Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1988 o,ca,lc AL 424›, 4-.0.014. VA. BE C 0 6 19" St Thomas I Isla c:1 1 St John I Culebra U.S. VIRGIN Isla de Vieques ISLANDS PUERTO RICO Saint Croix I U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-88-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies CALENDAR FOR WATER YEAR 1988 1987 OCTOBER NOVEMBER DE CEM BE R SMTWT F S SMTW T F S SMTW T F S 1 2 3 1 2 3 4 5 6 7 1 2 3 4 5 4 5 6 7 8 9 10 8 9 10 11 12 13 14 6 7 8 9 10 11 12 11 12 13 14 15 16 17 15 16 17 18 19 20 21 13 14 15 16 17 18 19 18 19 20 21 22 23 24 22 23 24 25 26 27 28 20 21 22 23 24 25 26 25 26 27 28 29 30 31 29 30 27 28 29 30 31 1988 JANUARY FEBRUARY MARCH SMTWT F S S MTWTI? S SMTW T F S 1 2 1 2 3 4 5 6 1 2 3 4 5 3 4 5 6 7 8 9 7 8 9 10 11 12 13 6 7 8 9 10 11 12 10 11 12 13 14 15 16 14 15 16 17 18 19 20 13 14 15 16 17 18 19 17 18 19 20 21 22 23 21 22 23 24 25 26 27 20 21 22 23 24 25 26 24 25 26 27 28 29 30 28 29 27 28 29 30 31 31 APRIL MAY JUNE SMTWT F S SMT WT F S SMT W T F S 1 2 1 2 3 4 5 6 7 1 2 3 4 3 4 5 6 7 8 9 8 9 10 11 12 13 14 5 6 7 8 9 10 11 10 11 12 13 14 15 16 15 16 17 18 19 20 21 12 13 14 15 16 17 18 17 18 19 20 21 22 23 22 23 24 25 26 27 28 19 20 21 22 23 24 25 24 25 26 27 28 29 30 29 30 31 26 27 28 29 30 JULY AUGUST SEPTEMBER SMTWT F S SMTWTFS SMT WT F S 1 2 1 2 3 4 5 6 1 2 3 3 4 5 6 7 8 9 7 8 9 10 11 12 13 4 5 6 7 8 9 10 10 11 12 13 14 15 16 14 15 16 17 18 19 20 11 12 13 14 15 16 17 17 18 19 20 21 22 23 21 22 23 24 25 26 27 18 19 20 21 22 23 24 24 25 26 27 28 29 30 28 29 30 31 25 26 27 28 29 30 31 Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1988 by R.E. Curtis, Jr., Z. Aquino, P.L. Diaz, and R.J. Vachier St Thomas I c:C • eeb Isla de? St John I Culebra U.S. VIRGIN Isla de Vieques ISLANDS EfZb PUERTO RICO Saint Croix I U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-88-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies DEPARTMENT OF THE INTERIOR MANUEL LUJAN, JR., Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, 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 GPO Box 4424 San Juan, PR 00936 (Telephone: (809) 749-4346) 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 Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing and tabulations of the data: Jose M. Agis Senen Guzman-Rios George Arroyo Karl G. Johnson Angel Class-Cacho Sandra Lagares Iris M. Concepcion Julio Oms Angel G. Ferrer Ana V. Sanchez Carlos Figueroa Josd Rene Sanchez Eduardo Figueroa Luis Santiago-Rivera Javier Garci'a Luis Soler Rend Garcia Jose A. Torres Ralph Gonzalez Heriberto Torres-Sierra Evelyn S. Guevara Ahmed Valencia 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 Allen L. Zack, District Chief, Caribbean District, San Juan, Puerto Rico. 1. REPORT NO. 2. 3. Recipient's Accession No. REPORT DOCUMENTATION PAGE USGS/WRIVHD-89/280 _ 4. Title and Subtitle 5. Report Date Water Resources Data for Puerto Rico and the U.S. Virgin Island- August 1989 Water Year 1988 6. 7. Author(s) S. Performing Organization Re pt. No. Russell E. Curtis, Jr., Zaida Aquino, USGS-WDR-PR-88-1 Ricardo J. Vachier, Pedro L. Diaz 9. Performing Organization Name and Address 10. Project/Task/Work Unit No. U.S. Geological Survey, Water Resources Division GPO Box 4424 11. Contract(C) or Grant(G) No. San Juan, Puerto Rico 00936 (C) (G) 12. Sponsoring Organization Name and Address 13. Type of Report & Period Covered Annual-Oct. 1, 1987 U.S. Geological Survey, Water Resources Division to Sept. 30, 1988 GPO Box 4424 San Juan, Puerto Rico 00936 14. 15. Supplementary Notes Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands and other agencies. 16. Abstract (Limit: 200 words) Water-resources data for surface-water, quality-of-water, and ground-water records for the 1988 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 lischarge records for 52 streamflow-gaging stations; stage records for 5 reservoirs; water quality records for 16 streamflow-gaging stations, 42 ungaged streamsites, 11 lake sites, 2 lagoons, and 1 bay; and water-level records for 63 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. 17. Document Analysis a. Descriptors *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data, Sediments, Streamflow, Water analysis, Water Levels, Lakes. b. Identifiers/Open.Ended Terms Puerto Rico, U.S. Virgin Islands, Sampling sites. c. CO' 471 Field/Group — 18. Availability State men: 19. Security Class (This Report) 21. No. of Pages UNCLASSIFIED 474 NO RESTRICTION ON DISTRIBUTION 70. Security Class (This Page) 22. Price UNCLASSIFIED (See ANSI-239.1S) See Instructions on Reverse OPTIONAL FORM 272 (4-77) (Formerly NTIS-35) Department of Commerce V CONTENTS Page Preface • iii List of surface-water and water-quality stations, in downstream List of ground-water wells, by basin, for which records are order, for which records are published viii published xii Introduction 1 Cooperation 2 Summary of hydrologic conditions 2 Precipitation 2 Surface water 3 Ground water 7 Water quality 9 Special networks and programs 11 Explanation of records 11 Station identification numbers 11 Downstream order system 19 Latitude-longitude system 19 Records of stage and water discharge 20 Data collection and computation 20 Data presentation 22 Identifying estimated daily discharge 25 Accuracy of the records 25 Records of surface-water quality 25 Classification of records 26 Arrangement of records 26 On-site measurements and sample collection 26 Water temperature 27 Sediment 28 Laboratory measurements . • • . 28 Data presentation 28 Remark codes 30 Records of ground-water levels 30 Data collection and computation 30 Data presentation 31 Records of ground-water quality 32 Data collection and computation 32 Data presentation 33 Access to WATSTORE data 33 Definition of terms 34 Publications on Techniques of Water-Reiources Investigations 48 Surface- and quality-of-water records for Puerto Rico 51 Water-quality at partial-record stations in Puerto Rico 377 Ground-water records for Puerto Rico 389 Surface-water records for the U.S. Virgin Islands 431 Ground-Water records for the U.S. Virgin Islands 439 Index 457 VI ILLUSTRATIONS Page Figure 1. Graph showing monthly-mean discharge of selected streams in Puerto Rico 4 2. Graph showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands 8 3. Map showing location of fecal coliform bacteria concentration at sampled sites 12 4. Map showing location of fecal streptococci bacteria concentration at sampled sites 13 5. Map showing location of continuous 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 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 site (latitude and longitude) 19 11. Map showing the Rio Guajataca basin 53 12. Map showing the Rio Camuy basin 63 13. Map showing the Rio Grande de Arecibo basin 69 14. Map showing the Rio Grande de Manati basin 93 15. Map showing the Rio Cibuco basin 113 16. Map showing the Rio de la Plata basin 121 17. Map showing the Rio Hondo to the Rio Puerto Nuevo basins 135 18. Map showing the Rio Grande de Loiza basin 155 19. Map showing northeastern river basins the Rio Herrera to the Rio Anton Ruiz basins 281 20. Map showing southeastern river basins the Rio Humacao to the Rio Seco basins 301 21. Map showing south coast river basins the Rio Salinas to the Rio Jacaguas basins 317 22. Map showing south coast river basins the Rio InabOn to the Rio Loco basins 325 23. Map showing the Rio Guanajibo basin 343 24. Map showing the Rio Yaguez and the Rio Grande de Afiasco basins 359 25. Map showing the Rio Culebrinas basin 369 VII TABLES Page Table 1. Island-wide monthly precipitation and annual averages for 1988 water year and the 30-year reference period, 1951-80 3 2. Peak discharges during November 26-27 and December 6-7, 1987 and previously recorded maximum at selected streamflow gaging stations in Puerto Rico 6 3. Maximum ground-water levels in 1988 water year and highest water levels of record in feet below land-surface, at selected ground-water wells in Puerto Rico and the U.S. Virgin Islands 7 4. Surface-water quality stations throughout Puerto Rico with the highest concentration of selected constituents during water year 1988 9 5. Maximum suspended-sediment concentration and load at each station within the Rio Grande de Loiza basin 10 6. Factors for conversion of chemical constituents in milligrams per liter to milli-equivalents per liter 39 viii SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED (Letter after station name designates type of data: (d) discharge, (c) chemical, (b) biological, (s) sediment, (p) pesticide, (e) elevation) Page RIO GUAJATACA BASIN Rio Guajataca at Lares (c,b) 54 Rio Guajataca above Lago Guajataca (d) 56 Canal Principal de Diversiones at Lago Guajataca (c,b) 58 Rio Guajataca above mouth near Quebradillas (d,c,b) 60 RIO CAMUY BASIN Rio Camuy near Bayaney (d) 64 Rio Camuy near Hatillo (d) 66 RIO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e) 70 Rio Grande de Arecibo near Adjuntas (c,b) 71 Rio Grande de Arecibo near Utuado (c,b) 73 Rio Caonillas above Lago Caonillas near Jayuya (c,b) 75 Rio Grande de Arecibo below Lago Dos Bocas near Florida (c,b) 77 Rio Grande de Arecibo above Arecibo (d) 79 Rio Tanama near Utuado (d,c,b,$) 81 Rio Tanama at Charco Hondo (d) 88 Rio Grande de Arecibo at Central Cambalache (c,b) 90 RIO GRANDE DE MANATI BASIN Rio Orocovis near Orocovis (c,b) 94 Rio Grande de Manati near Morovis (d,c,b) 96 Lago El Guineo at Damsite (e) 99 Lago Matrullas at Damsite (e) 100 Rio Grande de Manati at Ciales (d) 101 Rio Grande de Manati at Highway 149 at Ciales (c,b) 103 Rio Cialitos at Highway 649 at Ciales (c,b) 105 Rio Grande de Manati at Highway 2 near Manati (d,c,b,p) 107 LAGUNA TORTUGUERO BASIN Laguna Tortuguero Outlet near Vega Baja (c,b) 112 RIO CIBUCO BASIN Rio Cibuco below Corozal (d,c,b) 114 Rio Cibuco at Vega Baja (d,c,b) 117 RIO DE LA PLATA BASIN Rio de La Plata at Proyecto La Plata (d,c,b) 122 Rio de La Plata near Comerio (c,b) 125 Rio Guadiana near Naranjito (c,b) 127 Rio de La Plata at Toa Alta (c,b,s,p) 129 Rio de La Plata at Highway 2 near Toa Alta (d) 132 RIO HONDO BASIN Rio Hondo at Flood Channel near Catafio (c,b) 136 IX SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED--Continued . Page RIO DE BAYAMON BASIN Lago de Cidra at Damsite near Cidra (e) 138 Rio de Bayamon near Aguas Buenas (c,b) 139 Rio Guaynabo near Bayamon (c,b) 141 Rio de Bayamon at Flood Channel at Bayamon (c,b,p) 143 RIO PUERTO NUEVO BASIN Rio Piedras: Rio Piedras at El Seilorial (d) 145 Laguna San Jose: Bahia de San Juan: Rio Piedras near Rio Piedras (d,c,b,p) 146 Rio Piedras at Rio Piedras (d) 148 Rio Piedras at Hato Rey (c,b) 149 Quebrada Josefina at Pifieiro Avenue (d) 151 Laguna San Jose No.2 at San Juan (c,b) 152 Bahia de San Juan No.5 at San Juan (c,b) 153 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b) 156 RIO GRANDE DE LOIZA BASIN Rio Grande de Loiza at Quebrada Arenas (d) 158 Quebrada Blanca at El Jagual (d,$) Rio Gurabo: 160 Quebrada Salvatierra near San Lorenzo (d,$) 168 Rio Cayaguas at Cerro Gordo (d,$) 178 Rio Turabo at Borinquen (d,$) 189 Rio Grande de Loiza at Caguas (d,c,b,$) 199 Rio Caguitas at Highway 30 at Caguas (c,b) 219 Rio Bairoa near Caguas (c,b) 221 Quebrada Caimito near Juncos (s) 223 Rio Valenciano near Juncos (d,$) 231 Quebrada Mamey near Gurabo (d,$) 242 Rio Gurabo at Gurabo (d,$) 252 Rio Gurabo near Gurabo (c,b) 271 Lago Loiza at Damsite (c,b,e) 273 Rio Grande de Loiza below Damsite (d) 275 Rio Grande de Loiza below Trujillo Alto (c,b) 276 Rio Canovanas near Campo Rico (d) 278 RIO ESPIRITU SANTO BASIN Quebrada Sonadora near El Verde (d) 282 Quebrada Toronja at El Verde (d) 284 Rio Espiritu Santo near Rio Grande (d,c,b) 286 RIO MAMEYES BASIN Rio Mameyes near Sabana (d) 289 RIO SABANA BASIN Rio Sabana at Sabana (d) 291 X SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED--Continued RIO FAJARDO BASIN Rio Fajardo near Fajardo (d,c,b,s,p) Rio Fajardo below Fajardo (c,b) Page 293 296 RIO BLANCO BASIN Rio Icacos near Naguabo (d) 298 RIO HUMACAO BASIN Rio Humacao at Las Piedras (d) Rio Humacao at Highway 3 at Humacao (c,b) 302 303 RIO GUAYANES BASIN Rio Guayanes at Yabucoa (c,b,p) Rio Guayanes above mouth at Playa de Guayanes (c,b) 305 307 RIO MAUNABO BASIN Rio Maunabo at Maunabo (c,b) 309 RIO CHICO BASIN Rio Chico at Providencia (c,b) 311 RIO GRANDE DE PATILLAS BASIN Rio Grande de Patillas near Patillas (d,c,b,$) 313 RIO COAMO BASIN Rio Coamo near Coamo (c,b) 318 RIO DESCALABRADO BASIN Rio Descalabrado near Los Llanos (d) 320 RIO JACAGUAS BASIN Rio Jacaguas at Juana Diaz (d) 322 RIO INABON BASIN Rio Inabon at Real Abajo (d) 326 RIO BUCANA BASIN Rio Bucand: Rio Cerrillos near Ponce (c,b) Rio Bucana at Hwy 14 Bridge near Ponce (d) 328 330 RIO PORTUGUES BASIN Rio Portugues near Ponce (d,c,b) Rio Portugues at Ponce (c,b,p) 332 335 RIO GUAYANILLA BASIN Rio Guayanilla near Guayanilla (d) Rio Guayanilla at Central Rufina (c,b,p) 337 339 RIO LOCO BASIN Rio Loco at Guanica (c,b,p) 341 XI SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED--Continued Page LAGUNA JOYUDA BASIN Quebrada Mamey at Joyuda (d) 344 RIO GUANAJIBO BASIN Rio Guanajibo near San German (c,b) 346 Rio Rosario near Hormigueros (d,c,b,$) 348 Rio Guanajibo near Hormigueros (d,c,b,p) 355 RIO YAGUEZ BASIN Rio Yaguez near Mayaguez (c,b) 360 RIO GRANDE DE AFIASCO BASIN Rio Grande de Masco near Lares (c,b) 362 Rio Grande de Afiasco near San Sebastian (d,c,b,$) 364 Rio Grande de Afiasco near Afiasco (c,b,p) 367 RIO CULEBRINAS BASIN Rio Culebrinas near San Sebastian (c,b) 370 Rio Culebrinas at Highway 404 near Moca (d) 372 Rio Culebrinas near Aguada (c,b,p) 374 ST. THOMAS, U.S. VIRGIN ISLANDS Bonne Resolution Gut at Bonne Resolution (d) 432 Turpentine Run at Mariendal (d) 434 ST. JOHN, U.S. VIRGIN ISLANDS Guinea Gut at Bethany (d) 435 ST. CROIX, U.S. VIRGIN ISLANDS Jolly Hill Gut at Jolly Hill (d) 436 390 395 400 405 410 415 XII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RIO GUAJATACA BASIN Well 182422067015100 Local number 165 Well 182647066552400 Local number 202 391 RIO GRANDE DE ARECIBO BASIN Well 182737066370900 Local number 204 392 RIO GRANDE DE MANATI BASIN Well 182544066341500 Local number 205 393 Well 182757066325600 Local number 206 394 Well 182710066303700 Local number 207 Well 182534066283000 Local number 208 396 Well 182634066262500 Local number 209 397 Well 182308066260400 Local number 210 398 RIO CIBUCO BASIN Well 182647066201700 Local number 70 399 Well 182615066235300 Local number 211 Well 182515066194000 Local number 212 401 Well 182330066185700 Local number 213 402 RIO DE LA PLATA BASIN Well 182746066170800 Local number 214 403 Well 182530066135400 Local number 216 404 Well 182655066142400 Local number 217 RIO HONDO TO RIO PUERTO NUEVO BASINS Well 182623066111000 Local number 218 406 Well 182441066082600 Local number 219 407 Well 182413066044000 Local number 220 408 Well 182436066031200 Local number 221 409 RIO GRANDE DE LOIZA BASIN Well 182515065594100 Local number 222 RIO HUMACAO TO RIO SECO BASINS Well 175858066100200 Local number 6 411 RIO GUAYANES BASIN Well 180415065513900 Local number 96 412 RIO SALINAS TO RIO JACAGUAS BASINS Well 175829066232200 Local number 87 413 Well 180002066132200 Local number HW-TW-01 414 Well 180017066132100 Local number HW-TW-02 XIII GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page Well 180001066122000 Local number HW-TW-03 416 Well 180000066125200 Local number HW-TW-04 417 Well 175947066130601 Local number HW-TW-05B 418 Well 180006066123700 Local number HW-TW-07 419 Well 175939066121400 Local number HW-TW-08 420 Well 175950066125200 Local number HW-TW-10 421 Well 180012066125500 Local number HW-TW-11 422 Well 175957066123400 Local number HW-TW-13 423 Well 175946066102000 Local number HW-TW-14 424 Well 175955066103000 Local number HW-TW-15 425 RIO INABON TO RIO LOCO BASINS Well 180133066503300 Local number 132 426 RIO GUANAJIBO BASIN Well 180132067033800 Local number 143 427 RIO CULEBRINAS BASIN Well 182018066593200 Local number 83 428 Well 182442067091700 Local number 200 429 ST. CROIX, U.S. VIRGIN ISLANDS Well 174225064471900 Local number 1 440 Well 174225064472000 Local number 2 441 Well 174243064475100 Local number 3 442 Well 174245064475800 Local number 4 443 Well 174308064484400 Local number 6 444 Well 174525064460600 Local number 7 445 Well 174527064460100 Local number 8 445 Well 174532064460300 Local number 9 446 Well 174329064454700 Local number 10 446 ST. THOMAS, U.S. VIRGIN ISLANDS Well 182050064580400 Local number 1 447 Well 182138064543100 Local number 2 447 Well 182138064542500 Local number 3 447 Well 182136064541900 Local number 4 448 Well 182029064535200 Local number 5 448 Well 182038064550300 Local number 6 449 ST. JOHN, U.S. VIRGIN ISLANDS Well 182010064472600 Local number 1 450 Well 182109064460300 Local number 2 450 Well 182116064451000 Local number 3 451 Well 182042064454500 Local number 5 452 Well 182044064454600 Local number 6 453 Well 182044064454800 Local number 7 453 Well 182044064454900 Local number 8 453 Well 182044064455000 Local number 9 454 Well 182044064455200 Local number 10 454 Well 181956064464500 Local number 11 455 XIV THIS PAGE WAS LEFT BLANK INTENTIONALLY 1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 1988." This report includes records' on both surface and ground water. Specifically, it contains: (1) Discharge records for 52 streamflow-gaging stations, stage records for 5 reservoirs; (2) water-quality records for 16 streamflow-gaging stations, and for 42 ungaged streamsites, 11 lake sites, 2 lagoon, and 1 bay; and (3) water-level records for 63 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, and 1987 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 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-88-1". 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 title page or by telephone (809) 783-4660. 2 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 COOPERATION The U.S. Geological Survey has had cooperative agreements with organiza­ tions 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 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 Public Works Puerto Rico Highway Authority Puerto Rico Department of Natural Resources Puerto Rico Department of Health Puerto Rico Electric and Power Authority Puerto Rico Rice Corporation Puerto Rico Administration for Agricultural Development Puerto Rico Land Administration Center for Energy and Environment Research, University of Puerto Rico Water Resources Research Institute, University of Puerto Rico Water Resources Research Institute, College of the Virgin Islands Department of Public Works of the U.S. Virgin Islands Funds were also provided by the Corps of Engineers, U.S. Army, for the collection of records at five gaging stations published in this report. Ground-water quality data at selected sites was collected with support from the U.S. Environmental Protection Agency. SUMMARY OF HYDROLOGIC CONDITIONS Precipitation Precipitation was higher than usual in the 1988 water year. Precipitation averaged about 122 percent of normal, islandwide, varying from 135 percent of normal in the eastern part of the island to 99 percent of normal in the western part of the island. Monthly average precipitation islandwide for water year 1988 and the 30-year (1951-80) normal as reported by the National Oceanic and Atmospheric Administration are listed in table 1. 3 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Table 1. Island-wide monthly precipitation and annual averages for 1988 water year and the 30-year reference period, 1951-80. 30-year Water year 1988 normal Month (inches) (inches) Oct. 7.41 7.74 Nov. 13.22 5.95 Dec. 7.54 4.32 Jan. 3.10 3.08 Feb. 3.03 2.35 Mar. 2.36 2.62 Apr. 5.29 4.63 May 5.26 6.48 June 5.13 5.58 July 5.20 5.48 Aug. 11.56 7.28 Sept. 7.85 7.78 TOTAL 76.95 63.29 Surface Water Streamflow in Puerto Rico was above normal during water year 1988. A comparison of 1988 streamflow at 4 index or representative gaging stations to their long-term median and extreme monthly flows is shown in figure 1. Flows during October were below normal throughout much of the island. The October mean flow for the Rio Grande de Anasco gaging station, which is in the western part of the island, was only 53 percent of the median monthly flow. In November, an upper level trough became stationary over the eastern portion of the island. Heavy rain was developed during November 26, causing severe flooding over the eastern interior portion of Puerto Rico. Monthly mean flows at all four of the index stations were above the long term median in this month. At the Rio Fajardo gaging station in the eastern part of the island, the mean flow for the month was 297 percent of the long term median, and was the third highest November mean flow recorded since the station was installed in 1962. The floods in November 1987 resulted in three deaths and forced the evacuation of about 350 people. A total of about 2,850 houses in 21 municipios received flood damage. Damages to roads and highways due primarily to landslides associated with the flooding were reported in 27 municipios. Damages in terms of cost were estimated near $6 million. •••• 4 MO NTHLY MEAN DIS CHARGE. IN CUBICFEETPER SECOND WEST NORTH RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN RIO GRANDE DE MANATI AT HWY 2 (50144000) (50038100) 4000 4000 ~. 1988 MONTHLY MEAN :•••1 1000 1000 100 20 SOUTH RIO INABON AT REAL ABAJO (50112500) 400 1988 MONTHLY MEAN •.•• 1965-87 MEDIAN MONTHLY •••-.*:• 100 10 cr cr _J o_ 0 0 z w 2 tn 1987 1988 M O NTHLYMEAN DISCHA RGE. I N CUBICFEETPERSECOND 100 20 EAST RIO FAJARDO NEAR FAJARDO (50071000) Unshaded area indicates range between highest and lowest monthly mean discharges for the period of record Figure 1.--Monthly mean discharge of selected streams in Puerto Rico. 5 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 One week after the November 26-27 floods, a combination of an approaching cold front and a southeastern flow of moist tropical air induced intense showers and thunderstorms over southeastern and eastern interior parts of Puerto Rico. High rainfall amounts in combination with saturated soil conditions produced by the previous rains ten days before, resulted in severe flash flooding. This caused the death of one person, forced the evacuation of 1,276 people, and damaged or destroyed 13 bridges. During this period, streamflow at the four index recording stations was above average. The monthly mean flow at the Rio Fajardo gaging station was 246 percent of the long term median and the monthly mean flow of Rio Inabon was 200 percent of normal. Damages associated with this flood were estimated near $5 million. Peak discharges for the floods of November and December are given for 10 stations in the affected areas in table 2. In January, above average flows continued, specially along the north coast, where the index station at the Rio Grande de Manati recorded the largest monthly mean flow for January since the station was installed. The mean flow for January at this site was 235 percent of the long term median. At the gaging station on Rio Fajardo, the monthly mean discharge in January was 148 percent of the median. The station on the Rio Grande de Masco in the western part of the island was the only index station with a monthly mean discharge below the median. During February and March, streamflows in the southern and western parts of the island showed a seasonal decline. In the northern and eastern areas, flows continued above normal during February and began to decline in March. Flows for April and May showed a seasonal increase in response to increased rainfall. At most index stations, the monthly means were above the long term median. During June and July streamflow decreased seasonally and continued within the normal range for the season. Streamflows in the eastern and southern parts of the island were below the long term median. In August, increased rainfall produced higher flows islandwide. The monthly mean discharge was 246 percent of the long term median at the Rio Grande de Manati, 194 percent of the median at the Rio Fajardo station, and 162 percent of the median at the Rio Inabon. In September, flows began to decrease in the northern and eastern parts of the island, but continued to increase in the western and southern parts of the island. In general, streamflow islandwide was above the normal range. In the U.S. Virgin Islands, precipitation and streamflow patterns generally were similar to those in Puerto Rico. Precipitation was well above normal from November to February and June to September. The highest flows were during November when rainfall was 254 percent above normal. 6 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Table 2. Peak discharges during November 26-27 and December 6-7, 1987 and previously recorded maximum at selected streamflow gaging stations in Puerto Rico Peak discharge Maximum discharge Station Nov.26-27 Dec.6-7 of record Period number and (cubic feet (cubic feet (cubic feet Water of name per second) per second) per second) Year Record 50051310 Rio Cayaguas at Cerro Gordo 8,990 9,610 13,200 1979 10-77 to 9-88 50053050 Rio Turabo at Borinquen 13,800 3,600 11,600 1985 12-83 to 9-88 50055000 Rio Grande de Loiza at Caguas 28,900 28,000 71,500 1960 12-59 to 9-88 50056400 Rio Valenciano near Juncos 27,500 40,000 25,700 1985 1-71 to 9-88 50056900 Quebrada Mamey near Gurabo 2,740 2,190 1,190 1985 12-83 to 9-88 50057000 Rio Gurabo at Gurabo 45,000 50,600 74,600 1960 10-59 to 9-88 50061800 Rio Canovanas near Campo Rico 12,500 8,920 15,000 1982 3-67 to 9-88 50063440 Quebrada Sonadora near El Verde 635 2,230 1,410 1984 3-83 to 9-88 50063800 Rio Espiritu Santo near Rio Grande 9,330 20,000 12,400 1984 8-66 to 9-88 50067000 Rio Sabana at Sabana 3,940 1,830 9,010 1983 10-79 to 9-88 50081000 Rio Humacao at Las Piedras 6,580 20,000 20,800 1960 7-74 to 9-77 10-87 to 9-88 7 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 GROUND-WATER LEVELS Ground-water levels in many aquifers throughout the island increased during November and December 1987 and by May, August, and September of 1988 in response to above-normal rainfall. New record-high water levels were recorded at several wells in Puerto Rico and the U.S. Virgin Islands (table 3). Ground-water levels in wells in the north coast limestone aquifers of Puerto Rico remained practically unchanged during the first half of the water year but increased slighly in April, May and August as a result of above normal rainfall (fig. 2). Ground-water levels in the south coast alluvial aquifers followed a cyclic pattern associated with rainfall and ground-water withdrawals for public supply, industrial, and irrigation uses. Above normal precipitation during late November and early December caused the water levels to rise significantly. Water levels increased 6.0 ft at the Alomar index well, and 9.0 ft at the Yauco PPG-4 index well. The water levels generally decreased as a result of pumpage from December to August. During late August and early September this trend was reversed as above normal rainfall returned to the area. Ground-water levels fluctuations in the U.S. Virgin Islands (St. Thomas, St. Croix, and St. John) were similar to those in Puerto Rico. The water level in observation well 11 at Guinea Gut, on St. John Island increased 15.7 ft. during November 1987 and 10.7 ft. in September 1988 in response to above-normal precipitation, but declined during much of the intervening period (fig. 2). Table 3. Maximum ground-water levels in 1988 water year and highest water levels of record (in feet below land-surface) at selected ground-water wells in Puerto Rico and the U.S. Virgin Islands Well Local Location 1988 Date Previous Date Period of Name number extreme extreme Record Saltos 1 165 PR 44.06 09-30-88 47.62 09-30-87 1-82 to 9-88 Plazuela 2 206 PR 3.75 09-11-88 3.86 05-16-87 10-85 to 9-88 Hyde Park TW-10 221 PR 1.34 04-16-88 1.48 04-12-87 12-85 to 9-88 Yabucoa 7 96 PR 13.10 12-02-87 13.39 11-18-85 04-78 to 9-88 Aguadilla Cement 200 PR 2.24 08-25-88 2.85 05-14-87 10-85 to 9-88 Fairplains 2 2 St. Croix 20.82 01-22-88 20.91 11-27-85 6-83 to 9-88 11-29-85 Golden Grove 6 3 St. Croix 13.73 12-12-88 14.76 03-25-82 3-82 to 9-88 Concordia 14 7 St. Croix 10.76 01-19-88 12.54 06-17-87 3-82 to 9-88 Concordia 1 8 St. Croix 14.03 01-19-88 16.68 11-13 -84 3-82 to 9-88 Mahogany 16 3 St. Thomas 10.25 01-21-88 17.52 07-01-86 3-82 to 9-88 8 20 25 30 m WELL 70, SABANA HOYOS < 0 35 La OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 0 < 1987 1988 I. cr D Cr) I 15 0 Z < 20 WELL 87, ALOMAR 1 _I 25 _I L1J CO — 30 LI 1........ i LiZ 35 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 2 1987 1988 LA1 > LAI _J Lt LAJ I- 4tr 10 20 WELL 11, CUINEA GUT ST. JOHN, U.S.V.I. 30 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1987 1988 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, 1988 Water Quality In the 1988 water year, the U.S. Geological Survey, in cooperation with local goverment agencies, completed the fourth year of sampling for the constituents listed in table 4. These constituents were added to the water quality monitoring program in 1985 and are in addition to the major chemical constituents and physical properties monitored in the continuing water quality monitoring program in Puerto Rico. The highest concentration of selected constituents detected during the 1988 water year along with the station at which these concentrations were detected are summarized in table 4. Table 4. Surface-water quality stations throughout Puerto Rico with highest concentration of selected constituents during water year 1988 [All constituent concentrations are in milligrams per liter. MBAS: Methylene blue active substance] Station Number Station name Constituent Concentration 50035500 Rio Grande de Manati at Sulfide 0.8 Hwy 149 at Ciales 50047530 Rio Hondo at Flood Channel Boron .23 near Catano 50091000 Rio Maunabo at Maunabo Manganese 2.2 50091000 Rio Maunabo at Maunabo Iron 47 50055250 Rio Caguitas at Hwy 30 Zinc .79 at Caguas 50055250 Rio Caguitas at Hwy 30 Cyanide .2 at Caguas 50091800 Rio Chico at Providencia Phenols .03 50091800 Rio Chico at Providencia MBAS 3.8 The presence of high concentrations of fecal coliform (FC) and fecal streptococci (FS) bacteria continued to be the principal surface water quality problem in Puerto Rico during water year 1988. Bacteria concentration exceeding one million colonies per hundred milliliters of raw water were found at several stations including Rio Piedras at Hato Rey (50049100), Quebrada Blasina near Carolina (50050300), Rio Bairoa near Caguas (50055400), Rio Chico at Providencia (50091800), and Rio Culebrinas near Aguada (50149100). These sites are located near urban zones, industrial parks, and suburban zones and receive the effluent of the sewage treatment plants. 10 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Four sediment stations were operated during the water year. These stations are Rio Tanama near Utuado (50028000), Rio Grande de Loiza at Caguas (50055000), Rio Gurabo at Gurabo (50057000), and Rio Rosario near Hormigueros (50136400). Maximum sediment concentrations were 3,440 milligrams per liter (mg/L) at the Rio Tanama site, 4,880 mg/L at the Rio Grande de Loiza site, 9,220 mg/L at the Rio Gurabo site, and 3,380 mg/L at the Rio Rosario site. Maximum sediment loads at these sites were 16,200 tons per day (ton/d) at Rio Tanama site, 227,000 (ton/d) at Rio Grande de Loiza site, 686,000 (ton/d) at Rio Gurabo site, and 6,160 (ton/d) at Rio Rosario site. From October 1983 to September 1986, an investigation was conducted in one of the most important basins in Puerto Rico; Rio Grande de Loiza. During the study suspended-sediment samples were collected at nine stations within the basin to account the amount of suspended-sediment transported to Lago Loiza, the most important water-supply reservoir in the area. Maximum suspended- sediment concentration and load at each station are summarized in table 5. Table 5. Maximum suspended-sediment concentration and load at each station within the Rio Grande de Loiza Basin. [--, insufficient data to establish a relation of suspended-sediemnt condentration and discharge.] Maximum sediment Maximum sediment Station Station concentration loads name number (mg/L) (tons per day) 1984 1985 1986 1984 1985 1986 Quebrada Blanca at El Jagual 50051150 6,720 7,320 -- 25,800 15,200 Qbda. Salvatierra near San Lorenzo 50051180 2,350 2,570 2,430 15,400 15,500 12,300 Rio Cayaguas at Cerro Gordo 50051310 1,400 5,180 2,790 9,840 77,800 17,900 Rio Turabo near Borinquen 50053050 3,510 7,420 5,300 19,600 106,000 39,400 Rio Grande de Loiza at Caguas 50055000 1,860 2,870 7,470 9,840 77,800 17,900 Quebrada Caimito near Juncos 50055650 247 1,040 1,040 26 702 777 Rio Valenciano near Juncos 50056400 593 1,580 1,600 4,990 46,300 25,100 Quebrada Mamey near Gurabo 50056900 328 528 643 224 1,060 684 Rio Gurabo at Gurabo 50057000 732 1,870 1,670 7,030 93,200 60,800 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 SPECIAL NETWORKS AND PROGRAMS 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. EXPLANATION OF THE RECORDS The surface-water and ground-water records published in this report are for the 1988 water year that began October 1, 1987 and ended September 30, 1988. 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. Station Identification Numbers Each data station, whether streamsite 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. ATLANTIC° o' 18.30 Rio Culebri llfc Guallaba o Grande Rio Grande ff. Allesca Rib Degaeo dv Palma go 18*00' 102 p0 ti 3 KILOMETERS 20 MILES MAR CARIBE FECAL COLFORMS < 1000 1000 - 10,000 10,000 - 100,000 100,000 - 1,000,000 < 1,000,000 Figure 3.--Location of fecal coliform bacteria concentration at sampled sites. 87°15' 0 4 OCEAN° ATLANTIC° lao Culebri s Rfo GuaReba Rio Grand,* tore1:0‘"° o1: ate aPGG° to °9° 00 ot° " 64 *3 110.ara Seo e orate to 4044.0,111t tV Fajardo Rio Grande de ARasco Rio Yagu Rio Guenafibo \Rio Daguao Quabrada Palma flag* Rio 4 t Ruiz Humacao 18°0 • • • FECAL STREPTOCOCCI < 1000 1000 - 10,000 10,600 - 100.000 10 30 KILOMETERS 20 MILES M A R CARIBE • 100,000 - 1,000,000 > 1.000.000 Figure 4.--Location of fecal streptococci bacteria concentration at sampled sites. 45" OCEANO 30 15" ATLANTIC° 6640' 45' 18.30 Rio CulabtIna Rio GuaRatio Grand* f to 6, ,- 14o066o 0 0 01 t 66 13* so ia 11;4FAN 770 .0 3° o e 5­8000.0ted* 00 00 006 ode F lartio Rio Grand* de Afiasto Rio Guano'lb* Rio Rio Blanco Anto'n Rutz 4iit daa Palma 10 ere 30 KILOMETERS 8,\`' v MAR CARIBE EXPLANATION A09" CONTINUOUS STREAMFLOW STATION AND NUMBER Figure 5.--Location of continuous surface-water stations in Puerto Rico. 87•00' 46' 30' 15' 66°0©' 4 ATLANTIC° 18°30 1,110 Rio Calebrinas RIE, Goadab° Rio Grande Rio Grande de AlIsso 010790 0280 0381 Torfugu era 027250 027090 038320 03595• 5110 0396 047530 91 0590 0588 057025 - to Fajardo RA, Yaguez Rio Guano/lb° 140 \Illo Daguao Quebreda Palma Rio Santiago Rio Blanco Rio Antdo Rut, iiieliurnaceo EXPLANATION 30 KILOMETERS MAR CARIBE Figure 6.--Location of water-quality stations in Puerto Rico. *1 6' sr°00' 4 0' 15' 00°0 45' 915°30' OCEANO ATLANTIC° 18°90 (0010)* 44, 6* too VIsta .6° llef.° a as. as da tsia o v. a 306° 3 Rio Culabrina Rio Guillabo Grand* aiardo 1 Rio Grande do ARaso Rio Vague Rio Quanafibo io Dago.* Quabrada Palma Santiago nco Rio Anton Ruiz mace° uayanis 18'001- 10 20, c,0 er o 30 KILOMETERS I 20 MILES 46. $ 04$ le o 9. 0 Jos` <0a6 ,* 4 ,..oce 9 ‘4' e e MAR 6 W-TW-08 -TW- 0? 0,0" 0 see e CARIBE "40 y, e 0" .6 EXPLANATION WELL AND WELL NUMBER Figure 7.--Location of ground-water stations in Puerto Rico. 17 18°24' 18°20' 4 KLø RS 1. 1 3 4 MLES 06(y 4 4°40' ST. JOHN 18°22' 4 KLOMETERS 18°18' 3 4 MLES 17°46' 0 1 2 3 4 KLOMETERS 1I 1 17°401 I i 2 3 4 MLES Figure 8.--Location of surface-water stations in the U.S. Virgin Islands. 18 18°24' 85°08' ST. THOMAS 84%0' 18°20' ei) 0 1 2 3 4 KILOMETERS I I I i • 1 0 1 2 3 4 MILES 18°22' 84°50' ST. JOHN 4' urur C) 0 i 2 3 4 K LOMETERS I I I I I I 1 2 3 4 MLES i Figure 9.--Location of ground-water stations in the U.S. Virgin Islands. 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 down­ stream 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 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). 66°53' 52' 51' 50' 49' 48' 66°47' 18°02 COORDINATES FOR WELLS 27 (180150088474900) 134 127 .74 AND 74 (180135088471000) 1326! 01' 13111 COORDINATES FOR WELLS 132 (180133086503300) AND 134 (180120088503200) 18°00' NN, COORDINATES FOR WELL 131 (180068066602700) 16 40 COORDINATES FOR WELL 16 (175922088495800) 17°59' A' Figure 10.--Grid showing system for numbering wells and miscellaneous sites (latitude and longitude). 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 "Crest-stage partial records," or "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 and crest-stage partial-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 slected 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. 21 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 approx­ imate discharge for any stage within the range of the measurements are pre­ pared. If it is necessary to define extremes of discharge outside the range of the current-meter measurements, the curves are extended using: (1) loga­ rithmic plotting; (2) velocity-area studies; (3) results of indirect measure­ ments of peak discharge, such as slope-area or contracted-opening measure­ ments, 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 dis­ charge 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 stream-gaging stations the stage-discharge relation is affected by the backwater from reservoirs, tributary streams, or other sources. This necessitates the use of the slope method in which the slope or fall in a reach of the stream is a factor in computing discharge. The slope or fall is obtained by means of an auxiliary gage set at some distance from the base gage. 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 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 discharges are estimated from the recorded range in stage, previous or follow­ ing 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 The records published for each gaging station consist of two parts, the manuscript or station description and the data table for the current water year. The manuscript provides, under various headings, descriptive informa­ tion, such as station location; period of record; average discharge; histori­ cal extremes; record accuracy; and other remarks pertinent to station opera­ tion 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 station description. 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. 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 pub lished 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.--Published records, because of new information, occa­ sionally 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. 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 sec­ tion, "Identifying Estimated Daily Discharge.") If a remarks statement is used to identify estimated record, the paragraph will begin with this informa­ tion 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 spill­ way, 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. AVERAGE DISCHARGE.--The discharge value given is the arithmetic mean of the water-year mean discharges. It is computed only for stations having at least 5 water years of complete record, and only water years of complete record are included in the computation. It is not computed for stations where diversions, storage, or other water-use practices cause the value to be meaningless. If water developments significantly altering flow at a station are put into use after the station has been in operation for a period of years, a new average is computed as soon as 5 water years of record have accumulated following the development. The median of yearly mean discharges also is given under this heading for stations having 10 or more water years of record, if the median differs from the average given by more than 10 percent. EXTREMES FOR PERIOD OF RECORD.--Extremes may include maximum and minimum stages and maximum and minimum discharges or content. Unless otherwise qualified, the maximum discharge or content is the instantaneous maximum corresponding to the highest stage that occurred. The highest stage may have been obtained from a graphic or digital recorder, a crest-stage gage, or by direct observation of a nonrecording gage. If the maximum stage did not occur on the same day as the maximum discharge or content, it is given separately. Similarly, the minimum is the instantaneous minimum discharge, unless other­ wise qualified, and was determined and is reported in the same manner as the maximum. EXTREMES OUTSIDE PERIOD OF RECORD.--Included here is information concern­ ing 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. 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 EXTREMES FOR CURRENT YEAR.--Extremes given here are similar to those for the period of record, except the peak discharge listing may include secondary peaks. For stations meeting certain criteria, all peak discharges and stages occurring during the water year and greater than a selected base discharge are presented under this heading. The peaks greater than the base discharge, excluding the highest one, are referred to as secondary peaks. Peak dis­ charges are not published for canals, ditches, drains, or streams for which the peaks are subject to substantial control by man. The time of occurrence for peaks is expressed in 24-hour local standard time. For example, 12:30 a.m. is 0030, and 1:30 p.m. is 1330. The minimum for the current water year appears below the table of peak data. 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. The daily table for stream-gaging stations gives mean discharge for each day and is followed by monthly and yearly summaries. In the monthly summary below the daily table, the line headed "TOTAL" gives the sum of the daily figures. The line headed "MEAN" gives the average flow in cubic feet per second during the month. The lines headed "MAX" and "MIN" give the maximum and minimum daily discharges, respectively, for the 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 are omitted if there is extensive regulations or diversion or if the drainage area includes large noncontributing areas. In the yearly summary below the monthly summary, the figures shown are the appropriate discharges for the calendar and water years. Data collected at partial-record stations follow the information for continuous-record sites. Data for partial-record discharge stations are presented in two tables. The first is a table of annual maximum stage and discharge at crest-stage stations, and the second is a table of discharge measurements at low-flow partial-record stations. 25 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 stabil­ ity 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 3to the nearest hundredth of a cubic foot per sscond for values less than 1 ft /s; to the neirest tenth between 1.0 and 10 ft /s; to whole numbers betyeen 10 and 1,000 ft /s; and to 3 significant figures for more than 1,000 ft /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. Information used in the preparation of the records in this publication, such as discharge-measurement notes, gage-height records, temperature measure­ ments, 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. 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 collec­ ted 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 conduct­ ance, 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 sepa­ rate 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, care­ fully 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. Al, A3, and A4. Detailed information on collecting, treating, and shipping samples may be obtained from the Geological Survey District office. 27 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 repre­ sentative 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. 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 analy­ sis. In the rare case where an apparent inconsistency exists between a reported pH value and the relative abundance of carbon dioxide species (carbon­ ate 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 tempera­ tures 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. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Sediment Suspended-sediment concentrations are determined from samples collected by using depth-integrating 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 concentra­ tion, samples may have been collected more frequently (twice daily or, in some instances, 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 pub­ lished 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 concentra­ tions observed immediately before and after the periods, and suspended- sediment loads for other periods of similar discharge. 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 stream- flow 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 and bed material 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 ana­ lyzed 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. Cl. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. Al, A3, and A4. 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. 29 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 In the descriptive headings, if the location is identical to that of the discharge gaging station, neither the LOCATION nor the DRAINAGE AREA state­ ments 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 pub­ lished water-quality records for the station. The periods are shown separate­ ly 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 subse­ quently 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 miscel­ laneous 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. 30 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 observa­ tion 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 10. 31 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 approxi­ mately 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 descrip­ tion. 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. Data Presentation Each well record consists of two parts, the station description and the data table of water levels observed during the water year. 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. 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. 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 mean sea level datum, if available. It is reported with precision depending on the method of determina­ tion. 32 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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. Geologi­ cal 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 low­ est 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 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. 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. 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. 33 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 analy­ sis. 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 WATSTORE DATA The National WATer Data STOrage and REtrieval System (WATSTORE) was established for handling water data collected through the activities of the U.S. Geological Survey and to provide for more effective and efficient means of releasing the data to the public. The system is operated and maintained on the central computer facilities of the Survey at its National Center in Reston, Virginia. WATSTORE can provide a variety of useful products ranging from simple data tables to complex statistical analyses. A minimal fee, plus the actual computer cost incurred in producing a desired product, is charged to the requester. Information about the availability of specific types of data, the acquisition of data or products, and user charges can be obtained locally from each of the Water Resources Division's District offices (see address given on the back of the title page). General inquiries about WATSTORE may be directed to: Chief Hydrologist U.S. Geological Survey 437 National Center Reston, Virginia 22092 34 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 (nutri­ ent medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. 35 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Fecal coliform bacteria are bacteria that are present in the intestines or feces of warm-blooded animals. They are often used as in­ dicators 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 colo­ nies 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 lab­ oratory 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 ex- pressed 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, ex­ pressed 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 iooplankton and phytoplankton are expressed in grams per cubic meter (g/T ), and periphy­ ton and benthic organisms in grams per square meter (g/m ). 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 differ­ ence 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). 36 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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. Clorophyll 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. Control designates a feature downstream from the gage that determines the stage-discharge relation at the gage. This feature may be a natural constric­ tion 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. Crest-stage station is a special form of partial-record station that records the highest stage of the stream that occurred between periodic visits to the station. A stage-discharge relation for each gage may be developed from discharge measurements made by indirect methods or by current meter. Cubic foot per second (cfs) 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 (cfs-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. 37 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 n. n. 1 1 d = - E 11.-- log2 i=1 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. 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 (G.H.) 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. 38 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 hydrol­ ogy, including water quality, and related factors in representative un­ developed 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 differ­ ence 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 (ug/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 (UG/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 concentra­ tion 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. 39 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Table 6. Factors for conversion of chemical constituents in milligrams per liter to milliequivalents per liter. Ion Multiply by Ion Multiply by Aluminum (A1+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 (C1-1) .02821 Nitrate (NO3-1) .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. 40 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 atmos­ pheric deposition, which includes snow, rain, dust particles, aerosols, and gases. The core from which the NTN was built was the already-existing deposi­ tion-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 constitu­ ent. 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. Particle-size is the diameter, in millimeters (mm), of a particle deter­ mined 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 recommenda­ tions made by the American Geophysical Union Subcommittee on Sediment Termi­ nology. 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. 41 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 radio­ lu activity that yields 3.7 x 10 radioactive disintegrations per second. A picocurie yields 2.22 dpm (disintegrations per minute). 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. Phyto­ plankton growth is dependent upon solar radiation and nutrient substan­ ces. 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 sili­ ceous 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 ca­ pable of extensive movements within the water column and are often large enough to be seen with the unaided eye. Zooplankton are secondary consu­ mers 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. 42 WATER RESOURCES DATA FOR PUERTO RICO AND TilE U.S. VIRGIN ISLANDS, 1988 Primary productivity is a measure of the rate at which new organic matter is formed and accumulated through photosynthetic and chemosynthe­ tic 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 2 C/(m .time] for periphyton and macrophytes and [mg C/(m .time)] for phytoplankton are units for expressing primary productivity. They define the amount of carbon dioxide consumed as measured by radio- active 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 Sime [mg0 / 2 (m .time)] for periphyton and macrophytes and [mg0 /(m .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 mix­ tures of chlorinated biphenyl compounds having various percentages of chlo­ rine. 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. 43 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Sediment is solid material that originates mostly from disintegrated rocks and is transported by, suspended in, or deposited from water; it in­ cludes 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.main­ tained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. Suspended-sediment concentration is the velocity-weighted concentra­ tion 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 ft /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 trans­ port. It is not synonymous with total-sediment discharge. 44 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 plexigla§s strips for periphyton. 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. 45 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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 concen­ trations 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 Phylum Class Animal Arthopoda Insecta Order Family Genus Species Ephemeroptera Ephemeridae Hexagenia 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. 46 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 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. 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 RESOURCES FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1988 Water year in 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. 47 48 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, Books and Open-File Reports Section, Federal Center, Box 25425, 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." 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 Dl. 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. 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 Dl. 1974. 116 pages. 2-El. Application of borehole geophysics to water-resources investigations, by W. S. Keys and L. M. MacCary: USGS--TWRI Book 2, Chapter El. 1971. 126 pages. 3-Al. General field and office procedures for indirect discharge measurements, by M. A. Benson and Tate Dalrymple: USGS--TWRI Book 3, Chapter Al. 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. J. 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 measurements 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 and dispersion in streams by dye tracing, by E. F. Hubbard, F. A. Kilpatrick, L. A. Martens, and J. F. Wilson, Jr.: USGS--TWRI Book 3, Chapter A9. 1982. 44 pages. 3-A10. Discharge ratings at gaging stations, by E. J. Kennedy: USGS--TWRI Book 3, Chapter A10. 1984. 59 pages. 3-All. Measurement of discharge by moving-boat method, by G. F. Smoot and C. E. Novak: USGS--TWRI Book 3, Chapter All. 1969. 22 pages. 3-Al2. Fluorometric procedures for dye tracing, by J. F. Wilson, Jr., E. D. Cobb, and F. A. Kilpatrick: USGS--TWRI Book 3, Chapter Al2. 1986. 41 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-B1. Aquifer-test design, observation, and data analysis, by R. W. Stallman: USGS--TWRI Book 3, Chapter 61. 1971. 26 pages. 49 PUBLICATIONS ON TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS--Continued 3-B2. Introduction to ground-water hydraulics, a programed test 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-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems--An introduction, by 0. 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, 0. L. Franke, and G. D. Bennett: USGS--TWRI Book 3, Chapter B6. 1987. 28 pages. 3-Cl. Fluvial sediment concepts, by H. P. Guy: USGS--TWRI Book 3, Chapter Cl. 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. 4-Al. Some statistical tools in hydrology, by H. C. Riggs: USGS--TWRI Book 4, Chapter Al. 1968. 39 pages. 4-A2. Frequency curves, by H. C. Riggs: USGS--TWRI Book 4, Chapter A2. 1968. 15 pages. 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. 4-D1. Computation of rate and volume of stream depletion by wells, by C. T. Jenkins: USGS-TWRI Book 4, Chapter Dl. 1970. 17 pages. 5-Al. Methods for determination of inorganic substances in water and fluvial sediments, by M. W. Skougstad and others, editors: USGS--TWRI Book 5, Chapter Al. 1979. 626 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 analysis of organic substances in water, by D. F. Goerlitz and Eugene Brown: USGS--TWRI Book 5, Chapter A3. 1972. 40 pages. 5-A4. Methods for collection and analysis of aquatic biological and microbiological samples, edited by P. E. Greeson, T. A. Ehlke, G. A. Irwin, B. W. Lium, and K. V. Slack: USGS--TWRI Book 5, Chapter A4. 1977. 332 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. 5-Cl. Laboratory theory and methods for sediment analysis, by H. P. Guy: USGS--TWRI Book 5, Chapter Cl. 1969. 58 pages. 6-Al. A modular three-dimensional finite-difference ground-water flow model, by M. G. McDonald and A. W. Harbaugh: USGS--TWRI Book 6, Chapter Al. 1988. 586 pages. 7-Cl. 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 Cl. 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. Schaffrannek, R. A. Baltzer, and D. E. Goldberg: USGS--TWRI Book 7, Chapter C3. 1981. 110 pages. 8-Al. Methods of measuring water levels in deep wells, by M. S. Garber and F. C. Koopman: USGS-­ TWRI Book 8, Chapter Al. 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. 