23 e27 --- e22 e1.5 e1.0 e.56 e.45 e13 e24 --- e11 --- e4.8 --- e.38 e9.0 --­ TOTAL 1720.37 601.4 88.8 51.19 MEAN 55.5 20.0 2.86 1.65 MAX 791 353 4.5 2.9 MIN .00 2.1 2.0 .15 AC-FT 3410 1190 176 102 CFSM 5.55 2.00 .29 .17 IN. 6.40 2.24 .33 .19 265.76 55.61 125.45 66.16 29.86 19.80 397.72 1724.8 9.49 1.79 4.18 2.13 1.00 .64 12.8 57.5 201 22 21 7.4 3.4 1.4 160 560 .10 .41 .84 .76 .54 .27 .28 2.6 527 110 249 131 59 39 789 3420 .95 .18 .42 .21 .10 .06 1.28 5.75 .99 .21 .47 .25 .11 .07 1.48 6.42 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 1998, BY WATER YEAR (WY) MEAN 17.7 6.78 2.14 8.14 MAX 76.1 28.4 6.09 68.8 (WY) 1991 1991 1991 1992 MIN 1.46 1.07 .75 .47 (WY) 1992 1994 1995 1994 3.42 1.03 1.35 4.42 2.19 1.79 3.41 21.9 12.4 2.08 4.18 36.6 10.4 7.80 12.8 81.2 1991 1992 1998 1992 1993 1993 1998 1996 .49 .44 .28 .086 .036 .009 .001 .052 1990 1990 1990 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1988 - 1998 ANNUAL TOTAL 2524.84 ANNUAL MEAN 6.92 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 791 LOWEST DAILY MEAN .00 ANNUAL SEVEN-DAY MINIMUM .00 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 5010 ANNUAL RUNOFF (CFSM) .69 ANNUAL RUNOFF (INCHES) 9.39 10 PERCENT EXCEEDS 4.8 50 PERCENT EXCEEDS .40 90 PERCENT EXCEEDS .02 5146.92 14.1 6.19 14.1 1998 .57 1994 Oct 14 791 Oct 14 1900 Sep 10 1996 Sep 16 .00 Oct 4 .00 Jun 24 1994 Sep 16 .07 Oct 1 .00 Jul 21 1994 7320 Sep 21 18100 Sep 10 1996 14.30 Sep 21 18.65 Sep 10 1996 10210 4480 1.41 .62 19.15 8.41 14 6.0 1.8 1.1 .45 .12 e Estimated 363 RIO SALINAS BASIN 50100200 RIO LAPAS NEAR RABO DEL BUEY, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 100 10 1 0.1 0.01 0.001 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 364 RIO SALINAS BASIN 50100450 RIO MAJADA AT LA PLENA, PR LOCATION.--Lat 18°02'40", long 66°12'27", Hydrologic Unit 21010004, on right bank, upstream side of bridge on Hwy 712, about 0.3 mi (0.5 km),southwest of La Plena. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--January 1973 to April 1979 (montly measurements only), September 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 410 ft (125 m), from topographic map. REMARKS.-Records fair except those for estimated daily discharges, which are poor. Some regulation at low-flow upstream from station by local residents for agricultural purposes. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e.00 e10 11 6.1 1.3 2.3 2.6 e2.1 4.3 1.8 .86 7.4 2 e.00 e9.3 11 6.7 1.2 2.2 19 e1.9 3.4 1.8 1.0 12 3 e.00 e9.0 9.9 4.7 .88 2.8 4.9 e2.0 2.4 2.2 .91 49 4 e.00 e8.8 9.1 3.6 .74 3.5 1.8 e2.0 2.2 3.5 .91 84 5 e.00 e9.5 8.9 3.3 36 3.0 1.4 e1.7 2.3 4.7 .91 24 6 e.00 e10 8.2 4.1 13 2.6 1.2 1.6 3.1 3.0 1.7 16 7 e.00 e11 7.5 4.7 6.0 2.5 32 1.6 3.5 2.9 6.6 15 8 e.00 e11 7.3 4.1 4.3 2.1 15 1.5 2.8 2.6 7.4 14 9 e.00 e42 7.0 3.9 6.9 1.9 3.2 4.2 2.7 3.2 7.1 12 10 e.00 e400 7.0 3.5 4.5 1.8 1.8 3.1 3.3 2.7 3.2 9.3 11 e.00 e35 6.6 3.5 3.9 1.8 3.3 2.3 3.0 2.6 2.4 7.2 12 e.00 e30 6.2 3.8 3.6 1.6 30 2.9 2.8 2.2 1.9 6.7 13 e.00 e29 6.2 3.9 3.3 1.6 17 4.4 3.8 1.7 1.8 6.5 14 e547 e27 6.2 3.5 6.2 1.6 2.0 11 4.4 1.9 1.4 6.1 15 e98 e51 6.1 2.8 9.2 1.5 1.6 6.2 4.0 1.6 1.2 6.2 16 e50 e43 5.7 2.5 5.4 1.5 1.4 4.4 4.9 2.0 1.2 5.7 17 e33 e36 8.1 2.2 4.5 1.5 1.5 4.0 3.7 1.7 1.7 4.7 18 e36 e32 6.6 2.2 4.2 1.3 1.7 5.6 2.4 1.6 2.3 4.9 19 e25 e31 6.7 2.2 3.6 1.1 1.8 5.3 2.9 2.8 1.8 5.7 20 e22 e28 5.8 2.2 3.4 1.7 e1.9 3.3 3.6 1.9 1.5 4.1 21 e18 23 6.4 2.2 3.2 2.4 e3.7 2.8 3.4 2.2 2.0 e965 22 e17 24 6.7 2.2 3.0 1.8 e4.3 2.5 11 1.4 50 1080 23 e15 24 5.7 2.1 2.8 1.9 e7.1 2.4 2.8 1.0 16 224 24 e14 20 5.3 2.0 2.6 1.1 e6.4 2.4 1.9 1.3 151 139 25 e14 16 5.6 2.1 2.4 .96 e4.1 2.3 1.7 1.0 315 81 26 e13 15 5.7 2.3 2.4 1.0 e3.9 7.0 1.8 .87 60 69 27 e12 14 5.7 2.0 2.4 1.1 e3.3 13 1.9 .85 26 61 28 e11 13 5.7 1.6 2.4 2.1 e3.0 4.6 1.8 1.4 11 57 29 e11 12 5.7 1.6 1.6 e2.6 3.1 1.8 1.9 25 52 30 e11 12 6.2 1.5 32 e2.3 3.1 1.8 1.4 14 45 31 e11 5.7 1.3 16 15 1.2 8.8 TOTAL 958.00 1035.6 215.5 94.4 143.32 101.86 185.8 129.3 95.4 62.92 726.59 3073.5 MEAN 30.9 34.5 6.95 3.05 5.12 3.29 6.19 4.17 3.18 2.03 23.4 102 MAX 547 400 11 6.7 36 32 32 15 11 4.7 315 1080 MIN .00 8.8 5.3 1.3 .74 .96 1.2 1.5 1.7 .85 .86 4.1 AC-FT 1900 2050 427 187 284 202 369 256 189 125 1440 6100 CFSM 1.85 2.07 .42 .18 .31 .20 .37 .25 .19 .12 1.40 6.13 IN. 2.13 2.31 .48 .21 .32 .23 .41 .29 .21 .14 1.62 6.85 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 1998, BY WATER YEAR (WY) MEAN 14.4 9.33 3.61 9.07 3.27 2.06 1.90 3.82 3.18 3.09 4.29 28.2 MAX 76.4 34.5 9.67 68.8 12.1 3.92 6.19 25.5 12.1 12.9 23.4 109 (WY) 1991 1998 1991 1992 1991 1991 1998 1992 1992 1993 1998 1996 MIN 1.43 1.53 .62 .37 .63 .59 .30 .21 .042 .012 .010 .008 (WY) 1992 1994 1995 1995 1990 1990 1995 1994 1994 1997 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1973 - 1998 ANNUAL TOTAL 2335.44 6822.19 ANNUAL MEAN 6.40 18.7 7.17 HIGHEST ANNUAL MEAN 18.7 1998 LOWEST ANNUAL MEAN .81 1994 HIGHEST DAILY MEAN 547 Oct 14 1080 Sep 22 2270 Sep 10 1996 LOWEST DAILY MEAN .00 Jul 19 .00 Oct 1 .00 Oct 3 1994 ANNUAL SEVEN-DAY MINIMUM .00 Jul 19 .00 Oct 1 .00 Oct 8 1994 INSTANTANEOUS PEAK FLOW 12800 Sep 21 17700 Sep 10 1996 INSTANTANEOUS PEAK STAGE 15.63 Sep 21 19.69 Sep 10 1996 ANNUAL RUNOFF (AC-FT) 4630 13530 5200 ANNUAL RUNOFF (CFSM) .38 1.12 .43 ANNUAL RUNOFF (INCHES) 5.20 15.20 5.84 10 PERCENT EXCEEDS 11 27 8.9 50 PERCENT EXCEEDS .47 3.5 1.8 90 PERCENT EXCEEDS .00 1.3 .17 e Estimated 365 RIO SALINAS BASIN 50100450 RIO MAJADA AT LA PLENA, PR--Continued O N D J F M A M J J A S 0.1 10,000 0.2 0.5 1 2 5 10 20 50 100 200 500 1,000 2,000 5,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 366 RIO COAMO BASIN 50106100 RIO COAMO AT COAMO, PR LOCATION.--Lat 18°05'00", long 66°21'16", Hydrologic Unit 21010004, on Highway 14 bridge, 0.8 mi (1.3 km) northeast from Parque Atlético, 1.2 mi (1.9 km) southeast from (W.C.P.R.) Antena de Radio. DRAINAGE AREA.--3.5 mi2 (112.7 km2). PERIOD OF RECORD.--January 1987 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 335 ft (110 m), from topographic map. REMARKS.--Records poor. Low-flow is affected by domestic discharges about 200 ft (65.6 m), upstream from gaging station. Gage-height and precipitation satellite telemetry at station. The gage-height recovered for the instantaneous peak stage produced by Hurricane Georges was affected by backwater caused by the Hwy. 14 bridge which is about 100 ft.(30.40 m), downstream from gage. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.0 8.8 8.1 5.3 7.1 9.5 11 10 12 5.1 2.0 15 2 2.0 9.0 7.7 5.0 6.4 8.8 37 10 9.0 4.6 2.2 37 3 12 8.2 7.5 4.5 6.2 8.8 9.6 14 9.0 4.5 2.3 75 4 3.4 7.7 7.3 4.9 6.2 10 5.8 12 38 4.6 2.1 149 5 2.0 e7.5 6.7 4.8 328 8.7 5.3 10 10 5.9 2.1 21 6 2.3 e7.4 6.6 4.5 42 7.3 4.9 9.6 8.2 4.0 3.2 70 7 1.8 e7.2 6.5 6.3 8 42 e7.2 6.1 5.9 9 49 e18 5.6 5.5 10 13 e26 5.6 5.5 12 7.1 31 13 7.3 3.6 35 63 12 6.1 11 11 7.3 3.2 53 44 43 5.8 5.7 11 6.9 3.4 14 35 26 5.2 5.4 12 6.7 3.7 8.2 27 11 23 e11 5.5 5.8 12 16 e9.4 5.3 19 13 78 e9.0 5.3 11 14 351 e8.6 5.1 10 15 200 e18 5.0 11 22 4.6 14 8.8 6.3 3.9 6.2 22 20 4.0 126 7.3 5.9 3.8 5.7 20 16 3.7 46 10 6.2 3.8 4.9 18 15 3.5 22 39 6.3 3.6 4.4 16 13 4.0 17 75 6.3 4.6 3.9 16 16 113 e14 5.0 11 17 60 e12 5.2 9.0 18 51 e11 4.8 13 19 43 e10 5.0 13 20 34 e9.6 5.0 9.7 12 3.5 14 29 7.2 4.0 4.2 14 12 3.4 13 17 7.4 4.0 4.6 12 13 2.8 41 38 7.6 4.2 4.1 14 14 2.6 30 43 6.7 4.5 4.1 15 13 2.5 26 89 6.1 4.1 4.0 13 21 28 e9.2 5.2 8.5 22 23 e9.1 5.6 8.5 23 16 e9.0 5.6 8.2 24 17 e9.0 5.6 8.6 25 15 e9.0 5.6 9.0 11 3.6 24 212 6.8 4.7 4.2 e1550 9.7 3.3 25 200 12 3.0 75 e4530 9.2 3.0 20 131 7.1 2.6 23 e694 8.4 2.5 20 93 6.2 2.4 107 e283 7.7 2.4 25 67 5.8 2.2 348 e189 26 13 12 5.6 9.7 27 12 17 5.6 8.5 28 11 11 5.6 7.7 29 10 8.5 5.8 6.9 30 9.0 8.5 5.7 6.7 31 9.0 --- 5.3 6.2 10 2.7 21 54 5.8 2.3 64 e176 10 2.3 18 58 5.6 2.8 37 e177 9.5 2.6 14 30 5.4 2.7 30 e172 --- 3.6 13 20 5.5 2.9 27 e144 --- 12 12 16 5.2 2.7 20 e116 --- 26 --- 13 --- 2.8 16 --­ TOTAL 1261.5 321.9 180.1 253.2 MEAN 40.7 10.7 5.81 8.17 MAX 351 26 8.1 19 MIN 1.8 7.2 4.8 4.5 AC-FT 2500 638 357 502 CFSM .94 .25 .13 .19 IN. 1.08 .28 .15 .22 714.4 175.9 667.7 1362.7 245.8 114.2 921.4 8727 25.5 5.67 22.3 44.0 8.19 3.68 29.7 291 328 26 126 212 38 5.9 348 4530 6.2 2.3 4.9 7.3 5.2 2.2 2.0 12 1420 349 1320 2700 488 227 1830 17310 .59 .13 .51 1.01 .19 .08 .68 6.69 .61 .15 .57 1.17 .21 .10 .79 7.46 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1987 - 1998, BY WATER YEAR (WY) MEAN 54.1 25.7 16.6 17.4 MAX 274 62.9 83.8 79.0 (WY) 1991 1988 1988 1992 MIN 10.3 4.91 3.72 2.71 (WY) 1989 1995 1989 1995 10.6 5.84 11.5 18.1 13.7 6.97 10.5 50.6 25.5 9.79 27.6 69.6 76.1 15.5 29.7 291 1998 1988 1987 1992 1987 1988 1998 1998 3.17 3.09 2.49 1.66 1.99 .78 1.28 1.61 1989 1987 1995 1989 1989 1989 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1987 - 1998 ANNUAL TOTAL 3056.1 ANNUAL MEAN 8.37 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 351 LOWEST DAILY MEAN 1.4 ANNUAL SEVEN-DAY MINIMUM 1.4 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 6060 ANNUAL RUNOFF (CFSM) .19 ANNUAL RUNOFF (INCHES) 2.61 10 PERCENT EXCEEDS 12 50 PERCENT EXCEEDS 4.6 90 PERCENT EXCEEDS 1.8 14945.8 40.9 19.9 40.9 1998 4.52 1994 Oct 14 4530 Sep 22 4530 Sep 22 1998 Sep 12 1.8 Oct 7 .67 Aug 2 1989 Sep 16 2.3 Jul 30 .70 Jul 27 1989 52700 Sep 21 52700 Sep 21 1998 25.94 Sep 21 25.94 Sep 21 1998 29640 14380 .94 .46 12.78 6.20 50 35 9.0 6.9 3.5 2.2 e Estimated 367 RIO COAMO BASIN 50106100 RIO COAMO AT COAMO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 368 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'52", long 66°22'10", Hydrologic Unit 21010004, on Highway 153 bridge, 0.4 mi (0.6 km) above Río de la Mina, and 1.8 mi (2.9 km) south of Coamo plaza. DRAINAGE AREA.--46.0 mi2 (119.1 km2). PERIOD OF RECORD.--Water years 1978 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 04... 1240 9.1 638 8.8 30.0 4.5 8.6 88 <10 210 K190 MAR 13... 1010 6.3 672 7.8 26.5 .28 8.2 102 <10 K130 50 MAY 20... 1110 20 464 7.6 30.0 1.5 7.7 102 <10 K1900 K160 AUG 26... 0930 99 384 7.0 26.0 8.5 7.3 91 20 2400 K1700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 04... 240 24 44 13 .4 1.6 218 <.5 21 16 MAR 13... -- -- -- -- -- -- 250 -- -- -­ MAY 20... 170 45 14 26 .9 .23 170 -- 25 28 AUG 26... 200 31 30 16 .5 2.1 150 <1.0 18 17 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 04... .10 33 286 7.03 39 1.78 .022 1.80 .030 .39 MAR 13... -- -- -- -- 1 2.58 .017 2.60 .030 .28 MAY 20... .38 31 272 14.5 2 1.58 .018 1.60 .040 -­ AUG 26... .20 33 270 6.63 12 -- <.010 2.50 .020 .32 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 04... .42 2.2 9.8 .210 <1 <100 80 <1 <1 <10 MAR 13... .31 2.9 13 .150 -- -- -- -- -- -­ MAY 20... <.20 -- -- .150 <1 <100 50 <1 <1 <10 AUG 26... .34 2.8 13 .260 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 369 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 04... 40 <1 13 <.10 <1 <1 <10 <.010 <1 .09 MAR 13... MAY 20... 200 <1 12 <.10 <1 <1 <10 <.010 2 <.02 AUG 26... 370 RIO DESCALABRADO BASIN 50108000 RIO DESCALABRADO NEAR LOS LLANOS, PR LOCATION.--Lat 18°03'08", long 66°25'34", Hydrologic Unit 21010004, at bridge on Highway 14, 1.5 mi (2.4 km) west of Los Llanos, and 5.3 mi (8.5 km) east of Juana Díaz. DRAINAGE AREA.--12.9 mi2 (33.4 km2). PERIOD OF RECORD.--1959-65 (annual low-flow measurements only), 1965 (annual maximum discharge), January 1966 to June 1969, July to December 1969 (maximum discharge only), February 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 220 ft (67 m), from topographic map. REMARKS.--Records poor. Some regulation at low-flow by local resident upstream from station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.2 1.7 e1.3 .44 e.39 1.0 e14 1.6 e4.4 e1.7 e.58 e5.6 2 1.6 1.7 e1.2 .42 e.35 1.0 e1.5 1.8 e3.2 e1.6 e.64 e14 3 2.2 1.8 e1.2 .49 e.34 .94 e1.4 2.0 e3.3 e1.6 e.66 e29 4 1.7 1.7 e1.1 .46 e.34 .92 e1.3 1.7 e14 e1.6 e.62 e54 5 1.5 1.8 e1.1 .40 e60 .87 e1.3 1.7 e3.6 e2.0 e.62 e8.0 6 1.4 1.8 e1.1 .45 e5.4 .87 e1.3 1.7 e3.0 e1.4 e.82 e26 7 1.4 1.7 e1.0 .43 8 27 1.8 e1.0 .56 9 38 3.4 .90 .49 10 39 e6.9 .91 .49 e1.8 .90 e46 3.8 e2.7 e1.3 e9.6 e23 e1.8 .82 e4.8 2.5 e2.7 e1.1 e14 e17 e6.4 .87 e3.2 1.9 e2.5 e1.2 e3.7 e13 e3.8 .93 e2.7 1.8 e2.5 e1.3 e2.2 e10 11 e108 e2.1 .91 .45 12 e16 e2.2 .85 1.9 13 e159 e2.1 .79 1.0 14 e398 e2.0 .77 .67 15 91 e1.9 .73 .59 e3.3 .93 e5.2 1.7 e2.3 e1.4 e1.7 e8.2 e2.9 .91 e43 2.0 e2.2 e1.3 e1.7 e7.6 e2.4 .91 e5.0 e2.1 e2.3 e1.3 e1.5 e6.8 e2.3 .88 e3.0 e10 e2.3 e1.3 e1.5 e6.0 e2.0 .91 3.1 e18 e2.3 e1.7 e1.4 e6.0 16 22 e1.9 .72 .54 17 16 e1.9 .76 .51 18 9.8 e1.8 .80 .52 19 5.3 1.8 .74 .54 20 4.5 1.7 .72 e.70 e1.8 e.88 3.2 e7.0 e2.7 e1.1 e1.6 e5.4 e1.8 e.84 3.4 e4.0 e2.8 e1.1 e1.8 e4.6 e2.0 e.82 18 e9.0 e2.8 e1.2 e1.8 e5.2 e2.1 e.80 3.0 e11 e2.5 e1.3 e1.9 e5.6 e1.9 e.80 2.1 e21 e2.2 e1.2 e2.0 e5.0 21 4.1 1.4 .80 e.47 22 3.7 1.5 .70 e.47 23 3.4 1.4 .66 e.45 24 3.0 1.2 .62 e.48 25 2.8 1.2 .59 e.50 e1.6 e.82 3.5 e50 e2.5 e1.4 e2.2 e200 e1.4 e.80 2.6 e47 e4.5 e.86 e20 e1700 e1.3 e.78 1.8 e30 e2.6 e.72 e6.1 e260 e1.2 e.78 1.8 e23 e2.2 e.70 e30 e106 1.2 e.80 1.7 e18 e2.0 e.65 e92 e70 26 2.4 1.1 .57 e.54 27 2.2 1.0 .56 e.47 28 2.0 1.0 .58 e.43 29 1.9 .99 .54 e.38 30 1.9 .99 .49 e.37 31 2.0 --- .48 e.35 1.1 e.78 1.9 e13 e2.0 e.66 e25 e66 1.1 e.80 1.8 e14 e1.9 e.80 e14 e66 1.1 e.78 1.8 e11 e1.8 e.80 e11 e65 --- e.86 1.7 e7.2 e1.9 e.83 e10 e55 --- e1.2 1.6 e5.6 e1.8 e.74 e7.4 e44 --- e.97 --- e4.7 --- e.74 e6.0 --­ TOTAL 977.0 55.48 25.19 16.96 MEAN 31.5 1.85 .81 .55 MAX 398 6.9 1.3 1.9 MIN 1.4 .99 .48 .35 AC-FT 1940 110 50 34 CFSM 2.44 .14 .06 .04 IN. 2.82 .16 .07 .05 113.12 27.17 186.7 329.8 89.5 36.60 274.04 2892.0 4.04 .88 6.22 10.6 2.98 1.18 8.84 96.4 60 1.2 46 50 14 2.0 92 1700 .34 .78 1.3 1.6 1.8 .65 .58 4.6 224 54 370 654 178 73 544 5740 .31 .07 .48 .82 .23 .09 .69 7.47 .33 .08 .54 .95 .26 .11 .79 8.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 1998, BY WATER YEAR (WY) MEAN 26.9 14.1 4.77 4.60 MAX 117 41.0 24.5 36.4 (WY) 1986 1985 1988 1992 MIN 2.02 1.04 .19 .057 (WY) 1968 1995 1968 1968 3.67 1.92 4.33 14.6 4.87 2.61 4.25 38.3 23.9 8.93 18.8 62.2 25.2 10.5 13.1 395 1995 1996 1985 1985 1987 1991 1996 1996 .020 .012 .000 .032 .000 .000 .19 .063 1968 1968 1968 1968 1967 1967 1990 1967 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1966 - 1998 ANNUAL TOTAL 1451.39 ANNUAL MEAN 3.98 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 398 LOWEST DAILY MEAN .11 ANNUAL SEVEN-DAY MINIMUM .12 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 2880 ANNUAL RUNOFF (CFSM) .31 ANNUAL RUNOFF (INCHES) 4.19 10 PERCENT EXCEEDS 3.4 50 PERCENT EXCEEDS .62 90 PERCENT EXCEEDS .15 5023.56 13.8 11.0 41.7 1996 1.69 1994 Oct 14 1700 Sep 22 10000 Sep 10 1996 Sep 20 .34 Feb 3 .00 Jun 22 1966 Sep 3 .36 Jan 29 .00 Jun 22 1966 9180 Sep 21 30000 Oct 7 1985 16.15 Sep 21 24.37 Oct 7 1985 9960 7960 1.07 .85 14.49 11.57 18 14 1.8 1.4 .58 .06 e Estimated 371 RIO DESCALABRADO BASIN 50108000 RIO DESCALABRADO NEAR LOS LLANOS, PR--Continued O N D J F M A M J J A S 0.1 10,000 0.2 0.5 1 2 5 10 20 50 100 200 500 1,000 2,000 5,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 372 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR LOCATION.--Lat 18°07'37", long 66°27'24", Hydrologic unit 21010004, on right bank, off a dirt road about 0.3 mi (0.5 km) from road 553, 2.4 mi (3.9 km) southeast from Villalba Plaza, and 0.2 mi (0.3 km) downstream from confluence with Quebrada Limón. DRAINAGE AREA.--14.2 mi2 (36.77 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1989 to current year. GAGE.--Water stage recorder. Elevation of gage is 525 ft (160 m ), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17 7.3 3.5 1.9 2 16 7.0 3.3 2.0 3 13 6.6 3.0 2.1 4 12 6.4 2.9 1.9 5 10 6.1 2.9 1.7 1.6 1.9 16 7.4 18 5.4 7.1 14 1.6 1.8 31 7.3 17 4.8 12 30 1.5 2.5 15 7.8 21 4.4 7.4 93 2.0 2.5 5.5 7.5 45 5.6 3.4 153 93 2.2 2.9 7.5 53 5.8 2.5 37 6 9.8 5.9 2.9 1.6 7 11 5.7 2.8 2.4 8 75 7.0 2.8 2.2 9 44 7.4 2.4 2.0 10 29 24 2.3 1.7 4.5 2.0 2.1 16 34 4.2 4.1 150 2.2 2.0 86 11 29 4.6 19 92 24 2.5 53 13 28 4.5 31 49 33 1.9 28 15 26 4.3 19 35 8.3 1.5 17 9.5 25 4.7 11 28 11 66 7.5 2.3 1.6 12 55 6.1 2.1 1.8 13 71 5.2 2.1 3.0 14 236 4.7 1.9 3.5 15 129 4.7 2.0 2.2 4.5 1.5 17 7.7 23 4.6 13 47 3.0 1.4 217 7.0 23 4.5 18 34 2.4 1.4 58 22 22 4.9 13 23 3.0 1.4 26 67 19 10 6.2 18 3.7 1.4 17 74 18 15 3.4 18 16 68 5.0 2.0 1.7 17 53 4.7 2.4 1.5 18 36 4.3 2.4 15 19 26 4.0 2.4 14 20 22 3.9 2.0 3.9 2.6 1.5 13 36 27 12 3.0 34 2.6 1.5 11 29 40 9.8 10 19 2.5 1.6 10 124 25 9.5 3.3 41 2.1 1.7 9.0 42 14 7.6 3.9 37 2.1 1.7 8.6 243 11 9.5 14 26 21 15 3.9 2.0 2.8 22 13 4.0 1.7 2.4 23 11 3.8 2.6 2.2 24 10 3.5 2.4 2.2 25 9.3 3.3 2.3 2.3 1.9 2.0 11 456 11 11 9.0 1050 2.0 2.6 11 165 18 6.5 122 e1740 1.8 1.9 14 87 10 4.8 33 e224 2.0 2.0 13 62 9.2 4.7 455 e115 1.8 2.5 9.7 45 9.0 4.8 146 e85 26 8.6 3.2 2.2 2.5 27 8.2 3.1 2.1 1.9 28 7.9 3.0 2.1 1.8 29 7.9 3.0 2.0 1.8 30 7.7 4.3 1.9 1.6 31 7.5 --- 1.8 1.6 1.8 2.7 9.0 43 8.4 3.8 52 e73 1.8 2.2 7.7 31 7.2 5.9 34 e63 1.9 2.1 7.0 27 6.9 4.7 24 e59 --- 1.7 6.3 24 6.3 4.1 19 e93 --- 13 6.8 22 6.0 3.6 16 e86 --- 4.0 --- 20 --- 3.2 14 --­ TOTAL 1104.9 168.6 73.5 90.8 MEAN 35.6 5.62 2.37 2.93 MAX 236 24 3.5 15 MIN 7.5 3.0 1.7 1.5 AC-FT 2190 334 146 180 CFSM 2.51 .40 .17 .21 IN. 2.89 .44 .19 .24 215.2 72.6 738.6 1735.7 610.0 192.8 1128.3 4566 7.69 2.34 24.6 56.0 20.3 6.22 36.4 152 93 13 217 456 53 15 455 1740 1.5 1.4 2.1 7.0 6.0 3.2 2.5 14 427 144 1470 3440 1210 382 2240 9060 .54 .16 1.73 3.94 1.43 .44 2.56 10.7 .56 .19 1.93 4.55 1.60 .51 2.96 11.96 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1998, BY WATER YEAR (WY) MEAN 41.5 15.9 6.46 9.19 MAX 109 40.1 12.4 43.1 (WY) 1991 1991 1993 1992 MIN 4.61 2.19 1.42 1.79 (WY) 1992 1992 1992 1995 5.70 3.37 9.79 23.1 11.2 6.64 9.86 44.5 12.6 5.01 26.3 76.1 35.4 14.4 36.4 152 1996 1996 1993 1995 1992 1992 1998 1998 2.38 1.67 1.46 1.42 1.23 .71 2.74 3.21 1990 1990 1990 1997 1990 1990 1990 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1989 - 1998 ANNUAL TOTAL 2278.47 ANNUAL MEAN 6.24 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 236 LOWEST DAILY MEAN .57 ANNUAL SEVEN-DAY MINIMUM .64 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 4520 ANNUAL RUNOFF (CFSM) .44 ANNUAL RUNOFF (INCHES) 5.97 10 PERCENT EXCEEDS 9.9 50 PERCENT EXCEEDS 2.4 90 PERCENT EXCEEDS 1.1 10697.0 29.3 15.9 29.3 1998 4.02 1994 Oct 14 1740 Sep 22 2050 Sep 10 1996 Jul 25 1.4 Mar 12 .45 Aug 7 1990 Jul 22 1.4 Mar 10 .61 Jul 9 1990 Not determined Sep 21 Not determined Sep 21 1998 20.60 Sep 21 20.60 Sep 21 1998 .59 Apr 1 .42 Jul 14 1997 21220 11500 2.06 1.12 28.02 15.19 54 33 7.2 4.3 1.9 1.4 e Estimated 373 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 374 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water years 1988 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 1988 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment sampler since 1988. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected by a local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 11,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e93,300 tons (e84,700 tonnes) September 22, 1998; Minimum daily mean, <0.01 ton (<0.01 tonne) several years. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATION: Maximum daily mean, 11,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e93,300 tons (e84,700 tonnes) September 22, 1998; Minimum daily mean,0.01 tons (0.01 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 17 95 4.3 7.3 205 4.0 3.5 16 .16 2 16 89 3.9 7.0 231 4.3 3.3 17 .15 3 13 84 3.0 6.6 263 4.7 3.0 16 .13 4 12 79 2.5 6.4 293 5.0 2.9 15 .12 5 10 75 2.0 6.1 254 4.2 2.9 10 .08 6 9.8 70 1.8 5.9 205 3.2 2.9 6 .04 7 11 130 3.2 5.7 164 2.5 2.8 3 .03 8 75 1390 1040 7.0 131 2.4 2.8 3 .02 9 44 494 60 7.4 108 2.4 2.4 2 .01 10 29 328 26 24 350 37 2.3 2 .01 11 66 655 203 7.5 41 .87 2.3 2 .01 12 55 598 91 6.1 8 .13 2.1 3 .01 13 71 709 226 5.2 2 .02 2.1 3 .02 14 236 2350 2990 4.7 3 .03 1.9 3 .02 15 129 456 183 4.7 9 .11 2.0 4 .02 16 68 471 91 5.0 24 .33 2.0 4 .02 17 53 476 127 4.7 14 .17 2.4 5 .03 18 36 271 28 4.3 4 .05 2.4 5 .03 19 26 72 5.2 4.0 1 .01 2.4 6 .04 20 22 21 1.2 3.9 1 .01 2.0 6 .03 21 15 33 e1.4 3.9 1 .01 2.0 7 .04 22 13 86 2.9 4.0 1 .01 1.7 8 .04 23 11 210 6.4 3.8 3 .03 2.6 9 .06 24 10 229 6.3 3.5 8 .08 2.4 10 .06 25 9.3 200 5.0 3.3 12 .11 2.3 11 .07 26 8.6 175 4.1 3.2 4 .04 2.2 12 .07 27 8.2 168 3.7 3.1 5 .04 2.1 14 .08 28 7.9 165 3.5 3.0 5 .04 2.1 15 .09 29 7.9 163 3.5 3.0 7 .06 2.0 17 .09 30 7.7 174 3.6 4.3 11 .13 1.9 19 .10 31 7.5 188 3.8 1.8 18 .09 TOTAL 1104.9 5136.3 168.6 71.98 73.5 1.77 --- --- --- --- --- --- --- --- --- --- --- --- 375 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 1.9 17 .09 1.6 7 .03 1.9 31 .16 2 2.0 16 .09 1.6 6 .03 1.8 38 .19 3 2.1 15 .08 1.5 5 .02 2.5 46 .31 4 1.9 14 .07 2.0 9 .07 2.5 44 .29 5 1.7 13 .06 93 1610 1230 2.2 38 .23 6 1.6 12 .05 4.5 124 1.8 2.0 32 .18 7 2.4 12 .08 2.2 27 .16 2.0 17 .09 8 2.2 11 .06 24 184 87 2.5 8 .05 9 2.0 10 .05 33 214 29 1.9 4 .02 10 1.7 10 .04 8.3 42 .96 1.5 3 .01 11 1.6 9 .04 4.5 29 .35 1.5 3 .01 12 1.8 8 .04 3.0 19 .15 1.4 3 .01 13 3.0 8 .06 2.4 11 .07 1.4 4 .02 14 3.5 7 .07 3.0 6 .05 1.4 6 .02 15 2.2 7 .04 3.7 4 .04 1.4 8 .03 16 1.7 7 .03 2.6 6 .04 1.5 11 .04 17 1.5 6 .03 2.6 11 .08 1.5 14 .06 18 15 106 34 2.5 22 .15 1.6 18 .08 19 14 87 6.7 2.1 21 .12 1.7 22 .10 20 3.9 10 .10 2.1 16 .09 1.7 26 .12 21 2.8 10 .08 1.9 12 .06 2.0 30 .17 22 2.4 10 .07 2.0 10 .05 2.6 25 .13 23 2.2 10 .06 1.8 12 .06 1.9 18 .10 24 2.2 10 .06 2.0 16 .09 2.0 14 .08 25 2.3 10 .06 1.8 23 .11 2.5 16 .10 26 2.5 10 .07 1.8 38 .18 2.7 20 .14 27 1.9 10 .05 1.8 35 .17 2.2 23 .14 28 1.8 10 .05 1.9 28 .14 2.1 17 .10 29 1.8 10 .05 1.7 11 .05 30 1.6 9 .04 13 158 11 31 1.6 8 .04 4.0 42 .59 TOTAL 90.8 42.41 215.2 1351.07 72.6 14.62 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 16 335 69 7.4 2 31 394 86 7.3 3 15 206 9.2 7.8 32 .64 18 5 .25 43 .85 17 10 .46 48 1.0 21 110 11 4 5.5 69 1.1 7.5 53 1.1 45 297 88 5 2.9 23 .19 7.5 53 1.1 53 836 464 6 2.1 11 .06 7 86 1680 1290 8 53 130 22 9 28 26 2.0 10 17 32 1.4 16 84 19 34 73 6.9 11 87 2.7 29 30 2.3 13 168 3.4 28 29 2.2 15 138 5.8 26 28 2.0 9.5 61 1.6 25 28 1.9 11 17 62 3.5 7.7 12 217 2230 2060 7.0 13 58 685 111 22 14 26 384 28 67 15 17 215 9.8 74 38 .81 23 27 1.7 28 .53 23 27 1.7 176 27 22 26 1.6 933 429 19 26 1.3 727 176 18 26 1.2 16 13 121 4.3 17 11 68 2.0 18 10 39 1.1 19 9.0 39 .95 20 8.6 46 1.1 36 73 7.6 27 121 12 29 34 2.7 40 246 65 124 2030 3300 25 217 14 42 560 98 14 130 4.8 243 2160 6340 11 87 2.7 21 11 78 2.6 456 22 11 109 2.6 165 23 14 127 5.5 87 24 13 91 3.3 62 25 9.7 40 1.0 45 2560 10200 11 56 1.7 254 142 18 37 1.8 105 24 10 24 .67 127 21 9.2 16 .39 147 18 9.0 10 .25 26 9.0 28 .69 27 7.7 24 .49 28 7.0 18 .35 29 6.3 6 .10 30 6.8 12 .22 31 --- --- --- 43 88 10 8.4 7 .15 31 37 3.2 7.2 5 .09 27 4 .31 6.9 7 .14 24 2 .15 6.3 15 .25 22 3 .15 6.0 28 .45 20 3 .16 --- --- --­ TOTAL 738.6 --- 3719.55 1735.7 --- 20837.80 610.0 --- 690.90 --- --- --- --- --- --- 376 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 5.4 21 .30 7.1 28 3.7 14 9 .32 2 4.8 12 .15 12 75 8.3 30 224 47 3 4.4 7 .08 7.4 60 1.4 93 621 257 4 5.6 5 .08 3.4 22 .20 153 700 678 5 5.8 5 .07 2.5 16 .11 37 32 3.0 6 4.2 5 .05 4.1 22 .32 150 337 363 7 4.6 4 .05 19 103 20 92 77 23 8 4.5 3 .04 31 230 37 49 15 2.0 9 4.3 3 .04 19 211 12 35 7 .69 10 4.7 3 .04 11 80 2.5 28 4 .27 11 4.6 3 .04 13 92 6.2 47 240 63 12 4.5 3 .04 18 148 7.0 34 247 35 13 4.9 3 .04 13 57 2.1 23 35 2.2 14 10 3 .09 6.2 23 .40 18 4 .20 15 15 3 .12 3.4 15 .14 18 4 .19 16 12 3 .10 3.0 13 .23 34 246 44 17 9.8 3 .08 10 80 4.0 19 283 8.3 18 9.5 3 .08 3.3 27 .24 41 448 84 19 7.6 3 .07 3.9 19 .20 37 379 40 20 9.5 4 .10 14 167 6.9 26 226 16 21 11 4 .13 9.0 106 2.5 1050 6200 52000 22 6.5 5 .09 122 93 e252 e1740 11800 e93300 23 4.8 6 .07 33 128 e42 e224 1110 e4920 24 4.7 6 .08 455 131 e10200 e115 345 e252 25 4.8 7 .09 146 80 e252 e85 115 e252 26 3.8 8 .08 52 24 3.7 e73 77 e429 27 5.9 9 .14 34 9 .85 e63 60 e199 28 4.7 10 .13 24 6 .36 e59 47 e199 29 4.1 12 .13 19 3 .18 e93 37 e252 30 3.6 13 .13 16 4 .17 e86 28 e252 31 3.2 15 .13 14 6 .22 TOTAL 192.8 2.86 1128.3 10866.92 4566 153722.17 YEAR 10697.0 196458.35 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) OCT 15... 1500 212 942 539 98 15... 1600 224 882 533 91 APR 02... 1615 64 1980 342 99 07... 1520 437 9410 11100 66 MAY 18... 1645 1020 31700 87300 61 20... 2015 1530 18300 75600 39 21... 2330 327 537 474 89 SEP 06... 1645 1390 881 3310 83 11... 1645 279 4700 3540 67 377 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 08... 1600 363 8780 8610 27 37 51 MAR 30... 1645 23 959 60 63 77 90 APR 07... 1425 534 6870 9910 30 39 50 MAY 20... 1815 1500 14400 58300 14 19 25 21... 1630 2790 22800 172000 14 20 26 21... 1815 2080 11100 62300 7 9 11 SEP 04... 0230 428 7670 8860 22 29 39 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 08... 65 81 87 96 99 100 100 MAR 30... 97 97 99 100 100 100 100 APR 07... 59 63 68 82 95 100 100 MAY 20... 30 37 41 53 73 92 98 21... 33 40 44 55 73 90 97 21... 14 17 18 24 37 62 86 SEP 04... 50 61 64 81 93 98 100 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 379 RIO TOA VACA BASIN 50111210 LAGO TOA VACA AT DAMSITE NEAR VILLALBA, PR--Continued ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 489.90 499.32 500.12 499.88 501.45 497.88 500.21 506.24 504.44 500.90 502.02 2 489.89 499.33 500.12 499.85 499.70 501.32 498.04 500.09 506.16 504.33 500.79 502.03 3 489.89 499.34 500.11 499.85 499.65 501.22 497.97 499.97 506.10 504.20 500.67 502.52 4 489.88 499.34 500.10 499.83 499.71 501.09 497.87 499.84 506.12 504.11 500.53 503.80 5 489.86 499.36 500.09 499.81 501.90 500.96 497.74 499.72 506.26 504.00 500.41 503.86 6 489.84 499.36 500.08 499.81 501.94 500.83 497.62 499.73 506.19 503.92 504.73 7 489.85 499.38 500.07 499.84 501.95 500.70 498.89 499.66 506.12 500.35 504.99 8 490.58 499.41 500.06 499.82 500.57 498.91 499.58 506.05 500.34 505.03 9 490.76 499.54 500.06 499.82 502.32 500.43 498.81 499.49 505.98 500.24 505.02 10 490.81 499.68 500.05 499.81 502.30 500.29 498.71 499.38 505.89 500.12 504.99 11 491.35 499.70 500.03 499.81 502.30 500.14 498.67 499.26 505.79 500.02 505.11 12 491.51 499.72 500.02 499.81 502.29 500.01 501.53 499.15 505.70 499.92 505.20 13 492.56 499.73 500.02 499.81 502.28 499.87 501.73 499.21 505.61 499.80 505.20 14 495.73 499.72 500.02 499.80 502.31 499.74 501.72 499.63 505.51 499.67 505.14 15 497.35 500.11 500.01 499.80 502.31 499.60 501.67 499.96 505.40 499.55 505.11 16 497.82 500.13 499.99 499.78 502.30 499.47 501.58 499.96 505.34 499.41 505.21 17 498.45 500.14 500.00 499.76 502.29 499.32 501.50 499.90 505.80 499.38 505.15 18 498.68 500.14 499.99 499.77 502.31 499.18 501.49 500.79 505.76 499.26 505.23 19 498.83 500.15 500.00 499.78 499.04 501.40 501.11 505.66 499.13 505.24 20 498.94 500.15 499.98 499.78 502.28 498.93 501.30 503.14 505.56 499.01 505.20 21 499.02 500.14 499.99 499.77 498.80 501.21 505.82 505.52 498.89 512.73 22 499.08 500.14 499.98 499.83 502.26 498.68 501.13 506.35 505.46 499.23 529.60 23 499.13 500.14 499.98 499.80 502.21 498.54 501.05 506.55 505.35 499.31 531.01 24 499.16 500.14 499.97 499.78 502.12 498.41 500.97 506.58 505.24 500.62 530.58 25 499.20 500.13 499.95 499.79 501.98 498.29 500.88 506.58 505.13 502.29 528.79 26 499.23 500.13 499.93 499.77 501.85 498.15 500.78 506.58 505.02 502.37 526.73 27 499.25 500.13 499.92 499.75 501.72 498.02 500.70 506.55 504.90 502.42 526.17 28 499.27 500.13 499.92 499.75 501.59 497.89 500.58 506.50 504.79 502.36 526.52 29 499.29 500.12 499.91 499.74 497.77 500.45 506.44 504.67 502.30 526.74 30 499.30 500.11 499.90 499.73 497.87 500.34 506.38 504.55 502.21 526.89 31 499.31 499.88 499.71 497.76 506.31 500.92 502.11 TOTAL15353.72 14995.06 15500.25 15493.64 --- 15484.34 15003.12 15570.42 15167.87 --- 15356.54 MAX 499.31 500.15 500.12 499.88 501.45 501.73 506.58 506.26 531.01 MIN 489.84 499.32 499.88 499.71 497.76 497.62 499.15 504.55 502.02 --- --- --- --- --- --- --- --- --- 380 RIO JACAGUAS BASIN 50111300 LAGO GUAYABAL AT DAMSITE NEAR JUANA DIAZ, PR LOCATION.--Lat 18°05'17", long 66°30'09", Hydrologic Unit 21010004, at Damsite, 2.30 mi (3.70 km) northeast from Juana Díaz Plaza, 0.70 mi (1.13 km) northeast from Escuela Salvador Bousquets and 2.45 mi (3.94 km) southeast from Escuela Zoilo Gracia. DRAINAGE AREA.--21.0 mi2 (54.4 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guayabal was completed in 1913. The dam is a reinforced concrete, flatslab and buttress-type structure about 130 ft (40 m) height, a net crest lenght at the right side of the dam of 693 ft (211 m) and a crest elevation of 331 ft (101 m). It has a maximum storage capacity of 7,600 acre-feet (9.37 hm3). The Guayabal Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and its primary purpose is for irrigation of lands served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 341.55 ft (104.10 m), Sept. 10, 1996; minimum elevation, 325.99 ft (99.36 m), Sept. 29, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 341.42 ft (104.06 m), May 21; minimum elevation, 328.59 ft (100.20 m), Oct. 5. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 305 366 330 3,885 321 2,010 341 7,360 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 328.90 340.35 339.52 335.67 333.66 335.75 333.68 340.37 340.73 340.72 340.64 340.78 2 328.87 340.23 339.40 335.52 333.46 335.66 334.39 340.32 340.71 340.72 340.77 340.92 3 328.79 340.20 339.31 335.33 333.34 335.63 334.52 340.32 340.71 340.70 340.81 341.00 4 328.65 340.18 339.25 335.13 333.45 335.56 334.44 340.38 340.91 340.70 340.79 340.88 5 328.63 340.15 339.17 334.99 335.81 335.45 334.36 340.42 340.84 340.66 340.79 340.86 6 328.77 340.21 338.98 334.79 336.17 335.34 334.38 340.70 340.71 340.83 340.88 340.94 7 329.25 340.25 338.82 334.72 336.23 335.13 339.26 340.83 340.67 340.69 340.90 340.83 8 331.23 340.30 338.75 334.64 336.81 334.94 339.59 340.87 340.74 340.63 340.98 340.89 9 331.91 340.52 338.68 334.78 337.34 334.85 339.61 340.81 340.76 340.68 340.84 340.90 10 332.44 340.82 338.59 334.82 337.55 334.73 339.57 340.77 340.77 340.69 340.84 340.92 11 333.33 340.78 338.49 334.89 337.70 334.61 339.63 340.80 340.76 340.56 340.93 340.95 12 334.02 340.79 338.38 335.07 337.87 334.48 340.97 340.79 340.75 340.49 340.89 340.87 13 337.44 340.79 338.19 335.32 337.78 334.37 340.79 341.06 340.67 340.51 340.86 340.98 14 340.99 340.80 338.02 335.49 337.68 334.13 340.74 340.99 340.61 340.88 340.84 340.92 15 340.91 340.89 337.96 335.65 337.60 333.96 340.77 340.91 340.67 340.83 340.75 340.87 16 340.83 340.75 337.88 335.77 337.50 333.93 340.79 340.86 340.78 340.80 340.75 340.94 17 340.81 340.77 337.86 335.80 337.41 333.80 340.78 340.83 340.88 340.80 340.92 340.82 18 340.78 340.77 337.83 335.88 337.35 333.69 340.86 340.96 340.83 340.72 340.91 340.95 19 340.74 340.74 337.75 336.04 337.25 333.56 340.79 340.88 340.77 340.67 340.87 340.95 20 340.81 340.71 337.60 335.84 337.11 333.50 340.91 341.00 340.69 340.71 340.85 340.91 21 340.80 340.75 337.47 335.67 336.89 333.33 340.87 340.85 340.74 340.73 340.88 A 22 340.79 340.70 337.35 335.68 336.69 333.19 340.85 340.80 340.80 340.79 340.86 A 23 340.79 340.68 337.20 335.48 336.58 333.06 340.83 340.86 340.72 340.80 340.81 A 24 340.80 340.57 337.07 335.25 336.54 332.98 340.84 340.79 340.72 340.78 341.07 A 25 340.66 340.49 336.87 335.00 336.46 332.92 340.78 340.80 340.70 340.67 340.91 A 26 340.62 340.37 336.72 334.94 336.35 332.83 340.78 340.83 340.73 340.61 340.87 A 27 340.64 340.16 336.53 334.82 336.13 332.79 340.82 340.83 340.68 340.59 340.94 A 28 340.71 340.00 336.34 334.59 335.94 332.59 340.69 340.84 340.66 340.55 340.87 A 29 340.72 339.78 336.20 334.39 332.46 340.58 340.83 340.71 340.51 340.85 A 30 340.60 339.61 336.04 334.13 333.25 340.43 340.80 340.73 340.45 340.85 341.01 31 340.51 335.86 333.89 333.38 340.78 340.45 340.85 MAX 340.99 340.89 339.52 336.04 337.87 335.75 340.97 341.06 340.91 340.88 341.07 MIN 328.63 339.61 335.86 333.89 333.34 332.46 333.68 340.32 340.61 340.45 340.64 A No gage-height record 381 RIO JACAGUAS BASIN 50111500 RIO JACAGUAS AT JUANA DIAZ, PR LOCATION.--Lat 18°03'16", long 66°30'40", Hydrologic Unit 21010004, on Highway 14 bridge, 0.4 mi (0.6 km) west of Juana Díaz plaza, and 4.0 mi (6.4 km) downstream from Lago Guayabal. DRAINAGE AREA.--49.8 mi2 (129.0 km2). PERIOD OF RECORD.--March 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records poor. Flow regulation from Lago Guayabal. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.2 20 e6.6 e2.9 1.5 3.5 16 36 60 11 6.0 131 2 1.1 19 e5.5 e4.0 1.4 3.1 10 12 40 9.4 6.8 92 3 1.1 17 e5.2 e2.2 1.3 3.8 5.2 9.6 30 10 15 379 4 1.1 13 e5.2 e2.0 1.4 4.4 3.6 9.1 80 11 20 611 5 .96 11 e11 e1.3 127 3.7 2.9 8.7 233 10 14 289 6 .84 9.7 e15 e2.0 34 3.2 2.6 8.5 112 52 e37 314 7 .99 9.2 e12 e2.0 14 3.8 14 8.6 53 54 162 250 8 1.1 9.6 e11 e1.9 9.9 3.4 35 16 33 13 147 179 9 6.8 9.6 e9.8 e1.5 12 2.7 32 24 39 6.8 124 223 10 5.2 39 e9.3 e2.1 9.0 2.1 24 14 38 8.3 73 224 11 55 50 e9.7 e2.1 12 9.1 37 e8.6 e1.7 13 38 37 e7.6 e1.6 14 363 37 e6.9 e1.5 15 397 72 e6.3 e1.2 7.4 2.1 18 9.8 35 7.4 75 253 6.7 2.0 186 9.0 31 4.1 105 277 5.8 1.9 153 9.4 22 3.2 83 218 6.1 1.9 96 128 11 7.2 62 230 7.5 2.0 66 125 8.2 99 41 230 16 228 75 e5.7 e1.2 17 355 42 e7.1 e1.2 18 198 40 e6.4 e1.4 19 113 36 e6.7 e1.6 20 95 23 e6.8 e1.5 5.8 1.9 53 90 11 85 20 228 5.0 1.8 51 52 111 67 43 242 5.3 1.7 53 44 92 39 83 189 5.8 1.7 61 88 63 15 75 263 5.5 1.6 40 153 31 9.2 59 262 21 103 19 e4.9 e3.3 22 97 25 e3.2 e1.2 23 89 19 e3.4 1.2 24 84 15 e3.1 1.4 25 73 e11 e2.6 1.5 5.3 2.0 81 425 15 12 51 1230 5.6 2.0 66 218 36 14 285 8530 5.4 1.9 51 159 35 12 124 863 6.5 1.9 49 136 17 15 427 959 4.4 2.6 45 115 15 11 828 1030 26 55 e11 e2.2 1.3 27 44 e9.7 e2.8 1.3 28 38 e8.3 e2.2 1.3 29 40 e7.9 e1.7 1.2 30 36 e7.4 e1.5 1.3 31 25 --- e2.2 1.2 4.1 2.3 27 111 12 5.2 291 938 3.8 2.0 24 110 14 4.8 233 715 3.4 2.0 55 101 8.4 6.3 232 230 --- 2.0 42 92 7.3 4.9 185 219 --- 25 40 91 9.2 4.9 165 199 --- 7.3 --- 84 --- 5.1 145 --­ TOTAL 2555.49 739.4 192.2 53.1 MEAN 82.4 24.6 6.20 1.71 MAX 397 75 15 4.0 MIN .84 7.4 1.5 1.2 AC-FT 5070 1470 381 105 CFSM 1.66 .49 .12 .03 IN. 1.91 .55 .14 .04 310.9 103.3 1402.3 2496.7 1302.1 616.8 4216.8 19997 11.1 3.33 46.7 80.5 43.4 19.9 136 667 127 25 186 425 233 99 828 8530 1.3 1.6 2.6 8.5 7.3 3.2 6.0 92 617 205 2780 4950 2580 1220 8360 39660 .22 .07 .94 1.62 .87 .40 2.73 13.4 .23 .08 1.05 1.87 .97 .46 3.15 14.94 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 1998, BY WATER YEAR (WY) MEAN 114 81.6 32.5 23.0 MAX 445 287 151 144 (WY) 1986 1988 1988 1992 MIN 4.31 7.57 6.20 1.71 (WY) 1995 1995 1998 1998 9.04 5.03 13.2 66.5 38.6 21.7 26.9 81.8 16.9 8.60 46.7 215 198 82.4 136 667 1991 1996 1998 1985 1987 1987 1998 1998 1.98 1.95 1.84 1.46 .93 1.04 1.59 .76 1994 1994 1994 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1984 - 1998 ANNUAL TOTAL 5482.05 ANNUAL MEAN 15.0 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 397 LOWEST DAILY MEAN .37 ANNUAL SEVEN-DAY MINIMUM .51 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 10870 ANNUAL RUNOFF (CFSM) .30 ANNUAL RUNOFF (INCHES) 4.10 10 PERCENT EXCEEDS 33 50 PERCENT EXCEEDS 4.3 90 PERCENT EXCEEDS .84 33986.09 93.1 44.1 93.1 1998 6.23 1994 Oct 15 8530 Sep 22 8530 Sep 22 1998 Sep 3 .84 Oct 6 .24 Jan 3 1992 Aug 31 1.0 Oct 2 .51 Aug 31 1997 37600 Sep 22 40000 Oct 7 1985 28.71 Sep 22 29.42 Oct 7 1985 67410 31940 1.87 .89 25.39 12.03 218 93 13 8.2 1.7 2.2 e Estimated 382 RIO JACAGUAS BASIN 50111500 RIO JACAGUAS AT JUANA DIAZ, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR MARICAO Río San Patricio Río Río Río Río Río Inabón Guayo Río Río Río Río Río Río Río Inabón Río Río de de de Canal Canal Principal de Drenage Principal Valle V a lle Lajas Lajas Riego Río Río Río Tunnel Tunnel from Lago Prieto Tu n n e l fro m L a g o G a rz a s Duey Macaná Tallaboa boa Guayanés Cañas Pastillo Lago Luchetti Lago Loco Loco Yauco Y auco Quebrada del Agua Lago Cerrillos Lago Numero 1 Lago Numero 2 Lago Numero 5 Lago Ponceña Portugués C u ito B a y a n Bucaná CHANNELS CARIBBEAN SEA PONCE PEÑUELAS SABANA GRANDE GUÁNICA 0 0 1 1 2 2 3 3 4 4 1297 1247 125780 1289 132 AN-1 CO-3 CO-3 141 1242 R ío Talla h iq g á FLOW DIRECTION TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER EXPLANATION SEDIMENT STATION AND NUMBER WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER GUAYANILLA YAUCO ADJUNTAS Basin area PUERTO RICO 5 MILES 5 KILOMETERS LV-1 1162 1162 1138 1149 1159 1159 1150 1125 1140 1149 113950 114390 113950 383 Figure 22. South coast river basins -- Río Inabón to Río Loco basins. --- --- --- --- --- --- --- 384 RIO INABON BASIN 50112500 RIO INABON AT REAL ABAJO, PR LOCATION.--Lat 18°05'10", long 66°33'46", Hydrologic Unit 21010004, at bridge on private road, off Highway 511 at Hacienda La Concordia, 0.4 mi (0.6 km) upstream from diversion canal, 0.5 mi (0.8 km) north of Real Abajo, and 6.1 mi (9.8 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--9.70 mi2 (25.12 km2). PERIOD OF RECORD.--1962-63 (annual low-flow measurements only), February to June 1964 (monthly measurements only), July 1964 to July 1970, April 1971 to current year. GAGE.--Water-stage recorder. Elevation of gage is 410 ft (125 m), from topographic map. Prior to April 1971 non-recording gage and crest-stage gage at different datum. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.8 13 7.5 3.6 3.1 4.1 e21 28 22 15 17 13 2 6.6 14 8.5 3.8 3.1 4.3 e22 28 22 14 22 28 3 5.0 16 6.7 4.0 3.1 4.1 e22 28 26 15 17 78 4 4.4 15 6.2 4.2 12 4.2 20 29 41 15 13 79 5 3.8 14 5.4 3.9 e104 3.5 15 29 67 14 12 38 6 3.6 13 5.3 3.9 11 3.1 12 35 41 23 18 46 7 e30 13 5.3 7.6 5.6 e7.1 e100 35 29 20 26 37 8 e18 e13 5.0 6.2 14 e11 88 39 25 14 39 30 9 e27 e15 4.6 4.0 e16 5.7 37 38 24 15 23 26 10 e22 e27 4.5 4.4 6.9 4.2 30 31 23 e20 18 22 11 16 12 4.5 4.1 5.0 3.9 26 28 21 e16 19 26 12 13 10 4.3 8.1 4.2 3.8 54 27 20 15 17 24 13 79 9.2 4.6 6.3 3.6 3.7 43 32 19 e15 13 e32 14 290 7.6 4.3 4.3 4.1 e5.8 30 75 20 35 11 33 15 105 22 4.8 3.5 6.0 e26 24 51 21 e29 10 32 16 53 e16 4.6 3.4 4.8 19 21 32 24 18 8.6 44 17 179 10 4.2 3.4 4.9 10 19 25 35 15 12 47 18 87 8.0 4.5 4.0 3.8 7.2 46 21 e22 14 12 44 19 32 7.5 5.1 7.3 4.2 5.7 e36 18 17 19 11 40 20 22 7.7 4.6 6.4 4.6 6.3 52 34 16 25 10 36 21 17 7.2 5.2 3.9 5.3 e6.6 46 36 e16 23 14 e166 22 15 7.6 4.8 4.2 5.6 6.5 34 24 e19 21 21 e416 23 13 6.6 3.8 3.8 5.5 7.4 31 25 17 21 18 137 24 11 6.4 3.5 3.5 4.4 5.3 49 22 17 15 116 e88 25 11 6.3 3.4 3.6 3.4 6.0 46 21 16 13 e198 70 26 10 6.8 3.5 3.8 3.3 8.6 38 21 16 12 40 61 27 11 7.6 3.4 3.4 3.5 5.7 33 21 16 11 44 66 28 12 6.1 3.4 3.4 3.4 5.3 30 19 15 12 33 55 29 13 11 3.6 3.4 e4.6 27 19 15 11 22 49 30 13 13 e3.5 3.6 e36 26 20 15 12 17 49 31 13 3.5 3.3 e30 21 14 13 TOTAL 1143.2 341.6 146.1 136.3 258.4 264.7 1078 912 697 531 864.6 1912 MEAN 36.9 11.4 4.71 4.40 9.23 8.54 35.9 29.4 23.2 17.1 27.9 63.7 MAX 290 27 8.5 8.1 104 36 100 75 67 35 198 416 MIN 3.6 6.1 3.4 3.3 3.1 3.1 12 18 15 11 8.6 13 AC-FT 2270 678 290 270 513 525 2140 1810 1380 1050 1710 3790 CFSM 3.80 1.17 .49 .45 .95 .88 3.70 3.03 2.40 1.77 2.88 6.57 IN. 4.38 1.31 .56 .52 .99 1.02 4.13 3.50 2.67 2.04 3.32 7.33 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 1998, BY WATER YEAR (WY) MEAN 45.0 32.5 12.0 8.48 5.86 5.82 8.90 19.5 15.9 11.8 17.3 33.8 MAX 148 77.9 26.5 45.5 13.1 16.4 35.9 76.7 49.8 32.7 46.1 119 (WY) 1986 1978 1966 1992 1996 1972 1998 1969 1969 1979 1979 1975 MIN 14.5 8.32 4.43 4.11 3.05 1.85 2.76 1.94 2.75 1.77 4.47 6.16 (WY) 1994 1977 1977 1989 1977 1977 1975 1967 1967 1990 1974 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1964 - 1998 ANNUAL TOTAL 3289.3 8284.9 ANNUAL MEAN 9.01 22.7 17.9 HIGHEST ANNUAL MEAN 30.9 1969 LOWEST ANNUAL MEAN 7.44 1994 HIGHEST DAILY MEAN 290 Oct 14 416 Sep 22 2500 Sep 16 1975 LOWEST DAILY MEAN 1.7 May 25 3.1 Feb 1 .80 Jul 23 1977 ANNUAL SEVEN-DAY MINIMUM 2.0 May 14 3.3 Jan 28 1.1 Mar 31 1977 INSTANTANEOUS PEAK FLOW 3470 Sep 21 19000 Oct 7 1985 INSTANTANEOUS PEAK STAGE 17.94 Sep 21 25.30 Oct 7 1985 ANNUAL RUNOFF (AC-FT) 6520 16430 13000 ANNUAL RUNOFF (CFSM) .93 2.34 1.85 ANNUAL RUNOFF (INCHES) 12.61 31.77 25.13 10 PERCENT EXCEEDS 15 44 39 50 PERCENT EXCEEDS 4.7 15 9.0 90 PERCENT EXCEEDS 2.7 3.8 3.2 e Estimated 385 RIO INABON BASIN 50112500 RIO INABON AT REAL ABAJO, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 386 RIO BUCANA BASIN 50113800 RIO CERRILLOS ABOVE LAGO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18°07'01", long 66°36'17", Hydrologic Unit 21010004, on right bank, 0.3 mi (0.5 km) downstream from confluence with Río San Patricio, 0.1 mi (0.2 km) southwest of Hwy 139 and 2.4 mi (3.7 km) northwest of Mayagüez. DRAINAGE AREA.-- 15.4 mi2 (39.9 km2). PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 720 ft (210 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.1 14 14 7.9 6.1 6.3 61 e13 20 17 27 61 2 7.4 14 14 7.8 5.8 6.4 68 e13 19 29 39 86 3 6.9 13 13 7.4 5.6 6.4 e40 e13 29 21 25 127 4 6.4 13 12 7.4 22 6.7 e21 e13 50 18 19 160 5 6.1 13 11 7.3 96 6.1 16 e13 87 17 17 112 6 6.0 12 11 8.6 18 5.7 14 e31 57 19 23 123 7 65 12 10 14 11 14 341 e20 33 18 41 112 8 59 12 10 9.7 31 9.6 75 e35 27 16 73 89 9 45 33 9.8 7.7 32 6.5 29 e28 24 15 83 79 10 62 43 10 7.5 14 5.8 19 e19 22 19 106 67 11 60 15 10 7.3 11 5.5 19 e18 20 17 142 76 12 64 13 10 8.3 9.7 5.4 79 e18 19 14 111 74 13 151 11 10 7.8 8.7 5.3 58 e37 18 14 89 80 14 261 11 9.9 7.6 9.8 11 28 103 18 45 69 68 15 203 41 9.8 6.9 11 34 21 114 17 69 60 62 16 104 30 9.6 6.7 8.7 15 18 74 33 66 56 91 17 178 18 9.6 6.6 8.1 9.1 16 49 78 53 59 113 18 118 15 12 6.8 7.9 7.2 19 37 65 46 51 107 19 65 14 11 7.8 7.5 6.2 18 31 42 39 46 93 20 44 13 9.5 7.0 7.3 7.3 32 43 29 36 45 72 21 34 13 11 6.5 7.2 8.1 26 48 27 28 65 e384 22 28 12 9.8 6.7 7.0 e6.8 18 36 36 23 107 2510 23 24 12 9.5 6.3 6.9 e7.9 18 44 25 31 82 271 24 22 11 9.0 6.3 7.2 e6.4 39 35 32 25 302 177 25 20 15 8.8 6.6 6.6 e6.1 e36 28 26 21 309 150 26 19 18 8.6 6.7 7.3 e8.7 25 26 21 19 109 132 27 18 14 8.6 6.2 6.6 7.3 e22 24 20 19 111 122 28 17 12 8.6 6.8 6.2 7.0 e17 22 19 20 104 109 29 16 27 8.4 7.2 16 14 21 18 18 e81 97 30 15 18 8.4 6.7 47 13 21 18 17 65 90 31 15 8.4 6.1 28 20 18 67 TOTAL 1747.9 512 315.3 230.2 386.2 328.8 1220 1047 949 827 2583 5894 MEAN 56.4 17.1 10.2 7.43 13.8 10.6 40.7 33.8 31.6 26.7 83.3 196 MAX 261 43 14 14 96 47 341 114 87 69 309 2510 MIN 6.0 11 8.4 6.1 5.6 5.3 13 13 17 14 17 61 AC-FT 3470 1020 625 457 766 652 2420 2080 1880 1640 5120 11690 CFSM 4.74 1.43 .85 .62 1.16 .89 3.42 2.84 2.66 2.24 7.00 16.5 IN. 5.46 1.60 .99 .72 1.21 1.03 3.81 3.27 2.97 2.59 8.07 18.42 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 1998, BY WATER YEAR (WY) MEAN 64.5 31.7 15.1 15.8 12.3 11.0 16.4 25.0 23.5 15.8 33.7 69.3 MAX 154 59.3 26.2 59.0 26.1 27.5 40.7 68.2 46.4 26.7 83.3 196 (WY) 1991 1993 1993 1992 1996 1989 1998 1993 1996 1991 1998 1998 MIN 24.6 9.77 8.10 6.59 6.34 4.77 5.01 4.58 4.14 3.37 11.3 13.1 (WY) 1992 1994 1995 1995 1990 1990 1997 1990 1997 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1989 - 1998 ANNUAL TOTAL 5019.4 16040.4 ANNUAL MEAN 13.8 43.9 27.7 HIGHEST ANNUAL MEAN 43.9 1998 LOWEST ANNUAL MEAN 9.94 1994 HIGHEST DAILY MEAN 261 Oct 14 2510 Sep 22 2510 Sep 22 1998 LOWEST DAILY MEAN 3.1 Jul 6 5.3 Mar 13 3.0 Jul 6 1994 ANNUAL SEVEN-DAY MINIMUM 3.3 Jul 1 6.3 Feb 28 3.2 Jul 27 1994 INSTANTANEOUS PEAK FLOW 16200 Sep 21 16200 Sep 21 1998 INSTANTANEOUS PEAK STAGE 12.42 Sep 21 12.42 Sep 21 1998 INSTANTANEOUS LOW FLOW 5.1 Mar 13 3.0 Jul 6 1997 ANNUAL RUNOFF (AC-FT) 9960 31820 20060 ANNUAL RUNOFF (CFSM) 1.16 3.69 2.33 ANNUAL RUNOFF (INCHES) 15.69 50.14 31.61 10 PERCENT EXCEEDS 22 92 61 50 PERCENT EXCEEDS 8.5 18 14 90 PERCENT EXCEEDS 4.0 6.8 4.8 e Estimated 387 RIO BUCANA BASIN 50113800 RIO CERRILLOS ABOVE LAGO CERRILLOS NEAR PONCE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- 388 RIO BUCANA BASIN 50113950 LAGO CERRILLOS AT DAMSITE NEAR PONCE, PR LOCATION.--Lat 18°04'41", long 66°34'38", Hydrologic Unit 21010004, on left bank west from intake house of dam, 0.7 mi (1.1 km) southwest from Iglesia San Mateo at Real Abajo, 3.2 mi (5.1 km) northeast from Hospital de Distrito de Ponce, and 2.2 mi (3.5 km) northwest from Escuela Yuca. DRAINAGE AREA.--17.4 mi2 (45.1 km2). ELEVATION RECORDS PERIOD OF RECORD.--October 1992 to current year . REVISED RECORDS.--WDR PR-94-1: 1993,1994. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lake is formed by Cerrillos Dam, a rockfilled ungated structure completed in 1992. Elevation of crest is 611 ft (186 m) above mean sea level, with a structural height of 323 ft (98 m) and a lenght of 1,555 ft (474 m). The dam has a capacity of approximately 47,900 ac-ft (59.1 hm3). The dam is operated by U.S. Army Corps of Engineers and its purpose is for flood control, water supply, power generation, and recreation. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 602.84 ft (183.74 m), Sept. 22, 1998; minimum elevation, 416.63 ft (126.99 m), Oct. 1, 1992, (Revised). EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 602.84 ft (183.74 m), Sept. 22; minimum elevation, 551.69 ft (168.15 m), Feb. 26. Capacity Table (based on data from U.S. Army Corps of Engineers) Elevation , in feet Contents in acre-feet Elevation, in feet Contents in acre-feet 328 0 558 25,786 426 3,206 590 37,509 492 10,621 611 42,520 525 16,990 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 558.71 568.57 565.39 559.86 553.97 551.71 553.69 563.49 569.31 572.33 572.49 573.00 2 558.49 568.43 565.24 559.66 553.71 551.70 554.14 563.53 569.39 572.44 572.73 573.22 3 558.31 568.29 565.08 559.49 553.52 551.71 554.22 563.59 569.52 572.50 572.80 574.59 4 558.13 568.15 564.91 559.27 554.14 551.73 554.43 563.64 569.87 572.57 572.85 573.91 5 557.93 568.04 564.75 559.07 554.52 551.73 554.49 563.70 570.65 572.60 572.87 573.36 6 557.73 567.88 564.58 558.93 554.38 551.73 554.56 563.88 570.87 572.82 572.97 571.54 7 558.11 567.75 564.41 558.79 554.25 551.78 558.82 564.00 571.02 572.90 573.17 568.84 8 558.48 567.62 564.23 558.64 554.33 551.80 559.31 564.26 571.13 572.92 573.90 568.93 9 558.66 567.84 564.03 558.43 554.27 551.79 559.50 564.38 571.24 572.94 574.45 569.31 10 558.98 567.80 563.88 558.25 554.13 551.79 559.61 564.47 571.31 573.02 574.88 569.58 11 559.37 567.68 563.69 558.06 553.97 551.81 559.88 564.53 571.38 573.06 575.45 570.05 12 559.58 567.57 563.48 557.94 553.77 551.81 560.60 564.58 571.45 573.08 575.36 570.40 13 562.28 567.43 563.31 557.75 553.62 551.81 560.91 564.98 571.51 573.06 575.05 570.87 14 564.20 567.30 563.14 557.49 553.48 551.86 561.10 566.14 571.57 573.19 572.94 571.06 15 565.98 567.54 562.93 A 553.38 552.04 561.22 566.77 571.65 573.41 572.40 571.38 16 566.39 567.49 562.75 557.13 553.18 552.09 561.33 567.10 571.78 573.62 572.40 572.11 17 568.97 567.40 562.57 556.92 552.99 552.10 561.42 567.30 572.47 573.73 572.48 572.83 18 569.51 567.27 562.45 556.72 552.84 552.11 561.61 567.43 572.79 573.81 572.28 573.05 19 569.72 567.12 562.27 556.51 552.64 552.12 561.73 567.57 572.93 573.83 572.20 572.90 20 569.77 566.95 562.08 556.30 551.85 552.14 561.93 567.91 572.92 573.81 572.17 572.64 21 569.77 566.81 561.92 556.08 551.62 552.14 562.09 568.07 A 573.59 572.34 574.61 22 569.73 566.65 A 555.88 551.40 552.19 562.18 568.24 572.71 573.38 572.71 600.03 23 569.64 566.51 561.55 555.66 551.75 552.20 562.28 568.51 572.67 573.21 572.81 589.57 24 569.57 566.33 561.36 555.47 551.72 552.19 562.71 568.65 572.77 573.01 577.46 583.59 25 569.48 566.16 561.18 555.26 551.70 552.25 562.94 568.75 572.70 572.78 575.11 577.11 26 569.36 566.03 560.96 555.05 551.71 552.33 563.12 568.87 572.63 572.55 573.78 575.08 27 569.25 565.90 560.80 554.89 551.71 552.34 563.23 568.96 572.57 572.60 574.16 573.58 28 569.13 565.74 560.63 554.74 551.70 552.35 563.33 569.03 572.47 572.58 574.07 572.98 29 568.99 565.66 560.43 554.55 552.46 563.39 569.08 572.37 572.46 573.87 573.10 30 568.85 565.53 560.28 554.37 553.01 563.44 569.18 572.28 572.36 573.54 572.77 31 568.72 560.07 554.14 553.18 569.24 572.41 573.28 MAX 569.77 568.57 554.52 553.18 563.44 569.24 573.83 577.46 600.03 MIN 557.73 565.53 551.40 551.70 553.69 563.49 572.33 572.17 568.84 A No gage-height record 389 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18°04'15", long 66°34'51", Hydrologic Unit 21010004, on right bank off Highway 139, 0.8 mi (1.3 km) below Lago Cerrillos Dam, 2.3 mi (3.7 km) upstream from Quebrada Ausubo and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--17.8 mi2 (46.1 km2), excludes 17.4 mi2 (45.1 km2), upstream from Lago Cerrillos Dam. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to April 1964 (monthly measurements only), May 1964 to June 1985, July 1985 to April 1991 (semi-monthly measurements only), May 1991 to current year. GAGE.--Water-stage recorder. Datum of gage is 253.10 ft (77.145 m), above mean sea level. Prior to March 22, 1977 at site 0.15 mi (0.24 km) upstream and datum 9.90 ft (3.018 m) higher. REMARKS.--Records poor. Flow regulated by Lago Cerrillos Dam since May 1991. Gage-height and precipitation satellite telemetry at station. Prior to June 1985 some low-flow regulation by construction upstream. Maximum discharge prior to regulation, 22,400 ft3/s (6.34 m3/s), Sept. 16, 1975, gage-height, 11.2 ft (3.414 m), site and datum then in use from floodmarks, from rating curve extended above 150 ft3/s (4.25 m3/s), on basis of slope-area measurements of peak flow; minimum discharge prior to regulation, 2.2 ft3/s (0.062 m3/s), May 28, 1967. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.2 5.1 5.6 4.4 4.0 e4.4 4.3 4.1 4.8 17 4.0 114 2 4.3 5.1 5.6 4.4 4.0 e4.4 5.5 4.1 4.9 4.0 3.9 114 3 4.4 5.1 5.5 4.1 4.0 e4.4 4.6 4.1 5.2 3.8 3.9 114 4 4.6 4.9 5.5 3.9 5.7 e4.2 4.5 4.1 5.3 3.7 4.0 206 5 4.7 4.9 5.5 4.0 9.9 e4.2 4.4 4.1 5.0 3.7 4.0 147 6 4.7 4.7 5.5 3.9 5.0 e4.2 4.5 4.0 5.0 3.8 4.7 240 7 4.9 4.9 5.5 4.0 4.9 e4.1 e4.4 4.0 5.1 3.8 4.1 298 8 5.6 4.9 5.5 4.0 5.2 e4.2 e5.0 4.0 5.3 3.8 4.5 102 9 5.9 5.0 5.5 5.0 4.9 e4.0 e4.5 3.9 5.5 4.0 4.3 8.7 10 5.3 6.1 5.5 5.4 5.1 e3.8 e4.4 3.9 5.8 3.9 45 8.4 11 5.1 5.9 5.4 5.6 12 5.1 5.7 5.3 5.5 13 5.7 5.7 5.3 5.3 14 7.2 5.5 5.1 4.8 15 7.3 5.6 5.2 4.5 4.7 e3.8 e6.8 3.9 5.7 4.0 94 8.5 3.9 e4.0 e13 4.0 5.5 4.0 130 8.3 3.8 4.1 e5.6 4.1 5.4 17 132 8.4 3.9 4.2 e5.8 4.1 5.3 33 257 8.4 3.8 4.2 e6.6 4.1 5.3 33 161 8.6 16 6.6 5.9 5.2 4.1 17 7.1 5.7 5.0 4.1 18 6.5 5.5 4.9 4.1 19 6.2 5.5 4.8 3.9 20 6.1 5.8 4.7 3.9 3.8 4.2 e7.0 4.1 5.5 33 31 8.5 3.9 4.3 e6.6 4.1 5.8 32 31 8.5 4.0 4.4 e6.0 4.1 e5.3 32 63 53 4.0 4.3 e5.4 4.1 e14 32 62 106 4.1 4.4 e5.2 4.3 29 54 30 106 21 5.3 5.7 4.8 4.2 22 5.6 5.9 4.7 4.6 23 5.9 5.9 4.6 4.8 24 5.9 5.9 4.4 4.4 25 5.7 5.9 4.5 4.9 4.2 4.5 e6.2 4.2 29 68 30 169 4.1 4.4 e6.6 4.1 29 67 30 528 e8.5 4.4 e6.5 4.7 28 65 30 578 e8.5 4.6 e6.6 4.3 31 65 85 519 e4.7 4.6 e6.0 4.2 32 66 327 329 26 5.7 5.8 4.7 4.6 27 5.7 5.8 4.7 4.2 28 5.5 5.9 4.7 4.3 29 5.3 5.9 4.6 4.0 30 5.3 5.7 4.6 4.2 31 5.3 --- 4.5 4.0 e4.7 4.5 e5.0 4.3 32 66 270 177 e4.5 4.6 e4.6 4.3 32 25 115 176 e4.4 4.6 e4.4 4.4 31 20 115 95 --- 4.5 e4.2 4.6 31 32 115 38 --- 7.1 4.1 4.7 31 32 115 78 --- 4.6 --- 4.7 --- 14 115 --­ TOTAL 172.7 165.9 156.9 137.1 MEAN 5.57 5.53 5.06 4.42 MAX 7.3 6.1 5.6 5.6 MIN 4.2 4.7 4.4 3.9 AC-FT 343 329 311 272 CFSM .31 .31 .28 .25 IN. .36 .35 .33 .29 136.2 136.2 168.3 129.7 444.7 845.5 2420.4 4363.3 4.86 4.39 5.61 4.18 14.8 27.3 78.1 145 9.9 7.1 13 4.7 32 68 327 578 3.8 3.8 4.1 3.9 4.8 3.7 3.9 8.3 270 270 334 257 882 1680 4800 8650 .27 .25 .32 .24 .83 1.53 4.39 8.17 .28 .28 .35 .27 .93 1.77 5.06 9.12 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 1998, BY WATER YEAR (WY) MEAN 68.4 52.5 21.2 14.5 MAX 202 124 49.1 74.2 (WY) 1971 1978 1966 1992 MIN 4.93 5.21 4.81 4.42 (WY) 1996 1996 1995 1998 9.47 9.85 15.0 36.2 25.9 23.6 33.2 62.7 20.0 20.3 106 221 88.9 71.1 82.4 256 1969 1969 1985 1985 1969 1968 1968 1975 4.37 4.39 4.93 4.14 3.69 4.75 5.26 4.52 1993 1998 1979 1967 1995 1995 1995 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1964 - 1998 ANNUAL TOTAL 2888.8 ANNUAL MEAN 7.91 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 329 LOWEST DAILY MEAN 3.8 ANNUAL SEVEN-DAY MINIMUM 3.9 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 5730 ANNUAL RUNOFF (CFSM) .44 ANNUAL RUNOFF (INCHES) 6.04 10 PERCENT EXCEEDS 7.5 50 PERCENT EXCEEDS 5.5 90 PERCENT EXCEEDS 4.7 9276.9 25.4 30.5 53.9 1969 5.35 1995 Mar 21 578 Sep 23 11500 Oct 7 1985 Sep 16 3.7 Jul 4 .64 Aug 19 1992 Sep 16 3.8 Jul 2 1.7 Aug 24 1992 931 Sep 22 1320 Sep 10 1996 6.73 Sep 22 7.74 Sep 10 1996 18400 22130 1.43 1.72 19.39 23.32 65 73 5.1 13 4.0 4.9 e Estimated 390 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 391 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°04'15", long 66°34'51", Hydrologic unit 21010004, on right bank off Highway 139, 2.3 mi (3.7 km) upstream from Quebrada Ausubo and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--17.8 mi2 (46.1 km2) PERIOD OF RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 20... 1130 6.1 371 7.3 27.5 .40 8.8 111 <10 K190 50 MAR 12... 1045 4.1 341 7.7 25.5 .47 9.3 114 <10 K150 40 MAY 28... 1145 4.6 341 7.8 28.0 .47 8.8 113 <10 30 30 AUG 27... 1045 115 255 7.0 25.5 .90 7.2 88 <10 370 K1700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 20... 150 52 5.8 16 .5 .70 140 <.5 42 8.5 MAR 12... -- -- -- -- -- -- 150 -- -- -­ MAY 28... 150 50 5.3 15 .5 .75 140 -- 28 7.6 AUG 27... 110 20 15 6.5 .3 1.5 110 <1.0 8.5 7.1 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 20... .28 26 235 3.85 <1 .490 .010 .500 .020 .38 MAR 12... -- -- -- -- <1 -- <.010 .090 .020 -­ MAY 28... .21 22 214 2.66 3 -- <.010 .110 <.010 -­ AUG 27... .10 29 166 51.5 <1 -- <.010 .070 .260 .17 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 20... .40 .90 4.0 .040 <1 <100 20 <1 <1 <10 MAR 12... <.20 -- -- .040 -- -- -- -- -- -­ MAY 28... <.20 -- -- <.020 <1 <100 10 <1 <1 <10 AUG 27... .43 .50 2.2 .040 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 392 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 20... 50 <1 16 <.10 1 <1 <10 <.010 <1 <.02 MAR 12... MAY 28... 60 <1 <10 <.10 <1 <1 <10 <.010 <1 <.02 AUG 27... 393 RIO BUCANA BASIN 50114390 RIO BUCANA AT HWY 14 BRIDGE NEAR PONCE, PR LOCATION.--Lat 18°02'29", long 66°34'58", Hydrologic Unit 21010004, on left bank, 200 ft (61 m) upstream from bridge on Highway 14 and 4.0 mi (6.4 km) downstream from Lago Cerrillos Dam, 2.8 mi (4.5 km) northeast of Degetau Plaza in Ponce. DRAINAGE AREA.--24.9 mi2 (64.5 km2). PERIOD OF RECORD.--October 1985 to September 1986 (maximum only), published as "Río Bucana Floodway Channel at Highway 14 bridge", October 1986 to July 1987 (maximum only), August 1987 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 116.4 ft (35.50 m) above mean sea level. Prior to Oct. 1, 1986, crest-stage gage located at Highway 14 bridge, at elevation of mean sea level. REMARKS.--Records poor. Flow regulated by Lago Cerrillos Dam 4.0 mi upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.5 6.3 5.4 5.4 6.8 6.1 7.2 5.5 5.3 47 9.6 e541 2 5.0 7.0 5.6 5.3 6.8 5.6 9.8 5.6 5.0 4.8 8.2 521 3 5.1 7.4 5.6 5.9 6.6 5.4 7.2 5.6 5.0 5.1 7.6 517 4 5.9 6.1 5.7 5.9 6.7 5.2 5.7 5.4 4.8 7.2 7.5 e1070 5 5.6 5.7 5.9 5.6 176 6.1 5.4 5.3 4.4 4.7 8.5 e714 6 4.9 5.6 5.9 11 8.3 5.6 6.0 5.0 4.4 4.3 e7.3 e1270 7 4.6 4.9 6.0 12 8 14 6.7 6.1 9.2 9 23 6.9 6.1 8.4 10 16 11 6.3 8.1 7.4 5.2 7.6 5.3 3.9 4.1 e5.0 e1610 9.2 4.9 8.2 5.7 e4.5 3.6 8.4 e460 8.9 4.9 6.4 5.8 e10 3.5 5.7 e5.4 9.2 4.8 6.0 5.0 e13 3.3 52 e5.8 11 25 8.0 6.1 7.9 12 14 7.4 5.9 9.4 13 20 7.5 6.1 9.2 14 270 6.9 6.6 8.4 15 110 9.1 6.7 7.8 9.2 5.1 7.7 4.3 e15 3.5 204 e6.3 8.7 5.1 18 4.1 e7.6 4.0 463 e6.7 7.9 4.6 7.6 4.9 e10 6.5 560 e7.2 8.9 5.6 8.0 5.3 e10 e36 1600 e7.8 8.8 6.2 9.3 4.7 e13 61 1500 e8.3 16 36 8.5 7.0 7.3 17 165 7.5 7.1 7.3 18 155 6.8 6.3 7.3 19 18 6.8 5.9 7.3 20 12 6.5 5.7 7.0 8.2 6.2 10 5.3 e15 67 174 e8.4 8.4 5.7 9.5 4.6 e18 85 103 e7.2 8.3 5.3 8.6 4.4 e10 99 182 e15 8.5 5.2 e7.9 4.4 e7.6 87 323 e476 9.1 5.7 7.4 4.4 33 126 131 e484 21 10 5.9 6.9 6.8 22 9.8 6.0 6.7 6.8 23 8.6 5.9 5.8 6.6 24 8.8 6.0 5.7 6.6 25 8.7 5.9 5.7 6.7 8.2 5.2 8.2 5.2 42 216 128 856 7.2 5.8 9.3 4.6 48 215 110 e3510 7.3 5.4 9.1 7.0 42 201 120 e3280 8.3 5.0 9.6 6.2 50 200 380 e2930 6.7 6.4 8.7 4.7 59 206 2280 e1800 26 7.7 5.9 5.6 6.8 27 8.3 6.1 5.7 6.6 28 8.0 5.6 5.9 8.2 29 7.4 5.7 5.8 7.3 30 6.6 5.7 10 7.0 31 6.2 --- 5.7 6.8 6.3 5.3 7.2 4.7 58 208 1880 e892 7.0 5.2 6.5 4.9 56 142 e523 e879 6.1 5.1 6.3 4.7 55 27 527 e419 --- 5.2 5.9 4.8 58 99 532 e68 --- 59 5.8 5.2 59 100 540 e306 --- 26 --- 5.4 --- 73 541 --­ TOTAL 1004.7 201.3 191.5 231.9 MEAN 32.4 6.71 6.18 7.48 MAX 270 11 10 12 MIN 4.6 4.9 5.4 5.3 AC-FT 1990 399 380 460 CFSM 1.30 .27 .25 .30 IN. 1.50 .30 .29 .35 389.0 242.1 240.1 158.0 726.5 2349.6 12920.8 22681.1 13.9 7.81 8.00 5.10 24.2 75.8 417 756 176 59 18 7.0 59 216 2280 3510 6.1 4.6 5.4 4.1 3.9 3.3 5.0 5.4 772 480 476 313 1440 4660 25630 44990 .56 .31 .32 .20 .97 3.04 16.7 30.4 .58 .36 .36 .24 1.09 3.51 19.30 33.89 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1987 - 1998, BY WATER YEAR (WY) MEAN 114 56.1 16.0 40.6 MAX 527 222 49.1 337 (WY) 1991 1988 1988 1992 MIN 6.34 5.09 5.03 4.51 (WY) 1996 1994 1996 1994 10.4 13.8 13.3 22.4 23.9 22.8 72.1 131 19.3 48.0 42.5 94.9 80.5 75.8 417 756 1995 1989 1992 1992 1989 1998 1998 1998 4.10 4.49 4.74 4.29 4.90 4.37 4.06 5.66 1994 1994 1994 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1987 - 1998 ANNUAL TOTAL 4204.8 ANNUAL MEAN 11.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 664 LOWEST DAILY MEAN 4.2 ANNUAL SEVEN-DAY MINIMUM 4.4 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 8340 ANNUAL RUNOFF (CFSM) .46 ANNUAL RUNOFF (INCHES) 6.28 10 PERCENT EXCEEDS 10 50 PERCENT EXCEEDS 6.1 90 PERCENT EXCEEDS 4.9 41336.6 113 46.0 113 1998 7.43 1994 Mar 21 3510 Sep 22 4340 Jan 6 1992 May 16 3.3 Jul 10 2.5 Sep 28 1992 May 13 3.8 Jul 6 2.8 Sep 23 1992 5410 Sep 22 17400 Oct 7 1995 14.41 Sep 22 13.48 Oct 7 1995 81990 33290 4.55 1.85 61.76 25.08 207 73 7.2 8.6 5.0 4.6 e Estimated 394 RIO BUCANA BASIN 50114390 RIO BUCANA AT HWY 14 BRIDGE NEAR PONCE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 395 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR LOCATION.--Lat 18°06'00", long 66°38'34", Hydrologic Unit 21010004, 1.6 mi (2.6 km), north from Escuela Segunda Unidad of Corral Viejo, 0.3 mi (0.50 km) south from Hacienda Burenes and 6.0 mi (9.6 km) north-east from Peñuelas Plaza Church. DRAINAGE AREA.--7.27 mi2 (18.83 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1997 to September. GAGE.--Water-stage recorder. Elevation of gage is 918 ft (280 m), from topographic map. REMARKS.--Records poor. Some low-flow regulation due to PRASA intakes (2) 0.85 mi (1.36 km) upstream from station . Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e1.9 5.9 5.6 3.3 2.8 e4.0 e34 7.7 9.1 6.6 15 16 2 e1.4 5.8 5.3 3.3 e2.9 e3.6 24 7.1 8.6 17 17 32 3 e1.7 5.7 5.2 3.3 2.9 4.2 e16 7.2 9.4 8.7 17 38 4 e2.0 5.6 5.0 3.2 5.7 4.8 e7.8 7.0 31 7.4 16 76 5 e1.2 5.5 e4.8 3.1 25 4.8 7.4 7.0 23 6.8 15 18 6 e1.1 5.4 e4.6 e3.5 6.9 5.0 6.9 9.0 13 6.6 e15 45 7 e2.5 5.3 4.5 3.7 5.5 7.7 66 8.5 10 6.4 21 42 8 e26 5.7 4.4 3.4 e10 4.9 50 10 9.4 6.1 41 25 9 e15 13 4.2 3.2 9.3 3.5 25 9.8 8.9 5.9 37 18 10 e20 e16 4.0 3.1 6.2 3.1 e18 8.8 8.5 9.1 29 14 11 e13 e7.9 4.0 3.3 e5.4 2.8 17 8.5 7.8 7.4 45 e21 12 e56 e6.9 3.8 3.3 4.9 2.7 50 8.4 7.4 6.6 35 30 13 e13 6.5 3.8 3.1 e4.4 3.5 34 9.3 6.9 6.2 21 e25 14 e24 e6.3 3.8 3.1 e4.5 e3.5 24 56 6.5 8.1 18 23 15 e48 11 3.8 3.0 4.4 4.4 14 79 6.1 41 17 22 16 23 8.5 3.8 3.0 e4.0 3.9 11 13 8.3 43 16 37 17 36 7.0 3.7 2.9 4.0 2.8 10 9.3 20 26 17 32 18 23 6.6 3.7 3.0 3.9 e2.6 e9.8 8.7 11 28 16 e40 19 13 e6.3 3.7 3.0 3.8 e2.7 e9.8 8.0 7.4 26 16 e39 20 11 6.1 3.6 e2.9 3.7 2.9 10 7.6 9.0 29 20 e29 21 9.6 e6.0 e3.7 2.9 3.5 3.0 8.5 16 7.9 24 27 135 22 8.7 5.9 3.6 2.9 3.4 e3.1 8.0 11 9.5 19 37 e3000 23 8.1 5.8 3.5 3.0 e3.2 3.0 8.1 16 7.4 25 21 e230 24 7.7 5.7 3.5 e2.9 3.5 3.0 8.5 11 17 19 78 e100 25 7.2 5.9 3.5 e2.9 3.4 3.2 8.4 9.4 6.5 17 130 e66 26 6.7 6.0 e3.5 2.9 3.5 2.8 8.1 8.4 7.0 16 e48 e48 27 6.5 5.8 3.4 2.7 e3.8 2.6 8.4 8.1 7.3 16 30 e100 28 6.3 5.7 3.4 2.8 3.7 2.5 8.5 8.4 7.1 16 20 e49 29 6.2 7.3 e3.4 2.9 3.0 7.7 8.6 6.9 15 19 e35 30 6.1 6.2 e3.4 2.8 3.0 7.4 8.7 6.8 15 15 e22 31 5.9 e3.3 2.8 2.4 8.9 15 14 TOTAL 411.8 207.3 123.5 95.2 148.2 109.0 526.3 404.4 304.7 498.9 883 4407 MEAN 13.3 6.91 3.98 3.07 5.29 3.52 17.5 13.0 10.2 16.1 28.5 147 MAX 56 16 5.6 3.7 25 7.7 66 79 31 43 130 3000 MIN 1.1 5.3 3.3 2.7 2.8 2.4 6.9 7.0 6.1 5.9 14 14 AC-FT 817 411 245 189 294 216 1040 802 604 990 1750 8740 CFSM 1.83 .95 .55 .42 .73 .48 2.41 1.79 1.40 2.21 3.92 20.2 IN. 2.11 1.06 .63 .49 .76 .56 2.69 2.07 1.56 2.55 4.52 22.55 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1998 - 1998, BY WATER YEAR (WY) MEAN 13.3 6.91 3.98 3.07 5.29 3.52 17.5 13.0 10.2 16.1 28.5 147 MAX 13.3 6.91 3.98 3.07 5.29 3.52 17.5 13.0 10.2 16.1 28.5 147 (WY) 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 MIN 13.3 6.91 3.98 3.07 5.29 3.52 17.5 13.0 10.2 16.1 28.5 147 (WY) 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 1998 SUMMARY STATISTICS FOR 1998 WATER YEAR ANNUAL TOTAL 8119.3 ANNUAL MEAN 22.2 HIGHEST DAILY MEAN 3000 Sep 22 LOWEST DAILY MEAN 1.1 Oct 6 ANNUAL SEVEN-DAY MINIMUM 1.7 Oct 1 INSTANTANEOUS PEAK FLOW 10000 Sep 21 INSTANTANEOUS PEAK STAGE 22.46 Sep 21 ANNUAL RUNOFF (AC-FT) 16100 ANNUAL RUNOFF (CFSM) 3.06 ANNUAL RUNOFF (INCHES) 41.55 10 PERCENT EXCEEDS 33 50 PERCENT EXCEEDS 7.4 90 PERCENT EXCEEDS 3.0 e Estimated 396 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- 397 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- October, 1997 to current water year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October, 1997 to current water year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 11997. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected by local observer and automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, e17,500 mg/L September 22, 1998; Minimum daily mean, 2 mg/L March 1, 1998. SEDIMENT LOADS: Maximum daily mean, e143,000 tons (e130,000 tonnes) September 22, 1998; Minimum daily mean, 0.03 ton (0.02 tonne) several days. EXTREMES FOR CURRENT YEAR 1998. SEDIMENT CONCENTRATION: Maximum daily mean, e17,500 mg/L September 22, 1998; Minimum daily mean, 2 mg/L March 1, 1998. SEDIMENT LOADS: Maximum daily mean, e143,000 tons (e130,000 tonnes) September 22, 1998; Minimum daily mean, 0.03 ton (0.02 tonne) several days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e1.9 15 e.10 5.9 21 .33 5.6 61 .93 2 e1.4 15 e.10 5.8 30 .47 5.3 65 .94 3 e1.7 15 e.10 5.7 44 .67 5.2 75 1.0 4 e2.0 15 e.10 5.6 65 .99 5.0 86 1.1 5 e1.2 15 e.10 5.5 44 .66 e4.8 92 e1.2 6 e1.1 15 e.10 5.4 24 .34 e4.6 87 e1.1 7 e2.5 15 e.10 5.3 21 .30 4.5 46 .56 8 e26 1250 e36 5.7 73 1.3 4.4 23 .28 9 e15 330 e52 13 6240 696 4.2 20 .22 10 e20 116 e95 e16 1360 e68 4.0 19 .21 11 e13 201 e20 e7.9 275 e5.9 4.0 28 .30 12 e56 351 e2010 e6.9 231 e4.3 3.8 35 .36 13 e13 610 e22 6.5 168 3.0 3.8 18 .19 14 e24 1060 e50 e6.3 127 e2.2 3.8 12 .12 15 e48 1850 e332 11 454 23 3.8 28 .29 16 23 531 78 8.5 261 6.1 3.8 66 .67 17 36 1340 312 7.0 220 4.2 3.7 73 .73 18 23 531 73 6.6 210 3.7 3.7 73 .73 19 13 614 19 e6.3 159 e2.7 3.7 74 .74 20 11 415 11 6.1 117 1.9 3.6 74 .73 21 9.6 35 .90 e6.0 85 e1.4 e3.7 66 e.66 22 8.7 47 1.1 5.9 62 .98 3.6 52 .50 23 8.1 64 1.4 5.8 33 .51 3.5 31 .29 24 7.7 86 1.8 5.7 19 .29 3.5 17 .17 25 7.2 88 1.7 5.9 30 .49 3.5 10 .09 26 6.7 69 1.2 6.0 60 .98 e3.5 6 e.06 27 6.5 54 .94 5.8 32 .50 3.4 7 .07 28 6.3 42 .71 5.7 12 .19 3.4 20 .18 29 6.2 32 .54 7.3 126 3.8 e3.4 37 e.34 30 6.1 27 .44 6.2 108 1.8 e3.4 12 e.11 31 5.9 14 .23 e3.3 25 e.22 TOTAL 411.8 3121.66 207.3 837.00 123.5 15.09 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 398 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 3.3 61 .53 2.8 5 .04 e4.0 2 e.03 2 3.3 61 .54 e2.9 5 e.04 e3.6 3 e.03 3 3.3 48 .42 2.9 6 .04 4.2 10 .12 4 3.2 39 .34 5.7 152 13 4.8 38 .48 5 3.1 45 .38 25 2660 301 4.8 30 .39 6 e3.5 55 e.53 6.9 728 14 5.0 13 .17 7 3.7 63 .64 5.5 510 7.6 7.7 82 5.7 8 3.4 52 .47 e10 863 e57 4.9 18 .24 9 3.2 43 .38 9.3 654 19 3.5 14 .13 10 3.1 52 .44 6.2 78 1.3 3.1 11 .09 11 3.3 64 .58 e5.4 46 e.67 2.8 9 .07 12 3.3 77 .70 4.9 29 .38 2.7 9 .06 13 3.1 60 .50 e4.4 22 e.26 3.5 27 .27 14 3.1 34 .29 e4.5 17 e.21 e3.5 71 e.67 15 3.0 13 .11 4.4 12 .14 4.4 56 .66 16 3.0 6 .05 e4.0 9 e.10 3.9 39 .41 17 2.9 13 .10 4.0 13 .14 2.8 27 .21 18 3.0 18 .14 3.9 18 .19 e2.6 20 e.14 19 3.0 22 .18 3.8 16 .16 e2.7 18 e.13 20 e2.9 21 e.16 3.7 13 .13 2.9 20 .16 21 2.9 18 .14 3.5 10 .10 3.0 32 .26 22 2.9 17 .13 3.4 6 .06 e3.1 53 e.45 23 3.0 15 .12 e3.2 4 e.03 3.0 89 .70 24 e2.9 15 e.12 3.5 5 .05 3.0 148 1.2 25 e2.9 15 e.12 3.4 7 .06 3.2 198 1.7 26 2.9 15 .12 3.5 5 .05 2.8 121 .93 27 2.7 15 .11 e3.8 3 e.04 2.6 74 .53 28 2.8 15 .11 3.7 3 .03 2.5 62 .42 29 2.9 13 .10 3.0 54 .43 30 2.8 7 .05 3.0 48 .38 31 2.8 4 .03 2.4 44 .28 TOTAL 95.2 8.63 148.2 415.82 109.0 17.44 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 e34 2460 e757 7.7 42 .88 9.1 45 1.1 2 24 4920 618 7.1 71 1.4 8.6 62 1.4 3 e16 824 e40 7.2 52 1.0 9.4 1290 43 4 e7.8 272 6.0 7.0 31 .59 31 1730 445 5 7.4 191 3.8 7.0 26 .49 23 800 78 6 6.9 175 3.2 9.0 1770 76 13 302 11 7 66 6680 2640 8.5 265 6.1 10 51 1.5 8 50 2460 362 10 1110 52 9.4 62 1.6 9 25 531 36 9.8 413 11 8.9 98 2.4 10 e18 368 e17 8.8 355 8.5 8.5 98 2.2 11 17 1230 92 8.5 305 7.0 7.8 91 1.9 12 50 3460 794 8.4 262 5.9 7.4 77 1.5 13 34 2660 254 9.3 337 8.6 6.9 62 1.2 14 24 466 32 56 6090 2990 6.5 51 .89 15 14 330 12 79 3740 1100 6.1 42 .69 16 11 290 8.6 13 325 13 8.3 342 15 17 10 257 7.0 9.3 702 17 20 1470 237 18 e9.8 251 e6.7 8.7 922 22 11 423 22 19 e9.8 251 e6.6 8.0 384 8.5 7.4 86 1.9 20 10 173 4.7 7.6 103 2.1 9.0 36 .88 21 8.5 107 2.4 16 842 153 7.9 34 .72 22 8.0 106 2.3 11 216 7.2 9.5 25 .66 23 8.1 63 1.4 16 687 73 7.4 18 .37 24 8.5 78 1.8 11 265 8.4 17 810 126 25 8.4 55 1.2 9.4 112 2.8 6.5 152 2.7 26 8.1 36 .78 8.4 108 2.4 7.0 91 1.7 27 8.4 32 .78 8.1 112 2.4 7.3 89 1.8 28 8.5 14 .32 8.4 115 2.6 7.1 93 1.8 29 7.7 16 .33 8.6 62 1.4 6.9 68 1.3 30 7.4 24 .48 8.7 26 .60 6.8 49 .90 31 8.9 28 .68 TOTAL 526.3 5712.39 404.4 4586.54 304.7 1008.11 --- --- --- --- --- --- 399 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR--Continued WATER-QUALITY RECORDS SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 6.6 44 .78 15 16 .64 16 870 63 2 17 1310 252 17 17 .79 32 2320 586 3 8.7 207 5.3 17 17 .79 38 592 65 4 7.4 60 1.2 16 18 .76 76 2200 1020 5 6.8 49 .90 15 19 .75 18 727 44 6 6.6 50 .88 e15 19 e.81 45 1780 518 7 6.4 52 .90 21 889 97 42 377 44 8 6.1 54 .90 41 3110 720 25 203 14 9 5.9 52 .83 37 1590 196 18 242 13 10 9.1 440 32 29 1870 130 14 164 6.3 11 7.4 185 3.8 45 5580 1350 e21 867 e102 12 6.6 71 1.3 35 2320 283 30 1200 106 13 6.2 58 .97 21 58 3.6 e25 29 e2.0 14 8.1 972 42 18 18 .90 23 28 1.7 15 41 3430 873 17 21 .94 22 26 1.6 16 43 2260 387 16 19 .80 37 1360 256 17 26 1970 154 17 15 .69 32 1820 159 18 28 1950 168 16 16 .71 e40 729 e128 19 26 1390 99 16 20 .84 e39 86 e8.3 20 29 2110 220 20 798 70 e29 28 e2.2 21 24 319 22 27 2020 315 135 1910 15100 22 19 103 5.4 37 3980 440 e3000 17500 e143000 23 25 3100 539 21 1150 65 e230 12500 e2450 24 19 242 13 78 3060 2500 e100 2200 e1300 25 17 26 1.2 130 2200 1330 e66 4430 e919 26 16 28 1.2 e48 681 e86 e48 1780 e518 27 16 33 1.4 30 1420 139 e100 2220 e1300 28 16 29 1.3 20 999 53 e49 1780 e518 29 15 23 .95 19 1030 60 e35 1360 e256 30 15 26 1.1 15 728 30 e22 203 e14 31 15 18 .73 14 632 24 TOTAL 498.9 2832.04 883 7901.02 4407 168515.1 YEAR 8119.3 194970.84 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) NOV 10... 1145 FEB 05... 0900 07... 0900 APR 07... 1700 MAY 06... 1758 08... 1915 JUN 04... 2248 AUG 08... 2000 08... 2245 11... 1645 21... 1648 24... 2123 25... 0308 25... 1036 25... 2049 SEP 02... 1722 04... 0614 04... 1029 06... 2051 16... 1640 18... 1930 18... 2035 21... 2210 21... 2240 E14 2400 E91 94 25 2150 145 99 5.7 594 9.1 98 273 26600 19600 83 23 13600 844 99 24 6000 389 96 30 501 41 91 154 19400 8070 100 68 1280 235 99 187 15100 7620 98 107 13200 3800 100 335 8660 7830 98 211 4650 2650 98 137 1220 451 99 72 528 103 100 89 24500 5890 100 73 1220 240 100 73 843 166 99 67 944 171 99 117 8280 2620 99 E82 4120 E912 100 69 2390 445 100 367 2370 2350 100 453 2700 3300 100 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 400 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES AT TIBES, PR--Continued WATER-QUALITY RECORDS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) NOV 10... 1145 E14 2400 E91 41 55 71 FEB 05... 0900 25 2150 145 42 56 73 07... 0900 5.7 594 9.1 APR 07... 1700 273 26600 19600 32 43 56 MAY 06... 1758 23 13600 844 30 51 78 08... 1915 24 6000 389 JUN 04... 2248 30 501 41 AUG 08... 2000 154 19400 8070 49 65 82 08... 2245 68 1280 235 11... 1645 187 15100 7620 21... 1648 107 13200 3800 24... 2123 335 8660 7830 36 49 66 25... 0308 211 4650 2650 25... 1036 137 1220 451 25... 2049 72 528 103 SEP 02... 1722 89 24500 5890 48 64 82 04... 0614 73 1220 240 04... 1029 73 843 166 06... 2051 67 944 171 16... 1640 117 8280 2620 50 64 82 18... 1930 E82 4120 E912 81 92 98 18... 2035 69 2390 445 21... 2210 367 2370 2350 21... 2240 453 2700 3300 77 91 98 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) NOV 10... 84 89 FEB 05... 87 96 07... -- -- APR 07... 69 79 MAY 06... 93 95 08... -- -- JUN 04... -- -- AUG 08... 95 100 08... -- -- 11... -- -- 21... -- -- 24... 82 95 25... -- -- 25... -- -- 25... -- -- SEP 02... 96 99 04... -- -- 04... -- -- 06... -- -- 16... 94 98 18... 100 100 18... -- -- 21... -- -- 21... 99 100 94 99 100 100 100 99 100 100 100 100 98 -- -- -- -­ 83 93 99 100 100 99 100 100 100 100 96 -- -- -- -­ 91 -- -- -- -­ 100 100 100 100 100 99 -- -- -- -­ 98 -- -- -- -­ 100 -- -- -- -­ 98 99 100 100 100 98 -- -- -- -­ 99 -- -- -- -­ 100 -- -- -- -­ 100 100 100 -- 100 100 -- -- -- -­ 99 -- -- -- -­ 99 -- -- -- -­ 99 100 100 100 100 100 100 100 100 100 100 -- -- -- -­ 100 -- -- -- -­ 100 100 100 100 100 401 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 20... 0915 20 375 7.2 23.5 72 8.0 95 <10 3100 K1700 MAR 12... 0850 2.9 381 7.8 20.5 3.5 8.6 96 <10 930 670 MAY 28... 1000 9.5 355 7.8 24.5 7.5 8.5 103 <10 500 220 AUG 27... 0900 47 323 6.6 23.0 34 8.2 97 <10 2000 5100 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 20... 170 50 10 11 .4 1.4 150 .6 20 12 MAR 12... -- -- -- -- -- -- 160 -- -- -­ MAY 28... 170 49 10 11 .4 1.3 160 -- 14 9.1 AUG 27... 170 -- 12 35 1 1.8 150 <1.0 47 26 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 20... .14 21 215 11.6 80 1.57 .130 1.70 .180 .28 MAR 12... -- -- -- -- 7 -- <.010 .780 .020 .21 MAY 28... .11 19 210 5.38 10 -- <.010 1.30 .020 -­ AUG 27... .10 21 283 36.0 29 2.39 .012 2.40 .030 .61 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 20... .46 2.2 9.5 .120 <1 <100 20 1 1 11 MAR 12... .23 1.0 4.5 .030 -- -- -- -- -- -­ MAY 28... <.20 -- -- .030 <1 <100 10 <1 <1 <10 AUG 27... .64 3.0 13 .380 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 402 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 20... 4900 <1 190 <.10 <1 <1 20 <.010 <1 <.02 MAR 12... MAY 28... 530 <1 33 <.10 <1 <1 40 <.010 1 <.02 AUG 27... --- --- --- --- --- --- --- --- --- --- --- --- 403 RIO PORTUGUES BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR LOCATION.--Lat 18°01'09", long 66°36'26", Hydrologic Unit 21010004, on right bank upstream from bridge on Highway 14, 1.70 mi (2.74 km) downstream from Río Chiquito, and 0.6 mi (0.96 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--18.6 mi2 (48.17 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Occasional measurements 1963, annual maximum discharge and peaks above base at different datum, from 1965 to 1972. June 1997 to current year. GAGE.--Water-stage recorder. Elevation of gage is 67.2 ft (20.48 m), from topographic map. Prior to June 18, 1997 non-recording gage crested-stage gage at same site and different datum. REMARKS.--Records poor. Some low-flow regulation due to Río Portugués dam construction activity upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.7 1.6 7.8 2 1.6 1.5 140 3 1.6 30 50 4 1.6 5.7 15 5 1.6 3.0 7.8 6 1.9 2.5 6.0 7 2.1 2.5 4.8 8 2.6 2.8 4.2 9 3.7 2.8 4.1 10 2.7 10 4.0 11 1.8 22 3.9 12 1.9 8.1 4.5 13 4.8 11 6.4 14 2.4 15 5.3 15 1.8 19 5.3 16 2.1 6.8 5.4 17 4.3 5.1 4.7 18 e.97 2.8 6.7 4.5 19 1.4 5.8 4.4 4.5 20 6.0 9.5 3.6 3.8 21 2.5 28 11 4.1 22 1.7 15 3.1 4.9 23 1.5 5.2 3.1 6.7 24 2.1 3.5 4.2 5.5 25 2.3 2.4 3.3 4.7 26 1.5 2.0 3.2 5.2 27 1.6 1.7 3.4 6.3 28 1.7 1.7 3.8 5.9 29 1.7 1.7 4.1 30 30 1.8 1.5 3.8 11 31 1.4 3.3 TOTAL 122.4 210.4 376.3 MEAN 3.95 6.79 12.5 MAX 28 30 140 MIN 1.4 1.5 3.8 AC-FT 243 417 746 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 1997, BY WATER YEAR (WY) MEAN 3.95 6.79 12.5 MAX 3.95 6.79 12.5 (WY) 1997 1997 1997 MIN 3.95 6.79 12.5 (WY) 1997 1997 1997 e Estimated 404 RIO PORTUGUES BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1996 1997 WATER YEAR 405 RIO PORTUGUES BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR--Continued DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.0 8.7 7.6 5.5 5.0 e3.6 49 5.9 10 10 9.7 47 2 6.2 8.6 6.7 5.7 4.9 3.6 105 5.5 10 9.4 8.7 89 3 7.3 7.8 6.4 6.0 5.1 3.6 e69 5.4 9.5 44 19 229 4 8.7 8.0 6.2 5.7 6.1 e3.7 e21 4.9 30 22 9.5 537 5 4.9 7.5 6.4 5.0 341 e3.7 e8.7 4.6 39 19 11 207 6 4.6 7.1 6.2 24 7 17 7.2 6.0 7.8 8 178 6.9 5.9 7.8 9 89 e23 5.8 5.6 10 40 e95 6.1 5.4 31 e3.8 e7.0 4.6 39 13 e9.4 218 12 e4.0 e270 11 18 14 e15 214 9.3 e6.5 198 9.5 12 12 44 92 50 e4.4 e34 25 12 11 159 57 14 e3.7 e15 9.4 14 10 116 46 11 199 20 5.9 5.2 12 155 12 5.3 10 13 216 11 5.1 6.3 14 814 9.6 5.5 5.6 15 407 31 6.1 5.1 9.2 3.4 13 7.0 8.4 27 85 34 7.6 3.3 49 6.1 7.5 11 189 61 6.6 e3.5 e90 7.3 7.9 9.7 106 46 6.6 e4.9 25 13 8.2 8.8 47 33 7.8 4.2 15 253 8.2 49 41 89 16 185 54 5.7 4.9 17 326 17 6.5 4.8 18 298 13 6.8 4.8 19 55 11 6.4 4.7 20 29 9.4 5.7 4.5 6.2 6.7 12 50 19 117 25 92 5.5 5.6 14 26 53 79 18 111 5.1 4.7 10 16 80 59 45 80 4.6 4.6 9.2 16 55 55 29 158 4.3 4.7 8.8 12 22 31 30 53 21 20 8.5 6.4 4.6 22 16 8.2 5.8 4.4 23 14 7.7 5.6 4.5 24 12 7.5 5.6 4.4 25 12 7.1 5.5 5.3 4.3 5.2 8.9 19 24 65 52 85 4.1 4.6 9.4 39 41 26 175 5580 3.8 5.2 7.3 54 20 18 138 460 e4.2 4.8 e7.8 59 20 50 193 198 e4.5 7.7 e10 23 70 17 1310 123 26 11 e8.6 5.7 5.0 27 10 8.9 5.7 4.8 28 9.9 7.0 5.7 e5.5 29 9.6 6.6 5.8 5.4 30 9.1 14 6.0 5.4 31 8.5 --- 5.8 5.2 e4.7 6.7 e9.9 19 24 13 213 86 e4.7 6.0 e8.5 17 16 12 92 e188 e4.1 5.5 e12 12 14 31 121 91 --- 5.4 e8.2 12 13 13 78 64 --- 15 6.6 13 11 12 50 38 --- 13 --- 11 --- 11 35 --­ TOTAL 3179.8 451.9 185.9 188.9 MEAN 103 15.1 6.00 6.09 MAX 814 95 7.6 24 MIN 4.6 6.6 5.1 4.4 AC-FT 6310 896 369 375 576.3 165.3 1111.3 770.2 715.7 878.9 3473.3 9406 20.6 5.33 37.0 24.8 23.9 28.4 112 314 341 15 270 253 80 117 1310 5580 3.8 3.3 6.6 4.6 7.5 8.8 8.7 33 1140 328 2200 1530 1420 1740 6890 18660 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 1998, BY WATER YEAR (WY) MEAN 103 15.1 6.00 6.09 MAX 103 15.1 6.00 6.09 (WY) 1998 1998 1998 1998 MIN 103 15.1 6.00 6.09 (WY) 1998 1998 1998 1998 20.6 5.33 37.0 24.8 23.9 16.1 59.4 163 20.6 5.33 37.0 24.8 23.9 28.4 112 314 1998 1998 1998 1998 1998 1998 1998 1998 20.6 5.33 37.0 24.8 23.9 3.95 6.79 12.5 1998 1998 1998 1998 1998 1997 1997 1997 SUMMARY STATISTICS FOR 1998 WATER YEAR WATER YEARS 1997 - 1998 ANNUAL TOTAL 21103.5 ANNUAL MEAN 57.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 5580 LOWEST DAILY MEAN 3.3 ANNUAL SEVEN-DAY MINIMUM 3.7 INSTANTANEOUS PEAK FLOW 16300 INSTANTANEOUS PEAK STAGE 19.73 ANNUAL RUNOFF (AC-FT) 41860 10 PERCENT EXCEEDS 105 50 PERCENT EXCEEDS 10 90 PERCENT EXCEEDS 4.8 57.8 57.8 1998 57.8 1998 Sep 22 5580 Sep 22 1998 Mar 12 .97 Jun 18 1997 Mar 1 1.6 Jul 27 1997 Sep 22 16300 Sep 22 1998 Sep 22 19.73 Sep 22 1998 41890 89 8.3 3.3 e Estimated 406 RIO PORTUGUES BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 407 RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'20", long 66°36'28", 1,300 ft (400 m) south of Las Américas Avenue Bridge, 1.2 mi (1.9 km) south of CSC 50115900, 0.8 mi (1.3 km) west of Highways 1 and 2 junction, and 0.7 mi (1.1 km) southeast of Ponce. DRAINAGE AREA.--18.9 mi2 (49.0 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) NOV 04... 1015 13 494 7.7 29.3 17 7.9 102 <10 36000 4400 MAR 13... 0835 2.9 613 7.1 22.0 .85 4.4 50 <10 4500 650 MAY 20... 0930 13 436 7.4 27.0 21 6.5 81 <10 330 700 SEP 09... 0945 4.0 369 6.6 26.7 35 6.8 85 <10 2600 2000 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) NOV 04... 80 19 7.8 20 1 1.9 156 <.5 8.9 18 MAR 13... -- -- -- -- -- -- 220 -- -- -­ MAY 20... 180 52 12 21 .7 1.1 200 -- 27 18 SEP 09... 150 46 9.2 14 .5 1.4 170 <1.0 15 12 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) NOV 04... .10 37 213 7.47 5 .640 .200 .840 .570 .53 MAR 13... -- -- -- -- 14 .390 .130 .520 .580 .42 MAY 20... .15 16 267 9.23 39 .426 .014 .440 .040 .24 SEP 09... .12 21 221 2.32 62 1.27 .029 1.30 .060 .34 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) NOV 04... 1.1 1.9 8.6 .210 <1 <100 80 <1 <1 10 MAR 13... 1.0 1.5 6.7 .110 -- -- -- -- -- -­ MAY 20... .28 .72 3.2 .040 <1 <100 50 <1 <1 <10 SEP 09... .40 1.7 7.5 .060 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 408 RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) NOV 04... 700 <1 100 <.10 <1 <1 20 <.010 <1 .03 MAR 13... MAY 20... 1200 <1 64 <.10 <1 <1 10 <.010 2 <.02 SEP 09... 409 RIO GUAYANILLA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, PR LOCATION.--Lat 18°02'40", long 66°47'53", Hydrologic Unit 21010004, on left bank, 0.7 mi (1.1 km) north of junction of Highways 2 and 132, 0.6 mi (1.0 km) downstream from Quebrada Consejo, 1.8 mi (2.9 km) north-northwest from Plaza de Guayanilla. DRAINAGE AREA.