U.S. Department of the Interior U.S. Geological Survey Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 2003 By Pedro L. Díaz, Zaida Aquino, Carlos Figueroa-Alamo, René García, and Ana V. Sánchez Water-Data Report PR-03-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other agencies 2005 U.S. Department of the Interior Gale A. Norton, Secretary U.S. Geological Survey Charles G. Groat, Director U.S. Geological Survey GSA Center, Suite 400-15 651 Federal Drive Guaynabo, PR 00965 Telephone: (787) 749-4346 Information about the USGS, Caribbean District is available on the Internet at http://pr.water.usgs.gov/ Information about all USGS reports and products is available by calling 1-888-ASK-USGS or on the Internet via the World Wide Web at http://www.usgs.gov/ Additional earth science information is available by accessing the USGS home page at http://www.usgs.gov/ iii PREFACE This annual hydrologic data report of Puerto Rico and the U.S. Virgin Islands is one of a series of annual reports that document hydrologic data gathered from the U.S. Geological Survey's surface- and ground-water data-collection networks in each state, Puerto Rico, the U.S. Virgin Islands, and the other Trust Territories. These records of streamflow, ground-water levels, and quality-of-water provide the hydrologic information needed by state, local, and Federal agencies, and the private sector for developing and managing our Nation's land and water resources. The report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey, Water Resources Division, who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and assembled the report. In addition to the authors, who had primary responsibility for assuring that the information contained herein is accurate, complete, and adheres to the U.S. Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing, and tabulations of the data: José M. Agis Ronald T. Richards Alexander Avila Gilberto Rodríguez George Arroyo Manuel Rosario Iris M. Concepción José René Sánchez Israel Cruz Luis Santiago-Rivera Angel G. Ferrer Carlos Santos Senén Guzmán-Ríos Luis Soler Felipe Hernández Elliot M. Sosa Yaniré Martínez Angel Torres José Merced Heriberto Torres-Sierra Carlos Narvaez James Torres Julio Oms Sigfredo Torres-González Awilda Ortíz Ahmed Valencia Rafael Peña-Cortéz Luis Vega Francisco Maldonado prepared the illustrations and Ruth I. Guzmán typed the text of the report and was mainly responsible for the assemble of the book using Automated Annual Report (AAR) Scripts for Surface-Water Discharge and Water-Quality Stations. 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 Pedro L. Díaz, Caribbean District Chief, San Juan, Puerto Rico. REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER 9. SPONSORING / MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. AGENCY REPORT NUMBER 11. SUPPLEMENTARY NOTES 12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE 13. ABSTRACT (Maximum 200 words) 14. SUBJECT TERMS 15. NUMBER OF PAGES 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT 18. SECURITY CLASSIFICATION OF THIS PAGE 19. SECURITY CLASSIFICATION OF ABSTRACT 20. LIMITATION OF ABSTRACT 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED SPONSORING / MONITORING Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for r eviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding t his burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (07 04-0188), Washington, DC 20503. April 2005 Annual - October 1, 2002 to September 30, 2003 Water Resources Data for Puerto Rico and the U.S. Virgin Islands Water Year 2003 Pedro L. Díaz, Zaida Aquino, Carlos Figueroa-Alamo, René García, Ana V. Sánchez U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 USGS-WDR-PR-03-1 U.S. Geological Survey, Water Resources Division GSA Center, 651 Federal Drive, Suite 400-15 Guaynabo, Puerto Rico 00965 USGS-WDR-PR-03-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies. NO RESTRICTION ON DISTRIBUTIONS Water resources data for surface-water, quality-of-water, and ground-water records for the 2003 water year for Puerto Rico and the U.S. Virgin Islands consists of records of discharge, water quality of streams, and water levels of wells. This report contains discharge records for 86 streamflow-gaging stations; daily sediment records for 22 streamflow stations; stage records for 17 reservoirs; water-quality records for 17 streamflow-gaging stations, 39 ungaged stream sites, 2 lagoons, and 1 bay; and water- level records for 72 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. *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data sediments, Streamflow, Water analysis, Water levels, Lakes 584 Unclassified Unclassified NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std 239-18 298-102 v CONTENTS Page Preface........................................................................................................................................................................iii List of surface-water and water-quality stations, in downstream order, for which records are published in this volume ..................................................................................................................................vii List of ground-water wells, by basin, for which records are published in this volume ............................................ xii List of discontinued streamflow stations .................................................................................................................. xv Introduction................................................................................................................................................................. 1 Cooperation................................................................................................................................................................. 2 Summary of hydrologic conditions............................................................................................................................. 3 Precipitation ................................................................................................................................................................ 3 Surface water....................................................................................................................................................... 4 Ground water....................................................................................................................................................... 6 Water quality ....................................................................................................................................................... 9 Special networks and programs ................................................................................................................................ 13 Explanation of records .............................................................................................................................................. 14 Downstream order and station number ..................................................................................................................... 14 Numbering system for wells and miscellaneous sites............................................................................................... 19 Explanation of stage and water discharge records .................................................................................................... 19 Data collection and computation ....................................................................................................................... 19 Data presentation............................................................................................................................................... 20 Station manuscript ...................................................................................................................................... 21 Data table of daily mean values.................................................................................................................. 22 Statistics of monthly mean data.................................................................................................................. 22 Summary statistics...................................................................................................................................... 22 Identifying estimated daily discharge................................................................................................................ 24 Accuracy of field data and computed results .................................................................................................... 24 Other data records available .............................................................................................................................. 25 Records of surface-water quality .............................................................................................................................. 25 Classification of records....................................................................................................................................25 Arrangement of records..................................................................................................................................... 25 On-site measurements and sample collection.................................................................................................... 25 Water temperature ............................................................................................................................................. 26 Sediment............................................................................................................................................................ 26 Laboratory measurements .................................................................................................................................27 Data presentation............................................................................................................................................... 27 Remark codes .................................................................................................................................................... 28 Records of ground-water levels ................................................................................................................................ 28 Data collection and computation ....................................................................................................................... 28 Data presentation............................................................................................................................................... 29 Water-levels tables ............................................................................................................................................29 Access to U.S. Geological Survey Water Data ......................................................................................................... 30 Definition of terms .................................................................................................................................................... 31 Techniques of Water-Resources Investigations of the U.S. Geological Survey ....................................................... 49 Surface- and quality-of-water records for Puerto Rico ............................................................................................. 53 Ground-water records for Puerto Rico.................................................................................................................... 481 Ground-water records for U.S. Virgin Islands ....................................................................................................... 553 Index........................................................................................................................................................................ 561 vi ILLUSTRATIONS Page Figure 1. Graphs showing monthly-mean discharge of selected streams in Puerto Rico.....................................5 2. Graphs showing ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands ...........................................................................................................................6 3. Map showing location of maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico.............................................................................10 4. ­ Map showing location of maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico.............................................................................11 5. Map showing location of surface-water stations in Puerto Rico.........................................................15 6. Map showing location of water-quality stations in Puerto Rico .........................................................16 7. Map showing location of ground-water stations in Puerto Rico ........................................................17 8. Map showing location of ground-water stations in the U.S. Virgin Islands .......................................18 9. Grid showing system for numbering wells and miscellaneous sites (latitude and longitude) ............19 10. Map showing the Río Guajataca basin ................................................................................................ 55 11. Map showing the Río Camuy basin .................................................................................................... 65 12. Map showing the Río Grande de Arecibo basin..................................................................................69 13. Map showing the Río Grande de Manatí basin ................................................................................. 161 14. Map showing the Río Cibuco basin .................................................................................................. 193 15. Map showing the Río de la Plata basin .............................................................................................203 16. Map showing the Río Hondo to Río Puerto Nuevo basins................................................................231 17. Map showing the Río Grande de Loíza basin ...................................................................................267 18. Map showing northeastern river basins -- Río Herrera to Río Antón Ruíz basins............................317 19. Map showing southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins...........349 20. Map showing south coast river basins -- Río Salinas to Río Jacaguas basins...................................377 21. Map showing south coast river basins -- Río Inabón to Río Loco basins .........................................397 22. Map showing the Río Guanajibo basin .............................................................................................441 23. Map showing the Río Yagüez and Río Grande de Añasco basins ....................................................455 24. Map showing the Río Culebrinas basin.............................................................................................469 TABLES Page Table 1. Islandwide monthly rainfall for the water year 2003 and monthly normal rainfall for the 30-year reference period, 1971-2000 .........................................................................................3 2. Highest ground-water level recorded during 2003 water year and previous high ground-water levels at selected wells in Puerto Rico.......................................................................8 3. Lowest ground-water levels recorded during 2003 water year and previous lowest ground-water levels at selected wells in Puerto Rico.......................................................................8 4. Sediment yields at selected sediment stations for water year 2003 ....................................................12 vii SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME (Letter after station name designates type of data: (d) discharge, (c) chemical, (b) biological, (s) sediment, (p) pesticide, (e) elevation, gage heights) Station number Page RIO GUAJATACA BASIN Río Guajataca at Lares (c,b). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50010500. . . . . . . . . . . . . . .56 Lago Guajataca at Damsite near Quebradillas (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50010800 . . . . . . . . . . . . . 58 Canal Principal de Diversiones at Lago Guajataca (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . 50011000 . . . . . . . . . . . . . 60 Río Guajataca above mouth near Quebradillas (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50011400 . . . . . . . . . . . . . 62 RIO CAMUY BASIN Río Camuy near Bayaney (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50014800 . . . . . . . . . . . . . 66 RIO GRANDE DE ARECIBO BASIN Lago Garzas near Adjuntas (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50020100 . . . . . . . . . . . . . 70 Río Grande de Arecibo near Adjuntas (d,c,b,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50020500 . . . . . . . . . . . . . 72 Río Pellejas above Central Pellejas (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50021030 . . . . . . . . . . . . . 80 Río Grande de Arecibo above Utuado (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50021700 . . . . . . . . . . . . . 86 Río Viví below Hacienda El Progreso (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50022810 . . . . . . . . . . . . . 92 Río Grande de Arecibo below Utuado (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50024950 . . . . . . . . . . . . . 94 Río Grande de Arecibo near Utuado (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50025000 . . . . . . . . . . . . 100 Río Saliente at Coabey near Jayuya (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50025155 . . . . . . . . . . . . 102 Río Jauca at Paso Palma (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50025850 . . . . . . . . . . . . 107 Río Caonillas at Paso Palma (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50026025 . . . . . . . . . . . . 113 Rio Caonillas above Lago Caonillas near Jayuya (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50026050 . . . . . . . . . . . . 118 Río Caonillas below Lago Caonillas Tunnel (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50026200 . . . . . . . . . . . . 120 Río Yunes at Hwy 140 near Florida (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50026400 . . . . . . . . . . . . 125 Río Limón above Lago Dos Bocas (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50027000 . . . . . . . . . . . . 131 Lago Dos Bocas at Damsite near Utuado (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50027100 . . . . . . . . . . . . 139 Río Grande de Arecibo below Lago Dos Bocas near Florida (c,b) . . . . . . . . . . . . . . . . . . . 50027250 . . . . . . . . . . . . 141 Río Grande de Arecibo near San Pedro (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50027600 . . . . . . . . . . . . 143 Río Tanamá near Utuado (d,c,b,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50028000 . . . . . . . . . . . . 148 Río Tanamá at Charco Hondo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50028400 . . . . . . . . . . . . 155 Río Grande de Arecibo at Central Cambalache (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50029000 . . . . . . . . . . . . 157 RIO GRANDE DE MANATI BASIN Río Orocovis at Orocovis (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50030460 . . . . . . . . . . . . 162 Río Orocovis near Orocovis (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50030700 . . . . . . . . . . . . 164 Río Grande de Manatí near Morovis (d,c,b,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50031200. . . . . . . . . . . . . .166 Lago El Guineo at Damsite near Villalba (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50032290 . . . . . . . . . . . . 173 Lago de Matrullas at Damsite near Orocovis (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50032590 . . . . . . . . . . . . 175 Río Bauta near Orocovis (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50034000 . . . . . . . . . . . . 177 Río Grande de Manatí at Ciales (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50035000 . . . . . . . . . . . . 179 Río Grande de Manatí at Highway 149 at Ciales (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50035500 . . . . . . . . . . . . 184 Río Cialitos at Highway 649 at Ciales (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50035950 . . . . . . . . . . . . 186 Río Grande de Manatí at Highway 2 near Manatí (d,c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . 50038100 . . . . . . . . . . . . 190 LAGUNA TORTUGUERO BASIN Laguna Tortuguero outlet near Vega Baja (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50038200 . . . . . . . . . . . . 192 RIO CIBUCO BASIN Río Cibuco below Corozal (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50038320 . . . . . . . . . . . . 194 Río Cibuco at Vega Baja (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50039500 . . . . . . . . . . . . 198 viii SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO DE LA PLATA BASIN Lago Carite at Gate Tower near Cayey (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50039990 . . . . . . . . . . . . 204 Río de la Plata at Proyecto La Plata (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50043000 . . . . . . . . . . . . 206 Río de la Plata at Comerío (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50043800 . . . . . . . . . . . . 208 Río de la Plata near Comerio (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50044000 . . . . . . . . . . . . 214 Río Guadiana near Guadiana (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50044810 . . . . . . . . . . . . 216 Río Guadiana near Naranjito (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50044850 . . . . . . . . . . . . 221 Lago La Plata at Damsite near Toa Alta (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50045000 . . . . . . . . . . . . 223 Río de la Plata below La Plata Dam (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50045010 . . . . . . . . . . . . 225 Río de la Plata at Highway 2 near Toa Alta (d,c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50046000 . . . . . . . . . . . . 227 Río Hondo at Flood Channel near Cataño (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047530 . . . . . . . . . . . . 232 RIO DE BAYAMON BASIN Río de Bayamón at Arenas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047535 . . . . . . . . . . . . 234 Lago de Cidra at Damsite near Cidra (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047550 . . . . . . . . . . . . 236 Río de Bayamón below Lago Cidra (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047560 . . . . . . . . . . . . 238 Río de Bayamón near Aguas Buenas (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047600 . . . . . . . . . . . . 240 Río de Bayamón near Bayamón (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047850 . . . . . . . . . . . . 242 Río Guaynabo near Bayamón (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50047990 . . . . . . . . . . . . 244 Río de Bayamón at Flood Channel at Bayamón (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . 50048510 . . . . . . . . . . . . 246 RIO PUERTO NUEVO BASIN Río Piedras: Lago Las Curías at Damsite near Río Piedras (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50048680 . . . . . . . . . . . . 248 Quebrada Las Curías below Las Curias Dam (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50048690 . . . . . . . . . . . . 250 Río Piedras at El Señorial (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50048770 . . . . . . . . . . . . 252 Río Piedras near Río Piedras (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50048800. . . . . . . . . . . . . .258 Río Piedras at Hato Rey (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50049100 . . . . . . . . . . . . 260 Laguna San José: Laguna San José No. 2 at San Juan (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50049820. . . . . . . . . . . . . .264 Bahía de San Juan: Bahía de San Juan No. 5 at San Juan (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50049920. . . . . . . . . . . . . .265 QUEBRADA BLASINA BASIN Quebrada Blasina near Carolina (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50050300 . . . . . . . . . . . . 268 RIO GRANDE DE LOIZA BASIN Río Grande de Loíza at Quebrada Arenas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50050900 . . . . . . . . . . . . 270 Quebrada Salvatierra near San Lorenzo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50051180 . . . . . . . . . . . . 272 Río Cayaguas at Cerro Gordo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50051310 . . . . . . . . . . . . 274 Río Grande de Loíza at Highway 183 near San Lorenzo (d) . . . . . . . . . . . . . . . . . . . . . . . 50051800 . . . . . . . . . . . . 276 Río Turabo above Borinquén (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50053025 . . . . . . . . . . . . 278 Río Grande de Loíza at Caguas (d,c,b,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50055000 . . . . . . . . . . . . 280 Río Cagüitas: Río Cagüitas near Aguas Buenas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50055100 . . . . . . . . . . . . 288 Río Cagüitas at Villa Blanca at Caguas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50055225 . . . . . . . . . . . . 290 Río Cagüitas at Highway 30 at Caguas (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50055250 . . . . . . . . . . . . 292 Río Gurabo: Río Gurabo below El Mangó (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50055750 . . . . . . . . . . . . 296 Río Valenciano near Juncos (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50056400 . . . . . . . . . . . . 298 Río Gurabo at Gurabo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50057000 . . . . . . . . . . . . 300 Río Gurabo near Gurabo (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50057025 . . . . . . . . . . . . 302 Río Cañas at Río Cañas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50058350 . . . . . . . . . . . . 304 ix SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO GRANDE DE LOIZA BASIN—Continued Lago Loíza at Damsite near Trujillo Alto (c,b,e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50059000 . . . . . . . . . . . . 306 Río Grande de Loíza below Damsite (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50059050 . . . . . . . . . . . . 309 Río Grande de Loíza below Trujillo Alto (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50059100 . . . . . . . . . . . . 311 Río Canóvanas near Campo Rico (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50061800 . . . . . . . . . . . . 313 RIO ESPIRITU SANTO BASIN Quebrada Sonadora near El Verde (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50063440 . . . . . . . . . . . . 315 Río Espíritu Santo near Río Grande (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50063800 . . . . . . . . . . . . 318 Río Grande near El Verde (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50064200 . . . . . . . . . . . . 322 RIO MAMEYES BASIN Río Mameyes near Sabana (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50065500 . . . . . . . . . . . . 324 Río Mameyes at Mameyes (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50066000 . . . . . . . . . . . . 329 RIO SABANA BASIN Río Sabana at Sabana (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50067000 . . . . . . . . . . . . 331 RIO FAJARDO BASIN Río Fajardo near Fajardo (d,c,b,p,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50071000 . . . . . . . . . . . . 333 RIO BLANCO BASIN Quebrada Guabá near Naguabo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50074950 . . . . . . . . . . . . 342 Río Icacos near Naguabo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50075000 . . . . . . . . . . . . 344 Río Blanco near Florida (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50076000 . . . . . . . . . . . . 346 RIO HUMACAO BASIN Río Humacao at Las Piedras (d). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50081000. . . . . . . . . . . . . .350 Río Humacao at Highway 3 at Humacao (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50082000 . . . . . . . . . . . . 352 RIO GUAYANES BASIN Río Guayanés at Yabucoa (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50083500 . . . . . . . . . . . . 354 Río Guayanés above mouth at Playa de Guayanés (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . 50086500 . . . . . . . . . . . . 356 RIO MAUNABO BASIN Río Maunabo at Lizas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50090500 . . . . . . . . . . . . 358 Río Maunabo at Maunabo (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50091000 . . . . . . . . . . . . 360 RIO CHICO BASIN Río Chico at Providencia (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50091800 . . . . . . . . . . . . 362 RIO GRANDE DE PATILLAS BASIN Río Grande de Patillas near Patillas (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50092000 . . . . . . . . . . . . 364 Río Marín near Patillas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50093000 . . . . . . . . . . . . 368 Lago Patillas at Damsite near Patillas (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50093045 . . . . . . . . . . . . 370 Canal de Riego de Patillas above Guayama Filtration Plant (d) . . . . . . . . . . . . . . . . . . . . . 50093075 . . . . . . . . . . . . 372 Canal de Riego de Patillas below Guayama Filtration Plant (d) . . . . . . . . . . . . . . . . . . . . . 50093078 . . . . . . . . . . . . 374 RIO SALINAS BASIN Río Lapa near Rabo del Buey (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50100200 . . . . . . . . . . . . 378 Río Majada at La Plena (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50100450 . . . . . . . . . . . . 380 RIO COAMO BASIN Río Coamo at Hwy 14 at Coamo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50106100 . . . . . . . . . . . . 382 Río Coamo near Coamo (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50106500 . . . . . . . . . . . . 384 x SURFACE-WATER AND WATER-QUALITY STATIONS, IN DOWNSTREAM ORDER, FOR WHICH RECORDS ARE PUBLISHED IN THIS VOLUME--Continued Station number Page RIO DESCALABRADO BASIN Río Descalabrado near Los Llanos (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50108000 . . . . . . . . . . . . 386 RIO JACAGUAS BASIN Río Toa Vaca above Lago Toa Vaca (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50110900 . . . . . . . . . . . . 388 Lago Toa Vaca at Damsite near Villalba (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50111210 . . . . . . . . . . . . 390 Lago Guayabal at Damsite near Juana Díaz (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50111300 . . . . . . . . . . . . 392 Río Jacaguas at Juana Díaz (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50111500 . . . . . . . . . . . . 394 RIO INABON BASIN Río Inabón at Real Abajo (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50112500 . . . . . . . . . . . . 398 RIO BUCANA BASIN Río Cerrillos above Lago Cerrillos near Ponce (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50113800 . . . . . . . . . . . . 400 Lago Cerrillos at Damsite near Ponce (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50113950 . . . . . . . . . . . . 402 Río Cerrillos near Ponce (d,c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50114000 . . . . . . . . . . . . 404 RIO PORTUGUES BASIN Río Portugues at Tibes (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50114900 . . . . . . . . . . . . 408 Río Portugués near Ponce (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50115000 . . . . . . . . . . . . 410 Río Portugués at Highway 14 at Ponce (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50115900 . . . . . . . . . . . . 412 Río Portugués at Ponce (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50116200 . . . . . . . . . . . . 414 RIO GUAYANILLA BASIN Río Guayanilla near Guayanilla (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50124200 . . . . . . . . . . . . 416 Río Guayanilla at Central Rufina (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50124700 . . . . . . . . . . . . 418 RIO YAUCO BASIN Lago Lucchetti at Damsite near Yauco (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50125780 . . . . . . . . . . . . 420 Río Yauco above Diversion Monserrate near Yauco (d) . . . . . . . . . . . . . . . . . . . . . . . . . . 50126150 . . . . . . . . . . . . 422 RIO LOCO BASIN Lago Loco at Damsite near Yauco (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50128900 . . . . . . . . . . . . 424 Canal de Riego de Lajas below Lago Loco Dam at Yauco (d) . . . . . . . . . . . . . . . . . . . . . . 50128905 . . . . . . . . . . . . 426 Canal de Riego de Lajas above Majinas Filtration Plant (d) . . . . . . . . . . . . . . . . . . . . . . . 50128920 . . . . . . . . . . . . 428 Canal de Riego de Lajas below Majinas Filtration Plant (d) . . . . . . . . . . . . . . . . . . . . . . . 50128925 . . . . . . . . . . . . 430 Canal de Riego de Lajas above Lajas Filtration Plant at Lajas (d) . . . . . . . . . . . . . . . . . . . 50128935 . . . . . . . . . . . . 432 Canal de Riego de Lajas below Lajas Filtration Plant at Lajas (d) . . . . . . . . . . . . . . . . . . . 50128940. . . . . . . . . . . . . 434 Canal de Riego de Lajas at Bo. Palmarejo near Lajas (d) . . . . . . . . . . . . . . . . . . . . . . . . . . 50128945 . . . . . . . . . . . . 436 Río Loco at Guanica (c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50129700 . . . . . . . . . . . . 438 RIO GUANAJIBO BASIN Río Guanajibo near San Germán (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50133600 . . . . . . . . . . . . 442 Río Rosario near Hormigueros (d,c,b,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50136400 . . . . . . . . . . . . 444 Río Guanajibo near Hormigueros (d,c,b,p) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50138000 . . . . . . . . . . . . 451 RIO YAGÚEZ Río Yagüez near Mayagüez (c,b). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50138800. . . . . . . . . . . . . .456 RIO GRANDE DE AÑASCO BASIN Lago Guayo at Damsite near Castañer (e) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50141500 . . . . . . . . . . . . 458 Río Grande de Añasco near Lares (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50143000. . . . . . . . . . . . . .460 Río Grande de Añasco near San Sebastián (d,c,b). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50144000 . . . . . . . . . . . . 462 RIO CULEBRINAS BASIN Río Culebrinas near San Sebastián (c,b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50147600 . . . . . . . . . . . . 