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. 50 THIS PAGE WAS LEFT BLANK INTENTIONALLY 51 Surface and Quality-of-Water Records for Puerto Rico 52 THIS PAGE WAS LEFT BLANK INTENTIONALLY 53 de Diversion AGOADILLA Drainage boundaries indeterminate in limestone terrane stone Igneous anc \---• — sedimentary rocks .0 Rio Culbrinos: F41'0 Grande de s A sco in EXPLANATION Autos SURFACE—WATER STATION AND NUMBER V0105 QUALITY—OF—WATER STATION AND NUMBER QUALITY—OF—WATER PARTIAL RECORD V010720 STATION AND NUMBER 0165 WELL AND WELL NUMBER Map area SA IN 4 WILES 3 410LONETERS Figure 11.--Rio Guajataca basin. 54 RIO GUAJA1ACA BASIN 50010500 RIO GUAJATACA Al EARLS, 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 Anon, and 0.4 mi (0.6 km) northeast of Lares plaza. DRAINAGE AREA.--3.16 mi. (8.18 km.). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN. OXYGEN COI I- STREP­ CHARGE. SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR DATE TIME FEET PER DUCT- ANCE (STAND- ARD ATURE WATER BID- ITY D1S- SOLVED CENT SATUR- (HIGH LEVEL) UM-MF (COLS./ (COLS. PER SECOND (US/CM) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) SEP 1987 29... 0940 3.6 198 7.40 23.0 0.1 7.9 94 12 K6600 25000 DEC 14... 1020 5.0 244 7.20 22.0 4.8 7.7 90 40 2600 4100 FEB 1988 02... 1050 1.7 246 7.20 21.5 0.70 7.7 89 21 2700 22000 APR 11... 1115 0.87 250 7.10 23.0 1.2 8.7 104 27 2600 2000 JUN 07... 1030 2.8 249 6.90 23.5 2.3 7.4 89 55 1900 1600 AUG 02... 0945 2.0 252 6.70 22.5 0.90 7.5 88 17 30000 4100 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE D1S- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) SEP 1987 29... 89 10 26 5.9 12 0.6 2.4 79 -0.5 8.0 11 DEC 14... 90 FEB 1988 02... - 92 APR 11... 98 0 28 6.8 13 0.6 2.3 92 -0.5 12 12 JUN 07... 80 AUG 02... 94 0 27 6.5 12 0.6 2.1 89 9.8 10 SOLIDS. RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN. D1S- 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) SEP 1987 29... 0.20 31 140 1.40 1 1.59 0.01 1.60 0.03 0.17 DEC 14... 5 1.69 0.01 1.70 0.02 1.5 FEB 1988 02... 1 1.16 0.04 1.20 0.02 0.28 APR 11... 0.30 30 167 0.04 3 -0.01 0.50 0.02 JUN 07... -1 -0.01 1.10 0.03 AUG 02... 0.20 30 155 0.84 1 1.09 0.01 1.10 0.02 0.28 K = non-ideal count 55 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT TARES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE LABLE 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) SEP 1987 29... 0.2 1.8 0.07 1 <100 10 <1 9 10 DEC 14... 1.5 3.2 14 0.06 FEB 1988 02... 0.3 1.5 6.6 0.10 APR 11... <0.2 0.08 6 <100 30 <1 <1 260 JUN 07... <0.2 0.06 AUG 02... 0.3 1.4 6.2 0.06 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 1.6) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) SEP 1987 29... 860 ,5 60 <0.10 3 <1 10 <0.010 1 0.01 DEC 14... FEB 1988 02... APR 11... 170 <5 60 <0.10 <1 <1 60 <0.010 2 0.02 JUN 07... AUG 02... I RIO GUAJATACA BASIN 56 50010600 RIO GUAJATACA ABOVE LAGO GUAJATACA, PR LOCATION.--Lat 18'19'57", long 66°55'29", Hydrologic Unit 21010002, 1.0 mi (1.6 km) off road 451, 3 mi (5 km) south of Lap Guajataca, 1.0 mi (1.6 km) east of Eneas and 2.0 mi (3.2 km) west of Piletas. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 565 ft (172 m), from topographic map. REMARKS.--Records fair. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 2,600 ft'/s (73.6 110/s), May 18, 1985, gage height, 12.03 ft (3.667 ), from rating curve extended above 100 ft'/s (2.83 m'/s) on the basis of step-backwater analysis: minimum discharge, 1.9 ft ) /s (0.054 m /s), Feb. 11, 17, 1986, Feb. 9, 1988. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 1,500 ft'/s (42.5 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (mi/s) (ft) (m) Date Time (ft'/s) (m'/s) (ft) (m) Oct. 7 1615 *2,450 69.4 *11.77 3.587 Sept.20 1730 1,600 45.3 10.20 3.109 May 26 1645 2,190 62.0 11.33 3.453 Minimum discharge, 1.9 ft'/s (0.054 m'/s), Feb. 9. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 22 35 39 12 117 2 87 6.8 62 54 7.1 5.3 2.8 14 25 32 9.7 80 3 37 6.6 32 24 8.6 5.0 2.9 26 20 65 30 55 4 107 6.4 14 18 8.2 4.4 3.2 24 16 36 32 40 5 43 5.6 17 16 6.3 4.3 3.4 25 15 92 13 36 1 9.5 15 8.7 70 9.1 4.7 2.6 64 12 29 7 340 15 45 14 5.4 4.2 3.8 9.9 13 34 11 36 8 108 7.9 25 12 5.2 4.5 3.4 8.8 13 26 10 6 21 5.3 85 15 5.8 4.1 9.6 12 13 27 9 43 14 20 12 3.3 4.2 3.4 66 12 21 9.1 28 10 72 9.4 18 11 6.3 4.2 3.0 67 10 20 8.7 36 11 54 22 16 10 7.2 4.2 3.9 245 20 17 8.6 37 12 32 11 83 10 12 4.0 11 108 100 15 8.3 51 13 26 21 49 9.5 7.6 3.9 5.9 53 85 62 7.9 24 14 36 7.9 23 9.2 11 5.0 3.6 36 55 46 32 21 44 28 26 24 15 32 16 19 9.6 7.3 4.6 44 46 16 23 12 18 8.5 6.8 6.1 37 82 36 19 11 19 17 20 86 16 17 6.5 4.7 11 55 27 27 31 17 18 31 23 14 9.3 6.1 4.9 62 31 23 33 84 14 19 20 9.2 57 12 6.0 4.6 78 22 18 25 22 13 20 15 7.6 60 7.8 5.7 3.7 102 20 17 20 48 209 17 13 16 37 85 21 14 7.3 36 7.3 5.2 3.8 116 110 22 13 5.9 26 7.0 5.3 4.0 86 55 104 14 21 37 18 23 13 5.9 20 6.8 5.6 3.7 44 62 14 240 24 13 39 17 6.9 5.8 3.9 28 26 202 13 247 142 25 11 29 19 6.5 5.0 3.9 26 18 125 13 314 84 26 11 14 15 6.8 6.6 3.7 18 334 63 13 110 66 27 10 53 14 6.3 10 6.4 13 146 44 13 148 56 28 9.6 34 15 6.0 6.5 16 59 157 78 12 131 43 29 8.9 14 14 8.4 5.2 6.5 58 134 84 18 80 36 54 32 30 8.9 11 17 6.9 --- 3.1 45 81 55 15 31 53 --- 44 6.2 2.8 -- 51 --- 11 60 --- TOTAL 1321.9 520.8 918.7 424.0 196.7 148.4 882.5 2035.7 1427 873 1646.3 1807 MEAN 42.6 17.4 29.6 13.7 6.78 4.79 29.4 65.7 47.6 28.2 53.1 60.2 86 85 70 12 16 116 334 202 92 314 240 MAX 340 MIN 8.9 5.3 8.7 6.0 3.3 2.8 2.6 8.8 10 11 7.9 13 CAL YR 1987 TOTAL 11364.9 MEAN 31.1 MAX 340 MIN 3.0 WTR YR 1988 TOTAL 12202.0 MEAN 33.3 MAX 340 MIN 2.6 57 RIO GUAJATACA BASIN 50010600 RIO GUAJATACA ABOVE LAGO GUAJATACA, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1984 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 06 1039 19.8 351 23.5 APR, 11 1050 3.34 340 23.5 DEC. 17 0917 17.2 362 22.5 MAY, 30 1238 11.2 378 24.5 JAN, 12 1420 10.7 316 22.5 JUN, 06 1139 14.1 367 25.5 FEB, 18 1131 5.72 309 22.0 JUL. 11 1255 16.2 350 25.5 MAR, 07 1435 4.59 366 22.0 AUG. 01 1050 9.55 324 25.0 58 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT tAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18- 24'02", long 66 55'27", off Highway 476 at Lago (uajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quehradillas Plaza DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) SEP 1987 29... 1130 55 291 6.90 26.5 0.80 1.7 21 20 52 30 DEC 14... 1205 55 292 6.80 25.5 0.90 1.3 16 40 110 130 FEB 1988 02... 1230 60 315 6.90 25.0 2.1 26 K4 K15 APR 11... 1320 75 299 7.00 26.0 0.50 3.9 48 17 K37 170 JUN 07... 1230 El 273 7.50 28.0 0.90 10.3 133 28 300 80 AUG 02... 1140 75 315 6.50 25.5 0.40 1.8 22 20 K2 K2 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE D1S- DIS- (MG/L TOT FLU SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) SEP 1987 29... 130 3 47 3.8 5.6 0.2 2.0 130 <0.5 11 7.0 DEC 14... 13n FEB 1988 02... 140 APR 11... 130 0 46 4.5 6.4 0.3 2.0 120 ,0.5 11 9.1 JUN 07... 130 AUG 02... 150 9 53 3.6 5.1 0.2 1.6 130 11 7.6 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) SEP 1987 29... 0.10 8.1 170 25 1 0.09 0.01 0.10 0.08 0.42 DEC 14... 5 0.09 0.01 0.10 0.50 0.40 FEB 1988 02... 2 0.09 0.01 0.10 0.13 0.77 APR 11... 0.20 8.8 169 34 3 0.09 0.01 0.10 0.05 0.15 JUN 07... 1 0.09 0.01 0.10 0.05 0.35 AUG 02... 0.10 7.0 172 35 2 0.09 0.01 0.10 0.03 0.27 K non-ideal count E . estimate RIO GuAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR--Continued WATER-QUALITY UAIA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA • NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL IOTA. ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE DATE (MG/I (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/I AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS B) AS CD) AS CR) AS CU) SEP 1987 29... 0.5 0.52 0.01 2 -100 10 1 2 10 DEC 14... 0.9 0.50 0.02 FEB 1988 02... 0.9 0.90 4.4 0.03 APR 11... 0.2 0.25 0.02 2 -100 10 1 •1 400 JUN 07... 0.4 0.45 0.03 AUG 02... 0.3 0.40 0.02 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) SEP 1987 29... 130 ,5 180 ‹0.10 3 <1 10 -0.010 2 0.01 DEC 14... FEB 1988 02... -- APR 11... 70 <5 60 -4).10 -1 -1 100 -0.010 -1 0.02 JUN 07... AUG 02... 59 I --- RIO GUAJATACA BASIN 60 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR 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 the Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago Guajataca. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to May 1969 (monthly measurements only), July 1969 to December 1970, April 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 0.0 ft (0.0 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharge, which are poor. Flow regulated by lago Guajataca 6.6 i (10.6 km). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 6,200 ft'is (176 10/s), May 13, 1986, estimated based on a mean daily discharge correlation with station 50011200, 6.5 miles upstream; minimum discharge, 6.2 ft'/s (0.176 m'/s), Sept. 4, 9-12, 1984. EXTREMES FOR CURRENT YEAR.--Maximum discharge, 2,090 ft'/s (59.2 m'/s), June 27, gage height, 6.59 ft (2.009 m); minimum discharge, 15 ft 3/s (0.42 m'/s), Jan. 28, 29. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e21 23 18 ell() e16 e18 e18 18 233 645 18 26 2 e20 18 e18 ellO e18 e18 e18 16 234 605 18 33 3 e20 e18 e18 ell() e20 e18 17 23 234 588 18 112 4 e19 24 e18 120 e30 e18 17 32 234 571 18 41 5 e19 20 e18 152 e20 e18 17 18 219 457 18 38 19 17 22 37 17 36 7 e22 19 30 129 17 e18 19 16 e18 21 18 58 8 e38 26 e25 21 e16 e18 e18 16 e18 19 17 97 9 22 e21 e22 e20 e16 e18 e18 16 e17 18 17 270 10 e21 19 e21 19 e16 e18 ell 32 17 18 16 1110 6 e19 19 e18 146 ell e18 11 e20 17 e21 19 e16 e19 e17 483 17 18 16 818 12 e19 17 e85 19 16 e19 e17 80 17 18 16 553 13 19 17 e263 19 e16 e19 el6 27 17 18 16 317 14 61 e17 32 19 e16 e19 el6 21 18 18 16 439 15 57 e17 46 18 e16 e19 e22 20 32 19 16 169 34 19 17 34 17 e24 95 e29 e18 e16 e19 e17 20 69 19 17 31 18 22 54 e26 e18 e17 e19 e25 18 141 19 20 29 19 21 26 e25 e18 e17 e19 e22 17 31 18 18 29 20 20 30 e50 e17 18 e19 27 17 24 18 17 31 16 e26 e17 34 18 e16 e19 e19 19 18 22 18 e16 43 22 e20 18 e31 e17 e18 19 105 16 21 18 16 33 23 e19 e18 e28 17 18 18 21 24 24 18 e16 93 24 e19 el8 27 16 e18 18 17 21 e20 19 e37 ell 18 e19 206 41 26 17 e19 173 25 e19 e19 27 16 18 18 16 20 31 17 168 161 18 18 17 18 25 18 31 146 27 18 e18 e25 16 19 19 18 53 541 26 el8 e18 e26 16 21 21 163 za 17 el8 e24 15 e18 19 16 232 1110 18 23 161 29 17 el8 e24 e15 el8 21 17 230 786 18 19 152 30 17 18 e24 e15 --- 21 27 230 690 19 19 146 31 17 --- e43 e15 19 --- 230 --- 19 18 203B 4922 3364 710 5542 MEAN 22.9 23.2 36.5 41.8 17.7 18.7 27.9 65.7 164 TOTAL 711 696 1133 1295 513 579 836 109 22.9 185 MAX 61 95 263 152 30 21 206 483 645 168 1110 1110 MIN 17 17 18 15 16 18 16 16 17 17 16 26 CAL YR 1987 TOTAL 16373.2 MEAN 44.9 MAX 1190 MIN 6.2 WTR YR 1988 TOTAL 22339 MEAN 61.0 MAX 1110 MIN 15 e Estimated 61 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DATE SEP 1987 TIME DIS- CHARGE, INST. CUBIC FEET PER SECOND SPE- CIFIC CON- DUCT- ANCE (US/CM) PH (STAND- ARD UNITS) TEMPER- ATURE WATER (DEG C) TUR- BID- ITY (NTU) OXYGEN, DIS- SOLVED (MG/L) OXYGEN, DIS- SOLVED (PER- CENT SATUR- ATION) OXYGEN DEMAND, CHEM- ICAL (HIGH LEVEL) (MG/L) COLI- FORM, FECAL, 0.7 UM-MF (COLS./ 100 ML) STREP- TOCOCCI FECAL, KF AGAR (COLS. PER 100 ML) 29... 1515 21 443 7.20 26.0 0.5 8.5 104 10 K49 160 DEC 14... 1440 31 380 7.40 25.0 6.5 8.2 98 28 3200 3900 FEB 1988 02... 1520 ED 399 7.10 24.5 6.7 79 310 470 APR 11... 1600 ED 475 6.90 25.5 0.5 6.4 78 28 300 K10 JUN 07... 1550 19 461 7.00 27.0 1.2 8.6 106 29 K20 K51 AUG 02... 1420 18 475 7.00 25.5 0.6 11.1 133 <10 K29 K20 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SIUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) SEP 1987 29... 209 24 73 7.2 15 0.4 1.1 180 <0.5 9.4 25 DEC 14... 160 FEB 1988 02... 170 APR 11... 210 3 71 7.4 12 0.4 1.3 190 <0.5 7.9 19 JUN 07... 180 AUG 02... 200 13 68 7.2 15 0.5 1.1 180 - 8.9 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) SEP 1987 29... 0.10 6.6 250 14 1 1.39 0.01 1.40 0.03 0.27 DEC 14... 5 1.29 0.01 1.30 0.02 0.18 FEB 1988 02... 1 1.38 0.02 1 .40 0.02 0.18 APR 11... 0.10 7.0 249 <1 1.78 0.02 1.80 0.03 0.17 JUN 07... 1 1.49 0.01 1.50 0.04 0.16 AUG 02... 0.10 6.1 244 12 <1 1.49 0.01 1.50 0.02 0.68 K = non-ideal count E = estimate 62 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 CHRU- NITRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA • NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL IOTA( TOTAL ERABLE ERABLE ERABLE 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) SEP 1987 29... 0.3 1.7 0.01 1 •100 -10 • 1 • 1 10 DEC 14... 0.2 1.5 6.6 0.02 FEB 1988 02... 0.2 1.6 0.03 APR -1 -1 210 0.28 • 1 '100 -10 JUN 07... 0.2 1.7 7.5 0.01 AUG 02... 0.7 2.2 9.7 0.01 11... 0.2 2.0 - METHY- MANGA- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SHE- 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 SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) AS FE) AS PB) AS MN) AS HG) SEP 1987 '5 -1 <1 '10 -0.010 2 0.05 29... 129 30 -0.10 DEC 14... FEB 1988 02... APR -5 20 -0.10 -1 -1 -10 -0.010 2 0.02 11... 70 JUN 07... AUG 02... 63 OCEANO A ANTICO CAMUY. QUEBRADILLAS R ARECIBO 0157 0148 Drainage boundaries indeterminate in limestone terrane J 4 4uyoney River underground S L ARES Guoiatab basin Ri"o Tarsaindl 14(o Grande de Arecibo basin t_JMeS Igneous and sedimentary rocks UTUADO a Rio Grande Aliasco boctni e boundary A048 EXPLANATION. SURFACE—WATER STATION AND NUMBER p area SAN 4UA T 4 4 vas e motann Figure 12.--Rio Camuy basin. RIO CAMUY BASIN 64 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 Atlantic Ocean. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS 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. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 6,450 ft'/s (183 m'/s), Oct. 7, 1985, gage height, 17.66 ft (5.383 m), from rating curve extended above 300 ft'/s (8.50 m'/s) on basis of step-backwater analysis; minimum discharge, 28 ft'/s (0.79 m'/s), Mar. 15-17, 1985. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 2,000 ft 3 /s (56.6 .1 3 /s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (fti/s) (.0/s) (ft) (m) Date Time (W/s) (1. 3/s) (ft) (m) Apr. 21 1815 *2,910 82.4 *13.52 4.121 Sept. 23 2130 2,070 58.6 11.60 3.536 May 10 2030 2,640 74.8 12.92 3.938 Minimum daily discharge, 31 ft'/s (0.878 m'/s), Mar. 25-27. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 59 82 70 315 56 38 34 104 82 121 51 196 2 87 58 146 286 54 43 33 86 73 98 50 149 3 82 138 168 136 106 39 35 79 69 88 54 106 4 67 91 87 105 95 38 33 72 64 81 77 90 5 62 60 91 92 60 37 34 66 60 173 58 81 6 57 53 119 85 53 37 38 64 59 179 52 76 7 142 52 113 80 50 36 37 58 57 97 62 119 8 193 69 84 77 50 36 34 55 57 83 50 95 9 104 70 76 74 48 36 36 122 58 77 47 89 10 72 76 72 69 48 33 595 57 75 135 35 46 72 47 118 11 73 59 69 66 47 36 35 686 57 12 71 56 69 65 45 35 49 392 64 69 44 117 13 71 88 106 62 46 36 60 210 138 63 43 129 14 158 65 74 61 58 35 39 147 120 66 40 106 15 116 57 78 66 45 35 40 146 94 69 49 88 16 73 84 70 59 44 36 95 200 69 62 43 81 17 65 189 64 72 44 37 98 187 93 61 45 76 18 73 117 67 68 45 36 151 118 74 CO 98 75 19 117 79 137 62 44 35 268 100 66 67 69 73 20 119 70 202 56 43 33 244 98 74 58 50 428 21 81 64 153 55 41 33 845 98 61 57 85 384 22 69 102 40 486 499 54 58 53 32 87 54 177 23 61 56 85 52 39 34 150 81 374 54 49 581 24 66 77 79 51 39 32 99 76 255 53 285 397 25 60 129 99 51 39 e31 97 72 300 53 706 191 26 60 84 81 49 40 e31 97 76 162 52 264 154 27 55 143 76 48 50 31 95 158 105 52 220 168 28 53 167 70 48 41 88 163 140 276 51 262 152 29 50 94 66 49 39 87 212 194 351 52 263 120 30 50 78 63 50 --- 45 177 104 218 67 155 110 31 64 --- 183 47 40 --- 88 --- 57 113 --- TOTAL 2530 2563 3019 2509 1449 1211 3849 4749 4076 2341 3531 4861 MEAN 81.6 85.4 97.4 80.9 50.0 39.1 128 153 136 75.5 114 162 MAX 193 189 202 315 106 88 845 686 499 179 706 581 MIN 50 52 63 47 39 31 33 55 57 51 40 73 CAL YR 1987 TOTAL 31951 MEAN 87.5 MAX 472 MIN 31 WTR YR 1988 TOTAL 36688 MEAN 100 MAX 845 MIN 31 e Estimated RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS JUNE 1984 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE PURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 07 1401 53.7 299 24.5 APR, 12 1248 36.4 326 24.0 DEC, 14 1323 73 310 23.5 MAY, 05 1215 108 326 24.0 JAN, 13 1223 61 301 23.5 JUN, 08 1159 52.6 341 24.5 FEB, 17 1222 43.5 309 23.0 JUL, 13 1144 61.5 336 24.5 MAR, 08 1249 35.3 363 23.0 AUG, 03 1241 50.3 319 24.5 65 RIO CAMUY BASIN 66 50015700 RIO CAMUY NEAR HATILLO, PR LOCATION.--Lat 18- 27'44", long 66'49'56", Hydrologic Unit 21010002, 1.8 mi (2.9 km) southwest of Hatillo plaza. and 1.8 mi (2.9 km) southeast of Camuy plaza, 1.2 mi (1.9 km) south of Planta de Purification, and 3.3 mi (5.5 km) upstream from Atlantic Ocean. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1984 to current year. GAGE: --Water-stage recorder. Elevation of gage is 13 ft (4 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 10,500 ft'/s (297 m'/s), Oct. 7, 1985, gage height, 24.75 ft (7.544 m), from rating curve extended above 200 ft'/s (5.66 m'/s) on basis of step-backwater analysis; minimum discharge, 36 ft'/s (1.02 m'/s), Mar. 19, 1985. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 2,500 ft'/s (70.8 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (mi/s) (ft) (m) Date Time (ft-7s) (110/s) (ft) (m) Apr. 21 2300 6,170 175 20.58 6.273 Aug. 25 0300 3,090 87.5 15.96 4.865 May 11 0100 *7,540 214 *22.07 6.727 Sept.20 2345 3,320 94.0 16.40 5.000 June 22 2000 4,500 127 18.39 5.605 Sept.24 0015 3,220 91.2 16.21 4.941 Minimum daily discharge, 37 ft'is (1.05 m'/s), Apr.10. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 65 133 90 596 85 51 45 120 86 150 64 e350 2 76 90 190 782 79 54 43 99 80 121 62 e225 3 98 265 310 234 201 50 42 91 75 109 62 el80 4 74 391 110 158 223 49 41 87 71 101 81 e140 5 72 89 92 139 101 48 40 80 67 221 68 e120 6 68 76 140 127 83 48 41 76 69 J13 62 e110 7 148 73 153 119 75 48 40 70 65 125 72 e170 8 262 101 101 112 70 47 41 69 63 106 73 el20 9 182 87 87 107 66 46 39 106 63 96 61 e110 10 103 104 82 98 66 46 38 e2500 61 93 60 e200 11 101 75 78 90 65 45 39 3560 60 89 60 e180 12 97 71 112 90 63 45 48 1440 72 84 57 e150 13 100 127 164 82 60 46 74 458 119 80 56 e180 14 210 85 87 80 71 47 48 280 106 82 55 e160 15 200 76 152 85 61 46 45 197 110 85 62 155 16 112 95 109 78 59 46 105 262 78 76 60 132 17 103 766 87 89 58 47 114 260 98 75 57 121 18 96 234 83 90 57 46 236 139 172 91 108 115 19 140 125 260 84 55 44 433 117 82 85 85 116 20 206 104 551 76 54 43 399 113 81 73 62 466 21 131 94 328 71 53 42 1410 130 70 71 87 836 22 105 85 166 69 53 42 1670 104 1050 69 67 265 23 94 78 128 69 52 41 193 95 725 66 62 568 24 97 80 111 67 52 42 120 90 370 65 195 865 25 99 180 155 67 52 41 115 85 385 65 1710 240 26 107 109 123 66 54 41 123 82 248 64 357 176 27 92 147 110 65 67 41 120 156 131 64 295 182 28 85 280 101 63 57 73 175 127 293 64 361 196 29 89 125 95 65 53 114 265 193 510 67 e400 138 30 93 101 85 68 --- 58 267 114 366 81 e230 127 31 90 --- 232 64 48 --- 92 --- 70 e170 --- TOTAL 3595 4446 4672 4050 2145 1525 6409 11392 5826 3001 5261 7093 MEAN 116 148 151 131 74.0 49.2 214 367 194 96.8 170 236 MAX 262 766 551 782 223 114 1670 3560 1050 313 1710 865 MIN 65 71 78 63 52 41 38 69 60 64 55 110 CAL YR 1987 TOTAL 51109 MEAN 140 MAX 1480 MIN 37 WTR YR 1988 TOTAL 59415 MEAN 162 MAX 3560 MIN 38 e Estimated 67 RIO CAMUY BASIN 50015700 RIO CAMUY NEAR HATILLO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1984 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFWW, SFECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 07 1005 65.5 310 24.5 APR, 12 0833 46.9 336 24.0 DEC, 14 1044 88.9 299 24.0 MAY, 05 0852 79.8 347 23.5 JAN, 13 0911 77.2 326 22.5 JUN, 08 0853 62.3 362 24.0 FEB, 17 0906 57.1 337 22.0 JUL, 13 0842 79.9 355 24.0 MAR, 08 0908 46.6 396 22.5 AUG, 03 0903 60.5 341 24.5 68 THIS PAGE WAS LEFT BLANK INTENTIONALLY 69 HATILLO OCEAN° ATLANTIC° ARECI • BARCELONE TA 02775 eBoyaney Flerida IN Drainage boundaries indeterminate in limestone terrone 027250' e on Limestone Igneous and edimentary rock's 0280 5 0 Rib Comity basin OCC' UTUADO Logo Vie JAYUVA Logo • ,10.ear Pellejos ago A aiuntos Rib Grande de Anasco begirt ADJONTAS R Drainage -boundary ago Gorros EXPLANATION SURFACE-WATER STATION AND NUMBER V0205 QUALITY-OF-WATER STATION AND NUMBER , in QUALITY-OF-WATER PARTIAL RECORD V025 ' STATION AND NUMBER 204 .A6LIAD Li. A riiiRECIO0 AN JUAN • WELL AND WELL NUMBER MAYASUE cgeu4% FAJAROO. I i I I 2 11 I 3 4 MILES I I o E nrawA .....-„, ----‘,!! I 2 3 - 4 5 6 KILOMETERS Figure 13.--Rio Grande de Arecibo basin. 70 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 Rio Vacas, 1.7 mi (2.7 km) upstream from Rio Garzas, and 2.2 mi (3.5 km) southwest of Adjuntas. DRAINAGE AREA.--15.6 mi' (40.4 km 2). ELEVATION RECORDS PERIOD OF RECORD.--January to September 1988. GAGE.--Water-stage recorder. Datum of gage is 2,337.82 ft (712.567 m) above mean sea level; gage readings have been reduced to elevations above mean sea level. Prior to May 25, 1988 and May 25 to July 13, 1988, at datums 38.98 ft and 20.18 ft higher. REMARKS.--Satellite data collection platform at station. 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, 2,415.0 ft (736.09 m). Lake is used for irrigation and power production. Operated by P.R. Electric Power authority. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximun elevation 2,414.35 ft (735.894 m), Feb. 1; minimun elevation, 2,364.79 ft (720.788 m), Aug. 23, but may have been lower during period of no gage-height record Aug. 23-29. 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 2,394 2,250 2,382 1,500 2,415 4,082 ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 OBSERVATION AT 24:00 VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2414.08 2412.90 2403.82 2400.81 2382.71 A 2383.01 2393.59 2 2413.62 2412.55 2403.72 2400.43 2382.28 2383.28 A 3 2413.62 2412.25 2403.61 2399.98 2382.88 2383.05 4 2413.83 2411.93 2403.52 2399.67 2383.13 2382.95 5 2413.78 2411.60 2403.42 2399.24 2383.69 2382.36 6 2413.90 2411.20 2403.31 2398.74 2383.92 2382.26 7 2414.10 2410.87 2403.21 2397.70 2383.36 2381.79 8 2414.16 2410.02 2403.09 2397.63 2382.37 2379.88 9 2413.48 2409.92 2402.98 2397.32 2381.30 2379.35 10 2413.33 2409.37 2402.86 2396.38 2381.11 2379.63 11 2413.29 2409.28 2402.74 2395.81 2380.95 2378.76 12 2412.92 2408.90 2402.63 2395.14 2381.39 A 2378.24 13 2412.46 2409.11 2402.51 2394.56 2381.46 2383.99 2378.27 14 2412.46 2408.84 2402.40 2393.84 2383.62 2383.89 2378.30 15 2412.48 2408.20 2402.40 2393.23 2383.95 2383.35 2378.52 16 2412.48 2407.23 2402.34 2392.82 2384.25 2384.70 2378.10 17 2412.48 2406.36 2402.50 2392.30 2384.49 2385.48 2379.10 18 2412.50 2405.42 2402.48 2391.68 2385.28 2385.89 2380.08 19 2412.50 2404.42 2402.39 2391.03 2385.68 2385.64 2380.79 20 2412.52 2403.49 2402.70 2390.72 2386.05 2385.32 2381.26 21 --- 2412.52 2403.77 2402.68 2389.03 2385.55 2385.38 2381.66 22 --- 2412.82 2403.94 2402.77 2387.66 2384.89 2385.19 2382.22 23 2413.55 2413.00 2404.11 2402.14 2386.20 2384.51 2385.50 2364.89 24 2413.78 2413.17 2404.27 2402.64 2385.85 2384.20 2385.66 A 25 2413.67 2413.35 2404.03 2402.11 2384.80 2384.48 2385.93 26 2413.64 2413.18 2403.83 2401.22 2384.34 2385.47 2385.22 27 2413.62 2413.39 2403.84 2401.19 2383.97 2385.07 2384.66 28 2413.90 2413.56 2404.00 2401.15 2383.44 2388.10 2384.17 29 2413.89 2413.28 2404.06 2400.58 2383.06 A 2383.86 A 30 2414.08 --- 2404.02 2400.77 2382.48 A 2383.39 2394.16 A 31 2414.31 --- 2403.93 --- 2382.52 --- 2383.74 2393.58 MEAN 2413.18 2407.34 2402.53 2392.01 MAX 2414.16 2412.90 2403.82 2400.81 MIN 2412.46 2403.49 2400.58 2382.48 A No gage-height record. RIO GRANDE DE ARECIBO BASIN 71 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 mi 2 (32.9 km 2 ) this does not include 6.0 mi 2 (15.6 km 2) above Lago Garzas. PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 20... 1545 27 286 7.60 27.0 6.1 7.8 103 .10 K1200 2500 DEC 21... 1430 32 237 7.50 24.5 0.5 8.9 106 18 470 550 FEB 1988 23... 1040 14 307 7.90 22.0 0.6 10.3 122 11 250 200 APR 21... 1005 11 329 7.40 25.0 0.4 9.0 113 <10 4800 780 JUN 22... 0910 12 390 7.00 23.0 1.4 7.6 92 14 K1700 800 AUG 22... 0915 12 597 7.60 23.5 4.0 7.2 89 <10 K1300 5600 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM S1UM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED T1ON SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 20... 100 8 26 8.9 17 0.8 2.1 94 <0.5 12 17 DEC 21... 90 FEB 1988 23... 100 APR 21... 110 5 29 9.7 19 0.8 0.80 100 <0.5 10 25 JUN 22... 130 AUG 22... 130 9 32 11 57 2 3.4 110 12 94 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 N020403 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 20... 0.10 32 171 12 11 1.22 0.08 1.30 0.06 0.34 DEC 21... <1 1.30 0.10 1.40 0.08 0.12 FEB 1988 23... 4 0.98 0.12 1.10 0.07 0.43 APR 21... 0.20 29 187 5.6 ' <1 0.89 0.11 1.00 0.01 0.29 JUN 22... 3 0.91 0.09 1.00 0.11 0.49 AUG 22... 0.10 30 309 10 <1 0.98 0.12 1.10 0.14 0.36 K = non-ideal count RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NR ADJUNTAS, PR--Continued WATER QUALITY DATA. WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM. BORON, CADMIUM MIUM. COPPER. MONIA * NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABIE ERABLE ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L (UG/I (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) OCT 1987 20... 0.4 1.7 7.5 0.11 -1 •100 •10 1 6 <10 DEC 21... 0.2 1.6 7.1 0.12 - FEB 1988 23... 0.5 1.6 7.1 0.21 - APR 21... 0.3 1.3 5.8 0.25 -1 -100 -.10 1 1 <10 JUN 22... 0.6 1.6 7.1 0.15 AUG 22... 0.5 1.6 7.1 0.19 MANGA- METHY- IRON, LEAD. NESE. MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELF- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL FRABLE 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) OCT 1987 20... 940 <5 70 <0.10 -1 <1 -10 <0.010 7 0.02 DEC 21... FEB 1988 23... APR 21... 190 <5 70 1.3 ,1 1 40 <0.010 3 0.04 JUN 22... AUG 22... 12 I RIO GRANDE DE ARECIBO BASIN 73 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 Rio de Caguana, and 2.5 i (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 mil (170.9 km') this excludes 6.0 mil (15.5 km•) upstream from Lago Garzas to Rio Guayanes in the Rio Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 D1S- OXYGEN, OXYGEN COIL- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1981 20... 1230 114 225 7.50 29.0 68 7.2 93 250 K16000 K12000 DEC 21... 1155 144 248 7.20 25.5 4.1 7.9 96 <10 28000 7800 FEB 1988 22... 1100 227 304 7.00 23.5 36 9.2 107 33 29000 28000 APR 20... 1000 81 252 7.10 25.5 18 7.7 93 <10 K11000 4500 JUN 21... 0910 107 194 6.80 24.0 120 7.8 92 <10 25000 24000 AUG 22... 1140 44 304 7.90 27.5 6.8 7.2 46 <10 29000 11000 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- D1S- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 20... 87 13 23 7.1 13 0.6 2.3 74 <0.5 16 10 DEC 21... 79 FEB 1988 22... 72 APR 20... 85 9 22 7.2 12 0.6 1.9 67 <0.5 22 11 JUN 21... 57 AUG 22... 110 15 28 8.6 16 0.7 2.3 89 26 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) S102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 20... 0.10 27 143 44 14 1.17 0.03 1.20 0.08 0.82 DEC 21... 17 1.25 0.05 1.30 0.09 0.21 FEB 1988 22... 1.02 0.08 1.10 0.59 0.41 APR 20... 0.20 24 146 32 26 1.57 0.03 1.60 0.07 0.33 JUN 21... 148 1.08 0.02 1.10 0.04 1.20 AUG 22... 0.10 27 180 21 6 1.11 0.09 1.20 0.20 0.50 K non-ideal count 74 RIO GRANDE DE ARICIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 CHRO- NITRO- GEN.AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA • NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOv- RECOV- RECOV- RECOV- ERABLE ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE DATE (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS NO3) AS P) AS AS) AS BA) AS 8) AS CD) AS CR) AS CU) OLI 1987 .1 30 20... 0.9 2.1 9.3 0.09 -1 -100 -10 -1 DEC 21... 0.3 1.6 !.1 0.12 FEB 1988 22... 1.0 2.1 9.3 0.27 APR 20... 0.4 2.0 8.9 0.12 -I -100 -10 1 2 10 JUN 21... 1.2 0.09 AUG 22... 0.7 1.9 8.4 0.17 METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE BLUE MANGA- TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE ERABLE TOTAL PHENOLS SUB- (MG/L TOTAL STANCE DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CH) (UG/L) (MG/L) OCT 1987 -0.10 1 -1 20 -0.010 2 0.01 20... 5500 8 270 DEC 21... FEB 1988 22... APR 20... 2400 120 <0.10 <5 <1 1 10 • 0.010 2 0.04 JUN 21... AUG 22... 75 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18- 13'26", long 6638'22", 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 mi' (104.6 km•). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLT- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 21... 0730 105 160 7.40 23.5 3.2 8.0 96 <10 600 K1200 DEC 22... 0740 75 154 7.10 22.0 0.6 8.3 98 <10 390 K1200 FEB 1988 23... 1405 28 225 7.80 25.0 0.9 7.9 98 13 K20 K45 APR 21... 1315 36 200 7.40 27.5 1.8 7.1 9: <10 K760 270 JUN 22... 1205 35 196 7.30 26.0 26 7.5 93 13 2100 410 AUG 23... 0820 E200 173 7.80 24.0 1.0 8.3 101 <10 4200 4800 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FIT SULFIDE DIS- D1S- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAM) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 21... 62 8 16 5.3 10 0.6 1.5 54 <0.5 13 7.6 DEC 22... 53 FEB 1988 23... 70 APR 21... 69 5 18 5.9 10 0.5 1.4 56 <0.5 15 11 JUN 22... 62 AUG 23... 64 0 17 5.3 8.8 0.5 1.3 59 16 10 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 21... 0.10 24 110 31 4 0.69 0.01 0.70 0.02 0.18 DEC 22... -1 0.68 0.02 0.70 0.01 0.19 FEB 1988 23... - - 3 0.48 0.02 0.50 0.02 0.28 APR 21... 0.10 23 123 12 92 0.79 0.01 0.80 0.05 0.25 JUN 22... 7 0.59 0.01 0.60 0.03 0.27 AUG 23... 0.10 21 131 5 0.19 0.01 0.20 0.04 0.26 K = non-ideal count E = estimate 76 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR--Continued WATER-QUALITY DATA. WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN.AM- BARIUM. BORON. CADMIUM MIUM. COPPER. MONIA + NITRO- NITRO- PROS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN. PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE BABEL 'ABLE 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 8) AS CD) AS CR) AS CU) OCT 1987 21... 0.2 0.9 0.05 -1 <100 10 ,1 5 <10 DEC 22... 0.2 0.9 0.05 FEB 1988 23... 0.3 0.8 3.5 0.09 - APR 21... 0.3 1.1 4.9 0.11 1 <100 <10 <1 <1 <10 JUN 22... 0.3 0.9 4.0 0.07 AUG 23... 0.3 0.5 2.2 0.08 MANGA- METHY- IRON. LEAD, NESE, MERCURY SILVER, ZINC. LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL BLUE RECOV- RECOV- RECOV- RECOV- N1UM, 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) OCT 1987 21... 350 •5 20 -0.10 -1 ,1 <10 -0.010 5 0.02 DEC 22... FEB 1988 23... APR 21... 490 ,5 20 1.1 <1 •1 -10 <0.010 ,1 0.02 JUN 22... - AUG 23... 77 RIO GRANDE DE ARECIBO BASIN 50021250 RIO GRANDE DE ARECIBO BELOW IAGO 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 mi' (436 km') does not include 6.0 mi' (15.6 km') above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. D1S- OXYGEN. OXYGEN COL1- STREP- CHARGE. SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL. FECAL. CUBIC CON- PH TEMPER- TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR 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) OCT 1987 20... 1000 E1000 199 6.80 26.5 17 4.5 56 ,10 290 280 DEC 21... 1000 E1500 172 6.40 25.0 23 5.1 61 <10 660 980 FEB 1988 22... 1245 E1700 212 6.50 24.5 4.5 54 K27 K100 APR 20... 1235 E1900 198 6.60 25.5 28 4.9 59 <10 K710 K1400 JUN 21... 1125 35 250 6.40 27.0 5.7 5.1 64 <10 K70 K190 AUG 23... 1130 87 237 7.30 28.5 15 5.4 69 16 K150 920 HARD- ALKA- HARD- NESS MAGNI- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE. TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLO SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 20... 77 8 21 5.9 11 0.6 2.4 69 <0.5 11 9.4 DEC 21... 54 FEB 1988 22... APR 20... 72 4 19 5.9 10 0.5 2.0 61 <0.5 15 9.7 JUN 21... 77 AUG 23... 90 29 24 7.4 12 0.6 2.0 84 11 8.6 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) 5102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 20... 0.10 22 124 102 0.59 0.01 0.60 0.08 0.62 DEC 21... 16 0.79 0.01 0.80 0.02 0.18 FEB 1988 22... 29 0.59 0.01 0.60 0.02 0.28 APR 20... 0.10 19 121 36 0.48 0.02 0.50 0.14 0.16 JUN 21... 11 0.17 0.03 0.20 0.22 0.28 AUG 23... 0.10 23 125 29 35 0.09 0.01 0.10 0.14 0.36 K = non-ideal count E = estimate 78 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 20... 0.7 1.3 5.8 0.03 -1 -100 .10 -1 8 •10 DEC 21... 0.2 1.0 0.05 - FEB 1988 22... 0.3 0.9 4.0 0.02 APR 20... 0.3 0.8 3.5 0.03 5 -100 -10 1 2 20 JUN 21... 0.5 0.7 3.1 0.02 AUG 23... 0.5 0.6 0.04 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) OCT 1987 20... 830 <5 90 <0.10 -1 <1 40 -0.010 5 0.02 DEC 21... FEB 1988 22... APR 20... 3200 <5 80 <0.10 -1 <1 10 <0.010 1 0.02 JUN 21... AUG 23... 79 RIO GRANDE DE ARECIBU bASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR LOCATION.--Lat 18°25'29", long 66°41'44", Hydrologic Unit 21010002, 0.8 mi (1.3 km) upstream from Rio Tanama, 4.0 mi (6.4 km) south of Arecibo and 6.7 mi (10.8 km) above mouth, and 10.2 mi (16.4 km) downstream from Lago Dos Bocas. DRAINAGE AREA.--200 mi' (520 km 2 ), approximately, of which an undetermined amount does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS 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 lap Dos Bocas Dam 10.2 mi (16.4 km) upstream. AVERAGE DISCHARGE.--6 years (1983-88), 476 ft'/s (13.48 m'/s), 32.32 in/yr (821 mm/yr), 344,900 acre-ft/yr (425 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 45,800 ft'/s (1,300 m'/s), May 18, 1985, gage height, 18.22 ft (5.553 m), from floodmark, from rating curve extended above 2,430 ft'is (68.0 m'/s) on basis of slope-area measurement of peak flow; minimum discharge. 30 ft'/s (0.850 e/s), Mar. 30, 1986. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 4,300 ft'/s (122 m'is) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (e/s) (ft) (m) Date Time (ft 3 /s) (m'/s) (ft) (m) Nov. 27 2215 *9,680 274 *12.99 3.959 Minimum discharge, 36 ft'/s (1.020 m'/s), Oct. 11. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 145 111 1160 660 662 752 63 423 79 67 432 215 2 276 59 949 1200 809 115 51 685 86 61 257 178 3 92 198 831 451 928 64 51 178 139 809 88 218 4 245 321 708 815 544 56 368 545 185 386 86 957 5 153 400 175 469 727 56 232 520 66 509 147 239 6 107 542 186 331 243 125 335 329 163 116 306 147 7 270 106 781 459 170 509 109 115 299 585 68 100 8 331 72 1500 751 585 218 105 95 129 228 397 218 9 525 299 1180 572 113 115 358 102 321 842 227 691 10 1020 676 849 107 55 98 529 860 369 290 170 681 11 398 117 584 418 570 252 424 1940 93 88 172 471 12 573 451 200 715 577 576 93 1260 70 65 101 381 13 1080 642 276 441 329 146 497 1220 65 381 77 86 14 781 125 190 409 186 534 405 402 78 157 67 81 15 701 244 86 504 337 661 346 170 71 499 86 141 16 681 803 409 489 123 109 501 429 68 170 288 395 17 575 872 377 268 171 64 328 583 435 117 172 390 18 92 607 426 312 105 157 461 639 111 76 581 171 19 702 222 293 438 518 67 662 726 70 73 117 532 20 847 296 1040 299 84 54 921 144 66 306 761 829 21 127 140 740 372 202 525 1380 561 246 218 300 958 22 85 59 862 479 528 516 1360 837 483 421 78 1150 23 834 537 717 101 674 61 674 562 593 367 533 977 24 285 780 757 73 441 63 503 128 462 105 363 730 25 103 633 184 738 627 54 80 82 95 74 2920 517 26 158 162 278 493 628 54 129 76 71 396 1710 883 27 524 1960 203 241 642 63 646 79 91 91 357 757 28 413 3190 589 503 208 139 564 70 750 440 208 876 29 487 964 457 251 628 128 789 110 417 113 868 797 30 739 1020 403 135 --- 536 1000 297 121 330 1810 723 31 504 --- 279 59 291 --- 212 --- 120 937 --- TOTAL 13853 16608 17669 13553 12414 7158 13964 14379 6292 8500 14684 15489 MEAN 447 554 570 437 428 231 465 464 210 274 474 516 MAX 1080 3190 1500 1200 928 752 1380 1940 750 842 2920 1150 MIN 85 59 86 59 55 54 51 70 65 61 67 81 AC-FT 27480 32940 35050 26880 24620 14200 27700 28520 12480 16860 29130 30720 CFSM 3.19 3.95 4.07 3.12 3.06 1.65 3.32 3.31 1.50 1.96 3.38 3.69 IN. 3.68 4.41 4.69 3.60 3.30 1.90 3.71 3.82 1.67 2.26 3.90 4.12 CAL YR 1987 TOTAL 151217 MEAN 414 MAX 3190 MIN 38 AC-FT 299900 CFSM 2.96 IN. 40.18 WTR YR 1988 TOTAL 154563 MEAN 422 MAX 3190 MIN 51 AC-FT 306600 CFSM 3.02 IN. 41.07 80 RIO GRANDE DE ARECIBO BASIN 50027750 RIO GRANDE DE ARECIBO ABOVE ARECIBO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS APRIL 1982 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 15 1032 108.43 243 26.5 APR, 14 1026 79.6 240 25.0 DEC, 16 1107 99.8 290 25.0 MAY, 10 1002 86.4 276 25.5 JAN, 20 1017 49.3 224 23.5 JUN, 02 1032 63.0 286 27.5 FEB, 22 1027 98.9 229 24.0 JUL, 06 1009 98.8 263 26.0 MAR. 14 1043 56.5 307 25.0 AUG, 05 1025 65.9 252 27.5 RIO GRANDE DE ARECIBO BASIN e1 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 mi, (47.7 km 2 ). 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. Elevation of gage is 938.32 ft (286.00 m) above mean sea level. Datum of gage was lowered 3.00 ft (0.914 m) on Oct. 1978. Prior to Nov. 17, 1966, non-recording gage and Nov. 17, 1966 to Sept. 30, 1978 recording gage, both at present site. REMARKS.--Records fair except those for estimated daily discharges, which are poor. AVERAGE DISCHARGE.--28 years (1961-88), 48.3 fts/s (1.368 m7s), 35.65 in/yr (906 mm/yr), 34,990 acre-ft/yr (43.1 hm 3 /yr) median of yearly mean discharges, 48 ft 3/s (1.36 ml/s), 34,800 acre-ft/yr (43 hm 3/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 12,190 ft'is (345 e/s), Nay 18, 1985, gage height, 17.45 ft (5.319 m) new datum in use, from floodmark and recorder, from rating curve extended above 500 ft3/s (14.2 m 3/s) on basis of slope-area measurement of peak flow: minimum discharge, 6.6 ft3/s (0.187 e/s), June 12. 1977. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 3,000 ft'is (85.0 e/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft3/s) (m 3/s) (ft) (m) Date Time (ft 3/s) (m 3/s) (ft) (m) Nov.27 1600 *2,910 82.4 *11.55 3.520 Minimum discharge, 12 ft'/s (0.340 e/s), June 4-11. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23 61 52 84 42 28 19 20 14 22 16 140 2 54 37 66 67 39 27 18 19 14 21 16 e60 3 28 35 50 44 41 22 18 18 14 21 27 e45 4 24 29 45 39 34 21 18 18 13 20 25 e41 5 23 26 86 37 31 21 21 18 13 46 17 e39 6 22 25 79 36 30 20 23 17 12 27 17 38 7 81 81 54 35 29 20 18 17 13 20 17 40 8 140 42 48 33 28 20 17 16 13 19 17 37 9 45 33 44 33 27 19 17 23 12 19 17 42 10 57 28 42 32 27 19 16 73 12 19 18 61 11 63 26 41 32 27 19 21 56 25 19 21 58 12 39 27 39 31 29 19 28 31 68 19 16 67 13 29 29 38 30 29 19 23 22 49 24 15 46 14 63 29 36 65 29 19 17 22 26 26 18 40 15 43 37 37 44 26 18 45 22 21 18 30 73 16 35 29 39 35 25 18 38 18 22 19 21 60 17 28 53 35 42 24 19 33 17 20 147 36 56 18 39 32 34 35 24 19 86 16 54 e41 68 47 19 31 27 111 36 23 17 38 16 51 e24 23 44 20 26 24 84 33 24 17 97 16 44 21 38 93 21 43 24 50 31 23 17 108 15 42 21 31 167 22 47 23 41 31 23 16 83 14 30 22 25 107 23 53 24 37 31 23 16 42 14 25 19 29 213 24 35 90 36 30 23 16 28 14 30 18 403 119 25 27 53 51 30 23 16 23 14 68 20 265 104 26 25 36 35 29 25 16 21 20 40 18 105 189 27 26 351 34 29 34 26 20 26 28 18 98 e98 28 24 113 33 29 23 70 27 54 31 20 84 e70 29 69 67 32 35 22 31 30 32 25 31 55 e60 30 70 57 32 30 --- 21 23 17 23 19 46 e52 31 95 --- 70 29 21 --- 15 --- 17 60 --- TOTAL 1407 1548 1511 1157 807 667 1016 710 852 815 1674 2306 MEAN 45.4 51.6 48.7 37.3 27.8 21.5 33.9 22.9 28.4 26.3 54.0 76.9 MAX 140 351 111 84 42 70 108 73 68 147 403 213 MIN 22 23 32 29 22 16 16 14 12 17 15 37 AC-FT 2790 3070 3000 2290 1600 1320 2020 1410 1690 1620 3320 4570 CFSM 2.47 2.80 2.65 2.03 1.51 1.17 1.84 1.24 1.54 1.43 2.93 4.18 IN. 2.84 3.13 3.05 2.34 1.63 1.35 2.05 1.44 1.72 1.65 3.38 4.66 CAL YR 1987 TOTAL 13146 MEAN 36.0 MAX 351 MIN 14 AC-FT 26080 CFSM 1.96 IN. 26.58 WTR YR 1988 TOTAL 14470 MEAN 39.5 MAX 403 MIN 12 AC-FT 28700 CFSM 2.15 IN. 29.25 e Estimated 82 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED SEDIMENT DISCHARGE: January 1968 to current year. REMARKS.--Sediment samples were collected by a local observer on a weekly basis and during high flow events. Estimates for period of missing daily record were made from a sediment transport curve developed from a period of record over 5 years. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 20,400 mg/L November 27, 1968; minimum daily mean, 0 mg/L during water year 1985. SEDIMENT LOADS: Maximum daily, 167,000 tons (152,000 tonnes) May 18, 1985, minimum daily, 0.0 ton (0.0 tonne) several days during many years. EXTREMES FOR CURRENT YEAR.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 1,760 mg/L June 02, 1987; minimum daily mean, 2.0 mg/L several days. SEDIMENT LOADS: Maximum daily, 5,930 tons (5,380 tonnes) June 02, 1987; minimum daily, 0.08 ton (0.07 tonne) several days. WATER-QUALITY DATA, WATER YEARS OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLT- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 02... 1115 23 160 8.00 24.5 6.7 9.0 110 16 430 320 DEC 16... 1220 38 154 7.90 23.5 3.4 9.1 109 34 210 200 FEB 1988 04... 1400 35 154 7.90 23.5 2.3 8.8 106 <10 K880 K170 APR 14... 1150 17 166 7.50 23.0 22 9.0 107 29 K730 600 JUN 09... 1315 13 179 7.80 27.5 3.4 8.2 106 29 K80 380 AUG 04... 1400 20 163 7.40 27.0 22 7.9 101 <10 K1100 52 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED T1ON SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 02... 65 8 16 6.0 8.2 0.5 1.9 57 <0.5 13 7.9 DEC 16... 54 FEB 1988 04... 52 APR 14... 61 6 15 5.6 8.2 0.5 2.1 48 <0.5 14 8.4 JUN 09... 56 AUG 04... 63 7 16 5.6 7.8 0.4 2.0 f' 12 8.2 K = non-ideal count RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO. PR--Continued WATER-QUALITY DATA, WATER YEARS OCTOBER 1987 TO SEPTEMBER 1988 SOLIDS, RESIDUE FLUO- SILICA, SUM OF SOLIDS, TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- RIDE, DIS- CONSTI- D1S- AT 105 GEN, GEN, GEN. GEN, GEN, DIS- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO20403 AMMONIA ORGANIC SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL DATE (MG/L AS SOLVED PER PENDEO (MG/L (MG/L (MG/L (MG/L (MG/L AS F) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 02... 0.10 26 113 7.0 2 0.59 0.01 0.60 0.04 0.16 DEC 16... -- ,1 0.69 0.01 0.70 0.01 0.19 FEB 1988 04... 1 0.79 0.01 0.80 0.02 0.58 APR 14... 0.10 24 110 5.0 17 0.79 0.01 0.80 0.03 0.17 JUN 09... <1 0.39 0.01 0.40 0.02 0.48 AUG 04... 0.10 22 107 5.9 8 0.49 0.01 0.50 0.02 0.18 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN. GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 02... 0.2 0.02 <1 <100 50 1 4 20 DEC 16... 0.2 0.9 4.0 0.02 FEB 1988 04... 0.6 1.4 6.2 0.03 APR 14... 0.2 0.03 ,1 ,100 <10 2 <1 320 JUN 09... 0.5 0.9 4.0 0.01 AUG 04... 0.2 0.7 3.1 0.03 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) OCT 1987 02... 670 <5 20 <0.10 2 <1 <10 <0.010 7 0.01 DEC 16... FEB 1988 04... APR 14... 1200 7 60 0.20 50000 7.50 30.0 9.0 2.2 29 K150000 5600 130 RESIDUE NITRO- TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- CARBON, DEG. C, NITRATE NITRITE NO20403 AMMONIA ORGANIC ORGANIC GEN, GEN, PHOROUS ORGANIC SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE PENDED (MG/L (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) OCT 1987 23... 3 0.04 <0.10 1.00 0.9 1.9 0.28 11 DEC 17... 5 0.20 0.10 0.30 1.30 1.9 3.2 3.5 15 0.31 6.8 FEB 1988 25... 25 0.14 0.06 0.20 0.97 0.93 1.9 2.1 9.3 0.42 10 APR 26... 37 0.07 0.03 0.10 1.70 1.5 3.2 3.3 14 0.31 6.4 JUN 20... 6 0.03 <0.10 1.20 0.7 1.9 0.38 7.7 AUG 19... 8 0.02 <0.10 1.20 1.5 2.7 0.50 9.5 154 THIS PAGE WAS LEFT BLANK INTENTIONALLY 155 SAN JUAN A T C 0 (round LOIZA ALDEA Son *Jose O Coastal basin Coasfot basin RIO GRANDE N TRU I LO ALTO 't Rib Herrera basin Rib Piedras basin Droinoge boundary. Arena Rio Espiritu Santo basin Rib de Bayornab basin AGUAS BUENA GURABO CAGUAS JUNCOS de /03 ovobro SAN LORENZO LAS PIEDRAS 051180 Drainage boundary Rib de la Piata basin Ri'a Humacao basin EXPLANATION 5508 SURFACE—WATER STATION AND NUMBER 1,564 QUALITY—OF—WATER STATION AND NUMBER QUALITY—OF—WATER PARTIAL RECORD Ria Guayones basin V0575 STATION AND NUMBER .Ailt A 0222 WELL AND WELL NUMBER AYA6VEZ LAGUA 2 3 4 NILES I I I I I I I I I 1 2 3 4 3 6 StL08ETER3 Figure 18.--Rio Grande de Loiza basin. 156 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 ka) west-southwest of Carolina plaza. DRAINAGE AREA.--2.96 ail (7.67 km?). PERIOD OF RECORD.--Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- D1S- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 06... 1245 5.0 558 7.80 30.0 2.3 3.6 47 48 290000 3000 DEC 02... 1145 7.9 426 7.00 26.0 21 2.7 33 20 210000 8800 FEB 1988 11... 1210 5.7 776 7.00 26.5 4.4 0.6 7 34 K1500000 K1300000 APR 05... 1200 5.2 576 7.60 27.0 15 1.6 20 110 K600000 K600000 JUN 01... 1150 6.5 640 7.20 30.0 1.5 2.0 26 55 2300000 310000 AUG 09... 1125 2.6 512 6.60 28.5 2.2 0.8 10 34 K2300000 330000 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS 5) AS 504) AS CL) OCT 1987 06... 190 1 60 10 35 1 4.0 190 <0.5 23 54 DEC 02... 150 FEB 1988 11... - 190 APR 05... 180 0 54 9.8 49 2 3.8 200 <0.5 18 46 JUN 01... 170 AUG 09... 170 0 53 9.1 42 1 3.5 180 17 49 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) 5102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 06... 0.20 25 325 4.4 4 0.79 0.11 0.90 0.65 0.55 DEC 02... - 29 0.83 0.07 0.90 0.51 0.89 FEB 1988 11... 2 0.17 0.13 0.30 3.30 1.7 APR 05... 0.20 25 327 4.6 <1 0.11 0.09 0.20 0.43 1.1 JUN 01... 11 0.09 0.11 0.20 2.60 2.3 AUG 09... 0.20 27 312 2.2 5 0.07 0.03 0.10 2.80 1.6 K = non-ideal count RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM M1UM, COPPER, MONIA t NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 <1 06... 1.2 2.1 12 0.34 2 100 <10 1 20 DEC 02... 1.4 2.3 10 0.31 FEB 1988 11... 5.0 5.3 23 0.86 APR 05... 2.1 2.3 10 0.99 7 <100 <10 1 <1 10 JUN 01... 4.9 5.1 23 0.72 -- AUG 09... 4.4 4.5 18 0.79 METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LINE TOTAL TOTAL TOTAL TOTAL SELF- 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 MANGA- (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) OCT 1987 06... 400 <5 190 <0.10 <1 <1 10 <0.010 4 0.08 DEC 02... - FEB 1988 11... APR 05... 1500 <5 400 <0.10 <1 <1 30 <0.010 8 0.11 JUN 01... AUG 09... 157 --- RIO GRANDE DE LOIZA BASIN 158 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 1807'10", long 65°59'22", Hydrologic Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) upstream from confluence with Rio Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 mi' (15.54 km:). WATER-DISCHARGE RECORDS 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. AVERAGE DISCHARGE.--11 years (1978-88), 31.4 fti/s (0.889 m'/s), 71.07 in/yr, (1,805 mm/yr), 22,750 acre-ft/yr (28.05 hm'/yr); median of yearly mean discharges, 29 ft'/s (0.82 m'/s), 21,000 acre-ft/yr (26 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 11,700 ft'/s (331 m'/s), Nov. 5, 1983, gage height, 14.78 ft (4.505 m), from rating curve extended above 500 ft'/s (14.2 m'/s) on basis of step-backwater analysis; minimum discharge, 2.8 ft'/s (0.079 m'/s), May 5, 6, 1979. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 2,000 ft'is (56.6 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft7s) (m7s) (ft) (m) Date Time (ft'/s) (m)/s) (ft) (m) Nov.24 1800 2,770 78.4 9.03 2.752 Aug. 10 2015 2,010 56.9 8.21 2.502 Nov.27 0930 *6,510 184 *11.95 3.642 Aug. 24 1415 2,710 76.7 8.97 2.734 Nov.28 0815 2,390 67.7 8.64 2.633 Aug. 25 0700 2,330 66.0 8.57 2.612 Dec. 7 2315 4,380 124 10.44 3.182 Sept. 11 0815 3,500 99.1 9.71 2.960' July 2 0800 3,720 105 9.90 3.018 Minimum discharge, 4.2 ft'is (0.119 m'/s), Apr. 28, 29, May 5. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20 13 38 54 19 11 7.7 22 6.0 168 23 26 2 12 12 78 31 29 11 7.7 7.0 6.2 892 19 23 3 30 11 30 33 39 10 7.5 5.9 6.5 54 29 20 4 20 39 25 39 19 9.9 7.6 5.1 6.6 34 23 19 5 22 110 23 31 23 9.9 7.5 4.6 6.2 26 17 18 6 13 46 42 27 16 9.9 7.7 23 6.1 39 17 17 7 11 25 629 24 14 9.9 7.7 7.3 6.1 95 18 20 8 9.7 20 263 23 13 9.6 7.1 5.5 6.7 26 16 17 9 9.9 18 57 25 15 9.1 6.7 4.9 6.7 26 17 34 10 9.4 15 42 27 15 8.9 6.0 6.1 6.6 43 228 90 11 8.6 14 39 33 13 8.8 5.8 7.7 7.5 28 96 566 12 8.3 13 32 26 21 8.8 5.9 15 6.9 23 37 263 13 7.8 12 27 29 30 8.7 5.6 6.3 9.2 21 24 106 14 25 12 25 23 15 9.1 5.3 6.3 22 44 20 79 15 59 11 24 19 14 8.5 11 6.8 173 21 20 54 16 55 17 20 18 14 8.3 8.1 7.5 48 18 24 42 17 131 15 19 17 13 8.3 6.5 11 15 18 33 35 18 346 19 17 16 13 8.1 6.5 9.3 14 29 34 30 19 53 14 18 15 12 7.6 5.6 8.1 37 22 20 75 20 26 12 21 14 19 13 5.2 20 39 18 18 31 21 20 11 23 14 13 8.6 5.2 30 49 15 16 25 22 16 11 44 14 12 7.8 5.0 11 62 29 229 24 23 15 16 20 14 12 7.5 4.8 8.4 42 28 63 22 24 15 958 17 13 15 7.4 4.8 7.0 24 16 451 20 25 18 136 16 14 12 9.8 4.8 6.4 19 15 225 18 26 22 271 17 14 17 10 5.2 6.8 39 23 53 17 27 15 1180 18 17 19 28 5,5 6.8 21 16 46 16 28 78 500 25 14 12 24 4,6 6.7 17 129 39 16 29 25 85 18 23 11 11 5.1 8.2 16 34 34 14 30 15 50 17 14 --- 9.4 4.7 8.8 70 113 34 14 31 15 --- 27 14 8.1 --- 7.0 --- 31 27 TOTAL 1130.7 3666 1711 689 489 320.0 188.4 296.5 794.3 2094 1950 1751 MEAN 36.5 122 55.2 22.2 16.9 10.3 6.28 26.5 67.5 62.9 9.56 58.4 28 892 MIN 7.8 11 16 13 11 7.4 4.6 4.6 6.0 15 16 14 AC-FT 2240 7270 3390 1370 970 635 374 588 1580 4150 3870 3470 CFSM 6.08 20.4 9.20 3.70 2.81 1.05 1.59 4.41 10.5 9.73 MAX 346 1180 629 54 39 11 30 173 451 566 1.72 11.3 IN. 7.01 22.73 10.61 4.27 3.03 1.98 1.17 1.84 4.92 12.98 12.09 10.86 CAL YR 1987 TOTAL 12444.6 MEAN 34.1 MAX 1180 MIN 5.7 AC-FT 24680 CFSM 5.68 IN. 77.16 WTR YR 1988 TOTAL 15079.9 MEAN 41.2 MAX 1180 MIN 4.6 AC-FT 29910 CFSM 6.87 IN. 93.50 159 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 14 1209 42.6 94 26.5 MAR. 02 1315 11.0 148 23.0 NOV, 13 1100 12.4 148 25.0 APR. 05 1045 7.81 148 24.0 DEC, 09 0812 61.1 114 23.0 MAY, 06 1139 78.1 134 24.0 JAN, 04 1108 55.4 131 23.0 JUN, 03 1330 6.63 153 28.0 FEB. 01 1252 16.3 143 23.5 JUL, 12 1315 23.12 130 27.0 I I I RIO GRANDE DE LOIZA BASIN 160 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR LOCATION.--Lat 18°09'40", long 65°58'58", Hydrologic Unit 21010005, 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 i2 (8.42 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 459 ft (140 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 7,400 ft'is (210 m'/s), May 17, 1985, gage height, 14.58 ft (4.444 a), from floodmark, from rating curve extended above 400 ft 3 /s (11.3 m'/s) on basis of step-backwater analysis and slope-area measurement; minimum discharge, 0.46 ft'is (0.013 '/s), May 3, 1985. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 1,000 ft'/s (28.3 3 /s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (W/s) (e/s) (ft) (m) Date Time (W/s) (e/s) (ft) (m) Nov. 27 unknown 2,620 74.2 10.41 3.173 Aug. 24 1400 *2,910 82.4 10.76 3.280 Dec. 7 1630 2,810 79.3 10.65 3.246 Aug. 25 0715 1,350 38.2 8.77 2.673 July 2 0745 1,480 41.9 8.97 2.734 Minimum discharge, 1.2 ft'is (0.034 10/s), many days. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.4 2.8 7.0 28 3.6 6.8 1.8 1.4 1.5 28 2.6 5.3 2 1.6 2.2 34 13 3.6 14 1.8 1.4 1.4 192 2.3 4.4 3 2.7 1.9 5.9 7.8 6.8 4.9 1.9 1.2 1.4 11 4.2 3.6 4 2.4 2.1 5.1 7.5 3.8 3.8 1.9 1.2 1.4 4.9 3.9 3.1 5 1.7 5.1 4.1 9.4 4.1 3.3 1.8 1.2 1.3 3.5 3.0 2.7 6 1.5 4.2 6.6 9.4 3.7 3.1 2.1 4.7 1.3 10 2.7 2.5 7 1.7 2.8 457 7.7 3.4 3.0 2.0 1.8 1.2 52 4.6 2.5 8 1.3 2.2 168 7.8 3.4 3.0 1.9 1.4 1.3 5.0 4.0 2.4 9 1.4 2.0 32 8.1 3.6 2.8 1.9 1.4 1.6 3.6 2.9 6.0 10 1.4 2.0 19 6.9 3.5 2.6 1.8 16 1.8 5.7 75 6.9 11 1.3 1.9 13 9.0 3.4 2.5 1.7 2.5 1.4 6.0 16 156 12 1.3 3.4 9.4 7.7 8.9 2.3 1.7 1.6 1.3 4.2 5.8 62 13 1.2 2.0 7.8 9.0 20 2.4 1.7 1.5 1.8 3.6 4.0 24 14 2.7 1.7 6.7 7.0 3.3 2.5 1.5 1.5 2.2 5.4 3.3 15 15 13 1.6 6.4 5.4 3.1 2.0 3.7 2.0 15 3.2 3.1 10 16 21 12 5.7 4.7 3.0 2.0 2.4 1.4 12 2.9 5.6 7.7 17 61 4.1 5.3 4.3 2.9 1.9 4.6 1.4 2.7 2.9 15 5.7 18 167 2.9 4.8 3.8 2.9 2.0 2.5 1.3 1.8 11 23 4.8 19 24 2.3 5.8 3.6 2.8 1.9 1.7 1.4 1.6 4.7 5.4 16 20 7.0 2.0 10 3.4 3.1 2.1 1.6 2.2 15 3.2 4.0 5.0 21 4.1 1.9 8.1 3.3 2.7 2.1 1.5 1.9 10 2.7 3.4 3.9 22 3.2 1.9 40 3.1 2.5 1.9 1.4 1.6 5.6 5.1 9.2 3.3 23 2.8 8.9 11 3.1 2.6 1.9 1.5 1.5 2.4 3.1 4.8 3.0 24 2.7 e320 8.8 3.2 2.7 1.9 1.4 1.5 2.0 2.6 229 2.9 25 3.2 e24 7.0 3.2 2.8 2.0 1.4 1.4 18 2.5 113 2.6 18 2.4 27 10 e400 5.9 2.9 15 4.4 1.9 1.5 4.2 2.4 14 2.2 28 25 e100 6.6 2.9 4.3 2.4 1.4 1.4 2.5 3.7 18 2.1 26 3.6 e100 6.8 3.0 24 2.0 1.4 1.5 15 2.8 29 5.0 e35 5.7 3.5 3.6 1.9 1.2 1.8 2.2 7.7 13 2.0 30 3.2 e20 4.9 2.8 --- 1.9 1.2 3.0 2.4 4.0 8.6 1.8 31 2.9 --- 14 2.9 1.9 --- 1.7 --- 2.9 6.2 --- TOTAL 383.3 1072.9 932.4 197.4 153.1 93.2 56.3 67.3 133.3 402.3 627.6 371.8 MEAN 12.4 35.8 30.1 6.37 5.28 3.01 1.88 2.17 4.44 13.0 20.2 12.4 MAX 167 400 457 28 24 14 4.6 16 18 192 229 156 MIN 1.2 1.6 4.1 2.8 2.5 1.9 1.2 1.2 1.2 2.4 2.3 1.8 AC-FT 760 2130 1850 392 304 185 112 133 264 798 1240 737 CFSM 3.80 11.0 9.25 1.96 1.62 .93 .58 .67 1.37 3.99 6.23 3.81 IN. 4.39 12.28 10.67 2.26 1.75 1.07 .64 .77 1.53 4.60 7.18 4.26 CAL YR 1987 TOTAL 4009.3 MEAN 11.0 MAX 457 MIN 1.2 AC-FT 7950 CFSM 3.38 IN. 45.89 WTR YR 1988 TOTAL 4490.9 MEAN 12.3 MAX 457 MIN 1.2 AC-FT 8910 CFSM 3.78 IN. 51.40 e Estimated RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--JANUARY 1985 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURF DATE TIME INSTANTANEOUS DUCTANCE TURF (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 05 1148 1.75 258 28.0 MAR, 03 1106 4.41 226 24.0 NOV, 18 1013 2.95 255 25.5 APR, 06 0930 1.90 287 24.5 DEC, 09 1217 29.8 172 26.0 MAY, 06 1431 7.09 260 28.0 JAN, 05 1100 9.06 227 24.5 JUN, 02 1050 1.42 283 27.8 FEB, 02 1024 3.81 245 23.0 JUL, 11 0933 6.97 221 26.0 181 RIO GRANDE DE LOIZA BASIN 162 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1985 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1984 to September 1986. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. The suspended-sediment data for May 17, 1985, October 6, 1985, May 8, 1986, and May 13, 1986 are estimated. 