--18.9 mi2 (49.0 km2). PERIOD OF RECORD.--March 1981 to current year. GAGE.--Water-stage recorder. Elevation of gage is 80 ft (24 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e12 19 6.7 4.5 2 e10 18 6.6 4.3 3 e7.6 18 6.5 4.0 4 e6.6 18 5.8 3.8 5 e5.8 18 5.7 3.7 3.5 3.2 70 3.6 9.2 12 17 46 3.4 3.1 44 4.5 8.7 25 25 68 3.3 3.1 e22 3.8 8.3 29 24 176 3.6 3.4 e14 3.6 70 25 17 156 98 3.1 11 3.4 29 18 16 267 6 e5.4 17 5.6 7.4 7 e49 18 5.4 5.7 8 e46 17 5.2 4.3 9 e60 21 5.0 3.8 10 e54 39 4.9 3.8 12 2.9 9.6 6.2 24 20 27 143 7.4 3.5 36 9.5 16 19 e49 104 8.2 2.8 39 56 20 15 80 88 11 2.6 17 31 19 14 52 67 6.5 2.7 11 11 16 16 39 e55 11 e48 20 4.8 3.7 12 e37 18 4.5 4.0 13 e130 17 4.4 4.7 14 e440 16 4.3 3.8 15 e180 24 4.2 3.8 5.5 2.4 9.7 7.8 14 25 32 e60 4.9 2.5 11 6.5 13 15 29 54 4.6 2.5 11 6.4 14 14 24 54 4.9 2.6 8.1 7.3 13 13 28 47 6.0 2.8 6.9 40 12 17 30 53 16 e100 25 4.4 3.8 17 e280 16 4.3 3.8 18 e130 13 4.5 4.2 19 e50 11 4.6 4.7 20 e37 10 4.5 3.8 4.7 3.2 6.5 24 13 15 23 54 4.5 3.1 6.0 13 21 30 25 48 4.4 2.8 5.5 9.6 e23 24 21 45 4.2 2.5 5.6 10 e16 18 19 41 4.0 2.6 5.8 8.5 13 26 62 78 21 e34 9.4 4.8 3.7 22 30 9.1 4.1 3.5 23 28 8.6 3.8 3.3 24 26 8.3 3.8 3.4 25 25 8.3 3.8 3.7 4.1 3.1 5.5 19 13 21 50 238 3.9 2.9 5.6 27 16 16 113 e932 3.7 2.7 5.0 50 26 19 66 e175 3.5 2.5 4.6 34 46 22 92 e122 3.3 3.2 4.5 19 38 16 318 e108 26 24 8.2 4.0 3.5 27 23 8.1 4.2 3.5 28 22 7.6 4.5 3.6 29 21 7.2 4.6 4.3 30 20 7.1 e4.3 4.1 31 20 --- 4.4 3.7 3.8 3.6 4.8 14 25 14 69 e99 3.8 2.8 4.9 11 20 35 45 e104 3.4 2.9 5.2 58 17 36 36 e89 --- 2.8 3.9 43 14 22 28 e83 --- 26 3.6 16 13 18 23 e73 --- 18 --- 11 --- 16 19 --­ TOTAL 1961.4 454.9 148.2 125.9 MEAN 63.3 15.2 4.78 4.06 MAX 440 39 6.7 7.4 MIN 5.4 7.1 3.8 3.3 AC-FT 3890 902 294 250 CFSM 3.35 .80 .25 .21 IN. 3.86 .90 .29 .25 234.1 127.9 397.3 567.7 600.2 625 1498 3727 8.36 4.13 13.2 18.3 20.0 20.2 48.3 124 98 26 70 58 70 36 318 932 3.3 2.4 3.6 3.4 8.3 12 16 41 464 254 788 1130 1190 1240 2970 7390 .44 .22 .70 .97 1.06 1.07 2.56 6.57 .46 .25 .78 1.12 1.18 1.23 2.95 7.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 1998, BY WATER YEAR (WY) MEAN 59.7 45.6 17.4 10.2 MAX 167 110 41.9 27.5 (WY) 1986 1988 1988 1992 MIN 16.0 15.2 4.78 4.06 (WY) 1983 1998 1998 1998 7.53 6.03 10.0 25.2 14.4 12.2 18.8 44.1 11.6 13.2 26.6 80.4 41.0 25.9 48.5 124 1996 1989 1983 1985 1987 1986 1988 1998 3.10 2.85 2.76 2.33 2.35 2.45 5.14 3.62 1990 1981 1995 1994 1997 1994 1997 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1981 - 1998 ANNUAL TOTAL 4117.0 ANNUAL MEAN 11.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 440 LOWEST DAILY MEAN 1.5 ANNUAL SEVEN-DAY MINIMUM 1.6 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 8170 ANNUAL RUNOFF (CFSM) .60 ANNUAL RUNOFF (INCHES) 8.10 10 PERCENT EXCEEDS 21 50 PERCENT EXCEEDS 4.2 90 PERCENT EXCEEDS 1.9 10467.6 28.7 22.3 33.1 1986 8.94 1994 Oct 14 932 Sep 22 1500 Oct 7 1985 Jun 16 2.4 Mar 11 .77 Jul 30 1994 Jun 10 2.6 Mar 8 1.1 Sep 4 1994 18700 Sep 22 18700 Sep 22 1998 21.88 Sep 22 21.88 Sep 22 1998 2.2 Mar 11 .70 Apr 19 1995 20760 16150 1.52 1.18 20.60 16.03 60 49 13 9.6 3.5 3.2 e Estimated 410 RIO GUAYANILLA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 411 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18?00°40", long 66°46'49", at dirt road bridge, 0.7 mi (1.1 km) from mouth, 0.9 mi (1.4 km) east of Central Rufina and 0.9 mi (1.4 km) southeast of Guayanilla. DRAINAGE AREA.--22.8 mi2 (59.1 km2). PERIOD OF RECORD.--Water years 1960-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 23... 1200 26 402 8.5 29.0 4.9 12.0 155 <10 430 270 MAR 27... 1015 .38 897 7.9 29.0 2.5 8.4 109 16 2300 20 JUN 05... 1015 38 398 7.7 26.5 7.7 7.9 98 <10 4600 K1800 SEP 11... 1015 53 439 7.2 26.5 4.6 8.2 102 <10 38000 320 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 23... 170 46 14 15 .5 1.8 130 <.5 46 20 MAR 27... -- -- -- -- -- -- 210 -- -- -­ JUN 05... 170 46 14 17 .6 2.6 130 -- 35 18 SEP 11... 190 52 15 13 .4 .17 150 <1.0 39 18 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 23... <.10 17 237 16.9 24 1.99 .012 2.00 .020 .36 MAR 27... -- -- -- -- 1 1.54 .060 1.60 .180 2.1 JUN 05... <.10 19 229 23.4 19 2.29 .010 2.30 .020 .35 SEP 11... <.10 20 247 35.1 15 2.49 .014 2.50 .030 .25 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 23... .38 2.4 11 .150 1 <100 30 <1 2 <10 MAR 27... 2.3 3.9 17 .880 -- -- -- -- -- -­ JUN 05... .37 2.7 12 .100 1 <100 40 <1 2 <10 SEP 11... <.28 2.8 12 .250 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 412 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... 1400 <1 47 <.10 <1 <1 <10 <.010 <1 <.02 MAR 27... JUN 05... 730 <1 36 <.10 <1 <1 <10 <.010 1 <.02 SEP 11... --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 413 RIO YAUCO BASIN 50125780 LAGO LUCCHETTI AT DAMSITE NEAR YAUCO, PR LOCATION.--Lat 18°05'37", long 66°51'54, Hydrologic Unit 21010004, at Antonio Lucchetti Dam on Río Yauco, 3.9 mi (6.3 km) north of Yauco. DRAINAGE AREA.--17.4 mi2 (45.1 km2). ELEVATION RECORDS PERIOD OF RECORD.--December 1989 to current year. Prior to October 1994, published as Lago Lucchetti at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Lucchetti was completed in 1952. The dam is on Río Yauco and is a unit of the Southwestern Puerto Rico Project. It provides 16,500 acre-feet (20.3 hm3) of usable storage for power generation and irrigation. The dam is a concrete gravity structure with a total length of 591 ft (180 m), a maximum height of 178 ft (54 m), and a maximum width at the base of 150 ft (46 m). An ungated, overflow tipe spillway with a clear length of 171 ft (52 m), and a maximum capacity of 62,800 ft3/s (1,778 m3/s),at a design head of 20 ft (6 m). The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 577.56 ft (176.04 m), Sept. 22, 1998; minimum elevation, 512.09 ft (156.08 m), Sept. 9, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 577.56 ft (176.04 m), Sept. 22, minimum elevation, 529.98 ft (161.54 m), Oct 1. Capacity Table (based on data from Puerto Rico Water Resources Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 512 1,505 520 2,385 525 2,965 527 3,255 530 3,695 532 3,975 540 5,165 550 7,020 561 9,600 563 10,125 571 12,125 573 12,645 578 14,061 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 530.29 562.73 566.26 559.14 565.32 567.87 558.69 555.16 569.09 562.99 561.96 561.23 2 530.73 562.48 564.78 559.23 564.74 567.83 A 555.10 570.14 562.23 561.36 560.46 3 530.41 563.34 563.49 A 565.50 567.79 A 555.08 569.05 562.28 561.38 A 4 530.41 564.73 563.49 559.11 567.05 567.71 A 554.86 569.79 562.28 561.39 558.16 5 530.38 565.01 563.09 557.51 568.36 566.40 558.48 554.62 570.14 562.26 561.39 557.96 6 530.33 565.03 562.73 557.52 568.57 566.40 A 554.91 570.15 562.36 562.14 560.05 7 531.09 564.97 562.73 557.47 568.87 566.36 557.93 554.85 569.68 562.49 563.52 560.48 8 535.35 564.94 562.70 557.75 568.53 566.31 A 555.32 569.60 562.94 564.22 559.69 9 539.05 564.98 562.71 557.83 569.33 566.25 A 555.28 569.84 563.14 564.60 561.18 10 541.08 565.09 562.29 557.79 570.19 566.18 A 555.12 569.79 563.51 564.90 562.60 11 543.72 565.68 562.25 557.74 570.53 564.70 A 554.89 569.89 563.53 565.24 562.15 12 545.56 565.84 562.22 558.17 570.38 564.67 A 554.88 569.60 563.64 565.52 563.06 13 547.52 565.89 562.20 557.19 570.09 564.58 A 554.87 569.50 563.74 565.67 563.65 14 552.51 565.90 562.16 558.40 570.09 564.53 A 554.92 569.32 563.73 565.76 565.00 15 555.39 566.28 562.12 559.13 570.05 564.48 A 555.05 567.84 563.80 565.60 565.40 16 557.37 566.40 562.06 559.53 570.15 563.88 A 555.08 566.51 563.80 565.48 566.01 17 558.95 566.41 562.06 559.52 569.76 563.86 A 555.08 566.13 563.79 565.38 566.30 18 559.87 566.47 562.05 559.48 570.53 563.32 A 555.07 566.48 563.80 565.49 566.13 19 560.27 566.48 561.04 559.45 569.96 562.42 A 555.59 566.73 563.55 565.17 565.98 20 560.46 566.50 560.93 560.33 569.14 562.35 A 558.97 566.70 563.54 565.21 564.85 21 560.63 566.51 560.80 560.45 569.48 562.32 A 563.34 566.79 563.53 564.98 567.09 22 560.74 566.50 560.65 561.17 569.84 562.28 A 564.13 567.04 563.48 565.30 571.68 23 561.09 566.52 560.61 560.88 569.41 561.92 A 564.43 567.73 563.53 565.36 570.61 24 561.08 566.46 560.59 561.02 568.58 A A 564.61 566.90 563.43 565.66 570.40 25 561.27 566.42 560.55 561.39 568.06 561.55 A 565.33 565.37 563.40 565.99 571.07 26 562.36 566.50 560.51 562.47 568.04 A A 566.21 564.83 563.34 565.67 570.55 27 562.39 566.52 560.33 563.11 567.99 559.26 A 566.60 565.11 563.35 565.22 570.44 28 562.49 566.26 560.30 564.16 567.94 559.20 A 568.64 565.10 563.13 564.38 A 29 562.56 566.27 560.28 565.21 559.16 A 568.85 565.09 563.14 563.54 A 30 562.57 566.25 559.09 565.47 558.43 A 568.96 564.31 562.92 562.74 A 31 562.60 558.80 565.40 558.64 569.03 562.48 562.08 MAX 562.60 566.52 566.26 570.53 569.03 570.15 563.80 565.99 MIN 530.29 562.48 558.80 564.74 554.62 564.31 562.23 561.36 A No gage-height record --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 414 RIO LOCO BASIN 50128900 LAGO LOCO AT DAMSITE NEAR YAUCO, PR LOCATION.--Lat 18°02'41", long 66°53'16", Hydrologic Unit 21010004, at Damsite, 2.60 mi (4.18 km) northwest from Yauco Plaza, 0.45 mi (0.72 km) northeast from Escuela Río Cañas and 0.95 mi (1.53 km) northwest from Escuela Susua Alta. DRAINAGE AREA.--8.40 mi2 (21.8 km2). ELEVATION RECORDS PERIOD OF RECORD.--May 1995 to current year. GAGE.--Water stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Loco was completed in 1951. The dam is a concrete gravity structure with a total lenght of 600 ft (183 m), maximum structural height of 72 ft (21.9 m), the ungated overflow spillway is 150 ft (47.7 m), long with crest at elevation of 230 ft (70.1 m). It has a normal storage capacity of 1,950 acre-feet (2.40 hm3), as for May 4, 1979. The Loco Dam is owned by the Puerto Rico Electric Power Authority (P.R.E.P.A) and its part of the Southwestern Puerto Rico Project which was developed for electric power generation and irrigation of the lands in the Lajas Valley, some of the Project waters are used for water supply in the Lajas area. The maximum drawdown of the Dam is from 230 ft (70.1 m) to 220 ft (67.1 m) and the Capacity Table provided by P.R.E.P.A includes only that portion of the storage for the dam. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 234.77 ft (71.56 m), Sept. 22, 1998; minimum elevation, 217.77 ft (66.4 m), June 10, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 234.77 ft (71.56 m), Sept. 22; minimum elevation, 222.74 ft (67.8 m), Mar. 26. Capacity Table (based on data from Puerto Rico Electric Power Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 220 0 230 639 225 299 232 787 235 1,024 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 225.49 A A 228.77 223.45 228.11 229.08 229.47 229.14 230.85 230.43 230.98 2 223.93 230.31 230.41 228.97 229.09 227.37 227.41 229.31 228.28 229.89 230.36 230.52 3 229.57 230.72 230.47 A 230.67 226.27 A 229.14 230.29 229.29 229.35 230.98 4 229.39 229.41 229.99 226.83 228.45 224.83 225.88 230.09 229.79 229.20 228.23 231.02 5 229.20 228.33 230.09 230.29 230.97 229.78 225.29 230.05 230.54 229.03 226.83 230.94 6 228.49 230.19 230.31 A 230.54 228.87 224.65 230.15 229.93 228.64 A 231.02 7 227.25 230.32 230.29 230.78 230.88 228.41 227.33 230.20 230.65 229.98 230.44 230.95 8 A 230.97 229.48 228.27 230.48 227.93 226.59 230.13 230.72 230.04 230.37 230.95 9 228.55 230.34 229.98 226.87 230.07 226.89 225.79 230.13 230.61 230.87 230.16 230.18 10 229.28 229.89 230.15 225.99 229.86 225.25 225.66 230.12 229.93 230.15 229.67 230.66 11 230.43 229.55 A 225.02 229.61 230.04 224.67 230.00 230.20 230.91 229.23 230.69 12 230.19 229.09 229.27 224.34 229.26 228.39 223.72 229.52 230.57 230.54 228.84 230.23 13 230.29 228.49 228.97 229.69 A 227.24 226.96 228.84 230.45 230.72 228.48 230.15 14 230.47 228.06 228.67 227.84 A 226.82 224.53 228.06 229.83 230.58 230.43 230.28 15 230.28 A 228.04 225.69 228.90 225.97 228.75 227.64 230.79 230.86 230.51 230.04 16 230.19 228.51 226.71 A 230.49 227.48 227.06 227.45 230.33 230.87 230.77 230.05 17 230.32 A 225.56 227.37 230.66 225.60 230.04 227.55 230.47 230.13 230.40 229.99 18 230.93 229.51 224.28 226.96 A 227.18 229.76 226.76 229.29 229.79 230.29 230.69 19 230.94 230.19 228.48 226.51 230.23 228.89 229.48 225.88 230.87 230.95 230.38 230.64 20 230.40 229.58 229.49 225.15 230.39 227.45 229.20 225.24 230.87 230.78 230.88 230.67 21 A 229.18 229.58 227.62 229.96 226.77 228.37 224.86 229.87 230.92 230.99 230.86 22 230.80 229.63 A 225.46 229.77 226.05 227.82 224.54 230.30 230.38 230.99 230.83 23 230.81 230.18 A 228.95 230.55 226.69 226.79 224.26 230.66 230.32 230.94 230.52 24 230.16 230.01 228.41 230.18 230.51 226.46 226.19 223.88 230.64 230.96 231.09 230.45 25 230.27 230.12 228.00 230.25 230.32 223.94 225.81 224.05 230.64 229.88 231.07 230.60 26 A A 227.58 228.88 229.50 225.50 225.44 226.13 230.03 230.67 231.02 230.43 27 230.80 229.37 227.83 229.68 228.92 229.55 224.91 227.54 230.09 230.35 231.01 230.44 28 A 230.13 A 227.96 228.52 228.29 224.43 229.46 229.87 230.32 231.01 230.40 29 230.28 229.77 226.18 226.32 227.11 226.96 229.90 229.30 230.56 231.02 230.79 30 A 229.40 229.14 225.20 229.99 227.64 229.85 230.87 230.84 231.02 230.79 31 230.11 229.77 224.36 230.19 229.70 230.87 231.01 MAX 230.19 230.20 230.87 230.96 231.02 MIN 223.94 223.88 228.28 228.64 229.99 A No gage-height record 415 RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR WATER-QUALITY RECORDS LOCATION.--Lat 17°58'33", long 66°54'52", 0.6 mi (1.0 km) northwest of Guánica and 1.2 mi (1.9 km) northeast of Ensenada. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, OXYGEN COLI­ SPE- WATER DIS- DEMAND, FORM, STREP­ CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 23... 1025 314 7.1 29.0 8.4 5.5 71 <10 2000 2100 MAR 27... 0910 18400 7.3 29.0 1.5 3.3 46 93 46000 540 JUN 05... 0815 12500 7.4 29.0 3.7 2.4 32 27 230 220 SEP 11... 0915 315 6.8 26.8 12 5.7 71 <10 350 670 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 23... 130 30 13 13 .5 2.7 110 <.5 16 15 MAR 27... -- -- -- -- -- -- 240 -- -- -­ JUN 05... 1400 100 268 2110 25 87 130 -- 550 3900 SEP 11... 120 28 12 17 .7 3.1 120 <1.0 13 15 SOLIDS, RESIDUE NITRO­ FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) (00625) OCT 23... <.10 20 175 11 1.38 .017 1.40 .020 .36 .38 MAR 27... -- -- -- 4 .590 .050 .640 .130 .57 .70 JUN 05... .29 16 7120 17 .241 .029 .270 .170 .47 .64 SEP 11... .13 23 183 20 .686 .014 .700 .050 .33 .38 CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, IRON, NITRO- NITRO- PHOS- TOTAL TOTAL WATER TOTAL TOTAL TOTAL GEN, GEN, PHORUS ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV- RECOV­ TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) AS FE) (00600) (71887) (00665) (01002) (01007) (01022) (01027) (01034) (01042) (01045) OCT 23... 1.8 7.9 .080 <1 <100 30 <1 3 <10 560 MAR 27... 1.3 5.9 .160 -- -- -- -- -- -- -­ JUN 05... .91 4.0 .060 <1 <100 20 <1 2 <10 290 SEP 11... 1.1 4.8 .130 -- -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 416 RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... <1 44 <.10 <1 <1 <10 <.010 2 .05 MAR 27... JUN 05... <1 30 <.10 <1 <1 <10 <.010 <1 .02 SEP 11... MARICAO 417 Principal Principal Río de de de de Drenaje Riego Valle V a lle Lajas Lajas Viejo Guanajibo Guanajibo Río Río Río Río Río Río M a r i c a o P rieto Río Río Hoconuco Río Río Río Río Río Río Río Flores Guanajibo Cupeyes Caín Cruces Duey Rosario Rosario Quebrada Grande Vie j o Canal Canal Laguna Cart agena Laguna Joyuda 1364 131990 1336 CR-1 CHANNELS CARIBBEAN SEA MONA P ASSAGE SABANA GRANDE LAJAS CABO ROJO HORMIGUEROS SAN GERMÁN GUÁNICA MARICAO 0 0 1 1 2 2 3 3 4 4 1364 131990 1380 1336 CR-1 143 FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SEDIMENT STATION AND NUMBER SURFACE-WATER STATION AND NUMBER GUAYANILLA YAUCO Basin area PUERTO RICO 5 MILES 5 KILOMETERS CR-TW-9A CR-TW-9B Figure 23. Río Guanajibo basin. --- --- --- --- --- --- --- 418 RIO GUANAJIBO BASIN 50131990 RIO GUANAJIBO AT HWY 119 AT SAN GERMAN, PR LOCATION.--Lat 18°05'06", long 67°02'02", Hydrologic Unit 21010003, on left bank, at bridge on Hwy 119, 0.6 mi (1.0 km), southwest of junction of Highways 119 and 2, 0.2 mi (0.3 km), northeast of junction of Highways 119 and 102, 0.7 mi (1.1 km) east from public Plaza of San Germán. DRAINAGE AREA.--34.6 mi2 (89.6 km2). PERIOD OF RECORD.--April 1991 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 148 ft (45 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.3 21 13 7.8 4.7 6.1 3.6 6.6 38 14 14 40 2 6.8 21 13 6.9 4.5 5.7 3.2 6.3 31 165 49 52 3 5.6 20 13 6.2 4.3 5.2 3.2 6.0 32 153 34 221 4 4.8 21 12 6.2 42 5.8 3.2 5.1 297 55 16 583 5 6.9 19 11 6.1 924 5.2 3.1 5.5 156 26 15 362 6 4.9 19 11 6.3 52 5.2 3.1 37 106 35 e66 192 7 10 19 11 6.3 26 7.5 3.1 45 51 62 725 173 8 377 18 10 6.8 21 5.3 16 16 37 28 422 103 9 673 18 10 6.4 21 4.1 6.0 36 54 22 147 80 10 383 21 9.7 6.1 16 4.1 3.7 14 33 22 87 64 11 519 18 10 5.6 13 4.1 3.4 8.6 26 35 94 77 12 486 33 9.3 10 12 3.9 3.5 7.4 23 17 64 159 13 552 18 9.0 11 10 4.2 3.6 6.7 22 15 46 123 14 1180 17 8.8 7.1 10 4.0 3.2 6.1 19 15 42 64 15 380 279 8.5 6.2 12 7.1 2.8 12 17 14 94 53 16 233 126 8.4 6.2 10 5.5 12 12 16 13 48 50 17 282 42 8.0 6.2 8.5 5.1 237 8.5 184 14 41 44 18 218 30 9.6 6.8 7.9 12 23 8.5 91 16 34 60 19 116 25 10 6.7 7.9 6.3 9.4 143 38 22 29 85 20 84 22 8.8 5.8 7.2 4.7 18 160 27 20 38 217 21 62 19 9.2 5.2 7.1 4.2 9.8 300 23 17 33 248 22 50 18 8.4 5.4 6.6 3.9 7.5 196 28 15 109 e17300 23 43 16 7.5 4.9 6.8 3.6 5.8 51 34 14 59 e8830 24 38 15 7.9 4.8 6.1 3.2 5.1 30 53 15 48 e5440 25 34 16 7.4 4.9 6.7 4.5 7.5 322 37 12 507 e5030 26 32 30 7.2 4.6 7.2 4.0 39 257 26 10 198 e3490 27 29 19 7.2 4.5 7.7 3.8 13 72 22 18 100 e1800 28 27 15 7.2 4.6 6.1 3.8 15 419 18 33 80 e842 29 26 15 7.3 4.6 3.5 13 305 16 17 69 e1380 30 24 14 7.0 4.6 4.7 7.5 96 16 13 50 e394 31 23 9.2 4.4 4.2 54 12 41 TOTAL 5919.3 984 289.6 189.2 1268.3 154.5 487.3 2652.3 1571 939 3399 47556 MEAN 191 32.8 9.34 6.10 45.3 4.98 16.2 85.6 52.4 30.3 110 1585 MAX 1180 279 13 11 924 12 237 419 297 165 725 17300 MIN 4.8 14 7.0 4.4 4.3 3.2 2.8 5.1 16 10 14 40 MED 43 19 9.2 6.2 8.2 4.5 5.9 30 32 17 50 183 AC-FT 11740 1950 574 375 2520 306 967 5260 3120 1860 6740 94330 CFSM 5.52 .95 .27 .18 1.31 .14 .47 2.47 1.51 .88 3.17 45.8 IN. 6.36 1.06 .31 .20 1.36 .17 .52 2.85 1.69 1.01 3.65 51.13 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 1998, BY WATER YEAR (WY) MEAN 104 66.6 23.1 22.0 22.5 10.7 20.8 45.9 22.9 19.4 48.3 246 MAX 205 127 52.2 47.5 45.3 25.8 55.9 85.6 52.4 37.6 110 1585 (WY) 1993 1997 1993 1997 1998 1995 1996 1998 1998 1995 1998 1998 MIN 20.4 15.8 8.21 6.10 4.32 3.52 7.79 5.11 3.91 6.68 17.2 11.2 (WY) 1992 1992 1992 1998 1992 1992 1997 1994 1994 1994 1994 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1991 - 1998 ANNUAL TOTAL 11236.9 65409.5 ANNUAL MEAN 30.8 179 57.7 HIGHEST ANNUAL MEAN 179 1998 LOWEST ANNUAL MEAN 16.6 1994 HIGHEST DAILY MEAN 1180 Oct 14 17300 Sep 22 17300 Sep 22 1998 LOWEST DAILY MEAN 3.1 Jun 10 2.8 Apr 15 1.5 May 9 1992 ANNUAL SEVEN-DAY MINIMUM 3.7 Jun 8 3.2 Apr 1 1.8 May 6 1992 INSTANTANEOUS PEAK FLOW 24900 Sep 22 24900 Sep 22 1998 INSTANTANEOUS PEAK STAGE 19.53 Sep 22 19.53 Sep 22 1998 ANNUAL RUNOFF (AC-FT) 22290 129700 41780 ANNUAL RUNOFF (CFSM) .89 5.18 1.67 ANNUAL RUNOFF (INCHES) 12.08 70.32 22.65 10 PERCENT EXCEEDS 38 217 93 50 PERCENT EXCEEDS 9.3 16 15 90 PERCENT EXCEEDS 4.5 4.6 4.8 e Estimated 419 RIO GUANAJIBO BASIN 50131990 RIO GUANAJIBO AT HWY 119 AT SAN GERMAN, PR--Continued O N D J F M A M J J A S 1 100,000 2 5 10 20 50 100 200 500 1,000 2,000 5,000 10,000 20,000 50,000 DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 1997 1998 WATER YEAR 420 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°07'18", long 67°03'56", at bridge on Highway 347, 2.2 mi (3.5 km) northwest of San Germán. DRAINAGE AREA.--45.5 mi2 (117.8 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 1000 70 535 7.3 25.5 2.1 6.5 79 <10 800 550 MAR 26... 0940 3.7 784 7.2 26.0 .95 4.7 58 15 330 380 JUN 04... 1030 50 331 7.3 27.0 95 6.9 86 <10 K15000 5700 SEP 10... 1030 88 493 7.4 27.5 5.3 7.6 96 <10 2100 580 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 240 23 44 20 .6 2.8 260 .6 24 25 MAR 26... -- -- -- -- -- -- 250 -- -- -­ JUN 04... 150 14 27 12 .4 2.6 140 -- 14 15 SEP 10... 180 7.7 13 5.1 .3 1.0 220 <1.0 18 17 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 35 330 62.1 8 1.42 .180 1.60 .360 .74 MAR 26... -- -- -- -- <1 1.28 .020 1.30 .020 .52 JUN 04... <.10 27 196 26.6 120 .764 .096 .860 .180 .67 SEP 10... <.10 37 230 54.5 12 1.14 .062 1.20 .160 .15 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... 1.1 2.7 12 .160 <1 <100 60 <1 9 <10 MAR 26... .54 1.8 8.1 .210 -- -- -- -- -- -­ JUN 04... .85 1.7 7.6 .240 <1 <100 60 <1 75 15 SEP 10... .31 1.5 6.7 .160 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 421 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 550 1 69 <.10 <1 <1 10 <.010 5 .02 MAR 26... JUN 04... 5900 <1 210 <.10 <1 <1 20 <.010 <1 <.02 SEP 10... 422 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR LOCATION.--Lat 18°09'36", long 67°05'08", Hydrologic Unit 21010003, at bridge on Highway 348, 0.5 mi (0.8 km) southwest of Rosario Plaza. DRAINAGE AREA.--18.3 mi2 (47.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1985 to current year. GAGE.--Water-stage recorder. Elevation of gage is 50.0 ft (15.2 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. The gage-height recorded during the Hurricane Georges event was affected by backwater caused by the Hwy. 348 bridge which is about 32 ft. downstream from gage. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e105 38 30 24 2 e75 37 30 23 3 e61 37 29 19 4 e51 35 28 19 5 e42 33 27 20 20 10 9.2 8.4 16 13 76 59 18 11 9.4 8.0 15 62 75 248 15 9.3 9.9 7.7 16 114 49 156 17 9.2 9.0 9.2 23 41 47 181 56 8.9 9.1 9.7 30 21 40 138 6 e39 31 26 22 7 e37 31 26 49 8 e41 30 25 24 9 175 28 25 19 10 e229 30 24 19 20 9.2 9.2 20 28 122 54 280 15 9.0 27 40 22 e72 165 148 20 8.9 27 22 25 e36 159 113 25 8.6 13 22 35 25 120 99 16 8.5 10 19 40 51 142 85 11 e212 46 25 31 12 e141 38 24 28 13 e195 34 23 22 14 449 30 23 19 15 e244 67 22 17 14 8.1 9.0 16 31 42 162 85 13 7.9 8.9 13 23 28 e112 160 13 7.9 8.5 12 22 23 e82 131 12 15 8.7 12 21 22 e69 88 13 22 8.8 14 19 23 64 76 16 165 48 20 17 17 125 34 20 16 18 107 33 24 17 19 89 112 22 18 20 78 87 22 16 12 11 8.7 24 26 28 56 75 12 49 8.8 25 187 31 58 78 11 53 8.6 39 58 107 49 91 12 18 11 94 32 72 43 79 13 13 9.5 68 23 62 64 92 21 70 45 21 17 22 64 37 20 17 23 59 33 25 16 24 56 31 24 17 25 e56 31 22 17 13 11 9.0 67 20 40 63 120 12 9.5 12 63 19 32 71 e4420 12 8.3 8.8 32 20 65 61 422 12 7.9 8.7 32 19 45 48 287 12 8.0 9.8 138 17 36 152 258 26 e55 41 21 16 27 49 34 21 16 28 47 31 21 17 29 44 32 21 17 30 43 39 21 16 31 40 --- 23 15 14 9.9 10 75 16 33 85 244 11 11 9.7 30 16 92 263 237 11 9.6 19 31 14 69 130 233 --- 8.9 11 43 13 47 e81 336 --- 8.9 8.4 27 13 38 e68 224 --- 10 --- 21 --- 42 e64 --­ TOTAL 3243 1213 735 620 MEAN 105 40.4 23.7 20.0 MAX 449 112 30 49 MIN 37 28 20 15 AC-FT 6430 2410 1460 1230 CFSM 5.72 2.21 1.30 1.09 IN. 6.59 2.47 1.49 1.26 444 400.5 329.7 1042.0 859 1534 2772 9243 15.9 12.9 11.0 33.6 28.6 49.5 89.4 308 56 53 27 138 187 122 263 4420 11 7.9 8.4 7.7 13 13 40 59 881 794 654 2070 1700 3040 5500 18330 .87 .71 .60 1.84 1.56 2.70 4.89 16.8 .90 .81 .67 2.12 1.75 3.12 5.63 18.79 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 1998, BY WATER YEAR (WY) MEAN 102 68.5 31.6 22.8 MAX 206 117 53.7 39.7 (WY) 1986 1990 1995 1997 MIN 33.2 16.1 9.92 15.1 (WY) 1992 1992 1992 1994 19.4 21.3 23.2 43.7 41.7 42.5 62.3 105 37.8 77.0 57.7 122 91.1 75.2 102 308 1995 1989 1989 1993 1993 1989 1989 1998 8.55 10.1 11.0 14.8 12.0 23.2 25.1 32.7 1992 1992 1998 1997 1992 1990 1991 1986 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1986 - 1998 ANNUAL TOTAL 13311.9 ANNUAL MEAN 36.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 449 LOWEST DAILY MEAN 8.3 ANNUAL SEVEN-DAY MINIMUM 8.7 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 26400 ANNUAL RUNOFF (CFSM) 1.99 ANNUAL RUNOFF (INCHES) 27.06 10 PERCENT EXCEEDS 66 50 PERCENT EXCEEDS 25 90 PERCENT EXCEEDS 11 22435.2 61.5 48.8 70.6 1993 30.8 1992 Oct 14 4420 Sep 22 4420 Sep 22 1998 May 15 7.7 May 3 3.9 May 9 1992 Jun 5 8.4 Mar 7 4.2 May 6 1992 Not determined Sep 22 Not determined Sep 22 1998 18.66 Sep 22 18.66 Sep 22 1998 7.2 Mar 25 3.7 May 9 1992 44500 35370 3.36 2.67 45.61 36.25 121 110 26 28 9.4 11 e Estimated 423 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 O N D J F M A M J J A S 1997 1998 WATER YEAR 424 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water year 1979 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1985 to current year. INSTRUMENTATION.--US D-49 Sediment sampler since October 1985. Automatic sediment sampler since 1986. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 15,900 mg/L September 22,1998; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily, 356,000 tons (323,000 tonnes); September 22,1998 Minimum daily, 0.05 ton (0.04 Tonne) several days. EXTREMES FOR CURRENT YEAR 1998.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 15,900 mg/L ; September 22,1998; Minimum daily mean, 2.0 mg/L several days. SEDIMENT LOADS: Maximum daily, 356,000 tons (323,000 tonnes) September 22, 1998; Minimum daily 0.09 ton (0.08 tonne) several days. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 1150 64 263 7.5 25.0 .98 8.2 99 <10 K740 490 MAR 26... 1135 9.8 284 7.8 26.0 .49 8.7 108 <10 2000 45 JUN 04... 1215 13 261 8.2 29.0 1.0 8.0 104 <10 420 70 SEP 10... 1130 85 253 7.4 26.2 2.7 8.1 100 <10 590 470 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 120 22 16 7.1 .3 1.4 130 <.5 6.5 7.3 MAR 26... -- -- -- -- -- -- 160 -- -- -­ JUN 04... 130 23 18 7.2 .3 1.4 130 -- 6.8 8.4 SEP 10... 120 21 16 6.6 .3 1.4 110 <1.0 6.5 6.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 29 168 28.9 2 -- <.010 1.10 <.010 -­ MAR 26... -- -- -- -- 1 .620 .010 .630 .020 .21 JUN 04... .10 28 170 6.01 1 -- <.010 .540 .010 .21 SEP 10... <.10 28 152 34.7 4 1.18 .018 1.20 .030 -­ 425 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... <.20 -- -- <.020 <1 <100 20 <1 7 <10 MAR 26... .24 .86 3.8 .020 -- -- -- -- -- -­ JUN 04... .22 .76 3.4 <.020 <1 <100 20 <1 4 <10 SEP 10... <.20 -- -- .030 -- -- -- -- -- -­ MANGA- IRON, LEAD, NESE, MERCURY TOTAL TOTAL TOTAL TOTAL SELE- RECOV- RECOV- RECOV- RECOV- NIUM, ERABLE ERABLE ERABLE ERABLE TOTAL DATE (UG/L (UG/L (UG/L (UG/L (UG/L AS FE) AS PB) AS MN) AS HG) AS SE) (01045) (01051) (01055) (71900) (01147) METHY­ SILVER, ZINC, LENE TOTAL TOTAL BLUE RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE TOTAL PHENOLS SUB- (UG/L (UG/L (MG/L TOTAL STANCE AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01077) (01092) (00720) (32730) (38260) OCT 22... 130 <1 <10 <.10 <1 <1 <10 <.010 <1 .02 MAR 26... -- -- -- -- -- -- -- -- -- -­ JUN 04... 100 <1 11 <.10 <1 <1 <10 <.010 <1 <.02 SEP 10... -- -- -- -- -- -- -- -- -- -­ SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 e105 171 e51 38 2 e75 41 e8.5 37 3 e61 25 e4.1 37 4 e51 25 e3.4 35 5 e42 15 e1.8 33 7 .70 30 28 2.3 3 .27 30 16 1.3 6 .60 29 16 1.3 17 1.6 28 18 1.4 18 1.6 27 8 .58 6 e39 8 e.90 7 e37 7 e.69 8 e41 7 e.78 9 175 1020 1460 10 e229 1200 e1240 31 11 .94 26 3 .18 31 7 .58 26 2 .14 30 5 .36 25 2 .14 28 4 .34 25 4 .26 30 5 .42 24 9 .58 11 e212 822 e560 46 12 e141 549 e218 38 13 e195 705 e758 34 14 449 1730 2880 30 15 e244 709 e589 67 77 19 25 15 .99 80 9.1 24 21 1.3 31 2.9 23 20 1.3 24 2.0 23 17 1.0 215 109 22 18 1.1 16 165 193 94 48 17 125 62 21 34 18 107 47 14 33 19 89 29 7.0 112 20 78 17 3.5 87 67 9.8 20 19 1.1 20 1.8 20 9 .48 17 1.5 24 3 .18 510 643 22 2 .12 226 64 22 2 .12 21 70 10 1.9 22 64 7 1.2 23 59 6 .88 24 56 8 1.1 25 e56 16 e18 45 32 4.0 21 2 .13 37 16 1.6 20 4 .20 33 17 1.5 25 36 2.5 31 11 .92 24 6 .44 31 6 .47 22 2 .14 26 e55 28 e17 27 49 31 4.0 28 47 14 1.7 29 44 6 .70 30 43 8 .97 31 40 13 1.4 41 88 10 21 3 .17 34 33 3.0 21 4 .21 31 22 1.8 21 5 .29 32 27 3.3 21 7 .43 39 87 11 21 11 .62 --- --- --- 23 11 .68 TOTAL 3243 --- 7964.52 1213 --- 907.10 735 --- 21.68 --- --- --- --- --- --- --- --- --- 426 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 24 19 1.6 20 2 23 35 2.3 18 3 19 21 1.1 15 4 19 15 .75 17 5 20 12 .61 56 13 .67 10 6 .16 11 .52 11 5 .16 12 .47 9.3 5 .13 15 .87 9.2 5 .14 122 34 8.9 6 .15 6 22 9 .57 7 49 100 27 8 24 24 1.8 9 19 9 .44 10 19 10 .52 20 8 .42 9.2 8 .20 15 7 .30 9.0 11 .26 20 20 1.7 8.9 13 .31 25 44 3.4 8.6 14 .32 16 14 .63 8.5 9 .20 11 31 67 10 12 28 47 3.8 13 22 23 1.4 14 19 13 .65 15 17 7 .33 14 11 .42 8.1 5 .11 13 11 .38 7.9 5 .10 13 10 .36 7.9 4 .09 12 10 .33 15 22 2.9 13 11 .36 22 39 3.1 16 17 6 .27 17 16 6 .26 18 17 7 .30 19 18 8 .36 20 16 9 .38 12 12 .38 11 7 .22 12 12 .39 49 152 97 11 6 .19 53 103 27 12 5 .17 18 16 .81 13 6 .21 13 9 .33 21 17 10 .44 22 17 9 .41 23 16 8 .36 24 17 8 .36 25 17 8 .36 13 6 .21 11 7 .21 12 6 .18 9.5 6 .16 12 5 .17 8.3 6 .14 12 5 .16 7.9 6 .13 12 5 .17 8.0 6 .13 26 16 8 .32 27 16 7 .31 28 17 7 .33 29 17 8 .36 30 16 10 .45 31 15 14 .56 14 6 .21 9.9 6 .16 11 6 .18 11 5 .16 11 6 .18 9.6 5 .13 --- --- --- 8.9 6 .14 --- --- --- 8.9 7 .17 --- --- --- 10 9 .24 TOTAL 620 --- 58.70 444 --- 47.63 400.5 --- 135.46 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 9.2 11 .27 8.4 4 .09 16 9 .40 2 9.4 8 .19 8.0 4 .09 15 6 .26 3 9.9 5 .12 7.7 4 .09 16 7 .32 4 9.0 4 .11 9.2 5 .12 23 28 2.3 5 9.1 5 .12 9.7 5 .13 30 52 4.8 6 9.2 4 .10 20 33 5.0 28 24 2.0 7 27 44 9.8 40 82 10 22 11 .67 8 27 51 4.7 22 22 1.3 25 33 2.7 9 13 15 .52 22 7 .41 35 71 8.2 10 10 10 .28 19 6 .33 40 57 7.1 11 9.0 8 .20 16 7 .30 31 49 4.4 12 8.9 6 .14 13 7 .25 23 16 1.0 13 8.5 4 .10 12 7 .22 22 15 .86 14 8.7 5 .12 12 7 .22 21 15 .84 15 8.8 7 .16 14 13 .51 19 14 .71 16 8.7 5 .13 24 40 2.6 26 40 4.2 17 8.8 4 .10 25 54 6.4 187 818 1640 18 8.6 4 .09 39 76 8.4 58 135 23 19 11 18 .55 94 399 378 32 59 5.2 20 9.5 13 .34 68 119 24 23 32 2.0 21 9.0 9 .21 67 141 53 20 32 1.9 22 12 27 .90 63 129 27 19 15 .79 23 8.8 18 .44 32 31 3.1 20 23 1.7 24 8.7 10 .24 32 64 16 19 22 1.2 25 9.8 6 .17 138 744 683 17 17 .77 26 10 7 .18 75 197 50 16 9 .38 27 9.7 8 .20 30 28 2.4 16 9 .36 28 19 30 1.6 31 39 5.1 14 10 .39 29 11 20 .64 43 79 10 13 7 .27 30 8.4 6 .13 27 40 3.1 13 5 .20 31 21 15 .90 TOTAL 329.7 22.85 1042.0 1292.06 859 1718.92 --- --- --- --- --- --- 427 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 13 5 .18 76 197 84 59 55 15 2 62 208 112 75 192 47 248 1800 4740 3 114 507 650 49 93 13 156 395 168 4 41 75 11 47 101 16 181 688 447 5 21 18 1.0 40 95 10 138 416 157 6 122 489 505 54 131 27 280 1820 5300 7 e72 163 e38 165 795 1160 148 209 87 8 e36 17 e1.7 159 676 466 113 22 6.9 9 25 12 .80 120 297 125 99 12 3.3 10 51 168 65 142 980 469 85 9 2.1 11 42 72 8.7 162 625 349 85 56 18 12 28 23 1.8 e112 206 e67 160 639 856 13 23 20 1.3 e82 36 e8.2 131 164 64 14 22 26 1.6 e69 16 e3.0 88 19 4.6 15 23 32 2.2 64 93 19 76 28 5.7 16 28 38 3.3 56 122 19 75 46 9.3 17 31 47 5.0 58 92 15 78 116 29 18 107 332 192 49 28 3.8 91 170 54 19 72 137 30 43 12 1.4 79 114 26 20 62 107 23 64 124 32 92 172 80 21 40 59 6.7 63 63 11 120 1140 1240 22 32 17 1.5 71 100 22 e4420 15900 e356000 23 65 189 98 61 36 6.4 422 648 853 24 45 121 16 48 16 2.2 287 151 118 25 36 53 5.1 152 413 185 258 80 56 26 33 30 2.7 85 227 53 244 43 29 27 92 404 342 263 1280 3160 237 24 15 28 69 76 16 130 200 86 233 13 8.4 29 47 17 2.1 e81 15 3.2 336 1120 2540 30 38 9 .90 e68 10 1.8 224 85 55 31 42 37 5.9 e64 7 1.3 TOTAL 1534 2150.48 2772 6466.3 9243 372987.3 YEAR 22435.2 393773.00 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT DIS- CHARGE, INST. CUBIC FEET DATE TIME PER SECOND (00061) SEDI- SED. MENT, SUSP. SEDI- DIS- SIEVE MENT, CHARGE, DIAM. SUS- SUS- % FINER PENDED PENDED THAN (MG/L) (T/DAY) .062 MM (80154) (80155) (70331) MAY 25... 1130 32 164 14 99 JUL 03... 1730 794 3930 8430 94 27... 1730 517 2500 3490 90 AUG 10... 1930 586 4590 7260 91 11... 1635 233 1180 742 93 SEP 21... 2315 599 9980 16100 99 23... 1630 360 248 241 92 428 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARTICLE-SIZE DISTRIBUTION OF SUSPENDED SEDIMENT DIS- SEDI- SED. SED. SED. CHARGE, MENT, SUSP. SUSP. SUSP. INST. SEDI- DIS- FALL FALL FALL CUBIC MENT, CHARGE, DIAM. DIAM. DIAM. FEET SUS- SUS- % FINER % FINER % FINER DATE TIME PER PENDED PENDED THAN THAN THAN SECOND (MG/L) (T/DAY) .002 MM .004 MM .008 MM (00061) (80154) (80155) (70326) (70327) (70328) OCT 09... 1859 628 8620 14600 27 37 49 NOV 19... 1850 806 5330 11600 40 50 64 JUN 17... 1600 1760 7740 36800 37 48 62 AUG 07... 1645 1040 5460 15300 32 45 60 SEP 22... 0815 5510 22300 332000 35 51 69 WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SED. SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER % FINER % FINER % FINER % FINER DATE THAN THAN THAN THAN THAN THAN THAN .016 MM .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM (70329) (70330) (70331) (70332) (70333) (70334) (70335) OCT 09... 60 72 76 89 97 100 100 NOV 19... 75 83 86 94 99 100 100 JUN 17... 73 82 86 95 99 100 100 AUG 07... 72 85 89 96 99 100 100 SEP 22... 82 93 95 99 100 100 100 --- --- --- --- --- --- --- 429 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR LOCATION.--Lat 18°08'36", long 67°08'57", Hydrologic Unit 21010003, at bridge on Highway 100, 1.4 mi (2.3 km), west of Hormigueros, and 2.0 mi (3.2 km),downstream from Río Rosario. DRAINAGE AREA.--120 mi2 (311 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Annual low-flow measurements 1959, monthly measurements April 1959 to November 1967, January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is at mean sea level. Previous to Nov. 7, 1980, at site 0.3 mi (0.5 km) upstream at datum 7.36 ft (2.243 m) higher. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Daily discharges affected by sewage treatment plant about 2.1 mi (3.4 km) upstream from gage. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 216 91 51 35 15 20 16 e17 97 45 93 301 2 115 87 49 42 15 21 14 e16 81 141 256 748 3 89 85 55 28 13 19 14 e15 121 279 289 1550 4 76 83 47 26 17 19 12 e13 293 236 109 1200 5 70 80 44 32 439 19 11 e14 321 95 91 1030 6 64 77 42 28 146 20 11 e96 212 189 112 917 7 90 75 40 56 74 20 13 e120 109 219 462 1050 8 206 73 38 54 63 21 51 e43 91 108 1070 631 9 651 70 37 29 77 19 25 e97 99 84 551 467 10 1120 78 36 26 54 18 16 e35 103 89 420 342 11 1070 77 36 24 46 19 13 e23 84 127 538 246 12 810 104 35 46 41 18 13 e19 64 80 390 658 13 592 81 33 35 36 18 12 e17 67 68 218 1050 14 2770 70 32 28 33 22 11 16 57 64 192 358 15 2510 122 31 27 35 47 e10 19 48 73 324 243 16 1140 299 30 24 33 32 e50 46 48 72 223 214 17 655 113 29 23 28 26 e600 33 362 103 161 200 18 622 88 31 24 25 106 e60 51 329 331 137 238 19 406 121 31 24 24 39 e24 230 126 313 115 273 20 308 234 31 23 24 25 e46 346 86 144 169 248 21 251 98 29 22 22 20 e24 313 71 126 167 343 22 215 79 28 21 22 17 e18 290 74 106 169 e20200 23 168 69 29 19 21 15 e15 95 94 135 172 e6460 24 148 63 36 18 21 14 e13 76 172 111 122 2280 25 135 60 29 18 20 13 e19 452 122 82 1370 1440 26 e130 73 27 17 21 14 e100 565 81 73 847 e1310 27 117 67 26 17 22 15 e33 155 66 171 830 e869 28 e111 56 26 16 21 15 e39 163 58 214 1180 684 29 105 53 25 16 14 e33 551 51 139 438 632 30 101 63 25 16 14 e19 215 48 98 282 631 31 95 29 15 21 135 76 205 TOTAL 15156 2789 1067 829 1408 720 1335 4276 3635 4191 11702 46813 MEAN 489 93.0 34.4 26.7 50.3 23.2 44.5 138 121 135 377 1560 MAX 2770 299 55 56 439 106 600 565 362 331 1370 20200 MIN 64 53 25 15 13 13 10 13 48 45 91 200 AC-FT 30060 5530 2120 1640 2790 1430 2650 8480 7210 8310 23210 92850 CFSM 4.07 .77 .29 .22 .42 .19 .37 1.15 1.01 1.13 3.15 13.0 IN. 4.70 .86 .33 .26 .44 .22 .41 1.33 1.13 1.30 3.63 14.51 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 1998, BY WATER YEAR (WY) MEAN 462 397 123 59.5 51.4 45.6 68.6 167 105 99.9 223 491 MAX 1254 1518 422 112 119 244 316 636 504 240 757 2075 (WY) 1986 1978 1976 1997 1996 1989 1989 1980 1979 1984 1988 1975 MIN 97.5 42.7 15.4 13.8 13.9 10.6 16.1 12.7 9.23 26.4 42.3 78.5 (WY) 1992 1992 1992 1973 1977 1977 1977 1977 1977 1976 1976 1997 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1973 - 1998 ANNUAL TOTAL 36049 93921 ANNUAL MEAN 98.8 257 193 HIGHEST ANNUAL MEAN 402 1979 LOWEST ANNUAL MEAN 69.6 1994 HIGHEST DAILY MEAN 2770 Oct 14 20200 Sep 22 35000 Sep 16 1975 LOWEST DAILY MEAN 10 Jun 16 10 Apr 15 5.0 Jun 18 1977 ANNUAL SEVEN-DAY MINIMUM 11 Jun 10 13 Apr 1 5.5 Jun 17 1977 INSTANTANEOUS PEAK FLOW 40600 Sep 22 128000 Sep 16 1975 INSTANTANEOUS PEAK STAGE 28.03 Sep 22 28.50 Sep 16 1975 INSTANTANEOUS LOW FLOW 4.6 Jun 22 1977 ANNUAL RUNOFF (AC-FT) 71500 186300 139900 ANNUAL RUNOFF (CFSM) .82 2.14 1.61 ANNUAL RUNOFF (INCHES) 11.18 29.12 21.86 10 PERCENT EXCEEDS 150 551 419 50 PERCENT EXCEEDS 47 71 75 90 PERCENT EXCEEDS 19 17 21 e Estimated 430 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 431 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 23... 0840 175 425 7.2 25.5 3.6 5.3 64 <10 580 710 MAR 27... 0750 16 414 7.1 24.5 7.1 6.1 74 <10 22000 330 JUN 11... 1015 83 408 6.6 26.5 59 6.3 79 <10 3400 2900 SEP 11... 0745 250 487 7.0 26.5 31 5.6 69 <10 4500 260 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 23... 190 26 31 14 .4 2.5 180 <.5 16 15 MAR 27... -- -- -- -- -- -- 210 -- -- -­ JUN 11... 180 26 29 16 .5 2.9 180 -- 17 18 SEP 11... 240 44 32 8.4 .2 4.7 200 <1.0 12 11 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 23... <.10 30 242 114 9 1.04 .055 1.10 .020 .34 MAR 27... -- -- -- -- 6 .940 .010 .950 .010 .20 JUN 11... <.10 30 246 55.5 108 .950 .020 .970 .050 .23 SEP 11... .11 17 250 169 74 -- .011 <.020 .060 .68 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 23... .36 1.5 6.5 .160 <1 <100 50 <1 7 <10 MAR 27... .20 1.0 4.5 .050 -- -- -- -- -- -­ JUN 11... .28 1.3 5.5 .290 <1 100 60 <1 23 13 SEP 11... .74 -- -- .030 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 432 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 23... 750 <1 110 <.10 <1 <1 <10 <.010 2 <.02 MAR 27... JUN 11... 3800 2 180 <.10 <1 <1 20 <.010 <1 <.02 SEP 11... 433 Río Río Río Río Río Río Blanco Prieto Prieto Guayo Guilarte L im a n í de de Añasco Añasco Mayagüecilla Río Río Río Casei Río Río Río Río Río Río Río Lajas Guaba Río Río A r e n a s Guabá Cañas Yaguez Grande Grande Lago Guayo Lago Y ahuecas Lago Prieto Tunnel to Lago Luchetti Tunnel Tunnel Laguna Joyuda MONA P ASSAGE HORMIGUEROS MARICAO AÑASCO SAN SEBASTÍAN Bucarabones 0 0 1 1 2 2 3 3 4 4 1440 1440 1460 1430 1430 1388 1415 1415 CI-1 CI-1 MAYAGÜEZ Basin area PUERTO RICO LAS MARÍAS 5 MILES 5 KILOMETERS TUNNEL FLOW DIRECTION QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER LAKE-ELEVATION STATION AND NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER Figure 24. Río Yagüez to Río Grande de Añasco basins. 434 RIO YAGÜEZ BASIN 50138800 RIO YAGÜEZ NEAR MAYAGÜEZ, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°12'31", long 67°07'07", at steel-truss bridge on unnumbered paved road about 800 ft (244 m) south of Highway 106, 1.8 mi (2.9 km) west of Highways 106 and 352 junction, and 1.4 mi (2.3 km) east-northeast from Mayagüez plaza. DRAINAGE AREA.--6.7 mi2 (17.3 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 1400 13 300 7.6 26.0 1.4 6.5 80 <10 570 3300 MAR 26... 1300 1.5 307 8.0 25.5 .55 9.7 119 <10 340 K140 JUN 04... 1400 2.1 321 7.7 27.5 5.5 7.3 93 <10 K1600 2000 SEP 10... 1320 24 279 7.4 27.0 4.9 8.0 101 <10 K730 820 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 130 35 11 11 .4 2.2 130 <.5 6.9 9.5 MAR 26... -- -- -- -- -- -- 160 -- -- -­ JUN 04... 140 37 11 12 .5 2.6 140 -- 9.7 11 SEP 10... 120 32 9.1 9.9 .4 2.2 120 <1.0 6.7 8.5 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 31 183 6.28 1 -- <.010 1.00 .020 -­ MAR 26... -- -- -- -- 1 .950 .010 .960 .020 .20 JUN 04... <.10 31 198 1.14 1 -- <.010 .520 .030 .21 SEP 10... <.10 30 170 11.1 5 .988 .012 1.00 .020 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... <.20 -- -- .020 <1 <100 30 <1 <1 <10 MAR 26... .23 .86 3.7 .070 -- -- -- -- -- -­ JUN 04... .24 .76 3.4 .040 <1 <100 40 <1 1 <10 SEP 10... <.20 -- -- .040 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 435 RIO YAGÜEZ BASIN 50138800 RIO YAGÜEZ NEAR MAYAGüEZ, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 110 <1 <10 <.10 <1 <1 <10 <.010 <1 .02 MAR 26... JUN 04... 410 <1 27 .18 <1 <1 <10 <.010 <1 <.02 SEP 10... 436 RIO GRANDE DE AÑASCO BASIN 50141500 LAGO GUAYO AT DAMSITE NEAR CASTAÑER, PR LOCATION.--Lat 18°12'46", long 66°50'06", Hydrologic Unit 21010003, at Guayo Dam on Río Guayo, 1.1 mi (1.8 km),southwest of Lago Yahuecas, 2.6 mi (4.2 km),southwest of Lago Prieto, 2.1 mi (3.4 km) north of Castañer, and 6.0 mi (9.6 km) west of Adjuntas. DRAINAGE AREA.--9.60 mi2 (24.86 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1980 to January 1985, June 1989 to current year. Prior to October 1994, published as Lago Guayo near Castañer . GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guayo was completed in 1956. The dam is on Río Guayo and is the largest in the southwestern Puerto Rico project. The maximum storage is 17,400 ac-ft (21.5 hm3), for power and irrigation. The dam is a concrete gravity structure with a total length of 555 ft (169 m), a maximum structural height of 190 ft (58 m), and a maximum width at the base of 145 ft (44 m). The ungated overflow spillway with a crest elevation of 60.00 ft (18.29 m), and a crest length of 220 ft (67 m) was designed to pass a maximum flood of 30,200 ft3/s (855 m3/s) at a reservoir elevation of 70.00 ft (21.34 m). Timber flashboards that were added to increase storage capacity were subsequently removed and their use discontinued. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 1465.35 ft (446.64 m), Sept. 22, 1998; minimum elevation recorded, 1415.43 ft (431.42 m), June 2, 1990, but may have been less during period of no gage-height record June 2-5, 1990. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1465.35 ft (446.64 m), Sept. 22; minimum elevation 1434.66 ft (437.28 m), Feb 25. Capacity Table (based on data from Puerto Rico Water Resources Authority) Elevation, in feet Contents, in acre-feet Elevation, in feet Contents, in acre-feet 1,415 3,960 1,460 13,550 1,449 10,660 1,465 15,000 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1441.69 1451.58 1453.10 1456.35 1444.11 1435.58 1441.53 1448.91 1460.17 1458.63 1444.73 1459.81 2 1441.95 1451.82 1453.33 1456.11 1443.29 1435.76 1442.70 1449.07 1459.21 1459.80 1445.41 1460.30 3 1440.94 1450.73 1453.56 1456.25 1441.27 1435.93 A 1449.22 1459.64 1460.20 1445.91 1460.30 4 1441.16 1449.67 1453.60 1456.38 1440.46 1436.12 1443.52 1449.02 1460.39 1460.17 1446.33 1460.38 5 1441.38 1449.67 1453.81 1456.56 1444.61 1436.28 1443.74 1449.16 1459.86 1460.13 1446.70 1459.92 6 1441.66 1448.89 1454.01 1456.79 1443.74 1436.55 1443.67 1449.52 1460.21 1460.60 1448.03 1460.04 7 1442.91 1447.93 1453.99 1455.88 1442.38 1436.82 1444.94 1449.84 1460.20 1459.66 1452.59 1459.48 8 1444.54 1446.40 1454.19 1455.78 1442.96 1437.00 1445.98 1452.88 1459.93 1458.87 1454.25 1459.19 9 1445.79 1446.66 1454.01 1455.80 1442.46 1437.15 1446.34 1454.06 1459.41 1457.31 1455.11 1458.08 10 1446.67 1447.44 1454.21 1455.95 1441.67 1437.30 1446.43 1454.41 1459.09 1456.55 1455.78 1457.22 11 1448.20 1448.36 1454.30 1456.09 1440.86 1437.45 1446.65 1454.67 1458.75 1455.85 1456.85 1457.87 12 1451.54 1449.06 1454.50 1455.90 1440.13 1437.59 1446.91 1454.86 1457.84 1455.56 1457.65 1459.49 13 1454.24 1449.48 1454.68 1455.72 1440.36 1437.75 1446.69 1455.04 1457.13 1453.79 1458.25 1460.32 14 1458.09 1449.91 1454.87 1454.84 1440.64 1437.85 1446.92 1455.28 1457.46 1452.72 1457.63 1459.48 15 1460.75 1450.23 1455.05 1454.32 1440.92 1438.05 1447.15 1455.83 1457.76 1452.07 1457.33 1460.28 16 1460.41 1450.67 1455.21 1453.42 1440.32 1438.30 1447.37 1456.19 1458.07 1451.21 1457.42 1460.32 17 1460.45 1450.55 1455.28 1453.58 1439.44 1438.74 1446.76 1456.38 1459.62 1451.36 1456.61 1460.33 18 1459.93 1450.87 1455.37 1453.77 1438.10 1438.70 1447.02 1456.64 A 1452.27 1455.76 1460.48 19 1459.90 1450.86 1455.49 1453.94 1437.22 1438.88 1447.27 1458.80 1459.40 1451.97 1455.54 1460.28 20 1458.92 1451.19 1455.39 1453.25 1437.13 1439.03 1447.47 1461.13 1459.11 1451.83 1454.68 1460.32 21 1458.57 1451.49 1455.57 1452.45 1436.80 1439.19 1447.66 1461.31 1459.45 1451.00 1454.33 1462.46 22 1457.99 1451.63 1455.56 1451.89 1436.45 1439.32 1446.96 1460.46 1459.01 1449.71 1453.20 1461.23 23 1457.27 1451.67 1455.74 1451.29 1435.80 1439.45 1447.14 1460.27 1458.21 1450.14 1453.46 1460.83 24 1456.98 1451.33 1455.73 1450.44 1434.90 1439.58 1447.30 1460.24 1458.05 1449.58 1453.18 1460.66 25 1456.43 1451.54 1455.89 1448.32 1434.73 1439.73 1447.52 1460.23 1458.37 1449.99 1456.07 1460.67 26 1455.69 1451.85 1456.05 1447.31 1434.96 1439.88 1447.74 1459.64 1458.65 1450.03 1455.95 1460.49 27 1454.71 1452.12 1456.20 1446.11 1435.18 1440.04 1448.09 1459.51 1457.74 1449.05 1457.44 1460.43 28 1453.29 1452.37 1456.31 1445.08 1435.39 1440.16 1448.49 1458.70 1458.01 1448.53 1458.73 1460.40 29 A 1452.62 1456.45 1444.01 --- 1440.38 1448.69 1459.25 1458.26 1447.44 1459.81 1460.42 30 A 1452.87 1456.59 1443.79 --- 1440.76 1448.84 1459.76 1458.40 1446.31 1459.85 1460.39 31 1451.95 --- 1456.51 1443.96 --- 1440.20 --- 1460.11 --- 1444.65 1459.73 --­ MAX --- 1452.87 1456.59 1456.79 1444.61 1440.76 --- 1461.31 --- 1460.60 1459.85 1462.46 MIN --- 1446.40 1453.10 1443.79 1434.73 1435.58 --- 1448.91 --- 1444.65 1444.73 1457.22 A No gage-height record 437 RIO GRANDE DE AÑASCO BASIN 50143000 RIO GRANDE DE AÑASCO NEAR LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'26", long 66°55'00", at bridge on Highway 124, 0.7 mi (1.1 km) downstream from confluence of Río Blanco and Río Prieto, and 3.7 mi (6.0 km) southwest of Lares plaza. DRAINAGE AREA.--26.3 mi2 (68.1 km2) this does not include 36.2 mi2 (93.8 km2) which contributes only during high floods, and 3.5 mi2 (9.1 km2) which contributes only part of its storm runoff. PERIOD OF RECORD.--Water years 1959-68, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 20... 1100 85 269 8.0 25.5 3.0 7.7 93 <10 37000 K160 MAR 05... 0905 10 317 8.0 23.0 1.7 8.3 97 <10 200 K91 JUN 02... 1400 88 251 7.2 28.5 3.2 7.1 94 <10 220 K1100 SEP 09... 1130 100 267 7.7 27.5 4.0 7.5 97 <10 240 200 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 20... 110 30 8.9 10 .4 2.3 100 <.5 16 10 MAR 05... -- -- -- -- -- -- 130 -- -- -­ JUN 02... 110 29 8.9 20 .8 2.3 93 -- 9.6 29 SEP 09... 100 26 8.7 19 .8 3.1 98 <1.0 10 26 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 20... <.10 31 168 38.6 4 1.20 .150 1.40 1.50 .86 MAR 05... -- -- -- -- <1 -- <.010 .420 .030 -­ JUN 02... <.10 25 180 42.7 3 -- <.010 .310 .050 .63 SEP 09... <.10 28 196 52.9 6 1.79 .010 1.80 .010 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 20... 2.4 3.8 17 .940 <1 <100 10 <1 <1 <10 MAR 05... <.20 -- -- .030 -- -- -- -- -- -­ JUN 02... .68 .99 4.4 .040 <1 <100 20 <1 <1 12 SEP 09... <.20 -- -- .020 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 438 RIO GRANDE DE AÑASCO BASIN 50143000 RIO GRANDE DE AÑASCO NEAR LARES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 20... 300 <1 31 <.10 <1 <1 <10 <.010 <1 <.02 MAR 05... JUN 02... 230 <1 33 <.10 <1 <1 10 <.010 1 <.02 SEP 09... 439 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR LOCATION.--Lat 18°17'05", long 67°03'05", Hydrologic Unit 21010003, on left bank, at downstream side of bridge on Highway 108, 0.4 mi (0.6 km) downstream from Quebrada La Zumbadora, 4.4 mi (7.1 km) northwest of Las Marías, 5.4 mi (8.7 km) southwest of San Sebastián. DRAINAGE AREA.--94.3 mi2 (244.2 km2), does not include 36.2 mi2 (93.8 km2) which contributes only during high floods, and 3.5 mi2 (9.1 km2) which contributes only part of its storm runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1963 to current year. GAGE.--Water-stage recorder. Datum of gage is 103.72 ft (31.614 m) above mean sea level (Puerto Rico Department of Public Works bench mark). Previous to Oct. 30, 1975, at site 600 ft (180 m) upstream at same datum. REMARKS.--Records fair except those for estimated daily dischages, which are poor. Transbasin diversion (except during floods) to Río Yauco basin for hydroelectric power and irrigation above Lago Guayo, Yahuecas, and Prieto, combined useable storage 17,300 acre-ft (21.3 hm3). Limited storm runoff is contributed to basin by 3.5 mi2 (9.1 km2) above Río Toro Diversion dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 384 193 138 88 2 467 185 131 87 3 239 181 126 79 4 197 172 120 77 5 329 164 115 76 61 61 139 64 138 103 208 384 60 59 193 64 208 132 202 4200 60 58 121 63 185 213 230 1130 58 56 82 73 142 263 281 1020 286 76 72 66 426 186 218 800 6 210 160 113 81 7 191 157 109 103 8 236 154 111 108 9 362 150 109 81 10 413 151 108 77 121 72 66 97 298 462 167 1910 81 153 59 190 209 580 2200 816 90 106 261 190 195 346 1010 636 153 73 107 338 166 161 1120 574 94 69 79 118 134 305 1320 488 11 452 159 112 103 12 564 259 104 143 13 795 196 102 86 14 1980 175 101 88 15 1690 300 100 78 78 67 69 85 148 366 931 490 74 64 65 70 159 636 736 996 74 64 64 62 507 286 399 829 70 73 62 58 198 435 314 612 74 144 57 97 157 471 271 449 16 1380 280 98 74 17 775 170 95 71 18 727 155 98 114 19 461 151 95 85 20 384 181 94 76 74 100 55 140 709 419 246 1030 70 88 54 107 560 352 291 591 67 217 52 177 662 233 263 619 63 100 e73 496 350 246 213 624 62 77 75 943 199 197 198 480 21 304 148 93 74 22 282 141 93 112 23 264 135 97 74 24 250 140 119 68 25 237 169 94 67 61 68 70 5740 156 195 233 528 60 65 71 2660 151 156 287 69900 60 61 62 655 133 368 274 e4200 59 58 66 400 124 422 216 e2290 57 62 68 328 272 202 1050 e1450 26 231 311 88 67 27 218 221 86 66 28 209 164 83 65 29 202 165 82 63 30 197 183 82 62 31 196 --- 107 61 66 65 77 420 153 166 419 e1170 66 68 67 202 201 151 1430 e1110 62 68 133 159 129 150 838 e916 --- 63 107 258 114 322 435 e1050 --- 116 72 210 108 163 435 e3850 --- 146 --- 177 --- 411 614 --­ TOTAL 14826 5470 3203 2554 MEAN 478 182 103 82.4 MAX 1980 311 138 143 MIN 191 135 82 61 AC-FT 29410 10850 6350 5070 CFSM 5.07 1.93 1.10 .87 IN. 5.85 2.16 1.26 1.01 2261 2617 2598 14707 7291 9098 17049 105142 80.8 84.4 86.6 474 243 293 550 3505 286 217 261 5740 709 636 2200 69900 57 56 52 58 108 103 167 384 4480 5190 5150 29170 14460 18050 33820 208500 .86 .90 .92 5.03 2.58 3.11 5.83 37.2 .89 1.03 1.02 5.80 2.88 3.59 6.73 41.48 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1963 - 1998, BY WATER YEAR (WY) MEAN 660 428 221 141 MAX 1467 746 482 286 (WY) 1993 1982 1966 1997 MIN 344 182 103 82.4 (WY) 1983 1998 1992 1998 115 104 143 374 287 268 364 691 345 271 313 1084 815 657 936 3505 1996 1972 1971 1986 1979 1979 1979 1998 62.3 54.4 49.3 63.7 71.2 111 152 206 1992 1965 1968 1967 1977 1990 1967 1983 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1963 - 1998 ANNUAL TOTAL 75096 ANNUAL MEAN 206 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1980 LOWEST DAILY MEAN 56 ANNUAL SEVEN-DAY MINIMUM 58 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 149000 ANNUAL RUNOFF (CFSM) 2.18 ANNUAL RUNOFF (INCHES) 29.62 10 PERCENT EXCEEDS 381 50 PERCENT EXCEEDS 153 90 PERCENT EXCEEDS 72 186816 512 316 512 1998 189 1967 Oct 14 69900 Sep 22 69900 Sep 22 1998 Jun 17 52 Apr 18 32 Apr 18 1965 Jun 11 58 Apr 12 35 Apr 14 1965 163000 Sep 22 163000 Sep 22 1998 34.50 Sep 22 34.50 Sep 22 1998 51 Apr 18 31 Apr 19 1965 370500 229100 5.43 3.35 73.70 45.56 716 654 153 184 64 74 e Estimated 440 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR 441 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1963 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, INST. CIFIC WHOLE SOLVED CHEM- FECAL, CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) OCT 21... 1210 312 247 8.1 26.0 4.6 8.0 98 <10 360 FEB 24... 1150 58 264 7.7 24.0 3.0 8.6 101 <10 K90 JUN 03... 0900 145 245 7.5 26.5 17 7.6 95 <10 K1400 SEP 09... 1600 E488 219 7.3 26.5 36 7.7 96 <10 4000 STREP- HARD- MAGNE- TOCOCCI NESS CALCIUM SIUM, SODIUM, FECAL, TOTAL DIS- DIS- DIS- (COLS. (MG/L SOLVED SOLVED SOLVED DATE PER AS (MG/L (MG/L (MG/L 100 ML) CACO3) AS CA) AS MG) AS NA) (31679) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER AD- SIUM, UNFLTRD SULFATE SORP- DIS- FET SULFIDE DIS­ TION SOLVED FIELD TOTAL SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L AS K) CACO3 AS S) AS SO4) (00931) (00935) (00410) (00745) (00945) OCT 21... 390 110 27 9.6 8.3 .3 1.8 98 -- 9.9 FEB 24... K80 -- -- -- -- -- -- 110 -- -­ JUN 03... K600 100 26 8.6 8.8 .4 2.2 100 -- 11 SEP 09... 3100 89 22 8.0 8.4 .4 1.9 90 <1.0 8.5 SOLIDS, RESIDUE CHLO- FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO­ RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L AS CL) AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) (00940) (00950) (00955) (70301) (70302) (00530) (00615) (00630) (00610) (00605) OCT 21... 7.5 <.10 29 152 128 7 <.010 1.30 .020 -­ FEB 24... -- -- -- -- -- 1 <.010 .390 .020 .23 JUN 03... 8.2 .12 25 150 58.7 26 <.010 .730 .030 .25 SEP 09... 6.7 <.10 27 137 E180 54 <.010 1.30 .030 -­ NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 21... <.20 -- -- <.020 <1 <100 <10 -- 1 <10 FEB 24... .25 .64 2.8 .020 -- -- -- -- -- -­ JUN 03... .28 1.0 4.5 .040 <1 <100 <10 <1 1 <10 SEP 09... <.20 -- -- .050 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 442 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 21... 260 <1 70 <.10 <1 <1 <10 <.010 <1 <.02 FEB 24... JUN 03... 770 <1 70 <.10 <1 <1 <10 <.010 1 <.02 SEP 09... 443 RIO GRANDE DE AÑASCO BASIN 50146000 RIO GRANDE DE AÑASCO NEAR AÑASCO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°16'00", long 67°08'05", at bridge on Highway 430, 0.2 mi (0.3 km) south of Highway 109 at El Espino and 1.4 mi (2.3 km) east-southeast from Añasco plaza. DRAINAGE AREA.--139 mi2 (360 km2) this does not include 39.7 mi2 (102.8 km2), flow is diverted to south coast. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 21... 1415 E600 247 7.6 27.5 9.6 7.5 94 10 210 360 MAR 13... 0920 81 259 7.7 25.0 4.2 6.7 80 <10 K110 K40 JUN 04... 0830 219 237 7.3 27.0 60 6.7 84 <10 K1500 K1600 SEP 10... 1450 E500 220 7.3 27.5 31 7.2 91 <10 39000 2700 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 21... 100 26 9.5 8.3 .4 1.8 100 <1.0 9.7 7.8 MAR 13... -- -- -- -- -- -- 110 -- -- -­ JUN 04... 96 25 8.4 8.7 .4 2.3 97 -- 8.8 7.8 SEP 10... 89 23 8.0 8.3 .4 1.9 92 <1.0 7.8 6.7 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 21... <.10 29 153 E248 6 -- <.010 1.10 .020 -­ MAR 13... -- -- -- -- 8 -- <.010 .230 .040 .19 JUN 04... <.10 24 143 84.6 82 -- <.010 .670 .040 .45 SEP 10... <.10 27 138 E186 50 1.19 .012 1.20 .030 .22 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 21... <.20 -- -- .030 <1 <100 30 <1 <1 10 MAR 13... .23 .46 2.0 .040 -- -- -- -- -- -­ JUN 04... .49 1.2 5.1 .060 <1 <100 20 <1 2 <10 SEP 10... .25 1.5 6.4 .060 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 444 RIO GRANDE DE AÑASCO BASIN 50146000 RIO GRANDE DE AÑASCO NEAR AÑASCO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 21... 240 1 80 <.10 <1 <1 <10 <.010 <1 <.02 MAR 13... JUN 04... 1600 <1 140 <.10 <1 <1 <10 <.010 <1 <.02 SEP 10... 445 Río Río Río Río Río Río Río Guatemala Sonador Río Culebrinas Culebrinas Ingenio Grande Culebra los Moron es Cañas Quebrada Quebrada Grande AGUADILLA MONA P ASSAGE AÑASCO SAN SEBASTÍAN MOCA AGUADA RINCÓN LAS MARÍAS LARES 0 0 1 1 2 2 3 3 4 4 1478 1478 200 1491 1476 1476 R-4 C-4 C-4 Basin area PUERTO RICO MAYAGÜEZ 5 MILES 5 KILOMETERS QUALITY-OF-WATER STATION AND NUMBER EXPLANATION WELL AND WELL NUMBER DRAINAGE BASIN BOUNDARY TOWN OR CITY SURFACE-WATER STATION AND NUMBER Figure 25. Río Culebrinas basin. 446 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'51", long 67°02'40", at bridge on Highway 423, 1.3 mi (2.1 km) south of Quebrada El Salto Bridge on Highway 111, and 2.1 mi (3.4 km) west of Central La Plata. DRAINAGE AREA.--58.2 mi2 (150.7 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 0950 104 310 7.8 25.5 2.8 7.9 96 <10 5800 1000 MAR 12... 1205 31 330 7.9 24.5 4.4 7.9 94 <10 450 280 JUN 03... 1430 E1000 194 7.3 26.5 760 6.9 86 19 60000 53000 SEP 10... 0945 246 311 7.6 25.0 56 7.6 91 <10 24000 3500 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 140 45 5.8 11 .4 2.1 130 <1.0 11 11 MAR 12... -- -- -- -- -- -- 130 -- -- -­ JUN 03... 78 26 3.1 6.1 .3 3.9 77 -- 13 7.3 SEP 10... 130 45 4.6 8.5 .3 2.3 140 <1.0 11 8.4 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 29 194 54.6 3 1.17 .030 1.20 .040 -­ MAR 12... -- -- -- -- 4 1.28 .017 1.30 .030 .19 JUN 03... <.10 12 118 E318 1450 .766 .034 .800 .250 3.0 SEP 10... .10 20 184 123 62 .662 .018 .680 .060 .60 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... <.20 -- -- <.020 <1 <100 <10 <1 <10 30 MAR 12... .22 1.5 6.7 .080 -- -- -- -- -- -­ JUN 03... 3.2 4.0 18 .190 <1 <100 <10 <1 10 37 SEP 10... .66 1.3 5.9 .160 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 447 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 900 25 170 <.10 <1 <1 20 <.010 <1 .05 MAR 12... JUN 03... 3400 13 1100 <.10 <1 <1 50 <.010 <1 .05 SEP 10... 448 RIO CULEBRINAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR LOCATION.--Lat 18°21'42", long 67°05'33", Hydrologic Unit 21010003, on right bank, at bridge on Highway 404, 0.3 mi (0.5 km) downstream from Quebrada Yagruma, and 2.8 mi (4.5 km) southeast of Moca. DRAINAGE AREA.--71.2 mi2 (184.4 km2). PERIOD OF RECORD.--July 1967 to current year. GAGE.--Water-stage recorder. Elevation of gage is 45 ft (14 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 107 149 172 77 2 313 126 131 73 3 253 99 117 71 4 128 98 109 68 5 399 93 104 68 45 36 39 31 291 119 134 320 44 35 36 31 402 108 122 3170 45 35 34 31 640 104 151 508 44 34 34 34 277 114 235 567 80 227 33 37 403 163 169 290 6 259 90 100 66 7 172 88 97 86 8 186 87 95 77 9 125 85 92 67 10 114 85 90 65 50 172 32 37 586 128 107 8170 44 198 30 67 499 220 104 1820 55 132 31 44 261 208 109 972 68 54 30 39 193 130 312 707 46 46 30 36 163 180 394 344 11 107 93 89 103 12 1960 100 85 75 13 373 165 84 67 14 886 129 82 63 15 744 765 81 59 42 43 29 35 944 847 1330 262 42 41 32 36 4820 2590 3230 368 41 41 33 36 3320 e5680 511 4070 39 45 31 36 810 1180 282 497 41 48 31 37 1430 1370 236 316 16 650 247 78 57 17 234 128 78 67 18 186 111 79 150 19 160 102 80 143 20 146 98 78 100 40 49 32 46 3150 705 1450 525 38 41 33 50 581 402 329 290 38 47 32 58 1210 292 236 1460 38 51 35 208 527 235 308 647 37 40 64 1610 340 210 186 272 21 136 94 81 99 22 129 92 92 89 23 124 90 150 61 24 119 113 166 55 25 116 161 92 54 37 37 36 1170 e281 188 312 e240 37 35 34 2840 e222 165 260 e17000 36 e34 34 3490 e203 156 176 1500 36 e35 40 473 e300 615 157 1020 36 e37 40 211 e254 231 416 724 26 114 917 81 52 27 111 448 83 50 28 108 250 78 48 29 106 517 75 48 30 104 309 73 48 31 103 --- 121 45 37 e37 34 464 e276 165 352 565 37 e41 33 208 276 159 259 527 36 48 37 128 225 142 1490 404 --- 67 33 106 161 133 500 471 --- 79 31 1810 135 150 249 1510 --- 65 --- 629 --- 204 1260 --­ TOTAL 8772 5929 3013 2251 MEAN 283 198 97.2 72.6 MAX 1960 917 172 150 MIN 103 85 73 45 AC-FT 17400 11760 5980 4460 CFSM 3.97 2.78 1.37 1.02 IN. 4.58 3.10 1.57 1.18 1209 1930 1033 14068 23180 17293 15366 49536 43.2 62.3 34.4 454 773 558 496 1651 80 227 64 3490 4820 5680 3230 17000 36 34 29 31 135 104 104 240 2400 3830 2050 27900 45980 34300 30480 98250 .61 .87 .48 6.37 10.9 7.83 6.96 23.2 .63 1.01 .54 7.35 12.11 9.04 8.03 25.88 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 1998, BY WATER YEAR (WY) MEAN 614 321 142 91.6 MAX 1086 799 424 530 (WY) 1973 1982 1982 1997 MIN 231 108 72.1 51.2 (WY) 1968 1979 1992 1979 79.7 70.3 128 464 394 301 339 539 371 319 621 2054 773 847 831 1651 1996 1981 1986 1986 1998 1979 1979 1998 37.0 30.4 26.4 96.7 73.1 66.7 119 145 1992 1979 1970 1973 1997 1994 1970 1986 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1967 - 1998 ANNUAL TOTAL 71035 ANNUAL MEAN 195 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 11000 LOWEST DAILY MEAN 36 ANNUAL SEVEN-DAY MINIMUM 37 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 140900 ANNUAL RUNOFF (CFSM) 2.73 ANNUAL RUNOFF (INCHES) 37.11 10 PERCENT EXCEEDS 329 50 PERCENT EXCEEDS 93 90 PERCENT EXCEEDS 42 143580 393 292 457 1986 179 1977 Jan 22 17000 Sep 22 17000 Sep 22 1998 May 4 29 Apr 11 19 Apr 16 1979 Apr 30 31 Apr 6 20 Apr 13 1979 36900 Sep 22 69000 Sep 16 1975 unknown 36.60 Sep 16 1975 16 Apr 17 1979 284800 211700 5.52 4.11 75.02 55.78 752 600 109 133 36 42 e Estimated 449 RIO CULEBRINAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 O N D J F M A M J J A S 1997 1998 WATER YEAR -- -- 450 RIO CULEBRINAS BASIN 50149100 RIO CULEBRINAS NEAR AGUADA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'03", long 67°09'40", at bridge on Highway 2, 2.3 mi (3.7 km) northeast of Aguada plaza. DRAINAGE AREA.--97.0 mi2 (251.1 km2). PERIOD OF RECORD.--Water years 1958, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DIS- PH OXYGEN, OXYGEN COLI­ CHARGE, SPE- WATER DIS- DEMAND, FORM, STREP­ INST. CIFIC WHOLE SOLVED CHEM- FECAL, TOCOCCI CUBIC CON- FIELD TEMPER- TUR- OXYGEN, (PER- ICAL 0.45 FECAL, FEET DUCT- (STAND- ATURE BID- DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER ITY SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) (00061) (00095) (00400) (00010) (00076) (00300) (00301) (00340) (31616) (31679) OCT 22... 0745 361 7.1 26.0 18 6.8 83 <10 2300 640 MAR 12... 0915 354 8.1 25.0 9.8 6.7 80 <10 K1200 340 JUN 03... 1645 E1500 336 8.2 28.0 160 6.7 85 <10 K12000 4000 SEP 10... 1130 447 292 7.4 26.0 140 6.3 77 <10 51000 5800 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET SULFIDE DIS- DIS­ TION SOLVED FIELD TOTAL SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L AS K) CACO3 AS S) AS SO4) AS CL) (00931) (00935) (00410) (00745) (00945) (00940) OCT 22... 150 51 6.3 12 .4 2.3 130 <1.0 11 13 MAR 12... -- -- -- -- -- -- 150 -- -- -­ JUN 03... 140 49 5.0 9.5 .3 3.2 140 -- 18 11 SEP 10... 130 43 4.6 9.0 .3 2.6 130 <1.0 8.5 9.8 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (70302) (00530) (00620) (00615) (00630) (00610) (00605) OCT 22... <.10 29 203 -- 29 .848 .012 .860 .050 .19 MAR 12... -- -- -- -- 20 .839 .011 .850 .050 .46 JUN 03... <.10 17 197 E798 208 .795 .015 .810 .060 .72 SEP 10... <.10 19 175 211 192 .982 .018 1.00 .080 .38 NITRO- GEN,AM- MONIA + NITRO- NITRO- PHOS- ORGANIC GEN, GEN, PHORUS TOTAL TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) (00625) (00600) (71887) (00665) CHRO­ BARIUM, BORON, CADMIUM MIUM, COPPER, TOTAL TOTAL WATER TOTAL TOTAL ARSENIC RECOV- RECOV- UNFLTRD RECOV- RECOV­ TOTAL ERABLE ERABLE TOTAL ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS B) AS CD) AS CR) AS CU) (01002) (01007) (01022) (01027) (01034) (01042) OCT 22... .24 1.1 4.9 .030 <1 <100 30 <1 3 <10 MAR 12... .51 1.4 6.0 .060 -- -- -- -- -- -­ JUN 03... .78 1.6 7.0 .050 <1 <100 40 <1 4 <10 SEP 10... .46 1.5 6.5 .070 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 451 RIO CULEBRINAS BASIN 50149100 RIO CULEBRINAS NEAR AGUADA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 MANGA- METHY­ IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB­ DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (00720) (32730) (38260) OCT 22... 890 3 220 <.10 <1 <1 <10 <.010 2 <.02 MAR 12... JUN 03... 5500 2 280 <.10 <1 <1 10 <.010 3 <.02 SEP 10... 452 THIS PAGE WAS LEFT BLANK INTENTIONALLY 453 Discharge at Partial-Record Stations in Puerto Rico 454 THIS PAGE WAS LEFT BLANK INTENTIONALLY Q u e b r a d a Q u e b r a d a Quebrada Quebrada Quebrada Quebrada Río Río Río Río Hondo Hondo Río Río Usabón Cejas Arroyata de de La La Plata Plata Convento Doña Higüero Higüero Elena Q ueb r a d a Quebrada Quebrada Quebrada Piña Quebrada Grande Prieta Q u e b r a d a Tigre Quebrada Q u e d bra a La C a t a l ni a COMERÍO CIDRA N ar a n j o Q ue br a da Q ue br a da Cedrito Blanca Represa de Comerío Mula Prieta Q u e b r a d a C i é n a g a del Juicio 043575 0435 0436 043840 043820 044050 043845 043995 043980 043970 043950 043950 043803 043790 EXPLANATION DRAINAGE BASIN BOUNDARY TOWN OR CITY LOW-FLOW STATION AND NUMBER MUNICIPAL BOUNDARY OF COMERÍO Figure 26. Location of low-flow partial-record stations in Comerío, Puerto Rico. 455 PUERTO RICO Study area 0 0 1 1 2 MILES 2 KILOMETERS 456 DISCHARGE AT PARTIAL-RECORD STATIONS As the number of streams on which streamflow information is likely to be desired far exceeds the number of stream-gaging stations feasible to operate at one time, the Geological Survey collects limited streamflow data at sites other than stream-gaging stations. When limited streamflow data are collected on a systematic basis over a period of years for use in hydrologic analyses, the site at which the data are collected is called a partial-record station. Data collected at these partial-record stations are useable in low-flow or floodflow analyses, depending on the type of data collected. In addition, discharge measurements are made at other sites not included in the partial­ record program. These measurements are generally made in times of drought or flood to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellane­ ous sites. Low-flow partial-record stations Measurements of streamflow in the areas covered by this report made at low-flow partial-record stations are given in the following table. These measurements were made during periods of base flow when streamflow is pri­ marily from ground-water storage. These measurements, when correlated with the simultaneous discharge of nearby stream when continuous records are available, will give a picture of the low-flow potentiality of stream. Discharge measurements made at low-flow partial-records stations during water year 1998 PUBLICATION RECORD STATION STATION LOCATION DRAINAGE STREAM­ NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOW ft3/s (m3/s) BASIN Río de La Plata basin 50043500 Quebrada Prieta at Lat 18°12'27", long 66°14'38", 1.16 1/29/98 0745 0.14 barrio Río Hondo, PR Hydrologic Unit 21010005, at (3.00) (0.004) barrio Río Hondo, 0.3 mi (0.5 3/11/98 1045 0.15 Km) upstream of Río de La Plata, (0.004) 1.9 mi (3.0 km) southwest of 3/20/98 1425 1.03 Cerro Lazo, and 1.4 mi (2.2 km) (0.029) southwest from Comerío plaza. 6/09/98 0810 0.20 (0.006) 6/16/98 1350 0.17 (0.005) 6/24/98 1050 0.12 (0.003) 7/14/98 0645 0.07) (0.001) 1/26/99 1200 0.78 (0.022) 2/12/99 0820 0.52 (0.015) 2/24/99 1145 0.61 (0.017) 3/16/99 1145 0.34 (0.010) 50043575 Río Hondo at Highway Lat 18°13'18", long 66°15'07", 9.07 1/29/98 0820 2.82 776 at Río Hondo, PR Hydrologic Unit 21010005, at (23.5) (0.080) barrio Río Hondo on Highway 3/11/98 1000 3.43 776, 0.4 mi (0.6 km) north of (0.097) Escuela Segunda Unidad de Río 3/20/98 1315 8.32 Hondo, 4.3 mi (6.9 km) north- (0.236) east of Barranquitas, and 4.4 6/09/98 0840 5.67 mi (7.1 km) northeast from (0.160) Cañón San Cristóbal. 6/16/98 1250 4.92 (0.139) 6/24/98 1120 4.78 (0.135) 7/14/98 0805 3.77 (0.107) 7/15/98 0850 3.73 (0.106) 1/26/99 1005 13.9 (0.394) 2/12/99 0930 11.9 (0.337) 2/24/99 1050 10.4 (0.294) 3/16/99 1045 9.00 (0.255) 50043600 Río Hondo near Lat 18°12'38", long 66°14'37", 10.5 6/25/98 1045 4.97 Comerío, PR Hydrologic Unit 21010005, at (27.2) (0.141) Highway 156 at barrio Río 7/14/98 0715 3.56 Hondo, 0.6 mi (1.0 km) (0.101) upstream of Río La Plata, and 7/15/98 0810 3.41 1.3 mi (2.1 km) southwest from (0.096) Comerío plaza. 1/26/99 1100 16.1 (0.456) 2/12/99 0845 13.5 (0.382) 2/24/99 1000 10.4 (0.294) 3/16/99 1000 8.23 (0.233) 457 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río de La Plata basin 50043790 Quebrada Piña at Lat 18°13'00", long 66°13'37", 2.31 1/29/98 0935 0.24 Highway 775 at Hydrologic Unit 21010005, at (5.98) (0.007) Comerío, PR Comerío, 0.2 mi (0.3 km) 3/11/98 0850 0.32 upstream of Río de La Plata, (0.009) 0.7 mi (1.1 km) west of Cerro 3/23/98 1205 0.28 Lazo, and 0.3 mi (0.5 km) (0.008) south from Comerío plaza. 6/09/98 0720 0.23 (0.006) 6/15/98 1155 0.16 (0.004) 6/24/98 1215 0.18 (0.005) 7/14/98 0905 0.06 (0.002) 1/26/99 0850 1.77 (0.050) 2/12/99 1110 0.97 (0.027) 2/24/99 0845 0.83 (0.024) 3/16/99 0830 0.54 (0.015) 50043803 Quebrada Convento Lat 18°13'31", long 66°13'36", 0.98 1/29/98 1045 0.71 at Comerío, PR Hydrologic Unit 21010005, at (2.54) (0.020) Comerio, 0.5 mi (0.8 km) south 3/11/98 0750 0.74 of Cerro Magueyes, 0.1 mi (0.2 (0.021) km) upstream from Río de La 6/09/98 0935 0.65 Plata, and 0.3 mi (0.5 km) (0.018) north from Comerío plaza. 6/11/98 1455 0.46 (0.013) 6/24/98 1005 0.54 (0.015) 7/14/98 0930 0.51 (0.016) 1/26/99 0815 1.05 (0.030) 2/09/99 1005 1.02 (0.029) 2/24/99 0805 0.92 (0.026) 3/16/99 0755 0.84 (0.024) 50043820 Quebrada Higüero at Lat 18°14'37", long 66°14'51", 1.19 2/02/98 1520 0.46 Highway 780 at barrio Hydrologic Unit 21010005, at (3.08) (0.013) Doña Elena, PR (2.4 km) northwest of Cerro Magueyes, 0.8 mi (1.3 km) 3/25/98 1035 0.42 northwest of Escuela Segunda (0.012) Unidad de Palomas, and 2.1 mi 6/17/98 1210 0.81 (3.4 km) northwest from (0.023) Comerío plaza. 6/22/98 1315 0.71 (0.020) 7/15/98 0625 0.62 (0.018) 1/25/99 1220 2.06 (0.058) 2/09/99 1125 2.24 (0.063) 2/23/99 1150 1.91 (0.054) 3/15/99 1040 1.71 (0.048) 50043840 Tributario de Quebrada Lat 18°14'10", long 66°14'35", 0.47 2/02/98 1025 0.13 Higüero at barrio Hydrologic Unit 21010005, at (1.22) (0.004) Palomas, PR barrio Palomas, 1.1 mi (1.8 3/10/98 1235 0.15 km) west of Cerro Magueyes, (0.004) 0.2 mi (0.3 km) northwest of 3/23/98 1530 0.15 Escuela Segunda Unidad de (0.004) Palomas, and 1.5 mi (2.4 km) 6/17/98 1310 0.30 from Comerío plaza. (0.008) 6/22/98 1115 0.33 (0.009) 7/15/98 0705 0.18 (0.005) 1/25/99 1315 0.58 (0.016) 2/09/99 1045 0.63 (0.018) 2/23/99 1110 0.53 (0.015) 3/15/99 1130 0.47 (0.013) 458 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río de La Plata basin 50043845 Quebrada Higüero at Lat 18°14'15", long 66°12'55", 3.65 1/29/98 1125 2.54 Highway 156 near Hydrologic Unit 21010005, at (9.45) (0.072) Comerío, PR barrio Palomas, 0.8 mi (1.3 km) 3/10/98 1055 3.05 northeast of Cerro Magueyes, (0.086) 2.1 mi (3.4 km) southwest of 3/17/98 1110 2.16 Cerro La Tiza, and 1.4 mi (2.2 (0.061 km) northeast from Comerío 6/09/98 1030 3.25 plaza. (0.092) 6/11/98 1350 2.53 (0.072) 6/24/98 0920 2.85 (0.081) 7/14/98 1050 2.46 (0.070) 1/25/99 1050 7.77 (0.220) 2/09/99 0905 7.67 (0.217) 2/23/99 1000 6.40 (0.181) 3/15/99 0940 5.53 (0.157) 50043950 Río Arroyata at Lat 18°12'04", long 66°12'34", 9.42 1/28/98 1130 2.12 Highway 7774 Hydrologic Unit 21010005, at (24.4) (0.060) near Cidra, PR barrio Vega Redonda on Highway 3/16/98 1105 2.49 7774, 1.5 mi (2.4 km) northwest (0.070) of Cerro Almirante, 1.6 mi (2.6 6/25/98 0945 1.88 km) north of Cerro Viento (0.053) Caliente, and 1.8 mi (2.9 km) 7/13/98 0915 1.03 southeast of Comerío plaza. (0.029) 2/04/99 1100 9.28 (0.263) 2/11/99 1000 7.88 (0.223) 2/25/99 1035 6.44 (0.182) 3/17/99 1025 4.67 (0.132) 50043970 Quebrada Cejas at Lat 18°12'56", long 66°12'04", 1.29 1/28/98 1310 0.80 barrio Vega Redonda, Hydrologic Unit 21010005, at (3.34) (0.023) PR barrio Vega Redonda, 1.0 mi 3/16/98 1155 0.95 (1.6 km) east of Cerro Lazo, (0.027) 2.2 mi (3.5 km) southwest of 3/18/98 1335 0.68 Cerro La Tiza, and 1.7 mi (2.7 (0.019) km) southeast from Comerío 6/10/98 1625 0.82 plaza. (0.023) 6/25/98 0850 1.56 (0.044) 7/13/98 0950 0.14 (0.004) 2/04/99 1010 2.00 (0.057) 2/11/99 1050 2.03 (0.057) 2/25/99 0940 1.72 (0.049) 3/17/99 0940 1.44 (0.041) 50043980 Río Arroyata at barrio Lat 18°13'30", long 66°12'12", 12.9 1/28/98 1345 2.55 Naranjo, PR Hydrologic Unit 21010005, at (33.4) (0.072) barrio Naranjo, 1.1 mi (1.8 km) 3/16/98 1245 3.39 northeast of Cerro Lazo, 1.8 mi (0.096) (2.9 km) southwest of Cerro La 6/25/98 0805 2.82 Tiza, and 1.6 mi (2.6 km) (0.080) northeast of Comerío plaza. 7/13/98 1025 1.19 (0.034) 2/04/99 0925 12.1 (0.343) 2/11/99 1130 11.0 (0.312) 2/25/99 0855 9.17 (0.260) 3/17/99 0850 7.61 (0.216) 459 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río de La Plata basin 50043995 Quebrada Naranjo at Lat 18°13'54", long 66°12'06", 2.58 1/28/98 1430 1.16 barrio Naranjo, PR Hydrologic Unit 21010005, at (6.68) (0.033) barrio Naranjo, 1.5 mi (2.4 km) 3/16/98 1330 1.29 northeast of Cerro Lazo, 1.4 mi (0.036) (2.2 km) southwest of Cerro La 3/18/98 1430 1.08 Tiza, and 1.8 mi (2.9 km) north- (0.030) east from Comerío plaza. 6/10/98 1540 0.86 (0.024) 6/25/98 0720 1.13 (0.032) 7/13/98 1100 0.85 (0.024) 2/04/99 0835 4.37 (0.124) 2/11/99 1215 3.99 (0.113) 2/25/99 0805 3.43 (0.097) 3/17/99 0800 3.10 (0.088) 50044050 Quebrada Doña Elena Lat 18°15'04", long 66°12'29", 1.28 1/29/98 1220 0.70 at Highway 167 near Hydrologic Unit 21010005, at (3.32) (0.020) Comerío, PR barrio Doña Elena, 0.2 mi (0.3 3/10/98 1010 0.86 km) upstream of Río de La (0.024) Plata, 2.4 mi (3.9 km) south- 3/20/98 1020 0.70 east of Cerro Avispa, 4.3 mi (0.020) (6.9 km) southeast from 6/09/98 1200 0.70 Comerío plaza. (0.020) 6/11/98 1230 0.67 (0.019) 6/24/98 0825 0.62 (0.018) 7/13/98 1145 0.60 (0.017) 7/15/98 1005 0.54 (0.015) 1/25/99 0955 1.76 (0.050) 2/09/99 0820 1.68 (0.048) 2/23/99 0920 1.48 (0.042) 3/15/99 0905 1.36 (0.038) 460 THIS PAGE WAS LEFT BLANK INTENTIONALLY 058010 057750 0578 057725 055330 055120 0543 CAGUAS 055150 053950 053975 0532 053080 053060 053150 052950 052925 50052925 052925 Quebrada Quebrada Q u e b r a d a Q u e b r a d a Sonadora Maracai Naranjito EXPLANATION DRAINAGE BASIN BOUNDARY LOW-FLOW STATION AND NUMBER MUNICIPAL BOUNDARY OF CAGUAS TOWN OR CITY Río Río Río Río Río Río Cañaboncito Caguitas Bairoa Río Río Río Grande Gurabo de Cañas Cañas Arenas Q u e b r a d a Lago Loíza de las Quebradillas Quebrada Beatriz Turabo Turabo Loíza Study area PUERTO RICO Figure 27. Location of low-flow partial-record stations in Caguas, Puerto Rico. 0 0 1 1 2 MILES 2 KILOMETERS 461 462 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50052925 Río Turabo at barrio Lat 18°08'37", long 66°03'05", 1.38 2/24/98 1120 3.23 San Salvador, PR Hydrologic Unit 21010005, at (3.57) (0.091) barrio San Salvador, 2.7 mi 5/13/98 1220 3.16 (4.3 km) southwest of Cerro (0.089) Gregorio, 0.8 mi (1.3 km) 6/16/98 0655 3.20 northwest of Escuela Segunda (0.091) Unidad de Mercedes Palma, and 7/01/98 1025 2.59 2.4 mi (3.9 km) southwest (0.073) from Villa Borinquen. 9/17/98 1130 8.35 (0.236) 2/19/99 0805 3.99 (0.113) 3/05/99 0815 3.15 (0.089) 3/19/99 0735 2.60 (0.074) 4/19/99 0845 2.05 (0.058) 50052950 Quebrada Maracai at Lat 18°08'37", long 66°03'04", 2.31 2/24/98 1200 4.09 barrio San Salvador, Hydrologic Unit 21010005, at (5.98) (0.116) PR barrio San Salvador, 2.7 mi 5/13/98 1140 5.10 (4.3 km) southwest of Cerro (0.144) Gregorio, 0.8 mi (1.3 km) 6/16/98 0735 3.77 northwest of Escuela Segunda (0.107) Unidad de Mercedes Palma, and 7/01/98 1105 3.29 2.4 mi (3.9 km) southwest of (0.093) Villa Borinquen. 9/17/98 1210 5.54 (0.157) 2/19/99 0725 6.49 (0.184) 3/05/99 0730 5.19 (0.147) 3/19/99 0700 4.70 (0.133) 4/19/99 0810 3.45 50053060 Río Turabo at Highway Lat 18°10'45", long 66°02'33", 8.06 2/24/98 0750 12.2 765 at barrio Hydrologic Unit 21010005, at (20.9) (0.346) Borinquen, PR barrio Borinquen, 2.8 mi (4.5 3/19/98 1055 15.3 km) northwest of Cerro Gregorio, (0.433) 3.0 mi (4.8 km) northeast of 5/12/98 1355 13.7 Cerro Las Piñas, and 1.0 mi (0.388) (1.6 km) from El Naranjito. 7/01/98 0840 9.46 (0.268) 2/18/99 1150 15.6 (0.442) 3/04/99 1215 12.8 (0.362) 3/22/99 1055 10.0 (0.283) 4/19/99 1030 8.22 (0.233) 50053080 Quebrada Naranjito at Lat 18°10'56", long 66°02'35", 2.24 2/24/98 0715 1.14 barrio Borinquen, PR Hydrologic Unit 21010005, at (5.80) (0.032) barrio Borinquen, 3.0 mi (4.8 3/19/98 1025 0.95 km) northwest of Cerro Gregorio, (0.027) 3.1 mi (5.0 km) northeast of 5/12/98 1300 0.91 Cerro Las Piñas, and 1.1 mi (0.026) (1.8 km) northwest from El 7/01/98 0805 0.33 Naranjito. (0.009) 2/18/99 1240 1.15 (0.032) 3/04/99 1305 1.17 (0.033) 3/22/99 1140 0.61 (0.017) 4/19/99 1115 0.54 (0.015) 463 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50053150 Quebrada Sonadora Lat 18°10'22", long 66°03'42", 1.20 2/24/98 0900 1.33 at barrio Beatriz, Hydrologic Unit 21010005, at (3.11) (0.038) PR barrio Beatriz, 3.6 mi (5.8 km) 5/14/98 1210 0.98 northwest of Cerro Gregorio, (0.028) 1.8 mi (2.9 km) northeast of 6/16/98 0930 0.90 Cerro Las Piñas, and 1.4 mi (0.025) (2.2 km) southeast from Villa 7/02/98 1130 0.75 Borinquen. (0.021) 9/17/98 1405 1.98 (0.056) 2/19/99 1000 1.76 (0.050) 3/05/99 1000 1.56 (0.044) 3/19/99 0930 1.27 (0.036) 4/20/98 1105 1.06 (0.030) 50053200 Quebrada Beatriz at Lat 18°11'01", long 66°03'52", 4.39 2/24/98 1000 4.59 barrio Beatriz, PR Hydrologic Unit 21010005, at (11.4) (0.130) barrio Beatriz, 4.1 mi (6.6 km) 6/03/98 1045 1.99 northwest of Cerro Gregorio, (0.056) 2.3 mi (3.7 km) northeast of 6/16/98 1025 2.43 Cerro Las Piñas, and 1.6 mi (0.069) (2.6 km) northwest from Villa 7/02/98 1020 2.23 Borinquen. (0.063) 2/19/99 1050 5.74 (0.162) 3/05/99 1055 4.75 (0.134) 3/19/99 1030 3.90 (0.110) 4/20/99 0955 3.00 (0.085) 50053950 Quebrada de Las Lat 18°11'40", long 66°05'25", 3.85 2/04/98 1205 3.57 Quebradillas at Hydrologic Unit 21010005, at (9.97) (0.101) barrio Beatriz, barrio Beatriz, 2.8 mi (4.5 km) 6/04/98 1135 3.01 PR northwest of Cerro Las Piñas, (0.085) 1.8 mi (2.9 km) northeast of 6/16/98 1145 3.31 Las Cruces, and 3.4 mi (5.5 km) (0.094) northwest from Villa Borinquen. 