470 Río Culebrinas at Highway 404 near Moca (d) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50147800 . . . . . . . . . . . . 472 Río Culebrinas at Margarita Dam near Aguada (d,s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50148890 . . . . . . . . . . . . 474 xi GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED Page RIO GUAJATACA BASIN 182422067015100. Local number, 165. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 482 182647066552400. Local number, 202. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 RIO CAMUY BASIN 182723066511200. Local number, 1026. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 RIO GRANDE DE ARECIBO BASIN 182756066454700. Local number, 1051 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 182737066370900. Local number, 204. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491 182616066364100. Local number, 1052. 182626066345100. Local number, 1053. 182639066385200. Local number, 1056. 182209066340600. Local number, 1057. RIO GRANDE DE MANATI BASIN 182544066341500. Local number, 205. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 182549066304300. Local number, 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 493 182506066280200. Local number, 1076. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 182308066260400. Local number, 210. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 495 RIO CIBUCO BASIN 182712066251700. Local number, 1102. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 496 182615066235300. Local number, 211. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 182647066201700. Local number, 70. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 498 182330066185700. Local number, 213. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 499 RIO DE LA PLATA BASIN 182526066165001. Local number, 1127. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500 182548066164401. Local number, 1128. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501 182620066163403. Local number, 1130. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 182657066162701. Local number, 1132. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 182654066150600. Local number, 1133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 504 182530066135400. Local number, 216. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 505 180649066095500. Local number, 1134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506 RIO HONDO TO RIO PUERTO NUEVO BASINS 182441066082600. Local number, 219. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507 182531066075900. Local number, 652. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 182435066052700. Local number, 1153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 182445066043401. Local number, 1154. 182406066034700. Local number, 1158. 182451066080200. Local number, 1159. RIO GRANDE DE LOIZA BASIN 181352066025300. Local number, 1176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 181311066022500. Local number, 1177. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 181539066014500. Local number, 1179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 182515065594100. Local number, 222. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 RIO HERRERA TO RIO ANTON RUIZ BASINS 181217065453000. Local number, 1203. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 182131065421100. Local number, 1205. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 518 181917065382701. Local number, 1207. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 182234065440000. Local number, 1208. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 xii GROUND-WATER WELLS, BY BASIN, FOR WHICH RECORDS ARE PUBLISHED--Continued Page RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 180415065513900. Local number, 96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 175855066050500. Local number, 1228. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 1757280660722000. Local number, 1229. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 175719066085500. Local number, 1230. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 175858066100200. Local number, 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 175947066130601. Local number, 1233. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526 175814066102200. Local number, 1239. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 RIO SALINAS TO RIO JACAGUAS BASINS 175809066133100. Local number, 1251. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 529 530 531 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532 180104066152300. Local number, 1253. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175910066155500. Local number, 1254. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175903066165000. Local number, 1256. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175943066224800. Local number 1257. 175829066232200. Local number, 87. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 535 536 537 538 539 540 180020066261500. Local number, 1258. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180602066133100. Local number, 1260. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175833066145800. Local number, 1261. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175735066151800. Local number, 1262. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175734066233300. Local number, 146. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175843066244100. Local number, 1263. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RIO INABON TO RIO LOCO BASINS 175950066354200. Local number, 141. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 175934066364800. Local number, 1276. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542 RIO INABON TO RIO LOCO BASIN 180045066381600. Local number 1277. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 RIO INABON TO RIO LOCO BASINS 180156066434000. Local number, 1278. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 180133066503300. Local number, 132. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546 RIO GUANAJIBO BASIN 180132067033800. Local number, 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 180542067084000. Local number, 1301. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548 RIO CULEBRINAS BASIN 182017067143300. Local number, 1352. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550 182442067091700. Local number, 200. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551 ST. CROIX, U.S. VIRGIN ISLANDS 174225064472000. Local number, 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554 174243064475100. Local number, 3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555 174316064480800. Local number, 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556 ST. THOMAS, U.S. VIRGIN ISLANDS 182038064550300. Local number, 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558 182038064580000. Local number, 8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559 ST. JOHN, U.S. VIRGIN ISLANDS 181956064464500. Local number, 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 560 -- -- -- -- -- -- -- -- -- xiii DISCONTINUED STREAMFLOW STATIONS The following continuous-record streamflow stations in Puerto Rico and the U.S. Virgin Islands have been discontinued or converted to partial-record stations. Daily streamflow or stage records were collected for the period of record shown for each station. Station number Station name Drainage area (mi2) Period of record 50007000 Quebrada de los Cedros near Isabela 6.91 1970 50010600 Río Guajataca above Lago de Guajataca 1984-89 50011000 Canal Diversion Lago Guajataca 1970 50011200 Río Guajataca below Lago Guajataca 1969-70,1984-87 50011400 Río Guajataca above mouth near Quebradillas 1969-70,1984-89 50013000 Río Camuy near Lares 7.62 1969-71 50014000 Río Criminales near Lares 4.68 1969-70 50014600 Río Camuy at Tres Pueblos Sinkhole 1990-96 50015700 Río Camuy near Hatillo 1984-96 50016000 Río Camuy near Camuy 1969-73 50021050 Río Pellejas below Central Pellejas 7.89 1972-75 50021500 Río Pellejas near Utuado 9.55 1969-71 50023000 Río Viví near Central Pellejas 5.66 1969-75 50027200 Río Grande de Arecibo below Lago Dos Bocas 169 1970-71 50027250 Río Grande de Arecibo below Lago Dos Bocas near Florida 170 2000-2002 50027750 Río Grande de Arecibo above Arecibo 170 1982-2002 50031500 Río Sana Muerto near Orocovis 3.68 1965-70 50035200 Río Grande de Manatí at Hwy 145 at Ciales 132 1972 50035950 Río Cialitos at Hwy 649 at Ciales 17 1970-82 50038360 Río Mavilla near Corozal 9.51 1969-70 50038600 Río Unibón near Morovis 5.29 1969-70 50038700 Río Morovis at Morovis 1.26 1968 50038900 Río Indio at Vega Baja 1963,66,71 50039600 Río Cibuco at Central San Vicente 1969-72 50043200 Río Usabon near Barranquitas 9.15 1968-69,71 50043400 Río Aibonito Tributary near Aibonito 1.13 1968-71 50044600 Río Guadiana near Naranjito 1.73 1971 50044650 Quebrada del Toro near Naranjito 0.54 1971 50044800 Quebrada Anones near Naranjito 2.32 1971 50045700 Río Lajas at Toa Alta 8.65 1966-75 50047540 Río Sabana at Vista Monte 0.80 1993,1994-2002 50047820 Río de Bayamón at Hwy 174 near Bayamón 31.90 1966 50048000 Río de Bayamón at Bayamón 71.90 1963-67 50049000 Río Piedras at Río Piedras 12.5 1971-82, 1987-93 50049310 Quebrada Josefina at Piñero Avenue 3.84 1988-91 50051150 Quebrada Blanca at El Jagual 3.25 1984-2002 50053050 Río Turabo at Borinquen 7.89 1984-90 50054000 Quebrada de las Quebradillas near Caguas 6.25 1969-71,73 50055170 Río Cagüitas near Caguas 8.27 1992-97 50055390 Río Bairoa at Bairoa 5.08 1990-2001 xiv DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50055650 Quebrada Caimito near Juncos 0.82 1984-87 50056000 Río Valenciano near Las Piedras 6.85 1971 50056900 Quebrada Mamey near Gurabo 2.30 1984-92 50058300 Quebrada Arena near Caguas -- 1971 50061300 Río Canovanillas near Loíza 14.40 1968-73 50062500 Río Herrera near Colonia Dolores 2.75 1968-72 50063300 Río Espíritu Santo near El Verde 2.23 1968-73 50063500 Quebrada Toronja at El Verde 0.064 1983-96 50065700 Río Mameyes at Hwy 191 at Mameyes 11.80 1967-85 50070500 Río Fajardo above Fajardo 3.69 1995-2001 50072000 Río Fajardo at Fajardo 21.60 1960-63 50073200 Río Daguao at Daguao 2.26 1966-82 50073400 Quebrada Palma at Daguao 4.84 1972-77 50074000 Río Santiago at Naguabo 4.99 1966-82 50075500 Río Blanco at Florida 11.00 1966-82 50077000 Río Blanco at Río Blanco 17.60 1973-77 50077400 Río Blanco at Colonia La Fe 18.80 1967-70 50078500 Río Anton Ruíz at Central Pasto Viejo 4.33 1968 50081500 Río Humacao near Humacao 9.23 1973 50082000 Río Humacao at Hwy 3 at Humacao 17.30 1983-85 50082200 Río Humacao near La Suiza 19.90 1965-66, 1969-71 50082800 Río Guayanés near Colonia Laura 4.69 1969-82 50083500 Río Guayanés near Yabucoa 17.20 1969-71 50084000 Río Limones near Yabucoa 7.89 1969-71 50085100 Río Guayanés at Central Roig 26.60 1965-66, 1968,70 50086100 Río del Ingenio at Comunas 5.50 1965-66, 1968-69 50086500 Río Guayanés at Playa Guayanés 34.00 1965-66, 1968-71 50087200 Caño Santiago near Central Roig 6.04 1965-71 50091000 Río Maunabo at Maunabo 12.40 1965,67, 1969-82 50091200 Río Maunabo near Maunabo 12.70 1971-72 50091400 Río Jacaboa near Lamboglia 4.13 1965-73 50091700 Río Chico at Patillas 6.82 1965, 1969-72 50091800 Río Chico at Providencia 4.90 1965, 1967-69, 1971 50094200 Río Grande de Patillas at Patillas 27.90 1967, 1969, 1971 50094300 Río Grande de Patillas at Providencia 29.00 1971 50094400 Río Nigua at Pitahaya 50095200 Río Guamaní at Guayama 50095500 Río Guamaní near Guayama 50099000 Quebrada Aguas Verdes near Salinas 50106500 Río Coamo near Coamo 5.86 1965, 1969, 1970-71, 1973 8.22 1969-71 12.30 1969-70 0.39 1989 46.00 1967-68, 1984-85, 1986 50106900 Río Coamo below Lago Coamo near Coamo 65.40 1967-68 50107200 Río Coamo at mouth near Santa Isabel 69.30 1967-68 50108200 Río Descalabrado at Las Ollas 13.90 1965, 1967-71 50108500 Río Descalabrado near Santa Isabel 18.10 1966-67 50111200 Río Toa Vaca near Villalba 21.40 1966-70 xv DISCONTINUED STREAMFLOW STATIONS--Continued Station Station name Drainage Period of number area (mi2) record 50111700 Río Jacaguas near Juana Díaz 53.20 1966-68 50111750 Río Jacaguas below Quebrada Guanábana 56.30 1989 50112100 Río Jacaguas near Arús 59.60 1966-67 50112600 Río Inabón at Coto Laurel -- 1967-71 50113100 Río Guayo near Coto Laurel 11.80 1965, 1968-71 50113500 Río Inabón near Arús 30.20 1964-65 50114390 Río Bucaná at Hwy 14 Bridge near Ponce 24.9 1987-2002 50114400 Río Bucaná near Ponce 25.60 1965-81 50114700 Río Bucaná near Playa de Ponce 28.40 1964-67 50115000 Río Portugués near Ponce 8.82 1964-97 50116500 Río Portugués at Highway 2 Bypass at Ponce 20.50 1964-65 50119000 Río Matilde at Ponce 19.40 1965-66 50121000 Río Tallaboa at Peñuelas 24.20 1959-82 50122000 Río Tallaboa at Tallaboa 31.50 1959-63 50124000 Río Guayanilla nr Guayanilla 18.50 1961-69 50124500 Río Guayanilla at Guayanilla 20.80 1971-82 50125900 Río Duey above Diversion near Yauco 8.93 1977-80 50128000 Río Yauco near Yauco 45.50 1962-64, 1977-85 50129000 Río Loco near Yauco 8.50 1963-67 50129500 Río Loco near Guánica 21.00 1963-69 50129900 Laguna Cartagena near Boquerón -- 1984-86 50130320 Quebrada Mamey at Joyuda 0.38 1986-88 50136000 Río Rosario at Rosario 16.40 1975-86 50141000 Río Yahuecas near Adjuntas 15.40 1980-85 50145000 Río Grande de Añasco at El Espino 108.00 1959-66, 1961-63 50147000 Río Culebrinas at San Sebastian 16.70 1960-82 50214500 Quebrada Resaca near Monte Resaca, Culebra 0.23 1991-93 50215000 Drainage Canal at Culebra Airport, Culebra 0.08 1991-93 50231000 Quebrada Confresí Tributary near Isabel II, Vieques 0.28 1991-93 50232000 Quebrada La Mina near Esperanza, Vieques 0.68 1991-96 50233000 Quebrada Pilón at Colonia Puerto Real, Vieques 0.67 1991-96 50276000 Turpentine Run at Mariendal, St.Thomas 2.97 1963-69, 1978-86 50292600 Lameshur Bay Gut at Lameshur, St. John 0.38 1992-94 50294000 Fish Bay Gut at Fish Bay, St. John 1.48 1992-94 50295500 Cruz Bay Gut at Cruz Bay, St. John, VI 0.09 1992-93 50332000 River Gut at River 1.42 1991-93 50333500 River Gut near Golden Grove 5.40 1990-93 50333700 River Gut at Hwy 66 at Fairplanes 5.89 1990-96 50334500 Bethehem Gut at Hwy 66 at Fairplanes 4.11 1990-96 50337500 Gut 4.5 at Cane Valley 0.2 1991-93 50348000 Salt River at Canaan 0.36 1991-93 50349000 Gut 10 near Altona 0.13 1991-93 xvi THIS PAGE IS INTENTIONALLY BLANK 1 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 INTRODUCTION The Water Resources Division of the U.S. Geological Survey, in cooperation with local and Federal agencies obtains a large amount of data pertaining to the water resources of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands each water year. These data, accumulated during many water years, constitute a valuable data base for developing an improved understanding of the water resources of the area. To make these data readily available to interested parties outside the U.S. Geological Survey, the data are published annually in this report series entitled "Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 2003." This report includes records on both surface and ground water. Specifically, it contains: (1) discharge records for 86 streamflow-gaging stations, daily sediment records for 22 sediment stations, stage records for 18 reservoirs, and (2) water-quality records for 17 streamflow-gaging stations, and for 42 ungaged stream sites, 13 lake sites, 2 lagoons, and 1 bay, and (3) water-level records for 72 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 to 2001 water years consist of one volume each and contain data for streamflow, water quality, and ground water. Publications similar to this report are published annually by the U.S. Geological Survey for all States. These official Survey reports have an identification number consisting of the two-letter State abbreviation, the last two digits of the water year, and the volume number. For example, this volume is identified as "U.S. Geological Survey Water-Data Report PR-02-1." These water-data reports are for sale in paper copy or in microfiche by the National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia, 22161. Additional information, including current prices, for ordering specific reports may be obtained from the District Chief at the address given on back of the title page or by telephone (787) 749-4346. 2 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 COOPERATION The U.S. Geological Survey has had cooperative agreements with organizations of the Commonwealth of Puerto Rico and the Territory of the U.S. Virgin Islands for the systematic collections of water resources data since 1958. Organizations that supplied data are acknowledged in the station descriptions. Organizations that assisted in collecting data through cooperative agreements with the U.S. Geological Survey are: Puerto Rico Environmental Quality Board Puerto Rico Aqueduct and Sewer Authority Puerto Rico Department of Agriculture Puerto Rico Industrial Development Company Puerto Rico Highway Authority Puerto Rico Department of Natural and Environmental Resources Puerto Rico Department of Health Puerto Rico Electric Power Authority Puerto Rico Solid Waste Management Authority Puerto Rico Legislature Puerto Rico Emergency Management Agency U.S. Virgin Islands Department of Planning and Natural Resources Puerto Rico Infrastructure Financing Authority Funds were also provided by the U.S. Army, Corps of Engineers, for the collection of records at six gaging stations published in this report. 3 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 SUMMARY OF HYDROLOGIC CONDITIONS Precipitation Islandwide annual rainfall during water year 2003 (October 2002 to September 2003), was 93 percent below normal rainfall conditions. Annual rainfall averaged about 90 percent of normal in northern Puerto Rico, 90 percent of normal in southern Puerto Rico, 87 percent of normal in western Puerto Rico, and 106 percent of normal in eastern Puerto Rico. Normal rainfall is defined as the mean monthly rainfall for certain period of time. In Puerto Rico, the reference period used to define the monthly normal rainfall is 1971-2000 (table 1). During nine months, the rainfall was below the monthly normal rainfall (table 1). Significant deficient rainfall conditions were registered during October (27 percent below normal), November (47 percent below normal), May (41 percent below normal), and June (31 percent below normal). This significant rainfall deficiency was registered during part of the wet seasons. Recorded rainfall during the nine below-normal months averaged from 12 to 47 percent below monthly normal rainfall. During January, April, and August the rainfall throughout the Island was above normal rainfall conditions. Monthly rainfall during April (12.33 inches) almost triplicates the normal rainfall amount for this month (4.19 inches). This abnormal rainfall condition was generated by a strong upper level trough system combined with abundant moisture conditions which produced very heavy rainfall across Puerto Rico and the U.S. Virgin Islands during April 17 and 18, 2003. Rainfall throughout the U.S. Virgin Islands was deficient during water year 2003 with an annual rainfall average of 75 percent of normal. Monthly normal rainfall was below normal during ten months of the water year 2003. During these months, the normal rainfall averaged from 12 to 72 percent below monthly normal rainfall. As mentioned above, the U.S. Virgin Islands experienced very heavy rainfall during April 17 and 18, 2003. As much as 5.68 inches of rain was recorded at St. Thomas during 48-hour period. During April, the normal rainfall in the U.S. Virgin Islands was about 290 percent above normal. Table 1. Islandwide monthly rainfall for the water year 2003 and monthly normal rainfall for the 30-year reference period, 1971-2000. Data from the National Oceanographic and Atmospheric Administration Month 2003 Water Year (inches) 30-year normal (inches) October 5.84 7.98 November 3.48 6.53 December 3.16 4.05 January 3.76 3.20 February 2.56 2.90 March 2.24 2.96 April 12.33 4.19 May 3.94 6.67 June 3.07 4.46 July 4.32 4.88 August 6.76 6.51 September 6.33 7.91 TOTAL 57.79 62.24 4 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Surface Water Streamflow in Puerto Rico during most of the water year 2003 (October 1, 2002 to September 30, 2003), was below or near normal streamflow conditions, based on the index stations which are representative of the four geographical areas (figure 1). During this period of record, there was only one significant rainfall event that produced excessive rainfall which increased the streamflows islandwide. This rainfall event produced by a strong upper level trough combined with abundant moisture affected Puerto Rico and the U.S. Virgin Islands during April 17 and 18, 2003. Moderate to severe flooding occurred across areas of southern and eastern Puerto Rico. Comparisons of the monthly mean flows during water year 2003 with the long-term minimum, median, and maximum of the monthly mean flows, for the period of record at the index stations on the Río Grande de Manatí (northern area), the Río Fajardo (eastern area), the Río Inabón (southern area), and the Río Grande de Añasco (western area) are shown in figure 1. An overview describing the hydrologic conditions during water year 2003 at the four areas represented by the index stations are discussed next. In the northern area, the Río Grande de Manatí index station registered monthly mean flows below normal during the first six months and last four months of the water year. During these ten months, the monthly mean flows were from 28 to 61 percent below of the long-term median. The monthly mean flow was above normal during April while the monthly mean flow during May equaled the long-term median of the monthly mean flows. During April, the monthly mean was 166 percent above the long-term median of the monthly mean flows. In the eastern area, streamflow conditions, as showed by the Río Fajardo index station, were near normal during seven months of the water year. The monthly mean flow during October equaled the long-term median of the monthly mean flows. The historical minimum monthly mean flow was equaled during November and a historical minimum monthly mean flow was registered during March. During April, a historical maximum monthly mean was recorded at the Río Fajardo index station. In this station, the monthly mean flows ranged from 78 percent below normal during March to 381 percent above normal during April. The southern area that use to be dryer than the other areas, also showed below normal streamflow conditions but in less degree compared with the northern and eastern areas. Streamflow conditions, as recorded by the Río Inabón index station, were below normal during October, November, March, June, July, August, and September. The monthly mean flow during December equaled the long-term median of the monthly mean flows. During four months, January, February, April, and May, the monthly mean flows were above the long-term median of the monthly mean flows. Monthly mean flows recorded at the Río Inabón index station ranged from 60 percent below normal during July to 192 percent above normal during May. Streamflows registered at the Río Grande de Añasco index station serves to indicate the hydrologic conditions at the western area during water year 2003. Monthly mean flows in this area was in general, near normal or above normal during most of the water year. During November, December, January, April, May, and June, the Río Grande de Añasco index station registered monthly mean flows above the long-term median of the monthly mean flows. During October, the monthly mean flow was very close to the historical minimum monthly mean flow. Monthly mean flows were slightly below normal during the months of March, July, August, and September. The monthly mean flow during February equaled the long-term median of the monthly mean flows. At the Río Grande de Añasco index station, the monthly mean flows ranged from 48 percent below normal during October to 148 above normal during May. 5 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figure 1. Monthly-mean discharge of selected streams in Puerto Rico. 6 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Ground Water In Puerto Rico and the Virgin Islands, water year 2003 was a period of declining ground-water levels. Declining water level means that storage in the aquifer is declining. In Puerto Rico, 70 percent of all wells showed a decline for the year. In the Virgin Islands, ground-water levels at all the wells declined. One region where ground­ water levels rose was in the San Juan metropolitan area extending south to Caguas and Cayey and east to Luquillo and Fajardo. The only significant recharge event was the April 17-18, 2003 rainfall event. On these two days the National Weather Service identified 11 municipios that received from 7 to 22 inches of rain. The rains caused widespread flooding in northeastern Puerto Rico. At a number of wells this rainfall event caused ground-water levels to rise but not enough to reverse the downward trend for the year as a whole. Two ground-water stations hit record highs in water year 2003 (table 2). Piezometer Ft. Buchanan 1 continued a nine-year trend of gradually rising water levels and hit a record high. The rains on April 17, 2003, caused Piezometer Carlos Arroyo 1 to reach a record high. Ten ground-water stations reached record lows in water year 2003 (table 3). Cruce Dávila NC 5 is in the Lower Aquifer of the North Coast Limestone Ground Water Province and has been declining steadily for 15 years. Most months it establishes a new record low. No other ground-water station in Puerto Rico has maintained consistently downward trends as this one. Most of the wells that reached new record lows were on the south coast from Guayama to Santa Isabel and have records that began in 1997, which means that there is no data from the drought of the mid 90s. The record lows at Jobitos Battery and Godreau 7 were significant because both of these stations reached record lows although they have records only since 1991. At these two locations, water year 2003 was drier than the mid 90s which was a time of water rationing in most areas of the island. 7 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figur e 2. Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands. 8 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Table 2. Highest ground-water levels recorded during 2003 water year and previous high ground-water levels at selected wells in Puerto Rico. [PR, Puerto Rico; +, water level above land-surface datum; ft-blsd, feet below land-surface datum; mm-dd-yy, month-day-year; mm-yy, month-year] 2003 Previous highest highest Period of Local water level Date water level Date record Well name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) Piezometer 1159 PR 24.91 09-11-03 25.54 09-25-02 09-97 to 09-03 Fort Buchanan 1 Piezometer 1203 PR 1.55 04-17-03 1.66 11-13-99 10-97 to 09-03 Carlos Arroyo 1 Table 3. Lowest ground-water levels recorded during 2003 water year and previous lowest ground-water levels at selected wells in Puerto Rico. [PR, Puerto Rico; ft-blsd, feet below land-surface datum; mm-dd-yy, month-day-year; mm-yy, month-year] 2003 Previous lowest lowest Period of Local water level Date water level Date record Well name number Location (ft-blsd) (mm-dd-yy) (ft-blsd) (mm-dd-yy) (mm-yy) NC-5 Cruce Dávila 205 PR 104.78 09-15-03 96.61 08-27-02 12-86 to 09-03 Piezometer 1128 PR 29.49 07-21-03 29.44 06-23-01 06-95 to 09-03 Maguayo 2 06-24-01 Piezometer 1130 PR 36.33 06-29-03 36.15 05-01-95 01-95 to 09-03 Higuillar 4 05-11-95 05-13-95 06-16-01 06-17-01 Algarrobo 1228 PR 34.62 12-09-02 34.19 07-19-01 05-97 to 09-03 Domestic 1 07-20-01 Barranca Dug 1229 PR 24.69 03-14-03 24.21 06-07-97 04-97 to 09-03 06-08-97 06-09-97 Jobos 1239 PR 37.39 09-10-03 32.63 09-30-02 04-97 to 09-03 Coqui BTR 1 1251 PR 19.97 09-23-03 18.64 05-29-98 03-97 to 09-03 Piezometer 1254 PR 52.19 04-07-03 47.98 10-07-97 02-97 to 09-03 USGS D Godreau 7 1256 PR 36.96 08-25-03 34.87 09-03-96 09-91 to 09-03 to 09-06-03 Bauzá 1 1260 PR 232.84 08-25-03 to 219.20 08-26-02 10-97 to 09-03 09-06-03 Jobitos BTR 1263 PR 45.81 08-01-03 45.73 09-16-94 09-91 to 09-03 03-15-03 09-17-94 9 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Water Quality The U.S. Geological Survey, in cooperation with several Commonwealth agencies, collected water-quality data at 60 surface-water stations during water year 2003. Water-quality data collected at these stations included major ions, trace elements, nutrients, pesticides, as well as fecal indicator bacteria and physical parameters. The presence of high concentrations of fecal coliform (fig. 3) and fecal streptococcal (fig. 4) bacteria during water year 2003 continued to be one of the principal water-quality problems in Puerto Rico. Although water pollution control measures are being implemented to decrease the concentrations of these bacteria and even when there has been an improvement in the water quality of the majority of the streams in comparison with previous years, the values are still above the established water-quality standards for natural waters. Areas drained by major rivers where there is intense land use (agriculture, industry, urbanization) have, in general, fairly high concentrations of fecal indicator bacteria. The ability of communities to treat drinking water for bacteria is often inhibited by runoff with high suspended-sediment concentration and the associated turbidity problems. This is generally the principal cause in streams which suffer from intense resource utilization (agriculture and urban development) where soil movement is involved. The U.S. Geological Survey, in cooperation with various Commonwealth and Federal agencies, collected suspended-sediment samples at 22 stations in Puerto Rico during the 2003 water year. High suspended-sediment concentrations are a common problem in many streams in Puerto Rico. Most of the streams with high suspended- sediment concentrations are related to land use, especially urban development, agriculture, and activities which disturb soil cover. High suspended-sediment concentrations affect the operation of public surface-water supply filtration plants and contribute with the storage depletion capacities of reservoirs. Table 4 summarizes the annual sediment discharge (in tons) and sediment yield (in tons/mi²), for some of the monitored stations. Calculated sediment yields varied from a minimum of 62.7 tons/mi² at station 50027600, Río Grande de Arecibo near San Pedro, to a maximum of 10,500 tons/mi² at station 50048770, Río Piedras at El Señorial. The average sediment yield was 1,730 tons/mi² and the median was 1,160 tons/mi². 10 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figure 3. Location of maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico. 11 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figure 4. Location of maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico. 12 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Table 4. Sediment yields at selected sediment stations for water year 2003. [mi², square miles; tons/mi², tons per square miles] Station Station Drainage area, Annual sediment Sediment yields, number name in mi² discharge, in tons in tons/mi² 50020500 Río Grande de Arecibo near Adjuntas 12.7 28,500 2,240 50021030 Río Pellejas above Central Pellejas 6.83 8,330 1,220 50021700 Río Grande de Arecibo Above Utuado 36.0 27,500 764 50024950 Río Grande de Arecibo below Utuado 65.6 106,000 1,620 50025155 Río Saliente at Coabey near Jayuya 9.25 2,370 256 50025850 Río Jauca at Paso Palma 6.89 3,730 541 50026025 Río Caonillas at Paso Palma 37.9 23,100 609 50026400 Río Yunes at Hwy 140 near Florida 13.9 16,200 1,160 50027000 Río Limón above Lago Dos Bocas 33.2 53,700 1,620 50027600 Río Grande de Arecibo near San Pedro 173.7 10,900 63 50028000 Río Tanamá near Utuado 18.4 14,700 799 50031200 Río Grande de Manatí near Morovis 55.2 31,400 569 50035000 Río Grande de Manatí at Ciales 128 122,000 953 50043800 Río de la Plata at Comerío 109 154,000 1,410 50027000 Río Limón above Lago Dos Bocas 33.2 53,700 1,620 50048770 Río Piedras at El Señorial 7.49 78,600 10,500 50055000 Río Grande de Loíza at Caguas 89.8 67,900 756 50065500 Río Mameyes near Sabana 6.88 8,940 1,300 50071000 Río Fajardo near Fajardo 14.9 47,400 3,180 50136400 Río Rosario near Hormigueros 18.3 10,700 585 50148890 Río Culebrinas at Margarita Dam near 94.6 424,000 4,480 Aguada 13 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 SPECIAL NETWORKS AND PROGRAMS Hydrologic Benchmark Network is a network of 61 sites in small drainage basins in 39 States that was established in 1963 to provide consistent streamflow data representative of undeveloped watersheds nationwide, and from which data could be analyzed on a continuing basis for use in comparison and contrast with conditions observed in basins more obviously affected by human activities. At selected sites, water-quality information is being gathered on major ions and nutrients, primarily to assess the effects of acid deposition on stream chemistry. Additional information on the Hydrologic Benchmark Program may be accessed from http://water.usgs.gov/hbn/ National Stream-Quality Accounting Network (NASQAN) is a network of sites used to monitor the water quality of large rivers within the Nation’s largest river basins. From 1995 through 1999, a network of approximately 40 stations was operated in the Mississippi, Columbia, Colorado, and Rio Grande River basins. For the period 2000 through 2004, sampling was reduced to a few index stations on the Colorado and Columbia Rivers so that a network of 5 stations could be implemented on the Yukon River. Samples are collected with sufficient frequency that the flux of a wide range of constituents can be estimated. The objective of NASQAN is to characterize the water quality of these large rivers by measuring concentration and mass transport of a wide range of dissolved and suspended constituents, including nutrients, major ions, dissolved and sediment-bound heavy metals, common pesticides, and inorganic and organic forms of carbon. This information will be used (1) to describe the long-term trends and changes in concentration and transport of these constituents; (2) to test findings of the National Water-Quality Assessment (NAWQA) Program; (3) to characterize processes unique to large-river systems such as storage and re-mobilization of sediments and associated contaminants; and (4) to refine existing estimates of off-continent transport of water, sediment, and chemicals for assessing human effects on the world’s oceans and for determining global cycles of carbon, nutrients, and other chemicals. Additional information about the NASQAN Program may be accessed from http://water.usgs.gov/nasqan/. The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) is a network of monitoring sites that provide continuous measurement and assessment of the chemical constituents in precipitation throughout the United States. As the lead Federal agency, the USGS works together with over 100 organizations to provide a long-term, spatial and temporal record of atmospheric deposition generated from this network of 250 precipitation-chemistry monitoring sites. The USGS supports 74 of these 250 sites. This long-term, nationally consistent monitoring program, coupled with ecosystem research, provides critical information toward a national scorecard to evaluate the effectiveness of ongoing and future regulations intended to reduce atmospheric emissions and subsequent impacts to the Nation’s land and water resources. Reports and other information on the NADP/ NTN Program, as well as data from the individual sites, may be accessed from http://bqs.usgs.gov/acidrain/. The USGS National Water-Quality Assessment (NAWQA) Program is a long-term program with goals to describe the status and trends of water-quality conditions for a large, representative part of the Nation’s ground- and surface-water resources; to provide an improved understanding of the primary natural and human factors affecting these observed conditions and trends; and to provide information that supports development and evaluation of management, regulatory, and monitoring decisions by other agencies. Assessment activities are being conducted in 42 study units (major watersheds and aquifer systems) that represent a wide range of environmental settings nationwide and that account for a large percentage of the Nation’s water use. A wide array of chemical constituents is measured in ground water, surface water, streambed sediments, and fish tissues. The coordinated application of comparative hydrologic studies at a wide range of spatial and temporal scales will provide information for water-resources managers to use in making decisions and a foundation for aggregation and comparison of findings to address water-quality issues of regional and national interest. 