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. SEDIMENT LOADS: Maximum daily mean, 25,800 tons (23,400 tonnes) May 17 , 1985; Minimum daily mean, 0.01 tons (0.01) tonne several days. EXTREMES FOR WATER YEARS 1985-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1985 6,720 (May 18) 1 (several days) 25,800 (May 17) 0.01 (several days) 1986 7,300 (Oct. 06) 1 (several days) 15,200 (Oct. 06) 0.01 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 9.0 100 2.4 26 362 123 2.4 5 .03 2 8.0 95 2.1 69 994 582 15 252 68 3 16 224 34 265 4110 8870 4.1 7 .08 4 7.4 70 1.4 82 1110 276 2.8 4 .03 5 10 135 9.7 169 2480 1920 2.4 1 .01 6 7.0 100 1.9 160 2240 1270 2.3 1 .01 7 8.0 100 2.2 105 1350 471 2.5 1 .01 8 6.0 70 1.1 55 731 125 3.5 3 .03 9 55 795 744 35 450 43 3.9 2 .02 10 10 80 2.2 21 400 23 4.1 2 .02 11 8.0 60 1.3 11 150 4.5 14 229 78 12 7.0 70 1.3 8.2 40 .89 4.5 400 4.9 13 22 325 73 7.2 20 .39 3.1 18 .15 14 95 1540 2000 14 134 12 2.6 28 .20 15 8.1 100 2.2 13 144 7.7 2.4 22 .14 16 20 336 118 8.0 20 .43 2.2 19 .11 17 14 250 9.5 7.0 3 .06 2.0 8 .04 18 5.0 45 .61 6.1 3 .05 1.6 5 .02 19 4.5 28 .34 5.6 3 .05 1.7 5 .02 20 4.3 20 .23 5.0 3 .04 1.6 2 .01 21 4.2 20 .23 4.5 3 .04 1.6 4 .02 22 4.5 20 .24 4.3 3 .03 1.5 5 .02 23 5.0 18 .24 4.5 3 .04 1.4 5 .02 24 4.4 15 .18 3.8 3 .03 1.9 5 .03 25 9.0 46 .88 3.7 6 .11 3.4 30 .28 26 5.9 20 .32 4.4 30 .92 2.6 18 .13 27 5.5 15 .22 3.1 5 .04 2.9 16 .13 28 5.9 10 .16 2.8 5 .04 3.1 15 .13 29 5.6 8 .12 2.6 5 .04 2.0 14 .08 30 8.2 34 .95 2.5 5 .03 2.4 12 .08 31 6.4 25 .43 --- --- --- 1.9 11 .06 TOTAL 388.9 3011.45 1108.3 13730.43 103.4 152.81 163 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 5.9 88 11 1.1 5 .01 1.7 4 .02 2 4.7 74 1.3 1.0 5 .01 1.5 4 .02 3 2.5 6 .04 .96 4 .50 1.6 4 .02 4 2.3 4 .02 .92 4 .20 1.6 4 .02 5 1.8 3 .80 .92 4 .01 2.1 14 .12 6 1.8 3 .50 .90 4 .01 3.3 31 .32 7 1.7 3 .01 .85 4 .01 5.2 89 .77 8 1.5 3 .01 .89 4 .01 2.3 15 .09 9 1.4 3 .01 .99 3 .80 1.6 9 .50 10 1.6 3 .01 1.1 3 .70 1.2 9 .20 11 1.7 3 .01 1.2 3 .70 1.1 9 .20 12 1.8 3 .01 1.3 3 .70 1.0 9 .02 13 2.2 3 .02 1.5 3 .90 .94 9 .02 14 2.5 2 .90 1.8 3 .90 .87 9 .02 15 2.8 2 .80 2.0 3 .90 .81 8 .80 16 2.4 2 .50 1.9 3 .90 .78 8 .50 17 2.2 2 .01 1.7 3 .80 .19 8 .20 18 1.8 1 .90 1.6 3 .80 2.5 28 .46 19 1.6 1 .70 1.7 4 .02 1.1 12 .04 20 1.4 1 .50 1.5 4 .02 .86 12 .03 21 1.2 1 .30 1.1 4 .01 .84 12 .03 22 1.0 1 .20 .94 4 .01 .83 12 .03 23 1.1 1 .00 1.0 4 .01 .81 12 .03 24 1.1 1 .20 1.1 4 .01 .80 12 .03 25 .89 1 .80 1.1 4 .01 .77 10 .02 26 1.0 2 .01 1.2 4 .01 .78 10 .02 27 .96 2 .20 2.4 4 .03 .80 10 .02 28 1.0 3 .01 2.2 4 .02 .76 10 .02 29 .97 3 .50 --- --- --- 33 669 362 30 .99 4 .01 2.5 25 .17 31 1.0 4 .70 2.1 15 .09 TOTAL 56.81 20.98 36.87 9.01 76.84 366.83 APRIL MAY JUNE 1 1.5 10 .04 .79 4 .01 3.9 4 .04 2 1.6 6 .80 .69 4 .01 3.6 4 .04 3 1.7 5 .02 .67 4 .01 4.1 4 .04 4 1.7 4 .90 .61 3 .90 9.6 4 .10 5 1.6 4 .80 .60 3 .70 5.4 4 .06 6 1.6 4 .50 .58 3 .50 3.1 4 .03 7 1.5 4 .20 .55 3 .20 3.0 4 .03 8 1.2 4 .10 .51 3 .00 3.0 4 .03 9 1.0 4 .01 .63 3 .01 2.8 4 .03 10 .91 3 .70 .53 3 .00 2.8 4 .03 11 .86 3 .40 .56 2 .80 2.9 4 .03 12 .81 3 .01 1.5 22 .27 2.8 4 .03 13 .94 3 .01 1.6 20 .33 2.5 4 .03 14 .81 3 .01 12 181 13 2.4 4 .03 15 .83 3 .01 111 2790 2810 2.3 4 .02 16 .98 3 .01 16 225 15 2.1 4 .02 17 .87 3 .01 308 5780 25800 2.0 4 .02 18 1.0 5 .01 382 6720 15500 2.0 4 .02 19 .94 6 .02 40 90 9.7 2.0 4 .02 20 .68 3 .90 19 20 1.0 2.2 4 .02 21 .82 3 .50 12 5 .50 2.2 4 .02 22 .73 3 .30 12 5 .16 2.0 4 .02 23 48 807 489 11 4 .90 2.0 4 .02 24 11 206 25 9.0 4 .50 2.0 4 .02 25 35 641 442 6.3 4 .80 1.8 3 .90 26 4.4 50 .59 5.6 4 .50 1.8 3 .50 27 1.5 18 .07 5.1 4 .20 1.7 3 .01 28 1.0 7 .02 4.9 4 .05 1.7 2 .80 29 .97 4 .01 4.6 4 .05 1.7 2 .50 30 .89 4 .01 4.3 4 .05 1.6 2 .20 31 --- --- --- 4.1 4 .04 --- --- TOTAL 127.34 962.96 976.72 44156.19 83.0 3.66 184 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 1.6 12 .05 3.0 20 .16 2 1.7 2 .01 1.7 12 .06 9.8 217 24 3 1.8 2 .01 1.7 11 .05 3.8 25 .26 4 1.9 2 .01 1.5 10 .04 2.6 20 .14 5 1.6 2 .01 1.5 10 .04 2.2 20 .12 6 1.4 2 .50 1.6 10 .04 2.1 20 .11 7 1.4 2 .70 1.6 10 .04 1.9 20 .10 8 1.4 3 .01 1.5 10 .04 8.0 109 9.0 9 1.3 3 .50 1.5 10 .04 4.5 40 .49 10 1.2 3 .90 1.5 10 .04 2.7 20 .15 11 1.4 4 .20 1.5 10 .04 2.8 20 .15 12 1.3 5 .02 1.6 12 .06 97 628 714 13 1.3 5 .30 3.0 29 .42 69 1030 337 14 1.2 6 .02 1.9 17 .09 25 280 19 15 7.4 119 6.8 1.7 16 .07 14 180 6.8 16 5.9 75 1.8 1.5 15 .06 7.5 70 1.4 17 7.5 111 4.7 1.4 15 .06 5.8 50 .78 18 2.4 30 .19 1.5 14 .06 4.6 45 .56 19 2.3 29 .70 1.4 14 .05 4.1 40 .44 20 12 175 12 1.4 13 .05 3.6 35 .34 21 4.0 6 .50 1.5 13 .05 3.4 30 .28 22 2.4 6 .04 1.4 13 .05 3.2 30 .26 23 2.3 6 .04 1.4 12 .05 3.4 30 .28 24 3.0 6 .05 1.3 12 .04 16 230 52 25 2.2 6 .04 1.4 11 .04 87 2980 4940 26 2.7 6 .50 1.5 11 .04 14 140 5.3 27 2.0 6 .80 16 299 32 7.7 80 1.7 28 2.9 17 .19 4.3 40 .46 9.9 138 6.8 29 2.3 15 .09 2.6 20 .14 6.3 70 1.2 30 1.9 14 .07 2.1 20 .11 5.4 50 .73 31 1.7 13 .06 2.4 30 .19 --- --- --- TOTAL 85.6 31.77 68.5 34.57 430.3 6123.55 YEAR 3542.58 68604.21 165 RIO GRANDE DE LOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 DAY MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2 3 4 5 6.3 15 11 23 31 63 200 118 276 423 1.2 23 4.6 29 46 15 10 8.6 8.0 10 170 110 95 88 110 6.9 3.0 2.2 1.9 3.0 4.8 4.6 4.6 4.4 7.1 1 1 1 1 38 .01 .01 .01 .01 1.6 6 7 8 9 10 434 237 70 20 15 7300 4120 774 150 120 15200 8320 287 8.1 4.9 8.0 7.2 6.7 6.5 6.2 88 65 65 65 60 1.9 1.3 1.2 1.1 1.0 5.5 4.8 4.4 4.4 4.9 3 1 1 1 1 .04 .01 .01 .01 .01 11 12 13 14 15 11 10 9.0 7.9 7.1 110 100 100 90 80 3.3 2.7 2.4 1.9 1.5 6.1 17 9.3 8.3 32 60 284 100 80 403 .99 32 2.5 1.8 82 5.0 5.4 4.4 4.2 4.2 1 1 1 1 1 .01 .01 .01 .01 .01 16 17 18 19 20 6.9 6.9 49 110 10 78 75 638 1540 112 1.5 1.4 84 457 3.0 15 14 48 15 13 200 184 681 77 30 8.1 14 304 3.8 1.1 4.0 3.9 4.0 4.0 4.3 1 1 1 1 1 .01 .01 .01 .01 .01 21 22 23 24 25 8.0 7.0 70 80 40 88 76 940 1090 510 1.9 1.4 178 235 55 15 9.1 8.0 7.0 6.4 146 40 30 30 25 13 .98 .65 .57 .43 4.0 3.8 3.8 3.9 3.9 1 1 1 1 1 .01 .01 .01 .01 .01 26 27 28 29 30 31 45 25 19 34 20 45 580 300 220 430 230 580 70 20 11 39 12 70 6.0 5.6 5.4 5.0 5.4 --- 25 20 20 18 15 --- .41 .30 .29 .24 .22 --- 3.7 3.6 3.7 3.5 3.4 3.4 1 1 1 1 1 1 .01 .01 .01 .01 .01 .01 TOTAL 1483.1 25175.8 336.8 490.88 133.6 1.93 166 RIO GRANDE DE EOIZA BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 3.8 1 .01 4.0 3 .03 2.1 1 .01 2 3.8 1 .01 3.1 1 .50 2.1 1 .01 3 3.5 1 .01 3.3 1 .01 2.0 1 .01 4 3.6 1 .01 5.6 35 1.8 1.8 1 .00 5 3.3 1 .01 4.5 3 .04 1.8 1 .00 6 3.1 1 .01 3.5 1 .01 1.8 1 .00 7 3.1 1 .01 3.2 1 .01 1.7 1 .00 8 3.3 1 .01 2.9 1 .01 1.7 1 .00 9 13 144 15 2.8 1 .01 1.7 1 .00 10 5.0 1 .50 2.7 1 .01 1.7 1 .00 11 3.7 1 .01 2.8 1 .01 1.8 1 .00 12 3.3 1 .01 2.7 1 .01 1.7 1 .00 13 3.1 1 .01 2.6 1 .01 1.9 1 .01 14 2.9 1 .01 2.5 1 .01 2.1 4 .08 15 2.9 1 .01 2.4 1 .01 3.4 26 .42 16 2.8 1 .01 2.4 1 .01 1.8 6 .03 17 4.7 24 .79 2.5 1 .01 1.6 3 .01 18 3.2 1 .50 2.7 1 .01 1.5 3 .01 19 2.8 1 .01 2.7 1 .01 1.5 3 .01 20 2.6 1 .01 2.4 1 .01 1.5 2 .70 21 2.8 1 .01 2.4 1 .01 1.4 2 .20 22 2.6 1 .01 2.2 1 .01 1.4 1 .50 23 2.5 1 .01 2.2 1 .01 1.4 1 .20 24 2.7 1 .01 2.2 1 .01 1.4 1 .00 25 2.4 1 .01 2.2 1 .01 1.6 1 .00 26 2.3 1 .01 2.2 1 .01 1.9 1 .01 27 2.2 1 .01 2.1 1 .01 1.6 1 .00 28 2.2 1 .01 2.2 1 .01 1.4 1 .00 29 6.3 66 4.8 --- --- 4.6 47 1.4 30 3.4 20 .18 2.3 7 .04 31 9.2 65 5.5 2.1 6 .03 TOTAL 116.1 27.51 79.0 2.61 58.3 3.68 APRIL MAY JUNE 1 2.3 5 .50 5.9 81 8.6 3.7 20 .20 2 1.8 5 .02 2.6 20 .14 3.8 20 .21 3 2.0 5 .03 2.1 17 .10 3.0 18 .15 4 5.3 77 4.5 1.9 14 .07 2.5 18 .12 5 5.3 51 1.1 1.8 10 .05 2.2 16 .10 6 3.6 30 .29 2.2 20 .12 2.1 16 .09 7 2.3 28 .17 3.6 25 .24 2.1 16 .09 8 3.2 30 .26 121 2850 7370 2.3 15 .09 9 2.9 30 .23 20 238 18 3.0 25 .20 10 2.0 4 .02 43 585 166 12 199 46 11 1.8 1 .50 47 661 131 2.5 25 .17 12 1.7 1 .30 13 15 .53 2.2 20 .12 13 1.6 1 .00 161 3740 12200 4.3 50 .58 14 1.5 1 .00 78 1710 6320 4.7 40 .51 15 1.6 1 .00 7.3 70 1.4 3.2 25 .22 16 1.7 1 .00 4.7 50 .63 3.0 6 .05 17 1.6 1 .00 4.0 50 .54 3.0 3 .02 18 1.4 1 .00 17 240 26 2.4 3 .02 19 1.4 1 .00 6.8 90 1.7 2.7 3 .02 20 1.6 1 .80 4.6 50 .62 2.2 3 .02 21 1.6 2 .01 4.0 35 .38 2.1 3 .02 22 1.4 2 .01 3.7 30 .30 2.0 3 .02 23 1.3 1 .90 2.8 28 .21 1.9 3 .02 24 1.3 1 .80 2.5 25 .17 1.9 3 .02 25 1.3 1 .80 2.2 20 .12 1.8 3 .01 26 1.3 1 .60 2.2 20 .12 1.8 3 .01 27 1.6 1 .50 2.1 20 .11 1.8 3 .01 28 2.4 10 .06 2.1 18 .10 1.8 3 .01 29 35 720 374 2.6 19 .13 1.8 3 .01 30 5.1 50 .69 2.1 19 .11 1.8 3 .01 31 --- --- --- 26 436 240 --- --- --- TOTAL 98.9 387.09 599.8 26477.49 85.6 49.12 187 RIO GRANDE DE 1011.4 BASIN 50051150 QUEBRADA BLANCA AT EL JAGUAL, PR-Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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/1) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 1.8 3 .01 1.9 1 .70 3.1 30 .25 2 1.8 3 .01 1.9 1 .50 2.3 3 .02 3 1.9 3 .02 1.9 1 .50 1.8 2 .50 4 1.8 3 .01 1.9 1 .01 1.7 2 .01 5 1.8 3 .01 2.0 1 .50 1.6 1 .50 6 3.5 27 .70 2.0 1 .50 1.6 1 .00 7 2.2 5 .03 2.7 3 .04 1.5 0 .50 8 1.9 3 .02 2.5 4 .03 1.4 0 .50 9 1.8 3 .01 2.1 2 .20 1.4 0 .50 10 1.8 3 .01 3.6 17 .91 1.4 0 .80 11 2.5 3 .02 4.4 48 .83 1.3 1 .00 12 2.4 3 .02 2.5 25 .17 1.3 1 .00 13 1.9 3 .02 4.3 40 .46 1.5 3 .01 14 2.4 10 .06 3.5 30 .28 1.4 3 .01 15 2.1 4 .02 2.4 5 .03 1.3 2 .60 16 1.9 3 .50 2.1 3 .02 1.4 1 .00 17 1.8 3 .50 1.9 2 .80 1.3 1 .00 18 1.8 3 .20 1.8 2 .50 1.4 1 .00 19 1.9 3 .02 1.8 2 .50 1.3 1 .00 20 2.0 3 .02 1.6 2 .01 1.3 1 .00 21 2.2 3 .02 1.6 2 .01 1.4 1 .00 22 1.9 3 .02 1.8 2 .01 1.5 1 .00 23 1.8 3 .01 2.1 2 .01 1.7 1 .00 24 1.8 3 .01 1.9 2 .01 12 130 4.2 25 1.8 2 .80 1.8 2 .01 8.0 80 1.7 26 1.8 2 .50 1.8 2 .01 3.5 30 .28 27 1.8 2 .50 1.8 2 .01 2.5 20 .14 28 1.9 2 .20 5.9 86 3.3 1.8 1 .50 29 1.8 2 .20 77 1520 1410 1.7 1 .50 30 2.5 2 .01 4.1 45 .50 1.8 1 .50 31 2.2 1 .90 2.5 25 .17 --- --- --- TOTAL 62.5 5.38 151.1 1421.53 67.2 12.02 YEAR 3272.0 54065.04 168- RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR LOCATION.--Lat 1810'24", long 65'58'38", Hydrologic Unit 21010005, on left downstream side of bridge on Highway 181, 0.2 mi (0.3 km) upstream from Rio Grande de Loiza, and 1.5 mi (2.4 km) southwest of San Lorenzo. DRAINAGE AREA.--3.74 mi' (9.69 km•). 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 dicharges, which are poor. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 9,320 ft'/s (264 m'/s), May 17, 1985, gage height, 17.10 ft (5.212 m), from floodmark, from rating curve extended above 200 ft'/s (5.66 m'/s) on basis of step-backwater analysis and slope-area measurement; minimum discharge, 0.69 ft'/s (0.020 m'/s), Apr. 9-13, 15, 16, 1984. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 1,000 ft'/s (28.3 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m'/s) (ft) (m) Date Time (ftqs) (m'/s) (ft) (m) Nov. 27 0430 4,430 125 12.87 3.923 Aug. 24 1415 4,560 129 12.95 3.947 Dec. 7 1630 *4,740 134 *13.06 3.981 Minimum discharge, 0.87 ft'is (0.025 m'/s), May 5. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 el.2 el.9 20 24 3.6 e4.0 2.0 el.1 1.3 33 2.3 e6.0 2 el.2 el.7 26 15 3.5 e5.4 1.8 el.2 105 2.1 1.3 e5.4 3 el.4 el.6 21 8.1 5.6 e3.4 1.8 el.1 1.3 16 2.6 e5.4 4 el.3 el.7 19 7.6 2.8 e3.0 1.8 el.0 1.3 11 2.9 e5.2 5 el.2 e2.1 18 15 2.8 e2.8 1.6 el.1 1.2 10 2.0 e5.6 2.4 1.2 e6.0 6 1.1 e3.0 22 13 2.6 e2.6 2.9 11 1.9 7 1.1 e2.4 332 9.1 2.4 e2.5 el.8 1.3 1.2 e68 2.8 e6.4 2.4 e7.0 8 1.1 e2.0 e91 8.6 2.5 e2.3 e1.7 1.0 1.1 e19 9 1.1 el.6 e20 11 2.4 e2.2 el.7 1.0 1.6 e13 2.0 e10 12 34 10 1.1 el.5 9.9 9.6 2.6 e2.2 e1.6 2.2 e9.0 e7.0 2.3 1.4 e6.4 17 101 11 1.1 el.4 6.9 10 2.4 e2.3 e1.6 1.4 4.2 6.2 75 12 1.1 e2.0 5.6 8.6 4.1 e2.4 el.7 1.4 21 13 1.1 el.5 4.8 7.7 13 e2.7 e1.7 1.3 1.8 3.3 4.3 14 1.4 el.4 4.4 7.1 e2.7 e2.2 el.6 1.3 1.7 4.5 3.5 9.8 15 1.6 el.3 4.4 5.5 e2.5 e2.0 e5.7 1.4 11 2.7 3.3 7.6 16 3.1 e4.0 4.1 4.4 e2.3 1.9 e2.3 1.1 6.3 2.3 5.0 6.2 17 25 e2.6 3.8 3.8 e2.2 1.8 e13 1.1 2.6 2.2 8.4 5.1 18 102 e2.1 3.6 3.8 e2.2 1.7 e2.8 1.1 1.8 20 4.5 4.5 19 20 1.7 4.5 3.5 e2.1 1.8 e2.2 1.2 1.6 3.7 5.2 19 20 4.9 1.7 8.4 3.1 e2.1 2.2 el.9 2.6 4.4 2.6 4.0 6.3 21 3.6 1.6 6.3 3.0 e2.0 1.9 el.7 2.3 3.9 2.2 3.4 4.8 22 e3.2 1.6 15 2.9 e1.9 1.8 el.6 1.5 3.1 10 6.2 4.4 23 e2.9 3.8 6.4 2.9 e2.0 1.7 el.5 1.4 2.6 3.4 5.3 e4.3 24 e2.7 247 5.8 2.8 e2.1 1.8 el.4 1.3 2.6 2.7 155 e4.0 25 e2.8 24 5.0 2.6 e2.1 2.0 el.3 1.2 31 e87 2.5 e3.8 26 e2.9 96 4.9 2.6 e16 1.9 el.4 1.2 25 5.2 e17 e3.6 27 3.2 472 4.1 2.8 e14 2.9 el.3 1.2 18 3.1 9.9 e3.5 28 15 58 4.1 2.7 e3.3 2.0 el.2 1.2 12 3.7 10 e3.3 1.9 4.9 e3.1 30 e2.4 25 3.8 2.9 --- 2.3 el.1 2.3 3.7 e7.2 29 4.0 35 3.9 2.8 e2.8 el.1 1.4 11 8.3 10 e2.9 31 e2.0 --- 17 2.9 2.2 1.6 2.6 --- e6.4 --- 375.4 447.6 357.2 MEAN 7.03 33.4 22.8 6.75 3.88 2.38 2.21 1.78 5.56 12.1 11.9 TOTAL 217.8 1003.2 705.7 209.4 112.6 73.8 66.3 55.1 166.9 14.4 MAX 102 472 332 24 16 5.4 13 12 31 105 155 101 MIN 1.1 1.3 3.6 2.6 1.9 1.7 1.1 1.0 1.1 2.2 1.9 2.9 AC-FT 432 1990 1400 415 223 146 132 109 331 745 888 709 CFSM 1.88 8.94 6.09 1.81 1.04 .59 .48 1.49 .64 3.24 3.86 3.18 IN. 2.17 9.98 7.02 2.08 1.12 .73 .66 .55 1.66 3.73 4.45 3.55 CAL YR 1987 TOTAL 3122.99 MEAN 8.56 MAX 472 MIN .95 AC-FT 6190 CFSM 2.29 IN. 31.06 WTR YR 1988 TOTAL 3791.0 MEAN 10.4 MAX 472 MIN 1.0 AC-FT 7520 CFSM 2.77 IN. 37.71 e Estimated RIO GRANDE DE LO1ZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS FEBRUARY 1984 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 05 1412 1.15 371 28.0 MAR, 03 1323 3.37 287 24.0 NOV, 18 1151 2.07 350 26.0 APR, 06 1046 1.81 426 26.5 DEC, 09 1350 20 213 25.5 MAY, 05 1239 1.01 417 30.5 JAN, 05 1258 34.9 242 23.5 JUN, 02 1322 1.26 388 28.0 FEB, 02 1228 3.85 366 23.0 JUL, 11 1204 5.40 265 27.0 169 RIO GRANDE DE LOIZA BASIN 170 50051180 QUEBRADA SALvAT1ERRA NEAR SAN LORENZO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 1984 to September 1986. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,570 mg/L May 17, 1985; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 15,500 tons (14,060 tonnes) May 17, 1985; Minimum daily mean, 0.01 tons (0.01) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 2,350 (Jun. 10) 1 (several days) 15,400 (Jun. 10) 0.00 (several days) 1985 2,570 (May 17) 1 (several days) 14,060 (May 17) 0.01 (several days) 1986 2,430 (Oct. 06) 0 (several days) 12,300 (May 14) 0.00 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 2.0 1.7 3 .60 1.6 4 .02 2 1.8 - 1.5 3 .20 1.6 4 .02 3 1.7 - 1.5 3 .01 1.6 3 .90 4 1.6 1.9 3 .02 1.5 3 .60 5 1.5 1.6 3 .01 1.5 3 .20 6 1.5 - 1.5 3 .01 1.5 3 .20 7 1.5 1.5 3 .01 1.5 3 .20 8 1.5 1.5 3 .01 1.4 3 .20 9 1.6 1.9 3 .20 1.4 3 .20 10 1.8 4.2 4 .05 1.4 3 .20 11 1.6 3.7 4 .50 1.3 3 .01 12 3.2 --- --- 8.8 61 15 1.3 3 .01 13 14 89 16 33 152 32 1.3 3 .01 14 12 30 .97 11 75 2.2 1.4 2 .50 15 3.8 14 .14 106 1040 2250 1.3 2 .50 16 2.6 4 .02 88 593 1020 1.2 2 .50 17 2.0 4 .02 6.6 25 .45 1.2 2 .50 18 1.7 3 .01 3.3 10 .09 1.2 2 .50 19 1.7 2 .01 2.3 6 .04 1.2 2 .20 20 14 72 7.8 1.9 5 .03 1., 2 .01 21 3.5 10 .09 1.7 4 .50 1.1 2 .01 22 1.8 4 .01 1.6 4 .02 1.1 2 .01 23 1.7 3 .80 1.6 4 .02 1.2 2 .01 24 1.8 3 .80 1.6 4 .02 1.2 2 .01 25 1.8 3 .80 1.6 4 .02 1.1 2 .01 26 1.7 3 .80 1.6 4 .02 1.0 2 .01 27 1.7 3 .80 1.7 4 .02 1.0 2 .01 28 1.9 3 .70 1.7 4 .02 .97 2 .01 29 1.7 3 .70 1.6 4 .02 .96 2 .01 30 1.6 3 .60 --- --- --- .91 1 .80 31 1.6 3 .60 .88 --- --- TOTAL 93.9 31.67 298.1 3322.09 38.92 6.37 171 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE ?RATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (IONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE .1 .86 1 .50 .96 1 .00 1.8 3 .50 2 .86 1 .40 .93 1 .00 1.5 2 .60 3 .86 1 .40 .97 1 .00 1.2 2 .20 4 .81 1 .60 1.0 1 .00 1.3 2 .01 5 .80 1 .60 .93 1 .00 1.2 2 .01 6 .82 1 .70 .93 1 .00 10 3 .02 7 .84 1 .50 .97 1 .00 26 189 29 8 .85 1 .50 1.0 1 .00 9.8 60 1.6 9 .74 1 .30 .97 1 .00 5.3 20 .29 10 .71 1 .30 1.1 1 .00 295 2350 1540c 11 .72 1 .20 1.2 1 .00 15 70 2.8 12 .71 1 .20 1.1 1 .00 7.0 30 .57 13 .72 1 .00 1.8 1 .00 20 112 14 14 .74 1 .00 2.1 1 .01 9.9 25 .67 15 .74 1 .00 1.4 1 .00 5.9 15 .24 16 .73 1 .00 1.3 1 .00 5.9 25 .40 17 .77 1 .00 1.2 1 .00 5.3 20 .29 18 .80 1 .00 1.1 1 .10 3.8 10 .10 19 .79 1 .00 1.1 1 .10 3.2 7 .50 20 .80 1 .00 1.1 1 .20 2.6 6 .04 21 .86 1 .00 1.1 1 .20 2.3 5 .50 22 .93 1 .00 1.0 1 .10 2.1 4 .80 23 .93 1 .00 1.1 1 .00 1.8 4 .50 24 .93 1 .00 1.1 1 .00 1.7 4 .02 25 .90 1 .00 2.0 1 .20 1.6 3 .50 26 .93 1 .00 14 55 14 1.8 3 .01 27 1.4 1 .00 2.1 4 .02 1.5 2 .50 28 1.7 1 .00 2.2 4 .02 1.4 2 .01 29 1.1 1 .00 1.5 4 .02 2.0 1 .80 30 1.0 0 .00 18 70 9.6 1.6 1 .50 31 --- --- 3.1 6 .50 --- --- TOTAL 26.35 5.20 70.36 25.07 449.5 --- 15455.98 JULY AUGUST SEPTEMBER 1 1.9 1 .30 4.1 15 1.7 2.2 5 .03 2 2.3 1 .01 6.2 --- --- 1.8 5 .02 3 1.4 1 .00 1.4 3 .01 1.7 5 .02 4 30 255 183 6.6 81 10 1.9 5 .03 5 64 345 102 2.3 5 .03 16 118 31 6 6.2 25 .42 1.3 2 .50 5.4 25 .36 7 2.8 7 .05 1.1 2 .01 2.7 7 .05 8 2.0 4 .50 .99 2 .01 2.1 5 .03 9 1.7 4 .02 .95 1 .80 2.2 7 .04 10 1.8 3 .60 .86 1 :50 2.6 8 .06 11 1.5 3 .01 .83 1 .30 2.3 7 .04 12 1.3 2 .50 .83 1 .20 4.7 26 .74 13 1.1 2 .01 .82 1 .20 19 126 28 14 1.5 2 .01 .82 1 .20 86 503 419 15 1.5 2 .01 .84 1 .20 10 60 1.6 16 1.2 2 .01 1.0 1 .20 11 60 1.8 17 1.1 2 .01 .92 1 .20 24 151 19 18 .97 2 .01 .89 1 .20 54 391 178 19 1.0 2 .01 .89 1 .10 41 198 31 20 1.1 2 .01 1.1 1 .10 95 657 520 21 1.6 2 .01 1.0 1 .10 38 150 15 22 1.3 2 .01 .87 1 .10 13 55 1 9 23 1.2 2 .10 .87 1 .10 7.3 25 .49 24 1.0 2 .50 .82 1 .10 5.2 20 .28 25 .98 3 .01 .84 1 .10 4.2 18 .20 26 1.1 3 .01 2.8 12 .09 3.7 15 .15 27 .98 4 .01 3.8 5 .05 3.4 12 .11 28 .99 3 .80 2.4 4 .03 3.7 12 .12 29 1.7 5 .02 1.7 3 .01 3.1 10 .08 30 2.3 8 .05 16 91 29 5.0 10 .14 31 1.3 3 .01 4.1 15 .17 --- --- --- TOTAL 140.82 289.02 69.94 45.31 472.2 1249.29 YEAR 1660.09 20430.00 172 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO. PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 3.5 10 .09 6.2 24 .40 3.0 6 .05 2 3.0 7 .50 12 53 1.7 28 139 39 3 4.3 17 .37 60 360 58 7.0 27 .51 4 3.9 12 .13 20 100 5.4 4.3 12 .14 5 3.1 9 .08 246 981 825 3.7 10 .10 6 3.5 9 .09 158 1020 657 3.4 10 .09 7 2.7 7 .05 102 760 493 3.2 10 .09 8 2.7 7 .05 46 209 46 14 149 42 9 28 201 68 26 180 13 4.4 12 .14 10 7.9 25 .53 18 90 4.4 3.5 10 .09 11 4.3 13 .15 6.1 35 .58 2, 223 206 12 3.4 10 .09 4.1 35 .39 4.2 17 .19 13 22 200 75 3.1 35 .29 3.3 10 .09 14 98 709 678 7.3 64 3.7 3.3 10 .09 15 12 60 1.9 12 64 4.2 3.1 8 .07 16 7.3 30 .59 4.1 13 .14 3.3 8 .07 17 7.0 40 .76 3.4 7 .50 2.9 7 .05 18 4.5 14 .17 3.2 4 .03 2.5 6 .50 19 3.3 9 .10 2.9 3 .02 2.7 7 .05 20 3.2 7 .06 2.6 2 .01 2.7 6 .50 21 3.1 9 .08 2.5 2 .01 2.5 6 .04 22 3.2 10 .09 2.7 2 .01 2.4 6 .04 23 2.4 6 .50 4.0 15 .16 2.4 5 .80 24 2.1 6 .03 2.8 5 .04 3.0 6 .05 25 7.2 57 4.5 2.9 5 .04 4.7 8 .10 26 2.5 6 .04 5.6 20 .30 4.2 8 .09 27 2.1 3 .50 3.2 8 .07 4.0 8 .09 28 2.0 2 .01 3.0 8 .06 3.7 7 .07 29 1.9 1 .50 3.0 8 .06 2.8 6 .50 30 14 118 32 3.0 8 .06 3.5 6 .06 31 2.2 5 .60 --- --- --- 3.0 5 .90 TOTAL 270.3 865.56 775.7 2114.57 160.7 292.56 173 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 JANUARY FEBRUARY MARCH 1 6.7 5 .09 1.6 2 .01 1.8 3 .60 2 5.4 4 .20 1.5 2 .01 1.5 3 .50 3 3.3 4 .04 1.5 2 .01 1.4 3 .01 4 3.6 4 .04 1.4 2 .01 1.4 2 .50 5 3.4 4 .04 1.4 2 .01 1.8 3 .01 6 3.3 4 .04 1.4 2 .01 2.2 3 .90 7 2.7 4 .03 1.4 2 .01 3.9 5 .05 8 2.5 3 .80 1.4 2 .01 2.4 4 .03 9 2.3 3 .80 1.3 2 .01 1.8 4 .02 10 2.4 3 .20 1.2 2 .01 1.6 4 .02 11 2.2 2 .20 1.3 2 .01 1.5 3 .80 12 2.1 2 .01 1.3 2 .01 1.6 3 .01 13 2.0 2 .01 1.2 2 .01 1.6 3 .01 14 2.0 2 .01 1.4 2 .01 1.5 2 .80 15 2.1 2 .01 1.4 2 .01 1.5 2 .60 16 2.0 2 .01 1.4 2 .01 1.5 3 .01 17 2.0 2 .01 1.4 2 .01 1.5 3 .20 18 2.0 2 .01 1.3 2 .01 2.7 3 .90 19 2.0 2 .01 1.5 2 .01 1.7 3 .50 20 1.8 2 .01 1.8 2 .10 1.5 3 .01 21 1.7 2 .01 1.6 2 .10 1.5 2 .50 22 1.7 2 .01 1.5 2 .20 1.4 2 .01 23 1.7 2 .01 1.5 2 .20 1.4 2 .01 24 1.7 2 .01 1.6 2 .01 1.4 2 .01 25 1.7 2 .01 1.7 2 .01 1.4 2 .01 26 1.8 2 .01 1.7 2 .20 1.4 2 .01 27 1.7 2 .01 2.8 3 .02 1.5 2 .10 28 1.7 2 .01 2.7 4 .03 1.5 2 .20 29 1.6 2 .01 --- --- --- 83 558 454 30 1.6 2 .01 13 65 12 31 1.5 2 .01 12 60 1.9 TOTAL 74.2 2.68 43.2 1.06 155.9 475.23 APRIL MAY JUNE 1 3.1 8 .07 1.4 2 .20 2.7 4 .03 2 2.1 2 .50 1.3 2 .20 2.7 4 .03 3 1.7 2 .01 1.3 2 .01 2.7 4 .03 4 1.5 2 .01 1.2 2 .01 2.7 3 .80 5 1.4 2 .01 1.3 2 .01 2.6 3 .50 6 1.4 2 .01 1.2 2 .01 2.6 3 .02 7 1.8 2 .01 1.1 2 .01 2.6 2 .80 8 1.4 2 .01 1.1 2 .01 2.7 2 .30 9 1.2 2 .01 1.3 2 .01 2.6 2 .20 10 1.1 2 .01 1.2 3 .01 2.6 2 .01 11 1.2 2 .01 1.4 4 .10 2.5 2 .01 12 1.2 2 .01 2.1 5 .80 2.4 2 .01 13 1.3 2 .01 1.5 5 .02 2.1 1 .90 14 1.2 2 .01 15 139 17 2.0 1 .90 15 1.3 2 .01 172 1050 1540 2.0 1 .80 16 1.9 2 .01 62 214 90 2.0 1 .50 17 1.4 2 .01 400 2570 15500 1.9 1 .50 18 1.4 2 .01 356 2410 5670 1.9 1 .50 19 1.8 2 .01 29 170 13 1.8 1 .00 20 1.2 2 .01 9.6 35 .91 1.9 1 .01 21 1.4 2 .01 7.9 30 .64 1.9 1 .50 22 1.2 2 .01 6.3 25 .43 1.7 2 .01 23 78 468 413 4.9 17 .22 1.7 2 .01 24 33 279 74 4.5 14 .17 1.6 4 .02 25 36 229 96 4.4 12 .14 1,4 3 .60 26 9.1 25 .61 4.1 10 .11 1.6 3 .20 27 3.3 8 .07 3.9 7 .07 1.4 3 .01 28 2.1 4 .02 3.3 5 .04 1.4 3 .01 29 1.7 3 .80 3.1 4 .60 1.4 2 .50 30 1.6 3 .01 2.9 4 .20 I.! 2 .01 31 --- --- --- 2.7 4 .03 --- --- --- TOTAL 198.0 585.28 1109.0 22834.96 62.4 8.72 174 RIO GRANDE DE tOIZA BASIN 50051180 QUEBRADA SALVATIERRA HEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 JULY AUGUST SEPTEMBER 1 1.3 2 .01 1.4 1 .30 2.7 2 .01 2 1.2 2 .01 1.9 1 .30 6.2 24 1.4 3 1.4 2 .10 1.4 1 .30 4.0 5 .05 4 1.4 2 .10 1.4 1 .20 2.5 5 .03 . 5 1.2 2 .10 1.3 1 .00 2.2 5 .03 6 1.1 2 .10 1.3 1 .00 2.6 5 .04 7 .99 2 .20 1.3 1 .00 2.1 5 .03 8 1.0 2 .20 1.3 1 .00 8.1 24 1.4 9 .99 2 .50 1.3 1 .00 6.3 25 .43 10 .93 2 .50 1.2 1 .00 3.1 10 .08 11 1.1 2 .80 1.1 1 .00 2.8 9 .07 12 1.1 3 .01 1.2 1 .50 82 969 2150 13 .93 3 .01 2.8 6 .05 91 643 271 14 .89 3 .50 1.6 2 .01 23 143 12 15 6.5 61 4.1 1.5 1 .70 12 48 1.6 16 9.6 80 9.6 1.3 1 .60 7.2 30 .58 17 7.1 67 5.0 1.3 1 .60 5.5 20 .30 18 2.0 7 .04 1.3 1 .30 4.7 18 .23 19 1.4 4 .02 1.3 1 .20 4.2 15 .17 20 6.8 30 .55 1.2 1 .20 3.9 12 .13 21 2.4 4 .03 1.2 1 .20 3.7 12 .12 22 1.6 1 .50 1.2 1 .10 3.5 11 .10 23 1.5 1 .50 1.1 1 .00 3.8 11 .11 24 2.2 4 .50 1.1 1 .00 11 102 30 25 1.6 4 .50 1.2 1 .00 87 1230 1450 26 2.3 6 .04 1.4 1 .20 10 50 1.4 27 1.6 3 .60 13 85 7.7 5.9 30 .48 28 2.8 8 .06 5.3 12 .17 9.8 72 4.9 29 2.0 2 .50 2.6 2 .01 6.1 28 .46 30 1.7 1 .70 2.0 2 .01 4.8 25 .32 31 1.4 1 .60 2.0 2 .01 --- --- --- TOTAL 70.03 26.98 60.5 12.66 421.7 3927.47 YEAR 3401.63 31147.73 RIO GRANDE DE LOIZA BASIN 175 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 5.1 15 6 .24 2.9 2 .02 2' 7.3 9.6 4 .50 2.8 2 .02 3 9.2 7.6 3 .06 3.4 1 .70 4 16 --- --- 6.5 2 .50 4.2 1 .80 5 28 193 28 8.4 3 .07 6.8 2 .04 6 353 2430 5280 6.5 2 .50 5.8 2 .03 7 143 1210 2750 5.3 2 .03 4.9 2 .20 8 26 181 29 4.8 1 .70 4.2 2 .50 9 20 50 2.7 4.4 1 .50 4.1 4 .04 10 13 20 .70 4.3 1 .50 4.1 4 .04 11 10 8 .22 4.2 1 .40 4.4 4 .20 12 8.0 2 .04 16 111 17 4.2 4 .20 13 6.6 1 .20 7.9 45 .96 3.7 4 .50 14 5.8 1 .02 12 77 6.3 3.5 5 .05 15 5.4 1 .01 72 463 278 3.6 4 .50 16 5.0 0 .90 22 150 8.9 3.5 4 .50 17 5.2 0 .90 14 75 3.5 3.3 4 .20 18 10 26 .03 56 256 79 3.4 4 .04 19 5.6 3 .05 13 55 1.9 3.4 3 .50 20 5.2 1 .30 9.6 20 .52 3.7 3 .20 21 5.0 1 .01 22 111 27 3.2 3 .03 22 4,9 0 .80 7.3 30 .59 3.0 3 .02 23 86 922 1250 5.6 20 .30 3.2 3 .03 24 94 705 312 4.6 15 .19 3.5 3 .03 25 40 200 22 4.1 12 .13 3.3 3 .10 26 45 381 223 3.8 10 .10 3.1 3 .03 27 30 190 15 3.5 7 .07 2.8 3 .02 28 19 100 5.1 3.3 4 .50 2.8 3 .02 29 34 286 42 3.1 3 .50 2.6 3 .02 30 21 90 5.1 3.2 2 .50 2.5 3 .02 31 57 345 275 --- --- --- 2.5 3 .02 TOTAL 1123.3 10243.08 359.6 429.96 112.4 5.62 176 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 JANUARY FEBRUARY MARCH 1 3.0 3 .02 3.4 10 .09 1.3 1 .00 2 3.3 3 .03 2.4 4 .50 1.3 1 .00 3 2.7 3 .50 2.7 3 .02 1.1 1 .00 4 3.0 3 .60 2.4 3 .02 1.2 1 .00 5 2.6 4 .03 2.4 3 .02 1.4 1 .00 6 2.5 4 .50 2.0 3 .02 1.3 1 .00 7 2.4 5 .03 2.0 2 .90 1.3 1 .00 8 2.6 5 .10 1.9 2 .80 1.2 1 .00 9 10 65 5.7 1.8 2 .60 1.2 1 .00 10 5.5 15 .22 1.8 2 .60 1.2 1 .00 11 3.6 9 .09 1.9 2 .40 1.3 1 .00 12 2.9 6 .05 1.9 2 .30 1.2 1 .00 13 2.8 5 .04 1.7 2 .30 1.4 1 .00 14 2.6 5 .04 1.6 2 .20 1.5 1 .00 15 2.5 5 .03 1.6 2 .10 5.8 - --- 16 2.4 5 .03 1.6 2 .01 1.8 3 .50 17 7.2 39 2.5 1.7 2 .01 1.5 1 .00 18 3.3 9 .08 1.8 1 .90 1.4 1 .00 19 2.6 4 .50 1.7 1 .80 1.4 1 .00 20 2.5 2 .50 1.5 1 .60 1.3 1 .00 21 2.6 2 .01 1.5 1 .50 1.3 1 .00 22 2.4 2 .01 1.4 1 .20 1.3 1 .00 23 2.0 2 .01 1.4 1 .10 1.3 1 .00 24 2.1 2 .01 1.4 1 .00 1.3 1 .00 25 2.0 2 .01 1.4 1 .00 1.6 1 .00 26 1.9 2 .01 1.4 1 .00 2.0 1 .01 27 1.8 2 .01 1.3 1 .00 1.5 1 .00 28 1.8 2 .01 1.4 1 .00 1.3 1 .00 29 2.9 10 .08 --- 5.2 30 .21 30 2.3 5 .03 1.8 2 .50 31 11 59 7.6 1.7 1 .00 TOTAL 102.8 19.38 51.0 7.99 51.4 1.22 APRIL MAY JUNE 1 1.8 1 .00 2.9 6 .05 6.2 25 .42 2 1.4 1 .00 1.9 3 .02 5.8 20 .31 3 2.7 7 .12 1.7 1 .50 5.2 12 .17 4 2.6 7 .05 1.6 1 .00 3.7 12 .12 5 6.2 19 .83 1.5 1 .00 3.2 11 .10 6 3.3 10 .09 2.6 8 .06 2.8 10 .08 7 1.7 4 .02 6.3 23 .76 2.8 9 .07 8 4.4 35 2.9 74 914 2090 2.7 8 .06 9 2.4 6 .04 15 65 2.6 13 121 33 10 1.5 3 .50 27 108 17 34 233 151 11 1.4 3 .01 32 151 24 4.1 12 .13 12 1.3 3 .01 12 60 1.9 3.2 6 .05 13 1.5 3 .01 146 1440 6730 9.2 30 .75 14 1.3 3 .01 100 1870 12300 9.6 30 .78 15 1.2 2 .70 15 25 1.0 4.1 15 .17 16 1.5 2 .30 7 8 20 .42 3.7 7 .07 17 1.6 2 .00 5 5 18 .27 3.1 3 .50 18 1.2 1 .60 26 146 18 2.6 2 .01 19 1.2 1 .50 12 15 .49 3.2 1 .20 20 1.2 1 .20 7 2 13 .25 ;.; 1 .10 21 1.3 1 .00 5.6 12 .18 1.9 1 .10 22 1.2 1 .00 4.8 12 .16 1.7 1 .10 23 1.2 1 .00 4.0 11 .12 1.8 1 .00 24 1.2 1 .00 3.3 9 .08 2.1 1 .01 25 1.2 1 .00 3.1 8 .07 1.8 1 .00 26 1.2 1 .00 2.9 7 .60 1.8 1 .00 27 1.7 1 .00 2.7 7 .05 1.8 1 .00 28 3.3 1 .01 2.6 6 .30 1.8 1 .20 29 36 222 107 4.5 6 .07 1.6 1 .20 30 6.9 20 .37 3.4 6 .06 1.6 1 .50 31 --- --- --- 26 271 107 --- --- TOTAL 96.6 114.27 560.9 21296.01 142.5 189.20 RIO GRANDE DE IOIZA BASIN 177 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 JULY AUGUST SEPTEMBER 1 1.7 1 .80 1.4 2 .01 3.5 20 .19 2 1.7 1 .90 1.5 2 .01 2.0 15 .08 3 2.2 1 .90 1.2 2 .01 1.8 12 .06 4 1.6 2 .01 1.1 2 .01 1.7 11 .05 5 1.5 2 .01 1.0 2 .01 3.0 10 .08 6 3.0 2 .02 1.1 2 .01 2.0 10 .05 7 1.9 2 .01 1.8 2 .50 1.7 10 .05 8 1.5 2 .01 2.2 4 .02 1.5 9 .04 9 1.4 2 .01 1.5 2 .01 1.3 8 .03 10 1.4 2 .01 2.8 5 .04 1.2 8 .03 11 1.7 2 .01 7.5 25 .51 1.3 8 .03 12 2.0 2 .01 2.2 8 .05 1.1 8 .02 13 1.4 2 .01 8.6 82 26 1.5 7 .03 14 1.5 2 .01 4.7 4 .05 1.2 7 .02 15 1.7 2 .01 2.3 3 .02 1.1 9 .03 16 1.4 2 .01 1.7 2 .80 1.2 17 1.4 2 .01 1.4 2 .50 1.2 18 1.4 2 .01 1.3 2 .40 1.1 19 1.2 2 .01 1.3 2 .20 1.1 20 1.3 2 .01 1.2 2 .01 1.1 21 1.5 2 .01 1.1 2 .01 1.2 22 1.2 2 .01 3.0 5 .04 1.1 23 1.1 2 .01 1.7 4 .02 1.7 24 1.1 2 .01 1.4 3 .01 12 25 1.2 2 .01 2.1 5 .03 9.7 26 1.1 2 .01 1.2 2 .01 3.9 27 1.3 2 .01 1.1 2 .01 3.0 28 1.5 2 .01 3.8 5 .05 2.0 29 1.4 2 .01 73 508 296 1.7 30 2.7 2 .01 5.9 25 .40 1.6 31 1.9 2 .01 2.5 15 .10 --- TOTAL 48.9 2.89 144.6 325.85 69.5 0.79 YEAR 2863.5 32636.26 I I I 178 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18°09'13", long 65°57'20", Hydrologic Unit 21010005, at downstream side on bridge on Highway 912, at Barrio Cerro Gordo, 2.8 mi (4.5 km) south of San Lorenzo. DRAINAGE AREA.--10.2 •i 1 (26.4 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1977 to current year. GAGE:--Water-stage recorder and crest-stage gage. Elevation of gage is 490 ft (150 ), from topographic map. Prior to Oct. 1, 1983, at site 2,000 ft (610 ) downstream at different datum. REMARKS.--Records fair except those for estimated daily discharges, which are poor. AVERAGE DISCHARGE.--11 years (1978-88), 49.8 ft'/s (1.410 m'/s), 66.3 in/yr (1,684 mm/yr), 36,080 acre-ft/yr (44.49 hm'/yr); median of yearly mean discharges, 40.6 ft'/s (1.15 '/s), 29,400 acre-ft/yr (36.2 hm 3/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 13,200 ft'/s (374 m'/s), Aug. 31, 1979, gage height, 9.44 ft (2.877 •), site and datum then in use, from rating curve extended above 1,000 ft'/s (28.3 ml/s) on the basis of slope-area measurement; minimum discharge, 7.1 ft'/s (0.201 43/s), Feb. 4, May 3, 1981, Apr. 12, 13, 16, 17, 1983 EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 2,500 ft'/s (70.8 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (W/s) (m'/s) (ft) (m) Date Time (ft'/s) (m'/s) (ft) (m) Oct. 18 1900 3,860 109 15.23 4.642 Dec. 7 1815 *9,610 272 *21.05 6.416 Nov. 24 1815 3,070 86.9 14.15 4.313 Aug.24 1445 3,580 101 14.84 4.523 Nov. 27 0430 8,990 255 20.55 6.264 Minimum discharge, 7.2 ft'/s (0.204 10/s), June 29, 30. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 18 19 101 67 40 e25 21 15 14 19 21 66 2 17 17 145 62 38 e30 22 14 14 235 20 66 3 22 16 94 59 46 22 20 13 14 29 22 64 4 22 27 86 57 35 21 20 13 13 22 22 60 5 16 116 87 63 37 21 18 13 13 21 21 55 6 15 69 108 58 34 22 18 33 13 27 21 54 7 13 30 1690 54 32 24 16 14 14 48 24 54 8 12 24 798 53 32 24 15 13 14 26 23 46 9 14 22 130 52 31 24 17 13 15 25 25 46 10 12 19 118 51 43 22 16 17 15 40 127 45 11 11 19 114 51 33 20 17 17 16 29 77 371 12 11 18 100 50 36 22 e15 16 16 28 38 157 13 10 18 99 47 49 22 e13 13 18 31 34 91 14 39 18 97 49 33 22 e16 15 20 42 34 93 15 42 18 95 45 34 22 e18 14 40 31 37 75 16 32 19 91 44 35 20 e15 14 41 .28 42 72 17 176 23 83 43 29 21 e16 14 e19 27 47 69 18 651 28 79 41 29 21 e14 14 e16 30 48 68 19 134 23 78 42 29 19 e13 13 e22 27 41 113 20 45 22 82 40 31 20 e14 16 37 25 42 76 21 31 20 78 40 28 18 e12 14 34 24 42 67 22 23 20 109 38 28 18 e12 13 30 27 66 68 23 20 26 76 38 28 20 e16 13 18 25 88 68 24 15 1400 69 38 32 20 e14 13 14 22 531 58 25 22 320 66 38 30 21 e12 15 11 23 276 50 26 38 429 67 37 40 22 ell 17 13 23 78 47 27 33 2410 69 39 42 27 ell 17 11 22 77 44 28 29 420 67 36 28 25 e12 18 9.4 46 79 44 29 24 162 62 36 e27 21 e13 18 8.5 29 73 43 30 19 114 58 35 --- 20 13 21 9.0 28 69 40 31 20 --- 62 35 21 --- 15 --- 21 68 --- TOTAL 1586 5886 5058 1438 989 677 460 478 541.9 1080 2213 2270 MEAN 51.2 196 163 46.4 34.1 21.8 15.3 15.4 18.1 34.8 71.4 75.7 MAX 651 2410 1690 67 49 30 22 33 41 235 531 371 MIN 10 16 58 35 27 18 11 13 8.5 19 20 40 AC-FT 3150 11670 10030 2850 1960 1340 912 948 1070 2140 4390 4500 CFSM 5.02 19.2 16.0 4.55 3.34 2.14 1.50 1.51 1.77 3.42 7.00 7.42 IN. 5.78 21.47 18.45 5.24 3.61 2.47 1.68 1.74 1.98 3.94 8.07 8.28 CAL YR 1987 TOTAL 22542.8 MEAN 61.8 MAX 2410 MIN 8.1 AC-FT 44710 CFSM 6.06 IN. 82.21 WTR YR 1988 TOTAL 22676.9 MEAN 62.0 MAX 2410 MIN 8.5 AC-FT 44980 CFSM 6.07 IN. 82.70 e Estimated 179 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 14 1445 66.6 91.1 27.0 APR, 05 1337 17.9 137 30.0 NOV, 13 1338 18.0 100 28.0 MAY, 05 0953 17.2 139 26.5 JAN, 04 1347 57.4 121 25.5 JUN, 03 1018 13.9 138 26.5 FEB, 01 1611 35.8 129 24.0 JUL, 12 1040 26.9 131 26.5 MAR, 02 1624 24.8 132 24.0 RIO GRANDE DE LOIZA BASIN 180. 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1986. INSTRUMENTATION.-- USD-49 and automatic sediment sampler. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 5,180 mg/L May 18, 1985; Minimum daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 77,800 tons (70,580 tonnes) May 18, 1985; Minimum daily mean, 0.06 tons (0.05) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 1,220 (Nov. 5) 2 (several days) 9,840 (Feb. 15) 0.06 (several days) 1985 5,180 (May 18) 5 (several days) 77,800 (May 18) 0.22 (several days) 1986 2,790 (Oct. 6) 4 (several days) 17,900 (Oct. 06) 0.16 (March 19) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT CONCEN­ MEAN MEAN MEAN SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CUB) (MG/L) (TONS/DAY) DECEMBER OCTOBER NOVEMBER 1 53 30 4.3 188 391 866 29 30 2.3 2 33 20 1.8 54 100 15 306 806 3080 3 29 18 1.4 29 35 2.7 52 70 9.8 4 27 16 1.2 440 840 1650 39 45 4.7 5 27 15 1.1 478 1220 5650 36 40 3.9 6 27 18 1.3 194 349 267 39 38 4.0 7 29 17 1.3 74 110 22 34 35 3.2 8 29 18 1.4 52 65 9.1 28 30 2.3 25 29 2.0 9 41 25 2.8 42 52 5.9 10 31 20 1.7 37 45 4.5 26 26 1.8 11 27 15 1.1 35 42 15 26 26 1.8 12 27 16 1.2 33 40 3.6 24 25 1.6 25 1.6 13 31 40 3.3 32 39 3.4 23 24 1.5 14 31 40 3.3 32 38 3.3 23 15 31 40 3.3 33 40 3.6 26 25 1.8 16 33 45 4.0 32 40 3.5 33 35 3.1 31 35 2.9 3.2 18 23 22 1.4 30 40 3.2 31 17 25 30 2.0 30 40 35 2.9 19 37 50 5.0 30 40 3.2 29 35 2.7 20 22 22 1.3 30 40 3.2 32 35 3.0 25 35 2.4 21 22 21 1.2 30 35 2.8 2.7 27 1.7 22 25 21 1.4 29 35 23 35 23 22 1.4 35 2.7 22 22 1.3 23 21 21 1.2 29 2.7 24 20 20 1.1 29 25 20 20 1.1 28 32 2.4 22 23 1.4 32 22 1.4 26 24 20 1.3 28 2.4 23 32 2.5 23 23 1.4 27 20 20 1.1 29 28 19 20 1.0 28 32 2.4 29 30 2.3 29 25 25 1.7 28 30 2.3 25 30 2.0 30 31 35 2.9 27 2.2 30 30 40 3.2 31 21 25 1.4 --- --- --- 75 60 12 8562.5 1221 3167.4 TOTAL 861 59.6 2190 181 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 35 45 4.3 27 30 2.2 22 22 1.3 2 26 35 2.5 26 30 2.1 22 22 1.3 3 24 28 1.8 29 25 2.0 22 22 1.3 4 23 23 1.4 32 28 2.4 21 20 1.1 5 22 23 1.4 29 28 2.2 21 20 1.1 6 22 23 1.4 31 30 2.5 22 20 1.2 7 22 20 1.2 30 30 2.4 21 20 1.1 8 21 21 1.2 27 30 2.2 22 20 1.2 9 24 25 1.6 27 30 2.2 26 22 1.5 10 38 30 3.1 30 35 2.8 24 18 1.2 11 22 23 1.4 29 32 2.5 22 10 .59 12 24 25 1.6 100 198 199 23 5 .31 13 130 46 6.6 129 239 143 25 5 .34 14 85 75 17 48 56 9.8 37 5 .50 15 40 55 5.9 567 1140 9840 29 5 .39 16 35 45 4.3 464 976 4050 31 5 .42 17 33 32 2.9 52 70 9.8 36 5 .49 18 19 33 31 40 40 3.6 3.3 32 25 38 30 3.3 2.0 30 25 5 5 .41 .34 20 49 60 7.9 23 30 1.9 23 7 .43 21 33 40 3.6 23 30 1.9 21 6 .34 22 37 35 3.5 22 28 1.7 20 8 .43 23 32 35 3.0 22 23 1.4 22 8 .48 24 31 35 2.9 22 23 1.4 19 8 .41 25 38 35 3.6 22 23 1.4 18 8 .39 26 34 35 3.2 22 23 1.4 17 8 .37 27 32 35 3.0 23 22 1.4 17 7 .32 28 33 35 3.1 23 22 1.4 17 5 .23 29 29 32 2.5 22 22 1.3 18 4 .19 30 31 28 27 30 30 2.3 2.2 --- --- --- 17 16 4 4 .18 .17 TOTAL 1093 107.3 1958 14297.6 706 20.03 APRIL MAY JUNE 1 16 5 .22 11 2 .06 51 69 13 2 3 4 5 15 15 15 15 5 5 5 5 .20 .20 .20 .20 11 11 11 11 2 2 2 2 .06 .06 .06 .06 26 21 27 20 35 22 20 20 2.5 1.2 1.5 1.1 6 7 8 9 10 15 15 14 14 13 5 5 5 4 4 .20 .20 .19 .15 .14 12 11 11 11 13 2 2 2 2 2 .06 .06 .06 .06 .07 44 195 74 42 542 65 402 85 58 1400 21 461 17 6.6 8290 11 12 13 14 13 13 13 13 4 4 3 3 .14 .14 .11 .11 11 11 12 12 2 2 2 3 .06 .06 .06 .10 99 62 72 47 110 90 105 50 29 15 23 6.3 15 13 3 .11 11 3 .09 34 40 3.7 16 17 13 14 3 3 .11 .11 11 11 3 3 .09 .09 66 48 101 60 40 7.8 18 19 20 13 13 12 3 3 3 .11 .11 .10 11 11 11 3 3 3 .09 .09 .09 37 37 33 42 40 40 4.2 4.0 3.6 21 22 23 24 25 13 13 13 12 12 3 3 3 2 2 .11 .11 .11 .06 .06 12 12 17 13 26 8 10 10 12 35 .26 .32 .46 .42 2.5 32 30 29 28 26 35 32 32 30 30 3.0 2.6 2.5 2.3 2.1 26 27 28 29 30 12 13 17 13 11 2 2 2 3 2 .06 .07 .09 .11 .06 30 19 27 27 132 35 25 40 35 228 2.8 1.3 2.9 2.6 151 27 27 27 28 34 29 29 25 25 35 2.1 2.1 1.8 1.9 3.2 31 --- --- --- 39 60 6.3 --- --- --- TOTAL 406 3.89 579 172.29 1865 8975.1 182 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAVAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 35 45 4.3 32 46 8.3 19 20 1.0 2 34 40 3.7 43 55 6.4 18 18 .87 3 27 25 1.8 28 32 2.4 18 18 .87 4 126 336 604 105 372 553 27 30 2.2 5 167 327 212 33 40 3.6 46 87 37 6 38 46 4.7 23 24 1.5 43 60 7.0 7 29 32 2.5 24 23 1.5 21 22 1.2 8 26 30 2.1 23 22 1.4 21 22 1.2 9 25 30 2.0 22 20 1.2 18 22 1.1 10 24 30 1.9 20 20 1.1 22 30 1.8 11 24 30 1.9 21 20 1.1 41 55 7.0 12 24 28 1.8 21 20 1.1 39 85 9.0 13 24 25 1.6 21 25 1.4 64 135 48 14 26 25 1.8 25 20 1.4 155 303 251 15 26 25 1.8 22 20 1.2 41 70 7.7 16 24 25 1.6 25 30 2.0 29 40 3.1 17 23 25 1.6 19 20 1.0 118 274 239 18 23 25 1.6 19 20 1.0 89 179 51 19 24 30 1.9 21 19 1.1 70 95 21 20 25 30 2.0 18 18 .87 332 692 1830 21 27 30 2.2 19 18 .92 94 120 30 22 30 30 2.4 16 18 .78 46 55 6.8 23 31 30 2.5 17 18 .83 37 48 4.8 24 26 30 2.1 14 18 .68 33 42 3.7 25 24 30 1.9 14 18 .68 31 40 3.3 26 24 30 1.9 17 41 6.0 31 35 2.9 27 24 30 1.9 51 77 13 30 35 2.8 28 23 30 1.9 22 20 1.2 36 35 3.4 29 27 30 2.2 18 12 .58 32 35 3.0 30 34 30 2.8 20 12 .65 40 35 3.8 31 25 31 2.1 18 16 .78 --- --- --- TOTAL 1069 880.5 791 618.67 1647 2585.54 YEAR 14386 39450.42 RIO GRANDE DE LOIZA BASIN 183 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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) (MGM (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 33 40 3.6 142 224 134 36 50 4.9 2 33 40 3.6 243 544 692 74 161 66 3 39 50 5.3 1010 3030 16900 45 150 18 4 33 40 3.6 248 519 562 37 80 8.0 5 32 38 3.3 650 1510 5090 39 70 7.4 6 36 40 3.9 694 1580 5160 37 68 6.8 7 45 63 9.2 355 560 825 37 62 6.2 8 51 68 11 123 210 70 37 60 6.0 9 272 783 1950 84 180 41 44 55 6.5 10 90 115 28 74 145 29 38 50 5.1 11 53 80 11 62 120 20 47 96 32 12 40 50 5.4 55 100 15 39 80 8.4 13 63 98 31 52 90 13 36 35 3.4 14 350 811 1650 74 116 28 35 30 2.8 15 71 120 23 62 100 17 34 30 2.8 16 69 140 72 47 70 8.9 38 30 3.1 17 76 200 41 46 65 8.1 39 28 2.9 18 43 50 5.8 44 60 7.1 33 28 2.5 19 41 50 5.5 43 58 6.7 34 15 1.4 20 40 50 5.4 42 50 5.7 34 15 1.4 21 40 50 5.4 41 50 5.5 32 15 1.3 22 41 50 5.5 43 50 5.8 31 15 1.3 23 38 50 5.1 45 55 6.7 30 15 1.2 24 37 46 4.6 40 52 5.6 35 15 1.4 25 56 116 21 42 60 6.8 44 55 6.5 26 114 234 105 68 150 36 34 45 4.1 27 65 90 16 39 60 6.3 34 32 2.9 28 52 50 7.0 38 50 5.1 32 31 2.7 29 51 35 4.8 37 49 4.9 30 30 2.4 30 47 28 3.6 37 50 5.0 34 30 2.8 31 41 28 3.1 --- --- --- 29 30 2.3 TOTAL 2092 4052.7 4580 29720.2 1158 - 224.5 184 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 29 27 2.1 20 5 .27 21 30 1.7 2 33 25 2.2 19 5 .26 19 25 1.3 3 29 22 1.7 17 5 .23 26 22 1.4 4 42 50 5.7 16 5 .22 18 20 .97 5 28 20 1.5 16 5 .22 15 20 .81 6 29 20 1.6 16 5 .22 18 60 2.9 7 26 16 1.1 15 9 .36 48 110 14 8 26 10 .70 16 10 .43 42 55 6.2 9 25 10 .68 15 10 .41 25 20 1.4 10 26 10 .70 15 10 .41 22 10 .59 11 26 9 .63 15 10 .41 20 10 .54 12 26 10 .70 16 10 .43 20 9 .49 13 26 10 .70 18 12 .58 19 9 .46 14 25 10 .68 18 25 1.2 22 9 .53 15 25 9 .61 23 20 1.2 19 8 .41 16 25 10 .68 20 22 1.2 19 9 .46 17 27 12 .87 17 25 1.1 20 9 .49 18 19 27 26 10 10 .73 .70 19 30 25 40 1.3 3.2 46 22 63 46 13 2.7 20 25 9 .61 30 70 5.7 19 12 .62 21 25 5 .34 22 35 2.1 21 8 .45 22 23 26 25 5 5 .35 .34 22 20 25 20 1.5 1.1 19 19 8 8 .41 .41 24 24 9 .58 21 16 .91 21 8 .45 25 22 8 .48 20 15 .81 16 5 .22 26 27 28 29 30 22 20 20 19 19 8 5 5 5 5 .48 .27 .27 .26 .26 21 68 28 --- 15 157 45 --- .85 59 3.4 --- 18 22 19 332 44 8 8 8 850 125 .39 .48 .41 1560 15 31 19 5 .26 39 80 8.4 TOTAL 792 28.78 593 89.02 IC 1637.59 APRIL MAY JUNE 1 2 3 4 5 23 19 19 18 19 35 30 25 22 20 2.2 1.5 1.3 1.1 1.0 17 18 20 19 20 20 20 20 20 20 .92 .97 1.1 1.0 1.1 44 42 41 39 38 88 85 83 83 75 10 9.4 9.2 8.7 7.7 6 7 8 9 10 19 20 21 18 18 20 19 18 10 9 1.0 1.0 1.0 .49 .44 20 21 21 24 23 20 20 20 20 20 1.1 1.1 1.1 1.3 1.2 37 35 35 34 34 50 35 30 25 28 5.0 3.3 2.8 2.3 2.6 11 12 13 14 15 20 19 26 21 20 8 8 9 9 9 .43 .41 .63 .51 .49 31 40 32 199 958 20 50 40 430 1990 1.7 5.4 3.5 415 11300 34 32 30 29 28 28 30 30 30 30 2.6 2.6 2.4 2.3 2.3 16 17 18 19 20 36 28 36 26 23 60 30 30 28 25 5.8 2.3 2.9 2.0 1.6 240 396 1890 134 83 524 775 5180 200 100 809 1330 77800 71 22 26 25 24 24 25 29 28 25 22 20 2.0 1.9 1.6 1.4 1.4 21 22 23 24 25 29 40 454 191 95 25 55 1230 430 166 2.0 5.9 5640 416 69 64 60 59 57 57 100 100 100 100 100 17 16 16 15 15 25 24 25 26 26 20 20 20 20 20 1.4 1.3 1.4 1.4 1.4 26 27 28 29 30 41 23 20 19 18 60 30 20 20 20 6.6 1.9 1.1 1.0 .97 55 52 50 49 47 100 lu IOU 98 95 15 14 13 13 12 27 24 24 24 23 22 25 25 29 29 1.6 1.6 1.6 1.9 1.8 31 --- --- --- 45 90 11 --- --- --- TOTAL 1379 6172.57 4801 91925.49 904 96.9 RIO GRANDE DE LOIZA BASIN 185 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 DAY MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 2 3 4 5 26 28 28 28 25 29 30 30 30 30 2.0 2.3 2.3 2.3 2.0 24 24 22 20 17 30 30 30 28 25 1.9 1.9 1.8 1.5 1.1 27 26 23 22 23 30 29 29 25 25 2.2 2.0 1.8 1.5 1.6 6 7 8 9 10 23 23 22 23 23 30 25 22 20 21 1.9 1.6 1.3 1.2 1.3 21 22 22 20 24 25 21 19 15 15 1.4 1.2 1.1 .81 .97 25 25 39 40 30 25 25 50 65 42 1.7 1.7 5.3 7.0 3.4 11 12 13 14 15 24 23 22 22 66 21 22 22 22 101 1.4 1.4 1.3 1.3 28 21 23 32 29 28 15 17 18 15 15 .85 1.1 1.6 1.2 1.1 35 393 286 72 42 45 990 543 70 50 4.3 4460 743 14 5.7 16 17 18 19 20 90 212 38 25 62 135 542 40 25 110 55 1060 2.7 4.2 22 26 23 23 22 24 15 15 15 15 15 1.1 .93 .93 .89 .97 31 ,J 25 27 26 45 45 35 32 31 3.8 3.4 2.4 2.3 2.2 21 22 23 24 25 27 22 21 32 26 75 60 55 52 50 5.5 3.6 3.1 4.5 3.5 23 21 22 25 31 12 11 10 10 9 .75 .62 .59 .68 .75 25 24 24 35 390 30 30 30 30 936 2.0 1.9 1.9 2.8 3240 26 27 28 29 30 31 47 28 29 29 27 26 70 40 38 35 31 31 8.9 3.0 3.0 2.7 2.3 2.2 26 139 143 28 23 22 9 317 420 45 33 30 .63 356 353 3.4 2.0 1.8 64 40 73 41 40 --- 97 48 108 45 40 --- 23 5.2 27 5.0 4.3 --- TOTAL 1147 1237.8 970 744.57 2001 8582.4 YEAR 21467 144512.52 186 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE 'RATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/I) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 60 80 15 98 160 42 40 25 2.7 2 67 90 16 87 120 28 ,, 25 2.8 3 61 72 12 83 120 27 37 25 2.5 4 70 83 18 75 120 24 31 28 2.3 5 101 131 37 77 110 23 44 29 3.4 6 1530 2790 17900 65 100 18 45 29 3.5 7 664 879 2320 61 110 18 39 28 2.9 8 171 200 92 59 110 18 36 28 2.7 9 76 100 21 56 108 16 37 28 2.8 10 58 60 9.4 56 107 16 38 28 2.9 11 45 45 5.5 59 105 17 35 28 2.6 12 48 40 5.2 84 128 33 60 28 4.5 13 49 39 5.2 88 140 33 42 30 3.4 14 37 35 3.5 68 110 20 38 30 3.1 15 30 32 2.6 84 95 22 40 30 3.2 16 35 30 2.8 72 85 17 39 30 3.2 17 55 73 15 67 95 17 33 30 2.7 18 68 102 27 141 251 121 31 30 2.5 19 51 70 9.6 66 95 17 34 30 2.8 20 35 45 4.3 64 83 14 36 30 2.9 21 38 40 4.1 59 75 12 33 30 2.7 22 37 40 4.0 48 65 8.4 35 30 2.8 23 360 699 1350 44 55 6.5 46 30 3.7 24 644 1410 4300 42 50 5.7 53 30 4.3 25 173 250 117 40 50 5.4 35 30 2.8 26 120 150 49 41 37 4.1 32 30 2.6 27 117 140 44 41 28 3.1 30 30 2.4 28 105 140 40 39 27 2.8 32 30 2.6 29 277 629 1370 39 26 2.7 31 30 2.5 30 124 100 33 44 25 3.0 32 30 2.6 31 150 300 121 --- --- --- 28 30 2.3 TOTAL 5456 27953.2 1947 594.7 1163 90.7 187 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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) (MGM (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH '1 30 30 2.4 18 12 .58 15 12 .49 2 35 30 2.8 17 12 .55 14 12 .45 3 40 29 3.1 17 12 .55 16 12 .52 4 50 30 4.1 28 11 .83 17 15 .69 5 35 30 2.8 39 12 1.3 20 15 .81 6 27 30 2.2 20 15 .81 19 14 .72 7 25 28 1.9 18 12 .58 17 12 .55 8 30 27 2.2 19 12 .62 15 11 .45 9 74 123 60 18 12 .58 16 11 .48 10 60 25 4.1 19 15 .77 16 10 .43 11 30 22 1.8 21 12 .68 18 9 .44 12 22 22 1.3 19 12 .62 17 8 .37 13 21 21 1.2 16 12 .52 25 8 .54 14 25 22 1.5 19 12 .62 27 5 .36 15 23 22 1.4 18 15 .73 37 5 .50 16 27 22 1.6 18 15 .73 16 5 .22 17 41 57 15 21 15 .85 14 5 .19 18 27 21 1.5 22 15 .89 14 5 .19 19 20 22 1.2 63 64 17 15 4 .16 20 19 21 1.1 31 16 1.3 16 4 .17 21 30 25 2.0 20 14 .76 16 5 .22 22 24 25 1.6 18 15 .73 15 5 .20 23 19 25 1.3 17 15 .69 15 5 .20 24 23 22 1.4 15 15 .61 15 8 .32 25 18 20 .97 15 15 .61 14 8 .30 26 16 18 .78 16 15 .65 20 9 .49 27 15 15 .61 19 16 .82 • -• 8 .35 28 24 14 .91 15 12 .49 13 8 .28 29 20 15 .81 --- --- --- 174 355 306 30 22 15 .89 51 80 11 31 20 14 .76 27 25 1.8 TOTAL 892 125.23 596 36.47 740 329.89 APRIL MAY JUNE 1 62 85 27 25 15 1.0 20 40 2.2 2 26 25 1.8 20 8 .43 28 30 2.3 3 15 20 .81 25 8 .54 23 25 1.6 4 19 20 1.0 17 8 .37 21 25 1.4 5 38 50 5.1 24 7 .45 22 20 1.2 6 31 35 2.9 38 8 .82 20 20 1.1 7 16 20 .86 40 15 1.6 18 20 .97 8 28 47 15 48 32 5.9 16 40 1.7 9 58 79 22 22 15 .89 28 60 4.5 10 16 22 .95 254 779 1680 217 569 1130 11 13 20 .70 208 335 291 21 30 1.7 12 14 18 .68 65 120 21 16 25 1.1 13 16 15 .65 346 1520 5810 29 25 2.0 14 15 10 .41 495 681 1750 39 28 2.9 15 15 10 .41 62 130 22 52 72 19 16 15 10 .41 38 70 7.2 55 60 8.9 17 15 8 .32 28 60 4.5 40 40 4.3 18 15 7 .28 591 1400 9330 29 40 3.1 19 15 7 .28 88 128 35 35 40 3.8 20 14 6 .23 37 80 8.0 28 35 2.6 21 15 6 .24 30 70 5.7 23 35 2.2 22 15 6 .24 60 70 11 21 35 2.0 23 14 7 .26 30 45 3.6 19 35 1.8 24 16 8 .35 26 30 2.1 17 32 1.5 25 13 7 .25 24 25 1.6 16 32 1.4 26 13 7 .25 23 20 1.2 19 30 1.5 27 18 7 .34 24 20 1.3 25 30 2.0 28 45 43 14 22 20 1.2 27 25 1.8 29 693 1300 11200 60 20 3.2 20 25 1.4 30 81 124 52 23 30 1.9 19 22 1.1 31 --- --- --- 273 936 3920 --- --- --- TOTAL 1379 11349.72 3066 22923.50 963 1213.07 188 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 30 20 1.6 23 32 2.0 24 23 1.5 2 22 20 1.2 20 30 1.6 16 22 .95 3 22 20 1.2 18 27 1.3 14 20 .76 4 19 20 1.0 18 27 1.3 16 20 .86 5 19 20 1.0 17 22 1.0 41 40 4.4 6 65 76 18 16 22 .95 19 18 .92 7 35 45 4.3 33 42 7.3 17 15 .69 8 23 40 2.5 51 55 7.6 15 12 .49 9 20 35 1.9 20 21 1.1 16 12 .52 10 19 30 1.5 26 32 4.2 14 12 .45 11 46 61 9.9 61 82 18 13 12 .42 12 37 60 6.0 22 23 1.4 .j 12 .42 13 24 50 3.2 42 45 5.1 19 15 .77 14 26 45 3.2 51 30 4.1 24 15 .97 15 37 39 3.9 25 27 1.8 15 15 .61 16 27 37 2.7 18 25 1.2 17 15 .69 17 25 35 2.4 17 25 1.1 17 18 .83 18 25 31 2.1 16 25 1.1 18 18 .87 19 21 30 1.7 15 25 1.0 19 18 .92 20 22 28 1.7 15 20 .81 18 15 .73 21 27 28 2.0 14 20 .76 17 15 .69 22 20 27 1.5 15 20 .81 23 15 .93 23 19 26 1.3 16 18 .78 45 23 3.2 24 20 24 1.3 15 17 .69 70 52 8.6 25 18 23 1.1 14 16 .60 50 30 4.1 26 18 23 1.1 13 15 .57 30 28 2.3 27 21 22 1.2 12 15 .53 17 22 1.0 28 24 22 1.4 80 15 .49 15 20 .81 29 21 22 1.2 200 158 112 14 15 .57 30 63 91 24 59 50 8.0 13 15 .53 31 38 55 5.6 36 45 6.9 --- --- --- TOTAL 853 112.7 998 196.09 659 41.50 YEAR 18712 64966.77 I I 180 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR LOCATION.--Lat 18°10'10", long 66°02'37", Hydrologic Unit 21010005. at right upstream end of bridge on Highway 765, 0.5 mi (0.8 km) south of Villa Borinquen, and 7.3 mi (11.7 km) upstream from Rio Grande de Loiza. DRAINAGE AREA.--7.89 mi' (20.44 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 430 ft (131 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 13,800 ft'/s (391 m'/s), Nov.27, 1987, gage height, 18.02 ft (5.492 ), from floodmark, from rating curve extended above 200 ft'/s (5.66 '/s) on basis of step-backwater analysis and slope-area measurement; minimum discharge, 1.4 ft'/s (0.040 m)/s), Oct. 11, 1987. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 1,500 ft'/s (42.5 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m 3/s) (ft) (m) Date Time (ft'/s) (m'/s) (ft) (m) Nov. 24 unknown 4,100 116 unknown July 2 0530 2,940 83.3 10.13 3.088 Nov. 27 unknown *13,800 391 *18.02 5.492 Aug. 24 1430 1,610 45.6 8.33 2.539 Dec. 7 unknown 3,600 102 unknown Sept.11 0815 2,030 57.5 8.95 2.728 Minimum discharge, 1.4 ft'/s (0.040 m'/s), Oct. 11 . DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.5 8.7 e35 e70 e38 17 9.0 18 6.5 111 12 24 2 4.8 6.1 e50 e45 e46 22 8.6 9.7 6.5 504 11 22 3 7.1 5.8 e28 e36 e30 17 8.8 7.4 5.6 78 30 21 4 6.8 5.7 e25 e35 e24 14 8.0 7.1 6.4 43 17 20 5 6.2 39 e23 e36 e22 14 8.2 7.3 5.9 28 10 19 6 4.4 58 e30 e35 e20 14 13 18 5.8 39 9.9 20 7 3.3 29 e540 e33 e18 13 10 9.6 5.5 84 19 21 8 2.8 18 e390 e33 e18 13 8.2 7.6 5.9 32 17 20 9 2.5 15 e62 e32 e23 13 8.0 7.8 6.0 27 15 35 10 2.2 12 e45 e31 e20 12 7.9 26 6.1 37 150 53 11 2.0 10 e36 e32 e17 12 7.7 17 5.9 30 82 308 12 3.3 e8.0 e34 e31 e25 12 7.5 18 5.7 25 28 213 13 5.0 e6.8 e32 e30 e23 12 7.6 9.9 6.7 22 19 110 14 15 e6.5 e31 e29 e19 11 7.0 18 7.4 23 17 83 15 52 e6.3 e31 e27 e18 11 9.2 13 51 19 17 67 16 36 e6.3 e30 e26 e16 11 9.1 9.7 23 19 22 51 17 106 ell e30 e26 e14 11 54 12 8.4 19 35 41 18 327 e9.7 e36 e25 e14 11 18 11 7.9 23 40 37 19 80 e7.2 e38 e25 e13 11 12 8.6 8.4 26 19 39 20 44 e6.5 e40 e24 e13 14 9.3 10 11 22 16 33 21 30 e5.6 e64 e23 e13 11 9.0 18 11 20 15 29 22 24 e5.0 e50 e23 e12 11 8.3 9.3 20 29 41 28 23 19 e20 e38 e22 e13 11 7.9 7.8 13 32 31 27 24 22 e620 e36 e22 e14 11 8.2 7.3 19 20 293 25 25 18 el30 e37 e22 e16 11 7.9 7.1 10 17 210 24 26 23 e250 e37 e22 e35 11 8.2 7.0 8.9 23 61 22 27 16 e2000 e36 e23 36 20 8.2 7.0 7.9 18 49 21 28 29 e350 e34 e23 19 13 7.4 6.8 7.2 43 47 21 29 32 e90 e33 e23 16 11 7.3 14 8.3 15 37 20 30 17 e45 e55 e23 --- 11 8.0 8.3 70 22 31 19 31 14 --- e115 e35 9.7 --- 7.5 --- 13 27 _.- TOTAL 962.9 3791.2 2101 922 605 395.7 311.5 345.8 371.9 1463 1427.9 1473 MEAN 31.1 126 67.8 29.7 20.9 12.8 10.4 11.2 12.4 47.2 46.1 49.1 MAX 327 2000 540 70 46 22 54 26 70 504 293 308 MIN 2.0 5.0 23 22 12 9.7 7.0 6.8 5.5 13 9.9 19 AC-FT 1910 7520 4170 1830 1200 785 618 686 738 2900 2830 2920 CFSM 3.94 16.0 8.59 3.77 2.64 1.62 1.32 1.41 1.57 5.98 5.84 6.22 IN. 4.54 17.87 9.91 4.35 2.85 1.87 1.47 1.63 1.75 6.90 6.73 6.94 CAL YR 1987 TOTAL 12671.8 MEAN 34.7 MAX 2000 MIN 1.7 AC-FT 25130 CFSM 4.40 IN. 59.75 WTR YR 1988 TOTAL 14170.9 MEAN 38.7 MAX 2000 MIN 2.0 AC-FT 28110 CFSM 4.91 IN. 66.81 e Estimated 190 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS JANUARY 1985 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURF (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 16 1022 21.4 132 26.0 APR, 08 1102 8.97 163 27.5 NOV, 12 1355 10.8 155 29.0 MAY, 10 0928 7.92 174 25.0 DEC, 09 1559 73.5 135 27.0 JUN, 02 0827 7.16 165 24.0 JAN, 12 1505 33.5 146 25.0 JUL, 07 1400 47.70 117 26.5 MAR, 14 1420 11.6 157 30.5 RIO GRANDE DE LOIZA BASIN 191 50053050 RIO TURABO AT BORINQUEN, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 1984 to September 1986. INSTRUMENTATION.-- USD-49 and automatic sediment sampler. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,420 mg/L May 17, i985; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 106,000 tons (96,160tonnes) May 17, 1985; Minimum daily mean, 0.00 tons (0.00) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 3,510 (Feb. 15) 3 (several days) 19,600 (Feb. 15) 0.05 (several days) 1985 7,420 (May 17) 1 (several days) 106,000 (May 17) 0.00 (several days) 1986 5,530 (Oct. 06) 3 (several days) 39,400 (Oct. 06) 0.06 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 11 8 .50 7.4 4 .40 13 12 .42 2 9.1 6 .20 7.1 4 .10 13 12 .42 3 8.5 5 .50 7.6 4 .60 12 11 .36 4 8.5 5 .50 9.8 5 .20 12 11 .36 5 8.4 5 .50 7.4 4 .80 13 10 .35 6 9.6 7 .20 7.0 4 .50 13 10 .35 7 8.8 5 .80 7.4 4 .20 13 10 .35 8 8.8 5 .80 6.6 4 .07 13 10 .35 9 9.2 6 .40 18 30 1.5 13 10 .35 10 9.3 6 .60 27 40 2.9 13 10 .35 11 9.1 6 .20 20 35 1.9 12 9 .50 12 11 8 .24 116 952 1740 12 9 .29 13 89 534 1210 184 1020 1360 12 8 .80 14 36 55 5.3 50 90 12 14 8 .50 15 23 25 1.6 325 3510 19600 12 8 .26 16 19 25 1.3 208 1440 2190 12 7 „50 17 25 30 2.0 33 28 2.5 13 7 .25 18 29 38 3.0 23 25 1.6 12 6 .50 19 22 30 1.8 19 22 1.1 12 6 .19 20 48 65 8.4 17 21 .96 12 5 .50 21 28 36 2.7 16 20 .86 12 5 .16 22 24 28 1.8 16 18 .78 13 4 .80 23 15 15 .61 15 15 .61 16 4 .50 24 9.2 6 .50 14 15 .57 15 4 .16 25 24 25 1.6 14 15 .57 13 3 .80 26 11 7 .21 14 15 .57 16 3 .50 27 8.4 5 .40 14 15 .51 18 3 .50 28 12 11 .36 14 15 .57 17 3 .14 29 8.1 5 .10 14 15 .57 17 3 .14 30 7.9 4 .90 --- --- --- 16 3 .13 31 7.6 4 .60 12 3 .10 TOTAL 557.5 1248.62 1231.3 24923.00 416 11.88' 192 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 11 3 .09 7.3 3 .06 31 40 3.3 2 11 3 .09 8.1 3 .20 26 40 2.8 3 12 3 .10 8.5 3 .50 20 30 1.6 4 13 3 .11 7.7 3 .70 16 30 1.3 5 15 3 .12 7.4 4 .08 14 20 .76 6 14 3 .11 7.3 4 .08 25 40 2.7 7 11 3 .09 7.0 4 .08 53 100 14 8 9.9 3 .08 7.0 4 .08 43 60 7.0 9 9.7 3 .08 8.6 4 .10 29 30 2.3 10 9.3 3 .08 9.8 4 .10 430 3060 18400 11 9.7 3 .08 8.7 4 .09 50 70 9.5 12 8.4 3 .07 9.3 4 .10 33 50 4.5 13 8.2 3 .07 18 30 1.5 44 60 7.1 14 9.1 3 .07 9.9 10 .27 28 30 2.3 15 9.0 3 .07 9.4 6 .15 21 25 1.4 16 8.6 3 .10 8.8 5 .50 96 867 1550 17 8.8 3 .20 8.9 5 .50 29 45 3.5 18 8.0 3 .80 7.2 5 .20 19 30 1.5 19 7.7 4 .08 7.0 5 .20 26 50 3.5 20 8.2 4 .09 8.0 5 .10 17 16 .73 21 9.0 4 .10 8.8 5 .50 15 12 .49 22 9.6 4 .10 10 7 .19 14 9 .34 23 12 4 .13 22 26 1.5 13 8 .28 24 11 4 .12 20 21 1.1 11 8 .24 25 11 4 .12 26 26 1.8 11 8 .24 26 7.7 3 .80 52 181 73 11 8 .24 27 14 10 .38 38 65 6.7 10 8 .22 28 7.3 5 .10 36 65 6.3 10 8 .22 29 6.3 3 .05 37 65 6.5 11 8 .24 30 6.6 3 .05 101 486 288 13 8 .28 31 --- --- --- 37 60 6.0 --- --- TOTAL 296.1 4.53 561.7 397.18 1169 20022.58 JULY AUGUST SEPTEMBER 1 19 8 .41 6.4 5 .09 10 8 .22 2 17 8 .37 16 15 .65 10 8 .22 3 12 8 .26 10 10 .27 19 21 2.5 4 110 268 445 28 45 3.4 15 18 .73 5 396 2730 8570 19 24 1.2 69 610 792 6 41 65 7.2 17 21 .96 31 60 5.0 7 29 42 3.3 16 19 .82 15 10 .41 8 26 40 2.8 16 15 .65 11 8 .24 9 25 38 2.6 15 14 .57 13 15 .53 10 24 30 1.9 14 11 .42 11 15 .45 11 23 30 1.9 14 10 .38 11 15 .45 12 22 28 1.7 10 9 .24 14 18 .68 13 20 25 1.4 11 8 .50 14 15 .57 14 22 25 1.5 9 9 7 .80 25 38 4.2 15 20 22 1.2 11 8 .24 19 30 3.6 16 18 22 1.1 11 6 .18 23 55 7.0 17 17 22 1.0 9.1 6 .20 96 549 471 18 18 21 1.0 8.2 5 .20 87 466 179 19 16 18 .78 8.2 5 .20 74 246 70 20 18 18 .87 8.9 5 .90 1L8 558 870 21 23 18 1.1 8.9 5 .90 49 100 13 22 22 15 .89 7.4 4 .40 25 30 2.0 23 24 10 .65 7.4 4 .08 19 20 1.0 24 17 8 .37 6.9 4 .07 17 18 .83 25 17 8 .37 6.8 4 .01 16 11 .73 26 15 9 .36 27 59 8.8 15 16 .65 27 12 9 .29 20 20 1.1 15 16 .65 28 10 10 .27 11 6 .18 14 16 .60 29 16 22 .95 8.1 5 .10 14 16 .60 30 16 15 .65 10 8 .22 15 16 .65 31 8.0 8 .17 10 8 .22 --- --- --- TOTAL 1073.0 9052.36 382.2 25.01 894 2429.51 YEAR 7056.6 58121.01 RIO GRANDE DE LOIZA BASIN 193 50053050 RIO TURABO AT BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 26 .98 62 342 283 14 3 .11 2 13 26 .91 123 496 328 54 15 6.3 3 14 25 .95 611 3610 22500 27 12 1.0 4 12 24 .78 182 37 22 19 6 .31 5 12 24 .78 335 54 68 18 4 .19 6 13 26 .91 279 46 39 16 4 .17 7 12 26 .84 196 46 37 16 4 .17 8 12 26 .84 114 24 7.4 20 8 .64 9 51 40 16 80 20 4.3 19 6 .31 10 16 27 1.2 64 18 3.1 19 6 .31 11 13 25 .88 54 18 2.6 17 6 .28 12 12 26 .84 46 18 2.2 16 7 .30 13 12 28 .91 43 19 2.2 15 7 .28 14 26 40 4.8 51 27 7.9 15 8 .32 15 14 31 1.2 34 28 2.6 16 8 .35 16 18 33 2.2 28 18 1.4 22 12 .96 17 18 36 1.7 24 14 .91 14 9 .34 18 14 31 1.2 22 12 .71 12 10 .32 19 13 30 1.1 21 8 .45 12 10 .32 20 13 30 1.1 19 5 .26 11 10 .30 21 15 31 1.4 18 5 .24 9.0 9 .22 22 16 32 1.4 17 5 .23 8.5 9 .21 23 15 33 1.3 18 5 .24 8.4 9 .20 24 13 29 1.0 16 4 .17 9.7 9 .24 25 23 26 1.6 16 5 .32 21 25 5.1 26 19 23 1.2 31 15 1.9 12 11 .36 27 16 20 .86 19 5 .26 12 10 .32 28 19 18 .92 15 4 .16 11 9 .27 29 14 14 .53 15 4 .16 9.2 9 .22 30 58 571 1410 15 3 .12 12 10 .32 31 17 26 1.2 --- --- 10 9 .24 TOTAL 547 1461.53 2568 23316.83 494.8 20.98 RIO GRANDE DE LO1ZA BASIN 194 50053050 RIO TURABO AT BOPINQIJEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 13 1.1 10 7 .19 20 15 .81 2 17 12 .73 9.6 8 .21 18 14 .68 3 13 8 .28 9.4 8 .20 19 16 .82 4 18 13 1.1 9.7 9 .24 17 13 .60 5 12 8 .26 9.1 10 .25 18 12 .58 6 17 13 1.2 8.9 10 .24 29 136 31 7 12 8 .26 7.6 11 .23 38 18 1.8 8 11 8 .24 7.6 12 .25 30 15 1.5 9 11 8 .24 7.7 12 .25 22 11 .65 10 12 8 .26 8.0 13 .28 18 8 .39 11 10 8 .22 8.7 13 .31 16 5 .14 12 9.4 8 .20 8.9 13 .31 17 4 .18 13 9.3 7 .18 8.6 13 .30 15 4 .16 14 9.9 7 .19 10 13 .35 14 3 .11 15 11 6 .18 9.6 12 .31 13 3 .11 16 11 6 .18 9.0 8 .19 13 2 .07 17 11 6 .18 8.6 8 .19 13 2 .07 18 11 6 .18 8.4 8 .18 55 20 6.0 19 10 6 .16 22 19 1.1 23 12 .75 20 10 6 .16 20 18 .97 17 8 .37 21 9.7 6 .16 17 16 .73 16 5 .22 22 9.7 5 .13 14 13 .49 15 5 .20 23 9.4 5 .13 13 12 .42 15 5 .20 24 9.5 5 .13 15 11 .45 13 5 .18 25 9.7 4 .10 15 14 .57 13 5 .18 26 10 4 .11 16 14 .60 12 5 .16 27 9.2 4 .10 42 29 5.2 12 5 .16 28 9.3 4 .10 25 20 1.4 12 5 .16 29 8.9 5 .12 --- --- --- 67 35 12 30 8.9 6 .14 24 32 2.2 31 9.2 6 .15 24 22 2.1 TOTAL 346.1 8.87 358.4 16.41 648 64.55 APRIL MAY JUNE 1 14 10 .38 6.0 12 .2 11 6 .18 2 12 9 .29 5.7 10 .2 11 6 .18 3 11 8 .24 5.6 9 .1 11 6 .18 4 11 8 .24 5.2 8 .1 11 6 .18 5 11 6 .18 5.3 6 .1 10 5 .14 6 11 4 .12 5.1 6 .1 10 5 .14 7 12 4 .13 5.3 5 .1 9.7 5 .13 8 12 4 .13 4.8 4 .1 9.8 4 .11 9 9.3 3 .08 5.3 4 .1 9.2 4 .10 10 8.2 3 .07 4.8 3 .0 1C 4 .11 11 8.7 2 .05 5.5 2 .0 11 4 .12 12 8.3 2 .04 8.2 2 .0 12 4 .13 13 11 2 .06 6.8 1 .0 14 4 .15 14 9.0 2 .05 202 2180 1690 13 4 .14 15 8.0 1 .02 205 1200 2050 13 4 .14 16 14 6 .23 146 1330 3810 12 4 .13 17 12 5 .16 1300 7420 106000 11 4 .12 18 15 8 .32 900 5900 14300 11 5 .15 19 11 4 .12 50 95 13 11 5 .15 20 9.1 2 .05 16 14 .6 12 5 .16 21 18 10 1.1 10 10 .3 11 5 .15 22 10 4 .11 9.4 10 .3 12 5 .16 23 228 1340 4280 9.1 9 .2 12 5 .16 24 52 174 49 9.0 8 .2 12 5 .16 25 109 1010 2970 9.9 8 .2 12 5 .16 26 31 66 10 10 7 .2 11 5 .15 27 11 14 .42 11 6 .2 11 5 .15 28 8.6 14 .33 11 6 .2 11 4 .12 29 7.2 13 .25 11 6 .2 12 4 .13 30 6.4 12 .21 11 6 .2 11 4 .12 31 --- --- 11 6 .2 --- --- TOTAL 698.8 7314.38 3005.0 127867.1 337.7 4.30 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN. PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 4 .14 12 8 .26 12 16 .52 2 12 4 .13 12 8 .26 12 16 .52 3 12 4 .13 11 8 .24 12 16 .52 4 12 4 .13 11 8 .24 11 15 .45 5 11 4 .12 11 8 .24 15 18 1.1 6 10 4 .11 11 8 .24 13 14 .49 7 9.2 4 .10 10 8 .22 11 13 .39 8 9.3 4 .10 10 8 .22 18 17 1.5 9 9.3 4 .10 9.5 8 .21 18 19 .92 10 9.3 4 .10 9.3 8 .20 14 14 .53 11 10 4 .11 10 8 .22 12 10 .32 12 9.7 4 .10 12 8 .26 49 462 525 13 9.1 4 .10 17 8 .37 53 160 78 14 9.3 4 .10 14 8 .30 22 21 1.5 15 19 15 .77 13 9 .32 17 15 .69 16 18 20 .97 12 9 .29 14 12 .45 17 29 40 3.1 12 9 .29 12 11 .36 18 13 6 .21 13 9 .32 11 10 .30 19 12 6 .19 12 9 .29 11 9 .27 20 11 6 .18 11 10 .30 9.7 8 .21 21 9.7 6 .16 12 10 .32 9.7 9 .24 22 11 7 .21 13 11 .39 9.7 10 .26 23 12 7 .23 12 12 .39 10 8 .22 24 13 7 .25 12 12 .39 16 28 3.6 25 11 6 .18 14 12 .45 31 76 16 26 14 8 .30 13 12 .42 14 16 .60 27 12 7 .23 30 29 3.9 12. 15 .49 28 13 7 .25 23 23 1.7 12 16 .52 29 14 8 .30 14 16 .60 11 14 .42 30 13 8 .28 13 16 .56 10 14 .38 31 12 8 .26 13 16 .56 --- --- --- TOTAL 381.9 9.64 401.8 14.97 482.1 636.77 YEAR 10269.6 160736.33 195 196 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 61 182 78 44 70 8.3 21 21 1.2 2 54 100 15 39 66 6.1 20 20 1.1 3 54 100 15 36 60 5.8 20 19 1.0 4 58 150 23 33 59 5.3 20 19 1.0 5 70 150 28 35 52 4.9 22 19 1.1 6 989 5530 39400 31 48 4.0 20 18 .97 7 338 1910 2330 30 43 3.5 20 18 .97 8 255 1490 1510 29 42 3.3 19 17 .87 9 134 400 145 29 42 3.3 19 17 .87 10 93 250 63 28 40 3.0 19 17 .87 11 73 160 32 27 40 2.9 19 17 .87 12 65 130 23 59 150 24 25 15 1.0 13 61 120 20 33 40 3.6 .3 15 .77 14 58 120 19 45 100 12 18 14 .68 15 57 120 18 85 200 46 18 10 .49 16 56 110 17 51 100 14 17 8 .37 17 58 110 17 43 70 8.1 17 8 .37 18 81 200 44 73 150 30 17 8 .37 19 59 120 19 47 120 15 17 8 .37 20 54 110 16 42 70 7.9 17 8 .37 21 53 100 14 52 120 17 17 8 .37 22 52 100 14 34 50 4.6 16 8 .35 23 152 844 956 30 40 3.2 16 7 .30 24 131 548 277 27 35 2.6 18 7 .34 25 85 300 69 25 30 2.0 18 6 .29 26 137 824 1870 24 29 1.9 17 7 .32 27 82 200 44 23 29 1.8 16 7 .30 28 67 200 36 21 26 1.5 17 7 .32 29 95 250 64 21 25 1.4 16 7 .30 30 60 100 16 22 22 1.3 15 8 .32 31 60 70 11 --- --- --- 15 8 .32 TOTAL 3702 47203 1118 248.3 565 19.14 197 RIO GRANDE DE LOILA BASIN 50053050 RIO TURABO AT BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 7 .32 14 9 .34 8.0 4 .09 2 17 7 .32 13 7 .25 8.0 4 .09 3 18 7 .34 25 127 57 8.2 4 .09 4 21 5 .28 19 15 .77 9.0 4 .10 5 17 5 .23 17 12 .55 10 5 .14 6 15 4 .16 14 10 .38 8.4 5 .11 7 15 6 .24 14 9 .34 7.8 4 .08 8 15 8 .32 13 8 .28 7.4 4 .08 9 27 9 .66 13 7 .25 7.0 4 .08 10 17 9 .41 12 5 .16 8.0 5 .11 11 14 8 .30 12 4 .13 7.0 5 .09 12 14 7 .26 12 4 .13 6.9 5 .09 13 14 7 .26 11 4 .12 7.6 5 .10 14 13 7 .25 9.0 4 .10 8.2 4 .09 15 13 6 .21 8.2 4 .09 10 4 .11 16 12 6 .19 8.4 4 .09 6.4 4 .07 17 16 8 .35 8.8 3 .80 7.0 4 .08 18 14 7 .26 35 4 .38 f '. 4 .07 19 13 7 .25 25 5 .34 6.4 4 .07 20 13 5 .18 15 5 .20 6.4 4 .07 21 13 5 .18 10 4 .11 6.2 4 .07 22 11 5 .15 9.2 4 .10 6.0 4 .06 23 8.9 5 .12 8.8 4 .10 6.0 4 .06 24 12 5 .16 8.4 4 .09 7.0 5 .09 25 9.0 5 .12 9.0 4 .10 9.1 6 .15 26 8.5 5 .11 8.4 4 .09 9.6 6 .16 27 7.3 5 .10 8.6 4 .09 8.7 6 .14 28 7.6 5 .10 8.4 4 .09 8.8 6 .14 29 18 60 21 --- --- --- 26 25 1.8 30 13 12 .42 13 10 .35 31 16 10 .43 12 8 .26 TOTAL 439.3 28.68 369.2 63.47 266.7 5.09 APRIL MAY JUNE 1 11 8 .24 19 15 .77 25 12 .81 2 9.8 8 .21 13 10 .35 30 12 .97 3 15 9 .36 18 10 .49 23 11 .68 4 20 10 .54 13 10 .35 20 10 .54 5 20 10 .54 12 10 .32 23 9 .56 6 17 8 .37 11 12 .36 20 8 .43 7 13 7 .25 26 92 31 19 7 .36 8 12 7 .23 157 861 3420 17 7 .32 9 9.8 7 .19 42 80 9.1 20 8 .43 10 9.7 8 .21 50 80 11 100 1290 2160 11 9.3 8 .20 67 150 27 20 55 3.0 12 9.2 7 .17 31 40 3.3 17 20 .92 13 8.8 5 .12 251 2210 12400 30 82 23 14 8.8 5 .12 151 1490 9650 32 67 9,1 15 11 5 .15 29 50 3.9 29 54 8.0 16 11 6 .18 18 20 .97 34 93 14 17 10 7 .19 18 15 .73 23 30 1.9 18 10 8 .22 120 747 774 18 25 1.2 19 11 8 .24 29 45 3.5 26 23 1.6 20 11 8 .24 16 18 .78 16 18 .78 21 11 8 .24 15 10 .41 14 12 .45 22 13 8 .28 60 10 1.6 14 8 .30 23 11 9 .27 30 10 .81 13 5 .18 24 11 9 .27 26 8 .56 12 5 .16 25 11 9 .27 24 7 .45 11 4 .12 26 11 9 .27 23 7 .43 11 4 .12 27 13 9 .32 24 7 .45 12 7 .23 28 17 10 .46 22 5 .30 12 7 .23 29 75 478 789 56 10 1.5 12 7 .23 30 48 168 68 22 8 .48 11 5 .15 31 --- --- --- 90 457 313 --- --- --- TOTAL 458.4 864.35 1483 26657.91 664 2230.77 198 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 12 5 .16 15 3 .12 1E 20 .86 2 11 4 .12 15 3 .12 15 18 .73 3 12 5 .16 16 3 .13 14 15 .57 4 10 5 .14 16 3 .13 13 15 .53 5 11 5 .15 15 3 .12 19 15 .77 6 31 129 49 14 5 .19 13 12 .42 7 13 8 .28 17 10 .46 10 10 .27 8 10 6 .16 23 20 1.2 8.4 10 .23 9 9.5 8 .21 17 5 .23 9.1 10 .25 10 8.3 8 .18 20 8 .43 8.5 10 .23 11 22 20 1.2 44 102 34 8.4 10 .23 12 15 8 .32 24 20 1.3 9.9 12 .32 13 11 5 .15 79 279 132 11 12 .36 14 16 5 .22 68 200 37 9.4 12 .30 15 17 5 .23 40 70 7.6 8.6 11 .26 16 14 5 .19 30 40 3.2 7.9 10 .21 17 12 4 .13 22 25 1.5 7.0 9 .17 18 12 4 .13 19 1B .92 6.8 5 .09 19 11 5 .15 14 10 .38 6.8 5 .09 20 14 6 .23 11 10 .30 6.6 5 .09 21 14 6 .23 9.7 10 .26 6.2 5 .08 22 8.4 5 .11 17 10 .46 6.6 5 .09 23 9.8 5 .13 14 8 .30 8.0 9 .19 24 12 4 .13 18 9 .44 57 209 105 25 13 4 .14 10 8 .22 31 10 .84 26 9.0 3 .07 8.6 8 .19 16 5 .22 27 14 5 .19 6.8 8 .15 11 5 .15 28 17 5 .23 67 794 531 9.5 5 .13 29 12 3 .10 270 1920 4760 8.3 5 .11 30 14 3 .11 27 45 3.3 9.2 5 .12 31 16 3 .13 20 20 1.1 --- --- TOTAL 411.0 55.08 987.1 5518.75 371.2 113.91 YEAR 10834.9 83008.45 I 199 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 i (1.9 km) downstream from Rio Turabo, and 1.8 mi (2.9 km) east of Plaza de Caguas. DRAINAGE AREA.--89.8 mi' (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. Elevation 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. AVERAGE DISCHARGES.--28 years (1961-88), 226 ft 3 /s (6.400 m'/s), 34.18 in/yr (868 mm/yr), 163,700 acre-ft/yr (202 hm ) /yr); median of yearly mean discharges, 215 ftl/s (6.09 m'/s), 156,000 acre-ft/yr (192 hii0/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 71,500 ft 3 /s (2,020 m'/s), Sept. 6, 1960, gage height, 31.17 ft (9.501 m), from rating curve extended above 6,000 ft'/s (170 m'/s) on basis of slope-area measurement; minimum daily discharge, 10 ft'is (0.283 m'/s), Apr. 5, 10, 29, 1968. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 8,000 ft'is (227 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (e/s) (ft) (m) Date Time (W/s) (111)/S) (ft) (m) Nov. 24 1900 16.000 453 16.50 5.029 Aug. 24 1545 21,400 606 18.36 5.596 Nov. 27 0545 *28,900 818 *20.65 6.294 Aug. 25 0845 10,600 300 14.22 4.334 Dec. 7 1830 28,000 793 20.37 6.209 Sept.11 1230 13.800 391 15.60 4.755 July 2 0715 15,300 433 16.23 4.947 Minimum discharge, 18 ft'is (0.510 m'/s), Oct. 13, 14. DISCHARGE. CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 131 103 439 705 174 e138 62 53 48 657 129 194 2 73 91 636 486 186 e129 60 59 44 4220 108 e170 3 95 79 357 328 331 e113 59 39 42 396 119 el60 4 119 101 326 300 189 101 59 33 40 199 200 e150 5 83 250 296 394 163 94 58 33 37 142 111 e145 6 64 354 394 349 173 93 101 124 36 228 94 el40 7 57 165 7030 294 141 90 104 80 36 1210 171 e130 8 44 115 4480 286 140 89 63 42 35 240 139 139 9 47 93 776 294 147 85 59 37 47 167 101 292 10 48 86 540 304 168 80 53 161 52 256 1090 326 11 29 77 448 300 133 80 55 122 40 203 983 3810 12 25 76 381 312 140 82 50 83 41 187 262 2560 13 24 81 332 271 e385 81 52 58 48 141 168 834 14 136 65 301 297 e155 89 48 55 47 281 134 646 15 250 64 289 223 e147 76 65 66 409 132 129 437 16 236 92 274 203 e140 73 98 52 348 117 138 367 17 812 143 252 204 e123 74 137 50 117 -107 229 291 18 3160 124 238 189 e123 72 114 60 69 179 477 255 19 711 92 315 186 e116 70 63 53 60 162 172 472 20 234 82 406 176 e129 88 43 92 185 128 133 310 21 160 66 376 165 e115 82 39 101 194 100 119 231 22 125 60 587 157 e112 72 42 86 199 223 328 208 23 111 108 322 153 e110 66 36 54 157 169 587 196 24 109 7860 281 153 e121 63 41 47 105 134 4290 192 25 127 1650 270 149 e117 66 37 43 208 111 2620 180 26 159 2990 249 149 e300 74 34 42 185 132 533 166 27 162 14500 263 147 e400 116 46 46 151 122 373 160 28 259 2890 273 153 e150 112 36 43 81 284 360 153 29 189 905 256 153 e145 96 31 53 80 254 324 150 30 123 554 222 159 --- 75 35 75 198 281 255 144 31 104 --- 514 140 70 --- 75 --- 162 211 --- TOTAL 8006 33916 22123 7779 4973 2689 1780 2017 3339 11324 15087 13608 MEAN 258 1131 714 251 171 86.7 59.3 65.1 111 365 487 454 MAX 3160 14500 7030 705 400 138 137 161 409 4220 4290 3810 MIN 24 60 222 140 110 63 31 33 35 100 94 130 AC-FT 15880 67270 43880 15430 9860 5330 3530 4000 6620 22460 29930 26990 CFSM 2.88 12.6 7.95 2.79 1.91 .97 .66 .72 1.24 4.07 5.42 5.05 IN. 3.32 14.05 9.16 3.22 2.06 1.11 .74 .84 1.38 4.69 6.25 5.64 CAL YR 1987 TOTAL 110674 MEAN 303 MAX 14500 MIN 19 AC-FT 219500 CFSM 3.38 IN. 45.85 WTR YR 1988 TOTAL 126641 MEAN 346 MAX 14500 MIN 24 AC-FT 251200 CFSM 3.85 IN. 52.46 e Estimated 200 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1959 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 05... 0955 89 216 7.60 28.0 22 6.4 81 20 K19000 K1100 DEC 07... 0930 272 281 6.30 25.5 15 7.7 93 16 K15000 2100 FEB 1988 12... 1005 131 220 7.00 25.0 29 7.2 87 13 50000 2800 APR 06... 1045 58 272 7.70 27.0 35 6.8 85 11 9400 450 JUN 03... 0945 42 278 7.40 29.5 28 6.5 85 28 5300 320 AUG 05... 1015 113 209 6.50 26.5 97 7.6 94 <10 60000 K1400 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE D1S- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED GATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 05... 64 0 16 5.9 19 1 2.8 85 <0.5 14 16 DEC 07... 52 FEB 1988 12... 69 APR 06... 77 0 18 7.7 23 1 1.7 84 '0.5 18 20 JUN 03... 83 AUG 05... 61 0 15 5.7 17 1 1.8 56 12 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) S102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 5... 0.10 29 154 37 25 0.62 0.08 0.70 0.13 0.37 DEC 7... 4 1.34 . 0.06 1.40 0.12 0.68 FEB 1988 12... 39 0.43 0.07 0.50 0.17 0.33 APR 6... 0.20 33 171 27 54 0.52 0.08 0.60 0.19 0.41 JUN 03... 43 0.61 0.09 0.70 0.15 0.15 AUG 05... 0.10 29 135 41 157 0.42 0.08 0.50 0.20 0.50 K = non-ideal count RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA « NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN. PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 05... 0.5 1.2 6.8 0.20 <1 ,100 10 <1 2 20 DEC 07... 0.8 2.2 9.7 0.07 FEB 1988 12... 0.5 1.0 4.4 0.22 APR 06... 0.6 1.2 5.3 0.26 1 <100 <10 <1 <1 10 JUN 03... 0.3 1.0 4.4 0.33 AUG 05... 0.7 1.2 5.3 0.12 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) OCT 1987 5... 1700 <5 170 <0.10 <1 <1 <10 <0.010 2 0.03 DEC 7... FEB 1988 12... APR 6... 2800 6 290 <0.10 <1 <1 20 <0.010 1 0.02 JUN 03... AUG 05... 201 RIO GRANDE DE LOIZA BASIN 202 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD Of DAILY RECORD. -- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1986. INSTRUMENTATION.-- USD-49 and automatic sediment sampler. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD. -- SEDIMENT CONCENTRATION: Maximum daily mean, 7,470 mg/L May 13, 1986; Minimum daily mean, 11 mg/L August 12, 1985. SEDIMENT LOADS: Maximum daily mean, 290,000 tons (263,090 tonnes) May 13, 1986; I.. ,imun daily mean, 1.3 tons (1.2) July 14, 1985. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 1,860 (Nov. 05) 19 (several days) 91,400 (Nov. 05) 1.6 (April 25) 1985 2,870 (May 18) 11 (August 12) 115,000 (May 18) 1.3 (July 14) 1986 7,470 (May 13) 22 (several days) 290,000 (May 13) 2.1 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 1 340 253 361 187 136 176 100 75 20 2 181 125 61 193 178 195 1330 672 6680 3 277 208 312 110 90 27 219 160 95 4 165 140 62 2390 1090 10300 139 100 38 5 122 95 31 6500 1860 91400 122 95 31 6 110 85 25 1700 796 8640 165 95 42 7 110 80 24 400 270 292 127 92 32 8 109 80 24 286 190 147 114 88 27 9 150 123 58 225 165 100 105 82 23 10 122 90 30 194 145 76 103 82 23 11 104 82 23 175 130 61 108 80 23 12 108 80 23 160 120 52 98 75 20 13 115 85 27 150 112 45 90 70 17 14 137 95 35 141 108 41 86 65 15 15 117 98 33 136 105 39 87 65 15 16 150 119 55 140 105 40 91 68 17 17 110 90 27 131 100 35 91 70 17 18 103 90 25 124 95 32 94 72 18 19 151 130 67 122 92 30 86 70 16 20 99 85 23 116 90 28 82 65 14 21 113 85 22 110 88 26 82 65 14 22 137 105 38 107 85 25 80 70 15 23 94 78 20 103 81 23 88 72 17 24 84 70 16 102 80 22 79 65 14 25 81 65 14 102 80 22 75 60 12 26 87 62 15 100 78 21 75 61 12 27 79 60 13 97 75 20 80 62 13 28 74 60 12 96 73 19 82 65 14 29 86 70 16 93 75 19 82 63 14 30 136 92 34 103 75 21 100 88 28 31 121 85 28 --- --- --- 114 104 38 TOTAL 3972 1554 14593 111974 4374 7374 203 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 1 124 90 30 66 55 9.8 89 70 17 2 83 70 16 67 55 9.9 85 68 16 3 73 61 12 67 60 11 82 68 15 4 75 60 12 85 70 16 82 68 15 5 74 70 14 82 70 15 77 66 13 6 70 59 11 81 65 14 81 66 14 7 70 59 11 77 63 13 76 65 13 8 71 59 11 72 62 12 74 60 '2 9 72 59 11 109 93 33 78 70 15 10 93 62 16 137 115 46 81 70 15 11 74 65 13 125 95 32 70 65 12 12 67 63 11 293 176 592 66 60 11 13 354 237 669 951 588 2610 67 56 10 14 340 236 313 307 170 141 86 58 13 15 143 110 42 1830 803 18100 72 52 10 16 107 90 26 2300 841 11700 70 50 9.5 17 131 105 37 324 180 157 70 50 9.5 18 122 110 36 211 150 85 75 50 10 19 115 100 31 166 125 56 63 50 8.5 20 207 128 87 142 110 42 58 50 7.8 21 135 105 38 129 95 33 56 50 7.6 22 109 90 26 119 90 29 59 50 8.0 23 98 84 22 110 88 26 71 55 11 24 86 70 16 104 82 23 63 45 7.7 25 107 70 20 100 79 21 55 30 4.5 26 87 70 16 98 76 20 53 20 2.9 27 87 70 16 97 75 20 52 20 2.8 28 83 68 15 94 75 19 49 20 2.6 29 77 65 14 91 70 17 48 22 2.9 30 71 60 12 --- --- --- 48 22 2.9 31 68 55 10 47 22 2.8 TOTAL 3473 1614 8434 33902.7 2103 302.0 APRIL MAY JUNE 1 48 22 2.9 34 30 2.8 158 98 42 2 44 22 2.6 33 30 2.7 124 100 33 3 46 22 2.7 33 30 2.7 85 78 18 4 44 25 3.0 34 30 2.8 97 67 18 5 47 25 3.2 34 30 2.8 72 65 13 6 50 25 3.4 33 30 2.7 262 192 210 7 51 26 3.6 36 31 3.0 668 428 1110 8 46 25 3.1 35 31 2.9 343 220 204 9 43 22 2.6 35 35 3.3 198 170 91 10 44 22 2.6 44 38 4.5 4100 1300 47900 11 46 22 2.7 42 32 3.6 443 260 311 12 45 25 3.0 36 33 3.2 239 190 123 13 41 22 2.4 67 55 16 445 377 799 14 38 21 2.2 71 52 10 255 140 96 15 38 21 2.2 50 53 10 173 115 54 16 35 20 1.9 39 35 3.7 270 192 313 17 35 21 2.0 32 31 2.7 264 210 150 18 35 21 2.0 30 20 1.6 153 112 46 19 34 20 1.8 31 21 1.8 150 110 45 20 34 20 1.8 30 20 1.6 131 105 37 21 38 20 2.1 30 20 1.6 116 90 28 22 42 20 2.3 30 20 1.6 105 82 23 23 35 19 1.8 63 56 15 95 78 20 24 34 19 1.7 55 42 6.2 90 78 19 25 31 19 1.6 80 65 19 87 71 17 26 40 20 2.2 202 144 138 86 70 16 27 80 50 26 136 120 44 81 70 15 28 104 70 20 139 114 51 77 68 14 29 46 32 4.0 102 83 23 95 68 17 30 37 31 3.1 713 428 1230 103 75 21 31 --- --- --- 245 160 106 --- --- --- TOTAL 1331 116.5 2574 1719.8 9565 51803 RIO GRANDE DE LOIZA BASIN 204 50055000 RIO GRANDE OE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 1 120 101 38 94 88 56 90 78 19 2 142 95 36 247 180 120 93 55 14 3 90 78 19 100 90 24 84 45 10 4 380 359 2090 277 205 347 148 100 51 5 1900 666 5820 172 130 60 408 234 740 6 276 180 134 100 82 22 283 120 92 7 171 130 60 87 65 15 113 80 24 8 138 105 39 77 62 13 87 68 16 9 132 100 36 74 50 10 93 70 18 10 121 100 33 72 49 9.5 131 90 41 11 110 95 28 68 48 8.8 I d 140 67 12 102 88 24 65 50 8.8 176 118 65 13 92 82 20 62 149 25 319 174 250 14 116 114 49 61 52 8.6 957 901 4230 15 131 105 37 61 53 8.7 253 165 113 16 92 80 20 73 53 10 322 195 283 17 83 70 16 65 52 9.1 781 373 1800 18 79 69 15 58 50 7.8 983 379 1640 19 76 65 13 56 49 7.4 716 201 440 20 79 65 14 61 48 7.9 1720 949 12500 21 86 65 15 66 45 8.0 673 490 890 22 102 65 18 57 45 6.9 326 220 194 23 104 65 18 55 42 6.2 243 170 112 24 85 65 15 53 42 6.0 197 140 74 25 77 65 14 50 42 5.7 173 125 58 26 73 62 12 128 90 99 157 115 49 27 82 62 14 300 173 160 146 105 41 28 71 62 12 111 90 27 152 105 43 29 89 60 14 76 68 14 135 105 38 30 172 126 72 436 282 1130 177 115 55 31 93 82 21 149 120 48 --- --- --- TOTAL 5464 8766 3411 2289.4 10314 23967 YEAR 69608 245382.4 205 RIO GRANDE DE LOIZA BASIh 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 1 152 49 20 456 265 483 166 122 55 2 132 21 7.5 1180 560 3510 423 256 491 3 155 62 33 5950 2360 56100 287 203 188 4 155 46 21 1960 951 5780 193 148 77 5 143 43 26 4120 1740 29900 176 150 71 6 207 93 70 3790 1630 21900 168 150 44 7 145 59 23 2700 934 9260 159 153 66 8 151 45 18 1150 340 1090 165 160 71 9 930 432 3440 890 366 1080 209 213 136 10 392 217 258 621 148 257 189 188 96 11 243 128 84 434 112 131 334 262 453 12 179 91 44 363 92 90 225 255 170 13 265 129 137 320 80 69 167 219 99 14 1180 561 3190 434 144 240 144 190 74 15 331 151 139 483 251 343 141 194 74 16 254 145 107 308 92 77 158 195 83 17 335 150 132 290 79 62 165 187 83 18 195 70 37 267 156 112 140 181 68 19 169 51 2.2 241 144 94 135 180 66 20 161 52 23 226 149 91 146 176 69 21 184 70 36 214 151 87 126 168 57 22 177 50 19 211 156 89 121 160 52 23 143 39 15 237 179 115 118 160 51 24 129 30 10 214 159 92 137 160 59 25 221 86 58 195 145 76 183 159 79 26 236 99 71 327 225 229 167 129 58 27 221 105 65 200 150 81 159 128 55 28 217 96 63 187 138 70 162 125 55 29 193 75 43 180 132 64 132 105 37 30 473 237 761 172 131 61 152 116 48 31 220 168 111 --- --- --- 144 106 41 TOTAL 8288 9063.7 28320 131633 5491 3126 206 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 FEBRUAPY MARCH •1 129 105 37 68 82 15 100 93 25 2 224 165 107 71 87 17 75 62 14 3 146 110 43 65 89 16 77 60 12 4 174 173 84 59 88 14 68 58 11 5 143 116 45 59 85 14 66 56 10 6 141 110 38 57 85 13 91 120 38 7 128 111 38 55 84 12 208 143 85 8 115 110 34 56 83 13 220 149 95 9 110 109 32 55 84 12 107 82 24 10 113 108 33 54 84 12 81 62 14 11 109 102 30 55 82 12 68 56 10 12 101 99 27 56 80 12 65 52 9.1 13 97 90 24 54 80 12 69 59 11 14 92 89 22 62 80 13 61 55 9.1 15 94 91 23 76 83 17 58 48 7.5 16 87 83 19 75 81 16 58 50 7.8 17 86 82 19 60 80 13 58 52 8.1 18 84 82 19 57 68 10 219 160 148 19 88 89 21 73 70 14 105 92 31 20 82 80 18 107 82 24 69 23 4.3 21 80 79 17 75 62 13 60 72 12 22 75 77 16 66 58 10 59 71 11 23 76 76 16 62 50 8.4 57 69 11 24 77 79 21 66 55 9.8 54 68 9.9 25 73 82 16 66 55 9.8 51 66 9.1 26 85 87 20 68 59 11 51 66 9.1 27 80 88 19 229 230 171 53 65 9.3 28 74 84 17 166 240 91 60 71 12 29 69 83 15 --- --- --- 1410 649 3930 30 66 82 15 236 182 145 31 65 82 14 315 241 247 TOTAL 3163 899 2072 605.0 4329 4979.3 APRIL MAY JUNE 1 127 100 34 132 108 38 155 73 31 2 93 76 19 124 96 32 147 51 20 3 83 67 15 124 95 32 142 32 12 4 76 60 12 126 97 33 136 30 11 5 74 59 12 123 92 31 131 28 9.9 6 76 62 13 121 92 30 127 23 7.9 7 83 70 16 117 91 29 125 20 6.8 8 81 69 15 118 92 29 127 21 7.2 9 70 60 11 119 92 30 124 20 6.7 10 63 55 9 4 132 103 37 120 22 7.1 11 67 56 10 142 113 43 111 21 6.3 12 72 61 12 178 142 68 114 25 7.7 13 79 69 15 189 162 70 97 26 6.8 14 76 61 13 1070 569 2290 92 28 7.0 15 68 58 11 3280 1940 47500 88 29 6.9 16 111 89 27 1500 820 5020 87 30 7.0 17 103 80 22 5620 2480 77300 84 30 6.8 18 150 111 45 10400 2870 115000 83 35 7.8 19 109 85 25 3170 726 7350 78 40 8.4 20 84 69 16 518 344 481 75 42 8.5 21 119 97 40 374 249 251 76 45 9.2 22 131 102 47 303 212 173 71 55 11 23 1680 624 7160 262 183 129 70 60 11 24 1100 564 2110 237 170 109 69 67 12 25 864 569 3400 225 170 103 67 71 13 26 433 301 412 207 169 94 66 80 14 27 238 166 107 192 162 84 63 82 14 28 184 134 67 184 151 75 56 88 13 29 155 122 51 173 147 69 57 81 12 30 144 113 44 163 122 54 52 75 11 31 --- --- --- 157 99 42 --- --- --- TOTAL 6793 13790.4 29780 256626 2890 313.0 RIO GRANDE DE LOIZA BASIN 207 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 56 72 11 90 20 4.9 122 100 33 2 80 81 17 108 19 5.5 125 105 35 3 72 79 15 94 19 4.8 125 108 36 4 84 82 19 82 21 4.6 81 69 15 5 62 73 12 74 20 2.9 119 97 56 6 49 69 9.1 73 20 3.9 99 87 23 7 43 62 7.2 87 21 4.9 64 55 9.5 8 39 59 6.2 75 21 4.3 147 100 72 9 39 53 5.6 72 19 3.7 235 179 143 10 26 42 2.9 63 16 2.7 92 75 19 11 37 41 4.1 59 15 2.4 85 71 16 12 30 31 2.5 55 11 1.6 1270 787 15700 13 30 22 1.8 167 90 41 1970 1160 10400 14 23 21 1.3 130 71 25 707 420 850 15 270 203 331 99 50 13 492 320 432 16 531 411 1030 75 30 6.1 318 218 187 17 787 574 4320 62 22 3.7 264 190 135 18 224 162 98 62 28 4.7 237 174 111 19 139 110 41 69 32 6.0 220 164 97 20 375 258 352 54 41 6.0 209 159 90 21 189 120 61 63 46 7.8 197 148 79 22 135 80 29 61 54 8.9 188 140 71 23 117 70 22 51 58 8.0 193 140 73 24 180 114 64 48 56 7.3 312 259 286 25 155 92 39 56 57 8.6 1650 894 7530 26 217 128 88 79 67 14 465 317 424 27 141 82 31 502 312 643 368 259 301 28 147 83 33 525 343 629 392 266 319 29 153 80 33 167 130 59 305 211 174 30 116 61 19 112 90 27 261 188 132 31 97 39 10 98 81 21 --- --- --- TOTAL 4643 6715.7 3412 1585.3 11312 37848.5 YEAR 110493 467184.9 208 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 1 329 209 236 456 300 369 185 140 70 2 411 269 375 376 250 254 176 140 67 3 379 189 191 334 230 207 172 140 65 4 461 285 425 308 210 175 164 130 58 5 749 456 1020 314 220 187 202 150 82 6 8560 4270 171000 285 200 154 198 160 86 7 7600 2240 99600 258 180 125 180 130 63 8 2190 1050 8900 244 160 105 161 130 57 9 908 550 1350 238 160 103 164 125 55 10 672 370 671 226 155 95 165 125 56 11 530 348 498 221 160 95 167 120 54 12 447 320 386 335 317 548 193 120 63 13 396 290 310 447 306 435 180 150 73 14 363 260 255 457 306 508 157 120 51 15 338 250 228 1630 841 8320 153 120 50 16 323 245 214 581 400 627 146 120 47 17 398 312 402 352 255 316 135 120 44 18 675 507 1340 1270 746 4470 138 125 47 19 455 320 393 391 280 296 147 120 48 20 319 225 194 358 420 1780 153 120 51 21 297 220 176 893 396 806 136 100 37 22 289 272 215 310 220 184 133 105 38 23 2020 1340 15200 273 200 52 130 110 39 24 2760 1360 13700 253 170 116 140 110 42 25 1060 668 2930 234 165 104 130 110 39 26 1450 849 9960 223 160 96 132 100 36 27 807 470 1020 215 160 93 117 100 32 28 512 343 570 204 150 83 118 100 32 29 1260 701 3590 197 140 74 113 100 31 30 552 300 447 194 140 73 111 100 30 31 944 553 2040 --- --- --- 105 100 28 TOTAL 38454 337836 12077 20850 4701 1571 209 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 1 117 105 33 101 70 19 61 47 7.7 2 147 110 44 78 58 12 54 45 6.6 3 128 110 38 98 71 21 51 40 5.5 4 156 110 46 143 109 47 53 40 5.7 5 140 105 40 182 80 39 65 38 6.7 6 115 105 33 100 72 19 64 35 6.0 7 105 100 28 83 70 16 57 32 4.9 8 200 105 57 79 65 14 48 32 4.1 9 450 100 121 80 65 14 51 35 4.8 10 190 100 51 68 58 11 51 35 4.8 11 150 100 40 67 55 9.9 57 32 4.9 12 120 100 32 71 57 11 64 50 8.6 13 110 95 28 72 52 10 69 50 6.5 14 100 95 26 61 52 8.6 84 65 15 15 100 97 26 66 52 9.3 195 149 95 16 96 95 25 60 52 8.4 100 85 23 17 156 100 42 60 55 8.9 64 55 9.5 18 140 100 38 77 59 12 54 40 5.8 19 104 70 20 105 80 23 48 35 4.5 20 87 70 16 113 75 23 46 25 3.1 21 105 75 21 76 58 12 44 22 2.6 22 102 70 19 65 52 9.1 39 22 2.3 23 89 80 19 70 52 9.8 36 25 2.4 24 109 90 26 58 51 8.0 37 25 2.5 25 122 90 30 58 51 8.0 35 25 2.4 26 88 80 19 58 50 7.8 61 30 4.9 27 78 70 15 58 46 7.2 57 32 4.9 28 76 70 14 59 46 7.3 40 35 3.8 29 94 70 18 --- --- --- 480 253 483 30 102 80 22 180 125 61 31 95 80 21 108 90 26 TOTAL 3971 1008 2266 405.3 2453 828.5 APRIL MAY JUNE 1 142 110 42 278 213 247 222 150 90 2 97 75 20 144 110 43 177 140 67 3 110 98 48 102 90 25 203 130 71 4 238 195 287 98 85 22 160 100 43 5 226 184 146 95 75 19 132 90 32 6 198 105 56 160 129 74 118 80 25 7 98 52 14 545 605 3420 115 70 22 8 162 113 123 1980 1330 32000 135 90 33 9 193 149 106 630 558 2180 363 244 453 10 83 62 14 1060 504 3150 946 478 2820 11 61 55 9.1 1310 685 3380 203 150 82 12 52 50 7.0 308 205 170 160 120 52 13 48 48 6.2 2870 7470 290000 249 190 229 14 44 40 4.8 1320 671 3590 280 197 165 15 51 40 5.5 457 250 308 178 175 90 16 87 80 19 292 200 158 245 200 132 17 57 48 7.4 238 190 122 194 120 63 18 37 35 3.5 1940 1040 11600 168 120 54 19 33 31 2.8 482 225 293 222 180 108 20 93 82 52 296 200 160 174 115 54 21 62 60 10 266 200 144 147 105 42 22 39 40 4.2 289 256 260 132 100 36 23 42 38 4.3 206 140 78 126 100 34 24 33 35 3.1 180 120 58 126 95 32 25 32 35 2.7 160 115 50 108 90 26 26 28 31 2.3 150 110 45 103 89 25 27 39 35 3.7 138 110 41 126 90 31 28 124 90 30 132 100 36 121 90 29 29 1830 1640 22600 180 150 73 108 85 25 30 460 417 1130 163 120 53 100 82 22 31 --- --- --- 1040 714 7570 --- --- --- TOTAL 4799 24763.6 17509 359369 5841 4987 210 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 1 103 82 23 16 50 10 165 120 53 2 103 82 23 83 50 11 247 190 121 3 103 81 23 67 49 8.9 117 82 26 4 93 80 20 66 49 8.7 101 80 22 5 88 74 18 65 49 8.6 143 85 33 6 179 117 71 54 50 7.3 109 88 26 7 129 120 42 61 50 8.2 99 80 21 8 98 90 24 146 94 42 83 65 15 9 85 75 17 68 62 11 78 60 13 10 80 69 15 62 65 11 75 46 9.3 11 118 91 39 218 154 119 65 50 8.8 12 155 100 42 113 70 21 61 50 8.2 13 100 80 22 131 87 53 64 50 8.6 14 100 80 22 241 159 121 84 55 12 15 121 100 33 115 75 23 55 45 6.7 16 121 90 29 82 55 12 46 40 5.0 17 95 75 19 63 45 7.7 41 38 4.2 18 89 70 17 55 40 5.9 34 32 2.9 19 81 65 14 52 40 5.6 29 28 2.2 20 77 65 14 46 38 4.7 29 27 2.1 21 90 65 16 43 38 4.4 31 25 2.1 22 75 65 13 46 45 5.6 37 30 3.0 23 67 65 12 115 90 28 61 50 8.2 24 65 60 11 94 85 22 549 338 1130 25 69 59 11 81 60 13 350 250 236 26 66 52 9.3 58 50 7.8 211 170 97 27 65 50 8.8 49 43 5.7 130 90 32 28 76 50 10 136 85 31 89 70 17 29 66 50 8.9 2940 1320 18800 63 55 9.4 30 99 70 23 316 150 128 54 45 6.6 31 136 71 28 215 120 70 --- --- --- TOTAL 2992 678.0 5957 19615.1 3300 1947.3 YEAR 104320 773858.8 211 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS. PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 DAY MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2 3 4 5 60 55 49 49 44 35 32 29 29 27 5.7 4.8 3.8 3.8 3.2 76 86 86 85 164 43 48 48 48 89 8.8 11 11 11 48 119 121 156 155 150 65 62 80 80 70 21 20 34 33 28 6 7 8 9 10 44 49 50 185 169 27 30 30 89 92 3.2 2.3 4.1 68 47 232 239 330 198 191 129 128 176 109 87 109 89 186 61 42 124 189 132 140 152 65 90 50 50 80 22 46 18 19 33 11 12 13 14 15 89 96 64 82 85 55 45 40 45 45 13 12 6.9 10 10 412 2860 887 340 374 215 1080 434 125 197 325 14800 1470 126 237 333 220 169 215 160 150 115 90 115 85 181 68 41 67 37 16 17 18 19 20 319 159 105 80 64 158 84 57 45 37 220 36 16 9.7 6.4 655 954 446 248 198 336 454 226 110 80 1280 2500 329 74 43 185 139 131 112 116 95 80 70 65 68 47 30 25 20 21 21 22 23 24 25 59 176 99 142 311 34 93 54 76 160 5.4 44 14 29 134 177 170 158 140 167 65 52 45 38 60 31 24 19 14 27 121 100 91 86 108 70 60 52 48 55 23 16 13 11 16 26 27 28 29 30 31 219 162 120 88 86 83 114 86 65 49 48 46 67 38 21 12 11 10 167 269 159 150 143 --- 90 131 80 75 70 --- 41 118 34 30 27 --- 99 100 171 112 95 96 55 55 85 65 50 50 15 15 39 20 13 13 TOTAL 3442 871.3 10761 22125.8 4397 1005 212 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 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 84 48 11 174 110 52 10 38 7.2 2 80 45 9.7 118 70 22 68 38 7.0 3 78 42 8.8 100 60 16 84 45 10 4 81 50 11 88 52 12 173 80 37 5 223 112 83 88 48 11 205 100 55 6 179 104 62 95 45 12 97 55 14 7 336 160 178 85 45 10 76 40 8.2 8 232 114 103 74 45 9.0 63 35 6.0 9 206 123 81 71 42 8.1 59 32 5.1 10 119 65 21 69 38 7.1 58 32 5.0 11 109 55 16 732 340 1000 54 32 4.7 1? 100 50 13 163 140 62 132 70 25 13 89 45 11 638 293 1080 68 35 6.4 14 89 45 11 350 189 225 57 31 4.8 15 140 60 23 315 161 166 55 32 4.8 16 100 55 15 152 80 33 90 55 13 17 86 48 11 126 70 24 166 100 45 18 92 50 12 113 65 20 104 65 18 19 83 46 10 98 59 16 60 30 4.9 20 79 45 9.6 88 50 12 45 28 3.4 21 81 46 10 80 45 9.7 42 22 2.5 22 74 39 7.8 69 40 7.5 40 21 23 158 90 38 70 40 8.0 35 20 1.9 24 150 80 32 70 35 6.6 29 16 1.3 25 102 57 16 69 35 6.5 47 19 2.4 26 88 47 11 66 32 5.7 35 18 1.7 27 78 42 8.8 94 38 9.6 27 12 .87 28 72 40 7.8 80 40 8.6 24 12 .78 29 72 40 7.8 --- --- --- 24 12 .78 30 483 262 503 21 11 .62 31 202 108 66 20 11 .59 TOTAL 4145 1408.3 4335 2859.4 2128 300.24 RIO GRANDE DE LOIZA BASIN 213 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 DAY MEAN DISCHARGE (CfS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CfS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CfS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) APRIL MAY JUNE 1 2 3 4 5 20 19 22 21 40 11 10 11 11 25 .59 .51 .65 .62 2.7 24 43 55 76 52 12 20 30 45 35 .78 2.3 4.5 9.2 4.9 80 71 134 173 97 35 30 81 100 55 7.6 5.8 56 65 14 6 7 8 9 10 111 157 48 31 22 55 68 27 18 15 31 41 3.5 1.5 .89 208 71 34 31 29 104 40 20 18 17 75 7.7 1.8 1.5 1.3 82 95 85 100 80 48 50 25 40 40 11 13 5.7 11 8.6 11 12 13 14 15 37 595 366 315 207 20 284 203 156 110 2.0 1060 295 138 61 76 180 70 51 31 40 90 45 35 19 8.2 44 8.5 4.8 1.6 100 60 95 80 290 40 38 50 45 173 11 6.2 13 9.7 271 16 17 18 19 20 125 109 91 71 54 58 55 45 30 25 20 16 11 5.8 3.6 25 22 27 338 379 12 12 12 148 174 .81 .71 .87 489 203 270 95 100 270 2340 122 58 50 135 902 111 15 13 128 9670 21 22 23 24 25 45 42 41 37 28 22 22 21 20 17 2.7 2.5 2.3 2.0 1.3 1360 544 277 206 225 537 271 149 104 152 3890 471 133 63 177 3240 4000 690 2'1 319 1590 1050 160 160 140 32500 20600 166 166 121 26 27 28 29 30 31 28 24 24 24 23 --- 16 12 12 12 12 --- 1.2 .78 .78 .78 .75 --- 471 276 162 124 102 89 202 137 80 60 48 40 297 104 35 20 13 9 6 254 334 284 333 314 --- 120 180 140 180 160 --- 82 162 107 162 136 --- TOTAL 2777 1710.45 5658 6083 07 14849 64647.6 214 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1981 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 1 213 120 69 269 169 163 180 90 44 2 202 100 55 145 50 20 141 70 27 3 210 110 62 452 182 386 110 55 16 4 201 161 233 222 120 12 81 40 8.7 5 461 201 383 198 120 64 100 50 13 6 221 60 36 166 80 36 64 38 6.6 7 204 100 55 116 60 19 58 35 5.5 8 201 100 54 100 50 13 90 55 13 9 172 90 42 100 50 13 L.) 37 6.9 10 185 90 45 95 45 12 85 40 9.2 11 168 80 36 84 46 10 84 40 9.1 12 148 80 32 76 45 9.2 64 32 5.5 13 139 70 26 74 40 8.0 50 30 4.1 14 134 70 25 82 40 8.9 104 55 15 15 394 210 383 124 80 27 65 35 6.1 16 206 66 43 143 70 27 56 25 3.8 17 155 40 17 103 55 15 119 59 46 18 130 40 14 117 65 21 176 98 61 19 120 35 11 136 70 26 415 215 556 20 107 30 8 7 154 80 33 148 80 32 21 436 217 497 120 70 23 58 35 5 5 22 165 120 53 89 50 12 144 70 27 23 115 70 22 81 45 9.8 92 50 12 24 95 70 18 75 42 8.5 106 55 16 25 130 70 25 70 38 7.2 70 40 7.6 26 135 80 29 89 40 9.6 45 27 3.3 27 136 70 26 69 35 6.5 35 25 2.4 28 156 70 29 60 32 5.2 32 22 1.9 29 120 70 23 60 32 5.2 97 50 13 30 115 80 25 59 30 4.8 118 60 19 31 272 148 195 101 55 15 --- --- --- TOTAL 5852 2571.7 3829 1089.9 3056 996.2 215 RIO GRANDE DE 1011A BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO .APTEMBEE 1988 DAY MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2 3 4 5 131 73 95 119 83 62 35 50 60 40 22 6.9 13 19 9.0 103 91 79 101 250 28 27 27 48 119 1.8 6.6 5.8 13 134 439 636 357 326 296 195 321 180 160 160 231 982 174 141 128 6 7 8 9 10 64 57 44 47 48 30 29 25 25 25 5.2 4.5 3.0 3.2 3.2 354 165 115 93 86 114 80 65 55 45 231 36 20 14 10 394 7030 4480 776 540 200 2470 1220 200 200 213 134000 34300 419 292 11 12 13 14 15 29 25 24 136 250 20 15 12 73 122 1.6 1.0 .78 39 129 77 76 81 65 64 45 40 50 40 37 9.4 8.2 11 7.0 6.4 448 381 332 301 289 190 180 170 150 150 230 185 152 122 117 16 17 18 19 20 236 812 3160 711 234 129 363 1120 343 125 99 908 14400 1090 79 92 143 124 92 82 50 65 60 50 40 12 25 20 12 8.9 274 252 238 315 406 150 140 125 150 190 111 95 80 128 208 21 22 23 24 25 160 125 111 109 127 85 65 58 60 70 37 22 17 18 24 66 60 108 7860 1650 38 35 60 2590 799 6.8 5.7 17 71500 6780 376 587 322 281 270 190 220 170 140 140 193 349 148 106 102 26 27 28 29 30 31 159 162 259 189 123 104 85 85 131 80 30 28 36 37 71 41 10 7.9 2990 14500 2890 905 554 --- 1210 4880 1210 405 230 --- 21600 227000 12700 1120 344 --- 249 263 273 256 222 514 130 140 140 140 110 268 87 99 103 97 66 551 TOTAL 8006 17157.28 33916 341671.6 22123 174209 216 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 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 1 705 338 869 174 95 45 138 45 17 2 486 210 276 186 90 45 129 60 21 3 328 70 62 331 175 183 113 30 9.2 4 300 40 32 189 95 48 101 30 8.2 5 394 120 128 163 80 35 94 20 5.1 6 349 200 188 173 90 42 93 18 4.5 7 294 150 119 141 75 29 90 15 3.6 8 286 160 124 140 70 26 89 10 2.4 9 294 120 95 147 75 30 85 10 2.3 10 304 120 98 168 80 36 80 10 2.2 11 300 80 65 133 65 23 80 10 2.2 12 312 150 126 140 60 23 82 10 2.2 13 271 140 102 385 221 358 81 10 2.2 14 297 145 116 155 95 40 89 10 2.4 15 223 110 66 147 80 32 76 10 2.1 16 203 100 55 140 75 28 73 10 2.0 17 204 100 55 123 60 20 74 10 2.0 18 189 95 48 123 50 17 72 10 1.9 19 186 90 45 116 35 11 70 10 1.9 20 176 90 43 129 28 9.8 88 10 2.4 21 165 85 38 115 20 6.2 82 10 2.2 22 157 80 34 112 18 5.4 72 10 1.9 23 153 80 33 110 10 3.0 66 10 1.8 24 153 80 33 121 10 3.3 63 10 1.7 25 149 75 30 117 10 3.2 66 10 1.8 26 149 72 29 300 101 450 74 10 2.0 27 147 72 29 400 170 184 116 20 6.3 28 153 75 31 150 60 24 112 15 4.5 29 153 75 31 145 50 20 96 10 2.6 30 159 80 34 --- --- --- 75 10 2.0 31 140 75 28 70 10 1.9 TOTAL 7779 3062 4973 1779.9 2689 125.5 217 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DAY MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) MEAN DISCHARGE (CFS) MEAN CONCEN- TRATION (MG/L) SEDIMENT DISCHARGE (TONS/DAY) APRIL MAY JUNE 1 2 3 4 5 62 60 59 59 58 10 10 10 10 10 1.7 1.6 1.6 1.6 1.6 53 59 39 33 33 30 25 22 20 20 4.3 4.0 2.3 1.8 1.8 48 44 42 40 37 30 28 25 25 25 3.9 3.3 2.8 2.7 2.5 6 7 8 9 10 101 104 63 59 53 40 50 35 32 32 11 14 6.0 5.1 4.6 124 80 42 37 161 70 45 25 22 78 23 9.7 2.8 2.2 95 36 36 35 47 52 22 21 21 22 25 2.1 2.0 2.0 2.8 3.5 11 12 13 14 15 55 50 52 48 65 30 30 30 30 35 4.5 4.1 4.2 3.9 6.1 122 83 58 55 66 70 45 40 32 35 23 10 6.3 4.8 6.2 40 41 48 47 409 25 22 22 22 209 2.7 2.4 2.9 2.8 337 16 17 18 19 20 98 137 114 63 43 45 78 65 30 25 12 70 20 5.1 2.9 52 50 60 53 92 32 32 32 32 35 4.5 4.3 5.2 4.6 8.7 348 117 69 60 185 156 65 38 30 81 171 21 7.1 4.9 46 21 22 23 24 25 39 42 36 41 37 25 22 21 21 22 2.6 2.5 2.0 2.3 2.2 101 86 54 47 43 50 45 31 30 30 14 10 4.5 3.8 3.5 194 199 157 105 208 104 100 80 60 106 71 56 36 17 110 26 27 28 29 30 31 34 46 36 31 35 --- 20 20 20 20 20 --- 1.8 2.5 1.9 1.7 1.9 --- 42 46 43 53 75 75 30 29 28 35 40 40 3.4 3.6 3.3 5.0 8.1 8.1 185 151 81 80 198 --- 94 70 45 38 107 --- 64 29 9.8 8.2 94 --- TOTAL 1780 203.0 2017 291.8 3339 1120.4 218 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 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 1 657 346 930 129 65 23 194 95 50 2 4220 2860 66700 108 56 16 170 85 39 3 396 174 208 119 60 19 160 80 35 4 199 100 54 200 100 54 150 70 28 5 142 70 27 111 60 18 145 70 27 6 228 130 106 94 50 13 140 70 26 7 1210 489 2920 171 100 46 130 70 25 8 240 120 78 139 65 24 139 70 26 9 167 80 36 101 55 15 292 124 105 10 256 125 86 1090 716 7830 326 169 231 11 203 100 55 983 663 4260 3810 1360 26700 12 187 100 50 262 100 71 2560 940 8400 13 141 75 29 168 75 34 834 390 924 14 281 140 106 134 70 25 646 220 384 15 132 65 23 129 65 23 437 200 236 16 117 60 19 138 80 30 367 195 193 17 107 60 17 229 136 126 291 150 118 18 179 100 48 477 249 437 255 130 90 19 162 90 39 172 80 37 472 230 454 20 128 65 21 133 70 25 310 160 134 21 100 50 13 119 60 19 231 130 81 22 223 100 60 328 165 300 208 120 67 23 169 85 39 587 296 748 196 100 53 24 134 70 25 4290 1620 61500 192 100 52 25 111 65 19 2620 1180 18300 180 95 46 26 132 65 23 533 259 416 166 90 40 27 122 65 21 373 185 186 160 85 37 28 284 151 350 360 180 175 153 80 33 29 254 129 98 324 170 149 150 80 32 30 281 150 149 255 130 90 144 70 27 31 162 85 37 211 110 63 --- --- --- TOTAL 11324 72386 15087 95072 13608 38693 YEAR 126641 745771.48 219 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGUITAS 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 mi' (36.5 km'). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR 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) OCT 1987 09... 1140 27 492 7.50 29.0 31 3.2 41 63 26000 5900 DEC 14... 0935 41 500 6.60 25.0 3.8 3.7 45 44 K130000 76000 FEB 1988 12... 1225 31 557 7.10 27.0 2.8 35 K750000 70000 APR 8... 1130 22 583 7.60 28.0 9.3 4.8 61 50 5100 K1200 JUN 17... 1100 30 408 7.20 30.0 6.2 3.0 39 38 37000 K1800 AUG 29... 0845 33 522 7.30 28.0 3.0 3.5 44 28 410000 70000 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 9... 140 7 35 12 44 2 7.1 130 <0.5 48 41 DEC 14... 150 FEB 1988 12... 160 APR 08... 150 0 39 13 44 2 6.2 150 <0.5 58 45 JUN 17... 140 AUG 29... 150 35 38 13 35 1 6.3 170 41 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 09... 0.80 30 296 21 65 3.70 0.20 3.90 5.9 1.3 DEC 14... <1 0.83 0.17 1.00 4.8 0.5 FEB 1988 12... 0.88 0.22 1.10 8.0 1.4 APR 08... 0.50 30 331 19 16 0.87 0.23 1.10 8.0 5.0 JUN 17... 13 0.21 0.09 0.30 7.6 1.5 AUG 29... 0.20 30 267 24 6 0.49 0.11 0.60 5.0 1.6 K = non-ideal count -- RIO GRANDE DE LOIZA BASIN 220 50055250 RIO CAGUITAS AT HIGHWAY 30 AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER. MONIA + NITRO- NITRO- Pisus- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 09... 7.2 9.2 39 2.00 1 <100 20 60 31 490 DEC 14... 5.3 6.3 28 1.70 FEB 1988 12... 9.4 10 46 2.80 APR 8... 13 14 62 1.50 1 100 20 5 8 180 JUN 17... 9.1 9.4 42 2.80 AUG 29... 6.6 7.2 32 1.60 METHY- IRON, LEAD, NESE, MERCURY SILVER, ZINC, LENE TOTAL TOTAL TOTAL TOTAL SELE- TOTAL TOTAL MANGA- BLUE RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- RECOV- CYANIDE ACTIVE ERABLE ERABLE ERABLE ERABLE TOTAL FRABLE ERABLE TOTAL PHENOLS SUB- TOTAL STANCE DATE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L AS FE) AS PB) AS MN) AS HG) AS SE) AS AG) AS ZN) AS CN) (UG/L) (MG/L) OCT 1987 9... 1900 16 340 0.20 1 3 790 <0.010 6 0.75 DEC 14... - - FEB 1988 12... APR 08... 500 <5 210 0.20 <1 3 160 0.200 12 0.93 JUN _ - 17... - AUG 29... 221 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR WATER-QUALITY kECORDS LOCATION.--Lat 18°15'28", long 66'02'13", at bridge on Highway 1, about 2.5 mi (4.0 km) upstream from Rio Grande de Loiza, and 1.4 mi (2.3 km) north of Caguas plaza. DRAINAGE AREA.--5.4 mil (14.0 km2 ). PERIOD OF RECORD.--Water years 1958, 1962-66, 1973-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 09... 0840 7.4 390 7.60 25.0 69 4.2 50 66 K1600000 840000 DEC 14... 1145 7.8 420 7.20 25.0 1.2 6.2 75 50 360000 K120000 FEB 1988 16... 0900 7.1 378 6.90 22.0 2.2 8.4 95 27 K79000 28000 APR 22... 0925 4.1 425 7.90 25.0 3.1 7.5 90 <10 2300 KI900 JUN 17... 0905 3.3 436 7.50 25.5 32 5.1 62 <10 31000 23000 AUG 29... 1015 6.6 479 7.30 28.0 4.5 3.1 39 55 K3300000 410000 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- UNITY CHLO- NESS NONCARB CALCIUM SLUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 09... 110 0 26 10 24 1 6.2 120 <0.5 22 28 DEC 14... 140 FEB 1988 16... 120 APR 22... 160 22 38 15 24 0.9 3.0 130 <0.5 25 37 JUN 17... 130 AUG 29... 140 0 32 15 36 1 5.8 160 27 33 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) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 09... 0.30 22 210 4.2 71 0.94 0.06 1.00 6.20 DEC 14... <1 1.55 0.05 1.60 1.30 1.0 FEB 1988 16... 1 0.98 0.12 1.10 7.10 6.9 APR 22... 0.20 30 253 2.8 25 1.48 0.02 1.50 0.07 JUN 17... 13 1.07 0.03 1.10 0.20 0.40 AUG 29... 0.20 28 273 4.9 13 0.99 0.11 1.10 5.80 2.4 K = non-ideal count 222 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA t NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 09... <0.2 - 1.60 2 100 50 1 5 20 DEC 14... 2.3 3.9 17 0.97 FEB 1988 16... 14 15.1 45 1.60 - APR 22... <0.2 0.41 2 <100 <10 1 <1 20 JUN 17... 0.6 1.7 7.5 0.57 AUG 29... 8.2 9.3 41 2.80 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) OCT 1987 09... 4200 10 220 0.20 2 <1 50 <0.010 9 0.15 DEC 14... FEB 1988 16... APR 22... 420 <5 100 <0.10 ,1 <1 <10 <0.010 <1 0.05 JUN 17... AUG 29... RIO GRANDE DE LOIZA BASIN 223 50055650 QUEBRADA CAIMITO NEAR JUNCOS WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD. -- SUSPENDED-SEDIMENT DISCHARGE: January 1984 to September 1986. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended­ ' sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,040 mg/L few days; Minimum daily mean, 0 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 777 tons (705 tonnes) October 06, 1985; Minimum daily mean, 0.00 tons (0.00) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 247 (Sep. 20) 0 (several days) 26 (Sep. 20) 0.00 (several days) 1985 1,040 (May 18) 0 (several days) 702 (May 18) 0.00 (several days) 1986 1,040 (Oct. 06) 0 (several days) 777 (Oct. 06) 0.00 (several days) SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 .00 .00 0 .00 2 .00 .00 0 .00 3 .00 .00 0 .00 4 .00 .00 0 .00 5 .00 .00 0 .00 6 .00 --- --- .00 0 .00 7 .17 13 .02 .00 0 .00 8 .03 3 .00 .00 0 .00 9 .30 14 .03 .00 0 .00 10 .33 16 .01 .00 0 .00 11 .32 16 .01 .00 0 .00 12 .35 20 .02 .00 0 .00 13 1.5 50 .43 .00 0 .00 14 .59 33 .05 .00 0 .00 15 2.2 64 2.0 .00 0 .00 16 3.3 81 1.1 .00 0 .00 17 - .77 35 .07 .00 0 .00 18 .44 20 .02 .00 0 .00 19 .29 17 .01 .00 0 .00 20 .18 12 .01 .00 0 .00 21 .10 8 .00 .00 0 .00 22 .01 1 .00 .00 0 .00 23 .00 0 .00 .00 0 .00 24 --- .00 0 .00 .00 0 .00 25 .00 .00 0 .00 .00 0 .00 26 .00 0 .00 .00 0 .00 .00 0 .00 27 .00 0 .00 .00 0 .00 .00 0 .00 28 .00 0 .00 .00 0 .00 .00 0 .00 29 .00 0 .00 .00 0 .00 .00 0 .00 30 .00 0 .00 --- .00 0 .00 31 .00 0 .00 .00 0 .00 TOTAL 0.00 10.88 3.78 0.00 0.00 224 RIO GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 .00 0 .00 .00 0 .00 .09 7 .00 2 .00 0 .00 .00 0 .00 .07 4 .00 3 .00 0 .00 .00 0 .00 .03 2 .00 4 .00 0 .00 .00 0 .00 .00 0 .00 5 .00 0 .00 .00 0 .00 .00 0 .00 6 .00 0 .00 .00 0 .00 .00 0 .00 7 .00 0 .00 .00 0 .00 .32 14 .06 8 .00 0 .00 .00 0 .00 .36 20 .02 9 .00 0 .00 .00 0 .00 .19 14 .01 10 .00 0 .00 .00 0 .00 .65 31 .08 11 .00 0 .00 .00 0 .00 .49 10 .01 12 .00 0 .00 .00 0 .00 .28 2 .50 13 .00 0 .00 .00 0 .00 .17 2 .00 14 .00 0 .00 .00 0 .00 .11 2 .00 15 .00 0 .00 .00 0 .00 .00 0 .00 16 .00 0 .00 .00 0 .00 .00 0 .00 17 .00 0 .00 .00 0 .00 .00 0 .00 18 .00 0 .00 .00 0 .00 .00 0 .00 19 .00 0 .00 .00 0 .00 .00 0 .00 20 .00 0 .00 .00 0 .00 .00 0 .00 21 .00 0 .00 .00 0 .00 .00 0 .00 22 .00 0 .00 .00 0 .00 .00 0 .00 23 .00 0 .00 .00 0 .00 .00 0 .00 24 .00 0 .00 .00 0 .00 .00 0 .00 25 .00 0 .00 .00 0 .00 .00 0 .00 26 .00 0 .00 .00 0 .00 .00 0 .00 27 .01 12 .84 .00 0 .00 .00 0 .00 28 .09 7 .00 .41 21 .06 .00 0 .00 29 .00 0 .00 .05 2 .00 1.2 42 .99 30 .00 0 .00 .16 12 .01 .56 30 .05 31 --- --- --- 1.2 41 .72 --- --- --- TOTAL 0.10 0.84 1.82 0.79 4.52 1.72 JULY AUGUST SEPTEMBER 1 .17 18 .01 .44 12 .15 .00 0 .00 2 .07 5 .00 1.3 48 .22 .00 0 .00 3 .00 0 .00 .49 25 .03 .00 0 .00 4 .95 24 .59 .27 15 .01 .00 0 .00 5 1.9 57 .33 .16 10 .00 .13 7 .01 6 .94 38 .10 .01 1 .00 .15 10 .01 7 .48 23 .03 .00 0 .00 .00 0 .00 8 .23 13 .01 .00 0 .00 .00 0 .00 9 .11 7 .00 .00 0 .00 .00 0 .00 10 .01 1 .00 .00 0 .00 .00 0 .00 11 .00 0 .00 .00 0 .00 .00 0 .00 12 .00 0 .00 .00 0 .00 .34 16 .02 13 .00 0 .00 .00 0 .00 1.6 45 .95 14 .00 0 .00 .00 0 .00 1.4 38 .15 15 .00 0 .00 .00 0 .00 .77 32 .07 16 .00 0 .00 .00 0 .00 5.8 101 7.6 17 .00 0 .00 .00 0 .00 4.6 108 1.5 18 .00 0 .00 .00 0 .00 3.5 82 .82 19 .00 0 .00 .00 0 .00 2.6 47 .33 20 .00 0 .00 .00 0 .00 17 247 26 21 .00 0 .00 .00 0 .00 7.0 147 3.0 22 .00 0 .00 .00 0 .00 2.8 70 .53 23 .00 0 .00 .00 0 .00 1.4 45 .17 24 .00 0 .00 .00 0 .00 .94 40 .10 25 .00 0 .00 .00 0 .00 .72 30 .06 26 .00 0 .00 7.4 117 15 .58 28 .04 27 .00 0 .00 2.4 69 .77 .47 25 .03 28 .00 0 .00 .52 30 .04 .46 22 .03 29 1.4 28 .71 .27 15 .01 .41 22 .02 30 .56 25 .04 .13 10 .00 .43 20 .02 31 .15 10 .00 .09 7 .00 --- --- --- TOTAL 6.97 1.82 13.48 16.23 53.10 41.46 YEAR 90.87 66.64 225 RIO GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 .33 20 .02 .48 22 .03 .43 4 .20 2 .50 25 .03 1.0 44 .24 1.4 25 .22 3 1.1 41 .21 12 244 17 .54 6 .01 4 .51 25 .03 12 234 27 .42 2 .60 5 .44 20 .02 31 383 50 .38 2 .00 6 .45 25 .03 68 724 174 .33 2 .00 7 .33 20 .02 41 437 67 .33 2 .00 8 .29 18 .01 17 230 12 .33 2 .00 9 1.8 54 .72 12 220 8.5 .34 2 .00 10 1.6 55 .32 6.3 120 2.0 .33 2 .20 11 1.2 45 .15 3.4 80 .73 .31 2 .50 12 .86 35 .08 1.8 60 .29 .29 2 .80 13 .64 27 .05 1.1 50 .15 .25 3 .00 14 16 260 59 2.6 60 .42 .23 3 .00 15 2.8 80 .60 2.8 60 .45 .24 3 .20 16 1.1 40 .12 1.7 35 .16 .33 3 .20 17 .80 32 .07 1.7 12 .06 .46 3 .50 18 .64 27 .05 1.2 8 .03 .28 3 .50 19 .50 25 .03 1.0 7 .02 .27 4 .00 20 .46 25 .03 .91 7 .02 .25 4 .00 21 .45 25 .03 .79 6 .80 .23 4 .00 22 .37 20 .02 .71 6 .50 .24 4 .00 23 .32 18 .02 .77 6 .01 .24 4 .00 24 .26 17 .01 .72 5 .50 .30 4 .00 25 .53 25 .04 .70 5 .01 .34 4 .00 26 .33 20 .02 .62 5 .01 .29 4 .00 27 .28 18 .01 .52 5 .01 .38 4 .00 28 .38 20 .02 .48 4 .70 .41 4 .00 29 .49 27 .04 .42 4 .50 .29 3 .70 30 .32 20 .02 .41 4 .20 .38 3 .20 31 .25 17 .01 --- --- .40 3 .00 TOTAL 36.33 61.83 225.13 363.34 11.24 4.83 226 RIO GRANDE DE 1012A BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 .56 20 .03 .10 2 .20 .15 6 .00 2 2.1 65 2.4 .07 2 .00 .04 2 .00 3 .00 0 .00 .05 1 .90 .00 0 .00 4 .05 4 .50 .04 1 .30 .00 0 .00 5 .04 4 .30 .02 0 .90 .07 5 .00 6 .04 4 .00 .01 0 .50 .05 6 .00 7 .07 4 .00 .00 0 .00 .14 3 .00 8 .09 4 .00 .00 0 .00 .21 2 .00 9 .11 4 .00 .00 0 .00 .16 2 .00 10 .16 4 .00 .00 0 .00 .06 1 .00 11 .23 4 .00 .00 0 .00 .00 0 .00 12 .23 4 .00 .00 0 .00 .00 0 .00 13 .21 4 .00 .00 0 .00 .00 0 .00 14 .21 4 .00 .00 0 .00 .00 0 .00 15 .20 4 .00 .00 0 .00 .00 0 .00 16 .20 4 .00 .00 0 .00 .00 0 .00 17 .20 4 .10 .00 0 .00 .00 0 .00 18 .20 4 .10 .01 0 .00 .03 2 .00 19 .17 4 .00 .00 0 .00 .00 0 .00 20 .16 3 .90 .00 0 .00 .00 0 .00 21 .14 3 .60 .00 0 .00 .00 0 .00 22 .14 3 .40 .00 0 .00 .00 0 .00 23 .13 3 .20 .00 0 .00 .00 0 .00 24 .13 3 .20 .00 0 .00 .00 0 .00 25 .13 3 .00 .00 0 .00 .00 0 .00 26 .14 2 .90 .00 0 .00 .00 0 .00 27 .12 2 .80 .11 8 .00 .00 0 .00 28 .12 2 .60 .60 29 .22 .07 5 .00 29 .10 2 .50 --- --- --- 6.8 159 11 30 .09 2 .30 .41 20 .02 31 .08 2 .20 .25 12 .01 TOTAL 6.55 9.03 1.01 3.02 8.44 11.03 APRIL MAY JUNE 1 .14 10 .00 .06 5 .00 .25 1 .10 2 .10 8 .00 .12 20 .01 .22 1 .20 3 .06 5 .00 .10 25 .01 .20 1 .50 4 .03 2 .00 .08 4 .50 .19 1 .60 5 .00 0 .00 .07 4 .20 .17 2 .00 6 .00 0 .00 .07 4 .00 .15 1 .70 7 .01 0 .00 .05 3 .50 .13 1 .50 8 .00 0 .00 .04 3 ,00 .12 1 .30 9 .01 0 .00 .03 3 .00 .11 1 .00 10 .00 0 .00 .02 2 .00 .09 1 .00 11 .00 0 .00 .02 2 .00 .08 0 .80 12 .00 0 .00 .08 4 .00 .05 0 .50 13 .01 0 .00 .04 3 .00 .03 0 .20 14 .00 0 .00 .64 37 .39 .00 0 .00 15 .01 2 .00 57 766 372 .00 0 .00 16 .20 5 .00 15 99 7.4 .00 0 .00 17 .12 2 .00 28 310 75 .00 0 .00 18 .06 3 .00 129 1040 702 .00 0 .00 19 .02 2 .00 16 189 12 .00 0 .00 20 .00 0 .00 4.7 30 .38 .,.., 0 .00 21 .00 0 .00 2.0 12 .06 .00 0 .00 22 .00 0 .00 1.1 10 .03 .00 0 .00 23 5.2 100 9.3 .74 10 .02 .00 0 .00 24 .98 30 .08 .57 4 .01 .00 0 .00 25 .32 18 .02 .48 1 .90 .00 0 .00 26 .19 12 .01 .42 1 .80 .00 0 .00 27 .13 10 .00 .37 1 .20 .00 0 .00 28 .09 8 .00 .33 1 .00 .00 0 .00 29 .08 7 .00 .33 1 .00 .00 0 .00 30 .07 6 .00 .32 1 .00 .00 0 .00 31 --- --- --- .28 1 .10 --- --- TOTAL 7.83 9.41 258.06 1172.51 1.79 4.40 227 R10 GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 .00 0 .00 .01 1 .00 .00 0 .00 2 .00 0 .00 1.9 48 .70 .00 0 .00 3 .00 0 .00 1.8 42 .37 .00 0 .00 4 .00 0 .00 .00 0 .00 .00 0 .00 5 .00 0 .00 .00 0 .00 .00 0 .00 6 .00 0 .00 .00 0 .00 .,,O 0 .00 7 .00 0 .00 .00 0 .00 .00 0 .00 8 .00 0 .00 .00 0 .00 .00 0 .00 9 .00 0 .00 .00 0 .00 .86 40 .09 10 .00 0 .00 .00 0 .00 1.3 48 .17 11 .00 0 .00 .00 0 .00 1.1 40 .12 12 .00 0 .00 .00 0 .00 4.2 82 2.6 13 .00 0 .00 .00 0 .00 18 295 22 14 .00 0 .00 .00 0 .00 5.8 105 1.7 15 .28 11 .03 .00 0 .00 2.4 60 .39 16 1.2 46 .38 .00 0 .00 1.3 50 .18 17 1.4 54 .41 .00 0 .00 .70 35 .07 18 .24 14 .01 .00 0 .00 .39 20 .02 19 .04 2 .00 .00 0 .00 .27 15 .01 20 2.7 76 1.8 .00 0 .00 .19 10 .01 21 .87 25 .06 .00 0 .00 .15 10 .00 22 .32 20 .02 .00 0 .00 .10 10 .00 23 .27 19 .01 .00 0 .00 .29 16 .03 24 .29 18 .01 .00 0 .00 .75 34 .09 25 .18 15 .01 .00 0 .00 6.1 141 3.8 26 .11 10 .00 .00 0 .00 1.9 56 .30 27 .00 0 .00 .00 0 .00 1.0 40 .11 28 .05 5 .00 .00 0 .00 1.1 41 .13 29 .04 4 .00 .00 0 .00 .76 32 .07 30 .00 0 .00 .00 0 .00 .62 30 .05 31 .00 0 .00 .00 0 .00 --- --- --- TOTAL 7.99 2.74 3.71 1.07 49.28 31.94 YEAR 617.36 1675.15 228 RIO GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 3.6 97 3.4 3.3 70 .62 .51 18 .02 2 21 292 36 2.5 60 .41 .46 15 .02 3 4.3 48 .63 1.9 50 .26 .40 15 .02 4 8.0 113 21 1.5 50 .20 .37 15 .01 5 7.3 174 4.8 1.3 45 .16 .61 18 .03 6 136 1040 777 1.1 45 .13 .51 18 .02 7 71 553 207 .99 40 .11 .36 14 .01 8 14 261 13 .80 35 .08 .30 10 .01 9 5.8 120 1.9 .76 30 .06 .28 8 .01 10 3.3 75 .67 .68 25 .05 .24 6 .00 11 2.3 58 .36 .82 30 .07 .22 5 .00 12 1.7 52 .24 2.4 65 .57 .22 5 .00 13 1.0 48 .13 4.4 140 13 .22 5 .00 14 .70 40 .08 1.6 60 .26 .23 8 .00 15 .50 30 .04 30 405 66 .29 8 .01 16 .35 25 .02 11 209 7.7 .24 8 .01 17 .33 22 .02 3.7 90 .90 .26 8 .01 18 11 218 52 3.7 70 .70 .26 8 .01 19 3.5 80 .76 2.1 45 .26 .27 7 .80 20 1.6 50 .22 1.4 40 .15 .23 7 .20 21 .94 40 .10 2.2 35 .21 .22 6 .50 22 .65 35 .06 1.1 20 .06 .24 6 .00 23 8.3 150 2.8 .91 35 .09 .22 5 .00 24 23 334 33 1.0 35 .09 .22 5 .00 25 13 221 9.0 .75 30 .06 .35 4 .80 26 5.3 110 1.6 .64 28 .05 .26 4 .50 27 3.4 80 .73 .60 25 .04 .22 4 .10 28 2.8 70 .53 .51 22 .03 .25 3 .90 29 7.0 100 1.4 .51 22 .03 .30 3 .50 30 4.2 90 1.0 .52 20 .03 .31 3 .00 31 4.4 100 1.2 --- --- .31 2 .70 TOTAL 370.27 1170.69 84.69 92.38 9.38 5.19 229 RIO GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 .37 2 .40 .19 2 .10 .13 6 .80 2 .35 2 .00 .24 2 .10 .12 7 .00 3 .31 2 .00 .48 18 .02 .12 7 .00 4 .36 2 .00 .70 25 .05 .14 7 .00 5 .30 2 .00 .32 12 .01 .12 7 .00 6 .27 2 .00 .19 8 .00 .14 7 .00 7 .27 2 .00 .18 8 .00 .13 7 .00 8 .27 2 .00 .19 7 .50 .11 7 .00 9 1.4 2 .01 .18 7 .20 .12 7 .00 10 .43 2 .00 .18 7 .10 .12 7 .00 11 .27 2 .00 .21 7 .00 .16 7 .00 12 .24 2 .00 .20 6 .80 .13 7 .20 13 .25 2 .00 .18 6 .40 .17 8 .00 14 .24 2 .00 .16 6 .00 .32 10 .03 15 .20 2 .00 .12 6 .00 .41 19 .07 16 .24 2 .00 .12 6 .00 .09 7 .00 17 .27 2 .00 .14 6 .00 .08 6 .00 18 .25 2 .00 .12 6 .00 .08 6 .00 19 .24 2 .00 .12 6 .00 .'1 6 .00 20 .22 2 .00 .13 6 .00 .09 6 .00 21 .25 2 .00 .10 6 .00 .08 6 .00 22 .23 2 .00 .12 6 .00 .07 6 .00 23 .28 2 .00 .13 6 .00 .09 6 .00 24 .39 2 .00 .14 6 .10 .09 6 .00 25 .30 2 .00 .17 6 .10 .12 6 .00 26 .26 2 .00 .15 6 .10 .14 6 .10 27 .24 2 .00 .13 6 .10 .13 6 .20 28 .22 2 .00 .13 6 .20 .10 6 .20 29 .21 2 .20 --- .59 13 .05 30 .25 2 .20 .14 11 .00 31 .21 2 .20 .21 9 .01 TOTAL 9.59 1.01 5.42 2.88 4.62 1.66 APRIL MAY JUNE 1 .17 9 .00 .09 8 .00 2.4 55 .36 2 .13 8 .50 .06 3 .00 1.6 45 .19 3 .11 8 .00 .05 3 .00 1.1 40 .12 4 .17 10 .00 .03 3 .00 .55 30 .04 5 1.6 46 .31 .03 3 .00 .45 20 .02 6 .53 25 .04 .04 3 .00 .27 18 .01 7 .17 11 .01 .38 20 .02 .25 18 .01 8 .15 10 .00 .35 20 .02 .20 17 .01 9 .14 10 .00 11 661 423 1.2 40 .13 10 .10 8 .00 5.8 132 3.1 .25 15 .01 11 .09 7 .00 6.7 123 2.4 .15 10 .00 12 .09 7 .00 2.4 63 .43 .12 9 .50 13 .08 6 .00 32 461 153 .12 9 .00 14 .07 5 .00 23 183 27 .14 9 .00 15 .06 5 .00 4.6 40 .50 .14 9 .00 16 .05 5 .00 1.7 40 .18 .19 9 .00 17 .05 5 .00 .70 30 .06 .15 8 .80 18 .04 4 .20 1.0 30 .08 .12 8 .20 19 .03 4 .20 .51 22 .03 .11 7 .80 20 .04 4 .00 .27 18 .01 .09 7 .00 21 .04 4 .00 .27 16 .01 .07 5 .50 22 .03 4 .00 .25 15 .01 .06 5 .00 23 .03 4 .00 .18 14 .01 .05 4 .20 24 .03 4 .00 .14 12 .00 .04 3 .50 25 .02 4 .00 .11 12 .00 .03 2 .50 26 .02 4 .00 .11 11 .00 .03 4 .00 27 .10 10 .00 .10 10 .00 .08 6 .00 28 .20 8 .00 .09 10 .00 .03 3 .20 29 3.0 75 5.2 .09 9 .00 .02 3 .00 30 1.0 40 .11 .09 8 .00 .01 2 .50 31 --- --- 6.1 113 3.0 --- --- --- TOTAL 8.34 6.57 98.24 612.86 10.02 5.60 230 RIO GRANDE DE LOIZA BASIN 50055650 QUEBRADA CAIMITO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 .00 0 .00 .15 10 .00 2.9 60 .47 2 .01 2 .00 .05 4 .50 1.9 50 .26 3 .02 2 .00 .04 2 .00 1.! 40 .12 4 .01 2 .00 .02 1 .00 ./5 35 .07 5 .00 0 .00 .00 0 .00 .58 25 .04 6 .50 37 .43 .00 0 .00 1.5 50 .20 7 .13 10 .00 .01 2 .00 .67 30 .05 8 .04 3 .00 .01 2 .00 .28 18 .01 9 .02 2 .00 .00 0 .00 .15 10 .00 10 .00 0 .00 .00 0 .00 .11 7 .50 11 .01 2 .00 .34 50 .05 .09 6 .50 12 .04 2 .00 .03 4 .00 .07 6 .00 13 .01 2 .00 .01 2 .00 .71 25 .12 14 .02 3 .00 .03 3 .00 .25 18 .01 15 .11 5 .00 .00 0 .00 .07 4 .50 16 .03 3 .00 .30 25 .02 .04 3 .00 17 .01 1 .00 .02 2 .00 ' .00 0 .00 18 .00 0 .00 .01 1 .00 .00 0 .00 19 .00 0 .00 .00 0 .00 .00 0 .00 20 .00 0 .00 .00 0 .00 .00 0 .00 21 .00 0 .00 .00 0 .00 .00 0 .00 22 .00 0 .00 .00 0 .00 .00 0 .00 23 .00 0 .00 .00 0 .00 .05 7 .00 24 .00 0 .00 .00 0 .00 .02 3 .00 25 .00 0 .00 .00 0 .00 .03 5 .00 26 .00 0 .00 .00 0 .00 .01 2 .00 27 .00 0 .00 .00 0 .00 .00 0 .00 28 .00 0 .00 7.4 84 26 .00 0 .00 29 .11 8 .50 28 423 149 .00 0 .00 30 5.0 173 21 4.8 120 1.6 .00 0 .00 31 1.1 50 .15 5.0 100 1.4 --- --- TOTAL 7.17 22.08 46.22 178.57 11.28 2.85 YEAR 665.24 2102.34 231 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 Victor, 1.7 mi (2.7 km) upstream from Rio Gurabo and 1.0 mi (1.6 km) south of Juncos. DRAINAGE AREA.--16.4 mi' (42.5 km 2 ). 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 fair except those for estimated daily discharges, which are poor. Minor diversion from public water supply tank, 0.5 mi upstream, during low flow. AVERAGE DISCHARGE.--17 years (1972-88), 54.5 ft'/s (1.543 m'/s), 45.13 in/yr (1,150 mm/yr), 39,480 acre-ft/yr (48.7 NIP/yr); median of yearly mean discharges, 52 ft)/s (1.47 m'/s), 37,700 acre-ft/yr (46 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 40,000 ft'/s (1,130 m'/s), Dec. 8, 1987, gage height, 25.63 ft (7.812 m), from floodmark and rating curve extended above 100 ft'/s (2.83 m'/s) on basis of slope-area measurement and step-backwater analysis; minimum discharge, 1.4 ft'is (0.040 m'/s), Apr. 21, 1988, result of diversion. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges (no stages were recorded) of major floods are as follows: Sept. 6, 1960, 37,100 ft'/s (1,050 m'/s); Oct. 9, 1970, 18,200 ft'/s (515 m'/s). EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 3,400 ft'is (96.3 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m'/s) (ft) (m) Date Time (W/s) (e/s) (ft) (m) Oct.18 1830 12,200 346 14.55 4.435 Dec. 8 unknowm *40,000 1,130 *25.63 7.812 Nov.24 1445 6,530 185 10.57 3.222 July 7 0045 3,490 98.8 7.74 2.359 Nov.27 unknowm 27,500 779 21.99 6.703 Aug. 24 1500 11,300 320 13.98 4.261 Dec. 7 1900 34,600 980 24.17 7.367 Sept.11 1145 4,270 121 8.48 2.585 Minimum discharge, 1.4 ft'/s (0.040 m'/s), Apr. 21. result of diversion. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 20 94 44 22 29 6.1 7.8 9.3 175 18 29 2 7.8 18 143 41 22 e28 6.1 5.5 7.7 221 17 25 3 15 17 78 37 26 e15 5.7 4.2 7.0 36 20 23 4 14 54 76 36 20 e13 5.9 3.8 6.9 21 24 22 5 10 53 69 51 23 e13 6.5 4.4 5.9 18 17 21 6 14 53 206 57 19 e12 12 151 5.2 98 15 20 7 14 39 5690 46 17 el2 14 28 4.7 613 71 21 8 8.5 26 e9100 44 21 e12 8.4 12 4.8 44 35 20 9 9.0 23 e150 45 27 13 7.3 8.5 11 30 25 77 10 11 21 e120 47 23 11 6.9 31 14 42 78 50 11 7.0 19 elOO 52 25 11 6.5 27 6.1 46 130 783 12 6.4 38 e90 49 22 10 5.9 16 6.5 31 45 300 13 6.0 24 e85 44 50 11 5.7 15 17 25 27 100 14 278 19 e78 42 22 12 5.2 17 11 174 21 105 15 75 18 e73 36 22 10 8.7 20 109 -32 23 68 16 52 18 e68 33 20 9.6 8.8 14 108 24 23 54 17 371 23 e66 34 18 10 5.6 14 32 24 28 42 18 1260 19 59 30 17 11 11 13 15 32 27 37 19 140 17 57 29 16 9.3 7.1 13 12 40 19 213 20 54 18 62 27 17 12 5.3 36 157 24 18 68 21 38 15 60 26 15 11 5.7 46 107 19 17 43 22 28 14 80 23 15 11 4.2 15 51 72 65 38 23 26 38 61 23 15 11 5.1 11 27 34 48 35 24 21 2480 52 22 16 9.6 5.4 10 32 22 1260 31 25 27 366 47 22 16 12 4.3 8.0 19 24 259 29 26 26 673 50 21 31 11 4.1 8.6 18 24 59 27 27 29 e9000 54 22 53 13 4.2 11 16 20 57 26 28 34 422 51 22 16 9.2 4.4 5.6 21 34 48 25 29 26 165 45 22 14 7.8 4.4 11 16 31 40 25 30 21 111 40 20 --- 8.1 6.3 31 15 25 37 23 31 24 --- 44 20 6.6 --- 25 --- 20 29 --- TOTAL 2665.7 13821 17048 1067 640 374.2 196.8 623.4 872.1 2075 2600 2380 MEAN 86.0 461 550 34.4 22.1 12.1 6.56 20.1 29.1 66.9 83.9 79.3 MAX 1260 9000 9100 57 53 29 14 151 157 613 1260 783 MIN 6.0 14 40 20 14 6.6 4.1 3.8 4.7 18 15 20 AC-FT 5290 27410 33810 2120 1270 742 390 1240 1730 4120 5160 4720 CFSM 5.24 28.1 33.5 2.10 1.35 .74 .40 1.23 1.77 4.08 5.11 4.84 IN. 6.05 31.35 38.67 2.42 1.45 .85 .45 1.41 1.98 4.71 5.90 5.40 WTR YR 1988 TOTAL 44363.2 MEAN 121 MAX 9100 MIN 3.8 AC-FT 87990 CFSM 7.39 IN. 100.63 e Estimated 232 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 13 1305 5.6 235 28.0 MAR, 01 1259 16.6 257 25.0 NOV, 16 1223 18.6 240 26.5 APR, 07 1226 11.2 225 27.0 DEC, 09 -- 158 -- 24.5 MAY, 04 1317 4.34 265 29.0 JAN, 08 1100 45.1 235 23.5 JUN. 01 0918 10.8 228 25.0 FEB, 03 1401 28.6 240 26.0 JUL, 13 1342 22 250 29.5 233 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1986. INSTRUMENTATION.-- USD-49 and automatic sediment sampler. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,600 mg/L October 06, 1985; Minimum daily mean, 1 mg/1 several days. SEDIMENT LOADS: Maximum daily mean, 46,300 tons (42,000 tonnes) May 18. 1985; Minimum daily mean, 0.01 tons (0.01) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 741 (Jun. 10) 1 (several days) 4,990 (Nov. 05) 0.01 (several days) 1985 1,580 (May 18) 2 (several days) 46,300 (May 18) 0.05 (several days) 1986 1,600 (Oct. 06) 5 (several days) 25,100 (May 13) 0.10 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 27 23 2.4 24 20 1.3 17 7 .32 2 21 15 .85 18 13 .63 196 165 314 3 24 15 .97 20 12 .65 32 20 1.7 4 20 12 .65 724 494 1640 23 13 .81 5 19 12 .62 775 556 3370 22 11 .65 6 18 12 .58 469 241 312 29 11 .86 7 19 12 .62 61 50 8.2 22 11 .65 8 20 12 .65 41 30 3.3 22 10 .59 9 40 24 4.7 33 20 1.8 20 10 .54 10 20 12 .65 28 15 1.1 20 10 .54 11 17 10 .46 25 15 1.0 20 11 .59 12 26 17 1.2 24 14 .91 19 10 .51 13 20 18 .97 23 14 .87 18 10 .49 14 17 15 .69 22 13 .77 17 10 .46 15 19 17 .87 21 13 .74 18 10 .49 16 21 15 .85 22 12 .71 18 10 .49 17 17 10 .46 21 11 .62 18 9 ,44 18 32 31 16 20 10 .54 18 9 .44 19 39 39 10 19 10 .51 17 9 .41 20 19 10 .51 19 9 .46 16 9 .39 21 17 10 .46 18 8 .39 16 9 .39 22 16 10 .43 17 6 .28 18 10 .49 23 15 10 .41 18 10 .49 18 10 .49 24 14 9 .34 17 11 .50 16 10 .43 25 14 9 .34 17 11 .50 15 10 .41 26 44 34 7.7 16 10 .43 16 10 .43 27 17 11 .50 16 9 .39 19 10 .51 28 15 10 .41 15 8 .32 16 10 .43 29 20 12 .65 16 8 .35 17 10 .46 30 23 15 .93 17 7 .32 20 9 ,49 31 27 18 1.3 --- --- --- 19 9 .46 TOTAL 677 58.17 2576 5350.08 772 330.36 234 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 9 .41 12 2 .06 14 18 .68 2 15 9 .36 12 2 .06 13 18 .63 3 14 8 .30 12 2 .06 12 16 .52 4 14 8 .30 14 3 .11 11 14 .42 5 14 8 .30 12 2 .06 12 11 .36 6 13 8 .28 13 4 .14 12 11 .36 7 13 7 .25 14 3 .11 12 10 .32 8 13 6 .21 13 2 .07 12 10 .32 9 14 5 .19 13 2 .07 12 8 .26 10 16 5 .22 17 5 .23 12 6 .19 11 14 5 .19 22 25 1.5 11 4 .12 12 13 5 .18 18 17 .83 11 3 .09 13 27 21 4.5 134 126 174 11 1 .03 14 30 25 2.0 35 52 4.9 11 2 .06 15 17 10 .46 205 153 507 11 2 .06 16 16 10 .43 603 413 1510 11 3 .09 17 15 10 .41 41 50 5.5 11 3 .09 18 15 8 .32 26 33 2.3 11 4 .12 19 14 5 .19 21 31 1.8 10 4 .11 20 51 51 15 19 31 1.6 10 3 .08 21 20 12 .65 17 31 1.4 10 3 .08 22 17 10 .46 16 31 1.3 10 4 .11 23 14 10 .38 15 30 1.2 10 3 .08 24 13 10 .35 15 30 1.2 10 4 .11 25 18 9 .44 14 26 .98 10 4 .11 26 14 5 .19 14 24 .91 10 5 .14 27 14 4 .15 15 22 .89 9.5 5 .13 28 14 4 .15 15 22 .89 9.0 5 .12 29 13 3 .11 13 20 .70 9.0 5 .12 30 13 3 .11 --- --- --- 8.5 4 .09 31 12 2 .06 8.5 4 .09 TOTAL 517 29.55 1390 2219.87 334.5 6.09 APRIL MAY JUNE 1 8.5 4 .09 5.8 1 .02 35 20 1.9 2 8.5 4 .09 5.7 1 .02 26 15 1.1 3 8.5 4 .09 5.7 1 .02 18 10 .49 4 8.5 4 .09 7.1 1 .02 46 45 11 5 8.5 4 .09 5.8 1 .02 21 14 .79 6 8.5 4 .09 5.3 1 .01 128 146 92 7 9.0 5 .12 5.6 1 .02 209 222 270 8 8.2 4 .09 5.8 1 .02 83 70 16 9 7.1 4 .08 6.2 1 .02 43 50 5.8 10 7.2 3 .06 6.3 1 .02 983 741 4990 11 7.8 2 .04 4.2 1 .01 170 181 12" 12 7.1 2 .04 5.0 1 .01 66 45 4.5 13 7.3 2 .04 19 1 .05 241 236 626 14 6.6 2 .04 11 2 .06 87 55 13 15 6.4 2 .03 7.4 1 .02 48 35 4.5 16 6.1 2 .03 7.2 1 .02 37 28 2.8 17 6.8 2 .04 6.6 1 .02 33 45 4.0 18 6.5 2 .04 6.0 1 .02 30 20 1.6 19 6.6 2 .04 5.5 2 .03 43 35 4.1 20 9.1 5 .12 5.7 2 .03 34 28 2.6 21 7.4 5 .10 6.6 2 .04 26 18 1.3 22 8.7 4 .09 6.4 2 .03 23 12 .75 23 6.9 2 .04 15 2 .08 20 12 .65 24 6.6 2 .04 9.0 2 .05 19 10 .51 25 6.2 1 .02 17 20 .92 19 10 .51 26 6.0 1 .02 55 61 23 18 10 .49 27 12 1 .03 16 10 .43 17 10 .46 28 14 1 .04 39 33 5.9 17 10 .46 29 6.6 1 .02 21 10 .57 25 2.2 30 6.3 1 .02 296 308 1030 20 12 .65 31 --- --- 75 71 21 --- --- TOTAL 233.5 1.77 692.9 1082.48 2592 6182.16 23.5 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 19 10 .51 20 10 .54 14 10 .38 2 30 20 1.6 72 64 18 16 10 .43 3 17 10 .46 23 12 .75 21 10 .57 4 18 10 .49 41 37 7.3 25 10 .68 5 68 69 20 25 18 1.2 55 15 2.2 6 24 15 .97 19 10 .51 70 35 6.6 7 19 10 .51 17 10 .46 28 35 2.6 8 17 10 .46 15 10 .41 18 10 .49 9 15 9 .36 16 10 .43 16 10 .43 10 27 15 1.1 15 10 .41 18 10 .49 11 21 15 .85 14 10 .38 28 10 .76 12 15 10 .41 14 10 .38 40 33 6.1 13 14 10 .38 13 9 .32 334 310 1460 14 24 25 1.6 13 8 .28 686 593 2940 15 25 20 1.4 13 8 .28 80 70 15 16 15 10 .41 13 8 .28 195 173 37^, 17 14 10 .38 13 8 .28 333 353 696 18 13 9 .32 13 8 .28 323 423 822 19 12 8 .26 12 8 .26 138 120 45 20 14 7 .26 12 8 .26 414 371 855 21 23 20 1.2 12 8 .26 151 150 61 22 21 15 .85 13 8 .28 81 70 15 23 22 10 .59 12 7 .23 65 55 9.7 24 15 10 .41 12 7 .23 55 45 6.7 25 13 10 .35 12 6 .19 55 40 5.9 26 12 10 .32 230 77 31 47 35 4.4 27 14 10 .38 300 119 59 53 30 4.3 28 14 10 .38 60 50 8.1 50 30 4.1 29 54 45 23 40 30 3.2 43 30 3.5 30 60 64 17 60 25 4.1 51 30 4.1 31 22 13 .77 20 18 .97 --- --- --- TOTAL 691 77.98 1164 140.57 3503 7346.43 YEAR 15142.9 22825.51 238 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 44 35 4.2 93 100 43 30 18 1.5 2 43 25 2.9 325 250 558 45 44 7.0 3 65 53 9.6 1350 460 811 41 48 5.3 4 46 35 4.3 330 200 203 31 50 4.2 5 42 32 3.6 860 605 1830 29 50 3.9 6 59 45 8.2 920 455 929 28 46 3.5 7 68 65 14 470 180 228 26 42 2.9 8 53 45 6.4 170 65 30 25 40 2.7 9 138 116 71 116 40 13 30 45 3.6 10 121 119 50 112 39 12 28 45 3.4 11 80 62 12 85 39 9.0 205 184 608 12 70 55 10 74 37 7.4 216 345 786 13 96 87 30 67 35 6.3 59 90 14 14 85 103 30 93 85 40 37 60 6.0 15 80 75 16 93 111 32 32 60 5.2 16 62 65 11 60 85 14 28 59 4.5 17 53 40 5.4 57 80 12 30 58 4.7 18 45 30 3.6 54 75 11 73 57 3.5 19 41 28 3.1 47 70 8.9 .4 55 3.6 20 51 35 4.8 43 68 7.9 23 40 2.5 21 40 25 2.7 40 62 6.7 22 35 2.1 22 38 22 2.3 39 60 6.3 21 35 2.0 23 36 20 1.9 46 60 7.5 21 33 1.9 24 34 20 1.8 37 50 5.0 24 40 2.6 25 61 93 21 35 52 4.9 31 45 3.8 26 44 86 10 36 50 4.9 26 55 3.9 27 38 50 5.1 35 51 4.8 24 55 3.6 28 44 55 6.5 33 58 5.2 27 47 3.4 29 35 25 2.4 35 60 5.7 21 35 2.0 30 31 22 1.8 33 20 1.8 26 35 2.5 31 32 40 3.5 --- --- --- 21 30 1.7 TOTAL 1775 359.1 5788 4858.3 1254 1505.5 237 RIO GRANDE OE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS. PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 35 44 9.5 17 25 1.1 18 45 2.2 2 46 55 6.8 14 21 .79 12 42 1.4 3 25 40 2.7 13 21 .74 13 40 1.4 4 31 47 3.9 13 22 .77 11 40 1.2 5 26 30 2.1 12 22 .71 13 30 1.1 6 29 42 3.3 12 22 .71 16 20 .86 7 22 42 2.5 11 20 .59 52 71 16 8 21 41 2.3 11 19 .56 36 20 1.9 9 19 45 2.3 11 19 .56 17 20 .92 10 20 50 2.7 11 18 .53 14 12 .45 11 20 50 2.7 12 15 .49 13 11 .39 12 18 57 2.8 11 15 .45 13 10 .35 13 18 56 2.7 10 17 .46 12 9 .29 14 17 56 2.6 12 15 .49 11 9 .27 15 16 58 2.5 13 15 .53 9.8 8 .21 16 16 60 2.6 12 15 .49 10 9 .24 17 16 60 2.6 12 14 .45 11 9 .27 18 16 50 2.? 