7/02/98 0915 2.41 (0.068) 2/18/99 0935 8.14 (0.230) 3/03/99 1000 6.57 (0.186) 3/04/99 1010 7.77 (0.220) 3/22/99 0910 5.40 (0.153) 4/20/99 0845 4.57 (0.129) 50053975 Quebrada de Las Lat 18°11'37", long 66°04'10", 6.27 2/04/98 1050 4.70 Quebradillas above Hydrologic Unit 21010005, at (16.2) (0.133) Dam at barrio barrio Beatriz, 2.8 mi (4.5 km) 5/26/98 1200 9.15 Turabo, PR northeast of Cerro Las Piñas, (0.259) 2.1 mi (3.4 km) northwest of 6/16/98 1250 4.72 Villa Borinquen, and 3.7 mi (0.137) (6.0 km) southwest from 7/02/98 0845 4.14 Caguas plaza. (0.117) 2/18/99 0825 11.5 (0.326) 3/02/99 0930 12.3 (0.348) 3/04/99 0850 10.5 (0.297) 3/22/99 0810 8.57 (0.242) 4/20/99 0730 6.99 (0.198) 464 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50054300 Río Turabo at Villa Lat 18°12'51", long 66°02'30", 25.0 2/04/98 0945 10.8 del Rey near Caguas, Hydrologic Unit 21010005, at (64.8) (0.306) PR barrio Turabo, 2.5 mi (4.0 km) 6/02/98 1150 11.0 north of Villa Borinquen, 4.8 (0.312) mi (7.7 km) northwest of Cerro 6/16/98 1350 9.72 Gregorio, and 1.6 mi (2.6 km) (0.275) southwest from Caguas plaza. 7/01/98 0650 5.31 (0.150) 9/17/99 1015 37.1 (1.051) 2/18/99 1040 27.0 (0.765) 3/04/99 1110 21.2 (0.600) 3/19/99 1140 14.1 (0.400) 4/19/99 1310 12.1 (0.343) 50055120 Río Cagüitas at Highway Lat 18°14'41", long 66°03'52", 7.44 2/03/98 1140 0.89 156 near Caguas, PR Hydrologic Unit 21010005, at (19.3) (0.025) barrio Cañabón at Highway 156, 3/19/98 0820 1.35 3.4 mi (5.5 km) northeast of (0.038) Los Sumideros, 1.2 mi (1.9 km) 5/19/98 1010 3.51 northeast of Escuela Bunker, (0.099) and 2.0 mi (3.2 km) northwest 6/30/98 1135 1.73 from Caguas plaza. (0.049) 8/05/98 1015 3.04 (0.086) 2/17/99 1200 7.89 (0.223) 3/08/99 1125 6.62 (0.187) 3/18/99 1130 5.48 (0.153) 4/21/99 1200 4.27 (0.121) 50055150 Río Cañaboncito at Lat 18°12'53", long 66°04'31", 1.61 2/04/98 0845 0.65 barrio Cañaboncito, Hydrologic Unit 21010005, at (4.17) (0.018) PR barrio Cañaboncito, 2.6 mi 3/19/98 0910 0.83 (4.2 km) southeast of Los (0.024) Sumideros, 4.1 mi (6.6 km) 5/21/98 1035 0.50 northeast of Cerro Las Piñas, (0.014) and 3.0 mi (4.8 km ) Southwest 7/02/98 0715 0.58 from Caguas plaza. (0.016) 8/05/98 1125 0.64 (0.018) 9/18/98 1140 0.74 (0.021) 2/18/99 0715 2.75 (0.078) 3/04/99 0740 2.46 (0.070) 3/22/99 0715 1.65 (0.047) 4/19/99 1225 1.27 (0.036) 50055330 Río Bairoa at barrio Lat 18°15'44", long 66°04'31", 3.03 2/03/98 1050 2.38 Bairoa near Caguas, PR Hydrologic Unit 21010005, at (7.85) (0.067) barrio Bairoa, 0.5 mi (0.8 km) 3/19/98 0725 2.89 northwest of Las Carolinas, (0.082) 2.8 mi (4.5 km) southwest of 5/11/98 1310 2.66 Cerro La Marquesa, and 1.9 mi (0.075) (3.0 km) northeast of Aguas 6/30/98 1045 2.38 Buenas plaza. (0.067) 8/05/98 0930 1.91 (0.054) 9/18/98 1400 3.18 (0.090) 2/17/99 1250 6.15 (0.174) 3/08/99 1215 7.27 (0.206) 3/18/99 1215 6.09 (0.172) 4/21/99 1245 4.60 (0.130) 465 DISCHARGE AT PARTIAL-RECORD STATION Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50057725 Río Cañas at barrio Lat 18°16'54", long 66°04'41", 1.39 2/03/98 0725 0.30 Jagüeyes near Aguas Hydrologic Unit 21010005, at (3.60) (0.008) Buenas, PR barrio Jagüeyes, 2.8 mi (4.5 3/18/98 0900 0.54 km) east of Cerro La Marquesa, (0.015) 1.8 mi (2.9 km) northwest of 6/30/98 0655 0.37 Las Carolinas, and 2.3 mi, (0.010) (3.7 km) northeast of Aguas 2/17/99 0815 1.98 Buenas plaza. (0.056) 3/08/99 0835 1.69 (0.048) 3/18/99 0810 1.61 (0.045) 4/21/99 0815 1.25 (0.035) 50057750 Tributario de Río Lat 18°17'56", long 66°03'49", 0.68 2/03/98 0815 0.24 Cañas at barrio Hydrologic Unit 21010005, at (1.76) (0.007) Río Cañas, PR barrio Río Cañas, 3.3 mi (5.3 3/18/98 0950 0.24 km) east of Cerro Marquesa, (0.007) 1.7 mi (2.7 km) north of Las 6/30/98 0730 0.21 Carolinas, and 3.1 mi (5.0 km) (0.006) northeast from Aguas Buenas 2/17/99 0900 0.86 plaza. (0.024) 3/08/99 0910 0.90 (0.025) 3/18/99 0850 0.76 (0.022) 4/21/99 0855 0.54 (0.015) 50057800 Río Cañas at barrio Lat 18°17'09", long 66°04'21", 2.74 2/03/98 0850 0.86 Jagüeyes near Río Hydrologic Unit 21010005, at (7.10) (0.024) Cañas, PR barrio Jagüeyes, 2.7 mi (4.3 3/18/98 1025 1.06 km) northeast of Cerro (0.030) Marquesa, 2.0 mi (3.2 km) 5/05/98 0925 0.94 northwest of Las Carolinas, (0.027) and 2.8 mi (4.5 km) northeast 6/30/98 0825 0.77 from Aguas Buenas plaza. (0.022) 11/19/98 1155 9.15 (0.259) 2/17/99 0730 3.72 (0.105) 3/08/99 0735 2.90 (0.082) 3/18/99 0720 2.97 (0.084) 5/21/99 0715 2.10 (0.059) 50058010 Río Cañas at Highway 1 Lat 18°17'41", long 66°03'02", 3.60 2/03/98 0940 1.14 at barrio Río Cañas, Hydrologic unit 21010005, at (9.32) (0.032) PR barrio Río Cañas at Highway 1, 3/18/98 1115 1.64 2.7 mi (4.3 km) northeast of (0.046) Las Carolinas, 4.2 mi (6.8 km) 5/05/98 1045 1.11 northeast of Cerro Marquesa, (0.031) and 4.3 mi (6.9 km) northeast 6/30/98 0910 1.04 from Aguas Buenas plaza. (0.029) 11/19/98 1425 11.6 (0.328) 2/17/99 1000 5.24 (0.148) 3/08/99 0940 4.79 (0.136) 3/18/99 0935 4.31 (0.122) 4/21/99 0930 4.14 (0.117) 466 THIS PAGE WAS LEFT BLANK INTENTIONALLY Río Río Río Río Río Río Río Grande Grande de Cañas Lago Loíza Q u b r a d a Qubrada P as t r a n a Qubrada Q u e b r a d a Arenas Bairoa Gurabo Caguitas Loíza Canóvanas Canóvanillas M a r a c u t o TRUJILLO ALTO CANÓVANAS Laguna San José Laguna La Torrecilla Laguna de Piñones Caño de Martín Peña PUERTO RICO Study area ATLANTIC OCEAN 059210 EXPLANATION DRAINAGE BASIN BOUNDARY TOWN OR CITY LOW-FLOW STATION AND NUMBER MUNICIPAL BOUNDARY OF CAROLINA Figure 28. Location of low-flow partial-record stations in Carolina, Puerto Rico. CAROLINA Qubrada Blasina 467 0 0 1 1 2 2 3 3 4 MILES 4 KILOMETERS 059210 0602 060195 060160 061325 0612 060190 468 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50059210 Quebrada Grande at Lat 18°21'22", long 65°59'23", 12.9 2/26/98 0735 5.89 barrio Dos Bocas, Hydrologic Unit 21010005, at (33.4) (0.167) PR barrio Dos Bocas, 0.5 mi (0.8 3/17/98 1420 7.54 km) upstream of Río Grande de (0.214) Loíza, 4.0 mi (6.4 km) north- 6/29/98 1330 4.19 west of Cerro Gordo, and 1.5 (0.119) mi (2.4 km) northwest from 8/06/98 1420 8.21 Canto de Sapo. (0.232) 2/22/99 1350 9.63 (0.273) 3/09/99 1400 9.60 (0.272) 3/23/99 1335 7.96 (0.225) 4/22/99 1340 5.56 (0.157) 50060160 Quebrada Maracuta Lat 18°21'07", long 65°57'00", 6.31 2/25/98 1030 1.93 at barrio Santa Hydrologic Unit 21010005, at (16.3) (0.055) Cruz, PR barrio Santa Cruz, 1.6 mi 3/17/98 0940 1.77 (2.6 km) northwest of Cerro (0.050) Gordo, 1.2 mi (1.9 km) north- 6/29/98 0900 1.31 east from Canto de Sapo, and (0.037) 1.2 mi (1.9 km) northeast 8/06/98 1010 1.53 From Mariana. (0.046) 2/22/99 0915 3.37 (0.095) 3/09/99 0950 3.49 (0.099) 3/23/99 0925 2.82 (0.080) 4/22/99 0900 1.90 (0.054) 50060190 Quebrada Pastrana Lat 18°20'23", long 6557'35", 0.79 2/25/98 0940 0.50 near Mariana at Hydrologic Unit 21010005, at (2.05) (0.014) barrio Cacaos, PR barrio Cacaos, 1.8 mi (2.9 km) 3/17/98 1025 0.34 northwest of Cerro Gordo, 0.8 (0.010) mi (1.3 km) southeast of Canto 4/07/98 1340 0.35 de Sapo, and 5.7 mi (9.2 km) (0.010) northeast from Gurabo plaza. 6/29/98 0735 0.37 (0.010) 8/06/98 0940 0.52 (0.015) 8/07/98 1020 0.56 (0.016) 2/22/99 0835 0.69 (0.020) 3/09/99 0910 0.72 (0.020) 3/23/99 0845 0.50 (0.014) 4/22/98 0820 0.57 (0.016) 50060195 Quebrada Pastrana Lat 18°21'38", long 65°57'40", 2.04 2/25/98 0835 0.58 near mouth at Hydroloigc unit 21010005, at (5.28) (0.016) barrio Cacaos, PR barrio Cacaos, 2.6 mi (4.2 km) 3/17/98 0855 0.63 northwest of Cerro Gordo, 0.9 (0.018) mi (1.4 km) northeast of Canto 4/07/98 1130 0.27 de Sapo, and 2.6 mi (4.2 km) (0.008) southwest from Cambute. 6/29/98 0750 0.67 (0.019) 8/05/98 1120 1.92 (0.054) 8/06/98 0850 1.46 (0.041) 2/22/99 0750 1.39 (0.039) 3/09/99 0820 1.30 (0.037) 3/23/99 0805 0.96 (0.027) 4/22/99 0730 0.86 (0.024) 469 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM NUMBER NAME AND AREA mi2 (km2) DATE TIME FLOWS ft3/s (m3/s) BASIN Río Grande de Loíza basin 50060200 Quebrada Maracuta at Lat 18°22'11", long 65°57'28", 10.2 2/25/98 0735 3.70 Trujillo Bajo, PR Hydroloigc unit 21010005, at (26.4) (0.105) bridge on Highway 853, and 3/17/98 0815 3.49 0.3 mi (0.5 km) above Junction (0.099) with Río Grande de Loíza. 6/29/98 0700 2.80 (0.079) 8/06/98 0800 4.46 (0.126) 2/22/99 0700 5.40 (0.153) 3/09/99 0730 5.67 (0.160) 3/23/99 0715 4.02 (0.114) 4/97/99 0630 4.97 (0.141) 50061200 Río Canovanillas Lat 18°19'03", long 65°54'16", 9.10 2/25/98 1355 3.20 at Carruzos, PR Hydrologic Unit 21010005, at (23.6) (0.091) bridge on road 500 ft (152 m) 3/17/98 1310 3.13 off of Highway 185, and 0.7 (0.089) mi (1.1 km) east of Jesús T. 4/17/98 1335 7.46 Piñero school. (0.211) 6/29/98 1210 1.89 (0.054) 8/06/98 1310 2.26 (0.064) 8/14/98 1145 2.45 (0.069) 2/22/99 1240 6.56 (0.186) 3/09/99 1255 6.33 (0.179) 3/23/99 1225 6.32 (0.179) 4/22/99 1235 3.34 (0.094) 50061325 Río Canovanillas at Lat 18°21'51", long 65°55'09", 15.0 2/25/98 1120 5.18 barrio Canovanillas, Hydrologic Unit 21010005, at (38.8) (0.147) PR barrio Canovanillas, 3.6 mi 3/17/98 1105 5.53 (5.8 km) northwest of Cerro (0.157) Pitahaya, 2.2 mi (3.5 km) 4/13/98 1240 15.7 northeast of Cerro Gordo, and (0.445) 1.6 mi (2.8 km) southwest 6/29/98 0950 3.00 from Canóvanas plaza. (0.085) 8/06/98 1110 3.29 (0.093) 8/12/98 1245 4.88 (0.138) 2/22/99 1010 9.69 (0.274) 3/09/99 1045 8.57 (0.242) 3/23/99 1020 7.27 (0.206) 4/22/99 0955 5.34 (0.151) 470 THIS PAGE WAS LEFT BLANK INTENTIONALLY 471 Water-Quality at Partial Record Stations in Puerto Rico 472 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION Water-quality partial-record stations are particular sites where chemical-quality, biological and or sediment data are collected systematically over a period of years for use in hydrological analysis. The data are collected usually less tan quarterly. WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, COLI­ SPE- WATER TRANS- DIS- FORM, CIFIC WHOLE PAR- SOLVED FECAL, SAM- TEMPER- CON- FIELD ENCY OXYGEN, (PER- 0.45 PLING ATURE DUCT- (STAND- (SECCHI DIS- CENT UM-MF DATE TIME DEPTH WATER ANCE ARD DISK) SOLVED SATUR- (COLS./ (FEET) (DEG C) (US/CM) UNITS) (IN) (MG/L) ATION) 100 ML) (00003) (00010) (00095) (00400) (00077) (00300) (00301) (31616) RIO DE GUAJATACA BASIN 50010720 LAGO GUAJATACA NO.3 NR MOUTH NR QUEBRADILLAS,PR (LAT 180 22’05"N LONG 660 54’ 36"W) DEC 03... 0850 1.00 27.3 273 7.9 37.0 11.8 148 K13 MAR 18... 0900 1.00 26.3 312 8.0 51.0 10.5 132 K20 JUL 29... 0935 1.00 28.7 297 7.6 48.0 6.1 81 K4 RIO GRANDE DE ARECIBO BASIN 50025110 LAGO DOS BOCAS NO.3 AT WEST BRANCH NR UTUADO,PR (LAT 180 19’15"N LONG 660 40’ 11"W) DEC 08... 0830 1.00 26.4 238 7.6 37.0 6.7 83 K130 MAR 19... 1000 1.00 27.3 275 8.5 34.0 9.8 123 240 JUL 23... 0915 1.00 29.1 248 8.0 17.0 8.9 117 K120 RIO DE LA PLATA BASIN 50039900 LAGO CARITE NO.3 ON RIO DE LA PLATA NR CAYEY,PR (LAT 18005’04"N LONG 660 06’ 03"W) NOV 25... 0905 1.00 24.8 96 7.6 30.0 7.7 98 K26 MAR 24... 1035 1.00 24.2 121 8.5 42.0 9.0 112 44 JUL 16... 1015 1.00 28.6 114 7.3 40.0 7.53 103 K11 50044400 LAGO LA PLATA NO.5 NR MOUTH NR NARANJITO, PR (LAT 18019’33"N LONG 660 12’ 28"W) NOV 20... 1020 1.00 27.4 265 7.6 36.0 9.0 113 K72 MAR 26... 1000 1.00 27.1 408 8.2 42.0 12.8 160 64 JUL 22... 1015 1.00 29.6 422 8.0 15.0 7.2 96 K130 RIO DE BAYAMON BASIN 50047537 LAGO DE CIDRA NR RIO BAYAMON MOUTH (LAT 180 11’ 02"N LONG 660 08’ 6"W) DEC 01... 1015 1.00 25.9 211 7.3 31.0 6.5 83 K8 MAR 23... 1215 1.00 25.8 255 8.4 24.0 9.0 115 56 JUL 21... 0955 1.00 27.8 256 7.4 14.0 5.1 68 550 RIO GRANDE DE LOIZA BASIN 50057500 LAGO LOIZA NO.4 NR MOUTH NR CAGUAS, PR (LAT 180 16’ 51"N LONG 66O 00’ 35"W) NOV 21... 1130 1.00 28.0 293 7.2 6.00 5.3 68 490 MAR 25... 1030 1.00 27.4 264 6.8 4.00 4.6 57 500 JUL 24... 1035 1.00 29.9 304 7.1 10.0 5.5 73 84 -- -- -- 473 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 ANC RESIDUE STREP- WATER TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ TOCOCCI UNFLTRD AT 105 GEN, GEN, GEN, GEN, GEN, FECAL, FET DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC (COLS. FIELD SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE PER MG/L AS PENDED (MG/L (MG/L (MG/L (MG/L (MG/L 100 ML) CACO3 (MG/L) AS N) AS N) AS N) AS N) AS N) (31679) (00410) (00530) (00620) (00615) (00630) (00610) (00605) RIO GUAJATACA BASIN-Continued 50010720 LAGO GUAJATACA NO.3 NR MOUTH NR QUEBRADILLAS,PR (LAT 180 22’ 05"N LONG 660 54’ 36"W) DEC 03... K8 120 <1 <.010 <.020 .080 .92 MAR 18... 90 130 1 <.010 .210 .060 .56 JUL 29... K2 146 <1 <.010 <.020 .010 .56 RIO GRANDE DE ARECIBO BASIN-Continued 50025110 LAGO DOS BOCAS NO.3 AT WEST BRANCH NR UTUADO,PR (LAT 180 19’ 15"N LONG 660 40’ 11"W) DEC 08... 44 85 -- .533 .017 .550 .080 .36 MAR 19... K29 90 6 .253 .027 .280 .070 .51 JUL 23... 30 85 9 .406 .020 .430 .030 .64 RIO DE LA PLATA BASIN-Continued 50039900 LAGO CARITE NO.3 ON RIO DE LA PLATA NR CAYEY,PR (LAT 180 05’ 04"N LONG 660 06’ 03"W) NOV 25... 210 31 <1 -- <.010 <.020 .030 .24 MAR 24... K28 36 58 .010 .010 <.020 .040 .35 JUL 16... K20 35 7 -- <.010 <.020 .020 -­ 50044400 LAGO LA PLATA NO.5 NR MOUTH NR NARANJITO, PR (LAT 180 19’ 33"N LONG 660 12’ 28"W) NOV 20... 44 92 1 .706 .034 .740 .020 .44 MAR 26... 42 140 -- .020 .010 .030 .070 .68 JUL 22... K10 131 15 .380 .020 .040 .010 .39 RIO DE BAYAMON BASIN-Continued 50047537 LAGO DE CIDRA NR RIO BAYAMON MOUTH (LAT 180 11’ 02"N LONG 66008’ 06"W) DEC 01... K15 77 <1 -- <.010 <.020 .020 .65 MAR 23... K8 84 26 .420 .080 .500 1.20 .50 JUL 21... 690 79 28 .221 .05 .27 .68 .56 RIO GRANDE DE LOIZA BASIN-Continued 50057500 LAGO LOIZA NO.4 NR MOUTH NR CAGUAS, PR (LAT 180 16’ 51"N LONG 660 00’ 35"W) NOV 21... K120 88 40 -- <.010 1.80 .140 .83 MAR 25... K170 69 54 .448 .042 .490 .080 JUL 24... K110 80 19 1.51 .09 1.6 .35 .75 474 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- CHLOR-A CHLOR-B GEN,AM- PHYTO- PHYTO­ MONIA + NITRO- NITRO- PHOS- PLANK- PLANK- PLANK- PLANK­ ORGANIC GEN, GEN, PHORUS TON TON TON TON TOTAL TOTAL TOTAL TOTAL CHROMO CHROMO BIOMASS BIOMASS DATE (MG/L (MG/L (MG/L (MG/L FLUOROM FLUOROM ASH WT DRY WT AS N) AS N) AS NO3) AS P) (UG/L) (UG/L) (MG/L) (MG/L) (00625) (00600) (71887) (00665) (70953) (70954) (81353) (81354) RIO GUAJATACA BASIN-Continued 50010720 LAGO GUAJATACA NO.3 NR MOUTH NR QUEBRADILLAS,PR (LAT 180 22’ 5"N LONG 660 54’ 36"W) DEC 03... 1.0 1.1 4.9 .050 11 .1 271 276 MAR 18... .62 .83 3.7 .020 23 .5 274 284 JUL 29... .57 .68 3.0 .04 8.5 2.1 536 549 RIO GRANDE DE ARECIBO BASIN-Continued 50025110 LAGO DOS BOCAS NO.3 AT WEST BRANCH NR UTUADO,PR (LAT 180 19’ 15"N LONG 660 40 ’11"W) DEC 08... .44 .99 4.4 .030 5.10 .4 260 260 MAR 19... .58 .86 3.8 .040 8.4 .4 267 274 JUL 23... .67 1.1 4.9 .11 28 2.8 372 386 RIO DE LA PLATA BASIN-Continued 50039900 LAGO CARITE NO.3 ON RIO DE LA PLATA NR CAYEY,PR (LAT 180 05’ 04"N LONG 660 06’ 03"W) NOV 25... .27 -- -- <.020 3.9 .3 259 264 MAR 24... -- -- -- -- 6.9 .7 278 285 JUL 16... <.20 -- -- .02 6.5 1.7 611 623 50044400 LAGO LA PLATA NO.5 NR MOUTH NR NARANJITO, PR (LAT 180 19’ 33"N LONG 660 12’ 28"W) NOV 20... .46 1.2 5.3 .070 5.7 .7 265 272 MAR 26... -- -- -- -- 6.1 .4 240 251 JUL 22... -- -- -- -- 6.5 .1 393 403 RIO DE BAYAMON BASIN-Continued 50047537 LAGO DE CIDRA NR RIO BAYAMON MOUTH (LAT 180 11’ 02"N LONG 660 08’ 06"W) DEC 01... .67 -- -- .050 14 1.4 269 275 MAR 23... -- -- -- -- 14 2.1 272 282 JUL 21... .66 .93 4.1 .03 8.3 .9 544 558 RIO GRANDE DE LOIZA BASIN-Continued 50057500 LAGO LOIZA NO.4 NR MOUTH NR CAGUAS, PR (LAT 180 16’ 51"N LONG 660 00’ 35"W) NOV 21... .97 2.8 12 .270 17 .9 298 308 MAR 25... -- -- -- -- 1.6 <.1 1420 1460 JUL 24... 1.1 2.7 12 .34 7.6 1.2 567 583 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 475 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PH OXYGEN, COLI­ SPE- WATER TRANS- DIS- FORM, STREP­ CIFIC WHOLE PAR- SOLVED FECAL, TOCOCCI SAM- TEMPER- CON- FIELD ENCY OXYGEN, (PER- 0.45 FECAL, PLING ATURE DUCT- (STAND- (SECCHI DIS- CENT UM-MF (COLS. DATE TIME DEPTH WATER ANCE ARD DISK) SOLVED SATUR- (COLS./ PER (FEET) (DEG C) (US/CM) UNITS) (IN) (MG/L) ATION) 100 ML) 100 ML) (00003) (00010) (00095) (00400) (00077) (00300) (00301) (31616) (31679) RIO DE LA PLATA BASIN-Continued 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14’ 01"W) NOV 20... 0915 1.00 27.6 254 7.7 63.0 8.9 112 48 K33 20... 0930 48.0 24.3 185 7.0 MAR 26... 0930 1.00 27.3 313 7.1 82.0 8.3 103 44 K15 26... 0935 72.0 23.8 209 6.6 JUL 22... 1145 1.00 29.1 341 6.94 113 .2 2 K19 K21 22... 1200 48.0 24.3 249 6.9 RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) DEC 01... 0945 1.00 26.1 203 7.1 42.0 6.7 86 K14 K4 01... 0950 48.0 23.9 148 7.0 -- -- -- -- -­ MAR 23... 1135 1.00 25.8 242 8.5 32.0 9.2 117 K20 <2 23... 1145 52.0 23.0 174 7.2 -- -- -- -- -­ JUL 21... 0900 1.00 28.0 248 7.3 24.0 3.2 43 K180 100 21... 0910 42.0 23.7 229 7.0 -- -- -- -- -­ RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’ 47"W) NOV 21... 1100 1.00 28.8 254 7.1 9.00 5.4 70 K140 84 21... 1105 36.0 26.1 206 7.1 -- -- -- -- -­ MAR 25... 1000 1.00 27.1 235 6.6 4.00 4.0 50 K32 K150 25... 1005 56.0 25.3 316 6.4 -- -- -- -- -­ JUL 24... 1015 1.00 29.8 332 6.9 17.0 3.9 51 K110 84 24... 1020 35.0 26.8 179 6.8 -- -- -- -- -­ 476 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 HARD- MAGNE- NESS CALCIUM SIUM, SODIUM, TOTAL DIS- DIS- DIS- (MG/L SOLVED SOLVED SOLVED DATE AS (MG/L (MG/L (MG/L CACO3) AS CA) AS MG) AS NA) (00900) (00915) (00925) (00930) ANC SODIUM POTAS- WATER CHLO­ AD- SIUM, UNFLTRD SULFATE RIDE, SORP- DIS- FET DIS- DIS­ TION SOLVED FIELD SOLVED SOLVED RATIO (MG/L MG/L AS (MG/L (MG/L AS K) CACO3 AS SO4) AS CL) (00931) (00935) (00410) (00945) (00940) RIO DE LA PLATA BASIN-Continued 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14’ 01"W) NOV 20... 92 23 8.4 16 .7 2.7 87 13 20 20... 65 17 5.8 11 .6 2.8 56 11 15 MAR 26... 65 16 6.1 11 .6 2.8 61 9.5 14 26... 78 18 7.0 18 .9 2.4 98 12 21 JUL 22... 120 27 12 20 .8 2.8 116 12 23 22... 89 22 8.3 13 .6 2.7 123 9.3 15 RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) DEC 01... 61 12 7.3 17 1 3.5 71 5.2 17 01... 74 20 5.8 10 .5 2.4 69 8.7 10 MAR 23... 70 15 7.6 17 .9 3.0 80 7.1 18 23... 46 9.9 5.1 12 .8 3.5 90 7.5 11 JUL 21... 75 16 8.6 19 1 2.3 78 7.3 18 21... 64 14 6.9 15 .8 3.2 78 7.1 13 RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’47"W) NOV 21... 80 20 7.5 19 .9 3.4 80 14 21 21... 64 16 6.0 15 .8 3.3 64 11 17 MAR 25... 61 15 6.7 15 .8 3.3 57 10 14 25... 59 15 5.4 15 .9 2.7 61 11 16 JUL 24... 94 23 8.7 26 1 3.7 98 14 26 24... 58 15 5.3 14 .8 3.5 99 10 16 477 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 SOLIDS, RESIDUE FLUO- SILICA, SUM OF TOTAL NITRO- NITRO- NITRO- NITRO- NITRO­ RIDE, DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, DIS- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED (MG/L DIS- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SIO2) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) (00950) (00955) (70301) (00530) (00620) (00615) (00630) (00610) (00605) RIO DE LA PLATA BASIN-Continued 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’18’N LONG 660 14’ 01"W) NOV 20... .1 18 153 <1 .160 .010 .170 <.010 -­ 20... .2 15 112 -- -- -- -- -- -­ MAR 26... .2 23 119 <1 .120 .140 .260 .040 .56 26... .1 14 151 -- -- -- -- -- -­ JUL 22... .1 20 188 <1 -- <.010 <.020 .020 -­ 22... .1 16 139 -- -- -- -- -- -­ RIO DE BAYAMON BASIN-Continued ’ 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) DEC 01... <.1 17 122 1 -- <.010 <.020 .040 .52 01... <.1 23 120 -- -- -- -- -- -­ MAR 23... <.1 16 133 52 .280 .020 .300 .020 .28 23... <.1 11 114 -- -- -- -- -- -­ JUL 21... .1 21 139 9 .114 .030 .140 .480 -­ 21... <.1 16 130 -- -- -- -- -- -­ RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19 ’29"N LONG 660 00’ 47"W) NOV 21... .1 25 156 17 -- <.010 1.60 .060 .65 21... .1 19 126 -- -- -- -- -- -­ MAR 25... .1 17 110 11 .460 <.010 .460 .180 .50 25... <.1 18 120 -- -- -- -- -- -­ JUL 24... .1 29 189 7 .776 .080 .860 .140 .70 24... <.1 19 116 -- -- -- -- -- -­ -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 478 MISCELLANEOUS STATION ANALYSES ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATION WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 NITRO- GEN,AM- NITRO- MONIA + NITRO- GEN, ORGANIC GEN, NITRATE TOTAL TOTAL TOTAL DATE (MG/L (MG/L (MG/L AS N) AS N) AS NO3) (00625) (00600) (71850) CHLOR-A CHLOR-B PHYTO- PHYTO­ NITRO- PHOS- PLANK- PLANK- PLANK- PLANK­ GEN, PHORUS TON TON TON TON TOTAL TOTAL CHROMO CHROMO BIOMASS BIOMASS (MG/L (MG/L FLUOROM FLUOROM ASH WT DRY WT AS NO3) AS P) (UG/L) (UG/L) (MG/L) (MG/L) (71887) (00665) (70953) (70954) (81353) (81354) RIO DE LA PLATA BASIN-Continued 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14’ 01"W) NOV 20... .56 .73 3.2 .030 15 1.8 266 271 20... MAR 26... .60 .86 3.8 .160 5.60 <.1 260 270 26... JUL 22... <.20 .03 1.3 <.1 277 283 22... RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) DEC 01... .56 -- -- -- .030 12 .6 270 276 01... -- -- -- -- -- -- -- -- -­ MAR 23... .30 .60 1.5 2.8 .020 10 1.3 270 278 23... -- -- -- -- -- -- -- -- -­ JUL 21... .46 .70 1.8 2.6 .030 6.6 .9 344 353 21... -- -- -- -- -- -- -- -- -­ RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’ 47"W) NOV 21... .71 2.3 -- 10 .100 9.1 .4 271 278 21... -- -- -- -- -- -- -- -- -­ MAR 25... .40 .40 1.8 .070 3.1 .3 250 260 25... -- -- -- -- -- -- -- -- -­ JUL 24... .84 1.7 -- 7.5 .17 13 2.3 392 403 24... -- -- -- -- -- -- -- -- -­ 479 MISCELLANEOUS STATION ANALYSES PESTICIDE ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL RECORDS STATIONS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 CHLOR­ DANE, P,P'- P,P'- ENDO­ TECH- DDD P,P'- DDT DI- DI- SULFAN PCB, ALDRIN, NICAL UNFILT DDE, UNFILT AZINON, ELDRIN I DATE TIME TOTAL TOTAL TOTAL RECOVER TOTAL RECOVER TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39516) (39330) (39350) (39360) (39365) (39370) (39570) (39380) (39388) RIO GUAJATACA BASIN-Continued 50010790 LAGO GUAJATACA NO.1 NR DAM NR QUEBRADILLAS,PR (LAT 180 23’ 56"N LONG 660 55’ 23"W) JUL 29... 1000 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 RIO GRANDE DE ARECIBO BASIN-Continued 50020050 LAGO GARZAS NO.1 NR DAM NR ADJUNTAS,PR (LAT 180 08’ 21"N LONG 660 44’ 35"W) JUL 28... 1200 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 50027090 LAGO DOS BOCAS NO.1 NR DAM NR UTUADO,PR (LAT 180 20’ 09"N LONG 660 40’04"W) JUL 23... 0945 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 RIO DE LA PLATA BASIN-Continued 50039950 LAGO CARITE NO.1 NR DAM NR CAYEY, P.R. (LAT 180 04’ 39"N LONG 660 06’ 19"W) JUL 16... 1100 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14’ 01"W) JUL 22... 1145 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) JUL 21... 0900 <.100 <.010 <.100 <.010 <.010 <.010 <.010 <.010 <.010 RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’ 47"W) JUL 24... 1015 <.100 <.010 <.100 <.010 <.010 <.010 .018 <.010 <.010 480 MISCELLANEOUS STATION ANALYSES PESTICIDE ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL RECORDS STATIONS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 ENDRIN HEPTA- METH- METHYL METHYL WATER HEPTA- CHLOR MALA- OXY- PARA- TRI­ UNFLTRD ETHION, CHLOR, EPOXIDE LINDANE THION, CHLOR, THION, THION, MIREX, DATE REC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39390) (39398) (39410) (39420) (39340) (39530) (39480) (39600) (39790) (39755) RIO GUAJATACA BASIN-Continued 50010790 LAGO GUAJATACA NO.1 NR DAM NR QUEBRADILLAS,PR (LAT 180 23’ 56"N LONG 660 55’ 23"W) JUL 29... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 RIO GRANDE DE ARECIBO BASIN-Continued 50020050 LAGO GARZAS NO.1 NR DAM NR ADJUNTAS,PR (LAT 180 08’ 21"N LONG 660 44’ 35"W) JUL 28... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 50027090 LAGO DOS BOCAS NO.1 NR DAM NR UTUADO,PR (LAT 180 20’ 09"N LONG 660 40’ 04"W) JUL 23... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 RIO DE LA PLATA BASIN-Continued 50039950 LAGO CARITE NO.1 NR DAM NR CAYEY, P.R. (LAT 180 04’ 39"N LONG 660 06’ 19"W) JUL 16... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14" 01W) JUL 22... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’24"W) JUL 21... <.010 <.010 <.010 <.010 <.010 <.010 <.010 <.010 -- <.010 RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’ 47"W) JUL 24... <.010 <.010 <.010 <.010 <.010 .008 <.010 <.010 -- <.010 481 MISCELLANEOUS STATION ANALYSES PESTICIDE ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL RECORDS STATIONS WATER-QUALITY DATA, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 PARA- PCNS PER- TOX- TOTAL THION, UNFILT THANE APHENE, TRI- 2,4-D, 2,4,5-T 2,4-DP SILVEX, DATE TOTAL RECOVER TOTAL TOTAL THION TOTAL TOTAL TOTAL TOTAL (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (39540) (39250) (39034) (39400) (39786) (39730) (39740) (82183) (39760) RIO GUAJATACA BASIN-Continued 50010790 LAGO GUAJATACA NO.1 NR DAM NR QUEBRADILLAS,PR (LAT 180 23’ 56"N LONG 660 55’ 23"W) JUL 29... <.010 <.100 <.100 <1.00 <.010 .173 <.010 <.010 <.010 RIO GRANDE DE ARECIBO BASIN-Continued 50020050 LAGO GARZAS NO.1 NR DAM NR ADJUNTAS,PR (LAT 180 08’ 21"N LONG 660 44’ 35"W) JUL 28... <.010 <.100 <.100 <1.00 <.010 .024 <.010 <.010 <.010 50027090 LAGO DOS BOCAS NO.1 NR DAM NR UTUADO,PR (LAT 180 20’ 09"N LONG 660 40’ 04"W) JUL 23... <.010 <.100 <.100 <1.00 <.010 .109 <.010 <.010 <.010 RIO DE LA PLATA BASIN-Continued 50039950 LAGO CARITE NO.1 NR DAM NR CAYEY, P.R. (LAT 180 04’ 39"N LONG 660 06’ 19"w) JUL 16... <.010 <.100 <.100 <1.00 <.010 <.010 <.010 <.010 <.010 50044950 LAGO LA PLATA NO.3 NR DAM NR NARANJITO, PR (LAT 180 20’ 18"N LONG 660 14’ 01"W) JUL 22... <.010 <.100 <.100 <1.00 <.010 <.010 <.010 <.010 <.010 RIO DE BAYAMON BASIN-Continued 50047549 LAGO DE CIDRA NR DAM (LAT 180 11’ 52"N LONG 660 08’ 24"W) JUL 21... <.010 <.100 <.100 <1.00 <.010 .010 <.010 <.010 <.010 RIO GRANDE DE LOIZA BASIN-Continued 50058800 LAGO LOIZA NO.7 NR DAM NR TRUJILLO ALTO, PR (LAT 180 19’ 29"N LONG 660 00’ 47"W) JUL 24... <.010 <.100 <.100 <1.00 <.010 .157 <.010 <.010 <.010 482 THIS PAGE WAS LEFT BLANK INTENTIONALLY 483 Ground-Water Records for Puerto Rico --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 484 GROUND-WATER LEVELS RIO GUAJATACA BASIN 182925067031100. Local number, OT-1. LOCATION.--Lat 18°29'25", long 67°03'11", Hydrologic Unit 21010002, 0.15 mi northwest of Hwy 472, 1.90 mi northwest of the intersection of Hwy 112 with Hwy 2, and 1.32 mi east of Hwy 466. Owner: Otilio Milán, Name: Otilio No. 1. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 0-10 ft (0-3.05 m), open hole 10-347 ft (3.05-105.8 m). Depth 347 ft (105.8 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 295 ft (89.9 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4 in (0.10 m) casing, 3.08 ft (0.94 m), above land-surface datum. REMARKS.--Recording observation well. Eletronic Data Logger (EDL), installed on May 16, 1997, removed on June 16, 1998. PERIOD OF RECORD.--May 16, 1997 to September 30, 1998. From June 16, 1998 only tape down measurements. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 292.4 ft (89.1 m), below land-surface datum, Oct. 18, 19, 1997; lowest water level recorded, 293.5 ft (89.5 m), below land-surface datum, May 12, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 292.72 292.92 292.89 292.68 2 292.74 292.93 292.90 292.65 3 292.75 292.93 292.91 292.62 4 292.72 292.94 292.91 292.62 5 292.72 292.96 292.92 292.60 6 292.72 292.96 292.91 292.57 7 292.74 292.96 292.89 292.55 8 292.76 292.96 292.90 292.54 9 292.78 292.96 292.91 292.54 10 292.79 292.95 292.93 292.55 11 292.80 292.95 292.95 292.55 12 292.82 292.94 292.97 292.59 13 292.80 292.93 292.97 292.60 14 292.79 292.94 292.99 292.61 15 292.81 292.92 292.99 292.63 16 292.81 292.91 292.99 292.63 17 292.88 292.82 292.88 293.00 292.63 18 292.91 292.83 292.88 293.01 292.63 19 292.92 292.85 292.86 293.01 292.64 20 292.84 292.86 292.86 293.00 292.65 21 292.85 292.89 292.86 293.01 292.67 22 292.85 292.88 292.86 292.95 292.68 23 292.72 292.92 292.88 292.90 292.68 24 292.72 292.90 292.89 292.90 292.69 25 292.72 292.91 292.89 292.90 292.71 26 292.72 292.91 292.90 292.88 292.72 27 292.71 292.91 292.88 292.84 292.74 28 292.73 292.91 292.88 292.81 292.74 29 292.73 292.92 292.87 292.77 292.76 30 292.71 292.94 292.86 292.74 292.75 31 292.74 292.90 292.70 MEAN 292.78 292.82 292.91 292.91 292.64 WTR YR 1997 MEAN 292.82 HIGHEST 292.5 SEPT. 8, 1997 LOWEST 293.04 AUG. 18-21, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 485 GROUND-WATER LEVELS RIO GUAJATACA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 292.74 292.66 292.83 293.08 293.09 292.99 293.28 293.50 293.26 2 292.74 292.67 292.85 293.09 292.97 292.99 293.31 293.51 293.25 3 292.75 292.67 292.87 293.09 292.97 293.00 293.32 293.49 293.22 4 292.75 292.68 292.88 293.06 292.94 293.01 293.35 293.48 293.20 5 292.72 292.69 292.90 293.06 292.93 293.03 293.34 293.49 293.19 6 292.73 292.70 292.90 293.02 292.94 293.05 293.34 293.49 293.21 7 292.75 292.72 292.90 293.03 292.98 293.04 293.32 293.48 293.19 8 292.77 292.71 292.90 293.03 292.96 293.07 293.33 293.48 293.19 9 292.77 292.70 292.91 293.04 292.98 293.06 293.37 293.49 293.17 10 292.76 292.71 292.92 293.04 293.01 293.06 293.37 293.48 293.17 11 292.75 292.70 292.93 293.03 293.03 293.08 293.38 293.50 293.18 12 292.73 292.73 292.94 293.05 293.05 293.09 293.36 293.51 293.18 13 292.69 292.75 292.95 293.06 293.05 293.10 293.35 293.51 293.18 14 292.61 292.76 292.95 293.08 293.05 293.11 293.36 293.49 293.13 15 292.57 292.77 292.97 293.10 293.05 293.13 293.41 293.48 293.05 16 292.50 292.79 292.98 293.11 293.05 293.14 293.44 293.48 17 292.49 292.76 292.99 293.10 293.06 293.18 293.44 293.49 18 292.47 292.75 293.00 293.11 293.06 293.20 293.42 293.48 19 292.48 292.75 293.01 293.10 293.04 293.22 293.43 293.49 20 292.48 292.76 293.01 293.10 293.07 293.21 293.43 293.46 21 292.48 292.77 293.04 293.10 293.08 293.22 293.44 293.45 22 292.48 292.78 293.03 293.11 293.09 293.22 293.43 293.42 23 292.50 292.78 293.03 293.09 293.10 293.21 293.42 293.38 24 292.52 292.78 293.05 293.08 293.09 293.22 293.43 293.37 25 292.55 292.82 293.05 293.09 293.10 293.23 293.42 293.34 26 292.56 292.84 293.04 293.09 293.13 293.23 293.41 293.33 27 292.59 292.82 293.05 293.09 292.99 293.26 293.43 293.32 28 292.61 292.82 293.06 293.10 292.97 293.26 293.45 293.32 29 292.62 292.82 293.06 293.10 293.26 293.47 293.31 30 292.63 292.84 293.07 293.09 293.25 293.49 293.30 31 292.66 293.07 293.10 293.26 293.30 MEAN 292.63 292.75 292.97 293.08 293.03 293.14 293.39 293.44 293.18 WTR YR 1998 MEAN 293.06 HIGHEST 292.45 OCT. 18, 19, 1997 LOWEST 293.55 MAY 12, 1998 292 LAND-SURFACE DATUM 293 WATER LEVEL, IN FEET BELOW 294 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR 486 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GUAJATACA BASIN 182422067015100. Local number, 165. LOCATION.--Lat 18°24'22", long 67°01'51", Hydrologic Unit 21010003, 5.60 mi northeast of Moca plaza, 4.70 mi southeast of Aguadilla US Naval Reservation radio antenna, and 1.63 mi northwest of La Virgen del Rosario Church. Owner: PR Aqueduct and Sewer Authority, Name: Saltos # 1 (Mateo Pérez). AQUIFER.--Cibao Formation. Aguada Limestone. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 16 in (0.40 m), cased 16 in (0.40 m) 0-40.0 ft (0-12.2 m), cased 12 in (0.30 m) 40-200 ft (12.2-61.0 m). Depth 200 ft (61.0 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 689 ft (210 m), above mean sea level. Measuring point: Hole on pump base, 0.50 ft (0.15 m), above land-surface datum. Prior to October 6, 1988, hole on top of pipe on top of pump base, 0.80 ft (0.24 m), above land-surface datum. Prior to November 1985, hole on top of pump base, 1.00 ft (0.30 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recoder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. Formerly published as 182421067015000. PERIOD OF RECORD.--January 1982 to March 1985, November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 38.36 ft (11.7 m), below land-surface datum, July 12, 1993; lowest water level measured, 70.6 ft (21.5 m), below land-surface datum, June 18, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 39.78 39.66 39.31 39.92 2 39.70 39.58 39.32 39.81 3 39.55 39.50 39.32 39.71 4 39.48 39.44 39.82 39.62 5 39.48 39.97 39.71 40.01 39.61 39.65 40.35 40.36 41.10 40.47 40.32 40.31 39.58 39.57 40.26 40.29 40.98 40.37 40.17 40.05 39.41 39.49 40.14 40.21 40.84 40.28 40.74 40.04 39.24 39.45 40.01 40.71 40.72 40.67 40.62 40.00 39.23 39.44 40.39 40.60 40.65 40.57 40.50 39.87 6 39.43 39.78 39.61 39.85 7 39.38 39.66 39.50 39.75 8 39.30 39.54 39.47 39.72 9 39.30 39.46 39.39 39.65 10 39.25 39.41 39.33 39.60 39.23 39.35 40.22 40.48 40.59 40.48 40.38 39.75 39.81 39.83 40.23 40.38 41.15 40.88 40.28 39.64 39.71 39.70 40.82 40.28 40.98 40.70 40.23 40.18 39.61 39.64 40.60 40.27 40.89 40.62 40.08 40.01 39.59 39.58 40.40 40.40 40.76 40.52 40.57 39.91 11 39.70 39.41 39.88 39.48 12 39.47 39.37 39.79 39.43 13 39.34 39.88 39.62 39.40 14 39.24 39.74 39.54 39.93 15 39.12 39.69 39.42 39.78 40.15 40.04 40.29 40.96 40.66 40.40 40.42 39.73 40.07 39.90 40.16 40.77 40.56 40.83 40.36 39.63 39.93 39.86 40.24 40.68 40.99 40.64 40.24 39.57 39.82 39.94 40.89 40.55 40.78 40.53 40.08 39.54 39.74 39.74 40.64 40.45 40.69 40.44 40.02 39.52 16 39.17 39.58 39.94 39.71 17 39.81 39.49 39.82 39.66 18 39.73 39.44 39.76 39.53 19 39.65 39.40 39.73 39.42 20 39.55 39.33 39.63 39.38 39.72 39.64 40.50 40.92 40.65 40.37 40.31 39.45 39.58 40.25 40.40 40.78 41.22 40.29 40.18 39.96 39.51 40.06 40.30 40.69 40.96 40.68 39.99 39.74 39.51 39.94 40.17 41.22 40.84 40.56 39.83 39.64 40.06 39.81 40.11 41.02 40.71 40.43 40.39 39.98 21 39.46 39.22 39.46 39.94 22 39.37 39.22 39.46 39.83 23 39.33 39.46 40.00 39.75 24 39.30 39.37 39.87 39.70 25 39.22 39.30 39.76 39.62 39.83 39.64 40.07 40.87 40.65 40.36 40.08 39.66 39.79 40.23 40.00 40.73 40.63 40.24 40.02 39.51 39.67 40.07 39.93 40.67 40.56 40.11 39.94 39.50 39.58 40.01 39.92 40.62 40.50 40.04 39.81 39.51 39.50 39.99 40.52 40.68 40.42 40.64 39.80 39.43 26 39.83 39.22 39.70 39.59 27 40.33 39.78 39.59 39.47 28 40.15 39.70 39.46 39.42 29 39.96 39.53 40.14 39.91 30 39.85 39.40 40.04 39.78 31 39.73 --- 39.99 39.61 39.42 39.90 40.36 41.20 40.40 40.44 40.36 39.35 39.37 40.35 40.23 41.07 40.85 40.29 40.21 39.26 39.88 40.12 40.14 40.94 40.70 40.23 40.02 39.19 --- 39.99 40.69 40.78 40.63 40.68 39.98 39.18 --- 39.87 40.53 40.70 40.54 40.56 39.90 39.20 --- 39.79 --- 40.63 --- 40.43 39.85 --­ MEAN 39.55 39.52 39.66 39.68 39.65 39.83 40.32 40.67 40.75 40.48 40.18 39.68 WTR YR 1998 MEAN 40.00 HIGHEST 38.93 SEPT. 21, 22, 1998 LOWEST 41.27 MAY 19, JUNE 17, 1998 38 40 42 44 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 487 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GUAJATACA BASIN 182647066552400. Local number, 202. LOCATION.--Lat 18°26'47", long 66°55'24", Hydrologic Unit 21010002, 2.22 mi southeast of Quebradillas plaza, 1.29 mi north of Escuela José de Diego, and 1.99 mi northwest of El Calvario Church. Owner: PR Aqueduct and Sewer Authority, Name: Carmelo Barreto García well. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-296 ft (0-90.2 m), diameter 13 in (0.33 m), cased 13 in (0.33 m) 0-550 ft (0-168 m), perforated 270-529 ft (82.3-161 m). Depth 550 ft (168 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 475 ft (145 m), above mean sea level, from topographic map. Measuring point: Hole on side of casing, 1.50 ft (0.46 m,), above land-surface datum. Prior July 25, 1986, top of shelter floor, 3.30 ft (1.00 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. PERIOD OF RECORD.--November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 409.2 ft (125 m), below land-surface datum, Sept. 25, 1986; lowest water level recorded, 453.9 ft (138 m), below land-surface datum, May 14, 15, 16, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 434.72 435.20 436.83 438.57 440.69 442.46 444.16 445.78 445.90 443.29 442.61 442.44 2 434.75 435.23 436.89 438.63 440.74 442.53 444.22 445.85 445.85 443.21 442.61 442.35 3 434.83 435.29 436.91 438.69 440.76 442.59 444.25 445.89 445.77 443.17 442.61 442.32 4 434.90 435.34 436.90 438.75 440.81 442.66 444.29 445.94 445.67 443.14 442.66 442.25 5 434.92 435.39 436.93 438.83 440.94 442.76 444.33 446.01 445.60 443.12 442.69 442.10 6 434.99 435.43 436.96 438.91 441.02 442.80 444.38 446.08 445.54 443.08 442.71 442.00 7 435.01 435.49 437.02 438.96 441.09 442.88 444.49 446.12 445.47 443.04 442.74 441.89 8 435.05 435.53 437.07 439.04 441.14 442.96 444.55 446.17 445.42 443.03 442.79 441.77 9 435.06 435.59 437.10 439.11 441.23 442.98 444.58 446.23 445.39 443.04 442.84 441.66 10 435.07 435.70 437.14 439.19 441.31 443.01 444.61 446.27 445.31 443.03 442.83 441.46 11 435.08 435.74 437.19 439.24 441.36 443.03 444.70 446.33 445.27 442.99 442.88 441.20 12 435.08 435.40 437.24 439.33 441.43 443.09 444.77 446.41 445.21 443.00 442.94 440.99 13 435.08 435.87 437.28 439.42 441.47 443.13 444.87 446.46 445.17 443.00 442.93 440.85 14 435.07 435.91 437.32 439.46 441.55 443.17 444.91 446.51 445.16 443.02 442.92 440.71 15 435.10 435.98 437.40 439.51 441.61 443.18 444.94 446.57 445.07 443.02 442.92 440.58 16 435.19 436.06 437.45 439.61 441.67 443.23 445.03 446.63 444.97 443.00 442.92 440.44 17 435.17 436.10 437.54 439.67 441.72 443.29 445.10 446.70 444.79 442.96 442.87 440.24 18 435.14 436.16 437.60 439.74 441.79 443.33 445.14 446.74 444.59 442.92 442.80 439.97 19 435.11 436.19 437.68 439.80 441.85 443.38 445.19 446.79 444.44 442.89 442.77 439.76 20 435.04 436.23 437.73 439.87 441.90 443.41 445.25 446.81 444.28 442.82 442.77 439.59 21 435.00 436.31 437.78 439.95 441.97 443.46 445.32 446.81 444.15 442.80 442.69 439.40 22 434.98 436.36 437.86 440.01 442.04 443.54 445.35 446.78 444.04 442.74 442.70 439.41 23 434.97 436.41 437.93 440.10 442.09 443.61 445.39 446.75 443.92 442.71 442.68 439.10 24 434.94 436.47 438.00 440.14 442.14 443.69 445.46 446.70 443.83 442.68 442.63 438.40 25 434.94 436.54 438.08 440.21 442.21 443.76 445.51 446.61 443.72 442.67 442.72 437.38 26 434.96 436.61 438.14 440.27 442.29 443.79 445.57 446.54 443.62 442.63 442.69 436.57 27 434.97 436.70 438.18 440.34 442.34 443.86 445.60 446.46 443.54 442.61 442.65 436.06 28 435.01 436.77 438.24 440.41 442.40 443.92 445.64 446.36 443.48 442.63 442.61 435.70 29 435.07 436.79 438.33 440.47 --- 443.97 445.70 446.24 443.42 442.60 442.64 435.44 30 435.08 436.79 438.43 440.52 --- 444.02 445.75 446.14 443.35 442.60 442.57 435.15 31 435.14 --- 438.51 440.59 --- 444.11 --- 446.02 --- 442.60 442.52 --­ MEAN 435.01 435.99 437.54 439.59 441.56 443.28 444.97 446.38 444.73 442.90 442.74 439.91 WTR YR 1998 MEAN 441.21 HIGHEST 434.65 OCT. 1, 1997 LOWEST 446.85 MAY 20, 1998 420 440 460 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 488 GROUND-WATER LEVELS RIO CAMUY BASIN 182723066511200. Local number, Z-4. LOCATION.--Lat 18°27'23", long 66°51'12", Hydrologic Unit 21010002, 1.60 mi south of the intersection of Hwy 119 with Hwy 2, 1.35 mi east of Hwy 119 of, and 0.01 mi east of Hwy 486. Owner: PR Aqueduct and Sewer Authority, Name: Zanja 4. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.30 m). Depth 585 ft (178 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 360 ft (110 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4 in (0.10 m) casing, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Eletronic Data Logger (EDL), installed on February 25, 1997. Record is poor when the water level is below the level of the pressure transducer which is set at 331 ft (101 m), below land-surface datum. PERIOD OF RECORD.--February 25, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 161.8 ft (49.3 m), below land-surface datum, Sept. 22, 1998; lowest water level recorded, 331.2 ft (101 m), below land-surface datum, Mar. 11, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 310.79 323.19 329.10 324.09 329.12 329.15 329.17 2 311.40 323.54 329.12 324.33 329.12 329.15 329.17 3 311.96 323.85 329.07 326.65 329.12 329.15 329.17 4 312.56 324.14 329.06 328.29 329.12 329.15 329.17 5 313.12 324.29 329.07 329.10 329.12 329.15 329.17 6 313.54 324.51 329.07 329.10 329.12 329.15 329.18 7 314.13 324.80 329.08 329.10 329.12 329.15 329.18 8 314.80 325.06 323.38 329.10 329.12 329.16 329.18 9 315.25 325.36 324.53 329.10 329.12 329.16 329.18 10 315.61 325.67 325.07 329.10 329.12 329.16 329.18 11 315.98 325.96 325.32 329.10 329.14 329.16 329.18 12 316.45 326.23 327.19 329.11 329.13 329.15 329.18 13 317.02 326.40 328.74 329.11 329.13 329.16 329.18 14 317.49 326.60 329.08 329.11 329.13 329.16 329.18 15 317.91 326.81 329.08 329.11 329.13 329.16 329.18 16 318.30 326.93 329.08 329.11 329.13 329.15 329.18 17 318.71 327.04 329.08 329.10 329.13 329.16 329.18 18 319.15 327.11 329.09 329.11 329.13 324.30 329.18 19 319.52 327.32 329.08 329.11 329.13 329.16 329.18 20 319.22 327.60 329.08 329.11 329.14 321.29 329.18 21 318.91 327.87 329.08 329.12 329.14 327.02 329.18 22 319.74 327.03 329.08 329.12 329.14 309.51 329.18 23 320.39 327.09 329.08 329.11 329.14 318.41 329.18 24 320.93 327.65 329.09 329.11 329.14 324.83 329.18 25 307.11 321.41 328.12 329.09 329.11 329.14 329.31 329.18 26 307.81 321.83 328.50 329.09 329.12 329.14 329.16 329.18 27 309.00 322.11 328.74 328.28 329.12 324.66 329.17 329.18 28 309.98 322.36 328.94 283.86 329.11 329.14 329.17 329.18 29 322.51 329.00 300.94 329.12 329.14 322.89 329.18 30 322.67 329.07 314.41 329.11 329.15 326.94 329.18 31 322.92 319.78 329.15 329.17 MEAN 308.48 317.70 326.48 325.26 328.67 328.99 327.29 329.18 WTR YR 1997 MEAN 325.87 HUGHEST 280.21 MAY 28, 1997 LOWEST 329.31 AUG. 25, 1997 --- --- --- --- --- --- --- 489 GROUND-WATER LEVELS RIO CAMUY BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 329.18 329.17 316.73 329.43 330.20 330.89 331.01 330.49 295.49 311.10 323.20 246.03 2 329.18 329.17 322.86 329.46 330.23 330.92 330.86 330.48 288.68 313.36 323.94 271.72 3 304.16 329.17 327.38 329.48 330.25 330.94 330.85 330.47 295.87 314.88 324.70 250.30 4 315.80 329.17 329.26 329.51 330.28 330.97 330.83 330.46 299.54 315.66 325.57 257.91 5 323.70 329.17 329.26 329.53 330.30 330.99 330.82 330.44 304.21 316.37 326.39 270.89 6 301.34 329.17 329.26 329.56 330.42 297.79 330.81 330.43 308.70 318.13 327.12 280.40 7 313.20 329.17 329.25 329.58 330.35 318.15 330.80 330.42 304.28 319.40 327.29 262.91 8 306.01 329.17 329.17 329.61 330.38 300.45 330.79 330.41 306.00 320.14 327.22 269.87 9 315.32 329.17 329.17 329.63 330.40 318.46 330.77 330.39 310.02 321.02 327.15 278.39 10 321.37 329.17 329.16 329.66 330.43 327.41 330.76 330.38 312.72 321.85 304.53 259.25 11 326.50 329.17 329.17 329.68 330.45 331.14 330.75 330.37 315.07 323.00 315.30 272.47 12 329.17 329.17 329.17 329.71 330.48 331.13 330.74 330.36 246.70 322.49 280.84 280.19 13 297.76 329.17 329.16 329.73 330.50 331.11 330.72 330.35 241.90 305.71 242.11 284.48 14 275.36 329.17 329.16 329.75 330.53 331.10 330.71 330.33 227.53 311.21 276.31 255.92 15 285.25 329.17 329.16 329.77 330.55 331.09 330.70 330.32 237.77 316.11 291.87 274.57 16 265.40 329.17 329.16 329.81 330.58 331.08 330.69 324.61 261.57 309.12 299.51 278.48 17 286.14 329.17 329.16 329.82 330.60 331.07 330.45 321.12 273.20 281.93 297.86 281.02 18 299.20 329.17 329.08 329.85 330.63 331.04 330.66 243.14 279.41 297.28 305.32 286.44 19 310.14 329.17 329.11 329.87 330.65 331.04 330.65 248.30 280.08 306.51 309.46 269.29 20 317.02 329.17 329.13 329.90 330.68 331.02 296.67 250.77 288.21 312.21 311.83 280.35 21 321.10 329.17 329.16 329.92 330.70 331.01 314.42 232.17 294.33 314.41 313.35 286.63 22 324.50 329.17 329.18 329.95 330.73 330.99 324.76 262.12 298.65 316.46 296.31 162.04 23 326.89 329.17 329.21 329.97 330.75 330.98 330.69 284.22 301.07 318.14 306.60 190.66 24 328.67 329.17 329.23 330.00 330.78 330.98 330.68 252.10 305.81 316.26 311.53 220.76 25 329.27 329.17 329.26 330.02 330.79 330.97 330.58 279.04 308.88 309.03 277.28 230.14 26 329.27 329.17 329.28 330.05 330.82 330.95 330.55 291.21 309.24 315.14 290.01 243.13 27 329.18 287.98 329.31 330.07 330.84 330.93 330.54 234.99 311.18 317.86 278.31 256.79 28 329.17 266.06 329.33 330.10 330.87 330.92 330.53 262.12 286.29 317.36 290.01 263.65 29 329.18 293.14 329.36 330.13 330.91 330.52 278.26 299.02 319.19 237.67 264.95 30 329.17 309.26 329.38 330.15 321.31 330.50 283.61 306.83 320.90 268.60 268.40 31 329.17 329.41 330.18 329.92 289.96 322.21 282.34 MEAN 314.73 323.83 328.55 329.80 330.54 327.67 328.83 299.80 289.94 314.34 300.63 259.93 WTR YR 1998 MEAN 312.36 HIGHEST 161.80 SEPT. 22, 1998 LOWEST 331.22 MAR. 11, 1998 100 200 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 300 400 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 490 GROUND-WATER LEVELS RIO CAMUY BASIN 182431066463400. Local number, CA-4. LOCATION.--Lat 18°24'31", long 66°46'34", Hydrologic Unit 21010005, 0.02 mi west of the intersectiom of Hwy 129 with Hwy 130, 1.68 mi southeast of the intersection of Hwy 130 with Hwy 490, and 3.00 mi east of Río Camuy. Owner: PR Aqueduct and Sewer Authority, Name: Campo Alegre 4. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m). Depth 220 ft (67.1 m). INSTRUMENTATION.--Eletronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 606.8 ft (185 m), above mean sea level. Measuring point: Shelter floor on top of the 4 in (0.10 m) casing, 3.25 ft (0.99 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on Sept. 27, 1996, replaced by an Electronic Data Logger (EDL), installed on Jan. 14, 1997. PERIOD OF RECORD.--September 27, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 183.9 ft (56.1 m), below land-surface datum, Oct. 3, 1996; lowest water level recorded, 212.6 ft (64.8 m), below land-surface datum, May 28, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 184.12 186.38 187.06 191.42 186.32 2 184.09 186.65 187.06 191.25 186.09 190.26 3 183.98 186.85 187.03 191.08 185.81 190.31 4 184.04 186.53 187.45 190.89 185.61 190.47 5 184.12 186.67 187.22 190.71 185.46 190.61 6 184.17 186.77 187.37 190.51 185.30 190.70 7 184.18 186.78 186.75 190.45 185.17 190.77 8 184.29 186.80 186.80 190.07 185.17 190.74 9 184.31 186.69 186.89 189.93 185.20 190.67 10 184.41 186.55 187.13 189.79 185.27 187.83 190.65 11 184.42 186.62 187.14 189.68 185.33 187.83 190.79 12 184.45 186.77 187.17 189.61 185.45 187.84 191.00 13 184.50 186.90 187.13 189.66 185.68 188.05 191.04 14 184.50 186.92 187.01 189.58 185.70 187.93 191.18 15 184.64 186.86 187.04 189.51 185.72 188.10 191.20 16 184.87 186.90 187.14 189.46 185.75 188.34 191.20 17 185.02 187.02 187.16 189.41 185.77 188.55 191.15 18 185.13 187.07 187.43 189.40 185.79 188.75 191.00 19 185.13 186.78 187.75 189.43 185.81 188.84 190.98 20 185.17 186.91 188.09 189.60 185.84 188.97 191.13 21 185.39 186.96 188.42 189.66 185.86 189.00 191.25 22 185.59 186.98 188.76 189.88 186.00 189.02 191.43 23 185.63 186.78 189.13 189.78 186.06 191.51 24 185.70 186.87 189.46 189.69 186.06 25 185.87 187.04 189.81 189.45 186.48 26 186.05 187.08 190.21 188.86 186.63 27 186.22 187.05 190.60 188.70 186.78 201.34 28 186.23 187.03 190.84 188.28 186.96 201.32 29 186.22 187.03 191.15 187.82 201.28 30 186.30 187.03 191.45 187.52 201.26 31 186.38 191.51 186.67 MEAN 185.00 186.84 188.23 189.60 185.82 188.39 190.91 201.30 WTR YR 1997 MEAN 187.95 HIGHEST 183.96 OCT. 3, 1996 LOWEST 201.38 SEPT. 26, 1997 --- --- --- --- --- --- --- 491 GROUND-WATER LEVELS RIO CAMUY BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 201.20 197.86 196.55 198.33 199.90 202.80 206.32 210.19 211.02 197.01 194.35 192.72 2 201.13 197.74 196.58 198.48 199.99 202.87 206.49 210.28 210.39 196.86 194.26 192.57 3 201.08 197.69 196.73 198.54 200.02 202.93 206.65 210.39 209.80 196.63 194.16 192.53 4 201.26 197.48 196.89 198.55 199.94 202.98 206.81 210.48 209.23 196.37 194.10 192.51 5 200.71 197.30 196.95 198.51 199.85 203.07 206.98 210.57 208.64 196.18 194.10 192.48 6 200.79 197.14 196.94 198.49 199.99 203.19 207.12 210.65 208.10 196.06 194.10 192.46 7 200.89 196.89 197.00 198.46 200.11 203.17 207.26 210.74 207.65 195.94 194.10 192.44 8 200.95 196.65 197.07 198.51 200.33 203.20 207.42 210.81 207.23 195.83 194.10 192.42 9 201.02 196.49 197.17 198.60 200.61 203.34 207.57 210.90 206.78 195.76 194.07 192.39 10 201.07 196.40 197.24 198.70 200.75 203.44 207.70 210.99 206.31 195.70 194.05 192.37 11 201.10 196.42 197.19 198.73 200.94 203.49 207.84 211.07 205.82 195.62 193.96 192.35 12 201.07 196.42 197.31 198.78 201.14 203.60 207.98 211.16 205.29 195.53 193.98 192.33 13 200.99 196.42 197.34 198.88 201.35 203.78 208.11 211.23 204.74 195.44 194.02 192.30 14 200.77 196.42 197.36 198.99 201.47 203.94 208.26 211.31 204.12 195.37 194.02 192.28 15 200.42 196.49 197.37 199.05 201.60 204.09 208.40 211.40 203.57 195.31 193.90 192.26 16 200.30 196.56 197.37 199.14 201.74 204.20 208.52 211.46 203.09 195.29 193.87 192.23 17 200.35 196.55 197.40 199.27 201.84 204.32 208.66 211.54 202.66 195.25 193.90 192.21 18 200.33 196.55 197.46 199.38 201.93 204.28 208.78 211.61 202.16 195.22 193.84 192.19 19 200.24 196.56 197.61 199.43 202.05 204.38 208.91 211.69 201.62 195.15 193.62 192.17 20 200.08 196.53 197.75 199.51 202.17 204.53 209.03 211.76 201.05 195.10 193.44 192.14 21 199.85 196.53 197.78 199.58 202.28 204.68 209.15 211.72 200.52 195.06 193.26 192.12 22 199.66 196.55 197.84 199.70 202.40 204.79 209.26 211.85 200.09 195.04 193.05 190.60 23 199.54 196.61 197.92 199.55 202.49 204.91 209.38 211.99 199.66 195.04 193.05 190.58 24 199.39 196.71 197.94 199.76 202.50 205.10 209.48 212.13 199.26 194.71 192.90 190.55 25 199.21 196.71 198.00 199.96 202.53 205.28 209.59 212.25 198.86 194.70 192.81 190.53 26 199.04 196.67 198.08 200.02 202.62 205.47 209.68 212.38 198.45 194.70 192.85 190.51 27 198.88 196.62 198.09 200.03 202.67 205.63 209.78 212.50 198.03 194.59 192.84 190.49 28 198.74 196.67 198.03 200.03 202.74 205.78 209.89 212.62 197.69 194.46 192.81 190.46 29 198.59 196.73 197.99 199.99 205.92 210.00 212.53 197.41 194.40 192.73 190.44 30 198.34 196.65 198.01 199.94 206.05 210.08 212.16 197.19 194.38 192.73 190.42 31 198.07 198.16 199.88 206.17 211.63 194.38 192.75 MEAN 200.16 196.77 197.46 199.19 201.36 204.24 208.37 211.42 203.55 195.39 193.60 191.80 WTR YR 1998 MEAN 200.27 HIGHEST 190.41 SEPT. 30, 1998 LOWEST 212.64 MAY 28, 1998 180 LAND-SURFACE DATUM 200 WATER LEVEL, IN FEET BELOW 220 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR 492 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182756066454700. Local number, BARR-1 LOCATION.--Lat 18°27’56", long 66°45'47", Hydrologic Unit 21010002, 0.04 mi north of Hwy 653, 1.86 mi west of Hwy 129, and 1.55 mi west of the University of Puerto Rico, Arecibo Campus. Owner: Vaqueria Barreto, Name: Barreto #01. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m). Depth 300 ft (91.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 164 ft (50.0 m), above mean sea level, from topographic map. Measuring point: Top of white PVC cap 3.37 ft (1.03 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on October 24, 1997. Water levels affected by marine tides. PERIOD OF RECORD.--October 24, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 159.6 ft (48.7 m), below land-surface datum, Sept. 24-28, 1998; lowest water level recorded, 161.4 ft (49.2 m), below land-surface datum, Jan. 6, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 161.02 161.30 161.23 161.34 161.27 161.04 160.93 160.96 160.95 160.79 160.31 2 --- 161.03 161.30 161.22 161.33 161.25 161.00 160.93 160.96 160.96 160.81 160.30 3 --- 161.02 161.27 161.26 161.31 161.22 160.98 160.96 160.97 160.98 160.81 160.26 4 --- 161.02 161.24 161.27 161.33 161.23 160.96 160.97 160.97 160.97 160.81 160.24 5 --- 161.02 161.21 161.32 161.37 161.20 160.98 160.97 160.97 160.96 160.81 160.24 6 --- 161.04 161.27 161.36 161.35 161.22 160.98 160.96 161.00 160.96 160.82 160.23 7 --- 161.04 161.29 161.37 161.37 161.21 161.00 160.96 160.95 160.97 160.83 160.20 8 --- 161.10 161.30 161.36 161.37 161.18 161.00 160.96 160.93 160.99 160.81 160.15 9 --- 161.13 161.29 161.35 161.36 161.20 160.96 160.97 160.97 160.99 160.78 160.08 10 --- 161.16 161.31 161.38 161.36 161.18 160.94 160.95 160.97 160.97 160.77 160.05 11 --- 161.18 161.32 161.36 161.33 161.16 160.97 160.94 160.98 160.96 160.75 160.03 12 --- 161.20 161.31 161.36 161.30 161.17 161.02 160.96 160.98 160.93 160.72 160.03 13 --- 161.19 161.32 161.34 161.30 161.15 161.04 160.95 160.91 160.92 160.70 160.06 14 --- 161.19 161.33 161.32 161.30 161.15 160.98 160.97 160.87 160.91 160.71 160.02 15 --- 161.17 161.35 161.30 161.30 161.10 160.96 160.99 160.85 160.89 160.74 160.01 16 --- 161.18 161.35 161.31 161.30 161.10 160.93 161.01 160.87 160.87 160.72 159.99 17 --- 161.17 161.33 161.31 161.28 161.05 161.01 161.02 160.87 160.86 160.66 159.99 18 --- 161.16 161.35 161.30 161.27 161.02 161.01 161.01 160.84 160.84 160.63 159.97 19 --- 161.17 161.24 161.29 161.27 161.03 160.98 161.04 160.84 160.84 160.59 159.92 20 --- 161.17 161.24 161.31 161.26 161.01 161.04 161.09 160.83 160.82 160.57 159.90 21 --- 161.18 161.21 161.32 161.22 161.02 161.07 161.18 160.85 160.84 160.51 159.85 22 --- 161.18 161.26 161.32 161.19 161.03 161.07 161.12 160.89 160.83 160.41 159.81 23 --- 161.17 161.25 161.33 161.20 161.05 161.06 161.07 160.87 160.83 160.37 159.67 24 --- 161.20 161.25 161.34 161.23 161.04 161.08 161.08 160.90 160.82 160.33 159.64 25 160.99 161.21 161.24 161.35 161.21 161.04 161.07 161.06 160.91 160.75 160.35 159.64 26 161.01 161.21 161.23 161.34 161.22 161.03 161.06 161.05 160.93 160.78 160.29 159.66 27 161.01 161.24 161.24 161.34 161.25 160.98 161.04 161.01 160.93 160.79 160.32 159.66 28 161.01 161.26 161.24 161.35 161.28 160.98 161.02 160.95 160.92 160.79 160.37 159.65 29 161.01 161.25 161.25 161.33 --- 161.00 160.97 160.95 160.94 160.77 160.33 159.68 30 161.01 161.28 161.26 161.33 --- 161.08 160.96 160.98 160.92 160.79 160.33 159.72 31 161.03 --- 161.22 161.35 --- 161.05 --- 160.96 --- 160.80 160.34 --­ MEAN 161.01 161.15 161.28 161.32 161.29 161.11 161.01 161.00 160.92 160.88 160.61 159.97 WTR YR 1998 MEAN 160.96 HIGHEST 159.61 SEPT. 24-28, 1998 LOWEST 161.40 JAN. 6, 1998 159 160 161 162 October November December January February March April May June July August September 1998 WATER YEAR 493 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182737066370900. Local number, 204. LOCATION.--Lat 18°27'37", long 66°37'09", Hydrologic Unit 21010002, 5.26 mi west of Barceloneta plaza, 1.58 mi north of Hwy 2 km 63.7, and 3.67 mi southwest of Escuela Agustín Balseiro. Owner: Sucesión Marquez, Name: Gilberto Rivera well. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Abandoned unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is 48.0 ft (14.63 m), above mean sea level. Measuring point: Air hole on pump base, 0.50 ft (0.15 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 7, 1997. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 50.0 ft (15.2 m), below land-surface datum, May 14, 1986; lowest water level recorded, 53.1 ft (16.2 m), below land-surface datum, Jan. 29, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 51.93 52.12 52.09 52.18 2 51.90 52.10 52.09 52.18 3 51.92 52.11 52.15 52.19 4 51.90 52.15 52.23 52.15 5 51.92 52.16 52.26 52.07 51.99 52.04 52.29 52.31 51.82 51.89 51.98 51.93 52.01 52.07 52.31 52.27 51.79 51.90 52.00 51.91 52.04 52.11 52.32 52.25 51.79 51.91 52.02 51.85 52.01 52.11 52.38 52.22 51.80 51.91 52.04 51.88 51.94 52.12 52.36 52.21 51.83 51.89 52.06 51.85 6 51.95 52.18 52.21 52.04 7 52.02 52.22 52.16 52.04 8 52.03 52.14 52.14 52.03 9 52.02 52.10 52.15 52.02 10 52.02 52.07 52.14 52.01 51.93 52.09 52.30 52.21 51.84 51.91 52.10 51.84 51.94 52.10 52.27 52.19 51.84 51.91 52.06 51.83 51.94 52.11 52.28 52.20 51.87 51.94 52.01 51.80 51.93 52.14 52.31 52.16 51.88 51.94 52.00 51.74 51.94 52.14 52.34 52.20 51.89 51.89 52.03 51.74 11 52.01 52.07 52.13 51.99 12 51.96 52.07 52.15 52.00 13 51.89 52.08 52.13 52.01 14 51.81 52.08 52.16 52.05 15 51.75 52.09 52.13 52.06 51.98 52.12 52.29 52.22 51.88 51.87 52.03 51.74 52.03 52.12 52.24 52.22 51.89 51.84 52.04 51.81 52.04 52.14 52.20 52.20 51.81 51.81 52.08 51.82 52.03 52.18 52.27 52.18 51.69 51.81 52.12 51.82 52.02 52.20 52.32 52.13 51.63 51.83 52.14 51.84 16 51.71 52.12 52.13 52.05 17 51.80 52.12 52.12 52.05 18 51.90 52.17 52.13 52.04 19 51.97 52.17 52.19 52.03 20 52.01 52.17 52.22 52.01 52.04 52.22 52.32 52.12 51.62 51.84 52.14 51.91 52.06 52.25 52.28 52.10 51.66 51.86 52.12 51.92 52.04 52.28 52.26 52.06 51.72 51.88 52.11 51.89 52.05 52.29 52.27 52.02 51.76 51.89 52.04 51.84 52.07 52.30 52.21 51.99 51.79 51.89 51.98 51.80 21 52.05 52.17 52.21 52.00 22 52.09 52.17 52.18 52.00 23 52.10 52.17 52.17 51.98 24 52.15 52.14 52.18 52.00 25 52.17 52.13 52.18 51.98 52.10 52.28 52.17 51.91 51.81 51.89 51.89 51.78 52.10 52.26 52.16 51.91 51.84 51.90 51.84 51.70 52.10 52.24 52.14 51.88 51.83 51.85 51.81 51.47 52.07 52.26 52.14 51.87 51.84 51.84 51.76 51.39 52.06 52.25 52.12 51.85 51.85 51.86 51.79 51.39 26 52.16 52.12 52.17 52.01 27 52.15 52.12 52.16 51.98 28 52.15 52.09 52.16 51.98 29 52.15 52.09 52.09 51.98 30 52.14 52.10 52.12 51.99 31 52.13 --- 52.15 51.99 52.05 52.28 52.12 51.82 51.89 51.90 51.71 51.40 52.04 52.31 52.17 51.82 51.89 51.92 51.81 51.43 52.04 52.33 52.22 51.80 51.89 51.93 51.83 51.47 --- 52.33 52.26 51.81 51.89 51.94 51.85 51.52 --- 52.27 52.28 51.81 51.88 51.97 51.88 51.58 --- 52.26 --- 51.83 --- 51.96 51.91 --­ MEAN 52.00 52.13 52.16 52.04 52.02 52.20 52.25 52.06 51.81 51.89 51.97 51.73 WTR YR 1998 MEAN 52.02 HIGHEST 51.38 SEPT. 24, 25, 1998 LOWEST 52.42 APR. 3, 4, 1998 50 51 52 53 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 494 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182616066364100. Local number, EN-1. LOCATION.--Lat 18°26'16", long 66°36'41", Hydrologic Unit 21010002, 3.00 west of the intersection of Hwy 140 with Hwy 2 (Cruce Davila), 0.32 mi southwest of Hwy 22, 0.15 mi north of Hwy 2, and 0.22 mi northeast of the intersection of Hwy 2 with Hwy 639. Owner: PR Aqueduct and Sewer Authority, Name: PRASA Encantada 1. AQUIFER.--Tertiary Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 312 ft (95.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor 3.40 ft (1.04 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on Aug. 23, 1996, replaced by an Electronic Data Logger (EDL), installed on January 13, 1997. PERIOD OF RECORD.--August 23, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 312.23 ft (95.2 m), below land-surface datum, Sept. 13, 14, 1996; lowest water level recorded, 313.84 ft (95.7 m), below land-surface datum, April 3, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 313.40 313.57 313.56 313.65 313.44 313.51 313.70 313.74 313.25 313.32 313.38 313.26 2 313.37 313.57 313.56 313.66 313.44 313.53 313.71 313.72 313.20 313.33 313.40 313.23 3 313.39 313.57 313.59 313.63 313.46 313.56 313.76 313.69 313.20 313.36 313.41 313.17 4 313.37 313.61 313.66 313.59 313.44 313.56 313.79 313.66 313.22 313.36 313.42 313.16 5 313.39 313.61 313.68 313.53 313.36 313.56 313.76 313.64 313.23 313.33 313.43 313.17 6 313.42 313.63 313.65 313.46 313.36 313.54 313.71 313.64 313.26 313.33 313.46 313.17 7 313.44 313.61 313.59 313.46 313.36 313.54 313.67 313.66 313.25 313.36 313.46 313.15 8 313.46 313.57 313.58 313.46 313.36 313.56 313.69 313.64 313.29 313.37 313.42 313.15 9 313.44 313.54 313.58 313.46 313.36 313.57 313.75 313.64 313.30 313.39 313.42 313.10 10 313.42 313.51 313.59 313.44 313.39 313.59 313.76 313.65 313.32 313.37 313.45 313.10 11 313.40 313.49 313.59 313.44 313.44 313.57 313.71 313.67 313.32 313.34 313.45 313.09 12 313.34 313.51 313.60 313.45 313.48 313.56 313.67 313.67 313.32 313.31 313.44 313.11 13 313.28 313.51 313.61 313.46 313.48 313.59 313.64 313.67 313.26 313.28 313.47 313.12 14 313.22 313.54 313.63 313.50 313.48 313.61 313.70 313.65 313.15 313.28 313.48 313.11 15 313.17 313.55 313.60 313.51 313.46 313.65 313.76 313.59 313.10 313.29 313.49 313.10 16 313.13 313.58 313.61 313.50 313.48 313.67 313.78 313.57 313.08 313.32 313.47 313.11 17 313.24 313.58 313.61 313.50 313.50 313.69 313.70 313.56 313.10 313.32 313.46 313.11 18 313.35 313.61 313.60 313.50 313.48 313.72 313.69 313.53 313.14 313.30 313.46 313.11 19 313.42 313.61 313.63 313.46 313.50 313.76 313.68 313.49 313.14 313.29 313.39 313.06 20 313.47 313.60 313.65 313.45 313.51 313.76 313.60 313.44 313.16 313.29 313.35 313.04 21 313.48 313.60 313.66 313.44 313.54 313.74 313.57 313.29 313.19 313.31 313.29 313.03 22 313.48 313.59 313.65 313.42 313.56 313.71 313.56 313.27 313.23 313.32 313.21 23 313.50 313.60 313.61 313.42 313.54 313.68 313.56 313.24 313.25 313.30 313.17 24 313.51 313.58 313.61 313.42 313.53 313.70 313.54 313.25 313.25 313.30 313.16 25 313.53 313.56 313.61 313.42 313.50 313.70 313.54 313.25 313.28 313.31 313.16 26 313.54 313.55 313.61 313.45 313.51 313.72 313.54 313.22 313.31 313.36 313.13 27 313.53 313.55 313.61 313.45 313.50 313.76 313.58 313.22 313.32 313.36 313.16 28 313.54 313.55 313.61 313.45 313.48 313.76 313.64 313.22 313.32 313.37 313.18 29 313.56 313.55 313.60 313.44 313.73 313.69 313.24 313.33 313.37 313.19 30 313.56 313.56 313.60 313.44 313.69 313.70 313.24 313.32 313.39 313.22 31 313.57 313.61 313.42 313.67 313.26 313.38 313.24 MEAN 313.42 313.57 313.61 313.48 313.46 313.64 313.67 313.49 313.24 313.33 313.35 313.13 WTR YR 1998 MEAN 313.46 HIGHEST 312.95 SEPT. 21, 22, 1998 LOWEST 313.84 APR. 3, 1998 312 LAND-SURFACE DATUM 313 WATER LEVEL, IN FEET BELOW 314 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR 495 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182626066345100. Local number, TI-1. LOCATION.--Lat 18°26'26", long 66°34'51", Hydrologic Unit 21010002, 1.45 mi south of Hwy 682, 1.15 mi northwest of the intersection of Hwy 140 with Hwy 2 (Cruce Dávila), 0.48 mi north of Hwy 2, and approximately 100 feet south of Hwy 22. Owner: PR Aqueduct and Sewer Authority, Name: Tiburones 1. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 12 in (0.30 m). Depth 320 ft (97.5 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. Prior to December 19, 1996, pressure transducer with integrated electronic data logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 295 ft (89.9 m), above mean sea level, from topographic map. Measuring point: Top of 4 in (0.10 m) PVC cap, above shelter floor, 3.40 ft (1.04 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), re-intalled on October 27, 1997. PERIOD OF RECORD.--May 14, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 290.88 ft (88.7 m), below land-surface datum, Sept. 13, 14, 1996; lowest water level measured, 292.79 ft (89.2 m), below land-surface datum, Jan. 17, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 292.11 292.13 292.32 292.06 292.11 292.31 292.35 291.92 291.98 292.10 292.05 2 --- 292.09 292.13 292.32 292.07 292.13 292.31 292.34 291.87 292.00 292.11 292.02 3 --- 292.14 292.17 292.29 292.11 292.16 292.35 292.31 291.91 292.02 292.12 291.96 4 --- 292.18 292.25 292.23 292.07 292.15 292.41 292.27 291.88 292.01 292.13 291.97 5 --- 292.18 292.26 292.16 291.95 292.14 292.35 292.27 291.91 291.98 292.16 291.97 6 --- 292.20 292.20 292.13 291.94 292.11 292.30 292.25 291.92 291.99 292.18 291.97 7 --- 292.19 292.17 292.08 291.98 292.11 292.27 292.23 291.93 292.00 292.16 291.96 8 --- 292.14 292.14 292.08 291.95 292.14 292.27 292.22 291.98 292.03 292.14 291.94 9 --- 292.11 292.17 292.10 291.97 292.15 292.34 292.20 291.96 292.04 292.13 291.91 10 --- 292.06 292.14 292.09 292.00 292.20 292.35 292.25 292.00 292.02 292.16 291.91 11 --- 292.04 292.14 292.05 292.04 292.16 292.32 292.26 292.00 291.99 292.16 291.91 12 --- 292.08 292.17 292.06 292.10 292.16 292.28 292.29 291.99 291.96 292.17 291.93 13 --- 292.07 292.19 292.06 292.11 292.20 292.24 292.29 291.93 291.93 292.20 291.94 14 --- 292.09 292.20 292.13 292.07 292.24 292.31 292.27 291.84 291.92 292.23 291.93 15 --- 292.12 292.19 292.13 292.06 292.27 292.38 292.17 291.77 291.93 292.24 291.95 16 --- 292.14 292.18 292.13 292.07 292.26 292.36 292.16 291.75 291.95 292.24 291.95 17 --- 292.18 292.16 292.12 292.09 292.30 292.27 292.16 291.78 291.97 292.22 291.95 18 --- 292.18 292.16 292.12 292.10 292.34 292.29 292.12 291.82 291.98 292.20 291.93 19 --- 292.19 292.19 292.08 292.09 292.37 292.25 292.07 291.83 291.97 292.15 291.89 20 --- 292.16 292.25 292.06 292.13 292.37 292.18 292.04 291.86 291.97 292.10 291.88 21 --- 292.17 292.22 292.07 292.12 292.32 292.17 291.97 291.88 291.98 292.03 291.85 22 --- 292.19 292.21 292.06 292.15 292.31 292.14 291.94 291.91 291.99 291.96 291.74 23 --- 292.18 292.17 292.07 292.14 292.29 292.15 291.92 291.91 291.97 291.92 291.50 24 --- 292.13 292.30 292.05 292.14 292.28 292.12 291.92 291.92 291.96 291.90 291.39 25 --- 292.11 292.29 292.09 292.10 292.29 292.12 291.93 291.95 291.98 291.91 291.42 26 --- 292.12 292.28 292.06 292.10 292.34 292.14 291.90 291.98 292.03 291.88 291.46 27 --- 292.13 292.29 292.06 292.10 292.37 292.20 291.91 292.00 292.05 291.92 291.50 28 292.13 292.10 292.29 292.09 292.10 292.33 292.28 291.90 291.99 292.06 291.95 291.52 29 292.11 292.11 292.28 292.06 --- 292.33 292.31 291.90 291.99 292.07 291.97 291.57 30 292.14 292.12 292.25 292.06 --- 292.28 292.33 291.91 291.98 292.09 292.00 291.62 31 292.11 --- 292.27 292.05 --- 292.26 --- 291.92 --- 292.09 292.04 --­ MEAN 292.12 292.13 292.21 292.11 292.07 292.24 292.27 292.12 291.91 292.00 292.09 291.82 WTR YR 1998 MEAN 292.09 HIGHEST 291.37 SEPT. 24, 1998 LOWEST 292.46 APR. 5, 1998 290 291 292 293 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 496 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182603066333601. Local number, FA-2. LOCATION.--Lat 18°26'03", long 66°33'36", Hydrologic Unit 21010002, 0.70 south of the intersection of Hwy 140 with Hwy 22, 0.35 mi east of the intersection of Hwy 140 with Hwy 2, and 1.35 mi northeast of the intersection of Hwy 140 with Hwy 666. Owner: PR Aqueduct and Sewer Authority, Name: Florida Afuera No. 2. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 16 in (0.41 m), cased 0-270 ft (0-82.3 m), screened 200-270 ft (61.0-82.3 m). Depth 270 ft (82.3 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 213.3 ft (65.0 m), above mean sea level from topographic map. Measuring point: Shelter floor on top of the 4 in (0.10 m) casing, 4.00 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on August 23, 1996, replaced by an Electronic Data Logger (EDL), installed on January 17, 1997. PERIOD OF RECORD.--August 23, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 199.01 ft (60.7 m), below land-surface datum, Sept. 11, 12, 1996; lowest water level recorded, 201.63 ft (61.5 m), below land-surface datum, Apr. 10, 11, 12, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 201.15 201.41 201.31 201.37 2 201.15 201.41 201.31 201.37 3 201.17 201.41 201.31 201.37 4 201.17 201.41 201.31 201.37 5 201.18 201.41 201.34 201.37 6 201.20 201.41 201.34 201.36 7 201.18 201.41 201.34 201.36 8 201.20 201.43 201.34 201.27 9 201.21 201.43 201.32 201.27 10 201.26 201.41 201.29 201.27 11 201.30 201.41 201.29 201.29 12 201.30 201.41 201.31 201.29 13 201.30 201.40 201.34 201.29 14 201.30 201.32 201.32 201.30 15 201.29 201.32 201.35 201.30 16 201.15 201.29 201.32 201.35 201.32 17 201.15 201.30 201.32 201.35 201.32 18 201.15 201.32 201.34 201.35 201.31 19 201.15 201.32 201.31 201.38 201.31 20 201.17 201.33 201.28 201.38 201.31 21 201.18 201.33 201.25 201.38 201.37 22 201.20 201.33 201.25 201.38 201.37 23 201.20 201.35 201.25 201.38 24 201.18 201.38 201.25 201.38 25 201.17 201.39 201.23 201.38 26 201.15 201.39 201.25 201.37 27 201.15 201.41 201.25 201.37 28 201.15 201.41 201.25 201.37 29 201.14 201.41 201.28 201.37 30 201.15 201.41 201.29 201.37 31 201.15 201.32 201.37 MEAN 201.16 201.29 201.34 201.35 201.33 WTR YR 1997 MEAN 201.20 HIGHEST 199.29 JAN. 23, 24, 1997 LOWEST 201.44 JULY 7, 8, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 497 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 201.37 201.47 201.54 201.40 201.47 201.60 201.50 200.86 200.76 200.86 200.61 2 201.37 201.47 201.54 201.40 201.47 201.60 201.54 200.86 200.76 200.86 200.63 3 201.37 201.47 201.52 201.40 201.45 201.61 201.55 200.86 200.79 200.88 200.57 4 201.39 201.50 201.50 201.44 201.47 201.61 201.55 200.86 200.82 200.89 200.56 5 201.40 201.51 201.49 201.41 201.48 201.61 201.55 200.86 200.82 200.90 200.55 6 201.42 201.50 201.48 201.39 201.45 201.62 201.53 200.90 200.82 200.94 200.56 7 201.43 201.50 201.42 201.39 201.48 201.62 201.53 200.88 200.84 200.96 200.56 8 201.43 201.50 201.37 201.38 201.48 201.62 201.53 200.88 200.84 200.96 200.49 9 201.40 201.51 201.39 201.35 201.48 201.62 201.53 200.88 200.85 200.95 200.47 10 201.39 201.51 201.37 201.35 201.49 201.63 201.53 200.81 200.86 200.94 200.46 11 201.40 201.51 201.37 201.33 201.54 201.63 201.53 200.81 200.86 200.96 200.45 12 201.40 201.53 201.37 201.35 201.54 201.63 201.54 200.81 200.86 200.97 200.44 13 201.40 201.51 201.37 201.36 201.53 201.62 201.54 200.81 200.86 200.97 200.43 14 201.42 201.51 201.39 201.39 201.51 201.60 201.57 200.66 200.86 200.96 200.37 15 201.43 201.53 201.39 201.38 201.51 201.60 201.24 200.42 200.86 200.97 200.37 16 201.43 201.53 201.39 201.39 201.53 201.56 201.19 200.42 200.86 200.96 200.38 17 201.43 201.53 201.42 201.41 201.52 201.51 201.23 200.42 200.86 200.96 200.38 18 201.45 201.51 201.42 201.41 201.54 201.51 200.93 200.42 200.85 200.97 200.40 19 201.45 201.51 201.40 201.42 201.58 201.50 200.90 200.43 200.82 200.97 200.38 20 201.44 201.51 201.40 201.42 201.62 201.17 200.63 200.46 200.81 200.91 200.37 21 201.45 201.51 201.39 201.45 201.61 201.19 200.66 200.51 200.80 200.86 200.34 22 201.44 201.52 201.39 201.47 201.61 201.26 200.76 200.57 200.81 200.77 200.35 23 201.44 201.52 201.39 201.49 201.59 201.29 200.84 200.64 200.82 200.70 200.34 24 201.45 201.52 201.37 201.49 201.59 201.32 200.86 200.67 200.83 200.66 200.31 25 201.45 201.52 201.37 201.49 201.59 201.34 200.90 200.70 200.84 200.62 200.30 26 201.45 201.52 201.37 201.51 201.61 201.34 200.91 200.72 200.83 200.61 200.29 27 201.45 201.54 201.37 201.49 201.61 201.36 200.94 200.73 200.83 200.59 200.29 28 201.32 201.45 201.54 201.39 201.48 201.61 201.39 200.94 200.74 200.81 200.58 200.28 29 201.35 201.44 201.54 201.39 201.61 201.43 200.94 200.74 200.81 200.57 200.27 30 201.35 201.45 201.52 201.40 201.61 201.48 200.94 200.76 200.83 200.57 200.26 31 201.37 201.54 201.40 201.61 200.91 200.84 200.58 MEAN 201.35 201.42 201.51 201.41 201.42 201.54 201.50 201.20 200.70 200.83 200.83 200.42 WTR YR 1998 MEAN 201.16 HIGHEST 200.25 SEPT. 30, 1998 LOWEST 201.63 APR. 10, 11, 12, 1998 200 LAND-SURFACE DATUM 201 WATER LEVEL, IN FEET BELOW 202 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 498 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182209066340600. Local number, FL-1. LOCATION.--Lat 18°22'09", long 66°34'06", Hydrologic Unit 21010002, 0.20 north of the intersection of Hwy 140 with Hwy 642, 1.15 mi south of the intersection of Hwy 140 with Hwy 641, and approximately 100 ft west of Hwy 140. Owner: PR Aqueduct and Sewer Authority, Name: Florida 1. AQUIFER.--Cibao Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 12 in (0.30 m), Depth 200 ft (61.0 m). INSTRUMENTATION.--Pressure transducer with an electronic data logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 607 ft (185 m), above mean sea level from topographic map. Measuring point: Shelter floor 4.00 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--August 12, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 137.91 ft (42.0 m), below land-surface datum, Sept. 22, 1998; lowest water level recorded, 157.63 ft (48.0 m), below land-surface datum, Aug. 14, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 151.59 152.33 153.45 153.25 154.60 154.27 152.96 147.98 151.55 153.66 153.64 2 151.78 152.43 153.57 153.40 154.72 154.48 150.16 149.30 151.76 153.83 153.86 3 151.88 152.53 153.66 152.70 154.82 154.62 152.02 150.24 151.97 153.98 148.21 4 151.08 152.62 153.76 153.13 154.89 154.75 152.34 150.88 151.63 154.10 149.29 5 151.28 152.72 153.81 146.84 154.94 154.85 152.54 151.34 151.97 154.21 150.25 6 151.38 152.82 150.29 148.96 153.15 154.95 152.48 150.50 152.19 154.28 151.00 7 151.47 152.92 148.07 149.83 153.53 155.07 150.20 149.54 152.39 154.37 152.13 8 151.67 153.02 148.95 150.59 153.37 155.10 152.18 150.49 152.58 153.49 150.12 9 151.77 153.11 149.27 148.93 153.73 155.12 148.96 151.52 152.76 153.86 150.47 10 151.87 153.21 149.37 150.23 153.99 155.22 150.08 151.88 152.91 153.76 151.38 11 151.97 153.21 149.29 151.23 154.21 155.31 149.10 152.15 153.03 154.07 152.42 12 151.36 153.31 149.36 151.63 154.40 155.41 150.30 152.39 153.16 154.31 152.86 13 151.56 153.41 147.11 152.02 154.53 155.46 150.64 148.64 153.26 154.29 153.06 14 151.76 153.51 149.40 152.37 154.65 155.54 149.99 143.93 153.36 154.49 153.15 15 151.86 153.60 150.60 152.69 154.76 155.57 149.90 144.98 153.46 154.64 153.36 16 151.76 153.70 151.63 152.92 152.67 148.60 149.61 146.27 153.53 154.78 153.58 17 151.86 153.71 152.01 153.11 153.21 146.65 148.74 147.32 153.66 150.89 153.78 18 151.95 153.83 152.36 153.30 153.63 150.25 148.45 148.09 153.12 152.71 153.98 19 151.75 153.94 152.13 153.47 153.73 151.08 147.85 148.80 153.21 152.26 152.64 20 151.95 154.04 149.55 153.64 153.86 145.73 144.93 149.44 153.44 152.84 153.10 21 152.05 154.12 150.70 153.80 153.74 147.14 145.50 149.95 153.53 147.56 153.37 22 152.15 154.24 150.69 153.96 154.00 148.45 146.17 149.07 153.66 148.96 141.97 23 152.24 154.35 150.54 154.08 154.21 149.57 147.67 149.83 153.81 150.36 139.67 24 150.30 152.34 154.43 150.51 154.19 154.38 150.46 147.98 150.43 153.48 151.16 142.13 25 150.50 152.44 154.48 149.98 154.30 154.52 150.50 149.09 150.86 153.40 149.06 144.00 26 150.80 152.54 154.53 151.77 154.40 154.62 151.60 150.00 148.67 153.62 150.54 145.04 27 150.99 151.44 154.58 151.96 154.46 154.70 152.06 150.12 149.49 151.17 151.46 145.40 28 151.09 151.73 154.63 151.95 154.55 154.79 152.39 150.83 150.25 152.67 152.70 145.92 29 151.19 151.93 154.69 152.42 154.88 150.27 151.25 150.83 153.11 152.34 146.54 30 151.39 152.13 154.73 152.69 153.49 152.75 151.60 151.38 153.26 152.89 147.20 31 151.49 154.79 153.02 153.92 148.08 153.48 153.31 MEAN 150.97 151.82 153.66 151.09 152.43 154.15 152.44 149.73 149.55 152.91 152.75 149.78 WTR YR 1998 MEAN 151.83 HIGHEST 137.91 SEPT. 22, 1998 LOWEST 155.61 APR. 15, 16, 1998 130 140 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 150 160 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 499 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182757066325600. Local number, 206. LOCATION.--Lat 18°27'57", long 66°32'56", Hydrologic Unit 21010002, 0.84 mi northwest of Barceloneta plaza, 0.64 mi west of Central Plazuela, and 1.96 mi southeast of Escuela Agustín Balseiro. Owner: PR Department of Agriculture, Name: Plazuela No. 2. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m), cased 16 in (0.41 m) 0-85.0 ft (0-25.9 m), open hole 85-101 ft (25.9-30.8 m). Depth 101 ft (30.8 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 7.00 ft (2.1 m), above mean sea level, from topographic map. Measuring point: Hole on side of casing, 1.30 ft (0.40 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 7, 1997. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.75 ft (1.14 m), below land-surface datum, Sept. 11, 1988; lowest water level recorded, 6.03 ft (1.84 m), below land-surface datum, Sept. 15, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.32 5.47 5.44 5.50 5.32 5.42 5.57 5.66 5.20 5.26 5.37 5.28 2 5.30 5.45 5.45 5.49 5.33 5.44 5.61 5.64 5.18 5.29 5.39 5.25 3 5.31 5.46 5.49 5.49 5.38 5.46 5.66 5.61 5.18 5.30 5.40 5.21 4 5.30 5.54 5.55 5.46 5.34 5.47 5.69 5.57 5.19 5.30 5.41 5.21 5 5.31 5.56 5.57 5.41 5.22 5.47 5.67 5.56 5.21 5.27 5.44 5.19 6 5.33 5.56 5.54 5.36 5.25 5.44 5.60 5.56 5.22 5.28 5.46 5.20 7 5.38 5.54 5.49 5.30 5.26 5.46 5.56 5.54 5.19 5.29 5.44 5.19 8 5.39 5.50 5.48 5.30 5.26 5.47 5.56 5.55 5.23 5.31 5.41 5.17 9 5.37 5.47 5.48 5.31 5.26 5.48 5.62 5.53 5.25 5.31 5.39 5.14 10 5.37 5.45 5.48 5.29 5.27 5.49 5.65 5.56 5.25 5.29 5.43 5.14 11 5.35 5.44 5.47 5.28 5.31 5.47 5.58 5.57 5.25 5.26 5.42 5.14 12 5.31 5.45 5.48 5.29 5.38 5.47 5.53 5.56 5.25 5.24 5.43 5.14 13 5.23 5.45 5.48 5.30 5.42 5.48 5.50 5.56 5.21 5.22 5.46 5.17 14 5.16 5.46 5.49 5.38 5.39 5.53 5.57 5.55 5.13 5.21 5.49 5.16 15 5.12 5.47 5.48 5.41 5.36 5.55 5.64 5.44 5.06 5.22 5.51 5.17 16 5.11 5.48 5.48 5.39 5.41 5.56 5.63 5.42 5.06 5.23 5.50 17 5.20 5.49 5.48 5.41 5.44 5.59 5.58 5.42 5.09 5.25 5.50 18 5.32 5.51 5.48 5.41 5.43 5.63 5.58 5.37 5.13 5.26 5.47 19 5.37 5.52 5.51 5.37 5.43 5.64 5.58 5.35 5.14 5.26 5.40 20 5.42 5.52 5.54 5.33 5.46 5.65 5.51 5.31 5.16 5.25 5.34 21 5.44 5.50 5.54 5.32 5.49 5.61 5.47 5.24 5.18 5.26 5.26 22 5.46 5.51 5.51 5.31 5.50 5.58 5.46 5.23 5.22 5.27 5.21 23 5.45 5.52 5.48 5.31 5.49 5.58 5.46 5.22 5.22 5.25 5.18 24 5.50 5.49 5.50 5.32 5.46 5.59 5.46 5.22 5.22 5.24 5.16 25 5.52 5.48 5.50 5.31 5.44 5.59 5.44 5.22 5.24 5.25 5.15 26 5.50 5.46 5.50 5.33 5.43 5.61 5.46 5.17 5.26 5.29 5.13 27 5.47 5.46 5.49 5.32 5.42 5.64 5.50 5.18 5.28 5.30 5.15 28 5.49 5.45 5.48 5.32 5.39 5.64 5.55 5.18 5.27 5.32 5.19 29 5.49 5.45 5.45 5.31 5.62 5.59 5.19 5.27 5.33 5.20 30 5.49 5.46 5.45 5.32 5.56 5.62 5.20 5.26 5.34 5.22 31 5.48 5.47 5.32 5.55 5.21 5.36 5.26 MEAN 5.36 5.49 5.49 5.35 5.38 5.54 5.56 5.41 5.20 5.27 5.35 5.18 WTR YR 1998 MEAN 5.39 HIGHEST 5.03 JUNE 16, 1998 LOWEST 5.71 APR. 3, 4, 5, 1998 2 4 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 6 8 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 500 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182710066303700. Local number, 207. LOCATION.--Lat 18°27'10", long 66°30'37", Hydrologic Unit 21010002, 1.92 mi east of Barceloneta plaza, 1.35 mi north of Central Monserrate, and 2.68 mi northeast of Escuela José Cordero. Owner: PR Aqueduct and Sewer Authority, Name: Cantito La Luisa. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-30.0 ft (0-9.14 m), cased 10 in (0.25 m) 0-126 ft (0-38.4 m), perforated 80-126 ft (24.4-38.4 m). Depth 126 ft (38.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 59.0 ft (18.0 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 2.80 ft (0.85 m), above land-surface datum. Prior to Nov. 20, 1992, hole on side of casing, 2.00 ft (0.61 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 5, 1997. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 36.4 ft (11.1 m), below land-surface datum, May 15, 1986; lowest water level recorded, 89.8 ft (27.4 m), below land-surface datum, Oct. 5, 1985. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 39.09 39.05 38.76 39.28 2 39.08 39.07 38.77 39.25 3 39.08 39.07 38.80 39.23 4 39.05 39.07 38.84 39.20 5 39.05 38.50 38.86 39.17 39.01 39.00 --- 39.22 38.87 39.17 39.28 39.15 39.00 39.01 --- 39.25 38.87 39.17 39.28 39.15 39.01 39.03 --- 39.25 38.87 39.17 39.27 39.14 39.03 39.06 --- 39.25 38.87 39.18 39.27 39.15 38.95 39.08 --- 39.25 38.87 39.19 39.30 39.15 6 39.02 38.51 38.86 39.15 7 39.03 38.51 38.85 39.10 8 39.03 38.49 38.87 39.02 9 39.03 38.49 38.90 39.02 10 39.02 38.49 38.91 39.02 38.89 39.07 --- 39.26 38.87 39.19 39.31 39.15 38.87 39.08 --- 39.26 38.89 39.20 39.33 39.15 38.87 39.10 --- 39.26 38.89 39.22 39.31 39.13 38.86 39.13 --- 39.26 38.90 39.23 39.31 39.12 38.86 39.15 --- 39.27 38.92 39.24 39.32 39.11 11 39.00 38.50 38.93 39.01 12 38.95 38.52 38.95 38.97 13 38.85 38.53 38.97 38.96 14 38.76 38.57 39.00 38.97 15 38.70 38.61 39.00 38.98 38.86 39.16 --- 39.27 38.93 39.24 39.32 39.09 38.87 39.16 --- 39.26 38.94 39.25 39.31 39.09 38.88 39.17 --- 39.29 38.95 39.24 39.32 39.10 38.90 39.19 --- 39.29 38.95 39.23 39.33 39.08 38.90 39.21 --- 39.09 38.93 39.23 39.33 39.08 16 38.64 38.64 39.00 38.98 17 38.66 38.66 39.02 38.99 18 38.72 38.68 39.02 39.00 19 38.76 38.69 39.04 39.00 20 38.78 38.70 39.06 39.02 38.93 39.22 --- 39.07 38.93 39.23 39.33 39.09 38.97 39.24 --- 39.04 38.94 39.23 39.32 --- 38.98 39.27 --- 38.97 38.96 39.24 39.32 --- 38.99 39.28 --- 38.97 38.97 39.24 39.30 --- 38.99 39.32 --- 38.96 38.98 39.25 39.29 --­ 21 38.82 38.70 39.10 39.01 22 38.85 38.70 39.11 39.00 23 38.85 38.71 39.12 39.00 24 38.89 38.72 39.14 38.99 25 38.92 38.72 39.16 38.99 39.03 39.33 --- 38.92 39.00 39.25 39.25 --- 39.07 39.33 --- 38.89 39.04 39.26 39.21 --- 39.09 39.33 --- 38.88 39.04 39.26 39.18 --- 39.12 39.34 --- 38.87 39.06 39.26 39.17 --- 39.12 39.36 --- 38.87 39.07 39.26 39.15 --­ 26 38.96 38.74 39.18 39.00 27 38.99 38.76 39.22 39.01 28 39.01 38.75 39.23 39.02 29 39.03 38.75 39.23 39.03 30 39.06 38.76 39.27 39.04 31 39.06 --- 39.28 39.03 39.11 39.37 --- 38.87 39.12 39.26 39.12 --- 39.06 39.39 --- 38.87 39.17 39.27 39.12 --- 39.00 39.39 --- 38.87 39.17 39.28 39.12 --­ --- 39.39 39.22 38.87 39.17 39.28 39.12 --­ --- 39.38 39.21 38.87 39.17 39.28 39.12 --­ --- --- --- 38.87 --- 39.28 39.14 --­ MEAN 38.93 38.69 39.01 39.05 38.97 39.22 39.22 39.08 38.98 39.23 39.25 39.12 WTR YR 1998 MEAN 39.05 HIGHEST 38.48 NOV. 5, 8, 9, 10, 1997 LOWEST 39.39 MAR. 27, 28, 29, 30, 1998 37 38 39 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR Date level Sept. 9 23.77 501 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182549066304300. Local number, 166. LOCATION.--Lat 18°25'49", long 66°30'43", Hydrologic Unit 21010002, 0.95 mi east of the Rio Grande de Manatí Hwy 2 bridge, 0.40 mi southwest of Central Monserrate, 1.07 mi east of the intersection of Hwy 666 with Hwy 2, 1.20 mi west of the intersection of Hwy 685 with Hwy 2, 0.01 mi north of Hwy 2. Owner: PR Aqueduct and Sewer Authority Name: Manatí 3. AQUIFER.--Alluvial deposits. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 0-100 ft (0-39.49 m), diameter 14 in (0.36 m), cased 0-140 ft (0-42.7 m), slotted 80-90 ft (24.7-27.4 m), and 130-140 ft (39.6-42.7 m). Depth 140 ft (42.7 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 29.50 ft (9.0 m), above mean-sea level, from topographic map. Measuring point: A hole in the side of the 20 in (0.51 m) diameter well casing, 1.65 ft (0.50 m) above land-surface datum. Prior May 31, 1996, top of 14 in (0.36 m) casing, 0.80 ft (0.24 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 31, 1996. Formerly published as 182542066305200. From September 9, 1998, monthly measurements only. PERIOD OF RECORD.--January 1982 to December 1984, discontinued, May 31, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 22.11 ft (6.74 m), below land-surface datum, Jan. 25, 1997; lowest water level measured, 26.36 ft (8.04 m), below land-surface datum, Feb. 3, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.06 23.97 24.12 24.19 2 24.03 23.98 24.14 24.18 3 24.03 24.00 24.13 24.16 4 23.99 23.98 24.16 24.13 5 23.97 24.00 24.17 24.11 23.87 23.95 24.16 24.06 23.25 23.78 --- --- 23.88 23.97 24.19 24.10 23.25 23.75 --- --- 24.04 23.99 24.22 24.09 23.23 23.79 --- --- 24.11 24.03 24.22 24.10 23.32 23.87 --- --- 23.83 24.02 24.25 24.12 23.32 23.88 --- --­ 6 23.90 24.03 24.16 24.11 7 23.91 24.02 24.17 23.99 8 23.91 24.04 24.17 23.92 9 23.91 24.04 24.16 23.93 10 23.90 24.05 24.18 23.95 23.73 24.02 24.25 24.12 23.34 23.92 --- --- 23.63 24.02 24.25 24.09 23.27 23.93 --- --- 23.62 23.99 24.22 24.10 23.37 23.99 --- --- 23.58 24.04 24.20 24.09 23.46 23.93 --- --- 23.62 24.14 24.23 24.07 23.43 23.99 --- --­ 11 23.90 24.06 24.24 23.91 12 23.81 24.06 24.19 23.81 13 23.61 24.07 24.21 23.79 14 23.47 24.07 24.24 23.77 15 23.45 24.14 24.14 23.77 23.70 24.11 24.24 24.10 23.41 23.95 --- --- 23.71 24.10 24.22 24.17 23.41 23.94 --- --- 23.76 24.12 24.19 24.12 23.41 23.97 --- --- 23.77 24.12 24.30 24.13 23.42 23.99 --- --- 23.79 24.10 24.24 23.60 23.36 23.92 --- --­ 16 23.39 24.14 24.11 23.80 17 23.39 24.14 24.14 23.85 18 23.38 24.14 24.13 23.89 19 23.38 24.08 24.19 23.91 20 23.38 24.12 24.20 23.88 23.84 24.12 24.14 23.53 23.28 23.96 --- --- 23.86 24.13 23.99 23.45 23.40 23.98 --- --- 23.88 24.16 23.91 23.41 23.44 23.92 --- --- 23.91 24.15 23.91 23.37 23.46 23.98 --- --- 23.91 24.17 23.85 23.32 23.48 23.91 --- --­ 21 23.38 24.12 24.18 23.89 22 23.57 24.14 24.24 23.89 23 23.63 24.18 24.23 23.91 24 23.66 24.19 24.22 23.90 25 23.76 24.17 24.24 23.86 23.95 24.18 23.79 23.25 23.51 23.89 --- --- 23.98 24.21 23.80 23.19 23.42 23.90 --- --- 24.00 24.20 23.83 23.18 23.52 23.95 --- --- 24.03 24.19 23.84 23.18 23.57 23.91 --- --- 24.04 24.21 23.85 23.22 23.61 23.87 --- --­ 26 23.78 24.14 24.22 23.85 27 23.83 24.16 24.24 23.87 28 23.86 24.14 24.25 23.87 29 23.90 24.16 24.24 23.89 30 23.93 24.14 24.22 23.90 31 23.97 --- 24.21 23.89 24.05 24.17 23.87 23.23 23.68 23.87 --- --- 24.02 24.19 23.89 23.24 23.65 23.89 --- --- 23.98 24.24 23.91 23.29 23.67 --- --- --­ --- 24.20 23.96 23.33 23.70 --- --- --­ --- 24.21 24.03 23.25 23.73 --- --- --­ --- 24.16 --- 23.23 --- --- --- --­ MEAN 23.74 24.09 24.19 23.93 23.86 24.12 24.07 23.67 23.45 23.91 --- --­ WTR YR 1998 MEAN 23.90 HIGHEST 23.10 MAY 22, 1998 LOWEST 24.30 APR. 14, 1998 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS 22 Water 23 24 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 25 1996 1997 1998 WATER YEAR WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM --- --- --- --- --- --- --- 502 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182506066280200. Local number, HI-2. LOCATION.--Lat 18°25'06", long 66°28'02", Hydrologic Unit 21010002, 0.72 mi southwest of the intersection of Hwy 686 with Hwy 670, 0.73 mi southeast of intersection of Hwy 149 with Hwy 670, and 0.78 mi northeast of Escuela Sabana Seca. Owner: US Geological Survey, WRD, Name: USGS Hill 2. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), screened 360-410 ft (110-125 m). Depth 410 ft (125 m). INSTRUMENTATION.--Pressure transducer with integrated electronic data logger--60 minutes interval. DATUM.--Elevation of land-surface datum is about 312 ft (95.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.76 ft (1.15 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on May 28, 1996. PERIOD OF RECORD.--May 28, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 267.96 ft (81.7 m), below land-surface datum, Jan. 24, 1997; lowest water level recorded, 293.09 ft (89.3 m), below land-surface datum, Sept. 5, 6, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 288.65 288.66 289.45 290.21 290.27 290.44 290.61 290.41 289.07 288.96 288.70 289.07 2 288.65 288.72 289.54 290.19 290.28 290.47 290.76 290.42 289.06 288.92 288.67 289.04 3 288.65 288.74 289.61 290.16 290.19 290.49 290.82 290.41 288.96 288.87 288.71 289.18 4 288.73 288.81 289.57 290.14 290.12 290.54 290.79 290.39 288.90 288.85 288.80 289.32 5 288.75 288.86 289.56 290.15 290.19 290.60 290.72 290.43 288.88 288.87 288.83 289.31 6 288.73 288.85 289.54 290.19 290.29 290.59 290.74 290.44 288.85 288.90 288.83 289.32 7 288.65 288.80 289.64 290.15 290.25 290.58 290.91 290.41 288.88 288.87 288.82 289.30 8 288.59 288.82 289.70 290.24 290.17 290.67 291.04 290.39 289.00 288.89 288.86 289.35 9 288.59 288.91 289.68 290.26 290.20 290.71 291.00 290.43 289.07 288.89 288.83 289.38 10 288.57 289.05 289.69 290.25 290.27 290.73 290.90 290.44 289.08 288.87 288.82 289.42 11 288.55 289.09 289.71 290.19 290.32 290.67 290.88 290.39 289.07 288.82 288.88 289.38 12 288.49 289.13 289.74 290.20 290.32 290.74 290.87 290.40 288.92 288.78 288.93 289.37 13 288.37 289.14 289.72 290.23 290.27 290.79 291.05 290.41 288.87 288.75 288.89 289.40 14 287.38 289.15 289.70 289.83 290.25 290.77 291.08 290.36 288.86 288.75 288.86 289.47 15 286.34 289.21 289.73 289.66 290.27 290.67 291.04 290.24 288.90 288.78 288.88 289.59 16 287.48 289.26 289.78 289.73 290.30 290.70 290.96 290.25 288.98 288.76 288.95 289.62 17 287.62 289.30 289.84 289.82 290.21 290.75 290.78 290.29 289.00 288.77 289.00 289.67 18 287.76 289.35 289.87 289.87 290.21 290.78 290.67 290.28 288.95 288.70 288.96 289.69 19 287.88 289.35 289.95 289.90 290.24 290.80 290.52 290.23 288.97 288.75 288.93 289.74 20 287.92 289.32 289.93 289.96 290.29 290.78 290.47 290.04 288.97 288.78 289.03 289.79 21 288.03 289.39 289.88 290.05 290.31 290.68 290.33 289.88 289.00 288.77 288.92 289.70 22 288.16 289.39 289.94 290.08 290.39 290.74 290.15 289.74 289.06 288.72 289.04 288.89 23 288.27 289.41 289.95 290.16 290.36 290.83 290.16 289.71 289.06 288.71 289.10 288.82 24 288.33 289.40 289.96 290.16 290.36 290.90 290.23 289.72 289.07 288.69 289.07 286.97 25 288.37 289.36 290.01 290.20 290.39 290.97 290.34 289.69 289.04 288.79 289.13 287.53 26 288.44 289.37 290.02 290.20 290.42 291.00 290.38 289.69 288.99 288.71 289.16 287.94 27 288.47 289.38 289.97 290.20 290.44 290.90 290.39 289.76 288.95 288.66 288.97 288.04 28 288.50 289.48 289.97 290.21 290.46 290.76 290.43 289.73 288.97 288.68 288.84 288.19 29 288.53 289.45 290.02 290.19 290.65 290.51 289.69 289.01 288.68 288.93 288.44 30 288.54 289.40 290.09 290.15 290.54 290.50 289.69 288.98 288.71 288.97 288.63 31 288.61 290.18 290.16 290.50 289.47 288.69 289.07 MEAN 288.28 289.15 289.80 290.10 290.29 290.70 290.67 290.12 288.98 288.79 288.92 289.05 WTR YR 1998 MEAN 289.57 HIGHEST 285.27 SEPT. 22, 1998 LOWEST 291.10 APR. 14, 1988 270 280 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 290 300 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 503 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182308066260400. Local number, 210. LOCATION.--Lat 18°23'08", long 66°26'04", Hydrologic Unit 21010002, 4.88 mi southeast of Manatí plaza, 5.24 mi southwest of Vega Baja plaza, and 2.25 mi west of Escuela Evaristo Camacho. Owner: Gelo Martínez, Name: Gelo Martínez well. AQUIFER.--Lares Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.20 m), cased 8 in (0.20 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is about 574 ft (174.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.30 ft (1.01 m), above land-surface datum. Prior to January 14, 1993, hole on side of casing, 2.00 ft (0.61 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 17, 1997. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 40.56 ft (12.4 m), below land-surface datum, May 22, 1986; lowest water level recorded, 85.50 ft (26.1 m), below land-surface datum, Oct. 14, 15, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 80.14 80.95 82.75 85.12 85.72 82.93 83.00 82.44 79.85 78.30 2 80.14 80.98 82.83 85.15 85.71 82.93 82.98 82.41 79.72 78.31 3 80.13 81.00 82.90 85.19 85.71 82.93 82.96 82.38 79.60 78.33 4 80.15 81.01 82.98 85.26 85.69 82.93 82.95 82.37 79.51 78.38 5 80.19 81.06 83.08 85.31 85.69 82.93 82.94 82.34 79.39 78.39 6 80.22 81.10 83.15 85.33 85.67 82.93 82.92 82.31 79.32 78.42 7 80.26 81.12 83.26 85.37 85.67 82.92 82.91 82.28 79.25 78.43 8 80.29 81.15 83.34 85.38 85.66 82.92 82.89 82.25 79.20 78.43 9 80.33 81.18 83.42 85.40 85.62 82.93 82.88 82.18 79.14 78.44 10 80.38 81.22 83.49 85.51 82.93 82.87 82.15 79.08 78.55 11 80.43 81.27 83.57 85.54 82.94 82.83 82.11 79.01 78.58 12 80.48 81.31 83.64 85.58 82.95 82.80 82.07 78.97 78.62 13 80.52 81.34 83.77 85.61 82.98 82.79 82.03 78.92 78.63 14 80.57 81.39 83.85 85.65 82.99 82.77 81.98 78.90 78.64 15 80.58 81.42 83.93 85.69 83.01 82.76 81.93 78.84 78.65 16 80.62 81.46 84.00 85.70 83.04 82.74 81.88 78.80 78.62 17 80.65 81.50 84.08 85.73 83.05 82.74 81.79 78.76 78.66 18 80.68 81.58 84.16 85.74 83.07 82.73 81.76 78.73 78.68 19 80.71 81.67 84.24 85.75 83.08 82.71 81.70 78.70 78.70 20 80.74 81.75 84.31 85.75 83.10 82.69 81.62 78.67 78.73 21 80.76 81.84 84.37 85.76 83.11 82.67 81.53 78.63 78.77 22 80.78 81.95 84.43 85.76 83.11 82.66 81.50 78.58 78.25 23 80.80 82.04 84.49 85.77 83.11 82.63 81.34 78.53 77.90 24 80.82 82.14 84.54 85.78 83.11 82.61 81.17 78.46 77.67 25 80.84 82.22 84.73 85.78 83.10 82.58 81.06 78.42 77.27 26 80.86 82.30 84.80 85.79 83.10 82.56 80.89 78.39 76.72 27 80.88 82.36 84.90 85.79 83.08 82.54 80.71 78.38 76.15 28 80.89 82.46 84.96 85.78 83.07 82.51 80.51 78.35 75.68 29 80.90 82.55 85.03 85.77 83.04 82.49 80.33 78.32 75.35 30 80.91 82.65 85.07 85.74 82.93 83.03 82.46 80.14 78.31 75.16 31 80.93 85.09 85.73 83.01 79.98 78.30 MEAN 80.57 81.60 83.97 85.59 85.68 82.93 83.01 82.75 81.65 78.87 77.98 WTR YR 1998 MEAN 81.91 HIGHEST 75.10 SEPT. 30, 1998 LOWEST 85.79 JAN 26, 27, 1998 60 70 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 80 90 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 504 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182548066265700. Local number CS-7 LOCATION.Lat 18°25'48", long 66°26'57", Hydrologic Unit 21010002, 0.92 mi east of the intersection of Hwy 686 with Hwy 670, 0.79 mi south of Hwy 2, 0.27 mi east of the intersection of Hwy 672 with Hwy 670, and 0.01 mi south of Hwy 670. Owner: Puerto Rico Aqueduct and Sewer Authority, Name: Coto Sur No. 7. AQUIFER.--Tertiary Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m). INSTRUMENTATION.--Electronic water level ,logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 270.0 ft (82.3 m), above mean sea level, from topographic map. Measuring point: Top of 20 in (0.51 m) casing, 2.30 ft (0.70 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorded (ADR), installed on July 11, 1994, replaced by an Electronic Data Logger (EDL), installed on May 15, 1997. From Oct. 15, 1997, monthly measurements only. PERIOD OF RECORD.--July 11, 1994 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 254.41 ft (77.54 m), below land-surface datum, Sept. 15, 1996; lowest water level recorded, 260.63 ft (79.44 m), below land-surface datum, Aug. 14, 15, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 15 258.90 Dec. 15 259.63 Feb. 17 259.36 June 10 259.35 Oct. 21 258.92 Jan. 15 259.40 Apr. 29 259.54 June 16 259.39 Nov. 17 259.52 256.0 256.5 257.0 257.5 258.0 258.5 259.0 259.5 260.0 260.5 261.0 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- 505 GROUND-WATER LEVELS RIO CIBUCO BASIN 182614066261500. Local number, PA-2. LOCATION.--Lat 18°26'14", long 66°26'15", Hydrologic Unit 21010002, 1.80 mi east of the intersection of Hwy 686 with Hwy 670, 0.30 mi south of Hwy 2, 0.70 mi northeast of Escuela Ramirez de Arellano, and 0.32 mi north of Hwy 670. Owner: US Geological Survey, WRD, Name: Palo Alto 2. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), screened 265-310 ft (80.8-94.5 m). Depth 310 ft (94.5 m). INSTRUMENTATION.-Pressure transducer with integrated electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 245.5 ft (74.8 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.79 ft (1.16 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on May 28, 1996. PERIOD OF RECORD.--May 28, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 221.78 ft (67.6 m), below land-surface datum, Sept. 12, 1996; lowest water level recorded, 240.14 ft (73.2 m), below land-surface datum, Aug. 18, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 239.43 239.43 239.59 239.80 239.66 239.68 239.92 239.84 239.58 239.93 240.03 239.95 2 239.43 239.44 239.59 239.79 239.65 239.68 239.92 239.86 239.59 239.94 240.04 239.97 3 239.42 239.45 239.61 239.78 239.65 239.70 239.92 239.87 239.59 239.94 240.04 239.97 4 239.42 239.48 239.61 239.76 239.65 239.71 239.93 239.88 239.59 239.95 240.05 239.98 5 239.41 239.49 239.63 239.75 239.49 239.72 239.94 239.89 239.59 239.95 240.06 239.99 6 239.38 239.50 239.63 239.74 239.51 239.73 239.95 239.91 239.61 239.95 240.07 239.99 7 239.37 239.51 239.64 239.72 239.50 239.73 239.95 239.91 239.61 239.96 240.08 239.99 8 239.37 239.51 239.64 239.68 239.49 239.75 239.95 239.92 239.63 239.97 240.09 239.99 9 239.36 239.51 239.65 239.67 239.49 239.76 239.96 239.92 239.65 239.98 240.09 239.98 10 239.36 239.52 239.66 239.66 239.49 239.77 239.96 239.92 239.64 239.99 240.10 239.97 11 239.36 239.52 239.67 239.64 239.50 239.78 239.97 239.91 239.66 239.99 240.10 239.96 12 239.34 239.53 239.68 239.57 239.50 239.79 239.97 239.92 239.68 239.99 240.10 239.96 13 239.30 239.55 239.70 239.56 239.52 239.79 239.97 239.92 239.68 239.99 240.10 239.95 14 239.25 239.56 239.71 239.55 239.54 239.79 239.96 239.93 239.69 239.99 240.11 239.96 15 239.21 239.58 239.72 239.56 239.54 239.80 239.97 239.90 239.69 239.99 240.12 239.96 16 239.16 239.59 239.72 239.56 239.54 239.81 239.93 239.88 239.70 239.99 240.12 239.97 17 239.15 239.60 239.73 239.57 239.57 239.82 239.32 239.86 239.79 240.00 240.12 239.98 18 239.15 239.62 239.72 239.59 239.59 239.84 239.51 239.84 239.79 240.00 240.13 239.99 19 239.17 239.63 239.73 239.59 239.61 239.86 239.62 239.83 239.79 240.00 240.12 240.00 20 239.18 239.63 239.72 239.61 239.62 239.87 239.66 238.61 239.80 240.01 240.12 239.99 21 239.18 239.62 239.73 239.61 239.64 239.88 239.69 239.01 239.81 239.98 240.10 239.98 22 239.20 239.61 239.74 239.62 239.66 239.88 239.70 239.22 239.84 239.98 240.08 236.88 23 239.21 239.60 239.73 239.62 239.68 239.88 239.71 239.35 239.85 239.99 240.06 236.58 24 239.22 239.58 239.74 239.62 239.69 239.88 239.74 239.43 239.87 240.00 240.03 237.35 25 239.25 239.58 239.75 239.62 239.71 239.90 239.75 239.48 239.88 240.01 240.01 237.92 26 239.28 239.58 239.76 239.63 239.72 239.90 239.76 239.52 239.89 240.01 239.98 238.38 27 239.31 239.59 239.76 239.64 239.72 239.92 239.77 239.55 239.90 240.01 239.97 238.70 28 239.33 239.58 239.76 239.66 239.69 239.93 239.79 239.56 239.91 240.02 239.95 238.92 29 239.36 239.58 239.77 239.66 239.93 239.81 239.58 239.92 240.02 239.95 239.08 30 239.38 239.58 239.78 239.67 239.92 239.83 239.59 239.93 240.02 239.94 239.20 31 239.41 239.79 239.66 239.92 239.59 240.03 239.95 MEAN 239.30 239.55 239.70 239.65 239.59 239.82 239.83 239.69 239.74 239.99 240.06 239.42 WTR YR 1998 MEAN 239.70 HIGHEST 235.50 SEPT. 22, 1998 LOWEST 240.14 AUG. 18, 1998 220 230 WATER LAVEL, IN FEET BELOW LAND-SURFACE DATUM 240 250 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 506 GROUND-WATER LEVELS RIO CIBUCO BASIN 182712066251700. Local number, TO-3. LOCATION.--Lat 18°27'12", long 66°25'17", Hydrologic Unit 21010002, 0.60 mi north of the intersection of Hwy 687 with Hwy 2, 0.55 mi southeast of the eastern shoreline of Laguna Tortuguero, 0.32 mi east of Laguna Rica, and 0.12 mi west of Hwy 687. Owner: US Geological Survey WRD, Name: USGS Tortuguero TW-3. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), screened 68-218 ft (20.7-66.4 m). Depth 218 ft (66.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 30.0 ft (9.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.40 ft (1.04 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 31, 1996. PERIOD OF RECORD.--May 31, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.48 ft (7.16 m), below land-surface datum, Sept. 12, 13, 1996; lowest water level recorded, 25.26 ft (7.70 m), below land-surface datum, June 21, 22, 23, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.80 24.79 24.78 24.95 24.71 24.74 25.01 25.05 2 24.78 24.80 24.79 24.94 24.73 24.75 25.02 25.06 3 24.75 24.81 24.81 24.92 24.74 24.77 25.05 25.05 4 24.73 24.83 24.84 24.89 24.76 24.79 25.09 25.05 5 24.72 24.84 24.85 24.86 24.65 24.80 25.09 25.05 6 24.68 24.84 24.84 24.84 24.62 24.80 25.07 25.05 7 24.69 24.84 24.83 24.79 24.62 24.82 25.07 25.05 8 24.69 24.82 24.82 24.76 24.62 24.83 25.06 25.04 9 24.70 24.80 24.83 24.76 24.62 24.84 25.08 25.03 10 24.69 24.79 24.84 24.76 24.62 24.86 25.10 25.03 11 24.69 24.79 24.84 24.74 24.63 24.86 25.10 25.04 12 24.66 24.80 24.85 24.69 24.65 24.86 25.07 13 24.58 24.81 24.87 24.68 24.67 24.86 25.05 14 24.47 24.83 24.88 24.68 24.67 24.88 25.06 15 24.44 24.84 24.87 24.70 24.66 24.90 25.09 25.01 16 24.34 24.86 24.88 24.70 24.67 24.93 25.05 24.90 17 24.43 24.86 24.89 24.71 24.69 24.94 24.90 24.91 18 24.47 24.87 24.88 24.72 24.70 24.97 24.89 24.92 19 24.50 24.86 24.89 24.71 24.72 25.00 24.89 24.94 20 24.56 24.85 24.89 24.71 24.73 25.01 24.88 24.95 21 24.60 24.81 24.91 24.71 24.75 25.00 24.88 24.96 22 24.62 24.78 24.91 24.71 24.77 24.99 24.88 24.96 23 24.63 24.77 24.91 24.71 24.79 24.99 24.88 24.94 24 24.65 24.77 24.91 24.71 24.80 25.01 24.88 24.93 25 24.67 24.77 24.91 24.71 24.79 25.03 24.89 24.90 24.45 26 24.68 24.77 24.93 24.72 24.80 25.04 24.91 24.73 24.51 27 24.70 24.77 24.94 24.72 24.77 25.06 24.92 24.50 24.54 28 24.73 24.77 24.94 24.74 24.74 25.07 24.95 24.46 24.55 29 24.75 24.78 24.92 24.74 25.06 24.98 24.59 30 24.77 24.78 24.94 24.74 25.04 25.02 24.62 31 24.78 24.95 24.73 25.02 MEAN 24.64 24.81 24.88 24.76 24.70 24.92 24.99 24.94 24.54 WTR YR 1998 MEAN 24.82 HIGHEST 24.34 OCT. 16, 17, 1997 LOWEST 25.11 APR. 10-11, 15-16, 1998 23 24 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 25 26 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR 507 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO CIBUCO BASIN 182615066235300. Local number, 211. LOCATION.--Lat 18°26'15", long 66°23'53", Hydrologic Unit 21010002, 4.46 mi southeast of Manatí plaza, 5.48 mi southwest of Vega Baja plaza, and 1.22 mi east of Hwy 155 km 58.3. Owner: PR Aqueduct and Sewer Authority, Name: Rosario No. 2. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 14 in (0.36 m) 0-200 ft (0-61.0 m), diameter 12 in (0.30 m) 200-250 ft (61.0-76.2 m), cased 12 in (0.30 m) 0-250 ft (0-76.2 m), perforated 210-250 ft (64.0-76.2 m), diameter 10 in (0.25 m) 250-270 ft (76.2-82.3 m), open hole; concrete sealed 0-200 ft (0-61.0 m). Depth 270 ft (82.3 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 215 ft (65.5 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.10 ft (0.94 m), above land-surface datum. Prior to April 11, 1994, hole on side of casing, 1.15 ft (0.35 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 5, 1997. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 191.29 ft (58.3 m), below land-surface datum, May 16, 1986; lowest water level recorded, 194.1 ft (59.2 m), below land-surface datum, Mar. 31, Apr. 1 to 7, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 193.39 193.38 193.55 193.32 193.34 193.60 193.58 193.28 193.46 193.61 193.53 2 --- 193.39 193.38 193.55 193.32 193.34 193.60 193.59 193.29 193.46 193.61 193.53 3 193.36 193.38 193.38 193.55 193.33 193.34 193.60 193.58 193.29 193.47 193.61 193.53 4 193.34 193.38 193.43 193.53 193.34 193.36 193.60 193.58 193.29 193.48 193.61 193.53 5 193.33 193.39 193.45 193.52 193.24 193.38 193.61 193.58 193.30 193.48 193.64 193.53 6 193.31 193.44 193.45 193.50 193.21 193.38 193.61 193.58 193.30 193.48 193.64 193.53 7 193.30 193.44 193.44 193.47 193.21 193.40 193.61 193.57 193.30 193.48 193.65 193.53 8 193.30 193.44 193.44 193.44 193.22 193.41 193.61 193.57 193.30 193.49 193.65 193.53 9 193.30 193.43 193.44 193.43 193.22 193.42 193.61 193.57 193.31 193.54 193.65 193.53 10 193.30 193.42 193.44 193.43 193.22 193.42 193.61 193.56 --- 193.54 193.64 193.53 11 193.31 193.42 193.47 193.42 193.22 193.43 193.61 193.56 193.32 193.54 193.64 193.53 12 193.29 193.42 193.46 193.36 193.22 193.43 193.61 193.57 193.32 193.54 193.64 193.53 13 193.24 193.42 193.48 193.35 193.24 193.44 193.60 193.57 193.32 193.54 193.64 193.53 14 193.16 193.44 193.49 193.31 193.25 193.46 193.59 193.58 193.32 193.53 193.64 193.53 15 193.04 193.45 193.49 193.31 193.25 193.48 193.60 193.58 193.32 193.53 193.64 193.53 16 193.02 193.45 193.49 193.31 193.25 193.48 193.61 193.57 193.32 193.53 193.64 193.53 17 193.02 193.45 193.49 193.31 193.27 193.50 193.56 193.56 193.32 193.53 193.64 193.53 18 193.04 193.46 193.49 193.31 193.27 193.52 193.55 193.55 193.32 193.53 193.65 193.53 19 193.06 193.46 193.49 193.31 193.27 193.53 193.55 193.54 193.32 193.53 193.65 193.53 20 193.08 193.46 193.50 193.31 193.28 193.55 193.55 193.45 193.32 193.53 193.65 193.53 21 193.16 193.46 193.50 193.31 193.31 193.56 193.55 193.39 193.34 193.53 193.64 193.53 22 193.20 193.44 193.51 193.31 193.34 193.56 193.55 193.37 193.35 193.53 193.63 193.41 23 193.21 193.38 193.51 193.31 193.34 193.56 193.55 193.37 193.38 193.53 193.55 193.14 24 193.23 193.38 193.51 193.30 193.35 193.56 193.54 193.37 193.38 193.53 193.55 193.10 25 193.28 193.38 193.51 193.30 193.35 193.59 193.54 193.36 193.43 193.53 193.55 193.09 26 193.31 193.38 193.53 193.30 193.35 193.60 193.54 193.35 193.44 193.53 193.54 193.09 27 193.31 193.38 193.53 193.30 193.35 193.60 193.54 193.35 193.44 193.54 193.54 193.09 28 193.39 193.38 193.54 193.30 193.35 193.62 193.54 193.27 193.46 193.54 193.54 193.09 29 193.39 193.37 193.54 193.32 --- 193.62 193.53 193.27 193.46 193.54 193.54 193.10 30 193.40 193.38 193.55 193.32 --- 193.61 193.54 193.28 193.46 193.54 193.54 193.16 31 193.39 --- 193.55 193.32 --- 193.61 --- 193.28 --- 193.61 193.53 --­ MEAN 193.24 193.42 193.48 193.38 193.28 193.49 193.58 193.48 193.34 193.52 193.61 193.41 WTR YR 1998 MEAN 193.44 HIGHEST 193.02 OCT. 16, 17, 18, 1997 LOWEST 193.65 AUG. 6-21, 1998 192 193 194 195 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 508 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO CIBUCO BASIN 182647066201700. Local number, 70. LOCATION.--Lat 18°26'47", long 66°20'17", Hydrologic Unit 21010002, 1.52 mi north of Vega Alta plaza, 4.78 mi southwest of Dorado plaza, and 2.01 mi northwest of Escuela Industrial para Mujeres. Owner: PR Aqueduct and Sewer Authority, Name: Sabana Hoyos. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled unused artesian well, diameter 8 in (0.20 m), cased 0-90.0 ft (0-27.4 m), perforated. Depth 90.0 ft (27.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 49.0 ft (14.9 m), above mean sea level, from topographic map. Measuring point: Top of casing wooden cover, 1.30 ft (0.40 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 1998. PERIOD OF RECORD.--February 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.33 ft (6.50 m), below land-surface datum, Oct. 26, 1976; lowest water level recorded, 31.12 ft (9.48 m), below land-surface datum, May 12, 13, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29.96 29.52 29.54 29.97 2 29.96 29.54 29.55 29.98 3 29.96 29.57 29.56 29.98 4 29.94 29.59 29.58 29.98 5 29.92 29.61 29.59 29.97 29.45 29.58 30.03 30.05 29.64 29.72 30.09 29.93 29.46 29.60 30.03 30.07 29.63 29.75 30.10 29.93 29.48 29.61 30.03 30.08 29.62 29.77 30.11 29.93 29.50 29.63 30.04 30.09 29.58 29.79 30.12 29.94 29.47 29.65 30.06 30.10 29.56 29.79 30.13 29.94 6 29.87 29.63 29.60 29.95 7 29.85 29.64 29.60 29.87 8 29.83 29.66 29.60 29.83 9 29.81 29.66 29.61 29.80 10 29.80 29.68 29.63 29.77 29.43 29.65 30.07 30.12 29.56 29.80 30.15 29.93 29.38 29.66 30.09 30.13 29.55 29.82 30.16 29.91 29.35 29.68 30.10 30.13 29.55 29.84 30.15 29.90 29.33 29.70 30.12 30.13 29.56 29.85 30.16 29.88 29.32 29.72 30.13 30.14 29.56 29.87 30.16 29.88 11 29.81 29.69 29.64 29.74 12 29.79 29.70 29.64 29.65 13 29.75 29.71 29.65 29.59 14 29.64 29.73 29.67 29.53 15 29.59 29.74 29.67 29.46 29.32 29.73 30.14 30.14 29.56 29.89 30.16 29.88 29.34 29.75 30.14 30.16 29.57 29.91 30.17 29.87 29.35 29.77 30.16 30.18 29.58 29.92 30.17 29.87 29.36 29.80 30.18 30.20 29.58 29.93 30.18 29.87 29.36 29.81 30.19 30.19 29.59 29.95 30.18 29.87 16 29.50 29.76 29.70 29.41 17 29.44 29.76 29.72 29.38 18 29.41 29.77 29.74 29.35 19 29.38 29.75 29.75 29.33 20 29.36 29.74 29.77 29.32 29.37 29.83 30.07 30.16 29.60 29.97 30.18 29.89 29.38 29.86 30.04 30.12 29.61 29.98 30.19 29.90 29.39 29.88 30.00 30.10 29.61 30.00 30.20 29.91 29.41 29.91 29.99 30.08 29.59 30.01 30.19 29.91 29.43 29.93 29.99 30.06 29.59 30.01 30.19 29.91 21 29.34 29.62 29.80 29.33 22 29.35 29.59 29.81 29.33 23 29.36 29.57 29.82 29.34 24 29.37 29.55 29.84 29.36 25 29.38 29.54 29.86 29.36 29.45 29.95 29.98 30.02 29.58 30.01 30.18 29.91 29.47 29.97 29.97 29.99 29.58 30.03 30.16 29.79 29.49 29.99 29.96 29.96 29.59 30.03 30.15 29.55 29.50 30.00 29.96 29.93 29.60 30.04 30.13 29.31 29.53 30.02 29.96 29.91 29.63 30.05 30.08 29.12 26 29.39 29.53 29.87 29.38 27 29.42 29.52 29.89 29.39 28 29.43 29.52 29.90 29.40 29 29.44 29.52 29.92 29.41 30 29.46 29.53 29.94 29.42 31 29.48 --- 29.96 29.44 29.55 30.05 29.96 29.89 29.64 30.07 30.05 28.97 29.56 30.06 29.97 29.88 29.67 30.06 30.01 28.85 29.57 30.08 29.98 29.85 29.68 30.07 29.98 28.77 --- 30.08 30.00 29.84 29.68 30.07 29.96 28.71 --- 30.08 30.02 29.72 29.70 30.08 29.93 28.67 --- 30.04 --- 29.67 --- 30.09 29.93 --­ MEAN 29.61 29.63 29.72 29.58 29.43 29.84 30.05 30.04 29.60 29.94 30.12 29.66 WTR YR 1998 MEAN 29.77 HIGHEST 28.66 SEPT. 30, 1998 LOWRST 30.20 APR. 15, 16, MAY 14, 15, 1998 26 28 30 32 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 509 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO CIBUCO BASIN 182515066194000. Local number, 212. LOCATION.--Lat 18°25'15", long 66° 19'40", Hydrologic Unit 21010002, 5.15 mi southwest of Dorado plaza, 0.49 mi north of Vega Alta plaza, and 1.04 mi northwest of Escuela Industrial para Mujeres. Owner: US Geological Survey, WRD, Name: Ponderosa TW-1. AQUIFER.--Aguada Limestone-Cibao Formation. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-136 ft (0-41.1 m), perforated 121-131 ft (36.9-39.9 m); bentonite packed 0.5-121 ft (0.15-36.9 m). Depth 136 ft (39.9 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 98.0 ft (29.9 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 2.55 ft (0.78 m), above land-surface datum. Prior to November 3, 1989, hole on top of shelter floor casing, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 1998. Water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 63.05 ft (19.2 m), below land-surface datum, July 15, 1987; lowest water level recorded, 75.33 ft (22.9 m), below land-surface datum, Feb. 27, Mar. 4, 5, 6, 1995 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 69.93 68.76 68.98 70.61 2 69.91 68.77 68.96 72.34 3 69.88 68.77 68.98 72.72 4 69.86 68.78 68.99 70.47 5 69.83 68.83 69.00 72.26 69.60 72.67 73.71 71.24 70.18 69.38 73.09 73.53 69.59 72.71 73.72 72.17 70.07 70.36 73.12 73.53 69.54 72.74 73.74 72.38 70.00 71.54 73.19 73.55 69.53 72.77 73.75 72.54 69.95 70.38 73.23 73.56 69.51 72.84 73.78 72.66 69.88 69.77 73.33 73.58 6 69.77 68.84 69.01 72.71 7 69.77 68.86 69.02 70.77 8 69.70 68.91 69.06 72.71 9 69.66 68.92 69.09 72.82 10 69.61 68.95 69.14 72.85 69.49 72.86 73.79 72.72 69.82 69.74 73.41 73.59 69.46 72.88 73.81 72.78 69.77 71.23 73.44 73.61 69.46 72.92 71.73 72.84 69.72 71.84 73.45 73.63 69.40 72.97 73.59 72.87 69.69 71.51 73.48 73.62 69.39 72.98 73.71 72.90 69.63 72.05 73.50 73.63 11 69.60 68.95 69.15 72.85 12 69.56 68.97 69.16 72.78 13 69.46 68.98 69.17 72.71 14 69.36 68.99 69.18 72.66 15 69.26 69.01 69.22 72.59 69.37 73.02 73.76 72.72 69.59 72.21 73.53 73.64 69.35 73.08 73.77 73.00 69.57 72.31 73.55 73.66 69.34 73.12 71.89 73.05 69.57 72.43 73.56 73.68 69.35 73.14 71.39 73.11 69.53 72.56 73.56 72.88 69.33 73.17 71.50 73.12 69.45 72.66 73.56 73.40 16 69.19 69.06 70.35 72.57 17 69.12 69.09 69.98 72.55 18 69.02 69.10 69.55 72.52 19 68.96 69.10 69.57 72.51 20 68.93 69.11 71.76 72.43 69.32 73.21 71.12 73.12 69.42 72.70 73.57 73.54 69.31 73.31 70.89 73.12 69.40 72.74 73.59 73.63 71.49 73.35 70.76 73.12 69.38 72.78 73.59 73.67 71.77 73.39 70.65 73.12 69.35 72.84 73.70 73.73 71.40 73.44 70.48 73.12 69.32 72.86 73.51 73.80 21 68.88 69.11 71.95 72.44 22 68.82 69.03 72.14 72.44 23 68.78 69.01 72.29 72.45 24 68.77 69.00 72.40 70.21 25 68.77 68.97 72.54 69.99 71.89 73.45 70.42 73.10 71.33 71.35 73.52 73.84 72.07 73.49 70.35 73.02 71.00 72.40 73.69 71.49 72.21 73.53 70.32 73.02 69.89 72.77 73.71 71.25 72.30 71.61 70.25 73.01 69.54 72.86 73.13 71.03 72.39 71.14 70.22 73.01 69.78 72.92 73.52 70.84 26 68.77 68.95 72.59 69.89 27 68.77 68.94 72.68 69.80 28 68.77 68.94 72.73 69.71 29 68.76 68.94 72.82 69.65 30 68.76 68.94 72.86 69.62 31 68.76 --- 71.07 69.75 72.53 72.69 70.19 73.00 69.42 72.97 73.53 70.73 72.55 73.33 70.17 72.98 69.38 72.76 73.54 70.58 72.59 73.52 70.11 71.08 69.38 72.46 73.54 70.53 --- 73.58 70.08 70.73 69.37 72.85 73.53 70.40 --- 73.60 70.07 70.47 69.37 72.92 73.53 71.93 --- 73.71 --- 70.32 --- 73.03 73.53 --­ MEAN 69.26 68.95 70.43 71.69 70.48 73.04 71.79 72.56 69.72 72.04 73.48 72.80 WTR YR 1998 MEAN 71.37 HIGHEST 68.76 OCT. 29-1, NOV. 1, 2, 1997 LOWEST 73.84 SEPT. 21, 1998 65 70 75 80 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 510 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO CIBUCO BASIN 182330066185700. Local number, 213. LOCATION.--Lat 18°23'30", long 66°18'57", Hydrologic Unit 21010002, 1.82 mi southeast of Vega Alta plaza, 4.23 mi west of Toa Alta plaza, and 1.27 mi northwest off the intersection of Hwy 820 with Hwy 823. Owner: PR Aqueduct and Sewer Authority, Name: Pampano No. 2. AQUIFER.--Rio Indio Limestone-Lares Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-130 ft (0-39.6 m), diameter 14 in (0.36 m), cased 12 in (0.30 m) 0-220 ft (0-67.1 m); open hole 220-330 ft (67.6-101 m). Depth 330 ft (101 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 394 ft (120 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 9.32 ft (2.84 m), above land-surface datum. Prior April 27, 1993, hole on side of casing, 2.95 ft (0.90 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 1998. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.40 ft (10.5 m), below land-surface datum, Dec. 6, 1985; lowest water level recorded, 65.68 ft (20.0 m), below land-surface datum, Aug. 20, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 54.68 53.45 53.95 55.20 2 54.68 53.37 54.00 55.20 3 54.69 53.35 54.04 55.22 4 54.73 53.33 54.05 55.24 5 54.72 53.34 54.10 55.32 54.29 54.10 55.28 --- 54.92 55.28 55.79 55.40 54.30 54.11 55.30 --- 54.97 55.31 55.77 55.27 54.26 54.13 55.30 --- 54.97 55.33 55.79 55.28 54.25 54.18 55.29 --- 54.99 55.34 55.82 55.25 54.23 54.36 55.25 --- 55.04 55.42 55.82 55.17 6 54.71 53.33 54.12 55.37 7 54.65 53.30 54.19 55.36 8 54.61 53.30 54.23 55.39 9 54.61 53.36 54.30 55.41 10 54.57 53.47 54.34 55.43 54.17 54.39 55.27 --- 55.05 55.44 55.82 55.12 54.09 54.41 55.33 --- 55.09 55.48 55.82 55.07 54.05 54.50 55.41 --- 55.10 55.53 55.84 55.04 54.04 54.56 55.38 --- 55.11 55.62 55.82 55.00 54.00 54.60 55.34 --- 55.12 55.66 55.80 54.96 11 54.56 53.48 54.38 55.41 12 54.54 53.50 54.42 55.41 13 54.47 53.53 54.45 55.40 14 54.34 53.55 54.53 --- 15 54.28 53.60 54.58 54.99 53.99 54.61 55.35 --- 55.12 55.68 55.81 54.87 53.98 54.71 55.35 --- 55.10 55.70 55.83 54.84 53.95 54.76 55.45 --- 55.10 55.72 55.83 54.83 53.92 54.76 55.47 --- 55.08 55.77 55.83 54.86 53.92 54.77 55.48 54.85 55.08 55.82 55.84 54.90 16 54.31 53.64 54.59 54.90 17 54.28 53.67 54.62 54.82 18 54.27 53.69 54.67 54.67 19 54.25 53.69 54.78 54.56 20 54.16 53.70 54.79 54.48 53.92 54.78 55.45 54.86 55.10 55.87 55.87 54.89 53.87 54.85 --- 54.89 55.12 55.91 55.89 54.88 53.88 54.87 --- 54.90 55.11 55.93 55.88 54.88 53.89 54.91 --- 54.91 55.11 55.98 55.88 54.89 53.92 54.93 --- 54.91 55.10 55.98 55.90 54.91 21 54.18 53.74 54.79 54.45 22 54.17 53.75 54.86 54.42 23 53.80 53.78 54.88 54.40 24 53.64 53.80 54.91 54.34 25 53.50 53.80 54.95 54.33 53.94 54.92 --- 54.89 55.11 55.98 55.86 54.84 53.98 54.97 --- 54.89 55.13 55.92 55.90 --- 53.98 55.01 --- 54.92 55.13 55.89 55.96 --- 53.98 55.12 --- 54.93 55.14 55.88 55.94 --- 54.00 55.17 --- 54.91 55.14 55.87 55.95 --­ 26 53.45 53.82 54.98 54.30 27 53.33 53.85 54.98 54.29 28 53.29 53.92 55.00 54.29 29 53.29 53.92 55.04 54.27 30 53.76 53.90 55.12 54.25 31 53.50 --- 55.17 54.25 54.02 55.21 --- 54.91 55.13 55.84 55.92 --- 54.05 55.19 --- 54.94 55.14 55.79 55.89 --- 54.10 55.24 --- 54.94 55.17 55.79 55.82 --­ --- 55.24 --- 54.92 55.23 55.78 55.69 --­ --- 55.25 --- 54.93 55.26 55.80 55.61 --­ --- 55.28 --- 54.94 --- 55.80 55.44 --­ MEAN 54.19 53.60 54.57 54.85 54.03 54.77 55.36 54.91 55.10 55.71 55.83 55.01 WTR YR 1998 MEAN 54.80 HIGHEST 51.64 SEPT. 22, 1998 LOWEST 55.98 JULY 19, 20, 21, 1998 20 40 60 80 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 511 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182804066173500. Local number, DA-1. LOCATION.--Lat 18°28'04", long 66°17'35", Hydrologic Unit 21010005, 2.04 mi west of Dorado plaza, 1.15 mi north of Hwy 696, and 0.03 mi south of Hwy 693. Owner: Dorado Airport, Name: Dorado Airport Well. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m). Depth 98.0 ft (29.9 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 62.2 ft (18.9 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.88 ft (1.18 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on November 21, 1997. Water levels affected by nearby pumping well. PERIOD OF RECORD.--February 2, 1995 to July 31, 1998, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 56.7 ft (17.3 m), below land-surface datum, Sept. 11, 1996; lowest water level recorded, 59.2 ft (18.0 m), below land-surface datum Apr. 16, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 58.33 58.38 58.22 58.54 2 58.34 58.37 58.27 58.51 3 58.37 58.34 58.36 58.43 4 58.25 58.40 58.42 58.42 5 58.16 58.40 58.43 58.35 58.23 58.24 58.56 58.80 58.32 58.57 --- --- 58.27 58.29 58.62 58.76 58.34 58.59 --- --- 58.29 58.35 58.69 58.73 58.39 58.63 --- --- 58.28 58.38 58.68 58.70 58.33 58.65 --- --- 58.08 58.40 58.67 58.71 58.37 58.54 --- --­ 6 58.19 58.43 58.35 58.29 7 58.25 58.45 58.35 58.12 8 58.25 58.42 58.40 58.07 9 58.27 58.41 58.40 58.11 10 58.30 58.46 58.38 58.07 57.96 58.39 58.66 58.79 58.36 58.59 --- --- 58.01 58.35 58.67 58.83 58.35 58.58 --- --- 58.02 58.38 58.69 58.73 58.38 58.65 --- --- 58.02 58.40 58.73 58.68 58.38 58.62 --- --- 58.05 58.45 58.72 58.72 58.33 58.62 --- --­ 11 58.22 58.41 58.44 58.10 12 58.21 58.38 58.40 58.04 13 58.11 58.33 58.34 58.06 14 58.00 58.36 58.34 57.96 15 57.86 58.34 58.31 58.02 58.09 58.38 58.66 58.74 58.30 58.58 --- --­ --- 58.39 58.62 58.81 58.29 58.57 --- --­ --- 58.47 58.64 58.80 58.30 58.57 --- --­ --- 58.52 58.72 58.73 58.26 58.60 --- --­ --- 58.54 58.82 58.66 58.24 58.63 --- --­ 16 57.79 58.30 58.40 58.03 17 57.92 58.36 58.36 58.08 18 58.01 58.40 58.40 58.11 19 58.07 58.40 58.54 58.11 20 58.15 58.38 58.56 58.13 --- 58.57 58.72 58.63 58.31 58.67 --- --- 58.25 58.61 58.63 58.63 58.39 58.70 --- --- 58.26 58.65 58.63 58.63 58.40 58.70 --- --- 58.30 58.63 58.64 58.62 58.46 58.71 --- --- 58.29 58.59 58.63 58.62 58.51 58.68 --- --­ 21 58.18 58.42 58.61 58.17 22 58.22 58.37 58.60 58.15 23 58.29 58.33 58.55 58.15 24 58.37 58.30 58.46 58.13 25 58.43 58.29 58.53 58.14 58.34 58.55 58.58 58.55 58.54 58.59 --- --- 58.36 58.55 58.59 58.51 58.50 58.55 --- --- 58.30 58.57 58.63 58.52 58.48 58.58 --- --- 58.31 58.61 58.65 58.47 58.48 58.58 --- --- 58.30 58.65 58.63 58.40 58.48 58.59 --- --­ 26 58.40 58.28 58.53 58.15 27 58.37 58.25 58.54 58.13 28 58.42 58.28 58.51 58.20 29 58.40 58.29 58.46 58.18 30 58.36 58.25 58.50 58.13 31 58.34 --- 58.56 58.17 58.29 58.65 58.62 58.37 58.50 58.63 --- --- 58.24 58.61 58.63 58.32 58.51 58.60 --- --- 58.21 58.59 58.64 58.29 58.50 58.64 --- --­ --- 58.59 58.67 58.28 58.53 58.65 --- --­ --- 58.48 58.75 58.29 58.50 58.68 --- --­ --- 58.50 --- 58.33 --- --- --- --­ MEAN 58.22 58.36 58.44 58.17 58.21 58.49 58.66 58.60 58.40 58.62 --- --­ WTR YR 1998 MEAN 58.42 HIGHEST 57.78 OCT. 16, 1997 LOWEST 58.90 APR. 30, 1998 56 58 60 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR 512 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182526066165001. Local number, SR-2. LOCATION.--Lat 18°25'26", long 66°16'50", Hydrologic Unit 21010005, 1.03 mi north of Hwy 2, 0.93 mi west of the intersection of Hwy 659 with Hwy 693, and 0.03 mi north of Hwy 659. Owner: US Geological Survey, WRD, Name: Santa Rosa USGS No. 2. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-140 ft (0-42.7 m), screened 120-130 ft (36.6-39.6 m). Depth 140 ft (42.7 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 91.8 ft (28.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.31 ft (1.01 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed in February 6, 1997. PERIOD OF RECORD.--February 2, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 60.4 ft (18.4 m), below land-surface datum, Sept. 20, 1995; lowest water level recorded, 64.9 ft (19.8 m), below land-surface datum, May 2-5, 10-15, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 10 63.51 Jan. 27 Nov. 17 63.64 Feb. 23 Dec. 10 63.54 Mar. 13 63.37 Apr. 9 64.14 July 28 64.08 63.69 May 15 64.09 Sept. 2 64.05 63.99 60.0 60.5 61.0 61.5 62.0 62.5 63.0 63.5 64.0 64.5 65.0 65.5 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A 1995 1996 1997 1998 WATER YEAR 513 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182548066164401. Local number, MA-2 LOCATION.--Lat 18°25'48", long 66°16'44", Hydrologic Unit 2101005, 1.47 mi north of Hwy 2, 0.60 mi south of Hwy 695, 0.04 mi south of the intersection of Hwy 694 with 659, and 0.02 mi east of Hwy 659. Owner: US Geological Survey WRD, Name: Maguayo USGS No. 2 AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-110 ft (0-33.5 m), screened 95-105 ft (29.0-32.0 m). Depth 110 ft (33.5 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 39.4 ft (12.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.80 ft (1.16 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 6, 1997. PERIOD OF RECORD.--June 22, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 24.89 ft (7.59 m), below land-surface datum, Sept. 18, 19, 1996; lowest water level recorded, 29.05 ft (8.85 m), below land-surface datum, July 20, 21, 22, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.43 27.96 28.04 28.56 2 28.42 27.96 28.04 28.56 3 28.42 28.01 28.02 28.56 4 28.40 28.04 28.02 28.56 5 28.31 28.04 28.04 28.54 27.89 28.10 28.59 28.56 28.20 28.13 28.50 28.39 27.91 28.12 28.59 28.60 28.18 28.16 28.50 28.40 27.97 28.13 28.60 28.60 28.18 28.20 28.51 28.40 27.97 28.16 28.64 28.59 28.18 28.22 28.51 28.40 27.85 28.18 28.64 28.59 28.17 28.22 28.55 28.38 6 28.22 28.04 28.04 28.52 7 28.19 28.09 28.05 28.28 8 28.18 28.11 28.08 28.26 9 28.17 28.12 28.10 28.24 10 28.15 28.16 28.12 28.22 27.64 28.18 28.67 28.60 28.15 28.22 28.56 28.38 27.67 28.18 28.68 28.62 28.14 28.23 28.57 28.38 27.68 28.18 28.70 28.63 28.14 28.24 28.58 28.38 27.71 28.23 28.70 28.63 28.13 28.26 28.60 28.35 27.71 28.28 28.70 28.63 28.12 28.27 28.60 28.35 11 28.15 28.07 28.11 28.21 12 28.14 28.13 28.10 28.06 13 27.98 28.16 28.11 28.01 14 27.92 28.17 28.14 27.82 15 27.78 28.18 28.17 27.75 27.75 28.30 28.71 28.64 28.12 28.30 28.60 28.35 27.78 28.30 28.70 28.65 28.12 28.31 28.60 28.35 27.80 28.34 28.70 28.68 28.12 28.34 28.60 28.36 27.86 28.34 28.70 28.71 28.12 28.36 28.60 28.36 27.86 28.35 28.72 28.69 28.09 28.36 28.60 28.37 16 27.59 28.20 28.19 27.74 17 27.57 28.21 28.22 27.74 18 27.57 28.22 28.23 27.73 19 27.58 28.23 28.25 27.73 20 27.62 28.22 28.26 27.73 27.89 28.35 28.71 28.69 28.10 28.37 28.62 28.37 27.92 28.39 28.61 28.67 28.03 28.41 28.63 28.37 27.93 28.45 28.59 28.63 28.02 28.42 28.63 28.38 27.97 28.48 28.59 28.62 27.95 28.43 28.63 28.39 27.98 28.51 28.58 28.60 27.91 28.44 28.63 28.39 21 27.63 28.08 28.28 27.73 22 27.71 28.02 28.31 27.73 23 27.72 28.02 28.32 27.73 24 27.73 28.02 28.40 27.74 25 27.78 28.01 28.40 27.75 28.03 28.52 28.54 28.57 27.92 28.45 28.63 28.35 28.05 28.54 28.52 28.54 27.93 28.45 28.63 27.39 28.09 28.57 28.51 28.52 27.93 28.45 28.63 26.81 28.10 28.58 28.50 28.37 27.97 28.47 28.63 26.83 28.10 28.59 28.51 28.32 27.96 28.47 28.57 26.89 26 27.79 28.01 28.41 27.76 27 27.82 28.01 28.44 27.80 28 27.83 28.01 28.47 27.80 29 27.87 28.02 28.52 27.85 30 27.88 28.02 28.54 27.87 31 27.92 --- 28.56 27.87 28.10 28.62 28.51 28.30 28.01 28.49 28.41 26.89 28.10 28.62 28.51 28.27 28.02 28.50 28.37 26.88 28.10 28.64 28.51 28.20 28.03 28.50 28.36 26.91 --- 28.65 28.52 28.22 28.07 28.50 28.34 26.89 --- 28.66 28.55 28.23 28.10 28.50 28.34 26.87 --- 28.62 --- 28.22 --- 28.50 28.35 --­ MEAN 27.95 28.08 28.23 28.01 27.91 28.39 28.61 28.53 28.07 28.36 28.54 27.94 WTR YR 1998 MEAN 28.22 HIGHEST 26.80 SEPT. 23, 1998 LOWEST 28.76 APR. 15, 16, 1998 24 26 28 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 514 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182620066163400. Local number, HG-1. LOCATION.--Lat 18 °26'20", long 66°16'34", Hydrologic Unit 2101005, 1.85 mi south of Dorado plaza, 0.70 mi southwest of Laboratorio Dorado, 0.65 mi northwest of the intersection of Hwy 695 with Hwy 693, and 0.09 mi north of Hwy 695. Owner: US Geological Survey, WRD, Name: Higuillar No. 1. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-490 ft (0-149.4 m), screened 470-480 ft (143.3-146.3 m). Depth 490 ft (149.4 m) INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 49.2 ft (15.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.60 ft (1.10 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 16, 1996, replaced by an Electronic Data Logger (EDL), installed on February 23, 1998. Well screened below freshwater/saltwater interface at approximately 305 ft (93.0 m), below land-surface datum. From May 15, 1998, bi-monthly measurements only. PERIOD OF RECORD.--May 16, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 36.04 ft (11.0 m), below land-surface datum, Sept. 15, 16, 1996; lowest water level recorded, 39.89 ft (12.2 m), below land-surface datum, June 2, 3, 4, 9, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 39.88 39.83 39.61 39.31 2 39.88 39.81 39.61 39.31 3 39.88 39.81 39.60 39.33 4 39.87 39.79 39.59 39.32 5 39.85 39.81 39.57 39.22 6 39.79 39.80 39.57 39.22 7 39.80 39.77 39.56 39.23 8 39.83 39.62 39.55 39.24 9 39.84 39.45 39.57 39.16 10 39.84 39.53 39.57 37.72 11 39.84 39.56 39.56 36.39 12 39.87 39.63 39.58 36.37 13 39.87 39.67 39.57 36.28 14 39.86 39.68 39.62 36.18 15 39.85 39.57 39.57 36.12 16 39.70 39.85 39.39 39.46 36.07 17 39.70 39.78 39.46 39.33 36.08 18 39.68 39.69 39.51 39.34 36.11 19 39.67 39.61 39.52 39.37 36.12 20 39.68 39.57 39.55 39.37 36.20 21 39.70 39.60 39.59 39.37 36.30 22 39.70 39.64 39.62 39.38 36.36 23 39.75 39.66 39.64 39.43 36.46 24 39.75 39.68 39.66 39.27 36.50 25 39.76 39.66 39.65 39.30 36.58 26 39.75 39.68 39.59 39.35 36.62 27 39.75 39.72 39.62 39.37 36.68 28 39.75 39.72 39.64 39.35 36.70 29 39.77 39.76 39.64 39.31 36.77 30 39.79 39.78 39.64 39.30 36.82 31 39.87 39.63 39.31 MEAN 39.74 39.77 39.63 39.46 37.29 WTR YR 1996 MEAN 39.13 HIGHEST 36.04 SEPT. 15, 16, 1996 LOWEST 39.89 JUNE 2, 3, 4, 9, 1996 --- --- --- --- --- --- --- 515 GROUND-WATER LEVELS RIO DE LA PLATA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 36.84 37.52 36.75 36.96 36.40 36.79 37.41 37.89 38.25 38.62 38.79 38.49 2 36.89 37.55 36.77 36.95 36.42 36.80 37.46 37.95 38.26 38.64 38.78 38.47 3 36.94 37.56 36.76 36.90 36.43 36.81 37.40 38.00 38.27 38.67 38.78 38.45 4 37.02 37.57 36.81 36.86 36.49 36.82 37.41 37.97 38.28 38.68 38.77 38.43 5 37.06 37.58 36.84 36.85 36.51 36.83 37.45 38.03 38.29 38.70 38.78 38.44 6 37.09 37.60 36.84 36.87 36.53 36.84 37.49 38.05 38.33 38.68 38.74 38.43 7 37.14 37.61 36.88 36.88 36.55 36.89 37.54 38.08 38.35 38.68 38.78 38.41 8 37.21 37.56 36.95 36.90 36.55 36.92 37.54 38.10 38.35 38.69 38.77 38.39 9 37.29 37.53 37.01 36.89 36.57 36.93 37.50 38.10 38.39 38.67 38.79 38.41 10 37.31 37.53 37.05 36.88 36.55 36.95 37.56 38.00 38.40 38.69 38.80 38.39 11 37.32 37.54 37.06 36.89 36.54 36.95 37.57 38.04 38.36 38.70 38.76 38.42 12 37.35 37.54 37.01 36.89 36.58 36.96 37.58 38.06 38.40 38.71 38.77 38.43 13 37.35 37.36 37.01 36.91 36.58 36.97 37.61 38.11 38.43 38.68 38.75 38.43 14 37.40 37.24 37.04 36.93 36.61 36.98 37.62 38.12 38.44 38.72 38.77 38.42 15 37.44 37.19 37.07 36.96 36.61 36.99 37.67 38.14 38.44 38.76 38.80 38.42 16 37.48 37.23 37.05 36.97 36.68 37.00 37.67 38.15 38.47 38.77 38.82 38.42 17 37.51 37.26 37.07 36.98 36.70 37.05 37.66 38.18 38.49 38.79 38.78 38.40 18 37.55 37.27 37.12 37.03 36.75 37.09 37.70 38.18 38.53 38.82 38.70 38.41 19 37.59 37.24 37.15 37.09 36.77 37.09 37.77 38.21 38.55 38.83 38.68 38.41 20 37.63 37.27 37.19 37.12 36.80 37.09 37.78 38.24 38.52 38.83 38.68 38.40 21 37.65 37.30 37.23 37.11 36.81 37.15 37.82 38.25 38.54 38.81 38.67 38.41 22 37.71 37.30 37.26 36.82 36.81 37.16 37.83 38.27 38.55 38.79 38.67 38.40 23 37.73 37.16 37.29 36.63 36.82 37.19 37.84 38.30 38.55 38.81 38.54 38.38 24 37.79 37.09 37.30 36.50 36.81 37.22 37.87 38.29 38.52 38.81 38.52 38.37 25 37.79 36.90 37.28 36.40 36.77 37.28 37.90 38.18 38.52 38.77 38.46 38.35 26 37.79 36.87 37.28 36.38 36.79 37.30 37.92 38.14 38.53 38.75 38.46 38.37 27 37.73 36.87 37.16 36.39 36.79 37.30 37.91 38.10 38.54 38.77 38.47 38.38 28 37.75 36.82 37.13 36.38 36.79 37.31 37.91 38.12 38.56 38.83 38.48 38.39 29 37.73 36.82 37.11 36.40 37.34 37.91 38.16 38.59 38.85 38.50 38.39 30 37.60 36.81 37.03 36.40 37.34 37.93 38.19 38.61 38.83 38.54 38.41 31 37.52 37.00 36.39 37.38 38.23 38.82 38.52 MEAN 37.43 37.29 37.05 36.79 36.64 37.06 37.67 38.12 38.44 38.75 38.68 38.41 WTR YR 1997 MEAN 37.70 HIGHEST 36.33 JAN. 25, 26, 1997 LOWEST 38.86 JULY 29, 1997 516 GROUND-WATER LEVELS RIO DE LA PLATA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 38.39 37.94 37.95 38.42 37.86 37.90 38.26 --- --- --- --- --­ 2 38.39 37.94 37.95 38.39 37.87 37.91 38.30 --- --- --- --- --­ 3 38.39 37.96 37.93 38.37 37.87 37.92 38.32 --- --- --- --- --­ 4 38.34 37.95 37.92 38.35 37.86 37.98 38.37 --- --- --- --- --­ 5 38.21 37.94 37.93 38.32 37.72 38.00 38.36 --- --- --- --- --­ 6 38.12 37.95 37.92 38.28 7 38.09 37.97 37.94 38.11 8 38.09 37.98 37.97 38.03 9 38.09 37.98 37.99 38.02 10 38.08 38.07 38.00 38.02 37.34 37.98 38.41 --- --- --- --- --- 37.45 37.98 38.48 --- --- --- --- --- 37.52 38.02 38.48 --- --- --- --- --- 37.59 38.05 38.45 --- --- --- --- --- 37.62 38.09 38.44 --- --- --- --- --­ 11 38.08 37.89 38.00 38.00 12 38.04 38.00 38.02 37.91 13 37.88 38.06 38.04 37.87 14 37.82 38.08 38.05 37.68 15 37.69 38.10 38.09 37.60 37.68 38.08 38.46 --- --- --- --- --- 37.70 38.13 38.45 --- --- --- --- --- 37.72 38.16 38.48 --- --- --- --- --- 37.77 38.14 38.47 --- --- --- --- --- 37.75 38.12 38.46 --- --- --- --- --­ 16 37.47 38.11 38.09 37.62 17 37.45 38.11 38.12 37.61 18 37.44 38.11 38.12 37.60 19 37.46 38.08 38.13 37.63 20 37.52 38.06 38.15 37.63 37.76 38.15 38.44 --- --- --- --- --- 37.76 38.18 38.25 --- --- --- --- --- 37.80 38.23 38.21 --- --- --- --- --- 37.82 38.23 38.21 --- --- --- --- --- 37.84 38.26 38.20 --- --- --- --- --­ 21 37.55 37.96 38.15 37.65 22 37.64 37.85 38.20 37.66 23 37.66 37.85 38.21 37.68 24 37.68 37.85 38.27 37.69 25 37.74 37.86 38.28 37.73 37.90 38.23 38.19 --- --- --- --- --- 37.92 38.27 --- --- --- --- --- --- 37.92 38.31 --- --- --- --- --- --- 37.94 38.33 --- --- --- --- --- --- 37.95 38.39 --- --- --- --- --- --­ 26 37.77 37.87 38.30 37.74 27 37.81 37.88 38.30 37.77 28 37.84 37.91 38.36 37.81 29 37.87 37.92 38.42 37.84 30 37.87 37.92 38.44 37.84 31 37.89 --- 38.45 37.83 37.94 38.42 --- --- --- --- --- --- 37.93 38.42 --- --- --- --- --- --- 37.91 38.43 --- --- --- --- --- --­ --- 38.40 --- --- --- --- --- --­ --- 38.36 --- --- --- --- --- --­ --- 38.29 --- --- --- --- --- --­ MEAN 37.88 37.97 38.12 37.89 37.78 38.17 38.37 --- --- --- --- --­ WTR YR 1998 MEAN 38.01 HIGHEST 37.30 FEB. 6, 1998 LOWEST 38.50 APR. 7, 1998 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Water Water Date level Date level Date level May 15 38.37 July 28 38.25 Sept. 2 38.00 34 36 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 38 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR 517 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182620066163403. Local number, HG-4. LOCATION.--Lat 18 °26'20", long 66°16'34", Hydrologic Unit 2101005, 1.85 mi south of Dorado plaza, 0.70 mi southwest of Laboratorio Dorado, 0.65 mi northwest of the intersection of Hwy 695 with Hwy 693, and 0.09 mi north of Hwy 695. Owner: US Geological Survey, WRD, Name: Higuillar No. 4. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-100 ft (0-30.5 m), screened 80-90.0 ft (24.4-27.4 m). Depth 100 ft (30.5 m) INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 49.2 ft (15.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.60 ft (1.10 m), above land-©surface datum. REMARKS.--Recording observation well. Automated Digital recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 6, 1997. PERIOD OF RECORD.--January 23, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 31.84 ft (9.70 m), below land-surface datum, Sept. 11, 1996; lowest water level recorded, 36.15 ft (11.0 m), below land-surface datum, May 1, 11, 13, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 35.09 34.67 34.90 35.24 2 35.08 34.68 34.90 35.24 3 35.06 34.76 34.90 35.24 4 35.01 34.76 34.90 35.24 5 34.85 34.77 34.90 35.23 34.60 34.80 35.25 35.15 34.85 34.74 35.14 35.00 34.69 34.80 35.26 35.16 34.85 34.76 35.14 35.00 34.70 34.81 35.26 35.15 34.85 34.89 35.15 35.00 34.70 34.82 35.27 35.15 34.85 34.89 35.15 35.00 34.69 34.97 35.28 35.15 34.86 34.88 35.16 34.99 6 34.81 34.77 34.90 35.17 7 34.80 34.78 34.90 34.89 8 34.78 34.79 34.90 34.89 9 34.76 34.79 34.90 34.89 10 34.75 34.81 34.90 34.89 34.39 34.97 35.28 35.14 34.86 34.89 35.22 34.99 34.39 34.97 35.29 35.14 34.86 34.89 35.22 34.99 34.40 34.97 35.31 35.14 34.86 34.90 35.23 34.99 34.41 34.99 35.33 35.13 34.86 34.90 35.23 34.99 34.41 34.99 35.34 35.13 34.86 34.90 35.23 34.99 11 34.74 34.77 34.90 34.89 12 34.75 34.79 34.90 34.89 13 34.57 34.82 34.90 34.89 14 34.58 34.82 34.90 34.36 15 34.32 34.85 34.90 34.33 34.43 34.99 35.33 35.22 34.86 34.90 35.24 34.99 34.45 35.00 35.33 35.22 34.86 34.90 35.24 34.98 34.46 35.01 35.32 35.23 34.87 34.91 35.25 34.99 34.52 35.01 35.32 35.22 34.87 34.92 35.25 34.99 34.53 35.02 35.32 35.22 34.87 34.94 35.26 34.99 16 34.30 34.86 34.91 34.33 17 34.30 34.91 34.91 34.34 18 34.30 34.92 34.91 34.34 19 34.30 34.91 34.91 34.35 20 34.31 34.91 34.91 34.36 34.53 35.05 35.30 35.22 34.87 35.06 35.26 34.99 34.56 35.05 35.20 35.22 34.60 35.06 35.26 34.99 34.68 35.07 35.20 35.22 34.60 35.06 35.27 34.99 34.75 35.07 35.19 35.22 34.57 35.06 35.27 34.99 34.75 35.15 35.19 35.22 34.57 35.06 35.28 34.99 21 34.32 34.91 34.91 34.36 22 34.34 34.90 34.93 34.36 23 34.35 34.90 34.93 34.36 24 34.35 34.90 35.06 34.37 25 34.39 34.90 35.06 34.37 34.75 35.16 35.19 35.22 34.58 35.06 35.28 34.98 34.76 35.16 35.18 35.13 34.61 35.06 35.28 33.04 34.78 35.22 35.03 35.11 34.61 35.06 35.29 32.49 34.78 35.24 35.03 34.87 34.62 35.07 35.29 33.09 34.79 35.24 35.02 34.85 34.62 35.07 35.08 33.26 26 34.39 34.90 35.06 34.38 27 34.50 34.90 35.06 34.40 28 34.52 34.90 35.09 34.43 29 34.53 34.90 35.18 34.55 30 34.53 34.90 35.20 34.60 31 34.55 --- 35.25 34.60 34.79 35.24 35.02 34.85 34.62 35.09 34.95 33.45 34.79 35.25 35.01 34.84 34.70 35.12 34.96 33.45 34.79 35.25 35.01 34.85 34.70 35.12 34.96 33.55 --- 35.25 35.01 34.85 34.71 35.12 34.96 33.55 --- 35.26 35.14 34.85 34.72 35.13 34.98 33.54 --- 35.25 --- 34.85 --- 35.13 34.98 --­ MEAN 34.59 34.84 34.96 34.67 34.62 35.07 35.21 35.09 34.75 34.99 35.18 34.47 WTR YR 1998 MEAN 34.87 HIGHEST 32.48 SEPT. 23, 1998 LOWEST 35.34 APR. 9, 10, 1998 30 32 34 36 38 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR 518 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182657066162700. Local number, SA-1. LOCATION.--Lat 18°26'57", long 66°16'27", Hydrologic Unit 21010005, 1.16 mi south of Dorado plaza, 0.45 mi west of Laboratorio Dorado, 1.79 mi southeast of Dorado airport main gate, and 0.19 mi west of the PR Aqueduct and Sewer Authority San Antonio public supply well (San Antonio No. 3). Owner: US Geological Survey, WRD, Name: San Antonio No. 1. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-290 ft (0-88.4 m), screened 270-280 ft (82.3-85.3 m). Depth 290 ft (88.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 19.6 ft (6.00 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m), casing, 3.20 ft (0.98 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 21, 1997. PERIOD OF RECORD.--October 19, 1994 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 13.97 ft (4.26 m), below land-surface datum, Sept. 11, 1996; lowest water level recorded, 19.56 ft (5.96 m), below land-surface datum, May 3, 4, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.71 17.34 17.29 17.68 2 17.70 17.35 17.29 17.69 3 17.72 17.36 17.29 17.68 4 17.63 17.35 17.29 17.66 5 17.48 17.36 17.29 17.67 17.04 17.21 17.62 17.78 17.41 17.32 --- --- 17.04 17.21 17.63 17.78 17.41 17.32 --- --- 17.05 17.23 17.64 17.78 17.41 17.32 --- --- 17.05 17.25 17.64 17.78 17.38 17.50 --- --- 17.04 17.29 17.71 17.78 17.39 17.49 --- --­ 6 17.40 17.40 17.30 17.57 7 17.41 17.42 17.32 17.25 8 17.42 17.41 17.37 17.12 9 17.42 17.43 17.37 17.13 10 17.43 17.46 17.37 17.13 16.57 17.29 17.71 17.72 17.38 17.50 --- --- 16.57 17.29 17.74 17.78 17.38 17.53 --- --- 16.76 17.28 17.75 17.80 17.37 17.53 --- --- 16.76 17.28 17.75 17.77 17.34 17.53 --- --- 16.76 17.28 17.76 17.76 17.28 17.54 --- --­ 11 17.40 17.29 17.37 17.13 12 17.36 17.42 17.38 17.13 13 17.18 17.46 17.38 17.02 14 17.10 17.48 17.38 16.89 15 16.92 17.52 17.38 16.89 16.85 17.29 17.79 17.77 17.27 17.54 --- --- 16.86 17.34 17.80 17.77 17.27 17.54 --- --- 16.96 17.34 17.80 17.82 17.27 17.55 --- --- 16.99 17.34 17.81 17.82 17.25 17.55 --- --- 17.01 17.40 17.81 17.83 17.26 17.55 --- --­ 16 16.68 17.51 17.38 16.89 17 16.77 17.53 17.41 16.85 18 16.80 17.57 17.43 16.85 19 16.88 17.52 17.49 16.85 20 16.97 17.51 17.49 16.85 17.03 17.44 17.82 17.75 17.26 17.59 --- --- 17.07 17.45 17.82 17.74 17.25 17.61 --- --- 17.07 17.48 17.71 17.69 17.21 17.62 --- --- 17.07 17.51 17.72 17.69 17.21 17.63 --- --- 17.09 17.53 17.72 17.69 17.17 17.65 --- --­ 21 17.01 17.36 17.50 16.86 22 17.08 17.35 17.56 16.87 23 17.11 17.35 17.57 16.88 24 17.15 17.34 17.60 16.89 25 17.20 17.34 17.60 16.90 17.09 17.53 17.72 17.68 17.18 17.67 --- --- 17.15 17.53 17.70 17.68 17.18 17.67 --- --- 17.16 17.52 17.70 17.68 17.18 17.67 --- --- 17.18 17.52 17.70 17.48 17.20 17.67 --- --- 17.21 17.61 17.72 17.49 17.22 17.68 --- --­ 26 17.21 17.29 17.60 16.90 27 17.22 17.29 17.60 16.92 28 17.21 17.29 17.62 16.92 29 17.22 17.29 17.65 16.93 30 17.22 17.28 17.65 17.04 31 17.23 --- 17.66 17.04 17.21 17.65 17.71 17.49 17.26 17.69 --- --- 17.21 17.65 17.71 17.41 17.26 17.72 --- --- 17.21 17.65 17.72 17.41 17.31 17.73 --- --­ --- 17.64 17.73 17.41 17.31 17.73 --- --­ --- 17.64 17.73 17.41 17.31 17.73 --- --­ --- 17.63 --- 17.41 --- 17.73 --- --­ MEAN 17.23 17.40 17.45 17.10 17.00 17.43 17.73 17.67 17.29 17.58 --- --­ WTR YR 1998 MEAN 17.47 HIGHEST 16.57 FEB. 6, 7, 1998 LOWEST 17.73 JULY 28-30, 1998 14 16 18 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- 519 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182657066162701. Local number, SA-3. LOCATION.--Lat 18°26'57", long 66°16'27", Hydrologic Unit 21010005, 20 ft north of San Antonio USGS # 1. Owner: US Geological Survey, WRD, Name: San Antonio No. 3. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-80.0 ft (0-24.4 m), screened 65-75.0 ft (19.8-22.9 m). Depth 80.0 ft (24.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 19.6 ft (6.00 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m), casing, 3.38 ft (1.03 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 6, 1997. PERIOD OF RECORD.--October 19, 1994 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 13.95 ft (4.25 m), below land-surface datum, Sept. 11, 1996; lowest water level recorded, 19.03 ft (5.80 m), below land-surface datum, May 13, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.81 17.44 17.45 17.94 17.33 17.46 17.87 18.01 17.57 17.68 18.01 17.77 2 17.79 17.45 17.48 17.92 17.35 17.49 17.92 18.03 17.58 17.70 18.02 17.79 3 17.81 17.46 17.51 17.89 17.37 17.52 17.97 18.00 17.58 17.73 18.03 17.79 4 17.72 17.45 17.53 17.88 17.38 17.58 18.00 18.00 17.56 17.68 18.07 17.78 5 17.57 17.46 17.56 17.76 17.10 17.60 18.01 17.91 17.56 17.68 18.10 17.71 6 17.50 17.52 17.55 17.71 16.71 17.58 18.02 18.01 17.52 17.73 18.09 17.73 7 17.53 17.54 17.54 17.34 16.89 17.58 18.04 18.08 17.51 17.72 18.09 17.61 8 17.54 17.52 17.57 17.34 17.04 17.58 18.02 18.04 17.52 17.76 18.07 17.60 9 17.54 17.54 17.59 17.35 17.08 17.62 18.05 17.95 17.47 17.78 18.05 17.57 10 17.56 17.57 17.59 17.36 17.11 17.67 18.07 18.01 17.41 17.80 18.03 17.62 11 17.51 17.40 17.59 17.38 17.16 17.66 18.07 18.04 17.40 17.81 18.00 17.66 12 17.46 17.52 17.60 17.24 17.20 17.66 18.05 18.06 17.41 17.81 17.98 17.68 13 17.29 17.55 17.60 17.23 17.24 17.69 18.06 18.07 17.44 17.84 17.98 17.71 14 17.19 17.57 17.61 17.01 17.27 17.74 18.08 18.08 17.38 17.87 18.01 17.72 15 17.03 17.61 17.63 17.00 17.25 17.75 18.10 17.99 17.37 17.87 18.04 17.76 16 16.78 17.60 17.67 17.04 17.28 17.78 17.97 17.96 17.44 17.90 18.06 17.75 17 16.87 17.63 17.68 17.08 17.31 17.83 17.86 17.91 17.35 17.92 18.07 17.74 18 16.90 17.65 17.70 17.08 17.32 17.87 17.87 17.88 17.33 17.94 18.02 17.76 19 16.99 17.59 17.76 17.09 17.37 17.87 17.89 17.88 17.28 17.93 17.99 17.71 20 17.08 17.59 17.78 17.11 17.39 17.87 17.90 17.87 17.41 17.93 17.92 17.74 21 17.13 17.42 17.78 17.12 17.42 17.87 17.85 17.78 17.45 17.85 17.91 17.49 22 17.19 17.35 17.79 17.13 17.43 17.87 17.83 17.77 17.44 17.85 17.95 15.13 23 17.22 17.36 17.81 17.15 17.44 17.91 17.86 17.79 17.45 17.90 17.95 14.90 24 17.26 17.37 17.83 17.13 17.46 17.94 17.89 17.64 17.48 17.91 17.93 15.74 25 17.33 17.37 17.84 17.16 17.47 17.97 17.88 17.62 17.49 17.93 17.72 15.95 26 17.33 17.39 17.86 17.17 17.44 18.00 17.86 17.60 17.50 17.96 17.58 16.22 27 17.35 17.39 17.87 17.20 17.33 17.97 17.87 17.53 17.54 17.97 17.57 16.26 28 17.36 17.41 17.88 17.25 17.44 17.97 17.88 17.50 17.54 18.00 17.62 16.41 29 17.36 17.43 17.89 17.28 17.97 17.94 17.51 17.59 18.00 17.57 16.39 30 17.34 17.44 17.91 17.32 17.90 18.01 17.55 17.63 18.03 17.68 16.28 31 17.37 17.94 17.32 17.88 17.57 18.02 17.73 MEAN 17.35 17.49 17.69 17.32 17.27 17.76 17.96 17.86 17.47 17.85 17.93 17.17 WTR YR 1998 MEAN 17.60 HIGHEST 14.51 SEPT. 22, 23, 1998 LOWEST 18.13 APR. 15, MAY 13, 1998 14 16 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 18 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 520 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182654066150600. Local number, TB-1. LOCATION.--Lat 18°26'54", long 66°15'06", Hydrologic Unit 21010005, 0.92 mi southeast of the Dorado bridge, 0.66 mi east of Hwy 693, 0.09 mi north of the intersection of Hwy 165 with Hwy 867, and 0.01 mi east of Hwy 165. Owner: US Geological Survey, WRD, Name: Toa Baja TW-1. AQUIFER.--Tertiary Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-165 ft (0-50.3 m), screened 25-165 ft (7.62-50.3 m) . Depth 167 ft (50.9 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 7.00 ft (2.10 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor on top of 4 in (0.10 m) casing, 3.60 ft (1.10 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 25, 1997. Water levels affected by nearby pumping well. PERIOD OF RECORD.-- November 16, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.04 ft (0.93 m), below land-surface datum, Sept. 10, 1996; lowest water level recorded, 10.68 ft (3.25 m), below land-surface datum May 3, 4, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.95 9.79 9.58 9.96 9.69 9.70 10.05 10.19 9.90 2 9.80 9.75 9.69 9.92 9.76 9.79 10.18 10.24 9.90 3 9.87 9.76 9.78 9.83 9.78 9.82 10.30 10.23 9.85 4 9.76 9.74 9.76 9.89 9.78 9.91 10.22 10.33 9.83 5 9.52 9.75 9.83 9.80 9.32 9.92 10.31 10.31 9.55 6 9.58 9.75 9.81 9.72 9.05 9.85 10.26 10.19 9.63 7 9.66 9.78 9.81 9.31 9.33 9.79 10.32 10.18 9.43 8 9.70 9.80 9.92 9.36 9.37 9.83 10.24 10.18 9.43 9 9.78 9.81 9.90 9.43 9.36 9.93 10.31 10.09 9.39 10 9.76 9.89 9.88 9.45 9.42 9.97 10.34 9.94 9.51 11 9.65 9.74 9.86 9.49 9.49 9.90 10.27 9.96 9.52 12 9.63 9.83 9.85 9.38 9.53 9.88 10.24 9.89 9.60 13 9.43 9.79 9.76 9.47 9.58 9.93 10.24 9.88 9.57 14 9.31 9.79 9.78 9.17 9.58 10.03 10.30 10.00 9.68 15 9.06 9.81 9.76 9.35 9.55 10.03 10.35 10.07 9.77 16 8.84 9.72 9.80 9.41 9.62 10.10 10.17 10.12 9.73 17 9.13 9.76 9.71 9.50 9.69 10.16 10.06 10.06 9.70 18 9.23 9.77 9.89 9.53 9.72 10.20 10.12 9.96 9.70 19 9.34 9.72 10.05 9.58 9.76 10.14 10.17 9.99 9.52 20 9.48 9.74 10.06 9.59 9.73 10.12 9.98 9.50 21 9.59 9.54 10.09 9.60 9.78 10.11 9.77 9.03 22 9.65 9.54 10.06 9.60 9.80 10.14 9.83 4.27 23 9.70 9.60 9.97 9.62 9.77 10.19 9.82 4.68 24 9.73 9.61 10.00 9.56 9.79 10.24 9.68 4.70 25 9.82 9.61 9.98 9.62 9.74 10.28 9.39 7.95 26 9.80 9.64 10.00 9.55 9.71 10.20 9.50 8.35 27 9.76 9.64 10.02 9.61 9.60 10.17 9.50 8.48 28 9.77 9.68 9.98 9.66 9.66 10.12 9.55 8.61 29 9.76 9.66 9.90 9.67 10.11 9.59 8.65 30 9.74 9.62 9.94 9.63 9.92 9.75 8.65 31 9.73 9.95 9.67 9.99 10.16 9.79 MEAN 9.60 9.72 9.88 9.58 9.61 10.02 10.23 10.16 9.93 8.87 WTR YR 1998 MEAN 9.70 HIGHEST 4.04 SEPT. 22, 1998 LOWEST 10.42 APR. 15, 1998 4 6 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 8 10 12 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- 521 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182530066135400. Local number, 216. LOCATION.--Lat 18°25'30", long 66°13'54", Hydrologic Unit 21010005, 2.61 mi northeast of Toa Alta plaza, 2.73 mi southwest of Sabana Seca U.S. Naval Radio Station, and 1.76 mi southeast of Hwy 2 km 17.7. Owner: PR Aqueduct and Sewer Authority, Name: Pozo Navy-Campanillas. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m) 0-106 ft (0-32.3 m), cased 16 in (0.41 m) 0-20 ft (0-6.10 m), cased 12 in (0.30 m) 0-106 ft (0-32.3 m), perforated 20-106 ft (6.10-32.3 m), diameter 10 in (10.25 m) 106-140 ft (32.3-42.7 m), cased 10 in (0.25 m) 106-140 ft (32.3-42.7 m), perforated 106-140 ft (32.3-42.7 m). Depth 140 ft (42.7 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 13.0 ft (3.96 m), above mean sea level, from topographic map. Measuring point: Hole on side of casing, 1.80 ft (0.55 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 6, 1998. Water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.38 ft (2.86 m), below land-surface datum, June 23, 1987; lowest water level recorded, 18.40 ft (5.61 m), below land-surface datum, Sept. 24, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.52 14.84 14.57 16.16 16.31 14.63 15.90 15.73 15.30 14.74 15.81 15.04 2 15.00 14.86 14.55 16.33 16.14 14.66 15.86 15.83 15.37 14.69 15.70 15.07 3 14.98 14.93 14.54 15.86 16.18 14.66 15.93 15.85 15.41 14.71 15.81 15.07 4 15.09 14.76 14.60 15.79 16.13 14.71 15.97 15.89 14.33 14.66 15.90 15.06 5 14.87 14.82 14.49 15.80 14.34 14.82 15.98 15.82 14.77 14.60 15.93 14.97 6 14.71 14.82 14.47 15.45 14.26 14.77 15.81 15.87 15.16 14.64 15.88 14.98 7 14.70 14.81 14.49 15.47 14.28 14.80 15.88 15.99 15.28 14.63 15.95 14.51 8 14.77 14.39 14.51 15.47 14.26 14.80 15.88 16.05 15.33 14.62 15.98 14.74 9 14.77 14.12 14.47 15.46 14.22 14.86 15.96 15.99 15.38 14.68 16.05 14.71 10 14.83 14.15 14.65 15.59 14.30 14.92 15.92 16.19 15.30 14.77 15.84 14.81 11 14.89 14.69 14.71 15.66 14.37 14.92 15.93 16.13 15.31 14.77 15.70 14.89 12 14.59 14.81 14.67 15.64 14.44 14.80 15.90 16.19 15.37 14.64 13.85 14.91 13 14.29 14.85 14.77 15.55 14.46 14.87 15.86 16.16 15.45 14.68 13.93 14.93 14 14.29 14.96 14.83 15.58 14.46 14.87 15.60 16.34 15.41 14.52 14.03 14.93 15 14.32 15.08 14.84 15.76 14.40 15.88 14.97 16.05 15.27 14.45 14.50 14.87 16 14.20 14.98 14.88 15.76 14.40 15.95 14.19 16.00 15.27 14.46 15.07 14.92 17 14.19 14.92 14.93 15.94 14.40 15.02 14.88 15.89 14.88 14.47 15.06 14.90 18 14.26 14.95 14.92 15.89 14.40 15.98 15.11 15.53 14.89 14.69 14.14 14.91 19 14.27 14.88 15.01 15.93 14.43 15.96 15.10 15.32 14.86 14.72 14.43 14.95 20 14.37 14.77 14.84 15.91 14.43 16.00 15.14 15.25 14.92 14.79 14.71 15.01 21 14.38 14.44 15.19 15.94 14.46 16.10 15.09 15.07 14.94 14.80 14.88 14.85 22 14.42 14.37 15.16 15.94 14.50 16.10 15.09 15.21 14.98 14.93 14.86 10.85 23 14.45 14.44 15.44 15.96 14.45 16.19 15.12 15.51 14.84 15.14 15.15 10.37 24 14.52 14.38 15.69 16.14 14.60 16.19 15.19 15.14 14.85 15.26 15.12 10.52 25 14.64 14.41 15.66 16.20 14.74 16.16 15.22 15.35 14.80 15.39 14.94 10.56 26 14.62 14.46 15.62 16.16 14.79 16.16 15.19 15.19 14.80 15.67 14.92 10.62 27 14.26 14.46 15.72 16.21 14.62 16.16 15.15 15.25 14.84 15.63 14.84 10.65 28 14.69 14.46 15.73 16.29 14.64 16.22 15.19 15.16 14.87 15.77 14.88 10.67 29 14.72 14.50 15.76 16.30 16.25 15.54 15.19 14.88 15.76 14.95 10.69 30 14.79 14.57 15.68 16.28 16.04 15.65 15.19 14.92 15.77 15.02 10.70 31 14.79 16.45 16.32 15.90 15.25 15.76 14.97 MEAN 14.59 14.66 15.03 15.89 14.69 15.46 15.47 15.66 15.07 14.93 15.12 13.62 WTR YR 1998 MEAN 15.02 HIGHEST 10.36 SEPT. 23, 1998 LOWEST 16.45 DEC. 31, 1997 10 LAND-SURFACE DATUM 15 WATER LEVEL, IN FEET BELOW 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 522 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182655066142400. Local number, 217. LOCATION.--Lat 18°26'55", long 66°14'24", Hydrologic Unit 21010005, 4.00 mi northeast of Toa Alta plaza, 3.40 mi northwest of Hwy 2 km 17.7, and 3.49 mi northwest of Sabana Seca US Naval Radio Station. Owner: US Geological Survey, WRD, Name: Monserrate TW-2. AQUIFER.-Alluvial Deposits. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-80.0 ft (0-24.4 m), perforated 10-80 ft (3.05-24.4 m). Depth 80.0 ft (24.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 3.30 ft (1.00 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.50 ft (1.07 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 6, 1997. PERIOD OF RECORD.--November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.02 ft (0.006 m), below land-surface datum, May 16, 1986; lowest water level recorded, 3.72 ft (1.13 m), below land-surface datum, May 13, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.56 2.53 2.37 2.97 2.85 2.65 3.08 3.16 2.73 3.03 2 2.48 2.57 2.53 2.97 2.91 2.77 3.14 3.19 2.77 3.07 3 2.48 2.60 2.55 2.79 2.88 2.79 3.21 3.05 2.77 3.15 4 2.44 2.61 2.59 2.75 2.89 2.74 3.22 3.21 2.59 2.94 5 2.17 2.62 2.57 2.77 2.38 3.24 3.19 2.61 2.73 6 2.17 2.61 2.60 2.55 2.15 3.32 3.43 2.71 2.98 7 2.28 2.63 2.53 2.16 2.20 3.39 3.45 2.68 2.90 8 2.30 2.62 2.67 2.14 2.27 3.26 3.33 2.73 3.05 9 2.33 2.57 2.59 2.27 2.28 3.20 3.43 2.76 3.03 10 2.33 2.58 2.56 2.28 2.29 3.20 3.43 2.47 3.16 11 2.27 2.57 2.62 2.29 2.30 3.17 3.60 2.45 3.15 12 2.15 2.61 2.66 2.31 2.31 3.12 3.51 2.75 3.10 13 1.95 2.61 2.74 2.30 2.32 3.14 3.56 2.91 3.14 14 1.91 2.67 2.64 2.16 2.32 3.18 3.54 2.68 3.15 15 1.82 2.71 2.66 2.30 2.32 3.20 3.19 2.49 3.05 16 1.71 2.62 2.65 2.30 2.33 2.95 3.20 2.83 3.13 17 1.82 2.63 2.61 2.30 2.34 2.78 3.10 2.72 3.15 18 1.94 2.66 2.64 2.31 2.35 2.82 2.90 2.72 3.14 19 2.05 2.56 2.90 2.30 2.84 3.03 2.88 2.70 3.15 20 2.15 2.54 2.79 2.30 2.76 3.00 2.91 2.85 3.21 21 2.22 2.34 2.78 2.30 2.73 2.82 2.81 2.81 2.76 22 2.29 2.25 2.96 2.66 2.63 2.83 2.80 2.49 2.71 23 2.33 2.26 2.83 2.71 2.65 3.14 2.90 2.85 2.73 2.96 24 2.36 2.26 2.74 2.63 2.69 3.22 2.87 2.59 2.68 3.07 25 2.39 2.26 2.81 2.81 2.65 3.21 3.03 2.65 2.74 3.15 26 2.40 2.33 2.81 2.73 2.67 3.16 2.99 2.67 2.60 3.31 27 2.40 2.37 2.82 2.72 2.59 3.12 2.87 2.53 2.61 3.15 28 2.53 2.37 2.86 2.87 2.64 3.12 3.05 2.52 2.76 3.32 29 2.47 2.36 2.94 2.87 3.14 3.13 2.59 2.74 3.33 30 2.51 2.36 2.85 2.83 3.14 3.18 2.64 2.76 3.37 31 2.51 2.94 2.82 3.04 2.71 MEAN 2.25 2.51 2.70 2.53 2.52 3.02 3.08 3.05 2.69 3.08 WTR YR 1998 MEAN 2.73 HIGHEST 1.71 OCT. 16, 1997 LOWEST 3.64 MAY 11, 1998 0 LAN-SURFACE DATUM 2 WATER LEVEL, IN FEET BELOW 4 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 523 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182441066082600. Local number, 219. LOCATION.--Lat 18°24'41", long 66°08'26", Hydrologic Unit 21010005, 0.47 mi west of Fort Buchanan Military Res. main gate, 1.74 mi northeast of Bayamón plaza, and 1.88 mi southwest of PR National Cementery. Owner: US Department of Defense, Name: Buchanan Park No. 1. AQUIFER.--Cibao Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 10 in (0.25 m), cased 10 in (0.25 m) 0-270 ft (0-82.3 m), perforated 46-685 ft (14.0-20.7 m), 88-120 ft (26.8-36.6 m), 160-191 ft (48.8-58.2 m), 240-270 ft (73.2-82.3 m). Depth 270 ft (82.3 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 66.0 ft (20.1 m), above mean sea level, from topographic map. Measuring point: Hole on side of casing, 0.75 ft (0.23 m), above land-surface datum. Prior June 30, 1986, top of shelter floor, 3.59 ft (1.09 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on January 28, 1998. PERIOD OF RECORD.--December 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.9 ft (10.7 m), below land-surface datum, Nov. 12, 13, 14, 1989; lowest water level recorded, 55.67 ft (17.0 m), below land-surface datum, May 13, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 47.97 47.48 47.42 48.56 48.32 48.38 48.55 48.57 47.50 2 47.90 47.57 47.48 48.53 48.35 48.40 48.45 48.60 47.53 3 47.77 47.62 47.40 48.61 48.34 48.43 48.56 48.63 47.54 4 47.72 47.53 47.37 48.63 48.33 48.51 48.42 48.68 47.54 5 47.78 47.42 47.41 48.55 48.27 48.54 48.36 48.71 47.61 6 47.62 47.51 47.45 48.50 48.22 48.60 48.38 48.72 47.63 7 47.44 47.56 47.54 48.36 48.08 48.55 48.47 48.75 47.64 8 47.47 47.59 47.54 48.26 48.05 48.49 48.57 48.76 47.67 9 47.51 47.65 47.49 48.17 48.03 48.33 48.57 48.83 47.71 10 47.50 47.58 47.54 48.11 48.06 48.26 48.54 48.79 47.72 11 47.48 48.11 47.65 48.04 48.08 48.19 48.54 48.76 47.74 12 47.38 47.89 47.72 48.04 48.08 48.19 48.52 48.78 47.75 13 47.15 47.69 47.70 48.07 48.07 48.22 48.64 48.80 47.77 14 46.91 47.67 47.57 48.05 48.04 48.21 48.67 48.77 47.80 15 46.78 47.77 47.58 48.02 48.03 48.17 48.65 47.73 16 46.95 47.78 47.62 48.06 48.02 48.16 48.60 47.59 17 46.91 47.64 47.69 48.08 47.95 48.17 48.59 47.40 18 46.97 47.62 47.75 48.17 47.99 48.22 48.52 47.24 19 46.67 47.66 47.83 47.99 48.24 48.43 47.16 20 46.60 47.58 47.89 48.02 48.25 48.46 47.07 21 47.00 47.35 47.92 48.16 48.21 48.45 47.47 22 46.89 47.26 48.14 48.25 48.26 48.46 46.95 23 46.95 47.47 48.08 48.17 48.29 48.45 46.80 24 46.95 47.44 48.30 48.23 48.32 48.47 47.32 46.76 25 47.01 47.41 48.23 48.26 48.55 48.52 47.28 46.77 26 47.07 47.44 48.32 48.26 48.56 48.53 47.28 46.76 27 47.08 47.39 48.40 48.31 48.49 48.51 47.29 46.70 28 47.21 47.44 48.47 48.23 48.37 48.45 48.50 47.36 46.73 29 47.31 47.44 48.43 48.25 48.44 48.56 47.40 46.75 30 47.39 47.41 48.47 48.26 48.41 48.56 47.44 46.77 31 47.40 48.64 48.27 48.40 MEAN 47.25 47.57 47.84 48.26 48.15 48.35 48.52 48.73 47.34 47.33 WTR YR 1998 MEAN 47.92 HIGHEST 46.55 OCT. 15, 1997 LOWEST 48.83 MAY 10, 1998 45 50 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 55 60 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 524 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182531066075900. Local number, 652. LOCATION.--Lat 18°25'31", long 66°07'59", Hydrologic Unit 21010005, 0.07 mi north of Hwy 22, 0.32 mi southwest of the intersection of Hwy 165 with Hwy 28, and 1.40 mi south of the Cataño ferry building. Owner: US Geological Survey, WRD, Name: USGS Building 652. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4.0 in (0.10 m), cased 0-192 ft (0-58.5 m). Depth 192 ft (58.5 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 10.0 ft (3.05 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4.0 in (0.10 m) casing, 3.27 ft (1.00 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on May 14, 1997. Water level affected by marine tides. PERIOD OF RECORD.