14 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Communication and coordination between USGS personnel and other local, State, and Federal interests are critical components of the NAWQA Program. Each study unit has a local liaison committee consisting of representatives from key Federal, State, and local water-resources agencies, Indian nations, and universities in the study unit. Liaison committees typically meet semiannually to discuss their information needs, monitoring plans and progress, desired information products, and opportunities to collaborate efforts among the agencies. Additional information about the NAWQA Program may be accessed from http://water.usgs.gov/nawqa/. The USGS National Streamflow Information Program (NSIP) is a long-term program with goals to provide framework streamflow data across the Nation. Included in the program are creation of a permanent Federally funded streamflow network, research on the nature of streamflow, regional assessments of streamflow data and databases, and upgrades in the streamflow information delivery systems. Additional information about NSIP may be accessed from http://water.usgs.gov/nsip/. EXPLANATION OF RECORDS The surface- and ground-water records published in this report are for the 2002 water year that began October 1, 2001 and ended September 30, 2002. 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 8. 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. DOWNSTREAM ORDER AND STATION NUMBER Since October 1, 1950, hydrologic-station records in USGS reports have been listed in order of 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 entering between two main-stream stations is listed between those stations. A similar order is followed in listing stations on first rank, second rank, and other ranks of tributaries. The rank of any tributary on which a station is located with respect to the stream to which it is immediately tributary is indicated by an indention in that list of stations in the front of this report. Each indentation represents one rank. This downstream order and system of indentation indicates which stations are on tributaries between any two stations and the rank of the tributary on which each station is located. As an added means of identification, each hydrologic station and partial-record station has been assigned a station number. These station numbers are in the same downstream order used in this report. In assigning a station number, no distinction is made between partial-record stations and other stations; therefore, the station number for a partial-record station indicates downstream-order position in a list composed of both types of stations. Gaps are consecutive. The complete 8-digit (or 10-digit) number for each station such as 50028000, which appears just to the left of the station name, includes a 2-digit part number “50” plus the 6-digit (or 8-digit) downstream order number “028000.” In areas of high station density, an additional two digits may be added to the station identification number to yield a 10-digit number. The stations are numbered in downstream order as described above between stations of consecutive 8-digit numbers. 15 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figur e 5. Location of surface-water stations in Puerto Rico. 16 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figur e 6. Location of water-quality stations in Puerto Rico. 17 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figur e 7. Location of ground-water stations in Puerto Rico. 18 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Figure 8. Location of ground-water stations in the U.S. Virgin Islands. 19 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 NUMBERING SYSTEM FOR WELLS AND MISCELLANEOUS SITES The 8-digit downstream order station numbers are not assigned to wells and miscellaneous sites where only random water-quality samples or discharge measurements are taken. The well and miscellaneous site numbering system of the U.S. Geological Survey is based on the grid system of latitude and longitude. The system provides the geographic location of the well or miscellaneous site and a unique number for each site. The number consists of 15 digits. The first 6 digits denote the degrees, minutes, and seconds of latitude, the next 7 digits denote degrees, minutes, and seconds of longitude, and the last 2 digits (assigned sequentially) identify the wells or other sites within a 1-second grid. The numbers shown in the grid correspond to the local numbers assigned to each well as visited in the field. An example is well 16 (fig. 9). Figure 9. System for numbering wells and miscellaneous sites (latitude and longitude). EXPLANATION OF STAGE AND WATER DISCHARGE RECORDS Data Collection and Computation The base data collected at gaging stations (figs. 5 and 8) consist of records of stage and measurements of discharge of streams or canals, and stage, surface area, and volume of lakes or reservoirs. In addition, observations of factors affecting the stage-discharge relation or the stage-capacity relation, weather records, and other information are used to supplement base data in determining the daily flow or volume of water in storage. Records of stage are obtained from a water-stage recorder that is either downloaded electronically in the field to a laptop computer or similar device or is transmitted using telemetry such as GOES satellite, land-line or cellular-phone modems, or by radio transmission. Measurements of discharge are made with a current meter or acoustic Doppler current profiler, using the general methods adopted by the USGS. These methods are described in standard textbooks, USGS Water-Supply Paper 2175, and the Techniques of Water-Resources Investigations of the United States Geological Survey (TWRIs), Book 3, Chapters A1 through A19 and Book 8, Chapters A2 and B2. The methods are consistent with the American Society for Testing and Materials (ASTM) standards and generally follow the standards of the International Organization for Standards (ISO). For stream-gaging stations, discharge-rating tables for any stage are prepared from stage-discharge curves. If extensions to the rating curves are necessary to express discharge greater than measured, the extensions are made on the basis of indirect measurements of peak discharge (such as slope-area or contracted-opening measurements, or computation of flow over dams and weirs), step-backwater techniques, velocity-area studies, and logarithmic plotting. The daily mean discharge is computed from gage heights and rating tables, then the monthly and yearly mean discharges are computed from the daily values. If the stage-discharge relation is subject to change because of frequent or continual change in the physical features of the stream channel, the daily mean discharge is computed 134 132 131 27 74 16 COORDINATES FOR WELLS 27 (180150066474900) AND 74 (180135066471000) COORDINATES FOR WELLS 132 (180133066503300) AND 134 (180120066503200) COORDINATES FOR WELLS 131 (180058066502700) COORDINATES FOR WELLS 16 (175922066495800) 20 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 by the shifting-control method in which correction factors based on individual discharge measurements and notes by engineers and observers are used when applying the gage heights to the rating tables. If the stage-discharge relation for a station is temporarily changed by the presence of aquatic growth or debris on the controlling section, the daily mean discharge is computed by the shifting-control method. The stage-discharge relation at some stream-gaging stations is affected by backwater from reservoirs, tributary streams, or other sources. Such an occurrence 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 at some distance from the base gage. An index velocity is measured using ultrasonic or acoustic instruments at some stream-gaging stations and this index velocity is used to calculate an average velocity for the flow in the stream. This average velocity along with a stage-area relation is then used to calculate average discharge. At some stations, 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. At some stream-gaging stations in the northern United States, the stage-discharge relation is affected by ice in the winter; therefore, computation of the discharge in the usual manner is impossible. Discharge for periods of ice effect is computed on the basis of gage-height record and occasional winter-discharge measurements. Consideration is given to the available information on temperature and precipitation, notes by gage observers and hydrologists, and comparable records of discharge from other stations in the same or nearby basins. For a lake or reservoir station, capacity tables giving the volume or contents for any stage are prepared from stage-area relation curves defined by surveys. The application of the stage to the capacity table gives the contents, from which the daily, monthly, or yearly changes are computed. If the stage-capacity curve is subject to changes because of deposition of sediment in the reservoir, periodic resurveys of the reservoir are necessary to define new stage-capacity curves. During the period between reservoir surveys, the computed contents may be increasingly in error due to the gradual accumulation of sediment. For some stream-gaging stations, periods of time occur when no gage-height record is obtained or the recorded gage height is faulty and cannot be used to compute daily discharge or contents. Such a situation can happen when the recorder stops or otherwise fails to operate properly, the intakes are plugged, the float is frozen in the well, or for various other reasons. For such periods, the daily discharges are estimated on the basis of recorded range in stage, prior and subsequent records, discharge measurements, weather records, and comparison with records from other stations in the same or nearby basins. Likewise, lake or reservoir volumes may be estimated on the basis of operator’s log, prior and subsequent records, inflow-outflow studies, and other information. Data Presentation The records published for each continuous-record surface-water discharge station (stream-gaging station) consist of five parts: (1) the station manuscript or description; (2) the data table of daily mean values of discharge for the current water year with summary data; (3) a tabular statistical summary of monthly mean flow data for a designated period, by water year; (4) a summary statistics table that includes statistical data of annual, daily, and instantaneous flows as well as data pertaining to annual runoff, 7-day low-flow minimums, and flow duration; and (5) a hydrograph of discharge. 21 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Station Manuscript The manuscript provides, under various headings, descriptive information, such as station location; period of record; historical extremes outside the period of record; record accuracy; and other remarks pertinent to station operation and regulation. The following information, as appropriate, is provided with each continuous record of discharge or lake content. Comments follow that clarify information presented under the various headings of the station description. LOCATION.—Location information is obtained from the most accurate maps available. The location of the gaging station 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. River mileages, given for only a few stations, were determined by methods given in “River Mileage Measurement,” Bulletin 14, Revision of October 1968, prepared by the Water Resources Council or were provided by the U.S. Army Corps of Engineers. DRAINAGE AREA.—Drainage areas are measured using the most accurate maps available. Because the type of maps available varies from one drainage basin to another, the accuracy of drainage areas likewise varies. Drainage areas are updated as better maps become available. PERIOD OF RECORD.—This term indicates the time period for which records have been published 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 its flow reasonably can be considered equivalent to flow at the present station. REVISED RECORDS.—If a critical error in published records is discovered, a revision is included in the first report published following discovery of the error. GAGE.—The type of gage in current use, the datum of the current gage referred to a standard datum, 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 either will be identified by date in this paragraph of the station description for water-discharge stations or flagged in the daily discharge table. (See section titled Identifying Estimated Daily Discharge.) Information is presented relative to the accuracy of the records, to special methods of computation, and to conditions that affect natural flow at the station. In addition, information may be presented pertaining to average discharge data for the period of record; to extremes data for the period of record and the current year; and, possibly, to other pertinent items. For reservoir stations, information is given on the dam forming the reservoir, the capacity, the outlet works and spillway, and the purpose and use of the reservoir. COOPERATION.—Records provided by a cooperating organization or obtained for the USGS by a cooperating organization are identified here. EXTREMES OUTSIDE PERIOD OF RECORD.—Information here documents 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 USGS. REVISIONS.—Records are revised if errors in published records are discovered. Appropriate updates are made in the USGS distributed data system, NWIS, and subsequently to its Web-based National data system, NWISWeb (http://water.usgs.gov/nwis/nwis). Users are encouraged to obtain all required data from NWIS or NWISWeb to ensure that they have the most recent data updates. Updates to NWISWeb are made on an annual basis. 22 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Although rare, occasionally the records of a discontinued gaging station may need revision. Because no current or, possibly, future station manuscript would be published for these stations 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 (address given on the back of the title page of this report) to determine if the published records were revised after the station was discontinued. If, however, the data for a discontinued station were obtained by computer retrieval, the data would be current. 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 stage-capacity table when daily volumes are given. Data Table of Daily Mean Values The daily table of discharge records for stream-gaging stations gives mean discharge for each day of the water year. In the monthly summary for the table, the line headed TOTAL gives the sum of the daily figures for each month; the line headed MEAN gives the arithmetic average flow in cubic feet per second for the month; and the lines headed MAX and MIN give the maximum and minimum daily mean discharges, respectively, for each month. Discharge for the month is 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). Values for cubic feet per second per square mile and runoff in inches or in acre-feet may be omitted if extensive regulation or diversion is in effect or if the drainage area includes large noncontributing areas. At some stations, monthly and (or) yearly observed discharges are adjusted for reservoir storage or diversion, or diversion data or reservoir volumes are given. These values are identified by a symbol and a corresponding footnote. Statistics of Monthly Mean Data A tabular summary of the mean (line headed MEAN), maximum (MAX), and minimum (MIN) of monthly mean flows for each month for a designated period is provided below the mean values table. The water years of the first occurrence of the maximum and minimum monthly flows are provided immediately below those values. The designated period will be expressed as FOR WATER YEARS __-__, BY WATER YEAR (WY), and will list the first and last water years of the range of years selected from the PERIOD OF RECORD paragraph in the station manuscript. The designated period will consist of all of the station record within the specified water years, including complete months of record for partial water years, and may coincide with the period of record for the station. The water years for which the statistics are computed are consecutive, unless a break in the station record is indicated in the manuscript. Summary Statistics A table titled SUMMARY STATISTICS follows the statistics of monthly mean data tabulation. This table consists of four columns with the first column containing the line headings of the statistics being reported. The table provides a statistical summary of yearly, daily, and instantaneous flows, not only for the current water year but also for the previous calendar year and for a designated period, as appropriate. The designated period selected, WATER YEARS __-__, will consist of all of the station records within the specified water years, including complete months of record for partial water years, and may coincide with the period of record for the station. The water years for which the statistics are computed are consecutive, unless a break in the station record is indicated in the manuscript. All of the calculations for the statistical characteristics designated ANNUAL (see line headings below), except for the ANNUAL 7-DAY MINIMUM statistic, are calculated for the designated period using complete water years. The other statistical characteristics may be calculated using partial water years. 23 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 The date or water year, as appropriate, of the first occurrence of each statistic reporting extreme values of discharge is provided adjacent to the statistic. Repeated occurrences may be noted in the REMARKS paragraph of the manuscript or in footnotes. Because the designated period may not be the same as the station period of record published in the manuscript, occasionally the dates of occurrence listed for the daily and instantaneous extremes in the designated-period column may not be within the selected water years listed in the heading. When the dates of occurrence do not fall within the selected water years listed in the heading, it will be noted in the REMARKS paragraph or in footnotes. Selected streamflow duration-curve statistics and runoff data also are given. Runoff data may be omitted if extensive regulation or diversion of flow is in effect in the drainage basin. The following summary statistics data are provided with each continuous record of discharge. Comments that follow clarify information presented under the various line headings of the SUMMARY STATISTICS table. ANNUAL TOTAL.—The sum of the daily mean values of discharge for the year. ANNUAL MEAN.—The arithmetic mean for the individual daily mean discharges for the year noted or for the designated period. HIGHEST ANNUAL MEAN.—The maximum annual mean discharge occurring for the designated period. LOWEST ANNUAL MEAN.—The minimum annual mean discharge occurring for the designated period. HIGHEST DAILY MEAN.—The maximum daily mean discharge for the year or for the designated period. LOWEST DAILY MEAN.—The minimum daily mean discharge for the year or for the designated period. ANNUAL 7-DAY MINIMUM.—The lowest mean discharge for 7 consecutive days for a calendar year or a water year. Note that most low-flow frequency analyses of annual 7-day minimum flows use a climatic year (April 1­ March 31). The date shown in the summary statistics table is the initial date of the 7-day period. This value should not be confused with the 7-day 10-year low-flow statistic. MAXIMUM PEAK FLOW.—The maximum instantaneous peak discharge occurring for the water year or designated period. Occasionally the maximum flow for a year may occur at midnight at the beginning or end of the year, on a recession from or rise toward a higher peak in the adjoining year. In this case, the maximum peak flow is given in the table and the maximum flow may be reported in a footnote or in the REMARKS paragraph in the manuscript. MAXIMUM PEAK STAGE.—The maximum instantaneous peak stage occurring for the water year or designated period. Occasionally the maximum stage for a year may occur at midnight at the beginning or end of the year, on a recession from or rise toward a higher peak in the adjoining year. In this case, the maximum peak stage is given in the table and the maximum stage may be reported in the REMARKS paragraph in the manuscript or in a footnote. If the dates of occurrence of the maximum peak stage and maximum peak flow are different, the REMARKS paragraph in the manuscript or a footnote may be used to provide further information. INSTANTANEOUS LOW FLOW.—The minimum instantaneous discharge occurring for the water year or for the designated period. ANNUAL RUNOFF.—Indicates the total quantity of water in runoff for a drainage area for the year. Data reports may use any of the following units of measurement in presenting annual runoff data: Acre-foot (AC-FT) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet or about 326,000 gallons or 1,233 cubic meters. 24 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Cubic feet per square mile (CFSM) is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. Inches (INCHES) indicate the depth to which the drainage area would be covered if all of the runoff for a given time period were uniformly distributed on it. 10 PERCENT EXCEEDS.—The discharge that has been exceeded 10 percent of the time for the designated period. 50 PERCENT EXCEEDS.—The discharge that has been exceeded 50 percent of the time for the designated period. 90 PERCENT EXCEEDS.—The discharge that has been exceeded 90 percent of the time for the designated period. Data collected at partial-record stations follow the information for continuous-record sites. Data for partial- record discharge stations are presented in two tables. The first table lists annual maximum stage and discharge at crest-stage stations, and the second table lists discharge measurements at low-flow partial-record stations. The tables of partial-record stations are followed by a listing of discharge measurements made at sites other than continuous-record or partial-record stations. These measurements are often made in times of drought or flood to give better areal coverage to those events. Those measurements and others collected for a special reason are called measurements at miscellaneous sites. Identifying Estimated Daily Discharge Estimated daily-discharge values published in the water-discharge tables of annual State data reports are identified. This identification is shown either by flagging individual daily values with the letter “e” and noting in a table footnote, “e–Estimated,” or by listing the dates of the estimated record in the REMARKS paragraph of the station description. Accuracy of Field Data and Computed Results The accuracy of streamflow data depends primarily on (1) the stability of the stage-discharge relation or, if the control is unstable, the frequency of discharge measurements, and (2) the accuracy of observations of stage, measurements of discharge, and interpretations of records. The degree of accuracy of the records is stated in the REMARKS in the station description. “Excellent” indicates that about 95 percent of the daily discharges are within 5 percent of the true value; “good” within 10 percent; and “fair,” within 15 percent. “Poor” indicates that daily discharges have less than “fair” accuracy. Different accuracies may be attributed to different parts of a given record. Values of daily mean discharge in this report are shown to the nearest hundredth of a cubic foot per second for discharges of less than 1 ft3/s; to the nearest tenths between 1.0 and 10 ft3/s; to whole numbers between 10 and 1,000 ft3/s; and to 3 significant figures above 1,000 ft3/s. The number of significant figures used is based solely on the magnitude of the discharge value. The same rounding rules apply to discharge values listed for partial-record stations. Discharge at many stations, as indicated by the monthly mean, may not reflect natural runoff due to the effects of diversion, consumption, regulation by storage, increase or decrease in evaporation due to artificial causes, or to other factors. For such stations, values of cubic feet per second per square mile and of runoff in inches are not published unless satisfactory adjustments can be made for diversions, for changes in contents of reservoirs, or for other changes incident to use and control. Evaporation from a reservoir is not included in the adjustments for changes in reservoir contents, unless it is so stated. Even at those stations where adjustments are made, large errors in computed runoff may occur if adjustments or losses are large in comparison with the observed discharge. 25 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Other Data Records Available Information of a more detailed nature than that published for most of the stream-gaging stations such as discharge measurements, gage-height records, and rating tables is available from the District office. Also, most stream-gaging station records are available in computer-usable form and many statistical analyses have been made. Information on the availability of unpublished data or statistical analyses may be obtained from the District office (see address that is shown on the back of the title page of this report). RECORDS OF SURFACE-WATER QUALITY Records of surface-water quality ordinarily are obtained at or near stream gaging stations because interpretation of records of surface-water quality nearly always requires corresponding discharge data. Records of surface-water quality in this report may involve a variety of types of data and measurement frequencies. Classification of Records Water-quality data for surface-water sites are grouped into one of three classifications. A continuing-record station is a site where data are collected on a regularly scheduled basis. Frequency may be once or more times daily, weekly, monthly, or quarterly. A partial-record station is a site where limited water-quality data are collected systematically over a period of years. Frequency of sampling is usually less than quarterly. A miscellaneous sampling site is a location other than a continuing or partial-record station, where random samples are collected to give better areal coverage to define water-quality conditions in the river basin. A careful distinction needs to be made between "continuing records" as used in this report and "continuous recordings," which refers to a continuous graph or a series of discrete values punched at short intervals on a paper tape. Some records of water quality, such as temperature and specific conductance, may be obtained through continuous recordings; however, because of costs, most data are obtained only monthly or less frequently. Locations of stations for which records on the quality of surface water appear in this report are shown in figure 6. Arrangement of Records Water-quality records collected at a surface-water daily record station are published immediately following that record, regardless of the frequency of sample collection. Station number and name are the same for both records. Where a surface-water daily record station is not available or where the water quality differs significantly from that at the nearby surface-water station, the continuing water-quality record is published with its own station number and name in the regular downstream-order sequence. Water-quality data for partial-record stations and for miscellaneous sampling sites appear in separate tables following the table of discharge measurement at miscellaneous sites. On-site Measurements and Sample Collection In obtaining water-quality data, a major concern needs to be assuring that the data obtained represent the in situ quality of the water. To assure this, certain measurements, such as water temperature, pH, and dissolved oxygen, need to be made onsite when the samples are taken. To assure that measurements made in the laboratory also represent the in situ water, carefully prescribed procedures need to be followed in collecting the samples, in treating the samples to prevent changes in quality pending analysis, and in shipping the samples to the laboratory. Procedures for onsite measurements and for collecting, treating, and shipping samples are given in publications on "Techniques of Water-Resources Investigations," Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. Detailed information on collecting, treating, and shipping samples may be obtained from the Geological Survey District office. 26 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 One sample can define adequately the water quality at a given time if the mixture of solutes throughout the stream cross section is homogeneous. However, the concentration of solutes at different locations in the cross section may vary widely with different rates of water discharge, depending on the source of material and the turbulence and mixing of the stream. Some streams must be sampled through several vertical sections to obtain a representative sample needed for an accurate mean concentration and for use in calculating load. 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 analysis. In the rare case where an apparent inconsistency exists between a reported pH value and the relative abundance of carbon dioxide species (carbonate and bicarbonate), the inconsistency is the result of a slight uptake of carbon dioxide from the air by the sample between measurement of pH in the field and determination of carbonate and bicarbonate in the laboratory. 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. 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. Water temperatures measured at the time of water-discharge measurements are on file in the District office. Sediment Suspended-sediment concentrations are determined from samples collected by using depth-integrating and pumping sediment samplers. Samples usually are obtained at several verticals in the cross section, or a single sample may be obtained at a fixed point and a coefficient applied to determine the mean concentration in the cross sections. During periods of rapidly changing flow or rapidly changing concentration, samples may have been collected more frequently (twice daily or hourly). The published sediment discharges for days of rapidly changing flow or concentration were computed by the subdivided-day method (time-discharge weighted average). For periods when no samples were collected, daily discharges of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, suspended-sediment loads for other periods of similar discharge, and computed by the subdivided-day method using the transport curves. At other stations, suspended-sediment samples were collected periodically at many verticals in the stream cross section. Although data collected periodically may represent conditions only at the time of observations, such data are useful in establishing seasonal relations between quality and streamflow and in predicting long-term sediment- discharge characteristics of the stream. In addition to the records of suspended-sediment discharge, records of the periodic measurements of the particle-size distribution of the suspended sediment are included for some stations. 27 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Laboratory Measurements Samples for indicator bacteria are analyzed in the mobile laboratories immediately after collection. Sediment samples are analyzed in the U.S. Geological Survey laboratories in the Kentucky District Sediment Laboratory. All other samples are analyzed in the Geological Survey laboratories in Denver, Co. or Ocala, Fla. Methods used in analyzing sediment samples and computing sediment records are given in TWRI, Book 5, Chap. C1. Methods used by the Geological Survey laboratories are given in TWRI, Book 1, Chap. D2; Book 3, Chap. C2; Book 5, Chap. A1, A3, and A4. 