13 12 .42 26 24 1.7 19 16 48 2.1 13 15 .53 13 15 .53 20 16 48 2.1 21 20 1.1 11 6 .18 21 16 48 2.1 13 9 .32 10 5 .14 22 16 48 2.1 12 8 .26 10 5 .14 23 15 49 2.0 12 9 .29 10 4 .11 24 15 50 2.0 12 9 .29 9 1 2 .05 25 15 49 2.0 12 10 .32 9.1 2 .05 26 18 45 2.2 11 10 .30 11 5 .15 27 16 40 1.7 22 17 1.4 10 6 .16 28 16 38 1.6 44 64 15 10 6 .16 29 15 35 1.4 --- --- --- 509 490 2160 30 14 30 1.1 53 42 11 31 14 28 1.1 48 65 8.4 TOTAL 613 82.3 392 30.65 1021.2 2214.22 APRIL MAY JUNE 1 23 18 1.1 15 10 .41 24 7 .45 2 18 10 .49 14 10 .38 23 8 .50 3 14 9 .34 15 10 .41 21 8 .45 4 13 8 .28 14 10 .38 20 8 .43 5 12 7 .23 15 10 .41 21 8 .45 6 13 7 .25 11 13 .60 20 5 .27 7 16 5 .22 13 9 .32 20 5 .27 8 14 5 .19 13 9 .32 25 8 .54 9 14 5 .19 15 10 .41 21 10 .57 10 11 10 .30 13 10 .35 20 12 .65 11 25 30 2.0 15 10 .41 18 11 .53 12 26 20 1.4 30 20 1.6 19 10 .51 13 17 10 .46 21 20 1.1 17 9 .41 14 14 10 .38 245 246 285 17 8 .37 15 21 10 .57 2250 1090 14100 16 8 .35 16 27 10 .73 284 298 727 15 10 .41 17 21 10 .57 751 557 1670 14 10 .38 18 15 10 .41 3910 1580 46300 14 10 .38 19 15 10 .41 180 190 92 13 10 .35 20 12 10 .32 84 70 16 13 9 .32 21 12 10 .32 63 50 8.5 12 5 .16 22 13 10 .35 51 40 5.5 12 5 .16 23 530 372 1500 43 35 4.1 13 5 .18 24 144 193 149 41 30 3.3 12 5 .16 25 83 90 20 40 25 2.7 12 5 .16 26 46 80 9.9 36 20 1.9 11 5 .15 27 26 20 1.4 32 18 1.6 12 5 .16 28 20 12 .65 31 20 1.7 11 5 .15 29 18 10 .49 28 15 1.1 11 8 .24 30 17 10 .46 27 12 .87 11 10 .30 31 --- --- --- 25 10 .68 --- --- TOTAL 1250 1693.41 8331 63229.05 488 10.41 238 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 20 .70 18 15 .73 18 12 .58 2 16 15 .65 22 15 .89 17 10 .46 3 12 12 .39 18 16 .78 17 10 .46 4 11 12 .36 16 15 .65 14 10 .38 5 12 12 .39 15 14 .57 17 15 .69 6 11 17 .50 19 14 .72 13 9 .32 7 10 20 .54 27 25 1.8 12 9 .29 8 12 20 .65 20 11 .59 77 49 9 14 20 .76 20 15 .81 43 100 12 10 11 15 .45 16 11 .48 18 25 1.2 11 13 15 .53 15 11 .45 22 18 1.1 12 16 15 .65 15 10 .41 631 526 3550 13 12 15 .49 31 25 2.1 554 522 1580 14 11 17 .50 20 18 .97 98 90 24 15 49 83 29 17 16 .73 58 50 7.8 16 63 58 13 16 15 .65 40 35 3.8 17 93 96 69 15 13 .53 30 25 2.0 18 29 25 2.0 15 12 .49 25 15 1.0 19 21 14 .79 17 15 .69 20 12 .65 20 148 199 186 14 8 .30 21 12 .68 21 38 20 2.1 17 7 .32 20 12 .65 22 24 15 .97 16 4 .17 20 12 .65 23 21 11 .62 14 2 .08 24 20 1.3 24 33 25 2.2 13 3 .11 31 20 1.7 25 20 18 .97 16 4 .17 145 182 160 26 30 20 1.6 14 5 .19 42 30 3.4 27 19 10 .51 159 209 232 31 20 1.7 28 28 11 .83 54 105 15 46 35 4.3 29 21 12 .68 18 15 .73 52 40 5.6 30 19 12 .62 20 15 .81 37 25 2.5 31 16 15 .65 15 12 .49 --- --- --- TOTAL 846 319.10 722 265.41 2202 5418.21 YEAR 24682.2 79985.66 239 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DAY DISCHARGE (CFS) TRATION (MG/I) DISCHARGE (TONS/DAY) DISCHARGE (CFS) TRATION (MGM DISCHARGE (TONS/DAY) DISCHARGE (CFS) TRATION (MGM DISCHARGE (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 46 40 6.1 90 84 22 29 20 1.6 2 3 4 79 79 77 75 80 94 21 27 47 79 63 58 65 60 50 14 10 7.8 31 29 27 20 20 20 1.7 1.6 1.5 5 180 210 158 64 55 11 41 20 2.2 6 2920 1600 16500 55 45 6.7 38 25 2.6 7 1420 739 4060 50 40 5.4 30 20 1.6 8 428 363 930 45 38 4.6 26 20 1.4 9 136 120 45 42 35 4.0 25 18 1.2 10 95 90 23 40 30 3.2 26 12 .84 11 76 75 15 44 34 4.0 25 14 .95 12 66 60 11 56 45 7.8 34 20 1.8 13 59 45 7.2 51 45 6.2 25 16 1.1 14 53 30 4.3 51 40 5.5 23 14 .87 15 50 20 2.7 385 774 1690 24 15 .97 16 51 40 5.5 130 120 42 23 14 .87 17 72 65 16 74 65 14 22 14 .83 18 201 222 305 200 189 171 24 12 .78 19 80 64 16 63 60 10 23 14 .87 20 56 40 6.0 54 45 6.6 26 15 1.1 21 55 40 5.9 50 40 5.4 22 12 .71 22 47 40 5.1 41 38 4.2 22 12 .71 23 453 343 918 40 35 3.8 22 12 .71 24 1050 737 5200 37 25 2.5 25 13 .88 25 208 211 200 34 20 1.8 21 10 .57 26 150 146 85 31 20 1.7 23 11 .68 27 104 90 25 31 20 1.7 21 10 .57 28 77 60 12 30 20 1.6 21 10 .57 29 478 382 1330 30 20 1.6 19 18 .92 30 112 110 40 30 20 1.6 18 10 .49 31 160 154 70 --- --- --- 19 10 .51 TOTAL 9118 30096.8 2048 2071.7 784 33.70 240 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 24 10 .65 13 8 .28 8.8 5 .12 2 27 12 .87 13 8 .28 9.0 5 .12 3 22 12 .71 12 8 .26 9.1 5 .12 4 22 11 .65 15 10 .41 9.3 5 .13 5 20 10 .54 15 10 .41 11 6 .18 6 18 10 .49 12 8 .26 11 6 .18 7 18 10 .49 11 8 .24 9.0 5 .12 8 17 10 .46 11 8 .24 8.6 5 .12 9 35 20 1.9 11 8 .24 9.0 5 .12 10 27 12 .87 11 8 .24 8.8 5 .12 11 20 10 .54 12 8 .26 9.4 5 .13 12 18 10 .49 12 8 .26 8.8 5 .12 13 17 9 .41 11 7 .21 11 6 .18 14 16 8 .35 10 6 .16 13 6 .21 15 16 8 .35 10 6 .16 38 32 5.4 16 17 8 .37 10 6 .16 13 7 .25 17 61 67 33 12 11 .36 11 6 .18 18 24 12 .78 16 9 .39 8.2 5 .11 19 19 10 .51 12 8 .26 8.2 5 .12 20 17 10 .46 12 7 .23 8.2 5 .11 21 18 10 .49 11 7 .21 8.3 5 .11 22 16 10 .43 11 7 .21 8.8 5 .12 23 15 10 .41 9.9 6 .16 8.5 5 .11 24 17 10 .46 9.7 6 .16 7.4 5 .10 25 16 10 .43 11 6 .18 8.3 5 .11 26 16 10 .43 11 7 .21 17 14 1.1 27 14 10 .38 9.6 6 .16 8.8 5 .12 28 14 9 .34 9.0 6 .15 9.8 5 .13 29 13 8 .28 --- --- --- 93 111 77 30 14 8 .30 18 11 .53 31 13 8 .28 35 30 4.6 TOTAL 621 49.12 323.2 6.75 445.3 92.17 APRIL MAY JUNE 1 64 69 29 22 14 .83 42 40 4.5 2 17 10 .46 16 10 .43 57 22 1.2 3 13 8 .28 14 8 .30 53 30 4.3 4 29 28 7.5 16 10 .43 35 25 2.4 5 28 20 2.3 12 8 .26 32 18 1.6 6 23 14 .87 20 12 .65 27 15 1.1 7 14 8 .30 88 90 41 54 47 25 8 23 23 8.8 69 145 93 107 153 155 9 46 40 12 49 39 6.0 141 143 129 10 14 8 .30 308 328 758 204 181 341 11 11 7 .21 215 184 168 51 40 5.5 12 11 7 .21 53 42 6.0 42 30 3.4 13 10 6 .16 851 1020 25100 79 68 26 14 9.5 5 .13 831 472 2120 68 57 12 15 9.3 5 .13 89 75 18 46 30 3.7 16 9.5 5 .13 61 58 9.6 54 46 8.3 17 9.1 5 .12 54 42 6.1 34 22 2.0 18 9.0 5 .12 417 303 1330 33 25 2.2 19 8.6 5 .12 127 140 89 49 49 9.0 20 8.4 5 .11 69 70 13 31 15 1.3 21 8.3 5 .11 66 60 11 28 14 1.1 22 7.8 5 .11 63 82 18 26 14 .98 23 7.4 5 .10 42 30 3.4 25 14 .95 24 7.9 5 .11 36 22 2.1 24 13 .84 25 7.1 5 .11 32 21 1.8 22 13 .77 26 7.1 5 .10 29 18 1.4 23 12 .75 27 10 16 1.3 29 18 1.4 26 12 .84 28 21 13 .74 26 22 2.1 23 12 .75 29 365 471 2320 25 20 1.4 21 12 .68 30 60 51 11 23 12 .75 21 12 .68 31 --- --- --- 114 134 113 --- --- --- TOTAL 868.0 2396.93 3866 29916.95 1478 746.84 241 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 25 12 .81 20 12 .65 22 13 .77 2 21 12 .68 18 10 .49 19 12 .62 3 22 12 .71 13 5 .18 16 10 .43 4 20 12 .65 14 5 .19 15 8 .32 5 19 10 .51 12 5 .16 15 8 .32 6 40 31 4.9 12 5 .16 16 10 .43 7 30 15 1.2 18 10 .41 15 8 .32 8 20 12 .65 42 35 8.0 13 8 .28 9 19 12 .62 19 17 .87 12 8 .26 10 17 8 .37 20 20 1.1 12 8 .26 11 19 8 .41 33 22 2.0 11 8 .24 12 20 8 .43 17 22 1.0 11 7 .21 13 17 8 .37 50 65 48 12 7 .21 14 24 8 .52 49 47 16 18 12 .58 15 24 8 .52 25 12 .39 12 7 .23 16 19 8 .41 18 12 .58 11 7 .21 17 18 8 .39 16 10 .43 11 7 .21 18 18 8 .39 14 12 .45 9.5 7 .18 19 16 8 .35 14 8 .30 9.7 7 .18 20 16 7 .30 13 9 .32 9.5 7 .18 21 16 7 .30 12 10 .32 9.0 7 .17 22 15 7 .30 11 10 .30 11 6 .18 23 20 8 .43 11 10 .30 12 6 .19 24 18 8 .39 11 9 .27 33 18 1.6 25 15 5 .20 11 8 .24 26 16 1.1 26 14 5 .19 9.8 8 .21 16 9 .39 27 16 5 .22 9.5 8 .21 13 8 .28 28 17 6 .28 27 28 8.5 15 7 .28 29 14 5 .19 386 313 976 12 6 .19 30 23 12 .75 29 20 1.6 11 8 .24 31 24 12 .78 20 12 .65 --- --- --- TOTAL 616 19.22 974.3 1070.28 427.7 11.06 YEAR 21569.5 66511.52 242 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR LOCATION.--Lat 18°14'57", long 65°56 1 44", Hydrologic Unit 21010005, at left downstream side of bridge on Highway 189, 1.9 mi (3.0 km) southeast of Gurabo plaza, and 2.1 mi (3.4 km) northwest of Juncos plaza. DRAINAGE AREA.--2.30 min (5.96 km 2 ). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 180 ft (55 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 2,740 ft'/s (77.6 10/s), Nov. 26, 1987, gage height, 11.04 ft (3.365 a), from rating curve extended above 400 ft'/s (11.3 m'/s) on basis of indirect measurement of peak flow and step-backwater analysis; minimum discharge, 0.20 ft'is (0.006 m'/s), Feb. 10, 1987. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 500 ft'/s (14.2 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (e/s) (ft) (a) Date Time (ft'/s) (m'/s) (ft) (a) Nov.26 2400 *2,740 77.6 *11.04 3.365 Aug. 24 1430 1,311 37.9 8.76 2.670 Dec. 7 1800 2,190 62.0 10.25 3.124 Sept.11 1100 904 25.6 6.04 1.841 Minimum discharge, 0.26 ft'/s (0.007 110/s), June 8. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .35 .99 4.2 e3.2 1.6 .68 .59 .39 .36 28 .73 1.9 2 .32 .62 6.4 e3.0 1.7 .65 .58 .38 .32 27 .69 1.8 3 .50 .56 3.8 e2.1 2.1 .63 .54 .37 .30 3.4 .75 1.8 4 .44 1.2 3.6 e2.1 1.8 .64 .50 .35 .29 2.3 .97 1.8 5 .45 .78 3.6 e2.0 1.5 .64 .47 .35 .29 2.0 .71 1.8 6 .39 .80 5.6 e2.0 1.4 .61 .91 .66 .31 6.8 .65 1.8 7 .44 .72 219 el.9 1.3 .61 .78 .48 .27 13 .68 1.8 8 .45 .61 102 el.9 1.4 .61 .49 .38 .27 2.5 .76 el.8 9 .43 .56 5.1 el.8 1.3 .59 .44 .36 .27 1.9 .76 e5.0 10 .40 .55 e3.2 el.8 1.2 .58 .42 .67 .29 1.7 19 e2.0 11 .38 .54 e3.0 el.7 1.2 .58 .53 .53 .31 1.8 4.9 126 12 .37 .53 e2.8 el.8 1.4 .59 .42 .41 .33 3.0 2.4 e24 13 .36 .52 e2.6 1.8 1.2 .60 .40 .38 .31 5.5 1.7 e3.3 14 .52 .52 e2.4 1.8 1.2 .59 .39 .39 .35 5.0 1.5 e5.0 15 .65 .52 e2.1 1.7 1.4 .55 .48 .38 5.1 1.7 1.4 e3.5 16 .65 1.4 e2.0 1.6 1.3 .56 .43 .37 .98 3.5 1.5 e3.0 17 3.7 1.8 e2.0 1.7 1.2 .56 .40 .38 .61 2.2 1.8 e2.7 18 31 1.2 e3.0 1.7 1.2 .58 .40 .35 .47 1.9 1.7 e2.5 19 3.7 .73 e3.0 1.6 1.1 .59 .40 .42 .41 2.0 1.5 e13 20 .99 .62 e2.9 1.6 1.1 .64 .38 .41 .47 1.2 1.4 e3.0 21 .72 .59 e2.8 1.5 1.1 .61 .38 .36 .53 1.0 1.4 e2.5 22 .63 .58 e2.0 1.5 1.0 .57 .37 .36 .62 4.4 2.1 e2.2 23 .60 3.0 e2.0 1.4 .96 .55 .95 .34 .50 1.5 7.2 e2.0 24 .58 155 e2.0 1.5 1.0 .55 .59 .31 4.5 2.3 e192 el.8 25 .62 10 e2.0 1.7 .97 .57 .46 .31 2.2 2.2 e76 el.8 26 .59 94 el.9 1.6 .90 .62 .39 .31 2.4 1.3 e3.9 el.7 27 .58 343 e1.9 1.6 3.0 .66 .38 .30 1.3 1.0 2.6 el.7 28 .99 14 e1.9 1.7 .87 .65 .37 .30 .75 .83 2.4 el.6 29 .71 6.1 el.8 1.7 .73 .75 .36 .45 .70 .88 2.3 el.6 30 .57 5.0 e2.1 1.7 --- .67 .37 .44 .72 1.0 2.1 el.6 31 1.8 --- e3.2 1.6 .61 --- .43 --- .78 2.0 --- TOTAL 54.88 647.04 405.9 56.3 38.13 18.89 14.57 12.32 26.53 133.59 339.50 226.0 MEAN 1.77 21.6 13.1 1.82 1.31 .61 .49 .40 .88 4.31 11.0 7.53 MAX 31 343 219 3.2 3.0 .75 .95 .67 5.1 28 192 126 MIN .32 .52 1.8 1.4 .73 .55 .36 .30 .27 .78 .65 1.6 AC-FT 109 1280 805 112 76 37 29 24 53 265 673 448 CFSM .77 9.38 5.69 .79 .57 .26 .21 .17 .38 1.87 4.76 3.28 IN. .89 10.47 6.56 .91 .62 .31 .24 .20 .43 2.16 5.49 3.66 CAL YR 1987 TOTAL 1764.14 MEAN 4.83 MAX 343 MIN .21 AC-FT 3500 CFSM 2.10 IN. 28.53 WTR YR 1988 TOTAL 1973.65 MEAN 5.39 MAX 343 NIN .27 AC-FT 3910 CFSM 2.34 IN. 31.92 e Estimated 243 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS MARCH 1984 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFIOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- ,DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANT4NEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 15 1410 0.55 586 27.5 APR, 06 1239 0.43 594 28.0 NOV, 18 1318 0.95 455 27.0 MAY. 09 1502 0.37 576 27.0 JAN, 08 1422 1.91 600 26.5 JUN. 06 0913 0.34 610 26.5 FEB, 05 1226 1.55 612 26.0 JUL, 14 1347 3.50 311 26.5 MAR. 03 1543 0.63 578 26.0 244 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 1983 to September 1986. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 643 mg/L October 06, 1985; Minimum daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,060 tons (960 tonnes) May 18, 1985; Minimum daily mean, 0.00 tons (0.00) tonne several days. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 328 (Aug. 30) 1 (several days) 224 (Jun. 10) 0.01 (several days) 1985 587 (May 17) 2 (March 12) 1,060 (May 18) 0.01 (several days) 1986 643 (Oct. 06) 2 (September 30) 684 (Oct. 06) 0.00 (several days) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 .56 24 .04 .44 22 .03 .53 21 .03 2 .52 24 .03 .45 22 .03 .52 20 .03 3 .51 23 .03 .44 22 .03 .49 20 .03 4 .51 23 .03 .47 23 .03 .49 18 .02 5 .51 23 .03 .44 23 .03 .54 15 .02 6 .50 22 .03 .50 22 .03 .54 12 .02 7 .48 22 .03 .56 24 .04 .51 6 .80 8 .58 23 .04 .52 24 .03 .51 4 .50 9 .60 25 .04 5.8 108 4.6 .54 4 .01 10 .63 25 .04 6.9 132 6.8 .49 4 .01 11 .56 23 .03 2.3 50 .31 .49 4 .01 12 .67 25 .05 1.2 40 .13 .50 4 .01 13 1.1 35 .10 9.5 104 10 .50 4 .01 14 .76 28 .06 1.8 50 .24 .49 4 .01 15 .55 25 .04 28 161 38 .51 4 .01 16 .54 24 .03 44 253 84 .56 4 .01 17 .55 24 .04 1.6 40 .17 .55 4 .01 18 .52 23 .03 .97 33 .09 .51 4 .01 19 .75 28 .06 .81 30 .07 .53 4 .10 20 .91 28 .07 .73 28 .06 .51 4 .01 21 .54 24 .03 .65 26 .05 .49 4 .01 22 .50 23 .03 .63 26 .J4 .49 4 .01 23 .51 22 .03 .62 25 .04 .55 4 .01 24 .50 22 .03 .58 25 .04 .53 4 .01 25 .51 22 .03 .57 25 .04 .50 4 .01 26 .50 22 .03 .56 25 .04 .51 4 .01 27 .46 22 .03 .60 25 .04 ,1 4 .01 28 .45 22 .03 .59 23 .04 .52 4 .01 29 .44 22 .03 .53 22 .03 .51 4 .01 30 .44 22 .03 --- --- --- .51 4 .01 31 .43 22 .03 .53 4 .01 TOTAL 17.59 1.18 112.76 145.08 15.99 1.77 245 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 .54 4 .01 .53 21 .03 .95 27 .07 2 .55 3 .90 .53 19 .03 .73 22 .04 3 .56 3 .50 .53 18 .03 .52 15 .02 4 .57 3 .20 .51 16 .02 .52 10 .01 5 .57 3 .20 .50 14 .02 .54 6 .01 6 .62 3 .01 .49 13 .02 2.9 55 .96 7 .66 3 .01 .48 11 .01 4.3 63 1.6 8 .62 3 .01 .47 10 .01 2.1 53 .36 9 .64 3 .01 .47 9 .01 .84 33 .07 10 .66 3 .01 .45 8 .01 73 248 224 11 .67 3 .01 .43 8 .01 2.0 50 .27 12 .67 2 .80 .47 8 .01 .98 28 .07 13 .63 2 .70 .92 21 .09 .83 25 .06 14 .55 2 .60 1.0 15 .04 .69 25 .05 15 .53 2 .50 .66 12 .02 .59 24 .04 16 .49 2 .10 .59 10 .02 .55 22 .03 17 .50 2 .00 .54 9 .01 .60 22 .04 18 .51 2 .00 .52 8 .01 .56 20 .03 19 .52 2 .00 .51 8 .01 .56 20 .03 20 .48 2 .00 .50 8 .01 .58 19 .03 21 .46 2 .00 .51 8 .01 .56 18 .03 22 .47 2 .00 .48 8 .01 .56 16 .02 23 .47 2 .00 .55 8 .01 .52 15 .02 24 .46 .90 .48 8 .01 .50 14 .02 25 .44 .49 8 .01 .49 13 .02 26 .48 1 .90 .52 8 .01 .47 12 .02 27 1.1 19 .11 .58 12 .02 .46 11 .01 28 1.1 27 .09 .68 12 .02 .46 11 .01 29 .58 23 .04 .60 10 .02 .61 10 .02 30 .50 22 .03 5.8 81 1.9 .61 10 .02 31 --- --- --- 3.7 61 .81 --- --- --- TOTAL 17.60 6.64 25.49 3.25 99.58 227.98 JULY AUGUST SEPTEMBER 1 .48 9 .01 .60 25 .04 1.3 35 .12 2 .45 9 .01 1.7 32 .15 .80 30 .06 3 .46 9 .01 .64 25 .04 9.8 100 13 4 .47 9 .01 .58 20 .03 2.6 70 ,65 5 2.2 49 .34 .59 18 .03 14 113 18 6 .70 27 .05 .50 17 .02 3.6 73 1.0 7 .47 17 .02 .48 15 .02 1.0 35 .09 8 .44 15 .02 .47 14 .02 .73 25 ,05 9 .75 20 .04 .46 14 .02 .78 30 .06 10 1.3 37 .13 .42 13 .01 .81 30 .07 11 .76 33 .07 .38 12 .01 .63 25 .04 12 .55 32 .05 .38 12 .01 .70 25 .05 13 .48 32 .04 .39 12 .01 .75 28 .06 14 .70 32 .06 .38 11 .01 2.3 58 .72 15 .99 30 .08 .38 10 .01 .97 35 .09 16 .54 24 .03 .54 9 .01 27 129 49 17 .48 22 .03 .48 9 .01 39 250 49 18 .48 20 .03 .39 10 .01 30 227 31 19 .47 19 .02 .42 10 .01 11 125 5.4 20 .63 18 .03 .45 10 .01 29 202 32 21 .56 16 .02 .43 10 .01 5.7 70 1.1 22 .59 15 .02 .44 9 .01 2.8 58 .44 23 .51 14 .02 .41 8 .01 2,1 44 .25 24 .47 12 .02 .38 7 .01 1.8 40 .19 25 .43 11 .01 .38 7 ,01 1.7 30 .14 26 .42 9 .01 12 87 12 1.5 20 .08 27 .45 8 .01 3.8 101 2.2 1.4 20 .08 28 .43 7 .01 .42 50 .06 1.4 18 .07 29 3.4 44 2.2 .28 52 .04 1.3 17 .06 30 1.3 37 .13 79 328 202 1.3 15 .05 31 .65 27 .05 4.1 70 .77 --- --- --- TOTAL 23.01 3.58 112.27 211.60 197.77 202.92 YEAR 623.83 810.08 246 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 1.3 37 .13 3.0 60 .49 1.5 5 .02 2 1.3 37 .13 48 4.8 58 1.7 3 1.5 40 .16 116 379 226 2.1 35 .20 4 1.4 40 .15 60 274 76 1.7 12 .06 5 14 118 16 111 467 280 1.6 7 .03 6 3.0 68 .80 140 499 297 1.6 4 .02 7 1.5 40 .16 54 259 87 1.5 4 .02 8 1.3 37 .13 10 113 4.1 1.5 4 .02 9 16 129 19 9.4 130 4.5 1.6 4 .02 10 6.9 92 2.2 18 153 20 1.6 4 .02 11 2.3 52 .32 4.1 65 .72 4.7 48 3.8 12 1.7 45 .21 2.9 60 .47 3.8 66 1.0 13 3.4 65 1.8 2.5 58 .39 1.5 30 .12 14 43 202 89 4.2 85 .96 1.4 20 .08 15 3.7 65 .65 4.0 65 .70 1.3 17 .06 16 2.9 65 .51 2.3 33 .20 1.7 16 .07 17 11 106 13 2.5 20 .14 1.4 16 .06 18 4.3 83 1.3 2.2 15 .09 1 1 16 .06 19 2.0 45 .24 2.0 12 .06 I., 15 .05 20 1.7 43 .20 1.9 9 .05 1.3 15 .05 21 13 130 18 1.9 9 .05 1.3 15 .05 22 3.0 60 .49 1.9 9 .05 1.2 14 .05 23 1.9 45 .23 2.0 7 .04 1.3 13 .05 24 1.6 42 .18 1.9 7 .04 1.7 12 .06 25 14 141 21 1.9 7 .04 1.6 12 .05 26 2.5 50 .34 2.1 6 .03 1.4 11 .04 27 2.0 45 .24 1.8 6 .03 1.6 10 .04 28 12 131 7.4 1.8 6 .03 1.4 9 .03 29 3.9 90 1.0 1.7 5 .02 1.3 8 .03 30 44 213 86 1.5 5 .02 2.5 38 .48 31 4.4 80 1.2 --- --- --- 1.8 45 .22 TOTAL 226.5 282.17 616.5 999.22 56.3 8.56 RIO GRANDE GE lUIZA BASIN 247 50056900 QUEBRADA MAMEY NEAR GURABO. PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 DAY MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/1) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 2 3 4 5 2.1 9.9 1.6 1.4 1.3 46 120 35 25 24 .40 7.6 .15 .09 .08 .76 .73 .69 .66 .62 10 10 10 10 10 .02 .02 .02 .02 .02 1.3 .86 .81 .84 .88 38 32 29 27 24 .13 .07 .06 .06 .06 6 7 8 9 10 1.5 1.6 1.3 1.2 1.1 23 21 20 19 18 .09 .09 .01 .06 .05 .61 .60 .59 .58 .57 8 8 8 8 7 .01 .01 .01 .01 .01 1.0 1.1 1.1 .88 .87 20 16 13 9 6 .05 .05 .04 .02 .01 11 12 13 14 15 1.1 1.0 .96 .95 .93 17 16 16 16 15 .05 .04 .04 .04 .04 .56 .55 .53 .53 .59 7 7 7 7 7 .01 .01 .01 .01 .01 .86 .87 .86 .87 .87 3 2 3 3 4 .01 .00 .01 .01 .01 16 17 18 19 20 .89 .89 .86 .82 .79 15 15 14 13 12 .04 .04 .03 .03 .03 .61 .62 .74 .72 .74 8 8 7 8 8 .01 .01 .J1 .02 .02 .91 .95 1.1 .92 .81 5 5 6 7 8 .01 .01 .02 .02 .02 21 22 23 24 25 .78 .77 .78 .73 .74 11 11 11 10 10 .02 .02 .02 .02 .02 .72 .73 .70 .74 .77 7 7 7 7 7 .01 .01 .01 .01 .01 .79 .78 .79 ./9 .75 9 10 10 10 10 .02 .02 .02 .02 .02 26 27 28 29 30 31 .86 .79 .80 .75 .74 .74 10 10 10 10 11 11 .02 .02 .02 .02 .02 .02 .78 1.0 7.0 --- 7 10 84 --- .01 .03 3.1 --- .77 .78 .98 82 1.8 1.9 10 10 13 327 50 35 .02 .02 .12 227 .24 .18 TOTAL 40.67 9.28 25.04 3.46 110.79 228.35 APRIL MAY JUNE 1 2 3 4 5 .95 .83 .86 .74 .72 32 27 20 23 20 .08 .06 .05 .05 .04 .36 .35 .35 .32 .32 17 16 15 14 14 .02 .02 .01 .01 .01 .81 .80 .80 .78 .77 11 11 12 12 12 .02 .02 .03 .03 .02 6 7 8 9 10 .73 .70 .68 .66 .61 19 18 17 16 15 .04 .03 .03 .03 .02 .32 .30 .29 .28 .28 13 12 11 10 10 .01 .01 .01 .01 .01 .76 .73 .75 .73 .70 12 12 12 11 11 .02 .02 .02 .02 .02 11 12 13 14 15 .58 .57 .60 .56 .61 13 11 9 6 4 .02 .02 .01 .01 .01 .29 .36 .35 5.6 163 10 10 10 59 418 .01 .01 .01 .79 440 .68 .67 .64 .61 .60 11 10 10 11 11 .02 .02 .02 .02 .02 16 17 18 19 20 .82 .62 .55 .49 .48 4 4 5 6 8 .01 .01 .01 .01 .01 11 164 239 9.9 3.3 110 587 546 80 20 21 1060 796 2.1 .18 .63 .63 .63 .64 .62 11 11 11 10 10 .02 .02 .02 .02 .02 21 22 23 24 25 .46 .43 35 4.6 1.5 10 12 160 109 45 .01 .01 54 1.9 .18 2.1 1.6 1.4 1.2 1.1 14 14 13 12 11 .08 .06 .05 .04 .03 .68 .66 .63 .64 .65 10 11 12 12 10 .02 .02 .02 .02 .02 26 27 28 29 30 31 .66 .51 .43 .41 .39 --- 25 20 20 19 18 --- .04 .03 .02 .02 .02 --- 1.0 .99 .94 .89 .86 .83 11 12 12 10 10 10 .03 .03 .03 .02 .02 .02 .70 .66 .62 .60 .60 --- 11 11 11 11 11 .02 .02 .02 .02 .02 --- TOTAL 57.75 56.78 612.88 2320.63 20.42 0.62 248 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 .68 10 .02 .74 29 .06 .59 6 .01 2 .67 10 .02 .73 10 .02 .61 6 .01 3 .67 10 .02 .68 8 .01 .55 6 .01 4 .67 10 .02 .66 7 .01 .47 6 .01 5 .61 10 .02 .76 8 .02 .51 6 .01 6 .56 10 .02 .59 6 .01 .63 6 .01 7 .57 9 .01 .48 7 .01 s1 6 .01 8 .56 9 .01 .43 6 .01 2.i 42 .50 9 .55 8 .01 .40 6 .01 1.7 20 .09 10 .49 7 .01 .40 6 .01 .65 8 .01 11 .47 7 .01 .38 6 .01 .58 8 .01 12 .47 7 .01 .42 7 .01 17 85 22 13 .46 7 .01 .84 15 .03 34 252 50 14 .47 7 .01 .52 11 .02 3.1 60 .66 15 4.6 64 .59 .47 9 .01 1.7 45 .21 16 1.2 62 .76 .43 6 .01 1.2 37 .12 17 .88 32 .08 .39 6 .01 .90 32 .08 18 .80 30 .06 .44 7 .01 .75 29 .06 19 .90 32 .08 .44 8 .01 .60 26 .04 20 4.4 74 .88 .38 8 .01 .63 27 .05 21 1.1 36 .11 .85 15 .03 .60 26 .04 22 .80 30 .06 .51 10 .01 .60 26 .04 23 .82 30 .07 .43 10 .01 .72 28 .05 24 .81 30 .07 .40 9 .01 2.0 44 .26 25 .82 30 .07 .38 8 .01 27 189 30 26 .81 30 .07 .47 10 .01 1.8 40 .19 27 .73 30 .06 6.5 93 2.1 2.0 48 .44 28 .81 28 .06 1.1 25 .07 4.4 84 1.8 29 .84 31 .07 .68 12 .02 1.8 40 .19 30 .80 30 .06 .54 7 .01 1.1 35 .10 31 .77 29 .06 .51 6 .01 --- --- --- TOTAL 29.79 3.41 22.95 2.59 110.80 107.01 YEAR 1930.39 4022.08 249 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 2.8 54 .64 4.3 68 .79 2.3 7 .04 2 9.8 109 4.5 3.4 62 .57 2.2 8 .05 3 2.3 45 .28 3.1 59 .49 2.0 6 .03 4 17 95 36 3.0 58 .47 2.0 7 .04 5 17 184 20 3.0 57 .46 2.2 7 .04 6 251 643 684 2.8 52 .39 2.2 7 .04 7 189 542 549 2.7 50 .36 2.3 7 .04 8 54 399 171 2.5 50 .34 2.3 6 .04 9 8.6 100 2.3 2.6 50 .35 2.5 6 .04 10 5.2 80 1.1 2.5 50 .34 2.5 5 .03 11 4.1 65 .72 2.6 50 .35 2.5 5 .03 12 3.6 62 .60 3.2 55 .48 2.4 4 .03 13 3.4 62 .57 4.6 80 .99 2.2 5 .03 14 3.2 60 .52 3.4 20 .18 2.1 5 .03 15 3.2 60 .52 87 359 253 2.2 5 .03 16 3.2 60 .52 12 125 4.1 1.9 5 .03 17 3.1 60 .50 7.6 100 2.1 2.0 5 .03 18 14 132 12 31 228 58 1.9 5 .03 19 5.2 85 1.2 5.2 80 1.1 1.9 5 .03 20 3.4 70 .64 4.7 80 1.0 1.8 5 .02 21 3.2 65 .56 34 185 87 1.8 5 .02 22 3.1 60 .50 4.5 20 .24 1.7 5 .02 23 35 217 56 3.8 12 .12 1.6 5 .02 24 34 218 26 3.4 12 .11 1.6 5 .02 25 10 85 2.3 3.0 11 .09 1.7 5 .02 26 6.2 88 1.8 2.8 10 .08 1.6 4 .02 27 5.1 85 1.2 2.6 8 .06 1.4 4 .02 28 3.6 65 .63 2.5 7 .05 1.4 3 .01 29 21 172 19 2.4 7 .05 1.4 4 .02 30 6.3 90 1.8 2.4 7 .05 1.4 4 .02 31 25 170 43 --- --- --- 1.3 5 .02 TOTAL 755.6 1639.40 252.6 413.71 60.3 0.89 250 RIO GRANDE DE IOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 1.4 5 .02 1.1 7 .02 .88 6 .01 2 1.6 5 .02 1.1 7 .02 .85 6 .01 3 1.4 5 .02 1.1 8 .02 .77 6 .01 4 1.5 5 .02 5.9 61 3.6 .79 6 .01 5 1.5 5 .02 1.9 45 .23 .80 6 .01 6 1.5 4 .02 1.2 25 .08 ....0 6 .01 7 1.5 4 .02 1.1 14 .04 .79 6 .01 8 1.5 5 .02 1.1 10 .03 .75 6 .01 9 2.0 5 .03 1.1 9 .03 .72 6 .01 10 1.8 5 .02 1.1 8 .02 .72 6 .01 11 1.6 5 .02 1.1 7 .02 .76 6 .01 12 1.5 5 .02 1.1 6 .02 .74 6 .01 13 1.5 5 .02 1.0 6 .02 .74 7 .01 14 1.4 5 .02 1.0 6 .02 .82 12 .03 15 1.3 5 .02 1.0 6 .02 1.8 49 .25 16 1.4 5 .02 1.0 6 .02 .81 22 .05 17 1.4 5 .02 1.0 6 .02 .75 17 .03 18 1.3 5 .02 1.0 6 .02 .73 17 .03 19 1.3 5 .02 1.0 6 .02 .73 16 .03 20 1.2 5 .02 .99 6 .02 .73 15 .03 21 1.2 5 .02 .95 6 .02 .72 15 .03 22 1.3 5 .02 .94 6 .02 .70 14 .03 23 1.4 5 .02 .90 6 .01 .69 13 .02 24 1.4 5 .02 .88 6 .01 .72 13 .03 25 1.4 5 .02 .85 6 .01 .74 13 .03 26 1.3 5 .02 .83 6 .01 .75 13 .03 27 1.3 5 .02 .82 6 .01 .73 12 .02 28 1.3 5 .02 .91 6 .01 .69 11 .02 29 1.3 5 .02 --- --- 1.3 32 .17 30 1.2 5 .02 .80 30 .06 31 1.2 6 .02 1.0 23 .07 TOTAL 43.9 0.63 33.97 4.39 25.32 1.09 APRIL MAY JUNE 1 1.1 1 .02 2.2 6 .04 .96 35 .09 2 .73 7 .01 1.7 5 .02 2.8 49 .77 3 .71 7 .01 1.5 5 .02 1.2 30 .10 4 1.0 20 .05 1.4 5 .02 .92 30 .07 5 2.1 40 .39 1.4 5 .02 3.5 101 3.8 6 1.4 25 .09 1.4 5 .02 .99 29 .08 7 .83 10 .02 2.8 52 .48 .91 --- --- 8 27 158 72 17 119 19 .87 25 .06 9 3.5 20 .19 41 226 122 4.3 70 1.9 10 1.2 7 .02 21 159 20 1.3 30 .11 11 1.1 6 .02 18 173 14 .96 28 .07 12 .89 6 .01 2.9 60 .47 .91 25 .06 13 .84 6 .01 173 475 667 1.3 35 .12 14 .80 6 .01 87 219 274 1.5 40 .16 15 .84 6 .01 2.4 25 .16 .93 15 .04 16 .89 5 .01 1.4 20 .08 .95 15 .04 17 .82 5 .01 1.1 18 .05 .87 14 .03 18 .76 5 .01 2.8 64 1.5 .84 14 .03 19 .73 5 .01 5.4 80 4.7 .81 14 .03 20 7.4 45 5.3 1.3 20 .07 .80 13 .03 21 1.6 18 .08 1.0 18 .05 .79 13 .03 22 .86 10 .02 .99 15 .04 .78 13 .03 23 .73 10 .02 .92 15 .04 .79 13 .03 24 .69 10 .02 .88 15 .04 .78 13 .03 25 .66 10 .02 .83 15 .03 .76 12 .02 26 .62 10 .02 .84 15 .03 .74 12 .02 27 .69 14 .03 .83 15 .03 .83 13 .03 28 1.3 29 .17 .84 17 .04 .78 13 .03 29 40 175 115 .82 17 .04 .75 13 .03 30 4.7 17 .22 .79 19 .04 .76 14 .03 31 --- --- --- 3.1 56 .75 --- --- --- TOTAL 106.49 193.80 398.54 1124.78 35.38 7.87 251 RIO GRANDE DE LOIZA BASIN 50056900 QUEBRADA MAMEY NEAR GURABO. PR-Continued SEDIMENT DISCHARGE. SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 .75 14 .03 .67 10 .02 1.6 40 .17 2 .75 15 .03 .64 10 .02 .91 15 .04 3 .72 15 .03 .64 10 .02 .79 10 .02 4 .69 15 .03 .64 10 .02 .69 10 .02 5 .70 15 .03 .59 10 .02 .68 10 .02 6 1.1 30 .09 .57 10 .02 .74 10 .02 7 .87 17 .04 .62 15 .03 .66 10 .02 8 .79 16 .03 1.1 25 .07 .62 10 .02 9 .78 15 .03 .75 12 .02 .62 10 .02 10 .76 15 .03 .77 10 .02 .60 10 .02 11 .79 15 .03 2.0 50 .57 .57 10 .02 12 .82 15 .03 .84 7 .02 .56 10 .02 13 .80 15 .03 .74 5 .01 .56 9 .01 14 .72 15 .03 .84 5 .01 .56 9 .01 15 .75 14 .03 1.1 15 .04 .59 8 .01 16 .77 13 .03 .91 10 .02 .55 8 .01 17 .69 12 .02 .75 10 .02 .53 9 .01 18 .64 12 .02 .75 10 .02 .51 9 .01 19 .61 12 .02 .73 10 .02 .50 9 .01 20 .59 12 .02 .70 10 .02 .49 9 .01 21 .59 12 .02 .70 10 .02 .49 10 .01 22 .60 12 .02 .72 10 .02 .52 10 .01 23 .62 12 .02 .72 10 .02 .55 10 .01 24 .59 11 .02 .72 10 .02 .74 10 .02 25 .58 11 .02 .71 10 .02 .68 10 .02 26 .57 11 .02 .68 10 .02 .63 10 .02 27 .57 11 .02 .69 10 .02 .57 8 .01 28 .59 11 .02 11 65 10 .54 6 .01 29 .59 10 .02 55 255 98 .51 3 .00 30 2.0 41 .79 1.6 40 .17 .49 2 .00 31 .92 12 .03 1.0 30 .08 --- --- --- TOTAL 23.31 1.63 89.89 109.40 19.05 0.60 YEAR 1844.35 3498.19 252 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 Rio Grande de Loiza. DRAINAGE AREA.--60.2 mi' (155.9 km 2 ). 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. Elevation of gage is 136.58 ft (41.63 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. AVERAGE DISCHARGE.--29 years (1960-88), 138 ft'/s (3.908 ml/s), 31.13 in/yr (791 mm/yr), 99,980 acre-ft/yr (123 hm7yr); median of yearly mean discharges, 127 ft'/s (3.60 m'/s), 92,000 acre-ft/yr (110 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 74,600 ft'is (2,133 m'/s), Sept. 6, 1960, gage height, 27.7 ft (8.44m), from floodmark, from rating curve extended above 8,000 ft'/s (227 m'/s) on basis of slope-area measurement at gage height 21.6 ft (6.58 m), contracted opening, culvert and flow over road measurement at gage height 23.76 ft (7.242 m), and estimate of peak flow based on slope-area measurements of Rio Gurabo and Rio Valenciano, 7.0 mi (11.3 km) upstream, adjusted for channel storage and flow from intervening area; minimum discharge, 4.5 ft'/s (0.127 m'/s), Feb. 21,25, 1968. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate elevation to gage datum of the Aug. 4, 1945 flood, as pointed out by local residents, 26.6 ft (8.11 m). EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 3,000 ft'/s (85.0 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m'/s) (ft) (m) Date Time (fti/s) (m'/s) (ft) (m) Oct. 18 2100 9,670 274 15.37 4.685 July 7 0600 4,040 114 9.89 3.014 Nov. 24 2015 8,770 248 14.84 4.523 July 14 0345 3,270 92.6 8.79 2.679 Nov. 27 unknown 45,000 1,270 24.35 7.422 Aug. 24 1730 15,800 447 18.18 5.541 Dec. 6 0445 3,340 94.6 8.89 2.710 Sept.11 1415 10,900 309 16.02 4.883 Dec. 8 0100 *50,600 1,430 *25.09 7.647 Minimum discharge, 15 ft'is (0.425 m'/s), Apr. 22, 23, June 8, 9. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 50 59 143 394 139 37 23 21 32 570 52 60 2 33 45 455 192 113 50 22 20 23 793 47 55 3 33 40 119 138 147 36 21 17 20 172 44 51 4 57 123 95 116 89 32 20 16 19 87 57 49 5 41 100 79 124 66 32 20 16 18 62 46 46 6 32 235 641 127 69 30 27 218 18 119 41 40 7 35 104 9720 121 52 30 38 155 17 1280 68 42 8 30 60 11500 117 50 30 24 46 16 148 76 45 9 30 51 516 121 57 29 22 29 17 92 49 221 10 29 50 315 121 74 27 20 77 21 96 119 210 11 23 46 227 113 55 27 22 162 18 98 217 2870 12 22 58 186 120 51 27 21 53 53 102 109 930 13 22 63 164 104 89 27 19 32 29 69 58 320 14 256 41 150 107 72 28 18 31 40 780 48 353 15 161 39 143 98 54 26 32 59 585 108 47 232 16 173 44 139 91 62 26 27 41 244 71 45 161 17 667 73 131 89 50 26 20 32 164 66 96 102 18 2100 150 128 90 45 26 20 31 62 72 68 75 19 557 66 146 84 43 25 22 33 43 94 49 e597 20 153 70 179 82 42 26 17 46 272 68 42 e191 21 97 47 173 79 40 27 18 74 251 56 39 e121 22 72 44 212 75 39 26 15 45 162 129 70 120 23 62 181 139 74 37 24 46 29 112 84 131 155 24 70 4620 128 73 39 24 26 26 179 65 3290 101 25 97 1120 121 72 41 24 20 24 159 65 e730 81 26 85 1110 130 73 50 26 18 22 80 62 e166 65 27 78 e19800 129 71 245 29 19 23 75 64 e161 56 28 72 2310 126 73 56 32 18 20 53 59 e135 54 29 70 386 117 74 41 32 17 23 172 73 e113 54 30 53 207 113 73 --- 28 16 34 71 71 85 53 31 59 --- 179 67 28 --- 83 --- 59 69 --- TOTAL 5319 31342 26743 3353 2007 897 668 1538 3025 5740 6367 7510 MEAN 172 1045 863 108 69.2 28.9 22.3 49.6 101 185 205 250 MAX 2100 19800 11500 394 245 50 46 218 585 1280 3290 2870 MIN 22 39 79 67 37 24 15 16 16 56 39 40 AC-FT 10550 62170 53040 6650 3980 1780 1320 3050 6000 11390 12630 14900 CFSM 2.85 17.4 14.3 1.80 1.15 .48 .37 .82 1.67 3.08 3.41 4.16 IN. 3.29 19.37 16.53 2.07 1.24 .55 .41 .95 1.87 3.55 3.93 4.64 CAL YR 1987 TOTAL 91375 MEAN 250 MAX 19800 MIN 17 AC-FT 181200 CFSM 4.16 IN. 56.46 WTR YR 1988 TOTAL 94509 MEAN 258 MAX 19800 MIN 15 AC-FT 187500 CFSM 4.29 IN. 58.40 e Estimated RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURAGO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 15 1229 133 174 28.0 APR, 08 1427 31.9 346 31.0 NOV, 17 1352 72.9 325 28.0 MAY, 09 1254 28.3 274 30.0 JAN, 11 1616 108.0 308 26.5 JUN, 06 1200 16.7 351 31.0 FEB, 05 1029 62.2 265 24.0 JUL, 14 1150 609 209 25.0 MAR, 04 1021 31.9 328 25.0 253 254 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT WRABO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1984 to 1986 PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to September 1986. INSTRUMENTATION.-- USD-49 and automatic sediment sampler. REMARKS.-- The suspended-sediment data included in this report is part of a 5-year hydrologic investigation conducted in the Rio Grande de Loiza Basin to account the amount of suspended- sediment transported to Lago Loiza, a water supply reservoir. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,870 mg/L May 18, 1985; Minimum daily mean, 6 mg/L August 06, 1985. SEDIMENT LOADS: Maximum daily mean, 93,200 tons (84,570 tonnes) May 18, 1985; Minimum daily mean, 0.23 tons (0.20) May 12, 1984. EXTREMES FOR WATER YEARS 1984-86.-- Water suspeneded-sediment concentration (mg/L) suspended-sediment discharge (tons per day) Year maximum minimum maximum minimum 1984 732 (Nov. 06) 9 (March 24) 7,030 (Nov. 06) 0.23 (May 12) 1985 1,870 (May 18) 6 (August 06) 93,200 (May 18) 0.44 (August 06) 1986 1,670 (Oct. 06) 12 (several days) 60,800 (Oct. 06) 0.53 (April 26) SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE PISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (Li.,) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 83 50 11 64 60 10 60 50 8.1 2 60 50 8.1 61 50 8 2 100 50 13 3 82 49 12 52 45 6 3 76 50 10 4 58 48 7.5 1960 514 4320 54 42 6.1 5 52 42 5.9 1520 542 4770 52 42 5.9 6 49 41 5.4 2700 732 7030 70 50 9.5 7 50 40 5.4 297 120 96 52 50 7.0 8 95 59 17 154 80 33 61 50 8.2 9 127 78 24 118 50 16 58 50 7.8 10 76 50 10 101 50 14 53 50 7.2 11 54 45 6.6 89 60 14 51 48 6.6 12 67 54 11 83 60 13 48 45 5.8 13 58 50 7.8 75 60 12 46 40 5.0 14 53 50 7.2 71 60 12 46 40 5.0 15 312 123 297 68 60 11 45 40 4.9 16 129 93 47 69 60 11 50 40 5.4 17 95 70 24 66 50 8.9 49 40 5.3 18 73 70 14 62 50 8.4 46 40 5.0 19 121 83 35 59 50 8.0 45 38 4.6 20 92 71 23 58 50 7.8 42 37 4.2 21 142 114 122 56 50 7.6 44 38 4.5 22 69 60 11 55 50 7.4 45 40 4.9 23 54 45 6.6 53 50 7.2 51 40 5.5 24 47 42 5.3 53 50 7.2 42 40 4.5 25 45 40 4.9 53 50 7.2 39 40 4.2 26 90 65 25 50 40 5.4 36 32 3.1 27 52 42 5.9 49 40 5.3 39 35 3.7 28 46 40 5.0 734 233 1340 38 33 3.4 29 62 48 9.1 178 100 73 39 32 3.4 30 112 73 28 73 50 9.9 43 37 4.3 31 302 154 231 --- --- --- 50 40 5.4 TOTAL 2807 1032.7 9081 17879.8 1570 181.5 255 RIO GRANDE DE 10I1A BASIN 50057000 RIO GURABO AT GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 48 40 5.2 27 26 1.9 31 30 2.5 2 37 35 3.5 27 26 1.9 32 30 2.6 3 33 32 2.9 28 26 2.0 30 30 2.4 4 32 32 2.8 29 27 2.1 28 30 2.3 5 31 30 2.5 28 26 2.0 29 30 2.3 6 30 30 2.4 28 26 2.0 29 30 2.3 7 29 30 2.3 35 31 2.9 28 30 2.3 8 33 30 2.7 36 30 2.9 28 26 2.0 9 33 30 2.7 61 40 9.5 29 26 2.0 10 33 30 2.7 107 72 29 28 26 2.0 11 32 30 2.6 87 59 16 27 26 1.9 12 33 30 2.7 66 50 8.9 25 24 1.6 13 52 43 10 233 122 134 24 24 1.6 14 87 66 17 118 75 24 25 24 1.6 15 46 40 5.0 231 104 267 24 24 1.6 16 38 30 3.1 1610 391 3630 24 23 1.5 17 47 30 3.8 111 80 24 24 23 1.5 18 38 33 3.4 65 40 7.0 25 23 1.6 19 34 32 2.9 50 40 5.4 23 22 1.4 20 109 78 52 44 38 4.5 21 20 1.1 21 51 45 6.2 39 38 4.0 20 20 1.1 22 38 35 3.6 37 32 3.2 -,-; 20 1.1 23 34 35 3.2 35 31 2.9 21 20 1.1 24 34 30 2.8 34 30 2.8 24 9 .58 25 36 30 2.9 33 30 2.7 20 16 .86 26 38 30 3.1 32 30 2.6 19 10 .51 27 31 30 2.5 33 30 2.7 18 10 .49 28 31 30 2.5 34 32 2.9 17 10 .46 29 30 29 2.3 32 31 2.7 17 10 .46 30 29 30 2.3 --- --- --- 17 10 .46 31 28 26 2.0 17 10 .46 TOTAL 1235 165.6 3330 4203.5 744 45.68 APRIL MAY JUNE 1 16 10 .43 14 18 .18 138 50 19 2 16 10 .43 14 15 .57 111 35 10 3 16 10 .43 13 15 .61 81 25 5.5 4 16 10 .43 12 15 .65 100 36 5.9 5 16 10 .43 11 18 .73 73 25 4.9 6 17 10 .46 11 17 .69 262 110 130 I 18 10 .49 11 17 .69 399 175 258 8 19 11 .56 10 15 .61 254 100 69 9 17 11 .50 9.6 17 .64 155 60 25 10 16 10 .43 11 12 .39 1290 439 2970 11 15 10 .41 10 12 .32 352 159 176 12 15 10 .43 8.6 10 .23 170 110 50 13 14 10 .41 15 12 .49 330 159 262 14 14 10 .38 28 15 1.1 168 95 47 15 14 10 .38 15 12 .49 109 70 21 16 14 11 .42 14 11 .42 88 70 17 17 12 12 .42 13 10 .35 76 70 14 18 12 10 .32 13 10 .35 69 52 9.3 19 12 10 .32 12 10 .32 65 50 8.8 20 13 10 .35 12 10 .32 82 50 8.8 21 14 12 .45 13 10 .35 62 48 8.3, 22 14 12 .45 14 11 .42 54 48 8.2 23 14 12 .45 17 20 .92 47 47 7.7 24 13 12 .42 26 25 1.8 44 48 7.6 25 12 12 .42 ?2 25 1.5 44 49 7.3 26 11 12 .42 80 48 18 40 48 6.5 27 21 21 2.0 54 42 6.1 39 43 5.3 28 40 28 3.0 139 73 56 39 34 3.7 29 20 20 1.1 64 50 8.6 211 104 199 30 15 20 .81 448 195 452 167 96 52 31 --- --- --- 362 150 210 --- --- --- TOTAL 476 17.95 1496.2 766.44 5119 4416.8 256 RIO GRANDE DE LOIZA BASIN 50051000 RIO GURABO AT GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 87 70 16 51 50 E.9 33 38 3.4 2 72 60 12 319 150 190 31 30 2.5 3 71 50 9.6 94 75 19 49 41 8.3 4 66 50 8.9 78 70 15 61 20 4.4 5 355 283 273 77 60 12 140 71 68 6 116 85 27 52 50 7.0 1=.1 102 62 7 77 60 12 43 45 5.2 bb 30 5.3 8 74 60 12 38 32 3.3 41 20 2.2 9 72 60 12 36 31 3.0 36 15 1.5 10 80 65 14 34 30 2.8 47 18 2.3 11 70 70 13 29 28 2.2 39 20 2.1 12 57 55 8.5 26 25 1.8 96 51 22 13 48 50 6.5 25 23 1.6 383 136 392 14 38 50 5.1 23 23 1.4 972 278 889 15 80 70 15 22 23 1.4 163 120 53 16 55 39 5.8 30 23 1.9 509 176 874 17 45 35 4.3 26 21 1.5 633 337 1540 18 46 45 5.6 23 21 1.3 669 288 801 19 44 38 4.5 22 21 1.2 326 161 182 20 46 38 4.7 24 21 1.4 1010 368 1780 21 43 48 5.6 31 21 1.8 429 190 220 22 79 40 8.5 25 20 1.4 186 120 60 23 65 32 5.6 25 19 1.3 119 80 26 24 51 32 4.4 22 20 1.2 93 70 18 25 43 30 3.6 19 20 1.0 80 60 13 26 39 30 3.2 622 227 2260 67 50 9.0 27 40 30 3.2 839 302 1620 59 40 6.4 28 36 35 3.4 151 95 39 59 40 6.4 29 224 199 505 98 60 16 60 38 6.2 30 269 150 109 149 83 70 64 30 5.2 31 76 60 12 44 50 5.9 --- --- --- TOTAL 2564 1133.0 3097 4297.5 6701 7065.2 YEAR 38220.2 41205.67 257 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 DAY MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 2 3 4 5 65 55 120 80 95 55 48 87 61 70 9.7 7.1 41 16 27 165 391 2440 1180 2940 96 168 694 405 754 53 259 5430 1690 8540 72 154 147 86 74 55 91 90 65 60 11 63 36 15 12 6 7 8 9 10 115 75 47 486 430 83 58 40 202 204 31 14 5.1 751 351 3850 2070 599 510 320 969 605 228 248 156 11400 4530 381 483 135 67 63 59 58 81 41 43 38 40 57 7.4 7.3 6.1 6.3 13 11 12 13 14 15 172 160 110 1410 241 100 105 80 396 121 47 45 24 3360 77 200 150 145 240 325 140 110 95 111 156 98 45 37 95 153 171 334 160 76 65 93 157 95 56 50 152 240 60 11 8.8 16 17 18 19 20 161 195 119 94 126 91 105 70 65 79 38 72 22 16 28 148 165 160 134 125 90 95 90 85 80 36 42 39 31 27 65 80 61 54 54 50 58 60 62 62 8.8 13 9.9 9.0 9.0 21 22 23 24 25 125 80 76 68 136 80 55 56 58 83 27 12 11 11 33 115 110 125 109 100 75 70 70 72 70 23 21 24 21 19 48 47 46 54 81 40 40 40 40 57 5.2 5.1 5.0 5.8 13 26 27 28 29 30 31 95 80 123 139 145 92 70 60 76 87 90 68 18 13 27 33 48 17 211 104 91 81 79 --- 114 70 65 60 60 --- 89 20 16 13 13 --- 70 84 104 62 79 87 52 59 71 47 54 60 9.8 15 21 7.9 11 14 TOTAL 5515 5231.9 17382 33763 2743 811.4 258 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 52 10 32 25 2.2 99 65 18 2 287 143 136 33 26 2.3 48 42 5.4 3 96 66 18 29 26 2.0 36 35 3.4 4 79 57 12 27 25 1.8 32 30 2.6 5 68 50 9.2 26 25 1.8 28 30 2.3 6 97 65 17 25 25 1.7 '1 35 2.0 7 88 60 14 25 25 1.7 60 21 8 60 60 9.7 24 25 1.6 152 86 37 9 52 60 8.4 24 28 1.8 79 58 13 10 51 60 8.3 24 28 1.8 47 50 6.3 11 50 60 8.1 26 30 2.1 35 57 5.4 12 44 50 5.9 24 33 2.1 29 45 3.5 13 42 40 4.5 22 40 2.4 28 35 2.6 14 40 35 3.8 22 46 2.7 24 28 1.8 15 40 35 3.8 29 30 2.3 22 24 1.4 16 38 35 3.6 27 25 1.8 22 23 1.4 17 36 35 3.4 27 25 1.8 24 25 1.6 18 36 35 3.4 30 28 2.3 41 30 3.3 19 34 30 2.8 29 26 2.0 45 35 4.3 20 34 30 2.8 45 30 3.6 26 25 1.8 21 32 30 2.6 32 30 2.6 34 25 2.3 22 31 30 2.5 28 25 1.9 23 22 1.4 23 30 30 2.4 25 24 1.6 20 20 1.1 24 30 28 2.3 37 32 3.2 19 18 .92 25 29 25 2.0 37 31 3.1 17 15 .69 26 36 25 2.4 34 30 2.8 16 15 .65 27 35 25 2.4 48 36 5.2 23 25 1.6 28 34 25 2.3 273 129 142 35 27 2.6 29 33 25 2.2 --- --- --- 1530 451 3330 30 30 25 2.0 147 88 35 31 30 25 2.0 245 126 116 TOTAL 1685 309.8 1064 204.2 3024 3630.36 APRIL MAY JUNE 1 78 60 13 35 30 2.8 51 19 2.6 2 49 30 4.0 33 30 2.7 49 20 2.6 3 40 30 3.2 40 32 3.5 49 22 2.9 4 35 30 2.8 36 30 2.9 47 23 2.9 5 31 29 2.4 33 30 2.7 45 24 2.9 6 30 28 2.3 38 35 3.6 42 23 2.6 7 32 28 2.4 33 30 2.7 41 23 2.5 8 30 28 2.3 29 30 2.3 43 23 2.7 9 29 27 2.1 28 30 2.3 43 23 2.7 10 27 25 1.8 28 28 2.1 42 22 2.5 11 25 20 1.4 28 26 2.0 41 21 2.3 12 51 40 6.4 45 33 4.0 39 20 2.1 13 33 30 2.7 66 45 8.0 32 20 1.7 14 31 29 2.4 436 203 353 30 20 1.6 15 41 33 3.7 5930 1080 30500 27 20 1.5 16 55 43 6.4 1370 422 3180 27 20 1.5 17 55 43 6.4 2120 597 5150 28 19 1.4 18 46 45 5.6 10900 1870 93200 29 20 1.6 19 36 30 2.9 664 240 473 28 18 1.4 20 27 25 1.8 280 122 76 27 19 1.4 21 29 25 2.0 165 95 42 29 20 1.6 22 25 24 1.6 130 43 15 27 20 1.5 23 1020 262 2120 107 42 12 26 20 1.4 24 426 183 301 93 39 9.8 26 20 1.4 25 206 112 69 84 32 7.3 29 19 1.5 26 133 82 32 76 29 6.0 28 17 1.3 27 68 55 10 69 21 3.9 26 14 .98 28 49 45 6.0 63 18 3.1 23 14 .87 29 42 35 4.0 57 9 1.4 23 21 1.3 30 39 32 3.4 55 8 1.2 20 23 1.2 31 --- --- --- 52 11 1.5 --- --- --- TOTAL 2818 2625.0 23123 133076.8 1017 56.45 259 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO Al GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1984 TO SEPTEMBER 1985 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 36 2.3 29 10 .78 56 18 2.2 2 27 41 3.0 55 19 2.8 45 16 1.8 3 25 51 3.4 39 12 1.3 41 14 1.2 4 27 53 3.9 31 8 .67 32 10 .81 5 22 54 3.2 28 7 .53 82 44 28 6 23 40 2.5 27 6 .44 50 43 7.0 7 21 30 1.7 38 11 1.1 30 28 2.3 8 22 25 1.5 31 9 .75 208 95 146 9 23 22 1.4 30 8 .65 247 122 145 10 24 25 1.6 43 14 1.6 58 46 7.2 11 23 25 1.6 36 11 1.1 50 40 5.4 12 26 25 1.8 32 9 .78 695 194 2070 13 27 27 2.0 49 16 2.1 2380 675 5520 14 24 26 1.9 45 15 1.8 343 157 150 15 101 70 31 32 9 .78 173 102 51 16 218 104 73 27 10 .73 101 83 26 17 195 102 63 26 19 1.3 83 56 13 18 88 62 17 23 16 .99 59 45 7.2 19 48 35 4.0 27 20 1.5 49 40 5.3 20 401 202 472 29 26 2.0 41 32 3.5 21 126 70 24 41 43 4.8 37 30 3.0 22 65 48 8.4 36 40 3.9 35 30 2.8 23 51 38 5.2 27 34 2.5 40 35 3.8 24 77 27 5.6 26 35 2.5 87 69 21 25 53 18 2.6 26 33 2.3 778 301 1130 26 51 17 2.3 31 33 2.8 137 90 38 27 42 13 1.5 466 196 399 98 77 27 28 42 13 1.5 229 119 77 253 126 164 29 49 16 2.1 77 60 7.5 159 97 47 30 41 12 1.3 46 30 4.2 75 70 14 31 32 10 .86 52 34 5.1 --- --- TOTAL 2018 747.16 1734 535.30 6522 9643.51 YEAR 68645 190634.88 260 RIO GRANDE DE LOILA BASIN 50057000 RIO GURABO Al GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 1 210 123 148 235 150 106 65 50 8.8 2 725 302 907 199 120 64 65 50 8.8 3 205 129 79 177 110 53 65 50 8.8 4 214 135 133 149 90 36 62 50 8.4 5 833 319 921 177 104 59 89 60 14 6 8800 1670 60800 164 100 44 97 60 16 7 5470 1270 26400 139 82 31 82 55 12 8 1900 555 4740 114 80 25 70 55 10 9 413 180 201 104 80 22 69 52 9.7 10 261 130 92 98 70 19 70 50 9.5 11 202 120 65 101 70 19 68 50 9.2 12 168 100 45 173 110 51 74 50 10 13 149 90 36 265 150 139 71 50 9.6 14 136 85 31 198 160 86 61 52 8.6 15 119 75 24 2060 603 5540 60 52 8.4 16 111 75 22 584 232 458 63 53 9.0 17 128 90 31 233 120 75 59 51 8.1 18 587 218 1010 583 248 521 59 50 8.0 19 282 140 107 231 130 81 59 50 8.0 20 148 90 36 190 110 56 63 52 8.3 21 126 80 27 410 183 332 55 50 7.4 22 113 80 24 125 90 30 54 48 7.0 23 1170 411 2890 96 70 18 52 45 6.3 24 1840 560 4820 88 65 15 53 43 6.2 25 860 331 1810 83 50 11 50 42 5.7 26 351 163 176 80 50 11 56 45 6.8 27 317 160 137 78 55 12 49 45 6.0 28 240 140 91 72 50 9.7 47 42 5.3 29 973 398 2210 69 50 9.3 47 38 4.8 30 384 176 204 66 50 8.9 43 35 4.1 31 406 277 368 --- --- --- 43 39 4.5 TOTAL 27841 108585 7341 7941.9 1920 257.3 281 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continu,1 SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 44 45 5.3 32 26 2.2 21 20 1.1 2 59 45 7.2 30 26 2.1 21 20 1.1 3 47 42 5.3 31 25 2.1 21 20 1.1 4 48 43 5.6 64 60 10 20 20 1.1 5 48 43 5.6 70 45 8.5 27 21 1.5 6 40 39 4.2 39 38 4.0 25 21 1.4 7 37 38 3.8 32 30 2.6 23 20 1.2 8 35 35 3.3 30 30 2.4 21 20 1.1 9 83 60 13 30 29 2.3 20 20 1.1 10 94 80 20 29 28 2.2 20 20 1.1 11 50 45 6.1 28 30 2.3 21 20 1.1 12 41 40 4.4 27 31 2.3 25 22 1.5 13 36 39 3.8 25 32 2.2 22 25 1.5 14 34 35 3.2 24 30 1.9 38 35 3.6 15 33 30 2.7 24 28 1.8 173 98 64 16 33 30 2.7 25 25 1.7 51 50 6.9 17 76 54 19 25 25 1.7 32 38 3.3 18 56 45 6.8 30 28 2.3 26 30 2.1 19 41 30 3.3 31 27 2.3 20 25 1.4 20 35 30 2.8 28 23 1.7 20 20 1.1 21 37 31 3.1 28 22 1.7 19 18 .92 22 35 30 2.8 27 20 1.5 19 18 .92 23 35 30 2.8 25 19 1.3 16 15 .65 24 43 32 3.7 23 16 .99 19 15 .77 25 46 32 4.0 23 18 1.1 16 18 .78 26 37 31 3.1 24 19 1.2 25 19 1.3 27 31 30 2.5 21 20 1.1 24 18 1.2 28 30 28 2.3 21 20 1.1 19 15 .77 29 30 28 2.3 --- --- 179 82 82 30 32 28 2.4 84 55 12 31 34 27 2.5 71 55 11 TOTAL 1360 159.6 846 68.59 1138 210.61 APRIL MAY JUNE 1 138 90 45 55 45 6.7 182 103 55 2 51 32 4.4 32 30 2.6 126 83 31 3 40 28 3.0 21 22 1.2 126 80 27 4 42 40 4.5 19 15 .77 85 50 11 5 129 70 43 15 15 .61 140 88 39 6 132 55 20 21 19 1.1 85 60 14 7 45 38 4.6 205 119 125 71 60 12 8 85 50 11 192 113 159 164 101 59 9 175 109 78 515 177 471 304 324 558 10 44 45 5.3 678 245 861 269 139 153 11 31 32 2.7 818 296 902 124 78 26 12 28 30 2.3 158 100 43 89 70 17 13 26 27 1.9 3090 797 13300 106 80 23 14 24 22 1.4 3050 535 10900 145 85 33 15 23 19 1.2 260 160 112 94 75 19 16 22 18 1.1 174 110 52 156 103 50 17 21 12 .68 136 90 33 96 72 19 18 19 12 .62 464 200 467 81 65 14 19 17 12 .55 249 137 108 102 67 18 20 24 13 .84 160 90 39 73 60 12 21 21 16 .91 136 80 29 60 50 8.1 22 20 18 .97 128 80 28 59 48 7.6 23 16 19 .82 104 75 21 66 43 7.7 24 16 18 .78 88 65 15 51 40 5.5 25 15 18 .73 72 60 12 50 30 4.1 26 13 15 .53 66 50 8.9 51 25 3.4 27 16 15 .65 71 50 9.6 55 22 3.3 28 49 38 5.0 68 50 9.2 66 22 3.9 29 1240 412 4660 75 50 10 61 22 3.6 30 253 200 137 70 45 8.5 57 22 3.4 31 --- --- --- 476 230 582 --- --- --- TOTAL 2775 5039.48 11666 28318.18 3194 1240.6 262 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1985 TO SEPTEMBER 1986 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 51 22 3.0 55 45 6.7 99 75 20 2 50 21 2.8 40 35 3.8 68 50 9.2 3 49 20 2.6 32 30 2.6 48 35 4.5 4 47 20 2.5 29 25 2.0 42 35 4.0 5 45 20 2.4 27 24 1.7 41 35 3.9 6 126 55 50 26 22 1.5 69 50 9.3 7 122 132 53 29 20 1.6 57 35 5.4 8 48 55 7.1 67 45 8.1 39 31 3.3 9 37 32 3.2 27 30 2.2 35 29 2.7 10 34 30 2.8 31 40 3.3 33 25 2.2 11 33 30 2.7 98 78 30 31 23 1.9 12 40 30 3.2 50 40 5.4 29 25 2.0 13 34 30 2.8 39 30 3.2 29 28 2.2 14 34 25 2.3 152 94 78 41 25 2.8 15 73 40 7.9 38 28 2.9 32 25 2.2 16 55 40 5.9 52 35 4.9 29 22 1.7 17 37 28 2.8 33 25 2.2 27 20 1.5 18 36 27 2.6 29 25 2.0 26 19 1.3 19 31 27 2.3 28 25 1.9 25 19 1.3 20 28 25 1.9 27 25 1.8 24 19 1.2 21 28 22 1.7 23 25 1.6 23 19 1.2 22 26 21 1.5 25 25 1.7 24 20 1.3 23 26 21 1.5 30 22 1.8 29 20 1.6 24 25 21 1.4 30 20 1.6 57 25 3.8 25 25 20 1.4 31 21 1.8 49 25 3.3 26 23 20 1.2 27 20 1.5 37 25 2.5 27 24 20 1.3 26 18 1.3 31 22 1.8 28 27 20 1.5 102 57 76 32 22 1.9 29 34 25 2.3 1970 542 5890 28 21 1.6 30 285 169 247 132 80 29 26 21 1.5 31 146 88 45 87 60 14 --- --- --- TOTAL 1679 469.6 3392 6186.1 1160 103.1 YEAR 64312 158580.06 RIO GRANDE DE LOIZA BASIN 263 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY). WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 DAY MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER ' 1 2 3 4 5 27 25 23 23 23 30 30 27 27 27 2.2 2.0 1.7 1.7 1.7 59 71 72 51 101 60 70 70 56 90 9.6 13 14 7.7 25 72 70 79 72 67 75 70 80 80 66 15 13 17 16 12 6 7 8 9 10 22 26 27 30 46 26 28 30 38 45 1.5 2.0 2.2 3.1 5.6 113 211 291 131 199 100 203 268 110 157 31 248 302 39 95 62 93 69 65 69 65 85 75 70 70 11 21 14 12 13 11 12 13 14 15 33 27 24 31 51 37 30 26 33 60 3.3 2.2 1.7 2.8 8.3 197 1530 527 244 209 164 929 396 197 160 102 5730 1020 145 90 174 99 92 107 84 147 40 50 90 60 122 11 12 26 14 16 17 18 19 20 120 66 39 29 25 110 65 40 33 29 41 12 4.2 2.6 2.0 280 186 120 93 93 217 150 100 65 40 189 75 32 16 10 'JD 73 70 61 65 85 80 75 66 66 22 16 14 11 12 21 22 23 24 25 22 218 63 87 164 25 182 69 85 148 1.5 220 13 20 122 76 75 68 64 96 28 22 18 15 70 5.7 4.5 3.3 2.6 18 63 56 55 54 86 65 65 60 60 85 11 9.8 8.9 8.7 20 26 27 28 29 30 31 116 176 146 66 61 61 114 189 136 70 65 62 48 171 70 12 11 10 181 218 115 95 96 --- 159 190 110 95 85 --- 88 139 34 24 22 --- 65 84 102 65 57 57 70 70 105 70 60 58 12 16 29 12 9.2 8.9 TOTAL 1897 802.3 5862 8534.4 2382 549.5 264 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR lCTOBER 1986 TO SEPTEMBER 1987 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 54 55 8.0 70 75 14 44 18 2.1 2 53 52 7.4 44 50 5.9 42 18 2.0 3 50 52 7.0 38 43 4.4 41 18 2.0 4 51 60 8.3 35 30 2.8 76 65 13 5 88 80 19 35 22 2.1 174 157 107 6 119 110 35 39 18 1.9 61 35 5.8 7 187 158 98 38 15 1.5 49 30 4.0 8 66 70 12 35 12 1.1 45 28 3.4 9 71 70 13 31 7 .59 42 25 2.8 10 47 40 5.1 29 6 .47 42 21 2.4 11 44 25 3.0 192 181 139 42 23 2.6 12 41 18 2.0 73 75 15 73 55 11 13 39 15 1.6 136 127 96 47 12 1.5 14 39 18 1.9 154 142 68 42 12 1.4 15 45 25 3.0 101 100 27 42 13 1.5 16 38 25 2.6 64 60 10 95 62 54 17 35 25 2.4 56 45 6.8 152 140 68 18 34 22 2.0 52 39 5.5 77 85 18 19 33 21 1.9 50 38 5.1 37 45 4.5 20 33 20 1.8 48 35 4.5 31 40 3.3 21 31 19 1.6 48 32 4.1 27 35 2.6 22 31 19 1.6 46 28 3.5 26 30 2.1 23 49 35 4.6 44 25 3.0 25 25 1.7 24 54 25 3.6 41 20 2.2 22 20 1.2 25 37 22 2.1 42 18 2.0 24 20 1.3 26 35 22 2.1 43 15 1.7 24 20 1.3 27 33 21 1.9 47 15 1.9 22 20 1.2 28 32 20 1.7 45 15 1.8 21 20 1.1 29 33 25 2.2 --- --- --- 20 20 1.1 30 145 134 71 20 20 1.1 31 74 90 18 18 20 .97 TOTAL 1721 345.4 1676 431.86 1503 325.97 285 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 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 18 19 .92 29 10 .78 57 60 9.2 2 17 17 .78 30 11 .89 169 152 164 3 18 15 .73 47 25 3.2 310 299 597 4 22 15 .89 44 40 4.8 176 200 93 5 21 12 .68 51 55 7.6 72 45 8.7 6 21 11 .62 348 285 425 59 35 5.6 7 30 11 .89 71 55 11 53 32 4.6 8 19 11 .56 48 31 4.0 47 30 3.8 9 18 11 .53 40 30 3.2 50 30 4.1 10 78 63 59 46 45 5.6 64 30 5.2 11 83 95 31 63 55 9.4 54 35 5.1 12 222 181 220 136 115 42 45 35 4.3 13 210 170 133 57 65 10 78 75 16 14 177 150 155 45 55 6.7 80 80 17 15 128 178 83 39 49 5.2 612 445 2780 16 58 60 9.4 36 42 4.1 316 277 320 17 341 285 532 34 36 3.3 128 110 38 18 88 90 21 33 35 3.1 98 100 26 19 55 60 8.9 72 50 9.7 360 320 750 20 49 45 6.0 379 255 438 1640 1150 7790 21 44 35 4.2 367 296 528 2050 1310 16100 22 41 38 4.2 167 150 68 3950 2370 34000 23 38 33 3.4 109 100 29 393 265 281 24 36 15 1.5 68 70 13 204 160 88 25 34 10 .92 155 150 63 160 130 56 26 33 9 .80 1060 714 5550 140 125 47 27 32 8 .69 474 427 1040 233 197 193 28 31 8 .67 187 180 91 205 183 114 29 30 10 .81 87 85 20 164 140 62 30 29 10 .78 81 70 15 138 110 41 31 --- --- --- 57 60 9 2 --- -_, --- TOTAL 2021 1282.87 4460 8423.77 12105 63623.6 266 RIO GRANDE DE 10IZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1986 TO SEPTEMBER 1987 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 1 109 40 12 36 35 3.4 54 60 8.7 2 97 15 3.9 43 39 4.5 86 100 23 3 103 15 4.2 51 148 141 46 55 6.8 4 90 25 6.1 211 92 26 37 40 4.0 5 153 130 54 65 62 11 36 37 3.6 6 85 85 20 64 60 10 31 35 2.9 7 84 82 19 56 59 8.9 28 32 2.4 8 105 100 28 48 57 7.4 30 30 2.4 9 72 82 16 46 55 6.8 28 30 2.3 10 69 70 13 54 52 7.6 35 45 4.3 11 53 50 7.2 43 50 5.8 43 50 5.8 12 50 35 4.7 40 45 4.9 28 35 2.6 13 48 28 3.6 45 40 4.9 24 32 2.1 14 47 20 2.5 37 35 3.5 24 30 1.9 15 95 80 21 34 35 3.2 26 30 2.1 16 64 55 9.5 40 35 3.8 24 27 1.7 17 39 15 1.6 31 35 2.9 21 24 1.4 18 43 15 1.7 31 35 2.9 30 25 2.0 19 55 45 6.7 32 33 2.9 45 60 7.3 20 71 70 13 40 32 3.5 39 36 3.8 21 79 70 15 38 32 3.3 25 29 2.0 22 68 70 13 32 30 2.6 30 28 2.3 23 45 42 5.1 29 30 2.3 28 27 2.0 24 46 42 5.2 28 30 2.3 29 35 2.7 25 37 45 4.5 27 30 2.2 32 32 2.8 26 38 50 5.1 33 31 2.8 24 29 1.9 27 43 45 5.2 37 32 3.2 21 28 1.6 28 53 42 6.0 27 31 2.3 20 25 1.4 29 48 40 5.2 26 30 2.1 21 25 1.4 30 48 40 5.2 25 30 2.0 85 70 16 31 34 36 3.3 35 33 3.1 --- --- --- TOTAL 2071 320.5 1384 293.1 1030 125.2 YEAR 38112 85058.47 287 RIO GRANDE OE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 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 50 55 7.4 59 45 7.2 143 130 50 2 33 30 2.7 45 28 3.4 455 386 962 3 33 32 2.9 40 27 2.9 119 100 32 4 57 60 9.2 123 126 61 95 80 21 5 41 37 4.1 100 108 38 79 80 17 6 32 37 3.2 235 306 370 641 670 4020 7 35 37 3.5 104 100 28 9720 4520 424000 8 30 36 2.9 60 60 9.7 11500 5800 476000 9 30 35 2.8 51 50 6.9 516 638 1080 10 29 32 2.5 50 50 6.8 315 250 213 11 23 30 1.9 46 48 6.0 227 195 120 12 22 30 1.8 58 60 9.4 186 160 80 13 22 28 1.7 63 45 7.7 164 140 62 14 256 197 269 41 38 4.2 150 130 53 15 161 145 70 39 35 3.7 143 130 50 16 173 162 111 44 35 4.2 139 120 45 17 667 1110 4220 73 50 9.9 131 120 42 18 2100 1610 25800 150 178 111 128 120 41 19 557 326 957 66 70 12 146 140 55 20 153 75 31 70 65 12 179 145 70 21 97 40 10 47 50 6.3 173 160 75 22 72 40 7.8 44 50 5.9 212 170 97 23 62 40 6.7 181 158 289 139 110 41 24 70 40 7.6 4620 5910 95000 128 110 38 25 97 35 9.2 1120 525 2720 121 110 36 26 85 30 6.9 1110 994 8970 130 110 39 27 78 30 6.3 19800 9220 686000 129 105 37 28 72 98 24 2310 1410 18000 126 100 34 29 70 55 10 386 280 292 117 100 32 30 53 12 1.7 207 140 78 113 100 31 31 59 40 6.4 --- --- --- 179 120 58 TOTAL 5319 31601.2 31342 812075.2 26743 907531 268 RIO GRANDE DE LOU); BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 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 1 394 335 430 139 60 23 37 40 4.0 2 192 190 98 113 60 18 50 45 6.1 3 138 70 26 147 115 46 36 15 i.5 4 116 30 9.4 89 80 19 32 10 .86 5 124 25 8.4 66 60 11 32 10 .86 6 127 28 9.6 69 35 6.5 30 10 .81 7 121 28 9.1 52 25 3.5 30 10 .81 8 117 30 9.5 50 20 2.7 30 10 .81 9 121 29 9.5 57 35 5.4 29 10 .78 10 121 29 9.5 74 70 14 27 10 .73 11 113 29 8.8 55 60 8.9 27 10 .73 12 120 30 9.7 51 58 8.0 27 10 .73 13 104 25 7.0 89 85 20 27 10 .73 14 107 22 6.4 72 70 14 28 10 .76 15 98 20 5.3 54 55 8.0 26 10 .70 16 91 18 4.4 62 45 7.5 26 10 .70 17 89 15 3.6 50 35 4.7 26 10 .70 18 90 12 2.9 45 32 3.9 26 10 .70 19 84 10 2.3 43 28 3.3 25 10 .68 20 82 11 2.4 42 20 2.3 '6 10 .70 21 79 11 2.3 40 15 1.6 27 10 .73 22 75 10 2.0 39 12 1.3 26 10 .70 23 74 10 2.0 37 12 1.2 24 10 .65 24 73 10 2.0 39 12 1.3 24 10 .65 25 72 10 1.9 41 11 1.2 24 10 .65 26 73 10 2.0 50 20 2.7 26 10 .70 27 71 11 2.1 245 216 222 29 10 .78 28 73 11 2.2 56 80 12 32 10 .86 29 74 10 2.0 41 52 5.8 32 10 .86 30 73 10 2.0 --- --- --- 28 10 .76 31 67 12 2.2 28 10 .76 TOTAL 3353 694.5 2007 478.8 897 32.49 269 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 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 23 10 .62 21 12 .68 32 35 3.0 2 22 10 .59 20 11 .59 23 26 1.6 3 21 10 .57 17 10 .46 20 22 1.2 4 20 10 .54 16 10 .43 19 21 1.1 5 20 10 .54 16 12 .52 '9 20 .97 6 27 15 1.1 218 163 174 18 20 .97 7 38 25 2.6 155 178 96 17 20 .92 8 24 25 1.6 46 40 5.0 16 20 .86 9 22 20 1.2 29 30 2.3 17 20 .92 10 20 20 1.1 77 85 86 21 22 1.2 11 22 15 .89 162 133 102 18 22 1.1 12 21 15 .85 53 50 7.2 53 49 15 13 19 12 .62 32 38 3.3 29 30 2.3 14 18 11 .53 31 33 2.8 40 50 15 32 30 2.6 59 55 8.8 585 541 17A.4 16 27 25 1.8 41 40 4.4 244 213 174 17 20 20 1.1 32 35 3.0 164 168 109 18 20 19 1.0 31 32 2.7 62 60 10 19 22 17 1.0 33 35 3.1 43 40 4.6 20 17 15 .69 46 45 5.6 272 232 341 21 18 16 .78 74 70 14 251 208 182 22 15 15 .61 45 40 4.9 162 140 61 23 46 40 5.0 29 30 2.3 112 120 36 24 26 30 2.1 26 28 2.0 179 158 95 25 20 20 1.1 24 25 1.6 159 144 130 26 18 15 .73 22 22 1.3 80 80 17 27 19 15 .77 23 20 1.2 75 80 16 28 18 13 .63 20 20 1.1 53 50 7.2 29 17 12 .55 23 25 1.6 172 154 88 30 16 12 .52 34 40 3.7 71 70 13 31 --- ___ --- 83 80 18 --- --- --- TOTAL 668 34.33 1538 560.58 3025 3040.34 270 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO--Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRAT1ON DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 570 420 1180 52 50 7.0 60 65 11 2 793 607 2290 47 50 6.3 55 60 8.9 3 172 145 75 44 50 5.9 51 57 7.8 4 87 80 19 57 50 7.7 49 56 7.4 5 62 70 12 46 50 6.2 46 55 6.8 6 119 103 44 41 45 5.0 40 50 5.4 7 1280 906 5780 68 80 15 42 50 5.7 8 148 60 24 76 60 12 45 50 6.1 9 92 40 9.9 49 50 6.6 221 183 171 10 96 38 9.8 119 119 70 210 212 177 11 98 40 11 217 203 157 2870 1260 25200 12 102 40 11 109 105 31 930 653 2690 13 69 38 7 1 58 70 11 320 256 268 14 780 479 2490 48 60 7.8 353 311 377 15 108 105 31 47 55 7.0 232 208 158 16 77 80 17 45 60 7.3 161 140 61 17 66 75 13 96 100 26 102 105 29 18 72 80 16 68 80 15 75 80 16 19 94 90 23 49 65 8.6 597 300 1270 20 68 80 15 42 60 6.8 191 100 52 21 56 60 9.1 39 60 6.3 121 95 31 22 129 120 42 70 94 36 120 100 32 23 84 100 23 131 143 75 155 175 73 24 65 80 14 3290 1810 50000 101 110 30 25 65 76 13 730 540 1060 81 80 17 26 62 70 12 166 128 55 65 45 7.9 27 64 70 12 161 128 56 56 60 9.1 28 59 60 9 6 135 123 45 54 60 8.7 29 73 85 17 113 110 34 54 57 8.3 30 71 70 13 85 80 18 53 55 7.9 31 59 60 9.6 69 70 13 --- --- --- TOTAL 5740 12252.1 6367 51817.5 7510 30753.0 YEAR 94509 1850871.04 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 mi' (162.7 km:). PERIOD OF RECORD.--Water years 1919 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COLI- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE BID- DES- 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) OCT 1987 21... 0730 95 254 7.40 27.0 24 4.6 58 68 K9100 4100 DEC 18... 0730 E425 350 6.40 25.0 5.4 4.2 50 43 K1200 720 FEB 1988 18... 1330 382 6.80 29.0 4.4 57 3200 K1600 APR 08... 0910 25 418 7.40 27.5 17 3.5 44 95 K750 K220 JUN 06... 0910 19 400 7.30 29.5 35 3.7 48 41 4700 290 AUG 18... 1220 E30 330 7.20 28.5 25 4.2 54 16 27000 2700 HARD- ALKA- HARD- NESS MAGNE- SODIUM POTAS- LINITY CHLO- NESS NONCARB CALCIUM SIUM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DES- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CAC03 AS S) AS SO4) AS CL) OCT 1987 21... 77 3 18 7.7 20 1 4.9 74 <0.5 16 18 DEC 18... 110 FEB 1988 18... 120 APR 08... 130 0 29 13 31 1 4.2 110 <0.5 23 32 JUN 06... 130 AUG 18... 110 1 24 11 25 1 4.8 100 14 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, DES- 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) 5102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 21... 0.10 27 156 40 20 0.88 0.12 1.0 0.44 0.0 DEC 18... 16 0.81 0.09 0.9 0.20 0.40 FEB 1988 18... 1.08 0.12 1.2 0.38 0.72 APR 08... 0.20 29 242 16 37 0.85 0.15 1.0 0.73 0.77 JUN 06... 52 0.53 0.07 0.6 0.13 0.67 AUG 18... 0.10 28 191 23 0.88 0.12 1.0 0.58 0.72 K = non-ideal count E = estimate 271 272 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA • NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1987 21... 0.4 1.4 6.2 2.2 1 <100 90 ,1 <1 10 DEC 18... 0.6 1.5 6.6 0.24 FEB 1988 18... 1.1 2.3 10 0.39 APR 08... 1.5 2.5 11 0.50 1 100 <10 <1 ,1 10 JUN 06... 0.8 1.4 6.2 0.29 AUG 18... 1.3 2.3 10 0.40 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) OCT 1987 21... 1900 <5 230 <0.10 2 <1 10 <0.010 6 0.04 DEC 18... FEB 1988 18... APR 08... 1000 <5 550 <0.10 <1 <1 20 <0.010 3 0.04 JUN 06... AUG 18... 273 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE, 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 mil (539 km 2 ). ELEVATION RECORDS PERIOD OF RECORD.--December 1987 to September 1988. GAGE.--Water-stage recorder. Datum of gage is 97.99 ft (29.867 m) above mean sea level (Puerto Rico Aqueduct and Sewer Authority benchmark); gage readings have been reduced to elevations above mean sea level. REMARKS.--Satellite data collection platform at station. Lake is formed by Loiza Oam, a concrete structure completed in 1954. Useable capacity of impoundment is 30,000 acre-ft (37.0 hm 3 ). Out flow from lake is contolled by five slide gates in powerplant and pump intake structure, four sluice gates, and concrete spillway with eight radial gates. Lake is used for municipal water supply and intermittent power generation. EXTREMES FOR PERIOD OF RECORD.--Maximun elevation 136.16 ft (41.50 m), July 2; minimun elevation, 125.86 ft (38.36 m), June 12. ELEVATION (FEET NGVD), WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 OBSERVATION AT 24:00 VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 134.74 134.46 135.16 132.30 129.30 128.84 134.17 134.56 133.96 2 135.23 135.16 134.41 132.13 129.14 128.59 134.53 134.67 134.23 3 134.27 134.07 134.48 131.99 128.88 128.31 135.05 134.90 134.56 4 135.02 134.61 134.45 131.79 128.59 128.03 134.83 134.24 134.84 5 134.43 134.93 134.39 131.62 128.32 127.72 134.48 134.38 135.06 6 134.44 135.15 134.35 131.83 128.96 127.41 134.65 134.43 134.51 7 134.54 134.54 134.29 131.89 129.33 127.05 134.81 134.74 134.77 8 135.14 134.41 134.23 131.75 129.21 126.68 134.96 135.00 135.09 9 134.29 134.56 134.17 131.61 129.48 126.35 134.66 133.96 134.02 10 134.94 134.80 134.07 131.41 130.44 126.09 134.51 134.18 133.99 11 133.95 134.91 133.97 131.36 131.07 125.93 134.98 133.95 133.99 12 134.62 135.17 133.88 131.19 131.14 126.56 134.80 134.42 134.40 13 133.95 134.44 133.76 130.98 131.07 126.49 135.15 134.69 135.23 14 134.49 134.68 133.63 130.81 130.98 126.41 134.97 134.87 135.25 15 134.86 134.89 133.51 130.74 130.97 129.42 134.58 134.39 135.51 16 135.12 135.05 133.40 130.72 130.88 130.93 134.94 134.66 135.50 17 134.27 134.55 133.37 130.76 130.74 131.36 134.46 133.94 135.50 18 134.54 134.56 133.11 131.62 130.62 131.42 134.93 134.95 135.49 19 134.77 134.57 132.97 131.68 130.51 131.44 134.48 134.15 134.49 20 134.96 134.62 132.93 131.52 130.53 132.29 134.73 134.28 134.46 21 135.09 134.63 132.83 131.39 130.61 133.34 134.86 134.38 134.40 22 135.17 134.61 132.69 131.21 130.63 133.94 134.58 134.43 134.63 23 135.18 134.61 132.52 131.09 130.43 134.26 134.98 133.94 134.41 24 135.19 134.66 132.37 130.95 130.22 134.86 134.87 134.21 134.67 25 134.42 134.00 134.69 132.31 130.72 129.97 135.23 134.83 133.89 134.55 26 135.20 134.10 135.16 132.24 130.49 129.74 135.05 134.36 134.45 134.92 27 134.37 134.23 134.90 132.30 130.28 129.51 134.77 134.57 134.38 134.40 28 135.11 134.40 135.09 132.46 130.05 129.25 134.86 134.55 133.95 134.41 29 134.39 134.77 135.12 132.59 129.77 129.06 134.68 134.78 134,75 134.64 30 134.82 134.94 132.56 129.52 128.99 134.59 134.78 134,04 135.00 31 134.59 135.14 132.45 129.05 134.38 133.96 MEAN 134.67 134.74 133.41 131.17 129.92 130.43 134.72 134.38 134.70 MAX 135.23 135.17 135.16 132.30 131.14 135.23 135.15 135.00 135.51 MIN 133.95 134.07 132.24 129.52 128,32 125.93 134.17 133.89 133,96 WTR YR 1988 MEAN 133.17 MAX 135.51 MIN 125.93 274 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18'19'49", long 66'01'00", at pumphouse at damsite, and 1.9 mi (3.1 km) south of Tru­ jillo Alto plaza. DRAINAGE AREA.--208 sq mi (539 sq km). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COIL- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- OXYGEN, (PER- ICAL 0.7 KF AGAR FEET DUCT- (STAND- ATURE DIS- CENT (HIGH UM-MF (COLS. DATE TIME PER ANCE ARD WATER SOLVED SATUR- LEVEL) (COLS./ PER SECOND (US/CM) UNITS) (DEG C) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT 1987 05... 1220 287 7.00 29.5 0.4 5 27 K60 K140 DEC 7... 1230 178 7.00 26.0 4.4 54 18 300 K180 FEB 1988 16... 0940 215 6.90 25.5 2.0 24 57 K91 K170 APR 06... 1325 317 7.30 27.0 2.0 25 13 K4 K120 JUN 03... 1140 300 7.10 31.0 2.6 35 33 K10 K120 AUG 05... 1210 225 6.30 30.0 3.1 40 28 K8 48 ALKA- RESIDUE NITRO- LINITY TOTAL NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- WAT WH AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- TOT FET SULFIDE DEG. C, NITRATE NITRITE N020403 AMMONIA ORGANIC ORGANIC GEN, FIELD TOTAL SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE MG/L AS (MG/L PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L CAC03 AS S) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT 1987 05... 94 <0.5 <1 0.07 0.03 0.10 0.32 0.48 0.8 0.J DEC 07... 54 6 0.83 0.07 0.90 0.14 0.16 0.3 1.2 FEB 1988 18... 62 33 0.95 0.05 1.00 0.21 0.59 0.8 1.8 APR 06... 98 <0.5 <1 0.36 0.04 0.40 0.10 0.40 0.5 0.9 JUN 03... 92 4 0.15 0.05 0.20 0.20 0.10 0.3 0.5 AUG 05... 