--May 14, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.20 ft (1.89 m), below land-surface datum, May 26, 1998; lowest water level recorded, 9.02 ft (2.75 m), below land-surface datum, Dec. 13, 14, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.64 8.70 8.18 7.96 2 8.67 8.63 7.83 7.90 3 8.60 8.62 7.61 7.59 4 8.50 8.40 7.52 7.17 5 8.40 8.39 7.59 7.03 6 8.43 8.09 7.71 6.97 7 8.33 8.19 7.80 7.00 8 8.35 7.99 7.80 7.14 9 8.42 7.95 7.90 7.39 10 8.39 8.00 7.98 7.75 11 8.44 8.13 7.93 8.02 12 8.46 8.21 8.13 8.17 13 8.51 8.21 8.15 8.10 14 8.56 8.27 8.32 8.22 15 8.81 8.68 8.43 8.31 7.81 16 8.77 8.69 8.46 8.39 7.88 17 8.68 8.81 8.47 8.19 7.68 18 8.86 8.91 8.31 7.94 7.53 19 8.81 8.80 8.11 7.36 7.55 20 8.75 8.56 7.90 7.15 7.63 21 8.62 8.30 7.55 7.06 7.69 22 8.36 8.08 7.49 7.39 7.82 23 8.29 7.91 7.47 7.67 7.83 24 8.21 7.81 7.61 7.70 7.98 25 8.13 7.84 7.72 7.93 7.89 26 8.06 7.98 7.72 8.13 7.91 27 8.11 7.98 7.97 8.26 7.90 28 8.19 8.29 8.26 8.33 7.81 29 8.37 8.50 8.32 8.32 7.74 30 8.54 8.64 8.38 8.23 7.66 31 8.64 8.20 8.05 MEAN 8.48 8.42 8.13 7.90 7.69 WTR YR 1997 MEAN 8.09 HIGHEST 6.96 SEPT. 6, 7, 1997 LOWEST 8.95 JUNE 18, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 525 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.54 7.51 7.41 7.78 7.63 7.38 7.57 7.33 2 7.39 7.50 7.26 7.81 7.80 7.53 7.55 3 7.26 7.60 7.37 7.89 7.97 7.81 8.00 4 7.06 7.72 7.69 7.95 7.93 7.89 8.12 5 6.99 7.76 7.82 8.01 7.67 7.85 7.98 6 7.14 7.80 7.81 7.80 7.44 7.84 7.86 7 7.25 7.91 7.96 7.83 7.98 8.02 7.98 8 7.26 7.98 8.25 7.67 7.60 7.94 8.01 9 7.45 8.12 8.26 7.41 7.14 7.82 8.17 10 7.66 8.26 8.31 7.10 7.21 7.55 8.04 11 7.84 8.14 8.23 7.12 7.35 7.51 8.00 12 7.79 7.95 8.12 7.01 7.48 7.44 7.82 13 7.74 7.82 7.90 6.74 7.53 7.48 7.99 14 7.04 7.69 7.78 7.02 7.50 7.66 8.04 15 7.18 7.54 7.66 7.02 7.26 7.71 8.01 16 6.88 7.43 7.75 7.16 7.53 7.62 8.00 17 7.16 7.37 7.72 7.31 7.70 7.65 7.68 18 7.03 7.53 7.90 7.37 7.84 7.84 7.84 19 7.11 7.53 8.17 7.41 7.88 7.89 7.77 20 7.29 7.65 8.25 7.51 7.95 7.97 7.83 21 7.46 7.60 8.31 7.67 8.09 7.90 7.81 22 7.67 7.90 8.28 7.86 8.05 7.84 23 7.90 8.04 8.40 7.99 7.99 7.85 8.25 24 8.13 7.68 8.30 7.95 7.90 7.91 8.18 25 8.25 7.60 8.33 7.95 7.60 8.08 8.03 26 8.19 7.43 8.26 7.86 7.53 8.09 7.94 7.24 27 8.01 7.35 8.22 7.74 7.52 8.02 8.06 6.90 28 8.09 7.13 8.03 7.70 7.48 7.71 6.89 29 8.04 7.34 7.82 7.52 7.58 6.88 30 7.84 7.65 7.78 7.56 7.53 7.18 31 7.55 7.71 7.53 7.57 7.10 MEAN 7.52 7.68 7.97 7.56 7.66 7.76 7.94 7.03 7.33 WTR YR 1998 MEAN 7.70 HIGHEST 6.20 MAY 26, 1998 LOWEST 9.02 DEC. 13, 14, 1997 6 7 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 8 9 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 526 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182511066045401. Local number, PN-2. LOCATION.--Lat 18°25'11, long 66°04'54", Hydrologic Unit 21010005, 1.58 mi northeast of Fort Buchannan Military Res. main gate, 2.95 mi southeast of Cataño plaza, and 2.45 mi southeast of US Naval Reservation in Miramar. Owner: US Geological Survey, WRD, Name: La Esperanza No. 2. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-40 ft (0-12.2 m), perforated 30-40 ft ((9.15-12.2 m). Depth 40.0 ft (12.2 m). INSTRUMENTATION.--Electronic water level logger--15-minute interval. DATUM.--Elevation of land-surface datum is about 13 ft (3.96 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 3.17 ft (0.97 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on April 8, 1998. PERIOD OF RECORD.--July 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 7.71 ft (2.35 m), below land-surface datum, Sept. 23, 1998; lowest water level recorded, 11.90 ft (3.63 m), below land-surface datum, July 15, 16, 1991. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.43 9.97 8.94 10.73 10.16 10.11 10.42 10.52 9.45 10.49 9.12 8.86 2 9.45 9.98 8.97 10.73 10.26 10.16 10.41 10.54 9.53 10.54 9.21 8.97 3 9.28 10.04 9.06 10.60 10.30 10.19 10.42 10.62 9.61 10.57 9.33 8.76 4 9.19 10.05 9.16 10.50 10.35 10.32 10.43 10.64 9.60 10.57 9.42 8.65 5 9.05 10.04 9.26 10.42 9.99 10.33 10.47 10.67 9.64 10.53 9.55 8.53 6 8.92 9.99 9.30 10.23 9.56 10.33 10.53 10.73 9.70 10.57 9.65 8.43 7 8.90 9.99 9.40 9.71 9.40 10.34 10.59 10.76 9.75 10.62 9.72 8.25 8 8.89 9.99 9.52 9.36 9.40 10.34 10.54 10.74 9.79 10.66 9.72 8.17 9 8.90 10.02 9.59 9.23 9.37 10.35 10.56 10.72 9.71 10.67 9.76 8.11 10 8.98 10.11 9.66 9.11 9.32 10.35 10.60 10.75 9.63 10.69 9.74 8.14 11 9.02 10.11 9.72 9.03 9.39 10.36 10.65 10.79 9.51 10.69 9.77 8.26 12 8.92 10.19 9.81 8.99 9.46 10.36 10.66 10.81 9.49 10.72 9.78 8.38 13 8.75 10.26 9.86 9.05 9.55 10.37 10.69 10.88 9.46 10.75 9.82 8.52 14 8.61 10.31 9.94 8.99 9.56 10.37 10.68 10.92 9.48 10.82 9.91 8.64 15 8.45 10.32 10.01 9.03 9.54 10.38 10.73 10.76 9.57 10.66 9.96 8.57 16 8.39 10.33 10.07 9.08 9.52 10.38 10.68 10.47 9.67 10.16 10.03 8.39 17 8.44 10.34 10.12 9.15 9.61 10.39 10.36 9.97 9.75 9.86 10.05 8.44 18 8.49 10.38 10.17 9.21 9.64 10.47 10.23 9.56 9.78 9.58 10.00 8.50 19 8.63 10.27 10.21 9.28 9.73 10.53 10.21 9.36 9.82 9.53 8.27 20 8.82 10.10 10.25 9.39 9.78 10.60 10.17 9.21 9.86 9.31 8.17 21 8.93 9.82 10.30 9.49 9.74 10.56 10.20 8.99 9.95 9.18 8.20 22 9.07 9.41 10.38 9.57 9.78 10.54 10.24 8.94 10.00 9.00 7.92 23 9.18 9.30 10.39 9.65 9.87 10.58 10.29 8.91 10.03 8.92 7.75 24 9.30 9.33 10.40 9.94 10.70 10.32 8.97 10.09 8.92 7.80 25 9.36 9.32 10.43 10.02 10.75 10.36 9.07 10.16 8.61 7.88 26 9.46 9.24 10.48 10.05 10.80 10.41 9.16 10.21 8.51 8.02 27 9.60 9.01 10.53 10.09 10.85 10.49 9.20 10.27 8.52 8.00 28 9.71 8.99 10.56 10.00 10.09 10.81 10.50 9.30 10.32 8.47 8.01 29 9.79 9.01 10.60 10.07 10.83 10.47 9.35 10.37 8.44 8.11 30 9.88 9.01 10.68 10.10 10.68 10.50 9.36 10.41 8.58 8.10 31 9.94 10.71 10.11 10.52 9.43 9.06 8.73 MEAN 9.09 9.84 9.95 9.66 9.77 10.47 10.46 10.00 9.82 10.43 9.33 8.29 WTR YR 1998 MEAN 9.74 HIGHEST 7.71 SEPT. 23, 1998 LOWEST 10.94 MAY 14, 1998 6 8 WATER LEVEL, IN FEET BELOW LAND-SURFACE FATUM 10 12 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 527 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182435066052700. Local number, PN-5. LOCATION.--Lat 18°24'35", long 66°05'27", Hydrologic Unit 21010005, 2.94 mi southeast of Cataño plaza, 0.44 mi north of Escuela Superior Gabriela Mistral, and 1.19 mi northeast of WAPA TV radio anthena. Owner: US Geological Survey, WRD, Name: Salud Mental No. 1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4.0 in (0.10 m), cased 4.0 in (0.10 m), 0-83.0 ft (0-25.3 m), perforated 73-83.0 ft (22.2-25.3 m). Depth 83.0 ft (25.3 m). INSTRUMENTATION.--Digital water level recorder--15-minute punch. DATUM.--Elevation of land-surface datum is about 85.0 ft (25.9 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 2.85 ft (0.87 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--April 1989 to July 1, 1998, temporarily discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 25.37 ft (7.73 m), below land-surface datum, Feb. 5, 1993; lowest water level recorded, 32.82 ft (10.0 m), below land-surface datum, Sept. 25-28, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.85 28.10 28.20 28.88 2 28.84 28.10 28.20 28.89 3 28.78 28.10 28.20 28.89 4 28.80 28.14 28.20 28.90 5 28.80 28.16 28.20 28.92 28.98 29.25 29.67 29.83 29.26 28.62 --- --- 29.01 29.27 29.68 29.84 29.22 --- --- --- 29.04 29.28 29.69 29.85 29.17 --- --- --- 29.06 29.31 29.71 29.85 29.11 --- --- --- 28.95 29.34 29.71 29.86 29.04 --- --- --­ 6 28.79 28.11 28.20 28.91 7 28.77 28.15 28.21 28.89 8 28.75 28.15 28.22 28.89 9 28.74 28.17 28.24 28.89 10 28.72 28.20 28.25 28.89 29.00 29.35 29.72 29.86 29.02 --- --- --- 29.03 29.37 29.73 29.88 28.99 --- --- --- 29.05 29.34 29.75 29.88 28.97 --- --- --- 29.05 29.39 29.76 29.90 28.92 --- --- --- 29.05 29.42 29.76 29.91 28.84 --- --- --­ 11 28.66 28.23 28.27 28.88 12 28.62 28.26 28.29 28.87 13 28.58 28.28 28.31 28.86 14 28.53 28.30 28.33 28.85 15 28.48 28.33 28.35 28.84 29.06 29.46 29.76 29.91 28.80 --- --- --- 29.07 29.50 29.77 29.92 28.75 --- --- --- 29.08 29.52 29.76 29.93 28.73 --- --- --- 29.08 29.53 29.79 29.94 28.69 --- --- --- 29.08 29.54 29.80 29.96 28.66 --- --- --­ 16 28.46 28.33 28.37 28.83 17 28.42 28.35 28.39 28.83 18 28.38 28.39 28.44 28.83 19 28.33 28.41 28.47 28.82 20 28.29 28.46 28.52 28.80 29.08 29.51 29.77 29.97 28.64 --- --- --- 29.09 29.53 29.75 29.97 28.63 --- --- --- 29.10 29.55 29.77 29.96 28.61 --- --- --- 29.12 29.55 29.78 29.94 28.60 --- --- --- 29.13 29.56 29.79 29.93 28.58 --- --- --­ 21 28.25 28.46 28.54 28.82 22 28.22 28.40 28.56 28.83 23 28.20 28.38 28.59 28.85 24 28.17 28.34 28.61 28.86 25 28.16 28.30 28.64 28.87 29.15 29.57 29.80 29.86 28.58 --- --- --- 29.17 29.58 29.79 29.82 28.58 --- --- --- 29.18 29.60 29.79 29.79 28.56 --- --- --- 29.19 29.62 29.80 29.72 28.55 --- --- --- 29.20 29.63 29.80 29.68 28.55 --- --- --­ 26 28.13 28.26 28.68 28.88 27 28.11 28.24 28.71 28.90 28 28.10 28.23 28.75 28.91 29 28.10 28.22 28.79 28.92 30 28.10 28.20 28.83 28.93 31 28.10 --- 28.86 28.95 29.22 29.66 29.80 29.64 28.55 --- --- --- 29.23 29.66 29.80 29.57 28.56 --- --- --- 29.24 29.69 29.81 29.52 28.58 --- --- --­ --- 29.70 29.81 29.43 28.59 --- --- --­ --- 29.61 29.83 29.36 28.60 --- --- --­ --- 29.65 --- 29.31 --- --- --- --­ MEAN 28.46 28.26 28.43 28.87 29.10 29.50 29.77 29.80 28.76 28.62 --- --­ WTR YR 1998 MEAN 28.99 HIGHEST 28.10 Oct. 27-Nov. 3, 5, 6, 1997 LOWEST 29.97 MAY 16, 17, 1998 20 25 30 35 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 528 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182445066043401. Local number, PN-6. LOCATION.--Lat 18°24'45", long 66°04'34", Hydrologic Unit 21010005, 0.28 mi northeast of Escuela Dr. Pedreira, 3.52 mi southeast of Cataño plaza, and 0.53 mi south of Hiram Bithorn Stadium main gate. Owner: US Geological Survey, WRD, Name: Alsacia No. 2. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-27.0 ft (0-8.23 m), perforated 21-27.0 ft (6.40-8.23 m). Depth 27 ft (8.23 m). INSTRUMENTATION.--Electronic water level logger--15-minute interval. DATUM.--Elevation of land-surface datum is about 10.0 ft (3.05 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 3.03 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on January 26, 1998. PERIOD OF RECORD.--July 1989 to November 27, 1991, Temporary discontinued, September 9, 1993 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.11 ft (0.95 m), below land-surface datum, Sept. 18, 1989; lowest water level recorded, 13.65 ft (4.16 m), below land-surface datum, Oct. 6, 7, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.21 9.40 8.67 9.95 9.73 9.81 9.51 9.62 8.24 9.13 8.17 7.63 2 9.23 9.39 8.70 9.91 9.74 9.84 9.52 9.68 8.27 8.28 7.73 3 9.07 9.50 8.75 9.84 9.80 9.88 9.54 9.71 8.29 8.30 7.57 4 9.07 9.44 8.80 9.83 9.87 9.90 9.64 9.67 8.28 8.41 7.54 5 8.99 9.37 8.84 9.82 9.27 9.99 9.67 9.67 8.31 8.51 7.40 6 8.96 9.41 8.89 9.50 9.04 9.96 9.70 9.71 8.31 8.55 7.21 7 8.90 9.49 8.99 9.17 8.97 9.92 9.72 9.71 8.32 8.61 6.89 8 8.89 9.56 9.08 8.89 8.99 9.79 9.67 9.64 8.29 8.55 6.71 9 8.81 9.61 9.10 8.88 8.96 9.84 9.68 9.64 8.30 8.54 6.57 10 8.75 9.65 9.18 8.85 8.98 9.93 9.75 9.70 8.18 8.55 6.60 11 8.83 9.67 9.21 8.83 9.01 10.00 9.79 9.79 8.17 8.56 6.70 12 8.66 9.72 9.31 8.83 9.08 10.03 9.85 9.85 8.15 8.54 6.77 13 8.53 9.70 9.35 8.84 9.16 10.04 9.83 9.89 8.16 8.53 6.83 14 8.28 9.80 9.39 8.85 9.18 10.08 9.77 9.91 8.17 8.63 6.88 15 8.15 9.82 9.42 8.92 9.05 9.96 9.78 9.63 8.24 8.72 6.75 16 8.13 9.67 9.48 8.95 9.15 9.86 9.56 9.40 8.30 8.83 6.65 17 8.14 9.63 9.55 9.21 9.90 9.42 9.12 8.31 8.87 6.69 18 8.21 9.67 9.55 9.28 9.96 9.41 8.77 8.35 8.81 6.81 19 8.31 9.49 9.54 9.39 10.00 9.43 8.69 8.42 8.29 6.28 20 8.40 9.43 9.60 9.44 10.01 9.37 8.64 8.51 8.17 8.12 6.26 21 8.50 9.19 9.64 9.45 9.98 9.36 8.30 8.57 7.84 7.95 6.25 22 8.59 9.01 9.70 9.52 10.04 9.35 8.24 8.57 7.77 7.88 5.41 23 8.72 8.93 9.69 9.61 10.08 9.38 8.24 8.63 7.83 7.84 5.44 24 8.83 8.91 9.71 9.68 10.12 9.45 8.23 8.69 7.83 7.72 5.44 25 8.93 8.89 9.77 9.76 10.14 9.49 8.24 8.77 7.85 7.34 5.44 26 9.03 8.83 9.82 9.78 10.15 9.46 8.23 8.82 7.93 7.28 5.45 27 9.16 8.78 9.85 9.51 9.77 10.14 9.44 8.21 8.87 7.92 7.27 5.41 28 9.24 8.84 9.86 9.54 9.78 10.11 9.46 8.24 8.93 7.91 7.25 5.41 29 9.30 8.87 9.89 9.61 10.01 9.48 8.26 8.97 7.94 7.28 5.41 30 9.36 8.74 9.95 9.68 9.71 9.54 8.25 8.98 8.04 7.43 5.32 31 9.39 9.98 9.72 9.55 8.25 8.09 7.54 MEAN 8.79 9.35 9.40 9.33 9.38 9.96 9.57 9.07 8.45 8.02 8.17 6.45 WTR YR 1998 MEAN 8.85 HIGHEST 5.29 SEPT. 30, 1998 LOWEST 10.18 MAR. 24-27, 1998 5 LAND-SURFACE DATUM 10 WATER LEVEL, IN FEET BELOW 15 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 529 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182443066041502. Local number, PN-8c. LOCATION.--Lat 18°24'43", long 66°04'15", Hydrologic Unit 21010005, 2.29 mi east of Fort Buchannan Military Res. main gate, 3.83 mi southeast of Cataño plaza, and 0.16 mi southwest of Hospital del Maestro. Owner: US Geological Survey, WRD, Name: Parque Luis Muñoz Marin 1C. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.10 m), cased 4 in (0.10), 0-33.0 ft (0-10.1 m), perforated 33-40 ft (10.1-12.2 m). Depth 40.0 ft (12.2 m). INSTRUMENTATION.--Electronic water level logger--15-minute interval. DATUM.--Elevation of land-surface datum is about 13.0 ft (3.96 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on January 26, 1998. PERIOD OF RECORD.--February 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +7.28 ft (+2.22 m), above land-surface datum, Sept. 21, 1996; lowest water level recorded, 16.18 ft (4.93 m), below land-surface datum, Oct. 5, 6, 7, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.53 14.73 15.24 15.10 15.24 15.24 15.39 14.07 14.90 14.33 2 14.33 14.78 15.24 15.12 15.26 15.26 15.41 14.11 14.95 14.43 3 14.10 14.81 15.20 15.13 15.26 15.29 15.43 14.15 15.02 14.51 4 14.33 14.83 15.22 15.18 15.28 15.33 15.44 14.15 14.96 14.56 13.59 5 14.32 14.84 15.23 14.45 15.29 15.33 15.45 14.16 15.00 14.62 13.56 6 14.34 14.87 14.98 14.44 15.23 15.36 15.49 14.07 15.07 14.68 10.32 7 14.35 14.89 14.18 14.33 15.27 15.39 15.50 14.12 15.16 14.73 3.21 8 14.42 14.92 14.08 14.35 15.26 15.39 15.50 14.01 15.19 14.67 2.76 9 14.05 14.95 14.57 14.08 14.38 15.30 15.42 15.51 14.04 15.23 14.75 +1.86 10 14.23 14.92 14.59 14.09 14.45 15.31 15.42 15.53 13.80 15.33 14.75 +2.42 11 14.33 15.02 14.63 14.14 14.47 15.32 15.44 15.55 13.87 15.38 14.59 +1.11 12 14.12 15.05 14.68 14.19 14.54 15.37 15.44 15.57 13.81 15.42 14.23 .88 13 14.14 15.07 14.73 14.21 15.04 15.38 15.23 15.59 13.90 15.45 14.39 4.43 14 13.11 15.09 14.78 14.18 15.04 15.40 15.37 15.59 13.98 15.48 14.55 4.68 15 13.32 15.11 14.81 14.32 15.04 15.30 15.41 15.26 14.03 15.47 14.67 4.68 16 13.44 14.90 14.84 14.42 15.06 15.32 15.08 15.21 14.10 15.46 14.77 5.78 17 13.55 14.87 14.50 15.08 15.38 15.02 14.91 14.13 14.85 5.80 18 13.63 14.91 14.56 15.09 15.39 15.12 14.44 14.12 14.85 8.57 19 13.73 14.95 14.57 15.09 15.38 15.15 14.40 14.22 14.25 2.89 20 13.85 14.98 14.63 15.09 15.41 15.16 14.40 14.29 14.20 14.36 2.88 21 13.93 15.01 14.69 15.10 15.41 15.16 13.97 14.36 13.60 14.04 2.88 22 14.03 15.05 14.76 15.10 15.43 15.17 13.93 14.40 13.47 14.06 +7.28 23 14.16 15.08 14.81 15.10 15.46 15.22 13.95 14.45 13.55 14.03 24 14.22 15.08 14.87 15.11 15.48 15.25 13.94 14.51 13.52 13.97 25 14.33 15.12 14.91 15.14 15.49 15.27 14.00 14.58 13.70 12.81 26 14.40 15.13 14.96 15.17 15.50 15.24 13.98 14.61 13.81 12.73 27 14.48 15.15 14.96 15.20 15.50 15.27 13.94 14.66 13.88 12.75 28 14.54 15.17 14.98 15.23 15.51 15.29 14.05 14.74 13.94 12.83 29 14.59 15.20 15.02 15.51 15.35 14.01 14.80 14.06 13.43 30 14.63 15.22 15.05 15.22 15.37 14.04 14.85 14.17 13.67 31 14.67 15.25 15.08 15.20 14.06 14.25 14.40 MEAN 14.14 14.92 14.95 14.69 14.91 15.36 15.28 14.82 14.24 14.63 14.20 3.91 WTR YR 1998 MEAN 14.10 HIGHEST +7.28 SEPT. 21, 1998 LOWEST 15.59 MAY 13, 14, 1998 -10 +10 0 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 10 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR + above land-surface datum --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 530 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182417066042700. Local number, PN-10. LOCATION.--Lat 18°24'17", long 66°04'27", Hydrologic Unit 21010005, 3.96 mi southeast of Cataño plaza, 1.00 mi southwest of Escuela J.J. Osuna, and 2.26 mi east of WAPA TV radio anthena. Owner: US Geological Survey, WRD, Name: Las Américas No. 1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled observation well, cased 4 in (0.10 m), 0-80.0 ft (0-24.4 m), 4 in (0.10 m), perforated pipe 80-90.0 ft (24.4-27.4 m). Depth 90.0 ft (27.4 m). INSTRUMENTATION.--Electronic water level logger--15-minute interval. DATUM.--Elevation of land-surface datum is about 16.0 ft (4.89 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 3.10 ft (0.95 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on February 23, 1998. Well affected by pumping during June 1994. [+, above land-surface datum]. PERIOD OF RECORD.--October 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +2.30 ft (+0.70 m), above land-surface datum, Jan. 9-12, 1993; lowest water level recorded, 6.92 ft (2.11 m) below land-surface datum, Oct. 6-9, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.98 2.81 2.56 2.96 2.81 2.96 2.67 1.77 2.68 3.35 2 2.88 2.83 2.56 2.98 2.85 2.97 2.67 1.76 2.78 3.35 3 2.67 2.85 2.57 2.99 2.87 2.95 2.66 1.76 2.87 2.53 4 2.68 2.85 2.59 3.01 2.88 2.94 2.66 1.77 2.98 2.30 5 2.62 2.85 2.61 2.76 2.92 2.90 2.66 1.87 3.08 1.96 6 2.62 2.85 2.67 2.81 2.94 2.90 2.65 2.19 3.15 1.95 7 2.62 2.85 2.70 2.81 2.97 2.89 2.65 2.48 3.21 1.59 8 2.62 2.85 2.74 2.81 2.95 2.89 2.64 2.64 3.24 1.43 9 2.55 2.87 2.79 2.74 2.95 2.88 2.64 2.76 3.25 1.23 10 2.55 2.89 2.79 2.73 2.94 2.86 2.63 2.78 3.25 1.27 11 2.60 2.92 2.79 2.74 2.95 2.85 2.63 2.83 3.26 1.29 12 2.58 2.94 2.83 2.92 3.00 2.84 2.62 2.92 3.25 1.29 13 2.46 2.98 2.87 2.37 3.06 3.02 2.82 2.62 2.98 3.25 1.29 14 2.14 2.99 2.89 2.31 3.07 3.04 2.77 2.61 3.04 3.26 1.30 15 2.19 3.00 2.89 2.31 3.02 3.04 2.76 2.61 3.09 3.31 1.17 16 2.22 3.01 2.89 2.32 2.98 3.01 2.75 2.62 3.18 3.36 1.19 17 2.28 3.01 2.91 2.32 2.93 3.01 2.75 2.65 3.26 3.38 1.21 18 2.36 2.99 2.93 2.32 2.93 3.01 2.73 2.47 3.31 3.39 1.23 19 2.43 2.95 2.96 2.32 2.93 3.00 2.73 2.26 3.36 3.38 1.00 20 2.48 2.92 2.95 2.32 2.93 3.01 2.72 2.06 3.40 2.76 3.38 1.03 21 2.52 2.41 2.96 2.38 2.94 3.01 2.72 2.02 3.46 2.53 3.38 1.02 22 2.57 2.57 2.99 2.47 2.95 3.00 2.72 2.00 3.49 2.53 3.38 .44 23 2.63 2.59 2.99 2.55 2.86 3.00 2.71 1.97 3.55 2.53 3.38 .59 24 2.65 2.63 3.01 2.60 2.80 3.02 2.71 1.94 2.39 3.37 .64 25 2.67 2.66 3.02 2.66 2.80 3.03 2.70 1.91 2.38 3.37 .65 26 2.69 2.68 3.03 2.73 2.79 3.05 2.70 1.89 2.31 3.37 .68 27 2.72 2.68 3.03 2.76 2.79 3.05 2.69 1.84 2.19 3.37 .67 28 2.73 2.69 3.04 2.82 2.79 3.05 2.69 1.79 2.08 3.37 .67 29 2.76 2.69 3.04 2.86 3.04 2.68 1.79 2.09 3.37 .70 30 2.78 2.57 3.05 2.88 2.97 2.68 1.78 2.34 3.36 .62 31 2.81 3.07 2.93 2.92 1.78 2.54 3.36 MEAN 2.58 2.81 2.86 2.54 2.89 2.98 2.80 2.34 2.77 2.39 3.25 1.32 WTR YR 1998 MEAN 2.64 HIGHEST 0.44 SEPT. 22, 1998 LOWEST 3.55 JUNE 23, 1998 -5 +5 0 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 5 10 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR + above land-surface datum --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 531 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182349066032600. Local number, PN-13. LOCATION.--Lat 18°23'49", long 66°03'26", Hydrologic Unit 21010005, 5.15 mi southeast of Cataño plaza, 1.28 mi south of Escuela J.J. Osuna, and 0.69 mi southwest of University of Puerto Rico main gate. Owner: US Geological Survey, WRD, Name: Jardín Botánico No. 1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.10 m) cased 4.0 in (0.10 m), 0-45.0 ft (0-13.72 m), perforated 35-45.0 ft (10.67-13.72 m). Depth 45.0 ft (13.72 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 32 ft (9.75 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 2.84 ft (0.86 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on May 22, 1998. From July 30, 1998, monthly measurements only. PERIOD OF RECORD.--March 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.96 ft (2.12 m), below land-surface datum, Sept. 10, 1996; lowest water level recorded, 17.87 ft (5.45 m), below land-surface datum, Oct. 7, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 16.90 16.81 16.82 17.28 17.23 17.20 17.32 17.47 17.26 2 16.47 16.83 16.85 17.27 17.25 17.22 17.38 17.49 17.25 3 16.39 16.86 16.86 17.03 17.26 17.23 17.43 17.50 17.27 4 16.61 16.86 16.87 17.22 17.27 17.23 17.47 17.49 17.18 5 16.61 16.73 16.89 17.25 16.11 17.26 17.50 17.49 17.19 6 16.64 16.87 16.90 16.39 16.68 17.17 17.51 17.52 17.27 7 16.60 16.89 16.93 16.20 16.94 17.22 17.54 17.53 17.10 8 16.64 16.91 16.95 16.83 16.98 17.18 17.46 17.53 17.28 9 16.23 16.93 16.96 16.87 16.80 17.25 17.51 17.52 17.21 10 16.47 16.80 16.98 16.88 16.98 17.28 17.53 17.52 17.30 11 16.54 16.97 16.98 16.90 17.02 17.29 17.53 17.53 17.28 12 16.36 16.99 17.01 16.92 16.95 17.32 17.53 17.55 17.30 13 16.33 16.99 17.03 16.81 17.00 17.34 17.22 17.58 17.33 14 15.23 17.01 17.05 16.69 17.02 17.35 17.43 17.58 17.35 15 16.12 17.03 17.05 16.91 16.88 17.22 17.48 17.20 16 16.20 16.69 17.07 16.96 16.99 17.26 16.61 17.30 17 16.31 16.92 17.03 16.98 17.01 17.32 17.12 17.34 18 16.35 16.95 17.08 17.00 17.04 17.37 17.29 17.23 19 16.40 16.81 17.08 16.93 17.07 17.29 17.35 17.19 20 16.46 16.90 17.12 17.02 17.08 17.37 17.35 17.22 21 16.48 16.10 17.13 17.05 17.10 17.37 17.31 17.12 22 16.55 16.71 17.15 17.07 17.13 17.41 17.34 23 16.59 16.77 17.17 17.10 17.15 17.44 17.40 24 16.62 16.78 17.16 17.12 17.17 17.47 17.43 17.18 25 16.65 16.76 17.20 17.15 17.19 17.48 17.44 17.19 26 16.67 16.77 17.22 17.18 17.19 17.49 17.35 17.16 27 16.71 16.77 17.22 17.19 17.19 17.49 17.21 17.19 28 16.74 16.82 17.24 17.21 17.19 17.50 17.38 17.20 29 16.77 16.83 17.26 17.23 17.50 17.43 17.21 30 16.79 16.81 17.27 17.23 17.19 17.46 17.24 31 16.80 17.27 17.23 17.04 MEAN 16.49 16.83 17.06 17.00 17.03 17.31 17.38 17.42 17.20 17.26 WTR YR 1998 MEAN 17.07 HIGHEST 13.58 OCT. 14, 1997 LOWEST 17.59 MAY 13, 1998 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Date level July 30 17.88 10 15 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 532 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182406066034700. Local number, PN-19. LOCATION.--Lat 18°24'06", long 66°03'47", Hydrologic Unit 21010005, 4.65 mi southeast of Cataño plaza, 0.89 mi south of Escuela J.J. Osuna, and 0.78 mi southwest of University of Puerto Rico main gate. Owner: US Geological Survey, WRD, Name: Jardín Botánico No. 3. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.10 m) cased 4.0 in (0.10 m), 0-48.0 ft (0-14.6 m), perforated 38-48 ft (11.6-14.6 m). Depth 48.0 ft.(14.6 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 32.0 ft (9.75 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 2.91 ft (0.88 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on May 22, 1998. PERIOD OF RECORD.--June 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.84 ft (0.86 m), below land-surface datum, Sept. 22, 23, 1998; lowest water level recorded, 13.43 ft (4.09 m), below land-surface datum, Nov. 8, 9, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.13 9.43 7.62 11.21 10.45 10.11 10.62 11.29 6.83 7.13 6.23 2 6.19 9.56 7.70 11.24 10.55 10.22 10.68 11.37 7.10 7.43 6.53 3 5.78 9.70 7.88 11.25 10.64 10.36 10.75 11.44 7.53 7.76 5.85 4 6.15 9.78 8.09 11.24 10.68 10.48 10.83 11.49 7.87 8.07 5.81 5 5.78 9.89 8.31 11.28 6.47 10.62 10.90 11.54 8.22 8.39 5.18 6 5.94 9.94 8.52 10.47 6.10 10.64 11.00 11.60 8.52 8.63 5.19 7 6.11 10.01 8.74 6.43 6.26 10.67 11.13 11.64 8.79 8.84 4.69 8 6.31 10.07 8.92 6.09 6.67 10.62 11.25 11.66 8.96 9.00 4.81 9 6.03 10.16 9.10 6.26 6.20 10.63 11.33 11.70 8.09 9.09 4.37 10 6.11 10.27 9.29 6.13 6.11 10.69 11.39 11.73 7.10 9.23 4.58 11 6.33 10.36 9.43 6.45 6.51 10.75 11.43 11.79 6.87 9.36 4.77 12 5.95 10.47 9.57 6.84 6.86 10.85 11.47 11.82 6.88 9.50 4.94 13 5.72 10.51 9.68 7.17 7.19 10.94 11.47 11.88 7.12 9.59 5.10 14 5.07 10.60 9.82 7.41 7.57 11.03 11.47 11.91 7.48 9.66 5.26 15 5.39 10.70 9.93 7.72 7.78 11.05 11.47 11.22 7.83 9.78 4.71 16 5.66 10.69 10.03 7.96 8.00 10.99 11.34 10.24 8.19 9.93 4.75 17 5.80 10.68 10.11 8.20 8.19 10.99 8.58 9.17 8.49 10.03 4.91 18 6.01 10.70 10.20 8.41 8.45 11.05 8.73 7.62 8.71 10.06 5.05 19 6.22 10.58 10.32 8.59 8.65 11.10 9.42 7.83 8.92 7.48 4.13 20 6.53 10.48 10.40 8.76 8.83 11.14 9.89 8.25 9.13 7.33 4.18 21 6.93 7.71 10.46 8.92 8.97 11.16 10.16 6.85 9.35 4.45 6.59 4.21 22 7.28 6.44 10.56 9.09 9.17 11.21 10.42 6.89 9.53 4.93 6.37 2.91 23 7.60 6.68 10.65 9.30 9.31 11.28 10.63 7.32 5.21 6.16 2.96 24 7.89 7.11 10.71 9.48 9.48 11.36 10.80 7.64 5.23 6.01 3.30 25 8.13 7.43 10.80 9.60 9.61 11.46 10.93 7.98 5.21 4.59 3.54 26 8.34 7.78 10.87 9.74 9.74 11.53 11.03 7.18 5.29 5.02 3.75 27 8.58 7.97 10.91 9.89 9.88 11.54 11.06 6.65 5.47 5.26 3.86 28 8.79 8.22 10.97 10.00 10.00 11.58 11.10 6.61 5.71 5.39 4.04 29 8.95 8.47 11.05 10.09 11.60 11.17 6.53 6.04 5.53 4.20 30 9.10 7.92 11.11 10.17 11.08 11.24 6.61 6.47 5.66 4.17 31 9.28 11.18 10.27 10.79 6.76 6.81 5.89 MEAN 6.81 9.34 9.77 8.89 8.37 10.95 10.79 9.49 8.07 5.53 7.70 4.60 WTR YR 1998 MEAN 8.54 HIGHEST 2.84 SEPT. 22, 23, 1998 LOWEST 11.91 MAY 14, 1998 0 5 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 10 15 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 533 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181352066025300. Local number, CJ-TW19A. LOCATION.--Lat 18°13'52", long 66°02'53", Hydrologic Unit 21010005, 0.96 mi southwest of Caguas plaza, 1.02 mi northwest of Escuela Antonio S. Pedreira, and 0.30 mi southeast of Hwy 156 km 59.1. Owner: US Geological Survey, WRD, Name: CJ-TW19A, Bonneville. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-67.0 ft (0-20.4 m), screened 50-65 ft (15.2-19.8 m). Depth 67.0 ft (20.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 262 ft (79.8 m), above mean sea level, from topographic map. Measuring point: Top of casing 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.-- June 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 22.07 ft (6.73 m), below land-surface datum, Sept. 25, 26, 27, 1998; lowest water level recorded, 25.70 ft (7.83 m), below land-surface datum, May 31, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.91 24.51 24.77 25.08 2 24.89 24.53 24.79 25.07 3 24.87 24.55 24.80 25.08 4 24.86 24.56 24.80 25.08 5 24.85 24.57 24.81 25.09 24.85 24.39 24.27 24.55 24.80 24.71 24.72 23.84 24.87 24.42 24.27 24.56 24.82 24.74 24.72 23.86 24.88 24.45 24.26 24.57 24.82 24.75 24.72 23.92 24.88 24.48 24.26 24.59 24.85 24.76 24.73 23.92 24.83 24.51 24.27 24.60 24.87 24.77 24.76 23.90 6 24.85 24.58 24.83 25.09 7 24.85 24.58 24.86 25.06 8 24.86 24.59 24.88 25.02 9 24.87 24.61 24.88 24.97 10 24.87 24.62 24.89 24.93 24.72 24.49 24.29 24.59 24.88 24.78 24.77 23.88 24.64 24.47 24.34 24.60 24.89 24.79 24.78 23.88 24.59 24.27 24.36 24.61 24.89 24.81 24.78 23.90 24.45 24.15 24.37 24.63 24.89 24.82 24.77 23.92 24.36 24.10 24.36 24.63 24.90 24.83 24.71 23.94 11 24.87 24.62 24.90 24.88 12 24.87 24.61 24.91 24.87 13 24.87 24.60 24.92 24.86 14 24.78 24.60 24.93 24.84 15 24.67 24.60 24.94 24.79 24.31 24.09 24.37 24.63 24.91 24.84 24.68 23.94 24.30 24.10 24.38 24.64 24.91 24.84 24.67 23.95 24.29 24.13 24.43 24.66 24.91 24.84 24.66 23.98 24.28 24.14 24.44 24.66 24.91 24.86 24.65 24.01 24.25 24.15 24.45 24.67 24.87 24.88 24.65 24.04 16 24.60 24.61 24.95 24.76 17 24.54 24.62 24.96 24.75 18 24.42 24.62 24.97 24.74 19 24.35 24.63 25.02 24.72 20 24.30 24.64 25.01 24.72 24.17 24.18 24.45 24.67 24.87 24.89 24.66 24.04 24.13 24.19 24.45 24.69 24.87 24.90 24.69 24.01 24.12 24.22 24.46 24.70 24.85 24.89 24.69 24.00 24.13 24.26 24.46 24.70 24.84 24.91 24.69 24.01 24.15 24.29 24.49 24.70 24.82 24.91 24.68 24.03 21 24.28 24.67 25.00 24.74 22 24.27 24.68 25.01 24.75 23 24.28 24.69 25.01 24.77 24 24.32 24.71 25.02 24.78 25 24.32 24.69 25.03 24.78 24.17 24.28 24.51 24.71 24.81 24.85 24.61 24.03 24.22 24.29 24.50 24.72 24.80 24.82 24.56 23.68 24.24 24.31 24.49 24.73 24.79 24.78 24.47 23.19 24.26 24.33 24.48 24.74 24.76 24.77 24.40 22.98 24.30 24.35 24.49 24.74 24.75 24.77 24.16 22.90 26 24.35 24.71 25.04 24.79 27 24.37 24.73 25.04 24.81 28 24.39 24.75 25.04 24.80 29 24.42 24.75 25.05 24.81 30 24.46 24.75 25.06 24.81 31 24.47 --- 25.07 24.83 24.33 24.37 24.50 24.75 24.73 24.78 24.01 22.87 24.35 24.36 24.50 24.76 24.71 24.78 23.92 22.88 24.38 24.38 24.51 24.77 24.70 24.78 23.86 22.95 --- 24.36 24.53 24.77 24.70 24.77 23.82 23.00 --- 24.32 24.55 24.79 24.69 24.75 23.81 23.07 --- 24.29 --- 24.80 --- 24.73 23.83 --­ MEAN 24.61 24.63 24.94 24.87 24.41 24.29 24.42 24.68 24.83 24.81 24.50 23.68 WTR YR 1998 MEAN 24.56 HIGHEST 22.07 SEPT. 25, 26, 27, 1998 LOWEST 25.09 JAN. 4, 5, 6, 1998 22 24 26 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 534 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181311066022500. Local number, CJ-TW11. LOCATION.--Lat 18°13'11", long 66°02'25", Hydrologic Unit 21010005, 1.13 mi south of the intersection of Hwy 156 with Hwy 52, 0.15 mi southeast of the inserction of Hwy 172 with Hwy 1, and 0.20 mi northeast of Escuela Antonio S. Pereira. Owner: US Geological Survey, WRD, Name: CJ-TW11. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), 0-110 ft (0-33.5 m), screened 66-96 ft (20.1-29.3 m). Depth 110 ft (33.5 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 279 ft (85.0 m), above mean sea level. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.04 ft (0.24 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 2, 1997. PERIOD OF RECORD.--May 2, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.08 ft (7.03 m), below land-surface datum, Sept. 27 29, 1998; lowest water level recorded, 28.73 ft (8.76 m), below land-surface datum, Aug. 22, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.91 28.20 28.27 2 26.64 27.93 28.10 28.24 28.27 3 26.69 27.98 28.15 28.28 28.27 4 26.69 28.03 28.19 28.31 28.25 5 26.74 28.10 28.25 28.38 28.26 6 26.82 28.26 28.44 28.27 7 26.87 28.26 28.46 28.20 8 26.90 28.26 28.47 28.20 9 26.92 28.24 28.49 28.20 10 26.90 28.28 28.51 28.20 11 26.96 28.30 28.51 28.20 12 26.97 28.31 28.51 28.19 13 27.00 28.31 28.53 28.18 14 27.04 28.36 28.55 28.17 15 27.08 28.41 28.57 28.18 16 27.12 28.44 28.61 28.18 17 27.18 28.45 28.61 28.18 18 27.20 28.45 28.61 28.19 19 27.28 28.47 28.61 28.21 20 27.28 28.49 28.62 28.22 21 27.28 28.49 28.63 28.27 22 27.31 28.37 28.71 28.27 23 27.38 28.30 28.66 28.22 24 27.47 28.28 28.61 28.19 25 27.53 28.24 28.49 28.20 26 27.58 28.20 28.38 28.27 27 27.60 28.19 28.33 28.19 28 27.66 28.19 28.31 28.15 29 27.73 28.19 28.29 28.10 30 27.81 28.14 28.26 28.06 31 27.86 28.16 28.28 MEAN 27.18 27.99 28.29 28.47 28.21 WTR YR 1997 MEAN 28.04 HIGHEST 26.63 MAY 2, 1997 LOWEST 28.73 AUG. 22, 1997 535 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.99 26.59 26.96 27.91 2 27.98 26.62 27.03 27.93 3 27.95 26.63 27.06 27.97 4 27.97 26.64 27.07 28.00 5 28.00 26.70 27.07 28.04 27.49 26.50 25.81 26.19 26.99 27.16 27.50 25.81 27.51 26.53 25.84 26.19 27.04 27.19 27.52 25.80 27.52 26.58 25.84 26.24 27.07 27.21 27.56 25.84 27.52 26.64 25.84 26.23 27.10 27.23 27.61 25.82 27.45 26.67 25.83 26.24 27.12 27.27 27.65 25.74 6 28.03 26.69 27.13 28.09 7 28.05 26.68 27.18 27.82 8 28.08 26.70 27.20 27.63 9 28.11 26.75 27.20 27.52 10 28.11 26.74 27.22 27.47 27.14 26.64 25.92 26.25 27.14 27.29 27.67 25.74 26.98 26.61 25.91 26.26 27.16 27.31 27.68 25.72 26.92 26.23 25.94 26.27 27.16 27.33 27.69 25.72 26.72 26.10 25.93 26.30 27.20 27.37 27.64 25.72 26.67 26.01 25.91 26.33 27.21 27.40 27.58 25.70 11 28.13 26.67 27.25 27.43 12 28.03 26.61 27.29 27.42 13 27.91 26.59 27.30 27.40 14 27.44 26.59 27.32 27.25 15 27.04 26.63 27.34 27.15 26.58 25.94 25.91 26.33 27.22 27.44 27.58 25.64 26.54 25.94 25.91 26.39 27.23 27.46 27.61 25.63 26.52 25.97 25.99 26.44 27.19 27.48 27.63 25.64 26.51 25.97 26.00 26.47 27.11 27.51 27.64 25.62 26.41 25.94 25.99 26.51 27.11 27.55 27.68 25.58 16 26.91 26.65 27.36 27.11 17 26.79 26.68 27.49 27.10 18 26.56 26.70 27.46 27.07 19 26.42 26.72 27.53 27.08 20 26.32 26.73 27.56 27.10 26.32 25.97 25.99 26.55 27.12 27.58 27.74 25.51 26.26 25.99 26.00 26.59 27.16 27.62 27.77 25.46 26.27 26.02 26.02 26.64 27.07 27.66 27.75 25.43 26.28 26.05 26.03 26.67 27.03 27.68 27.73 25.46 26.27 26.06 26.05 26.70 27.02 27.67 27.76 25.48 21 26.28 26.79 27.56 27.14 22 26.28 26.84 27.59 27.17 23 26.31 26.86 27.60 27.22 24 26.33 26.86 27.63 27.26 25 26.37 26.85 27.68 27.29 26.28 26.01 26.07 26.72 27.03 27.58 27.64 25.43 26.32 26.00 26.08 26.75 27.03 27.49 27.58 24.68 26.30 26.02 26.07 26.81 26.98 27.47 27.42 23.57 26.31 26.06 26.09 26.83 26.96 27.47 27.28 23.26 26.34 26.08 26.12 26.86 26.96 27.49 26.75 23.17 26 26.43 26.87 27.71 27.30 27 26.45 26.89 27.71 27.31 28 26.48 26.93 27.73 27.34 29 26.49 26.93 27.77 27.36 30 26.52 26.93 27.82 27.36 31 26.55 --- 27.87 27.39 26.36 26.09 26.13 26.90 26.97 27.49 26.22 23.14 26.41 26.04 26.13 26.93 26.98 27.47 26.04 23.09 26.49 26.04 26.14 26.93 27.03 27.48 25.90 23.10 --- 26.01 26.18 26.94 27.07 27.48 25.85 23.09 --- 25.87 26.19 26.97 27.11 27.48 25.85 23.12 --- 25.79 --- 26.99 --- 27.48 25.83 --­ MEAN 27.17 26.74 27.41 27.44 26.67 26.14 26.00 26.56 27.09 27.44 27.27 24.96 WTR YR 1998 MEAN 26.75 HIGHEST 23.08 SEPR. 27, 29, 1998 LOWEST 28.13 OCT. 10, 11, 1997 22 24 26 28 30 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 536 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181446066013400. Local number, CJ-TW20. LOCATION.--Lat 18°14'46", long 66°01'34", Hydrologic Unit 21010005, 0.63 mi east of Hwy 1, 1.59 mi west of the intersection of Hwy 189 with Hwy 931, and 0.70 mi northeast of the intersection of Hwy 189 with Hwy 1. Owner: US Geological Survey, WRD, Name: CJ-TW20. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), caser 4 in (0.10 m), 0-37.0 ft (0-11.3 m), screened 25-35 ft (7.62-11.3 m). Depth 35.0 ft (11.3 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 187.0 ft (57.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.63 ft (1.11 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 5, 1997. PERIOD OF RECORD.--May 5, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 14.19 ft (4.32 m), below land-surface datum, Sept. 22 1998; lowest water level recorded, 19.89 ft (6.06 m), below land-surface datum, July 15, 16, 17, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.55 19.78 19.37 18.23 2 19.54 19.78 19.35 18.33 3 19.53 19.81 19.36 18.36 4 19.48 19.82 19.12 18.41 5 19.60 19.53 19.87 19.05 18.48 6 19.65 19.57 19.86 19.09 18.50 7 19.69 19.58 19.86 19.09 18.35 8 19.71 19.61 19.83 19.12 18.29 9 19.73 19.66 19.81 19.16 18.38 10 19.73 19.68 19.86 19.23 18.51 11 19.74 19.67 19.86 19.22 18.62 12 19.74 19.66 19.84 19.23 18.64 13 19.75 19.69 19.81 19.25 18.39 14 19.73 19.71 19.87 19.27 18.09 15 19.70 19.70 19.89 19.30 18.02 16 19.70 19.69 19.88 19.34 17.93 17 19.68 19.72 19.89 19.34 17.93 18 19.67 19.75 19.85 19.28 18.02 19 19.66 19.76 19.85 19.27 18.08 20 19.64 19.74 19.85 19.29 18.14 21 19.63 19.74 19.82 19.33 18.24 22 19.63 19.77 19.68 19.36 18.19 23 19.66 19.78 19.56 18.90 18.18 24 19.63 19.76 19.55 18.80 18.23 25 19.62 19.76 19.47 18.39 18.30 26 19.62 19.77 19.45 18.27 18.42 27 19.62 19.77 19.46 18.34 17.96 28 19.64 19.77 19.47 18.28 17.84 29 19.60 19.79 19.39 18.11 17.85 30 19.57 19.80 19.38 18.07 17.91 31 19.57 19.35 18.15 MEAN 19.66 19.68 19.72 18.99 18.23 WTR YR 1997 MEAN 19.25 HIGHEST 17.76 SEPT. 28, 1997 LOWEST 19.86 JULY 15, 16, 17, 1997 537 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.94 18.06 18.44 19.39 2 17.98 18.11 18.54 19.38 3 17.92 18.16 18.60 19.38 4 17.97 18.19 18.60 19.38 5 18.06 18.25 18.63 19.40 18.98 18.26 18.04 18.50 18.74 18.30 18.14 16.59 19.03 18.33 18.11 18.53 18.79 18.34 18.18 16.70 18.99 18.40 18.10 18.60 18.82 18.36 18.24 16.92 18.99 18.48 18.09 18.65 18.87 18.37 18.32 16.88 18.68 18.53 18.07 18.68 18.71 18.38 18.38 16.71 6 18.15 18.24 18.65 19.44 7 18.21 18.24 18.74 18.89 8 18.27 18.26 18.80 18.60 9 18.34 18.32 18.80 18.51 10 18.37 18.33 18.83 18.33 18.22 18.45 18.11 18.69 18.64 18.41 18.44 16.62 18.10 18.39 18.26 18.72 18.67 18.42 18.44 16.56 18.11 18.00 18.25 18.73 18.69 18.43 18.22 16.59 17.67 17.78 18.19 18.75 18.72 18.48 17.86 16.25 17.50 17.75 18.13 18.75 18.74 18.52 17.63 16.17 11 18.38 18.21 18.87 18.28 12 18.27 18.19 18.93 18.34 13 18.16 18.19 18.93 18.40 14 17.66 18.22 18.95 18.24 15 17.11 18.27 18.98 18.15 17.57 17.77 18.15 18.74 18.76 18.56 17.65 16.20 17.67 17.86 18.16 18.79 18.77 18.60 17.77 16.32 17.76 17.93 18.29 18.84 18.77 18.66 17.84 16.50 17.82 17.95 18.34 18.83 18.76 18.71 17.90 16.63 17.55 17.94 18.35 18.79 18.81 18.79 17.98 16.80 16 16.93 18.25 19.00 18.20 17 16.88 18.25 19.03 18.26 18 16.83 18.25 19.07 18.28 19 16.84 18.26 19.13 18.33 20 16.93 18.27 19.13 18.40 17.41 17.97 18.35 18.75 18.88 18.85 18.13 16.80 17.38 18.03 18.31 18.79 18.93 18.90 18.24 16.84 17.46 18.10 18.31 18.80 18.58 18.89 18.16 16.91 17.55 18.16 18.33 18.81 18.46 18.85 17.95 17.01 17.66 18.21 18.36 18.83 18.42 18.79 17.91 17.07 21 17.04 18.35 19.11 18.48 22 17.21 18.38 19.16 18.54 23 17.35 18.43 19.15 18.62 24 17.44 18.47 19.16 18.66 25 17.54 18.48 19.20 18.72 17.73 18.15 18.27 18.81 18.46 18.49 17.63 16.87 17.87 18.19 18.13 18.79 18.37 18.34 17.27 15.95 17.91 18.25 18.10 18.84 18.24 18.33 16.94 14.34 17.96 18.33 18.14 18.87 18.25 18.39 16.84 14.60 18.04 18.40 18.21 18.86 18.07 18.48 16.28 14.82 26 17.65 18.51 19.22 18.76 27 17.73 18.42 19.19 18.79 28 17.82 18.44 19.22 18.83 29 17.89 18.42 19.26 18.86 30 17.94 18.40 19.30 18.85 31 17.99 --- 19.35 18.88 18.09 18.38 18.26 18.90 17.97 18.49 15.96 15.08 18.16 18.31 18.29 18.86 17.98 18.47 15.95 15.05 18.25 18.30 18.36 18.77 18.08 18.28 15.94 14.96 --- 18.28 18.45 18.74 18.16 18.06 16.11 15.06 --- 18.06 18.49 18.75 18.23 18.07 16.27 15.18 --- 17.99 --- 18.75 --- 18.10 16.47 --­ MEAN 17.70 18.29 18.97 18.70 18.00 18.16 18.23 18.76 18.54 18.49 17.52 16.17 WTR YR 1998 MEAN 18.13 HIGHEST 14.19 SEPT. 22, 1998 LOWEST 19.46 JAN. 6, 1998 14 16 18 20 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 538 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181539066014500. Local number, CJ-TW15. LOCATION.--Lat 18°15'39", long 66°01'45", Hydrologic Unit 21010005, 0.55 mi southeast of the intersection of Hwy 1 with Hwy 30, 0.75 mi southeast of the inserction of Hwy 1 with Hwy 52, and 0.06 mi north of Hwy 796. Owner: US Geological Survey, WRD, Name: CJ-TW15. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), 0-70.0 ft (0-21.3 m), screened 25-70 ft (7.62-21.3 m). Depth 70.0 ft (21.3 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 167.3 ft (51.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.75 ft (1.14 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 5, 1997. PERIOD OF RECORD.--May 5, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 5.93 ft (1.81 m), below land-surface datum, Oct. 14, 1997; lowest water level recorded, 9.58 ft (2.92 m), below land-surface datum, May 11, 12, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.57 8.05 7.76 7.11 2 7.62 8.09 7.81 7.20 3 7.67 8.09 7.84 7.21 4 7.77 8.11 7.32 7.23 5 7.87 8.15 7.45 7.25 6 7.64 7.95 8.16 7.50 7.30 7 7.68 8.00 8.17 7.55 7.19 8 7.71 8.00 8.15 7.61 7.28 9 7.70 8.00 8.13 7.66 7.32 10 7.68 7.97 8.13 7.71 7.33 11 7.68 7.94 8.14 7.69 7.39 12 7.69 7.91 8.16 7.67 7.39 13 7.73 7.94 8.16 7.62 7.03 14 7.73 8.00 8.19 7.53 7.06 15 7.77 8.04 8.21 7.53 7.09 16 7.80 8.08 8.22 7.53 7.14 17 7.76 8.18 8.16 7.49 7.16 18 7.79 8.24 8.15 7.36 7.22 19 7.82 8.22 8.05 7.46 7.28 20 7.83 8.18 7.97 7.45 7.33 21 7.79 8.19 7.94 7.44 7.35 22 7.75 8.20 7.83 7.19 7.34 23 7.75 8.19 7.81 6.84 7.36 24 7.74 8.14 7.85 6.97 7.42 25 7.68 8.14 7.85 6.52 7.48 26 7.63 8.15 7.88 6.70 7.34 27 7.58 8.14 7.94 6.83 6.99 28 7.54 8.14 7.92 6.91 7.08 29 7.47 8.10 7.92 6.96 7.13 30 7.44 8.05 7.89 7.01 7.21 31 7.50 7.73 7.07 MEAN 7.69 8.02 8.04 7.35 7.24 WTR YR 1997 MEAN 7.67 HIGHEST 6.51 AU. 25, 1997 lOWEST 8.24 JULY 15, 16, 1997 539 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.19 6.99 7.73 8.28 8.90 8.69 8.98 9.43 9.04 8.56 9.15 8.55 2 7.08 7.05 7.76 8.33 8.94 8.73 8.96 9.44 9.03 8.66 9.20 8.51 3 7.02 7.09 7.78 8.33 8.95 8.78 8.98 9.46 9.03 8.72 9.27 8.46 4 7.04 7.10 7.78 8.32 8.97 8.84 9.06 9.48 9.02 8.69 9.31 8.53 5 7.07 7.16 7.79 8.32 8.97 8.80 9.06 9.48 8.87 8.72 9.31 8.62 6 7.13 7.24 7.81 8.32 8.01 8.82 9.08 9.43 8.87 8.80 9.07 8.51 7 7.15 7.34 7.85 8.30 8.12 8.54 9.11 9.46 8.89 8.90 8.73 8.56 8 7.20 7.39 7.86 7.90 8.19 8.64 9.13 9.49 8.88 8.75 8.72 8.65 9 7.24 7.43 7.89 7.77 7.67 8.72 9.19 9.52 8.85 8.87 8.83 8.72 10 7.23 7.32 7.87 7.72 7.66 8.81 9.21 9.54 8.85 8.97 8.94 8.78 11 7.20 7.37 7.89 7.87 12 7.10 7.43 7.91 7.99 13 7.03 7.45 7.95 8.10 14 6.02 7.49 7.98 8.20 15 6.07 7.51 7.99 8.19 7.76 8.89 9.25 9.57 8.83 9.02 8.99 8.86 7.84 8.88 9.23 9.58 8.82 9.04 9.04 8.85 7.88 8.91 9.18 9.46 8.80 9.09 9.07 8.82 7.91 8.93 9.22 9.48 8.78 9.15 9.17 8.77 7.73 8.99 9.27 9.54 8.80 9.22 9.25 8.75 16 6.12 7.50 8.00 8.16 17 6.25 7.51 7.94 8.25 18 6.40 7.53 7.96 8.31 19 6.50 7.55 7.99 8.37 20 6.58 7.58 8.02 8.42 7.83 9.03 9.29 9.47 8.82 9.26 9.20 8.72 7.91 9.08 9.32 9.49 8.81 9.30 9.08 8.70 7.98 9.11 9.21 9.50 8.04 9.33 9.16 8.64 8.07 9.04 9.23 9.46 8.16 9.21 9.01 8.65 8.16 9.12 9.27 9.36 8.25 9.17 8.90 8.19 21 6.67 7.60 8.05 8.47 22 6.76 7.62 8.00 8.54 23 6.78 7.66 8.04 8.53 24 6.79 7.68 8.04 8.59 25 6.86 7.69 8.05 8.65 8.25 9.17 9.31 9.37 8.31 8.96 8.93 6.27 8.33 9.21 9.31 9.37 8.25 9.05 8.30 6.10 8.38 9.20 9.33 9.34 8.22 9.04 7.96 6.41 8.45 9.21 9.36 9.32 8.27 9.05 8.18 6.61 8.51 9.21 9.39 9.31 8.30 9.13 8.00 6.73 26 6.90 7.66 8.09 8.70 27 6.93 7.64 8.16 8.75 28 6.94 7.67 8.18 8.80 29 6.93 7.69 8.17 8.83 30 6.94 7.69 8.18 8.87 31 6.98 --- 8.20 8.87 8.56 9.22 9.41 9.24 8.17 9.16 8.15 6.68 8.61 8.75 9.42 9.19 8.21 8.95 8.30 6.73 8.65 8.75 9.43 9.17 8.26 8.88 8.44 6.71 --- 8.84 9.45 9.14 8.35 8.97 8.54 6.74 --- 8.91 9.44 9.11 8.44 9.04 8.62 6.81 --- 8.97 --- 9.07 --- 9.10 8.62 --­ MEAN 6.84 7.45 7.96 8.36 8.26 8.93 9.24 9.40 8.61 8.99 8.82 7.95 WTR YR 1998 MEAN 8.40 HIGHEST 5.93 OCT. 14, 1997 LOWEST 9.58 MAY 11, 12, 1998 4 6 8 10 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 540 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181550065593200. Local number, 50. LOCATION.--Lat 18°15'50", long 65°59'32", Hydrologic Unit 21010005, 1.36 mi northwest of Gurabo plaza, 0.70 mi north of Estación Experimental Agrícola, and 2.42 mi southwest of Escuela José M. Gallardo. Owner: Gurabo Agricultural Experimental Station, Name: Gurabo. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 13 in (0.34 m), cased 4 in (0.10 m), 0-145 ft (0-44.2 m). Depth 145 ft (44.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 148 ft (45.1 m), above mean sea level, from topographic map. Measuring point: Top of 12 in (0.30 m) casing, 0.80 ft (0.24 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--December 1960 to March 1985, September 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.6 ft (3.86 m), below land-surface datum, Sept. 9, 1975; lowest water level measured, 44.4 ft (13.5 m), below land-surface datum, June 18, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30.50 29.20 30.68 30.48 29.99 29.09 28.73 31.46 33.02 30.96 2 30.46 29.21 30.82 30.54 30.04 28.63 29.04 31.15 33.02 30.99 3 30.34 29.20 30.93 30.60 30.07 25.77 29.28 31.98 33.04 31.11 4 30.24 29.19 31.04 30.68 30.16 26.67 29.39 32.52 33.09 31.05 5 30.17 29.21 30.81 30.78 30.15 28.66 29.62 32.86 33.15 31.09 6 30.14 29.26 30.63 30.67 30.11 29.36 29.58 33.11 33.17 31.05 7 30.09 29.35 30.14 27.32 30.13 29.76 29.68 33.22 33.20 31.07 8 30.06 29.42 29.79 29.42 30.10 28.18 29.76 33.85 32.79 31.01 9 30.00 29.30 29.61 29.74 30.09 27.49 29.91 33.59 32.47 31.08 10 29.97 29.44 29.41 29.83 30.08 27.02 30.88 33.69 32.24 31.05 11 29.94 29.56 29.28 29.82 30.11 27.30 31.47 33.80 32.14 31.08 12 29.90 29.62 29.13 29.84 30.09 27.30 31.81 33.92 32.05 31.08 13 29.96 29.67 29.03 29.83 29.85 30.11 26.72 32.03 34.07 31.98 31.08 14 28.44 29.74 28.98 29.84 29.86 30.08 24.20 32.21 34.13 31.96 31.14 15 28.29 29.80 28.93 29.82 29.88 30.00 26.41 32.28 34.28 32.00 31.17 16 28.41 29.86 28.84 29.83 29.89 29.95 26.74 32.52 34.37 32.06 31.20 17 28.71 26.48 29.93 28.79 29.82 29.99 29.87 26.90 32.13 34.44 32.10 31.29 18 28.88 28.38 29.98 28.78 29.45 30.05 29.85 26.97 31.44 34.54 31.93 31.30 19 28.94 28.79 30.05 28.78 27.96 30.08 29.89 27.02 31.10 34.61 31.94 31.37 20 28.99 29.03 30.09 28.80 28.48 30.13 29.89 27.06 30.79 34.65 31.95 31.36 21 28.98 29.18 30.15 28.82 29.32 29.49 29.56 27.12 31.32 34.33 31.83 31.72 22 29.05 29.26 30.24 28.88 29.72 29.65 29.88 27.17 31.59 34.13 31.70 25.80 23 29.10 29.28 30.33 28.98 29.96 29.84 26.74 27.32 31.73 33.96 31.76 23.80 24 29.19 29.27 28.56 29.02 30.13 29.89 25.31 27.36 31.86 33.79 31.70 22.87 25 29.24 29.23 28.17 29.06 30.24 30.03 28.22 27.40 31.95 33.65 30.22 22.36 26 29.30 29.22 27.96 29.15 30.31 30.05 29.09 27.52 32.02 33.52 29.71 22.07 27 29.33 29.25 27.85 29.21 30.41 30.02 29.48 28.53 32.09 33.43 30.72 21.94 28 29.40 29.27 27.84 30.45 29.98 29.67 28.67 32.13 33.26 30.81 21.86 29 29.44 29.24 28.17 29.90 29.81 29.12 32.11 33.19 30.88 23.97 30 28.43 29.20 29.90 29.94 29.84 27.51 31.88 33.11 30.90 26.92 31 30.44 29.94 28.28 33.05 30.89 MEAN 29.46 28.93 29.38 29.49 29.72 29.94 29.61 27.52 31.08 33.54 31.95 28.86 WTR YR 1998 MEAN 30.03 HIGHEST 21.77 SEPT. 29, 1998 LOWEST 34.67 JULY 20, 1998 20 30 WATER LAVEL, IN FEET BELOW LAND-SURFACE DATUM 40 50 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- 541 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 182515065594100. Local number, 222. LOCATION.--Lat 18°25'15", long 65°59'41", Hydrologic Unit 21010005, 3.56 mi northwest of Carolina plaza, 1.21 mi northwest of Escuela Extensión El Comandante, and 0.74 mi southwest of Escuela Vistamar. Owner: US Geological Survey, WRD, Name: Campo Rico TW-1. AQUIFER.--Surficial Deposits. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m). Depth 100 ft (30.5 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 10.0 ft (3.05 m), above mean sea level, from topographic map. Measuring point: Hole on side of casing, 0.80 ft (0.24 m), above land-surface datum. Prior July 28, 1986, top of shelter floor, 3.10 ft (0.94 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--February 1986 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 4.33 ft (1.32 m), below land-surface datum, Sept. 6, 1995; lowest water level recorded, 7.42 ft (2.26 m), below land-surface datum, Feb. 9, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.45 5.68 5.55 5.62 5.55 5.18 5.51 5.72 5.48 5.64 5.74 5.68 2 5.40 5.70 5.60 5.73 5.62 5.33 5.52 5.68 5.48 5.66 5.68 5.63 3 5.42 5.74 5.66 5.75 5.69 5.48 5.52 5.67 5.54 5.68 5.76 5.61 4 5.33 5.86 5.77 5.76 5.55 5.49 5.55 5.60 5.52 5.65 5.78 5.61 5 5.43 5.91 5.84 5.72 5.27 5.45 5.54 5.60 5.57 5.59 5.78 5.42 6 5.58 5.97 5.83 5.57 5.32 5.33 5.52 5.62 5.54 5.66 5.76 5.30 7 5.70 5.96 5.76 5.38 5.31 5.40 5.51 5.63 5.53 5.61 5.65 5.23 8 5.68 5.84 5.76 5.45 5.19 5.43 5.55 5.56 5.50 5.67 5.56 5.18 9 5.78 5.83 5.69 5.34 5.16 5.45 5.56 5.56 5.53 5.58 5.49 5.16 10 5.80 5.86 5.64 5.28 5.21 5.41 5.58 5.64 5.50 5.53 5.57 5.30 11 5.67 5.83 5.62 5.27 5.28 5.31 5.57 5.64 5.48 5.43 5.55 5.39 12 5.52 5.69 5.64 5.27 5.33 5.29 5.55 5.63 5.45 5.41 5.65 5.49 13 5.42 5.56 5.58 5.31 5.40 5.36 5.54 5.65 5.40 5.38 5.76 5.58 14 5.21 5.55 5.54 5.46 5.37 5.46 5.59 5.59 5.37 5.48 5.82 5.58 15 5.01 5.48 5.46 5.56 5.35 5.49 5.59 5.54 5.40 5.56 5.82 5.64 16 5.01 5.51 5.63 5.69 5.49 5.51 5.60 5.55 5.48 5.61 5.82 5.60 17 5.32 5.63 5.64 5.78 5.51 5.60 5.60 5.57 5.57 5.64 5.82 5.55 18 5.45 5.74 5.71 5.74 5.48 5.68 5.60 5.61 5.56 5.66 5.78 5.42 19 5.59 5.81 5.92 5.69 5.48 5.66 5.61 5.62 5.60 5.66 5.61 5.25 20 5.70 5.85 6.00 5.68 5.49 5.61 5.61 5.66 5.67 5.60 5.54 5.21 21 5.79 5.82 5.98 5.64 5.51 5.55 5.61 5.58 5.65 5.62 5.25 5.07 22 5.84 5.88 5.89 5.49 5.43 5.49 5.49 5.56 5.70 5.58 5.31 5.10 23 5.89 5.90 5.84 5.52 5.32 5.46 5.45 5.51 5.57 5.50 5.27 5.17 24 6.01 5.79 5.78 5.46 5.23 5.47 5.46 5.48 5.55 5.46 5.16 5.14 25 6.03 5.70 5.76 5.45 5.15 5.47 5.43 5.40 5.55 5.50 5.35 5.37 26 5.96 5.62 5.71 5.44 5.11 5.51 5.43 5.40 5.58 5.56 5.35 5.49 27 5.88 5.54 5.70 5.41 4.91 5.48 5.54 5.42 5.60 5.56 5.41 5.49 28 5.89 5.56 5.63 5.43 5.01 5.47 5.65 5.42 5.57 5.64 5.54 5.56 29 5.82 5.57 5.56 5.30 5.43 5.69 5.42 5.61 5.67 5.60 5.58 30 5.75 5.54 5.58 5.41 5.40 5.70 5.48 5.59 5.68 5.66 31 5.72 5.59 5.43 5.43 5.49 5.74 5.74 MEAN 5.61 5.73 5.71 5.52 5.35 5.45 5.56 5.56 5.54 5.59 5.60 5.41 WTR YR 1998 MEAN 5.55 HIGHEST 4.56 SEPT. 21, 22, 1998 LOWEST 6.4 NOW. 14, 1997 4 5 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 6 7 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 542 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181540065580300. Local number, CJ-TW18. LOCATION.--Lat 18°15'40", long 65°58'03", Hydrologic Unit 21010005, 0.75 mi northeast of the intersection of Hwy 181 with Hwy 30, 0.88 mi south of the intersection of Hwy 943 with Hwy 181, and 0.01 mi west of Hwy 181. Owner: US Geological Survey, WRD, Name: CJ-TW18. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), 0-65.0 ft (0-19.8 m), screened 25-65 ft (7.62-19.8 m). Depth 65.0 ft (19.8 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 164.0 ft (50.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.65 ft (1.11 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on June 23, 1997. Found destroyed due to construction in the area, Since then, tape down measurements only. PERIOD OF RECORD.--June 23, 1997 to November 19, 1997. Found destroyed, temporally discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 12.08 ft (3.68 m), below land-surface datum, Oct. 16, 1997; lowest water level recorded, 15.81 ft (4.82 m) below land-surface datum, July 15, 16, 17, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 15.74 15.04 14.37 2 15.75 15.07 14.42 3 15.76 15.09 14.42 4 15.77 15.10 14.48 5 15.78 15.13 14.53 6 15.79 15.16 14.58 7 15.78 15.19 14.62 8 15.78 15.22 14.69 9 15.79 15.26 14.74 10 15.79 15.28 14.80 11 15.78 15.23 14.87 12 15.78 15.23 14.87 13 15.78 15.23 14.81 14 15.79 15.18 14.81 15 15.80 15.20 14.79 16 15.81 15.25 14.81 17 15.81 15.25 14.84 18 15.79 15.23 14.90 19 15.79 15.25 14.92 20 15.77 15.29 14.94 21 15.74 15.32 14.97 22 15.37 15.06 14.98 23 15.77 15.23 14.79 15.00 24 15.68 15.13 14.66 15.02 25 15.64 15.07 14.34 15.04 26 15.64 15.05 14.29 14.98 27 15.65 15.04 14.28 14.82 28 15.67 15.06 14.28 14.74 29 15.69 15.01 14.29 14.74 30 15.72 15.02 14.32 14.71 31 15.01 14.35 MEAN 15.68 15.56 14.96 14.77 WTR YR 1997 MEAN 15.15 HIGHEST 14.28 AUG. 27, 28, 29, 1997 LOWEST 15.81 JULY 15. 16, 17, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 543 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.72 13.74 2 14.54 13.91 3 14.39 13.94 4 14.35 13.97 5 14.35 14.06 6 14.35 14.12 7 14.36 14.15 8 14.40 14.20 9 14.42 14.30 10 14.47 14.07 11 14.51 13.94 12 14.49 13.93 13 14.48 13.93 14 12.25 13.94 15 12.27 13.95 16 12.14 13.96 17 12.14 13.99 18 12.21 14.08 19 12.32 14.12 20 12.43 21 12.54 22 12.68 23 12.82 24 12.93 25 13.06 26 13.16 27 13.27 28 13.39 29 13.56 30 13.65 31 13.71 MEAN 13.50 14.02 WTR YR 1998 MEAN 13.69 HIGHEST 12.08 OCT. 16, 1997 LOWEST 14.74 OCT. 1, 2, 1997 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Feb. 19 14.39 Feb. 20 14.47 Mar. 24 15.46 June 15 14.80 12 LAND-SURFACE DATUM 14 WATER LEVEL, IN FEET BELOW 16 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 544 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181513065554601. Local number, CJ-TW3B. LOCATION.--Lat 18°15'13", long 65°55'46", Hydrologic Unit 21010005, 2.86 mi east of Gurabo plaza, 3.57 mi southwest of Hwy 186 km 4.7, and 1.39 mi southwest of Hwy 185 km 15.7. Owner: US Geological Survey, WRD, Name: CJ-TW3B. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-38 ft (0-11.6 m) screened 25-35 ft (7.62 m). Depth 38.0 ft (11.6 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 187 ft (57.0 m), above mean sea level, from topographic map. Measuring point: Top of casing 2.95 ft (0.90 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--September 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 10.64 ft (3.24 m), below land-surface datum, Sept. 11, 1996; lowest water level recorded, 20.31 ft (6.19 m), below land-surface datum, Sept. 19, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.27 18.02 18.29 18.70 18.75 17.97 18.54 18.50 18.81 18.90 2 19.27 18.04 18.31 18.71 18.76 18.02 18.56 18.50 18.82 18.90 3 19.28 18.05 18.34 18.71 18.76 18.04 18.57 18.53 18.82 18.90 4 19.28 18.07 18.34 18.73 18.76 18.06 18.58 18.55 18.82 18.90 16.41 5 19.28 18.08 18.34 18.74 18.72 18.08 18.59 18.58 18.82 18.90 16.39 6 19.27 18.09 18.35 18.75 18.63 18.08 18.60 18.59 18.82 18.90 16.36 7 19.26 18.10 18.38 18.75 18.55 18.09 18.63 18.62 18.82 18.90 16.35 8 19.26 18.11 18.39 18.75 18.48 18.11 18.64 18.63 18.82 18.90 16.34 9 19.26 18.12 18.38 18.74 18.40 18.12 18.66 18.63 18.82 18.90 16.34 10 19.26 18.13 18.39 18.74 18.30 18.14 18.67 18.63 18.82 18.90 16.34 11 19.26 18.12 18.40 18.71 18.20 18.14 18.68 18.60 18.82 18.90 16.34 12 19.25 18.10 18.41 18.70 18.12 18.16 18.69 18.57 18.82 18.90 16.35 13 19.22 18.09 18.41 18.69 18.10 18.24 18.72 18.56 18.82 18.90 16.39 14 18.92 18.09 18.42 18.68 18.07 18.24 18.72 18.56 18.82 18.90 16.43 15 18.54 18.09 18.43 18.67 18.04 18.24 18.73 18.56 18.82 16.44 16 18.34 18.10 18.45 18.65 17.97 18.25 18.74 18.57 18.85 16.44 17 18.18 18.11 18.47 18.64 17.94 18.29 18.75 18.59 18.85 16.44 18 18.10 18.13 18.49 18.64 17.91 18.30 18.76 18.62 18.85 16.47 19 18.04 18.13 18.52 18.63 17.88 18.33 18.78 18.63 18.85 16.48 20 17.98 18.13 18.53 18.63 17.85 18.34 18.80 18.65 18.85 16.48 21 17.96 18.14 18.54 18.64 17.85 18.35 18.75 18.67 18.85 22 17.95 18.15 18.57 18.65 17.85 18.37 18.69 18.68 18.85 23 17.96 18.17 18.58 18.67 17.85 18.39 18.64 18.69 18.85 24 17.96 18.17 18.59 18.68 17.86 18.40 18.59 18.70 18.85 25 17.96 18.19 18.60 18.69 17.89 18.42 18.56 18.72 18.86 26 17.96 18.21 18.62 18.69 17.91 18.43 18.54 18.73 18.87 27 17.96 18.24 18.63 18.71 17.93 18.44 18.52 18.75 18.87 28 17.96 18.26 18.64 18.71 17.95 18.47 18.51 18.76 18.87 29 17.96 18.26 18.65 18.72 18.48 18.50 18.77 18.90 30 17.96 18.29 18.67 18.73 18.50 18.50 18.78 18.92 31 17.97 18.69 18.74 18.51 18.80 MEAN 18.58 18.13 18.48 18.70 18.19 18.26 18.64 18.64 18.84 18.90 16.40 WTR YR 1998 MEAN 18.40 HIGHEST 15.92 SEPT. 21, 1998 LOWEST 19.28 OCT. 2-5, 1997 10 15 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 25 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 545 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 182344065490801. Local number, RE-2A. LOCATION.--Lat 18°23'44", long 65°49'08", Hydrologic Unit 2101005, 0.35 mi west of Hwy 187, 1.30 mi southwest of the intersection of Hwy 187 with Hwy 3, and 1.83 mi south of Punta San Agustín. Owner: US Geological Survey, WRD, Name: Río Espíritu-2A. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 0-22.0 ft (0-6.70 m), screened 3.00-22.0 ft (0.90-6.70 m). Depth 22.0 ft (6.7 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is 5.78 ft (41.8 m), above mean sea level, from survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 5.60 ft (1.71 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on December 24, 1996 replaced by an Eletronic Data Logger (EDL), installed on January 14, 1997. PERIOD OF RECORD.--December 24, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.41 ft (0.12 m), below land-surface datum, Feb. 2, 1997; lowest water level recorded, 6.02 ft (1.83 m), below land-surface datum, Aug. 19, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.68 1.29 2.04 3.32 4.38 5.00 5.50 5.77 2 1.80 .44 2.08 3.36 4.41 5.02 5.53 5.77 3 1.88 .69 2.16 3.36 4.44 5.06 5.55 5.78 4 1.97 .95 2.23 3.43 4.47 5.06 5.55 5.79 5 2.04 .93 2.28 3.47 4.53 5.07 5.58 5.84 6 2.10 1.18 2.28 3.50 4.55 5.10 5.58 5.84 7 2.15 1.09 2.32 3.53 4.58 5.12 5.59 5.84 8 2.20 .84 2.35 3.55 4.59 5.13 5.59 5.88 9 2.26 .99 2.43 3.59 4.64 5.13 5.60 5.88 10 2.30 .96 2.45 3.64 4.64 5.16 5.63 5.88 11 2.36 .91 2.53 3.71 4.67 5.18 5.63 5.88 12 2.40 1.09 2.55 3.74 4.70 5.20 5.65 5.90 13 2.45 1.01 2.59 3.75 4.72 5.22 5.66 5.90 14 2.49 1.17 2.66 3.81 4.72 5.22 5.68 5.91 15 2.52 1.12 2.68 3.83 4.73 5.22 5.69 5.91 16 2.56 1.35 2.72 3.86 4.73 5.23 5.71 5.96 17 2.59 1.53 2.74 3.87 4.78 5.26 5.71 5.96 18 2.63 1.66 2.78 3.92 4.81 5.28 5.72 5.96 19 2.67 1.74 2.80 3.97 4.84 5.29 5.72 5.99 20 2.71 1.83 2.84 4.02 4.87 5.29 5.72 21 2.70 1.86 2.87 4.02 4.88 5.32 5.72 22 2.15 1.56 2.93 4.08 4.90 5.34 5.72 23 1.10 1.42 2.96 4.12 4.93 5.35 5.72 24 2.36 .77 1.51 3.02 4.14 4.96 5.35 5.74 25 2.30 .66 1.57 3.05 4.19 4.96 5.38 5.75 26 2.30 .91 1.72 3.09 4.23 4.97 5.43 5.75 5.61 27 2.31 1.17 1.84 3.16 4.26 4.99 5.43 5.75 5.42 28 2.28 1.37 1.93 3.17 4.28 4.99 5.43 5.75 5.35 29 2.19 1.40 3.25 4.34 5.00 5.43 5.75 5.32 30 1.65 1.52 3.26 4.35 5.00 5.47 5.77 5.27 31 1.60 1.62 3.30 5.00 5.77 MEAN 2.12 1.97 1.29 2.70 3.84 4.75 5.24 5.67 5.88 5.39 WTR YR 1997 MEAN 3.82 HIGHEST 0.41 FEB. 2, 1997 LOWEST 6.02 AUG. 19, 1997 546 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.22 3.29 2.14 3.52 2.91 3.11 2.47 --- --- --- --- --­ 2 5.19 3.32 2.27 3.57 2.91 3.13 2.38 --- --- --- --- --­ 3 5.10 3.35 2.34 3.57 3.00 3.16 2.29 --- --- --- --- --­ 4 5.02 3.41 2.40 3.58 3.01 3.21 2.25 --- --- --- --- --­ 5 4.99 3.41 2.45 3.58 2.67 3.21 2.31 --- --- --- --- --­ 6 4.97 3.47 2.52 3.42 2.57 2.89 2.36 --- --- --- --- --­ 7 4.93 3.50 2.54 2.61 2.53 2.85 2.46 --- --- --- --- --­ 8 4.93 3.52 2.64 2.29 2.55 1.63 2.53 --- --- --- --- --­ 9 4.91 3.56 2.70 2.22 2.46 1.63 2.56 --- --- --- --- --­ 10 4.91 3.59 2.70 2.16 2.41 1.63 2.64 --- --- --- --- --­ 11 4.93 3.61 2.79 2.16 12 4.45 3.64 2.84 2.20 13 4.12 3.64 2.88 2.27 14 3.21 3.67 2.90 1.95 15 2.77 3.67 2.93 1.90 2.41 1.63 --- --- --- --- --- --- 2.46 1.63 --- --- --- --- --- --- 2.52 1.63 --- --- --- --- --- --- 2.56 1.66 --- --- --- --- --- --- 2.61 1.68 --- --- --- --- --- --­ 16 2.68 3.70 2.96 1.99 17 2.65 3.73 3.03 2.08 18 2.65 3.73 3.05 2.16 19 2.65 3.73 3.09 2.25 20 2.70 3.73 3.15 2.31 2.67 1.71 --- --- --- --- --- --- 2.70 1.77 --- --- --- --- --- --- 2.70 1.81 --- --- --- --- --- --- 2.76 1.93 --- --- --- --- --- --- 2.82 2.04 --- --- --- --- --- --­ 21 2.70 3.65 3.16 2.38 22 2.80 3.56 3.21 2.42 23 2.86 3.56 3.24 2.47 24 2.89 3.54 3.27 2.55 25 2.96 3.54 3.33 2.56 2.82 2.05 --- --- --- --- --- --- 2.86 2.09 --- --- --- --- --- --- 2.91 2.17 --- --- --- --- --- --- 2.94 2.23 --- --- --- --- --- --- 2.94 2.32 --- --- --- --- --- --­ 26 3.01 2.70 3.37 2.64 27 3.07 2.13 3.37 2.70 28 3.11 2.07 3.42 2.70 29 3.17 2.07 3.44 2.73 30 3.25 2.07 3.49 2.79 31 3.25 --- 3.51 2.86 2.95 2.34 --- --- --- --- --- --- 3.04 2.40 --- --- --- --- --- --- 3.06 2.46 --- --- --- --- --- --­ --- 2.52 --- --- --- --- --- --­ --- 2.53 --- --- --- --- --- --­ --- 2.50 --- --- --- --- --- --­ MEAN 3.74 3.34 2.94 2.60 2.74 2.24 2.42 --- --- --- --- --­ WTR YR 1998 MEAN 2.91 HIGHEST 1.63 MAR. 8-13, 1998 LOWEST 5.22 OCT. 1, 1997 0 2 4 6 8 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR 547 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 182223065455900. Local number, RM-02. LOCATION.--Lat 18°22’23", long 65°45'59", Hydrologic Unit 21010005, 0.06 mi south of Hwy 2 amd 0.27 mi east of Hwy 181. Owner: US Geological Survey, WRD, Name: Pozo Río Mameyes No. 02. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled piezometer well, constructed in 1993 as part of a study of northeast of Puerto Rico, diameter 2 in (0.05 m), screened 13-24.0 ft (3.96-7.32 m). Depth 24.0 ft (7.32 m). INSTRUMENTATION.--Electronic Data Logger (EDL)--60-minute interval. DATUM.--Elevation of land surface datum is about 20.0 ft (6.10 m), above mean sea level, from topographic map. Measuring point: On shelter floor, 6.65 ft (2.03 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on Sept. 25, 1997. PERIOD OF RECORD.--September 25, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.35 ft (2.85 m), below land-surface datum, June 1, 1998; lowest water level recorded, 14.08 ft (4.29 m), below land-surface datum, May 26, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12.74 --- --- --- 2 11.93 --- --- 13.97 3 11.62 --- --- 13.96 4 11.69 --- --- 13.85 5 11.87 --- --- 13.73 13.94 14.00 12.82 13.36 9.37 --- 13.61 --- 13.96 14.00 12.94 13.48 9.37 --- 13.76 --- 13.96 14.00 12.86 13.54 9.82 --- 13.82 12.43 13.97 14.06 12.88 13.58 10.52 --- 13.84 12.31 13.39 14.06 13.06 13.58 11.06 --- 13.91 12.37 6 11.91 --- --- 13.39 7 11.91 --- --- 12.32 8 12.42 --- --- --- 9 12.73 --- --- --- 10 12.73 --- --- --- 13.04 12.49 13.14 13.58 11.11 --- 14.03 --- 12.94 12.05 13.31 13.64 11.84 13.55 14.03 12.50 12.97 9.48 13.50 13.72 12.01 --- 13.97 --- 13.06 10.05 13.50 13.73 12.44 13.27 13.87 --- 13.10 10.69 13.63 13.72 12.50 12.99 13.82 --­ 11 12.83 --- --- --- 12 12.53 --- --- --- 13 12.28 --- --- --- 14 11.57 --- --- --- 15 11.57 --- --- --- 13.25 11.20 13.72 13.73 12.83 12.94 13.82 --- 13.36 11.50 13.81 13.81 12.97 12.94 13.88 --- 13.45 12.01 13.63 13.87 12.77 13.09 13.94 --- 13.58 12.38 13.57 13.94 12.62 13.33 13.96 --- 13.67 12.50 13.50 13.84 12.74 13.45 13.99 --­ 16 11.57 --- --- --- 17 11.57 --- --- --- 18 11.57 --- --- --- 19 11.57 --- --- --- 20 11.72 --- --- --- 13.72 12.50 12.19 13.64 11.56 13.46 13.99 --- 13.78 12.94 10.34 13.63 11.42 13.50 13.99 --- 13.88 13.13 10.84 13.63 11.77 13.59 13.99 --- 13.88 13.19 --- 13.72 11.98 13.55 13.96 --- 13.97 13.31 --- 13.78 12.01 13.42 13.89 --­ 21 12.04 --- --- --- 22 12.28 --- --- --- 23 12.50 --- --- --- 24 12.70 --- --- 13.89 25 12.83 --- --- 13.94 13.96 13.33 --- 13.87 12.34 12.83 13.78 --- 13.96 13.34 --- 13.93 12.50 12.64 13.58 --- 13.96 13.40 --- 13.97 12.73 12.68 13.46 --- 13.93 13.50 --- 14.00 12.94 12.86 13.45 --- 13.87 13.54 --- 14.05 13.09 12.92 12.02 --­ 26 12.89 --- --- 13.96 27 12.98 --- --- 13.99 28 13.13 --- --- 13.99 29 13.14 --- --- 13.99 30 --- --- --- 13.88 31 --- --- --- 13.87 13.89 13.57 --- 14.08 13.24 12.94 11.35 --- 13.93 13.59 --- 13.91 13.34 13.09 11.54 --- 13.93 13.63 12.99 13.88 --- 13.22 11.80 --­ --- 13.59 13.09 13.85 --- 13.40 11.96 --­ --- 12.91 13.25 9.37 --- 13.43 --- --­ --- 12.83 --- 9.37 --- 13.58 --- --­ MEAN 12.24 --- --- 13.77 13.65 12.80 12.98 13.48 11.96 13.19 13.48 12.40 WTR YR 1998 MEAN 13.01 HIGHEST 9.35 JUNE 1,1998 LOWEST 14.08 MAY 26, 1998 8 10 12 14 16 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 548 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 181217065453000. Local number, ARR-1. LOCATION.--Lat 18°12'17", long 65°45'30", Hydrologic Unit 21010005, 0.01 mi south of Hwy 927 at Km 8.0 and 0.62 mi south of Hwy 31. Owner: Carlos Arroyo, Name: Arroyo TW-1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. INSTRUMENTATION.--Digital water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 16.0 ft (4.87 m), above mean sea level, from topographic map. Measuring point: Shelter floor, 4.80 ft (1.46 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on Oct. 26, 1997. Well is affected by stage in nearby Río Blanco. PERIOD OF RECORD.--October 26, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 4.95 ft (1.51 m), below land-surface datum, Jan. 7, 1998; lowest water level recorded, 10.65 ft (3.25 m), below land-surface datum, Apr. 6, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.42 8.41 9.84 9.77 9.93 10.34 2 9.39 8.74 9.33 9.81 9.96 10.30 3 9.50 8.88 9.61 9.85 9.98 10.41 4 9.57 8.97 9.41 9.88 10.03 10.54 5 9.53 9.09 9.28 7.27 10.08 10.61 6 9.39 9.20 7.29 8.64 10.13 10.65 7 9.51 9.24 5.66 8.91 10.13 8 9.71 9.31 7.30 8.98 9.98 9 9.38 9.38 7.91 8.27 10.13 10 6.34 9.45 7.06 8.72 10.20 11 7.92 9.54 7.63 8.92 10.26 12 8.29 9.68 7.84 8.87 10.31 13 8.46 9.72 8.04 9.06 10.33 14 8.62 9.75 8.06 9.15 10.36 15 8.80 9.78 8.45 9.03 10.16 16 8.49 9.82 8.65 9.22 10.16 17 8.33 9.72 8.83 9.29 10.28 18 8.64 9.74 8.87 9.35 10.36 19 8.47 9.54 8.93 9.41 10.40 20 8.85 9.71 9.09 9.46 10.44 21 8.55 9.25 9.18 9.58 10.21 22 8.96 9.40 9.25 9.67 10.35 23 9.08 9.54 9.32 9.70 10.33 24 8.99 9.26 9.36 9.75 10.47 25 9.20 9.47 9.38 9.81 10.53 26 6.15 9.66 9.45 9.85 10.52 27 7.40 9.69 9.56 9.88 10.39 28 8.10 9.74 9.64 9.90 10.39 29 9.29 8.41 9.78 9.67 10.34 30 9.34 8.12 9.83 9.70 10.42 31 9.39 9.87 9.73 10.09 MEAN 9.34 8.65 9.46 8.75 9.29 10.25 10.47 WTR YR 1998 MEAN 9.33 HIGHEST 4.95 JAN. 7, 1998 LOWEST 10.65 APR. 6, 1998 6 8 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 10 12 October November December January February March April May June July August September 1998 WATER YEAR --- --- --- --- --- --- --- 549 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 182138065431800. Local number, RS-02. LOCATION.--Lat 18°21'38", long 65°43'18", Hydrologic Unit 21010005, 0.87 mi southwest of Hwy 3, 0.39 mi south of the intersection of Hwy 992 with Hwy 991, 0.39 mi north of Hwy 983, and 0.07 mi east of Hwy 991. Owner: US Geological Survey, WRD, Name: Río Sabana No. 02. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-56.0 ft (0-17.1 m), screened 2.56-56.0 ft (0.78-17.1 m). Depth 56.0 ft (17.1 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 33.9 ft (10.3 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.34 ft (1.02 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--August 22, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.91 ft (0.28 m), below land-surface datum, Oct. 14, 1997; lowest water level recorded, 7.13 ft (2.17 m), below land-surface datum, July 9-13, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.20 5.64 4.26 6.08 6.17 6.31 5.80 6.20 3.70 6.20 5.66 5.05 2 3.06 5.66 4.50 6.00 6.19 6.33 5.68 6.24 3.96 6.26 5.74 5.11 3 3.02 5.76 4.70 6.00 6.23 6.38 5.53 6.30 4.30 6.28 5.88 4.99 4 3.53 5.84 4.84 5.96 6.27 6.40 5.75 6.32 4.62 6.26 5.94 5.11 5 4.05 5.85 5.00 5.83 4.83 6.42 5.90 6.32 4.95 5.58 5.96 5.19 6 4.53 5.83 5.10 5.33 4.43 5.54 5.98 6.37 5.17 5.70 6.00 5.25 7 4.91 5.87 5.22 4.15 4.57 4.64 6.11 6.39 5.31 5.64 5.90 5.33 8 5.21 5.95 5.32 3.79 4.92 4.03 6.11 6.39 5.51 5.60 5.88 5.27 9 4.07 5.95 5.40 4.05 4.50 4.21 6.13 6.33 5.59 4.92 5.88 5.33 10 3.73 3.71 5.46 4.31 4.64 4.53 6.20 6.33 5.57 4.74 5.93 5.33 11 3.91 3.01 5.42 4.49 4.94 4.89 6.26 6.39 5.75 4.84 5.99 5.47 12 3.01 3.43 5.44 4.73 5.16 5.20 6.27 6.43 5.84 5.08 5.91 5.65 13 2.59 3.83 5.54 4.91 5.40 5.30 5.99 6.48 5.46 5.28 5.85 5.75 14 1.47 4.21 5.56 4.69 5.54 5.48 5.92 6.42 5.34 5.40 5.81 5.33 15 2.37 4.52 5.60 4.85 5.50 5.28 5.98 4.60 5.54 5.60 5.83 5.25 16 2.85 4.66 5.70 5.04 5.66 5.50 5.19 4.22 5.12 5.58 5.97 4.51 17 3.23 4.74 5.74 5.20 5.72 5.71 4.44 4.42 4.86 5.56 6.03 4.55 18 3.59 4.92 5.74 5.34 5.84 5.73 4.58 4.82 4.92 5.50 5.89 4.63 19 3.85 4.84 5.78 5.46 5.93 5.87 4.80 5.14 4.99 5.54 5.85 4.57 20 4.13 4.40 5.84 5.56 5.99 5.95 5.00 5.38 5.03 5.42 5.73 4.49 21 4.41 4.50 5.86 5.68 5.99 5.96 4.97 5.59 5.25 5.02 5.59 4.51 22 4.64 4.68 5.84 5.72 6.05 6.00 5.15 5.75 5.19 5.06 5.41 1.69 23 4.86 4.88 5.88 5.82 6.09 6.14 5.43 5.89 5.23 5.22 5.35 2.49 24 5.04 4.98 5.94 5.90 6.18 6.18 5.61 5.99 5.45 5.00 5.45 3.03 25 5.16 5.04 6.00 5.94 6.20 6.19 5.79 6.09 5.63 4.96 3.49 3.33 26 5.26 4.66 6.08 5.96 6.24 6.21 5.89 5.77 5.79 5.06 3.57 3.61 27 5.42 3.46 6.10 6.03 6.27 6.24 5.93 5.51 5.90 5.18 3.95 3.85 28 5.54 3.64 6.14 6.07 6.31 6.26 6.01 5.72 5.96 5.30 4.25 4.03 29 5.66 3.94 6.16 6.11 5.73 6.06 5.68 6.06 5.44 4.45 4.23 30 5.74 4.12 6.18 6.05 5.53 6.14 4.14 6.14 5.56 4.63 4.33 31 5.66 6.12 6.09 5.60 3.34 5.58 4.87 MEAN 4.18 4.75 5.56 5.39 5.63 5.67 5.69 5.71 5.27 5.43 5.44 4.58 WTR YR 1998 MEAN 5.27 HIGHEST 0.91 OCT. 14, 1997 LOWEST 6.48 MAY 13, 14, 1998 0 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 2 4 6 8 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR 550 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 182131065241100. Local number, RP-04. LOCATION.--Lat. 18 °21'31", long. 65°24'11", Hydrologic Unit 21010005, 1.39 mi southeast of the intersection of Hwy 992 with Hwy 3, 0.40 mi southeast of the intersection of Hwy 983 with Hwy 3, 0.12 mi northwest of the intersection with Hwy 940 with Hwy 983, and 0.03 mi southwest of Hwy 983. Owner: US Geological Survey, WRD, Name: Río Pitahaya No. 04. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-39.0 ft (0-11.9 m), screened 4.00-39.0 ft (1.20-11.9 m). Depth 39.0 ft (11.9 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 82.1 ft (25.0 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 4.18 ft (1.27 m), above land-surface datum. REMARKS.--Recording observation well. Water levels affected by nearby pumping well. PERIOD OF RECORD.--August 15, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.91 ft (0.28 m), below land-surface datum, Sept. 18, 1995; lowest water level recorded, 14.05 ft (4.28 m), below land-surface datum, Aug. 21, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11.65 8.26 2.27 4.62 5.11 7.29 6.62 7.66 5.59 6.93 7.27 6.65 2 10.40 8.11 2.23 4.70 4.64 7.70 6.72 8.77 5.47 8.05 7.41 6.62 3 9.57 8.11 2.30 4.16 4.72 6.54 6.79 8.08 5.23 7.32 7.46 6.51 4 9.15 9.72 2.34 4.84 4.08 7.85 6.85 7.96 5.66 7.21 8.60 6.56 5 9.22 9.92 6.31 4.77 3.94 8.17 6.93 8.00 5.75 6.92 8.91 6.60 6 9.63 10.06 6.63 4.14 3.78 8.18 7.03 8.17 5.91 6.88 8.73 6.62 7 8.58 10.24 3.65 3.09 3.09 7.44 7.15 8.09 5.98 6.53 9.12 6.66 8 9.69 10.36 3.05 3.09 3.11 3.71 7.30 8.10 6.11 6.26 8.22 6.68 9 7.98 10.53 2.87 3.12 2.34 4.93 7.32 6.47 6.29 7.61 7.90 6.78 10 8.34 8.94 2.52 2.60 2.10 5.37 7.37 6.25 6.26 6.83 7.84 6.84 11 8.46 7.89 2.68 3.06 12 8.07 5.85 2.63 3.22 13 6.62 3.97 2.62 2.97 14 6.77 3.48 2.65 3.12 15 6.09 6.10 3.12 3.12 2.33 5.52 7.45 8.83 6.38 6.48 7.88 6.93 2.35 5.45 7.52 8.40 6.46 6.61 7.93 6.94 2.77 5.51 7.55 8.36 6.45 6.71 7.98 7.05 2.93 4.68 7.56 8.45 6.40 7.85 7.99 6.84 2.95 4.99 7.59 6.71 6.50 8.37 7.82 6.74 16 5.02 6.91 2.82 3.12 17 5.97 7.09 3.55 3.13 18 6.44 7.63 3.46 3.22 19 5.88 7.69 4.39 3.23 20 7.40 7.03 4.55 3.23 3.00 5.24 7.50 5.89 6.46 8.34 8.06 6.46 3.03 5.39 7.20 5.74 6.40 8.35 8.19 6.42 2.52 4.46 7.20 5.78 6.49 8.36 8.18 6.40 --- 4.90 7.23 5.86 6.29 8.31 8.17 6.33 --- 5.34 7.06 5.98 6.15 8.13 8.10 6.32 21 7.70 7.33 4.59 3.23 22 7.95 7.41 3.74 3.64 23 8.05 7.49 3.33 3.74 24 8.22 7.57 4.09 3.88 25 8.56 6.34 3.98 3.91 --- 5.51 7.04 6.02 6.20 7.80 8.89 7.56 --- 5.67 7.11 5.96 6.08 6.76 9.32 3.66 --- 6.66 7.20 6.08 6.10 6.13 9.43 2.74 5.45 6.73 7.24 6.24 6.16 6.61 9.46 2.47 5.62 6.80 7.26 6.37 6.23 6.71 8.36 2.37 26 8.84 5.98 4.74 4.40 27 9.78 3.88 4.87 4.70 28 9.67 2.98 4.88 4.25 29 9.69 2.69 3.94 4.23 30 9.06 2.44 3.71 4.26 31 8.62 --- 4.61 4.89 5.75 6.86 7.35 6.22 4.57 6.78 8.10 2.31 6.05 6.89 7.36 5.97 6.73 6.83 6.88 2.26 6.39 6.92 7.44 6.08 4.97 6.96 6.66 2.25 --- 6.85 7.52 6.11 7.31 7.07 6.62 2.26 --- 6.62 7.62 5.83 6.82 6.87 6.57 2.22 --- 6.59 --- 5.58 --- 7.12 6.61 --­ MEAN 8.29 7.07 3.65 3.73 3.83 6.15 7.24 6.90 6.11 7.22 8.02 5.43 WTR YR 1998 MEAN 6.18 HIGHEST 2.08 FEB. 10, 1998 LOWEST 12.18 OCT. 1, 2, 1997 0 5 10 15 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR 551 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 181823065401900. Local number, RF-04. LOCATION.--Lat 18°18'23", long 65°40'19", Hydrologic Unit 2101005, 1.72 mi southwest of the intersection of Hwy 3 with Hwy 976, 1.44 mi west of Hwy 3, 1.33 mi northwest of Hwy 982, and 0.49 mi south of Hwy 976. Owner: US Geological Survey, WRD, Name: Río Fajardo No. 04. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m) 0-40.0 ft (0-12.2 m), screened 20-40 ft (6.1-12.2 m). Depth 40.0 ft (12.2 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is 86.3 ft (26.3 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.50 ft (1.07 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on May 22, 1998. PERIOD OF RECORD.--August 31, 1993 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 10.70 ft (3.26 m), below land-surface datum, Oct. 14, 15, 1997; lowest water level recorded, 18.82 ft (5.74 m), below land-surface datum, July 21-25, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13.63 14.22 --- 15.88 2 12.67 14.34 --- 15.90 3 12.48 14.41 --- 15.93 4 12.68 14.51 --- 15.94 5 12.86 14.59 --- 15.94 16.02 16.17 16.67 17.28 --- --- --- --- 16.11 16.29 16.66 17.46 --- --- --- --- 16.17 16.36 16.69 17.63 --- --- --- --- 16.22 16.46 16.72 17.80 --- --- --- --- 15.35 16.54 16.76 17.96 --- --- --- --­ 6 13.01 14.64 --- 15.94 7 13.18 14.70 --- 14.30 8 13.32 14.74 --- 12.87 9 13.44 14.73 --- 12.83 10 13.00 12.27 --- 12.92 14.45 16.59 16.79 18.10 --- --- --- --- 14.26 16.65 16.75 18.21 --- --- --- --- 14.26 16.37 16.75 18.32 --- --- --- --- 13.71 16.28 16.78 18.41 --- --- --- --- 13.52 16.28 16.81 18.47 --- --- --- --­ 11 12.95 --- --- 13.06 12 13.01 --- --- 13.22 13 12.83 --- --- 13.41 14 10.70 --- --- 13.58 15 10.88 --- --- 13.76 13.58 16.30 16.88 18.55 --- --- --- --- 13.76 16.34 17.01 18.61 --- --- --- --- 13.93 16.44 17.12 18.68 --- --- --- --- 14.06 16.53 17.21 18.77 --- --- --- --- 14.25 16.44 17.33 18.61 --- --- --- --­ 16 11.37 --- 14.93 13.95 17 11.80 --- 14.98 14.11 18 12.09 --- 15.10 14.29 19 12.45 --- 15.23 14.48 20 12.68 --- 15.30 14.66 14.43 16.27 17.33 17.56 --- --- --- --- 14.64 16.23 16.31 16.84 --- --- --- --- 14.80 16.25 15.91 16.80 --- --- --- --- 14.94 16.28 15.86 16.83 --- --- --- --- 15.07 16.34 15.90 17.04 --- --- --- --­ 21 12.87 --- 15.38 14.80 22 13.04 --- 15.46 14.94 23 13.20 --- 15.51 15.10 24 13.36 --- 15.56 15.25 25 13.51 --- 15.62 15.41 15.22 16.42 15.94 17.28 --- --- --- --- 15.42 16.49 16.00 17.60 --- --- --- --- 15.54 16.56 16.03 17.52 --- --- --- --- 15.69 16.59 16.03 17.31 --- --- --- --- 15.75 16.67 16.06 17.13 --- --- --- --­ 26 13.68 --- 15.65 15.57 27 13.80 --- 15.68 15.66 28 13.92 --- 15.73 15.76 29 14.03 --- 15.75 15.82 30 14.12 --- 15.80 15.89 31 14.13 --- 15.84 15.96 15.87 16.77 16.25 17.03 --- --- --- --- 15.98 16.85 16.47 17.06 --- --- --- --- 16.06 16.93 16.68 17.25 --- --- --- --­ --- 17.00 16.89 17.40 --- --- --- --­ --- 17.00 17.09 17.95 --- --- --- --­ --- 16.81 --- 18.46 --- --- --- --­ MEAN 12.93 14.31 15.47 14.75 14.97 16.50 16.59 17.74 --- --- --- --­ WTR YR 1998 MEAN 15.51 HIGHEST 10.70 OCT. 14, 15, 1997 LOWEST 18.81 MAY 15, 1998 10 15 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR 552 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 181917065382701. Local number, RF-12. LOCATION.--Lat 18°19'17", long 65°38'27", Hydrologic Unit 2101005, 1.20 mi northwest of Punta Barrancas, 0.81 mi east of Hwy 3, 0.82 mi south of Hwy 195, and 0.61 mi east of Hwy 194. Owner: US Geological Survey, WRD, Name: Río Fajardo No. 12. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-34.0 ft (0-10.4 m), screened 3.75-34.0 ft (1.14-10.4 m). Depth 34.0 ft (10.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is 13.7 ft (4.18 m), above mean sea level, from topographic survey. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 4.16 ft (1.27 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--August 11, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.71 ft (0.83 m), below land-surface datum, Oct. 14, 1997; lowest water level recorded, 10.64 ft (3.24 m), below land-surface datum, Aug. 21, 22, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.97 5.61 3.73 5.86 5.89 5.58 6.47 4.87 5.37 6.32 6.81 7.05 2 7.34 5.66 3.91 5.88 5.93 5.65 6.50 4.97 5.46 6.38 6.89 7.09 3 6.97 5.74 4.02 5.90 5.97 5.76 6.53 5.13 5.28 6.45 6.94 7.14 4 6.97 5.81 4.20 5.93 6.02 5.83 6.55 5.23 5.24 6.50 7.03 7.21 5 7.05 5.85 4.34 5.93 3.90 5.88 6.38 5.34 5.32 5.97 7.10 7.26 6 7.14 5.89 4.45 5.92 3.91 5.94 5.27 5.45 5.41 6.04 7.16 7.32 7 7.18 5.93 4.59 5.21 4.18 5.98 5.33 5.53 5.51 6.10 7.23 7.35 8 7.21 5.96 4.69 4.65 4.49 6.01 5.46 5.60 5.58 6.14 7.29 --­ 9 7.22 5.99 4.76 4.66 3.00 5.99 5.58 5.62 5.66 6.10 7.33 --­ 10 7.04 4.94 4.86 4.79 3.23 6.04 5.63 5.65 5.64 6.13 7.38 --­ 11 6.82 4.46 4.92 4.91 12 6.80 4.56 4.98 4.93 13 6.29 4.71 5.05 4.99 14 2.74 4.86 5.13 5.06 15 2.97 4.95 5.19 5.12 3.66 6.09 5.72 5.68 5.65 6.19 7.48 --- 3.96 6.17 5.78 5.76 5.67 6.27 7.54 --- 4.14 6.25 5.81 5.83 5.69 6.35 7.62 --- 4.30 6.30 5.78 5.88 5.69 6.39 7.67 --- 4.42 6.31 5.75 5.91 5.70 6.50 7.76 --­ 16 3.25 5.02 5.24 5.19 17 3.60 5.10 5.28 5.25 18 3.87 5.15 5.32 5.30 19 4.04 5.16 5.38 5.35 20 4.20 5.05 5.44 5.41 4.54 6.24 4.50 5.68 5.76 6.56 7.83 --- 4.65 6.18 4.12 5.58 5.73 6.62 7.89 --- 4.75 6.17 4.29 5.60 5.66 6.65 7.92 --- 4.83 6.20 4.60 5.63 5.65 6.65 7.95 --- 4.91 6.23 4.85 5.66 5.67 6.64 8.01 --­ 21 4.37 5.04 5.47 5.44 22 4.55 5.08 5.49 5.48 23 4.72 5.16 5.47 5.56 24 4.87 5.12 5.49 5.58 25 4.98 5.03 5.55 5.60 4.97 6.24 3.67 5.69 5.72 6.56 8.02 --- 5.05 6.29 2.92 5.72 5.77 6.55 8.04 --- 5.13 6.34 3.16 5.77 5.82 6.57 8.07 --- 5.20 6.35 3.57 5.86 5.87 6.56 8.09 --- 5.27 6.36 3.91 5.91 5.91 6.40 7.44 --­ 26 5.10 4.97 5.59 5.63 27 5.19 2.84 5.62 5.66 28 5.29 3.06 5.66 5.69 29 5.39 3.31 5.72 5.76 30 5.47 3.55 5.80 5.79 31 5.55 --- 5.83 5.84 5.37 6.38 4.17 5.69 5.96 6.40 7.18 --- 5.44 6.36 4.33 5.33 6.02 6.46 7.03 --- 5.54 6.38 4.45 5.24 6.08 6.51 6.95 --­ --- 6.39 4.62 5.30 6.16 6.60 6.95 --­ --- 6.39 4.76 5.35 6.27 6.67 6.96 --­ --- 6.42 --- 5.31 --- 6.74 6.99 --­ MEAN 5.55 4.99 5.07 5.43 4.74 6.15 5.02 5.54 5.70 6.42 7.44 7.20 WTR YR 1998 MEAN 5.68 HIGHEST 2.71 OCT. 14, 1997 LOWEST 8.09 AUG. 23, 24, 1998 0 5 10 15 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 553 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 180358065503700. Local number, YDO-1. LOCATION.--Lat 18°03’58", long 65°50'37", Hydrologic Unit 21010004, 2.01 mi east of Central Roig, 1.37 mi north of Yabucoa Sun Oil Refinery, and 0.19 mi east of Hwy 53. Owner: US Geological Survey, WRD, Name: Yabucoa Deep Observation. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled piezometer well, constructed in 1993 as part of study of Valle de Yabucoa, diameter 2 in (0.05 m), screened in brackish water, 320-340 ft (97.5-104 m). Depth 350 ft (107 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 2.00 ft (0.61 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 7.30 ft (2.22 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on September 16, 1997. PERIOD OF RECORD.