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 suspended sediment then follow in sequence. In the descriptive headings, if the location is identical to that of the discharge gaging station, neither the LOCATION nor the DRAINAGE AREA statements are repeated. The following information, as appropriate, is provided with each continuous-record station. Comments that follow clarify information presented under the various headings of the station description. LOCATION.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. DRAINAGE AREA.--See Data Presentation under "Records of Stage and Water Discharge;" same comments apply. PERIOD OF RECORD.--This indicates the periods for which there are published water-quality records for the station. The periods are shown separately for records of parameters measured daily or continuously and those measured less than daily. For those measured daily or continuously, periods of record are given for the parameters individually. INSTRUMENTATION.--Information on instrumentation is given only if a water-quality monitor temperature record, sediment pumping sampler, or other sampling device is in operation at a station. REMARKS.--Remarks provide added information pertinent to the collection, analysis, or computation of the records. COOPERATION.--Records provided by a cooperating organization or obtained for the Geological Survey by a cooperating organization are identified here. EXTREMES.--Maximums and minimums are given only for parameters measured daily or more frequently. None are given for parameters measured weekly or less frequently, because the true maximums or minimums may not have been sampled. Extremes, when given, are provided for both the period of record and for the current water year. 28 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 REVISIONS.--If errors in published water-quality records are discovered after publication, appropriate updates are made to the Water-Quality File in the U.S. Geological Survey's computerized data system, WATSTORE, and subsequently by monthly transfer of update transactions to the U.S. Environmental Protection Agency's STORET system. Because the usual volume of updates makes it impractical to document individual changes in the State data-report series or elsewhere, potential users of U.S. Geological Survey water-quality data are encouraged to obtain all required data from the appropriate computer file to insure the most recent updates. The surface-water-quality records for partial-record stations and miscellaneous sampling sites are published in separate tables following the table of discharge measurements at miscellaneous sites. No descriptive statements are given for these records. Each station is published with its own station number and name in the regular downstream- order sequence. Remark Codes The following remark codes may appear with the water-quality data in this section: Printed Output Remark E or 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. M Presence verified, not quantified RECORDS OF GROUND-WATER LEVELS Only ground-water level data from a basic network of observation wells are published herein. This basic network contains observation wells so located that the most significant data are obtained from the fewest wells in the most important aquifers. Data Collection and Computation Measurements of water levels are made in many types of wells under varying conditions, but the methods of measurement are standardized to the extent possible. The equipment and measuring techniques used at each observation well ensure that measurements at each well are of consistent accuracy and reliability. Each well is identified by means of (1) a 15-digit number that is based on latitude and longitude and (2) a local number that is provided for easy reference. See figure 9. Water-level records are obtained from direct measurements with a steel tape at about monthly intervals at all observation wells and also from digital water-stage data logger at 60-minute intervals at selected wells. The water- level measurements in this report are given in feet with reference to land-surface datum (lsd). Land-surface datum is a datum plane that is approximately at land surface at each well. If known, the elevation of the land-surface datum is given in the well description. The height of the measuring point (MP) above or below land-surface datum is given in each well description. Water levels in wells equipped with recording gages are reported for every day and as an instantaneous observation at noon. Water levels are reported to as many significant figures as can be justified by the local conditions. For example, in a measurement of a depth to water of several hundred feet, the error of determining the absolute value of the total depth to water may be a few tenths of a foot, whereas the error in determining the net change of water level between successive measurements may be only a hundredth of a few hundredths of a foot. For lesser depths to water, the accuracy is greater. Accordingly, most measurements reported to a hundredth of a foot. 29 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Data Presentation Each well record consists of three parts, the station description, the data table of water levels observed during the water year and a graph of the water levels for the current water year and other selected period. The description of the well is presented first through use of descriptive headings preceding the tabular data. The comments to follow clarify information presented under the various headings of the well description. LOCATION.--This paragraph follows the well-identification number and reports the latitude and longitude (given in degrees, minutes, and seconds); a landline location designation; the hydrologic-unit number; the distance and direction from a geographic point of reference; and the observation well name. AQUIFER.--This entry designates by name (if a name exists) and geologic unit open to the well. WELL CHARACTERISTICS.--This entry describes the well in terms of depth, diameter, casing depth and/or screened interval, method of construction, use, and additional information such as casing breaks, collapsed screen, and other changes since construction. INSTRUMENTATION.--This paragraph provides information on both the frequency of measurement and the collection method used, allowing the user to better evaluate the reported water-level extremes by knowing whether they are based on weekly, monthly, or some other frequency of measurement. DATUM.--This entry describes both the measuring point and the land-surface elevation at the well. The measuring point is described physically (such as top of collar, notch in top of casing, plug in pump base and so on), and in relation to land surface (such as 1.3 ft above land-surface datum). The elevation of the land-surface datum is described in feet above (or below) sea level; it is reported with a precision depending on the method of determination. REMARKS.--This entry describes factors that may influence the water level in a well or the measurement of the water level. It should identify wells that also are water-quality observation wells, and may be used to acknowledge the assistance of local (non-Survey) observers. PERIOD OF RECORD.--This entry indicates the period for which there are published records for the well. It reports the month and year of the start of publication of water-level records by the U.S. Geological Survey and the words "to current year" if the records are to be continued into the following year. Periods for which water-level records are available, but are not published by the Geological Survey, may be noted. EXTREMES FOR PERIOD OF RECORD.--This entry contains the highest and lowest water levels of the period of published record, with respect to land-surface datum, and the dates of their occurrence. Water-Level Tables A table of water levels follows the station description for each well. Water levels are reported in feet below land-surface datum and all taped measurements of water level are listed. For wells equipped with recorders, daily values tables are published for the instantaneous water-level observation at noon. The highest and lowest water levels of the water year and their dates of occurrence are shown on a line below the table. Because all values are not published for wells with data loggers, the extremes may be values that are not listed in the table. Missing records are indicated by dashes in place of the water level. A hydrograph for a selected period of record follows each water-level table. 30 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 ACCESS TO U.S. GEOLOGICAL SURVEY WATER DATA The U.S. Geological Survey provides near real-time stage and discharge data for many of the gaging stations equipped with the necessary telemetry and historic daily-mean and peak-flow discharge data for most current or discontinued gaging stations through the world wide web (WWW). These data may be accessed at http:// water.usgs.gov. Water-quality data and ground-water data also are available through the WWW. In addition, data can be provided in various machine-readable formats on various media. Information about the availability of specific types of data or products, and user charges, can be obtained locally from each Water Discipline District Office (See address that is shown on the back of the title page of this report.) 31 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 DEFINITION OF TERMS Specialized technical terms related to streamflow, water-quality, and other hydrologic data, as used in this report, are defined below. Terms such as algae, water level, and precipitation are used in their common everyday meanings, definitions of which are given in standard dictionaries. Not all terms defined in this alphabetical list apply to every State. See also table for converting English units to International System (SI) Units. Other glossaries that also define water-related terms are accessible from http:/ /water.usgs.gov/glossaries.html. Acid neutralizing capacity (ANC) is the equivalent sum of all bases or base-producing materials, solutes plus particulates, in an aqueous system that can be titrated with acid to an equivalence point. This term designates titration of an “unfiltered” sample (formerly reported as alkalinity). Acre-foot (AC-FT, acre-ft) is a unit of volume, commonly used to measure quantities of water used or stored, equivalent to the volume of water required to cover 1 acre to a depth of 1 foot and equivalent to 43,560 cubic feet, 325,851 gallons, or 1,233 cubic meters. (See also “Annual runoff”) Adenosine triphosphate (ATP) is an organic, phosphate-rich compound important in the transfer of energy in organisms. Its central role in living cells makes ATP an excellent indicator of the presence of living material in water. A measurement of ATP therefore provides a sensitive and rapid estimate of biomass. ATP is reported in micrograms per liter. Adjusted discharge is discharge data that have been mathematically adjusted (for example, to remove the effects of a daily tide cycle or reservoir storage). Algal 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 at stationary phase and is expressed as milligrams dry weight of algae produced per liter of sample. (See also “Biomass” and “Dry weight”) Alkalinity is the capacity of solutes in an aqueous system to neutralize acid. This term designates titration of a “filtered” sample. Annual runoff is the total quantity of water that is discharged (“runs off”) from a drainage basin in a year. Data reports may present annual runoff data as volumes in acre-feet, as discharges per unit of drainage area in cubic feet per second per square mile, or as depths of water on the drainage basin in inches. Annual 7-day minimum is the lowest mean value for any 7-consecutive-day period in a year. Annual 7-day minimum values are reported herein for the calendar year and the water year (October 1 through September 30). Most low-flow frequency analyses use a climatic year (April 1-March 31), which tends to prevent the low-flow period from being artificially split between adjacent years. The date shown in the summary statistics table is the initial date of the 7-day period. (This value should not be confused with the 7-day, 10-year low-flow statistic.) Aroclor is the registered trademark for a group of poly-chlorinated biphenyls that were manufactured by the Monsanto Company prior to 1976. Aroclors are assigned specific 4-digit reference numbers dependent upon molecular type and degree of substitution of the biphenyl ring hydrogen atoms by chlorine atoms. The first two digits of a numbered aroclor represent the molecular type, and the last two digits represent the percentage weight of the hydrogen-substituted chlorine. Artificial substrate is a device that purposely is 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 collected. Examples of artificial substrates are basket samplers (made of wire cages filled with clean streamside rocks) and multiplate samplers (made of hardboard) for benthic organism collection, and plexiglass strips for periphyton collection. (See also “Substrate”) Ash mass is the mass or amount of residue present after the residue from a dry-mass determination has been ashed in a muffle furnace at a temperature of 500 ºC for 1 hour. Ash mass of zooplankton and phytoplankton is expressed in grams per cubic meter (g/m3), and periphyton and benthic organisms in grams per square meter (g/m2). (See also “Biomass” and “Dry mass”) Aspect is the direction toward which a slope faces with respect to the compass. 32 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Bacteria are microscopic unicellular organisms, typically spherical, rodlike, or spiral and threadlike in shape, often clumped into colonies. Some bacteria cause disease, whereas 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. Bankfull stage, as used in this report, is the stage at which a stream first overflows its natural banks formed by floods with 1- to 3-year recurrence intervals. Base discharge (for peak discharge) is a discharge value, determined for selected stations, above which peak discharge data are published. The base discharge at each station is selected so that an average of about three peak flows per year will be published. (See also “Peak flow”) Base flow is sustained flow of a stream in the absence of direct runoff. It includes natural and human-induced streamflows. Natural base flow is sustained largely by ground-water discharge. Bed material is the sediment mixture of which a stream-bed, lake, pond, reservoir, or estuary bottom is composed. (See also “Bedload” and “Sediment”) Bedload is material in transport that primarily is supported by the streambed. In this report, bedload is considered to consist of particles in transit from the bed to the top of the bedload sampler nozzle (an elevation ranging from 0.25 to 0.5 foot). These particles are retained in the bedload sampler. A sample collected with a pressure-differential bedload sampler also may contain a component of the suspended load. Bedload discharge (tons per day) is the rate of sediment moving as bedload, reported as dry weight, that passes through a cross section in a given time. NOTE: Bedload discharge values in this report may include a component of the suspended- sediment discharge. A correction may be necessary when computing the total sediment discharge by summing the bedload discharge and the suspended-sediment discharge. (See also “Bedload,” “Dry weight,” “Sediment,” and “Suspended­ sediment discharge”) Benthic organisms are the group of organisms inhabiting the bottom of an aquatic environment. They include a number of types of organisms, such as bacteria, fungi, insect larvae and nymphs, snails, clams, and crayfish. They are useful as indicators of water quality. Biochemical oxygen demand (BOD) is a measure of the quantity of dissolved oxygen, in milligrams per liter, necessary for the decomposition of organic matter by microorganisms, such as bacteria. Biomass is the amount of living matter present at any given time, expressed as mass per unit area or volume of habitat. Biomass pigment ratio is an indicator of the total proportion of periphyton that are autotrophic (plants). This also is called the Autotrophic Index. Blue-green algae (Cyanophyta) are a group of phytoplankton and periphyton organisms with a blue pigment in addition to a green pigment called chlorophyll. Blue-green algae can cause nuisance water-quality conditions in lakes and slow-flowing rivers; however, they are found commonly in streams throughout the year. The abundance of blue-green algae in phytoplankton samples is expressed as the number of cells per milliliter (cells/mL) or biovolume in cubic micrometers per milliliter (P m3/mL). The abundance of blue-green algae in periphyton samples is given in cells per square centimeter (cells/ cm2) or biovolume per square centimeter (P m3/cm2). See also “Phytoplankton”and “Periphyton”) Bottom material (See “Bed material”) Bulk electrical conductivity is the combined electrical conductivity of all material within a doughnut-shaped volume surrounding an induction probe. Bulk conductivity is affected by different physical and chemical properties of the material including the dissolved-solids content of the pore water, and the lithology and porosity of the rock. Canadian Geodetic Vertical Datum 1928 is a geodetic datum derived from a general adjustment of Canada’s first order level network in 1928. 33 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Cell volume (biovolume) determination is one of several common methods used to estimate biomass of algae in aquatic systems. Cell members of algae are used frequently in aquatic surveys as an indicator of algal production. However, cell numbers alone cannot represent true biomass because of considerable cell-size variation among the algal species. Cell volume (P m3) is determined by obtaining critical cell measurements or cell dimensions (for example, length, width, height, or radius) for 20 to 50 cells of each important species to obtain an average biovolume per cell. Cells are categorized according to the correspondence of their cellular shape to the nearest geometric solid or combinations of simple solids (for example, spheres, cones, or cylinders). Representative formulae used to compute biovolume are as follows: sphere 4/3 Sr3 cone 1/3 Sr2h cylinder Sr2h. pi (S is the ratio of the circumference to the diameter of a circle; pi = 3.14159…. From cell volume, total algal biomass expressed as biovolume (P m3/mL) is thus determined by multiplying the number of cells of a given species by its average cell volume and then summing these volumes for all species. Cells/volume refers to the number of cells of any organism that 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 volume, and generally are reported as cells or units per milliliter (mL) or liter (L). Cfs-day (See “Cubic foot per second-day”) Channel bars, as used in this report, are the lowest prominent geomorphic features higher than the channel bed. 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 BOD or with carbonaceous organic pollution from sewage or industrial wastes. [See also “Biochemical oxygen demand (BOD)”] Clostridium perfringens (C. perfringens) is a spore-forming bacterium that is common in the feces of human and other warmblooded animals. Clostridial spores are being used experimentally as an indicator of past fecal contamination and the presence of microorganisms that are resistant to disinfection and environmental stresses. (See also “Bacteria”) Coliphages are viruses that infect and replicate in coliform bacteria. They are indicative of sewage contamination of water and of the survival and transport of viruses in the environment. Color unit is produced by 1 milligram per liter of platinum in the form of the chloroplatinate ion. Color is expressed in units of the platinum-cobalt scale. Confined aquifer is a term used to describe an aquifer containing water between two relatively impermeable bound-aries. The water level in a well tapping a confined aquifer stands above the top of the confined aquifer and can be higher or lower than the water table that may be present in the material above it. In some cases, the water level can rise above the ground surface, yielding a flowing well. 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. Continuous-record station is a site where data are collected with sufficient frequency to define daily mean values and variations within a day. Control designates a feature in the channel that physically affects the water-surface elevation and thereby determines the stage-discharge relation at the gage. This feature may be a constriction of the channel, a bedrock outcrop, a gravel bar, 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 saltwater. 34 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Cubic foot per second (CFS, ft3/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point in 1 second. It is equivalent to approximately 7.48 gallons per second or approximately 449 gallons per minute, or 0.02832 cubic meters per second. The term “second-foot” sometimes is used synonymously with “cubic foot per second” but is now obsolete. Cubic foot per second-day (CFS-DAY, Cfs-day, [(ft3/s)/d]) is the volume of water represented by a flow of 1cubic foot per second for 24 hours. It is equivalent to 86,400cubic feet, 1.98347 acre-feet, 646,317 gallons, or 2,446.6 cubic meters. The daily mean discharges reported in the daily value data tables numerically are equal to the daily volumes in cfs-days, and the totals also represent volumes in cfs-days. Cubic foot per second per square mile [CFSM, (ft3/s)/mi2] is the average number of cubic feet of water flowing per second from each square mile of area drained, assuming the runoff is distributed uniformly in time and area. (See also “Annual runoff”) Daily mean suspended-sediment concentration is the time-weighted mean concentration of suspended sediment passing a stream cross section during a 24-hour day. (See also “Sediment” and “Suspended-sediment concentration”) Daily record station is a site where data are collected with sufficient frequency to develop a record of one or more data values per day. The frequency of data collection can range from continuous recording to data collection on a daily or near-daily basis. Data collection platform (DCP) is an electronic instrument that collects, processes, and stores data from various sensors, and transmits the data by satellite data relay, line-of-sight radio, and/or landline telemetry. Data logger is a microprocessor-based data acquisition system designed specifically to acquire, process, and store data. Data usually are downloaded from onsite data loggers for entry into office data systems. Datum is a surface or point relative to which measurements of height and/or horizontal position are reported. A vertical datum is a horizontal surface used as the zero point for measurements of gage height, stage, or elevation; a horizontal datum is a reference for positions given in terms of latitude-longitude, State Plane coordinates, or Universal Transverse Mercator (UTM) coordinates. (See also “Gage datum,” “Land-surface datum,” “National Geodetic Vertical Datum of 1929,” and “North American Vertical Datum of 1988”) Diatoms (Bacillariophyta) are unicellular or colonial algae with a siliceous cell wall. The abundance of diatoms in phytoplankton samples is expressed as the number of cells per milliliter (cells/mL) or biovolume in cubic micrometers per milliliter (P m3/mL). The abundance of diatoms in periphyton samples is given in cells per square centimeter (cells/cm 2) or biovolume per square centimeter (P m3/cm2). (See also “Phytoplankton” and “Periphyton”) Diel is of or pertaining to a 24-hour period of time; a regular daily cycle. Discharge, or flow, is the rate that matter passes through a cross section of a stream channel or other water body per unit of time. The term commonly refers to the volume of water (including, unless otherwise stated, any sediment or other constituents suspended or dissolved in the water) that passes a cross section in a stream channel, canal, pipeline, and so forth, within a given period of time (cubic feet per second). Discharge also can apply to the rate at which constituents, such as suspended sediment, bedload, and dissolved or suspended chemicals, pass through a cross section, in which cases the quantity is expressed as the mass of constituent that passes the cross section in a given period of time (tons per day). Dissolved refers to that material in a representative water sample that passes through a 0.45-micrometer membrane filter. This is a convenient operational definition used by Federal and State agencies that collect water-quality data. Determinations of “dissolved” constituent concentrations are made on sample water that has been filtered. Dissolved oxygen (DO) is the molecular oxygen (oxygen gas) dissolved in water. The concentration in water is a function of atmospheric pressure, temperature, and dissolved-solids concentration of the water. The ability of water to retain oxygen decreases with increasing temperature or dissolved-solids concentration. Photosynthesis and respiration by plants commonly cause diurnal variations in dissolved-oxygen concentration in water from some streams. 35 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Dissolved solids concentration in water is the quantity of dissolved material in a sample of water. It 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, the bicarbonate (generally a major dissolved component of water) is converted to carbonate. In the mathematical calculation, the bicarbonate value, in milligrams per liter, is multiplied by 0.4926 to convert it to carbonate. Alternatively, alkalinity concentration (as mg/L CaCO3) can be converted to carbonate concentration by multiplying by 0.60. Diversity index (H) (Shannon index) is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: s ni ni d = – ¦ ----log2----, n n 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. 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 specific location is that area upstream from the location, measured in a horizontal plane, that has a common outlet at the site for its surface runoff from precipitation that normally drains by gravity into a stream. Drainage areas given herein include all closed basins, or noncontributing areas, within the area unless otherwise specified. Drainage basin is a part of the Earth’s surface that contains a drainage system with a common outlet for its surface runoff. (See “Drainage area”) Dry mass refers to the mass of residue present after drying in an oven at 105 qC, 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. (See also “Ash mass,” “Biomass,” and “Wet mass”) Dry weight refers to the weight of animal tissue after it has been dried in an oven at 65 °C until a constant weight is achieved. Dry weight represents total organic and inorganic matter in the tissue. (See also “Wet weight”) Embeddedness is the degree to which gravel-sized and larger particles are surrounded or enclosed by finer-sized particles. (See also “Substrate embeddedness class”) Enterococcus bacteria commonly are found in the feces of humans and other warmblooded animals. Although some strains are ubiquitous and not related to fecal pollution, the presence of enterococci in water is an indication of fecal pollution and the possible presence of enteric pathogens. Enterococcus bacteria are those bacteria that produce pink to red colonies with black or reddish-brown precipitate after incubation at 41 qC on mE agar (nutrient medium for bacterial growth) and subsequent transfer to EIA medium. Enterococci include Streptococcus feacalis, Streptococcus feacium, Streptococcus avium, and their variants. (See also “Bacteria”) EPT Index is the total number of distinct taxa within the insect orders Ephemeroptera, Plecoptera, and Trichoptera. This index summarizes the taxa richness within the aquatic insects that generally are considered pollution sensitive; the index usually decreases with pollution. Escherichia coli (E. coli) are bacteria present in the intestine and feces of warmblooded animals. E. coli are a member species of the fecal coliform group of indicator bacteria. In the laboratory, they are defined as those bacteria that produce yellow or yellow-brown colonies on a filter pad saturated with urea substrate broth after primary culturing for 22 to 24 hours at 44.5 °C on mTEC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) 36 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Estimated (E) value of a concentration is reported when an analyte is detected and all criteria for a positive result are met. If the concentration is less than the method detection limit (MDL), an E code will be reported with the value. If the analyte is identified qualitatively as present, but the quantitative determination is substantially more uncertain, the National Water Quality Laboratory will identify the result with an E code even though the measured value is greater than the MDL. A value reported with an E code should be used with caution. When no analyte is detected in a sample, the default reporting value is the MDL preceded by a less than sign (<). For bacteriological data, concentrations are reported as estimated when results are based on non-ideal colony counts. Euglenoids (Euglenophyta) are a group of algae that usually are free-swimming and rarely creeping. They have the ability to grow either photosynthetically in the light or heterotrophically in the dark. (See also “Phytoplankton”) Extractable organic halides (EOX) are organic compounds that contain halogen atoms such as chlorine. These organic compounds are semivolatile and extractable by ethyl acetate from air-dried streambed sediment. The ethyl acetate extract is combusted, and the concentration is determined by microcoulometric determination of the halides formed. The concentration is reported as micrograms of chlorine per gram of the dry weight of the streambed sediment. Fecal coliform bacteria are present in the intestines or feces of warmblooded animals. They often are used as indicators of the sanitary quality of the water. In the laboratory, they are defined as all organisms that produce blue colonies within 24 hours when incubated at 44.5qC plus or minus 0.2 qC on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) Fecal streptococcal bacteria are present in the intestines of warmblooded animals and are ubiquitous in the environment. They are characterized as gram-positive, cocci bacteria that are capable of growth in brain-heart infusion broth. In the laboratory, they are defined as all the organisms that produce red or pink colonies within 48 hours at 35 qC plus or minus 1.0 qC on KF-streptococcus medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. (See also “Bacteria”) Fire algae (Pyrrhophyta) are free-swimming unicells characterized by a red pigment spot. (See also “Phytoplankton”) Flow-duration percentiles are values on a scale of 100 that indicate the percentage of time for which a flow is not exceeded. For example, the 90th percentile of river flow is greater than or equal to 90 percent of all recorded flow rates. Gage datum is a horizontal surface used as a zero point for measurement of stage or gage height. This surface usually is located slightly below the lowest point of the stream bottom such that the gage height is usually slightly greater than the maximum depth of water. Because the gage datum is not an actual physical object, the datum is usually defined by specifying the elevations of permanent reference marks such as bridge abutments and survey monuments, and the gage is set to agree with the reference marks. Gage datum is a local datum that is maintained independently of any national geodetic datum. However, if the elevation of the gage datum relative to the national datum (North American Vertical Datum of 1988 or National Geodetic Vertical Datum of 1929) has been determined, then the gage readings can be converted to elevations above the national datum by adding the elevation of the gage datum to the gage reading. Gage height (G.H.) is the water-surface elevation, in feet above the gage datum. If the water surface is below the gage datum, the gage height is negative. Gage height often is used interchangeably with the more general term “stage,” although gage height is more appropriate when used in reference to a reading on a gage. Gage values are values that are recorded, transmitted, and/or computed from a gaging station. Gage values typically are collected at 5-, 15-, or 30-minute intervals. Gaging station is a site on a stream, canal, lake, or reservoir where systematic observations of stage, discharge, or other hydrologic data are obtained. Gas chromatography/flame ionization detector (GC/FID) is a laboratory analytical method used as a screening technique for semivolatile organic compounds that are extractable from water in methylene chloride. Geomorphic channel units, as used in this report, are fluvial geomorphic descriptors of channel shape and stream velocity. Pools, riffles, and runs are types of geomorphic channel units considered for National Water-Quality Assessment (NAWQA) Program habitat sampling. 