66 6 0.48 0.02 0.50 0.10 0.50 0.6 1.1 MANGA- METHY- BORON, COPPER, IRON, NESE, ZINC, LENS NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL BLUE GEN, PHOROUS RECOV- RECOV- RECOV- RECOV- RECOV- CYANIDE ACTIVE TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL PHENOLS SUB- DATE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (MG/L TOTAL STANCE AS NO3) AS P) AS B) AS CU) AS FE) AS MN) AS ZN1 8 C CN) (UG/L) (MG/L) OCT 1987 05... 4.8 0.24 80 10 280 310 50 <0.01 3 0.05 DEC 07... 5.3 0.11 FEB 1988 18... 8.0 0.19 APR 6... 4.0 0.17 <10 <10 100 100 40 ,0.01 3 0.05 JUN 03... 2.2 0.17 AUG 05... 4.9 0.16 K = non-ideal count 275 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LO1ZA 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 Loiza Dam. DRAINAGE AREA.--209 mil (541 km 2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1986 to current year. GAGE.--Water-stage recorder. Elevation of gage is 32 ft (10 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Flow regulated by Lago Loiza Dam. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 124,300 ft'is (3,520 m'/s), Nov. 27, 1987, gage height, 39.57 ft (12.1 s), from floodmarks and rating curve extended above 100 ft'is (2.83 m'/s) on basis of step-back water analysis; minimum discharge, 1.6 ft'A (0.045 20/s), July 7, 1988. EXTREMES FOR CURRENT YEAR.--Maximum discharge, 124,300 ft 3 /s (3,520 03/s), Nov. 27, 1987, gage height, 39.57 ft (12.1 a), from floodmarks and rating curve extended above 100 ftgs (2.83 m'/s) on basis of step-back water analysis; minimum discharge, 1.6 ft'/s (0.045 m'/s), July 7, 1988. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1937 TO SE°TEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 61 66 393 1500 165 83 61 54 42 668 7.3 1030 2 62 66 571 618 78 342 62 51 42 4420 5.8 11 3 61 64 439 838 743 61 61 49 41 254 5.9 10 4 61 65 18 44 53 62 61 42 38 46 370 9.8 5 61 416 348 557 56 62 60 43 37 133 5.7 9.9 6 61 134 801 240 78 63 54 43 37 123 5.7 348 7 62 58 e17800 379 226 62 55 44 38 1430 5.6 21 8 63 71 e40000 65 205 62 45 45 42 123 6.1 11 9 61 71 el0000 850 71 65 42 57 42 171 397 e1000 10 61 67 e1520 78 73 63 45 88 40 202 994 e15 11 63 64 628 811 73 63 48 55 26 5.7 1230 e2750 12 61 60 51 74 76 63 51 49 11 185 45 2810 13 61 61 581 467 647 64 54 49 7.9 5.5 5.2 715 14 61 58 473 88 68 65 74 48 7.2 874 4.9 829 15 62 55 83 67 63 66 75 47 8.4 227 192 943 16 62 55 466 73 68 65 60 43 7.8 5.7 6.8 489 17 808 70 52 505 249 64 60 45 7.5 114 478 831 18 3940 369 254 79 78 64 152 46 7.2 6.6 7.9 6.0 19 588 55 698 78 76 63 76 49 7.2 318 353 1420 20 332 55 689 75 76 62 60 51 7.7 5.6 371 64 21 64 56 761 77 78 62 87 51 17 5.4 5.7 374 22 61 54 767 97 77 62 60 50 8.6 228 213 24 23 66 56 68 113 76 61 58 51 7.6 5.9 827 555 24 89 14100 638 119 74 64 58 49 7.7 135 9750 6.6 25 574 2870 351 513 74 66 56 47 20 83 4600 213 26 63 4110 86 77 173 62 55 45 103 112 421 7.9 27 64 51200 631 73 855 62 54 48 163 7.8 406 418 28 63 6140 63 73 76 58 54 48 8.2 56 449 5.4 29 64 1290 495 78 87 63 52 44 179 200 19 5.2 30 67 116 74 75 --- 62 53 43 149 183 517 5.2 31 67 --- 905 82 61 --- 41 --- 169 550 --- TOTAL 7894 81972 80704 8863 4792 2247 1843 1515 1160.0 10502.2 22254.6 14937.0 MEAN 255 2732 2603 286 165 72.5 61.4 48.9 38.7 339 718 498 MAX 3940 51200 40000 1500 855 342 152 88 179 4420 9750 2810 MIN 61 54 18 44 53 58 42 41 7.2 5.4 4.9 5.2 AC-FT 15660 162600 160100 17580 9500 4460 3660 3010 2300 20830 44140 29630 CFSM 1.22 13.1 12.5 1.37 .79 .35 .29 .23 .19 1.62 3.43 2.38 IN. 1.41 14.59 14.36 1.58 .85 .40 .33 .27 .21 1.87 3.96 2.66 CAL YR 1987 TOTAL 219713.0 MEAN 602 MAX 51200 MIN 4.9 AC-FT 435800 CFSM 2.88 IN. 39.11 WTR YR 1988 TOTAL 238683.8 MEAN 652 MAX 51200 MIN 4.9 AC-FT 473400 CFSM 3.12 IN. 42.48 e Estimated 276 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 Loiza Reservoir. DRAINAGE AREA.--213 mil (552 kml. PERIOD OF RECORD.--Water years 1981 to current year. REMARKS: Flow controlled by Lago Loiza reservoir. WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 DIS- OXYGEN, OXYGEN COL1- STREP- CHARGE, SPE- DIS- DEMAND, FORM, TOCOCCI INST. CIFIC SOLVED CHEM- FECAL, FECAL, CUBIC CON- PH TEMPER- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR 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) OCT 1987 21... 1040 42 188 7.60 28.0 80 5.0 64 70 3400 K6000 DEC 18... 0940 E5.3 215 6.90 25.0 1 6.4 77 <10 34000 K76000 FEB 1988 29... 0845 95 290 7.60 25.0 1.5 6.3 75 16 K110 K50 APR 22... 1150 72 322 7.80 27.0 160 6.5 81 ,10 17000 K15000 JUN 06... 1150 44 343 7.70 31.0 11 8.5 114 35 460 K150 AUG 29... 1150 16 180 7.30 28.0 110 4.5 57 <10 2000 K1500 HARD- AAA- HARD- NESS MAGNE- SODIUM POTAS- UNITY CHLO- NESS NONCARB CALCIUM S1UM, SODIUM, AD- SLUM, WAT WH SULFATE RIDE, TOTAL WH WAT DIS- DIS- DIS- SORP- DIS- TOT FET SULFIDE DIS- DIS- (MG/L TOT FLD SOLVED SOLVED SOLVED TION SOLVED FIELD TOTAL SOLVED SOLVED DATE AS MG/L AS (MG/L (MG/L (MG/L RATIO (MG/L MG/L AS (MG/L (MG/L (MG/L CAC03) CAC03 AS CA) AS MG) AS NA) AS K) CACO2 AS S) AS SO4) AS CL) OCT 1987 21... 61 5 15 5.8 15 0.8 3.5 56 <0.5 12 13 DEC 16... 62 FEB 1988 29... 100 APR 22... 110 0 26 10 22 1 2.2 110 <0.5 18 20 JUN 06... 110 AUG 29... 63 9 15 6.1 15 0.9 2.8 54 16 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/i (MG/i AS F) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) OCT 1987 21... 0.10 19 120 14 26 0.92 0.08 1.00 0.10 0.50 DEC 16... 4 0.99 0.01 1.00 0.12 1.10 FEB 1988 29... <1 0.66 0.04 0.70 0.59 0.80 APR 22... 0.20 21 180 35 239 0.90 0.10 1.00 0.21 0.29 JUN 06... 18 0.87 0.13 1.00 1.00 0.90 AUG 29... 0.20 17 115 5.1 60 0.91 0.09 1.00 0.25 0.45 K = non-ideal count E = estimate RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 NITRO- CHRO- GEN,AM- BARIUM, BORON, CADMIUM MIUM, COPPER, MONIA + NITRO- NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL ORGANIC GEN, GEN, PHOROUS ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE 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) OCT 1981 21... 0.6 1.6 4.8 0.20 1 <100 30 <1 <1 20 DEC 16... 1.2 2.1 5.8 0.25 FEB 1988 29... 1.4 2.1 4.4 0.18 - APR 22... 0.5 1.5 6.6 0.20 1 <100 <10 <1 10 30 JUN 06... 1.9 2.9 13 0.36 AUG 29... 0.7 1.7 7.5 0.30 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) OCT 1987 21... 4500 21 120 <0.10 0) w I 53 -J CI Z LAJ < I- --I < 54 ONDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1988 1985 1986 1987 393 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182544066341500. Local numnber, 205. LOCATION.--Lat 18- 25'44", long 66 34'15". Owner: U.S. Geological Survey. Name: NC-05 Barceloneta near Cruce Davila. AQUI'ER.--Montebello Limestone. WELL CHARACTERISTICS.--Artesian observation well, diameter 6 in (0.15 n), 0-2.564 ft (0-782 m) , cased 2.5 in (0.06 m), iron pipe 0-1,075 ft (0-328 m), open hole 1,075-2,564 ft (328-782 m). Depth 2,564 ft (782 m) measured. DATUM.--Elevation of land surface datum is 312 ft (95.1 m) above mean sea level, from topographic map. Measuring point: Top of shelter floor, 6.65 ft (2.03 m) above land-surface datum. REMARKS.--Recording observation ell. PERIOD OF RECORDS.--December 1986 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.16 ft (2.79 m) below land-surface datum. Aug. 18, 1987; lowest water level recorded, 13.65 ft (4.16 m) below land-surface datum, Dec. 9, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.59 9.27 9.22 8.87 9.21 8.80 8.99 9.21 8.60 9.23 9.63 10.39 2 9.60 9.42 9.22 8.81 9.29 9.00 8.97 9.18 8.44 9.20 9.78 10.46 3 9.60 9.29 9.20 8.77 9.24 9.00 8.93 9.17 8.49 9.20 9.77 10.43 4 9.61 9.31 9.20 8.73 9.24 8.99 8.97 9.18 8.36 9.22 9.83 10.26 5 9.54 9.34 9.19 8.72 9.22 8.82 9.06 9.15 8.40 9.23 9.75 10.39 6 9.96 9.44 9.19 8.69 9.70 8.73 9.05 8.95 8.55 9.27 9.76 10.47 7 9.78 9.33 9.19 8.73 9.56 8.75 9.02 8.78 8.64 9.30 9.81 10.49 8 9.73 9.31 9.34 8.73 9.55 8.90 9.06 8.46 8.72 9.31 9.86 10.45 9 9.60 9.26 --- 8.73 9.51 8.88 9.07 8.27 8.81 9.30 9.84 10.53 10 9.47 9.27 8.72 9.52 8.88 9.13 8.10 8.86 9.30 9.88 10.46 11 9.58 9.25 --- 8.72 9.52 8.89 9.08 7.92 8.82 9.47 9.91 10.47 12 9.79 9.22 9.33 8.72 9.45 8.87 9.14 7.59 8.79 9.45 9.95 10.53 13 9.70 9.26 9.22 8.72 9.40 8.84 9.17 7.41 8.93 9.39 9.95 10.53 14 9.64 --- 9.30 8.70 9.11 8.84 9.18 7.37 8.96 9.47 9.93 10.53 15 9.69 9.26 8.51 9.11 8.82 9.21 7.54 8.98 9.54 9.97 10.54 16 9.58 9.22 8.54 9.08 9.07 9.26 7.52 8.92 9.38 9.99 10.68 17 9.41 9.23 8.50 9.02 8.99 8.96 7.61 8.96 9.35 9.99 10.68 18 9.45 9.28 8.51 9.00 9.14 9.18 7.64 8.91 9.36 10.00 10.62 19 9.55 9.16 8.57 8.99 8.99 9.05 7.93 8.88 9.44 10.01 10.64 20 9.56 9.16 8.51 8.94 8.99 9.05 7.92 9.01 9.49 10.04 10.77 21 9.54 9.26 8.46 8.93 9.00 9.02 7.80 9.12 9.60 10.00 10.65 22 9.55 9.29 9.43 8.96 8.98 8.93 7.87 9.08 9.60 10.07 10.64 23 9.52 --- 9.23 9.41 9.00 --- 8.94 8.09 9.18 9.61 10.20 10.69 24 9.44 9.21 9.20 9.41 9.01 --- 8.94 7.97 9.13 9.58 10.26 10.52 25 9.25 9.25 9.05 9.41 8.95 8.85 8.94 8.05 9.12 9.57 10.26 10.44 26 9.32 9.30 8.99 9.42 8.90 8.94 9.16 8.12 9.12 9.64 10.26 10.50 27 9.34 9.30 9.07 9.38 8.85 8.94 9.17 8.17 9.19 9.73 10.28 10.57 28 9.34 9.30 9.09 9.36 8.83 8.87 9.19 8.25 9.22 9.72 10.31 10.55 29 9.42 9.30 8.99 9.34 8.85 8.92 9.19 8.28 9.22 9.72 10.26 10.51 30 9.21 9.22 9.09 9.30 --- 8.97 9.28 8.33 9.23 9.69 10.37 10.50 31 9.23 --- 9.10 9.29 8.95 --- 8.57 --- 9.63 10.44 --- LOW 9.96 9.43 9.70 9.28 9.21 9.23 9.73 10.44 10.77 HIGH 9.21 8.46 8.83 8.93 7.37 8.36 9.20 9.63 10.26 c) 6 Le La 0 8 t4W z < 10 i 12 ae DJ FMAMJJ ASONDJ FMAMJJ AS 1986 1987 1988 14 394 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182757066325600. Local number, 206. LOCATION.--Lat 18'27'57", long 66°32'56". Owner: P.R. Department of Agriculture. Name: Plazuela No. 2. AQUIFER.--Aymamon Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m), cased 16 in (0.41 m) 0-85 ft (0-25.9 m), open hole 85-101 ft (25.9-30.8 m). Depth 101 ft (30.8 m). DATUM.--Elevation of land-surface datum is about 7.0 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. 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, 5.72 ft (1.76 m) below land-surface datum, Oct. 8-9, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.06 5.14 5.09 5.04 5.09 5.37 5.30 5.23 5.25 5.22 5.27 4.73 2 5.03 5.11 5.10 4.84 5.02 5.39 5.32 5.24 5.25 5.22 5.29 4.82 3 4.99 5.09 5.18 4.89 4.95 5.44 5.35 5.22 5.26 5.20 5.30 4.89 4 4.94 5.09 5.21 4.94 4.91 5.50 5.34 5.23 5.26 5.19 5.01 4.97 5 4.90 5.10 5.22 4.99 4.99 5.54 5.33 5.28 5.31 5.21 5.15 5,02 6 4.88 5.12 5.20 5.05 5.08 5.55 5.32 5.27 5.32 5.24 5.22 5.04 7 4.86 5.17 5.25 5.08 5.14 --- 5.31 5.25 5.32 5.27 5.30 5.07 8 4.88 5.24 5.28 5.12 5.20 5.27 5.23 5.30 5.32 5.28 5.06 9 4.91 5.28 5.30 5.11 5.22 5.27 5.21 5.30 5.37 5.25 4.60 10 4.98 5.30 5.24 5.12 5.23 5.27 4.84 5.30 5.38 5.22 3.79 11 5.03 5.29 5.23 5.13 5.26 5.25 4.58 5.32 5.38 5.19 3.75 12 5.06 5.29 5.22 5.15 5.30 5.18 4.50 5.31 5.39 5.17 3.95 13 5.05 5.30 5.24 5.16 5.34 5.20 4.66 5.29 5.40 5.15 4.10 14 5.05 5.28 5.25 5.18 5.36 5.21 4.76 5.30 5.39 5.15 4.31 15 5.06 5.26 5.20 5.22 5.37 5.22 4.84 5.31 5.39 5.15 4.53 16 5.05 5.25 5.17 5.21 5.38 4.98 4.89 5.30 5.39 5.18 4.71 17 4.99 5.20 5.14 5.19 5.35 5.11 4.94 5.29 5.38 5.18 4.84 18 4.98 5.18 5.12 5.21 5.34 5.19 4.99 5.31 5.38 4.62 4.88 19 4.97 5.17 5.15 5.20 5.33 5.24 5.05 5.32 5.39 4.73 4.98 20 4.95 5.11 5.20 5.21 5.33 5.25 5.09 5.34 5.41 4.85 5.02 21 4.95 5.07 4.92 5.22 5.35 5.20 5.14 5.34 5.42 4.98 5.04 22 4.95 5.08 4.99 5.26 5.35 --- 5.20 5.17 5.30 5.44 5.07 5.05 23 5.03 5.12 5.03 5.26 5.36 5.70 5.21 5.18 5.28 5.47 4.56 5.03 24 5.07 5.15 5.06 5.25 5.36 5.47 5.23 5.20 4.95 5.47 4.19 5.03 25 --- 5.15 5.08 5.19 5.37 5.47 5.26 5.22 5.06 5.47 4.04 5.05 26 5.13 5.02 5.23 5.33 5.44 5.23 5.22 5.11 5.46 4.19 5.06 27 --- 5.11 4.95 5.27 5.31 5.40 5.19 5.24 5.16 5.45 3.86 5.08 28 5.13 5.03 4.99 5.31 5.34 5.35 5.16 5.25 5.11 5.41 4.10 5.13 29 5.13 5.03 4.99 5.32 5.36 5.29 5.16 5.24 5.15 5.37 4.29 5.18 30 5.16 5.05 5.01 5.32 --- 5.26 5.19 5.24 5.21 5.31 4.45 5.21 31 5.16 --- 5.02 5.36 5.30 --- 5.22 --- 5.27 4.60 --- LOW 5.30 5.30 5.36 5.38 5.35 5.28 5.34 5.47 5.30 5.21 HIGH 5.03 4.92 4.84 4.91 4.98 4.50 4.95 5.19 3.86 3.75 9 3 CO I-. LAJ < o La 4 ze. >v) 5 J 0 .q< -1 6 ONDJFMAMJJ ASONDJ FMAMJJ ASONDJ FMAMJJ AS 1985 1986 1987 1988 395 GROUND-WATER LEVELS RIO GRANDE DE MANAT1 BASIN 182710066303700. Local number, 207. LOCATION.--Lat 1827'10", long 66'30'37". Owner: P.R. Aqueduct and Sewer Authority. Name: Cantito La Luisa. AQUIFER.--Aymamon Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-30 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). DATUM.--Elevation of land-surface datum is about 59.0 ft (18.0 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 36.38 ft (11.09 m) below land-surface datum, May 15, 1986; lowest water level recorded, 89.83 ft (27.38 m) below land-surface datum, Oct. 5, 1985. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 38.52 38.84 38.61 38.45 38.80 38.90 39.15 38.89 38.67 38.90 39.12 38.62 2 38.51 38.84 38.19 38.44 38.78 38.90 39.15 38.90 38.70 38.90 39.12 38.65 3 38.51 38.84 38.33 38.42 38.73 38.91 39.15 38.91 38.74 38.90 39.13 38.68 4 38.49 38.85 38.45 38.41 38.70 38.93 39.15 38.92 38.75 38.89 39.10 38.71 5 38.50 38.87 38.53 38.41 38.67 38.96 39.16 38.94 38.78 38.89 39.10 38.73 6 38.50 38.88 38.56 38.43 38.67 38.98 39.16 38.94 38.81 38.90 39.09 38.74 7 38.50 38.89 38.59 38.45 38.67 38.98 39.16 38.94 38.82 38.91 39.09 38.73 8 38.52 38.91 38.62 38.47 38.68 39.00 39.15 38.94 38.83 38.93 39.09 38.73 9 38.54 38.93 38.65 38.48 38.69 39.02 39.15 38.94 38.84 38.96 39.08 38.72 10 38.57 38.93 38.66 38.46 38.68 39.04 39.16 38.91 38.85 38.98 39.07 38.62 11 38.60 38.93 38.67 38.47 38.69 39.02 39.14 38.36 38.86 38.98 39.06 38.57 12 38.62 38.93 38.68 38.51 38.72 38.98 39.14 38.10 38.87 39.00 39.04 38.53 13 38.63 38.94 38.72 38.53 38.76 38.99 39.12 38.04 38.88 39.01 39.05 38.49 14 38.63 38.94 38.76 38.55 38.79 39.00 39.10 38.06 38.88 39.02 39.06 38.50 15 38.66 38.92 38.70 38.58 38.82 39.00 39.10 38.08 38.89 39.04 39.07 38.53 16 38.64 38.91 38.63 38.60 38.83 39.01 39.00 38.11 38.90 39.06 39.09 38.55 17 38.65 38.90 38.62 38.60 38.83 39.04 38.97 38.15 38.90 39.06 39.08 38.58 18 38.66 38.90 38.62 38.60 38.83 39.04 38.94 38.20 38.91 39.07 39.03 38.61 19 38.67 38.90 38.64 38.57 38.83 39.06 38.92 38.25 38.92 39.08 38.99 38.63 20 38.68 38.89 38.63 38.57 38.83 39.06 38.91 38.32 38.93 39.09 39.00 38.63 21 38.68 38.86 38.57 38.59 38.85 39.08 38.90 38.37 38.94 39.12 39.00 38.64 22 38.69 38.85 38.54 38.60 38.87 39.12 38.86 38.43 38.93 39.13 39.00 38.64 23 38.71 38.86 38.52 38.62 38.88 39.15 38.83 38.48 38.91 39.14 38.93 38.64 24 38.74 38.84 38.52 38.64 38.89 39.17 38.81 38.51 38.91 39.13 38.92 38.64 25 38.75 38.81 38.52 38.66 38.90 39.18 38.83 38.53 38.90 39.16 38.74 38.66 26 38.78 38.80 38.52 38.70 38.90 39.18 38.83 38.56 38.90 39.16 38.66 38.70 27 38.79 38.78 38.49 38.74 38.90 39.18 38.84 38.58 38.90 39.17 38.60 38.71 28 38.80 38.64 38.47 38.77 38.90 39.17 38.84 38.60 38.90 39.15 38.57 38.72 29 38.80 38.60 38.47 38.79 38.90 39.15 38.85 38.63 38.90 39.15 38.56 38.73 30 38.81 38.59 38.46 38.80 39.13 38.87 38.66 38.90 39.14 38.58 38.72 31 38.83 38.48 38.80 39.14 38.66 .39.12 38.59 LOW 38.83 38.94 38.76 38.80 38.90 39.18 39.16 38.94 38.94 39.17 39.13 38.74 HIGH 38.49 38.59 38.19 38.41 38.67 38.90 38.81 38.04 38.67 38.89 38.56 38.49 WTR YR 1988 MEAN 38.79 LOW 39.18 HIGH 38.04 36 gx cl 37 w w lr LI 38 vt' 14 CII 39 -J CEZ La I _Je 235 - I CI IX Z 240 J FM AMJ J ASONDJ F MAM J J A S ON DJ FMAM J J AS 1986 1987 1988 397 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182634066262500. Local number, 209. LOCATION.--Lat 18'26'34", long 66°26'25". Owner: P.R. Aqueduct and Sewer Authority. Name: Coto Norte No. 3. AQUIFER.--Aymamon-Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m), caed 16 in (0.41 m) 0-495 ft (0-150.9 m), perforated 255-455 ft (77.7-138.7 m). Depth 495 FT (150.9 m). DATUM.--Elevation of land-surface datum is about 99.0 ft (30.2 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 2.30 ft (0.70 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--October 1985 to October 30, 1987, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 71.50 ft (21.79 m) below land-surface datum, July 23, 1986; lowest water level recorded, 81.96 ft (24.98 m) below land-surface datum, June 24, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 80.92 2 80.94 3 80.94 4 80.94 5 80.94 6 80.94 7 80.94 8 80.94 9 80.94 10 80.94 11 80.94 12 80.94 13 80.96 14 80.96 15 80.97 16 80.97 17 80.97 18 80.97 19 80.97 20 80.97 21 80.97 22 80.85 23 80.80 24 80.75 25 80.74 26 80.72 27 80.72 28 80.11 29 80.70 30 31 LOW HIGH of 65 La m ticl 70 Lu 75 La CI1 80 < I- 85 ONDJFMAMJJASONDJEMAIAJJASONDJFIAAMJJAS 1985 1986 1987 1988 398 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182308066260400. Local number, 210. LOCATION.--Lat 18- 23'08", long 66'26'04". Owner: Gelo Martinez. Name: Gelo Martinez well. AQUIFER.--tares Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.20 m), cased 8 in (0.20 m). DATUM.--Elevation of land-surface datum is about 574 ft (174.9 m) above mean sea level, from topographic map. •Measuring point: Hole on side of casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 40.56 ft (12.36 m) below land-surface datum, May 22, 1986; lowest water level recorded, 67.67 ft (20.62 m) below land-surface datum, Apr. 6, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 INSTANTANEOUS OBSERVATION AT 1200 TO SEPTEMBER 1988 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 57.52 62.34 57.07 49.65 49.76 53.35 58.91 49.26 49.52 50.03 65.04 50.07 2 57.74 62.39 57.33 49.00 49.33 53.66 58.90 49.33 49.50 50.07 65.14 50.88 3 58.13 62.44 58.51 48.59 49.04 53.90 58.96 49.39 49.47 50.10 65.24 52.70 4 58.42 62.50 59.39 48.79 49.05 54.10 59.11 49.45 49.46 50.15 65.30 54.64 5 58.56 62.54 60.08 49.02 49.05 54.26 59.33 49.47 49.45 50.25 65.33 56.65 6 58.73 62.61 60.75 49.29 49.15 54.35 59.58 49.50 49.45 50.49 65.41 58.54 7 58.98 62.67 61.39 49.49 49.39 54.50 59.97 49.52 49.46 51.55 65.48 59.67 8 59.34 62.72 61.86 49.64 49.62 54.67 60.40 49.55 49.52 --- 65.44 60.49 9 59.82 62.77 62.12 49.71 49.77 54.82 60.96 49.56 49.58 65.49 61.35 10 60.14 62.83 62.28 49.82 49.91 54.99 61.57 49.57 49.66 65.55 61.74 11 60.39 62.98 62.36 49.97 50.06 55.22 62.08 49.51 49.69 - 65.58 60.10 12 60.64 63.29 62.44 50.12 50.16 55.49 62.32 48.97 49.71 65.63 55.43 13 60.86 63.59 62.54 50.27 50.28 55.74 62.43 49.03 49.69 65.68 50.18 14 61.06 63.77 62.60 50.40 50.42 56.02 62.44 49.11 49.69 65.73 49.94 15 61.18 63.96 62.66 50.48 50.54 56.34 62.43 49.19 49.69 65.78 50.06 16 61.27 64.08 62.72 50.65 50.70 56.66 62.14 49.29 49.71 65.81 50.35 17 61.49 64.22 62.81 50.88 50.86 56.96 53.00 49.34 49.71 65.87 50.55 18 61.59 64.25 62.91 51.16 51.04 57.15 48.77 49.38 49.75 65.90 50.35 19 61.55 64.23 63.11 51.38 51.20 57.31 48.11 49.44 49.79 65.88 50.24 20 61.50 64.12 63.20 51.57 51.34 57.48 48.19 49.46 49.85 65.83 50.39 21 61.46 64.10 62.13 51.69 51.53 57.67 48.03 49.47 49.86 - 65.79 50.55 22 61.46 64.14 49.92 51.82 51.74 57.82 48.03 49.49 49.90 - 65.77 50.44 23 61.38 64.21 49.21 52.00 51.88 57.95 48.06 49.52 49.91 65.76 50.72 24 61.34 64.30 49.26 52.18 52.09 58.13 48.13 49.48 49.90 65.71 51.93 25 61.31 64.35 49.51 52.36 52.28 58.32 48.18 49.47 49.90 63.98 53.34 26 61.36 64.36 49.60 52.54 52.51 58.58 48.32 49.47 49.93 52.72 54.97 27 61.50 64.30 49.44 52.72 52.81 58.75 48.60 49.49 49.96 --- 49.15 56.23 28 61.71 63.54 49.33 52.84 53.00 58.82 48.91 49.49 49.99 64.32 49.06 57.34 29 61.96 62.12 49.50 52.99 53.17 58.87 49.08 49.50 49.98 64.57 49.27 58.26 30 62.15 58.77 49.79 53.11 --- 58.90 49.16 49.50 49.98 64.79 49.53 58.92 31 62.24 --- 49.92 50.15 58.89 --- 49.52 --- 64.92 49.80 --- LOW 62.24 64.36 63.20 53.11 53.17 58.90 62.44 49.57 49.99 65.90 61.74 HIGH 57.52 58.77 49.21 48.59 49.04 53.35 48.03 48.97 49.45 49.06 49.94 0 20 4( wo LW 40 zgs >v160 aZ W 4c FMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1986 1987 1988 399 GROUND-WATER LEVELS RIO CIBUCO BASIN 182647066201700. Local number, 70. LOCATION.--Lat 18 26'47", long 66'20'17". Owner: P.R. 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 ft (0-27.43 m), perforated. Depth 90 ft (27.43 m). DATUM.--Elevation of land-surface datum is about 49 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. 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, 31.10 ft (9.48 m) below land-surface datum, July 31, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANMTANEOUS OBSERVATION 41 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.21 27.32 27.07 26.89 27.14 27.30 27.90 27.42 26.69 27.21 27.54 26.71 2 27.22 27.34 27.05 26.86 27.12 27.33 27.92 27.44 26.71 27.23 27.55 26.73 3 27.23 27.36 27.06 26.81 27.08 27.35 27.93 27.46 26.74 27.24 27.56 26.74 4 27.24 27.38 27.07 26.78 27.05 27.38 27.94 27.49 26.77 27.25 27.52 26.76 5 27.24 27.39 27.09 26.76 27.02 27.40 27.95 27.51 26.79 27.25 27.52 26.78 6 27.27 27.42 27.10 26.76 27.01 27.42 27.97 27.53 26.82 27.26 27.51 26.80 7 27.28 27.44 27.11 26.75 27.00 27.45 27.98 27.55 26.84 27.26 27,50 26.82 8 27.30 27.46 27.12 26.76 27.01 27.46 27.99 27.57 26.87 27.28 27.50 26.84 9 27.31 27.48 27.13 26.77 27.01 27.49 28.01 27.59 26.89 27.29 27.50 26.84 10 27.30 27.49 27.14 26.78 27.03 27.51 28.02 27.51 26.91 27.31 27.49 26.78 11 27.32 27.51 27.14 26.79 27.05 27.54 28.03 26.82 26.94 27.31 27.49 26.74 12 27.33 27.53 27.16 26.80 27.06 27.56 28.05 26.50 26.95 27.33 27.49 26.67 13 27.32 27.55 27.18 26.82 27.08 27.57 28.07 26.40 26.97 27.34 27.50 26.62 14 27.35 27.57 27.20 26.83 27.10 27.59 28.08 26.36 26.99 27.35 27.51 26.59 15 27.36 27.58 27.18 26.85 27.11 27.61 28.09 26.34 27.01 27.38 27.51 26.58 16 27.36 27.60 27.15 26.87 27.13 27.63 27.96 26.34 27.03 27.40 27.52 26.58 17 21.38 27.59 27.13 26.89 27.14 27.66 27.88 26.34 27.05 27.41 27.52 26.59 18 27.38 27.56 27.13 26.91 27.68 27.72 26.36 27.07 27.43 27.52 26.59 19 27.38 27.54 27.15 26.93 27.71 27.57 26.38 27.10 27.44 27.49 26.60 20 27.37 27.53 27.15 26.94 27.15 27.74 27.48 26.41 27.11 27.46 27.49 26.62 21 27.31 27.52 27.09 26.96 27.17 27.75 27.41 26.43 27.12 27.47 27.49 26.62 22 27.22 27.52 27.03 26.98 27.18 27.77 27.39 26.46 27.13 27.48 27.49 26.64 23 27.20 27.53 26.99 21.00 27.20 27.79 27.37 26.48 27.12 27.50 27.48 26.64 24 27.22 27.53 26.97 27.02 21.21 27.81 27.36 26.51 27.14 27.51 27.46 26.65 25 27.21 27.50 26.95 27.04 27.23 27.83 27.36 26.53 27.15 27.52 27.18 26.66 26 27.23 27.43 26.93 27.06 27.24 27.86 27.37 26.55 27.16 27.54 27.04 26.68 27 27.25 27.40 26.90 27.08 27.26 27.87 27.38 26.58 27.., 27.55 26.94 26.70 28 27.26 27.33 26.89 27.10 27.26 27.88 27.38 26.61 27.18 27.56 26.81 26.72 29 27.26 27.19 26.88 27.12 27.28 27.88 27.39 26.62 27.19 27.57 26.75 26.73 30 27.28 27.10 26.88 27.13 27.89 27.41 26.64 27.19 27.54 26.72 26.74 31 27.31 26.89 27.15 27.89 26.66 27.52 26.71 LOW 27.38 27.60 27.20 27.15 27.89 28.09 27.59 27.19 27.57 27.56 26.84 HIGH 27.20 27.10 26.88 26.75 27.30 27.36 26.34 26.69 27.21 26.71 26.58 20 o3 1- 4t u. 1.4 wo 24 zitz -1% La> In 28 WI -I CI Z -5 4 32 ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1985 1986 1987 1988 400 GROUND-WATER LEVELS RIO CIBUCO BASIN 182615066235300. Local number, 211. LOCATION.--Lat 1826'15", long 66'23'53". Owner: P.R. 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). DATUM.--Elevation of land-surface datum is about 215 ft (65.5 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 1.15 ft (0.35 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 191.29 ft (58.30 m) below land-surface datum, May 16, 1986; lowest water level recorded, 193.10 ft (58.86 m) below land-surface datum, Mar. 21, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 192.37 192.47 192.44 192.38 192.62 192.96 192.51 192.23 192.47 192.66 192.46 2 192.38 192.50 192.46 192.31 192.62 192.96 192.54 192.25 192.47 192.66 192.45 3 192.39 192.51 192.51 192.27 192.62 192.96 192.55 192.27 192.48 192.66 192.45 4 192.39 192.56 192.53 192.26 192.58 192.96 192.57 192.28 192.48 192.66 192.45 5 192.40 192.58 192.56 192.27 192.55 192.96 192.58 192.31 192.48 192.66 192.45 6 192.40 192.60 192.56 192.27 192.50 192.96 192.64 192.33 192.48 192.65 192.45 7 192.41 192.63 192.56 192.27 192.50 192.95 192.64 192.33 192.48 192.65 192.48 8 192.42 192.64 192.56 192.27 192.50 192.95 192.64 192.33 192.50 192.62 192.48 9 192.42 192.66 192.57 192.27 192.50 192.94 192.63 192.33 192.50 192.73 192.48 10 192.43 192.71 192.57 192.29 192.50 192.94 192.60 192.33 192.49 192.73 192.48 11 192.43 192.71 192.57 192.29 192.50 192.94 192.00 192.35 192.51 192.73 192.47 12 192.44 192.71 192.58 192.30 192.50 192.94 191.60 192.37 192.51 192.73 192.41 13 192.45 192.71 192.58 192.31 192.50 192.93 191.50 192.37 192.51 192.73 192.35 14 192.45 192.71 192.58 192.36 192.50 192.93 191.49 192.38 192.53 192.72 192.35 15 192.46 192.71 192.59 192.40 192.50 192.91 191.55 192.40 192.54 192.72 192.35 16 192.46 192.71 192.59 192.43 192.52 192.75 191.66 192.41 192.54 192.72 192.35 17 192.47 192.71 192.58 192.45 192.52 192.59 191.72 192.41 192.58 192.72 192.35 18 192.48 192.71 192.56 192.46 192.54 192.51 191.79 192.42 192.58 192.72 192.35 19 192.48 192.69 192.56 192.46 192.54 192.44 191.87 192.46 192.58 192.72 192.34 20 192.49 192.68 192.56 192.48 192.59 192.40 191.93 192.47 192.58 192.72 192.34 21 192.49 192.65 192.52 192.50 192.64 192.34 191.99 192.48 192.61 192.72 192.34 22 192.40 192.63 192.48 192.51 192.30 192.04 192. 192.64 192.72 192.34 23 192.39 192.62 192.44 192.51 192.93 192.30 192.08 192.48 192.66 192.72 192.34 24 192.39 192.62 192.42 192.51 192.98 192.31 192.12 192.49 192.68 192.71 192.34 25 192.40 192.62 192.42 192.51 192.97 192.37 192.14 192.49 192.68 192.63 192.34 26 192.41 192.62 192.43 192.51 192.98 192.38 192.15 192.49 192.67 192.51 192.33 27 192.41 192.62 192.42 192.54 192.98 192.40 192.20 192.49 192.67 192.49 192.33 28 192.41 192.55 192.41 192.58 192.98 192.40 192.23 192.48 192.67 192.48 192.33 29 192.43 192.48 192.41 192.59 192.98 192.44 192.24 192.47 192.67 192.47 192.33 30 192.45 192.47 192.41 192.60 192.97 192.48 192.24 192.47 192.67 192.46 192.33 31 192.46 192.40 192.62 192.96 192.24 192.67 192.46 LOW 192.49 192.71 192.59 192.62 192.96 192.64 192.49 192.68 192.73 192.48 HIGH 192.37 192.47 192.40 192.26 --- 192.30 191.49 192.23 192.47 192.46 192.33 \\I ONDJ FMAMJJ ASONDJ FMAMJJ ASONDJ FMAMJ J AS 1985 1986 1987 1988 401 GROUND-WATER LEVELS RIO CIBUCO BASIN 182515066194000. Local number, 212. LOCATION.--Lat 1825'15", long 6619'40". Owner: U.S. Geological Survey. 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). 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, 3.00 ft (0.91 m) above land-surface datum. REMARKS.--Recording observation well. 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 (19.22 m; b(1-w land-surface datum, July 15, 1987; lowest water level recorded, 74.63 ft (22.75 m) below land-surface datum, uct. 27,28, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 66.42 66.87 66.81 66.35 66.59 66.95 68.01 67.39 67.30 68.50 67.06 65.74 2 66.44 66.90 66.61 66.28 66.58 67.00 68.02 67.36 67.41 68.55 67.08 65.83 3 66.47 66.93 66.46 66.22 66.56 67.05 68.04 67.35 67.52 68.58 67.09 65.80 4 66.51 67.00 66.35 66.16 66.53 67.09 68.06 67.36 67.62 68.62 67.10 65.78 5 66.54 67.05 66.27 66.10 66.49 67.14 68.09 67.38 67.71 68.66 67.09 65.77 6 66.57 67.11 66.24 66.06 66.46 67.16 68.20 67.39 67.66 68.69 67.07 65.77 7 66.60 67.15 66.20 66.03 66.43 67.19 68.20 61.40 67.71 68.74 67.08 65.78 8 66.64 67.18 66.17 65.99 66.41 67.22 68.20 67.42 67.76 68.76 67.08 65.81 9 66.69 67.21 66.25 65.98 66.40 67.23 68.23 67.47 67.88 68.82 67.11 65.84 10 66.71 67.25 66.33 65.97 66.40 67.26 68.25 67.97 67.90 68.85 67.10 65.83 11 66.73 67.29 66.41 65.96 66.40 67.31 68.27 68.50 67.99 68.89 67.11 65.82 12 66.77 67.33 66.48 65.96 66.40 67.35 68.61 67.79 68.06 68.91 67.13 65.74 13 66.80 67.37 66.56 65.98 66.40 67.38 68.42 66.00 68.15 68.94 67.15 65.67 14 66.85 67.42 66.63 66.00 66.42 67.40 68.41 65.35 67.61 68.97 67.16 65.61 15 66.91 67.46 66.82 66.04 66.45 67.44 68.43 65.08 66.76 67.84 67.18 65.59 16 66.93 67.50 66.80 66.07 66.48 67.48 68.30 64.90 66.34 67.31 67.20 65.57 17 66.98 67.55 66.80 66.11 66.51 67.54 68.10 64.78 66.21 67.15 67.21 65.54 18 67.01 67.55 66.83 66.13 66.53 67.60 67.94 64.70 66.16 67.08 67.22 65,51 19 67.05 67.54 66.87 66.18 66.55 67.67 67.76 64.66 66.13 67.04 67.22 65.50 20 67.07 67.49 66.89 66.21 66.58 67.71 67.62 64.62 66.11 67.01 67.23 65.53 21 67.07 67.47 66.87 66.25 66.64 67.74 67.51 64.60 67.28 66.98 67.24 65.48 22 66.93 67.46 66.83 66.29 66.67 67.79 67.42 64.58 67.86 66.96 67.25 65.46 23 66.85 67.46 66.80 66.33 66.70 67.80 67.36 64.68 67.94 66.96 67.24 65.45 24 66.80 67.46 66.76 66.36 66.73 67.84 67.32 64.62 68.08 66.96 67.23 65.44 25 66.75 67.47 66.73 66.40 66.75 67.87 67.28 64.62 68.17 66.96 67.00 65.44 26 66.73 67.46 66.69 66.45 66.79 67.92 67.24 64.62 68.23 66.97 66.77 65.44 27 66.74 67.45 66.62 66.49 66.83 67.95 67.26 66.00 68.29 66.99 66.61 65.44 28 66.74 67.40 66.55 66.52 66.86 67.97 67.22 66.64 68.35 67.00 66.30 65.46 29 66.77 67.26 66.47 66.52 66.91 67.98 67.20 66.87 68.39 67.13 66.08 65.48 30 66.80 67.01 66.43 66.53 67.98 67.78 67.03 68.45 67.04 65.91 65.51 31 66.82 66.40 66.55 68.00 67.17 67.05 65.81 LOW 67.07 67.55 66.89 66.55 66.91 68.00 68.61 68.50 68.45 68.97 67.25 65.84 HIGH 66.42 66.87 66.17 65.96 66.40 66.95 67.20 64.58 66.11 66.96 65.81 65.44 WTR YR 1988 MEAN 66.92 LOW 68.97 HIGH 64.58 0 60 F.< W 0 z 70 >14 -J CI Z 1.4 < 1-4 80 ONDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ 1988 1985 1986 1987 402 GROUND-WATER I FVL1S RIO CIBUCO BASIN 182330066185700. Local number, 213. LOCATION.--Lat 18 23'30", long 66- 18'57". Owner: P.R. 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- 100.6 m). Depth 330 ft (100.6 m). DATUM.--Elevation of land-surface datum is about 394 ft (120 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 2.95 ft (0.90 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.40 ft (10.50 m) below land-surface datum, Dec. 6, 1985; lowest water level recorded, 49.55 ft (15.10 m) below land-surface datum, May 1, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY jUN JUL AUG SEP 1 40.96 42.85 43.19 41.93 40.34 40.75 42.92 40.41 37.47 43.39 42.95 2 41.01 42.68 43.16 41.38 40.30 40.85 42.95 40.27 37.55 43.44 42.76 3 41.22 42.56 43.10 41.18 40.15 40.98 43.03 40.20 37.66 --- 42.70 4 41.17 42.58 43.06 40.87 40.05 41.07 43.08 40.38 37.85 42.65 5 41.15 42.61 43.03 40.61 39.92 41.12 43.07 40.41 37.98 - 42.62 6 41.30 42.66 43.03 40.44 39.80 41.13 43.07 40.45 38.07 - 43.74 42.62 • 7 41.40 42.67 42.98 40.2U 39.14 41.23 43.07 40.45 38.16 43.83 42.63 8 41.47 43.24 42.97 40.05 39.65 41.35 43.12 40.51 38.27 43.89 42.68 9 41.56 43.42 42.94 39.92 39.56 41.37 43.22 40.58 38.44 43.97 42.16 10 41.76 43.52 42.92 39.85 39.54 41.39 43.29 40.59 38.57 44.02 42.62 11 41.80 43.62 42.93 39.76 39.53 41.51 43.37 40.18 38.62 44.06 42.58 12 41.86 43.68 42.94 39.45 39.56 41.63 43.46 39.51 38.71 44.12 42.24 13 42.00 43.80 43.05 39.53 39.53 41.68 43.35 38.97 38.85 44.15 41.86 14 42.12 43.89 43.09 39.48 39.59 41.65 43.55 38.49 39.02 44.19 41.62 15 42.13 43.97 43.16 39.48 39.63 41.77 43.58 38.08 39.10 - 44.20 41.45 16 42.11 44.03 43.18 39.48 39.68 41.93 43.18 37.80 39.20 44.31 41.27 11 42.23 44.11 43.17 39.52 39.76 42.06 42.82 37.58 39.35 44.29 41.14 18 42.39 43.99 43.24 39.51 39.74 42.13 42.48 37.38 39.53 --- 44.32 40.99 19 42.41 44.10 43.39 39.57 39.80 42.16 42.22 37.22 39.62 42.20 44.36 40.88 20 42.52 44.05 43.44 39.61 39.90 42.11 41.99 37.07 39.76 42.31 44.40 40.82 21 42.58 44.05 43.25 39.72 39.96 41.91 41.66 36.98 39.81 42.37 44.44 40.21 22 42.56 44.09 43.04 39.78 40.01 42.07 41.42 37.01 39.69 42.47 44.48 40.11 23 42.52 44.04 42.90 39.82 40.07 41.88 41.22 36.99 39.95 42.61 44.51 39.74 24 42.58 44.08 42.80 39.91 40.12 42.19 41.00 36.98 40.09 42.69 44.44 39.53 25 42.63 44.04 42.68 39.95 40.17 42.39 40.80 36.96 40.09 42.79 44.19 39.36 26 42.52 43.91 42.54 39.72 40.22 42.52 40.64 37.00 40.31 42.90 43.72 39.19 27 42.58 43.83 42.40 39.93 40.35 42.59 40.57 37.09 40.43 42.99 43.66 38.85 28 42.57 43.67 42.26 39.96 40.51 42.64 40.47 37.19 40.61 43.07 43.47 38.55 29 42.62 43.34 42.16 40.07 40.66 42.75 40.47 37.27 --- 43.15 43.22 38.71 30 42.65 43.13 42.14 40.18 --- 42.18 40.44 37.32 43.27 43.00 38.70 31 42.73 --- 42.15 40.26 42.85 --- 37.22 43.33 42.98 --- LOW 42.73 44.11 43.44 41.93 40.66 42.85 43.58 40.59 42.95 HIGH 40.96 42.56 42.14 39.45 39.53 40.75 40.44 36.96 - - 38.55 0 25 _1 W 1- < 35 c.) >v) 45 -JO cr Z L.1 4 < 55 ONDJ FMAMJJ ASONDJFMAMJ J AS ONDJ FM AMJ J AS 1985 1986 1987 1988 J \I\ 19 87 19851986 NDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1988 ti (ROUND-WATER 1 LVEI S RIO DE LA PtAIA BASIN 182746066170800. local number. 214. LOCATION.--Lat 18 27'46". long 66 17'08'. Owner: Dorado Beach Hotel. Name: Dorado Beach No. 7. AQUIFER.--Aymamon Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 18 in (0.46 m). Depth 100 ft (30.5 m). DATUM.--Elevation of land-surface datum is about 39.0 ft (11.9 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 1.10 ft (0.34 m) above land-surface datum. REMARKS.--Recording observation well. Water levels affected by nearby pumping well. PERIOD OF RECORD.-- November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.23 ft (5.56 m) below land-surface datum, Nov. 16, 1985; lowest water level recorded, 20.31 ft (6.19 m) below land-surface datum, Mar. 8, 1987. 403 DAY OCT 1 19.60 2 19.55 3 19.51 4 19.42 5 19.36 6 19.31 7 19.30 8 19.30 9 19.37 10 19.46 11 19.51 12 19.54 13 19.54 14 19.54 15 19.60 16 19.58 17 19.55 18 19.54 19 19.48 20 19.43 21 19.37 22 19.40 23 19.45 24 19.47 25 19.48 26 19.51 27 19.55 28 19.57 29 19.62 30 19.66 31 19.66 LOW 19.66 HIGH 19.30 WATER LEVEL, IN FEET BElOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 19.63 19.34 19.25 19.37 19.77 19.90 19.79 19.57 19.72 19.69 19.19 19.57 19.35 19.21 19.38 19.81 19.96 19.80 19.58 19.68 19.74 19.32 19.52 19.40 19.21 19.36 19.82 19.99 19.79 19.59 19.63 19.75 19.39 19.50 19.42 19.22 19.37 19.80 19.98 19.81 19.59 19.65 19.71 19.43 19.51 19.4? 19.23 19.38 19.73 19.97 19.85 19.65 19.70 19.76 19.46 19.56 19.40 19.29 19.42 19.73 19.95 19.82 19.65 19.74 19.80 19.42 19.60 19.46 19.29 19.45 19.75 19.95 19.79 19.65 19.79 19.84 19.37 19.66 19.50 19.32 19.48 19.74 19.91 19.80 19.63 19.88 19.78 19.33 • 19.68 19.51 19.29 19.48 19.71 19.94 19.83 19.69 19.94 19.72 19.21 19.73 19.46 19.33 19.48 19.75 19.95 19.80 19.74 19.93 19.65 19.00 19.71 19.48 19.31 19.45 19.81 19.95 19.56 19.76 19.93 19.61 19.07 19.74 19.50 19.34 19.43 19.88 19.96 19.45 19.73 19.93 19.61 18.84 19.80 19.57 19.33 19.42 19.92 19.94 19.46 19.73 19.92 19.61 18.82 19.78 19.62 19.31 19.46 19.98 19.98 19.46 19.74 19.89 19.62 18.97 19.74 19.60 19.31 19.52 20.01 19.94 19.43 19.73 19.89 19.64 19.06 19.73 19.52 19.28 19.53 19.81 19.43 19.71 19.85 19.66 19.09 19.67 19.43 19.23 19.52 - 19.79 19.40 19.73 19.83 19.64 19.19 19.63 19.39 19.22 19.53 19.74 19.44 19.74 19.82 19.59 19.24 19.60 19.40 19.20 19.54 19.72 19.49 19.76 19.85 19.58 19.26 19.51 19.48 19.25 19.47 19.70 19.51 19./9 19.89 19.64 19.27 19.46 19.42 19.29 19.45 19.66 19.54 19.77 19.92 19.69 19.29 19.49 19.39 19.46 19.48 20.02 19.65 19.55 19.72 19.92 19.71 19.17 19.54 19.34 19.46 19.53 20.03 19.67 19.55 19.71 19.96 19.66 19.10 19.62 19.36 19.43 19.54 20.01 19.71 19.58 19.72 19.95 19.51 19.14 19.41 19.40 19.45 19.58 20.00 19.73 19.60 19.73 19.97 19.12 19.14 19.49 19.39 19.45 19.70 19.97 19.72 19.59 19.79 19.95 19.08 19.08 19.48 19.36 19.40 19.76 19.93 19.73 19.64 19.75 19.92 19.03 19.05 19.03 19.35 19.30 19.78 19.90 19.72 19.64 19.76 19.86 19.04 1941 19.18 19.29 19.30 19.78 19.85 19.75 19.62 19.77 19.80 19.06 1942 19.27 19.29 19.30 --- 19.84 19.78 19.62 19.77 19.72 19.09 19.14 --- 19.29 19.35 19.90 --- 19.59 --- 19.66 19.14 --- 19.80 19.62 19.46 19.78 19.99 19.85 19.:9 19.97 19.84 19.46 19.03 19.29 19.20 19.36 19.65 19.40 19.57 19.63 19.03 18.82 • 18 0 1 18.5 co $__ 1-4 19 w w u.C.) z 4t u- 19.5 w en 20 W I -J CI • 20.5 4 404 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182530066135400. Local number, 216. LOCATION.--Lat 18- 25'30", long 66'13'54". Owner: P.R. 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 it 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). 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. 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. 14.72 ft (4.49 m) below land-surface dat,,m, Apr. 28. 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12.22 12.81 12.21 11.87 12.24 11.81 12.25 11.57 11.43 11.89 11.96 10.55 2 12.25 12.81 12.28 11.72 12.16 11.80 12.95 11.59 11.43 11.88 11.99 10.57 3 12.29 12.82 12.37 11.80 12.11 11.97 13.08 11.54 11.35 12.20 11.99 10.62 4 12.30 12.86 12.43 11.80 12.06 12.11 13.13 11.54 11.42 12.38 11.78 10.67 5 12.30 12.90 12.48 11.83 12.07 12.17 13.19 11.50 11.59 12.44 11.79 10.70 6 12.36 12.95 12.44 11.84 12.11 12.20 13.24 11.41 11.56 12.29 11.81 10.74 7 12.39 12.98 12.39 11.86 12.09 12.23 13.28 12.13 11.69 12.20 11.83 10.76 8 12.40 13.01 12.30 11.88 12.08 12.27 13.32 12.23 11.75 12.21 11.67 10.78 9 12.44 13.03 12.30 11.89 12.17 12.29 12.88 12.30 11.85 11.78 11.64 10.61 10 12.48 13.05 12.32 11.90 12.23 12.19 12.87 12.01 11.23 11.75 11.62 10.45 11 12.51 13.10 12.36 11.91 12.25 12.09 12.88 10.99 11.61 11.75 11.99 10.29 12 12.54 13.12 12.40 11.91 12.30 12.07 12.91 10.72 11.91 11.78 12.03 10.07 13 12.57 13.16 12.44 11.93 12.28 12.66 12.90 10.54 11.98 11.77 11.82 10.02 14 12.61 13.19 12.48 11.94 12.13 12.47 12.92 10.46 12.03 11.81 12.07 10.07 15 12.65 13.19 12.39 11.98 12.09 12.46 12.49 10.43 12.10 11.85 12.13 10.12 16 12.b7 13.21 12.36 12.02 12.24 12.50 12.22 10.31 11.55 11.88 12.18 10.12 17 12.65 13.06 12.38 12.12 12.29 12.44 12.36 10.48 12.07 11.90 12.16 10.15 18 12.65 12.93 12.43 12.11 12.30 12.53 12.23 10.72 12.14 11.87 12.09 10.17 19 12.59 12.90 12.46 12.09 12.33 12.56 12.03 10.81 12.16 11.86 12.07 10.22 20 12.25 12.86 12.42 12.10 12.37 12.60 11.98 10.88 12.18 11.89 11.79 10.26 21 12.50 12.86 12.17 12.12 12.40 12.64 11.47 10.90 11.49 11.92 11.11 10.26 22 12.59 12.89 12.12 12.16 12.42 12.68 11.42 10.98 11.40 11.93 11.71 10.25 23 12.61 12.90 12.07 12.18 12.42 12.70 11.46 11.03 12.05 12.26 11.50 10.27 24 12.74 12.86 12.06 12.21 12.02 12.72 11.27 10.85 12.16 12.43 11.29 10.30 25 12.72 12.48 11.9/ 12.20 11.99 12.71 11.39 11.06 12.22 12.48 10.67 10.34 26 12.64 12.47 11.93 12.24 11.98 12.70 11.42 11.10 12.23 12.30 10.65 10.37 27 12.64 12.44 11.89 12.28 11.98 12.68 11.45 11.14 12.26 12.13 10.64 10.40 28 12.67 11.97 11.88 12.30 11.99 12.65 11.49 10.74 12.30 12.12 10.55 10.45 29 12.71 12.01 11.88 12.26 11.90 12.61 11.51 10.79 11.98 12.13 10.52 10.50 30 12.90 12.11 11.91 12.27 12.34 11.55 10.83 11.89 12.00 10.49 10.49 31 12.82 11.94 12.29 12.27 10.87 11.95 10.51 LOW 12.90 13.21 12.48 12.30 12.42 12.12 13.32 12.30 12.30 12.48 12.18 10.78 HIGH 12.22 11.97 11.88 11.72 11.90 11.80 11.27 10.31 11.23 11.75 10.49 10.02 WTR YR 1988 MEAN 11.95 LOW 13.32 HIGH 10.02 l\I\A\11" ONDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1985 1986 1987 1988 405 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182655066142400. Local number, 217. LOCATION.--Lat 1826'55", long 66'14'24". Owner: U.S. Geological Survey. 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 ft (0-24.4 m), perforated 10-80 ft (3.05-24.4 m). Depth 80 ft (24.4 m). 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. 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, 1.92 ft (0.58 m) below land-surface datum, Apr. 12, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.16 1.15 .67 .61 1.00 1.06 1.34 .95 .96 1.25 1.25 .45 2 1.13 1.13 .77 .53 .92 1.08 1.42 .98 .97 1.22 1.28 .54 3 1.12 1.12 .90 .54 .83 1.14 1.47 .97 1.02 1.18 1.31 .59 4 1.08 1.17 .94 .57 .79 1.21 1.48 .99 1.04 1.23 1.15 .65 5 1.04 1.21 .99 .61 .79 1.24 1.47 1.04 1.10 1.27 1.17 .70 6 1.04 1.26 .89 .67 .83 1.25 1.46 1.00 1.13 1.27 1.15 .70 7 1.06 1.29 .92 .69 .86 1.25 1.47 1.04 1.13 1.20 1.19 .71 8 1.07 1.32 .90 .70 .87 1.27 1.46 1.05 1.13 1.21 1.05 .67 9 1.12 1.35 .85 .68 .88 1.29 1.45 1.09 1.19 1.22 1.04 .55 10 1.14 1.35 .85 .70 .90 1.29 1.46 1.05 1.22 1.21 1.01 .32 11 1.17 1.36 .88 .70 .94 1.23 1.47 .46 1.22 1.22 1.00 .29 12 1.19 1.35 .88 .70 .99 1.22 1.48 .34 1.25 1.22 1.03 .08 13 1.19 1.38 .93 ./3 1.00 1.25 1.47 .35 1.27 1.25 1.01 .02 14 1.20 1.38 .97 .72 1.01 1.34 1.49 .35 1.30 1.25 1.06 .15 15 1.23 1.35 .94 .76 1.02 1.32 1.28 .35 1.26 1.28 1.09 .24 16 1.22 1.35 .88 .78 1.04 1.35 .77 .38 1.26 1.28 1.12 .28 17 1.17 1.30 .84 .79 1.03 1.37 .78 .43 1.25 1.27 1.11 .35 18 1.16 1.21 .85 .80 1.01 1.39 .77 .49 1.29 1.25 1.02 .38 19 1.11 1.19 .90 .77 1.00 1.43 .69 .58 1.31 1.25 .98 .42 20 .99 1.14 .94 .81 1.00 1.48 .71 .63 1.33 1.29 1.03 .45 21 1.02 1.11 .78 .85 1.05 1.50 .69 .66 1.28 1.32 1.05 .42 22 1.07 1.13 .73 .87 1.05 1.51 .70 .71 1.19 1.34 1.07 .30 23 1.14 1.18 .65 .87 1.05 1.51 .73 .84 1.16 1.38 .88 .29 24 1.19 1.21 .67 .87 1.03 1.51 .80 .82 1.18 1.41 .74 .30 25 1.17 .88 .67 .89 1.04 1.48 .80 .84 1.19 1.45 .16 .33 26 1.07 .87 .65 .94 1.02 1.46 .81 .84 1.23 1.47 .21 .40 27 1.10 .84 .58 .97 1.01 1.44 .83 .88 1.21 1.42 .22 .43 28 1.11 .19 .59 1.00 1.03 1.41 .86 .91 1.24 1.39 .25 .50, 29 1.13 .38 .59 1.01 1.08 1.37 .88 .91 1.24 1.39 .30 .551 30 1.16 .51 .60 1.00 --- 1.34 .92 .91 1.24 1.30 .32 .58 31 1.16 --- .65 1.03 1.34 --- .91 --- 1.24 .38 --- LOW 1.23 1.38 .99 1.03 1.08 1.51 1.49 1.09 1.33 1.47 1.31 .71 HIGH .99 .19 .58 .53 .79 1.06 .69 .34 .96 1.18 .16 .02 WTR YR 1988 MEAN .98 LOW 1.51 HIGH .02 N 2 NDJ FMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 19851986 1987 1988 406 GROUND-WATER I EVILS RIO HONDO TO RIO PUERIO NIJEVO BASINS 182623066111000. local number, 218. LOCATION.--Tat 1826'23", long 66 11'10". Owner: P.R. Aqueduct and Sewer Authority. Name: Levittown No. 7 . AQUIFER.--Alluvial deposits-Aymamon Limestone. WELL CHARACTERISTICS.--Drilled water-table well. 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 pump base, 1.55 ft (0.47 m) above land-surface datum. REMARKS.--Recording observation well, water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.13 ft (1.87m) below land-surface datum, Feb. 22, 1987; lowest water level recorded, 9./7 ft (2.98 m) below land-surface datum, Mar. 23, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUT AUG SEP 1 7.58 7.65 7.46 6.90 7.20 7.47 7.85 6.92 7.22 8.15 7.77 6.59 2 7.56 7.64 7.51 6.91 7.19 7.48 7.86 6.96 7.23 8.14 7.80 6.71 3 7.60 7.63 7.58 6.90 7.15 7.54 7.85 6.97 7.27 8.36 7.80 6.77 4 7.56 7.64 7.49 6.89 7.15 7.60 7.84 6.96 7.28 8.41 7.73 6.70 5 7.54 7.66 7.49 6.90 7.15 7.61 7.87 7.01 7.32 8.38 7.74 6.73 6 7.56 7.67 7.38 6.92 7.17 7.64 7.83 6.97 7.38 8.33 7.79 6.71 7 7.56 7.71 7.39 6.91 7.17 7.63 7.05 6.99 7.44 7.85 7.80 6.71 8 7.53 7.75 7.37 6.93 7.20 7.65 7.83 7.00 7.82 7.83 7.48 6.72 9 7.55 7.81 7.34 6.94 7.18 7.70 7.81 7.07 8.11 7.81 7.55 6.61 10 7.55 7.82 7.30 6.96 7.19 7.69 7.81 6.98 8.17 7.78 7.52 6.52 11 7.56 7.85 7.31 6.94 7.22 7.71 7.82 6.70 8.21 7.77 7.50 6.47 12 7.59 7.86 7.31 6.96 7.25 7.72 7.81 6.61 8.23 7.78 7.49 6.23 13 7.63 7.86 7.34 6.97 7.26 8.39 7.79 6.51 8.25 7.77 7.50 6.16 14 7.63 7.87 7.37 6.98 7.28 7.82 7.79 6.48 8.29 7.77 7.48 6.17 15 7.66 1.86 7.34 6.97 7.28 7.78 7.72 6.43 8.29 7.78 7.50 6.19 16 7.67 7.87 7.31 6.98 7.28 7.81 7.14 6.45 7.97 7.57 7.52 6.21 17 7.65 7.80 7.28 7.04 7.30 7.82 7.07 6.46 7.93 7.53 7.50 6.25 18 7.63 7.75 7.26 7.10 7.31 7.85 7.02 6.49 7.95 7.51 7.41 6.28 19 7.62 7.71 7.28 7.03 7.31 7.88 6.94 6.53 7.97 7.73 7.47 6.32 20 7.53 7.64 7.30 7.03 7.34 7.91 6.92 6.60 7.99 7.78 7.51 6.36 21 7.51 7.60 7.18 7.05 7.37 7.96 6.83 6.68 8.14 7.83 7.53 6.39 22 7.52 7.60 7.11 7.07 7.37 7.98 6.82 7.36 8.13 7.79 7.53 6.37 23 7.56 7.61 7.02 7.09 7.40 8.00 6.82 7.50 8.13 7.87 7.36 6.38 24 7.58 7.67 6.99 7.09 7.42 7.96 6.84 7.02 8.15 7.86 7.25 6.42 25 7.59 7.62 6.99 7.11 7.42 7.97 6.85 7.02 8.16 7.92 6.86 6.43 26 7.45 7.59 6.97 7.14 7.43 7.94 6.84 7.06 8.18 7.90 6.76 6.43 27 7.47 7.53 6.94 7.16 7.40 7.93 6.85 7.15 8.16 7.88 6.68 6.38 28 7.50 7.38 6.92 7.16 7.41 7.91 6.86 7.19 8.17 7.87 6.65 6.50 29 7.54 7.30 6.88 7.15 7.46 7.89 6.87 7.17 8.16 7.85 6.62 6.54 30 7.69 7.39 6.88 7.17 --- 7.87 6.90 7.07 8.17 7.79 6.59 6.58 31 7.66 --- 6.89 7.20 7.86 --- 7.18 --- 7.77 6.59 --- LOW 7.69 7.87 7.58 7.20 7.46 8.39 7.87 7.50 8.29 8.41 7.80 6.77 HIGH 7.45 7.30 6.88 6.89 7.15 7.47 6.82 6.43 7.22 7.51 6.59 6.16 WTR YR 1988 MEAN 7.37 LOW 8.41 HIGH 6.16 0 6 LaJ CO < lal w la- I la. 8 w- v, W I - 1 aZ 4C J 10 ONDJ FM AMJ J ASONDJ FMAMJJ ASONDJ FMAMJJ AS 1985 1986 1987 1988 407 GROUND-WATER lEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182441066082600. Local number, 219. LOCATION.--Lat 18- 24'41", long 66'08'26". Owner: Department of Defense. Name: Ft. Buchanan No. 1, Buchanan Park well 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 (73.7-82.3 m). Depth 270 ft (82.3 m). 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. PERIOD OF RECORD.--December 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 38.10 ft (11.61 m) below land-surface datum, June 16, 1986; lowest water level recorded, 43.32 ft (13.20 m) below land-surface datum, Mar. 15, 1987. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 41.66 40.10 40.38 39.66 40.60 41.67 42.37 40.32 40.31 40.94 40.87 39.49 2 41.71 40.11 40.38 39.53 40.51 41.74 42.35 40.30 40.35 40.94 40.89 39.47 3 41.73 40.24 40.27 39.48 40.43 41.82 42.33 40.35 40.38 40.94 40.90 39.38 4 41.70 40.39 40.21 39.46 40.31 41.86 42.32 40.44 40.44 40.95 40.89 39.35 5 41.68 40.55 40.24 39.47 40.28 41.86 42.29 40.47 40.49 40.96 40.86 39.34 6 41.71 40.71 40.27 39.50 40.28 41.84 42.26 40.47 4U 40.93 40.84 39.37 7 41.73 40.81 40.22 39.53 40.31 41.86 42.25 40.48 40.52 40.82 40.85 39.40 8 41.66 40.77 40.08 39.59 40.31 41.90 42.26 40.50 40.56 40.68 40.76 39.50 9 41.56 40.75 39.96 39.64 40.32 41.91 42.29 40.53 40.62 40.58 40.70 39.41 10 41.40 40.77 39.94 39.71 40.45 41.95 42.31 40.56 40.69 40.53 40.61 39.08 11 41.23 40.82 39.99 39.77 40.52 42.01 42.29 40.43 40.68 40.54 40.59 38.84 12 41.12 40.92 40.06 39.81 40.58 42.06 42.33 40.24 40.69 40.52 40.62 38.68 13 41.09 41.07 40.21 39.85 40.60 42.07 42.32 40.12 40.73 40.52 40.66 38.49 14 41.12 41.18 40.30 39.84 40.65 42.06 42.36 40.01 40.78 40.57 40.68 38.43 15 41.03 41.30 40.36 39.86 40.71 42.14 42.33 39.89 40.80 40.66 40.70 38.42, 16 40.96 41.41 40.27 39.92 40.78 42.24 42.00 39.83 40.81 40.69 40.73 38.41 17 40.84 41.47 40.27 39.97 40.83 42.32 41.72 39.81 40.84 40.69 40.80 38.40 18 40.69 41.44 40.38 40.00 40.87 42.37 41.49 39.82 40.87 40.69 40.76 38.36 19 40.58 41.34 40.48 40.06 40.96 42.36 41.25 39.85 40.88 40.69 40.77 38.37 20 40.54 41.26 40.46 40.10 41.04 42.39 41.02 39.87 40.90 40.70 40.76 38.44 21 40.54 41.24 40.21 40.15 41.12 42.39 40.82 39.88 40.87 40.70 40.76 38.49 22 40.54 41.22 39.99 40.23 41.20 42.42 40.74 39.90 40.86 40.70 40.78 38.52 23 40.57 41.20 39.86 40.27 41.24 42.44 40.72 39.99 40.87 40.74 40.73 38.56 24 40.55 41.14 39.78 40.32 41.30 42.45 40.68 40.02 40.90 40.73 40.54 38.60 25 40.43 40.89 39.74 40.38 41.36 42.47 40.47 40.03 40.90 40.74 40.28 38.63 26 40.15 40.75 39.69 40.49 41.42 42.47 40.32 40.07 40.92 40.75 40.04 38.65 27 40.04 40.59 39.62 40.55 41.51 42.47 40.29 40.13 40.95 40.80 40.00 38.71 28 40.00 40.46 39.61 40.61 41.56 42.46 40.30 40.16 41.00 40.81 39.87 38.76 29 40.02 40.35 39.57 40.60 41.63 42.46 40.32 40.17 40.96 40.83 39.76 38.81 30 40.02 40.30 39.62 40.60 42.42 40.33 40.19 40.93 40.86 39.59 38.83 31 40.07 39.71 40.62 42.40 40.23 40.86 39.49 LOW 41.73 41.47 40.48 40.62 41.63 42.47 42.37 40.56 41.00 40.96 40.90 39.50 HIGH 40.00 40.10 39.57 39.46 40.28 41.67 40.29 39.81 40.31 40.52 39.49 38.36 WTR YR 1988 MEAN 40.62 LOW 42.47 HIGH 38.36 0 36 --IX Ci 38 ZQ -"a- 40 >v) Jo 42 Ce Z 4 44 DJ FMAMJ J ASONDJFMAMJJ ASONDJ FMAMJ J AS 1985 1986 1987 1988 r \I\ 1986 1987 1988 FMAMJJ ASONDJ FMAMJJ ASONDJ F W +4 m • cl +2 La La z< 0 --J La.l - > -J Lai 2 IX Z aJ 4 MAMJ AS GROUND-WATER LEVELS RIO HONDO 10 RIO PUERTO NUEVO BASINS 182413066044000. Local number, 220. LOCATION.--tat 18- 24'13", long 66'04'40". Owner: P.R. Aqueduct and Sewer Authority. Name: Parque San Luis Rey-Americo Miranda AQUIFER.--Surficial Deposits-Cibao Formation. WELL CHARACTERISTICS.--Drilled unused artesian well, diameter 10 in (0.25 m), cased 8 in (0.20 m) 0-166 ft (U- 50.6 m), perforated 39-166 ft (11.9-50.6 m). Depth 166 ft (50.6 m). DATUM.--Elevation of land-surface datum is about 16.4 ft (5.0 m) above mean sea level, from topographic map. Measuring point: Top of shelter flour, 3.00 ft (0.91 m) above land-surface datum. REMARKS.--Recording observation well. Water levels affected by nearby pumping well. PERIOD OF RECORD.--February 1986 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +2.99 ft (+0.91 m) above land-surface datum, Feb. 6, May 8-9, 1986; lowest water level recorded, 0.90 ft (0.21 m) below land-surface datum, Oct. 16, 1986. DAY OCT WATER LEVEL, IN FEET NOV DEC BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 INSTANTANEOUS OBSERVATION AT 1200 JAN FEB MAR APR MAY JUN TO SEPTEMBER 1988 JUL AUG SEP 1 .22 • .23 .1.01 '1.04 + .96 + .51 • .29 .1.09 .79 .75 + .56 +1.01 2 .27 • .20 +1.07 +1.04 +1.06 .48 • .28 *1.09 + .75 • .78 . .53 + .99 3 .19 + .16 +1.08 +1.04 +1.09 + .44 + .27 .1.06 .72 .78 + .52 + .86 4 .12 + .16 .1.08 .1.05 +1.11 + .41 * .26 +1.02 + .68 .77 .55 .82 5 .03 + .11 .1.08 .1.04 +1.11 + .40 . .25 + .98 + .65 .74 .53 • .78 6 .02 + .05 +1.08 .1.04 .1.11 + .39 .25 + .95 + .62 + .72 + .50 .73 7 .02 * .01 +1.08 +1.04 +1.11 * .38 + .24 * .92 * .61 + .84 + .47 + .70 8 .00 .00 +1.09 +1.03 +1.11 + .35 + .23 + .88 + .57 + .97 + .44 + .66 9 .00 .01 .1.10 +1.03 +1.11 + .35 + .19 + .85 + .55 + .98 + .41 + .86 10 .01 .04 +1.10 +1.02 +1.08 + .33 + .16 + .97 .52 * .98 + .39 +1.05 11 .01 .07 +1.10 +1.02 +1.02 + .31 .14 +1.09 • .52 + .95 . .47 +1.11 12 .02 .10 +1.09 +1.00 * .99 + .29 * .11 +1.11 + .51 . .94 + .49 +1.12 13 .05 .08 +1.09 +1.00 + .96 + .27 + .12 +1.11 + .49 * .91 . .48 +1.13 14 .07 .09 +1.07 +1.00 + .92 + .27 + .08 +1.12 • .46 + .90 + .47 +1.13 15 .02 .11 +1.07 +1.00 + .87 • .25 + .25 +1.11 + .51 + .88 . .45 .1.13 16 + .04 .11 +1.07 + .97 + .84 + .21 + .59 +1.13 • .54 .85 + .48 .1.13 17 + .09 .05 +1.06 + .94 + .79 + .18 + .75 +1.12 * .53 .81 + .49 +1.13 18 .18 * .02 +1.05 • .95 + .78 + .15 + .97 +1.12 + .53 • .85 + .55 +1.13 19 + .24 + .02 +1.02 + .94 + .75 + .14 +1.09 +1:11 + .52 + .81 + .55 +1.13 20 + .24 + .08 +1.05 + .94 + .72 + .12 .1.09 +1.10 + .52 + .79 .52 +1.12 . . 21 * .22 + .11 +1.05 * .90 + 68 . .09 +1.09 +1.11 + .57 .77 + .49 *1.12 22 + .20 + .11 +1.06 + 65 . .08 .1.09 +1.09 + .61 + .77 + .49 +1.11 23 .18 + .15 .1.07 + 63 + .07 +1.08 +1.07 + .60 + .76 + .50 +1.11 24 + .15 + .24 *1.07 + 63 + .05 *1.09 +1.04 + .61 + .74 + .68 *1.11 25 + .22 + .43 +1.07 + 63 f .10 +1.10 +1.01 . .60 + .72 + .87 .1.10 26 * .30 + .58 +1.06 + .61 + .15 .1.10 + .98 + .58 * .70 + .98 .1.09 27 + .32 + .80 +1.06 + .87 + .60 + .15 +1.10 + .95 + .57 + .68 .1.00 .1.05 28 * .31 + .98 +1.06 + .85 + .57 + .20 +1.10 + .91 + .53 + .64 +1.02 +1.00 29 + .28 +1.06 +1.06 * .91 + .54 + .25 +1.10 + .88 + .67 + .62 +1.03 + .97 30 + .26 +1.06 +1.04 + .90 + .28 +1.09 • .85 + .73 + .60 +1.04 + .94 31 + .24 +1.04 + .90 + .29 + .82 + .58 +1.02 LOW .27 .11 +1.01 + .54 + .05 + .08 + .82 .46 + .58 + .39 + .66 HIGH + .32 +1.06 +1.10 +1.11 + .51 +1.10 +1.13 + .79 * .98 +1.04 +1.13 408 + Above land-surface datum. 409 GROUND-WATER lEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182436066031200. Local number, 221. LOCATION.--Lat 18- 24'36", long 66 - 03'12". Owner: P.R. Highway Authority Name: Hyde Park TW-10. AQUIFER.--Surficial Deposits-CiLao Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m) 0-107 ft (0-32.36 m), perforated 19-107 ft (5.79-32.6 m). Depth 107 ft (32.6 m). DATUM.--Elevation of land-surface datum is about 82.0 ft (25.0 m) above mean sea level, from topographic map. Measuring point: Hole on side of casing, 0.70 ft (0.21 m) above land-surface datum. Prior July 28, 1986, top of shelter floor, 3.14 ft (0.96 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--December 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.34 ft (`1.41 m) below land-surface datum, Apr. 16, 1988; lowest water level recorded, 15.59 ft (4.75 m) below land-surface datum, Apr. 5, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY YIN JUL AUG SEP 1 11.47 9.30 6.33 6.02 6.71 7.67 7.72 5.35 6.59 6.25 1.55 5.49 2 11.60 9.37 5.44 5.45 6.31 7.72 7.77 5.51 6.68 6.27 7.62 5.60 3 11.46 9.47 4.42 5.34 5.78 7.76 7.84 5.71 6.76 6.44 7.67 5.76 4 10.81 9.47 5.U5 5.45 5.59 7.79 7.89 5.83 6.88 6.56 7.63 5.87 5 9.33 9.52 5.48 5.63 5.86 7.82 7.96 5.93 6.95 6.66 7.72 6.00 6 9.18 9.63 4.52 5.81 6.15 7.85 8.02 6.01 7.01 6.78 7.79 6.10 7 9.17 8.30 4.98 5.74 6.38 7.91 8.09 6.13 7.09 5.23 7.84 6.19 8 9.24 9.13 3.58 5.86 6.54 7.96 8.17 6.24 7.21 5.56 7.90 6.30 9 9.28 9.44 4.20 5.99 6.67 7.98 8.26 6.26 7.32 5.72 7.96 5.45 10 9.34 9.67 4.71 6.14 6.80 7.99 8.36 5.11 7.34 5.82 7.99 3.97 11 9.39 9.86 5.15 6.21 6.86 8.05 8.45 4.25 7.38 5.95 7.60 2.29 12 9.46 10.04 5.50 6.28 6.88 8.10 8.52 4.55 7.39 6.09 7.53 3.41 13 9.57 9.54 5.73 6.38 6.85 8.14 8.50 4.88 7.48 6.24 7.61 3.43 14 9.67 8.82 5.86 6.10 6.91 8.18 8.57 5.06 7.53 6.29 7.68 4.25 15 9.72 9.63 6.00 6.24 6.95 8.24 4.43 5.22 7.57 6.44 7.74 4.59 16 9.76 9.99 6.08 6.37 7.04 8.32 2.75 5.20 1.60 6.54 7.82 4.81 17 9.47 10.00 6.22 6.48 7.13 8.37 4.20 5.42 7.66 6.64 7.68 4.96 18 9.00 9.85 6.22 6.55 7.17 8.40 2.97 5.61 7.63 6.71 7.44 5.11 19 8.93 9.81 6.36 6.51 7.25 8.43 4.06 5.74 7.61 6.69 7.47 5.23 20 8.93 9.75 5.92 6.52 7.29 8.48 4.56 5.81 7.60 6.78 7.54 5.26 21 8.96 9.80 4.65 6.57 7.33 8.51 4.86 5.46 7.48 6.89 7.62 5.35 22 8.89 9.92 4.65 6.68 7.36 8.56 5.13 5.56 7.10 6.96 7.67 5.44 23 8.90 10.08 5.02 6.80 7.40 8.62 5.32 5.64 7.07 /.03 7.65 5.53 24 8.90 9.86 5.26 6.90 7.41 8.66 5.45 5.68 7.11 7.09 1.31 5.64 25 8.85 8.49 5.47 6.92 7.43 8.43 4.49 5.76 7.12 7.20 4.85 5.73 26 8.84 7.92 5.62 6.99 7.51 8.41 4.42 5.89 7.21 7.27 5.25 5.83 27 8.85 6.30 5.68 7.04 7.55 8.18 4.22 6.02 7.31 7.34 5.44 5.93 28 8.93 5.72 5.72 7.05 7.58 7.97 4.61 6.09 7.40 7.41 5.48 6.05 29 9.01 5.66 5.84 6.98 7.63 7.93 4.96 6.23 6.58 7.44 4.77 6.11 30 9.12 6.05 5.98 6.91 --- 7.73 5.18 6.35 6.19 7.48 5.07 6.21 31 9.19 --- 6.09 6.95 7.68 --- 6.45 --- 7.47 5.28 --- LOW 11.60 10.08 6.36 7.05 7.63 8.66 8.57 6.45 7.66 7.48 7.99 6.30 HIGH 8.84 5.66 3.58 5.34 5.59 7.67 2.75 4.25 6.19 5.23 4.77 2.29 WTR YR 1988 MEAN 6.94 LOW 11.60 HIGH 2.29 \\.\ AK).1•\\A, NfrNki. DJ FMAMJJ ASONDJFMAMJJ ASONDJFMAMJ J AS 1985 1986 1987 1988 410 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 182515065594100. Local number, 222. LOCATION.--Lat 1825'15", long 65'59'41". Owner: U.S. Geological Survey. 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). 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, 4.42 ft (1.35 m) below land-surface datum, Aug. 31, 1986; lowest water level recorded, 7.42 ft (2.2b m) below land-surface datum, Feb. 9, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.91 5.73 5.63 5.49 5.72 5.72 5.89 5.93 5.86 5.79 5.70 5.51 2 5.76 5.16 5.63 5.63 5.50 5.15 6.04 5.94 5.86 5.14 5.81 5.65 3 5.76 5.63 5.65 5.66 5.62 5.97 6.10 5.82 5.83 5.72 5.79 5.85 4 5.68 5.57 5.60 5.65 5.67 6.09 6.09 5.88 5.82 5.76 5.96 5.93 5 5.55 5.53 5.60 5.64 5.71 6.14 6.07 5.92 6.00 5.88 6.13 5.93 6 5.48 5.58 5.53 5.67 5.82 6.10 6.04 5.81 5.99 6.04 6.11 5.86 7 5.48 5.63 5.66 5.69 5.83 5.99 5.98 5.77 6.03 6.07 6.15 5.76 8 5.47 5.78 5.67 5.77 5.87 6.09 5.81 5.77 6.02 6.28 6.10 5.68 9 5.57 5.81 5.14 5.71 5.84 6.12 5.96 5.76 6.13 6.36 5.96 5.35 10 5.71 5.91 5.72 5.78 5.81 6.08 5.89 5.79 6.19 6.28 5.81 5.20 11 5.78 5.90 5.53 5.71 5.80 5.89 5.86 5.79 6.23 6.13 5.72 5.35 12 5.74 5.94 5.77 5.80 5.82 5.89 5.89 5.83 6.11 6.10 5.63 5.19 13 5.76 6.03 5.83 5.75 5.81 5.91 5.85 6.04 6.05 6.02 5.55 5.15 14 5.75 5.96 5.87 5.71 5.17 5.87 5.89 6.06 6.03 5.87 5.53 5.34 15 5.74 5.87 5.88 5.70 5.73 S.82 5.12 5.95 6.02 5.90 5.58 5.41 16 5.18 5.86 5.83 5.60 5.52 5.81 5.60 5.90 5.96 5.88 5.65 5.50 17 5.68 5.81 5.69 5.45 5.69 5.85 5.80 5.85 5.97 5.81 5.59 5.63 18 5.66 5.76 5.57 5.39 5.71 5.99 5.77 5.77 6.00 5.86 5.57 5.74 19 5.65 5.75 5.52 5.32 5.68 6.16 5.81 5.81 6.01 5.89 5.66 5.83 20 5.63 5.54 5.64 5.48 5.79 6.24 5.83 5.85 6.06 6.04 5.75 5.81 21 5.60 5.44 5.64 5.58 5.86 6.29 5.78 5.80 6.04 6.16 5.86 5.89 22 5.61 5.43 5.69 5.71 5.85 6.28 5.78 5.83 5.90 6.16 5.98 5.75 23 5.63 5.53 5.65 5.78 5.86 6.29 5.78 5.86 6.00 6.30 5.96 5.61 24 5.63 5.63 5.13 5.81 5.87 6.30 5.83 5.97 6.05 6.33 5.68 5.52 25 5.65 5.75 5.84 5.83 5.85 6.31 5.90 6.00 6.06 6.34 5.64 5.43 26 5.75 5.78 5.84 5.89 5.71 6.17 5.78 5.98 6.11 6.24 5.48 5.36 27 5.75 5.70 5.84 5.87 5.64 6.08 5.78 6.11 6.10 6.17 5.27 5.36 28 5.75 5.62 5.83 5.81 5.67 5.94 5.77 6.10 6.10 6.04 5.19 5.51 29 5.88 5.64 5.71 5.75 5.72 5.87 5./8 6.04 6.04 5.90 5.26 5.56 30 5.75 5.62 5.60 5.71 --- 5.88 5.82 6.01 5.97 5.70 5.29 5.69 31 5.74 --- 5.51 5.72 5.98 --- 5.96 --- 5.61 5.35 --- LOW 5.91 6.03 5.88 5.89 5.81 6.31 6.10 6.11 6.23 6.36 6.15 5.93 HIGH 5.47 5.43 5.51 5.32 5.50 5.72 5.60 5.76 5.82 5.61 5.19 5.15 WTR YR 1988 MEAN 5.80 LOW 6.36 HIGH 5.15 FMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1986 1987 1988 411 GROUND-WATER lEVEIS RIO HUMACAO TO RIO SECO BASINS 175858066100200. Local number, 6. IOCATION.--Lat 11 58'58", long 66 10'02". Owner: Doctor Bruno. Name: Juana 5. AQUIFER.--Alluvium of Quaternary Aye. WELL CHARACTERISTICS. --Dri l led unused water-table well, diameter 16 in (0.41 m). Depth 173 ft (52.74 in) reported, 110 ft (33.54 m) measured. DATUM.