--September 16, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.51 ft (0.15 m), below land-surface datum, Mar. 2, 3, 4, 1998; lowest water level recorded, 5.83 ft (1.78 m), below land-surface datum, June 10-17, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.69 1.83 .54 2.94 4.48 5.78 5.82 5.77 2 3.05 1.83 .51 3.04 4.49 5.78 5.82 5.77 3 3.93 1.83 .51 3.06 4.54 5.78 5.82 5.77 4 3.97 1.86 .51 3.08 4.63 5.82 5.82 5.77 5 3.95 1.86 .57 3.08 4.77 5.82 5.82 5.77 6 3.86 .70 3.13 4.81 5.82 5.82 5.77 7 3.77 .81 3.13 4.89 5.82 5.82 5.77 8 3.67 1.08 3.08 4.92 5.82 5.82 5.77 9 3.55 1.30 3.01 5.01 5.82 5.82 5.77 10 3.36 1.30 3.00 5.05 5.82 5.82 5.77 11 3.35 1.35 3.12 5.07 5.83 5.82 5.77 12 3.28 1.41 3.15 5.11 5.83 5.82 5.77 13 3.01 1.57 3.15 5.14 5.83 5.82 5.77 14 1.06 1.65 3.35 5.26 5.83 5.82 5.77 15 2.80 1.75 3.49 5.26 5.83 5.82 16 2.80 1.69 3.58 5.29 5.83 5.82 17 2.75 1.71 3.64 5.31 5.82 5.82 18 2.69 1.83 3.78 5.34 5.82 5.82 19 2.68 1.93 3.81 5.43 5.82 5.82 20 2.57 1.94 3.85 5.55 5.82 5.82 21 2.48 1.86 1.92 3.94 5.56 5.82 5.81 22 2.47 1.59 2.05 3.97 5.59 5.82 5.81 23 2.44 1.32 2.14 4.00 5.64 5.82 5.79 24 2.44 1.14 2.33 4.05 5.64 5.82 5.79 25 .99 2.44 4.14 5.64 5.82 5.79 26 .82 2.49 4.15 5.64 5.82 5.79 27 .66 2.49 4.15 5.64 5.82 5.79 28 .55 2.64 4.35 5.64 5.82 5.79 29 2.76 4.39 5.71 5.82 5.77 30 1.81 2.82 4.47 5.74 5.82 5.77 31 1.83 2.85 5.74 5.77 MEAN 3.07 1.82 1.84 1.12 1.66 3.57 5.24 5.82 5.81 5.77 WTR YR 1998 MEAN 4.14 HIGHEST .51 MAR. 2, 3, 4, 1998 LOWEST 5.83 JUNE 10­17, 1998 0 2 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 4 6 October November December January February March April May June July August September 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- 554 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES 180415065513900. Local number, 96. LOCATION.--Lat 18°04'15", long 65°51'39", Hydrologic Unit 21010005, 2.44 mi northwest of Escuela Eugenio María de Hostos 4.67 mi southwest of Escuela Segunda Unidad Luciano, and 3.93 mi southwest of Escuela Asunción López. Owner: PR Aqueduct and Sewer Authority, Name: USGS TW-2 or Yabucoa 7. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 16 in (0.41 m), cased 0-10 ft (0-3.05 m), diameter 6 in (0.15 m), cased about 0-183 ft (0-55.8 m), perforated 56-81 ft (17.1-24.7 m), 102-123 ft, (31.1-37.5 m), 144-181 ft (43.9-55.2 m). Depth 181 ft (55.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 25 ft (7.62 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 4.00 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--April 25, 1978 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.67 ft (2.95 m), below land-surface datum, Sept. 30, 1998; lowest water level recorded, 28.29 ft (8.62 m) below land-surface datum, Sept. 20, 1980. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20.64 18.25 18.18 18.38 18.18 16.52 19.75 21.39 20.33 21.71 21.59 20.10 2 20.15 18.34 18.09 18.33 18.16 16.41 19.82 21.39 20.30 21.73 21.52 20.09 3 20.05 18.49 18.06 18.36 18.14 16.32 19.85 21.43 20.43 21.78 21.41 19.99 4 20.12 18.55 18.06 18.46 18.18 16.26 19.83 21.56 20.41 21.44 21.33 19.95 5 20.39 18.62 18.06 18.52 18.20 16.27 19.95 21.66 20.41 21.19 21.30 19.93 6 20.46 18.64 18.08 17.79 18.16 16.39 20.06 21.73 20.42 21.19 21.10 19.76 7 20.36 18.67 18.13 17.86 18.23 16.68 20.12 21.74 20.56 21.27 21.01 19.58 8 20.09 18.72 18.03 17.96 18.29 17.06 19.97 21.73 20.72 21.37 20.96 19.52 9 20.13 18.76 17.96 17.85 18.28 17.17 19.97 21.77 20.82 21.42 20.98 19.52 10 20.38 18.63 17.77 17.68 18.35 17.16 20.09 21.83 20.97 21.68 21.04 19.07 11 20.52 18.79 17.49 17.48 18.51 17.34 20.31 21.84 21.09 21.77 21.07 18.93 12 20.56 18.87 17.50 17.39 18.63 17.38 20.43 21.84 21.21 21.74 21.00 18.90 13 20.32 18.89 17.75 17.36 18.73 17.63 20.47 21.96 21.18 21.66 20.90 18.79 14 19.16 18.95 17.97 17.38 18.81 17.59 20.67 21.98 21.24 21.78 20.82 18.99 15 19.49 18.92 18.00 17.40 18.75 17.50 20.83 22.01 21.32 22.11 20.80 19.17 16 18.96 18.87 18.07 17.46 18.68 17.45 20.89 22.08 21.29 22.27 20.77 19.14 17 17.86 18.79 18.13 17.47 18.61 17.61 20.89 22.09 21.24 22.40 20.76 19.18 18 17.59 18.75 18.23 17.45 18.31 17.64 20.93 22.09 21.22 22.45 20.74 19.31 19 17.43 18.76 18.29 17.40 18.09 17.69 20.99 22.19 21.09 22.43 20.70 19.31 20 17.29 18.46 18.32 17.43 17.97 17.79 21.04 21.92 21.03 22.68 20.74 19.10 21 17.13 18.37 18.38 17.42 17.89 17.79 21.12 21.71 21.06 22.79 20.81 18.96 22 17.06 18.38 18.33 17.57 17.65 18.01 21.15 21.66 21.08 22.85 20.84 16.39 23 17.08 18.46 18.34 17.69 17.39 18.07 21.17 21.68 21.17 22.89 20.78 15.13 24 17.17 18.54 18.34 17.77 17.19 18.19 21.22 21.72 21.29 22.84 20.71 14.00 25 17.27 18.63 18.33 17.83 17.08 18.28 21.35 21.77 21.36 22.82 20.11 13.10 26 17.48 18.67 18.33 17.89 16.89 18.36 21.39 21.82 21.38 22.67 20.22 12.41 27 17.59 18.60 18.44 17.95 16.76 18.50 21.38 21.80 21.46 22.49 20.14 11.60 28 17.68 18.55 18.50 18.02 16.62 18.87 21.41 21.80 21.57 22.22 19.86 10.78 29 17.70 18.42 18.51 18.10 19.16 21.38 21.65 21.84 19.68 10.18 30 17.94 18.29 18.51 18.14 19.41 21.39 21.66 21.71 19.89 9.78 31 18.16 18.45 18.16 19.66 21.65 19.99 MEAN 18.85 18.62 18.15 17.80 18.03 17.62 20.66 21.79 21.03 22.03 20.76 17.36 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WTR YR 1998 MEAN 19.38 HIGHEST 9.67 SEPT. 30, 1998 LOWEST 22.90 JULY 23, 1998 0 10 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 555 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 175855066023100. Local number, FID-2. LOCATION.--Lat 17°58’55", long 66°02'31", Hydrologic Unit 21010004, 0.25 mi north of Hwy 3 @ km 128.5, and 1.74 mi northeast of Arroyo plaza. Owner: Santón Trucking, Name: Fidel 2 AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Unused water-table well, diameter 15 in (0.38 m). Depth 116 ft (35.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute interval. DATUM.--Elevation of land-surface datum is about 41.0 ft (12.5 m), above mean sea level, from topographic map. Measuring point: Shelter floor, 3.12 ft (0.95 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on December 11, 1996. PERIOD OF RECORD.--December 11, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.39 ft (6.52 m), below land-surface datum, Oct. 5, 1997; lowest water level recorded, 27.88 ft (8.50 m), below land-surface datum, Aug. 16-28, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 25.62 24.87 25.20 25.70 25.10 25.05 24.71 25.82 26.25 2 25.64 24.64 25.25 25.71 25.20 25.10 24.73 25.88 26.33 3 25.63 24.55 25.26 25.66 25.27 25.01 24.75 25.81 26.37 4 25.51 24.57 25.28 25.64 25.31 25.07 24.82 25.67 26.45 5 25.29 24.68 25.27 25.64 25.34 25.15 24.91 25.55 26.53 6 25.13 24.35 25.34 25.62 25.37 25.22 24.98 25.44 26.61 7 25.01 24.43 25.39 25.59 25.38 25.24 25.01 25.33 26.69 8 24.79 24.52 25.41 25.59 25.53 25.30 25.02 25.28 26.76 9 24.75 24.62 25.44 25.61 25.60 25.35 25.05 25.23 26.86 10 24.92 24.70 25.49 25.65 25.62 25.38 25.08 25.08 26.94 11 25.89 25.03 24.75 25.52 25.63 25.70 25.39 25.13 24.90 26.99 12 25.88 25.07 24.83 25.53 25.59 25.66 25.38 25.15 24.77 27.04 13 25.86 25.13 24.91 25.51 25.51 25.67 25.37 25.21 24.88 27.04 14 25.83 25.18 24.95 25.46 25.34 25.60 25.36 25.26 24.97 27.03 15 25.81 25.16 25.02 25.40 25.20 25.45 25.35 25.28 25.04 26.80 16 25.79 25.05 25.08 25.38 25.13 25.40 25.32 25.29 25.10 26.62 17 25.81 25.02 25.13 25.39 25.07 25.34 25.26 25.31 25.21 26.65 18 25.84 25.00 25.19 25.36 25.09 25.32 25.29 25.36 25.28 26.72 19 25.77 25.01 25.24 25.41 25.01 25.29 25.20 25.38 25.41 26.78 20 25.66 24.98 25.28 25.48 25.03 25.23 25.06 25.40 25.54 26.87 21 25.51 25.00 25.21 25.50 25.08 25.12 25.03 25.36 25.65 26.89 22 25.47 25.02 25.08 25.55 25.05 25.05 25.01 25.36 25.64 26.55 23 25.45 25.03 25.14 25.58 25.00 25.03 25.00 25.39 25.53 26.54 24 25.54 25.08 25.15 25.60 24.92 25.02 24.95 25.41 25.63 26.60 25 25.58 25.10 25.09 25.62 24.87 25.03 24.93 25.44 25.71 25.54 26 25.60 25.15 25.19 25.64 24.91 25.13 24.82 25.51 25.76 25.43 27 25.61 24.99 25.18 25.66 24.89 25.22 24.73 25.57 25.82 25.43 28 25.61 25.17 25.14 25.69 24.95 24.79 24.75 25.59 25.90 24.95 29 25.61 25.12 25.67 24.99 24.74 24.68 25.64 25.98 25.04 30 25.61 25.13 25.70 25.05 24.81 24.72 25.70 26.07 25.30 31 25.60 25.02 25.70 24.94 25.76 26.17 MEAN 25.68 25.12 24.91 25.47 25.29 25.27 25.12 25.24 25.49 26.42 WTR YR 1997 MEAN 25.39 HIGHEST 24.34 FEB. 6, 1997 LOWEST 27.05 SEPT. 13, 1997 556 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 25.49 23.73 --- --- 2 25.66 23.76 --- --- 3 25.81 23.86 --- --- 4 23.27 23.96 --- --- 5 21.45 24.04 --- --- 24.10 24.67 25.17 25.90 26.88 27.29 27.69 27.87 24.14 24.71 25.19 25.89 26.94 27.18 27.75 27.87 24.18 24.74 25.28 25.87 27.00 27.07 27.78 27.87 24.21 24.68 25.36 25.87 27.05 27.10 27.80 27.87 24.20 24.73 25.43 25.91 27.10 27.15 27.83 27.87 6 21.56 --- --- --- 7 21.94 --- --- --- 8 22.25 --- --- 23.57 9 22.47 --- --- 23.65 10 22.68 --- --- 23.52 24.02 24.76 25.50 25.93 27.16 27.21 27.87 27.87 24.07 24.74 25.59 25.91 27.21 27.28 27.87 27.87 24.12 24.79 25.58 25.92 27.26 27.35 27.87 27.87 24.16 24.82 25.51 25.98 27.30 27.42 27.87 27.87 24.25 24.84 25.47 26.03 27.34 27.50 27.87 27.87 11 22.87 --- --- 23.55 12 23.16 --- --- 23.47 13 23.36 --- --- 23.49 14 23.55 --- --- 23.51 15 23.52 --- --- 23.68 24.33 24.86 25.46 26.09 27.38 27.55 27.87 27.87 24.37 24.89 25.47 26.16 27.43 27.60 27.87 27.87 24.40 24.90 25.48 26.21 27.48 27.66 27.87 27.87 24.45 24.87 25.51 26.25 27.53 27.65 27.87 27.87 24.40 24.84 25.57 26.31 27.57 27.75 27.87 27.87 16 23.54 --- --- 23.80 17 23.57 --- 24.11 23.82 18 22.31 --- 24.16 23.91 19 22.34 --- 24.19 23.98 20 22.52 --- 24.19 24.05 24.41 24.88 25.62 26.36 27.61 27.78 27.87 --- 24.39 24.93 25.56 26.40 27.60 27.79 27.88 --- 24.38 24.93 25.44 26.46 27.60 27.80 27.88 --- 24.42 24.93 25.46 26.51 27.57 27.82 27.88 --- 24.46 24.92 25.56 26.55 27.56 27.81 27.88 --­ 21 22.68 --- 24.20 24.09 22 22.72 --- 24.22 24.13 23 22.86 --- 24.17 24.15 24 22.96 --- 24.05 24.17 25 23.01 --- 24.10 24.12 24.49 24.88 25.64 26.60 27.57 27.65 27.88 --- 24.57 24.95 25.68 26.67 27.57 27.59 27.88 --- 24.60 24.98 25.59 26.71 27.59 27.57 27.88 --- 24.63 25.05 25.60 26.78 27.61 27.54 27.88 --- 24.67 25.05 25.64 26.82 27.63 27.53 27.88 --­ 26 23.11 --- 24.03 24.10 27 23.20 --- 23.93 24.12 28 23.29 --- 23.93 24.14 29 23.41 --- 23.55 23.97 30 23.52 --- --- 23.99 31 23.62 --- --- 24.04 24.68 25.10 25.67 26.71 27.67 27.53 27.88 --- 24.64 25.10 25.72 26.62 27.70 27.53 27.88 --- 24.66 25.10 25.77 26.68 27.62 27.54 27.87 --­ --- 25.06 25.82 26.71 27.52 27.56 27.87 --­ --- 25.14 25.86 26.74 27.39 27.60 27.87 --­ --- 25.15 --- 26.78 --- 27.64 27.87 --­ MEAN 23.15 23.87 24.06 23.88 24.37 24.90 25.54 26.33 27.41 27.52 27.86 27.87 WTR YR 1998 MEAN 25.72 HIGHEST 21.39 OCT. 5, 1997 LOWEST 16-28, 1998 20 25 30 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 557 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES 175855066050500. Local number, ALG-1. LOCATION.--Lat 17°58'55", long 66°05'05", Hydrologic Unit 21010004, 1.97 mi east-southeast of the intersection of Hwy 16 with Hwy 3, 1.00 mi west of the intersection of Hwy 3 with Hwy 178, and 0.04 mi south of Hwy 3. Owner: PR Land Authority, Name: Algarrobos. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. Depth 57.0 ft (17.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 89.0 ft (27.1 m), above mean sea level. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 2.95 ft (0.90 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 24, 1997. PERIOD OF RECORD.--May 24, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.19 ft (5.54 m), below land-surface datum, June 26, 1997; lowest water level recorded, 33.85 ft (10.32 m), below land-surface datum, July 2, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 33.19 31.70 24.01 25.16 30.99 31.68 2 33.23 31.08 25.11 26.03 31.09 31.88 3 33.26 30.16 22.34 26.79 30.67 32.05 4 33.28 29.26 19.90 26.87 30.30 32.23 5 33.30 29.27 20.07 27.04 30.19 32.41 6 33.33 29.39 22.41 27.26 30.13 32.56 7 33.35 29.61 23.85 27.43 30.07 32.71 8 33.37 28.68 23.29 27.65 30.08 32.83 9 33.39 29.20 22.27 27.85 30.06 32.97 10 33.42 29.48 22.04 28.16 29.69 33.09 11 33.45 29.06 22.89 28.40 29.37 33.20 12 33.48 29.24 25.73 28.43 24.58 33.30 13 33.50 29.92 26.22 28.46 21.88 33.36 14 33.52 30.18 24.22 28.21 24.98 33.22 15 33.55 30.11 23.75 27.95 26.36 32.73 16 33.58 30.14 25.60 28.05 23.54 32.08 17 33.60 30.04 23.54 28.32 21.78 31.67 18 33.63 28.92 24.92 28.64 21.64 31.24 19 33.66 27.81 26.15 28.98 25.40 30.79 20 33.67 26.11 23.93 29.21 26.62 30.30 21 33.69 25.22 20.67 29.29 26.99 29.35 22 33.72 26.57 20.46 29.28 27.22 28.38 23 33.58 26.64 20.97 29.07 27.61 27.45 24 32.88 32.80 23.62 19.77 28.92 28.53 26.58 25 32.93 31.56 24.88 18.70 29.05 29.20 27.32 26 32.97 30.84 25.45 18.22 29.25 29.75 28.85 27 33.01 30.74 25.75 18.78 29.53 30.19 29.26 28 33.06 31.25 26.05 20.39 29.80 30.57 29.81 29 33.10 31.85 26.13 23.19 29.97 30.91 30.23 30 33.14 31.99 20.44 24.93 30.33 31.20 30.58 31 33.17 22.25 30.67 31.44 MEAN 33.03 33.03 27.82 22.61 28.39 28.16 31.14 WTR YR 1997 MEAN 28.71 HIGHEST 18.19 JUNE 26, 1997 LOWEST 33.72 APR. 22, 23, 1997 558 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30.87 29.34 29.41 31.72 2 31.10 29.46 29.48 31.79 3 31.28 29.58 29.58 31.86 4 31.48 28.93 29.65 31.92 5 31.66 27.77 29.74 31.98 31.99 32.84 33.70 21.29 27.47 33.79 26.44 32.08 32.02 32.89 33.71 22.23 27.22 33.84 28.10 32.11 32.06 32.93 33.71 24.80 27.10 33.73 29.12 32.15 32.10 32.97 33.71 25.43 27.63 33.37 29.81 32.19 32.14 33.00 33.71 23.43 28.28 32.18 30.33 32.23 6 31.83 26.83 29.82 32.02 7 31.98 26.33 29.91 32.01 8 32.11 25.98 30.00 32.02 9 32.24 25.75 29.99 32.01 10 32.39 25.24 29.52 31.97 32.17 33.03 33.70 23.28 28.98 31.42 30.81 32.28 32.19 33.05 33.69 24.59 29.64 31.16 31.16 32.30 32.20 33.10 33.69 25.58 30.19 30.89 31.48 32.10 32.21 33.14 33.69 26.89 30.62 30.71 31.74 31.90 32.23 33.17 33.69 27.89 30.99 30.57 31.97 31.64 11 32.48 25.63 29.14 31.95 12 32.60 26.23 28.96 31.92 13 32.69 26.71 29.29 31.89 14 32.12 27.08 29.76 31.85 15 29.66 27.41 30.02 31.81 32.25 33.20 33.69 28.50 31.30 30.32 32.17 31.50 32.29 33.23 33.70 29.03 31.57 29.09 32.38 31.41 32.33 33.27 33.70 29.58 31.79 27.91 32.55 31.37 32.36 33.30 33.70 30.03 31.99 27.33 32.72 31.28 32.38 33.34 33.70 30.43 32.16 27.90 32.88 31.14 16 28.41 27.67 30.20 31.78 17 27.70 27.87 30.32 31.75 18 27.37 28.05 30.43 31.73 19 27.25 28.20 30.56 31.71 20 27.19 28.32 30.66 31.70 32.40 33.37 33.70 30.76 32.35 28.12 33.01 31.03 32.42 33.39 33.70 31.05 32.50 27.86 33.14 30.94 32.43 33.42 33.70 31.31 32.64 27.53 33.26 30.89 32.47 33.44 33.71 31.54 32.78 27.47 33.36 30.86 32.51 33.49 33.71 31.71 32.90 27.37 33.45 30.83 21 27.26 28.46 30.76 31.70 22 27.48 28.59 30.87 31.70 23 27.75 28.70 30.96 31.72 24 27.99 28.80 31.04 31.74 25 28.22 28.88 31.14 31.76 32.54 33.52 33.71 31.75 33.01 26.85 33.55 30.79 32.57 33.54 33.71 30.92 33.11 26.40 33.64 24.97 32.61 33.56 33.57 30.05 33.22 25.07 33.71 20.51 32.64 33.58 31.57 30.04 33.30 23.99 33.77 21.39 32.69 33.61 29.55 30.14 33.37 25.08 32.97 22.40 26 28.44 28.99 31.22 31.79 27 28.63 29.06 31.31 31.81 28 28.80 29.16 31.40 31.85 29 28.96 29.24 31.49 31.89 30 29.08 29.31 31.57 31.92 31 29.23 --- 31.63 31.96 32.73 33.62 28.26 29.96 33.44 26.35 32.49 23.13 32.77 33.64 27.00 30.24 33.52 26.52 32.19 23.52 32.81 33.66 25.34 30.34 33.59 26.23 32.04 23.77 --- 33.67 24.55 30.23 33.67 24.41 32.02 23.93 --- 33.68 22.59 29.52 33.73 24.04 32.03 24.08 --- 33.69 --- 28.14 --- 25.07 32.06 --­ MEAN 29.88 27.92 30.32 31.85 32.38 33.33 32.13 28.41 31.47 28.47 31.95 29.02 WTR YR 1998 MEAN 30.58 HIGHEST 20.51 SEPT. 23, 1998 LOWEST 33.85 JULY 2, 1998 10 20 30 40 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 559 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 1757280660722000. Local number, BAR-1. LOCATION.--Lat 17°57'28", long 66°07'22", Hydrologic Unit 21010004, 0.65 mi west of Central Machete. 0.75 mi northwest of Playita Machete, 2.00 mi south of the intersection of Hwy 15 with Hwy 3, and 1.13 mi southeast of intersection of Hwy 710 with Hwy 3. Owner: PR Land Authority, Name: Barranca. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Hand-dug unused water-table well. Depth 38.0 ft (11.7 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 59.1 ft (18.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 4.60 ft (1.40 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on April 3, 1997. PERIOD OF RECORD.--April 3, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 20.33 ft (6.20 m), below land-surface datum, Sept. 30, 1998; lowest water level recorded, 24.21 ft (7.38 m), below land-surface datum, June 7, 8, 9, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.81 24.15 24.03 22.72 22.18 2 23.83 24.16 23.99 22.66 22.19 3 23.42 23.84 24.17 23.97 22.61 22.20 4 23.44 23.86 24.18 23.94 22.55 22.21 5 23.46 23.87 24.19 23.91 22.49 22.23 6 23.48 23.88 24.20 23.87 22.44 22.24 7 23.49 23.89 24.20 23.84 22.40 22.25 8 23.51 23.91 24.21 23.79 22.36 22.26 9 23.52 23.92 24.21 23.76 22.33 22.28 10 23.53 23.93 24.20 23.72 22.30 22.30 11 23.55 23.94 24.20 23.70 22.27 22.31 12 23.56 23.95 24.19 23.68 22.25 22.33 13 23.58 23.96 24.19 23.65 22.23 22.34 14 23.59 23.97 24.19 23.62 22.20 22.36 15 23.61 23.98 24.19 23.59 22.18 22.38 16 23.62 23.99 24.18 23.56 22.17 22.40 17 23.63 24.00 24.17 23.51 22.16 22.42 18 23.65 24.01 24.17 23.48 22.15 22.44 19 23.66 24.02 24.17 23.45 22.15 22.45 20 23.68 24.02 24.16 23.40 22.15 22.46 21 23.69 24.03 24.16 23.36 22.15 22.48 22 23.70 24.04 24.15 23.31 22.15 22.50 23 23.70 24.05 24.15 23.27 22.14 22.52 24 23.72 24.06 24.14 23.22 22.14 22.55 25 23.73 24.07 24.13 23.17 22.14 22.57 26 23.75 24.08 24.12 23.10 22.14 22.57 27 23.76 24.10 24.11 23.04 22.15 22.60 28 23.78 24.11 24.08 22.99 22.16 22.62 29 23.79 24.12 24.06 22.91 22.16 22.63 30 23.80 24.13 24.05 22.85 22.17 22.66 31 24.14 22.78 22.18 MEAN 23.62 23.98 24.16 23.50 22.27 22.40 WTR YR 1997 MEAN 23.32 HIGHEST 22.13 AUG. 23, 1997 LOWEST 24.21 JUNE 7, 8, 9, 1997 560 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22.68 22.11 22.14 22.13 2 22.69 22.11 22.13 22.14 3 22.71 22.11 22.13 22.15 4 22.73 22.11 22.12 22.16 5 22.74 22.12 22.11 22.16 --- --- --- --- --- --- --- 22.42 --- --- --- --- --- --- --- 22.44 --- --- --- --- --- --- --- 22.45 --- --- --- --- --- --- --- 22.46 --- --- --- --- --- --- --- 22.48 6 22.76 22.12 22.10 22.17 7 22.77 22.13 22.10 22.18 8 22.79 22.13 22.09 22.19 9 22.81 22.14 22.08 --- 10 22.83 22.14 22.08 --- --- --- --- --- --- --- --- 22.49 --- --- --- --- --- --- --- 22.50 --- --- --- --- --- --- --- 22.50 --- --- --- --- --- --- --- 22.51 --- --- --- --- --- --- --- 22.52 11 22.84 22.15 22.08 --- 12 22.86 22.15 22.08 --- 13 22.88 22.15 22.07 --- 14 22.79 22.16 22.07 --- 15 22.73 22.16 22.07 --- --- --- --- --- --- --- --- 22.53 --- --- --- --- --- --- --- 22.53 --- --- --- --- --- --- --- 22.54 --- --- --- --- --- --- --- 22.55 --- --- --- --- --- --- --- 22.56 16 22.60 22.16 22.06 --- 17 22.50 22.18 22.06 --- 18 22.43 22.18 22.06 --- 19 22.37 22.18 22.06 --- 20 22.33 22.18 22.07 --- --- --- --- --- --- --- --- 22.57 --- --- --- --- --- --- --- 22.57 --- --- --- --- --- --- 22.21 22.58 --- --- --- --- --- --- 22.22 22.58 --- --- --- --- --- --- 22.24 22.59 21 22.29 22.17 22.07 --- 22 22.26 22.17 22.07 --- 23 22.22 22.17 22.07 --- 24 22.21 22.17 22.08 --- 25 22.19 22.16 22.09 --- --- --- --- --- --- --- 22.25 22.59 --- --- --- --- --- --- 22.27 22.14 --- --- --- --- --- --- 22.29 21.14 --- --- --- --- --- --- 22.30 20.59 --- --- --- --- --- --- 22.31 20.58 26 22.17 22.16 22.09 --- 27 22.15 22.15 22.09 --- 28 22.14 22.15 22.10 --- 29 22.13 22.15 22.11 --- 30 22.12 22.14 22.11 --- 31 22.11 --- 22.12 --- --- --- --- --- --- --- 22.33 20.52 --- --- --- --- --- --- 22.35 20.44 --- --- --- --- --- --- 22.36 20.39 --- --- --- --- --- --- 22.38 20.37 --- --- --- --- --- --- 22.40 20.34 --- --- --- --- --- --- 22.41 --­ MEAN 22.51 22.15 22.09 22.16 --- --- --- --- --- --- 22.31 21.98 WTR YR 1998 MEAN 22.20 HIGHEST 20.33 SEPT> 30, 1998 LOWEST 22.88 OCT. 13, 1997 20 22 24 26 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- 561 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 175719066085500. Local number, P-13 LOCATION.--Lat 17°57'19", long 66°08'55", Hydrologic Unit 2101004, 1.0 mi east of the intersection of Hwy 3 with Hwy 707, 0.28 mi south of Hwy 3, and 0.25 mi northwest of the Phillps Petroleum oil refinery. Owner: Phillips Petroleum, Name: Phillips Petroleum No. 13. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 33.0 ft (10.1 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.21 ft (0.98 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on April 15, 1998. Sampling performed on June 7, 1996 by private company. PERIOD OF RECORD.--September 25, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 14.47 ft (4.41 m), below land-surface datum, Mar. 22, 24, 1993; lowest water level recorded, 31.22 ft (9.52 m), below land-surface datum, Aug. 24, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.80 26.99 26.45 26.48 26.06 26.77 27.92 27.36 28.28 29.42 30.52 30.87 2 28.78 26.92 26.19 26.39 26.01 26.90 27.87 27.12 28.22 29.46 30.58 30.84 3 28.81 26.86 26.36 26.30 25.66 26.72 27.90 27.17 28.34 29.51 30.63 30.86 4 28.91 27.04 26.40 26.34 25.78 26.68 27.93 27.30 28.44 29.50 30.67 30.81 5 28.97 27.04 26.44 26.29 25.79 26.35 27.85 27.42 28.50 29.53 30.70 30.74 6 28.93 26.93 26.48 26.22 25.78 26.28 27.69 27.51 28.55 29.59 30.62 30.66 7 28.91 27.01 26.53 26.09 25.62 26.31 27.56 27.55 28.48 29.62 30.64 30.58 8 28.95 27.03 26.56 25.89 25.39 26.40 27.71 27.80 28.52 29.67 30.70 30.41 9 29.07 26.96 26.61 25.79 25.56 26.40 27.94 27.83 28.57 29.71 30.79 30.31 10 29.17 26.95 26.62 25.74 25.57 26.54 27.92 27.67 28.64 29.72 30.83 30.27 11 29.26 26.94 26.65 25.74 25.60 26.74 27.81 27.62 28.73 29.77 30.84 30.09 12 29.33 26.87 26.67 25.67 25.68 26.80 27.62 27.80 28.77 29.76 30.86 30.06 13 29.42 26.84 26.66 25.73 25.50 26.92 27.48 27.73 28.68 29.81 30.88 30.02 14 29.17 26.77 26.63 25.89 25.53 26.94 27.39 27.70 28.68 29.85 30.90 30.01 15 28.65 26.81 26.62 25.86 25.63 26.96 27.59 27.63 28.72 29.90 30.93 30.02 16 28.45 26.73 26.56 25.88 25.76 26.99 27.55 27.63 28.76 29.87 30.97 29.97 17 28.19 26.67 26.56 25.97 25.75 26.86 27.49 27.61 28.78 29.89 31.00 29.76 18 27.95 26.60 26.49 25.99 25.82 26.95 27.57 27.56 28.79 29.96 31.04 29.63 19 27.58 26.60 26.57 25.98 25.90 26.88 27.36 27.55 28.83 30.03 31.06 29.45 20 27.34 26.61 26.57 26.08 25.97 26.97 27.42 27.77 28.96 30.04 31.09 29.36 21 27.27 26.42 26.58 26.09 26.02 27.05 27.51 27.92 29.05 30.11 31.10 28.99 22 27.20 26.53 26.57 26.12 26.04 27.48 27.33 27.80 28.97 30.16 31.13 27.36 23 27.13 26.62 26.53 26.13 26.07 27.41 27.31 27.92 29.06 30.20 31.19 26.00 24 27.02 26.64 26.50 26.13 26.14 27.45 27.63 28.07 29.10 30.24 31.22 25.12 25 27.03 26.63 26.51 26.15 26.39 27.57 27.33 28.13 29.14 30.28 31.17 24.32 26 26.89 26.64 26.51 26.20 26.58 27.62 27.10 28.16 29.23 30.31 31.10 23.70 27 26.83 26.66 26.51 26.20 26.59 27.87 26.94 28.18 29.28 30.32 31.02 23.16 28 26.97 26.59 26.51 26.27 26.77 27.76 27.30 28.16 29.30 30.36 30.98 29 26.95 26.57 26.50 26.16 27.68 27.33 28.14 29.31 30.40 30.98 22.86 30 27.01 26.50 26.50 26.04 27.86 27.42 28.11 29.37 30.46 30.94 22.71 31 26.98 26.47 26.07 27.88 28.23 30.50 30.89 MEAN 28.13 26.77 26.53 26.06 25.89 27.03 27.56 27.75 28.80 29.93 30.90 28.58 WTR YR 1998 MEAN 27.84 HIGHEST 22.69 SEPT. 30, 1998 LOWEST 31.22 AUG. 24, 1998 10 20 WATER LEVEL,IN FEET BELOW LAND-SURFACE DATUM 30 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- 562 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES 175858066100200. Local number, 6. LOCATION.--Lat 17°58'58", long 66°10'02", Hydrologic Unit 21010004, 4.23 mi northeast of Central Aguirre Church, 4.08 mi northeast of Colegio del Perpetuo Socorro Church, and 1.77 mi northwest of Hwy 3 km 144.2. Owner: Doctor Bruno, Name: Juana 5. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m). Depth 173 ft (52.74 m) reported, 110 ft (33.54 m) measured. INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 127 ft (38.7 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.00 ft (0.91 m), above land-surface datum. After Aug. 7, 1981, top of 16 in (0.41 m) casing, 1.55 ft (0.47 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital recorde (ADR), replaced by an Electronic Data Logger (EDL), installed on April 15, 1998. PERIOD OF RECORD.--November 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 26.20 ft (7.99 m), below land-surface datum, Dec. 10, 1979; lowest water level recorded, 65.95 ft (20.1 m), below land-surface datum, June 2, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 62.38 60.66 53.20 52.23 50.37 52.65 53.83 50.81 56.08 56.83 58.50 59.36 2 62.39 60.50 53.09 52.09 50.17 52.48 53.95 51.06 56.20 56.84 58.58 59.28 3 62.41 60.33 53.00 51.81 49.99 52.31 54.08 51.31 56.32 56.89 58.66 59.21 4 62.41 60.14 52.92 51.55 49.84 52.14 54.17 51.55 56.44 56.94 58.75 59.13 5 62.41 59.96 52.86 51.28 49.76 51.91 54.21 51.80 56.55 56.98 58.83 59.04 6 62.42 59.75 52.79 51.04 49.56 51.73 54.18 52.02 56.63 57.00 58.90 58.92 7 62.43 59.46 52.75 50.79 49.51 51.55 54.04 52.23 56.67 57.02 58.96 58.81 8 62.44 59.07 52.70 50.62 49.68 51.40 53.80 52.38 56.72 57.04 58.96 58.69 9 62.46 58.72 52.65 50.59 49.89 51.26 53.51 52.51 56.79 57.08 58.93 58.58 10 62.48 58.46 52.62 50.68 50.13 51.18 53.19 52.63 56.86 57.14 58.92 58.49 11 62.49 58.28 52.58 50.80 50.37 51.28 52.78 52.81 56.95 57.17 58.96 58.39 12 62.51 58.13 52.56 50.95 50.60 51.40 52.21 52.99 57.03 57.21 59.00 58.24 13 62.53 58.01 51.10 50.82 51.47 51.49 53.18 57.12 57.24 59.04 58.03 14 62.54 57.89 51.24 51.03 51.45 50.66 53.37 57.22 57.27 59.03 57.75 15 62.57 57.77 52.35 51.38 51.23 51.39 50.07 53.56 57.33 57.33 59.04 57.32 16 62.54 57.65 52.33 51.53 51.41 51.34 49.63 53.74 57.42 57.39 59.08 56.71 17 62.47 57.53 52.32 51.66 51.59 51.50 49.29 53.93 57.51 57.45 59.14 55.94 18 62.38 57.42 52.31 51.78 51.77 51.66 49.04 54.09 57.59 57.53 59.19 55.06 19 62.26 57.32 52.23 51.91 51.95 51.85 48.88 54.26 57.66 57.62 59.25 54.21 20 62.11 57.20 52.05 52.03 52.10 52.03 48.83 54.43 57.72 57.70 59.33 53.41 21 61.95 57.06 51.94 52.15 52.27 52.21 48.86 54.59 57.78 57.78 59.40 52.60 22 61.79 56.86 51.90 52.25 52.42 52.38 48.95 54.74 57.79 57.85 59.48 51.86 23 61.64 56.59 51.90 52.31 52.56 52.57 49.09 54.87 57.66 57.93 59.55 50.92 24 61.50 56.20 51.93 52.20 52.72 52.75 49.25 55.01 57.60 58.01 59.54 49.75 25 61.36 55.61 51.96 52.00 52.87 52.92 49.43 55.15 57.52 58.08 59.45 48.63 26 61.24 54.92 52.01 51.78 52.96 53.07 49.62 55.29 57.45 58.12 59.44 47.64 27 61.14 54.34 52.04 51.54 52.95 53.21 49.82 55.43 57.25 58.16 59.46 46.73 28 61.04 53.91 52.09 51.29 52.83 53.35 50.05 55.56 57.01 58.22 59.49 45.91 29 60.95 53.60 52.14 51.05 53.47 50.32 55.70 56.88 58.27 59.50 45.18 30 60.87 53.36 52.20 50.80 53.58 50.56 55.82 56.84 58.34 59.49 44.54 31 60.77 52.25 50.61 53.70 55.96 58.42 59.43 MEAN 62.03 57.56 52.40 51.45 51.19 52.17 51.26 53.64 57.09 57.51 59.14 54.61 WTR YR 1998 MEAN 55.05 HIGHEST 44.28 SEPT. 30, 1998 LOWEST 62.57 OCT. 15, 1997 40 50 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 60 70 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 563 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180002066132200. Local number, HW-TW-01. LOCATION.--Lat 18°00'02", long 66°13'22", Hydrologic Unit 21010004, 3.30 mi southwest of Cerro Guaraco, 8.71 mi southwest of Cayey plaza, and 2.80 mi southeast of Hwy 1 km 82.3 on Rabo del Buey. Owner: US Geological Survey, WRD, Name: HW-TW-01. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-39.5 ft (0-12.0 m), cased 4 in (0.10 m), 0-38.2 ft (0-11.6 m), screened 32-37.0 ft (9.75-11.3 m). Depth 39.5 ft (12.0 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 190 ft (58.0 m), above mean sea level. Measuring point: Hole on side of 4 in (0.10 m) casing, 2.84 ft (0.87 m), above land-surface datum. Prior October 13, 1988, top of shelter floor, 3.48 ft (1.06 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 10, 1998. PERIOD OF RECORD.--April 14, 1988 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 19.34 ft (5.89 m), below land-surface datum, Dec. 18, 1990 to Jan. 26, 1991; lowest water level recorded, 37.45 ft (11.4 m), below land-surface datum, Sept. 10, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.41 27.14 26.45 26.87 2 28.41 27.12 26.44 26.89 3 28.41 27.11 26.43 26.94 4 28.41 27.09 26.43 26.95 5 28.41 27.09 26.43 26.97 27.54 27.86 28.53 28.90 29.53 30.03 30.61 --- 27.58 27.86 28.55 28.92 29.54 30.04 30.63 --- 27.60 27.87 28.55 28.96 29.54 30.07 30.64 --- 27.62 27.86 28.55 28.98 29.54 30.10 30.66 --- 27.64 27.89 28.56 29.01 29.55 30.12 30.68 --­ 6 28.41 27.08 26.43 27.01 7 28.41 27.06 26.43 27.02 8 28.41 27.06 26.43 27.03 9 28.43 27.06 26.43 27.04 10 28.44 27.04 26.43 27.05 27.66 27.90 28.56 29.02 29.59 30.13 30.70 --- 27.68 27.93 28.56 29.02 29.61 30.14 30.71 --- 27.68 27.96 28.58 29.02 29.63 30.18 30.73 --- 27.68 27.97 28.59 29.04 29.68 30.20 30.75 --- 27.68 28.00 28.60 29.05 29.70 30.22 30.75 --­ 11 28.45 27.01 26.43 27.06 12 28.48 26.97 26.44 27.08 13 28.48 26.94 26.47 27.09 14 28.32 26.88 26.49 27.09 15 28.16 26.85 26.51 27.11 27.67 28.19 28.62 29.08 29.71 30.22 30.77 --- 27.67 28.19 28.64 29.15 29.72 30.23 30.77 --- 27.66 28.22 28.64 29.15 29.72 30.26 30.77 --- 27.65 28.27 28.65 29.15 29.73 30.28 30.77 --- 27.65 28.28 28.66 29.16 29.79 30.31 30.77 --­ 16 27.97 26.83 26.56 27.14 17 27.86 26.80 26.56 27.17 18 27.77 26.77 26.58 27.19 19 27.62 26.71 26.59 27.21 20 27.55 26.67 26.59 27.23 27.67 28.31 28.66 29.17 29.81 30.33 30.78 --- 27.68 28.32 28.66 29.20 29.82 30.35 30.78 --- 27.69 28.35 28.67 29.21 29.84 30.37 30.78 --- 27.69 28.38 28.68 29.26 29.86 30.39 30.78 --- 27.73 28.40 28.68 29.29 29.88 30.42 30.78 --­ 21 27.47 26.64 26.61 27.27 22 27.42 26.60 26.63 27.28 23 27.36 26.58 26.65 27.31 24 27.33 26.57 26.67 27.34 25 27.31 26.56 26.70 27.36 27.75 28.40 28.68 29.31 29.91 30.44 30.78 --- 27.77 28.42 28.69 29.32 29.94 30.45 30.78 --- 27.79 28.44 28.71 29.35 29.94 30.45 30.79 --- 27.80 28.46 28.74 29.38 29.94 30.48 30.80 --- 27.81 28.49 28.76 29.40 29.95 30.49 30.80 --­ 26 27.27 26.54 26.73 27.40 27 27.24 26.53 26.75 27.43 28 27.22 26.51 26.78 27.46 29 27.19 26.49 26.81 27.48 30 27.16 26.47 26.82 27.50 31 27.15 --- 26.84 27.52 27.81 28.50 28.79 29.41 29.96 30.50 30.73 --- 27.85 28.52 28.81 29.44 29.97 30.52 30.68 --- 27.85 28.52 28.83 29.46 29.98 30.56 30.64 --­ --- 28.52 28.86 29.47 29.99 30.57 --- --­ --- 28.53 28.88 29.49 30.01 30.59 --- --­ --- 28.53 --- 29.51 --- 30.60 --- --­ MEAN 27.90 26.83 26.57 27.18 27.70 28.24 28.66 29.20 29.78 30.32 30.74 --­ WTR YR 1998 MEAN 28.45 HIGHEST 26.43 DEC. 3- 12, 1997 LOWEST 30.80 AUG. 24, 25, 1998 25 30 35 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 564 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180001066122002. Local number, HW-TW-03C. LOCATION.--Lat 18°00'01", long 66°12'20", Hydrologic Unit 21010004, 8.27 mi southwest of Cayey plaza, 2.38 mi soutwest of Cerro Garau, and 3.45 mi southeast of Hwy 1 km 82.3. Owner: US Geological Survey, WRD, Name: HW-TW-03C. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-220 ft (0-67.0 m), cased 4 in (0.10 m), 0-150 ft (0-45.7 m), open hole 150-220 ft (45.7-67.0 m). Depth 220 ft (67.0 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 270 ft (82.6 m), above mean sea level. Measuring point: Top of shelter floor, 3.32 ft (1.01 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on April 15, 1998. Aquifer test performed during May 24, 25, 26, 1989. PERIOD OF RECORD.--December 15, 1988 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 26.29 ft (8.01 m), below land-surface datum, Dec. 15, 1990; lowest water level recorded, 59.82 ft (18.2 m), below land-surface datum, Mar. 1, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 53.80 53.91 53.93 54.16 54.40 54.68 54.82 55.22 55.48 55.76 55.92 2 53.79 53.91 53.92 54.14 54.42 54.66 54.85 55.24 55.49 55.77 55.94 3 53.79 53.90 53.91 54.10 54.42 54.66 54.89 55.26 55.49 55.77 55.96 4 53.80 53.87 53.91 54.10 54.43 54.72 54.90 55.29 55.52 55.79 56.03 5 53.80 53.90 53.92 54.11 54.42 54.74 54.92 55.31 55.53 55.83 56.05 6 53.81 53.91 53.92 54.15 54.46 54.77 54.94 55.35 55.55 55.86 56.06 7 53.84 53.92 53.97 54.15 54.49 54.79 54.99 55.33 55.63 55.87 55.63 8 53.87 53.93 54.01 54.19 54.51 54.83 55.04 55.34 55.63 55.89 55.78 9 53.90 53.99 54.02 54.22 54.51 54.87 55.05 55.36 55.65 55.90 55.72 10 53.92 53.94 54.03 54.24 54.53 54.89 55.04 55.37 55.65 55.90 55.64 11 53.97 53.97 54.05 54.21 54.57 54.85 55.03 55.37 55.63 55.88 55.63 12 53.95 53.98 54.06 54.24 54.57 54.88 55.00 55.38 55.61 55.85 55.63 13 53.96 53.95 54.06 54.23 54.57 54.88 54.99 55.38 55.57 55.83 14 53.75 53.95 54.05 54.21 54.54 54.87 54.99 55.34 55.55 55.84 15 53.65 53.94 54.04 54.21 54.56 54.85 55.07 55.32 55.58 55.85 16 53.62 53.91 54.02 54.21 54.56 54.82 55.05 55.34 55.59 55.88 17 53.61 53.88 54.00 54.23 54.56 54.82 55.06 55.36 55.61 55.90 18 53.59 53.87 54.01 54.24 54.58 54.83 55.08 55.38 55.62 55.93 19 53.56 53.87 54.04 54.25 54.58 54.84 55.08 55.41 55.67 55.97 20 53.58 53.89 54.05 54.27 54.59 54.84 55.10 55.44 55.71 55.97 21 53.58 53.91 54.04 54.29 54.61 54.83 55.12 55.46 55.73 56.01 22 53.62 53.92 54.07 54.32 54.66 54.84 55.16 55.48 55.71 55.92 23 53.67 53.93 54.07 54.36 54.68 54.87 55.24 55.51 55.74 55.90 24 53.71 53.95 54.09 54.38 54.69 54.91 55.27 55.53 55.74 55.90 25 53.74 53.95 54.12 54.41 54.73 54.95 55.29 55.52 55.71 55.90 26 53.79 53.96 54.14 54.43 54.72 55.00 55.29 55.51 55.69 55.88 27 53.81 53.97 54.13 54.46 54.74 54.98 55.26 55.50 55.68 55.84 28 53.86 53.99 54.13 54.46 54.73 54.96 55.26 55.48 55.68 55.85 29 53.88 53.96 54.14 54.44 54.92 55.24 55.46 55.71 55.88 30 53.90 53.94 54.16 54.40 54.87 55.22 55.46 55.74 55.91 31 53.91 54.16 54.37 54.85 55.47 55.92 MEAN 53.78 53.93 54.04 54.26 54.57 54.84 55.07 55.39 55.63 55.88 55.83 WTR YR 1998 MEAN 54.78 HIGHEST 53.45 OCT. 15, 16, 1997 LOWEST 56.13 AUG. 7, 1998 45 50 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 55 60 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 565 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175947066130601. Local number, HW-TW5B. LOCATION.--Lat 17°59'47", long 66°13'06", Hydrologic Unit 21010004, 2.70 mi northeast of Central Aguirre Church, 6.16 mi northwest of Escuela de Guayama, and 2.70 mi northeast of Hwy 3 km 151.3. Owner: US Geological Survey, WRD, Name: HW-TW-5B. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-52.0 ft (0-15.8 m), cased 4 in (0.10 m), 0-51.0 ft (0-15.5 m), screened 41-46 ft (12.5-14.0 m). Depth 52.0 ft (15.8 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 145 ft (44.2 m), above mean sea level. Measuring point: Hole on side of casing, 3.00 ft (0.91 m), above land-surface datum. Prior October 13, 1989 top of shelter floor, 3.47 ft (1.06 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on April 15, 1998. PERIOD OF RECORD.--April 13, 1988 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 5.93 ft (1.81 m), below land-surface datum, Sept. 22, 1998; lowest water level recorded, 28.55 ft (8.70 m), below land-surface datum, Aug. 14, 15, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.41 18.81 17.37 18.26 19.06 19.67 20.55 21.43 22.69 23.12 23.68 2 24.41 18.81 17.39 18.30 19.09 19.71 20.55 21.48 22.72 23.12 23.71 3 24.39 18.81 17.43 18.33 19.11 19.75 20.56 21.54 22.75 23.12 23.74 4 24.38 18.81 17.45 18.33 19.16 19.77 20.56 21.57 22.78 23.12 23.76 5 24.37 18.82 17.48 18.34 19.19 19.84 20.58 21.62 22.82 23.13 23.78 6 24.37 18.82 17.50 18.39 19.19 19.88 20.59 21.65 22.84 23.14 23.80 7 24.37 18.82 17.54 18.36 19.14 19.91 20.62 21.65 22.89 23.15 23.82 8 24.37 18.84 17.56 18.35 19.12 19.96 20.65 21.66 22.93 23.16 23.85 9 24.37 18.87 17.59 18.35 19.10 20.01 20.68 21.69 22.96 23.18 23.70 10 24.37 18.45 17.62 18.35 19.11 20.05 20.73 21.71 22.99 23.20 23.57 11 24.37 17.86 17.65 18.35 19.11 20.10 20.75 21.75 23.04 23.21 23.53 12 24.35 17.62 17.69 18.36 19.13 20.13 20.76 21.83 23.07 23.22 23.53 13 24.28 17.55 17.73 18.38 19.15 20.17 20.78 21.87 23.10 23.24 23.53 14 21.28 17.47 17.75 18.38 19.19 20.22 20.79 21.89 23.14 23.25 23.53 15 20.40 17.43 17.77 18.42 19.19 20.25 20.80 21.93 23.18 23.27 23.54 16 19.91 17.40 17.81 18.45 19.21 20.28 20.81 21.97 23.21 23.28 23.58 17 19.49 17.36 17.84 18.49 19.23 20.30 20.83 22.01 23.21 23.30 23.64 18 19.27 17.34 17.86 18.51 19.26 20.34 20.86 22.04 23.21 23.31 23.64 19 19.12 17.34 17.90 18.54 19.29 20.40 20.88 22.10 23.21 23.35 23.56 20 19.02 17.32 17.92 18.59 19.34 20.44 20.92 22.15 23.21 23.38 23.53 21 18.97 17.32 17.96 18.66 19.40 20.44 20.96 22.19 23.21 23.39 23.49 22 18.92 17.32 17.99 18.67 19.43 20.46 21.00 22.24 23.20 23.40 23.49 6.09 23 18.90 17.32 18.00 18.73 19.47 20.46 21.04 22.32 23.19 23.43 23.37 24 18.85 17.32 18.01 18.76 19.51 20.49 21.09 22.36 23.17 23.44 23.32 25 18.83 17.31 18.03 18.82 19.54 20.52 21.15 22.40 23.15 23.46 22.47 9.00 26 18.80 17.31 18.05 18.85 19.58 20.54 21.19 22.45 23.14 23.48 21.70 9.70 27 18.81 17.31 18.08 18.89 19.61 20.54 21.22 22.49 23.13 23.53 21.50 10.26 28 18.80 17.32 18.11 18.92 19.64 20.54 21.28 22.52 23.12 23.55 21.39 10.67 29 18.80 17.34 18.13 18.94 20.54 21.32 22.55 23.12 23.58 21.17 11.02 30 18.80 17.35 18.18 18.96 20.54 21.38 22.61 23.12 23.60 11.32 31 18.80 18.21 19.02 20.54 22.65 23.64 MEAN 21.37 17.86 17.79 18.55 19.27 20.22 20.86 22.01 23.05 23.31 23.27 9.72 WTR YR 1998 MEAN 20.46 HIGHEST 5.93 SEPT. 22, 1998 LOWEST 24.43 OCT. 1, 1997 0 10 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 566 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175957066123400. Local number, HW-TW-13. LOCATION.--Lat 17°59'57", long 66°12'34", Hydrologic Unit 21010004, 3.11 northeast of Central Aguirre Church, 5.76 mi northwest of Escuela de Guayama, and 2.03 mi northeast of Hwy 3 km 151.3. Owner: US Geological Survey, WRD, Name: HW-TW-13. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-69.0 ft (0-21.0 m), cased 4 in (0.10 m), 0-69.0 ft (0-21.0 m), screened 4.0-69 ft (1.22-21.0 m). Depth 69.0 ft (21.0 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is about 203 ft (61.9 m), above mean sea level. Measuring point: Hole on side of casing, 2.33 ft (0.71 m), above land-surface datum. Prior October 14, 1988, top of shelter floor, 3.47 ft (1.06 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on July 22, 1998 PERIOD OF RECORD.--April 14, 1988 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.39 ft (10.5 m), below land-surface datum, Oct. 27, 1990; lowest water level recorded, 48.12 ft (14.7 m), below land-surface datum, Sept. 3, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 47.58 46.82 46.86 46.99 47.02 47.11 47.18 47.21 47.12 47.13 47.62 48.09 2 47.58 46.82 46.86 46.99 47.02 47.11 47.18 47.22 47.12 47.13 47.64 48.09 3 47.58 46.82 46.86 46.99 47.03 47.11 47.18 47.22 47.12 47.13 47.65 48.10 4 47.58 46.82 46.86 46.99 47.03 47.13 47.18 47.22 47.12 47.13 47.67 48.09 5 47.58 46.82 46.87 46.99 47.02 47.14 47.18 47.22 47.12 47.13 47.69 48.07 6 47.58 46.82 46.87 46.99 47.03 47.14 47.18 47.23 47.12 47.70 48.09 7 47.58 46.82 46.87 47.00 47.03 47.14 47.18 47.22 47.12 47.72 48.09 8 47.58 46.82 46.93 47.00 47.04 47.14 47.19 47.22 47.12 47.74 48.09 9 47.58 46.82 46.93 47.01 47.04 47.14 47.19 47.21 47.12 47.75 48.11 10 47.57 46.82 46.93 47.01 47.04 47.14 47.19 47.21 47.12 47.77 48.08 11 47.57 46.82 46.93 47.01 47.04 47.14 47.19 47.21 47.12 47.79 48.06 12 47.57 46.82 46.94 47.02 47.04 47.14 47.19 47.20 47.12 47.80 48.05 13 47.57 46.82 46.94 47.02 47.04 47.14 47.19 47.22 47.12 47.83 48.03 14 47.61 46.82 46.94 47.02 47.04 47.14 47.19 47.21 47.12 47.85 48.01 15 47.61 46.82 46.94 47.02 47.04 47.15 47.19 47.21 47.11 47.86 47.98 16 47.41 46.83 46.94 47.02 47.04 47.15 47.20 47.20 47.11 47.88 47.96 17 47.14 46.83 46.94 47.03 47.04 47.15 47.20 47.20 47.11 47.90 47.93 18 46.99 46.83 46.94 47.03 47.05 47.15 47.20 47.19 47.12 47.91 47.92 19 46.90 46.83 46.94 47.03 47.05 47.15 47.20 47.19 47.12 47.93 47.91 20 46.90 46.83 46.95 47.03 47.05 47.15 47.20 47.18 47.12 47.95 47.89 21 46.90 46.83 46.95 47.03 47.05 47.15 47.20 47.18 47.12 47.96 47.87 22 46.89 46.84 46.95 47.03 47.05 47.15 47.20 47.17 47.12 47.48 47.98 42.65 23 46.89 46.84 46.96 47.03 47.05 47.16 47.20 47.17 47.12 47.47 48.00 43.53 24 46.89 46.84 46.96 47.03 47.05 47.16 47.21 47.16 47.12 47.49 48.01 46.31 25 46.82 46.84 46.96 47.03 47.09 47.16 47.21 47.16 47.12 47.50 48.00 46.89 26 46.82 46.84 46.97 47.02 47.09 47.17 47.21 47.15 47.12 47.52 48.02 46.88 27 46.82 46.84 46.97 47.02 47.10 47.17 47.21 47.15 47.13 47.54 48.03 46.88 28 46.82 46.84 46.97 47.02 47.11 47.17 47.21 47.14 47.13 47.55 48.05 46.88 29 46.82 46.85 46.98 47.02 47.17 47.21 47.14 47.13 47.57 48.08 46.88 30 46.82 46.85 46.98 47.02 47.17 47.21 47.13 47.13 47.59 48.05 46.88 31 46.82 46.99 47.02 47.18 47.13 47.60 48.02 MEAN 47.24 46.83 46.93 47.01 47.05 47.15 47.19 47.19 47.12 47.40 47.87 47.41 WTR YR 1998 MEAN 47.19 HIGHEST 41.61 SEPT. 22, 1998 LOWEST 48.12 SEPT. 3, 1998 42 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 44 46 48 50 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 567 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175809066133100. Local number, CQ-1. LOCATION.--Lat 17°58'09", long 66°13'31", Hydrologic Unit 21010004, 0.49 mi southwest of the intersection of Hwy 706 with Hwy 3, 0.30 mi south of Hwy 3, and 0.12 mi east of Hwy 705. Owner: PR Land Authority, Name: Coqui Btr 1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 18 in (0.46 m). Depth 199 ft (60.7 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is 16.4 ft (5.00 m), above mean sea level, from topographic map. Measuring point: Hole in the side of the 18 in (0.46 m) casing, 1.33 ft (0.41 m), above land-surface datum. REMARKS.--Recording observation well . Automated Digital Recorder (ADR), installed on March 6, 1997. PERIOD OF RECORD.--March 6, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.30 ft (1.00 m), below land-surface datum, Sept. 22, 23, 1998; lowest water level recorded, 18.64 ft (5.68 m), below land-surface datum, May 29, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 15.26 14.08 12.79 13.92 13.53 13.02 13.42 16.13 15.88 15.81 16.32 2 15.15 15.35 14.61 13.64 13.24 12.48 13.57 16.47 15.74 15.90 16.26 3 15.05 15.86 12.96 14.43 13.20 12.73 15.66 16.64 15.65 16.19 4 15.02 15.68 13.05 13.66 13.50 12.83 14.16 16.76 15.41 16.02 5 15.05 14.24 14.43 13.44 13.25 13.05 14.85 16.19 15.42 15.99 6 15.02 13.98 14.55 13.42 13.67 13.03 16.02 16.63 15.47 16.16 14.17 7 15.02 13.91 14.60 13.28 13.22 13.04 16.18 17.08 15.39 15.94 16.07 8 15.27 13.80 14.66 13.06 14.31 13.02 14.38 17.24 15.36 15.93 16.09 9 15.13 13.72 13.94 13.04 13.65 12.98 17.07 17.36 15.40 15.77 16.12 10 15.14 12.62 13.60 12.96 13.48 12.90 16.97 17.35 15.38 15.72 16.19 11 15.00 12.32 13.47 12.95 13.44 12.92 17.05 17.39 15.36 16.27 16.21 12 15.07 12.40 13.58 12.93 13.40 12.92 17.15 17.46 14.01 16.75 16.24 13 15.23 12.41 13.59 12.87 12.95 12.94 17.21 17.46 13.27 16.82 16.29 14 14.08 12.46 13.38 13.08 13.44 12.93 17.09 17.50 12.62 16.86 16.29 15 13.02 12.53 13.28 12.89 13.37 12.92 17.20 17.61 15.37 16.90 16.16 16 13.06 12.58 14.38 12.96 13.23 12.94 18.25 17.65 15.45 16.92 16.03 17 13.05 12.60 14.62 12.85 13.15 12.97 17.72 17.71 15.50 17.20 14.58 18 13.05 12.53 13.91 12.85 13.35 13.05 17.62 16.88 15.54 17.27 15.85 19 13.04 12.59 13.52 12.84 13.58 13.11 17.61 17.52 15.59 16.99 15.92 20 13.05 12.61 13.42 13.49 13.27 13.15 17.62 17.70 15.45 16.95 16.00 21 13.07 12.68 13.35 14.30 13.08 13.20 13.57 17.79 15.63 16.93 15.99 22 12.59 12.43 13.31 13.33 13.12 13.23 17.15 18.00 15.71 16.80 7.06 23 12.45 12.49 13.40 13.33 13.66 13.27 17.38 17.90 15.58 16.83 3.37 24 12.44 12.65 13.32 13.21 13.44 13.24 17.42 17.89 15.81 16.79 4.04 25 13.96 11.96 13.30 14.10 13.34 13.29 17.47 18.04 15.88 16.10 4.44 26 14.38 12.51 13.27 13.99 13.24 13.37 17.55 18.13 15.89 16.24 4.43 27 14.18 12.62 13.41 13.22 13.07 13.43 17.58 18.07 15.75 16.25 4.32 28 12.94 12.73 13.33 13.06 12.85 13.47 17.72 18.08 15.44 16.28 4.24 29 12.64 12.80 14.26 13.14 13.60 16.99 18.21 15.67 16.23 4.19 30 12.50 12.79 14.56 13.10 13.57 14.54 17.93 15.71 16.17 4.09 31 14.41 14.61 13.09 13.67 16.29 16.53 MEAN 14.01 13.13 13.76 13.30 13.36 13.11 16.47 17.39 15.34 15.85 16.52 12.51 WTR YR 1998 MEAN 14.43 HIGHEST 3.30 SEPT. 22, 23, 1998 LOWEST 18.64 MAY 29, 1998 0 LAND-SURFACE DATUM 10 WATER LEVEL, IN FEET BELOW 20 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- 568 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180206066135500. Local number, RM-5. LOCATION.--Lat 18°02'06", long 66°13'55", Hydrologic Unit 21010004, 6.98 mi southwest of Cayey plaza, 0.63 mi east of Hwy 1 km 82.3 on Rabo del Buey, and 1.75 mi southeast of Capilla de Santa Marta. Owner: US Geological Survey, WRD, Name: RM # 5. AQUIFER.--Quaternary alluvium. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-34.0 ft (0-10.4 m), screened 24-34.0 ft (7.32-10.7 m). Depth 34.0 ft (10.4 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is about 276 ft (84.2 m), above mean sea level. Measuring point: Top of shelter floor, 3.28 ft (1.00 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on June 3, 1998. PERIOD OF RECORD.--March 9, 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 5.56 ft (1.69 m), below land-surface datum, Sept. 10, 1996; lowest water level recorded, 24.24 ft (7.39 m), below land-surface datum, Sept. 20, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20.95 11.71 11.51 11.68 11.83 11.84 11.56 11.83 11.79 12.00 13.62 11.67 2 20.90 11.71 11.53 11.68 11.83 11.84 11.66 11.84 11.82 12.00 13.76 11.71 3 20.85 11.74 11.54 11.68 11.83 11.85 11.51 11.84 11.84 12.03 13.88 11.46 4 20.78 11.75 11.56 11.68 11.83 11.85 11.61 11.84 11.85 12.04 14.01 10.88 5 19.48 11.75 11.57 11.68 11.76 11.85 11.65 11.85 11.84 12.04 14.15 11.23 6 17.96 11.77 11.58 11.68 11.51 11.86 11.68 11.85 11.85 12.03 14.32 11.37 7 17.09 11.78 11.60 11.68 11.63 11.86 11.70 11.86 11.86 12.04 14.19 11.42 8 16.55 11.79 11.62 11.68 11.67 11.86 11.34 11.87 11.86 12.04 12.74 11.50 9 16.11 11.80 11.62 11.68 11.69 11.87 11.51 11.87 11.86 12.04 12.06 11.52 10 15.56 9.85 11.62 11.68 11.69 11.87 11.60 11.80 11.86 12.05 12.09 11.59 11 15.27 10.61 11.63 11.68 11.75 11.87 11.63 11.81 11.86 12.05 12.09 11.66 12 13.18 10.78 11.64 11.68 11.75 11.87 11.50 11.81 11.86 12.10 12.10 11.69 13 12.73 10.88 11.64 11.68 11.76 11.87 11.50 11.81 11.90 12.17 12.13 11.72 14 9.74 10.97 11.65 11.68 11.76 11.87 11.52 11.76 11.90 12.34 12.14 11.73 15 10.44 11.05 11.66 11.68 11.72 11.87 11.63 11.76 11.91 12.50 12.17 11.73 16 10.47 11.11 11.66 11.70 11.73 11.87 11.67 11.77 11.91 12.61 12.27 11.73 17 10.79 11.16 11.68 11.70 11.73 11.87 11.68 11.77 11.91 12.73 12.39 11.74 18 10.84 11.23 11.68 11.70 11.73 11.87 11.71 11.77 11.91 12.88 12.43 11.77 19 10.97 11.26 11.68 11.71 11.74 11.87 11.75 11.79 11.92 13.01 12.56 11.75 20 11.11 11.30 11.68 11.81 11.75 11.87 11.75 11.79 11.92 13.19 12.73 11.77 21 11.23 11.36 11.68 11.81 11.76 11.82 11.76 11.79 11.93 13.26 12.83 11.77 22 11.33 11.37 11.68 11.81 11.78 11.82 11.77 11.80 11.76 13.42 11.58 6.70 23 11.40 11.38 11.68 11.81 11.79 11.82 11.77 11.83 11.82 13.47 11.70 8.07 24 11.45 11.40 11.68 11.82 11.80 11.82 11.78 11.83 11.86 13.32 11.80 8.60 25 11.52 11.43 11.68 11.82 11.82 11.82 11.80 11.84 11.90 13.18 9.59 8.99 26 11.58 11.46 11.68 11.82 11.83 11.82 11.81 11.86 11.92 13.16 10.78 9.43 27 11.62 11.47 11.68 11.82 11.83 11.82 11.81 11.81 11.96 13.16 11.12 9.77 28 11.65 11.49 11.68 11.82 11.84 11.81 11.81 11.78 11.96 13.16 11.31 10.08 29 11.68 11.50 11.68 11.82 11.81 11.83 11.79 11.98 13.18 11.35 10.36 30 11.70 11.51 11.68 11.82 11.81 11.83 11.82 11.98 13.31 11.46 10.58 31 11.70 11.68 11.83 11.46 11.79 13.48 11.58 MEAN 13.83 11.35 11.64 11.74 11.75 11.83 11.67 11.81 11.88 12.64 12.35 10.87 WTR YR 1998 MEAN 11.95 HIGHEST 6.63 SEPT. 22, 1998 LOWEST 20.97 OCT. 1, 1997 0 10 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 569 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180104066152300. Local number, RM-10. LOCATION.--Lat 18°01'04", long 66°15'23", Hydrologic Unit 21010004, 8.00 mi southeast of Coamo plaza, 1.07 mi northeast of Escuela de Coco, and 0.70 mi southwest of Escuela Sabana Llana. Owner: US Geological Survey, WRD, Name: RM # 10. AQUIFER.--Quaternary alluvium. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-37.0 ft (0-11.3 m), screened 27-37 ft (8.23-11.3 m). Depth 37.0 ft (11.3 m). INSTRUMENTATION.--Electronic water level logger--15-minute interval. DATUM.--Elevation of land-surface datum is about 164 ft (50.0 m), above mean sea level, from leveling survey. Measuring point: Top of shelter floor, 3.62 ft (1.10 m), above land-surface datum. REMARKS.--Recording observation well. Pumping test performed on February 8, 1990. Well dry at 35.77 ft (10.9 m). Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 11, 1998. From Sept. 14, 1998, monthly measurements only. PERIOD OF RECORD.--March 13, 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.0 ft (5.49 m), below land-surface datum, Nov. 9, 1990; lowest water level recorded, 35.77 ft (10.9 m), below land-surface datum, Sept. 14 to Oct. 5, 1994 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 35.61 27.53 23.91 24.10 25.56 25.98 27.32 26.03 27.32 29.00 30.97 2 35.61 27.41 23.91 24.12 25.65 26.06 27.08 26.18 27.27 29.07 31.05 3 35.61 27.34 23.91 24.18 25.72 26.24 26.81 26.37 27.27 29.15 31.10 4 35.61 27.27 23.91 24.19 25.80 26.36 26.60 26.49 27.28 29.20 31.11 5 35.60 27.21 23.91 24.17 25.90 26.38 26.38 26.65 27.36 29.31 31.19 6 35.60 27.15 23.91 24.16 25.82 26.43 26.15 26.73 27.37 29.36 31.25 7 35.60 27.05 23.91 24.14 25.67 26.50 26.04 26.74 27.49 29.46 31.30 8 35.60 26.94 23.91 24.12 25.53 26.65 25.69 26.90 27.63 29.55 31.33 9 35.60 26.82 23.91 24.12 25.42 26.73 25.63 26.90 27.68 29.59 30.56 10 35.60 26.09 23.91 24.13 25.27 26.73 25.56 26.99 27.79 29.68 29.90 11 35.60 25.51 23.93 24.16 25.18 26.74 25.49 26.99 27.89 29.79 29.75 12 35.60 25.16 23.93 24.20 25.13 26.86 25.24 27.04 27.97 29.84 29.78 13 35.59 24.95 23.93 24.25 25.13 26.93 25.13 27.09 28.04 29.91 29.91 14 35.59 24.76 23.93 24.26 25.13 27.08 25.08 27.10 28.11 29.99 30.06 15 34.39 24.58 23.93 24.29 25.10 27.08 25.08 27.14 28.21 30.06 30.15 16 33.06 24.44 23.95 24.35 25.00 27.25 25.08 27.10 28.32 30.13 30.27 17 32.28 24.33 23.95 24.40 25.01 27.32 25.08 27.08 28.39 30.19 30.39 18 31.73 24.23 23.94 24.46 25.01 27.34 25.08 27.07 28.48 30.26 30.48 19 31.21 24.14 23.93 24.54 25.02 27.41 25.09 27.07 28.54 30.32 30.56 20 30.82 24.07 23.93 24.61 25.02 27.49 25.09 27.06 28.59 30.38 30.69 21 30.45 24.03 23.92 24.69 25.12 27.49 25.10 27.06 28.70 30.42 22 30.08 23.99 23.91 24.77 25.22 27.61 25.10 27.06 28.77 30.49 23 29.74 23.97 23.90 24.86 25.31 27.61 25.19 27.07 28.77 30.49 24 29.35 23.95 23.90 24.95 25.39 27.73 25.27 27.17 28.77 30.54 25 29.04 23.92 23.90 25.05 25.49 27.72 25.37 27.30 28.77 30.62 26 28.73 23.91 23.91 25.12 25.61 27.72 25.45 27.35 28.77 30.67 27 28.44 23.91 23.96 25.17 25.72 27.72 25.57 27.42 28.86 30.74 28 28.20 23.91 23.99 25.21 25.85 27.72 25.68 27.50 28.86 30.77 29 28.02 23.91 24.00 25.28 27.72 25.76 27.43 28.93 30.83 30 27.87 23.91 24.02 25.36 27.72 25.93 27.38 28.95 30.89 31 27.68 24.08 25.45 27.62 27.37 30.94 MEAN 32.56 25.21 23.93 24.54 25.38 27.09 25.64 26.99 28.17 30.05 30.59 WTR YR 1998 MEAN 27.20 HIGHEST 23.90 DEC. 23-26, 1997 LOWEST 35.61 OCT. 1-5, 1997 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Date level Sept. 14 24.78 20 30 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 570 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175910066155500. Local number, SA-D. LOCATION.--Lat 17°59'10", long 6615'55", Hydrologic Unit 21010004, 0.55 mi south of Hwy 52, 0.92 mi north of the Salinas Speedway, and 2.27 mi northeast of the intersection if Hwy 1 with Hwy 3. Owner: US Geologial Survey, WRD, Name: USGS piezometer D. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), 0-86.0 ft (0-26.2 m). Depth 86.0 ft (26.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 73.0 ft (22.3 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--recording observation well. Automated Digital Recorder (ADR), installed on Feb. 19, 1997. PERIOD OF RECORD.--February 19, 1997 to September 30, 1997. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 35.80 ft (10.9 m), below land-surface datum, Feb, 19 1997; lowest water level recorded, 47.98 ft (14.6 m) below land-surface datum, Oct. 7, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 37.01 39.67 41.36 42.68 44.24 45.55 46.86 2 37.09 39.73 41.38 42.72 44.24 45.56 46.89 3 37.33 39.74 41.42 42.76 44.43 45.53 46.95 4 37.39 39.76 41.45 42.78 44.38 45.66 46.98 5 37.47 39.77 41.62 42.81 44.38 45.63 47.00 6 37.54 39.79 41.55 42.87 44.37 45.63 47.00 7 37.68 39.84 41.57 42.91 44.46 45.70 47.05 8 37.81 39.89 41.63 42.96 44.42 45.74 47.05 9 37.90 39.94 41.68 43.11 44.58 45.75 47.21 10 38.05 40.13 41.70 43.21 44.62 45.75 47.24 11 38.14 40.11 41.67 43.15 44.63 45.81 47.28 12 38.31 40.19 41.67 43.20 44.89 45.88 47.35 13 38.43 40.23 41.69 43.37 44.91 45.88 47.41 14 38.54 40.41 41.71 43.35 44.90 45.92 47.40 15 38.70 40.38 41.73 43.35 44.93 45.95 47.49 16 38.76 40.41 41.88 43.36 45.12 46.03 47.46 17 38.85 40.49 41.84 43.48 45.09 46.05 47.56 18 39.03 40.56 41.87 43.48 45.08 46.36 47.57 19 35.86 39.05 40.60 41.93 43.48 45.07 46.32 47.64 20 35.96 39.07 40.71 42.12 43.62 45.09 46.42 47.68 21 36.00 39.12 40.86 42.21 43.63 45.09 46.43 47.69 22 36.11 39.20 40.79 42.19 43.63 45.08 46.55 47.67 23 36.22 39.24 40.85 42.17 43.78 45.09 46.58 47.66 24 36.32 39.31 40.93 42.21 43.97 45.10 46.54 47.66 25 36.54 39.38 41.14 42.28 43.97 45.10 46.53 47.68 26 36.71 39.43 41.07 42.45 43.98 45.10 46.66 47.70 27 36.86 39.52 41.11 42.42 43.98 45.12 46.62 47.70 28 36.95 39.60 41.18 42.48 44.06 45.15 46.63 47.70 29 39.63 41.22 42.53 44.07 45.19 46.65 47.70 30 39.62 41.39 42.57 44.31 45.33 46.73 47.72 31 39.62 42.70 45.34 46.76 MEAN 36.35 38.57 40.43 41.93 43.40 44.86 46.12 47.40 WTR YR 1997 MEAN 42.93 HIGHEST 35.80 FEB. 19, 1997 LOWEST 47.72 SEPT. 30, 1997 571 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 47.72 --- --- 40.20 2 47.72 --- --- 40.32 3 47.72 --- --- 40.07 4 47.88 --- --- 39.96 5 47.95 --- --- 39.87 38.79 38.72 38.98 39.62 40.66 41.74 43.36 44.03 38.96 38.94 38.98 39.72 40.86 41.75 43.32 44.01 38.82 38.95 38.99 39.66 40.87 41.99 43.46 43.95 38.80 38.82 39.00 39.92 41.00 41.69 43.54 43.76 38.81 38.93 39.00 39.92 40.91 41.67 43.68 43.61 6 47.98 --- --- 39.81 7 --- --- --- 39.67 8 --- --- --- 39.61 9 --- --- --- 39.49 10 --- --- --- 39.39 38.75 39.00 39.05 39.85 40.86 41.65 43.73 43.55 38.67 38.82 39.06 39.85 40.86 41.86 43.68 43.41 38.61 38.83 39.08 39.81 40.98 42.03 43.72 43.38 38.56 38.95 39.08 39.86 41.05 42.12 43.68 43.38 38.71 38.96 39.03 39.85 41.24 42.14 43.55 43.36 11 --- --- --- 39.30 12 --- --- --- 39.40 13 --- --- --- 39.23 14 --- --- --- 39.10 15 --- --- --- 39.08 38.64 38.98 39.05 40.07 41.12 41.97 43.68 42.98 38.62 38.91 39.06 40.05 41.33 42.04 43.82 43.03 38.83 38.98 39.09 40.11 41.25 42.31 44.14 42.95 38.68 39.05 39.10 40.09 41.24 42.40 44.16 42.97 38.66 38.92 39.11 40.06 41.32 42.53 44.29 42.78 16 --- --- --- 39.04 17 --- --- 42.00 39.06 18 --- --- 41.98 39.06 19 --- --- 41.72 39.08 20 --- --- 41.56 38.93 38.66 39.01 39.13 40.01 41.23 42.52 44.16 42.60 38.59 38.95 39.10 39.98 41.18 42.66 44.37 42.56 38.64 39.03 39.16 40.16 41.25 42.53 44.29 42.37 38.60 38.99 39.14 40.04 41.25 42.52 44.28 42.20 38.78 38.98 39.32 40.11 41.23 42.68 44.27 42.19 21 --- --- 41.43 38.97 22 --- --- 41.28 38.87 23 --- --- 41.17 39.01 24 --- --- 41.08 38.87 25 --- --- 40.92 38.85 38.81 38.93 39.26 40.16 41.23 42.59 44.29 42.19 38.72 38.96 39.40 40.34 41.15 42.62 44.28 41.87 38.82 39.03 39.36 40.18 41.09 42.75 44.26 41.86 38.73 39.27 39.55 40.20 41.25 42.97 44.21 39.70 38.73 39.12 39.57 40.53 41.23 42.90 44.15 39.14 26 --- --- 40.93 38.96 27 --- --- 40.70 38.95 28 --- --- 40.78 38.84 29 --- --- 40.51 38.89 30 --- --- 40.45 38.82 31 --- --- 40.44 38.79 38.81 39.06 39.53 40.39 41.24 42.89 44.15 38.96 38.90 39.06 39.61 40.32 41.29 43.12 44.13 38.32 38.76 39.05 39.66 40.32 41.52 43.17 44.13 38.02 --- 39.01 39.67 40.44 41.59 43.08 44.13 37.78 --- 38.99 39.74 40.52 41.66 43.15 44.14 37.27 --- 38.98 --- 40.47 --- 43.38 44.02 --­ MEAN 47.83 --- 41.13 39.27 38.73 38.97 39.23 40.08 41.16 42.43 43.97 41.94 WTR YR 1998 MEAN 40.83 HIGHEST 37.08 SEPT. 30, 1998 LOWEST 47.98 OCT. 7, 1997 35 40 45 50 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 572 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175708066163000. Local number, EC-1. LOCATION.--Lat 17°57’08", long 66°16'30", Hydrologic Unit 21010004, 1.55 mi southesat of Playa de Salinas, 143 mi south of Hwy 3, and 0.98 mi West of Las Mareas community. Owner: US Geological Survey. WRD, Name: Pozo Monsanto (Ermitaño Central). AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m). Depth 112 ft (34.1 m). INSTRUMENTATION.--Digital water level recorder--60-minute interval. DATUM.--Elevetion of land-surface datum is about 2.00 ft (0.61 m), above mean sea level, from topographic map. Measuring point: On shelter floor 5.10 ft (1.55 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on July 15, 1997. Well level is affected by marine tides. PERIOD OF RECORD.--July 15, 1997 to January 7, 1998, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +0.28 ft (+0.08 m), above land-surface datum, Jan. 7, 1998; lowest water level measured, 0.88 ft (0.27 m), below land-surface datum, Oct. 8, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .26 .14 2 .19 .18 3 .12 .07 4 .09 .15 5 .09 .13 6 .04 .12 7 .07 .13 8 .08 .25 9 .16 .39 10 .21 .41 11 .25 .62 12 .33 .34 13 .32 .34 14 .33 .29 15 .26 .32 .21 16 .32 .30 .14 17 .33 .20 .14 18 .26 .17 .17 19 .15 .20 .15 20 .13 .12 .19 21 .14 .12 .24 22 .16 .19 .29 23 .07 .22 .40 24 .07 .26 .40 25 .07 .27 .31 26 .08 .30 .38 27 .14 .37 .28 28 .24 .31 .23 29 .27 .29 .18 30 .25 .16 .20 31 .22 .16 MEAN .19 .21 .25 WTR YR 1997 MEAN .22 HIGHEST +.13 JULY 19, 20, 1997 LOWEST .62 SEPT. 11, 1997 573 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .14 +.02 +.07 +.14 --- --- --- --- --- --- --- --­ 2 .27 +.02 +.01 +.18 --- --- --- --- --- --- --- --­ 3 .27 .01 .14 +.13 --- --- --- --- --- --- --- --­ 4 .36 .14 .08 +.10 --- --- --- --- --- --- --- --­ 5 .36 .05 .10 +.15 --- --- --- --- --- --- --- --­ 6 .41 .17 .05 +.18 --- --- --- --- --- --- --- --­ 7 .31 .19 .07 +.28 --- --- --- --- --- --- --- --­ 8 .60 .22 .14 --- --- --- --- --- --- --- --- --­ 9 .15 .18 .05 --- --- --- --- --- --- --- --- --­ 10 .03 .00 +.07 --- --- --- --- --- --- --- --- --­ 11 +.02 .00 +.13 --- --- --- --- --- --- --- --- --­ 12 .01 +.06 +.13 --- --- --- --- --- --- --- --- --­ 13 +.01 +.11 +.16 --- --- --- --- --- --- --- --- --­ 14 .00 +.14 +.04 --- --- --- --- --- --- --- --- --­ 15 .02 +.12 +.07 --- --- --- --- --- --- --- --- --­ 16 .07 +.03 .08 --- 17 +.06 +.09 +.04 --- 18 +.09 +.05 +.02 --- 19 +.03 +.03 .03 --- --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 20 .03 .01 .06 --- --- --- --- --- --- --- --- --­ 21 .10 .09 .11 --- --- --- --- --- --- --- --- --­ 22 .17 .00 .00 --- --- --- --- --- --- --- --- --­ 23 .18 .02 +.02 --- --- --- --- --- --- --- --- --­ 24 .22 +.01 +.12 --- --- --- --- --- --- --- --- --­ 25 .20 .04 +.08 --- --- --- --- --- --- --- --- --­ 26 .16 +.04 +.13 --- --- --- --- --- --- --- --- --­ 27 .13 +.12 +.17 --- --- --- --- --- --- --- --- --­ 28 .18 +.12 +.14 --- --- --- --- --- --- --- --- --­ 29 .15 +.13 +.10 --- --- --- --- --- --- --- --- --­ 30 .05 +.10 +.10 --- --- --- --- --- --- --- --- --­ 31 +.03 --- +.15 --- --- --- --- --- --- --- --- --­ MEAN .14 .00 +.03 +.17 --- --- --- --- --- --- --- --­ WTR YR 1998 MEAN .02 HIGHEST +.28 JAN. 7, 1998 LOWEST .88 OCT. 8, 1997 -0.5 +0.5 0 0.5 1.0 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR + above land-surface datum --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 574 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175903066165000. Local number, PG-07 LOCATION.--Lat 17°59'03", long. 66°16'50", Hydrologic Unit 21010004, 0.42 mi north of Hwy 3, 0.60 mi southeast of the intersection of Hwy 1 with Hwy 52, and 1.56 mi northeast of Punta Salinas. Owner: C. Godreau, Name: Pozo Godreau No. 7. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-120 ft (0-36.6 m), perforated 30-120 ft (9.1-36.6 m). Depth 120 ft (36.6 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is about 54.0 ft (16.5 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 20 in (0.50 m) casing, 3.63 ft (1.11 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on June 3, 1998. PERIOD OF RECORD.--September 25, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 24.62 ft (7.50 m), below land-surface datum, Oct. 18, 1992; lowest water level recorded, 34.87 ft (10.6 m), below land-surface datum, Sept. 3, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 34.09 33.33 32.16 30.83 29.71 29.30 29.21 30.02 30.85 2 34.09 33.31 32.13 30.77 29.70 29.29 29.24 30.07 30.89 3 34.09 33.29 32.09 30.71 29.67 29.29 29.27 30.15 30.92 4 34.09 33.28 32.06 30.66 29.66 29.30 29.30 30.15 30.95 5 34.09 33.27 32.02 30.59 29.65 29.30 29.32 30.16 30.96 6 34.09 33.24 31.97 30.54 29.64 29.29 29.34 30.21 30.98 7 34.09 33.24 31.94 30.48 29.59 29.28 29.39 30.24 30.99 8 34.09 33.24 31.89 30.43 29.56 29.28 29.39 30.27 31.03 9 34.09 33.22 31.84 30.37 29.53 29.29 29.40 30.30 31.08 10 34.09 33.18 31.80 30.33 29.51 29.29 29.42 30.32 31.09 11 34.09 33.08 31.77 30.28 29.47 29.29 29.47 30.34 31.14 31.12 12 34.09 33.02 31.74 30.23 29.46 29.29 29.47 30.37 31.17 31.11 13 34.09 32.96 31.70 30.19 29.46 29.29 29.49 30.40 31.20 31.08 14 34.09 32.92 31.66 30.14 29.44 29.29 29.51 30.44 31.22 31.00 15 34.09 32.85 31.48 30.10 29.42 29.30 29.53 30.47 31.25 30.95 16 34.09 32.79 31.57 30.06 29.40 29.32 29.17 29.55 30.50 31.29 30.90 17 34.05 32.74 31.53 30.03 29.38 29.33 29.17 29.58 30.50 31.33 30.85 18 33.99 32.69 31.48 30.01 29.37 29.35 29.17 29.61 30.52 31.37 30.81 19 33.86 32.64 31.44 29.97 29.36 29.36 29.17 29.64 30.54 31.40 30.76 20 33.83 32.58 31.39 29.95 29.34 29.38 29.17 29.68 30.56 31.43 30.71 21 33.80 32.55 31.35 29.90 29.32 29.38 29.16 29.70 30.60 31.45 30.67 22 33.60 32.51 31.29 29.89 29.32 29.39 29.16 29.75 30.67 30.31 23 33.59 32.47 31.25 29.88 29.32 29.41 29.16 29.78 30.67 29.16 24 33.52 32.44 31.21 29.86 29.32 29.43 29.16 29.82 30.70 28.57 25 33.47 32.41 31.13 29.85 29.30 29.44 29.16 29.85 30.72 28.39 26 33.45 32.37 31.09 29.82 29.30 29.44 29.17 29.87 30.73 28.21 27 33.42 32.33 31.04 29.81 29.30 29.17 29.89 30.76 28.05 28 33.40 32.29 31.00 29.78 29.30 29.18 29.90 30.79 27.89 29 33.39 32.25 30.95 29.76 29.19 29.94 30.80 27.75 30 33.38 32.22 30.90 29.73 29.20 29.98 30.83 27.63 31 33.36 30.86 29.72 30.00 MEAN 33.86 32.82 31.54 30.15 29.46 29.33 29.17 29.59 30.46 31.14 29.80 WTR YR 1998 MEAN 30.79 HIGHEST 27.55 SEPT. 30, 1998 LOWEST 34.09 OCT. 1-16, 1997 25 30 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 35 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 575 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175943066224800. Local number PS-07 LOCATION.--Lat 17°59'43", long 66°22'48", Hydrologic Unit 2101004, 0.74 mi east of Hwy 153, 1.45 mi northeast of Estación Santa Isabel, and 1.98 mi north of Hwy 1. Owner: Luce and Company, Name: Paso Seco No. 7. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. Depth 235 ft (71.6 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 89.0 ft (27.1 m) above mean sea level, from topographic map. Measuring point: Side of the casing, 0.80 ft (0.24 m) above land-surface datum. REMARKS.--Recording observation well. Water levels affected by nearby pumping wells. PERIOD OF RECORD.--March 27, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 81.11 ft (24.72 m) below land-surface datum, Dec. 3, 4, 6, 7, 1992; lowest water level recorded, 101.28 ft (30.87 m) below land-surface datum, Sept. 13, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION Water Water Water Water Date level Date level Date level Date level Oct. 1 91.89 Nov. 6 91.20 Feb. 17 91.18 May 18 89.53 Oct. 24 91.60 Jan. 14 91.35 Mar. 11 91.32 June 8 89.71 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 84 102 84 86 88 90 92 94 96 98 100 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 1993 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 576 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175829066232200. Local number, 87. LOCATION.--Lat 17°58'29", long 66°23'22", Hydrologic Unit 21010004, 1.10 mi northeast of Santa Isabel plaza, 3.69 mi southeast of Escuela Playita Cortada, and 1.07 mi southeast of Estación Experimental Santa Isabel. Owner: Francisco Alomar, Name: Alomar 1. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), iron cased. Depth 112 ft (34.14 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 35.3 ft (10.8 m), above mean sea level. Measuring point: Bottom of clean-out shelter door, 2.50 ft (0.76 m), above land-surface datum. Prior to August 1981, top of recorder shelter floor, 4.00 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on December 16, 1997. PERIOD OF RECORD.--April 1967 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 8.45 ft (2.58 m), below land-surface datum, Dec. 10, 1970; lowest water level recorded, 49.18 ft (14.99 m) below land-surface datum, July 27, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 45.21 44.86 43.85 44.34 44.45 43.92 44.04 44.14 43.70 44.27 43.01 2 45.42 44.66 44.05 44.19 44.29 43.83 44.13 44.25 44.00 44.10 43.06 3 45.52 44.57 44.01 44.33 44.37 43.88 44.04 44.26 44.07 44.00 43.13 4 45.60 44.67 44.12 44.21 44.42 44.00 43.91 44.36 44.12 43.88 42.97 5 45.67 44.74 44.19 44.06 44.46 43.96 44.10 44.55 43.92 43.88 42.85 6 45.61 44.93 44.22 44.16 44.24 43.96 44.19 44.39 43.87 43.93 42.77 7 45.77 44.99 44.17 43.94 44.11 43.97 44.37 44.54 43.89 43.97 42.73 8 45.81 45.06 44.11 43.81 43.94 43.99 44.17 44.34 44.04 44.06 42.73 9 45.77 44.92 44.31 43.75 43.81 43.85 44.15 44.34 44.76 43.87 42.74 10 45.87 44.62 44.37 43.82 43.81 43.77 44.04 44.36 44.35 43.77 42.74 11 45.68 44.35 44.47 43.79 43.84 44.42 43.75 43.98 44.70 44.30 43.83 42.74 12 45.49 44.14 44.57 43.77 44.05 44.48 43.75 44.09 44.33 44.29 44.18 42.78 13 45.29 43.99 44.52 43.82 44.20 44.49 43.66 44.14 44.33 44.03 44.03 42.81 14 45.08 43.90 44.42 43.69 44.25 44.53 43.58 44.22 44.36 44.08 44.08 42.81 15 44.86 43.96 44.36 43.71 44.07 44.55 43.55 44.21 44.35 44.15 44.16 42.85 16 44.61 43.99 44.45 43.90 43.90 44.58 43.48 44.30 44.34 44.28 44.18 42.84 17 44.39 43.96 44.47 43.99 44.58 43.49 44.17 44.18 44.27 44.01 42.82 18 44.41 43.90 44.51 43.92 44.66 43.51 43.99 44.12 44.39 43.99 42.83 19 44.42 43.97 44.51 43.87 44.68 43.54 43.98 44.15 44.18 43.87 42.84 20 44.36 44.04 44.54 44.01 44.68 43.48 44.00 44.20 44.14 43.69 42.79 21 44.34 44.07 44.43 44.10 44.61 43.72 44.01 44.16 43.97 43.60 42.61 22 44.31 44.10 44.21 44.36 46.28 43.74 44.18 43.78 44.06 43.60 42.13 23 44.41 43.96 44.07 44.38 44.91 43.82 44.21 43.62 44.01 43.46 41.93 24 44.50 43.89 44.08 44.42 44.76 43.91 44.07 43.57 44.19 43.37 41.62 25 44.60 43.93 44.01 44.24 44.73 43.99 43.95 43.58 44.21 43.30 41.48 26 44.47 44.00 43.91 44.08 44.55 43.91 44.04 43.96 44.08 43.22 41.33 27 44.40 44.09 44.01 44.30 44.42 43.81 44.09 44.01 43.93 43.17 41.17 28 44.56 43.98 44.17 44.40 44.35 43.90 44.19 43.98 44.08 43.11 40.98 29 44.71 44.06 44.16 44.44 44.13 43.98 44.31 43.66 43.95 43.11 40.74 30 44.91 43.96 44.30 44.45 43.98 44.06 44.38 43.68 43.95 43.04 40.60 31 44.78 44.34 44.48 43.98 44.20 44.10 43.01 MEAN 44.99 44.28 44.26 44.09 44.14 44.59 43.79 44.12 44.15 44.11 43.73 42.38 WTR YR 1998 MEAN 44.04 HIGHEST 40.53 SEPT. 30, 1998 LOWEST 46.41 MAR. 22, 1998 38 40 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 42 44 46 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 577 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180020066261500. Local number, CA-1. LOCATION.--Lat 18°00'20", long 66°26'15", Hydrologic Unit 21010004, 1.04 mi north of the intersection of Hwy 536 with Hwy 1, 0.60 mi northwest of Central Cortada, and 0.10 mi west of Hwy 536. Owner: PR Land Authority, Name: Cabrera 1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 18 in (0.46 m). Depth 80.0 ft (24.4 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 65.6 ft (20.0 m), above mean sea level, from topographic map. Measuring point: Shelter floor on the top of 4 in (0.10 m) casing, 3.12 ft (0.95 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on Mar. 1, 1997. Well level affected by nearby pumping well. PERIOD OF RECORD.--March 18, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 43.3 ft (13.2 m), below land-surface datum, Mar. 19, 20, 1997; lowest water level recorded, 55.0 ft (16.8 m), below land-surface datum, Apr. 14, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 45.78 46.62 47.87 2 45.94 46.67 48.06 3 45.86 46.70 50.57 4 44.14 45.87 46.74 48.72 5 44.27 45.93 46.77 48.29 6 45.23 46.08 46.82 48.39 7 44.26 46.08 46.80 48.05 8 44.48 46.06 46.75 48.15 9 48.78 47.44 46.74 48.15 10 46.78 46.10 46.78 50.70 11 44.90 46.07 46.84 50.92 12 48.09 46.12 46.87 50.30 13 48.22 46.15 46.91 49.61 14 48.66 46.22 46.97 48.53 15 47.92 46.23 47.02 48.61 16 47.01 46.26 47.02 48.87 17 49.50 46.25 47.02 18 47.91 46.26 49.05 19 43.60 45.51 46.27 49.10 20 43.31 48.19 47.81 48.41 21 43.60 45.39 46.46 47.36 22 47.50 45.51 46.40 47.47 23 46.01 46.50 50.59 24 49.29 46.48 50.67 25 45.71 46.44 47.91 26 45.61 46.45 47.67 27 48.90 46.47 47.80 28 46.06 46.58 47.95 29 50.01 46.59 50.49 30 45.87 46.57 48.16 31 46.65 MEAN 44.50 46.75 46.33 47.62 48.99 WTR YR 1997 MEAN 47.12 HIGHEST 43.31 MAR. 19, 20, 1997 LOWEST 51.23 JULY 11, 1997 578 WATEWR LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- --- 48.60 2 --- --- --- 48.63 3 --- --- --- 48.67 4 --- --- --- 48.72 5 --- --- --- 48.76 49.82 53.31 51.01 50.44 --- --- 49.18 48.84 49.86 50.41 50.99 50.48 --- --- 49.18 48.82 49.91 50.39 50.90 52.61 --- --- 49.17 48.69 49.94 50.37 52.48 51.17 --- --- 49.24 48.49 49.98 52.43 50.83 50.50 --- --- 49.38 48.30 6 --- --- --- 48.80 7 --- --- --- 48.84 8 --- --- --- 48.88 9 --- --- --- 48.92 10 --- --- --- 48.95 50.02 50.79 50.72 50.74 --- --- 49.60 48.19 50.06 50.52 53.49 49.80 --- --- 49.65 48.05 50.10 50.45 50.97 49.64 --- --- 49.63 48.02 50.14 51.26 51.61 49.42 --- --- 49.57 47.89 50.19 50.57 50.66 49.33 --- --- 49.45 47.82 11 --- --- --- 48.99 12 --- --- --- 49.03 13 --- --- --- 49.07 14 --- --- --- 49.11 15 --- --- --- 49.15 53.17 50.57 52.41 49.27 --- --- 49.58 47.76 50.26 53.07 50.53 49.30 --- --- 49.63 47.68 50.36 50.87 50.79 49.35 --- --- 49.69 47.46 50.34 50.86 51.37 49.47 --- --- 49.72 47.21 50.38 52.59 52.24 49.98 --- --- 49.74 47.07 16 --- --- --- 49.19 17 --- --- --- 49.23 18 --- --- 48.04 49.26 19 --- --- 48.08 49.30 20 --- --- 48.12 50.40 50.42 50.76 53.38 49.19 --- --- 49.79 46.95 52.04 50.75 50.63 49.08 --- --- 49.85 46.90 52.00 50.88 50.76 49.21 --- --- 49.91 46.87 51.60 50.97 50.29 49.43 --- --- 49.90 46.83 50.61 51.13 53.11 49.22 --- --- 49.83 46.61 21 --- --- 48.16 50.32 22 --- --- 48.20 49.43 23 --- --- 48.24 50.25 24 --- --- 48.29 49.52 25 --- --- 48.32 49.55 50.64 51.35 51.65 --- --- --- 49.75 46.46 51.90 52.55 52.09 --- --- 48.94 49.69 45.87 50.70 51.32 50.38 --- --- 49.02 49.63 45.32 51.19 54.11 50.88 --- --- 49.07 49.51 44.94 52.96 51.64 50.35 --- --- 49.09 49.35 44.68 26 --- --- 48.36 49.59 27 --- --- 48.39 49.62 28 --- --- 48.43 49.78 29 --- --- 48.48 49.70 30 --- --- 48.52 49.74 31 --- --- 48.56 49.74 54.57 52.13 50.27 --- --- 49.13 49.24 44.46 50.66 52.51 52.28 --- --- 49.09 49.08 44.19 50.73 53.18 50.22 --- --- 49.09 49.04 43.94 --- 51.10 52.17 --- --- 49.09 49.02 43.78 --- 51.16 50.41 --- --- 49.14 48.96 43.55 --- 51.16 --- --- --- 49.15 48.89 --­ MEAN --- --- 48.30 49.28 50.88 51.46 51.33 49.88 --- 49.08 49.48 46.72 WTR YR 1998 MEAN 49.72 HIGHEST 43.41 SEPT. 30, 1998 LOWEST 55.00 APR. 14, 1998 40 45 50 55 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 579 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180048066301800. Local number, FA-1. LOCATION.--Lat 18°00'48", long 66°30'18", Hydrologic Unit 21010004, 3.85 mi east of Central Mercedita, 2.13 mi south of the intersection of Hwy 149 with Hwy 52, and 0.64 mi west of hwy 149. Owner: US Geological Survey, WRD, Name: Fort Allen TW-1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 0-201 ft (0-61.3 m), screened 30-201 ft (9.1-61.3 m). Depth 201 ft (61.3 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 38.0 ft (11.6 m), above mean sea level, from topographic map. Measuring point: Shelter floor on the top of 4 in (0.10 m) casing, 3.19 ft (0.97 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on March 12, 1997. Well destroyed for radar construction. PERIOD OF RECORD.--March 12, 1997 to February 24, 1998, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.33 ft (7.11 m), below land-surface datum, Mar. 12, 13, 14, 1997; lowest water level recorded, 28.93 ft (8.82 m), below land-surface datum, Feb. 24, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.59 24.05 24.88 25.91 26.69 27.52 2 23.62 24.07 24.91 25.94 26.71 27.55 3 23.62 24.10 24.94 25.98 26.74 27.58 4 23.63 24.11 24.97 26.01 26.76 27.61 5 23.64 24.13 25.00 26.04 26.78 27.63 6 23.65 24.15 25.03 26.08 26.80 27.67 7 23.67 24.20 25.07 26.10 26.82 27.70 8 23.67 24.22 25.10 26.13 26.82 27.73 9 23.68 24.23 25.13 26.16 26.85 27.77 10 23.69 24.26 25.16 26.19 26.87 27.80 11 23.70 24.28 25.19 26.22 26.91 27.83 12 23.34 23.70 24.30 25.21 26.24 26.92 27.86 13 23.35 23.72 24.33 25.25 26.27 26.95 27.90 14 23.35 23.74 24.35 25.27 26.30 26.97 27.93 15 23.35 23.75 24.38 25.32 26.33 27.00 27.96 16 23.38 23.77 24.41 25.36 26.35 27.02 27.99 17 23.38 23.78 24.43 25.40 26.39 27.05 28.02 18 23.40 23.80 24.46 25.43 26.41 27.09 28.05 19 23.40 23.82 24.49 25.47 26.43 27.11 28.08 20 23.42 23.84 24.52 25.51 26.46 27.14 28.11 21 23.44 23.86 24.54 25.55 26.48 27.18 28.15 22 23.46 23.87 24.56 25.59 26.50 27.21 28.19 23 23.48 23.89 24.60 25.62 26.52 27.22 28.22 24 23.50 23.91 24.62 25.66 26.53 27.26 28.25 25 23.51 23.94 24.65 25.70 26.55 27.30 28.28 26 23.54 23.95 24.68 25.73 26.57 27.33 28.31 27 23.55 23.97 24.72 25.77 26.58 27.36 28.36 28 23.56 23.99 24.75 25.79 26.61 27.39 28.40 29 23.57 24.01 24.78 25.83 26.62 27.42 28.43 30 23.57 24.03 24.81 25.87 26.64 27.46 28.45 31 23.58 24.84 26.67 27.49 MEAN 23.46 23.78 24.42 25.36 26.33 27.05 27.98 WTR YR 1997 MEAN 25.59 HIGHEST 23.33 MAR. 12, 13, 14, 1997 LOWEST 28.50 SEPT. 30, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 580 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.50 28.92 28.67 28.58 28.62 2 28.54 28.92 28.67 28.58 28.64 3 28.57 28.92 28.66 28.58 28.65 4 28.60 28.93 28.66 28.58 28.65 5 28.63 28.93 28.65 28.59 28.69 6 28.67 28.93 28.65 28.58 28.70 7 28.69 28.93 28.65 28.58 28.70 8 28.71 28.93 28.65 28.58 28.70 9 28.76 28.93 28.65 28.57 28.71 10 28.79 28.93 28.65 28.57 28.72 11 28.80 28.93 28.65 28.57 28.74 12 28.83 28.91 28.65 28.56 28.74 13 28.86 28.89 28.65 28.56 28.75 14 28.88 28.88 28.64 28.55 28.76 15 28.90 28.85 28.64 28.54 28.76 16 28.90 28.85 28.64 28.54 28.76 17 28.91 28.82 28.65 28.53 28.76 18 28.91 28.80 28.64 28.53 28.77 19 28.90 28.79 28.64 28.52 28.78 20 28.90 28.78 28.63 28.52 28.79 21 28.90 28.77 28.63 28.52 28.79 22 28.90 28.76 28.62 28.52 28.80 23 28.90 28.75 28.61 28.52 28.82 24 28.91 28.74 28.61 28.52 28.82 25 28.91 28.73 28.60 28.53 26 28.91 28.72 28.59 28.55 27 28.92 28.71 28.59 28.56 28 28.92 28.70 28.59 28.57 29 28.92 28.69 28.59 28.58 30 28.92 28.68 28.58 28.59 31 28.92 28.58 28.60 MEAN 28.82 28.83 28.63 28.56 28.73 WTR YR 1998 MEAN 28.71 HIGHEST 28.50 OCT. 1, 1997 LOWEST 28.93 FEB. 24, 1998 22 24 26 28 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 30 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 581 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 175950066354200. Local number, 141. LOCATION.--Lat 17°59'50", long 66°35'42", Hydrologic Unit 21010004, 1.71 mi southeast of Plaza Degetau at Ponce, 1.31 mi southeast of the intersection between Hwy 10 and Hwy 2, and 2.60 mi notheast of Muellle de Ponce. Owner: PR Aqueduct and Sewer Authority, Name: Restaurada 8A. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused public supply well, diameter 16-10 in (0.41-0.25 m), cased 16 in (0.41 m) 2.00-20.0 ft (0.6-6.1 m), perforated 20-130 ft (6.10-39.6 m), 10 in (0.25 m) 128-165 ft (39.0-50.3 m), perforated. Depth 165 ft (50.3 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 24.0 ft (7.30 m), above mean sea level, from topographic map. Measuring point: Bottom edge of hole on side of casing 1.90 ft (0.58 m), above land-surface datum, 26.2 ft (7.67 m), above mean sea level. REMARKS.--Recording observation well. Discontinued on Nov. 8, 1994 due to apparent collapsed casing, repair on August 7, 1996. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 12, 1998. PERIOD OF RECORD.--October 1981 to March 1, 1986, discontinued, November 18, 1991 to November 8, 1994, discontinued, August 7, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 11.2 ft (3.41 m), below land-surface datum, Oct. 9, 1985; lowest water level recorded, 28.6 ft (8.71 m), below land-surface datum, July 9, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 26.15 24.45 23.41 23.54 22.84 24.66 24.43 23.51 23.33 21.78 2 26.16 24.55 23.02 23.69 22.81 24.73 24.42 23.54 23.44 21.85 3 26.18 24.60 22.94 23.54 22.71 24.73 24.36 23.64 23.46 21.93 4 25.89 24.49 22.87 23.70 22.71 24.41 24.45 23.63 23.49 21.89 5 25.50 24.55 23.34 23.75 22.69 24.16 24.53 23.57 23.52 21.76 6 25.44 23.87 23.77 22.69 24.20 24.53 23.62 23.49 21.75 7 25.37 24.02 23.83 22.72 24.20 24.52 23.52 23.48 21.71 8 26.01 23.92 23.86 22.70 24.16 24.52 23.51 23.38 21.67 9 26.04 22.92 23.89 22.74 23.99 24.50 23.51 23.25 21.64 10 26.06 23.64 23.87 22.78 24.01 24.54 23.50 23.17 21.74 11 25.96 23.87 23.88 22.81 24.00 24.60 23.64 23.17 21.63 12 25.94 23.98 23.07 23.96 22.68 23.98 24.61 23.68 23.17 21.68 13 25.88 23.96 22.88 23.92 22.64 23.57 24.59 23.67 23.20 21.67 14 25.69 23.98 22.76 23.80 22.57 23.60 24.56 23.69 23.10 21.53 15 25.61 24.04 22.64 23.70 22.52 23.97 24.52 23.71 23.06 21.54 16 25.30 24.13 23.88 22.65 23.74 22.50 23.95 24.24 23.76 22.97 21.38 17 25.00 24.11 24.05 22.60 23.84 22.50 24.09 24.61 23.80 22.96 21.32 18 24.80 23.44 24.07 22.55 23.84 22.50 24.14 24.52 23.77 22.80 21.33 19 24.70 24.06 24.09 22.57 23.87 22.50 24.31 24.46 23.68 22.80 21.31 20 24.55 24.09 24.09 22.06 23.72 22.54 24.35 24.44 23.65 22.77 21.30 21 24.63 23.86 24.14 21.77 23.77 22.56 24.36 24.39 23.62 22.69 21.23 22 24.65 23.98 21.70 23.66 22.56 24.39 21.95 23.62 21.98 17.23 23 24.64 24.05 22.29 23.71 22.58 24.42 20.85 23.53 22.41 15.67 24 24.44 24.07 23.16 23.72 22.63 24.42 20.37 23.64 22.43 14.79 25 24.41 24.08 23.41 23.42 22.63 24.35 20.02 23.63 22.27 14.34 26 24.36 24.10 23.43 23.43 22.55 24.36 21.37 23.61 22.01 14.13 27 24.29 24.09 23.46 23.28 22.44 24.37 22.92 23.54 21.85 17.40 28 24.28 24.09 23.52 23.27 22.43 24.40 23.20 23.44 21.79 18.03 29 24.29 24.11 23.17 21.96 24.39 23.24 23.35 21.80 18.40 30 24.18 24.12 23.19 24.40 24.44 23.41 23.32 21.77 18.71 31 24.35 24.14 22.88 24.41 23.34 21.81 MEAN 25.19 24.53 24.03 23.72 22.74 23.65 22.66 24.24 23.72 23.59 22.80 20.08 WTR YR 1998 MEAN 23.32 HIGHEST 14.12 SEPT. 26, 1998 LOWEST 26.18 OCT. 3, 1997 10 LAND-SURFACE DATUM 20 WATER LEVEL, IN FEET BELOW 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 582 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 175934066364800. Local number, CO-3. LOCATION.