37 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Green algae (Chlorophyta) are unicellular or colonial algae with chlorophyll pigments similar to those in terrestrial green plants. Some forms of green algae produce mats or floating “moss” in lakes. The abundance of green algae in phytoplankton samples is expressed as the number of cells per milliliter (cells/mL) or biovolume in cubic micrometers per milliliter (P m3/ mL). The abundance of green algae in periphyton samples is given in cells per square centimeter (cells/cm 2) or biovolume per square centimeter (P m3/cm2). (See also “Phytoplankton” and “Periphyton”) Habitat, as used in this report, includes all nonliving (physical) aspects of the aquatic ecosystem, although living components like aquatic macrophytes and riparian vegetation also are usually included. Measurements of habitat typically are made over a wider geographic scale than are measurements of species distribution. Habitat quality index is the qualitative description (level 1) of instream habitat and riparian conditions surrounding the reach sampled. Scores range from 0 to 100 percent with higher scores indicative of desirable habitat conditions for aquatic life. Index only applicable to wadable streams. Hardness of water is a physical-chemical characteristic that commonly is recognized by the increased quantity of soap required to produce lather. It is computed as the sum of equivalents of polyvalent cations (primarily calcium and magnesium) and is expressed as the equivalent concentration of calcium carbonate (CaCO3). High tide is the maximum height reached by each rising tide. The high-high and low-high tides are the higher and lower of the two high tides, respectively, of each tidal day. See NOAA Web site: http://www.co-ops.nos.noaa.gov/tideglos.html Hilsenhoff’s Biotic Index (HBI) is an indicator of organic pollution that uses tolerance values to weight taxa abundances; usually increases with pollution. It is calculated as follows: n a H B I s u m---------------, = N where n is the number of individuals of each taxon, a is the tolerance value of each taxon, and N is the total number of organisms in the sample. Horizontal datum (See “Datum”) Hydrologic index stations referred to in this report are continuous-record gaging stations that have been selected as representative of streamflow patterns for their respective regions. Station locations are shown on index maps. Hydrologic unit is a geographic area representing part or all of a surface drainage basin or distinct hydrologic feature as defined by the former Office of Water Data Coordination and delineated on the State Hydrologic Unit Maps by the USGS. Each hydrologic unit is identified by an 8-digit number. Inch (IN., in.), in reference to streamflow, as used in this report, refers to the depth to which the drainage area would be covered with water if all of the runoff for a given time period were distributed uniformly on it. (See also “Annual runoff”) Instantaneous discharge is the discharge at a particular instant of time. (See also “Discharge”) International Boundary Commission Survey Datum refers to a geodetic datum established at numerous monuments along the United States-Canada boundary by the International Boundary Commission. Island, as used in this report, is a mid-channel bar that has permanent woody vegetation, is flooded once a year, on average, and remains stable except during large flood events. 38 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Laboratory reporting level (LRL) generally is equal to twice the yearly determined long-term method detection level (LT­ MDL). The LRL controls false negative error. The probability of falsely reporting a nondetection for a sample that contained an analyte at a concentration equal to or greater than the LRL is predicted to be less than or equal to 1 percent. The value of the LRL will be reported with a “less than” (<) remark code for samples in which the analyte was not detected. The National Water Quality Laboratory (NWQL) collects quality-control data from selected analytical methods on a continuing basis to determine LT-MDLs and to establish LRLs. These values are reevaluated annually on the basis of the most current quality- control data and, therefore, may change. The LRL replaces the term ‘non-detection value’ (NDV). Land-surface datum (lsd) is a datum plane that is approximately at land surface at each ground-water observation well. Latent heat flux (often used interchangeably with latent heat-flux density) is the amount of heat energy that converts water from liquid to vapor (evaporation) or from vapor to liquid (condensation) across a specified cross-sectional area per unit time. Usually expressed in watts per square meter. Light-attenuation coefficient, also known as the extinction coefficient, is a measure of water clarity. Light is attenuated according to the Lambert-Beer equation: –O L I I e , = o where Io is the source light intensity, I is the light intensity at length L (in meters) from the source, O is the light-attenuation coefficient, and e is the base of the natural logarithm. The light-attenuation coefficient is defined as 1 I O = –---loge----. L Io Lipid is any one of a family of compounds that are insoluble in water and that make up one of the principal components of living cells. Lipids include fats, oils, waxes, and steroids. Many environmental contaminants such as organochlorine pesticides are lipophilic. Long-term method detection level (LT-MDL) is a detection level derived by determining the standard deviation of a minimum of 24 method detection limit (MDL) spike-sample measurements over an extended period of time. LT-MDL data are collected on a continuous basis to assess year-to-year variations in the LT-MDL. The LT-MDL controls false positive error. The chance of falsely reporting a concentration at or greater than the LT-MDL for a sample that did not contain the analyte is predicted to be less than or equal to 1 percent. Low tide is the minimum height reached by each falling tide. The high-low and low-low tides are the higher and lower of the two low tides, respectively, of each tidal day. See NOAA Web site: http://www.co-ops.nos.noaa.gov/tideglos.html Macrophytes are the macroscopic plants in the aquatic environment. The most common macrophytes are the rooted vascular plants that usually are arranged in zones in aquatic ecosystems and restricted in the area by the extent of illumination through the water and sediment deposition along the shoreline. Mean concentration of suspended sediment (Daily mean suspended-sediment concentration) is the time-weighted concentration of suspended sediment passing a stream cross section during a given time period. (See also “Daily mean suspended-sediment concentration” and “Suspended-sediment concentration”) Mean discharge (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. (See also “Discharge”) Mean high or low tide is the average of all high or low tides, respectively, over a specific period. Mean sea level is a local tidal datum. It is the arithmetic mean of hourly heights observed over the National Tidal Datum Epoch. Shorter series are specified in the name; for example, monthly mean sea level and yearly mean sea level. In order that they may be recovered when needed, such datums are referenced to fixed points known as benchmarks. (See also “Datum”) 39 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Measuring point (MP) is an arbitrary permanent reference point from which the distance to water surface in a well is measured to obtain water level. Megahertz is a unit of frequency. One megahertz equals one million cycles per second. Membrane filter is a thin microporous material of specific pore size used to filter bacteria, algae, and other very small particles from water. Metamorphic stage refers to the stage of development that an organism exhibits during its transformation from an immature form to an adult form. This developmental process exists for most insects, and the degree of difference from the immature stage to the adult form varies from relatively slight to pronounced, with many intermediates. Examples of metamorphic stages of insects are egg-larva-adult or egg-nymph-adult. Method detection limit (MDL) is the minimum concentration of a substance that can be measured and reported with 99­ percent confidence that the analyte concentration is greater than zero. It is determined from the analysis of a sample in a given matrix containing the analyte. At the MDL concentration, the risk of a false positive is predicted to be less than or equal to 1 percent. Method of Cubatures is a method of computing discharge in tidal estuaries based on the conservation of mass equation. Methylene blue active substances (MBAS) indicate the presence of detergents (anionic surfactants). 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, P g/g) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the element per unit mass (gram) of material analyzed. Micrograms per kilogram (UG/KG, P g/kg) is a unit expressing the concentration of a chemical constituent as the mass (micrograms) of the constituent per unit mass (kilogram) of the material analyzed. One microgram per kilogram is equivalent to 1 part per billion. Micrograms per liter (UG/L, P g/L) is a unit expressing the concentration of chemical constituents in water as mass (micrograms) of constituent per unit volume (liter) of water. One thousand micrograms per liter is equivalent to 1milligram per liter. One microgram per liter is equivalent to 1 part per billion. Microsiemens per centimeter (US/CM, P S/cm) is a unit expressing the amount of electrical conductivity of a solution as measured between opposite faces of a centimeter cube of solution at a specified temperature. Siemens is the International System of Units nomenclature. It is synonymous with mhos and is the reciprocal of resistance in ohms. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical constituents in water as the mass (milligrams) of constituent per unit volume (liter) of water. Concentration of suspended sediment also is expressed in milligrams per liter and is based on the mass of dry sediment per liter of water-sediment mixture. Minimum reporting level (MRL) is the smallest measured concentration of a constituent that may be reliably reported by using a given analytical method. Miscellaneous site, miscellaneous station, or miscellaneous sampling site is a site where streamflow, sediment, and/or water- quality data or water-quality or sediment samples are collected once, or more often on a random or discontinuous basis to provide better areal coverage for defining hydrologic and water-quality conditions over a broad area in a river basin. Most probable number (MPN) is an index of the number of coliform bacteria that, more probably than any other number, would give the results shown by the laboratory examination; it is not an actual enumeration. MPN is determined from the distribution of gas-positive cultures among multiple inoculated tubes. Multiple-plate samplers are artificial substrates of known surface area used for obtaining benthic invertebrate samples. They consist of a series of spaced, hardboard plates on an eyebolt. 40 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Nanograms per liter (NG/L, ng/L) is a unit expressing the concentration of chemical constituents in solution as mass (nanograms) of solute per unit volume (liter) of water. One million nanograms per liter is equivalent to 1milligram per liter. National Geodetic Vertical Datum of 1929 (NGVD 29) is a fixed reference adopted as a standard geodetic datum for elevations determined by leveling. It formerly was called “Sea Level Datum of 1929” or “mean sea level.” Although the datum was derived from the mean sea level at 26 tide stations, it does not necessarily represent local mean sea level at any particular place. See NOAA Web site: http://www.ngs.noaa.gov/faq.shtml#WhatVD29VD88 (See “North American Vertical Datum of 1988”) Natural substrate refers to any naturally occurring immersed or submersed solid surface, such as a rock or tree, upon which an organism lives. (See also “Substrate”) Nekton are the consumers in the aquatic environment and consist of large, free-swimming organisms that are capable of sustained, directed mobility. Nephelometric turbidity unit (NTU) is the measurement for reporting turbidity that is based on use of a standard suspension of formazin. Turbidity measured in NTU uses nephelometric methods that depend on passing specific light of a specific wavelength through the sample. North American Datum of 1927 (NAD 27) is the horizontal control datum for the United States that was defined by a location and azimuth on the Clarke spheroid of 1866. North American Datum of 1983 (NAD 83) is the horizontal control datum for the United States, Canada, Mexico, and Central America that is based on the adjustment of 250,000 points including 600 satellite Doppler stations that constrain the system to a geocentric origin. NAD 83 has been officially adopted as the legal horizontal datum for the United States by the Federal government. North American Vertical Datum of 1988 (NAVD 88) is a fixed reference adopted as the official civilian vertical datum for elevations determined by Federal surveying and mapping activities in the United States. This datum was established in 1991 by minimum-constraint adjustment of the Canadian, Mexican, and United States first-order terrestrial leveling networks. Open or screened interval is the length of unscreened opening or of well screen through which water enters a well, in feet below land surface. Organic carbon (OC) is a measure of organic matter present in aqueous solution, suspension, or bottom sediment. May be reported as dissolved organic carbon (DOC), particulate organic carbon (POC), or total organic carbon (TOC). Organic mass or volatile mass of a living substance is the difference between the dry mass and ash mass and represents the actual mass of the living matter. Organic mass is expressed in the same units as for ash mass and dry mass. (See also “Ash mass,” “Biomass,” and “Dry mass”) Organism count/area refers to the number of organisms collected and enumerated in a sample and adjusted to the number per area habitat, usually square meter (m2), acre, 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 milliliter (mL) or liter (L). Numbers of planktonic organisms can be expressed in these terms. Organochlorine compounds are any chemicals that contain carbon and chlorine. Organochlorine compounds that are important in investigations of water, sediment, and biological quality include certain pesticides and industrial compounds. Parameter code is a 5-digit number used in the USGS computerized data system, National Water Information System (NWIS), to uniquely identify a specific constituent or property. Partial-record station is a site where discrete measurements of one or more hydrologic parameters are obtained over a period of time without continuous data being recorded or computed. A common example is a crest-stage gage partial-record station at which only peak stages and flows are recorded. 41 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Particle size is the diameter, in millimeters (mm), of a particle determined by sieve or sedimentation methods. The sedimentation method uses the principle of Stokes Law to calculate sediment particle sizes. Sedimentation methods (pipet, bottom-withdrawal tube, visual-accumulation tube, sedigraph) 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, as used in this report, agrees with the recommendation made by the American Geophysical Union Subcommittee on Sediment Terminology. The classification is as follows: Classification Size (mm) Method of analysis Clay >0.00024 - 0.004 Sedimentation Silt >0.004 - 0.062 Sedimentation Sand >0.062 - 2.0 Sedimentation/sieve Gravel >2.0 - 64.0 Sieve Cobble >64 - 256 Manual measurement Boulder >256 Manual measurement The particle-size distributions given in this report are not necessarily representative of all particles in transport in the stream. For the sedimentation method, 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. Peak flow (peak stage) is an instantaneous local maximum value in the continuous time series of streamflows or stages, preceded by a period of increasing values and followed by a period of decreasing values. Several peak values ordinarily occur in a year. The maximum peak value in a year is called the annual peak; peaks lower than the annual peak are called secondary peaks. Occasionally, the annual peak may not be the maximum value for the year; in such cases, the maximum value occurs at midnight at the beginning or end of the year, on the recession from or rise toward a higher peak in the adjoining year. If values are recorded at a discrete series of times, the peak recorded value may be taken as an approximation of the true peak, which may occur between the recording instants. If the values are recorded with finite precision, a sequence of equal recorded values may occur at the peak; in this case, the first value is taken as the peak. Percent composition or percent of total 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, weight, mass, or volume. Percent shading is a measure of the amount of sunlight potentially reaching the stream. A clinometer is used to measure left and right bank canopy angles. These values are added together, divided by 180, and multiplied by 100 to compute percentage of shade. Periodic-record station is a site where stage, discharge, sediment, chemical, physical, or other hydrologic measurements are made one or more times during a year but at a frequency insufficient to develop a daily record. Periphyton is the assemblage of microorganisms attached to and living upon submerged solid surfaces. Although primarily consisting of algae, they also include bacteria, fungi, protozoa, rotifers, and other small organisms. Periphyton are useful indicators of water quality. Pesticides are chemical compounds used to control undesirable organisms. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. pH of water is the negative logarithm of the hydrogen-ion activity. Solutions with pH less than 7.0 standard units are termed “acidic,” and solutions with a pH greater than 7.0 are termed “basic.” Solutions with a pH of 7.0 are neutral. The presence and concentration of many dissolved chemical constituents found in water are affected, in part, by the hydrogen-ion activity of water. Biological processes including growth, distribution of organisms, and toxicity of the water to organisms also are affected, in part, by the hydrogen-ion activity of water. 42 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Phytoplankton is the plant part of the plankton. They usually are microscopic, and their movement is subject to the water currents. Phytoplankton growth is dependent upon solar radiation and nutrient substances. Because they are able to incorporate as well as release materials to the surrounding water, the phytoplankton have a profound effect upon the quality of the water. They are the primary food producers in the aquatic environment and commonly are known as algae. (See also “Plankton”) Picocurie (PC, pCi) is one-trillionth (1 x 10-12) of the amount of radioactive nuclide represented by a curie (Ci). A curie is the quantity of radioactive nuclide that yields 3.7 x 1010 radioactive disintegrations per second (dps). A picocurie yields 0.037 dps, or 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. Concentrations are expressed as a number of cells per milliliter (cells/mL) of sample. Polychlorinated biphenyls (PCBs) are industrial chemicals that are mixtures of chlorinated biphenyl compounds having various percentages of chlorine. They are similar in structure to organochlorine insecticides. Polychlorinated naphthalenes (PCNs) are industrial chemicals that are mixtures of chlorinated naphthalene compounds. They have properties and applications similar to polychlorinated biphenyls (PCBs) and have been identified in commercial PCB preparations. Pool, as used in this report, is a small part of a stream reach with little velocity, commonly with water deeper than surrounding areas. Primary productivity is a measure of the rate at which new organic matter is formed and accumulated through photo­ synthetic and chemosynthetic activity of producer organisms (chiefly, green plants). The rate of primary production is estimated by measuring the amount of oxygen released (oxygen method) or the amount of carbon assimilated (carbon method) by the plants. Primary productivity (carbon method) is expressed as milligrams of carbon per area per unit time [mg C/(m2/time)] for periphyton and macrophytes or per volume [mg C/(m3/time)] for phytoplankton. The carbon method defines the amount of carbon dioxide consumed as measured by radioactive carbon (carbon-14). The carbon-14 method is of greater sensitivity than the oxygen light- and dark-bottle method and is preferred for use with unenriched water samples. Unit time may be either the hour or day, depending on the incubation period. (See also “Primary productivity”) Primary productivity (oxygen method) is expressed as milligrams of oxygen per area per unit time [mgO/(m2/time)] for periphyton and macrophytes or per volume [mg O/(m3/time)] for phytoplankton. The oxygen method defines 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. (See also “Primary productivity”) Radioisotopes are isotopic forms of elements that exhibit radioactivity. Isotopes are varieties of a chemical element that differ in atomic weight but are very nearly alike in chemical properties. The difference arises because the atoms of the isotopic forms of an element differ in the number of neutrons in the nucleus; for example, ordinary chlorine is a mixture of isotopes having atomic weights of 35 and 37, and the natural mixture has an atomic weight of about 35.453. Many of the elements similarly exist as mixtures of isotopes, and a great many new isotopes have been produced in the operation of nuclear devices such as the cyclotron. There are 275 isotopes of the 81 stable elements, in addition to more than 800 radioactive isotopes. Reach, as used in this report, is a length of stream that is chosen to represent a uniform set of physical, chemical, and biological conditions within a segment. It is the principal sampling unit for collecting physical, chemical, and biological data. 43 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Recoverable from bed (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. (See also “Bed material”) Recurrence interval, also referred to as return period, is the average time, usually expressed in years, between occurrences of hydrologic events of a specified type (such as exceedances of a specified high flow or nonexceedance of a specified low flow). The terms “return period” and “recurrence interval” do not imply regular cyclic occurrence. The actual times between occurrences vary randomly, with most of the times being less than the average and a few being substantially greater than the average. For example, the 100-year flood is the flow rate that is exceeded by the annual maximum peak flow at intervals whose average length is 100 years (that is, once in 100 years, on average); almost two-thirds of all exceedances of the 100­ year flood occur less than 100 years after the previous exceedance, half occur less than 70 years after the previous exceedance, and about one-eighth occur more than 200 years after the previous exceedance. Similarly, the 7-day, 10-year low flow (7Q10) is the flow rate below which the annual minimum 7-day-mean flow dips at intervals whose average length is 10 years (that is, once in 10years, on average); almost two-thirds of the nonexceedances of the 7Q10 occur less than 10 years after the previous nonexceedance, half occur less than 7years after, and about one-eighth occur more than 20 years after the previous nonexceedance. The recurrence interval for annual events is the reciprocal of the annual probability of occurrence. Thus, the 100-year flood has a 1-percent chance of being exceeded by the maximum peak flow in any year, and there is a 10­ percent chance in any year that the annual minimum 7-day-mean flow will be less than the 7Q10. Replicate samples are a group of samples collected in a manner such that the samples are thought to be essentially identical in composition. Return period (See “Recurrence interval”) Riffle, as used in this report, is a shallow part of the stream where water flows swiftly over completely or partially submerged obstructions to produce surface agitation. River mileage is the curvilinear distance, in miles, measured upstream from the mouth along the meandering path of a stream channel in accordance with Bulletin No. 14 (October 1968) of the Water Resources Council and typically is used to denote location along a river. Run, as used in this report, is a relatively shallow part of a stream with moderate velocity and little or no surface turbulence. Runoff is the quantity of water that is discharged (“runs off”) from a drainage basin during a given time period. Runoff data may be presented as volumes in acre-feet, as mean discharges per unit of drainage area in cubic feet per second per square mile, or as depths of water on the drainage basin in inches. (See also “Annual runoff”) Sea level, as used in this report, refers to one of the two commonly used national vertical datums (NGVD 1929 or NAVD 1988). See separate entries for definitions of these datums. Sediment is solid material that originates mostly from disintegrated rocks; when transported by, suspended in, or deposited from water, it is referred to as “fluvial sediment.” Sediment includes chemical and biochemical precipitates and decomposed organic material, such as humus. The quantity, characteristics, and cause of the occurrence of sediment in streams are affected by environmental and land-use factors. Some major factors are topography, soil characteristics, land cover, and depth and intensity of precipitation. Sensible heat flux (often used interchangeably with latent sensible heat-flux density) is the amount of heat energy that moves by turbulent transport through the air across a specified cross-sectional area per unit time and goes to heating (cooling) the air. Usually expressed in watts per square meter. 44 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Seven-day, 10-year low flow (7Q10) is the discharge below which the annual 7-day minimum flow falls in 1 year out of 10 on the long-term average. The recurrence interval of the 7Q10 is 10 years; the chance that the annual 7-day minimum flow will be less than the 7Q10 is 10 percent in any given year. (See also “Annual 7-day minimum” and “Recurrence interval”) Shelves, as used in this report, are streambank features extending nearly horizontally from the flood plain to the lower limit of persistent woody vegetation. 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. Sodium hazard in water is an index that can be used to evaluate the suitability of water for irrigating crops. Soil heat flux (often used interchangeably with soil heat-flux density) is the amount of heat energy that moves by conduction across a specified cross-sectional area of soil per unit time and goes to heating (or cooling) the soil. Usually expressed in watts per square meter. Soil-water content is the water lost from the soil upon drying to constant mass at 105 qC; expressed either as mass of water per unit mass of dry soil or as the volume of water per unit bulk volume of soil. Specific electrical conductance (conductivity) is a measure of the capacity of water (or other media) to conduct an electrical current. It is expressed in microsiemens per centimeter at 25 qC. Specific electrical conductance is a function of the types and quantity of dissolved substances in water and can be used for approximating the dissolved-solids content of the water. Commonly, the concentration of dissolved solids (in milligrams per liter) is from 55 to 75percent of the specific conductance (in microsiemens). 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. Stable isotope ratio (per MIL) is a unit expressing the ratio of the abundance of two radioactive isotopes. Isotope ratios are used in hydrologic studies to determine the age or source of specific water, to evaluate mixing of different water, as an aid in determining reaction rates, and other chemical or hydrologic processes. Stage (See “Gage height”) Stage-discharge relation is the relation between the water-surface elevation, termed stage (gage height), and the volume of water flowing in a channel per unit time. 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. Substrate embeddedness class is a visual estimate of riffle streambed substrate larger than gravel that is surrounded or covered by fine sediment (<2 mm, sand or finer). Below are the class categories expressed as the percentage covered by fine sediment: 0 no gravel or larger substrate 3 26-50 percent 1 > 75 percent 4 5-25 percent 2 51-75 percent 5 < 5 percent Surface area of a lake is that area (acres) encompassed by the boundary of the lake as shown on USGS topographic maps, or other available maps or photographs. Because surface area changes with lake stage, surface areas listed in this report represent those determined for the stage at the time the maps or photographs were obtained. Surficial bed material is the upper surface (0.1 to 0.2 foot) of the bed material that is sampled using U.S. Series Bed-Material Samplers. 45 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Surrogate is an analyte that behaves similarly to a target analyte, but that is highly unlikely to occur in a sample. A surrogate is added to a sample in known amounts before extraction and is measured with the same laboratory procedures used to measure the target analyte. Its purpose is to monitor method performance for an individual sample. Suspended (as used in tables of chemical analyses) refers to the amount (concentration) of undissolved material in a water- sediment mixture. It is defined operationally as the material retained on a 0.45-micrometer filter. Suspended, recoverable is the amount of a given constituent that is in solution after the part of a representative suspended water-sediment sample that is retained on a 0.45-micrometer 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 95percent) 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 directly analyzing the suspended mate-rial collected on the filter or, more commonly, by difference, on the basis of determinations of (1) dissolved and (2) total recoverable concentrations of the constituent. (See also “Suspended”) Suspended sediment is the sediment maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. (See also “Sediment”) Suspended-sediment concentration is the velocity-weighted concentration of suspended sediment in the sampled zone (from the water surface to a point approximately 0.3 foot above the bed) expressed as milligrams of dry sediment per liter of water- sediment mixture (mg/L). The analytical technique uses the mass of all of the sediment and the net weight of the water- sediment mixture in a sample to compute the suspended-sediment concentration. (See also “Sediment” and “Suspended sediment”) Suspended-sediment discharge (tons/d) is the rate of sediment transport, as measured by dry mass or volume, that passes a cross section in a given time. It is calculated in units of tons per day as follows: concentration (mg/L) x discharge (ft3/s) x 0.0027. (See also “Sediment,” “Suspended sediment,” and “Suspended-sediment concentration”) Suspended-sediment load is a general term that refers to a given characteristic of the material in suspension that passes a point during a specified period of time. The term needs to be qualified, such as “annual suspended-sediment load” or “sand- size suspended-sediment load,” and so on. It is not synonymous with either suspended-sediment discharge or concentration. (See also “Sediment”) Suspended solids, total residue at 105 °C concentration is the concentration of inorganic and organic material retained on a filter, expressed as milligrams of dry material per liter of water (mg/L). An aliquot of the sample is used for this analysis. Suspended, total is the total amount of a given constituent in the part of a water-sediment sample that is retained on a 0.45- micrometer membrane filter. This term is used only when the analytical procedure assures measurement of at least 95 percent of the constituent determined. 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 directly analyzing portions of the suspended material collected on the filter or, more commonly, by difference, on the basis of determinations of (1) dissolved and (2) total concentrations of the constituent. (See also “Suspended”) Synoptic studies are short-term investigations of specific water-quality conditions during selected seasonal or hydro-logic periods to provide improved spatial resolution for critical water-quality conditions. For the period and conditions sampled, they assess the spatial distribution of selected water-quality conditions in relation to causative factors, such as land use and contaminant sources. Taxa (Species) richness is the number of species (taxa) present in a defined area or sampling unit. 46 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Taxonomy is the division of biology concerned with the classification and naming of organisms. The classification of organisms is based upon a hierarchial scheme beginning with Kingdom and ending with Species at the base. The higher the classification level, the fewer features the organisms have in common. For example, the taxonomy of a particular mayfly, Hexagenia limbata, is the following: Kingdom: Animal Phylum: Arthropeda Class: Insecta Order: Ephemeroptera Family: Ephemeridae Genus: Hexagenia Species: Hexagenia limbata Thalweg is the line formed by connecting points of minimum streambed elevation (deepest part of the channel). Thermograph is an instrument that continuously records variations of temperature on a chart. The more general term “temperature recorder” is used in the table descriptions and refers to any instrument that records temperature whether on a chart, a tape, or any other medium. Time-weighted average is computed by multiplying the number of days in the sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the total number of days. A time-weighted average represents the composition of water resulting from the mixing of flow proportionally to the duration of the concentration. Tons per acre-foot (T/acre-ft) is the dry mass (tons) of a constituent per unit volume (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, tons/d) is a common chemical or sediment discharge unit. It is the quantity of a substance in solution, in suspension, or as bedload that passes a stream section during a 24-hour period. It is equivalent to 2,000 pounds per day, or 0.9072 metric ton per day. Total is the amount of a given constituent in a representative whole-water (unfiltered) 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 at least 95 percent of the constituent in the sample.) Total coliform bacteria are a particular group of bacteria that are used as indicators of possible sewage pollution. This group includes coliforms that inhabit the intestine of warmblooded animals and those that inhabit soils. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod-shaped bacteria that ferment lactose with gas formation within 48hours at 35 qC. In the laboratory, these bacteria are defined as all the organisms that produce colonies with a golden-green metallic sheen within 24 hours when incubated at 35 qC plus or minus 1.0 qC on M-Endo medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 milliliters of sample. (See also “Bacteria”) Total discharge is the quantity of a given constituent, measured as dry mass or volume, that passes a stream cross section per unit of time. When referring to constituents other than water, this term needs to be qualified, such as “total sediment discharge,” “total chloride discharge,” and so on. Total in bottom material is the amount of a given constituent in a representative sample of bottom material. 