--Elevation of land-surface datum is about 127 ft (38.1 m) above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.00 ft (0.91 m) above land-surface datum. Atter Aug. 1, 1981, top of 16 in (0.41 m) casing, 1.55 ft (0.47 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--November 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2o.20 ft (1.99 m) below land-surface datum, Dec. 10, 1979; lowest water level recorded, 65.95 ft (20.10 m) below land-surface datum, June 2, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVAT104 AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 50.02 52.10 51.03 41.34 40.34 42.19 43.74 47.83 51.27 51.50 53.44 49.86 2 50.09 52.22 50.31 41.26 40.20 42.35 43.81 48.00 51.18 51.44 53.49 49.81 3 50.15 52.34 49.65 41.21 40.13 42.48 43.86 48.18 51.13 51.56 53.52 49.77 4 50.23 52.45 49.02 41.17 40.22 42.60 43.92 48.36 51 • 51.70 53.37 49.81 5 50.33 52.58 48.48 41.14 40.40 42.66 44.09 48.52 51.09 51.81 53.01 49.91 6 50.46 52.70 47.99 41.12 40.56 42.68 44.28 48.67 50.94 51.88 52.96 50.03 7 50.57 52.82 47.52 41.10 40.73 42.54 44.48 48.75 50.74 51.93 53.06 50.15 8 50.64 52.93 47.07 41.09 40.92 42.44 44.64 48.79 50.56 51.96 53.18 50.27 9 50.70 53.02 46.60 41.09 41.09 42.63 44.75 48.81 50.34 51.98 53.27 50.36 10 50.78 53.09 46.17 41.10 41.17 42.77 44.84 48.88 50.19 52.03 53.30 50.47 11 50.87 53.16 45.78 41.11 41.19 42.94 44.97 49.02 50.20 52.11 53.17 50.60 12 50.97 53.22 45.45 41.13 41.23 43.05 45.11 49.20 50.40 52.20 52.87 50.72 13 51.09 53.29 45.13 41.16 41.27 43.05 45.27 49.39 50.62 52.30 52.57 50.83 14 51.20 53.35 44.83 41.18 41.09 42.99 45.42 49.58 50.83 52.40 52.36 50.92 15 51.29 53.40 44.55 41.22 40.70 42.91 45.54 49.76 51.04 52.49 52.28 51.03 16 51.37 53.47 44.27 41.26 40.45 42.96 45.63 49.94 51.20 52.58 52.26 51.10 17 51.46 53.54 43.98 41.32 40.41 42.98 45.69 50.11 51.34 52.65 52.20 51.15 18 51.56 53.61 43.68 41.32 40.39 43.06 45.80 50.27 51.46 52.72 51.97 51.20 19 51.65 53.68 43.39 41.30 40.39 43.14 45.97 50.43 51.58 52.80 51.66 51.27 20 51.74 53.74 43.14 41.30 40.59 43.14 46.11 50.58 51.72 52.89 51.32 51.33 21 51.77 53.78 42.93 41.23 40.87 43.19 46.24 50.71 51.86 52.98 50.98 51.39 22 51.78 53.79 42.71 41.11 41.07 43.30 46.39 50.81 51.91 53.07 50.67 51.45 23 51.81 53.76 42.51 41.17 41.15 43.41 46.55 50.88 51.85 53.14 50.35 51.51 24 51.84 53.69 42.31 41.26 41.14 43.47 46.71 50.95 51.88 53.18 50.14 51.58 25 51.85 53.59 42.12 41.32 41.27 43.56 46.88 51.06 51.82 53.24 50.13 51.64 26 51.84 53.41 41.95 41.19 41.48 43.64 47.05 51.15 51.75 53.32 50.14 51.71 27 51.73 53.21 41.79 41.18 41.67 43.68 47.21 51.24 51.64 53.39 50.10 51.77 28 51.70 52.93 41.67 41.23 41.85 43.74 47.31 51.30 51.57 53.45 50.05 51.84 29 51.79 52.33 41.58 41.20 42.02 43.79 47.49 51.38 51.54 53.48 49.99 51.89 30 51.89 51.71 41.53 41.04 43.77 47.66 51.42 51.53 53.46 49.94 51.92 31 51.99 41.44 40.67 43.70 51.37 53.41 49.90 LOW 51.99 53.79 51.03 41.34 42.02 43.79 47.66 51.42 51.91 53.48 53.52 51.92 HIGH 50.02 51.71 41.44 40.67 40.13 42.19 43.74 47.83 50.19 51.44 49.90 49.77 WTR YR 1988 MEAN 48.04 LOW 53.79 HIGH 40.13 62 ONDJFMAMJJ ASONDJFMAMJJ ASONDJ FMAMJJ AS 1985 1986 1987 1988 412 GROUND-WATER LEVELS RIO HUMACAO 10 RIO SECO BASINS 180415065513900. Local number, 96. LOCATION.--Lat 1804'15", long 65 - 51'39". Owner: P.R. 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 (0-55.79 m), perforated 56-81 ft (17.07-24./0 m), 102-123 ft (31.10-37.50 m), 144-181 ft (43.90-55.18 m). Depth 181 ft (55.18 m). 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 REMARKS.--Observation recording well. PERIOD OF RECORD.--April 25, 1978 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 13.10 ft (3.99 m) below land-surface datum, Dec. 2, 1987: lowest water level recorded, 28.29 ft (8.62 m) below land-surface datum, Sept. 20, 1980. WATER TEVE1, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17.13 17.23 14.26 13.71 14.77 16.10 18.23 18.14 1/.55 16.10 19.09 18.66 2 17.14 17.22 14.22 13.74 14.80 16.22 18.25 18.04 17.45 16.06 19.06 18.61 3 17.16 17.22 13.21 13.76 14.84 16.50 18.24 17.99 17.36 16.03 19.04 18.59 4 17.17 17.20 13.10 13.78 14.86 16.55 18.23 17.95 17.30 15.98 19.04 18.55 5 17.19 17.18 13.69 13.80 14.61 16.60 18.21 18.00 17.23 15.93 19.03 18.46 6 17.51 17.16 13.70 13.83 14.10 16.64 18.20 18.05 17.15 15.95 19.02 18.37 7 17.64 17.14 13.12 13.85 14.57 16.64 18.19 18.16 17.16 16.10 19.00 18.29 8 9 17,55 17.64 17.11 17.10 13.62 13.67 13.87 13.89 14.22 14.29 16.64 16.47 18.19 18.20 18.26 18.29 17.29 17.42 16.31 16.55 18.98 18.95 18.26 18.27 10 17.12 17.09 13.56 13.92 14.20 16.53 18.20 18.28 17.47 16.80 18.92 18.26 11 17.16 17.10 13.27 13.94 14.15 16.59 18.18 18.26 17.44 17.03 18.89 18.19 12 17.23 17.13 13.20 13.96 14.12 16.86 18.16 18.25 17.35 17.27 18.90 18.08 13 18.12 17.18 13.14 13.98 14.18 16.91 18.14 18.23 17.26 17.46 18.93 17.97 14 18.19 17.23 13.27 14.01 14.16 16.94 18.10 18.19 17.15 17.63 18.95 17.82 15 18.23 17.28 13.20 14.03 14.54 16.96 18.05 18.17 17.04 17.78 18.97 17.67 16 18.10 17.54 13.17 14.05 14.66 17.02 18.04 18.17 16.96 17.94 19.01 17.52 17 18.16 17.57 13.18 14.07 14.60 17.18 18.03 18.17 16.89 18.0/ 19.05 17.38 18 18.15 17.57 13.24 14.10 14.17 17.36 18.03 18.16 16.83 18.18 19.09 17.26 19 18.05 17.57 13.14 14.13 15.14 17.52 18.05 18.14 16.77 18.26 19.14 17.15 20 18.12 17.57 13.47 14.15 15.10 17.65 18.09 18.08 16.71 18.39 19.20 17.04 21 17.13 17.58 13.56 14.17 15.24 17.80 18.15 18.03 16.64 18.48 19.27 16.98 22 17.59 17.60 13.45 14.40 15.57 17.94 18.20 17.96 16.56 18.60 19.30 16.94 23 17.46 17.63 13.48 14.41 15.67 18.14 18.28 17.88 16.49 18.69 19.31 16.94 24 17.58 17.62 13.52 14.42 15.56 18.19 18.37 17.82 16.44 18.81 19.31 16.93 25 17.53 17.26 13.55 14.43 15.62 18.23 18.45 17.77 16.40 18.90 19.24 16.92 26 17.49 17.23 13.58 14.46 15.10 18.22 18.46 17.75 16.34 18.98 19.15 16.94 27 17.26 16.57 13.60 14.49 15.18 18.20 18.38 17.72 16.30 19.03 19.06 17.00 28 17.24 16.13 13.62 14.54 16.09 18.17 18.30 17.71 16.24 19.05 18.97 17.10 29 17.22 15.26 13.65 14.60 16.18 18.17 18.24 17.69 16.20 19.09 18.88 17.22 30 17.21 14.68 13.67 14.66 18.18 18.18 17.67 16.16 19.15 18.80 17.37 31 17.22 13.69 14.72 18.20 17.62 19.11 18.73 LOW 18.23 17.63 14.26 14.72 16.18 18.23 18.46 18.29 17.55 19.15 19.31 18.66 HIGH 17.12 14.68 13.10 13.71 14.12 16.10 18.03 17.62 16.16 15.93 18.73 16.92 WTR YR 1988 MEAN 16.83 LOW 19.31 HIGH 13.10 10 -.I a) I- I- < 14 Lal 0 w w U.. 0 • 18 La > La I 22 -J C) Z< 1- 26 ONDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1987 1988 1985 1986 413 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175829066232200. Local number, 87. LOCATION.--Lat 17 - 58'29", long 66'23'22". 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). DATUM.--Elevation of land-surface datum is 35.32 ft (10.77 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. 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 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.20 26.47 21.96 23.60 24.49 24.13 24.84 25.65 23.13 25.47 23.41 2 27.43 26.77 22.23 23.46 24.40 23.85 24.94 25.65 23.02 25.78 23.35 3 27.86 26.87 22.10 23.59 24.37 23.47 25.38 25.66 23.03 25.86 23.28 4 27.86 26.58 21.98 23.73 24.61 23.72 25.50 24.93 22.78 25.22 23.24 5 27.88 26.58 22.03 23.82 24.72 24.12 25.32 24.51 22.46 25.13 23.21 6 27.58 26.18 21.98 23.81 24.13 23.99 25.12 24.11 22.64 24.94 23.13 27.29 24.95 22.03 23.75 23.70 24.19 25.10 24.25 22.36 24.94 23.11 8 27.41 25.30 22.19 22.12 23.72 23.71 24.39 25.03 24.89 22.77 24,86 22.97 9 27.32 25.46 22.14 22.05 23.86 23.61 24.44 25.10 24.79 23.00 24.88 22.94 10 27.28 25.62 22.11 22.02 23.85 24.62 24.45 25.43 24.85 23.08 24.90 22.87 11 27.25 25.72 22.10 22.39 23.84 24.49 24.41 25.28 24.46 23.20 24.97 22.93 12 27.25 25.76 22.07 22.78 23.85 24.47 24.73 25.38 24.20 23.61 25.54 22.95 13 27.70 25.84 22.04 22.85 23.88 24.43 24.79 25.44 24.74 23.80 25.96 22.98 14 28.19 25.86 22.02 22.84 23.86 24.41 24.86 25.36 24.75 24.01 25.91 23.01 15 28.29 25.92 22.00 22.92 23.77 24.54 25.04 25.41 24.75 24.12 25.95 23.05 16 27.83 25.97 21.99 22.90 23.82 24.70 25.00 25.38 24.63 24.30 26.05 23.09 17 26.94 26.41 22.14 22.88 23.86 24.65 25.02 25.86 23.89 24.19 26.29 23.12 18 26.81 26.13 22.07 22.90 23.91 24.70 25.06 25.66 23.84 24.14 25.21 23.15 19 26.85 26.10 22.02 23.02 23.29 24.94 25.31 25.68 23.70 24.15 24.91 23.20 20 26.93 26.26 21.98 23.08 23.98 24.83 25.28 25.60 24.20 24.32 24.87 23.21 21 27.05 26.17 21.96 23.13 24.08 24.37 24.93 25.59 24.58 24.30 24.81 23.19 22 27.12 26.14 22.05 23.27 23.86 24.75 25.75 25.54 24.71 24.39 24.80 23.19 23 27.17 26.13 22.04 23.34 23.96 23.95 25.06 25.87 23.58 24.50 24.73 23.13 24 27.18 26.11 22.00 23.38 24.25 24.50 24.73 25.62 23.90 24.47 24.69 23.31 25 27.19 21.95 23.28 24.08 24.63 24.72 25.62 23.79 24.48 24.10 23.23 26 27.47 21.93 23.36 24.41 24.70 24.68 25.91 23.12 24.50 23.92 23.24 27 27.00 21.95 23.42 24.26 24.57 24.89 26.16 22.59 25.21 23.85 23.34 28 26.42 22.27 23.46 24.18 24.40 25.09 26.04 22.39 25.30 23.73 23.35 29 26.42 21.96 23.57 24.44 24.74 25.25 25.81 22.71 25.73 23.63 23.63 30 26.43 21.97 23.62 --- 25.12 25.13 25.71 23.16 25.62 23.50 23.53 31 26.43 21.97 23.61 25.34 --- 25.64 --- 25.44 23.54 --- LOW 28.29 23.62 24.44 25.34 25.75 26.16 25.66 25.73 26.29 23.63 HIGH 26.42 21.96 23.29 23.61 23.47 24.84 22.39 22.36 23.50 22.87 0 16 W 1-4 21 La. W zric 26 w v) > ' 31 ocz -1 36 ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1985 1986 1987 1988 414 GROUND-WATER IEVEIS RIO SALINAs TO RIO JACAG:AS BASINS 180002066132200. Local number, HW-TW-01. LOCATION.--Lat 18 00'02", long 66 - 13'22". Owner: U.S. Geological Survey, WRU. 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 ft (9.75-11.3 m). Depth 39.5 ft (12.0 m). DATUM.--Elevation of land-surface datum is 190 ft (58.0 m) above mean sea level. Measuring point: Top of shelter floor, 3.48 ft (1.06 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 14, 1988. PERIOD OF RECORD.--April 14, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 19.82 ft (6.04 m) below land-surface datum, Apr. 14, 1988; lowest water level recorded, 22.78 ft (6.95 m) below land-surface datum, Aug. 23-24, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.98 20.50 21.12 21.93 21.83 2 19.99 20.52 21.12 21.97 21.81 3 20.01 20.54 21.12 22.02 21.79 4 20.04 20.59 21.12 22.07 21.78 5 20.04 20.62 21.13 22.09 21.79 6 20.05 20.65 21.14 22.12 21.82 7 20.05 20.67 21.16 22.16 21.85 8 20.06 20.70 21.18 22.21 21.90' 9 20.06 20.74 21.20 22.24 21.94 10 20.07 20.77 21.22 22.27 21.98 11 20.09 20./8 21.23 22.33 22.05 12 20.10 20.80 21.24 22.38 22.09 13 20.11 20.,, 21.24 22.42 22.11 14 20.12 20.86 21.24 22.47 22.14 15 19.84 20.14 20.89 21.28 22.51 22.17 16 19.84 20.16 20.90 21.30 22.56 22.20 17 19.85 20.17 20.91 21.31 22.63 22.23 18 19.87 20.19 20.93 21.33 22.67 22.26 19 19.90 20.21 20.94 21.36 22.69 22.31 20 19.89 20.23 20.96 21.39 22.72 22.38 21 19.90 20.24 20.97 21.42 22.74 22.42 22 19.91 20.26 20.99 21.46 22.76 22.46 23 19.94 20.29 21.01 21.50 22.78 22.49 24 19.94 20.31 21.02 21.56 22.78 22.53 25 19.94 20.34 21.03 21.62 22.58 22.57 26 19.94 20.36 21.04 21.67 22.38 22.61 21 19.96 20.39 21.05 21.72 22.22 22.66 28 19.96 20.40 21.07 21.77 22.10 22.70 29 19.97 20.42 21.08 21.82 22.00 22.73 30 19.98 20.45 21.09 21.86 21.92 22.76 31 20.47 21.89 21.87 LOW 20.47 21.09 21.89 22.78 22.76 HIGH 19.98 20.50 21.12 21.87 21.78 19 En I... W 0< 20 W 0 z 21 _Trx > 22 -J O CrZ ag 23 APR MAY JUN JUL AUG SEP 1988 415 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180011066132100 Local number, HW-IW-02. LOCATION.--Lat 18-00'17", long b6 13'21". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-02. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-74 ft (0-22.6 m), cased 4 in (0.10 a), 0-70 ft (0-21.3 m), screened 60-65 ft (18.3-19.8 m). Depth 74 ft (22.6 m). DAIUM.--Elevation of land-surface datum is 224 ft (68.3 m) above mean sea level. Measuring point: Top of shelter floor. 3.60 ft (1.10 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on March 30. 1988 PERIOD OF RECORD.--March 30, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded. 15.44 ft (4.71 m) below land-surface datum, Mar. 30, 1988; lowest water level recorded, 23.72 ft (7.23 m) below land-surface datum, Sept. 30, 1988. WATER LEVEL. IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER lbi TO SEFTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 15.53 17.05 18.47 19.89 21.41 22.69 2 15.57 17.09 18.52 19.93 21.46 22.74 3 15.63 17.14 18.57 19.98 21.50 22.78 4 15.67 17.19 18.61 20.02 21.55 22.82 5 15.71 17.25 18.66 20.07 21.60 22.87 6 15.74 17.28 18.71 20.11 21.65 22.91. 7 15.78 17.33 18.75 20.16 21.70 22.95 8 15.83 17.38 18.78 20.22 21.76 22.99 9 15.87 17.44 18.86 20.26 21.78 23.03 10 15.93 17.49 18.89 20.30 21.82 23.06 11 15.91 17.54 18.93 20.37 21.87 23.11 12 16.03 17.58 18.97 20.42 21.92 23.16 13 16.08 17.63 19.02 20.47 21.97 23.19 14 16.13 17.67 19.08 20.52 22.02 23.23 15 16.26 17.70 19.13 20.58 22.06 23.27 16 16.30 17.76 19.17 20.63 22.11 23.30 17 16.36 17.79 19.21 20.68 22.16 23.33 18 16.40 17.84 19.26 20.73 22.21 23.35 19 16.45 17.89 19.31 20.78 22.27 23.41 20 16.49 17.92 19.36 20.82 22.31 23.42 21 16.53 17.97 19.41 20.87 22.36 23.45 22 16.59 18.02 19.45 20.91 22.41 23.47 23 16.65 18.06 19.50 20.97 22.46 23.50 24 16.70 18.11 19.55 21.02 22.50 23.53 25 16.74 18.15 19.59 21.07 22.41 23.56 26 16.79 18.19 19.64 21.12 22.36 23.59 27 16.85 18.25 19.70 21.17 22.42 23.62 28 16.89 18.28 19.75 21.22 22.49 23.65 29 16.95 18.33 19.79 21.26 22.54 23.68 30 17.00 18.38 19.84 21.33 22.58 23.71 31 15.48 18.42 21.36 22.64 LOW 17.00 18.42 19.84 21.36 22.64 23.71 HIGH 15.53 17.05 18.47 19.89 21.41 22.69 14 g1-4 16 w La. zav 18 ../fr > 20 1) trz 22 ag 24 MAR APR MAY JUN JUL AUG SEP 1988 416 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180001066122000 Local number, HW-TW-03. LOCATION.--Lat 18'00'01", long 66'12'20". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-03. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-60 ft (0-18.3 m), cased 4 in (0.10 m), 0-59 ft (0-18.0 m), screened 53-58 ft (16.2-17.7 m). Depth 60 ft (18.3 m). DATUM.--Elevation of land-surface datum is 271 ft (82.6 m) above mean sea level. Measuring point: Top of shelter floor, 3.42 ft (1.04 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on March 31, 1988. PERIOD OF RECORD.--March 31, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.68 ft (7.22 m) below land-surface datum, Mar. 31, 1988; lowest water level recorded, 46.58 ft (14.2 m) below land-surface datum, Sept. 30, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DAIUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 120U DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.89 27.69 32.75 39.16 43.62 45.86 2 24.04 27.77 32.95 39.35 43.72 45.88 3 24.22 27.91 33.14 39.55 43.79 45.88 4 24.35 28.03 33.35 39.73 43.91 45.89 5 24.51 28.14 33.55 39.92 44.00 45.89 6 24.64 28.26 33.74 40.11 44.10 45.90 7 24.80 28.37 33.91 40.29 44.18 45.92 8 24.97 28.51 34.10 40.47 44.27 45.94 9 25.10 28.67 34.32 40.64 44.33 45.94 10 25.26 28.83 34.51 40.79 44.39 45.94 11 25.31 29.01 34.68 40.96 44.49 45.98 12 25.54 29.17 34.85 41.13 44.58 46.02 13 25.68 29.33 35.06 41.27 44.65 46.03 14 25.83 29.47 35.26 41.42 44.72 46.06 15 25.95 29.63 35.46 41.57 44.81 46.09 16 26.07 29.81 35.68 41.72 44.88 46.12 17 26.20 29.96 35.92 41.84 44.96 46.17 18 26.31 30.13 36.16 41.98 45.03 46.17 19 26.43 30.32 36.36 42.12 45.10 46.21 20 26.52 30.48 36.56 42.24 45.18 46.25 21 26.63 30.66 36.73 42.34 45.24 46.26 22 26.76 30.85 36.96 42.48 45.31 46.31 23 26.89 31.04 37.21 42.60 45.39 46.33 24 26.98 31.23 37.49 42.71 45.44 46.35 25 27.05 31.40 3/.69 42.82 45.53 46.38 26 - - 27.15 31.59 31.93 42.94 45.60 46.41 27 - 27.28 31.79 38.22 43.05 45.67 46.43 28 - 27.38 31.97 38.52 43.23 45.72 46.48 29 - 27.50 32.17 38.74 43.35 45.78 46.50 30 27.59 32.37 38.95 43.45 45.81 46.52 31 - - --- 32.56 --- 43.53 45.84 -_- LOW 27.59 32.56 38.95 43.53 45.84 46.52 HIGH 23.89 27.69 32.75 39.16 43.62 45.86 0 20 03 < W "ha c.) z< 30 > (1) La I -J Ci 40 < a-' 50 APR MAY JUN JUL AUG SEP 1988 417 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180000066125200 Local number, HW-1W-04. LOCATION.--Lat 18'00'00", long 66'12'52". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-04. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-48.5 ft (0-14.8 m) cased 4 in (0.10 m), 0-48 ft (0-14.6 m), screened 42-47 ft (12.8-14.3 m). Depth 48.5 ft (14.8 m). DATUM.--Elevation of land-surface datum is 177 ft (53.9 m) above mean sea level. Measuring point: Top of shelter floor, 3.50 ft (1.07 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 5, 1988. PERIOD OF RECORD.--April 5, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.39 ft (5.60 m) below land-surface datum, Apr. 5, 1988: lowest water level recorded, 21.79 ft (6.64 m) below land-surface datum, Aug. 24, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATION Al 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.02 19.70 20.46 21.10 20.28 2 19.05 19.73 20.46 21.14 20.24 3 19.08 19.77 20.45 21.18 20.21 4 19.11 19.80 20.42 21.22 20.20 5 18.39 19.14 19.85 20.40 21.25 20.19 6 18.42 19.16 19.88 20.40 21.28 20.19 7 18.78 19.17 19.91 20.39 21.31 20.20 8 18.63 19.17 19.93 20.39 21.34 20.23 9 18.61 19.17 20.00 20.39 21.37 20.25 10 18.60 19.18 20.02 20.39 21.40 20.27 11 18.64 19.19 20.06 20.40 21.42 20.30 12 18.67 19.20 20.09 20.42 21.47 20.32 13 18.66 19.18 20.13 20.44 21.50 20.37 14 18.67 19.18 20.16 20.46 21.52 20.40 15 18.69 19.21 20.20 20.48 21.56 20.42 16 18.71 19.22 20.24 20.51 21.60 20.44 17 18.73 19.22 20.26 20.54 21.63 20.47 18 18.74 19.22 20.28 20.58 21.66 20.48 19 18.77 19.33 20.30 20.60 21.68 20.48 20 18.78 19.34 20.34 20.65 21.70 20.51 21 18.80 19.36 20.36 20.68 21.73 20.55 22 18.82 19.38 20.37 20.72 21.76 20.59 23 18.85 19.43 20.39 20.76 21.78 20.62 24 18.88 19.45 20.41 20.80 21.79 20.66 25 18.89 19.49 20.42 20.84 21.58 20.69 26 18.94 19.55 20.42 20.88 21.18 20.73 27 18.94 19.56 20.43 20.92 20.90 20.78 28 18.95 19.58 20.43 20.95 20.69 20.81 29 18.99 19.60 20.44 20.99 20.53 20.85 30 19.00 19.64 20.45 21.04 20.42 20.89 31 19.66 21.07 20.34 LOW 19.66 20.45 21.07 21.79 20.89 HIGH 19.02 19.70 20.39 20.34 20.19 APR MAY JUN JUL AUG SEP 1988 418 GROUND-WATER LEVEL RIO SALINAS TO R10 JACAGUAS BASINS 175947066130601 Local number, HW-TW-05B. LOCATION.--Lat 1759'47", long 66 13'06". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-058. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-52 ft (0-15.8 m), cased 4 in (0.10 m), 0-51 ft (0-15.5 m), screened 41-46 ft (12.5-14.0 m). Depth 52 ft (15.8 m). DATUM.--Elevation of land-surface datum is 145 ft (44.2 m) above mean sea level. Measuring point: Top of shelter floor, 3.47 ft (1.06 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 13, 1988. PERIOD OF RECORD.--April 13, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.40 ft (2.86 m) below land-surface datum, Aug. 25, 1988: lowest water level recorded, 14.73 ft (4.49 m) below laid-surface datum, Aug. 17, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSIANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12.72 12.76 12.15 14.08 11.70 2 12.72 12.79 12.15 14.17 11.85 3 12.73 12.82 12.26 14.25 11.96 4 12.76 12.85 12.33 14.24 12.04 5 13.08 12.87 12.38 14.24 12.12 6 13.03 12.90 12.42 14.29 12.21 7 12.48 12.94 12.44 14.34 12.26 8 12.50 13.01 12.47 14.37 12.29 9 13.09 13.09 12.50 14.43 12.31 10 12.66 13.14 12.54 14.44 12.30 11 12.88 13.19 12.59 14.45 12.25 12 12.52 13.23 12.64 14.47 12.21 13 12.52 13.29 12.68 14.52 12.21 14 12.57 12.52 13.35 12.73 14.58 12.10 15 12.59 12.53 13.41 12.78 14.63 12.15 16 12.59 12.52 13.14 12.83 14.70 12.18 11 12.62 12.52 13.11 12.87 14.73 12.21 18 12.63 12.53 13.10 12.93 14.66 12.24 19 12.66 12.51 13.11 13.00 14.62 12.28 20 12.67 12.43 13.14 13.06 14.61 12.13 21 12.67 12.44 13.13 13.14 14.64 12.18 22 12.69 12.46 13.11 13.24 14.70 12.22 23 12.70 12.49 13.11 13.34 14.30 12.25 24 12.65 12.51 13.11 13.42 14.18 12.26 25 12.65 12.54 12.66 13.52 9.78 12.31 26 12.65 12.55 12.91 13.62 9.58 12.36 27 12.66 12.60 12.92 13.73 10.05 12.42 28 12.67 12.63 12.93 13.84 10.50 12.48 29 12.68 12.67 12.93 13.91 10.91 12.55 30 12.70 12.70 12.94 13.99 11.22 12.61 31 12.73 13.99 11.50 LOW 13.09 13.41 13.99 14.73 12.61 HIGH 12.43 12.76 12.15 9.58 11.70 9 < W0 uj 11 Z LAJ > LaJ I 13 0 Z 4C 15 APR MAY JUN JUL AUG SEP 1988 419 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180006066123700 Local number, HW-TW-07. LOCATION.--Lat 18'00'06", long 66'12'37". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-07. AQUIFER.--Fractured, volcanic ruck, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-88 ft (0-26.8 m), cased 4 in (0.10 m), 0-82 ft (0-25.0 m), screened 69-71 ft (21.0-29.5 m). Depth 88 ft (26.8 m). DATUM.--Elevation of land-surface datum is 240 ft (73.2 m) above mean sea level. Measuring point: Top of shelter floor, 3.48 ft (1.06 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on March 31, 1988. PERIOD OF RECORD.--April 1988 to September 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.79 ft (1.25 m) below land-surface datum, Apr. 1, 1988; lowest water level recorded, 30.22 ft (9.21 m) below land-surface datum, Aug. 24, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.83 25.38 26.. .3 28.00 29.22 28.95 2 23.90 25.43 26.77 28.01 29.26 28.95 3 23.95 25.48 26.81 28.03 29.32 28.95 4 23.98 25.55 26.86 28.05 29.36 28.91 5 24.03 25.59 26.90 28.07 29.39 28.99 6 24.14 25.62 26.94 28.09 29.44 29.02 7 24.19 25.64 27.00 28.12 29.51 29.05 . 8 24.22 25.65 27.04 28.16 29.55 29.09 9 24.26 25.61 27.10 28.19 29.61 29.12 10 24.27 25.68 27.15 28.23 29.66 29.13 11 24.37 25.69 27.20 28.27 29.71 29.17 12 24.44 25.88 27.25 28.31 29.75 29.21 13 24.49 25.92 27.31 28.37 29.80 29.23 14 24.56 25.96 27.36 28.41 29.85 29.26 15 24.62 26.00 27.41 28.45 29.90 29.29 16 24.66 26.04 27.44 28.49 29.94 29.31 17 24.71 26.08 27.48 28.53 29.99 29.34 18 24.75 26.12 27.52 28.57 30.02 29.36 19 24.80 26.16 27.55 28.61 30.05 29.40 20 24.85 26.20 27.59 28.66 30.08 29.44 21 24.88 26.24 27.62 28.70 30.12 29.49 22 24.94 26.28 27.75 28.15 30.16 29.52 23 24.99 26.32 27.70 28.80 30.20 29.55 24 25.03 26.36 27.75 28.85 30.21 29.59 25 25.08 26.40 27.78 28.89 29.81 29.61 26 25.13 26.45 27.81 28.95 29.43 29.64 27 25.19 26.50 27.85 29.00 29.25 29.68 28 25.22 26.54 27.88 29.05 29.14 29.73 29 25.27 26.58 27.93 29.10 29.07 29.78 30 25.33 26.61 27.97 29.14 29.01 29.81 LOW 25.33 26.65 27.97 29.18 30.21 29.81 HIGH 23.83 25.38 26.73 28.00 28.97 28.95 o 22 La CD 24 < W 0 IA. 0 26 z< 28 Lai>in 30 z 32 MAR APR MAY JUN JUL AUG SEP 1988 420 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175939066121400 Local number, HW-TW-08. LOCATION.--Lat 17'59'39", long 66'12'14". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-08. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-49 ft (0-14.9 m ), cased 4 in (0.10 m), 0-49 ft (0-14.9 m), screened 43-48 ft (13.1-14.6 m). Depth 49 ft (14.9 m). DATUM.--Elevation of land-surface datum is 172 ft (52.4 m) above mean sea level. Measuring point: Top of shelter floor, 3.55 ft (1.08 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 13, 1988 PERIOD OF RECORD.--April 13, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 12.55 ft (3.82 m) below land-surface datum, Apr. 13, 1988; lowest water level recorded, 28.98 ft (8.83 m) below land-surface datum, Sept. 30, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCIOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION Al 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.68 18.3U 21.73 25.55 28.43 2 14.81 18.39 21.84 25.69 28.44 3 14.93 18.51 21.96 25.79 28.43 4 15.06 18.63 22.08 25.93 28.42 5 15.19 18.76 22.18 26.06 28.40 6 15.30 18.86 22.31 26.16 28.39 7 15.42 18.97 22.42 26.28 28.36 8 15.53 19.08 22.54 26.39 28.36 9 15.67 19.18 22.66 26.49 28.33 10 15.79 19.30 22.77 26.57 28.31 11 15.93 19.41 22.91 26.70 28.35 12 16.06 19.52 23.04 26.82 28.37 13 16.15 19.65 23.17 26.96 28.36 14 12.66 16.25 19.77 23.91 27.07 28.38 15 12.77 16.37 19.88 23.59 27.19 28.40 16 12.88 16.48 19.98 23.66 27.32 28.42 17 12.99 16.58 20.10 23.75 27.46 28.41 18 13.11 16.69 20.21 23.85 27.58 28.43 19 13.23 16.83 20.34 23.97 27.68 28.46 20 13.35 16.94 20.46 24.10 27.80 28.50 21 13.44 17.05 20.57 24.20 27.91 28.54 22 13.58 17.18 20.69 24.33 28.03 28.58 23 13.70 17.27 20.81 24.45 28.15 28.62 24 13.82 17.38 20.92 24.57 28.26 28.66 25 13.94 17.49 21.03 24.69 28.38 28.70 26 14.06 17.62 21.15 24.82 28.38 28.74 27 14.22 17.73 21.27 24.95 28.34 28.79 28 14.32 17.84 21.37 25.07 28.34 28.84 29 14.45 17.95 21.49 25.18 28.37 28.90 30 14.56 18.08 21.60 25.32 28.39 28.95 31 18.18 25.43 28.41 LOW 18.18 21.60 25.43 28.41 28.95 HIGH 14.68 18.30 21.73 25.55 28.31 10 co ci 15 c.) zrit 20 LaJ > 4.1 25 C) Z 4 30 APR MAY JUN JUL AUG SEP 1988 421 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS bASINS 175950066125200 Local number, HW-TW-10. LOCATION.--Lat 17'59'50", long 66'12'52". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-10. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-55 ft (0-16.8 m), cased 4 in (0.10 m), 0-54 ft (0-16.4 m), screened 48-53 ft (14.6-16.2 m). Depth 55 ft (16.8 m). DATUM.--Elevation of land-surface datum is 159 ft (48.5 m) above mean sea level. Measuring point: Top of shelter floor, 3.61 ft (1.10 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 5, 1988. PERIOD OF RECORD.--April 5, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.39 ft (6.52 m) below land-surface datum, Apr. 5, 1988; lowest water level recorded, 24.79 ft (7.55 m) below land-surface datum, Aug. 22-23, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22.19 22.87 23.55 24.18 23.58 2 22.32 22.89 23.53 24.21 23.54 3 22.31 22.92 23.52 24.24 23.52 4 22.32 22.95 23.52 24.26 23.51 5 21.40 22.35 22.97 23.52 24.29 23.50 6 21.42 22.37 23.00 23.54 24.33 23.50 7 21.45 22.37 23.02 23.55 24.35 23.50 8 21.49 22.39 23.05 23.56 24.39 23.50 9 21.53 22.41 23.08 23.57 24.43 23.50 10 21.56 22.43 23.12 23.58 24.46 23,49 11 21.60 22.46 23.14 23.62 24.48 23.52 12 21.64 22.49 23.16 23.64 24.52 23.53 13 21.67 22.50 23.20 23.66 24.54 23.53 14 21.70 22.51 23.24 23.68 24.57 23.53 15 21.74 22.52 23.26 23.69 24.60 23.53 16 21.77 22.55 23.27 23.72 24.64 23.54 17 21.81 22.56 23...9 23.74 24.67 23.55 18 21.83 22.58 23.32 23.77 24.69 23.55 19 21.87 22.60 23.35 23.79 24.71 23.59 20 21.89 22.61 23.37 23.82 24.73 23.60 21 21.92 22.62 23.40 23.84 24.75 23.61 22 21.96 22.65 23.42 23.86 24.78 23.63 23 22.00 22.67 23.44 23.90 24.78 23.65 24 22.02 22.69 23.45 23.93 24.78 23.67 25 22.04 22.71 23.45 23.96 24.37 23.69 26 22.08 22.73 23.47 24.00 24.08 23.72 27 22.10 22.76 23.48 24.03 23.94 23.76 28 21.93 22.78 23.50 24.06 23.84 23.78 29 22.13 22.80 23.52 24.09 23.76 23.82 30 22.17 22.82 23.54 24.13 23.66 23.84 31 22.85 24.14 23.61 LOW 22.85 23.54 24.14 24.78 23.84 HIGH 22.19 22.87 23.52 23.61 23.49 21 9:E chip 1- 4t La o 22 23 _TS LaJ (1) 24 cez 25 • APR MAY JUN JUL AUG SEP 1988 422 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180012066125500 Local number, HW-TW-11. LOCATION.--Lat 1800'12", long 66 - 12'55". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-11. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-94.9 ft (0-28.9 m), cased 4 in (0.10 m), 0-94 ft (0-28.6 m), screened 79-89 ft (24.1-27.1 m). Depth 94.9 ft (28.9 m). DATUM.--Elevation of land-surface datum is 240 ft (73.2 m) above mean sea level. Measuring point: Top of shelter floor, 3.74 ft (1.14 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 14, 1988. PERIOD OF RECORD.--April 14, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 57.00 ft (17.4 m) below land-surface datum, Apr. 14, 1988; lowest water level recorded, 63.86 ft (19.5 m) below land-surface datum, Sept. 30, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 - 57.60 58.90 60.31 61.58 62.70 2 - 57.64 59.00 60.35 61.63 62.72 3 - 57.70 59.05 60.38 61.67 62.73 4 - 57.75 59.07 60.43 61.71 62.77 5 - 57.79 59.07 60.47 61.77 62.78 6 57.82 59.07 60.52 61.82 62.80 7 57.85 59.40 60.57 61.87 62.82 8 57.93 59.31 60.61 61.90 62.85 9 57.96 59.32 60.65 61.97 62.87 10 58.01 59.35 60.69 62.00 62.89 11 58.05 59.39 60.74 62.04 62.92 12 58.08 59.43 60.78 62.09 62.96 13 58.13 59.48 60.83 62.15 62.98 14 58.16 59.54 60.87 62.20 63.03 15 57.03 58.19 59.58 60.89 62.26 63.06 16 57.05 58.25 59.63 60.94 62.30 63.09 17 57.09 58.28 59.67 60.96 62.36 63.12 18 57.11 58.32 59.72 61.01 62.41 63.13 19 57.16 58.36 59.76 61.06 62.47 63.18 20 57.19 58.40 59.82 61.09 62.52 63.23 21 57.23 58.45 59.87 61.12 62.58 63.28 22 57.27 58.50 59.91 61.16 62.63 63.31 23 57.31 58.74 59.95 61.21 62.68 63.35 24 57.35 58.35 59.99 61.24 62.71 63.39 25 57.39 58.57 60.04 61.28 62.76 63.43 26 57.42 58.62 60.08 61.32 62.75 63.46 27 57.46 58.65 60.13 61.37 62.71 63.51 28 57.49 58.76 60.17 61.41 62.70 63.55 29 57.51 58.80 60.22 61.44 62.70 63.59 30 57.54 58.84 60.27 61.50 62.69 63.62 31 58.84 61.52 62.69 LOW 58.84 60.27 61.52 62.76 63.62 HIGH 57.60 58.90 60.31 61.58 62.70 W56 C14 ui < 58 us z < 60 >(1) - LAJ 62 -az • 64 APR MAY JUN JUL AUG SEP 1988 423 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175957066123400 local number, HW-TW-13. LOCATION.--lat 17 - 59'57", long 66- 12'34". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-I3. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-69 ft (0-21.0 m), cased 4 in (0.10 m), 0-4.0 ft (0-1.22 m), screened 4.0-69 ft (1.22-21.0 m). Depth 69 ft (21.0 m). DATUM.--Elevation of land-surface datum is 203 ft (61.9 m) above mean sea level. Measuring point.: Top of shelter floor, 3.47 ft (1.06 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on April 14, 1988. PERIOD OF RECORD.--April 14, 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 44.56 ft (13.6 m) below land-surface datum. Aug. 25. 1988; lowest water level recorded, 46.95 ft (14.3 m) below land-surface datum, June 8, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUL AUG SEP 1 46.16 46.82 46.81 46.71 46.31 2 46.20 46.81 46.81 46.71 46.32 3 46.21 46.85 46.79 46.71 46.36 4 46.27 46.86 46.79 46.66 46.38 5 46.35 46.88 46.77 46.65 46.43 6 46.43 46.90 46.79 46.64 46.47 7 46.45 46.93 46.77 46.62 46.49 8 46.48 46.93 46.77 46.63 46.50 9 46.47 46.95 46.75 46.63 46.51 10 46.42 46.94 46.75 46.61 46.48 11 46.43 46.92 46.75 46.62 46.47 12 46.42 46.92 46.75 46.63 46.48 13 46.45 46.91 46.75 46.61 46.51 14 46.46 46.90 46.74 46.58 46.45 15 45.57 46.47 46.91 46.74 46.57 46.42 16 45.61 46.49 46.85 46.73 46.56 46.43 17 45.63 46.50 46.87 46.72 46.53 46.49 18 45.66 46.51 46.88 46.70 46.53 46.48 19 45.70 46.55 46.86 46.70 46.55 46.44 20 45.75 46.57 46.86 46.70 46.57 46.44 21 45.78 46.59 46.87 46.70 46.57 46.47 22 45.82 46.62 46.84 46.70 46.56 46.45 23 45.87 46.64 46.84 46.66 46.57 46.49 24 45.88 46.65 46.82 46.66 46.54 46.45 25 45.92 46.68 46.82 46.70 45.86 46.46 26 45.96 46.73 46.82 46.71 45.63 46.49 27 46.00 46.73 46.82 46.70 46.16 46.50 28 46.03 46.72 46.82 46.71 46.34 46.50 29 46.10 46.79 46.83 46.71 46.30 46.51 30 46.12 46.82 46.79 46.71 46.31 46.50 31 46.82 46.71 46.30 LOW 46.82 46.95 46.81 46.71 46.51 HIGH 46.16 46.79 46.66 45.63 46.31 44 46 48 APR MAY JUN JUL AUG SEP 1988 424 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175946066102000 Local number, HW-TW-14 . LOCATION.--Lat 17'59'46", long 66'10'20". Owner: U.S. Geological Survey, WRD. Name: Hw-Tw-14. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-79 ft (0-24.4 m), cased 4 in (0.10 m), 0-79 ft (0-24.1 m), screened 71-78 ft (21.6-23.8 m). Depth 79 ft (24.1 m). DATUM.--Elevation of land-surface datum is 205 ft (62.5 m) above mean sea level. Measuring point: Top of shelter floor, 3.67 ft (1.12 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--December 1987 to September 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 41.1 ft (12.5 m) below land-surface datum, Dec. 17, 1987; lowest water level measured, 65.0 ft (19.8 m) below land-surface datum, Aug. 8, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Dec. 11 42.81 Jan. 19 45.69 Feb. 22 50.52 May 10 60.01 17 41.10 25 46.56 29 51.69 June 8 61.03 21 41.31 Feb. 4 47.95 Mar. 7 52.84 July 13 62.33 22 41.39 8 48.45 15 54.13 Aug. 8 65.00 Jan. 4 43.43 16 49.58 31 56.45 Sept. 16 63.66 11 44.55 425 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175955066103000 Local number, HW-TW-15. LOCATION.--Lat 1759'55", long 66- 10'30". Owner: U.S. Geological Survey. WRD. Name: Hw-Tw-15. AQUIFER.--Fractured, volcanic rock, water-table aquifer. WELL CHARACTERISTICS.--Drilled observation well, diameter 7 in (0.18 m), 0-85 ft (0-25.9 m), cased 4 in (0.10 m), 0-85 ft (0-25.9 m), screened 70-80 ft (21.3-24.4 m). Depth 85 ft (25.9 m). DATUM.--Elevation of land-surface datum is 269 ft (82.0 m) above mean sea level. Measuring point: Top of shelter floor, 3.60 ft (1.10 m) above land-surface datum. REMARKS.--Recording observation well. Automatic digital recorder installed on Mar. 30. 1988. PERIOD OF RECORD.--March 30. 1988 to September 30, 1988. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 36.20 ft (11.0 m) below land-surface datum. Mar. 30, 1988; lowest water level recorded. 48.99 ft (14.9 m) below land-surface datum. Aug. 2, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 36.68 41.79 44.80 47.79 48.96 2 36.92 41.93 44.89 47.86 48.99 3 37.13 42.07 44.97 47.92 4 37.35 42.19 45.07 48.01 5 37.55 42.32 45.15 48.07 6 37.75 42.42 45.24 48.12 7 37.95 42.55 45.33 48.16 8 38.15 42.68 45.42 48.27 49.51 9 38.33 42.78 45.62 48.31 10 38.52 42.78 45.72 48.34 11 38.71 42.87 45.81 48.48 12 38.89 42.98 45.91 48.55 13 39.06 43.08 46.01 48.20 14 39.23 43.19 46.09 48.21 15 39.40 43.27 46.17 48.22 16 39.55 43.37 46.26 48.31 17 39.72 43.46 46.38 48.43 18 39.87 43.56 46.43 48.50 19 40.03 43.66 46.54 48.56 50.63 20 40.18 43.74 46.68 48.65 21 40.35 43.82 46.76 48.72 22 40.50 43.92 46.84 48.75 23 40.67 44.01 46.95 48.81 24 40.80 44.10 47.06 48.92 25 40.96 44.18 47.13 48.94 26 41.11 44.27 47.22 48.94 27 41.25 44.35 47.31 48.94 28 41.39 44.45 47.39 48.95 29 41.52 44.53 47.53 48.95 30 41.66 44.61 47.56 48.95 31 36.45 44.71 48.95 LOW 41.66 44.71 47.56 48.95 HIGH 36.68 41.79 44.80 47.79 thj W iy0j 40 e Z Wy 46 ce z .43 52 MAR APR MAY JUN JUL AUG SEP 1988 34 426 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180133066503300. local number, 132. LOCATION.--Lat 18'01'33", long 66'50'33". 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 ft (0-6.1 m), 12 in (0.30 m) perforated pipe 20-84 ft (6.1-25.61 m), 10 in (0.25 m) perforated pipe 84-190 ft (25.61-57.93 m). Depth 190 ft (57.93 m). DATUM.--Elevation of land-surface datum is about 75 ft (22.87 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. PERIOD OF RECORD.--July 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +0.12 ft (0.04 m) below 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 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12.01 10.11 7.22 8.42 9.88 9.56 11.69 12.66 12.62 2 12.03 10.07 7.26 8.46 10.01 9.59 11.79 12.58 12.70 3 12.08 10.07 7.30 8.52 10.09 9.61 11.89 12.58 12.73 4 12.10 10.00 7.33 8.57 10.19 9.62 11.95 12.69 12.82 5 12.19 10.03 7.37 8.64 10.26 9.68 12.05 12.25 12.93 6 12.28 9.98 7.40 8.70 10.29 9.73 12.13 12.14 13.01 --- 7 12.40 9.84 7.41 8.74 10.01 9.80 12.22 12.07 13.02 6.55 8 12.50 9.80 7.43 8.80 10.08 9.85 11.97 12.04 13.11 6.54 9 12.20 9.83 7.49 8.87 10.17 9.97 12.14 12.02 13.20 6.56 10 12.17 9.84 7.54 8.94 10.26 9.82 12.27 11.85 13.30 6.50 11 11.63 9.87 7.59 9.01 10.33 9.89 1. 16 11.96 13.39 6.50 12 11.58 9.87 7.62 9.08 10.40 10.03 12.43 12.08 13.49 6.00 13 11.58 9.92 --- 7.67 9.16 10.47 10.14 12.42 12.14 13.53 6.09 14 11.57 9.94 6.30 7.71 9.25 10.55 10.20 12.41 12.15 13.22 6.18 15 11.59 9.92 6.36 7.75 9.32 10.56 10.27 12.48 12.23 13.42 6.25 16 11.59 10.02 6.43 7.80 9.40 10.66 10.32 12.52 12.28 13.57 6.17 17 11.58 10.00 6.49 7.82 9.47 10.74 10.35 12.56 12.34 13.69 6.10 18 11.58 9.97 6.56 7.85 9.50 10.80 10.43 12.59 12.08 12.25 6.13 19 11.10 9.90 6.62 7.88 9.57 10.88 10.52 12.43 12.15 12.45 6.20 20 11.07 9.90 6.66 7.93 9.67 10.89 10.60 12.47 12.18 12.11 6.24 21 11.04 9.94 6.69 7.97 9.73 10.89 10.69 12.62 12.21 12.24 6.27 22 10.80 9.90 6.76 8.01 9.81 10.95 10.79 12.70 12.32 12.31 6.19 23 10.81 10.02 6.80 8.04 9.86 10.16 10.88 12.78 12.41 11.31 6.00 24 10.68 9.54 - 6.83 8.10 9.97 9.69 10.98 12.86 12.37 10.90 5.26 25 10.36 8.40 - 6.87 8.16 10.04 9.69 11.08 12.34 12.28 --- 5.46 26 10.36 8.34 6.94 8.21 10.12 9.69 11.19 12.26 12.33 - 5.40 27 10.24 4.6z 7.00 8.24 10.20 9.69 11.30 12.36 12.44 5.57 28 10.18 --- 7.03 8.32 10.27 9.69 11.38 12.48 12.51 5.74 29 10.18 7.08 8.35 10.31 9.56 11.45 12.57 12.55 5.86 30 10.19 7.12 --- 10.38 9.55 11.52 12.61 12.64 5.94 31 10.16 7.19 9.84 --- 11.58 --- 12.50 --- LOW 12.50 8.35 10.38 10.95 11.58 12.86 12.69 HIGH 10.16 7.22 8.42 9.55 9.56 11.69 11.85 2 1-4 6 10 t >v) _J O 14 CKZ -I 18 ONDJFMAMJJ ASONDJFMAMJJ ASONDJFMAMJJ AS 1985 1986 1987 1988 + Above land-surface datum. 427 GROUND-WATER LEVELS RIO GUANAJIBO PASIN 180132067033800. Local number, 143. LOCATION.--Lat 18"01'32", long 6703'38". 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). Del. . 200 ft (60.98 m). 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. PERIOD OF RECORD.--December 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 37.36 ft (11.39 m) below land-surface datum, Nov. 20, 1985; lowest water level recorded, 39.90 ft (12.16 m) below land-surface datum, July. 27, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 39.39 39.33 38,63 38.61 38.88 39.14 39.38 39.50 39.70 39.49 39.82 39.18 2 39.41 39.28 38.62 38.60 38.90 39.18 39.40 39.47 39.69 39.48 39.84 39.19 3 39.44 39.26 38.61 38.61 38.86 39.22 39.42 39.50 39.68 39.49 39.83 39.16 4 39.41 39.28 38.58 38.62 38.87 39.24 39.41 39.53 39.71 39.48 39.84 39.16 5 39.39 39.28 38.57 38.65 38.88 39.24 39.39 39.52 39.73 39.60 39.83 39.13 6 39.42 39.31 38.56 38.62 38.91 39.22 39.37 39.50 39.71 39.75 39.84 39.13 7 39.42 39.30 38.54 38.62 38.94 39.23 39.36 39.48 39.69 39.78 39.86 39.11 8 39.43 39.30 38.53 38.62 38.93 39.23 39.37 39.49 39.66 39.79 39.86 39.11 9 39.43 39.28 38.52 38.62 38.91 39.19 39.38 39.51 39.68 39.80 39.87 39.06 10 39.45 39.28 38.50 38.63 38.93 39.19 39.40 39.53 39.66 39.78 39.87 38.98 11 39.37 39.25 38.50 38.64 38.95 39.23 39.40 39.56 39.62 39.82 39.85 39.00 12 39.35 39.22 38.50 38.71 38.96 39.23 39.45 39.59 39.59 39.86 39.87 39.03 13 39.34 39.23 38.53 38.70 38.96 39.23 39.47 39.61 39.60 39.85 39.89 39.02 14 39.36 39.24 38.57 38.70 38.99 39.20 39.51 39.59 39.60 39.81 39.88 39.01 15 39.36 39.24 38.58 38.71 38.99 39.24 39.52 39.59 39.59 39.85 39.87 39.02 16 39.36 39.24 38.56 38.71 39.02 39.29 39.53 39.60 39.58 39.86 39.86 39.01 17 39.37 39.22 38.56 38.71 39.03 39.34 39.53 39.58 39.55 39.83 39.84 38.98 18 39.36 39.24 38.56 38.71 39.00 39.36 39.50 39.57 39.55 39.83 39.78 38.94 19 39.34 39.24 38.59 38.72 39.02 39.35 39.51 39.60 39.56 39.84 39.78 38.96 20 39.36 39.22 38.60 38.74 39.02 39.38 39.49 39.59 39.55 39.85 39.76 38.99 21 39.37 39.19 38.59 38.74 39.04 39.37 39.47 39.60 39.55 39.84 39.74 38.99 22 39.37 39.18 38.61 38.76 39.06 39.37 39.51 39.63 39.55 39.83 39.74 38.97 23 39.36 39.16 38.60 38.74 39.04 39.36 39.54 39.65 39.54 39.87 39.70 38.96 24 39.34 39.11 38.58 38.76 39.03 39.36 39.47 39.66 39.54 39.86 39.62 38.97 25 39.32 38.98 38.59 38.76 39.02 39.36 39.47 39.65 39.51 39.86 39.11 38.95 26 39.31 38.93 38.57 38.79 39.01 39.36 39.46 39.66 39.49 39.87 39.15 38.90 27 39.32 38.69 38.56 38.81 39.02 39.36 39.48 39.68 39.49 39.89 39.18 38.89 28 39.30 38.66 38.58 38.80 39.08 39.37 39.49 39.68 39.49 39.88 39.23 38.89 29 39.33 38.64 38.53 38.83 39.12 39.36 39,51 39.68 39.48 39.87 39.22 38.89 30 39.31 38.63 38.58 38.85 39.36 39.51 39.68 39.49 39.88 39.17 38.88 31 39.32 38.63 38.88 39.36 39.69 39.84 39.17 LOW 39.45 39.33 38.63 38.88 39.12 39.38 39.54 39.69 39.73 39.89 39.89 39.19 HIGH 39.30 38.63 38.50 38.60 38.86 39.14 39.36 39.47 39.48 39.48 39.11 38.88 WTR YR 1988 MEAN 39.27 LOW 39.89 HIGH 38.50 37 ▪ CO 1- 1- < W u. Wo w 38 zrit IAD >v) 39 40 ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1985 1986 1987 1988 428 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182018066593200. Local number, 83. LOCATION.--Lat 18'20'18", long 66'59'32". Owner: P.R. Energy and Power Authority. Name: San Sebastian Well. AQUIFER.--San Sebastian Formation. WELL CHARACTERISTICS.--Drilled observation well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 300 ft (91.4 m). DATUM.--Elevation of land-surface datum is about 230 ft (70.1 m) above mean sea level, from topographic map. Measuring point: Shelter floor on top of 6 in (0.15 m) casing, 2.75 ft (0.84 m) above land-surface datum. Prior November 1985, top of casing, 2.40 ft (0.73 m) above land-surface datum. REMARKS.--Recording observation well. Formerly published as 182032066591800. PERIOD OF RECORD.--May 1967 to January 16, 1985. November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.95 ft (6.69 m) below land-surface datum, May 8, 1986; lowest water level recorded, 40.20 ft (12.25 m) below land-surface datum, Jan. 29, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 28.44 28.35 28.09 28.36 29.19 30.15 28.55 25.84 26.42 28.20 26.41 2 28.51 28.37 28.15 28.31 29.21 30.17 28.52 26.01 26.53 28.28 26.36 3 28.48 28.40 27.80 28.34 29.22 30.21 28.53 26.19 26.62 28.32 26.10 4 28.48 28.44 27.77 28.36 29.23 30.22 28.56 26.42 26.43 28.31 26.14 5 28.31 28.49 27.84 28.41 29.25 30.22 28.56 26.63 26.37 28.35 26.25 6 28.36 28.55 27.89 28.44 29.29 30.23 28.58 26.78 26.27 28.40 26.40 7 28.37 28.58 27.82 28.47 29.31 30.25 28.61 26.92 26.35 28.34 26.55 8 27.98 28.33 27.77 28.50 29.33 30.27 28.67 27.06 26.48 28.34 26.70 9 27.99 28.02 27.76 28.55 29.34 30.30 28.71 27.22 26.62 28.40 26.84 10 27.88 27.93 27.80 28.60 29.37 30.31 28.74 27.35 26.74 28.43 26.86 11 27.88 27.93 27.85 28.62 29.40 30.33 28.77 27.;; 26.92 28.45 26.99 12 27.90 27.96 27.92 28.66 29.37 30.35 28.56 27.44 --- 28.52 26.89 13 27.98 28.04 27.92 28.69 29.38 30.29 28.30 27.22 27.13 28.56 26.91 14 27.84 28.11 27.94 28.73 29.40 30.30 28.26 27.13 26.87 28.61 27.00 15 27.81 28.18 27.97 28.76 29.42 30.30 28.27 26.90 26.93 28.24 27.19 16 27.86 27.97 27.98 28.79 29.43 30.19 28.16 26.82 27.03 28.17 27.28 17 27.89 27.75 28.03 28.83 29.46 30.16 27.18 26.85 27.11 28.18 27.35 18 27.96 27.74 28.09 28.84 29.48 30.14 27.76 26.76 27.18 27.88 27.42 19 28.01 27.73 28.09 28.88 29.51 29.86 27.78 26.80 27.26 27.77 27.53 20 28.07 27.76 28.01 28.91 29.51 29.70 27.81 26.90 27.37 27.78 27.64 21 28.11 27.84 27.96 28.92 29.54 29.37 27.82 26.93 27.44 27.71 27.34 22 28.18 27.93 28.01 28.96 29.58 29.28 27.89 26.94 27.55 27.73 27.30 23 28.24 27.97 28.03 28.97 29.59 29.22 27.42 26.72 27.65 27.78 27.11 24 28.30 28.05 28.07 29.01 29.61 29.20 27.37 26.62 27.71 27.80 27.04 25 28.33 27.93 28.10 29.02 29.62 29.19 27.26 26.41 27.79 26.94 27.05 26 28.14 27.92 28.16 29.06 29.64 29.17 27.26 26.43 27.88 26.73 27.11 27 28.18 27.96 28.21 29.08 29.65 29.19 26.84 26.32 27.92 26.64 27.19 28 28.22 27.96 28.25 29.09 29.22 26.57 26.38 27.97 26.36 27.29 29 28.28 27.98 28.27 29.13 30.12 29.13 26.20 26.31 28.02 26.32 27.37 30 28.31 28.04 28.35 29.14 30.11 28.79 26.08 26.33 28.12 26.24 27.31 31 28.36 28.39 29.17 30.13 25.80 28.14 26.34 LOW 28.51 28.58 28.39 29.17 30.35 28.77 27.44 28.61 27.64 HIGH 27.81 27.73 27.76 28.31 28.79 25.80 25.84 26.24 26.10 91r 24 • r ajel 28 rM 3e,e it 28 30 J 32 NDJ F14AMJJ ASONDJ F ASONDJ F J AS 19851986 1987 1988 429 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182442067091700. Local number, 200 . LOCATION.--Lat 18°24'42", long 67°09'17". Owner: Carmelo Sanchez Name: Aguadilla Cement Well. AQUIFER.--Surficial deposits. WELL CHARACTERISTICS.--Abandoned water-table industrial well, diameter 4 in (0.10 m), cased 0-20 ft (0-6.10 m), perforated 11-20 ft (3.35-6.10 m). Depth 20 ft (6.10 m). DATUM.--Elevation of land-surface datum is about 10 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. Water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.24 ft (0.68 m) below land-surface datum, Aug 25, 1988; lowest water level recorded, 8.46 ft (2.58 m) below land-surface datum, Apr. 17, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5.75 5.63 6.16 6.51 7.10 7.82 7.78 6.84 5.83 6.29 3.78 3.03 2 5.98 5.78 6.20 6.45 7.16 7.88 7.80 6.90 6.00 6.09 3.95 3.10 3 5.60 5.82 6.02 6.51 7.21 7.85 7.84 6.98 6.00 6.21 4.15 2.79 4 5.67 5.87 6.20 6.54 7.16 1.87 7.91 7.01 6.04 6.28 3.89 2.91 5 5.74 6.04 6.21 6.56 7.20 7.86 7.92 7.05 6.11 6.41 4.08 3.03 6 5.78 6.03 6.28 6.59 7.21 7.87 7.91 7.07 6.20 5.96 4.21 3.18 7 5.83 6.05 6.28 6.62 7.24 7.93 7.97 7.07 6.23 5.62 4.31 3.28 8 5.88 5.50 5.16 6.64 7.30 8.01 8.02 6.85 6.29 5.70 3.98 3.34 9 6.02 5.66 5.83 6.67 7.33 7.96 7.96 6.47 6.27 5.84 4.23 3.33 10 5.69 5.23 5.94 6.70 7.36 7.99 7.96 6.47 6.30 5.96 4.36 3.27 11 5.81 5.47 6.03 6.74 7.38 7.99 8.00 6.10 6.33 5.26 4.44 3.43 12 5.96 5.52 6.10 6.79 7.43 7.99 8.03 5.27 5.97 5.44 4.51 3.43 13 6.07 5.65 6.17 6.80 7.41 .01 8.02 5.20 6.19 5.49 4.52 3.53 14 6.11 5.10 6.28 6.82 7.43 .05 8.06 5.36 6.11 5.54 4.66 3.45 15 5.83 5.75 6.05 6.85 7.49 .12 8.03 5.43 5.73 5.64 3.92 3.54 16 5.96 5.82 6.11 6.85 7.51 .10 7.81 5.64 5.71 5.70 4.16 3.56 17 5.54 5.86 6.20 6.82 7.53 .12 7.87 5.33 5.84 5.74 4,26 3.72 18 5.65 5.84 6.28 6.89 7.57 .19 7.96 5.49 5.91 5.85 4,00 3.78 19 5.68 6.01 6.31 6.89 7.58 .13 7.98 5.68 6.02 5.59 4.21 3.94 20 5.81 6.01 6.09 6.90 7.58 .14 7.61 5.78 6.13 5.87 4.30 3.90 21 5.82 6.01 6.16 6.93 7.60 .19 7.66 5.84 5.97 5.92 4.12 3.62 22 5.86 6.06 6.33 6.97 7.64 .20 7.47 5.90 6.02 5.96 4.34 3.78 23 6.02 6.12 6.33 6.96 7.66 .26 7.51 5.98 6.06 5.99 3.79 3.88 24 6.05 6.13 6.37 6.97 7.68 .24 7.55 6.03 5.88 6.06 3.81 3.93 25 6.08 5.83 6.26 7.00 7.76 .26 7.38 6.11 5.76 6.12 2.24 4.01 26 5.97 5.79 6.33 7.04 7.74 .24 7.34 6.19 5.90 5.60 2.53 4.12 27 5.98 5.88 6.38 7.06 7.66 .25 7.03 6.23 6.02 3.68 2.60 4.18 28 6.05 5.92 6.44 7.12 7.71 .00 6.97 6.25 6.12 3.78 2.67 3.57 29 6.14 5.98 6.48 7.11 7.77 7.71 7.01 6.05 6.24 3.87 2.75 3.63 30 6.17 6.08 6.50 7.06 --- 7.73 7.01 5.68 6.22 3.41 2.85 3.63 31 6.17 --- 6.52 7.11 7.77 --- 5.69 --- 3.50 2.99 --- LOW 6.17 6.13 6.52 7.12 7.77 8.26 8.06 7.07 6.33 6.41 4.66 4.18 HIGH 5.54 5.23 5.76 6.45 7.10 7.71 6.97 5.20 5.71 3.41 2.24 2.79 WTR YR 1988 MEAN 6.08 LOW 8.26 HIGH 2.24 2 tael CI 4 44 0 Zti 6 ccz v) > 8 rez 4( 10 NDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 19851986 1987 1988 430 THIS PAGE WAS LEFT BLANK INTENTIONALLY Surface- Water Records for U.S. Virgin Islands 432 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 Atlantic Ocean, and 2.5 mi (4.02 km) northwest of Fort Christian, Charlotte Amalie. DRAINAGE AREA.--0.49 mi" (1.27 km )• WATER-DISCHARGE RECORDS 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 at site about 100 ft (30 m) downstream at different datum. March 1979 to April 1981 at site about 100 ft (30 m) upstream at different datum. REMARKS.--Records poor. AVERAGE DISCHARGE.--10 years (1964-66, 1980, 1983-88), 0.32 ft'/s (0.009 mqs), 8.87 in/yr (225 mm/yr), 232 acre-ft/yr (0.286 hm'/yr); median of yearly mean discharges, 0.38 ft'/s (0.01 m /s), 275 acre ft/yr (0 34 ho0/yr) EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 1,650 ft'/s (46.7 m'/s), Apr. 18, 1983, gage height, 7.00 ft (2.134 m), from floodmarks, from rating curve extended above 1.0 ft'/s (0.03 m'/s) on basis of critical-depth analysis and slope-area measurement of peak flow; no flow at times in most years. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 50 ft'/s (1.42 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m'/s) (ft) (m) Date Time (ft'/s) (m'/s) (ft) (m) Nov. 25 2045 333 9.43 3.12 0.951 May 10 1500 265 7.50 3.81 1.161 Nov. 27 2300 *1,440 40.8 *7.66 2.335 Aug. 24 1115 51 1.44 2.46 0.750 No flow many days. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .06 .17 e.06 e.05 .05 .03 .02 .11 .04 .08 .01 e.00 2 .06 .03 e.05 e.04 .04 .03 .02 .14 .03 .06 .01 e.00 3 .08 .02 e.07 e.04 .04 .04 .04 .17 .03 .05 .03 e.02 4 .04 .20 e.05 e.04 .04 .03 .04 .18 .03 .04 .01 e.00 5 .06 .07 e.04 e.04 .07 .04 .05 .16 .03 .04 .01 e.00 6 .06 .04 e.04 e.08 .04 .04 .03 .03 .03 .06 .01 e.00 7 .07 .04 e.05 e.04 .03 .04 .04 .07 .03 .98 .03 e.05 8 .05 .04 e.05 e.05 .03 .03 .05 .76 .03 .04 .02 ,..05 9 .04 .05 e.04 e.04 .04 .03 .05 .14 .05 .03 .02 e14 10 .05 .06 e.04 e.04 .03 .03 .07 10 .03 .03 .02 e.30 11 .07 .06 e.04 e.05 .03 .03 .07 .38 .03 .06 .01 e.20 12 .06 .07 e.12 e.06 .03 .03 .07 .11 .04 .03 .01 e.15 13 .14 .08 e.08 e.04 .03 .03 .07 .07 .04 .47 .01 e.11 14 .06 .10 e.05 e.06 .03 .03 .07 .06 .04 2.4 .01 e.07 15 .04 .10 e.06 e.04 .04 .03 .07 .06 .05 .05 .01 e.06 16 .14 .07 e.05 e.04 .03 .03 .06 .05 .02 .03 2.2 e.08 17 .31 .10 e.04 e.03 .04 .04 .05 .05 .02 .05 .19 e.08 18 .15 .06 e.04 e.03 .03 .08 .07 .05 .02 .02 .02 e.08 19 .07 .04 e.09 e.04 .03 .08 .09 .05 .02 .75 .01 e.08 20 .05 .03 e.10 e.03 .03 .07 .10 .04 .04 .05 .01 e.08 21 .05 .02 e.08 e.04 .04 .09 .11 .05 .02 .02 .01 e.08 22 .05 .02 e.11 e.05 .04 .07 .11 .05 .02 .02 .01 e.06 23 .07 .12 e.06 .06 .04 .03 .09 .04 .04 .02 .02 e.04 24 .04 .27 e.05 .04 .04 .01 .09 .05 .03 .02 4.0 e.03 25 .06 17 e.04 .05 .03 .02 .09 .04 02 .01 .16 e.02 26 .05 12 e.04 .05 .05 .03 .08 .05 .04 .01 .04 e.02 27 .05 e90 e.04 .04 .05 .09 .08 .05 .02 .01 .03 e.02 28 .04 e5.6 e.05 .06 .04 .07 .09 .05 .00 .02 e.02 e.02 29 .03 e.18 e.04 .04 .04 .22 .09 .20 .00 .02 e.03 e.02 30 .02 e.08 e.11 .04 --- .05 .10 .07 .32 .02 e.05 e.02 31 .02 --- e.06 .04 .04 --- .05 --- .01 e.04 --- TOTAL 2.14 126.72 1.84 1.39 1.10 1.51 2.06 13.38 1.16 5.50 7.06 15.74 MEAN .069 4.22 .059 .045 .038 .049 .069 .43 .039 .18 .23 .52 MAX .31 90 .12 .08 .07 .22 .11 10 .32 2.4 4.0 14 MIN .02 .02 .04 .03 .03 .01 .02 .03 .00 .01 .01 .00 AC-FT 4.2 251 3.6 2.8 2.2 3.0 4.1 27 2.3 11 14 31 CFSM .14 8.62 .12 .09 .08 .10 .14 .88 .08 .36 .46 1.07 IN. .16 9.62 .14 .11 .08 .11 .16 1.02 .09 .42 .54 1.19 CAL YR 1987 TOTAL 245.03 MEAN .67 MAX 90 MIN .01 AC-FT 486 CFSM 1.37 IN. 18.60 WTR YR 1988 TOTAL 179.60 MEAN .49 MAX 90 MIN .00 AC-FT 356 CFSM 1.00 IN. 13.63 e Estimated ST. THOMAS U.S. VIRGIN ISLANDS 50252000 BONNE RESOLUTION GUT AT BONNE RESOLUTION, ST. THOMAS, VI--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS MARCH 1983 TO JANUARY 1985, JANUARY 1988 TO AUGUST 1988 WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CUN- IEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) JAN, 21 1310 -- 1564 23.0 JUN, 01 1024 0.03 -- 25.0 MAR, 23 0923 0.05 -- 23.0 AUG, 25 1153 0.11 25.0 433 434 ST. THOMAS, U.S. VIRGIN ISLANDS 50276000 TURPENTINE RUN AT MARIENDAI, ST. THOMAS, VI LOCATION.--tat 1819'48", long 6452'58", Hydrologic Unit 21020001, on right bank, at Mariendal, 1.0 mi (1.6 km) upstream from mouth, and 3.3 mi (5.3 km) southeast of Fort Christian, Charlotte Amalie. DRAINAGE AREA.--2.97 mil (7.69 km'). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to April 1969, October 1978 to September 1980, June 1982 to July 1986, July 1986 to current year (high-water discharges only). GAGE.--Crest-stage gage. Elevation of gage is 40 ft (12 m), from topographic map. REMARKS.--Records poor, peak discharges only. AVERAGE DISCHARGES.--10 years (1964-68, 1979-80, 1983-85), 1.22 ft'/s (0.034 m 3 /s), 5.58 in/yr (142 mm/yr), 884 acre-ft/yr (1.09 hm'/yr); median of yearly mean discharges, 0.54 ft ) /s (0.015 m-/s), 390 acre-ft/yr (0.48 hol'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 9,710 ft'/s (275 m'/s), Apr. 18, 198J, gage height, 11.09 ft (3.380 m), from floodmark, from rating curve extended above 500 ft'/s (14.2 m'/s) on basis of slope area measurement and step-backwater analysis; no flow many days from 1963 to 1969, and in 1984. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 100 ft'/s (2.83 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m7s) (ft) (m) Date Time (ft'/s) (m'/s) (ft) (m) Nov. 27 2315 *1,760 49.8 *6.24 1.902 Sept. 9 1030 821 23.2 5.27 1.606 435 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 (133 m) southeast of Bethany Church, and 1.0 mi (1.6 km) east of Government House at Cruz Bay. DRAINAGE AREA.--0.37 mil (0.96 km?). WATER-DISCHARGE RECORDS 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 (19 m), from topographic map. Prior to September 1982, at datum 1.00 ft (0.30 m) higher. REMARKS.--Records poor. AVERAGE DISCHARGE.--10 years (1964-67, 1983-88), 0.091 ft'is (0.003 m'/s), 3.34 in/yr (85 mm/yr), 65.93 acre-ft/yr (0.081 hm'/yr); median of yearly mean discharges. 0.04 ft'/s (0.001 m'/s), 29.0 acre ft/yr (0.04 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 946 ftqs (26.8 10/s), Apr. 18, 1983, gage height, 5.33 ft (1.625 m), from floodmark, from rating curve extended above 1.0 ft'/s (0.028 m'/s) on basis of step-backwater analysis and slope-area measurement of peak flow; no flow many days each year. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 10 ft'/s (0.283 m 3 /s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (W/s) (m0/s) (ft) (m) Date Time (ft'/s) (m ) /s) (ft) (m) Nov. 27 2245 *270 1.65 *3.56 1.085 Sept. 9 1000 171 4.84 3.12 0.951 Nov. 28 2000 46 1.30 2.43 0.741 No flow many days. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .00 .01 .02 .02 .01 .00 .01 .00 .0 .00 .01 .01 2 .00 .01 .02 .02 .01 .00 .01 .00 .0 .00 .01 .02 3 .00 .01 .02 .02 .01 .00 .01 .00 .0 .00 .01 .02 4 .01 .01 .02 .02 .01 .00 .01 .00 .0 .00 .02 .02 5 .00 .01 .02 .01 .01 .00 .01 .00 .0 .00 .01 .02 6 .00 .01 .02 .01 .01 .00 .01 .00 .0 .00 .01 .02 7 .01 .01 .02 .01 .01 .00 .01 .00 .0 .00 .01 .02 8 .01 .01 .02 .01 .00 .00 .01 .00 .0 .00 .01 .03 9 .01 .01 .02 .01 .00 .00 .01 .00 .0 .00 .01 15 10 .01 .01 .02 .01 .00 .00 .01 .00 .0 .00 .01 1.3 11 .00 .01 .02 .01 .00 .00 .01 .00 .0 .00 .01 .65 12 .00 .01 .02 .01 .00 .00 .01 .00 .00 .00 .00 .24 13 .01 .01 .02 .01 .01 .00 .01 .00 .00 .00 .00 .17 14 .01 .01 .02 .01 .01 .0 .01 .00 .00 .00 .00 .13 15 .02 .01 .02 .01 .01 .0 .01 .01 .00 .00 .00 .10 16 .02 .01 .02 .01 .01 .02 .01 .00 .00 .00 .13 .10 17 .02 .01 .02 .01 .01 .01 .01 .00 .00 .00 .09 .10 18 .02 .01 .02 .01 .00 .01 .02 .01 .00 .00 .06 .10 19 .01 .01 .02 .01 .00 .02 .02 .01 .00 .00 .06 .10 20 .02 .01 .02 .02 .01 .01 .01 .01 .00 .00 .06 .10 21 .02 .01 .02 .01 .00 .01 .00 .00 .00 .00 .03 .10 22 .01 .01 .02 .01 .00 .01 .00 .00 .00 .00 .02 .10 23 .01 .01 .02 .04 .01 .01 .00 .00 .00 .CO .03 .09 24 .01 .01 .02 .02 .02 .01 .01 .00 .00 .00 .10 .07 25 .01 .03 .02 .02 .03 .0 .00 .00 .00 .00 .02 .07 26 .01 1.7 .02 .01 .04 .01 .00 .00 .00 .00 .01 .07 27 .01 11 .02 .01 .01 .0 .00 .01 .01 .00 .01 .06 28 .01 5.6 .02 .01 .00 .0 .00 .01 .00 .00 .02 .06 29 .01 1.2 .02 .01 .00 .00 .00 .01 .00 .00 .02 .06 30 .01 .03 .02 .01 .01 .00 .01 .00 .01 .03 .06 31 .01 --- .02 .01 .01 --- .0 --- .01 .01 --- TOTAL 0.30 19.80 0.62 0.41 0.24 0.14 0.23 0.08 0.01 0.02 0.82 18.99 MEAN .010 .66 .020 .013 .008 .005 .008 .003 .000 .001 .026 .63 MAX .02 11 .02 .04 .04 .02 .02 .01 .01 .01 .13 15 MIN .00 .01 .02 .01 .00 .00 .00 .00 .00 .00 .00 .01 AC-FT .6 39 1.2 .8 .5 .3 .5 .2 .02 .04 1.6 38 CFSM .03 1.78 .05 .04 .02 .01 .02 .01 .00 .00 .07 1.71 IN. .03 1.99 .06 .04 .02 .01 .02 .01 .00 .00 .08 1.91 CAL YR 1987 TOTAL 22.66 MEAN .062 MAX 11 MIN .00 AC-FT 45 CFSM .17 IN. 2.28 WTR YR 1988 TOTAL 41.66 MEAN .11 MAX 15 MIN .00 AC-FT 83 CFSM .31 IN. 4.19 I 436 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 mil (5.44 km 2 ). WATER-DISCHARGE RECORDS 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 ), from topographic map. REMARKS.--Records poor. AVERAGE DISCHARGE.--11 years (1964-68, 1983-88), 0.159 ft'/s (0.004 m/'s), 1.03 in/yr (26 mm/yr), 115 acre-ft/yr (0.14 he/yr); median of yearly mean discharges, 0.04 ft'/s (0.001 110/s), 29.0 acre-ft/yr (0.04 hm'/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 430 ft'is (12.18 m 3 /s), Nov.27, 1987, gage height, 4.14 ft (1.262 m); no flow many days each year. EXTREMES FOR CURRENT YEAR.--Peak discharges greater than base discharge of 25 ft'/s (0.71 m'/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (ft'/s) (m'/s) (ft) (m) Date Time (ft'/s) (m0/s) (ft) (m) Nov. 25 0400 33 0.934 2.09 0.637 Nov. 27 2145 *430 12.18 *4.14 1.262 Nov. 26 1330 26 0.736 1.99 0.606 No flow many days. DISCHARGE, CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .06 .01 5.2 1.4 .84 .34 .16 .16 .05 e.02 e.04 .06 2 .06 .01 4.2 1.2 .81 .33 .16 .14 .05 e.04 e.04 .06 3 .06 .01 3.8 1.0 .78 .33 .14 .17 .04 e.04 e.03 .06 4 .05 .00 3.5 .86 .73 .33 .14 .18 .04 e.04 e.03 .06 5 .04 .00 3.3 .99 .71 .33 .14 .21 .04 e.04 e.04 .06 6 .04 .00 3.2 1.0 .71 .30 .59 .22 .04 e.04 e.04 .05 7 .04 .00 3.4 1.0 .69 .28 .19 .19 .04 e.10 e.02 .04 8 .04 .00 3.5 1.0 .65 .30 .19 .18 .04 e.04 e.04 .03 9 .04 .00 3.0 .99 .64 .27 .20 .18 .04 e.04 e.04 .05 10 .03 .01 2.7 .90 .62 .24 .20 .22 .04 e.04 e.10 .06 11 .03 .01 2.5 .84 .59 .24 .20 .20 .05 e.04 e.07 .15 12 .03 .00 2.4 .84 .57 .24 .20 .20 .05 e.02 e.08 .08 13 .03 .00 2.1 .86 .58 .22 .20 .20 .06 e.04 e.04 .07 14 .03 .00 2.0 .86 .52 .22 .20 .22 .06 e.10 e.04 .08 15 .04 .00 1.8 .85 .52 .21 .20 .22 .07 e.04 e.04 .07 16 .06 .00 1.6 .89 .52 .18 .20 .20 .07 e.04 e.03 .07 17 .05 .00 1.6 .70 .52 .18 .21 .20 .07 e.03 e.07 .07 18 .04 .00 2.9 .75 .52 .17 .25 .20 .07 e.04 e.04 .07 19 .03 .00 3.9 .78 .50 .16 .24 .20 .06 e.05 e.03 .07 20 .02 .00 2.3 .82 .46 .16 .24 .20 .11 e.04 e.02 .07 21 .01 .00 1.5 .82 .43 .16 .24 .20 .12 e.03 e.04 .07 .19 .07 22 .01 .00 1.4 .82 .41 .16 .24 .10 e.04 e.03 23 .01 .12 1.2 .77 .41 .16 .24 .20 e.04 e.04 e.04 .07 24 .01 2.0 1.2 .75 .41 .19 .23 .20 e.07 e.04 .07 .06 25 .01 6.4 1.2 .87 .40 .20 .22 .20 e.04 e.03 .08 .05 26 .01 5.8 1.2 .84 .39 .18 .22 .20 e.04 e.02 .08 .06 27 .01 22 1.1 .82 .39 .18 .21 e.20 e.09 e.02 .06 .06 28 .02 19 1.1 .78 .38 .18 .18 e.22 e.03 e.06 .06 .07 29 .02 8.5 1.1 .81 .36 .22 .18 e.26 e.04 e.03 .06 .07 30 .02 6.0 1.3 .80 --- .19 .18 e.08 e.05 e.03 .06 .07 31 .01 --- 1.2 .82 .18 --- e.06 --- e.02 .06 --- TOTAL 0.96 69.87 72.4 27.43 16.06 7.03 6.39 5.90 1.71 1.24 1.52 1.98 MEAN .031 2.33 2.34 .88 .55 .23 .21 .19 .057 .040 .049 .066 MAX .06 22 5.2 1.4 .84 .34 .59 .26 .12 .10 .10 .15 MIN .01 .00 1.1. .70 .36 .16 .14 .06 .03 .02 .02 .03 AC-FT 1.9 139 144 54 32 14 13 12 3.4 2.5 3.0 3.9 CFSM .01 1.11 1.11 .42 .26 .11 .10 .09 .03 .02 .02 .03 IN. .02 1.24 1.28 .49 .28 .12 .11 .10 .03 .02 .03 .04 CAL YR 1987 TOTAL 213.39 MEAN 58 MAX 22 MIN .00 AC-FT 423 CFSM .28 IN. 3.78 WTR YR 1988 TOTAL 212.49 MEAN 58 MAX 22 MIN .00 AC-FT 421 CFSM .28 IN. 3.76 e Estimated ST. CROIX, U.S. VIRGIN ISLANDS 50345000 JOLLY HILL GUT AT JOLLY HILL, ST. CROIX, VI--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS MARCH 1983 TO JANUARY 1985, OCTOBER 1967 TO JUNE 1988 WATER-QUALITY DATA, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 06 1421 0.04 1116 26.0 JUN, 01 1017 1020 25.0 JAN, 19 1420 0.78 812 24.0 437 438 THIS PAGE WAS LEFT BLANK INTENTIONALLY Ground-Water Records for U.S. Virgin Islands 440 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174225064471900. Local number, 1. LOCATION.--Lat 17- 42'25", long 64 - 47'19". Owner: Virgin Islands Government. Name: Fairplains 6 (FP6). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). DATUM.--Elevation of land-surface datum is about 20 ft (6.10 m) above mean sea level, from topographic map. Measuring point: Top of pump concrete base, 2.20 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 15.64 ft (4.77 m) below land-surface datum, Mar. 25, 1982; lowest water level measured, a59.08 ft (18.0 m) below land-surface datum, Oct. 6, 1987. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a59.08 Mar. 21 a56.07 May 31 a56.90 Aug. 23 17.05 Jan. 19 a56.26 a Pumping. 441 GROUND-WATER LEVELS Si. CROIX, U.S. VIRGIN ISLANDS 174225064472000. Local number, 2. LOCATION.--Lat 17- 42'25", long 64 47'20". Owner: U.S. Government, Virgin Islands Government. Name: USGS-10, Fairplains 2 (VP?). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). 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. Nearby pumping well. PERIOD OF RECORD.