--Lat 17°59'34", long 66°36'48", Hydrologic Unit 21010004, 0.35 mi southeast of the intersection of Hwy 10 with Hwy 2, 0.32 mi south of Hwy 2, 0.10 mi southwest of Plaza del Caribe Mall, and 1.90 mi north of Punta Carenero. Owner: Plaza del Caribe, Name: Constancia 3. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 13 in (0.33 m). Depth 84 ft (25.6 m). INSTRUMENTATION.--Electronic water level logger--60-minute punch. DATUM.--Elevation of land-surface datum is 16.0 ft (4.90 m), above mean sea level, from topographic map. Measuring point: Shelter floor on the top of 4 in (0.10 m) casing, 3.12 ft (0.95 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 30, 1996, replaced by an Electronic Data Logger (EDL,) installed during Mar. 19 to April 9, 1997. Automated Digital Recorder (ADR), re-installed on April 9, 1997, replaced by an Electronic Data Logger (EDL), installed on June 4, 1998. PERIOD OF RECORD.--May 30, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 10.83 ft (3.30 m), below land-surface datum, Sept. 30, 1998; lowest water level recorded, 17.96 ft (5.47 m), below land-surface datum, July 19, 20, 21, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.62 17.19 16.51 16.12 2 17.64 17.17 16.51 16.12 3 17.64 17.17 16.50 16.12 4 17.66 17.14 16.50 16.07 5 17.68 17.13 16.50 16.04 6 17.70 17.11 16.49 16.03 7 17.70 17.10 16.49 16.02 8 17.70 17.04 16.49 16.01 9 17.70 17.03 16.49 15.99 10 17.69 16.99 16.49 15.59 11 17.69 16.99 16.49 15.47 12 17.69 16.97 16.49 15.46 13 17.68 16.96 16.49 15.39 14 17.68 16.93 16.49 15.33 15 17.64 16.81 16.49 15.26 16 17.52 16.80 16.48 15.20 17 17.52 16.80 16.43 15.15 18 17.51 16.78 16.41 15.09 19 17.49 16.76 16.38 15.04 20 17.47 16.76 16.38 15.00 21 17.47 16.75 16.36 14.89 22 17.42 16.72 16.35 14.84 23 17.40 16.72 16.28 14.78 24 17.40 16.72 16.28 14.73 25 17.37 16.71 16.28 14.70 26 17.37 16.71 16.28 14.68 27 17.35 16.71 16.28 14.66 28 17.32 16.70 16.28 14.65 29 17.30 16.52 16.28 14.63 30 17.24 16.52 16.28 14.61 31 17.63 16.51 16.12 MEAN 17.63 17.54 16.87 16.41 15.32 WTR YR 1996 MEAN 16.55 HIGHEST 14.59 SEPT. 30, 1996 LOWEST 17.70 JUNE 6-10, 1996 --- --- --- --- --- --- --- --- 583 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS--continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.57 14.32 13.56 13.66 14.08 14.66 15.16 15.88 16.94 17.71 17.86 17.45 2 14.55 14.27 13.54 13.65 14.09 14.68 15.16 15.91 16.96 17.73 17.86 17.43 3 14.52 14.26 13.52 13.64 14.11 14.69 15.17 15.94 16.97 17.75 17.86 17.42 4 14.50 14.25 13.51 13.64 14.13 14.73 15.17 15.99 16.98 17.76 17.82 17.41 5 14.50 14.24 13.51 13.63 14.14 14.74 15.17 16.06 16.99 17.77 17.81 17.38 6 14.49 14.23 13.51 13.63 14.16 14.76 15.16 16.08 17.04 17.78 17.79 17.36 7 14.48 14.22 13.51 13.63 14.18 14.78 15.16 16.10 17.08 17.79 17.79 17.34 8 14.46 14.20 13.52 13.63 14.19 14.80 15.18 16.12 17.09 17.80 17.78 17.32 9 14.45 14.18 13.53 13.65 14.21 14.81 15.21 16.13 17.14 17.80 17.76 17.28 10 14.44 14.03 13.53 13.67 14.23 14.83 15.21 16.15 17.15 17.83 17.74 17.27 11 14.44 14.04 13.53 13.70 14.25 14.85 15.24 16.22 17.17 17.84 17.73 17.27 12 14.44 14.02 13.54 13.72 14.28 14.87 15.27 16.30 17.19 17.86 17.68 17.26 13 14.44 13.97 13.55 13.73 14.31 14.89 15.29 16.32 17.21 17.87 17.68 17.26 14 14.44 13.96 13.55 13.74 14.33 14.92 15.32 16.35 17.23 17.89 17.68 17.26 15 14.46 13.94 13.56 13.76 14.36 14.92 15.33 16.39 17.29 17.91 17.66 17.26 16 14.48 13.94 13.57 13.78 14.38 14.93 15.34 16.45 17.32 17.92 17.62 17.26 17 14.49 13.92 13.60 13.80 14.40 14.96 15.36 16.54 17.35 17.92 17.57 17.26 18 14.50 13.88 13.61 13.83 14.43 15.38 16.55 17.37 17.93 17.53 17.26 19 14.50 13.86 13.64 13.85 14.45 15.01 15.41 16.58 17.40 17.95 17.48 17.27 20 14.42 13.77 13.65 13.87 14.47 15.02 15.44 16.60 17.41 17.96 17.46 17.28 21 14.41 13.76 13.67 13.88 14.52 15.03 15.48 16.64 17.45 17.96 17.46 17.30 22 14.40 13.74 13.68 13.91 14.53 15.04 15.52 16.68 17.47 17.89 17.46 17.31 23 14.39 13.72 13.69 13.91 14.55 15.05 15.54 16.71 17.49 17.89 17.46 17.32 24 14.38 13.70 13.71 13.93 14.57 15.07 15.57 16.74 17.50 17.89 17.46 17.33 25 14.38 13.68 13.71 13.94 14.60 15.10 15.59 16.75 17.53 17.89 17.46 17.34 26 14.38 13.65 13.71 13.95 14.62 15.13 15.63 16.79 17.58 17.89 17.46 17.35 27 14.38 13.63 13.70 13.97 14.63 15.15 15.70 16.81 17.60 17.87 17.46 17.35 28 14.36 13.62 13.70 13.98 14.65 15.16 15.74 16.86 17.63 17.87 17.46 17.35 29 14.35 13.59 13.70 13.99 15.16 15.79 16.89 17.66 17.86 17.46 17.35 30 14.34 13.57 13.69 14.05 15.15 15.84 16.92 17.69 17.86 17.46 17.35 31 14.34 13.66 14.06 15.15 16.93 17.86 17.45 MEAN 14.44 13.94 13.60 13.80 14.35 14.93 15.38 16.43 17.30 17.85 17.62 17.32 WTR YR 1997 MEAN 15.59 HIGHEST 13.61 DEC. 3-7, 1996 LOWEST 17.96 JULY 19, 20, 21, 1997 --- --- --- --- --- --- --- 584 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS--continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.35 16.12 16.10 16.36 16.36 16.23 16.32 15.90 16.08 15.50 15.26 14.04 2 17.37 16.11 16.11 16.34 16.36 16.24 16.32 15.90 16.08 15.50 15.26 14.00 3 17.38 16.09 16.13 16.33 16.38 16.27 16.23 15.91 16.07 15.51 15.25 13.97 4 17.26 16.08 16.14 16.31 16.39 16.30 16.23 15.91 15.91 15.51 15.25 13.79 5 17.24 16.08 16.15 16.30 16.29 16.33 16.23 15.94 15.91 15.50 15.25 13.79 6 17.26 16.07 16.16 16.21 16.28 16.34 16.23 15.95 15.91 15.49 15.24 13.69 7 17.27 16.07 16.18 16.15 16.28 16.35 16.22 15.97 15.91 15.49 15.16 13.67 8 17.28 16.07 16.19 16.15 16.26 16.37 16.22 15.97 15.90 15.48 15.15 13.65 9 17.29 16.08 16.20 16.15 16.23 16.37 16.21 15.97 15.90 15.49 15.08 13.61 10 17.29 16.01 16.21 16.15 16.23 16.38 16.21 15.97 15.87 15.50 15.04 13.59 11 17.10 16.00 16.23 16.16 16.22 16.40 16.21 15.97 15.87 15.51 14.99 13.69 12 17.12 16.00 16.27 16.16 16.21 16.42 15.99 15.97 15.86 15.51 14.97 13.68 13 17.11 16.01 16.29 16.17 16.21 16.43 16.01 15.99 15.85 15.51 14.94 13.64 14 16.86 16.01 16.31 16.19 16.20 16.45 16.02 16.00 15.84 15.52 14.92 13.57 15 16.77 16.02 16.32 16.19 16.19 16.47 16.01 16.01 15.83 15.53 14.89 13.56 16 16.61 16.02 16.34 16.20 16.17 16.50 15.99 16.03 15.82 15.55 14.83 13.22 17 16.57 16.02 16.34 16.21 16.16 16.52 15.99 16.03 15.81 15.57 14.80 13.23 18 16.53 16.02 16.34 16.21 16.16 16.54 15.98 16.05 15.75 15.58 14.78 13.22 19 16.40 16.02 16.36 16.21 16.16 16.56 15.97 16.07 15.75 15.39 14.73 13.21 20 16.37 16.02 16.37 16.21 16.16 16.59 15.97 16.08 15.74 15.43 14.70 13.21 21 16.34 16.02 16.38 16.22 16.17 16.59 15.97 16.09 15.73 15.44 14.68 13.19 22 16.31 16.03 16.38 16.23 16.17 16.59 15.95 16.09 15.55 15.45 14.66 12.13 23 16.30 16.03 16.39 16.26 16.17 16.59 15.95 16.10 15.55 15.45 14.65 11.28 24 16.24 16.04 16.39 16.29 16.18 16.59 15.95 16.11 15.55 15.46 14.62 11.17 25 16.20 16.05 16.40 16.30 16.19 16.58 15.93 16.11 15.54 15.46 14.17 11.06 26 16.17 16.06 16.41 16.31 16.20 16.54 15.91 16.12 15.53 15.47 14.21 10.98 27 16.16 16.07 16.40 16.32 16.22 16.51 15.90 16.12 15.52 15.47 14.20 10.91 28 16.16 16.08 16.39 16.33 16.23 16.47 15.90 16.10 15.49 15.30 14.17 10.87 29 16.16 16.08 16.37 16.33 16.44 15.90 16.10 15.50 15.23 14.14 10.84 30 16.15 16.09 16.37 16.34 16.43 15.90 16.10 15.50 15.26 14.10 10.83 31 16.13 16.36 16.35 16.31 16.09 15.26 14.07 MEAN 16.73 16.05 16.29 16.25 16.23 16.44 16.06 16.02 15.77 15.46 14.78 12.84 WTR YR 1998 MEAN 15.75 HIGHEST 10.83 SEPT. 30, 1998 LOWEST 17.38 OCT. 3, 4, 1997 10 LAND-SURFACE DATUM 15 WATER LEVEL, IN FEET BELOW 20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 585 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASIN 180045066381600. Local number AN-1 LOCATION.--Lat 18°00'45", long 66°38'16", Hydrologic Unit 21010004, 0.27 mi east of the intersection of Hwy 10 with Hwy 132, 0.60 mi northwest of Parque Montaner, and 0.04 mi south of Hwy 132. Owner: Albergue de Niños de Ponce, Name: Albergue de Niños. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 49.0 ft (14.90 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 5.42 ft (1.65 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on February 12, 1998. PERIOD OF RECORD.--March 30, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 28.57 ft (8.71 m), below land-surface datum, Sept. 27, 1998; lowest water level recorded, 51.88 ft (15.81 m), below land-surface datum, Aug. 30, 1994. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30.98 29.63 30.97 32.24 32.47 32.74 33.31 33.87 34.76 34.58 35.82 34.61 2 30.94 29.61 31.05 32.68 32.48 32.81 33.38 33.95 34.82 34.65 35.79 34.51 3 30.97 30.21 31.09 32.21 32.54 32.82 32.85 33.94 35.36 34.94 35.82 34.44 4 30.80 30.30 31.12 32.03 32.47 33.41 33.39 34.00 34.91 35.08 35.87 34.35 5 30.77 30.51 31.21 31.88 32.46 32.99 33.39 33.86 34.95 35.18 35.87 34.24 6 31.26 30.02 31.08 31.77 32.43 33.79 33.41 33.94 34.99 35.27 35.92 34.14 7 30.98 30.12 31.13 32.01 32.34 33.01 33.41 33.99 35.03 35.36 35.94 34.03 8 30.96 30.06 31.28 31.55 32.29 32.92 33.55 34.48 35.09 35.55 35.52 34.20 9 31.07 30.05 31.31 31.52 32.32 33.45 33.81 34.09 35.59 35.51 35.31 33.95 10 30.98 30.25 31.37 31.82 32.36 33.82 33.15 34.08 34.72 35.60 35.32 33.88 11 30.74 30.28 31.46 31.88 32.39 33.36 33.22 34.11 34.60 35.62 35.64 34.28 12 30.60 30.23 31.38 31.97 32.37 34.06 33.35 33.84 34.52 36.11 33.74 13 30.89 30.11 31.41 32.03 32.39 33.55 33.51 33.71 34.49 35.91 33.67 14 30.46 30.06 31.45 32.49 32.37 33.53 33.60 33.74 34.46 35.74 33.67 15 30.36 30.10 31.63 32.14 32.39 33.44 33.59 34.12 34.52 35.75 33.64 16 30.15 30.19 31.56 32.16 32.43 33.56 33.62 34.07 34.90 35.75 33.34 17 30.14 30.37 31.73 32.17 32.45 33.60 34.13 34.15 35.09 35.76 33.40 18 29.99 30.49 31.79 32.15 32.68 33.41 33.72 34.20 35.19 35.74 33.38 19 29.92 30.53 32.28 32.15 32.51 33.41 33.71 34.28 35.31 35.67 33.33 20 29.97 30.60 31.84 32.17 32.55 33.82 33.85 34.33 35.37 35.67 33.28 21 30.09 30.66 31.87 32.21 32.58 33.28 33.90 34.37 35.39 35.60 33.17 22 30.02 30.27 31.96 32.28 32.54 33.24 34.07 34.39 35.47 35.57 31.65 23 29.95 30.35 32.01 32.31 32.54 33.32 33.91 34.44 35.54 35.80 35.58 30.45 24 29.88 31.01 32.36 32.33 32.54 33.34 33.94 34.44 35.57 35.81 35.56 29.69 25 29.68 30.75 32.12 32.33 32.55 33.29 33.95 34.46 35.55 35.82 35.44 29.21 26 29.66 30.82 32.15 32.35 32.54 33.28 33.93 34.53 35.73 35.79 35.29 28.77 27 29.85 30.75 32.13 32.42 33.14 33.24 34.43 35.04 35.19 35.80 35.18 29.03 28 29.70 30.80 32.13 32.42 33.24 33.25 34.05 34.66 35.12 35.82 35.13 29.18 29 29.64 30.81 32.16 32.48 33.23 34.07 34.69 34.84 35.83 34.98 29.15 30 29.67 30.79 32.21 32.47 33.78 33.74 34.70 35.13 35.81 34.80 29.20 31 29.71 32.25 32.43 33.31 34.72 35.83 34.75 MEAN 30.35 30.36 31.66 32.16 32.51 33.36 33.66 34.23 35.07 35.48 35.57 32.59 WTR YR 1998 MEAN 33.02 HIGHEST 28.57 SEPT. 27, 1998 LOWEST 36.27 JULY 27, 1998 20 LAND-SURFACE DATUM 40 WATER LEVEL, IN FEET BELOW 60 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 586 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180156066434000. Local number, LV-1. LOCATION.--Lat 18°01’56", long 66°43'40", Hydrologic Unit 21010004, 1.23 mi north of Hwy 2, 0.10 mi west of Hwy 385, and 0.14 mi east of Río Tallaboa. Owner: CORCO, Name: Luciana Ventura. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. Depth 66.4 ft (20.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute interval. DATUM.--Elevation of land-surface datum is about 66.0 ft (20.1 m), above mean sea level, from topographic map.. Measuring point: Top of shelter floor, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on September 5, 1997. PERIOD OF RECORD.--September 5, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 16.65 ft (5.07 m), below land-surface datum, Sept. 23, 1998; lowest water level recorded, 28.87 ft (8.80 m), below land-surface datum, Sept. 28, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 24.75 6 24.75 7 25.16 8 25.27 9 24.56 10 24.33 11 25.05 12 25.12 13 25.30 14 26.28 15 25.86 16 26.38 17 25.87 18 25.84 19 26.83 20 27.31 21 27.34 22 27.83 23 27.68 24 27.60 25 27.75 26 27.63 27 27.90 28 28.65 29 28.40 30 27.36 31 MEAN 26.42 WTR YR 1997 MEAN 26.42 HIGHEST 24.33 SEPT. 10, 1997 LOWEST 28.87 SEPT. 28, 1997 587 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 26.55 24.42 24.85 --- 2 26.18 24.18 25.07 --- 3 26.13 24.73 24.98 --- 4 25.89 25.04 24.79 --- 5 26.23 25.13 24.63 --- --- --- --- --- --- 23.50 23.97 23.84 --- --- --- --- --- 23.62 24.64 23.70 --- --- --- --- --- 23.31 24.88 23.48 --- --- --- --- --- 23.26 24.83 22.78 --- --- --- --- --- 23.20 24.86 22.54 6 26.58 25.22 24.68 --- 7 27.17 25.16 24.92 --- 8 26.70 25.13 25.29 --- 9 25.13 25.19 25.19 --- 10 24.97 25.14 25.20 --- --- --- --- --- --- 23.58 25.03 22.71 --- --- --- --- --- 23.64 24.79 22.29 --- --- --- --- --- 23.30 24.38 22.76 --- --- --- --- --- 23.34 24.36 22.47 --- --- --- --- --- 23.35 23.94 22.59 11 25.18 25.06 24.57 --- 12 25.06 24.60 25.37 --- 13 24.70 24.16 25.36 --- 14 24.40 24.05 25.51 --- 15 23.90 24.09 25.30 --- --- --- --- --- --- 23.35 23.69 22.68 --- --- --- --- --- 23.39 23.50 22.65 --- --- --- --- --- 24.12 23.62 22.87 --- --- --- --- --- 24.59 23.87 22.76 --- --- --- --- --- 24.73 23.31 23.13 16 23.49 23.86 25.38 --- 17 23.74 23.81 25.39 --- 18 23.65 23.61 25.46 --- 19 23.57 23.63 24.95 --- 20 23.93 23.62 24.93 --- --- --- --- --- 24.66 24.67 23.10 23.21 --- --- --- --- 25.05 24.85 23.08 23.49 --- --- --- --- 24.47 25.08 23.12 23.29 --- --- --- --- 24.39 24.69 23.13 23.73 --- --- --- --- 24.37 24.85 23.25 23.42 21 23.88 24.27 25.09 --- 22 23.91 23.81 25.10 --- 23 24.02 24.33 25.48 --- 24 23.67 24.61 24.63 --- 25 24.15 24.55 24.29 --- --- --- --- --- 24.43 24.77 23.21 23.19 --- --- --- --- 23.93 24.87 23.18 21.26 --- --- --- --- 24.11 24.19 23.08 16.75 --- --- --- --- 23.54 24.51 23.20 --­ --- --- --- --- 23.82 24.67 23.19 --­ 26 24.13 24.70 24.54 --- 27 24.37 24.77 24.90 --- 28 24.50 24.65 25.29 --- 29 24.59 24.84 --- --- 30 24.16 24.87 --- --- 31 24.77 --- --- --- --- --- --- --- 23.69 24.00 23.18 --­ --- --- --- --- 23.25 24.67 23.16 --­ --- --- --- --- 23.71 24.40 23.39 --­ --- --- --- --- 23.47 23.97 23.47 --­ --- --- --- --- 23.28 24.20 23.33 --­ --- --- --- --- --- 24.07 23.53 --­ MEAN 24.82 24.51 25.04 --- --- --- --- --- 24.01 24.09 23.72 22.68 WTR YR 1998 MEAN 24.18 HIGHEST 16.65 SEPT. 23, 1998 LOWEST 27.23 OCT. 7, 1997 15 20 25 30 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 588 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180133066503300. Local number, 132. LOCATION.--Lat 18°01'33", long 66°50'33", Hydrologic Unit 21010004, 0.90 mi southeast of Yauco plaza, 3.46 mi west of Guayanilla plaza, and 1.32 mi north of Escuela Segunda Unidad Barinas. Owner: Pittsburg Plate Glass 4, Name: Yauco 2. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled observation well, cased 20 in (0.51 m) 0-20.0 ft (0-6.10 m), 12 in (0.30 m) perforated pipe 20-84.0 ft (6.10-25.6 m), 10 in (0.25 m) perforated pipe 84-190 ft (25.6-57.9 m). Depth 190 ft (57.9 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 75.0 ft (22.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 2.35 ft (0.72 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 1998. [+, above land-surface datum]. From July 27, 1998, monthly measurements only. PERIOD OF RECORD.--July 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +0.12 ft (0.04 m), above land-surface datum, July 19, 1979; lowest water level recorded, 36.91 ft (11.25 m), below land-surface datum, June 27, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 32.78 24.26 22.81 25.18 22.42 25.88 24.39 22.43 2 32.69 24.26 22.89 25.03 22.47 25.55 24.51 22.29 3 32.48 24.25 22.86 24.90 22.58 25.30 24.57 22.25 4 32.58 24.20 22.97 24.77 22.65 25.00 24.67 22.20 5 32.40 23.11 24.73 22.83 24.81 24.81 6 32.29 24.24 23.13 24.77 22.92 24.66 24.91 7 31.56 24.26 23.26 24.67 22.92 24.65 24.93 8 31.96 24.26 24.59 22.93 24.56 25.02 9 31.05 24.20 24.53 23.03 24.51 25.04 10 29.94 23.98 24.58 23.15 24.50 25.04 11 29.30 23.76 24.63 23.30 24.41 25.00 12 28.60 23.58 24.56 23.45 24.39 25.08 13 28.09 23.34 24.58 23.50 24.25 25.10 14 27.11 23.21 23.67 24.13 25.17 15 26.63 23.14 23.85 23.99 25.10 16 26.23 22.98 23.90 23.93 24.86 17 25.95 22.84 24.03 23.92 24.62 18 25.41 22.64 22.77 24.18 23.79 24.44 19 25.11 22.56 22.57 24.35 23.64 24.39 20 24.85 22.58 22.48 24.49 23.53 24.29 21 24.54 22.55 22.49 24.52 23.60 24.12 22 24.39 22.55 22.38 24.61 23.77 23.91 23 24.74 22.49 22.36 24.81 23.79 23.62 24 24.56 22.54 24.96 22.41 25.00 23.87 23.45 25 24.59 22.61 25.13 22.31 25.14 23.96 23.26 26 24.51 22.57 25.15 22.29 25.20 24.00 23.21 27 24.35 22.67 25.20 22.31 25.27 24.00 23.16 28 24.36 22.61 25.18 22.37 25.38 24.07 23.10 29 24.37 22.71 25.24 25.44 24.18 22.90 30 24.30 22.66 25.35 25.56 24.28 22.77 31 24.22 25.42 25.77 22.60 MEAN 27.61 23.26 24.18 24.73 22.43 23.98 24.30 24.26 22.29 WTR YR 1998 MEAN 24.49 HIGHEST 22.19 JUNE 4, 1998 LOWEST 32.83 OCT. 1, 1997 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Date level July 27 20.78 0 20 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 + above land-surface datum WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 589 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180132067033800. Local number, 143. LOCATION.--Lat 18°01'32", long 67°03'38", Hydrologic Unit 21010003, 1.86 mi south of Lajas plaza, 1.27 mi southeast of the Estación Experimental Agrícola, and 1.30 mi northwest of the intersection of Hwy 116 with Hwy 305. Owner: Pedro P. Vivoni, Name: Vivoni, Hacienda Amistad. AQUIFER.--Limestone of unknown age. WELL CHARACTERISTICS.--Drilled unused irrigation well, diameter 12 in (0.30 m). Depth 200 ft (60.98 m). INSTRUMENTATION.--Electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 52.5 ft (16.0 m), above mean sea level, from topographic map. Measuring point: Hole side of casing, 0.80 ft (0.24 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on January 14, 1998. From July 27, 1998, monthly measurements only. PERIOD OF RECORD.--December 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 37.4 ft (11.4 m), below land, -surface datum, Nov. 20, 1985; lowest water level recorded, 40.85 ft (12.45 m) below land-surface datum, Oct. 8, 9, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 40.75 40.68 40.56 40.70 40.62 40.50 40.63 40.67 40.74 2 40.75 40.68 40.59 40.68 40.62 40.52 40.67 40.66 40.76 3 40.75 40.68 40.61 40.66 40.57 40.52 40.68 40.68 40.77 4 40.78 40.67 40.60 40.64 40.59 40.54 40.67 40.67 40.78 5 40.80 40.68 40.58 40.64 40.48 40.56 40.65 40.70 6 40.83 40.67 40.58 40.67 40.54 40.55 40.66 40.69 7 40.84 40.66 40.62 40.64 40.53 40.57 40.70 40.69 8 40.83 40.63 40.64 40.66 40.53 40.59 40.76 40.67 9 40.83 40.65 40.64 40.67 40.53 40.63 40.77 40.72 10 40.77 40.65 40.63 40.67 40.59 40.64 40.73 40.72 11 40.76 40.67 40.64 40.65 40.62 40.63 40.74 40.70 12 40.71 40.67 40.65 40.66 40.58 40.63 40.72 40.73 13 40.70 40.64 40.64 40.66 40.58 40.65 40.77 40.74 14 40.56 40.63 40.64 40.64 40.58 40.64 40.78 40.72 15 40.58 40.63 40.63 40.64 40.58 40.60 40.78 40.70 16 40.62 40.64 40.62 40.65 40.55 40.60 40.78 40.71 17 40.65 40.63 40.62 40.66 40.52 40.60 40.74 40.73 18 40.66 40.61 40.63 40.64 40.52 40.63 40.69 40.75 19 40.67 40.59 40.66 40.62 40.52 40.63 40.68 40.75 20 40.66 40.57 40.65 40.63 40.52 40.62 40.70 40.77 21 40.65 40.59 40.63 40.63 40.51 40.59 40.71 40.75 22 40.66 40.57 40.65 40.65 40.55 40.62 40.72 40.75 23 40.67 40.58 40.64 40.68 40.53 40.65 40.72 40.76 24 40.66 40.59 40.64 40.66 40.54 40.69 40.73 40.77 25 40.66 40.58 40.65 40.67 40.54 40.73 40.74 40.75 26 40.67 40.57 40.66 40.66 40.52 40.73 40.74 40.75 27 40.66 40.57 40.63 40.67 40.53 40.71 40.71 40.77 28 40.67 40.60 40.63 40.68 40.52 40.68 40.70 40.76 29 40.69 40.58 40.65 40.66 40.67 40.72 40.75 30 40.68 40.55 40.67 40.62 40.63 40.71 40.75 31 40.67 40.69 40.60 40.61 40.75 MEAN 40.70 40.62 40.63 40.65 40.55 40.62 40.72 40.73 40.76 WTR YR 1998 MEAN 40.66 HIGHEST 40.42 FEB. 5, 1998 LOWEST 40.85 OCT. 8, 9, 1997 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATIONS Water Date level July 27 40.84 Water Date level Sept. 17 40.32 38 39 40 41 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 590 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180541067084000. Local number, CR-1. LOCATION.--Lat 18°05'41", long 67°08'40", Hydrologic Unit 21010003, 0.35 mi east of Hwy 311, 0.30 mi north of Hwy 102 in Central Cabo Rojo, and 0.50 mi norhwest of the intersection of Hwy 102 with hwy 103. Owner: PR Aqueduct and Sewer Authority, Name: Cabo Rojo 1. AQUIFER.--Coquí Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.30 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 18.9 ft (12.0 m), above mean sea level, from topographic map. Measuring point: Hole in the side of the 12.0 in (0.30 m) casing, 1.30 ft (0.40 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 25, 1996. PERIOD OF RECORD.--May 25, 1996 to September 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.37 ft (2.86 m), below land-surface datum, Sept. 27, 1998; lowest water level recorded, 28.41 ft (8.66 m) below land-surface datum, Apr. 8, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.18 16.73 18.10 15.55 2 14.20 17.18 17.56 15.51 3 14.27 17.35 17.28 15.65 4 14.53 17.22 16.69 15.73 5 14.78 17.18 16.39 15.66 6 14.91 17.30 16.36 15.60 7 14.31 17.20 16.42 16.06 8 14.84 17.36 16.08 16.12 9 14.87 16.75 15.62 16.55 10 15.00 17.16 15.68 15.81 11 15.21 17.36 15.06 15.90 12 15.37 17.39 14.77 15.86 13 15.50 17.69 14.67 15.88 14 15.20 17.54 14.58 16.04 15 15.39 17.53 14.35 16.17 16 15.47 16.93 14.46 16.27 17 15.54 17.36 14.67 16.53 18 15.66 17.22 14.51 16.71 19 15.85 17.36 14.50 16.83 20 15.77 17.40 14.84 16.86 21 15.89 17.29 14.99 17.10 22 15.97 17.26 15.27 16.65 23 16.02 17.53 15.55 16.76 24 16.18 17.64 15.45 16.78 25 16.41 17.89 15.05 16.98 26 16.61 17.98 14.82 17.17 27 16.73 18.12 15.17 17.08 28 16.94 17.99 15.13 17.23 29 16.84 17.77 15.17 16.95 30 13.87 16.67 17.74 15.34 16.75 31 13.95 18.01 15.54 MEAN 13.91 15.50 17.43 15.49 16.36 WTR YR 1996 MEAN 16.16 HIGHEST 13.76 MAY 29, 1996 LOWEST 18.29 JULY 31, 1996 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 591 GROUND-WATER LEVELS RIO GUANAJIBO BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 16.69 15.13 12.12 18.79 17.72 18.50 20.10 21.93 24.75 2 16.69 15.76 12.26 18.87 17.80 18.55 20.11 22.05 24.80 3 16.51 15.55 12.67 19.01 17.79 18.72 20.37 22.21 24.89 4 16.34 15.57 13.14 18.90 17.56 18.97 20.31 22.19 24.83 5 15.98 15.83 13.38 18.93 17.53 19.15 20.38 22.34 24.76 6 15.38 15.71 15.08 19.00 17.27 19.21 20.32 22.49 24.75 7 15.10 15.66 15.24 19.03 16.98 19.27 20.31 22.57 25.15 8 15.03 15.78 15.50 19.29 17.05 19.21 20.35 22.49 25.38 9 14.97 15.74 15.67 19.09 16.95 19.22 20.35 22.61 25.24 10 14.85 15.23 15.86 18.53 16.95 19.26 20.52 22.48 25.40 11 14.86 15.07 16.08 18.05 16.86 19.41 20.43 22.53 25.46 12 14.88 14.98 16.20 17.67 16.77 19.39 20.54 22.53 25.56 13 14.72 14.41 16.25 17.50 16.82 19.51 20.68 23.36 25.69 14 14.66 14.34 16.37 17.58 17.03 19.60 20.69 23.53 26.02 15 14.68 13.96 16.71 17.83 17.13 19.75 21.00 23.73 26.04 16 14.66 13.52 17.02 17.73 17.28 19.78 20.95 23.98 26.14 17 14.68 13.32 16.95 17.74 17.55 19.78 20.98 24.11 18 14.96 13.15 17.09 17.83 17.80 19.86 20.99 24.11 19 15.01 12.81 17.25 17.88 17.83 19.86 20.88 24.15 20 14.95 12.42 17.24 17.83 17.88 19.95 20.89 24.15 21 14.70 12.46 17.53 18.02 18.20 20.17 21.11 24.27 22 14.75 12.32 17.66 17.81 18.19 20.24 21.04 24.27 23 15.20 12.05 17.90 17.63 18.22 20.24 21.25 24.27 24 15.42 11.78 18.19 17.58 18.32 20.28 21.29 24.34 25.97 25 15.38 11.77 18.44 17.48 18.45 20.38 21.28 24.31 26.05 26 15.26 12.06 18.51 17.43 18.44 20.54 21.30 24.43 25.94 27 15.02 11.93 18.65 17.44 18.43 20.58 21.44 24.54 25.89 28 14.94 12.00 18.63 17.42 18.42 20.60 21.56 24.63 25.93 29 15.13 11.86 18.58 17.19 20.59 21.80 24.69 25.96 30 15.45 11.87 18.66 17.43 20.45 21.85 24.77 25.44 31 15.29 18.60 17.69 20.37 24.89 MEAN 15.23 13.80 16.43 18.07 17.61 19.72 20.84 23.51 25.30 25.88 WTR YR 1997 MEAN 18.80 HIGHEST 11.63 NOV. 25, 1996 LOWEST 26.39 JUNE 16, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 592 GROUND-WATER LEVELS RIO GUANAJIBO BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.87 18.39 20.35 23.56 26.16 24.94 27.75 19.95 2 24.50 18.56 20.46 23.58 26.42 25.01 27.78 19.40 3 24.03 18.75 20.60 23.59 26.57 25.37 27.90 18.74 4 23.89 18.85 20.80 23.63 26.62 25.54 28.00 17.98 5 23.59 18.96 20.86 23.69 26.43 25.81 28.04 17.48 6 23.50 18.97 20.86 23.75 26.16 26.01 28.05 17.01 7 23.38 18.72 20.92 23.77 25.98 26.08 28.19 16.45 8 23.00 19.03 20.96 23.91 25.59 26.22 28.41 16.21 9 22.47 19.22 21.09 24.09 25.43 26.32 16.11 10 21.90 19.14 21.28 24.33 25.47 26.70 16.43 11 21.54 19.14 21.31 24.23 25.34 26.88 16.66 12 21.14 19.11 21.42 24.03 25.21 27.04 16.93 13 20.81 19.20 21.63 23.92 25.02 27.04 16.96 14 20.16 19.23 21.71 24.10 24.89 26.99 16.92 15 19.16 19.35 21.82 24.30 24.82 26.85 16.98 16 18.33 19.33 22.23 24.42 24.64 26.84 16.73 17 17.74 19.45 22.32 24.54 24.65 26.78 17.06 18 17.36 19.61 22.48 24.62 24.69 26.78 17.37 19 17.10 19.58 22.56 24.77 24.61 26.88 17.70 20 16.97 19.55 22.69 24.86 24.62 26.92 18.09 21 17.00 19.59 22.61 25.07 24.64 26.97 18.00 22 17.03 19.67 22.76 25.35 24.73 26.94 14.31 23 17.08 19.79 22.89 25.46 24.68 26.90 11.45 24 17.52 19.86 23.14 25.56 24.80 26.97 10.54 25 17.51 20.04 23.16 25.53 24.87 27.07 9.98 26 17.73 20.18 23.08 25.55 24.81 27.10 9.58 27 17.82 20.31 23.11 25.60 24.95 27.37 9.50 28 17.87 20.46 23.27 25.64 25.05 27.46 11.23 29 17.96 20.37 23.27 25.78 27.60 12.56 30 18.06 20.44 23.39 26.03 27.68 13.55 31 18.23 23.50 26.14 27.85 20.02 MEAN 19.98 19.43 22.02 24.63 25.28 26.67 28.01 20.02 15.60 WTR YR 1998 MEAN 22.15 HIGHEST 9.37 SEPT. 27, 1998 LOWEST 28.41 APR. 8, 1998 0 10 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 593 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180628067084300. Local number, CR-TW9A. LOCATION.--Lat 18°06'28", long 67°08'43", Hydrologic Unit 21010003, 1.29 mi north of Cabo Rojo plaza, 1.54 mi northwest of Escuela Segunda Unidad Antonio Acarón Correa, and 1.23 mi southeast of Escuela Sabana Alta. Owner: US Geological Survey, WRD, Name: CR-TW-9A. AQUIFER.--Sandy and clay. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-24.0 ft (0-7.32 m), screened 19-24 ft (5.79-7.32 m). Depth 24.0 ft (7.32 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 33.2 ft (10.1 m), above mean sea level, from topographic map. Measuring point: Hole on shelter floor, 4.51 ft (1.37 m), above land-surface datum. REMARKS.--Recording observation well. Drilled on Mar. 25, 1992. Automatic Digital Recorder (ADR), re-installed on May 29, 1996. PERIOD OF RECORD.--July 1992 to January 1994, discontinued, May 27, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +0.24 ft (+0.07 m), below land-surface datum, Oct. 12, 1992; lowest water level recorded, 8.53 ft (2.60 m), below land-surface datum, Mar. 21, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.95 3.37 4.02 5.62 7.17 7.41 3.07 2 4.71 3.44 4.09 5.66 7.17 7.51 2.56 3 4.55 3.49 4.11 5.73 7.17 7.60 1.96 4 4.46 3.53 4.14 5.77 7.17 7.71 1.60 5 4.40 3.59 4.18 5.83 7.16 7.83 1.74 6 4.37 3.60 4.22 5.89 7.06 7.91 1.53 7 4.34 3.60 4.27 5.94 6.84 8.01 .92 8 4.30 3.60 4.33 5.98 6.74 8.15 1.47 9 3.87 3.64 4.34 6.07 6.57 8.24 1.86 10 3.53 3.63 4.38 6.17 6.57 8.34 2.08 11 3.24 3.60 4.42 6.25 6.57 8.48 2.27 12 3.16 3.61 4.45 6.35 6.57 8.51 2.43 13 3.08 3.61 4.49 6.41 6.57 8.51 2.32 14 1.85 3.62 4.55 6.46 6.57 8.51 2.39 15 1.18 3.65 4.62 6.56 6.57 8.52 2.52 16 1.39 3.65 4.71 6.70 6.57 8.52 2.56 17 1.71 3.66 4.75 6.85 6.57 8.52 2.60 18 1.89 3.66 4.81 6.97 6.59 8.52 2.67 19 2.09 3.66 4.86 7.09 6.65 8.52 2.50 20 2.27 3.69 4.88 7.13 6.74 8.52 2.52 21 2.44 3.73 4.94 7.16 6.80 2.54 22 2.63 3.76 5.02 7.16 6.90 23 2.74 3.80 5.06 7.16 6.96 24 2.84 3.85 5.11 7.16 7.05 25 2.95 3.87 5.18 7.16 7.13 26 3.03 3.91 5.25 7.16 7.14 27 3.10 3.91 5.30 7.16 7.27 28 3.17 3.95 5.39 7.16 7.36 29 3.23 3.96 5.46 7.16 30 3.26 3.96 5.53 7.16 31 3.30 5.61 7.17 3.07 MEAN 3.16 3.69 4.72 6.59 6.86 8.19 3.07 2.20 WTR YR 1998 MEAN 5.00 HIGHEST 0.87 SEPT. 7, 1998 LOWEST 8.53 MAR. 21, 1998 0 LAND-SURFACE DATUM 5 WATER LEVEL, IN FEET BELOW 10 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 594 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180628067084301. Local number, CR-TW9B. LOCATION.--Lat 18°06'28", long 67°08'43", Hydrologic Unit 21010003, 1.29 mi north of Cabo Rojo plaza, 1.54 mi northwest of Escuela Segunda Unidad Antonio Acarón Correa, and 1.23 mi southeast of Escuela Sabana Alta. Owner: US Geological Survey, WRD, Name: CR-TW-9B. AQUIFER.--Cotuí Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m), 0-109 ft (0-33.2m), screened 104-109 ft (31.7-33.2 m). Depth 109 ft (33.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 33.2 ft (10.1 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 4.73 ft (1.44 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 29, 1996. PERIOD OF RECORD.--May 29, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.18 ft (1.88 m), below land-surface datum, Nov. 23, 1996; lowest water level recorded, 23.38 ft (7.13 m), below land-surface datum, May 18, 19, 20, 1998. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.21 9.42 2 8.42 9.59 3 9.79 4 9.80 5 9.76 6 9.95 7 9.96 8 9.86 10.22 9 9.47 10.45 10 9.20 10.04 11 9.56 12 9.45 13 8.34 9.27 14 8.10 9.38 15 7.95 9.59 16 7.89 9.81 17 7.92 10.01 18 8.13 10.13 19 8.31 10.23 20 8.50 10.33 21 8.68 10.45 22 8.90 10.58 23 9.06 10.51 24 9.16 10.45 25 9.01 10.62 26 9.07 10.84 27 9.11 10.81 28 9.21 10.87 29 9.21 10.70 30 7.91 9.25 10.61 31 8.02 9.32 MEAN 7.97 8.32 8.80 10.11 WTR YR 1996 MEAN 9.45 HOGHEST 7.92 MAY 29, 1996 LOWEST 10.88 SEPT. 28, 1996 --- --- --- --- --- --- --- 595 GROUND-WATER LEVELS RIO GUANAJIBO BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10.47 9.71 7.60 11.67 11.17 12.95 13.98 15.78 18.14 19.85 23.19 15.79 2 10.37 9.90 7.71 11.67 11.28 12.98 14.01 15.93 18.19 19.99 23.16 15.74 3 9.85 10.12 7.96 11.67 11.43 13.02 14.04 16.05 18.27 20.14 22.46 15.68 4 9.45 10.30 8.34 11.67 11.42 13.05 14.08 16.15 18.33 20.28 21.89 15.59 5 9.18 10.42 8.79 11.67 11.23 13.08 14.11 16.21 18.41 20.39 21.55 15.50 6 9.01 10.49 8.99 11.67 11.10 13.12 14.14 16.24 18.29 20.57 21.27 15.46 7 8.93 10.56 9.12 11.67 10.97 13.15 14.18 16.32 18.46 20.77 21.04 15.41 8 8.93 10.60 9.30 11.66 10.91 13.18 14.21 16.38 18.60 20.90 20.85 15.42 9 8.95 10.21 9.47 11.66 10.93 13.22 14.24 16.45 18.75 21.08 20.61 15.46 10 9.10 9.77 9.60 11.54 11.07 13.25 14.27 16.47 18.87 21.28 20.46 15.45 11 9.25 9.49 9.70 11.11 11.15 13.28 14.31 16.56 18.99 21.46 19.89 15.50 12 9.19 9.30 9.77 10.71 11.15 13.32 14.34 16.66 19.12 21.59 19.64 15.52 13 9.31 8.33 9.87 10.54 11.13 13.35 14.37 16.77 19.26 21.72 19.44 15.49 14 9.41 7.86 9.94 10.55 11.25 13.38 14.41 16.89 19.43 21.89 18.96 15.54 15 9.52 7.58 10.17 10.84 11.51 13.41 14.44 17.00 19.59 22.03 18.47 15.54 16 9.56 7.41 10.42 10.96 11.80 13.45 14.47 17.09 19.76 22.16 18.16 15.61 17 9.61 7.32 10.53 10.98 12.03 13.48 14.55 17.22 19.94 22.29 17.89 15.64 18 9.60 7.23 10.58 11.00 12.25 13.51 14.63 17.34 20.16 22.42 17.64 15.64 19 9.51 6.84 10.64 11.08 12.38 13.55 14.71 17.45 20.03 22.44 17.42 15.65 20 9.51 6.72 10.70 11.17 12.50 13.58 14.82 17.58 19.81 22.50 17.25 15.66 21 9.55 6.70 10.87 11.20 12.58 13.61 14.96 17.68 19.77 22.57 17.10 15.69 22 9.58 6.30 11.10 11.15 12.72 13.65 15.01 17.73 19.73 22.63 16.96 15.72 23 9.65 6.19 11.29 10.91 12.75 13.68 15.09 17.82 19.61 22.70 16.87 15.93 24 9.88 6.30 11.47 10.73 12.79 13.71 15.16 17.88 19.57 22.77 16.76 15.98 25 10.04 6.53 11.61 10.67 12.82 13.75 15.24 17.86 19.54 22.84 16.50 16.05 26 9.82 6.77 11.67 10.71 12.85 13.78 15.31 17.85 19.52 22.93 16.38 16.07 27 9.63 7.01 11.67 10.75 12.89 13.81 15.42 17.88 19.52 23.05 16.20 16.08 28 9.41 7.26 11.67 10.70 12.92 13.84 15.48 17.88 19.55 23.17 16.05 16.14 29 9.23 7.36 11.67 10.60 13.88 15.56 17.93 19.65 23.29 15.98 16.12 30 9.60 7.41 11.67 10.75 13.91 15.66 18.02 19.75 23.31 16.01 15.10 31 9.72 11.67 10.99 13.94 18.08 23.24 15.84 MEAN 9.51 8.27 10.18 11.12 11.82 13.45 14.64 17.07 19.22 21.88 18.77 15.67 WTR YR 1997 MEAN 14.32 HIGHEST 6.18 NOV. 13, 1996 LOWEST 23.31 JULY 29, 30, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 596 GROUND-WATER LEVELS RIO GUANAJIBO BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.39 8.96 11.43 14.85 17.57 15.46 18.52 22.72 19.71 16.79 14.02 2 13.89 9.16 11.57 14.88 17.72 15.50 18.55 22.76 19.62 16.79 14.13 3 13.55 9.33 11.67 14.92 17.87 15.64 18.69 22.82 19.56 16.59 14.13 4 13.23 9.46 11.72 14.97 18.04 15.91 18.80 22.82 19.42 16.34 14.13 5 13.06 9.61 11.79 15.03 17.63 16.15 18.92 22.89 19.29 16.19 14.14 6 12.94 9.68 11.88 15.08 17.09 16.35 19.07 23.01 19.02 16.07 14.17 7 12.82 9.65 12.02 15.13 16.59 16.56 19.25 23.01 18.89 15.94 13.94 8 12.54 9.61 12.13 15.19 16.20 16.77 19.41 23.01 18.79 15.87 13.70 9 11.96 9.85 12.20 15.29 15.87 16.98 19.56 22.98 18.74 15.83 13.38 10 11.12 9.91 12.30 15.39 15.65 17.13 19.74 23.02 18.65 15.77 13.14 11 10.76 10.00 12.38 15.45 15.51 17.29 19.94 23.06 18.60 15.55 12.66 12 10.44 10.08 12.48 15.42 15.37 17.45 20.05 23.14 18.59 15.36 12.45 13 10.23 10.16 12.65 15.26 15.25 17.59 20.19 23.22 18.59 15.21 12.30 14 8.93 10.21 12.79 15.22 15.13 17.72 20.32 23.29 18.57 15.11 12.21 15 8.36 10.29 12.92 15.42 15.03 17.64 20.49 23.34 18.59 15.04 12.18 16 7.87 10.35 13.12 15.60 14.97 17.55 20.72 23.35 18.66 14.94 12.18 17 7.48 10.42 13.28 15.77 14.91 17.61 20.99 23.35 18.69 14.89 12.22 18 7.20 10.49 13.38 15.92 14.91 17.61 21.16 23.38 18.24 14.68 12.27 19 7.09 10.54 13.51 16.08 14.93 17.64 21.36 23.38 18.09 14.41 12.33 20 7.07 10.60 13.64 16.22 14.97 17.68 21.54 23.38 17.98 14.28 12.41 21 7.13 10.66 13.73 16.37 15.00 17.72 21.72 23.15 17.87 14.13 12.38 22 7.23 10.73 13.85 16.48 15.09 17.81 21.90 22.42 17.72 14.03 12.44 23 7.37 10.83 13.98 16.60 15.12 17.88 22.07 21.91 17.51 13.88 12.48 24 7.64 10.94 14.08 16.73 15.18 17.90 22.24 21.52 17.33 13.84 12.57 25 7.87 10.97 14.16 16.83 15.24 18.04 22.39 21.21 17.29 13.81 11.73 26 8.06 11.06 14.26 16.92 15.29 18.11 22.55 20.87 17.17 13.76 11.15 27 8.29 11.14 14.33 17.00 15.36 18.17 22.66 20.63 17.03 13.70 10.61 28 8.47 11.24 14.44 17.10 15.44 18.24 22.70 20.40 16.93 13.66 10.07 29 8.49 11.31 14.54 17.16 18.33 22.77 20.20 16.86 13.72 9.81 30 8.61 11.35 14.65 17.28 18.43 22.78 20.02 16.80 13.85 9.69 31 8.71 14.77 17.41 18.54 19.86 13.91 MEAN 9.77 10.29 13.09 15.90 15.82 17.34 20.70 22.39 18.29 14.97 12.50 WTR YR 1998 MEAN 15.55 HIGHEST 7.07 OCT. 19, 20, 1997 LOWEST 23.38 MAY 18, 19, 20 1998 0 10 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 597 GROUND-WATER LEVELS RIO YAGÜEZ AND RIO GRANDE AÑACO BASINS 181232067083700. Local number, CI-1. LOCATION.--Lat 18°12'32", long 67°08'37", Hydrologic Unit 21010003,0.10 mi east of Hwy 2, 0.92 mi southeast of the intersection of Hwy 104 with Hwy 2, and 0.20 mi southwest of the University of Puerto Rico, Mayagüez Campus. Owner: Cervecería India, Name: Cervecería India. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled emergency use water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-100 ft (0-30.5 m), perforated 85-95.0 ft (25.9-28.9 m). Depth 100 ft (30.5 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minute interval. DATUM.--Elevation of land-surface datum is about 10.0 ft (3.05 m), above mean sea level. Measuring point: Top of shelter floor, 2.80 ft (0.85 m), above land-surface datum. Prior to Nov. 20, 1992, hole on side of casing, 2.00 ft (0.61 m), above land-surface datum. REMARKS.--Recording observation well. Eletronic Data Logger (EDL), installed on August 29, 1997. PERIOD OF RECORD.--August 29, 1997 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 4.89 ft (1.49 m), below land-surface datum, Oct. 15, 1997; lowest water level recorded, 18.82 ft (5.74 m), below land-surface datum, Oct. 22, 1997. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.54 2 5.55 3 5.55 4 5.49 5 5.48 6 5.49 7 5.50 8 5.51 9 5.52 10 5.55 11 5.86 12 5.72 13 5.57 14 5.53 15 5.53 16 5.56 17 5.55 18 5.57 19 5.60 20 5.63 21 5.58 22 5.51 23 5.31 24 5.30 25 5.27 26 5.28 27 5.34 28 5.38 29 5.40 30 5.53 5.27 31 5.52 MEAN 5.53 5.50 WTR YR 1997 MEAN 5.50 HIGHEST 5.10 SEPT. 29, 1997 LOWEST 6.59 SEPT. 10, 1997 598 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO YAGÜEZ AND RIO GRANDE AÑACO BASINS-Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.24 5.76 5.70 6.05 5.94 6.17 6.23 7.49 5.78 --- --- --­ 2 5.25 5.79 5.75 6.02 5.94 6.14 6.26 6.66 5.78 --- --- --­ 3 5.29 5.80 5.77 6.01 5.92 6.16 6.27 6.57 5.80 --- --- --­ 4 5.35 5.82 5.79 5.97 5.91 6.17 6.29 9.79 5.79 --- --- --­ 5 5.39 5.89 5.80 5.95 5.87 6.24 6.29 6.70 5.81 --- --- --­ 6 5.33 18.73 5.81 5.95 5.88 6.22 6.28 6.55 5.82 --- --- --­ 7 5.33 6.42 5.84 5.94 5.89 6.22 6.31 6.44 5.86 --- --- --­ 8 5.36 6.10 5.85 5.77 5.91 6.22 6.30 6.42 5.87 --- --- --­ 9 5.40 6.12 5.87 5.74 5.84 6.21 6.29 6.40 5.85 --- --- --­ 10 5.27 5.99 5.89 5.74 5.85 6.22 6.27 6.40 5.68 --- --- --­ 11 5.19 5.94 5.90 5.74 12 5.11 5.66 5.92 5.65 13 5.08 5.58 5.94 5.54 14 4.95 5.56 5.95 5.54 15 4.96 5.59 5.95 5.56 5.87 6.23 6.25 6.38 5.63 --- --- --- 5.90 6.25 6.25 6.40 5.64 --- --- --- 5.91 6.28 6.27 6.40 5.66 --- --- --- 5.93 6.30 6.30 6.41 5.66 --- --- --- 5.95 6.22 6.31 6.38 5.68 --- --- --­ 16 4.93 5.58 5.97 5.59 17 4.99 5.58 5.99 5.63 18 5.07 5.60 6.00 5.66 19 5.13 5.63 6.02 5.68 20 5.17 5.57 6.04 5.68 5.97 6.16 6.32 6.31 --- --- --- --- 5.96 6.15 6.33 6.28 --- --- --- --- 5.98 6.10 6.35 6.25 --- --- --- --- 6.01 6.09 6.37 6.21 --- --- --- --- 6.03 6.08 6.38 6.20 --- --- --- --­ 21 5.22 5.59 6.04 5.80 22 5.29 5.62 6.04 5.76 23 6.46 5.65 6.04 5.77 24 5.84 5.66 6.05 5.80 25 5.71 5.68 6.06 5.83 6.28 6.09 6.39 6.19 --- --- --- --- 6.63 6.11 6.42 6.13 --- --- --- --- 6.23 6.14 6.67 6.15 --- --- --- --- 6.17 6.16 6.53 6.06 --- --- --- --- 6.17 6.19 6.49 6.00 --- --- --- --­ 26 5.68 5.69 6.06 5.84 27 5.66 5.66 6.06 5.85 28 5.68 5.66 6.07 5.87 29 5.70 5.68 6.07 5.89 30 5.71 5.69 6.09 5.89 31 5.73 --- 6.06 5.92 6.16 6.20 6.47 5.87 --- --- --- --- 6.16 6.21 6.46 5.86 --- --- --- --- 6.16 6.21 6.48 5.86 --- --- --- --­ --- 6.21 6.75 5.79 --- --- --- --­ --- 6.20 7.70 5.74 --- --- --- --­ --- 6.20 --- 5.72 --- --- --- --­ MEAN 5.37 6.18 5.95 5.79 6.01 6.19 6.41 6.39 5.75 --- --- --­ WTR YR 1998 MEAN 6.02 HIGHEST 4.89 OCT. 15, 1997 LOWEST 18.82 OCT. 22, 1997 0 5 10 15 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 599 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 181911067140500. Local number, C-4. LOCATION.--Lat 18°19'11", long 67°14'05", Hydrologic Unit 21010003, 0.32 mi east of the intersection of Hwy 429 with Hwy 115, 0.75 mi northwest of the intersection of Hwy 411 with Hwy 115, and 0.01 mi north of Hwy 115. Owner: PR Aqueduct and Sewer Authority, Name: Rincón-Calvache 4. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.30 m). Depth 80 ft (24.8 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 23.0 ft (7.00 m), above mean sea level, from topographic map. Measuring point: Hole in the side of the 12 in (0.30 m) casing, 1.07 ft (0.33 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 30, 1996. Station discontinued on July 1, 1997 due to nearby highway construction. Well depth from specific conductance profile conducted on April 18, 1996. PERIOD OF RECORD.--May 30, 1996 to Jult 1, 1997, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.63 ft (2.02 m), below land-surface datum, Oct. 23, 1996; lowest water level recorded, 18.19 ft (5.54 m), below land-surface datum, June 2, 4, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 18.16 12.86 11.96 2 18.17 12.81 11.72 3 18.18 12.77 11.11 4 18.15 12.72 10.74 5 17.92 12.71 10.10 6 16.99 12.71 10.02 7 16.80 12.81 11.06 8 16.68 12.75 11.11 9 16.62 12.74 11.16 10 16.59 12.74 11.21 11 16.46 12.75 10.69 12 16.38 12.74 10.57 13 15.78 12.68 10.51 14 15.61 12.68 10.51 15 15.46 12.65 10.24 16 15.34 12.41 10.18 17 14.47 12.36 10.19 18 13.76 12.34 10.11 19 13.42 12.23 10.04 20 13.30 12.19 10.06 21 13.24 12.19 10.18 22 13.16 12.19 10.30 23 13.14 12.19 9.74 24 13.11 12.23 9.76 25 13.05 12.24 9.79 26 13.05 12.29 27 13.03 12.29 28 13.01 12.33 29 13.11 12.29 30 18.18 12.96 12.27 31 18.15 12.23 MEAN 18.17 15.17 12.50 10.52 WTR YR 1996 MEAN 12.98 HIGHEST 9.67 AUG. 24, 25, 1996 LOWEST 18.19 JUNE2, 4, 1996 600 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS RIO CULEBRINAS BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 7.77 8.35 --- 8.90 10.34 12.42 15.00 16.48 --- --- --­ 2 --- 7.07 8.46 --- 9.05 10.41 12.38 15.11 16.33 --- --- --­ 3 7.84 7.25 8.57 --- 9.17 10.57 12.42 15.24 16.31 --- --- --­ 4 8.05 7.40 8.70 --- 9.26 10.56 12.56 15.33 16.29 --- --- --­ 5 8.11 7.57 8.81 --- 9.35 10.57 12.61 15.39 16.29 --- --- --­ 6 8.21 7.79 8.91 --- 9.42 10.61 12.73 15.48 16.29 --- --- --­ 7 8.36 7.96 8.98 --- 9.51 10.71 12.85 15.56 16.35 --- --- --­ 8 8.57 8.09 9.06 --- 9.52 10.80 12.95 15.64 16.45 --- --- --­ 9 8.64 8.21 9.14 --- 9.54 10.87 13.10 15.56 16.52 --- --- --­ 10 8.59 8.36 9.16 --- 9.53 11.01 13.12 15.54 16.63 --- --- --­ 11 8.64 8.50 9.15 --- 12 8.76 8.56 9.17 --- 13 8.85 8.41 9.19 --- 14 8.78 8.45 9.22 --- 15 7.57 8.44 9.25 --- 9.56 11.07 13.19 15.62 16.64 --- --- --- 9.60 11.18 13.29 15.70 16.71 --- --- --- 9.66 11.26 13.38 15.78 16.79 --- --- --- 9.73 11.36 13.46 15.87 16.73 --- --- --- 9.79 11.40 13.55 15.95 16.77 --- --- --­ 16 7.47 8.58 9.30 --- 17 7.63 8.06 9.39 --- 18 7.75 7.60 --- --- 19 7.92 6.98 --- --- 20 8.12 7.05 --- --- 9.85 11.48 13.61 16.02 16.84 --- --- --- 9.91 11.56 13.71 16.08 16.91 --- --- --- 9.99 11.66 13.79 16.28 17.04 --- --- --- 10.02 11.78 13.88 16.29 17.09 --- --- --- 10.04 11.74 13.98 16.32 16.68 --- --- --­ 21 8.26 7.07 --- --- 22 6.72 7.14 --- --- 23 6.74 7.24 --- --- 24 7.03 7.38 --- 8.02 25 7.40 7.55 --- 8.13 10.10 11.79 14.07 16.38 16.48 --- --- --- 10.07 11.91 14.20 16.46 16.36 --- --- --- 10.13 12.02 14.26 16.50 16.37 --- --- --- 10.16 12.13 14.34 16.54 16.33 --- --- --- 10.14 12.26 14.47 16.60 16.40 --- --- --­ 26 7.70 7.74 --- 8.25 27 7.92 7.89 --- 8.38 28 8.07 8.03 --- 8.51 29 7.78 8.15 --- 8.63 30 7.87 8.26 --- 8.73 31 8.04 --- --- 8.81 10.19 12.34 14.51 16.65 16.46 --- --- --- 10.24 12.33 14.59 16.58 16.37 --- --- --- 10.29 12.40 14.69 16.52 16.38 --- --- --­ --- 12.43 14.79 16.53 16.48 --- --- --­ --- 12.49 14.90 16.60 16.57 --- --- --­ --- 12.54 --- 16.67 --- --- --- --­ MEAN 7.98 7.82 8.99 8.43 9.74 11.47 13.59 15.99 16.54 --- --- --­ WTR YR 1997 MEAN 11.60 HIGHEST 6.63 OCT. 23, 1996 LOWEST 17.10 JUNE 19, 1997 5 10 15 20 Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept Oct Nov Dec Jan Feb Mar Apr May June July Aug Sept 1996 1997 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 601 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182017067143300. Local number, R-4. LOCATION.--Lat 18°20'17", long 67°14'33", Hydrologic Unit 21010003, 0.63 mi southeast of the intersection of Hwy 412 with Hwy 115, 1.13 mi south of the intersection of Hwy 413 with Hwy 115, and 0.01 mi north of Hwy 411. Owner: PR Aqueduct and Sewer Authority, Name: Rincón 4. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.30 m), cased 0-69.0 ft (0-21.0 m). Depth 64.0 ft (21.0 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 39.0 ft (11.9 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4 in (0.10 m) casing, 3.53 ft (1.08 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 30, 1996. PERIOD OF RECORD.--May 30, 1996 to September 30, 1998. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 20.80 ft (6.34 m), below land-surface datum, Sept. 27, 1998; lowest water level recorded, 34.07 ft (10.4 m), below land-surface datum, May 30, 1996. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1995 TO SEPTEMBER 1996 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 33.87 28.73 2 33.85 28.76 3 33.86 28.73 4 33.89 28.71 5 33.68 28.66 6 33.24 28.77 7 32.86 29.27 28.83 8 32.61 29.61 28.92 9 32.46 29.72 29.03 10 32.39 29.86 28.63 11 32.26 29.80 27.39 12 32.09 29.71 26.62 13 31.83 29.65 26.83 14 31.62 29.60 27.22 15 31.50 29.42 27.44 16 31.39 29.36 27.56 17 31.17 31.17 29.39 27.54 18 31.18 29.29 27.33 19 31.20 29.02 27.14 20 31.20 28.97 27.08 21 31.21 28.82 27.08 22 31.25 28.79 27.13 23 31.32 28.76 27.22 24 31.37 28.70 27.30 25 31.42 28.63 27.40 26 31.47 28.62 27.14 27 31.17 28.67 26.63 28 28.67 26.30 29 28.70 26.15 30 34.05 28.72 26.17 31 33.93 28.73 MEAN 33.99 32.62 31.27 29.14 27.61 WTR YR 1996 MEAN 29.69 HIGHEST 26.14 SEPT. 29, 1996 LOWEST 34.07 MAY 30, 1996 --- --- --- --- --- --- --- --- --- 602 GROUND-WATER LEVELS RIO CULEBRINAS BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1996 TO SEPTEMBER 1997 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 26.24 25.56 26.87 29.26 29.20 30.02 31.50 32.10 32.68 32.70 32.03 30.37 2 26.33 25.42 26.94 29.27 29.26 30.06 31.53 32.13 32.53 32.66 32.03 30.28 3 26.41 25.30 27.02 29.50 29.31 30.13 31.55 32.14 32.42 32.63 32.04 30.22 4 26.50 25.27 27.12 29.59 29.37 30.17 31.57 32.18 32.36 32.61 32.07 30.16 5 26.59 25.28 27.19 29.60 29.43 30.20 31.58 32.19 32.36 32.64 32.13 30.02 6 26.64 25.32 27.27 29.71 29.49 30.21 31.59 32.16 32.38 32.65 32.20 29.95 7 26.72 25.40 27.35 29.80 29.55 30.36 31.56 32.17 32.40 32.67 32.26 29.93 8 26.81 25.43 27.45 29.84 29.56 30.42 31.56 32.17 32.43 32.66 32.30 29.93 9 26.89 25.47 27.52 29.93 29.57 30.46 31.57 32.15 32.48 32.68 32.33 29.95 10 26.94 25.56 27.60 29.95 29.56 30.51 31.58 32.17 32.53 32.71 32.38 29.97 11 26.95 25.65 27.68 29.98 29.50 30.57 31.49 32.23 32.57 32.73 32.42 30.01 12 26.93 25.71 27.78 30.04 29.30 30.61 31.55 32.25 32.60 32.75 32.35 30.05 13 26.93 25.81 27.86 30.10 29.14 30.65 31.58 32.40 32.63 32.77 32.24 30.06 14 26.97 25.92 27.93 30.16 29.09 30.74 31.61 32.53 32.65 32.79 32.22 30.11 15 26.74 26.03 28.03 30.21 29.13 30.77 31.61 32.55 32.66 32.80 32.20 30.16 16 26.41 26.13 28.10 30.24 29.17 30.78 31.62 32.62 32.68 32.74 32.07 30.18 17 26.18 26.20 28.18 30.26 29.23 30.87 31.73 32.65 32.72 32.71 31.86 30.20 18 26.09 26.23 28.28 30.40 29.30 30.90 31.77 32.64 32.76 32.71 31.71 30.23 19 26.09 26.26 28.36 30.46 29.37 30.97 31.87 32.60 32.79 32.60 31.62 30.26 20 26.16 26.26 28.44 30.51 29.43 31.01 31.92 32.60 32.69 32.37 31.64 30.29 21 26.23 26.24 28.51 30.55 29.51 31.05 31.98 32.62 32.55 32.15 31.63 30.33 22 26.06 26.17 28.60 29.57 31.09 31.96 32.65 32.53 32.06 31.56 30.28 23 25.83 26.14 28.67 29.60 31.13 31.94 32.70 32.55 32.05 31.53 30.26 24 25.70 26.19 28.77 29.04 29.68 31.19 31.94 32.73 32.57 32.06 31.41 30.24 25 25.65 26.26 28.81 28.94 29.73 31.21 31.97 32.76 32.60 32.08 31.03 30.17 26 25.62 26.35 28.85 28.91 29.79 31.24 31.99 32.76 32.51 32.12 30.74 30.10 27 25.62 26.47 28.99 28.94 29.89 31.27 32.01 32.71 32.59 32.16 30.57 30.09 28 25.63 26.58 29.05 28.98 29.94 31.35 32.03 32.73 32.66 32.18 30.50 30.11 29 25.60 26.67 29.10 29.02 31.39 32.05 32.68 32.70 32.13 30.44 30.13 30 25.57 26.79 29.19 29.08 31.43 32.08 32.75 32.72 32.07 30.43 30.11 31 25.56 29.24 29.15 31.47 32.76 32.04 30.43 MEAN 26.28 25.94 28.09 29.70 29.45 30.78 31.74 32.47 32.58 32.47 31.69 30.14 WTR YR 1997 MEAN 30.12 HIGHEST 25.26 NOV. 4, 1996 LOWEST 32.80 JULY 14, 15, 1997 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 603 GROUND-WATER LEVELS RIO CULEBRINAS BASIN--Continued WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30.17 29.96 29.22 31.35 30.41 31.82 2 30.22 29.72 29.27 31.21 30.44 31.87 3 30.22 29.87 29.35 31.04 30.53 31.93 4 30.25 29.94 29.42 30.89 30.57 31.96 5 30.26 30.03 29.48 30.82 30.65 31.97 6 30.21 30.04 29.54 30.82 30.71 31.98 7 30.18 30.12 29.63 30.81 30.74 32.03 8 30.19 30.14 29.69 30.71 30.77 32.09 9 30.22 30.20 29.75 30.57 30.82 32.13 10 30.27 30.24 29.82 30.49 30.86 32.18 31.67 11 30.30 30.20 29.89 30.43 30.91 32.22 31.58 12 30.31 30.01 29.93 29.90 30.94 32.26 31.51 13 29.66 29.74 30.04 29.45 30.99 32.30 31.50 14 29.90 29.57 30.12 29.29 31.03 32.34 31.48 15 29.84 29.43 30.18 29.26 31.08 32.36 31.45 16 29.67 29.26 30.24 29.30 31.14 32.38 31.35 17 29.56 29.12 30.31 29.37 31.24 32.40 31.24 18 29.54 29.05 30.37 29.43 31.29 32.44 31.09 19 29.53 29.08 30.44 29.49 31.37 32.47 30.96 20 29.54 29.15 30.49 29.57 31.41 32.50 30.80 21 29.51 29.20 30.63 29.67 31.44 32.48 30.68 22 29.57 29.26 30.67 29.71 31.46 32.50 28.43 23 29.65 29.33 30.74 29.76 31.48 32.54 24.08 24 29.66 29.36 30.82 29.78 31.63 22.02 25 29.68 29.38 30.88 29.93 31.67 21.18 26 29.71 29.40 30.92 29.97 31.74 20.92 27 29.77 29.31 31.05 30.05 31.77 20.84 28 29.80 29.14 31.10 30.14 31.80 21.64 29 29.83 29.17 31.15 30.21 22.56 30 29.88 29.18 31.22 30.26 23.05 31 29.91 31.31 30.31 MEAN 29.90 29.59 30.25 30.13 31.10 32.22 27.62 WTR YR 1998 MEAN 30.15 HIGHEST 20.80 SEPT. 27, 1998 LOWEST 32.57 MAR. 24, 1998 20 25 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 30 35 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 604 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182442067091700. Local number, 200. LOCATION.--Lat 18°24'42", long 67°09'17", Hydrologic Unit 21010002, 1.40 mi south of Aguadilla plaza, 3.04 mi northeast of Aguada plaza, and 0.20 mi north of Hwy 2 km 146.4. Owner: Carmelo Sánchez, Name: Aguadilla Cement North Well. AQUIFER.--Surficial deposits. WELL CHARACTERISTICS.--Abandoned water-table industrial well, diameter 4 in (0.10 m), cased 0-20.0 ft (0-6.10 m), perforated 11-20.0 ft (3.35-6.10 m). Depth 20.0 ft (6.10 m). INSTRUMENTATION.--Electronic water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 10.0 ft (3.05 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.10 m) casing, 3.25 ft (0.99 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR) replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. Water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.61 ft (0.49 m), below land-surface datum, Sept. 22, 1998; lowest water level recorded, 9.60 ft (2.93 m), below land-surface datum, Feb. 20, 1992. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.24 6.42 6.20 7.55 8.31 7.22 2 7.28 6.40 6.23 7.65 8.37 7.15 3 7.31 6.46 6.27 7.75 8.39 7.17 4 7.31 6.52 6.33 7.79 8.53 8.39 7.22 5 7.31 6.52 6.35 7.73 8.46 8.39 7.26 6 7.36 6.57 6.35 7.76 8.40 8.42 7.19 7 7.40 6.58 6.37 7.80 8.40 8.42 7.04 8 7.41 6.58 6.45 7.84 8.08 8.45 6.91 5.08 9 7.45 6.58 6.52 7.85 8.09 8.46 6.91 5.10 10 7.51 6.61 6.54 7.89 8.09 8.47 6.97 5.13 11 7.51 6.72 6.58 7.93 8.10 8.47 7.01 5.22 12 7.51 6.71 6.58 8.00 8.18 8.47 6.68 5.28 13 7.34 6.42 6.58 8.05 8.18 8.47 6.46 6.17 5.24 14 6.92 6.43 6.60 8.10 8.19 8.52 5.60 5.97 4.16 15 6.81 6.26 6.61 8.15 8.19 8.52 8.49 5.56 6.06 3.90 16 6.66 6.22 6.66 8.23 8.22 8.52 8.33 5.46 5.80 3.84 17 6.65 6.24 6.70 8.32 8.24 8.50 8.29 5.37 5.71 3.86 18 6.68 6.29 8.26 8.50 8.28 5.45 5.77 3.86 19 6.78 6.29 8.27 8.50 8.28 5.18 5.87 3.31 20 6.91 6.36 8.19 8.54 8.26 5.26 5.96 3.19 21 6.94 6.43 8.19 8.54 8.13 5.44 6.04 3.27 22 7.05 6.44 8.16 8.54 8.17 5.59 6.11 1.81 23 6.12 6.46 7.25 8.17 8.55 8.03 6.20 2.04 24 6.16 6.58 7.29 8.21 8.55 7.81 2.43 25 6.16 6.15 7.33 8.22 8.55 7.81 2.48 26 6.20 6.09 7.40 8.24 8.56 7.81 2.60 27 6.26 6.07 7.45 8.25 8.56 7.45 2.65 28 6.32 6.06 7.50 8.22 8.57 7.39 29 6.34 6.07 7.54 8.22 8.58 7.41 30 6.36 6.09 7.47 8.28 8.58 7.43 31 6.39 7.51 8.28 7.36 MEAN 6.89 6.39 6.47 7.42 7.91 8.23 8.49 7.93 6.37 5.97 3.72 WTR YR 1998 MEAN 6.97 HIGHEST 1.61 SEPT. 22, 1998 LOWEST 8.59 APR. 30, 1998 0 LAND-SURFACE DATUM 5 WATER LEVEL, IN FEET BELOW 10 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 605 Surface-Water Records for U.S. Virgin Islands --- --- --- --- --- --- --- 606 ST. THOMAS, U.S. VIRGIN ISLANDS 50252000 BONNE RESOLUTION GUT AT BONNE RESOLUTION, ST. THOMAS, VI LOCATION.--Lat 18°21'57", long 64°57'34", Hydrologic Unit 21020001, on right bank near Hull Bay Road, 0.5 mi (0.8 km), upstream from mouth, and 2.5 mi (4.0 km) northwest of Fort Christian, Charlotte Amalie. DRAINAGE AREA.--0.49 mi2 (1.27 km2). PERIOD OF RECORD.--December 1962 to February 1967, March 1979 to April 1981, May 1982 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 280 ft (85 m), from topographic map. December 1962 to February 1967 and March 1979 to April 1981 at site about 100 ft (30 m),upstream at different datum. REMARKS.--Records poor. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .04 .03 .04 .06 .01 .03 .01 .02 .01 .04 .11 .02 2 .04 .03 .03 .05 .01 .03 .01 .02 .01 .04 .10 .02 3 .04 .03 .03 .06 .01 .02 .01 .02 .01 .04 .10 .02 4 .05 .04 .03 .06 .01 .02 .01 .02 .01 .07 .09 .01 5 .05 .04 .03 .08 .03 .01 .01 .01 .02 .05 .10 .02 6 .06 .04 .03 .47 .02 .01 .01 .02 .01 .05 .10 .02 7 .05 .04 .03 .89 .02 .01 .02 .02 .01 .06 .10 .04 8 .05 .04 .04 .05 .02 .01 .01 .02 .01 .07 .11 .03 9 .06 .04 .04 .02 .03 .01 .01 .02 .01 .05 .13 .02 10 .05 .06 .04 .02 .03 .01 .01 .02 .01 .06 .14 .01 11 .10 .08 .04 .01 .02 .01 .01 .02 .01 .07 .11 .01 12 .33 .04 .04 .01 .03 .01 .01 .02 .01 .07 .11 .01 13 2.2 .02 .04 .01 .03 .01 .05 .02 .01 .06 .11 .01 14 4.6 .02 .04 .01 .03 .01 .01 .02 .01 .06 .11 .01 15 1.2 .03 .04 .01 .02 .01 .01 .01 .01 .07 .12 .01 16 .33 .03 .04 .01 .03 .01 .28 .01 .01 .08 .13 .01 17 .21 .03 .05 .01 .02 .01 .02 .01 .14 .07 .14 .01 18 .14 .10 .04 .01 .02 .01 .01 .01 .10 .10 .14 .02 19 .09 .10 .04 .01 .02 .01 .01 .01 .04 .08 .13 .02 20 .07 .05 .04 .01 .02 .01 .01 .01 .04 .10 .13 .01 21 .07 .03 .22 .01 .02 .01 .01 .01 .04 .09 .18 9.6 22 .06 .03 .08 .01 .02 .01 .02 .01 .04 .09 .16 4.0 23 .06 .03 .06 .01 .02 .01 .02 .01 .04 .10 .13 .14 24 .06 .03 .05 .01 .02 .01 .01 .01 .04 .11 .35 .06 25 .06 .02 .04 .01 .02 .01 .02 .01 .04 .09 .05 .04 26 .06 .03 .04 .01 .03 .01 .02 .01 .04 .09 .03 .03 27 .05 .02 .04 .01 .03 .01 .02 .01 .04 .09 .02 .03 28 .04 .03 .04 .01 .03 .01 .01 .01 .04 .09 .02 .03 29 .03 .03 .05 .01 .01 .02 .01 .04 .09 .01 .03 30 .03 .03 .06 .01 .01 .02 .01 .03 .10 .01 .03 31 .03 .06 .01 .01 .01 .11 .02 TOTAL 10.31 1.17 1.49 1.97 0.62 0.37 0.70 0.44 0.88 2.34 3.29 14.32 MEAN .33 .039 .048 .064 .022 .012 .023 .014 .029 .075 .11 .48 MAX 4.6 .10 .22 .89 .03 .03 .28 .02 .14 .11 .35 9.6 MIN .03 .02 .03 .01 .01 .01 .01 .01 .01 .04 .01 .01 AC-FT 20 2.3 3.0 3.9 1.2 .7 1.4 .9 1.7 4.6 6.5 28 CFSM .68 .08 .10 .13 .05 .02 .05 .03 .06 .15 .22 .97 IN. .78 .09 .11 .15 .05 .03 .05 .03 .07 .18 .25 1.09 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 1998, BY WATER YEAR (WY) MEAN .47 .71 .061 .067 .058 .048 .060 .31 .12 .046 .058 .94 MAX 3.09 4.22 .30 .35 .38 .31 .34 2.06 .89 .18 .23 8.91 (WY) 1986 1988 1993 1992 1992 1987 1986 1987 1987 1988 1988 1989 MIN .011 .011 .002 .016 .005 .001 .000 .002 .004 .010 .010 .009 (WY) 1997 1995 1995 1986 1995 1995 1995 1995 1995 1994 1994 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1963 - 1998 ANNUAL TOTAL 23.74 37.90 ANNUAL MEAN .065 .10 .24 HIGHEST ANNUAL MEAN .77 1989 LOWEST ANNUAL MEAN .026 1969 HIGHEST DAILY MEAN 4.6 Oct 14 9.6 Sep 21 169 Apr 18 1983 LOWEST DAILY MEAN .00 Mar 25 .01 Jan 11 .00 Apr 11 1980 ANNUAL SEVEN-DAY MINIMUM .01 Mar 19 .01 Jan 11 .00 Jan 31 1986 INSTANTANEOUS PEAK FLOW 117 Sep 21 1650 Apr 18 1983 INSTANTANEOUS PEAK STAGE 2.98 Sep 21 7.00 Apr 18 1983 ANNUAL RUNOFF (AC-FT) 47 75 186 ANNUAL RUNOFF (CFSM) .13 .21 .49 ANNUAL RUNOFF (INCHES) 1.80 2.88 6.65 10 PERCENT EXCEEDS .12 .10 .11 50 PERCENT EXCEEDS .03 .03 .02 90 PERCENT EXCEEDS .01 .01 .01 607 ST. THOMAS, U.S. VIRGIN ISLANDS 50252000 BONNE RESOLUTION GUT AT BONNE RESOLUTION, ST. THOMAS, VI--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 O N D J F M A M J J A S 1997 1998 WATER YEAR 608 ST. THOMAS, U.S. VIRGIN ISLANDS 50274000 TURPENTINE RUN AT MOUNT ZION, ST. THOMAS, VI LOCATION.--Lat 18°19'55", long 64°53'20", Hydrologic Unit 21020001, on left bank at Mount Zion, 0.6 mi (0.9 km), east southeast from Donoe School, 0.5 mi (0.8 km), northwest from Mariendal, and 0.4 mi (0.6 km) southeast from conjunction of roads 38 and 32. DRAINAGE AREA.--2.33 mi2 (6.03 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to December 1969, October 1992 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 120 ft (36 m), from topographic map. Datum of gage for period of October 1992 to current year is 1.62 ft (0.49 m), higher than previous record. REMARKS.--Records poor. Flow affected by three sewage treatment plants, Donoe, Old Tutu and New Tutu that discharges to a retention pond located 0.80 mi (1.28 km) upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .26 e.56 .65 .55 .54 .47 .51 .29 .35 e.66 .19 .23 2 1.1 e.56 .58 .54 .56 .48 .69 .31 .42 e.66 .19 .48 3 .54 e.56 .57 .54 .39 .43 .48 .29 .32 e.77 .15 .27 4 .41 e.78 .59 .67 .40 .40 .47 .28 .32 e1.9 .13 .19 5 .35 e.78 .62 .66 1.1 .43 .40 .19 .38 e.94 .11 .20 6 .32 e.78 .61 2.6 .46 .47 .42 .19 .39 e.62 .63 .23 7 .30 e.78 .61 6.3 .41 .49 .48 .20 .41 e.94 1.1 .91 8 .38 e.78 .58 1.2 1.0 .46 .45 .24 .30 e.58 .60 .64 9 .35 e.78 .52 .93 .94 .42 .44 .17 .26 e.39 .37 .42 10 .30 e1.2 .57 .69 .57 .35 .42 .19 .31 e.35 .34 .29 11 .80 e1.7 .52 .98 12 5.0 e1.1 .52 1.4 13 9.2 .61 .69 1.0 14 62 .46 .57 .72 15 5.3 .47 .52 .64 .53 .33 .41 .22 .28 e.28 .31 .24 .50 .34 4.5 .18 e.39 e.26 .21 .21 .53 .37 1.7 .19 e.38 e.26 .23 .53 .55 .77 .45 .13 e.40 e.36 .16 .29 .52 .58 .35 .43 e.40 e.18 .25 .21 16 2.0 .47 .47 .57 17 2.3 .44 3.0 .58 18 1.2 2.2 1.4 .58 19 1.0 1.1 .67 .64 .60 .42 .39 .22 e1.0 e.16 .54 .19 .51 .44 .36 .19 e1.9 e.60 .36 .19 .47 .42 .28 .17 e.85 e.91 1.5 .17 .45 .43 .36 .58 e.45 e.32 .61 .29 20 .78 .70 1.0 .53 .41 .56 .32 .26 e.45 e.65 .47 .59 21 .74 .69 3.7 .52 .44 .45 .32 .14 e1.1 e.18 3.9 83 22 .68 .69 .85 .46 .46 .44 .39 .22 e1.1 e.14 .91 19 23 .67 .63 .69 .44 .45 .57 .21 .14 e.44 e.21 .29 1.9 24 .99 1.3 .65 .50 .42 .74 .20 .13 e.45 .20 6.6 1.1 25 .76 .79 .61 .50 .44 .54 .31 1.2 e.49 .18 1.1 .86 26 .69 2.3 .60 .54 .41 .44 .25 .70 e.53 .20 .70 .78 27 .66 .87 .56 .46 .44 1.4 .24 .37 e.62 .24 1.2 1.1 28 .61 .75 .56 .43 .44 1.2 .25 .43 e.35 .30 .42 .73 29 .56 .71 .57 1.0 --- 2.2 .28 2.1 e.44 .21 .59 .67 30 .62 .66 .59 .49 --- 1.1 .25 1.0 e.64 .37 .31 .65 31 .59 --- .57 .45 --- .63 --- .44 --- .20 .27 --­ TOTAL 101.46 26.20 25.21 28.11 MEAN 3.27 .87 .81 .91 MAX 62 2.3 3.7 6.3 MIN .26 .44 .47 .43 AC-FT 201 52 50 56 CFSM 1.40 .37 .35 .39 IN. 1.62 .42 .40 .45 14.94 18.77 16.58 11.79 16.12 14.22 24.74 116.56 .53 .61 .55 .38 .54 .46 .80 3.89 1.1 2.2 4.5 2.1 1.9 1.9 6.6 .39 .33 .20 .13 .26 .14 .11 .17 30 37 33 23 32 28 49 231 .23 .26 .24 .16 .23 .20 .34 1.67 .24 .30 .26 .19 .26 .23 .39 1.86 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1993 - 1998, BY WATER YEAR (WY) MEAN 1.17 2.42 1.37 .63 MAX 3.27 6.49 4.79 .91 (WY) 1998 1993 1993 1998 MIN .33 .37 .23 .16 (WY) 1994 1996 1994 1994 .38 .31 .41 .37 .76 .41 .45 8.92 .95 .61 .92 .77 3.16 .74 .80 38.0 1997 1998 1993 1993 1993 1996 1998 1995 .13 .076 .025 .15 .18 .15 .16 .25 1994 1995 1995 1995 1994 1994 1993 1994 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1964 - 1998 ANNUAL TOTAL 295.89 ANNUAL MEAN .81 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 62 LOWEST DAILY MEAN .09 ANNUAL SEVEN-DAY MINIMUM .12 INSTANTANEOUS PEAK FLOW INSTANTANEOUS PEAK STAGE ANNUAL RUNOFF (AC-FT) 587 ANNUAL RUNOFF (CFSM) .35 ANNUAL RUNOFF (INCHES) 4.72 10 PERCENT EXCEEDS 1.1 50 PERCENT EXCEEDS .41 90 PERCENT EXCEEDS .19 414.70 1.14 .81 3.43 1995 .00 1965 Oct 14 83 Sep 21 802 Sep 16 1995 Jul 31 .11 Aug 5 .00 Mar 1 1965 Jul 27 .19 May 8 .00 Mar 1 1965 1060 Oct 14 10500 Sep 16 1995 5.35 Oct 14 7.28 Sep 16 1995 823 1060 .49 .35 6.62 4.73 1.1 1.0 .50 .32 .21 .10 e Estimated 83 609 ST. THOMAS, U.S. VIRGIN ISLANDS 50274000 TURPENTINE RUN AT MOUNT ZION, ST. THOMAS, VI--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 610 ST. JOHN, U.S. VIRGIN ISLANDS 50295000 GUINEA GUT AT BETHANY, ST. JOHN, VI LOCATION.--Lat 18°19'55", long 64°46'50", Hydrologic Unit 21020001, 600 ft (183 m), southeast of Bethany Church, and 1.0 mi (1.6 km) east of Government House at Cruz Bay. DRAINAGE AREA.--0.37 mi2 (0.96 km2). PERIOD OF RECORD.--January 1963 to October 1967, September 1982 to current year. GAGE.--Water-stage recorder and concrete control. Elevation of gage is 260 ft (79 m), from topographic map. Prior to September 1982, at datum 1.00 ft (0.30 m) higher. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .00 .03 .04 .02 .01 .00 .01 .01 e.01 .02 .00 .00 2 .02 .02 .03 .02 .01 .01 .01 .01 e.01 .02 .01 .02 3 .00 .02 .02 .02 .01 .01 .01 .01 e.01 e.02 .01 .00 4 .00 .02 .02 .02 .01 .01 .01 .01 e.01 e.03 .01 .00 5 .00 .03 .02 .02 .01 .01 .01 .01 e.02 e.02 .01 .00 6 .00 .03 .01 .03 .01 .02 .01 .01 e.01 e.02 e.01 .00 7 .00 .03 .01 .02 .01 .02 .05 .01 e.01 e.02 .01 .00 8 .00 .03 .01 .02 .01 .02 .01 .01 e.01 e.02 .00 .00 9 .00 .03 .01 .01 .01 .01 e.01 .01 e.01 e.03 .00 .00 10 .00 .04 .01 .01 .01 .01 e.01 .01 e.01 e.02 .00 .00 11 .00 .03 .01 .01 .01 .01 e.01 .01 e.01 .02 .00 .00 12 .42 .02 .01 .01 .01 .01 e.01 .01 e.01 .02 .00 .00 13 2.2 .02 .02 .01 .01 .01 e.05 .01 e.01 .02 .00 .00 14 8.6 .01 .02 .01 .01 .01 e.02 .01 e.01 .02 .00 .00 15 1.2 .02 .01 .01 .01 .01 e.01 .01 e.01 .02 .00 .00 16 .27 .01 .02 .01 .01 .01 e.33 .01 e.01 .01 .00 .00 17 .11 .01 .02 .01 .01 .01 e.01 .01 e.02 .01 .00 .00 18 .06 .04 .02 .01 .00 .01 e.01 .01 e.01 .01 .00 .00 19 .04 .04 .02 .01 .00 .01 e.01 .01 .01 .01 .00 .00 20 .02 .03 .02 .01 .00 .01 e.01 .01 .01 .00 .00 .00 21 .02 .03 .02 .01 .00 .01 e.01 .01 .01 .00 .01 7.9 22 .01 .03 .02 .01 .00 .01 e.03 .01 .01 .00 .01 4.1 23 .01 .03 .02 .01 .00 .01 e.01 .01 .01 .00 .00 .30 24 .01 .02 .02 .01 .00 .01 e.01 .01 .01 .01 .01 .08 25 .01 .01 .02 .01 .00 .01 e.01 .01 .01 .01 .00 .05 26 .01 .02 .01 .01 .00 .01 e.01 .01 .01 .01 .00 .03 27 .01 .01 .01 .01 .01 .01 e.02 .01 .01 .02 .00 1.2 28 .01 .01 .01 .01 .01 .02 e.01 e.01 .01 .01 .00 .16 29 .02 .01 .01 .01 .01 .01 .01 .01 .00 .00 .09 30 .02 .02 .01 .01 .01 .01 .03 .02 .00 .00 .06 31 .03 .02 .01 .01 e.01 .00 .00 TOTAL 13.10 0.70 0.52 0.40 0.19 0.34 0.74 0.33 0.33 0.42 0.09 13.99 MEAN .42 .023 .017 .013 .007 .011 .025 .011 .011 .014 .003 .47 MAX 8.6 .04 .04 .03 .01 .02 .33 .03 .02 .03 .01 7.9 MIN .00 .01 .01 .01 .00 .00 .01 .01 .01 .00 .00 .00 AC-FT 26 1.4 1.0 .8 .4 .7 1.5 .7 .7 .8 .2 28 CFSM 1.14 .06 .05 .03 .02 .03 .07 .03 .03 .04 .01 1.26 IN. 1.32 .07 .05 .04 .02 .03 .07 .03 .03 .04 .01 1.41 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 1998, BY WATER YEAR (WY) MEAN .071 .33 .028 .016 .008 .006 .27 .084 .010 .011 .014 .31 MAX .42 2.52 .11 .052 .032 .023 4.03 .89 .031 .041 .082 2.35 (WY) 1998 1985 1989 1997 1997 1996 1983 1986 1987 1996 1983 1989 MIN .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 (WY) 1992 1992 1987 1992 1992 1986 1995 1994 1991 1987 1991 1991 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1963 - 1998 ANNUAL TOTAL 19.06 31.15 ANNUAL MEAN .052 .085 .078 HIGHEST ANNUAL MEAN .35 1983 LOWEST ANNUAL MEAN .00 1967 HIGHEST DAILY MEAN 8.6 Oct 14 8.6 Oct 14 110 Apr 18 1983 LOWEST DAILY MEAN .00 Mar 26 .00 Oct 1 .00 Oct 3 1982 ANNUAL SEVEN-DAY MINIMUM .00 Aug 1 .00 Oct 3 .00 Jan 9 1983 INSTANTANEOUS PEAK FLOW 54 Oct 14 946 Apr 18 1983 INSTANTANEOUS PEAK STAGE 2.48 Oct 14 5.33 Apr 18 1983 ANNUAL RUNOFF (AC-FT) 38 62 56 ANNUAL RUNOFF (CFSM) .14 .23 .21 ANNUAL RUNOFF (INCHES) 1.92 3.13 2.86 10 PERCENT EXCEEDS .05 .03 .04 50 PERCENT EXCEEDS .01 .01 .01 90 PERCENT EXCEEDS .00 .00 .00 e Estimated 611 ST. JOHN, U.S. VIRGIN ISLANDS 50295000 GUINEA GUT AT BETHANY, ST. JOHN, VI--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 O N D J F M A M J J A S 1997 1998 WATER YEAR --- --- --- --- --- --- --- 612 ST. CROIX, U.S. VIRGIN ISLANDS 50345000 JOLLY HILL GUT AT JOLLY HILL, ST. CROIX, VI LOCATION.--Lat 17°44'00", long 64°51'47", Hydrologic Unit 21020002, on Mahogany Road at Jolly Hill, 1.8 mi (2.9 km), northeast of Frederiksted. DRAINAGE AREA.--2.10 mi2 (5.44 km2). PERIOD OF RECORD.--January 1963 to December 1968. Monthly measurements, 1962-69. October 1982 to current year. GAGE.--Water-stage recorder, crest-stage gage and sharp-crested concrete control. Elevation of gage is 140 ft (43 m), from topographic map. REMARKS.--Records poor. Low-water diversions upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .00 .01 e.08 e.00 .00 .00 .00 .00 .00 .00 .00 .00 2 .00 .01 e.06 e.00 .00 .00 .00 .00 .00 .00 .00 .00 3 .00 .01 e.03 e.00 .00 .00 .00 .00 .00 .00 .00 .00 4 .00 .02 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 5 .00 .02 .00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 6 .00 .07 .00 e.00 .00 .00 .00 .00 .00 .00 e.00 .00 7 .00 .01 .00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 8 .00 .01 .00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 9 .00 .00 .00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 10 .00 .00 .00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 11 .00 .00 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 12 .00 e.01 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 13 .03 e.03 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 14 1.3 e.02 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 15 1.4 e.04 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 16 1.0 e.04 e.00 e.00 .00 .00 .06 .00 .00 .00 .00 .00 17 .59 e.69 e.00 e.00 .00 .00 .00 .00 .10 .00 .00 .00 18 .24 e.37 e.00 e.00 .00 .00 .00 .00 .01 .00 .00 .00 19 .11 e.41 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 20 .08 e.64 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 .00 21 .07 e.50 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 3.6 22 .06 e.59 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 5.1 23 .05 e.38 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.36 24 .04 e.33 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.30 25 .04 e.31 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.30 26 .01 e.26 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.29 27 e.00 e.18 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.30 28 e.01 e.13 e.00 e.00 .00 .00 .00 .00 .00 .00 .00 e.29 29 .00 e.34 e.00 e.00 .00 .00 .00 .00 .00 .00 e.27 30 .00 e.17 e.00 .00 .00 .00 .00 .00 .00 .00 .26 31 .01 e.00 .00 .00 .00 .00 .00 TOTAL 5.04 5.60 0.17 0.00 0.00 0.00 0.06 0.00 0.11 0.00 0.00 11.07 MEAN .16 .19 .005 .000 .000 .000 .002 .000 .004 .000 .000 .37 MAX 1.4 .69 .08 .00 .00 .00 .06 .00 .10 .00 .00 5.1 MIN .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 AC-FT 10 11 .3 .00 .00 .00 .1 .00 .2 .00 .00 22 CFSM .08 .09 .00 .00 .00 .00 .00 .00 .00 .00 .00 .18 IN. .09 .10 .00 .00 .00 .00 .00 .00 .00 .00 .00 .20 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 1998, BY WATER YEAR (WY) MEAN .86 .73 .46 .27 .18 .088 .063 .086 .16 .077 .027 .71 MAX 5.92 2.33 2.34 .88 .55 .34 .23 .46 1.43 .52 .18 3.80 (WY) 1996 1988 1988 1988 1988 1990 1990 1992 1987 1987 1987 1995 MIN .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 .000 (WY) 1987 1992 1992 1992 1989 1989 1989 1989 1989 1989 1989 1991 SUMMARY STATISTICS FOR 1997 CALENDAR YEAR FOR 1998 WATER YEAR WATER YEARS 1964 - 1998 ANNUAL TOTAL 38.51 22.05 ANNUAL MEAN .11 .060 .22 HIGHEST ANNUAL MEAN .94 1996 LOWEST ANNUAL MEAN .0003 1965 HIGHEST DAILY MEAN 1.4 Oct 15 5.1 Sep 22 62 Sep 10 1996 LOWEST DAILY MEAN .00 Jun 16 .00 Oct 1 .00 Oct 1 1985 ANNUAL SEVEN-DAY MINIMUM .00 Jun 16 .00 Oct 1 .00 Sep 4 1986 INSTANTANEOUS PEAK FLOW 37 Sep 21 937 Sep 15 1995 INSTANTANEOUS PEAK STAGE 2.15 Sep 21 5.38 Sep 15 1995 ANNUAL RUNOFF (AC-FT) 76 44 159 ANNUAL RUNOFF (CFSM) .050 .029 .10 ANNUAL RUNOFF (INCHES) .68 .39 1.42 10 PERCENT EXCEEDS .29 .06 .59 50 PERCENT EXCEEDS .04 .00 .03 90 PERCENT EXCEEDS .00 .00 .00 e Estimated 613 ST. CROIX, U.S. VIRGIN ISLANDS 50345000 JOLLY HILL GUT AT JOLLY HILL, ST. CROIX, VI--Continued DAILY MEAN DISCHARGE, IN CUBIC FEET PER SECOND 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 0.005 0.002 0.001 O N D J F M A M J J A S 1997 1998 WATER YEAR 614 THIS PAGE WAS LEFT BLANK INTENTIONALLY 615 Ground-Water Records for U.S. Virgin Islands --- --- --- --- --- --- --- 616 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174225064472000. Local number, 2. LOCATION.--Lat 17°42'25", long 64°47'20", Hydrologic Unit 21020002, 0.90 mi southeast of the Experimental Station, 0.6 mi southwest of Christiansted Plaza, and 0.18 mi northeast of the Alexander Hamilton Airport entrance on Hwy 64. Owner: US Virgin Islands Government, Name: USGS-10, Fairplains 2 (FP2). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 20 ft (6.10 m), above mean sea level, from topographic map. Measuring point: Top of 0.5 in (0.01 m) hole at concrete base wall, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Water level affected by nearby pumping well. PERIOD OF RECORD.--June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 19.02 ft (5.80 m), below land-surface datum, Feb. 8, 1997; lowest water level recorded, 26.46 ft (8.06 m), below land-surface datum, Aug. 25, 1990. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20.31 19.36 19.55 19.87 20.04 20.15 20.69 20.85 20.94 21.12 20.47 20.49 2 20.31 19.32 19.57 19.80 20.08 20.16 20.70 20.80 20.95 21.03 20.45 20.46 3 20.22 19.45 19.63 19.84 20.10 20.27 20.68 20.83 21.00 21.03 20.53 20.55 4 20.32 19.33 19.53 19.87 20.13 20.30 20.66 20.77 21.01 20.94 20.55 20.60 5 20.33 19.38 19.60 19.94 20.09 20.43 20.60 20.86 21.07 20.98 20.65 20.53 6 20.39 19.37 19.60 19.85 20.11 20.47 20.68 20.77 20.97 20.93 20.59 20.48 7 20.37 19.38 19.71 19.82 20.09 20.42 20.72 20.73 20.99 20.91 20.59 20.43 8 20.37 19.31 19.67 19.90 19.99 20.45 20.76 20.75 21.03 20.89 20.63 20.41 9 20.36 19.30 19.73 19.92 20.14 20.42 20.80 20.80 20.98 20.88 20.59 20.40 10 20.38 19.32 19.71 19.90 20.15 20.36 20.67 20.84 20.99 20.85 20.55 20.53 11 20.33 19.32 19.64 19.89 20.13 20.49 20.71 20.87 20.97 20.84 20.60 20.55 12 20.20 19.28 19.74 19.87 20.22 20.50 20.73 20.89 21.01 20.82 20.60 20.50 13 20.25 19.42 19.74 19.90 20.18 20.54 20.77 20.90 20.93 20.66 20.57 20.48 14 20.11 19.38 19.75 19.87 20.15 20.55 20.71 20.92 20.95 20.64 20.57 20.60 15 19.99 19.37 19.78 19.89 20.19 20.51 20.79 20.93 21.02 20.70 20.56 20.52 16 20.02 19.30 19.82 19.95 20.15 20.53 20.80 20.85 20.97 20.67 20.55 20.47 17 19.94 19.41 19.76 19.86 20.13 20.56 20.76 20.90 20.92 20.64 20.65 20.43 18 19.85 19.48 19.85 19.89 20.26 20.64 20.76 20.85 20.93 20.61 20.55 20.41 19 19.75 19.53 19.82 19.91 20.27 20.55 20.79 20.88 20.96 20.58 20.51 20.55 20 19.77 19.42 19.80 19.92 20.27 20.58 20.70 20.93 21.02 20.65 20.49 20.56 21 19.67 19.54 19.80 19.92 20.30 20.50 20.75 20.94 21.10 20.63 20.43 20.36 22 19.68 19.50 19.81 19.93 20.30 20.49 20.79 20.89 21.06 20.57 20.53 20.35 23 19.59 19.49 19.87 19.95 20.33 20.60 20.76 20.84 21.05 20.54 20.60 20.25 24 19.65 19.50 19.81 19.94 20.39 20.65 20.71 20.86 21.05 20.61 20.51 20.18 25 19.56 19.44 19.84 19.87 20.43 20.64 20.77 20.91 21.08 20.58 20.46 20.10 26 19.53 19.54 19.78 20.00 20.29 20.69 20.77 20.87 21.06 20.52 20.42 20.05 27 19.47 19.44 19.84 20.04 20.30 20.69 20.69 20.92 21.03 20.50 20.40 19.94 28 19.53 19.52 19.80 20.06 20.28 20.64 20.80 20.96 21.01 20.52 20.39 19.90 29 19.50 19.51 19.82 20.02 20.58 20.83 21.01 21.06 20.51 20.50 19.96 30 19.38 19.43 19.86 20.07 20.65 20.85 20.97 20.99 20.51 20.58 20.03 31 19.49 19.95 19.98 20.66 20.84 20.50 20.57 MEAN 19.96 19.41 19.75 19.92 20.20 20.51 20.74 20.87 21.00 20.72 20.54 20.37 WTR YR 1998 MEAN 20.33 HIGHEST 19.27 NOV, 10, 12, 1997 LOWEST 21.12 JULY 1, 1998 18 20 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 22 24 26 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 617 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174243064475100. Local number, 3. LOCATION.--Lat 17°42'43", long 64°47'51", Hydrologic Unit 21020002, 0.75 mi northwest of the Alexander Hamilton Airport entrance on Hwy 64, 6.45 mi southwest of Christiansted Plaza, and 0.57 mi southwest of the Experimental Station. Owner: US Virgin Islands Government, Name: Golden Grove - 6 (PW6). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.20 m), cased 8 in (0.20 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 40 ft (12.2 m), above mean sea level, from topographic map. Measuring point: Upper edge of hole at 8 in (0.20 m) casing, 4.20 ft (1.28 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 12.99 ft (3.96 m), below land-surface datum, Nov. 10, 1990; lowest water level recorded, 41.05 ft (12.5 m), below land-surface datum, Sept. 15, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.67 25.97 26.41 27.09 2 27.66 25.97 26.45 27.10 3 27.65 25.97 26.45 27.10 4 27.66 25.98 26.45 27.10 5 27.67 26.00 26.46 27.12 27.46 27.68 28.16 28.65 29.06 29.48 29.56 29.31 27.46 27.70 28.18 28.65 29.09 29.45 29.55 29.31 27.46 27.73 28.20 28.68 29.11 29.45 29.54 29.36 27.46 27.77 28.20 28.67 29.12 29.47 29.55 29.36 27.50 27.78 28.19 28.70 29.12 29.50 29.56 29.35 6 27.69 25.99 26.46 27.13 7 27.67 25.99 26.53 27.13 8 27.67 26.01 26.55 27.15 9 27.67 26.04 26.56 27.17 10 27.65 26.07 26.58 27.17 27.52 27.78 28.21 28.70 29.14 29.51 29.53 29.33 27.52 27.78 28.24 28.71 29.16 29.50 29.52 29.32 27.52 27.83 28.26 28.70 29.19 29.50 29.51 29.32 27.53 27.84 28.26 28.73 29.21 29.51 29.50 29.31 27.55 27.86 28.24 28.73 29.22 29.51 29.49 29.31 11 27.65 26.07 26.60 27.16 12 27.63 26.08 26.64 27.19 13 27.60 26.08 26.65 27.19 14 27.55 26.04 26.67 27.18 15 27.51 26.06 26.70 27.20 27.56 27.90 28.26 28.73 29.23 29.53 29.49 29.28 27.57 27.92 28.26 28.76 29.24 29.59 29.50 29.28 27.57 27.93 28.29 28.78 29.25 29.64 29.49 29.28 27.55 27.93 28.31 28.78 29.27 29.65 29.47 29.29 27.59 27.93 28.31 28.79 29.28 29.66 29.47 29.31 16 27.26 26.08 26.71 27.23 17 27.01 26.10 26.78 27.23 18 26.66 26.13 26.78 27.23 19 26.45 26.15 26.81 27.24 20 26.28 26.16 26.81 27.26 27.61 27.93 28.31 28.80 29.29 29.66 29.49 29.30 27.60 27.95 28.31 28.82 29.30 29.66 29.49 29.30 27.63 27.96 28.35 28.85 29.30 29.64 29.43 29.29 27.60 27.99 28.44 28.87 29.32 29.64 29.42 29.31 27.61 27.99 28.52 28.89 29.32 29.62 29.41 29.33 21 26.09 26.19 26.80 27.29 22 26.00 26.20 26.86 27.30 23 25.96 26.20 26.86 27.32 24 25.91 26.22 26.87 27.34 25 25.83 26.22 26.90 27.36 27.62 27.96 28.57 28.89 29.32 29.62 29.40 29.10 27.66 28.00 28.59 28.90 29.35 29.62 29.41 29.33 27.67 28.01 28.65 28.92 29.38 29.61 29.41 29.22 27.67 28.08 28.68 28.92 29.42 29.61 29.36 28.94 27.66 28.12 28.69 28.92 29.43 29.62 29.39 28.66 26 25.83 26.27 26.91 27.37 27 25.81 26.30 26.90 27.38 28 25.83 26.32 26.94 27.45 29 25.84 26.35 26.98 27.43 30 25.84 26.34 27.02 27.41 31 25.87 --- 27.08 27.44 27.64 28.12 28.69 29.00 29.41 29.60 29.38 28.40 27.66 28.10 28.69 29.02 29.42 29.58 29.34 28.17 27.69 28.12 28.71 29.02 29.44 29.58 29.33 28.03 --- 28.10 28.72 29.03 29.45 29.58 29.34 27.88 --- 28.11 28.65 29.05 29.47 29.58 29.35 27.87 --- 28.12 --- 29.05 --- 29.58 29.36 --­ MEAN 26.87 26.12 26.72 27.24 27.58 27.94 28.40 28.83 29.28 29.57 29.45 29.06 WTR YR 1998 MEAN 28.09 HIGHEST 25.77 OCT. 27, 28, 1997 LOWEST 29.66 JULY 14-19, 1998 20 30 40 50 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 618 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174316064480800. Local number, 13. LOCATION.--Lat 17°43'16", long 64°48'08", Hydrologic Unit 21020002, 5.25 mi east of Fort Frederick at Frederickstead, 0.95 mi southeast of Holy Cross Church, and 0.65 mi northeast of Adventure Ruins. Owner: US Virgin Islands Water and Power Authority, Name: WAPA-17 at Adventure well field. AQUIFER.--Kingshill Limestone. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.10 m), cased 0-95.0 ft (0-29.0 m), screened 10-40.0 ft (3.05-12.2 m). Depth 95.0 ft (29.0 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 75.0 ft (22.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 2.33 ft (0.71 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--February 28, 1990 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.27 ft (0.08 m), below land-surface datum, Sept. 10, 1996; lowest water level recorded, 27.88 ft (8.50 m), below land-surface datum, Sept. 6, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13.04 10.17 10.70 10.78 10.77 11.38 12.45 14.05 14.90 15.25 16.34 2 13.07 10.15 10.76 10.78 10.77 11.42 12.62 14.07 14.92 15.28 16.39 3 13.07 10.11 10.80 10.78 10.79 11.47 12.68 14.10 14.93 15.31 16.48 4 13.06 10.07 10.80 10.78 10.83 11.52 12.73 14.14 14.93 15.36 16.52 5 13.10 10.05 10.84 10.78 10.83 11.62 14.16 14.71 15.40 16.57 6 13.15 10.03 10.89 10.78 10.86 11.68 14.19 14.73 15.41 16.61 7 13.17 10.02 10.96 10.70 10.91 11.76 13.61 14.20 14.82 15.43 16.67 8 13.21 10.02 10.99 10.20 10.94 11.80 13.62 14.22 14.79 14.82 16.73 9 13.22 10.02 11.03 10.11 10.96 11.89 13.62 14.24 14.64 14.80 16.37 10 13.24 10.02 11.03 10.15 10.98 11.95 13.63 14.25 14.73 15.07 16.34 11 13.24 10.02 11.03 10.26 11.01 12.03 13.64 14.27 14.85 15.21 16.46 12 13.24 10.02 11.03 10.35 11.04 12.08 13.07 13.67 14.30 14.94 15.30 16.54 13 12.40 10.02 11.01 10.35 11.08 12.13 13.07 13.69 14.32 14.97 15.39 16.64 14 10.36 10.02 11.01 10.39 11.10 12.18 13.10 13.72 14.39 15.01 15.43 16.73 15 9.88 10.03 11.00 10.43 11.11 12.21 13.13 13.72 14.43 15.03 15.50 16.75 16 10.41 10.03 11.00 10.43 11.13 12.27 13.18 13.74 14.47 15.06 15.57 16.80 17 10.76 10.05 10.99 10.50 11.13 12.28 13.08 13.78 15.06 15.67 16.85 18 10.83 10.07 10.98 10.50 11.18 12.31 13.02 13.82 15.08 15.71 16.92 19 10.91 10.09 10.98 10.53 11.21 12.36 13.03 13.84 15.10 15.79 16.94 20 10.93 10.13 10.98 10.53 11.22 12.36 13.11 13.88 15.12 15.85 16.96 21 10.93 10.18 10.89 10.53 11.26 12.37 13.13 13.91 15.14 15.91 16.98 22 10.87 10.20 10.55 10.57 11.28 12.41 13.18 13.93 15.13 15.93 13.41 23 10.83 10.28 10.55 10.61 11.31 12.47 13.24 13.96 15.13 15.97 12.10 24 10.83 10.34 10.58 10.63 11.34 12.52 13.28 13.97 15.13 16.02 12.19 25 10.82 10.38 10.62 10.63 11.37 12.57 13.31 13.99 15.13 16.02 12.59 26 10.82 10.44 10.64 10.63 11.37 12.61 13.35 14.01 15.14 16.02 12.74 27 10.44 10.50 10.67 10.64 11.37 12.63 13.38 14.04 15.15 16.02 12.89 28 10.36 10.54 10.68 10.66 11.37 12.63 13.43 14.07 15.18 16.02 12.75 29 10.30 10.61 10.68 10.67 12.48 13.48 14.09 15.20 16.14 12.79 30 10.30 10.66 10.75 10.74 12.48 14.10 15.24 16.22 12.87 31 10.21 10.76 10.75 12.44 14.04 15.24 16.28 MEAN 11.65 10.18 10.84 10.55 11.09 12.14 13.09 13.84 14.24 15.00 15.62 15.46 WTR YR 1998 MEAN 12.73 HIGHEST 9.83 OCT. 15, 1997 LOWEST 16.98 SEPT. 20, 21, 1998 0 10 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 20 30 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- 619 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182038064550300. Local number, 6. LOCATION.