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 judge when the results should be reported as “total in bottom material.” 47 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Total length (fish) is the straight-line distance from the anterior point of a fish specimen’s snout, with the mouth closed, to the posterior end of the caudal (tail) fin, with the lobes of the caudal fin squeezed together. Total load refers to all of a constituent in transport. When referring to sediment, it includes suspended load plus bed load. Total organism count is the number of organisms collected and enumerated in any particular sample. (See also “Organism count/volume”) Total recoverable is the amount of a given constituent in a whole-water sample after a 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 for whole-water samples, equivalent digestion procedures are required of all laboratories performing such analyses because different digestion procedures may produce different analytical results. Total sediment discharge is the mass of suspended-sediment plus bed-load transport, measured as dry weight, that passes a cross section in a given time. It is a rate and is reported as tons per day. (See also “Bedload,” “Bedload discharge,” “Sediment,” “Suspended sediment,” and “Suspended-sediment concentration”) Total sediment load or total load is the sediment in transport as bedload and suspended-sediment load. The term may be qualified, such as “annual suspended-sediment load” or “sand-size suspended-sediment load,” and so on. It differs from total sediment discharge in that load refers to the material, whereas discharge refers to the quantity of material, expressed in units of mass per unit time. (See also “Sediment,” “Suspended-sediment load,” and “Total load”) Transect, as used in this report, is a line across a stream perpendicular to the flow and along which measurements are taken, so that morphological and flow characteristics along the line are described from bank to bank. Unlike a cross section, no attempt is made to determine known elevation points along the line. Turbidity is the reduction in the transparency of a solution because of the presence of suspended and some dissolved substances. The measurement technique records the collective optical properties of the solution that cause light to be scattered and attenuated rather than transmitted in straight lines; the higher the intensity of scattered or attenuated light, t he higher the value of the turbidity. Turbidity is expressed in nephelometric turbidity units (NTU). Depending on the method used, the turbidity units as NTU can be defined as the intensity of light of a specified wavelength scattered or attenuated by suspended particles or absorbed at a method specified angle, usually 90 degrees, from the path of the incident light. Currently approved methods for the measurement of turbidity in the USGS include those that conform to USEPA Method 180.1, ASTM D1889-00, and ISO 7027. Measurements of turbidity by these different methods and different instruments are unlikely to yield equivalent values. Ultraviolet (UV) absorbance (absorption) at 254 or 280nanometers is a measure of the aggregate concentration of the mixture of UV absorbing organic materials dissolved in the analyzed water, such as lignin, tannin, humic substances, and various aromatic compounds. UV absorbance (absorption) at 254 or 280 nanometers is measured in UV absorption units per centimeter of path length of UV light through a sample. Unconfined aquifer is an aquifer whose upper surface is a water table free to fluctuate under atmospheric pressure. (See “Water-table aquifer”) Vertical datum (See “Datum”) Volatile organic compounds (VOCs) are organic compounds that can be isolated from the water phase of a sample by purging the water sample with inert gas, such as helium, and, subsequently, analyzed by gas chromatography. Many VOCs are human-made chemicals that are used and produced in the manufacture of paints, adhesives, petroleum products, pharmaceuticals, and refrigerants. They often are components of fuels, solvents, hydraulic fluids, paint thinners, and dry- cleaning agents commonly used in urban settings. VOC contamination of drinking-water supplies is a human-health concern because many are toxic and are known or suspected human carcinogens. Water table is that surface in a ground-water body at which the water pressure is equal to the atmospheric pressure. 48 WATER RESOURCES DATA—PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 2003 Water-table aquifer is an unconfined aquifer within which the water table is found. Water year in USGS reports dealing with surface-water supply is the 12-month period October 1 through September30. The water year is designated by the calendar year in which it ends and which includes 9 of the 12months. Thus, the year ending September 30, 2002, is called the “2002 water year.” Watershed (See “Drainage basin”) 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. Wet mass is the mass of living matter plus contained water. (See also “Biomass” and “Dry mass”) Wet weight refers to the weight of animal tissue or other substance including its contained water. (See also “Dry weight”) WSP is used as an acronym for “Water-Supply Paper” in reference to previously published reports. Zooplankton is the animal part of the plankton. Zooplankton are capable of extensive movements within the water column and often are large enough to be seen with the unaided eye. Zooplankton are secondary consumers feeding upon bacteria, phytoplankton, and detritus. Because they are the grazers in the aquatic environment, the zooplankton are a vital part of the aquatic food web. The zooplankton community is dominated by small crustaceans and rotifers. (See also “Plankton”) 49 TECHNIQUES OF WATER-RESOURCES INVESTIGATIONS OF THE U.S. GEOLOGICAL SURVEY The USGS publishes a series of manuals, the Techniques of Water-Resources Investigations, 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. Reports in the Techniques of Water-Resources Investigations series, which are listed below, are online at http:/ /water.usgs.gov/pubs/twri/. Printed copies are for sale by the USGS, Information Services, Box 25286, Federal Center, Denver, Colorado 80225 (authorized agent of the Superintendent of Documents, Government Printing Office), telephone 1-888-ASK-USGS. Please telephone 1-888-ASK-USGS for current prices, and refer to the title, book number, chapter number, and mention the “U.S. Geological Survey Techniques of Water-Resources Investigations.” Products can then be ordered by telephone, or online at http://www.usgs.gov/sales.html, or by FAX to (303)236-469 of an order form available online at http://mac.usgs.gov/isb/pubs/forms/. Prepayment by major credit card or by a check or money order payable to the “U.S. Geological Survey” is required. Book 1. Collection of Water Data by Direct Measurement Section D. Water Quality 1-D1. Water temperature—influential factors, field measurement, and data presentation, by H.H.Stevens, Jr., J.F. Ficke, and G.F. Smoot: USGS–TWRI book 1, chap. D1. 1975. 65p. 1-D2. Guidelines for collection and field analysis of ground-water samples for selected unstable constituents, by W.W. Wood: USGS– TWRI book 1, chap. D2. 1976. 24 p. Book 2. Collection of Environmental Data Section D. Surface Geophysical Methods 2-D1. Application of surface geophysics to ground-water investigations, by A.A. R. Zohdy, G.P. Eaton, and D.R. Mabey: USGS–TWRI book 2, chap. D1. 1974. 116 p. 2-D2. Application of seismic-refraction techniques to hydrologic studies, by F.P. Haeni: USGS–TWRI book 2, chap. D2. 1988. 86 p. Section E. Subsurface Geophysical Methods 2-E1. Application of borehole geophysics to water-resources investigations, by W.S. Keys and L.M.MacCary: USGS–TWRI book 2, chap. E1. 1971. 126 p. 2-E2. Borehole geophysics applied to ground-water investigations, by W.S. Keys: USGS–TWRI book 2, chap. E2. 1990. 150 p. Section F. Drilling and Sampling Methods 2-F1. Application of drilling, coring, and sampling techniques to test holes and wells, by Eugene Shuter and W.E. Teasdale: USGS– TWRI book 2, chap. F1. 1989. 97 p. Book 3. Applications of Hydraulics Section A. Surface-Water Techniques 3-A1. General field and office procedures for indirect discharge measurements, by M.A. Benson and Tate Dalrymple: USGS–TWRI book 3, chap. A1. 1967. 30 p. 3-A2. Measurement of peak discharge by the slope-area method, by Tate Dalrymple and M.A. Benson: USGS–TWRI book 3, chap. A2. 1967. 12 p. 3-A3. Measurement of peak discharge at culverts by indirect methods, by G.L. Bodhaine: USGS–TWRI book 3, chap. A3. 1968. 60 p. 3-A4. Measurement of peak discharge at width contractions by indirect methods, by H.F. Matthai: USGS-TWRI book 3, chap. A4. 1967. 44 p. 3-A5. Measurement of peak discharge at dams by indirect methods, by Harry Hulsing: USGS–TWRI book 3. chap. A5. 1967. 29 p. 3-A6. General procedure for gaging streams, by R.W. Carter and Jacob Davidian: USGS–TWRI book 3, chap. A6. 1968. 13 p. 3-A7. Stage measurement at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A7. 1968. 28 p. 3-A8. Discharge measurements at gaging stations, by T.J. Buchanan and W.P. Somers: USGS–TWRI book 3, chap. A8. 1969. 65 p. 50 3-A9. Measurement of time of travel in streams by dye tracing, by F.A. Kilpatrick and J.F. Wilson, Jr.: USGS–TWRI book 3, chap. A9. 1989. 27 p. 3-Al0. Discharge ratings at gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A10. 1984. 59 p. 3-A11. Measurement of discharge by the moving-boat method, by G.F. Smoot and C.E. Novak: USGS–TWRI book 3, chap. A11. 1969. 22 p. 3-A12. Fluorometric procedures for dye tracing, Revised, by J.F. Wilson, Jr., E.D. Cobb, and F.A. Kilpatrick: USGS–TWRI book 3, chap. A12. 1986. 34 p. 3-A13. Computation of continuous records of streamflow, by E.J. Kennedy: USGS–TWRI book 3, chap. A13. 1983. 53 p. 3-A14. Use of flumes in measuring discharge, by F.A. Kilpatrick and V.R. Schneider: USGS–TWRI book 3, chap. A14. 1983. 46 p. 3-A15. Computation of water-surface profiles in open channels, by Jacob Davidian: USGS–TWRI book 3, chap. A15. 1984. 48 p. 3-A16. Measurement of discharge using tracers, by F.A. Kilpatrick and E.D. Cobb: USGS–TWRI book 3, chap. A16. 1985. 52 p. 3-A17. Acoustic velocity meter systems, by Antonius Laenen: USGS–TWRI book 3, chap. A17. 1985. 38 p. 3-A18. Determination of stream reaeration coefficients by use of tracers, by F.A. Kilpatrick, R.E.Rathbun, Nobuhiro Yotsukura, G.W.Parker, and L.L. DeLong: USGS–TWRI book 3, chap. A18. 1989. 52 p. 3-A19. Levels at streamflow gaging stations, by E.J. Kennedy: USGS–TWRI book 3, chap. A19. 1990. 31 p. 3-A20. Simulation of soluble waste transport and buildup in surface waters using tracers, by F.A. Kilpatrick: USGS–TWRI book 3, chap. A20. 1993. 38 p. 3-A21 Stream-gaging cableways, by C. Russell Wagner: USGS–TWRI book 3, chap. A21. 1995. 56 p. Section B. Ground-Water Techniques 3-B1. Aquifer-test design, observation, and data analysis, by R.W. Stallman: USGS–TWRI book 3, chap. B1. 1971. 26 p. 3-B2. Introduction to ground-water hydraulics, a programed text for self-instruction, by G.D. Bennett: USGS–TWRI book 3, chap. B2. 1976. 172 p. 3-B3. Type curves for selected problems of flow to wells in confined aquifers, by J.E. Reed: USGS–TWRI book 3, chap. B3. 1980. 106 p. 3-B4. Regression modeling of ground-water flow, by R.L. Cooley and R.L. Naff: USGS–TWRI book 3, chap. B4. 1990. 232 p. 3-B4. Supplement 1. Regression modeling of ground-water flow --Modifications to the computer code for nonlinear regression solution of steady-state ground-water flow problems, by R.L. Cooley: USGS–TWRI book 3, chap. B4. 1993. 8 p. 3-B5. Definition of boundary and initial conditions in the analysis of saturated ground-water flow systems—An introduction, by O.L.Franke, T.E. Reilly, and G.D. Bennett: USGS–TWRI book 3, chap. B5. 1987. 15 p. 3-B6. The principle of superposition and its application in ground-water hydraulics, by T.E. Reilly, O.L.Franke, and G.D.Bennett: USGS–TWRI book 3, chap. B6. 1987. 28 p. 3-B7. Analytical solutions for one-, two-, and three-dimensional solute transport in ground-water systems with uniform flow, by E.J. Wexler: USGS–TWRI book 3, chap. B7. 1992. 190 p. 3-B8. System and boundary conceptualization in ground-water flow simulation, by T.E. Reilly: USGS–TWRI book 3, chap. B8. 2001. 29 p. Section C. Sedimentation and Erosion Techniques 3-C1. Fluvial sediment concepts, by H.P. Guy: USGS–TWRI book 3, chap. C1. 1970. 55 p. 3-C2. Field methods for measurement of fluvial sediment, by T.K. Edwards and G.D. Glysson: USGS–TWRI book 3, chap. C2. 1999. 89 p. 3-C3. Computation of fluvial-sediment discharge, by George Porterfield: USGS–TWRI book 3, chap.C3. 1972. 66 p. Book 4. Hydrologic Analysis and Interpretation Section A. Statistical Analysis 4-A1. Some statistical tools in hydrology, by H.C. Riggs: USGS–TWRI book 4, chap. A1. 1968. 39p. 4-A2. Frequency curves, by H.C. Riggs: USGS–TWRI book 4, chap. A2. 1968. 15 p. 4–A3. Statistical methods in water resources, by D.R. Helsel and R.M. Hirsch: USGS–TWRI book 4, chap. A3. 1991. Available only online at http://water.usgs.gov/pubs/twri/twri4a3/. (Accessed August 30, 2002.) Section B. Surface Water 4-B1. Low-flow investigations, by H.C. Riggs: USGS–TWRI book 4, chap. B1. 1972. 18 p. 4-B2. Storage analyses for water supply, by H.C. Riggs and C.H. Hardison: USGS–TWRI book 4, chap. B2. 1973. 20 p. 4-B3. Regional analyses of streamflow characteristics, by H.C. Riggs: USGS–TWRI book 4, chap.B3. 1973. 15 p. 51 Section D. Interrelated Phases of the Hydrologic Cycle 4-D1. Computation of rate and volume of stream depletion by wells, by C.T. Jenkins: USGS–TWRI book4, chap. D1. 1970. 17 p. Book 5. Laboratory Analysis Section A. Water Analysis 5-A1. Methods for determination of inorganic substances in water and fluvial sediments, by M.J.Fishman and L.C. Friedman, editors: USGS–TWRI book 5, chap. A1. 1989. 545 p. 5-A2. Determination of minor elements in water by emission spectroscopy, by P.R. Barnett and E.C.Mallory, Jr.: USGS– TWRI book 5, chap. A2. 1971. 31 p. 5-A3. Methods for the determination of organic substances in water and fluvial sediments, edited by R.L. Wershaw, M.J.Fishman, R.R. Grabbe, and L.E. Lowe: USGS–TWRI book 5, chap. A3. 1987. 80 p. 5-A4. Methods for collection and analysis of aquatic biological and microbiological samples, by L.J.Britton and P.E. Greeson, editors: USGS–TWRI book 5, chap. A4. 1989. 363 p. 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, chap. A5. 1977. 95p. 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, chap. A6. 1982. 181p. Section C. Sediment Analysis 5-C1. Laboratory theory and methods for sediment analysis, by H.P. Guy: USGS–TWRI book 5, chap.C1. 1969. 58 p. Book 6. Modeling Techniques Section A. Ground Water 6-A1. A modular three-dimensional finite-difference ground-water flow model, by M.G. McDonald and A.W. Harbaugh: USGS–TWRI book 6, chap. A1. 1988. 586 p. 6-A2. Documentation of a computer program to simulate aquifer-system compaction using the modular finite-difference ground-water flow model, by S.A. Leake and D.E. Prudic: USGS–TWRI book 6, chap. A2. 1991. 68 p. 6-A3. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 1: Model Description and User’s Manual, by L.J. Torak: USGS–TWRI book 6, chap. A3. 1993. 136 p. 6-A4. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 2: Derivation of finite-element equations and comparisons with analytical solutions, by R.L. Cooley: USGS–TWRI book 6, chap. A4. 1992. 108 p. 6-A5. A modular finite-element model (MODFE) for areal and axisymmetric ground-water-flow problems, Part 3: Design philosophy and programming details, by L.J. Torak: USGS–TWRI book 6, chap. A5, 1993. 243 p. 6-A6. A coupled surface-water and ground-water flow model (MODBRANCH) for simulation of stream-aquifer interaction, by Eric D. Swain and Eliezer J. Wexler: USGS–TWRI book 6, chap. A5,1996. 125 p. 6–A7. User’s guide to SEAWAT: A computer program for simulation of three-dimensional variable-density ground-water flow, by Weixing Guo and Christian D. Langevin: USGS–TWRI book 6, chap. A7. 2002. 77 p. Book 7. Automated Data Processing and Computations Section C. Computer Programs 7-C1. Finite difference model for aquifer simulation in two dimensions with results of numerical experiments, by P.C. Trescott, G.F.Pinder, and S.P. Larson: USGS–TWRI book 7, chap. C1. 1976. 116 p. 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, chap. C2. 1978. 90 p. 7-C3. A model for simulation of flow in singular and interconnected channels, by R.W. Schaffranek, R.A.Baltzer, and D.E.Goldberg: USGS–TWRI book 7, chap. C3. 1981. 110 p. 52 Book 8. Instrumentation Section A. Instruments for Measurement of Water Level 8-A1. Methods of measuring water levels in deep wells, by M.S. Garber and F.C. Koopman: USGS–TWRI book 8, chap. A1. 1968. 23 p. 8-A2. Installation and service manual for U.S. Geological Survey manometers, by J.D. Craig: USGS–TWRI book 8, chap. A2. 1983. 57 p. Section B. Instruments for Measurement of Discharge 8-B2. Calibration and maintenance of vertical-axis type current meters, by G.F. Smoot and C.E. Novak: USGS–TWRI book 8, chap. B2. 1968. 15 p. Book 9. Handbooks for Water-Resources Investigations Section A. National Field Manual for the Collection of Water-Quality Data 9-A1. National Field Manual for the Collection of Water-Quality Data: Preparations for Water Sampling, by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A1. 1998. 47 p. 9-A2. National Field Manual for the Collection of Water-Quality Data: Selection of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A2. 1998. 94 p. 9-A3. National Field Manual for the Collection of Water-Quality Data: Cleaning of Equipment for Water Sampling, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A3. 1998. 75 p. 9-A4. National Field Manual for the Collection of Water-Quality Data: Collection of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A4. 1999. 156 p. 9-A5. National Field Manual for the Collection of Water-Quality Data: Processing of Water Samples, edited by F.D. Wilde, D.B. Radtke, Jacob Gibs, and R.T. Iwatsubo: USGS–TWRI book 9, chap. A5. 1999, 149 p. 9-A6. National Field Manual for the Collection of Water-Quality Data: Field Measurements, edited by F.D. Wilde and D.B. Radtke: USGS–TWRI book 9, chap. A6. 1998. Variously paginated. 9-A7. National Field Manual for the Collection of Water-Quality Data: Biological Indicators, edited by D.N. Myers and F.D. Wilde: USGS–TWRI book 9, chap. A7. 1997 and 1999. Variously paginated. 9-A8. National Field Manual for the Collection of Water-Quality Data: Bottom-material samples, by D.B. Radtke: USGS– TWRI book 9, chap. A8. 1998. 48 p. 9-A9. National Field Manual for the Collection of Water-Quality Data: Safety in Field Activities, by S.L. Lane and R.G. Fay: USGS–TWRI book 9, chap. A9. 1998. 60 p. 53 54 THIS PAGE IS INTENTIONALLY BLANK 55 Figure 10. Río Guajataca basin. 56 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q18'01", long 66q52'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anón and 0.4 mi (0.6 km) northeast of Lares Plaza. DRAINAGE AREA.--3.16 mi2 (8.18 km2). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 11... 1300 1.6 2.3 8.1 94 6.3 256 21.9 92 27.2 5.92 2.25 .5 MAR 19... 1330 .45 2.4 8.7 -- 7.9 256 23.8 97 27.8 6.58 3.93 .6 MAY 12... 1630 11 7.5 8.1 -- 7.7 224 24.5 84 25.9 4.76 2.75 .4 AUG 20... 1615 4.5 12 7.2 -- 7.5 254 26.3 -- -- -- -- -­ SEP 16... 1100 3.4 2.1 8.0 -- 7.6 258 24.0 100 32.4 5.67 2.63 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 11... 11.9 119 10.7 <.17 33.7 5.3 -- 168 .74 <10 .20 .03 1.74 MAR 19... 13.0 95 12.9 .09 30.5 11.1 .2 163 .20 <10 <.20 .01 -­ MAY 12... 9.35 59 9.51 <.17 24.4 9.2 .1 121 3.64 <10 <.20 <.01 -­ AUG 20... -- 92 -- -- -- -- -- -- -- <10 .30 .11 1.49 SEP 16... 10.2 101 11.0 <.2 26.6 8.8 -- 158 -- <10 <.20 <.01 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 11... 1.80 .06 .17 .06 2.0 8.9 <10 2,000 880 -- -- -- -­ MAR 19... .800 <.01 -- .04 -- -- <10 200 -- 5,300 E1 17.8 E17 MAY 12... 1.70 <.01 -- .03 -- -- <10 640 -- 6,300 E2 23.2 29 AUG 20... 1.50 .01 .19 .03 1.8 8.0 10 E14,000 -- 57,000 -- -- -­ SEP 16... 1.40 <.01 -- .04 -- -- <10 300 -- 30,000 -- -- -­ 57 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 11... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 19... <.2 <.8 <10 <.01 40 <1 11.9 <.02 <3 <.3 <25 <.10 <16 MAY 12... <.2 <.8 <10 <.01 220 <1 21.6 <.02 <3 <.3 <25 <.10 <16 AUG 20... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 16... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 58 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR LOCATION.--Lat 18q24'02", long 66q55'25", Hydrologic Unit 21010002, on right bank, in a concrete intake tower at Damsite, 5.2 mi (8.4 km) southeast from Quebradillas Plaza, 0.5 mi (0.8 km) northeast from Iglesia San Antonio de Padua and 2.8 mi (4.5 km) from Escuela Segunda Unidad Baldorioty de Castro. DRAINAGE AREA.--24.6 mi2 (63.71 km2). ELEVATION RECORDS PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guajataca was completed in 1928. The dam is a semihydraulic earthfill structure about 123 ft (37 m) high, a top w idth of 31 ft (9.5 m) at crest elevation of 664 ft (202.5 m), a base width of 623 ft (190 m), a crest length of 1,036 ft (316 m) and has a maximum storage capacity of 49,200 acre- feet (60.6 hm3). The Guajataca Dam is owned by the Puerto Rico Electric Power Authority (PREPA) and provides water for the municipalities of Aguadilla, Isabela, Moca, Aguada, and Quebradillas although its primary purpose is for agricultural irrigation for the flatlands of the area. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-4044, January 1999. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 648.3 ft (197.60 m), September 23, 1998; minimum elevation, 608.07 ft (185.34 m) May 17, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 643.58 ft (196.16 m), November 16; minimum elevation, 629.19 ft (191.78 m), April 5. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4044, 1999) (Elevation in ft, capacity in acre-ft) Elevation Contents 557 0 577 916 597 5,253 Elevation Contents 616 13,393 636 26,332 646 34,277 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 639.22 642.87 643.03 639.88 636.54 633.95 629.48 637.36 640.93 638.44 634.63 635.97 2 639.16 642.53 642.69 639.77 636.44 633.81 629.40 637.28 640.95 638.32 634.48 635.90 3 640.27 642.04 642.63 639.63 636.36 633.66 629.33 637.20 640.90 638.32 634.36 635.87 4 640.94 641.90 642.62 639.51 636.59 633.52 629.24 637.25 640.82 638.19 634.33 635.80 5 641.19 641.85 642.59 639.39 636.93 633.36 629.73 637.37 641.06 638.06 634.20 635.77 6 641.22 641.78 642.52 639.26 636.95 633.21 629.95 637.35 641.05 637.92 634.05 635.68 7 641.29 641.71 642.43 639.13 636.86 633.05 629.88 637.28 640.99 637.79 633.95 635.63 8 641.70 641.63 642.35 639.05 636.75 632.92 629.77 637.21 640.92 637.68 633.80 635.55 9 642.08 641.56 642.27 638.93 636.62 632.76 629.82 637.19 640.83 637.54 633.67 635.74 10 641.94 641.71 642.17 638.80 636.50 632.61 629.73 637.15 640.73 637.41 633.51 635.66 11 641.96 641.70 642.07 638.66 636.38 632.45 629.62 637.36 640.64 637.28 633.49 636.12 12 642.06 641.76 641.97 638.53 636.25 632.29 629.48 637.40 640.54 637.15 633.54 636.58 13 641.80 642.13 641.87 638.40 636.12 632.13 629.36 637.90 640.42 637.02 633.42 637.21 14 641.66 642.91 641.76 638.27 636.01 631.97 629.56 638.14 640.30 636.88 633.36 637.53 15 642.08 643.56 641.66 638.13 635.88 631.82 629.82 638.34 640.19 636.76 633.30 637.51 16 641.76 643.49 641.55 637.99 635.75 631.65 629.80 638.43 640.08 636.62 633.20 637.45 17 641.48 642.96 641.44 637.86 635.61 631.49 629.77 639.43 639.97 636.55 633.07 637.44 18 641.56 642.32 641.33 637.73 635.48 631.25 630.87 640.13 639.99 636.45 632.94 637.40 19 641.54 641.94 641.23 637.59 635.34 631.09 631.22 640.60 639.97 636.33 633.64 637.32 20 641.53 641.92 641.13 637.45 635.21 630.92 631.28 641.32 639.87 636.17 633.85 637.24 21 641.73 641.92 641.02 637.32 635.08 630.74 632.55 641.70 639.77 636.04 633.78 637.25 22 641.87 641.88 640.91 637.21 634.95 630.56 633.08 641.74 639.66 635.91 633.67 637.16 23 641.96 641.81 640.93 637.09 634.82 630.37 633.18 641.69 639.53 635.76 634.27 637.09 24 641.95 641.74 640.82 637.01 634.68 630.21 634.84 641.58 639.41 635.62 634.71 637.06 25 641.90 641.67 640.71 637.02 634.54 630.04 635.91 641.44 639.29 635.47 635.22 637.16 26 641.89 642.30 640.60 637.11 634.40 629.90 636.95 641.28 639.16 635.32 635.49 637.23 27 641.83 642.53 640.48 637.05 634.25 629.93 637.38 641.15 639.02 635.22 635.63 637.15 28 641.75 642.59 640.36 636.94 634.10 629.93 637.44 641.07 638.87 635.11 635.68 637.06 29 641.67 642.54 640.24 636.81 629.86 637.42 641.00 638.71 634.96 635.64 636.94 30 641.60 643.02 640.12 636.71 629.74 637.41 640.92 638.58 634.81 635.71 636.83 31 642.37 640.00 636.61 629.59 640.84 634.66 635.96 MAX 642.37 643.56 643.03 639.88 636.95 633.95 637.44 641.74 641.06 638.44 635.96 637.53 MIN 639.16 641.56 640.00 636.61 634.10 629.59 629.24 637.15 638.58 634.66 632.94 635.55 59 RIO GUAJATACA BASIN 50010800 LAGO GUAJATACA AT DAMSITE NEAR QUEBRADILLAS, PR—Continued O N D J F M A M J J A S 628 630 632 634 636 638 640 642 644 ELEVATION, IN FEET 2002 2003 60 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q24'02", long 66q55'27", off Highway 476 at Lago Guajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 05... 1440 70 2.9 .8 10 6.5 305 25.4 150 53.0 3.28 1.96 .2 MAR 27... 0900 70 4.2 6.9 -- 8.0 296 26.7 130 46.3 3.49 1.90 .2 MAY 14... 0855 60 6.3 .2 -- 7.2 340 25.3 160 58.1 3.61 2.09 .2 AUG 26... 1235 70 7.8 1.4 -- 7.2 313 27.1 -- -- -- -- -­ SEP 18... 0855 70 4.1 1.4 -- 7.3 314 27.0 140 52.0 3.60 2.09 .2 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 05... 4.74 138 5.66 <.17 7.3 6.7 -- 165 48.2 <10 .50 .12 -­ MAR 27... 5.51 130 6.56 .12 6.7 7.5 <.1 156 45.5 <10 .30 .04 -­ MAY 14... 5.48 148 8.05 <.17 7.2 9.0 <.1 182 45.7 <10 .40 .12 -­ AUG 26... -- 137 -- -- -- -- -- -- -- <10 .60 .34 -­ SEP 18... 5.10 140 7.91 <.2 7.3 9.1 -- 171 49.9 <10 .50 .12 .05 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 05... <.020 <.01 .38 <.02 -- -- <10 E8 E4 -- -- -- -­ MAR 27... <.020 <.01 .26 <.02 -- -- <10 <1 -- E49 <2 3.3 <18 MAY 14... .280 <.01 .28 <.02 .68 3.0 10 E12 -- 45 E2 13.1 E12 AUG 26... <.020 <.01 .26 <.02 -- -- 10 100 -- E560 -- -- -­ SEP 18... .060 .01 .38 <.02 .56 2.5 10 E6 -- 44 -- -- -­ 61 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 05... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 27... <.2 <.8 <10 <.01 50 <1 22.9 <.02 <3 <.3 <25 <.10 <16 MAY 14... <.2 <.8 M <.01 40 <1 68.3 <.02 E1 <.3 E17 <.10 <16 AUG 26... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 18... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 62 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q28'31", long 66q57'46", Hydrologic Unit 21010002, on left bank at ford 1.7 mi (2.7 km) upstream from bridge on Highway 2, 1.6 mi (2.6 km) west of Quebradillas Plaza, 2.1 mi (3.4 km) upstream from Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago Guajatac a. DRAINAGE AREA.--Indeterminate PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 06... 0915 17 2.5 6.8 79 6.8 483 23.6 220 75.5 7.24 1.33 .4 MAR 26... 1430 7.3 4.4 8.4 -- 7.5 630 25.6 260 86.4 11.1 1.07 .7 MAY 15... 0845 12 1.8 8.9 -- 8.1 234 26.2 220 75.7 8.27 1.41 .6 AUG 26... 1050 26 5.5 6.3 -- 7.5 375 25.2 -- -- -- -- -­ SEP 18... 1050 12 2.3 5.9 -- 7.3 522 25.1 220 73.6 7.88 1.47 .5 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 06... 15.1 197 25.6 <.17 6.8 7.3 -- 257 11.7 <10 <.20 <.01 -­ MAR 26... 27.0 231 48.9 <.17 6.7 7.6 <.1 327 6.49 <10 <.20 .02 3.29 MAY 15... 20.6 89 37.1 <.17 6.1 8.2 <.1 211 6.71 <10 <.20 .02 -­ AUG 26... -- 154 -- -- -- -- -- -- -- <10 <.20 .02 -­ SEP 18... 18.0 201 36.5 <.2 6.7 8.2 -- 273 8.90 <10 <.20 .08 -­ Nitrite Fecal Fecal Total Chrom­ + COD, coli- strep- coli- Barium, Boron, ium, Copper, nitrate Nitrite Phos- high form, tococci form, water, water, water, water, water water, phorus, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd unfltrd unfltrd unfltrd water, water, 0.7u MF MF, immed, water recover recover water, recover recover mg/L mg/L unfltrd unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, -able, Date as N as N mg/L mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L ug/L (00630) (00615) (00665) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) (01042) DEC 06... 2.00 <.01 <.02 <10 76 E167 -- -- -- -- -- -- -­ MAR 26... 3.30 .01 <.02 <10 E130 -- 4,700 <2 8.1 36 <.2 1.3 <10 MAY 15... 2.10 <.01 <.02 <10 E13 -- 450 <2 10.0 21 <.2 E.7 M AUG 26... .820 <.01 <.02 <10 54 -- E10,600 -- -- -- -- -- -­ SEP 18... 2.10 <.01 <.02 <10 50 -- E1,800 -- -- -- -- -- -­ 63 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, Selen- water, water, com- Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 06... -- -- -- -- -- -- -- -- -- -- MAR 26... <.01 60 <1 15.5 <.02 <3 <.3 <25 <.10 <16 MAY 15... <.01 40 <1 9.0 <.02 <3 <.3 <25 <.10 <16 AUG 26... -- -- -- -- -- -- -- -- -- -- SEP 18... -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 64 THIS PAGE IS INTENTIONALLY BLANK Río Camuy basin. 65 Figure 11. Figure 11. Río Camuy basin. 66 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR LOCATION.--Lat 18q23'48", long 66q49'04", Hydrologic Unit 21010002, on left bank at Highway 488, 1.4 mi (2.2 km) southeast of school at Santiago, 0.9 mi (1.4 km) northwest from Escuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upstream from mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--May 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 341 ft (104 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 87 297 84 49 2 112 221 72 49 3 113 141 69 49 4 208 93 68 48 5 206 82 74 47 e43 32 e38 75 81 41 e41 e112 e43 32 75 67 85 e43 e38 e74 e41 31 47 60 80 e47 37 e68 e61 31 45 60 73 e42 e69 e71 e71 30 88 130 70 41 e77 e60 6 108 76 69 46 7 155 76 64 46 8 189 69 63 e45 9 169 67 63 e45 10 147 84 61 45 e62 30 123 138 70 42 49 e52 45 30 63 78 67 40 46 e49 41 30 42 85 62 40 43 e65 39 31 38 98 60 40 35 60 38 30 35 188 59 38 33 50 11 116 74 59 e44 12 92 79 58 43 13 108 483 57 43 14 138 493 58 42 15 181 309 56 42 37 30 34 168 58 37 e32 e79 37 30 35 172 57 e35 e43 e80 37 30 56 124 55 e35 e34 e100 38 29 78 123 54 e34 e34 e173 37 29 136 136 52 e34 67 73 16 159 227 55 41 17 108 171 55 42 18 89 121 57 40 19 82 105 e53 39 20 76 96 53 38 36 29 62 147 52 34 e55 63 35 28 45 219 51 32 44 54 35 28 175 241 53 32 36 52 34 32 174 201 71 38 66 e49 35 37 95 388 55 33 119 e52 21 224 94 51 38 22 144 87 52 e38 23 119 82 137 42 24 118 79 101 e39 25 88 77 69 e71 36 33 306 280 51 33 e69 e63 34 30 266 193 49 e33 e46 88 33 29 145 159 47 32 e46 85 33 29 359 131 45 32 e147 96 33 29 419 112 45 e31 e163 117 26 91 87 58 e108 27 85 90 55 e71 28 74 75 52 e54 29 69 73 51 e45 30 67 72 e50 e43 31 94 --- e49 e42 33 29 262 100 45 e41 e137 236 34 35 162 95 45 36 e78 174 32 40 106 87 43 45 e72 125 --- e41 88 82 45 42 e64 80 --- e47 80 77 42 35 e57 69 --- e33 --- 74 --- 35 e171 --­ TOTAL 3,816 4,180 1,973 1,474 MEAN 123 139 63.6 47.5 MAX 224 493 137 108 MIN 67 67 49 38 1,113 984 3,677 4,288 1,722 1,153 2,048 2,569 39.8 31.7 123 138 57.4 37.2 66.1 85.6 71 47 419 388 85 47 171 236 32 28 34 60 42 31 32 49 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 2003, BY WATER YEAR (WY) MEAN 197 138 76.1 58.4 MAX 427 310 179 163 (WY) (1986) (2002) (2000) (1997) MIN 81.6 53.4 30.2 33.1 (WY) (1988) (1998) (2001) (1991) 49.8 47.0 94.7 165 112 72.6 95.6 183 96.4 93.7 289 624 322 109 187 726 (1996) (1999) (2002) (1986) (1999) (1989) (1998) (1998) 29.1 23.7 28.0 43.2 42.7 37.2 47.9 61.8 (1998) (1994) (1994) (1989) (1997) (2003) (1993) (1997) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1984 - 2003 ANNUAL TOTAL 40,431 ANNUAL MEAN 111 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 791 LOWEST DAILY MEAN 26 ANNUAL SEVEN-DAY MINIMUM 27 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW 10 PERCENT EXCEEDS 221 50 PERCENT EXCEEDS 74 90 PERCENT EXCEEDS 40 28,997 79.4 107 179 1986 61.5 1994 Apr 8 493 Nov 14 9,010 Sep 22, 1998 Mar 23 28 Mar 17 16 Mar 18, 1994 Mar 20 29 Mar 12 17 Mar 16, 1994 5,440 Nov 13 11,600 Sep 22, 1998 16.76 Nov 13 21.69 Sep 22, 1998 27 Mar 16 15 Mar 22, 1994 159 209 58 67 33 33 e Estimated 67 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR—Continued O N D J F M A M J J A S 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 68 THIS PAGE IS INTENTIONALLY BLANK 69 Figure 12. Río Grande de Arecibo basin. 70 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR LOCATION.--Lat 18q08'20", long 66q44'29", Hydrologic Unit 21010002, in power gate tower of Garzas Dam on Río Vacas, 1.7 mi (2.7 km) upstream from Río Garzas, and 2.2 mi (3.5 km) southwest of Adjuntas. DRAINAGE AREA.--15.6 mi2 (40.4 km2). PERIOD OF RECORD.--January 1988 to May 1989, March 1993 to current year. GAGE.--Water-stage recorder. Datum of gage is 2,400.00 ft (731.52 m) above mean sea level. Prior to May 25, 1988, at datum 2,376 .80 ft (724.45 m), May 25 to July 13, 1988, at datum 2,338.08 ft (712.65 m), July 14, 1988, to May 25, 1989, at datum 2,337.82 ft (712.56 m), above mean sea level. REMARKS.--Lake is formed by earthfill dam completed in 1943. Outflow from lake controlled by vertical-lift sluice gate and fixed -crest concrete spillway. Spillway elevation, 2,415.00 ft (736.09 m).Lake is used for irrigation and power production. Operated by Puerto Rico Electric Po wer Authorithy. Gage- height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4143, September 1996. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,418.28 ft (737.09 m), September 22, 1998; minimum elevation, 2,364.79 ft (720.79 m), August 23, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,416.68 ft (736.60 m), October 10; minimum elevation, 2,412.17 ft (735.23 m), June 26. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4143, 1996) (Elevation in ft, capacity in acre-ft) Elevation Contents 2,317 0 2,336 243 2,359 794 Elevation Contents 2,376 1,419 2,399 2,700 2,415 4,143 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2,415.71 A 2,415.33 2,414.95 2,414.73 2,414.43 2,414.94 2,414.96 2,414.97 2,414.26 2,414.86 2,415.03 2 2,415.72 A 2,415.32 2,414.97 2,415.12 2,414.53 2,414.73 2,414.96 2,414.97 2,414.35 2,414.86 2,414.99 3 2,415.67 A 2,415.28 2,414.94 2,415.01 2,414.64 2,415.05 2,414.96 2,414.94 2,414.43 2,414.86 2,414.89 4 2,415.78 A 2,415.27 2,414.94 2,415.00 2,414.76 2,414.93 2,414.95 2,414.93 2,414.49 2,414.86 2,414.88 5 2,415.64 A 2,415.22 2,414.94 2,415.01 2,414.86 2,414.97 2,414.98 2,415.01 2,414.71 2,414.85 2,414.87 6 2,415.63 A 2,415.15 2,414.94 2,415.00 2,414.91 2,414.91 2,414.96 2,414.95 2,414.80 2,414.92 2,414.98 7 2,415.60 2,416.01 2,415.12 2,414.96 2,414.99 2,414.66 2,414.55 2,415.03 2,414.94 2,414.85 2,414.88 2,415.13 8 2,415.66 2,415.99 2,415.12 2,414.96 2,414.97 2,414.80 2,414.71 2,415.06 2,414.94 2,414.90 2,414.86 2,415.01 9 2,415.61 2,416.08 2,415.06 2,414.96 2,414.97 2,414.89 2,414.88 2,414.99 2,414.94 2,414.84 2,414.86 2,414.98 10 2,415.63 2,415.99 2,415.04 2,415.02 2,414.98 2,414.81 2,414.91 2,414.98 2,414.95 2,414.87 2,414.85 2,415.10 11 2,415.55 2,415.96 2,415.02 2,414.95 2,414.98 2,414.77 2,414.65 2,414.98 2,414.91 2,414.88 2,414.86 2,415.08 12 2,415.52 2,416.04 2,414.98 2,414.94 2,414.97 2,414.73 2,414.80 2,414.98 2,414.93 2,414.89 2,414.85 2,415.23 13 2,415.48 2,416.01 2,414.96 2,414.94 2,414.97 2,414.82 2,414.87 2,414.96 2,414.96 2,414.91 2,414.95 2,415.06 14 2,415.01 2,415.88 2,414.96 2,414.95 2,414.62 A 2,414.91 2,414.97 2,414.96 2,414.90 2,414.90 2,415.05 15 2,415.35 2,415.82 2,414.96 2,414.96 2,414.75 2,414.87 2,414.91 2,414.97 2,414.96 2,414.91 2,414.87 2,415.11 16 2,415.42 2,415.78 2,414.96 2,414.96 2,414.88 A 2,414.95 2,415.00 2,414.94 2,414.94 2,414.87 2,415.04 17 2,415.31 2,415.76 2,415.12 2,414.95 2,414.93 A 2,415.02 2,415.01 2,414.94 2,414.90 2,414.89 2,415.04 18 2,415.37 2,415.78 2,414.97 2,414.94 2,414.95 A 2,415.11 2,414.94 2,414.95 2,414.89 2,414.90 2,415.14 19 2,415.34 2,415.71 2,414.96 2,414.93 2,414.96 2,414.70 2,415.02 2,414.96 2,414.94 2,414.89 2,414.89 2,415.13 20 2,415.31 2,415.66 2,414.94 2,414.92 2,414.95 2,414.80 2,415.02 2,414.97 2,414.92 2,414.90 2,414.89 2,415.06 21 2,415.26 2,415.83 2,414.93 2,414.97 2,414.41 2,414.75 2,414.99 2,415.09 2,414.92 2,414.88 2,414.84 2,415.09 22 2,415.22 2,415.64 2,415.01 2,414.90 2,414.56 2,414.81 2,415.04 2,415.00 2,414.92 2,414.88 2,414.86 2,415.03 23 2,415.20 2,415.61 2,414.96 2,415.01 2,414.64 2,414.79 2,414.94 2,414.97 2,414.78 2,414.88 2,414.90 2,415.02 24 2,415.17 2,415.58 2,414.95 2,415.05 2,414.78 2,414.68 2,415.00 2,414.95 2,414.85 2,414.87 2,414.93 2,415.03 25 2,415.14 2,415.18 2,414.95 2,415.06 2,414.91 2,414.67 2,414.76 2,414.94 2,413.07 2,414.88 2,414.97 2,415.04 26 2,415.12 2,415.53 2,414.94 2,415.00 2,414.93 2,414.93 2,414.97 2,414.94 2,413.81 2,414.97 2,415.01 2,415.01 27 2,415.08 2,415.47 2,414.93 2,414.98 2,414.94 2,414.93 2,414.97 2,414.94 2,413.90 2,414.95 2,414.96 2,415.01 28 2,415.06 2,415.44 2,414.92 2,414.98 2,414.32 2,414.91 2,414.95 2,414.96 2,413.99 2,414.97 2,415.03 2,414.97 29 2,415.07 2,415.41 2,414.93 2,414.98 --- 2,414.91 2,414.94 2,414.97 2,414.06 2,414.90 2,415.04 2,415.05 30 A 2,415.36 2,414.94 2,414.98 --- 2,414.88 2,414.96 2,414.78 2,414.15 2,414.88 2,414.95 2,415.01 31 A --- 2,414.93 2,414.58 --- 2,414.90 --- 2,414.93 --- 2,414.87 2,414.95 --­ MAX --- --- 2,415.33 2,415.06 2,415.12 --- 2,415.11 2,415.09 2,415.01 2,414.97 2,415.04 2,415.23 MIN --- --- 2,414.92 2,414.58 2,414.32 --- 2,414.55 2,414.78 2,413.07 2,414.26 2,414.84 2,414.87 A No gage-height record 71 RIO GRANDE DE ARECIBO BASIN 50020100 LAGO GARZAS NEAR ADJUNTAS, PR—Continued O N D J F M A M J J A S 2,413.0 2,413.5 2,414.0 2,414.5 2,415.0 2,415.5 2,416.0 2,416.5 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 72 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR LOCATION.--Lat 18q10'54", long 66q44'12", Hydrologic Unit 21010002, at Highway 135 bridge junction with Highway 10, 1.4 mi (2.2 km) south from Lago Adjuntas and 1.5 mi (2.4 km) northwest of Adjuntas Plaza. DRAINAGE AREA.--12.7 mi2 (32.9 km2), this does not include 6.0 mi2 (15.6 km2) above Lago Garzas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1946 to April 1950 (operated by Puerto Rico Water Resources Authority), March 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,443 ft (440 m), from topographic map. REMARKS.--Records poor. Flow affected by Lago Garzas, 2.63 mi (4.23 km) and sewage treatment plant 1.1 mi (1.77 km) upstream fro m gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 59 34 37 11 11 18 32 25 8.2 8.5 105 2 27 44 34 41 294 11 19 32 27 8.6 7.7 59 3 31 126 34 40 200 11 262 29 22 7.5 7.8 79 4 184 53 42 33 62 10 54 28 17 6.9 7.5 18 5 64 38 37 31 228 11 152 30 179 14 6.8 12 6 35 34 31 31 74 14 35 32 63 8.5 10 11 7 33 32 27 31 45 16 18 58 31 7.6 13 209 8 91 30 47 31 34 11 11 68 27 9.7 9.0 61 9 176 110 33 31 29 11 14 51 26 12 7.3 24 10 312 65 27 43 27 15 16 32 25 10 6.8 200 11 114 40 28 40 28 11 19 28 25 12 8.4 282 12 78 185 e29 28 27 9.9 14 27 21 12 7.1 525 13 55 283 e27 26 26 9.2 13 26 26 15 70 226 14 38 91 e26 25 22 11 15 35 25 15 30 70 15 16 50 e26 26 13 13 17 28 25 15 20 344 16 46 113 e424 26 13 14 35 114 24 75 14 134 17 38 50 e203 26 19 13 171 62 23 24 17 64 18 142 83 139 22 22 11 580 46 21 15 17 289 19 137 75 53 22 24 11 220 25 23 13 16 346 20 151 52 44 21 24 9.7 115 30 20 11 12 162 21 92 82 38 23 22 10 86 395 18 13 11 214 22 54 e42 420 20 13 9.3 108 164 18 11 10 102 23 51 e38 107 30 12 10 75 55 15 10 8.5 67 24 45 e34 61 35 12 10 84 33 9.4 9.4 9.8 57 25 40 e25 51 110 12 11 52 27 11 12 15 59 26 38 31 48 63 18 11 29 24 9.8 13 62 54 27 35 42 43 31 22 26 42 22 8.4 23 30 42 28 34 38 38 25 19 29 40 21 8.2 21 60 36 29 126 45 36 25 19 33 23 8.4 21 124 70 30 52 38 37 24 18 32 19 8.4 12 47 54 31 60 35 20 12 12 9.7 23 TOTAL 2,406 2,028 2,259 1,017 1,352 399.1 2,379 1,608 789.6 455.1 696.2 3,975 MEAN 77.6 67.6 72.9 32.8 48.3 12.9 79.3 51.9 26.3 14.7 22.5 132 MAX 312 283 424 110 294 29 580 395 179 75 124 525 MIN 11 25 26 20 11 9.2 11 12 8.2 6.9 6.8 11 AC-FT 4,770 4,020 4,480 2,020 2,680 792 4,720 3,190 1,570 903 1,380 7,880 CFSM 6.11 5.32 5.74 2.58 3.80 1.01 6.24 4.08 2.07 1.16 1.77 10.4 IN. 7.05 5.94 6.62 2.98 3.96 1.17 6.97 4.71 2.31 1.33 2.04 11.64 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1947 - 2003, BY WATER YEAR (WY) MEAN 77.4 55.0 41.8 23.6 27.7 15.1 34.3 39.0 27.0 25.6 44.9 91.6 MAX 119 75.2 72.9 32.8 56.9 21.6 95.1 72.2 36.0 49.3 94.5 132 (WY) (2001) (2001) (2003) (2003) (1950) (1949) (2002) (2001) (2000) (1949) (2000) (2003) MIN 48.6 27.3 30.8 19.7 14.8 10.2 10.4 12.2 14.7 14.7 22.5 55.8 (WY) (2002) (1950) (1947) (1948) (2002) (2001) (1948) (1948) (2001) (2003) (2003) (1947) 73 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1947 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 16,601.7 ANNUAL MEAN 45.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 424 LOWEST DAILY MEAN 8.6 ANNUAL SEVEN-DAY MINIMUM 8.9 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 32,930 ANNUAL RUNOFF (CFSM) 3.58 ANNUAL RUNOFF (INCHES) 48.63 10 PERCENT EXCEEDS 94 50 PERCENT EXCEEDS 27 90 PERCENT EXCEEDS 11 19,364.0 53.1 43.2 53.1 2003 39.5 2002 Dec 16 580 Apr 18 1,510 Aug 23, 2000 Jul 25 6.8 Aug 5 6.8 Mar 31, 2001 Mar 22 8.0 Jun 28 7.1 Mar 27, 2001 4,740 Sep 12 12,000 May 6, 2001 11.21 Sep 12 15.49 May 6, 2001 38,410 31,330 4.18 3.41 56.72 46.27 125 90 28 25 10 11 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 74 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued LOCATION.--Lat 18q10'54", long 66q44'12", at Highway 135 bridge, 1.0 mi (1.6 km) upstream from Lago Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas Plaza. DRAINAGE AREA.--12.7 mi2 (32.9 km2) this does not include 6.0 mi2 (15.5 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 10... 0845 26 2.4 8.3 96 6.7 247 19.9 91 24.2 7.56 1.48 .5 MAR 24... 1415 9.8 16 9.4 -- 8.7 359 26.6 -- -- -- -- -­ MAY 20... 1215 25 1.5 8.5 -- 8.2 249 25.7 96 25.5 7.81 1.54 .6 AUG 20... 0815 12 2.5 7.7 -- 7.6 294 23.4 -- -- -- -- -­ SEP 15... 1620 -- 44 7.5 -- 7.6 177 25.0 70 19.1 5.47 1.61 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 10... 11.3 89 12.5 <.17 26.1 5.5 -- 142 -- <10 .20 <.01 -­ MAR 24... -- 114 -- -- -- -- <.1 -- -- -- .20 .03 .81 MAY 20... 12.9 93 14.3 <.2 26.8 6.1 <.1 151 10.4 <10 <.20 .03 .49 AUG 20... -- 110 -- -- -- -- -- -- -- <10 <.20 .02 .62 SEP 15... 6.89 71 7.96 <.2 20.8 6.2 -- 111 -- 11 .30 .02 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 10... .750 <.01 -- .06 .95 4.2 <10 460 294 -- -- -- -­ MAR 24... .820 .01 .17 .15 1.0 4.5 -- 120 -- 600 -- -- -­ MAY 20... .500 .01 -- .04 -- -- <10 E162 -- E800 <2 13.1 E13 AUG 20... .630 .01 -- .05 -- -- <10 150 -- 2,800 -- -- -­ SEP 15... .530 <.01 .28 .08 .83 3.7 10 4,800 -- E8,000 -- -- -­ 75 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 10... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 24... -- -- -- -- -- -- -- -- -- -- -- <.10 <16 MAY 20... <.2 <.8 <10 <.01 80 <1 16.9 <.02 <3 <.3 <25 <.10 E11 AUG 20... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 15... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- 76 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--March 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,390 mg/L April 23, 2002; Minimum daily mean, 1 mg/L several days during 2001, 2002 and 2003. SEDIMENT LOADS: Maximum daily mean, 14,400 tons (13,064 tonnes) May 6, 2001; Minimum daily mean, 0.03 ton (0.03 tonne) June 1, 2 , 2001 and March 5, 2003. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 741 mg/L November 12, 2002; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,450 tons (2,223 tonnes) September 12, 2003; Minimum daily mean, 0.03 ton (0.03 tonne) Marc h 5, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 11 5 0.15 59 152 51 34 12 1.1 2 27 25 2.4 44 28 3.3 34 10 0.94 3 31 57 4.9 126 294 455 34 8 0.76 4 184 517 821 53 26 4.2 42 6 0.64 5 64 88 23 38 35 3.7 37 4 0.35 6 35 53 5.0 34 58 5.3 31 3 0.23 7 33 52 4.6 32 79 6.8 27 2 0.17 8 91 147 104 30 83 6.7 47 16 3.6 9 176 384 509 110 282 269 33 18 1.6 10 312 737 1,910 65 50 10 27 15 1.1 11 114 147 56 40 28 3.0 28 11 0.80 12 78 54 11 185 741 1,760 e29 e7 e0.48 13 55 36 5.3 283 665 1,540 e27 e6 e0.47 14 38 18 2.0 91 150 45 e26 e7 e0.50 15 16 7 0.27 50 48 6.5 e26 e5 e0.36 16 46 18 2.4 113 258 366 e424 e350 e1,640 17 38 11 1.4 50 46 6.2 e203 e281 e1,160 18 142 371 477 83 59 27 139 55 41 19 137 236 182 75 45 19 53 11 1.6 20 151 258 268 52 12 1.7 44 7 0.88 21 92 34 13 82 71 48 38 6 0.58 22 54 14 2.1 e42 e50 e19 420 352 1,650 23 51 14 1.9 e38 e19 e2.4 107 11 4.7 24 45 9 1.1 e34 e18 e2.1 61 3 0.42 25 40 6 0.70 e25 e17 e1.6 51 2 0.25 26 38 7 0.71 31 15 1.3 48 1 0.17 27 35 7 0.70 42 14 1.6 43 4 0.49 28 34 8 0.72 38 15 1.5 38 9 0.90 29 126 282 407 45 22 3.3 36 11 1.1 30 52 33 5.0 38 13 1.4 37 8 0.81 31 60 149 76 35 7 0.68 TOTAL 2,406 4,898.35 2,028 4,671.6 2,259 4,516.68 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 77 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 37 6 0.62 11 4 0.12 11 4 0.11 2 41 5 0.56 294 463 1,670 11 3 0.09 3 40 4 0.46 200 425 495 11 2 0.07 4 33 5 0.40 62 65 11 10 2 0.04 5 31 5 0.43 228 652 1,300 11 1 0.03 6 31 6 0.52 74 268 55 14 1 0.04 7 31 11 0.94 45 210 25 16 1 0.06 8 31 18 1.5 34 152 14 11 2 0.04 9 31 17 1.4 29 94 7.5 11 2 0.05 10 43 19 2.4 27 36 2.7 15 2 0.07 11 40 15 1.8 28 12 0.88 11 2 0.06 12 28 10 0.72 27 12 0.86 9.9 4 0.11 13 26 7 0.50 26 11 0.81 9.2 6 0.16 14 25 5 0.33 22 11 0.68 11 8 0.24 15 26 6 0.42 13 11 0.39 13 8 0.30 16 26 8 0.59 13 11 0.39 14 8 0.29 17 26 9 0.60 19 11 0.53 13 7 0.26 18 22 8 0.49 22 10 0.63 11 10 0.29 19 22 8 0.45 24 10 0.65 11 14 0.41 20 21 7 0.39 24 10 0.64 9.7 15 0.39 21 23 7 0.44 22 9 0.56 10 15 0.40 22 20 7 0.38 13 9 0.30 9.3 15 0.37 23 30 17 2.2 12 8 0.25 10 14 0.39 24 35 12 1.2 12 7 0.23 10 14 0.38 25 110 120 49 12 6 0.21 11 21 0.78 26 63 33 8.9 18 6 0.28 11 16 0.46 27 31 7 0.55 22 5 0.30 26 13 0.89 28 25 5 0.37 19 4 0.23 29 17 2.2 29 25 8 0.52 19 10 0.51 30 24 8 0.52 18 9 0.44 31 20 4 0.22 12 9 0.29 TOTAL 1,017 79.82 1,352 3,589.14 399.1 10.22 APRIL MAY JUNE 1 18 8 0.38 32 11 1.0 25 11 1.1 2 19 8 0.41 32 4 0.35 27 8 0.62 3 262 151 402 29 9 0.67 22 7 0.43 4 54 16 3.0 28 15 1.1 17 6 0.29 5 152 181 251 30 22 1.7 179 242 661 6 35 24 2.4 32 22 1.9 63 28 8.7 7 18 17 0.83 58 33 8.4 31 5 0.45 8 11 14 0.39 68 33 7.2 27 6 0.41 9 14 11 0.39 51 28 4.3 26 6 0.45 10 16 8 0.35 32 23 2.0 25 13 0.85 11 19 8 0.40 28 23 1.8 25 20 1.4 12 14 8 0.31 27 22 1.6 21 27 1.6 13 13 8 0.27 26 22 1.5 26 30 2.2 14 15 8 0.32 35 22 2.2 25 33 2.2 15 17 8 0.37 28 17 1.3 25 33 2.2 16 35 19 2.3 114 203 275 24 32 2.1 17 171 85 92 62 33 9.1 23 32 2.0 18 580 323 1,100 46 10 2.0 21 32 1.9 19 220 133 94 25 4 0.27 23 33 2.0 20 115 24 8.9 30 3 0.26 20 34 1.8 21 86 16 3.8 395 389 968 18 34 1.7 22 108 17 5.9 164 29 17 18 34 1.6 23 75 10 2.4 55 7 1.0 15 34 1.4 24 84 26 10 33 6 0.58 9.4 34 0.86 25 52 37 5.4 27 6 0.44 11 35 1.0 26 29 31 2.4 24 6 0.38 9.8 36 0.94 27 42 27 3.1 22 6 0.36 8.4 36 0.81 28 40 24 2.6 21 6 0.34 8.2 35 0.78 29 33 25 2.2 23 6 0.37 8.4 35 0.79 30 32 21 1.8 19 6 0.31 8.4 34 0.78 31 12 6 0.19 TOTAL 2,379 1,999.62 1,608 1,312.62 789.6 704.36 --- --- --- --- --- --- 78 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 8.2 35 0.77 8.5 16 0.38 105 178 164 2 8.6 43 1.0 7.7 16 0.34 59 42 8.4 3 7.5 54 1.1 7.8 16 0.33 79 125 127 4 6.9 64 1.2 7.5 15 0.31 18 25 1.2 5 14 90 4.2 6.8 24 0.43 12 21 0.66 6 8.5 89 2.0 10 30 0.85 11 16 0.46 7 7.6 87 1.8 13 29 1.0 209 219 362 8 9.7 79 2.0 9.0 28 0.69 61 48 7.7 9 12 68 2.2 7.3 27 0.53 24 37 2.5 10 10 67 1.8 6.8 26 0.48 200 201 284 11 12 69 2.2 8.4 36 0.92 282 239 530 12 12 72 2.3 7.1 35 0.67 525 470 2,450 13 15 74 3.0 70 252 220 226 161 145 14 15 77 3.1 30 26 2.3 70 20 4.1 15 15 79 3.2 20 22 1.2 344 285 536 16 75 203 107 14 21 0.78 134 35 16 17 24 63 4.2 17 21 1.0 64 13 2.2 18 15 61 2.4 17 21 0.99 289 273 739 19 13 59 2.1 16 21 0.87 346 323 703 20 11 58 1.8 12 21 0.69 162 52 32 21 13 56 1.9 11 21 0.63 214 83 132 22 11 55 1.6 10 20 0.55 102 17 4.9 23 10 53 1.4 8.5 20 0.47 67 10 1.9 24 9.4 43 1.1 9.8 20 0.53 57 10 1.5 25 12 30 0.99 15 20 0.82 59 25 4.1 26 13 19 0.65 62 24 4.6 54 46 6.7 27 23 18 1.1 30 21 1.6 42 66 7.4 28 21 18 1.0 60 34 9.4 36 69 6.7 29 21 18 0.98 124 41 26 70 74 15 30 12 17 0.54 47 17 2.2 54 66 9.5 31 9.7 17 0.44 23 13 0.82 TOTAL 455.1 161.07 696.2 282.38 3,975 6,304.92 YEAR 19,364.0 28,530.78 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) NOV 03... 1810 1,100 97 2,920 8,670 JUN 05... 2221 280 98 656 496 JUL 16... 1656 195 100 616 324 SEP 10... 1721 971 98 1,360 3,570 -- -- -- -- -- RIO GRANDE DE ARECIBO BASIN 79 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) NOV 12... 1900 1,800 36 48 62 74 88 92 98 99 100 100 9,100 SEP 11... 1500 1,520 90 95 99 100 100 2,380 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) NOV 12... 44,300 SEP 11... 9,790 --- --- --- --- --- --- --- 80 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR LOCATION.--Lat 18q12'17',long 66q42'13", Hydrologic Unit 21010002, 0.2 mi (0.3 km) southeast from Escuela Lucas Valdivieso, 3.0 mi (4.8 km) north from Adjuntas Hospital and 2.0 mi (3.2 km) west from Lago Adjuntas. DRAINAGE AREA.--2.99 mi2 (7.74 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,148 ft (350 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Adjuntas with tunnel system outflow about 0.4 mi (0.6 km) upstream gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e18 28 45 33 e20 24 19 14 13 13 e19 20 2 e19 21 45 34 e80 23 20 14 13 13 e19 20 3 e19 19 44 35 e60 23 23 14 11 13 e20 43 4 e18 18 45 34 e40 23 19 14 10 13 e19 23 5 e18 18 44 33 54 22 32 15 26 13 e18 21 6 18 18 44 32 35 21 20 15 14 13 e19 20 7 e18 18 43 32 31 21 17 15 9.6 12 e20 29 8 e29 18 44 32 30 22 16 16 9.2 12 e19 25 9 e21 24 44 33 30 22 16 15 11 12 e18 22 10 e25 21 43 33 29 22 15 14 9.3 21 e17 22 11 e13 19 42 34 29 21 16 14 9.2 21 e21 58 12 e13 27 42 33 29 21 17 14 9.0 18 e18 75 13 13 20 42 33 28 20 18 14 9.2 18 e25 34 14 17 14 42 33 28 14 16 14 9.0 19 e20 23 15 15 11 41 33 29 15 15 14 8.8 19 21 60 16 14 16 41 32 28 16 16 14 8.6 22 22 29 17 14 13 101 33 28 16 24 15 9.1 19 22 44 18 18 11 47 32 28 16 70 16 9.8 19 22 61 19 15 14 41 32 28 17 20 14 12 21 23 67 20 25 13 40 31 29 16 13 23 9.8 21 22 66 21 37 11 40 29 29 17 15 46 9.5 20 21 109 22 19 10 63 29 28 17 18 70 9.4 18 21 70 23 17 10 19 30 28 17 17 22 22 18 18 66 24 17 9.9 15 32 24 17 17 16 18 19 16 58 25 17 9.5 15 40 21 17 16 14 15 20 17 62 26 17 32 23 38 22 19 17 13 13 20 22 58 27 16 57 39 32 23 25 17 13 13 20 19 50 28 16 46 37 e27 24 22 16 12 13 21 19 48 29 18 45 35 e27 21 16 12 13 20 22 48 30 19 46 34 e26 20 15 12 13 20 21 59 31 21 34 e25 19 11 20 21 TOTAL 574 637.4 1,274 992 892 606 586 539 359.5 548 621 1,390 MEAN 18.5 21.2 41.1 32.0 31.9 19.5 19.5 17.4 12.0 17.7 20.0 46.3 MAX 37 57 101 40 80 25 70 70 26 22 25 109 MIN 13 9.5 15 25 20 14 13 11 8.6 12 16 20 AC-FT 1,140 1,260 2,530 1,970 1,770 1,200 1,160 1,070 713 1,090 1,230 2,760 CFSM 2.71 3.11 6.02 4.69 4.66 2.86 2.86 2.55 1.75 2.59 2.93 6.78 IN. 3.13 3.47 6.94 5.40 4.86 3.30 3.19 2.94 1.96 2.98 3.38 7.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 32.3 27.5 30.3 24.8 24.2 20.5 25.1 25.2 29.8 26.5 24.6 36.5 MAX 63.2 39.5 41.1 32.0 31.9 23.2 37.1 34.6 57.2 36.7 33.7 49.0 (WY) (2001) (2001) (2003) (2003) (2003) (2002) (2002) (2001) (2000) (2000) (2000) (2000) MIN 15.2 21.2 19.5 12.0 18.1 18.9 18.6 17.4 12.0 17.7 20.0 24.9 (WY) (2002) (2003) (2002) (2002) (2002) (2001) (2001) (2003) (2003) (2003) (2003) (2001) 81 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 8,734.3 ANNUAL MEAN 23.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 101 LOWEST DAILY MEAN 9.5 ANNUAL SEVEN-DAY MINIMUM 9.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 17,320 ANNUAL RUNOFF (CFSM) 3.50 ANNUAL RUNOFF (INCHES) 47.57 10 PERCENT EXCEEDS 40 50 PERCENT EXCEEDS 22 90 PERCENT EXCEEDS 12 9,018.9 24.7 25.6 30.3 2001 21.8 2002 Dec 17 109 Sep 21 232 May 6, 2001 Nov 25 8.6 Jun 16 8.6 Jun 16, 2003 Feb 4 9.0 Jun 11 9.0 Jun 11, 2003 1,480 May 22 2,290 May 6, 2001 8.37 May 22 9.42 May 6, 2001 17,890 18,560 3.62 3.75 49.12 50.97 44 40 20 22 13 13 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 82 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--May 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,170 mg/L September 21, 2003; Minimum daily mean, 2.0 mg/L several days during Water Years 2002 and 2003. SEDIMENT LOADS: Maximum daily mean, 2,810 tons (2,549 tonnes) May 6, 2001; Minimum daily mean, 0.05 ton (0.04 tonne) June 8, 200 3. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,170 mg/L September 21, 2003; Minimum daily mean, 2.0 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 1,440 tons (1,306 tonnes) May 22, 2003; Minimum daily mean, 0.05 ton (0.04 tonne) June 8, 20 03. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean concen- Load discharge tration (tons/ Day (cfs) (mg/l) day) Mean Mean Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 e18 e40 e1.9 28 2 e19 e40 e2.1 21 3 e19 e40 e2.1 19 4 e18 e40 e2.0 18 5 e18 e40 e2.0 18 91 10 45 104 13 59 3.3 45 104 13 58 3.0 44 104 12 58 2.8 45 104 13 58 2.9 44 103 12 6 18 40 1.9 7 e18 e40 e2.0 8 e29 e106 e16 9 e21 e43 e2.5 10 e25 e64 e6.7 18 58 2.8 44 103 12 18 57 2.7 43 103 12 18 57 2.7 44 103 12 24 84 6.8 44 103 12 21 41 2.3 43 103 12 11 e13 e15 e0.59 12 e13 e13 e0.45 13 13 13 0.44 14 17 26 1.4 15 15 19 0.77 19 36 1.8 42 103 12 27 109 17 42 103 12 20 41 3.1 42 103 12 14 16 0.65 42 103 12 11 9 0.25 41 102 11 16 14 17 0.66 17 14 15 0.57 18 18 32 2.3 19 15 50 2.1 20 25 173 36 16 25 1.7 41 102 11 13 11 0.38 101 867 633 11 8 0.25 47 141 20 14 18 1.0 41 104 12 13 15 0.62 40 103 11 21 37 333 147 22 19 52 2.8 23 17 19 0.84 24 17 24 1.1 25 17 29 1.3 11 6 0.18 40 103 11 10 7 0.19 63 372 259 10 7 0.19 19 11 0.59 9.9 6 0.17 15 15 0.60 9.5 6 0.16 15 20 0.76 26 17 33 1.5 27 16 37 1.6 28 16 40 1.8 29 18 43 2.0 30 19 45 2.3 31 21 67 5.8 32 198 53 23 24 1.5 57 291 48 39 28 3.0 46 121 15 37 32 3.2 45 104 13 35 36 3.4 46 104 13 34 39 3.6 --- --- --- 34 40 3.6 TOTAL 574 --- 252.52 637.4 --- 208.94 1,274 --- 1,159.25 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 83 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 33 39 3.5 e20 e26 e1.5 24 31 2.0 2 34 39 3.6 e80 e668 e609 23 29 1.8 3 35 38 3.6 e60 e512 e131 23 25 1.6 4 34 39 3.6 e40 e255 e30 23 23 1.4 5 33 40 3.6 54 671 286 22 24 1.4 6 32 40 3.5 35 45 4.5 21 21 1.2 7 32 41 3.5 31 13 1.1 21 17 0.96 8 32 42 3.7 30 13 1.1 22 13 0.76 9 33 43 3.8 30 14 1.1 22 14 0.81 10 33 44 4.0 29 14 1.1 22 16 0.91 11 34 46 4.2 29 15 1.1 21 18 1.0 12 33 48 4.3 29 11 0.84 21 19 1.1 13 33 49 4.4 28 6 0.49 20 21 1.1 14 33 45 4.0 28 7 0.52 14 23 0.87 15 33 39 3.4 29 9 0.70 15 25 0.98 16 32 33 2.9 28 11 0.86 16 26 1.1 17 33 32 2.8 28 13 0.99 16 28 1.2 18 32 32 2.8 28 15 1.1 16 29 1.2 19 32 32 2.7 28 17 1.3 17 24 1.1 20 31 32 2.6 29 18 1.4 16 23 1.0 21 29 32 2.5 29 20 1.5 17 23 1.0 22 29 32 2.5 28 21 1.6 17 24 1.1 23 30 32 2.6 28 23 1.7 17 25 1.1 24 32 32 2.7 24 25 1.6 17 25 1.1 25 40 72 8.5 21 26 1.5 17 26 1.2 26 38 92 11 22 28 1.7 19 26 1.3 27 32 24 2.1 23 30 1.9 25 25 1.7 28 e27 e22 e1.7 24 30 2.0 22 25 1.5 29 e27 e22 e1.7 21 24 1.4 30 e26 e22 e1.7 20 23 1.2 31 e25 e25 e1.6 19 23 1.2 TOTAL 992 109.1 892 1,089.20 606 37.29 APRIL MAY JUNE 1 19 22 1.2 14 9 0.35 13 7 0.24 2 20 21 1.1 14 9 0.37 13 7 0.26 3 23 45 3.5 14 10 0.39 11 8 0.22 4 19 22 1.1 14 10 0.39 10 8 0.23 5 32 177 44 15 10 0.39 26 280 106 6 20 19 1.1 15 10 0.40 14 21 0.94 7 17 18 0.80 15 11 0.44 9.6 2 0.06 8 16 17 0.77 16 12 0.50 9.2 2 0.05 9 16 14 0.61 15 13 0.51 11 3 0.08 10 15 11 0.47 14 14 0.53 9.3 4 0.09 11 16 12 0.51 14 14 0.53 9.2 4 0.11 12 17 12 0.56 14 13 0.50 9.0 5 0.13 13 18 12 0.57 14 13 0.48 9.2 6 0.15 14 16 12 0.48 14 12 0.46 9.0 7 0.17 15 15 11 0.47 14 10 0.38 8.8 7 0.16 16 16 11 0.49 14 7 0.28 8.6 6 0.14 17 24 53 5.2 15 5 0.21 9.1 6 0.14 18 70 642 424 16 5 0.20 9.8 5 0.13 19 20 18 1.2 14 4 0.17 12 5 0.16 20 13 12 0.43 23 72 11 9.8 5 0.13 21 15 13 0.54 46 554 194 9.5 5 0.13 22 18 15 0.73 70 1,020 1,440 9.4 5 0.13 23 17 16 0.72 22 44 2.8 22 59 8.7 24 17 16 0.71 16 11 0.48 18 25 1.2 25 16 15 0.67 14 5 0.20 15 25 1.0 26 17 15 0.69 13 6 0.20 13 24 0.89 27 17 13 0.59 13 6 0.21 13 24 0.83 28 16 11 0.47 12 6 0.19 13 24 0.83 29 16 9 0.36 12 6 0.19 13 24 0.81 30 15 8 0.34 12 6 0.19 13 23 0.80 31 11 6 0.19 TOTAL 586 494.38 539 1,657.13 359.5 124.91 --- --- --- --- --- --- 84 RIO GRANDE DE ARECIBO BASIN 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 13 23 0.80 e19 e50 e2.6 20 64 3.5 2 13 23 0.81 e19 e46 e2.4 20 82 4.5 3 13 23 0.80 e20 e41 e2.2 43 713 261 4 13 23 0.80 e19 e33 e1.8 23 26 1.7 5 13 24 0.82 e18 e33 e1.7 21 23 1.3 6 13 32 1.1 e19 e32 e1.6 20 21 1.2 7 12 40 1.3 e20 e30 e1.6 29 89 11 8 12 49 1.6 e19 e29 e1.6 25 42 2.8 9 12 57 1.9 e18 e29 e1.6 22 21 1.3 10 21 66 3.7 e17 e36 e1.9 22 21 1.2 11 21 74 4.1 e21 e45 e2.4 58 562 430 12 18 82 3.9 e18 e53 e2.8 75 668 609 13 18 86 4.3 e25 e62 e3.7 34 208 19 14 19 88 4.4 e20 e69 e4.1 23 200 12 15 19 91 4.6 21 57 3.3 60 512 131 16 22 93 5.5 22 40 2.4 29 318 25 17 19 95 5.0 22 38 2.2 44 255 30 18 19 97 4.9 22 39 2.3 61 241 40 19 21 88 5.1 23 39 2.4 67 241 44 20 21 75 4.3 22 40 2.4 66 242 43 21 20 62 3.4 21 41 2.4 109 1,170 1,100 22 18 49 2.4 21 40 2.2 70 435 82 23 18 37 1.8 18 39 1.9 66 348 62 24 19 31 1.5 16 38 1.6 58 267 42 25 20 29 1.6 17 36 1.7 62 231 44 26 20 38 2.1 22 35 2.1 58 64 10 27 20 50 2.7 19 34 1.8 50 57 7.7 28 21 59 3.3 19 34 1.7 48 55 7.1 29 20 32 1.8 22 33 2.0 48 54 7.0 30 20 33 1.8 21 34 1.9 59 54 8.5 31 20 49 2.6 21 46 2.6 TOTAL 548 84.73 621 68.9 1,390 3,042.8 YEAR 9,018.9 8,329.15 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) DEC 17... 1857 593 97 3,170 5,070 MAY 21... 1425 114 95 5,150 1,580 RIO GRANDE DE ARECIBO BASIN 85 50021030 RIO PELLEJAS ABOVE CENTRAL PELLEJAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) APR 18... 1335 672 36 49 59 65 86 92 98 99 100 100 5,830 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) APR 18... 10,600 --- --- --- --- --- --- --- 86 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR LOCATION.--Lat 18q14'39", long 66q43'20", Hydrologic Unit 21010001, 0.4 mi (0.6 km) southwest from Escuela Segunda Unidad Salto Arriba, 2.2 mi (3.5 km) southwest from Utuado Plaza, 1.1 mi (1.8 km) west from Escuela Arenas Abajo and 1.0 mi (1.7 km) northwest from Escuela Puente Blanco. DRAINAGE AREA.--36.0 mi2 (93.2 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1989 to May 1999, monthly measurements and peak flow above 5,000 ft 3/s (142 m3/s), June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 508 ft (155 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Flow regulated by Lago Adjuntas 2.55 mi (4.10 km). Gage height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 85 20 12 6.2 6.4 e11 22 25 4.2 4.2 26 2 18 50 19 14 146 4.6 17 21 39 4.9 3.6 33 3 25 105 18 14 209 4.3 149 19 31 4.7 3.9 65 4 102 77 21 14 65 e4.2 71 19 26 4.3 5.2 18 5 86 40 26 12 225 e4.0 91 19 128 4.8 4.2 6.6 6 28 39 19 9.3 94 4.1 44 23 91 7.2 4.2 4.5 7 36 35 17 8.2 30 4.1 18 21 32 4.6 5.5 102 8 43 34 16 8.3 22 4.1 11 46 28 4.6 5.3 71 9 151 70 25 8.9 16 4.0 9.0 48 28 6.9 3.9 14 10 270 84 16 9.4 13 4.0 13 24 30 5.9 3.6 76 11 117 48 15 13 12 3.9 15 23 27 6.6 4.1 255 12 72 239 15 12 12 3.8 13 22 24 3.7 3.9 474 13 57 368 15 9.9 13 3.8 11 21 27 3.8 19 256 14 49 167 15 8.8 12 3.7 9.9 22 28 3.8 23 71 15 25 79 14 8.0 7.8 3.7 11 27 26 3.8 13 297 16 35 116 14 7.6 5.9 3.7 18 100 25 26 5.6 123 17 49 70 310 7.3 5.5 5.3 77 69 24 22 4.1 59 18 110 75 146 7.0 5.3 6.3 502 68 32 8.2 3.8 171 19 128 76 29 6.7 5.2 6.5 176 29 27 5.6 4.0 227 20 139 74 21 6.0 5.2 7.5 72 92 24 4.2 3.7 111 21 131 49 16 5.6 6.3 5.6 73 412 21 3.7 3.5 228 22 65 108 293 5.9 6.1 5.4 74 336 20 3.6 3.8 83 23 60 53 e156 6.6 4.9 5.1 75 111 28 3.4 4.0 49 24 45 47 e57 7.9 4.4 4.7 54 55 8.7 3.2 4.2 37 25 40 41 41 66 4.3 5.0 177 40 5.0 3.2 3.8 128 26 37 29 35 73 4.4 7.1 49 34 4.5 3.5 12 48 27 34 e48 24 17 4.5 13 40 31 4.1 5.8 21 28 28 34 e23 19 9.5 5.0 24 34 30 3.9 11 9.9 20 29 99 22 17 8.1 e27 27 29 3.8 11 52 17 30 73 28 14 7.5 e16 25 29 3.9 6.3 41 28 31 55 13 7.0 e11 21 4.6 13 TOTAL 2,225 2,379 1,476 410.5 950.0 215.9 1,966.9 1,863 824.9 199.1 296.0 3,126.1 MEAN 71.8 79.3 47.6 13.2 33.9 6.96 65.6 60.1 27.5 6.42 9.55 104 MAX 270 368 310 73 225 27 502 412 128 26 52 474 MIN 12 22 13 5.6 4.3 3.7 9.0 19 3.8 3.2 3.5 4.5 AC-FT 4,410 4,720 2,930 814 1,880 428 3,900 3,700 1,640 395 587 6,200 CFSM 1.99 2.20 1.32 0.37 0.94 0.19 1.82 1.67 0.76 0.18 0.27 2.89 IN. 2.30 2.46 1.53 0.42 0.98 0.22 2.03 1.93 0.85 0.21 0.31 3.23 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1999 - 2003, BY WATER YEAR (WY) MEAN 139 130 57.7 18.5 15.3 7.12 67.2 78.0 44.1 21.6 64.4 139 MAX 239 220 75.2 30.5 33.9 10.3 173 102 90.2 31.5 135 224 (WY) (2001) (2000) (2002) (2002) (2003) (2002) (2002) (2001) (2000) (2000) (2000) (1999) MIN 71.5 79.3 43.4 8.38 6.06 4.55 9.58 50.3 10.2 6.42 9.55 70.6 (WY) (2002) (2003) (2001) (2001) (2001) (2001) (2000) (2002) (2001) (2003) (2003) (2002) 87 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1999 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 19,270.3 ANNUAL MEAN 52.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 556 LOWEST DAILY MEAN 4.3 ANNUAL SEVEN-DAY MINIMUM 4.3 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 38,220 ANNUAL RUNOFF (CFSM) 1.47 ANNUAL RUNOFF (INCHES) 19.91 10 PERCENT EXCEEDS 106 50 PERCENT EXCEEDS 29 90 PERCENT EXCEEDS 7.4 15,932.4 43.7 62.1 87.2 2000 43.7 2003 Apr 23 502 Apr 18 2,210 Aug 23, 2000 Mar 22 3.2 Jul 24 3.2 Jul 24, 2003 Mar 21 3.5 Jul 20 3.5 Jul 20, 2003 4,290 Sep 12 45,600 Sep 22, 1998 7.88 Sep 12 19.72 Sep 22, 1998 31,600 44,990 1.21 1.72 16.46 23.44 109 146 20 26 4.1 5.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 88 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--June 1999 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1999. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, e1,600 mg/L May 6, 2001; Minimum daily mean, 1 mg/L several days during water years 2001, 2002 and 2003. SEDIMENT LOADS: Maximum daily mean, e32,200 tons (e29,210 tonnes) May 6, 2001; Minimum daily mean,<0.01 ton (<0.01 tonne) July 2 4-26, 2003. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 946 mg/L September 21, 2003; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 3,600 tons (3,266 tonnes) September 12, 2003; Minimum daily mean, <0.01 ton (<0.01 tonne) Ju ly 24-26, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 12 4 0.12 85 84 24 20 8 0.45 2 18 5 0.23 50 32 4.5 19 5 0.26 3 25 4 0.30 105 91 95 18 3 0.13 4 102 107 148 77 78 21 21 3 0.17 5 86 95 38 40 21 2.4 26 4 0.29 6 28 9 0.72 39 24 2.6 19 9 0.44 7 36 15 2.2 35 13 1.3 17 21 0.92 8 43 26 11 34 13 1.2 16 18 0.75 9 151 174 114 70 58 40 25 13 0.89 10 270 396 870 84 86 26 16 8 0.36 11 117 132 49 48 27 3.9 15 5 0.19 12 72 71 14 239 346 994 15 2 0.09 13 57 51 8.0 368 504 972 15 2 0.08 14 49 40 5.5 167 245 137 15 3 0.10 15 25 8 0.53 79 70 15 14 3 0.13 16 35 11 1.5 116 123 81 14 4 0.16 17 49 16 2.6 70 66 13 310 544 2,590 18 110 98 107 75 66 19 146 182 144 19 128 125 66 76 33 8.9 29 27 2.2 20 139 145 92 74 44 13 21 9 0.55 21 131 96 49 49 13 1.7 16 4 0.18 22 65 61 11 108 92 36 293 624 2,010 23 60 55 11 53 44 6.3 e156 e172 e100 24 45 40 4.9 47 37 4.7 e57 e13 e2.5 25 40 39 4.2 41 29 3.2 41 5 0.51 26 37 38 3.8 29 23 2.2 35 5 0.51 27 34 37 3.4 e48 e52 e7.1 24 6 0.41 28 34 36 3.3 e23 e44 e2.7 19 7 0.36 29 99 106 96 22 43 2.5 17 8 0.36 30 73 75 17 28 12 0.92 14 9 0.35 31 55 51 8.6 13 11 0.38 TOTAL 2,225 1,742.90 2,379 2,542.12 1,476 4,857.72 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 89 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 12 11 0.36 6.2 12 0.21 6.4 7 0.12 2 14 11 0.41 146 468 969 4.6 8 0.10 3 14 10 0.41 209 388 329 4.3 6 0.06 4 14 8 0.30 65 71 18 e4.2 e3 e0.03 5 12 6 0.18 225 266 603 e4.0 e3 e0.04 6 9.3 3 0.08 94 214 61 4.1 5 0.05 7 8.2 1 0.03 30 89 7.5 4.1 6 0.07 8 8.3 1 0.03 22 43 2.5 4.1 8 0.09 9 8.9 2 0.04 16 33 1.4 4.0 10 0.11 10 9.4 2 0.05 13 24 0.83 4.0 11 0.12 11 13 3 0.09 12 20 0.67 3.9 11 0.11 12 12 3 0.10 12 19 0.60 3.8 9 0.09 13 9.9 4 0.10 13 17 0.60 3.8 7 0.07 14 8.8 4 0.08 12 14 0.48 3.7 5 0.06 15 8.0 3 0.07 7.8 11 0.24 3.7 5 0.05 16 7.6 3 0.05 5.9 8 0.13 3.7 4 0.04 17 7.3 2 0.05 5.5 5 0.07 5.3 4 0.06 18 7.0 6 0.11 5.3 4 0.06 6.3 5 0.08 19 6.7 10 0.18 5.2 5 0.07 6.5 6 0.10 20 6.0 14 0.22 5.2 6 0.08 7.5 6 0.13 21 5.6 15 0.22 6.3 5 0.09 5.6 7 0.10 22 5.9 15 0.25 6.1 5 0.08 5.4 6 0.09 23 6.6 16 0.28 4.9 4 0.05 5.1 5 0.08 24 7.9 16 0.34 4.4 4 0.05 4.7 5 0.06 25 66 59 13 4.3 5 0.06 5.0 4 0.06 26 73 72 23 4.4 5 0.06 7.1 5 0.11 27 17 12 0.55 4.5 6 0.07 13 7 0.27 28 9.5 17 0.43 5.0 6 0.09 24 14 1.1 29 8.1 16 0.35 e27 e18 e1.6 30 7.5 13 0.27 e16 e8 e0.35 31 7.0 13 0.24 e11 e7 e0.20 TOTAL 410.5 41.87 950.0 1,995.99 215.9 5.60 APRIL MAY JUNE 1 e11 e6 e0.16 22 3 0.20 25 4 0.29 2 17 4 0.19 21 4 0.22 39 4 0.39 3 149 152 267 19 5 0.23 31 4 0.32 4 71 72 25 19 5 0.26 26 5 0.32 5 91 102 74 19 6 0.30 128 401 846 6 44 46 7.0 23 6 0.35 91 392 144 7 18 13 0.68 21 5 0.31 32 163 14 8 11 10 0.30 46 25 5.1 28 80 6.1 9 9.0 8 0.19 48 26 5.0 28 11 0.78 10 13 5 0.19 24 9 0.59 30 4 0.35 11 15 2 0.08 23 13 0.80 27 5 0.33 12 13 3 0.11 22 16 0.97 24 5 0.30 13 11 5 0.16 21 19 1.1 27 5 0.36 14 9.9 7 0.20 22 22 1.3 28 4 0.33 15 11 9 0.29 27 25 1.8 26 4 0.26 16 18 10 0.46 100 121 85 25 3 0.21 17 77 74 47 69 68 16 24 3 0.17 18 502 628 1,880 68 64 14 32 19 2.7 19 176 286 157 29 23 1.9 27 4 0.26 20 72 49 10 92 110 59 24 3 0.20 21 73 68 15 412 738 2,680 21 3 0.15 22 74 61 18 336 493 985 20 2 0.13 23 75 70 17 111 54 22 28 12 2.1 24 54 39 8.8 55 17 2.5 8.7 4 0.12 25 177 221 318 40 8 0.91 5.0 2 0.03 26 49 32 6.9 34 6 0.56 4.5 3 0.04 27 40 3 0.33 31 5 0.43 4.1 5 0.05 28 34 2 0.21 30 5 0.40 3.9 6 0.06 29 27 2 0.17 29 5 0.39 3.8 8 0.08 30 25 3 0.20 29 5 0.40 3.9 10 0.10 31 21 5 0.28 TOTAL 1,966.9 2,854.62 1,863 3,887.30 824.9 1,020.53 --- --- --- --- --- --- 90 RIO GRANDE DE ARECIBO BASIN 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 4.2 11 0.13 4.2 1 0.01 26 22 6.2 2 4.9 8 0.11 3.6 1 0.01 33 31 3.8 3 4.7 4 0.06 3.9 2 0.02 65 70 36 4 4.3 1 0.02 5.2 2 0.03 18 15 1.2 5 4.8 2 0.02 4.2 2 0.02 6.6 7 0.12 6 7.2 2 0.05 4.2 1 0.01 4.5 7 0.09 7 4.6 4 0.05 5.5 1 0.02 102 136 195 8 4.6 7 0.09 5.3 2 0.02 71 83 30 9 6.9 10 0.19 3.9 3 0.03 14 12 0.49 10 5.9 13 0.21 3.6 3 0.03 76 61 60 11 6.6 13 0.23 4.1 4 0.04 255 364 680 12 3.7 11 0.11 3.9 2 0.03 474 662 3,600 13 3.8 9 0.09 19 16 4.1 256 788 570 14 3.8 7 0.07 23 9 0.91 71 419 88 15 3.8 5 0.05 13 4 0.13 297 218 209 16 26 23 6.3 5.6 6 0.09 123 123 44 17 22 17 1.3 4.1 8 0.08 59 56 9.0 18 8.2 4 0.09 3.8 6 0.06 171 175 290 19 5.6 3 0.04 4.0 5 0.05 227 193 207 20 4.2 2 0.03 3.7 3 0.03 111 146 49 21 3.7 2 0.02 3.5 2 0.02 228 946 1,620 22 3.6 2 0.02 3.8 3 0.03 83 352 89 23 3.4 1 0.01 4.0 4 0.04 49 133 18 24 3.2 1 <0.01 4.2 4 0.05 37 131 13 25 3.2 1 <0.01 3.8 5 0.05 128 537 681 26 3.5 1 <0.01 12 5 0.18 48 41 5.7 27 5.8 1 0.02 21 6 0.32 28 7 0.59 28 11 1 0.03 9.9 6 0.15 20 5 0.29 29 11 1 0.03 52 43 11 17 5 0.22 30 6.3 1 0.02 41 36 5.9 28 5 0.37 31 4.6 1 0.01 13 4 0.16 TOTAL 199.1 9.43 296.0 23.62 3,126.1 8,507.07 YEAR 15,932.4 27,488.77 e Estimated < Actual value is known to be less than the value shown WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) DEC 22... 1700 1,250 96 3,990 13,500 RIO GRANDE DE ARECIBO BASIN 91 50021700 RIO GRANDE DE ARECIBO ABOVE UTUADO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) DEC 17... 2030 2,250 35 49 60 76 85 91 96 98 99 99 5,190 JUN 05... 2049 374 14 17 20 25 36 44 54 63 78 89 13,600 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) DEC 17... 31,500 JUN 05... 13,800 --- --- --- --- --- --- --- 92 RIO GRANDE DE ARECIBO BASIN 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO, PR LOCATION.--Lat 18q11'21", long 66q40'20", Hydrologic Unit 21010001, 4.05 mi (6.52 km) east from Lago Adjuntas Dam, 2.90 mi (4.66 km) south of Lago Viví Dam, 3.80 mi (6.11 km) northeast from Adjuntas Plaza, 2.76 mi (4.44 km) northwest from Escuela de San Patricio. DRAINAGE AREA.--2.99 mi2 (7.74 km2). PERIOD OF RECORD.