--June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 20.82 ft (6.34 m) below land-surface datum, Jan. 22, 1988; lowest water level recorded, 25.02 ft (7.63 m) below land-surface datum, Aug. 22, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JuN ,;UL AUG SEP 1 23.13 23.16 22.48 21.21 21.58 21.82 22.13 21.97 22.42 22.06 21.96 21.49 2 23.18 23.13 22.42 21.24 21.34 21.82 22.04 21.95 22.47 22.04 21.91 21.47 3 23.28 23.11 22.35 21.25 21.32 21.85 21.98 22.04 22.53 22.01 21.86 21.34 4 23.33 23.06 22.32 21.25 21.27 21.88 22.08 22.17 22.42 21.96 21.83 21.32 5 23.36 22.95 22.12 21.25 21.26 21.88 21.99 22.20 22.57 21.93 21.81 21.32 6 23.39 23.05 22.03 21.17 21.23 21.86 21.94 22.13 22.59 22.02 21.82 21.32 7 23.43 23.05 21.94 21.11 21.20 21.85 21.93 22.18 22.73 22.06 21.82 21.32 8 23.45 23.03 21.88 21.15 21.11 21.86 21.95 22.18 22.64 22.03 21.90 21.27 9 23.48 23.04 21.82 21.11 21.13 21.78 21.97 22.04 22.51 22.06 21.93 21.24 10 23.48 23.07 21.79 21.16 21.16 21.73 22.08 22.24 22.45 22.02 21.95 21.23 11 23.48 23.07 21.69 21.07 21.18 21.77 22.09 22.24 22.47 22.07 21.98 21.18 12 23.47 23.05 21.63 21.02 21.20 21.83 22.22 22.38 22.49 22.11 21.95 21.14 13 23.47 22.91 21.58 20.96 21.19 21.84 22.31 22.47 22.46 22.19 21.88 21.10 14 23.46 22.87 21.53 21.01 21.21 21.86 22.37 22.50 22.57 22.19 21.84 21.08 15 23.45 22.83 21.43 21.02 21.22 21.92 22.41 22.37 22.63 22.22 21.82 21.06 16 23.44 22.82 21.51 21.01 21.26 21.98 22.46 22.26 22.67 22.21 21.81 21.07 17 23.42 22.84 21.45 21.13 21.27 21.93 22.46 22.18 22.63 22.18 21.72 21.06 18 23.41 22.84 21.41 21.16 21.58 21.90 22.38 22.17 22.57 22.19 21.70 21.05 19 23.27 22.78 21.34 21.17 21.58 21.88 22.37 22.16 22.64 22.10 21.70 21.02 20 23.15 23.19 21.29 21.15 21.56 21.93 22.34 22.17 22.69 22.03 21.70 20.98 21 23.29 23.27 21.28 20.86 21.47 21.96 22.32 22.14 22.41 21.97 21.69 20.96 22 23.30 23.27 21.27 20.98 21.47 22.07 22.31 22.11 22.30 21.95 21.69 20.94 23 23.32 23.33 21.32 21.18 21.60 22.06 22.27 22.03 22.23 21.99 21.68 20.96 24 23.32 23.28 21.12 21.25 21.50 22.07 22.23 22.01 22.29 22.03 21.61 20.96 25 23.31 23.14 21.24 21.32 21.65 22.10 22.24 22.06 22.30 22.09 21.58 20.96 26 23.30 23.06 21.25 21.38 21.73 22.12 22.08 22.12 22.32 22.11 21.58 20.97 27 23.29 22.89 21.24 21.44 21.75 22.22 22.03 22.25 22.25 22.10 21.54 21.00 28 23.30 22.74 21.23 21.47 21.80 22.21 21.98 22.27 22.17 22.00 21.55 21.01 29 23.26 22.61 21.22 21.53 21.76 22.22 21.99 22.27 22.11 21.93 21.56 21.17 30 23.26 22.56 21.22 21.56 22.25 21.99 22.25 22.08 21.97 21.55 21.08 31 23.23 21.17 21.58 22.25 22.27 22.00 21.51 LOW 23.48 23.33 22.48 21.58 21.80 22.25 22.46 22.50 22.73 22.22 21.98 21.49 HIGH 23.13 22.56 21.12 20.86 21.11 21.73 21.93 21.95 22.08 21.93 21.51 20.94 WTR YR 1988 MEAN 22.02 LOW 23.48 HIGH 20.86 20 c:4 o- 4c W• W 22 U Z thJ • 24 W• I -J C) tx Z • 26 ONDJFMAMJJ 1985 1986 ASONDJFM 1987 AMJ JASON DJFMAMJJ AS 1988 442 GROUND-WATER LEVELS SI. CROIX, U.S. VIRGIN ISLANDS 174243064475100. Local number, 3. LOCATION.--Lat 17 - 42'43", long 64 - 47'51". Owner: U.S. Government, Virgin Islands Government. Name: Golden Grove-6 (PW6). AQUIFER.--Alluvium and marl. WELL CHARACTERIST1CS.--Drilled unused water-table well, diameter 8 in (0.20 m), cased 8 in (0.20 m). 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. Estimated record; Jan. 8-18, Feb. 4 to Mar. 21. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 13.73 ft (4.18 m) below land-surface datum, Dec. 12, 1988; lowest water level recorded, 29.27 ft (8.90 m) below land-surface datum, May 30-31, June 1-5, 1987. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 26.14 27.02 16.12 15.88 17.90 20.06 21.97 23.12 24.25 24.92 24.81 25.08 2 26.17 27.04 15.11 15.06 18.00 20.13 22.00 23.16 24.27 24.93 24.83 25.09 3 26.21 27.06 14.58 14.43 18.09 20.21 22.05 23.23 24.29 24.94 24.84 25.10 4 26.23 27.09 14.38 14.00 18.19 20.28 22.07 23.27 24.32 24.96 24.86 25.10 5 26.27 27.13 14.48 13.78 18.31 20.35 22.09 23.31 24.37 24.99 24.87 25.11 6 26.29 27.16 14.68 13.88 18.38 20.42 22.12 23.33 24.39 25.01 24.89 25.12 7 26.30 27.18 14.91 14.10 18.45 20.49 22.14 23.36 24.42 25.02 24.92 25.13 8 26.32 27.21 14.86 14.26 18.52 20.56 22.18 23.39 24.44 25.03 24.93 25.13 ' 9 26.37 27.22 14.27 14.42 18.59 20.62 22.23 23.46 24.50 25.04 24.94 25.13 10 26.39 27.24 13.99 14.58 18.67 20.69 22.26 23.49 24.53 25.05 24.92 25.14 11 26.40 27.26 13.86 14.74 18.74 20.76 22.30 23.54 24.53 25.08 24.93 25.15 12 26.45 27.29 13.76 14.89 18.81 20.83 22.36 23.59 24.54 25.12 24.93 25.15 13 26.48 27.32 13.94 15.05 18.88 20.90 22.40 23.61 24.60 25.12 24.94 25.16 14 26.52 27.35 14.21 15.20 18.95 20.97 22.45 23.63 24.64 25.11 24.93 25.17 15 26.55 27.37 14.48 15.36 19.02 21.04 22.50 23.67 24.65 25.07 24.94 25.18 16 26.57 27.38 14.69 15.51 19.09 21.11 22.53 23.72 24.65 24.97 24.95 25.18 17 26.60 27.41 14.89 15.71 19.16 21.18 22.57 23.73 24.69 24.87 24.94 25.19 18 26.62 27.44 15.07 15.88 19.22 21.25 22.62 23.76 24.72 24.81 24.95 25.20 19 26.65 27.46 15.25 16.14 19.29 21.32 22.65 23.80 24.75 24.76 24.96 25.21 20 26.66 27.50 15.43 16.28 19.36 21.39 22.68 23.84 24.77 24.71 24.97 25.21 21 26.68 27.52 15.57 16.42 19.43 21.54 22.71 23.89 24.76 24.68 24.98 25.22 22 26.74 27.53 15.77 16.56 19.50 21.59 22.77 23.95 24.78 24.69 25.00 25.23 23 26.78 27.55 15.92 16.68 19.57 21.62 22.83 23.98 24.79 24.70 25.00 25.24 24 26.81 27.55 16.03 16.84 19.64 21.66 22.86 24.01 24.81 24.72 25.01 25.24 25 26.84 27.33 16.20 16.95 19.71 21.70 22.90 24.02 24.82 24.74 25.02 25.24 26 26.87 25.94 16.35 17.11 19.78 21.73 22.94 24.06 24.83 24.76 25.03 25.25 27 26.89 24.30 16.51 17.26 19.85 21.77 22.99 24.10 24.85 24.78 25.03 25.26 28 26.92 21.85 16.67 17.39 19.92 21.81 23.02 24.13 24.87 24.79 25.05 25.26 29 26.95 19.23 16.81 17.55 19.99 21.85 23.07 24.15 24.89 24.79 25.06 25.27 30 26.97 17.57 17.00 17.71 21.88 23.10 24.18 24.90 24.81 25.07 25.28 31 27.01 16.69 17.81 21.92 24.22 24.80 25.07 LOW 27.01 27.55 17.00 17.81 19.99 21.92 23.10 24.22 24.90 25.12 25.07 25.28 HIGH 26.14 17.57 13.76 13.78 17.90 20.06 21.97 23.12 24.25 24.68 24.81 25.08 WTR YR 1988 MEAN 22.48 LOW 27.55 HIGH 13.76 12 Lciaj 17 1-‹ LI-0 22 Law 27 -JOZ 32 ONDJFMAMJJASONDJFMAMJ J ASONDJFMAMJJ AS 1988 1985 1986 1987 GROUND-WATER tEVEIS ST. CROIX, U.S. VIRGIN ISLANDS 174245064475800. local number. 4. LOCATION.--Lat 17 - 42'45", long 64 47'58". Owner: Virgin Islands Government. Name: Golden Grove - 1 (PW1). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m), 0-104 ft (0-31.70 m), perforated 64-104 ft (19.51-31.70 m). Depth 104 ft (31. 70 DATUM.--Elevation of land-surface datum is about 40 ft (12.2 m) above mean sea level, from topographic map. Measuring point: Lower edge of 1 in. (0.02 m) pipe at pump base, 3.40 ft (1.04 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--January 1983 to current year. EXTREMES FOR PERIOD OF RECORD: Highest water level measured, a20.76 ft (6.33 m) below land-surface datum, Jan. 19, 1988; lowest water level measured, a58.30 ft (17.77 m) below land-surface datum, September 27, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 28.12 Mar. 21 a23.04 May 31 a23.26 Aug. 23 a27.76 Jan. 19 a20.76 a Pumping. 443 444 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174303064484400. Local number, 6. LOCATION.--tat 17 43'03", long 64 48'44". Owner: U.S. Government, Virgin Islands Government. Name: Adventure 28. AQUIFER.--Alluvium of Pleistocene age and marl of Oligocene age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m). Depth 97 ft (29.6 m). DATUM.--Elevation of land-surface datum is about 80 ft (24.39 m) above mean sea level, from topographic map. Measuring point: Upper edge of hole at 4 in (0.10 m) casing, 2.00 ft (0.61 m) above land-surface datum. Prior June 20, 1983, top of 4 in (0.10 m) casing, 0.90 ft (0.27 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--August 1973 to March 1974, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 24.90 ft (7.59 m) below land-surface datum, Mar. 25, 1982; lowest water level recorded, 40.18 ft (12.25 m) below land-surfac.? datum, Aug. 5, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 38.04 38.21 35.84 32.12 30.76 31.36 31.46 31.85 32.42 32.15 31.46 30.84 2 38.07 38.20 35.49 31.88 30.79 31.38 31.47 31.85 32.46 32.11 31.49 30.88 3 38.10 38.19 35.16 31.73 30.76 31.43 31.46 31.91 32.47 32.10 31.54 30.87 4 38.11 38.19 34.87 31.55 30.75 31.46 31.44 31.94 32.51 32.09 31.55 30.92 5 38.13 38.18 34.58 31.39 30.76 31.46 31.43 31.97 32.55 32.08 31.57 30.96 6 38.15 38.18 34.35 31.28 30.77 31.46 31.41 31.97 32.56 32.08 31.62 31.01 7 38.15 38.19 34.13 31.21 30.79 31.46 31.37 32.01 32.57 32.05 31.67 31.01 8 38.17 38.19 33.71 31.14 30.80 31.49 31.36 32.03 32.58 32.05 31.70 31.03 9 38.18 38.19 33.69 31.08 30.82 31.48 31.38 32.07 32.61 32.01 31.71 30.95 10 38.19 38.19 33.46 31.04 30.89 31.49 31.39 32.10 32.63 31.97 31.56 30.83 11 38.20 38.19 33.27 30.99 30.92 31.51 31.39 32.03 32.61 31.98 31.47 30.83 12 38.21 38.19 33.13 30.95 30.94 31.53 31.44 32.06 32.58 31.98 31.34 30.79 13 38.22 38.19 33.04 30.92 30.95 31.52 31.45 32.07 32.54 32.01 31.22 30.72 14 38.23 38.19 32.96 30.90 31.00 31.51 31.48 32.02 32.55 31.93 31.14 30.68 15 38.24 38.21 32.88 30.89 31.03 31.54 31.50 32.08 32.57 31.90 31.11 30.64 16 38.24 38.21 32.80 30.87 31.09 31.55 31.52 32.16 32.56 31.81 31.08 30.60 17 38.25 38.21 32.73 30.85 31.10 31.59 31.53 32.15 32.56 31.69 31.01 30.57 18 38.25 38.21 32.69 30.82 31.10 31.62 31.54 32.16 32.59 31.61 30.98 30.55 19 38.25 38.21 32.67 30.82 31.13 31.62 31.54 32.18 32.60 31.58 31.01 30.54 20 38.25 38.21 32.65 30.80 31.17 31.64 31.54 32.21 32.60 31.57 31.00 30.51 21 38.24 38.21 32.60 30.81 31.21 31.71 31.55 32.24 32.46 31.55 31.02 30.51 22 38.24 38.21 32.57 30.80 31.25 31.71 31.59 32.28 32.40 31.53 30.99 30.46 23 38.23 38.21 32.55 30.77 31.25 31.66 31.65 32.30 32.38 31.52 30.95 30.46 24 38.23 38.22 32.51 30.85 31.24 31.63 31.64 32.34 32.35 31.52 30.91 30.44 25 38.23 38.22 32.49 30.80 31.23 31.62 31.65 32.36 32.31 31.50 30.87 30.41 26 38.22 38.22 32.47 30.80 31.24 31.61 31.70 32.36 32.26 31.51 30.86 30.41 27 38.22 38.18 32.44 30.76 31.25 31.59 31.73 32.37 32.23 31.52 30.85 30.47 28 38.22 38.18 32.43 30.74 31.30 31.55 31.76 32.38 32.21 31.52 30.86 30.47 29 38.22 38.16 32.38 30.73 31.32 31.52 31.79 32.39 32.20 31.48 30.85 30.48 30 38.22 38.16 32.37 30.77 31.48 31.82 32.40 32.18 31.43 30.82 30.49 31 38.21 32.23 30.78 31.45 32.40 31.44 30.81 LOW 38.25 38.22 35.84 32.12 31.32 31.71 31.82 32.40 32.63 32.15 31.71 31.03 HIGH 38.04 38.16 32.23 30.73 30.75 31.36 31.36 31.85 32.18 31.43 30.81 30.41 WTR YR 1988 MEAN 32.76 LOW 38.25 HIGH 30.41 ONDJFMAMJJASONDJFMAMJ JASONDJFMAMJJ AS 1985 1986 1987 1988 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 114525064460600. Local number, 7. LOCATION.--Lat 17- 45'25", long 64 46'06". Owner: Virgin Islands Government. Name: Concordia 14. AQUIFER.--Sand and gravel. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m). cased 6 in (0.15 m). Depth 85 ft (25.91 m). DAIUM.--Elevation of land-surface datum is about 40 ft (12.2 m) above mean sea level, from topographic map. Measuring point: Top of 0.50 in (0.01 m) pipe on top of pump concrete base, 2.30 ft (0.70 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumpage. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 10.16 ft (3.28 m) below land-surface datum, Jan. 19, 1988; lowest water level measured, 41.75 ft (12.73 m) below land-surface datum, Feb. 24, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS 08SERVATION:3 Water Water Water Water Date level Date level Date level Date level Oct. 6 19.34 Mar. 21 14.26 May 31 18.40 Aug. 23 18.34 Jan. 19 10.76 174527064460100. Local number, 8. LOCATION.--Lat 17- 45'27", long 64- 46'01". Owner: Virgin Islands Government. Name: Concordia 1 (Main pump house). AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 82 ft (25.0 m). DATUM.--Elevation of land-surface datum is about 40 ft (12.2 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 2.20 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumpage. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured. 14.03 ft (4.28 m) below land-surface datum, Jan. 19, 1988; lowest water level measured, a28.39 ft (a8.66 m) below land-surface datum. Dec. 8, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 19.86 Mar. 21 16.42 May 31 19.02 Aug. 23 18.92 Jan. 19 14.03 a Pumping. 445 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174532064460300. Local number, 9. LOCATION.--Lat 17 - 45'32", long 64 - 46'03". Owner: Virgin Islands Government. Name: Concordia 7. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 0-81 ft (0-24.7 m). Depth 81 ft (24.7 m). DATUM.--Elevation of land-surface datum is 35 ft (10.7 m) above mean sea level, from topographic map. Measuring point: Hole in pump base, 2.20 ft (0.67 m) above land-surface datum. Previous to Mar. 25, 1982, hole in pump base 2.50 ft (0.76 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--June 1962 to October 1968, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 1.75 ft (0.53 m) below land-surface datum, May 11, 1966; lowest water level measured, 57.40 ft (17.5 m) below land-surface datum, Mar. 5, 1964. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a21.53 Mar. 21 al8.25 May 31 a14.50 Aug. 23 a16.40 Jan. 19 a13.63 174329064454700. Local number, 10. LOCATION.--Lat 17- 43'29", long 64- 45'47". Owner: Virgin Islands Government. Name: Barren Spot 5 (PWD-5). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 0-130 ft (0-39.63 m), Perforated 71-130 ft (21.64-39.63 m). Depth 130 ft (39.63 m). DATUM.--Elevation of land-surface datum is about 75 ft (22.86 m) above mean sea level, from topographic map. Measuring point: Hole on top of pump base, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 61.86 ft (18.86 m) below land-surface datum, Mar. 26, 1982; lowest water level measured, a75.52 ft (a23.02 m) below land-surface datum, Sept. 8. 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a74.25 Mar. 21 a68.55 May 31 a68.55 Aug. 24 a68.18 Jan. 19 a68.52 a Pumping. 446 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182050064580400. Local number, 1. LOCATION.--Lat 18- 20'50", long 6458'04". Owner: U.S. Government. Virgin Islands Government. Name: USGS-B (Family well - Thatch Farm). AQUIFER.--Volcanic rocks of Cretaceous age. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m). cased 6 in (0.15 m) 0-25 ft (0-7.62 m), open hole 25-80 ft (7.62-24.4 m). Depth 80 ft (24.4 m). DATUM.--Elevation of land-surface datum is 80 ft (24.4 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing. 2.50 ft (0.76 m) above land-surface datum. Prior to Mar. 23, 1982, top of 6 in (0.15 m) casing, 1.30 ft (0.40 m) above land-surface datum. REMARKS.--Non-potable public-water supply and observation wel,. PERIOD OF RECORD.--October 1963 to August 1969, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 2.33 ft (0.71 m) below land-surface datum, Nov. 20, 1984; lowest water level measured, a57.94 ft (17.66 a) below land-surface datum, Jan. 21. 1987. WATER LEVEL. IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 32.78 Mar. 21 32.14 June 1 35.63 Aug. 25 36.10 Jan. 19 19.41 182138064543100. Local number, 2. LOCATION.--tat 18'21'38", long 6454'31". Owner: Mahogany Run Resort. Name: Mahogany 15. AQUIFER.--Fractured rocks. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Elevation of land-surface datum is 120 ft (36.6 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 1.20 ft (0.36 m) below land-surface datum. REMARKS.--Observation well. Water levels affected by nearby pumping well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.45 ft (3.79 m) below land-surface datum. July 1, 1986; lowest water level measured, 88.62 ft (27.01 m) below land-surface datum, Oct. 4, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 8 29.72 Mar. 23 23.49 June 1 32.36 Aug. 25 42.46 Jan. 21 14.19 182138064542500. Local number, 3. LOCATION.--Lat 18- 21'38". long 6454'25". Owner: Mahogany Run Resort. Name: Mahogany 16. AQUIFER.--Fractured rocks. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m). cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Elevation of land-surface datum is 130 ft (39.6 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 1.30 ft (0.40 m) below land-surface datum. REMARKS.--Water levels affected by nearby pumping well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 10.25 (3.12 m) below land-surface datum Jan. 21, 1988; lowest water level measured, a103.85 ft (31.65 m) below land-surface datum, Oct. 4, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 8 35.33 Mar. 23 29.13 June 1 37.83 Aug. 25 45.16 Jan. 21 10.25 a Pumping. 447 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182136064541900. Local number, 4. LOCATION.--Lat 18- 21'36", long 6454'19". Owner: Mahogany Run Resort Name: Mahogany 17. AQUIFER.--Fractured rock. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Elevation of land-surface datum is 140 ft (42.7 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing at land-surface datum. REMARKS.--Public water supply. Water levels affected by nearby pumping well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 17.49 ft (5.33 m) below land-surface datum, Dec. 11 1985; lowest water level measured, a60.40 ft (18.41 m) below land-surface datum, Sept. 10, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 8 36.70 Mar. 23 31.17 June I 38.80 Aug. 25 40.60 Jan. 21 20.23 182029064535200. Local number, 5. LOCATION.--Lat 1820'29", long 6453'52". Owner: Virgin Islands Government, V.I. Housing Authority. Name: Donoe 3. AQUIFER.--Volcanic rock undifferentiated. Fracture at 165 ft (50.3 m), from drilling log. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 0-20 ft (0-6.10 m), open hole 20-400 ft (6.10-122 m). Depth 400 ft (122 m). DATUM.--Elevation of land-surface datum is about 235 ft (71.6 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 2.30 ft (0.70 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 54.24 ft (16.53 m) below land-surface datum, Nov. 20, 1984; lowest water level measured, 90.98ft (27.73m) below land-surface datum, Apr. 30, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 8 79.40 Jan. 21 66.95 Mar. 22 81.23 Aug. 25 58.59 a Pumping. 448 449 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182038064550300. Local number, 6. LOCATION.--Lat 18 20'38", long 64'55'03". Owner: U.S. Government, Virgin Islands Government. Name: Grade School 3. AQUIFER.--Volcanic breccia. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter I, in (0.15 m), cased 6 in (0.15 m). Depth 70 ft (21.3 m). 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, 3.72 ft (1.13 m) below land-surface datum, May 22, 1986; lowest water level recorded, 35.38 ft (10.79 m) below land-surface datum, July 21, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 25.99 24.11 8.52 10.75 16.75 19.77 22.82 23.77 23.77 22.80 23.77 21.75 2 26.01 24.16 8.36 10.77 16.95 19.95 22.89 23.77 23.87 22.52 23.95 21.99 3 26.02 24.22 8.33 10.88 17.13 20.13 22.99 23.77 23.94 22.39 24.09 22.22 4 26.03 24.32 8.38 11.02 17.29 20.29 23.11 23.77 24.00 22.37 24.13 22.45 5 26.06 24.18 8.49 11.18 17.42 20.44 23.22 23.80 24.07 22.46 24.09 22.67 6 26.11 24.07 8.60 11.37 17.41 20.59 23.32 23.85 24.15 22.60 24.09 22.85 7 26.16 24.08 8.68 11.57 17.33 20.75 23.38 23.90 24.24 22.72 24.14 23.02 8 26.21 24.18 8.81 11.71 17.32 20.92 23.40 23.91 24.32 22.48 24.23 23.19 9 26.26 24.34 8.88 11.88 17.35 21.06 23.39 23.48 24.38 22.33 24.35 22.75 10 26.33 24.46 9.00 12.01 17.41 21.20 23.37 22.91 24.40 22.32 24.41 18.19 11 26.39 24.60 9.12 12.21 17.50 21.33 23.37 22.43 24.42 22.43 24.40 16.82 12 26.45 24.73 9.05 12.34 17.64 21.45 23.38 22.13 24.42 22.60 24.39 15.53 13 26.50 24.82 9.11 12.50 17.78 21.55 23.42 21.98 24.20 22.76 24.42 14.74 14 26.53 24,90 9.20 12.62 17.88 21.62 23.49 21.93 23.90 22.91 24.47 14.35 15 26.55 24.86 9.38 12.73 17.97 21.70 23.56 21.91 23.69 22.93 24.56 14.30 16 26.49 24.83 9.51 12.95 18.05 21.79 23.63 21.92 23.32 22.96 24.63 14.44 17 26.35 24.84 9.70 13.10 18.15 21.91 23.65 21.95 23.07 23.01 24.15 14.71 18 25.94 24.77 9.89 13.24 18.27 22.00 23.65 22.04 22....) 23.13 23.36 15.01 19 25.42 24.70 10.11 13.40 18.41 22.08 23.63 22.19 22.98 23.24 22.95 15.36 20 25.12 24.67 10.08 13.58 18.60 22.19 23.65 22.30 23.10 22.97 22.77 15.74 21 24.98 24.67 9.67 13.77 18.74 22.24 23.68 22.43 23.12 22.75 22.69 16.13 22 24.84 24.68 9.32 14.02 18.91 22.33 23.72 22.55 22.85 22.66 22.69 16.53 23 24.75 24.70 8.94 14.30 19.05 22.39 23.76 22.67 22.59 22.66 22.74 16.94 24 24.60 24.53 9.00 14.62 19.24 22.48 23.77 22.79 22.44 22.72 22.75 17.35 25 24.37 23.69 9.22 14.96 19.37 22.57 23.76 22.89 22.38 22.83 22.02 17.75 26 24.11 19.41 9.47 15.27 19.50 22.66 23.77 23.01 22.46 22.97 21.48 18.12 27 23.98 17.17 9.71 15.58 19.62 22.70 23.80 23.14 22.58 23.10 21.23 18.50 28 23.94 14.10 9.93 15.86 19.61 22.69 23.81 23.27 22.75 23.23 21.15 18.83 29 23.96 10.93 10.15 16.13 19.65 22.72 23.79 23.41 22.89 23.35 21.20 19.19 30 23.99 9.01 10.40 16.36 --- 22.76 23.76 23.53 23.04 23.46 21.34 19.51 31 24.05 --- 10.63 16.55 22.78 --- 23.66 --- 23.59 21.54 --- LOW 26.55 24.90 10.63 16.55 19.65 22.78 23.81 23.91 24.42 23.59 24.63 23.19 HIGH 23.94 9.01 8.33 10.75 16.75 19.77 22.82 21.91 22.38 22.32 21.15 14.30 WTR YR 1988 MEAN 20.40 LOW 26.55 HIGH 8.33 ONDJFMAMJJ ASONDJFMAIAJJ ASONDJFMAMJ J AS 1986 1987 1988 GROUND-WATER LEVELS SI. JOHN, U.S. VIRGIN ISLANDS 182010064472600. local number, I. LOCATION.--Lat 18"20'10", long 64 47'26". Owner: U.S. Government, National Park Services. Name: NPS-2 (Cruz Bay). AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), 4•in (0.10 m) cased, 0-20 ft (0-6.10 m), open hole 20-99 ft (6.10-30.2 m). Depth 99 ft (30.2 m). DATUM.--Elevation of land-surface datum is 60 ft (18.3 m) above mean sea level, from topographic map. Measuring point: Top of 4 in (0.10 m) casing, 4.10 ft (1.25 m) above old land-surface datum after 1.40 ft (0.43 m) land fill and 2.70 ft (0.82 m) casing extension occurred. Prior to June 29, 1983, top of 4 in (0.10 m) casing, 1.40 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping nearby well. PERIOD OF RECORD.--May 1964, discontinued. June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, .1.41ft (0.43 m) above land-surface datum, May 1, 1986; lowest water level measured, 42.56 ft (12.98 m) below land-surface datum, Aug. 30, 1967. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 33.18 Mar. 22 32.00 June 2 34.14 Aug. 26 1.23 Jan. 20 3.62 182109064460300. Local number, 2. LOCATION.--Lat 18 21'09", long 64 - 46'03". Owner: U.S. Government, National Park Service. Name: NPS-5 (Trunk Bay). AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 0-12 ft (0-3.66 m), open hole 12-60 ft (3.66-18.3 m). Depth 60 ft (18.3 m). DATUM.--Elevation of land-surface datum is 60 ft (18.3 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 0.70 ft (0.21 m) above land-surface datum. Prior to Mar. 24, 1982 top of 6 in (0.15 m) casing, 1.00 ft (0.30 m) above land-surface datum. REMARKS.--Active water supply well for recreation facilities at Trunk Bay. PERIOD OF RECORD.--August 1964 to December 1969, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.83 ft (3.91 m) below land-surface datum, Jan. 24, 1985; lowest water level measured, a57.29 ft (17.47 m) below land-surface datum, Nov. 27, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WA1ER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 38.16 Mar. 22 a41.80 June 2 40.03 Aug. 26 37.92 Jan. 20 a29.78 a Pumping. + Above land-surface datum. 450 451 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182116064451000. Local number, 3. LOCATION.--Lat 18 21'16", long 64 - 45'10". Owner: U.S. Government, National Park Service. Name: NPS-6 (Cinnamon Bay). AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled water-table abandoned production well, diameter 6-in (0.15 m), cased 0-51 ft (0-15.55 m), open hole 51-70 ft (15.55-21.34 m). Depth 70 ft (21.34 m). DATUM.--Elevation of land-surface datum is about 60 ft (18.3 m) above mean sea level, from topographic map. Measuring point: Hole on 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. Prior to June 29, 1983, top of 6 in (0.15 m) casing at land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--August 1964 to December 1969, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 41.12 ft (12.54 m) below land-surface datum, Aug. 15, 1969; lowest water level recorded, 63.15 ft (19.25 m) below land-surface datum, July 1, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 5/.78 57.33 54.48 53.72 57.04 57.24 57.52 57.59 57.95 57.26 2 57.77 57.34 54.02 53.75 57.05 57.27 57.51 57.60 57.95 57.26 3 57.75 57.35 53.76 53.77 57.05 57.31 57.50 57.61 57.95 57.27 4 57.73 57.35 53.65 53.80 57.05 57.33 57.50 57.62 57.95 57.29 5 57.70 57.35 53.65 53.90 57.06 57.36 57.53 57.63 57.96 57.32 6 57.67 57.33 53.71 53.98 57.08 57.39 57.56 57.64 57.98 57.3 7 57.63 57.32 53.76 54.03 57.10 57.39 57.58 57.65 57.99 57.35 8 57.59 57.32 53.80 54.13 - 57.11 57.37 57.58 57.65 57.99 57.37 9 57.57 57.34 53.86 54.20 - 57.13 57.37 57.58 57.65 58.00 57.35 10 57.57 57.34 53.90 54.24 57.14 57.35 57.56 57.68 57.99 56.97 11 57.60 57.32 53.92 54.24 57.13 57.28 57.56 57.69 57.95 56.47 12 57.62 57.31 53.95 54.21 57.10 57.18 57.57 57.70 57.88 56.21 13 57.62 57.31 54.01 54.20 57.07 57.13 57.59 57.74 57.84 55.72 14 57.60 57.33 54.11 54.01 57.04 57.12 57.60 57.76 57.81 55.45 15 57.59 57.34 54.20 53.89 57.04 57.12 57.60 57.79 57.81 55.26 16 57.56 57.32 54.31 53.80 57.02 57.14 57.59 57.80 57.81 55.14 17 57.51 57.31 54.39 53.66 56.99 57.16 57.56 57.82 57.81 55.06 18 57.42 57.31 54.46 53.53 56.98 57.20 57.56 57.84 57.74 55.03 19 57.35 57.33 54.60 53.48 - 56.96 57.24 57.56 57.86 57.67 55.05 20 57.33 57.35 54.65 53.45 - 56.97 57.28 57.57 57.89 57.64 55.13 21 57.32 57.37 54.74 53.41 56.98 57.31 57.60 57.92 57.61 55.19 22 57.31 57.39 54.78 53.44 --- 57.00 57.34 57.60 57.94 57.58 55.25 23 57.31 57.40 54.64 53.56 56.84 57.02 57.36 57.58 57.95 57.55 55.34 24 57.32 57.37 54.34 53.66 56.91 57.04 57.40 57.54 57.96 57.53 55.44 25 57.32 57.30 54.01 53.77 56.93 57.04 57.45 57.53 57.97 57.45 55.56 26 57.30 57.19 53.76 53.93 - 56.96 57.07 57.47 57.52 57.98 57.37 55.64 27 57.29 56.96 53.64 54.03 56.97 57.10 57.50 57.51 51.98 57.33 1 55.74 28 57.28 56.65 53.55 54.17 56.99 57.13 57.54 57.51 57.98 57.30 55.84 29 57.28 55.94 53.54 --- 57.01 57.17 57.55 57.53 57.98 57.28 55.94 30 57.30 55.14 53.57 57.01 57.22 57.56 57.56 57.98 57.27 56.04 31 57.32 --- 53.60 57.02 --- 57.54 --- 57.96 57.26 --- LOW 57.78 57.40 54.78 57.22 57.56 57.60 57.98 58.00 57.37 HIGH 57.28 55.14 53.54 56.96 57.12 57.50 57.59 57.26 55.03 44 47 50 53 56 59 ONDJ FMAMJJ ASONDJ FMAMJJ ASONDJ FMAMJJ AS 1985 1986 1987 1988 452 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182042066454500. Local number, 5. LOCATION.--Lat 1820'42", long 66 - 45'45". Owner: Virgin Islands Government. Name: DPW-6. (Sussanaberg) AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 10 ft (21.3 m). DATUM.--Elevation of land-surface datum is about 640 ft (195 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 1.60 ft (0.49 m) above land-surface datum. Prior to June 28, 1983, top of 6 in (0.15 m) casing, 1.30 ft (0 40 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.33 ft (0.40 m) below land-surface datum, May 18, 1986; lowest water level recorded, 22.78 ft (6.94 m) below land-surface datum, Oct. 5, 1985. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.31 20.09 - 8.43 14.84 16.85 18.32 19.23 20.14 19.01 2 19.34 20.11 8.50 - 14.95 16.91 1°.43 19.25 20.17 19.01 3 19.37 20.13 8.70 15.04 16.97 10.45 19.28 20.20 19.04 4 19.43 20.14 8.76 15.13 17.04 18.50 19.34 20.23 19.07 5 19.47 20.14 8.81 15.20 17.11 18.55 19.37 20.25 19.10 6 19.50 20.20 8.80 15.23 17.16 18.60 19.40 20.29 19.14 7 19.53 20.20 15.30 17.24 18.63 19.44 20.32 19.19 8 19.56 20.21 15.38 17.30 18.67 19.47 20.35 19.23 9 19.59 20.23 15.43 17.34 18.72 19.50 20.37 4.80 10 19.63 20.24 15.52 17.40 18.77 19.52 20.38 4.67 11 19.66 20.25 - 15.59 17.41 18.80 19.55 20.38 4.45 12 19.69 20.27 15.67 17.48 18.83 19.57 20.40 --- 13 19.72 20.30 15.76 17.54 18.88 19.59 20.44 14 19.77 20.32 15.83 17.57 18.91 19.63 20.46 15 19.80 20.34 15.89 17.58 18.94 19.68 20.48 16 19.81 20.36 15.96 17.63 18.94 19.71 20.50 17 19.81 20.39 16.04 17.68 18.95 19.73 20.48 18 19.81 20.42 - 16.10 17.72 18.97 19.75 20.45 19 19.82 20.44 - 16.11 17.76 18.99 19.77 20.38 20 19.83 20.45 16.16 17.80 19.02 19.80 20.35 21 19.84 20.48 6.91 16.21 17.84 19.03 19.83 20.34 22 19.86 20.51 7.05 --- 16.28 17.90 19.04 19.85 20.34 23 19.88 20.54 7.18 14.01 16.36 17.95 19.04 19.88 20.34 24 19.91 20.54 7.33 14.11 16.40 18.00 19.05 19.91 11.20 25 19.92 19.45 7.40 14.19 16.46 18.02 19.07 19.93 19.31 26 19.95 9.71 7.59 14.31 16.52 18.07 19.09 19.96 19.50 27 19.97 8.31 7.77 14.40 16.58 18.14 19.12 20.00 19.40 28 19.99 --- 7.88 14.51 16.65 18.17 19.16 20.03 19.29 --- 29 20.01 8.02 14.58 16.73 18.22 19.18 20.05 19.19 13.39 30 20.03 8.17 14.62 16.80 18.25 19.21 20.06 19.13 13.54 31 20.06 8.30 14.73 --- 18.29 --- 20.11 19.01 --- LOW 20.06 16.80 18.29 19.21 20.11 20.50 HIGH 19.31 14.84 16.85 18.32 19.23 11.20 0 cOj 1- 4t L 5 la c 0La 10 zitt 15 W AO. 20 ce z fr f, 25 ONDJFMAMJJ ASONDJFMAMJ J ASONDJFM AMJ J AS 1985 1986 1987 1988 GROUND-WATER [EVILS SI. JOHN. U.S. VIRGIN ISLANDS 182044064454600. Local number. 6. LOCATION.--Lat 18'20'44", long 64- 45'46". Owner: Virgin Islands Government. Name: DPW-5 AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 145 ft (44.2 m). DATUM.--Elevation of land-surface datum is about 640 ft (195 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 1.40 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 18.85ft (5.74m) below land-surface datum. July 2. 1986; lowest water level measured, a107.4 ft (32.7 m) below land-surface datum, Sept. 19, 1985. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 42.03 Mar. 22 35.55 June 2 39.74 Aug. 26 41.07 Jan. 20 27.35 182044064454800. Local number, 7. LOCATION.--Lat 18 20'44, long 64 45'48". Owner: Virgin Islands Government. Name: DPW-4 AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 60 ft (18.3 m). DATUM.--Elevation of land-surface datum is about 640 ft (195 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 0.60 ft (0.18 a) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 14.48 ft (4.41 m) below land-surface datum, July 2, 1986: lowest water level measured, a50.66 ft (15.44 m) below land-surface datum, Jan. 22. 1987. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM. WATER YEAR OCTOBER 1981 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Wa.er Date level Date level Date level ' Date level Oct. 7 31.34 Mar. 22 43.61 June 2 29.26 Aug. 26 26.76 Jan. 20 20.79 182044064454900. Local number, 8. LOCATION.--Lat 18- 20'44", long 64- 45'49". Owner: Virgin Islands Government. Name: DPW-3. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 110 ft (33.5 m). DATUM.--Elevation of land-surface datum is about 640 ft (195 m) above mean sea level, from topographic mpa. Measuring point: Top of 6 in (0.15 m) casing, 1.80 ft (0.55 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.17ft (3.71 m) below land-surface datum. July 2, 1986; lowest water level measured, 69.58 ft (21.21 m) below land-surface datum, Feb. 27, 1986. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 19b, 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 26.75 Mar. 20 59.39 June 2 24.90 Aug. 26 25.18 Jan. 20 17.56 a Pumping. 453 GROUND-WATER tEVIIS SI. JOHN, U.S. VIRGIN ISLANDS 182044064455000. Local number, 9. LOCATION.--Lat 18 20'44", long 64 45'50". Owner: Virgin Islands Government. Name: OPW-2. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 65 ft (19.8 m). DATUM.--Elevation of land-surface datum is about 640 ft (195 m) above mean sea level, from topographic map. Measuring point: Top of 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 17.10 ft (5.21 m) below land-surface datum, July 2, 1986; lowest water level measured, 52.84 ft (16.1 m) below land-surface datum, Mar 22, 1988. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 10 SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 38.43 Mar. 22 52.84 June 2 35.14 Aug. 26 35.55 Jan. 20 24.10 182044064455200. Local number, 10. LOCATION.--Lat 18- 20'44", long 64- 45'52". Owner: Virgin Islands Government. Name: DPW-1. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 60 ft (18.3 m). DATUM.--Elevation of land-surface datum about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 16.60 ft (5.06 m) below land-surface datum, July 2, 1986; lowest water level measured, 38.92 ft (11.86 m) below land-surface datum, Feb. 27, 1986 WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 34.40 Mar. 22 30.65 June 2 32.82 Aug. 26 34.24 Jan. 20 22.73 454 455 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 181956064464500. Local number, 11. LOCATION.--Lat 18'19'56", long 64 46'45". Owner: 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 ft (25.9 m). 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, 3.05 ft (0.93 m) below land-surface datum, June 13, 1986; lowest water level recorded, 25.25 ft (7.70 m) below land-surface datum, Oct. 2, 1985. WATER LEVEL. IN FEET BFIOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1987 TO SEPTEMBER 1988 INSTANTANEOUS OBSERVATION AT 1200 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 18.69 19.55 7.05 4.94 - 9.32 11.82 14.70 16.79 18.40 17.56 2 18.77 19.58 6.75 4.92 9.51 11.93 14.77 16.88 18.48 17.56 3 18.84 19.61 6.54 4.97 9.63 12.05 14.82 16.96 18.57 17.56 4 18.91 19.66 6.38 4.98 9. 7 8 12.17 14.91 17.04 18.64 17.56 5 18.97 19.67 6.30 5.00 9.89 12.26 15.01 17.12 18.70 17.56 6 19.04 19.64 6.21 4.96 9.87 12.36 15.11 17.21 18.77 17.56' 7 19.10 19.62 6.01 4.92 9.87 12.45 15.21 17.30 18.86 17.57 8 19.14 19.64 5.81 4.88 9.93 12.57 15.33 17.36 18.95 17.60 9 19.18 19.67 5.76 4.76 10.03 12.66 15.46 17.39 19.03 14.40 10 19.21 19.69 5.73 4.71 10.16 12.75 15.55 17.44 19.06 10.15 11 19.25 19.72 5.71 4.59 10.25 12.76 15.61 17.48 19.06 8.70 12 19.31 19.73 5.69 4.05 10.40 12.84 15.71 17.51 19.07 7.93 13 19.37 19.77 5.72 4.14 10.56 12.94 15.79 17.55 19.11 7.49 14 19.41 19.82 5.71 3.74 10.66 13.04 15.86 17.59 19.17 7.24 15 19.45 19.85 5.72 3.86 10.77 13.12 15.89 17.63 19.25 7.09 16 19.45 19.91 5.73 4.01 10.88 13.18 15.93 17.66 19.31 7.01 17 19.42 19.96 5.74 4.15 11.03 13.23 16.00 17.68 19.17 6.95 18 19.39 20.02 5.74 4.26 11.13 13.33 16.06 17.73 18.98 6.90 19 19.41 20.06 5.71 4.36 10.94 13.37 16.14 17.77 18.86 6.90 20 19.42 20.11 5.57 --- 10.92 13.48 16.23 17.77 18.79 6.85 21 19.43 20.15 5.42 10.92 13.54 16.29 17.78 18.75 6.85 22 19.46 20.20 5.08 --- 10.93 13.66 16.35 17.82 18.73 6.85 23 19.47 20.26 4.52 8.76 11.01 13.77 16.36 17.86 18.72 6.95 24 19.49 20.26 4.56 8.88 11.10 13.90 16.39 17.89 18.64 7.09 25 19.47 19.81 4.67 8.93 11.17 14.00 16.41 17.94 18.08 7.23 26 19.45 16.85 4.76 9.02 11.27 14.12 16.47 18.01 17.87 7.35 27 19.43 12.21 4.86 9.13 11.39 14.25 16.52 18.07 17.81 7.48 28 19.45 9.50 4.90 9.20 11.54 14.38 16.59 18.13 17.72 7.53 29 19.48 8.20 4.93 - 9.29 11.64 14.51 16.66 18.20 17.65 7.55 30 19.51 7.43 4.91 9.23 11.74 14.58 16.74 18.26 17.58 7.96 31 19.53 --- 4.94 9.28 --- 14.64 --- 18.32 17.56 --- LOW 19.53 20.26 7.05 11.74 14.64 16.74 18.32 19.31 17.60 HIGH 18.69 7.43 4.52 9.32 11.82 14. . 16.79 17.56 6.85 0 ‹ Laci 9 w Z 18 V Lai I J0 Z W:5 27 ONDJ FMAMJ J ASONDJ FMAMJ J ASONDJ FMAMJ J AS 1985 1986 1987 1988 456 THIS PAGE WAS LEFT BLANK INTENTIONALLY 457 Page Page Access to WATSTORE data 33 Control, definition of 36 Acre-foot, definition of 34 Control structure, definition of 36 Adenosine triphosphate, definition of 34 Cooperation 2 Adjuntas, Lago Garzas near 70 Corozal, Rio Cibuco below 114-116 Adjuntas, Lago Germs No. 1 near dam near 381-387 Crest-stage station, definition of 36 Adjuntas, Rio Grande de Arecibo near 71-72 Cubic foot per second, definition of 36 Aguada, Rio Culebrinas near 374-375 Cubic foot per second-day, definition of 36 Aguas Buenas, Rio de Bayamon near 139-140 Cubic feet per second per square mile, definition of 36 Algae growth potential, definition of 34 Culebrinas, at Highway 404 near Moca, Rio 372-373 Analyses of samples collected at water-quality near Aguada 374-375 partial-record stations in Puerto Rico 378-387 near San Sebastian 370-371 Arlasco, Rio Grande de Anasco near 367-368 Culebrinas basin, Rio, gaging station records in 372-371 Aquifer, definition of 34 ground-water records in 428-429 Arecibo, Rio Grande de Arecibo above 79-80 water-quality records in 370-375 Artesian, definition of 34 Artificial substrate, definition of 44 Damsite, Lago El Guineo at 99 Ash mass, definition of 35 Damsite, Lago Loiza at 273-274 Damsite, Lago Matrullas at 100 Bairoa near Caguas, Rio 221-222 Damsite, Rio Grande de Loiza below 275 Bacteria, definition of 34 Definition of terms 34-47 Bahia de San Juan No. 5 at San Juan 153 Descalabrado basin, Rio, gaging stations records in 320-321 Bayamon, at Flood Channel at Bayamon, Rio de 143-144 Descalabrado near Los Uanos, Rio 320-321 near Aguas Buenas 139-140 Diatoms, definition of 41 Bayamon basin, Rio de, gaging-station records in 138 Discharge, definition of 36 ground-water records in 407 Dissolved, definition of 37 water-quality records in 139-144 Dissolved-solids concentrations 37 Bayamon, Rio Guaynabo near 141-142 Diversity index, definition of 37 Bayaney, Rio Camuy near 64-6 Drainage area, definition of 37 Bed material, definition of 35 Drainage basin, definition of 37 Bed load, definition of 43 Dry mass, definition of 35 Bed load discharge, definition of 43 Biochemical oxygen demand, definition of 35 El Seriorial, Rio Piedras at 145 Biomass, definition of 35 El Verde, Quebrada Sonadora near 282-283 Blanca at El Jagual, Quebrada 160-167 El Verde, Quebrada Toronja at 284-285 Blanco basin, Rio, gaging station records in 298-299 Espiritu Santo basin, Rio, gaging station records in 282-286 Blasina near Carolina, Quebrada 156-157 water-quality records in 283-288 Blue-green algae, definition of 41 Espiritu Santo near Rio Grande, Rio 286-288 Bonne Resolution Gut at Bonne Resolution, St Thomas, VI 432-433 Explanation of records 11.33 Borinquen, Rio Turabo at 189-198 Bottom material, definition of 35 Fajardo basin, Rio, gaging station records in 293 Bucana at Highway 14 near Ponce 330-331 water-quality records in 294-297 Bucana basin, Rio, gaging-station records in 330-331 Fajardo below Fajardo, Rio 296-297 water-quality records in 328-329 near Fajardo 293-295 Fecal coliform bacteria, definition of 135 Caguas, Lago Loiza No. 4 near mouth near 378-380 Fecal streptococcal bacteria, definition of 35 Caguas, Rio Bairoa near 221-222 Florida, Rio Grande de Arecibo below Lago Dos Bocas near 77-78 Caguas, Rio Caguitas at Highway 30 at 289-220 Caguas, Rio Grande de Loiza at 199-218 Gage-height, definition of 37 Caguitas at Highway 30 at Caguas, Rio 219-220 Gaging station, definition of 37 Caimito near Juncos, Quebrada 223-230 Grande de Masco basin, Rio, gaging station records in 364 Campo Rico, Rio Canovanas near 278-279 water-quality records in 362-368 Camuy basin, Rio, gaging station records in 64-67 Grande de Masco near Ariasco, Rio 367-368 Camuy near Bayaney, Rio 64-65 near Lares 362-363 near Hatillo 66-67 near San Sebastian 364-366 Canal Principal de Diversiones at Lago de Guajataca 58-59 Grande de Arecibo at Central Cambalache, Rio 90-91 Canovanas near Campo Rico, Rio 278-279 above Arecibo 79-80 Caonillas above Lago Caonillas near Jayuya, Rio 75-76 below Lago Dos Bocas near Florida 77-78 Carolina, Quebrada Blasina near 156-157 near Adjuntas 71-72 Catario, Rio Hondo at Flood Channel near 136-137 near Utuado 73-74 Cayaguas at Cerro Gordo, Rio 178-188 Grande de Arecibo basin, Rio, gaging station records in 178-89 Cayey, Lago Carite No. 1 near dam 381-387 ground-water records in 392 Cayey, Lago Carite No. 3 on Rio de la Plata near 378-380 water-quality partial-record stations, analyses of Cells/volume, definition of 35 samples collected in 378-387 Central Cambalache, Rio Grande de Arecibo at 90-91 water-quality records in 71-91 Central Rufina, Rio Guayanilla o Guayanilla at 339-340 Grande de Loiza at Caguas, Rio 199-218 Cerrillos near Ponce, Rio 328-329 at Quebrada Arenas 158-159 Cerro Gordo, Rio Cayaguas at 178-188 below Damsite 275 Charco Hondo, Rio Tanamit at 88-89 below Trujillo Alto 270-277 Chemical oxygen demand, definition of 36 Grande de Loiza basin, Rio, gaging station records in 158-279 Chico at Providencia, Rio 311-312 ground-water records in 410 Chico basin, Rio, water-quality records in 311-312 water-quality partial-record stations, analyses of Chlorophyll, definition of 36 samples collected in 378-387 Ciales, Rio Cialitos at Highway 649 at 105-106 water-quality records in 156-277 Ciales, Rio Grande de Manati at 101-102 Grande de Manati at Ciales, Rio 101-102 Ciales, Rio Grande de Manati at Highway 149 at 103-104 at Highway 2 near Manati 107-111 Cialitos at Highway 649 at Ciales, Rio 105-106 at Highway 149 at Ciales 103-104 Cibuco at Vega Baja, Rio 117-119 near Morovis 96-98 below Corozal 114-116 Grande de Manati basin, Rio, gaging station records in 96-108 Cibuco basin, gaging-station records in 114-117 ground-water records in 393-398 ground-water records in 399-402 water-quality records in 94-111 water-quality records in 115-119 Grande de Patillas near Patillas, Rio 313-315 Cidra, Lago de Cidra at Damsite near 138 Grande de Patillas basin, Rio, gaging station records in i 313 Coamo basin, Rio, ground-water records in 413 water-quality records in 314-315 water-quality records in 318-319 Graphs: Coamo near Coamo, Rio 318-319 Ground-water levels at selected wells in Puerto Rico and the US Virgin Islands . 8 Color unit, definition of 36 Monthly-mean discharge of selected streams in Puerto Rico 4 Comerio, Rio de la Plata near 125-126 Green algae, definition of 41 Contents, definition of 36 458 Page Grid showing system for numbering wells and miscellaneous sites (latitude and longitude) 19 Ground-water level, records of 30-32 Ground-water quality, records of 32-33 Ground-water records for Puerto Rico 390-429 Ground-water records for US Virgin Islands 440-455 Ground-water station, definition of 37 Ground-water stations in Puerto Rico, map showing location of 16 Ground-water stations in the US Virgin Islands, map showing location of . . 18 Guadiana near Naranjito, Rio 127-128 Guajataca above Lago de Guajataca, Rio 56-57 above mouth near Quebradillas 60-62 at Lares 54-55 Guajataca basin, Rio, gaging station records in 56-60 ground-water records in 390-391 water-quality partial-record stations, analyses of samples collected in 378-387 water-quality records in 54-62 Guanajibo near Hormigueros, Rio 355-357 near San German 346-347 Guanajibo basin, Rio, gaging station records in 348-355 ground-water records in 427 water-quality records in 346-357 Guanica, Rio Loco at 341-342 Guayanes above mouth at Playa de Guayanes, Rio 307-308 at Yabucoa 305-306 Guayanes basin, Rio, ground-water records in 415 water-quality records in 305-308 Guayanilla at Central Rufina, Rio 339-340 near Guayanilla 337-338 Guayanilla basin, Rio, gaging station records in 337-338 water-quality records in 339-340 Guaynabo near Bayamon, Rio 141-142 Guinea Gut at Bethany, St John, VI 435 Gurabo at Gurabo, Rio 252-270 near Gurabo 271-272 Gurabo, Quebrada Mamey near 242-251 Hardness, definition of 38 Hatillo, Rio Camuy near 66-67 Hato Rey, Rio Piedras at 149-150 Hondo at Flood Channel near Cate°, Rio 136-137 Hondo basin, Rio, ground-water records in 406-409 water-quality records in 136-137 Hormigueros, Rio Guanajibo near 355-357 Hormigueros, Rio Rosario near 348-354 Humacao at Highway 3 at Humacao, Rio 303-304 Humacao at Las Piedras, Rio 302 Humacao basin, Rio, gaging-station records in 302 water-quality records in 303-304 Hydrologic Bench-Mark Network, definition of 38 Hydrologic conditions, summary of 2-10 Hydrologic unit, definition of 38 Icacos near Naguabo, Rio 298-299 Identification numbers, stations 11-19 Inabon at Real Abajo, Rio 326-327 Inabon basin, Rio, gaging station records in 326-327 ground-water station in 426 Instantaneous discharge, definition of 36 Introduction 1 Jacaguas at Juana Diaz, Rio 322-323 Jacaguas basin, Rio, gaging station records in 322-323 Jagual, Quebrada Blanca at El 160-167 Jayuya, Rio Caonillas above Lago Caonillas near 75-76 Jolly Hill Gut at Jolly Hill, St Croix, VI 436-437 Josefina at Pinar() Avenue, Quebrada 151 Joyuda, Quebrada Mamey at 344-345 Juana Diaz, Rio Jacaguas at 322-323 Juncos, Quebrada Caimito near 223-230 Juncos, Rio Valenciano near 231-241 Lago Carite No.1 near dam near Cayey 381-387 No. 3 on Rio de la Plata near Cayey 378-380 Lago de Cidra at Damsite near Cidra 138 Lago de Guajataca, Canal Principal de Diversiones at 58-59 No. 1 near dam near Quebradillas 381-387 No. 3 near mouth near Quebradillas 378-380 Rio Guajataca above 56-57 Lago Dos Bocas No. 1 near dam near Utuado 341-387 No. 3 at west branch near Utuado 378-380 Lago El Guineo at Damsite 99 Lago Garzas near Adjuntas 70 No. 1 near dam near Adjuntas 381-387 Lago La Plata No. 3 near dam near Naranjito 381-387 No. 5 near mouth near Naranjito 378-380 Page Lago Loiza at damsite 273-274 No. 4 near mouth near Caguas 378-380 No. 7 near dam near Trujillo Alto 381-387 Lago Matrullas at Damsite 100 Laguna Joyuda basin, gaging station records in 344-345 Laguna San Josi No. 2 at San Juan 152 Laguna Tortuguero basin, water-quality records in 112 Laguna Tortuguero outlet near Vega Baja 112 Land-surface datum, definition of 38 La Plata at Proyecto La Plata, Rio de 122-124 at Highway 2 near Toa Alta 132-133 at Toa Alta 129-131 near Come& 125-126 La Plata basin, Rio de, gagin station records in 122-133 ground-water records in 403-405 water-quality partial-record stations, analyses of samples collected in 378-387 water-quality records in 123-131 Lares, Rio Grande de Anasco near 362-363 Lares, Rio Guajataca at 54-55 Las Piedras, Rio Humacao at 302 Levels for Puerto Rico, ground-water 390-429 Levels for US Virgin Islands, ground water 440-455 Loco at Guanica, Rio 341-342 Loco basin, Rio, water-quality records in 341-342 ground-water records in 403-405 water-quality partial-record stations, analyses of samples collected in 378-387 water-quality records in 123-131 Lares, Rio Grande de Ariasco near 362-363 Lares, Rio Guajataca at 54-55 Las Piedras, Rio Humacao at 302 Levels for Puerto Rico, ground-water 390-429 Levels for US Virgin Islands, ground water 440-455 Loco at Guitica, Rio 341-342 Loco basin, Rio, water-quality records in 341-342 Los Llanos, Rio Descalabrado near 320-321 Mamey at Joyuda, Quebrada 344-345 Mamey near Gurabo, Quebrada 242-251 Mameyes near Sabana, Rio 289-290 Mameyes basin, Rio, gaging station records in 289-290 Manati , Rio Grande de Manati at Highway 2 near 107-111 Maps: Location of continuous surface-water stations Puerto Rico 14 Location of ground-water stations in Puerto Rico 16 Location of ground-water stations in the US Virgin Islands 18 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 US Virgin Islands 17 Location of water-quality stations in Puerto Rico 15 Rio Camuy basin 63 Rio Cibuco basin 113 Rio Culebrinas basin 369 Rio Grande de Arecibo basin 69 Rio Grande de Loiza basin 155 Rio Grande de Manati basin 93 Rio Guajataca basin 53 Rio Guanajibo basin 343 Rio Herrera to the Rio Anton Ruiz basins 281 Rio Hondo to the Rio Puerto Nuevo basins 135 Rio Humacao to the Rio Seco basins 301 Rio Inabon to the Rio Loco basins 325 Rio de la Plata basin 121 Rio Salinas to the Rio Jacaguas basins 317 Rio YagOez and the Rio Grande de Ariasco basins 359 Maunabo at Maunabo, Rio 309-310 Maunabo basin, Rio, water-quality records in 309-310 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 Mayaguez, Rio YagUez near 360-361 Mean concentration, definition of 43 Mean discharge, definition of 36 Measuring point, definition of 38 Metamorphic stage, definition of 38 Methylene blue active substances, definition of 38 Micrograms per gram, definition of 38 Micrograms per liter, definition of 38 Milligrams of carbon per area or volume per unit time for periphyton and macrophytes and for phytoplankton, definition of 42 Milligrams of oxygen per area or volume per unit time for periphyton and macrophytes and for phytoplankton, definition of 42 Milligrams per liter, definition of 38 Moca, Rio Culebrinas at Highway 404 near 372-373 Morovis, Rio Grande de Manati near 96-98 459 Page Page Naguabo, Rio Icacos near 298-299 Sonadora near El Verde, Quebrada 282-283 Naranjito, Lago La Plata No. 3 near dam near 381-387 Solute, definition of 44 Naranjito, Lago La Plata No. 5 near mouth near 378-380 Special network and programs 11 Naranjito, Rio Guadiana near 127-128 44 Specific conductance, definition of 19 National Stream-Quality Accounting Network, definition of 39 Stage-discharge relation, definition of 11_4 National Trends Network, definition of 40 Station identification numbers Natural substrate, definition of 44 St Croix, VI, Jolly Hill Gut at Jolly Hill 436-437 Networks and programs, special 11 St John, VI, Guinea Gut at Bethany 435 Streamfiow, definition of 44 Organic mass, definition of 35 St Thomas, VI, Bonne Resolution Gut at Bonne Resolution 432-433 Organism, definition of 40 St Thomas, VI, Turpentine Run at Mariendal 434 Organism count/area, definition of 40 Substrate, definition of 44 Organism count/volume, definition of 40 Summary of hydrologic conditions 2-10 Orocovis near Orocovis, Rio 94-95 Surface and quality-of-water records for Puerto Rico 53-375 Surface area, definition of 44 Parameter code, definition of 40 Surface-water quality, records of 25-30 Partial record station, definition of 40 Surface-water records for US Virgin Islands 432-437 Partial record stations In Puerto Rico, Surface-water stations in Puerto Rico, map showing location of 14 water quality at 378-387 Surface-water stations in US Virgin Islands, map showing location of 17 Particle size, definition of 40 Surficial bed material, definition of 44 Particle-size classification, definition of 40 Suspended, definition of 44 Patillas, Rio Grande de Patillas near 313-315 Suspended-recoverable, definition of 45 Percent composition, definition of 41 Suspended sediment, definition of 43 Periphyton, definition of 41 Suspended-sediment concentration, definition of 43 Pesticides, definition of 41 Suspended-sediment discharge, definition of 43 Phytoplankton, definition of 41 Suspended-sediment load, definition of 43 Picocurie, definition of 41 Suspended-total, definition of 45 Piedras, at Hato Rey, Rio 149-150 at Rio Piedras 148 Taname at Charco Hondo, Rio 88-89 at El Seriorial 145 near Utuado 81-87 near Rio Piedras 146.147 Taxonomy, definition of 45. Piriero Avenue, Quebrada Josefina at 151 Techniques of water-resources investigations, publications on 48-49 Plankton, definition of 41 Terms, definition of 34-47 Playa de Guayanes, Rio Guayanes above mouth at 307-308 Thermograph, definition of 45 Polychlorinated biphenyls, definition of 42 Time-weighted average, definition of 48 Ponce, Rio Bucana at Highway 14 near 330,131 Toa Alta, Rio de La Plata at 129-131 Ponce, Rio Cerrillos near 328-329 Toa Alta, Rio de La Plata at Highway 2 near 132-133 Ponce, Rio Portugues at 335-336 Tons per acre-foot, definition of 46 Ponce, Rio Portugues near 332.334 Tons per day, definition of 46 Portugues at Ponce, Rio 335-336 Toronja at El Verde, Quebrada 284-285 near Ponce 332-334 Total, definition of 46 Portugues basin, Rio, gaging station records in 332 Total col form bacteria, definition of 34 water-quality records in 333-336 Total discharge, definition of 46 Primary productivity, definition of 42 Total organism count, definition of 40 Programs, special networks and 11 Total-recoverable, definition of 48 Providencia, Rio Chico at 311-312 Total sediment discharge, definition of 43 Proyecto La Plata, Rio de La Plata at 122-124 Total-sediment load, definition of 43 Publications on techniques of water-resources investigations 48-49 Tritium network, definition of 46 Puerto Nuevo basin, Rio, gaging-station records in 145-151 Trujillo Alto, Lago Loiza No. 7 near dam near 381-387 ground-water records in 408-409 Trujillo Afto, Rio Grande de Loiza below 276-277 water-quality records in 146-153 Turabo at Borinquen, Rio 189-198 Turpentine Run at Mariendal, St. Thomas, VI 434 Quality of water records of Puerto Rico, surface and 53-375 Quebrada Arenas, Rio Grande de Loiza at 158-159 Utuado, Lago Dos Bocas No. 1 near dam near 381-387 Quebradillas, Lago Guajataca No. 1 near dam near 381-387 Utuado, Lago Dos Bocas No. 3 at west branch near ....... . 378-380 Quebradillas, Lago Guajataca No. 3 near mouth near 378-380 Utuado, Rio Grande de Arecibo near 73-74 Quebradillas, Rio Guajataca above mouth near 60-62 Utuado, Rio Tanama near 81-87 Radiochemical program, definition of 42 Valenciano near Juncos, Rio 231-241 Real Abajo, Rio Inabon at 326-327 Vega Baja, Laguna Tortuguero outlet near 112 Records, explanation of 11-33 Vega Baja, Rio Cibuco at 117-119 Records of ground-water levels 30-32 Records of ground-water quality 32-33 Water-discharge, records of stage and 20-25 Records of stage and water discharge 20-25 Water-quality partial-record stations in Puerto Rico, Records of surface-water quality 25-30 analyses of samples collected at 33'8-387 Recoverable from bottom material, definition of 42 Water-quality stations in Puerto Rico, map showing location of 15 Return period, definition of 42 Water-resources investigations, publications on techniques of 48-49 Rio Grande, Rio Espiritu Santo near 286-288 Water year, definition of 47 Rio Piedras, Rio Piedras near 146-147 WATSTORE data, Access to 33 Rosario near Hormigueros, Rio 348-354 WDR, definition of 47 Runoff, in inches, definition of 42 Weighted average, definition of 47 Wells - Puerto Rico: Sabana at Sabana, Rio 291-292 Bayamon basin, Rio de Sabana basin, Rio, gaging station records in 291-292 Well 219 - Fort Buchanan No. 1 407 Sabana, Rio Mameyes near 289-290 Cibuco basin, Rio Salvatierra near San Lorenzo, Quebrada 168-177 Well 70 - Sabana Hoyos 399 Salinas basin, Rio, ground-water records in 414-425 Well 211 - Rosario No. 2 400 San German, Rio Guanajibo near 346-347 Well 212 - Ponderosa TW-1 401 San Juan, Bahia de San Juan No. 5 at 153 Well 213 - Pampano No 2 402 San Juan, Laguna San Jose No. 2 at 152 Coamo basin, Rio San Lorenzo, Quebrada Salvatierra near 168-177 Well 87 - Alomar 1 413 San Sebastian, Rio Culebrinas near 370-371 Culebrinas basin, Rio San Sebastian, Rio Grande de Masco near 364-366 Well 83 - San Sebastian 428 Seco basin, Rio, ground-water records in 411 Well 200 - Aguadilla Cement north 429 Sediment, definition of 43 Grande de Arecibo basin, Rio Sodium-adsorption-ratio, definition of 44 Well 204 - Gilberto Rivera 392 460 Page Page Grande de Loiza basin, Rio Wells - US Virgin Islands: Well 222 - Campo Rico TW-1 410 St Croix Grande de Manati basin, Rio Well 1 - Fairplains 6 (FP6) 440 Well 205 - NC-05 Barceloneta near Cruce Davila 393 Well 2 - USGS-10, Fairplains 2 (FP2) 441 Well 206 - Plazuela No. 2 394 Well 3 - Golden Grove 6 (PW6) 442 Well 207 - Cantito La Luisa 395 Well 4 - Golden Grove 1 (PW1) 443 Well 208 - Acropolis - Manati 396 Well 8 - Adventure 28 444 Well 209 - Coto Norte No. 3 397 Well 7 - Concordia 14 445 Well 210 - Gelo Martinez 398 Well 8 - Concordia 1 (main pump house) 445 Guajataca basin, Rio Well 9 - Concordia 7 446 Well 165 - Mateo Perez, Bo. Salto 390 Well 10 - Barren Spot 5 (PWD-5) 446 Well 202 - Carmelo Barreto-Garcia 391 St John Guanajibo.basin, Rio Well 1 - NPS-2 (Cruz Bay) 450 Well 143 - Vivoni, Hacienda Amistad 427 Well 2 - NPS-5 (Trunk Bay) 450 Guayanes basin, Rio Well 3 - NPS-6 (Cinnamon Bay) 451 Well 96 - USGS TW-2 or Yabucoa 7 412 Well 5 - DPW-6 452 Hondo basin, Rio Well 6 - DPW-5 453 Well 218 - Levittown No. 7 406 Well 7 - DPW-4 453 La Plata basin, Rio de Well 8 - DPW-3 453 Well 214 - Dorado Beach No. 7 403 Well 9 - DPW-2 454 Well 216 - Pozo Navy - Campanillas 404 Well 10 - DPW-1 454 Well 217 - Monserrate TW-2 405 Well 11 - Guinea Gut Well 455 Puerto Nuevo basin, Rio St Thomas Well 220 - Parque San Luis Rey 408 Well 1 - USGS-8 (Family well-Thatch Farm) 447 Well 221 - Hyde Park TW-10 409 Well 2 - Mahogany 15 447 Salinas basin, Rio Well 3 - Mahogany 16 447 Well - HW - TW - 01 414 Well 4 - Mahogany 17 448 Well - HW - TW - 02 415 Well 5 - Donoe 3 448 Well - HW - TW - 03 416 Well 6 - Grade School 3 449 Well - HW - TW - 04 417 Yauco basin, Rio Well - HW - TW - 05B 418 Well 132 - Yauco 2 426 Well - HW - TW - 07 419 Wet mass, definition of 35 Well - HW - TW - 08 420 WSP, definition of 47 Well - HW - TW - 10 421 Well - HW - TW - 11 422 Yabucoa, Rio Guayanes at 305-306 Well - HW - 1W - 13 423 YagUez near Mayaguez, Rio 360-361 Well - HW - TW - 14 424 YagUez basin, Rio, water-quality records in 360-361 Well - HW - TW - 15 425 Yauco basin, Rio, ground-water records in 426 Seco basin, Rio Well 8 - Juana 5 411 Zooplankton, definition of 41 October 1, 1978 FACTORS FOR CONVERTING INCH-POUND UNITS TO INTERNATIONAL SYSTEM UNITS (SI) The following factors may be used to convert the inch-pound units published herein to the International System of Units (SI). Multiply inch-pound units inches (in) feet (ft) miles (mi) acres square miles (mil) gallons (gal) million gallons cubic feet (ft3 ) cfs-days acre-feet (acre-ft) cubic feet per second (ft3 /s) gallons per minute (gal/min) million gallons per day tons (short) By Length 2.54x101 2.54x10-2 3.048x10-' 1.609x10° Area 4.047x103 4.047x1Cri 4.047x10-3 2.590x10° Volume 3.785x10° 3.785x10° 3.785x10-3 3.785x103 3.785x1V 2.832x101 2.832x1CT2 2.447x103 2.447x10-3 1.233x103 1.233x10-3 1.233x10-6 Flow 2.832x101 2.832x10' 2.832x10-2 6.309x1T2 6.309x10-2 6.309x10-s 4.381x101 4.381x10-2 Mass 9.072x1Cri To obtain SI units millimeters (mm) meters (m) meters (m) kilometers (km) square meters (m2 ) square hectometers (hm2 ) square kilometers (km2 ) square kilometers (km2 ) liters (L) cubic decimeters (dm3 ) cubic meters (m3 ) cubic meters (m3 ) cubic hectometers (hm3 ) cubic decimeters (dm3 ) cubic meters (m3 ) cubic meters (m3 ) cubic hectometers (hm3 ) cubic meters (m3 ) cubic hectometers (hm3 ) cubic kilometers (km3 ) liters per second (L/s) cubic decimeters per second (dm3 /s) cubic meters per second (m3 /s) liters per second (L/s) cubic decimeters per second (dm3 /s) cubic meters per second (m3 /s) cubic decimeters per second (dm3 /s) cubic meters per second (m3 /s) megagrams (Mg) or metric tons 9 SLE991700 91-81- 6 lin 11 1111 Hall NaLS38 - AEIV8911 sosn US. DEPARTMENT OF THE INTERIOR Geological Survey GPO Box 4424 ( U.S.MAIL San Juan, PR 00936 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE $300 SPECIAL 4TH CLASS BOOK RATE