--Lat 18°20'38", long 64°55'03", Hydrologic Unit 21020001, 1.12 mi east of Charlotte Amalie, 0.75 mi southwest of Winterberg Peak, and 1.08 mi southeast of Canaan. Owner: US Virgin Islands Government, Name: Grade School 3. AQUIFER.--Volcanic breccia. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 70.0 ft (21.3 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 60 ft (18.3 m), above mean sea level, from topographic map. Measuring point: Top of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.30 ft (0.40 m), above land-surface datum. Prior to June 27, 1983, top of 6 in (0.15 m) casing, 2.90 ft (0.88 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.53 ft (0.47 m), below land-surface datum, Oct. 1, 1989; lowest water level recorded, 35.38 ft (10.8 m), below land-surface datum, July 21, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.06 17.95 20.47 23.13 23.23 25.01 24.81 26.34 27.58 27.27 28.36 23.85 2 24.30 18.12 20.66 23.21 23.36 24.79 24.83 26.46 27.66 27.42 28.44 24.09 3 24.46 18.31 20.84 23.31 23.47 24.90 24.93 26.56 27.73 27.58 28.55 24.36 4 24.64 18.53 20.99 23.39 23.59 25.08 25.00 26.66 27.81 27.75 28.66 24.55 5 24.85 18.77 21.17 23.50 23.73 25.26 24.98 26.75 27.90 27.87 28.77 24.73 6 25.09 18.98 21.24 23.50 23.81 25.42 25.08 26.84 28.00 27.91 28.90 24.94 7 25.33 19.19 21.26 23.02 23.87 25.57 25.26 26.91 28.09 27.95 29.00 25.14 8 25.60 19.40 21.43 22.03 23.95 25.72 25.44 26.98 28.20 27.98 28.99 25.25 9 25.84 19.62 21.59 21.58 24.01 25.87 25.60 27.01 28.29 27.81 28.94 25.09 10 25.96 19.83 21.70 21.39 24.00 26.00 25.75 26.63 28.40 27.73 28.92 25.06 11 26.06 19.75 21.86 21.30 24.01 26.12 25.91 26.10 28.50 27.75 28.95 25.12 12 25.82 19.60 22.03 21.12 24.05 26.24 26.07 25.91 28.62 27.84 29.01 25.23 13 23.77 19.60 22.19 20.32 24.11 26.37 25.89 26.10 28.72 27.94 29.02 25.40 14 20.10 19.63 22.37 19.69 24.16 26.47 25.27 26.37 28.82 28.06 29.02 25.44 15 17.55 19.74 22.52 19.62 24.25 26.50 25.00 26.65 28.94 28.18 29.05 25.42 16 16.23 19.87 22.69 19.74 24.33 26.45 24.93 26.82 29.04 28.32 29.10 25.47 17 15.35 20.03 22.85 19.94 24.41 26.41 24.74 26.61 29.15 28.44 29.17 25.57 18 14.58 20.18 22.81 20.16 24.47 26.39 24.63 26.38 28.75 28.44 29.22 25.69 19 14.18 20.17 22.76 20.42 24.57 26.40 24.65 26.52 27.68 28.33 29.19 25.68 20 14.08 19.99 22.80 20.70 24.67 26.46 24.75 26.74 27.17 28.28 29.10 25.82 21 14.15 19.96 22.76 20.98 24.77 26.48 24.86 26.93 27.02 28.16 28.92 25.88 22 14.39 20.05 22.17 21.24 24.87 26.52 25.00 27.08 26.93 28.07 27.76 22.33 23 14.68 20.15 21.97 21.53 24.97 26.57 25.15 27.23 26.65 28.08 27.04 19.28 24 15.02 20.28 21.97 21.78 25.05 26.60 25.32 27.39 26.57 28.13 26.84 18.08 25 15.39 20.35 22.07 22.02 25.13 26.60 25.51 27.54 26.61 28.08 25.32 17.48 26 15.78 20.41 22.19 22.23 25.14 26.60 25.67 27.69 26.69 28.06 24.24 17.20 27 16.15 20.21 22.34 22.44 25.20 26.60 25.82 27.79 26.78 28.09 23.83 17.13 28 16.52 20.05 22.53 22.65 25.27 26.37 25.94 27.86 26.89 28.11 23.57 17.18 29 16.90 20.10 22.71 22.81 25.96 26.06 27.93 27.00 28.16 23.48 17.35 30 17.27 20.25 22.88 22.96 25.39 26.20 27.82 27.13 28.23 23.53 17.60 31 17.65 23.03 23.11 24.94 27.62 28.29 23.67 MEAN 19.73 19.64 22.03 21.77 24.30 26.00 25.30 26.91 27.78 28.01 27.63 23.05 WTR YR 1998 MEAN 24.35 HIGHEST 14.07 OCT. 20, 1997 LOWEST 29.24 AUG. 18, 19, 1998 10 20 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM 30 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 620 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182038064580000. Local number, 8. LOCATION.--Lat 18°20'38", long 64°58'00", Hydrologic Unit 21020001, 2.08 mi northwest of Charlotte Amalie, 0.50 mi northeast of Harry S. Truman Airport entrance on Hwy 302, and 1.15 mi southwest of Dorothea. Owner: US Virgin Islands Water and Power Authority, Name: Kirwan Terrace, VIEO-6. AQUIFER.--Alluvial deposits, volcanic rock. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.10 m), cased 0-56 in (0-17.1 m), screened 56-76.0 ft (17.1-23.2 m). Depth 76.0 ft (23.2 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 35.0 ft (10.7 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.00 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Drilled on July 1, 1991. PERIOD OF RECORD.--October 2, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 14.3 ft (4.37 m), below land-surface datum, Dec. 6, 7, 1996; lowest water level recorded, 32.7 ft (9.96 m), below land-surface datum, July 27, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30.55 27.50 27.14 27.83 2 30.54 27.49 27.18 27.84 3 30.52 27.48 27.19 27.88 4 30.53 27.48 27.24 27.89 5 30.54 27.51 27.28 27.95 28.37 29.29 29.86 29.68 30.70 30.23 30.28 29.36 28.40 29.34 29.84 29.70 30.70 30.26 30.33 29.31 28.42 29.36 29.81 29.73 30.69 30.28 30.37 29.31 28.46 29.40 29.79 29.75 30.68 30.31 30.41 29.29 28.51 29.43 29.78 29.80 30.68 30.31 30.45 29.27 6 30.57 27.51 27.32 28.00 7 30.60 27.51 27.35 27.95 8 30.62 27.55 27.37 27.86 9 30.65 27.57 27.41 27.76 10 30.65 27.55 27.46 27.69 28.56 29.46 29.76 29.85 30.70 30.29 30.50 29.26 28.59 29.48 29.80 29.90 30.69 30.28 30.55 29.24 28.64 29.52 29.81 29.95 30.70 30.30 30.57 29.21 28.67 29.56 29.84 30.01 30.71 30.27 30.57 29.21 28.71 29.62 29.88 30.06 30.72 30.22 30.63 29.20 11 30.65 27.52 27.51 27.66 12 30.63 27.48 27.54 27.66 13 30.49 27.44 27.58 27.69 14 30.01 27.37 27.62 27.69 15 29.37 27.33 27.67 27.74 28.74 29.66 29.92 30.10 30.74 30.22 30.67 29.21 28.74 29.71 29.98 30.14 30.75 30.20 30.59 29.21 28.77 29.75 30.02 30.20 30.76 30.20 30.56 29.22 28.81 29.77 30.02 30.25 30.76 30.18 30.52 29.24 28.84 29.74 29.99 30.30 30.77 30.21 30.52 29.25 16 28.84 27.32 27.70 27.79 17 28.43 27.30 27.72 27.82 18 28.15 27.28 27.73 27.85 19 27.94 27.28 27.74 27.87 20 27.81 27.25 27.74 27.91 28.88 29.73 29.96 30.33 30.76 30.27 30.53 29.25 28.91 29.75 29.81 30.37 30.76 30.30 30.51 29.29 28.94 29.77 29.67 30.40 30.63 30.34 30.50 29.34 28.97 29.83 29.54 30.43 30.47 30.36 30.52 29.40 29.01 29.87 29.49 30.46 30.33 30.33 30.53 29.52 21 27.71 27.24 27.72 27.96 22 27.66 27.24 27.72 27.99 23 27.62 27.23 27.69 28.02 24 27.61 27.22 27.67 28.06 25 27.55 27.19 27.66 28.09 29.04 29.93 29.45 30.51 30.23 30.31 30.55 29.54 29.08 30.00 29.47 30.56 30.15 30.27 30.55 29.32 29.11 30.02 29.49 30.62 30.08 30.25 30.49 28.88 29.15 30.09 29.53 30.64 30.04 30.24 30.41 28.55 29.18 30.14 29.57 30.66 30.01 30.22 30.24 28.28 26 27.48 27.20 27.68 28.11 27 27.39 27.17 27.68 28.13 28 27.41 27.14 27.70 28.17 29 27.44 27.14 27.71 28.21 30 27.45 27.13 27.76 28.25 31 27.47 --- 27.79 28.32 29.20 30.17 29.59 30.69 30.02 30.22 30.02 28.06 29.23 30.20 29.61 30.72 30.05 30.22 29.83 27.92 29.26 30.21 29.62 30.72 30.10 30.21 29.70 27.77 --- 30.17 29.64 30.75 30.11 30.18 29.60 27.69 --- 30.07 29.66 30.76 30.18 30.21 29.48 27.63 --- 29.96 --- 30.74 --- 30.23 29.41 --­ MEAN 29.06 27.35 27.56 27.92 28.83 29.77 29.74 30.28 30.49 30.26 30.34 28.97 WTR YR 1998 MEAN 29.22 HIGHEST 27.12 NOV. 28, DEC. 1, 1997 LOWEST 30.77 JUNE 14, 15, 16, 1998 10 20 30 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR --- --- --- --- --- --- --- 621 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 181956064464500. Local number, 11. LOCATION.--Lat 18°19'56", long 64°46'45", Hydrologic Unit 21020001, 1.05 mi southeast of Cruz Bay plaza, 0.25 mi southeast of Bethany Church, and 0.48 mi southeast of Margaret Hill. Owner: US Virgin Islands Government, Name: Guinea Gut Well. AQUIFER.--Louisenhoj Formation (Donnelly, 1959). WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 85.0 ft (25.9 m). INSTRUMENTATION.--Digital water level recorder--60-minute punch. DATUM.--Elevation of land-surface datum is about 280 ft (85.36 m), above mean sea level, from topographic map. Measuring point: Bottom of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.50 ft (0.46 m), above land-surface datum. Prior to June 28, 1983, top of 6 in (0.15 m) casing, 1.80 ft (0.55 m), above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.71 ft (0.79 m), below land-surface datum, Jan. 3, 1990; lowest water level recorded, 34.18 ft (10.4 m), below land-surface datum, Sept. 6, 1995. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1997 TO SEPTEMBER 1998 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.41 8.43 7.31 10.28 11.87 16.10 19.43 14.60 16.39 19.05 21.39 22.06 2 23.41 8.29 6.36 10.43 12.03 16.27 19.51 14.69 16.39 19.18 21.46 22.06 3 23.29 8.26 6.22 10.56 12.15 16.42 19.54 14.82 16.39 19.30 21.51 21.89 4 23.09 8.26 6.21 10.67 12.32 16.60 19.61 14.90 16.40 19.39 21.58 21.81 5 22.93 8.23 6.25 10.75 12.45 16.76 19.68 14.86 16.38 19.46 21.68 21.74 6 22.85 8.28 6.33 10.78 12.50 16.91 19.76 14.87 16.39 19.55 21.76 21.73 7 22.78 8.35 6.45 10.67 12.57 16.97 19.84 14.91 16.52 19.67 21.84 21.72 8 22.75 8.44 6.55 10.58 12.74 17.13 19.84 14.90 16.61 19.77 21.86 21.70 9 22.71 8.53 6.62 10.58 12.90 17.31 19.81 15.02 16.74 19.80 21.85 21.69 10 22.67 8.64 6.75 10.61 13.02 17.46 19.78 15.10 16.83 19.84 21.86 21.69 11 22.64 8.63 6.90 10.61 13.16 17.63 19.80 15.17 16.96 19.88 21.90 21.68 12 22.60 8.71 7.13 10.62 13.29 17.80 19.82 15.31 17.06 19.96 21.93 21.69 13 19.45 8.63 7.30 10.41 13.41 17.95 16.05 15.43 17.15 20.04 21.95 21.72 14 14.11 8.67 7.36 10.30 13.44 18.07 13.61 15.53 17.28 20.15 21.99 21.74 15 12.04 8.75 7.54 10.35 13.57 18.15 12.81 15.49 17.42 20.23 22.05 21.78 16 10.77 8.90 7.70 10.45 13.71 18.29 12.94 15.46 17.55 20.32 22.13 21.81 17 10.00 8.96 7.86 10.52 13.83 18.41 12.98 15.49 17.63 20.41 22.16 21.82 18 9.48 9.05 8.00 10.59 14.00 18.60 13.15 15.52 17.65 20.48 22.16 21.86 19 9.14 8.53 8.15 10.67 14.17 18.74 13.31 15.58 17.76 20.57 22.12 21.89 20 8.91 8.46 8.29 10.74 14.39 18.85 13.50 15.67 17.87 20.64 22.16 21.91 21 8.72 8.57 8.41 10.87 14.60 18.96 13.63 15.75 18.00 20.72 22.13 21.82 22 8.58 8.63 8.57 10.93 14.84 19.07 13.77 15.87 18.08 20.82 22.15 16.15 23 8.49 8.71 8.71 11.09 15.05 19.14 13.89 15.95 18.10 20.89 22.13 13.31 24 8.43 8.76 8.89 11.26 15.26 19.20 14.01 16.04 18.14 20.97 22.11 11.85 25 8.32 8.71 9.07 11.31 15.43 19.25 14.13 16.12 18.26 21.05 22.06 11.02 26 8.29 8.52 9.26 11.43 15.59 19.33 14.24 16.22 18.36 21.13 22.02 10.49 27 8.28 8.16 9.43 11.48 15.74 19.38 14.28 16.35 18.49 21.20 21.99 9.47 28 8.23 8.16 9.64 11.44 15.92 19.43 14.40 16.46 18.62 21.26 21.96 8.22 29 8.27 8.20 9.83 11.52 19.37 14.50 16.56 18.76 21.31 21.97 7.72 30 8.34 8.19 10.03 11.59 19.36 14.59 16.54 18.91 21.34 21.99 7.51 31 8.45 10.23 11.72 19.38 16.45 21.36 22.04 MEAN 14.88 8.52 7.85 10.83 13.71 18.14 16.21 15.54 17.44 20.31 21.93 18.45 WTR YR 1998 MEAN 15.33 HIGHEST 6.04 DEC. 2, 1997 LOWEST 23.42 OCT. 1, 2, 1997 0 LAND-SURFACE DATUM 20 WATER LEVEL, IN FEET BELOW 40 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S 1994 1995 1996 1997 1998 WATER YEAR 622 THIS PAGE WAS LEFT BLANK INTENTIONALLY 623 INDEX Page A Access to U.S. Geological Survey Water Data................................ 29 Acre-foot, definition of .................................................................... 30 Adenosine triphosphate, definition of.............................................. 30 Adjuntas, Lago Garzas near ............................................................. 62 Adjuntas, Lago Garzas No. 1 near dam near .......................... 479-481 Adjuntas, Río Grande de Arecibo near ....................................... 63,64 Aguada, Río Culebrinas near .................................................. 450,451 Aguas Buenas, Río Cagüitas near ........................................... 243-248 Aguas Buenas, Río Cañas at Barrio Jagüeyes near........................ 465 Aguas Buenas, Río de Bayamón near..................................... 177,178 Aguas Verdes basin, Quebrada, ground-water records in .............................................. 553-562 Algae growth potential, definition of............................................... 30 Almirante Sur, Río Unibón off Highway 160 near........................ 441 Annual 7-day minimum, definition of ............................................. 32 Añasco, Río Grande de Añasco near ...................................... 443,444 Aquifer, definition of ....................................................................... 30 Arecibo, Río Grande de Arecibo above ...................................... 86-91 Arenas, Río de Bayamón at .................................................... 166,167 Artesian, definition of ...................................................................... 30 Artificial substrate, definition of...................................................... 37 Ash mass, definition of .................................................................... 31 B Bacteria, definition of ...................................................................... 30 Bahía de San Juan No. 5 at San Juan ............................................. 204 Bairoa at Bairoa, Río............................................................... 257-262 near Caguas ........................................................................ 263,264 Bairoa at Barrio Bairoa near Caguas, Río...................................... 464 Bauta near Orocovis, Río........................................................ 116,117 Bayamón at Flood Channel at Bayamón, Río de.................... 183,184 at Arenas............................................................................. 166,167 Bayamón basin, Río de, gaging station records in..................................................................... 166-184 water-quality records in...................................................... 173-178 water-quality partial-record analysis of samples collected at ......................................... 472-481 Bayamón below Lago de Cidra, Río de .................................. 171-176 Bayamón Mouth, Lago de Cidra near..................................... 472-474 near Aguas Buenas ............................................................. 177,178 near Bayamón..................................................................... 179,180 Bayamón, Río Guaynabo near ................................................ 181,182 Bayaney, Río Camuy near .......................................................... 58,59 Beatriz, Quebrada Beatriz at Barrio............................................... 463 Beatriz, Quebrada de las Quebradillas at Barrio............................ 463 Beatriz, Quebrada Sonadora at Barrio ........................................... 463 Bed material, definition of ............................................................... 31 Bed load, definition of ..................................................................... 36 Bed load discharge, definition of ..................................................... 36 Biochemical oxygen demand, definition of ..................................... 31 Biomass, definition of ...................................................................... 31 Blanca at El Jagual, Quebrada ................................................ 210-215 Blanco basin, Río, gaging station records in........................... 337,340 Blasina near Carolina, Quebrada ............................................ 206,207 Blue-green algae, definition of ........................................................ 35 Bonne Resolution Gut at Bonne Resolution, St. Thomas, VI ............................................ 606,607 Borinquen, Quebrada Naranjito at Barrio ...................................... 462 Borinquen, Río Turabo at Highway 765 at Barrio......................... 462 Borinquen, Río Turabo above................................................. 230-235 Bottom material, definition of.......................................................... 31 Bucaná at Highway 14 bridge near Ponce, Río ...................... 393,394 Bucaná basin, Río, gaging station records in......................... 386-394 water-quality records in....................................................... 391,392 Page C Cacaos, Quebrada Pastrana near Mariana at Barrio ................................................................... 468 mouth at Barrio ........................................................................... 468 Caguas, Lago Loíza No. 4 near mouth near ............................472-474 Caguas, Río Bairoa at Barrio Bairoa near ...................................... 464 Caguas, Río Bairoa near .......................................................... 263,264 Caguas, Río Cagüitas at Highway 30 at ................................. 255,256 Caguas, Río Cagüitas at Highway 156 near ................................... 464 Caguas, Río Cagüitas at Villa Blanca at..................................249-254 Caguas, Río Cagüitas near.......................................................242-247 Caguas, Río Grande de Loíza at ............................................. 236-242 Caguas, Río Turabo at Villa del Rey near...................................... 464 Cagüitas at Highway 30 at Caguas, Río .................................. 255,256 at Villa Blanca at Caguas.....................................................249-254 near Caguas..........................................................................242-247 near Aguas Buenas...............................................................243-248 Cagüitas at Highway 156 near Caguas, Río ................................... 464 Campo Rico, Río Canóvanas near........................................... 301,302 Camuy basin, Río, gaging station records in...............................57-59 ground-water records in .......................................................488-491 low-flow partial-records stations in ............................................ 436 Camuy near Bayaney, Río........................................................... 58,59 Canal Principal de Diversiones at Lago de Guajataca............................................................... 53,54 Canóvanas near Campo Rico, Río.......................................... 301,302 Canovanillas at Barrio Canovanillas, Río ...................................... 469 Canovanillas at Carruzos, Río ........................................................ 469 Cañaboncito at Barrio Cañaboncito, Río........................................ 464 Cañas at Achiote near Naranjito, Río at Río Cañas ................285-290 Cañas basin, Río, gaging station records in.............................285-290 water-quality records in .......................................................287-290 Cañas at Barrio Jagüeyes near Aguas Buenas, Río ................................................................. 465 Río Cañas, Río ............................................................................ 465 Cañas at Highway 1 at Barrio Río Cañas ....................................... 465 Caonillas above Lago Caonillas near Jayuya, Río ...................... 81,82 Caonillas at Paso Palma, Río.......................................................75-80 Caonillas, Lago Caonillas at Damsite near Utuado.......................... 83 Carolina, Quebrada Blasina near............................................. 206,207 Carruzos, Río Canovanillas at ........................................................ 469 Castañer, Lago Guayo at Damsite near .......................................... 436 Cataño, Río Hondo at Flood Channel near.............................. 164,165 Cayaguas at Cerro Gordo, Río ............................................... 222,223 Cayey, Lago Carite at Gate Tower near ......................................... 140 Cayey, Lago Carite No. 1 near dam near ................................479-481 Cayey, Lago Carite No. 3 on Río de la Plata near...................472-474 Cells/volume, definition of............................................................... 31 Central Cambalache, Río Grande de Arecibo at .....................101-104 Central Rufina, Río Guayanilla at ........................................... 411,412 Cerrillos above Lago Cerrillos near Ponce, Río...................... 386,387 near Ponce...........................................................................389-392 Cerro Gordo, Río Cayaguas at ................................................ 222,223 Charco Hondo, Río Tanamá at .................................................. 99,100 Chemical oxygen demand, definition of .......................................... 31 Chico at Providencia, Río........................................................ 354,355 Chico basin, Río, water-quality records in .............................. 354,355 Chlorophyll, definition of................................................................. 31 Ciales, Río Cialitos at Highway 649 at .................................. 121,122 Ciales, Río Grande de Manatí at ............................................. 118,119 Ciales, Río Grande de Manatí at Highway 149 at .......................... 120 Cialitos at Highway 649 at Ciales, Río ................................... 121,122 Cibuco at Vega Baja, Río ....................................................... 134-137 below Corozal .................................................................... 130-133 Cibuco basin, Río, gaging station records in...........................129-137 ground-water records in ......................................................505-510 624 INDEX Page water-quality records in...................................................... 132-137 Cidra, Lago de Cidra at Damsite near.............................. 170,480,481 Coamo basin, Río, gaging station records in ........................................................................ 366-369 ground-water records in ............................................................. 511 water-quality records in....................................................... 368,369 Coamo at Coamo, Río............................................................. 366,367 near Coamo ......................................................................... 368,369 Color unit, definition of ................................................................... 31 Comerío, location of low-flow partial records in Puerto Rico ........................................................................ 455 Comerío, Quebrada Convento at.................................................... 457 Comerío, Quebrada Doña Elena at Highway 167 near.................. 459 Comerío, Quebrada Higüero at Highway 156 near ....................... 458 Comerío, Quebrada Piñas at Highway 775.................................... 457 Comerío, Río Arroyatas at mouth near .......................................... 443 Comerío, Río de la Plata at ..................................................... 143-148 Comerío, Río de la Plata near ................................................. 149,150 Comerío, Río Hondo near .............................................................. 456 Contents, definition of ..................................................................... 31 Control, definition of ....................................................................... 32 Control structure, definition of ........................................................ 32 Cooperation........................................................................................ 2 Corozal, Río Cibuco below..................................................... 130-133 Cubic foot per second, definition of ................................................ 32 Cubic foot per second-day, definition of ......................................... 32 Cubic feet per second per square mile, definition of ....................... 32 Culebrinas at Highway 404 near Moca, Río ........................... 448,449 near Aguada......................................................................... 450,451 Culebrinas basin, Río, gaging station records in............................................................. 448,449 ground-water records in ...................................................... 599-604 water-quality records in......................................... 446,447,450,451 D Definition of terms ...................................................................... 30-39 Descalabrado basin, Río, gaging station records in ................ 370,371 Descalabrado near Los Llanos, Río ........................................ 370,371 Diatoms, definition of ...................................................................... 35 Discharge at low-flow partial-record stations in Puerto Rico ...................................................... 53-459 Discharge, definition of ................................................................... 32 Discharge of partial-record stations in Puerto Rico ....................... 453 Dissolved, definition of.................................................................... 32 Dissolved-solids concentrations, definition of................................. 32 Diversity index, definition of........................................................... 32 Doña Elena, Quebrada Higüero at Highway 780 at Barrio .......................................................... 457 Dos Bocas, Quebrada Grande at Barrio ......................................... 468 Drainage area, definition of ............................................................. 32 Drainage basin, definition of............................................................ 33 Dry mass, definition of .................................................................... 31 E El Jagual, Quebrada Blanca at ................................................ 210-215 El Mangó, Río Gurabo below ................................................. 265-270 El Señorial, Río Piedras at ...................................................... 186-196 El Verde, Quebrada Sonadora near......................................... 304,305 El Verde, Río Grande near...................................................... 310,311 Espíritu Santo basin, Río, gaging station records in ......................................................... 304-311 water-quality records in...................................................... 308,309 Espíritu Santo near Río Grande, Río....................................... 306-309 Explanation of records ..................................................................... 10 Page F Fajardo above Fajardo, Río .....................................................323-328 below Fajardo ..................................................................... 335,336 near Fajardo ........................................................................329-334 Fajardo basin, Río, gaging station records in .....................................................................323-336 water-quality records in ....................................... 325-328,331-336 Fecal coliform bacteria, definition of .............................................. 31 Fecal streptococcal bacteria, definition of........................................ 31 Florida, Río Grande de Arecibo below Lago Dos Bocas near....................................................... 84,85 G Gage-height, definition of ................................................................ 33 Gaging station, definition of............................................................. 33 Grande de Añasco basin, Río, gaging station records in..........................................................436-444 water-quality records in ........................................437,438,441-444 Grande de Añasco near Añasco, Río....................................... 443,444 near Lares............................................................................ 437,438 near San Sebastián ..............................................................439-442 Grande de Arecibo at Central Cambalache, Río .........................................101-104 above Arecibo .........................................................................86-91 below Lago Dos Bocas near Florida....................................... 84,85 below Utuado..........................................................................65-70 near Adjuntas .......................................................................... 63,64 near Utuado............................................................................. 71,72 Grande de Arecibo basin, Río, gaging station records in............................................................61-104 ground-water records in ......................................................492-498 water-quality partial-record stations, analyses of samples collected at ..................................472-481 water-quality records in ....................... 63,64,67-72,77-82,103,104 Grande de Loíza at Caguas, Río ..............................................236-242 at Highway 183 near San Lorenzo......................................224-229 at Quebrada Arenas............................................................. 208,209 below Damsite ....................................................................293-298 below Trujillo Alto ............................................................. 299,300 Grande de Loíza basin, Río, gaging station records in..........................................................205-302 ground-water records in ......................................................533-544 water-quality partial-record stations, analyses of samples collected at ..................................472-481 water-quality records in ......................................................206-300 Grande de Manatí at Ciales, Río ............................................. 118,119 at Highway 2 near Manatí....................................................123-126 at Highway 149 at Ciales ............................................................ 120 near Morovis ........................................................................110-113 Grande de Manatí basin, Río, gaging station records in .............................................................105-126 ground-water records in .......................................................499-504 water-quality records in .................................. 108,109,113,125,126 Grande de Patillas near Patillas, Río .......................................356-358 Grande de Patillas basin, Río, gaging station records in ......................................................356-359 water-quality records in .............................................................. 358 Grande near El Verde, Río ...................................................... 310,311 Graphs: Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands .................................... 7 Monthly-mean discharge of selected streams in Puerto Rico ............................................................... 4 Green algae, definition of ................................................................. 35 Grid showing system for numbering wells and 625 INDEX Page miscellaneous sites (latitude and longitude) ............................ 19 Ground-water level, records of ................................................... 27,28 Ground-water quality, records of................................................ 28,29 Ground-water records for Puerto Rico.................................... 483-604 Ground-water records for U.S. Virgin Islands............................... 615 Ground-water station, definition of.................................................. 33 Ground-water stations in Puerto Rico, map showing location of.......................................................... 16 Ground-water stations in U.S. Virgin Islands, map showing location of.......................................................... 18 Guabá near Naguabo, Quebrada ............................................. 337,338 Guadiana near Naranjito, Río ................................................. 151,152 Guajataca above mouth near Quebradillas, Río ................................................................ 55,56 at Lares .................................................................................... 48-51 Guajataca basin, Río, gaging station records in ............................................................................ 48-56 ground-water records in ...................................................... 484-487 water-quality partial-record stations, analyses of samples collected at ..................................... 472-481 water-quality records in........................................................... 50-56 Guanajibo at Highway 119 at San Germán, Río..................... 418,419 near Hormigueros ................................................................ 429-432 near San Germán ................................................................. 420,421 Guanajibo basin, Río, gaging station records in ........................................................................ 418-430 ground-water records in ...................................................... 589-596 water-quality records in........................... 420,421,424-428,431,432 Guánica, Río Loco at .............................................................. 415,416 Guayanés above mouth at Playa de Guayanés, Río................................................................. 348,349 at Yabucoa.......................................................................... 346,347 Guayanés basin, Río, water-quality records in ....................... 346-349 Guayanilla at Central Rufina, Río........................................... 411,412 near Guayanilla .................................................................. 409,410 Guayanilla basin, Río, gaging station records in ......................................................... 409-412 water-quality records in..................................................... 411,412 Guaynabo at Highway 836 near Guaynabo, Río ........................... 445 Guaynabo below Guaynabo, Río ................................................... 445 Guaynabo near Bayamón, Río ................................................ 181,182 Guinea Gut at Bethany, St. John, VI....................................... 610,611 Gurabo at Gurabo, Río ............................................................ 277-282 below El Mangó ................................................................. 265-270 near Gurabo ........................................................................ 283,284 H Hardness, definition of..................................................................... 33 Hato Rey, Río Piedras at ......................................................... 199-202 Herrera to Río Antón Ruíz Basin, Río .................................... 545-552 Hondo at Flood Channel near Cataño, Río ............................. 164,165 Hondo near Comerío...................................................................... 456 Hondo basin, Río ground-water records in .............................................. 523-532 water-quality records in...................................................... 164,165 Hormigueros, Río Guanajibo near .......................................... 429-432 Hormigueros, Río Rosario near .............................................. 422-428 Humacao at Highway 3 at Humacao, Río............................... 344,345 at Las Piedras ..................................................................... 342,343 Humacao basin, Río, gaging station records in..................................................................... 342-345 water-quality records in...................................................... 344,345 Humacao to Quebrada Aguas Verdes basin, Río.................... 553-562 Hydrologic Bench-Mark Network, definition of ............................. 33 Hydrologic conditions, summary of ............................................... 3-9 Hydrologic unit, definition of .......................................................... 33 Page I Icacos near Naguabo, Río........................................................ 339,340 Identification numbers, stations ....................................................... 11 Inabón at Real Abajo, Río ....................................................... 384,385 Inabón basin, Río, gaging station records in .......................... 384,385 ground-water records in ......................................................581-588 Instantaneous discharge, definition of.............................................. 32 Introduction ........................................................................................ 1 J Jacaguas at Juana Díaz, Río .................................................... 381,382 Jacaguas basin, Río, gaging station records in .....................................................................372-382 water-quality records in ......................................................374-377 Jayuya, Río Caonillas above Lago Caonillas near ...................... 81,82 Jayuya, Río Saliente at Coabey near ........................................... 73,74 Jolly Hill Gut at Jolly Hill, St. Croix, VI ................................ 612,613 Juana Díaz, Lago Guayabal at Damsite near.................................. 380 Juana Díaz, Río Jacaguas at .................................................... 381,382 Juncos, Río Valenciano near ...................................................271-276 L Lago Caonillas at Damsite near Utuado........................................... 83 Lago Carite at Gate Tower near Cayey .......................................... 140 Lago Carite No. 1 near dam near Cayey .................................479-481 No. 3 on Río de La Plata near Cayey...................................472-474 Lago Cerrillos at Damsite near Ponce ............................................ 388 Lago Cerrillos near Ponce, Río Cerrillos above......................386-387 Lago de Cidra at Damsite near Cidra ............................................. 170 Lago de Cidra near Dam .......................................... 475-478,479-481 Lago de Cidra near Río de Bayamón Mouth...........................472-474 Lago de Cidra, Río de Bayamón below ..................................171-176 Lago de Guajataca, at Damsite near Quebradillas ........................... 52 Canal Principal de Diversiones at ............................................ 53,54 No. 1 near dam near Quebradillas .......................................479-481 No. 3 near mouth near Quebradillas ....................................472-474 Lago de Matrullas at Damsite near Orocovis ................................. 115 Lago Dos Bocas No. 1 near dam near Utuado ........................479-481 No. 3 at west branch near Utuado........................................472-474 Lago El Guineo at Damsite near Villalba ...................................... 114 Lago Garzas near Adjuntas .............................................................. 62 Lago Garzas No. 1 near dam near Adjuntas............................479-481 Lago Guayabal at Damsite near Juana Díaz................................... 380 Lago Guayo at Damsite near Castañer ........................................... 436 Lago La Plata at Damsite near Toa Alta ........................................ 153 Lago La Plata No. 3 near dam near Naranjito .........................475-478 No. 5 near mouth near Naranjito .........................................472-474 Lago Las Curias at Damsite near Río Piedras ................................ 185 Lago Loco at Damsite near Yauco ................................................. 414 Lago Loíza at Damsite near Trujillo Alto .............................. 291,292 No. 4 near mouth near Caguas.............................................472-474 No. 7 near dam near Trujillo Alto......................... 475-478,479-481 Lago Lucchetti at Damsite near Yauco .......................................... 413 Lago de Matrullas at Damsite near Orocovis ................................. 115 Lago Patillas at Damsite near Patillas ............................................ 359 Lago Toa Vaca, at Damsite near Villalba ............................... 378,379 Lago Toa Vaca, Río Toa Vaca above......................................372-377 Laguna San José No. 2 at San Juan ................................................ 203 Laguna Tortuguero basin, water quality records in........................ 127 Laguna Tortuguero outlet near Vega Baja ..................................... 127 Land-surface datum, definition of .................................................... 33 Lapas near Rabo del Buey, Río ............................................... 362,363 La Plata at Proyecto La Plata, Río de .............................................................................. 141,142 626 INDEX Page at Comerío ........................................................................... 143-148 at Highway 2 near Toa Alta ................................................ 159-162 below La Plata Dam ............................................................ 154-158 near Comerío ....................................................................... 149,150 La Plata basin, Río de, gaging station records in ......................................................... 139-162 ground-water records in ..................................................... 511-522 water-quality partial-record stations, analyses of samples collected at.................................. 472-481 water-quality records in........................................ 141,142,145-152 La Plena, Río Majada at.......................................................... 364,365 Lares, Río Grande de Añasco near ......................................... 437,438 Lares, Río Guajataca at ............................................................... 48-51 Las Piedras, Río Humacao at .................................................. 342,343 Levels for Puerto Rico, ground water ..................................... 484-604 Levels for U.S. Virgin Islands, ground water ......................... 616-621 Lizas, Río Maunabo at ............................................................ 350,351 Loco at Guánica, Río .............................................................. 415,416 Loco basin, Río, gaging-stations records in............................ 414-416 Loco basin, Río, water-quality records in ............................... 399,400 Los Llanos, Río Descalabrado near ........................................ 370,371 Low-flow partial-record stations in Puerto Rico, Discharge at................................................................. 456-469 M Majada at La Plena, Río.......................................................... 364,365 Majada basin, Río, ground-water records in ........................... 517-519 Mameyes basin, Río, gaging station records in ...................... 312-320 water-quality records in...................................................... 314-316 Mameyes at Mameyes, Río..................................................... 317-320 Mameyes near Sabana, Río..................................................... 312-316 Manatí, Río Grande de Manatí at Highway 2 near ................. 123-126 Maps: Location of surface-water stations in Puerto Rico ...................... 14 Location of ground-water stations in Puerto Rico ...................... 16 Location of ground-water stations in the U.S. Virgin Islands............................................................... 18 Location of low-flow partial-record stations in Caguas, Puerto Rico ........................................................... 461 Carolina, Puerto Rico......................................................... 467 Comerío, Puerto Rico......................................................... 455 Location of maximum concentration of fecal coliform bacteria at sample sites .......................................... 12 Location of maximum concentration of fecal streptococci bacteria at sample sites .................................... 13 Location of surface-water stations in the U.S. Virgin Islands............................................................... 17 Location of water-quality stations in Puerto Rico....................... 15 Río Camuy basin ......................................................................... 57 Río Cibuco basin ....................................................................... 129 Río Culebrinas basin ................................................................. 445 Río Grande de Arecibo basin ...................................................... 61 Río Grande de Loíza basin ........................................................ 205 Río Grande de Manatí basin...................................................... 105 Río Guajataca basin...................................................................... 47 Río Guanajibo basin ................................................................... 417 Río Herrera to the Río Antón Ruiz basins.................................. 303 Río Hondo to the Río Puerto Nuevo basins ............................... 163 Río Humacao to Quebrada Aguas Verdes basins....................... 341 Río Inabón to the Río Loco basins ............................................. 383 Río de la Plata basin ................................................................... 139 Río Salinas to the Río Jacaguas basins....................................... 361 Río Yagüez and Río Grande de Añasco basins ........................................................................ 433 Maunabo at Lizas, Río ............................................................ 350,351 at Maunabo .......................................................................... 352,353 Page Maunabo basin, Río, gaging stations records in.........................................................................350-353 water-quality records in ....................................................... 352,353 Maximum concentrations of fecal coliform bacteria at sampled sites, map showing location of............................... 12 Maximum concentrations of fecal streptococci bacteria at sampled sites, map showing location of................................................................................. 13 Mayagüez, Río Yagüez near ................................................... 434,435 Mean concentration, definition of .................................................... 37 Mean discharge, definition of........................................................... 32 Measuring point, definition of.......................................................... 33 Metamorphic stage, definition of ..................................................... 33 Methylene blue active substances, definition of .............................. 33 Micrograms per gram, definition of ................................................. 33 Micrograms per liter, definition of ................................................... 33 Milligrams of carbon per area or volume per unit time or periphyton and macrophytes and for phytoplankton, definition of ........................................ 36 Milligrams of oxygen per area or volume per unit time for periphyton and macrophytes and for phytoplankton, definition of ........................................ 36 Milligrams per liter, definition of..................................................... 33 Moca, Río Culebrinas at Highway 404 near ........................... 448,449 Morovis, Río Grande de Manatí near ......................................110-113 N Naguabo, Quebrada Guabá near.............................................. 337,338 Naguabo, Río Icacos near........................................................ 339,340 Naranjito, Lago La Plata No. 3 near dam near ........................475-478 Naranjito, Lago La Plata No. 5 near mouth near.....................472-474 Naranjito, Río Guadiana near .................................................. 151,152 Naranjo, Quebrada Naranjo at Barrio............................................. 459 National Stream-Quality Accounting Network, definition of .......................................................... 34 National Trends Network, definition of ........................................... 34 Natural substrate, definition of ......................................................... 37 Networks and programs, special ...................................................... 10 O Organic mass, definition of .............................................................. 31 Organism, definition of .................................................................... 34 Organism count/area, definition of................................................... 34 Organism count/volume, definition of ............................................. 34 Orocovis, Lago de Matrullas at Damsite near ................................ 115 Orocovis, Río Bauta near ........................................................ 116,117 Orocovis, Río Orocovis at ....................................................... 106,107 Orocovis, Río Orocovis near ................................................... 108,109 P Palomas, Tributario de Quebrada Higüero at Barrio...................... 457 Parameter code, definition of ........................................................... 34 Partial-record station, definition of .................................................. 34 Partial-record stations in Puerto Rico, Discharge at....................... 453 Partial-record stations in Puerto Rico, water quality at ............................................................472-481 Particle size, definition of................................................................. 35 Particle-size classification, definition of .......................................... 35 Paso Palma, Río Caonillas at.......................................................75-80 Patillas, Lago de Patillas Damsite near .......................................... 359 Patillas, Río Grande de Patillas near .......................................356-358 Percent composition, definition of ................................................... 35 Periphyton, definition of................................................................... 35 Pesticides, definition of .................................................................... 35 627 INDEX Page Phytoplankton, definition of ............................................................ 35 Picocurie, definition of..................................................................... 35 Piedras at Hato Rey, Río ......................................................... 199-202 near Río Piedras ................................................................. 197,198 Plankton, definition of ..................................................................... 35 Playa de Guayanés, Río Guayanés above mouth at ................ 348,349 Polychlorinated biphenyls, definition of.......................................... 36 Ponce, Río Bucaná at Highway 14 Bridge near...................... 393,394 Ponce, Río Cerrillos above Lago Cerrillos near ..................... 386,387 Ponce, Lago Cerrilos at Damiste near............................................ 388 Ponce, Río Cerrillos near ........................................................ 389-392 Ponce, Río Portugués at .......................................................... 407,408 Highway 14 at .................................................................... 403-406 Ponce, Río Portugués near ...................................................... 401,402 Portugués at Ponce, Río ..................................................... 407,408 near Ponce .......................................................................... 401,402 Portugués at Highway 14 at Ponce, Río.................................. 403-406 Portugués basin, Río, gaging station records in............................................................. 395-408 Portugués at Tibes, Río ....................................................... 395-400 water-quality records in......................................... 397-402,407,408 Prieta at Barrio Río Hondo, Quebrada ........................................... 456 Primary productivity, definition of .................................................. 36 Programs, special networks and ...................................................... 10 Providencia, Río Chico at ....................................................... 354,355 Proyecto La Plata, Río de La Plata at ..................................... 141,142 Publications on Techniques of Water-Resources Investigations ......................................... 40-43 Puerto Nuevo basin, Río, gaging station records in............................................................. 185-200 water-quality records in.........................................190-198,201-204 Q Quality of water records of Puerto Rico, surface- and....................................................................... 48-451 Quebrada Aguas Verdes basin, ground-water records in.................................................. 553-562 Quebrada Arenas, Río Grande de Loíza at ............................. 208,209 Quebrada Beatriz at Barrio Beatriz................................................ 463 Quebrada Cejas at Barrio Vega Redonda ...................................... 458 Quebrada Convento at Comerío..................................................... 457 Quebrada de las Quebradillas above Dam at Barrio Turabo ................................................. 463 at Barrio Beatriz ......................................................................... 463 Quebrada Doña Elena at Highway 167 near Comerío ......................................................................... 459 Quebrada Grande at Barrio Dos Bocas .......................................... 468 Quebrada Higüero at Highway 780 at Barrio Doña Elena....................................... 457 Highway 156 near Comerío ....................................................... 458 Quebrada Maracai at Barrio San Salvador..................................... 462 Quebrada Maracuta at Barrio Santa Cruz .................................................................. 468 Trujillo Bajo ............................................................................... 469 Quebrada Naranjito at Barrio Borinquen....................................... 462 Quebrada Naranjo at Barrio Naranjo ............................................. 459 Quebrada Pastrana near Mariana at Barrio Cacaos ...................................................... 468 mouth at Barrio Cacaos .............................................................. 468 Quebrada Piñas at Highway 775 at Comerío................................. 457 Quebrada Prieta at Barrio Río Hondo ............................................ 456 Quebrada Sonadora at Barrio Beatriz ............................................ 463 Quebradillas, Lago Guajataca at Damsite near................................ 52 Quebradillas, Lago Guajataca No. 1 near dam near.................................................................. 479,480 Quebradillas, Lago Guajataca No. 3 Page near mouth near...............................................................472-474 Quebradillas, Río Guajataca above mouth near........................................................................... 55,56 R Rabo del Buey, Río Lapas near ............................................... 362,363 Radiochemical program, definition of.............................................. 36 Real Abajo, Río Inabón at ....................................................... 384,385 Records, explanation of ................................................................. 9,10 Records of ground-water levels................................................... 27,28 Records of ground-water quality ................................................. 28,29 Records of stage and water discharge .........................................19-27 Records of surface-water quality.................................................24-27 Recoverable from bottom material, definition of ............................. 36 Return period, definition of .............................................................. 36 Río Cañas, Río Cañas at ..........................................................285-290 Río Cañas, Tributario de Río Cañas at Barrio................................ 465 Río Grande, El Verde near ...................................................... 310,311 Río Grande, Río Espíritu Santo near .......................................306-309 Río Hondo at Highway 776 at Río Hondo ..................................... 456 Río Hondo, Quebrada Prieta at Barrio ........................................... 456 Río Piedras at El Señorial........................................................ 186,196 Río Piedras, Lago Las Curias at Damsite near ............................... 185 Río Piedras, Río Piedras near .................................................. 197,198 at Hato Rey ..........................................................................199-202 Rosario near Hormigueros, Río...............................................422-428 Runoff, in inches, definition of ........................................................ 36 S Sabana at Vista Monte, Río ..................................................... 168,169 Sabana Hoyos ................................................................................. 508 Sabana basin, Río, gaging station records in........................... 321,322 ground-water records in ...................................................... 506,507 at Sabana ............................................................................. 321,322 Sabana, Río Mameyes near .....................................................312-316 Saliente at Coabey near Jayuya, Río ........................................... 73,74 Salinas, Río gaging station records in .....................................362-365 Salinas to Río Jacaguas basin, Río ground-water station in ...................................................563-580 Salvatierra near San Lorenzo, Quebrada .................................216-221 San Germán, Río Guanajibo at Highway 119 at ..................... 418,419 San Germán, Río Guanajibo near............................................ 420,421 San Juan, Bahía de San Juan No. 5 at ............................................ 204 San Juan, Laguna San José No. 2 at .............................................. 203 San Lorenzo, Quebrada Salvatierra near .................................216-221 San Lorenzo, Río Grande de Loíza at Highway 183 near........................................................224-229 San Salvador, Quebrada Maracai at Barrio .................................... 462 San Salvador, Río Turabo at Barrio ............................................... 462 San Sebastián, Río Culebrinas near......................................... 430,431 San Sebastián, Río Grande de Añasco near ............................439-442 Santa Cruz, Quebrada Maracuta at Barrio...................................... 468 Sediment, definition of ..................................................................... 36 7-day 10-year low flow, definition of .............................................. 37 Sodium-adsorption-ratio, definition of............................................. 37 Solute, definition of .......................................................................... 37 Sonadora near El Verde, Quebrada ......................................... 304,305 Special network and programs ......................................................... 10 Specific conductance, definition of .................................................. 37 Stage-discharge relation, definition of ............................................. 37 Station identification numbers.......................................................... 10 St. Croix, VI, Jolly Hill Gut at Jolly Hill ................................ 612,613 St. John, VI, Guinea Gut at Bethany ....................................... 610,611 Streamflow, definition of ................................................................. 37 628 INDEX Page St. Thomas, VI, Bonne Resolution Gut at Bonne Resolution ............................................ 606,607 St. Thomas, VI, Turpentine Run at Mount Zion..................... 608,609 Substrate, definition of..................................................................... 37 Summary of hydrologic conditions................................................. 3-9 Surface and quality-of-water records for Puerto Rico .............. 45-451 Surface area, definition of................................................................ 38 Surface-water quality, records of ................................................ 24-27 Surface-water records for U.S. Virgin Islands............................... 605 Surface-water stations in Puerto Rico, map showing location of ...................................................... 14 Surface-water stations in U.S. Virgin Islands, map showing location of ...................................................... 17 Surficial bed material, definition of ................................................. 38 Suspended, definition of .................................................................. 38 Suspended-recoverable, definition of ............................................. 38 Suspended sediment, definition of ................................................... 36 Suspended-sediment concentration, definition of............................ 37 Suspended-sediment discharge, definition of .................................. 37 Suspended-sediment load, definition of........................................... 37 Suspended-total, definition of .......................................................... 38 T Tanamá at Charco Hondo, Río.................................................. 99,100 near Utuado ............................................................................. 92-98 Taxonomy, definition of .................................................................. 38 Techniques of Water-Resources Investigations, publications on ........................................... 40-42 Terms, definition of .................................................................... 30-39 Thermograph, definition of.............................................................. 38 Tibes, Río Portugués at .......................................................... 395-400 Time-weighted average, definition of ............................................. 38 Toa Alta, Lago La Plata at Damsite near....................................... 153 Toa Alta, Río de la Plata at Highway 2 near........................... 159-162 Toa Vaca above Lago Toa Vaca, Río ..................................... 372-377 Tons per acre-foot, definition of ...................................................... 38 Tons per day, definition of............................................................... 39 Total, definition of ........................................................................... 39 Total coliform bacteria, definition of............................................... 30 Total discharge, definition of........................................................... 39 Total organism count, definition of ................................................. 34 Total-recoverable, definition of ....................................................... 39 Total sediment discharge, definition of .......................................... 37 Total sediment load, definition of .................................................... 37 Tributario de Quebrada Higüero at Barrio Palomas ...................... 457 Tributario de Río Cañas at Barrio Río Cañas ................................ 465 Tritium network, definition of ......................................................... 39 Trujillo Alto, Lago Loíza at Damsite near..................................... 291 Trujillo Alto, Lago Loíza No. 7 near dam near ........475-478,479-481 Trujillo Alto, Río Grande de Loíza below .............................. 299,300 Trujillo Bajo, Quebrada Maracuta at ............................................. 469 Turabo above Borinquen, Río................................................. 230-235 Turabo at Barrio San Salvador, Río ............................................... 462 Turabo at Highway 775 at Barrio Borinquen, Río......................... 462 Turabo at Villa del Rey near Caguas, Río ..................................... 464 Turabo, Quebrada de las Quebradillas above Dam at Barrio.............................................................. 463 Turpentine Run at Mount Zion, St. Thomas, VI..................... 608,609 U Utuado, Lago Caonillas at Damsite near ......................................... 83 Utuado, Lago Dos Bocas No. 1 near dam near....................... 479-481 Utuado, Lago Dos Bocas No. 3 at west branch near ............................................................. 472-474 Utuado, Río Grande de Arecibo below....................................... 65-70 Page Utuado, Río Grande de Arecibo near .......................................... 71,72 Utuado, Río Tanamá near............................................................92-98 V Valenciano near Juncos, Río ...................................................271-276 Vega Baja, Laguna Tortuguero outlet near .................................... 127 Vega Baja, Río Cibuco at ........................................................134-137 Vega Redonda, Quebrada Cejas at Barrio...................................... 458 Villalba, Lago El Guineo at Damsite near ..................................... 114 Villalba, Lago Toa Vaca at Damsite near ............................... 378,379 Vista Monte, Río Sabana at ..................................................... 168,169 W Water-discharge, records of stage and ........................................19-24 Water-quality partial-record stations in Puerto Rico ....................................................472-481 Water-quality stations in Puerto Rico, map showing location of................................................. 15 Water-Resources Investigations, publications on Techniques of ............................................40-43 Water year, definition of .................................................................. 39 U.S. Geological Survey Water Data, Access to ............................... 29 WDR, definition of........................................................................... 39 Weighted average, definition of ....................................................... 39 Wells - Puerto Rico: Camuy basin, Río Campo Alegre 4........................................................... 490,491 Zanja 4 ......................................................................... 488,489 Cibuco basin, Río Well 70 - Sabana Hoyos ..................................................... 508 Well 211 - Rosario No. 2.................................................... 507 Well 212 - Ponderosa TW-1............................................... 509 Well 213 - Pampano No. 2 ................................................. 510 Well PA-2 Palo Alto #2...................................................... 505 Well TO-3 Tortuguero TW-3 ............................................. 506 Culebrinas basin, Río Well 200 - Aguadilla Cement north ................................... 604 Well C-4 ...................................................................... 599,600 Well R-4 ......................................................................601-603 Grande de Arecibo basin, Río Well 204 - Gilberto Rivera ................................................. 493 Well EN-1 Encantada #1 PRASA ...................................... 494 Well FA-2 Florida Afuera No. 2 ................................. 496,497 Well FL-1 Florida #1.......................................................... 498 Well TI-1 Tiburones #1 ...................................................... 455 Grande de Loíza basin, Río Well 50 - USGS #50 Experimental Gurabo ....................... 540 Well 222 - Campo Rico TW-1 ........................................... 541 Well CJ-TW-3B - Gurabo Oeste ........................................ 544 Well CJ-TW-11 ........................................................... 534,535 Well CJ-TW-15 ........................................................... 538,539 Well CJ-TW-19A - Bonneville .......................................... 533 Well CJ-TW-18 ........................................................... 542,543 Well CJ-TW-20 ........................................................... 536,537 Grande de Manatí basin, Río Well 166 Manatí USGS #166............................................. 501 Well 206 - Plazuela No. 2................................................... 499 Well 207 - Cantito La Luisa ............................................... 500 Well 210 - Gelo Martínez................................................... 503 Well CS-7 Cotto Sur #7...................................................... 504 Well HI-2 Hill OBO #2 ...................................................... 502 Guajataca basin, Río Well 165 - Mateo Pérez, Bo. Saltos ................................... 486 Well 202 - Carmelo Barreto-García ................................... 487 Well OT-1 Otilio No. 1 ............................................... 484,485 629 INDEX Page Guanajibo basin, Río Well 143 - Vivoni, Hacienda Amistad............................... 589 Well CR-1 ................................................................... 590-592 Well CR-TW-9A - Bajura #9A .......................................... 593 Well CR-TW-9B ......................................................... 594-596 Herrera to Río Antón Ruíz basin, Río Well ARR-1 - Arroyo TW-1 .............................................. 548 Well RE-2A................................................................. 545,546 Well RF-04......................................................................... 551 Well RF-12......................................................................... 552 Well RM-02 - Pozo Río Mameyes No. 2........................... 547 Well RP-04......................................................................... 550 Well RS-02......................................................................... 549 Hondo to Río Puerto Nuevo basins, Río Well 219 - Fort Buchanan No. 1 ........................................ 523 Well 652 - USGS Building 652 .................................. 524,525 Well PN-2 .......................................................................... 526 Well PN-5 .......................................................................... 527 Well PN-6 .......................................................................... 528 Well PN-8c......................................................................... 529 Well PN-10 ........................................................................ 530 Well PN-13 ........................................................................ 531 Well PN-19 ........................................................................ 532 Humacao to Quebrada Aguas Verdes basin, Río Well 6 - Juana 5 ................................................................. 562 Well 96 - USGS TW-2 or Yabucoa 7 ............................... 554 Well ALG-1 ................................................................ 557,558 Well BARR-1.............................................................. 559,560 Well FID-2 .................................................................. 555,556 Well P-13 ........................................................................... 561 Well YDO-1 ....................................................................... 553 Inabón to Río Loco basins, Río Well 132 - Yauco 2 ............................................................ 538 Well 141 - Restaurada 8A .................................................. 581 Well AN-1.......................................................................... 585 Well CO-3 ................................................................... 582-584 Well LV-1 ................................................................... 586-587 La Plata basin, Río de Well 216 - Pozo Navy - Campanillas................................. 521 Well 217 - Monserrate TW - 2 .......................................... 522 Well DA-1.......................................................................... 511 Well HG-1................................................................... 514-516 Well HG-4.......................................................................... 517 Well SA-1 .......................................................................... 518 Well SA-3 .......................................................................... 519 Well MA-2 ......................................................................... 513 Page Well SR-2 ........................................................................... 512 Well TB-1 ........................................................................... 520 Salinas to Río Jacaguas basins, Río Well 87 - Alomar 1............................................................. 576 Well CA-1 ................................................................... 577,578 Well CA-D................................................................... 570,571 Well CQ-1 .......................................................................... 567 Well EC-1 .................................................................... 572,573 Well FA-1 ....................................................................579-580 Well HW-TW-01................................................................ 563 Well HW-TW-03C ............................................................. 564 Well HW-TW-05B ............................................................. 565 Well HW-TW-13................................................................ 566 Well PG-07 ......................................................................... 574 Well PS-07.......................................................................... 575 Well RM-05........................................................................ 568 Well RM-10........................................................................ 569 Yagüez and Río Grande de Añasco basins Well CI-1 ..................................................................... 597,598 Wells - U.S. Virgin Islands St. Croix Well 2 - USGS-10, Fairplains 2 (FP2) ............................... 616 Well 3 - Golden Grove 6 (PW6)......................................... 617 Well 13 - WAPA - 17 ......................................................... 618 St. John Well 11 - Guinea Gut Well................................................. 621 St. Thomas Well 6 - Grade School 3 ..................................................... 619 Well 8 - VIEO-6 ................................................................. 620 Wet mass, definition of .................................................................... 31 WSP, definition of ........................................................................... 39 Y Yabucoa, Río Guayanés at ...................................................... 346,347 Yagüez and Río Grande de Añasco basins, Río ground-water records in ..................................................597-598 Yagüez basin, Río, water-quality records in ........................... 434,435 Yagüez near Mayagüez, Río ................................................... 434,435 Yauco basin, Río, gaging station records in ................................... 413 Yauco, Lago Loco at Damsite near ................................................ 414 Yauco, Lago Lucchetti at Damsite near ......................................... 413 Z Zooplankton, definition of................................................................ 35 U.S. DEPARTMENT OF THE INTERIOR U.S. Geological Survey, WRD GSA Center, 651 Federal Dr., Suite 400-15 Guaynabo PR 00965