--December 2000 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,710 ft (521 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.9 9.2 e4.0 3.4 2.8 2.5 e3.2 2.8 8.4 2.0 e1.4 2.2 2 e5.7 4.9 e4.0 e3.4 26 2.5 3.7 2.8 e5.9 2.1 e1.3 2.0 3 4.4 4.9 e4.1 e3.2 23 2.5 26 2.8 4.5 1.9 e1.3 6.7 4 8.8 4.2 e5.0 3.2 6.3 2.4 4.1 2.7 4.0 1.9 e1.3 1.9 5 5.3 5.8 e4.0 3.2 16 2.4 41 2.8 21 2.2 e1.3 1.4 6 3.7 4.3 3.3 3.3 e7.6 2.4 6.4 2.8 5.2 1.9 e1.5 1.3 7 4.0 3.7 3.2 3.2 e4.3 2.3 3.5 3.4 3.4 1.7 e1.6 3.8 8 15 3.6 4.9 3.0 3.8 2.2 3.0 3.3 3.1 1.8 1.4 2.0 9 7.4 16 3.4 3.1 3.4 2.2 3.0 3.0 3.1 1.8 1.3 1.5 10 20 11 3.0 3.6 3.3 2.2 2.9 2.8 2.9 e1.7 1.2 1.5 11 6.3 5.7 3.0 3.2 3.2 2.1 3.3 3.0 2.8 e1.8 1.7 33 12 4.6 12 2.9 2.9 3.1 2.2 6.1 2.9 2.8 e1.8 1.4 11 13 4.2 8.3 2.9 2.9 3.0 2.2 3.9 2.8 2.7 e2.0 5.3 7.1 14 9.1 5.8 2.8 2.9 3.0 2.4 3.1 3.2 2.7 e1.9 2.0 4.5 15 9.3 5.3 2.8 2.8 2.9 2.6 2.8 3.4 2.6 e2.0 1.6 65 16 5.8 11 2.9 2.8 2.9 e2.8 3.2 3.2 2.6 e2.0 1.4 14 17 5.2 5.8 54 2.7 3.0 e2.8 22 7.9 2.5 e2.3 1.3 6.6 18 13 e10 8.8 2.9 2.9 e2.8 75 4.1 3.0 e1.7 1.5 6.3 19 5.3 e9.0 4.5 2.9 2.8 2.9 11 3.2 4.2 e1.6 1.4 37 20 11 e6.2 3.9 2.8 2.8 3.0 4.8 3.7 2.6 e1.5 1.3 8.0 21 35 e10 3.6 2.8 2.8 e2.7 3.6 26 2.4 e1.6 1.2 12 22 8.0 e5.0 35 2.8 2.7 2.8 5.7 60 2.3 e1.5 1.3 5.7 23 5.4 e4.5 9.9 5.1 2.7 e2.9 4.5 19 2.2 e1.5 1.2 4.8 24 4.6 e3.9 5.4 7.7 2.7 e2.8 7.4 12 2.1 e1.4 1.1 4.5 25 4.2 e3.5 4.4 17 2.6 3.6 6.2 11 2.1 e1.6 1.2 15 26 4.1 e3.6 4.4 8.3 2.7 6.5 4.0 11 2.0 e1.6 3.2 7.8 27 3.8 e5.1 4.0 3.7 2.8 4.2 3.4 6.8 2.0 e2.2 1.6 5.6 28 3.7 e4.6 3.7 3.1 2.6 3.6 3.2 5.3 1.9 e2.1 1.6 4.8 29 8.2 e5.4 3.6 2.9 e3.0 3.0 4.7 1.9 e2.1 1.6 4.5 30 4.3 e4.5 3.5 2.8 e2.8 2.9 5.1 1.8 e1.5 2.7 4.3 31 15 3.4 2.9 e2.6 5.0 e1.4 1.7 TOTAL 251.3 196.8 208.3 120.5 147.7 86.9 275.9 232.5 110.7 56.1 50.9 285.8 MEAN 8.11 6.56 6.72 3.89 5.28 2.80 9.20 7.50 3.69 1.81 1.64 9.53 MAX 35 16 54 17 26 6.5 75 60 21 2.3 5.3 65 MIN 3.7 3.5 2.8 2.7 2.6 2.1 2.8 2.7 1.8 1.4 1.1 1.3 AC-FT 498 390 413 239 293 172 547 461 220 111 101 567 CFSM 2.71 2.19 2.25 1.30 1.76 0.94 3.08 2.51 1.23 0.61 0.55 3.19 IN. 3.13 2.45 2.59 1.50 1.84 1.08 3.43 2.89 1.38 0.70 0.63 3.56 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 9.17 12.0 11.1 4.21 3.74 2.81 9.56 8.44 4.38 5.10 5.23 11.1 MAX 10.2 17.5 15.6 5.63 5.28 3.16 16.4 10.8 4.79 9.80 8.69 18.8 (WY) (2002) (2002) (2002) (2002) (2003) (2002) (2002) (2001) (2002) (2001) (2001) (2001) MIN 8.11 6.56 6.72 3.12 2.45 2.45 3.10 7.00 3.69 1.81 1.64 5.03 (WY) (2003) (2003) (2003) (2001) (2001) (2001) (2001) (2002) (2003) (2003) (2003) (2002) RIO CAMUY BASIN 93 50022810 RIO VIVI BELOW HACIENDA EL PROGRESO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2001 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 2,311.2 ANNUAL MEAN 6.33 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 69 LOWEST DAILY MEAN 2.1 ANNUAL SEVEN-DAY MINIMUM 2.1 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 4,580 ANNUAL RUNOFF (CFSM) 2.12 ANNUAL RUNOFF (INCHES) 28.75 10 PERCENT EXCEEDS 9.9 50 PERCENT EXCEEDS 4.4 90 PERCENT EXCEEDS 2.9 2,023.4 5.54 6.85 8.17 2002 5.54 2003 Apr 26 75 Apr 18 108 May 6, 2001 Mar 24 1.1 Aug 24 1.1 Aug 24, 2003 Mar 22 1.2 Aug 19 1.2 Aug 19, 2003 1,020 May 22 1,150 Dec 21, 2001 6.18 May 22 6.51 Dec 21, 2001 1.6 Mar 17, 2001 4,010 4,970 1.85 2.29 25.17 31.15 10 12 3.2 4.1 1.6 2.1 e Estimated 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 94 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR LOCATION.--Lat 18q18'07", long 66q42'15", Hydrologic Unit 21010001, 2.4 mi (3.9 km) north of Utuado Plaza, 3.4 mi (5.5 km) southwest from Lago Dos Bocas Dam, 3.5 mi (5.6 km) northwest from Lago Caonillas Dam. DRAINAGE AREA.--65.6 mi2 (170 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1996 to September 1998, June 1999 to current year. GAGE.--Water-stage recorder. Elevation of gage is 295.28 ft (90 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e66 246 e106 e86 67 e54 79 221 149 54 45 71 2 e73 204 e103 e87 e131 e54 83 206 146 66 40 104 3 e82 165 e100 e87 e211 e53 156 205 101 56 45 180 4 154 172 e102 e87 e121 51 131 182 88 53 60 115 5 180 e112 e107 e85 e246 47 122 167 283 54 46 60 6 73 e111 e99 e83 e166 46 125 159 230 59 40 47 7 225 e106 e97 e82 e83 43 53 149 95 48 47 81 8 125 e105 e94 e80 e90 43 40 192 80 48 48 167 9 283 e141 e99 e81 e79 42 35 209 75 52 39 78 10 420 e156 e91 e80 e72 39 43 202 76 50 36 78 11 293 e119 e90 e76 e69 38 51 176 72 62 49 263 12 237 e347 e91 e76 e57 37 55 142 66 45 46 356 13 254 e464 e89 e73 e55 36 52 127 64 51 35 319 14 411 e263 e89 e72 e67 34 38 138 70 48 92 115 15 265 e160 89 e72 e65 37 39 166 63 46 66 302 16 171 e196 88 e72 e60 39 44 210 68 57 48 179 17 158 e149 271 e71 e56 40 137 383 63 86 41 84 18 163 e156 339 e71 e60 43 673 374 227 53 40 136 19 233 e155 e99 e70 e59 66 335 320 131 50 43 262 20 229 295 e94 e69 e63 53 239 553 92 47 41 218 21 e226 232 e89 e69 e64 42 320 557 76 45 36 268 22 e202 281 e369 e69 e63 40 314 551 70 41 36 238 23 261 192 485 e70 e58 38 299 341 69 39 117 121 24 157 162 e260 e68 e55 36 402 189 77 36 101 195 25 129 135 e114 e120 e46 36 734 129 62 44 64 297 26 120 115 e106 e134 e49 58 424 108 54 49 66 218 27 110 138 e97 e78 e47 121 305 97 51 49 82 127 28 106 134 e91 e72 e50 101 272 91 48 67 55 86 29 138 112 e88 76 133 249 84 51 58 83 72 30 125 140 e86 77 83 231 85 51 47 156 80 31 185 e85 71 e54 76 49 131 TOTAL 5,854 5,463 4,207 2,464 2,309 1,637 6,080 6,789 2,848 1,609 1,874 4,917 MEAN 189 182 136 79.5 82.5 52.8 203 219 94.9 51.9 60.5 164 MAX 420 464 485 134 246 133 734 557 283 86 156 356 MIN 66 105 85 68 46 34 35 76 48 36 35 47 AC-FT 11,610 10,840 8,340 4,890 4,580 3,250 12,060 13,470 5,650 3,190 3,720 9,750 CFSM 2.88 2.78 2.07 1.21 1.26 0.80 3.09 3.34 1.45 0.79 0.92 2.50 IN. 3.32 3.10 2.38 1.40 1.31 0.93 3.45 3.85 1.61 0.91 1.06 2.79 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2003, BY WATER YEAR (WY) MEAN 265 287 131 90.2 68.9 53.2 155 167 92.1 94.5 161 382 MAX 490 766 242 166 102 76.7 457 249 130 184 393 1,100 (WY) (2000) (2000) (2000) (2000) (2000) (2000) (2002) (2000) (2000) (1998) (1998) (1998) MIN 148 84.8 53.0 39.5 46.6 33.8 46.2 50.8 40.8 36.6 60.5 87.3 (WY) (2002) (1998) (1998) (1998) (1998) (1998) (1997) (1997) (1997) (1997) (2003) (1997) RIO GRANDE DE ARECIBO BASIN 95 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1996 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 55,792 ANNUAL MEAN 153 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,210 LOWEST DAILY MEAN 25 ANNUAL SEVEN-DAY MINIMUM 28 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 110,700 ANNUAL RUNOFF (CFSM) 2.33 ANNUAL RUNOFF (INCHES) 31.63 10 PERCENT EXCEEDS 288 50 PERCENT EXCEEDS 99 90 PERCENT EXCEEDS 47 46,051 126 158 233 2000 99.6 1997 Apr 25 734 Apr 25 17,900 Sep 22, 1998 Mar 27 34 Mar 14 22 Mar 20, 1998 Mar 21 37 Mar 10 23 Mar 19, 1998 5,820 Apr 25 76,400 Sep 22, 1998 11.50 Apr 25 32.92 Sep 22, 1998 13 Jul 3, 2002 91,340 114,400 1.92 2.41 26.11 32.69 264 312 86 87 44 40 e Estimated 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 96 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- April 1996 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 1996 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 10,600 mg/L September 10, 1996; Minimum daily mean, 2 mg/L May 31, 2003. SEDIMENT LOADS: Maximum daily mean, e768,000 tons (e698,000 tonnes) September 22,1998; Minimum daily mean, 0.41 ton (0.37 tonne) May 31, 2003. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 3,590 mg/L April 25, 2003; Minimum daily mean, 2 mg/L May 31, 2003. SEDIMENT LOADS: Maximum daily mean, 26,000 tons (23,590 tonnes) April 25, 2003; Minimum daily mean, .41 ton (.37 tonne) May 31, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 e66 e24 e3.8 246 453 366 e106 e44 e14 2 e73 e24 e3.8 204 233 138 e103 e44 e14 3 e82 e24 e3.8 165 194 109 e100 e44 e14 4 154 142 131 172 197 105 e102 e44 e14 5 180 146 110 e112 e132 e39 e107 e44 e14 6 73 46 9.1 e111 e132 e39 e99 e44 e14 7 225 485 1,060 e106 e53 e15 e97 e44 e14 8 125 124 44 e105 e53 e15 e94 e47 e11 9 283 306 272 e141 e93 e62 e99 e44 e14 10 420 2,730 8,160 e156 e132 e56 e91 e47 e11 11 293 337 301 e119 e139 e45 e90 e47 e11 12 237 252 209 e347 e620 e4,240 e91 e50 e12 13 254 275 271 e464 e2,730 e8,160 e89 e55 e13 14 411 1,680 4,750 e263 e131 e119 e89 e53 e13 15 265 305 247 e160 e91 e40 89 50 12 16 171 109 51 e196 e114 e59 88 47 11 17 158 83 36 e149 e95 e38 271 1,100 4,240 18 163 136 118 e156 e64 e46 339 620 1,100 19 233 196 147 e155 e64 e46 e99 e24 e13 20 229 165 141 295 131 119 e94 e21 e11 21 e226 e165 e141 232 41 26 e89 e21 e11 22 e202 e233 e138 281 208 188 e369 e620 e1,100 23 261 350 501 192 114 59 485 e1,680 e4,750 24 157 132 56 162 91 40 e260 e1,100 e4,240 25 129 168 58 135 74 27 e114 e53 e15 26 120 139 45 115 56 18 e106 e53 e15 27 110 94 28 138 95 38 e97 e47 e11 28 106 53 15 134 76 32 e91 e47 e11 29 138 93 62 112 44 14 e88 e47 e11 30 125 106 46 140 71 29 e86 e47 e11 31 185 260 301 e85 e47 e11 TOTAL 5,854 17,459.5 5,463 14,327 4,207 15,756 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 97 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 e86 e47 e11 67 43 7.9 e54 e17 e2.3 2 e87 e47 e11 e131 e65 e30 e54 e17 e2.3 3 e87 e47 e11 e211 e130 e144 e53 e17 e2.3 4 e87 e47 e11 e121 e65 e30 51 17 2.3 5 e85 e47 e11 e246 e130 e144 47 14 1.8 6 e83 e47 e11 e166 e130 e112 46 13 1.6 7 e82 e47 e11 e83 e72 e14 43 12 1.4 8 e80 e47 e11 e90 e72 e14 43 10 1.2 9 e81 e47 e11 e79 e72 e14 42 8 0.95 10 e80 e47 e11 e72 e72 e14 39 8 0.85 11 e76 e46 e9.1 e69 e35 e9.7 38 8 0.83 12 e76 e46 e9.1 e57 e27 e42 37 8 0.80 13 e73 e46 e9.1 e55 e27 e42 36 8 0.77 14 e72 e46 e9.1 e67 e35 e9.7 34 8 0.75 15 e72 e46 e9.1 e65 e35 e9.7 37 8 0.83 16 e72 e46 e9.1 e60 e35 e9.7 39 9 0.90 17 e71 e46 e9.1 e56 e35 e9.7 40 9 0.95 18 e71 e46 e9.1 e60 e35 e9.7 43 9 1.1 19 e70 e46 e9.1 e59 e35 e9.7 66 35 9.7 20 e69 e46 e9.1 e63 e35 e9.7 53 15 2.2 21 e69 e46 e9.1 e64 e35 e9.7 42 13 1.5 22 e69 e46 e9.1 e63 e35 e9.7 40 14 1.5 23 e70 e46 e9.1 e58 e27 e4.2 38 21 2.1 24 e68 e46 e9.1 e55 e27 e4.2 36 27 2.6 25 e120 e90 e43 e46 e13 e1.6 36 27 2.7 26 e134 e90 e43 e49 e13 e1.6 58 27 4.2 27 e78 e46 e9.1 e47 e13 e1.6 121 90 43 28 e72 e46 e9.1 e50 e17 e2.3 101 30 8.3 29 76 110 22 133 65 30 30 77 101 21 83 30 6.9 31 71 72 14 e54 e20 e2.9 TOTAL 2,464 398.6 2,309 720.4 1,637 141.53 APRIL MAY JUNE 1 79 59 20 221 14 8.5 149 122 131 2 83 33 7.4 206 14 7.5 146 67 29 3 156 156 231 205 74 52 101 36 10 4 131 106 67 182 56 29 88 36 8.5 5 122 124 110 167 26 12 283 400 772 6 125 132 53 159 23 9.8 230 290 287 7 53 66 9.5 149 20 8.0 95 42 11 8 40 50 5.4 192 69 42 80 33 7.1 9 35 39 3.7 209 95 67 75 26 5.4 10 43 30 3.4 202 143 131 76 34 6.9 11 51 34 4.8 176 72 39 72 43 8.3 12 55 37 5.6 142 18 6.8 66 52 9.3 13 52 30 4.3 127 17 5.7 64 60 10 14 38 24 2.5 138 44 21 70 61 11 15 39 23 2.4 166 51 37 63 61 10 16 44 27 3.7 210 130 144 68 60 11 17 137 603 300 383 376 826 63 60 10 18 673 1,610 4,260 374 268 481 227 383 592 19 335 244 302 320 178 296 131 246 87 20 239 152 127 553 1,150 4,420 92 76 20 21 320 406 550 557 589 1,640 76 26 5.3 22 314 336 480 551 767 1,620 70 24 4.5 23 299 115 120 341 191 209 69 22 4.2 24 402 1,080 4,220 189 14 7.2 77 21 4.3 25 734 3,590 26,000 129 11 3.9 62 19 3.2 26 424 216 339 108 9 2.7 54 18 2.6 27 305 22 18 97 7 2.0 51 19 2.6 28 272 20 15 91 6 1.4 48 23 2.9 29 249 18 12 84 4 0.93 51 25 3.5 30 231 16 10 85 3 0.58 51 26 3.6 31 76 2 0.41 TOTAL 6,080 37,286.7 6,789 10,131.42 2,848 2,073.2 --- --- --- --- --- --- 98 RIO GRANDE DE ARECIBO BASIN 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 54 26 3.9 45 31 3.7 71 23 4.9 2 66 27 4.8 40 30 3.2 104 42 15 3 56 27 4.1 45 30 3.7 180 175 164 4 53 27 3.8 60 30 4.9 115 65 28 5 54 26 3.8 46 32 4.0 60 25 4.1 6 59 26 4.1 40 42 4.5 47 23 2.9 7 48 25 3.3 47 52 6.5 81 75 66 8 48 25 3.2 48 62 8.0 167 111 85 9 52 25 3.5 39 72 7.5 78 19 4.0 10 50 24 3.3 36 69 6.6 78 41 26 11 62 24 4.0 49 63 8.1 263 265 367 12 45 25 3.1 46 55 6.9 356 491 1,450 13 51 27 3.7 35 32 3.1 319 405 513 14 48 28 3.7 92 33 8.2 115 27 8.5 15 46 30 3.7 66 37 6.6 302 308 349 16 57 35 6.9 48 36 4.7 179 170 87 17 86 38 9.6 41 34 3.7 84 72 17 18 53 23 3.3 40 31 3.4 136 150 150 19 50 20 2.7 43 30 3.5 262 527 441 20 47 20 2.6 41 29 3.2 218 541 339 21 45 21 2.5 36 28 2.7 268 635 652 22 41 21 2.3 36 28 2.7 238 544 369 23 39 25 2.6 117 145 144 121 467 153 24 36 31 3.0 101 111 68 195 570 392 25 44 37 4.4 64 41 7.1 297 781 1,060 26 49 43 5.6 66 38 6.7 218 108 72 27 49 45 5.9 82 36 8.1 127 20 6.9 28 67 46 8.4 55 36 5.3 86 14 3.2 29 58 47 7.4 83 36 8.2 72 12 2.3 30 47 43 5.4 156 114 66 80 12 2.6 31 49 36 4.7 131 86 48 TOTAL 1,609 133.3 1,874 470.8 4,917 6,834.4 YEAR 46,051 105,732.85 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 25... 1700 2,740 89 12,100 89,200 25... 1829 3,390 67 38,000 347,000 RIO GRANDE DE ARECIBO BASIN 99 50024950 RIO GRANDE DE ARECIBO BELOW UTUADO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) APR 24... 1414 2,610 38 46 51 63 77 86 97 99 100 100 12,700 24... 1525 1,540 26 35 48 65 76 85 96 98 100 100 6,360 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) APR 24... 89,200 24... 26,400 100 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR :OCATION.--Lat 18q18'11", long 66q41'59", at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km) downstream from Río de Caguana, and 2.5 mi (4.0 km) north of Utuado Plaza. DRAINAGE AREA.--66.0 mi2 (170.9 km2) this excludes 6.0 mi2 (15.5 km2) upstream from Lago Garzas to Río Guayanes in the Río Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 10... 1200 91 21 8.3 101 6.8 267 24.8 98 26.7 7.62 1.85 .5 MAR 20... 1415 42 53 6.9 -- 8.0 305 30.5 110 31.2 8.61 2.43 .6 MAY 12... 1150 66 47 8.1 -- 8.0 271 26.7 110 29.4 7.95 2.16 .5 AUG 19... 1445 36 33 7.8 -- 8.4 288 32.6 -- -- -- -- -­ SEP 19... 0930 149 170 8.1 -- 7.8 206 24.2 79 21.9 6.00 2.24 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 10... 12.0 107 12.1 <.17 28.7 18.6 -- 172 42.2 19 .30 .01 1.16 MAR 20... 15.3 95 14.0 .12 29.0 26.8 <.1 184 20.8 79 .70 .06 1.22 MAY 12... 13.0 92 11.3 <.17 26.1 18.8 <.1 164 29.3 51 .40 .07 .80 AUG 19... -- 95 -- -- -- -- -- -- -- 42 .30 .07 .94 SEP 19... 8.04 76 8.62 <.2 22.6 11.8 -- 127 51.1 150 .60 .10 .62 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 10... 1.20 .04 .29 .11 1.5 6.6 <10 E1,200 380 -- -- -- -­ MAR 20... 1.30 .08 .64 .18 2.0 8.9 10 3,700 -- 28,000 E1 61.8 E9.9 MAY 12... .830 .03 .33 .12 1.2 5.4 <10 E1,200 -- 60,000 <2 61.3 22 AUG 19... 1.00 .06 .23 .14 1.3 5.8 <10 400 -- 6,800 -- -- -­ SEP 19... .650 .03 .50 .20 1.2 5.5 20 E17,000 -- 100,000 -- -- -­ 101 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 10... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 20... E.1 1.5 10 <.01 2,070 2 134 <.02 <3 <.3 E25 <.10 <16 MAY 12... <.2 1.5 20 <.01 1,830 2 123 <.02 <3 <.3 43 <.10 <16 AUG 19... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 19... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 102 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR LOCATION.--Lat 18q12'48", long 66q33'49", Hydrologic Unit 21010002, 2.0 mi (3.2 km) southeast of Jayuya, 1.4 mi (2.2 km) northeast of Hacienda Gripiñas. DRAINAGE AREA.--9.25 mi2 (24.0 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,706 ft (520 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24 24 9.2 7.0 8.9 7.0 e7.6 13 19 8.5 6.2 e11 2 33 21 9.2 7.1 45 6.9 12 12 19 8.5 5.8 9.2 3 56 17 9.3 6.9 33 e6.9 8.6 12 16 8.1 5.5 e51 4 31 15 11 6.5 40 6.6 7.4 11 e15 8.0 7.8 e16 5 17 15 11 6.5 65 6.4 18 11 14 8.7 8.0 10 6 14 15 9.5 6.9 40 6.2 11 11 13 8.6 8.3 8.7 7 12 13 9.3 e7.2 22 6.1 7.0 13 14 7.6 9.8 10 8 58 12 9.5 6.3 17 e6.0 5.9 13 13 7.7 7.3 e12 9 42 13 9.4 7.2 14 6.0 5.5 12 12 8.0 6.5 e9.9 10 32 13 8.8 8.5 12 6.0 5.5 14 12 7.1 6.0 e8.0 11 20 12 8.7 12 11 6.1 15 13 11 6.9 6.3 e40 12 16 13 8.6 6.9 11 5.9 31 11 11 6.8 7.5 e95 13 15 15 8.5 e6.3 9.9 5.6 13 11 11 9.3 5.9 45 14 30 20 8.3 6.1 9.5 5.5 8.1 12 11 8.4 5.8 e23 15 56 18 8.1 6.0 9.0 5.5 6.8 11 11 e8.0 e5.7 74 16 57 15 8.2 5.8 8.8 5.9 8.8 10 11 e9.5 e6.9 34 17 36 14 10 5.9 9.4 e5.3 193 54 10 8.3 8.2 20 18 23 13 13 5.9 8.7 5.4 e226 68 21 7.2 6.0 15 19 19 11 9.3 6.7 8.0 6.5 e94 41 15 6.8 5.9 13 20 17 11 11 5.8 7.8 e6.2 50 70 11 6.7 5.2 12 21 51 13 9.3 5.7 8.0 5.6 33 131 10 6.5 5.1 14 22 28 11 38 e5.5 7.5 5.4 31 90 10 6.9 5.5 13 23 20 10 16 7.3 7.1 5.3 34 59 9.5 6.8 5.3 12 24 18 9.9 11 11 7.0 5.1 49 38 9.2 6.2 5.1 e11 25 16 9.8 9.2 49 7.1 5.1 42 29 9.0 11 5.8 108 26 15 11 8.9 45 6.9 e28 26 24 8.8 e9.3 10 32 27 14 11 9.0 15 6.8 28 20 21 8.4 6.4 8.5 15 28 13 9.8 7.8 11 e7.5 12 17 19 8.3 9.7 12 10 29 15 9.8 7.4 8.9 e6.5 15 18 8.0 8.8 11 8.6 30 e16 9.1 7.1 8.3 6.0 14 17 7.9 6.0 16 8.2 31 29 6.9 8.3 e5.0 16 5.9 18 TOTAL 843 404.4 320.5 312.5 447.9 234.0 1,015.2 885 359.1 242.2 236.9 748.6 MEAN 27.2 13.5 10.3 10.1 16.0 7.55 33.8 28.5 12.0 7.81 7.64 25.0 MAX 58 24 38 49 65 28 226 131 21 11 18 108 MIN 12 9.1 6.9 5.5 6.8 5.0 5.5 10 7.9 5.9 5.1 8.0 AC-FT 1,670 802 636 620 888 464 2,010 1,760 712 480 470 1,480 CFSM 2.94 1.46 1.12 1.09 1.73 0.82 3.66 3.09 1.29 0.84 0.83 2.70 IN. 3.39 1.63 1.29 1.26 1.80 0.94 4.08 3.56 1.44 0.97 0.95 3.01 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY) MEAN 41.2 33.0 17.1 16.7 15.4 11.8 25.2 35.7 23.7 16.0 26.3 85.7 MAX 72.0 91.5 39.3 48.1 44.4 22.9 71.9 98.6 41.5 50.9 74.5 365 (WY) (1996) (2000) (2000) (1992) (1996) (2002) (2002) (1995) (1999) (1996) (1998) (1996) MIN 11.6 10.0 5.41 4.13 4.67 4.79 5.95 5.35 5.30 2.83 7.64 10.8 (WY) (1992) (1994) (1998) (1995) (1994) (1994) (1994) (1990) (1997) (1994) (2003) (1994) RIO GRANDE DE ARECIBO BASIN 103 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1989 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 8,668.9 ANNUAL MEAN 23.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 274 LOWEST DAILY MEAN 6.9 ANNUAL SEVEN-DAY MINIMUM 8.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 17,190 ANNUAL RUNOFF (CFSM) 2.57 ANNUAL RUNOFF (INCHES) 34.86 10 PERCENT EXCEEDS 42 50 PERCENT EXCEEDS 14 90 PERCENT EXCEEDS 9.3 6,049.3 16.6 28.9 64.0 1996 10.9 1994 Jun 5 226 Apr 18 4,700 Sep 10, 1996 Dec 31 5.0 Mar 31 2.3 Jul 27, 1994 Dec 25 5.4 Aug 19 2.5 Jul 23, 1994 1,820 Sep 25 18,500 Sep 21, 1998 9.41 Sep 25 20.00 Sep 21, 1998 4.5 Apr 1 2.1 Jul 26, 1994 12,000 20,960 1.79 3.13 24.33 42.49 33 55 10 13 6.0 5.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 104 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--October 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since October 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 693 mg/L July 14, 2001; Minimum daily mean, 1 mg/L several days during several years. SEDIMENT LOADS: Maximum daily mean, 2,480 tons (2,250 tonnes) July 14, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) March 19, 2001 and January 22, 2003. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, e414 mg/L April 18, 2003; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, e560 tons (e508 tonnes) April 18, 2003; Minimum daily mean, e0.01 ton (e0.01 tonne) January 22, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 24 21 4.5 24 10 0.67 9.2 2 0.05 2 33 25 4.7 21 5 0.34 9.2 2 0.05 3 56 71 39 17 5 0.24 9.3 2 0.05 4 31 21 2.1 15 4 0.18 11 2 0.06 5 17 9 0.43 15 4 0.16 11 2 0.06 6 14 7 0.26 15 4 0.17 9.5 2 0.05 7 12 7 0.23 13 4 0.15 9.3 2 0.05 8 58 74 42 12 5 0.16 9.5 2 0.05 9 42 30 3.9 13 5 0.17 9.4 2 0.05 10 32 21 2.5 13 5 0.16 8.8 2 0.05 11 20 9 0.49 12 5 0.14 8.7 2 0.05 12 16 7 0.30 13 4 0.15 8.6 2 0.05 13 15 7 0.29 15 6 0.29 8.5 2 0.05 14 30 21 2.9 20 11 1.1 8.3 2 0.04 15 56 69 32 18 7 0.38 8.1 2 0.04 16 57 54 18 15 2 0.08 8.2 2 0.03 17 36 24 2.6 14 2 0.07 10 1 0.04 18 23 12 0.78 13 2 0.07 13 1 0.04 19 19 9 0.45 11 2 0.06 9.3 2 0.04 20 17 5 0.23 11 2 0.06 11 2 0.07 21 51 49 18 13 2 0.07 9.3 3 0.07 22 28 14 1.2 11 2 0.05 38 37 11 23 20 1 0.06 10 1 0.04 16 7 0.36 24 18 1 0.05 9.9 1 0.03 11 3 0.08 25 16 1 0.04 9.8 2 0.04 9.2 2 0.05 26 15 1 0.04 11 2 0.07 8.9 2 0.05 27 14 1 0.04 11 3 0.09 9.0 2 0.05 28 13 1 0.04 9.8 3 0.09 7.8 2 0.04 29 15 3 0.19 9.8 4 0.10 7.4 2 0.03 30 e16 e3 e0.13 9.1 3 0.08 7.1 1 0.02 31 29 14 2.5 6.9 1 0.02 TOTAL 843 179.95 404.4 5.46 320.5 12.74 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 105 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 7.0 1 0.02 8.9 2 0.04 7.0 4 0.07 2 7.1 1 0.02 45 63 37 6.9 8 0.14 3 6.9 1 0.02 33 20 2.2 e6.9 e11 e0.20 4 6.5 1 0.02 40 28 3.1 6.6 10 0.17 5 6.5 1 0.02 65 110 39 6.4 7 0.12 6 6.9 1 0.02 40 34 4.2 6.2 5 0.08 7 e7.2 e1 e0.02 22 12 0.72 6.1 2 0.04 8 6.3 3 0.04 17 6 0.29 e6.0 e2 e0.04 9 7.2 5 0.09 14 2 0.06 6.0 3 0.04 10 8.5 6 0.15 12 1 0.04 6.0 3 0.05 11 12 5 0.18 11 2 0.05 6.1 3 0.05 12 6.9 3 0.06 11 2 0.06 5.9 3 0.05 13 e6.3 e1 e0.03 9.9 2 0.06 5.6 4 0.06 14 6.1 1 0.02 9.5 3 0.07 5.5 4 0.06 15 6.0 1 0.02 9.0 3 0.07 5.5 4 0.06 16 5.8 1 0.02 8.8 3 0.08 5.9 4 0.06 17 5.9 1 0.02 9.4 4 0.09 e5.3 e4 e0.06 18 5.9 1 0.02 8.7 4 0.09 5.4 4 0.06 19 6.7 1 0.02 8.0 3 0.07 6.5 4 0.07 20 5.8 1 0.02 7.8 3 0.06 e6.2 e4 e0.06 21 5.7 1 0.02 8.0 2 0.04 5.6 3 0.04 22 e5.5 e1 e0.01 7.5 1 0.02 5.4 2 0.03 23 7.3 1 0.02 7.1 1 0.02 5.3 2 0.03 24 11 1 0.04 7.0 1 0.02 5.1 3 0.04 25 49 46 20 7.1 1 0.02 5.1 3 0.04 26 45 40 8.8 6.9 1 0.02 e28 e26 e7.0 27 15 4 0.17 6.8 1 0.02 28 20 2.1 28 11 2 0.05 e7.5 e1 e0.03 12 5 0.18 29 8.9 1 0.03 e6.5 e3 e0.06 30 8.3 1 0.02 6.0 2 0.04 31 8.3 1 0.03 e5.0 e1 e0.02 TOTAL 312.5 30.02 447.9 87.54 234.0 11.12 APRIL MAY JUNE 1 e7.6 e2 e0.03 13 2 0.09 19 15 1.0 2 12 2 0.08 12 3 0.10 19 34 1.7 3 8.6 3 0.07 12 4 0.12 16 33 1.4 4 7.4 4 0.08 11 4 0.11 e15 e28 e1.1 5 18 11 1.0 11 3 0.09 14 11 0.42 6 11 6 0.18 11 2 0.06 13 6 0.20 7 7.0 4 0.07 13 2 0.07 14 5 0.19 8 5.9 3 0.04 13 2 0.07 13 5 0.16 9 5.5 2 0.04 12 2 0.07 12 4 0.14 10 5.5 2 0.03 14 7 0.39 12 3 0.11 11 15 11 1.0 13 20 0.67 11 3 0.08 12 31 27 4.0 11 19 0.55 11 2 0.07 13 13 13 0.48 11 18 0.52 11 3 0.09 14 8.1 12 0.27 12 17 0.54 11 4 0.11 15 6.8 11 0.21 11 16 0.49 11 5 0.14 16 8.8 10 0.24 10 15 0.42 11 6 0.17 17 193 328 287 54 86 40 10 5 0.14 18 e226 e414 e560 68 104 49 21 12 1.2 19 e94 e110 e33 41 30 3.8 15 5 0.25 20 50 39 5.4 70 129 48 11 3 0.10 21 33 24 2.1 131 205 160 10 4 0.11 22 31 14 1.4 90 46 12 10 4 0.12 23 34 10 1.2 59 13 2.0 9.5 5 0.13 24 49 32 7.6 38 16 1.6 9.2 5 0.12 25 42 18 2.4 29 18 1.4 9.0 5 0.12 26 26 5 0.37 24 15 0.98 8.8 5 0.11 27 20 4 0.24 21 10 0.55 8.4 5 0.11 28 17 4 0.17 19 4 0.23 8.3 5 0.10 29 15 3 0.12 18 3 0.15 8.0 5 0.10 30 14 2 0.08 17 3 0.14 7.9 4 0.10 31 16 3 0.13 TOTAL 1,015.2 908.90 885 324.34 359.1 9.89 --- --- --- --- --- --- 106 RIO GRANDE DE ARECIBO BASIN 50025155 RIO SALIENTE AT COABEY NEAR JAYUYA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 8.5 4 0.10 6.2 5 0.09 e11 e3 e0.10 2 8.5 4 0.10 5.8 5 0.08 9.2 3 0.07 3 8.1 4 0.09 5.5 5 0.07 e51 e262 e143 4 8.0 4 0.09 7.8 4 0.09 e16 e15 e1.1 5 8.7 4 0.09 8.0 4 0.09 10 7 0.20 6 8.6 4 0.08 8.3 5 0.12 8.7 6 0.15 7 7.6 3 0.06 9.8 5 0.15 10 6 0.17 8 7.7 2 0.05 7.3 3 0.07 e12 e6 e0.19 9 8.0 2 0.04 6.5 2 0.04 e9.9 e6 e0.16 10 7.1 2 0.04 6.0 2 0.03 e8.0 e6 e0.13 11 6.9 2 0.04 6.3 2 0.03 e40 e12 e1.1 12 6.8 2 0.04 7.5 2 0.04 e95 e275 e195 13 9.3 4 0.10 5.9 2 0.03 45 40 5.7 14 8.4 6 0.13 5.8 2 0.03 e23 e11 e0.75 15 e8.0 e8 e0.17 e5.7 e2 e0.03 74 156 70 16 e9.5 e9 e0.23 e6.9 e2 e0.04 34 26 2.5 17 8.3 10 0.22 8.2 2 0.04 20 11 0.62 18 7.2 11 0.21 6.0 2 0.03 15 7 0.28 19 6.8 11 0.19 5.9 2 0.04 13 7 0.25 20 6.7 10 0.18 5.2 3 0.04 12 7 0.23 21 6.5 9 0.16 5.1 3 0.04 14 7 0.27 22 6.9 9 0.17 5.5 3 0.04 13 7 0.25 23 6.8 8 0.15 5.3 3 0.04 12 7 0.22 24 6.2 8 0.13 5.1 3 0.04 e11 e7 e0.21 25 11 11 0.53 5.8 3 0.05 108 205 369 26 e9.3 e8 e0.26 10 3 0.08 32 19 2.4 27 6.4 6 0.11 8.5 3 0.07 15 3 0.12 28 9.7 6 0.15 12 6 0.31 10 3 0.08 29 8.8 6 0.14 11 5 0.15 8.6 3 0.06 30 6.0 6 0.09 16 14 1.8 8.2 2 0.05 31 5.9 5 0.08 18 9 0.52 TOTAL 242.2 4.22 236.9 4.32 748.6 794.36 YEAR 6,049.3 2,372.86 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus­ sedi­ pended Sus- Instan­ ment, sedi­ pended taneous sieve ment sedi­ dis­ diametr concen­ ment charge, percent tration load, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) SEP 25... 1656 1,180 88 2,790 8,890 --- --- --- --- --- --- --- 107 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR LOCATION.--Lat 18q12'50", long 66q38'44", Hydrologic Unit 21010001, 5.13 mi (8.2 km) southeast from Utuado Plaza, 4.5 mi (7.24 km) south of Lago Caonillas Dam and 6.15 mi (9.89 km) northeast from Adjuntas Plaza. DRAINAGE AREA.--6.89 mi2 (17.8 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,197 ft (365 m), from topographic map. REMARKS.--Records fair except those for September 16-30 and estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 30 8.6 7.0 6.1 5.5 e6.4 8.5 9.5 5.8 3.9 5.5 2 14 18 8.4 7.0 47 5.4 8.1 8.2 11 5.9 4.0 4.7 3 11 25 8.2 6.8 34 5.2 12 7.8 9.4 6.0 3.7 13 4 17 17 9.0 6.4 19 5.1 9.6 7.6 9.4 5.8 3.8 6.0 5 12 16 8.8 6.4 41 4.9 12 7.4 9.1 5.8 e3.6 4.5 6 8.6 16 8.1 6.5 23 4.9 12 7.7 11 6.0 3.8 4.1 7 8.8 13 7.8 6.6 13 4.7 7.7 8.1 8.9 5.2 4.2 15 8 11 12 8.4 6.2 10 4.7 6.7 8.7 8.5 5.2 4.1 11 9 14 19 8.3 6.2 9.2 4.6 6.7 7.8 8.3 5.4 3.7 5.8 10 36 24 7.6 6.6 8.5 4.6 6.9 7.4 8.1 5.0 3.5 4.8 11 14 16 7.5 6.8 8.1 4.6 6.7 7.6 7.9 5.0 5.3 70 12 10 24 7.3 6.1 7.7 4.5 11 7.3 7.8 4.7 5.3 20 13 8.8 15 7.2 6.0 7.5 4.4 9.5 7.0 7.5 5.0 5.6 18 14 14 13 7.1 5.8 7.8 4.3 7.5 7.3 7.4 5.3 6.5 7.6 15 77 16 7.0 5.7 7.1 4.3 6.6 7.5 7.3 4.8 4.5 71 16 22 28 7.1 5.6 6.8 4.3 6.6 7.8 7.3 6.0 4.0 24 17 17 15 39 5.6 7.0 4.2 51 35 7.1 5.6 4.0 14 18 16 12 19 5.5 6.8 4.1 137 29 9.4 4.6 3.8 e12 19 14 11 8.7 6.2 6.5 4.4 37 13 9.4 4.4 3.9 19 20 13 10 7.9 5.5 6.5 4.3 18 14 7.9 4.2 3.7 16 21 78 9.9 7.4 5.4 6.3 4.2 13 62 6.9 4.1 3.6 45 22 24 10 65 5.3 6.0 4.1 14 89 6.8 4.0 3.5 19 23 18 9.4 19 5.6 5.9 3.9 18 31 6.5 4.0 3.7 14 24 16 9.1 12 10 5.7 3.9 22 16 6.4 3.7 3.5 14 25 15 8.8 9.5 17 5.9 3.9 21 12 6.1 10 3.7 82 26 14 9.0 8.8 17 5.6 9.6 15 11 6.1 11 5.1 32 27 14 9.8 8.9 7.8 5.6 16 12 9.7 6.2 4.6 5.3 17 28 13 9.0 7.9 6.7 5.8 9.6 10 9.0 6.2 4.7 4.4 9.6 29 13 9.6 7.5 6.2 8.9 9.6 8.6 5.9 4.5 4.9 e9.4 30 15 10 7.3 6.0 8.4 9.0 8.1 5.7 4.0 8.4 e9.4 31 23 7.0 5.9 e6.5 7.9 3.9 8.7 TOTAL 594.2 444.6 361.3 217.4 329.4 172.0 522.6 479.0 235.0 164.2 139.7 597.4 MEAN 19.2 14.8 11.7 7.01 11.8 5.55 17.4 15.5 7.83 5.30 4.51 19.9 MAX 78 30 65 17 47 16 137 89 11 11 8.7 82 MIN 8.6 8.8 7.0 5.3 5.6 3.9 6.4 7.0 5.7 3.7 3.5 4.1 AC-FT 1,180 882 717 431 653 341 1,040 950 466 326 277 1,180 CFSM 2.78 2.15 1.69 1.02 1.71 0.81 2.53 2.24 1.14 0.77 0.65 2.89 IN. 3.21 2.40 1.95 1.17 1.78 0.93 2.82 2.59 1.27 0.89 0.75 3.23 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 27.9 23.1 15.0 8.23 8.06 6.00 18.7 17.2 8.53 7.76 11.7 27.0 MAX 45.9 30.4 22.7 11.3 11.8 7.10 32.1 21.9 9.12 13.7 18.9 43.4 (WY) (2001) (2002) (2002) (2002) (2003) (2002) (2002) (2001) (2001) (2001) (2000) (2000) MIN 18.6 14.8 10.7 6.34 5.04 5.36 6.60 14.2 7.83 5.30 4.51 9.72 (WY) (2002) (2003) (2001) (2001) (2001) (2001) (2001) (2002) (2003) (2003) (2003) (2002) 108 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 4,616.9 ANNUAL MEAN 12.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 83 LOWEST DAILY MEAN 4.8 ANNUAL SEVEN-DAY MINIMUM 5.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 9,160 ANNUAL RUNOFF (CFSM) 0.000 ANNUAL RUNOFF (INCHES) 0.00 10 PERCENT EXCEEDS 21 50 PERCENT EXCEEDS 9.0 90 PERCENT EXCEEDS 5.9 4,256.8 11.7 14.4 16.6 2001 11.7 2003 Apr 25 137 Apr 18 235 Aug 23, 2000 Mar 26 3.5 Aug 10 3.5 Mar 17, 2001 Mar 22 3.7 Aug 19 3.6 Mar 14, 2001 870 Sep 25 1,590 May 6, 2001 5.10 Sep 25 6.59 May 6, 2001 3.2 Mar 17, 2001 8,440 10,410 0.000 0.000 0.00 0.00 19 29 7.8 8.9 4.3 4.9 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 109 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--May 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 911 mg/L September 21, 2001; Minimum daily mean, 1 mg/L during water years 2001 and 2002. SEDIMENT LOADS: Maximum daily mean, 1,050 tons (952 tonnes) September 21, 2001; Minimum daily mean, 0.01 ton (0.01 tonne) several days during water year 2001. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 654 mg/L April 18, 2003; Minimum daily mean, 2 mg/L April 12 and September 6, 2003. SEDIMENT LOADS: Maximum daily mean, 646 tons (586 tonnes) April 18, 2003; Minimum daily mean, 0.02 ton (0.02 tonne) September 6, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 13 26 4.3 30 72 8.3 8.6 10 0.23 2 14 29 1.5 18 43 2.2 8.4 9 0.21 3 11 17 0.51 25 65 11 8.2 9 0.20 4 17 33 2.2 17 32 1.5 9.0 8 0.19 5 12 23 0.86 16 32 1.8 8.8 7 0.16 6 8.6 16 0.38 16 20 0.99 8.1 5 0.12 7 8.8 16 0.38 13 11 0.38 7.8 5 0.11 8 11 23 1.4 12 10 0.33 8.4 5 0.12 9 14 29 1.4 19 37 4.2 8.3 6 0.13 10 36 260 109 24 54 7.4 7.6 6 0.12 11 14 25 1.0 16 19 0.97 7.5 4 0.09 12 10 17 0.48 24 56 11 7.3 4 0.08 13 8.8 17 0.41 15 34 1.4 7.2 4 0.08 14 14 28 1.3 13 31 1.1 7.1 4 0.08 15 77 323 314 16 41 2.4 7.0 4 0.08 16 22 64 3.9 28 86 16 7.1 4 0.08 17 17 42 1.9 15 28 1.2 39 150 75 18 16 33 1.5 12 18 0.62 19 46 4.4 19 14 26 1.0 11 17 0.52 8.7 8 0.19 20 13 24 0.85 10 16 0.46 7.9 6 0.14 21 78 389 315 9.9 15 0.41 7.4 6 0.12 22 24 52 3.6 10 14 0.38 65 638 347 23 18 28 1.4 9.4 13 0.33 19 40 2.5 24 16 16 0.69 9.1 13 0.31 12 10 0.33 25 15 9 0.36 8.8 12 0.29 9.5 12 0.30 26 14 9 0.34 9.0 12 0.29 8.8 14 0.32 27 14 9 0.32 9.8 11 0.30 8.9 15 0.37 28 13 8 0.29 9.0 11 0.27 7.9 15 0.33 29 13 8 0.29 9.6 11 0.28 7.5 14 0.29 30 15 8 0.33 10 10 0.28 7.3 13 0.26 31 23 38 10 7.0 12 0.23 TOTAL 594.2 780.89 444.6 76.91 361.3 433.86 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 110 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 7.0 11 0.21 6.1 5 0.08 5.5 7 0.10 2 7.0 10 0.19 47 217 183 5.4 7 0.10 3 6.8 9 0.17 34 101 15 5.2 8 0.11 4 6.4 8 0.14 19 36 2.1 5.1 8 0.11 5 6.4 7 0.13 41 145 58 4.9 8 0.10 6 6.5 6 0.11 23 55 4.2 4.9 7 0.10 7 6.6 5 0.10 13 11 0.40 4.7 7 0.09 8 6.2 7 0.12 10 7 0.20 4.7 10 0.13 9 6.2 10 0.17 9.2 7 0.17 4.6 14 0.18 10 6.6 13 0.23 8.5 6 0.14 4.6 12 0.15 11 6.8 12 0.22 8.1 6 0.12 4.6 5 0.07 12 6.1 10 0.17 7.7 5 0.11 4.5 4 0.05 13 6.0 8 0.12 7.5 5 0.09 4.4 4 0.05 14 5.8 5 0.09 7.8 4 0.09 4.3 4 0.05 15 5.7 4 0.07 7.1 5 0.09 4.3 5 0.06 16 5.6 4 0.06 6.8 10 0.19 4.3 6 0.07 17 5.6 3 0.05 7.0 18 0.34 4.2 8 0.09 18 5.5 3 0.05 6.8 24 0.44 4.1 9 0.10 19 6.2 4 0.06 6.5 21 0.37 4.4 10 0.12 20 5.5 4 0.06 6.5 15 0.27 4.3 10 0.12 21 5.4 5 0.07 6.3 10 0.17 4.2 10 0.11 22 5.3 5 0.07 6.0 8 0.13 4.1 10 0.11 23 5.6 3 0.05 5.9 7 0.11 3.9 10 0.11 24 10 28 2.6 5.7 5 0.08 3.9 10 0.10 25 17 96 5.2 5.9 4 0.07 3.9 10 0.10 26 17 68 4.8 5.6 5 0.08 9.6 17 0.93 27 7.8 7 0.16 5.6 6 0.09 16 26 1.6 28 6.7 6 0.11 5.8 6 0.10 9.6 8 0.21 29 6.2 5 0.09 8.9 7 0.16 30 6.0 5 0.08 8.4 5 0.11 31 5.9 5 0.08 e6.5 e6 e0.11 TOTAL 217.4 15.83 329.4 266.23 172.0 5.60 APRIL MAY JUNE 1 e6.4 e9 e0.15 8.5 18 0.41 9.5 9 0.22 2 8.1 6 0.12 8.2 18 0.39 11 8 0.26 3 12 16 0.92 7.8 17 0.36 9.4 8 0.21 4 9.6 12 0.38 7.6 17 0.35 9.4 8 0.21 5 12 17 0.88 7.4 17 0.34 9.1 8 0.21 6 12 11 0.43 7.7 17 0.34 11 9 0.25 7 7.7 5 0.10 8.1 16 0.36 8.9 9 0.22 8 6.7 4 0.08 8.7 16 0.38 8.5 9 0.21 9 6.7 4 0.07 7.8 16 0.33 8.3 10 0.22 10 6.9 3 0.06 7.4 16 0.31 8.1 11 0.23 11 6.7 3 0.05 7.6 15 0.31 7.9 16 0.33 12 11 2 0.06 7.3 15 0.30 7.8 21 0.45 13 9.5 3 0.07 7.0 13 0.25 7.5 27 0.55 14 7.5 3 0.07 7.3 11 0.22 7.4 29 0.58 15 6.6 4 0.08 7.5 9 0.19 7.3 17 0.33 16 6.6 5 0.09 7.8 9 0.18 7.3 5 0.10 17 51 186 64 35 133 67 7.1 14 0.26 18 137 654 646 29 80 12 9.4 12 0.31 19 37 123 15 13 26 1.0 9.4 9 0.23 20 18 30 1.5 14 147 8.8 7.9 6 0.13 21 13 14 0.49 62 256 115 6.9 3 0.06 22 14 13 0.49 89 390 280 6.8 3 0.06 23 18 27 1.6 31 85 8.8 6.5 4 0.07 24 22 42 2.9 16 34 1.5 6.4 4 0.07 25 21 38 2.4 12 24 0.80 6.1 5 0.08 26 15 15 0.60 11 14 0.40 6.1 6 0.09 27 12 14 0.45 9.7 10 0.26 6.2 6 0.10 28 10 15 0.43 9.0 10 0.23 6.2 7 0.12 29 9.6 17 0.43 8.6 9 0.22 5.9 10 0.15 30 9.0 18 0.43 8.1 9 0.20 5.7 12 0.19 31 7.9 9 0.19 TOTAL 522.6 740.33 479.0 501.42 235.0 6.50 --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 111 50025850 RIO JAUCA AT PASO PALMA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 5.8 14 0.23 3.9 9 0.09 5.5 9 0.13 2 5.9 12 0.20 4.0 9 0.10 4.7 5 0.06 3 6.0 9 0.15 3.7 12 0.12 13 26 2.8 4 5.8 7 0.10 3.8 15 0.16 6.0 9 0.16 5 5.8 4 0.07 e3.6 e16 e0.16 4.5 5 0.06 6 6.0 5 0.08 3.8 9 0.09 4.1 2 0.02 7 5.2 5 0.08 4.2 3 0.04 15 35 6.1 8 5.2 6 0.08 4.1 5 0.06 11 21 0.71 9 5.4 6 0.09 3.7 8 0.08 5.8 14 0.23 10 5.0 6 0.08 3.5 8 0.08 4.8 14 0.17 11 5.0 6 0.08 5.3 8 0.11 70 308 203 12 4.7 6 0.08 5.3 8 0.11 20 44 2.7 13 5.0 6 0.09 5.6 8 0.12 18 38 2.4 14 5.3 7 0.10 6.5 8 0.14 7.6 15 0.31 15 4.8 7 0.09 4.5 8 0.10 71 188 54 16 6.0 6 0.10 4.0 8 0.09 24 54 3.6 17 5.6 5 0.07 4.0 8 0.09 14 47 1.8 18 4.6 4 0.05 3.8 9 0.09 e12 e46 e1.6 19 4.4 3 0.04 3.9 9 0.09 19 67 6.0 20 4.2 3 0.04 3.7 8 0.08 16 88 3.7 21 4.1 4 0.04 3.6 6 0.06 45 243 87 22 4.0 4 0.04 3.5 4 0.04 19 24 1.4 23 4.0 4 0.04 3.7 3 0.03 14 13 0.50 24 3.7 3 0.03 3.5 3 0.03 14 13 0.46 25 10 34 3.7 3.7 4 0.04 82 460 475 26 11 22 1.3 5.1 4 0.06 32 291 27 27 4.6 6 0.08 5.3 7 0.10 17 158 7.9 28 4.7 7 0.09 4.4 10 0.12 9.6 25 0.69 29 4.5 8 0.10 4.9 12 0.16 e9.4 e13 e0.44 30 4.0 8 0.09 8.4 21 0.80 e9.4 e10 e0.39 31 3.9 9 0.09 8.7 18 0.46 TOTAL 164.2 7.50 139.7 3.90 597.4 890.33 YEAR 4,256.8 3,729.30 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) OCT 21... 1755 312 98 2,840 2,390 SEP 11... 1759 371 98 1,480 1,480 21... 1409 262 93 1,120 794 112 RIO GRANDE DE ARECIBO BASIN 50025850 RIO JAUCA AT PASO PALMA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) DEC 22... 1715 236 57 70 80 92 93 97 98 99 99 100 3,000 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) DEC 22... 1,910 --- --- --- --- --- --- --- 113 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR LOCATION.--Lat 18q13'53", long 66q38'14", Hydrologic Unit 21010001, 3.5 mi (5.6 km) south of Lago Caonillas Dam, 4.8 mi (7.72 km) southeast of Utuado Plaza and 2.78 mi (4.47 km) east of Lago Viví Dam. DRAINAGE AREA.--37.9 mi2 (98.3 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 984 ft (300 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e36 e77 26 23 23 22 e31 47 57 27 19 30 2 e71 e59 26 24 69 22 41 44 62 24 17 30 3 e97 e53 26 23 162 21 38 41 47 22 15 146 4 e90 e43 29 21 127 20 35 40 43 21 18 73 5 e58 e38 31 22 177 20 39 38 40 21 21 36 6 e42 e41 28 22 127 19 46 38 41 23 21 26 7 e65 e33 26 23 69 19 29 42 38 20 28 38 8 e77 e32 28 21 53 19 24 45 37 19 24 51 9 e93 e39 29 21 44 18 23 39 35 20 17 34 10 e85 e48 25 23 39 18 23 36 33 18 16 26 11 e61 e40 23 27 36 17 23 40 32 17 57 98 12 e48 e45 23 22 34 17 56 34 32 16 33 124 13 e44 e51 23 21 32 17 42 32 31 20 21 139 14 e83 e38 22 20 32 16 29 32 30 23 36 83 15 e152 45 22 20 30 16 23 33 29 19 31 175 16 e106 51 22 20 29 16 25 32 29 23 19 104 17 e94 40 65 19 29 16 215 83 29 22 21 64 18 e69 34 62 19 28 16 431 140 51 18 18 49 19 e59 32 29 20 27 18 211 93 51 17 18 50 20 e54 29 29 19 25 19 121 209 33 16 16 47 21 e125 32 24 18 25 18 101 506 30 18 15 133 22 e90 30 108 18 24 17 99 305 29 16 15 84 23 e61 29 75 19 23 17 122 184 26 16 16 57 24 e51 27 41 28 23 16 145 115 25 15 14 44 25 e46 26 32 88 23 16 139 88 25 25 18 163 26 e44 27 31 119 23 44 97 72 24 46 25 143 27 e39 30 32 38 23 83 76 63 23 20 26 87 28 e26 27 27 29 23 58 63 57 22 22 24 58 29 e34 32 25 24 44 56 52 21 24 33 48 30 e44 32 24 24 39 51 49 21 17 45 44 31 e51 24 23 24 45 16 51 TOTAL 2,095 1,160 1,037 858 1,379 742 2,454 2,674 1,026 641 748 2,284 MEAN 67.6 38.7 33.5 27.7 49.2 23.9 81.8 86.3 34.2 20.7 24.1 76.1 MAX 152 77 108 119 177 83 431 506 62 46 57 175 MIN 26 26 22 18 23 16 23 32 21 15 14 26 AC-FT 4,160 2,300 2,060 1,700 2,740 1,470 4,870 5,300 2,040 1,270 1,480 4,530 CFSM 1.78 1.02 0.88 0.73 1.30 0.63 2.16 2.27 0.90 0.55 0.64 2.01 IN. 2.05 1.14 1.02 0.84 1.35 0.73 2.41 2.62 1.01 0.63 0.73 2.24 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1996 - 2003, BY WATER YEAR (WY) MEAN 145 128 71.5 53.2 48.4 36.7 77.7 87.4 65.2 48.6 77.8 248 MAX 248 292 143 89.8 86.0 51.4 235 130 161 117 156 815 (WY) (1999) (2000) (2000) (1997) (1996) (2002) (2002) (1998) (1999) (1996) (1998) (1998) MIN 63.7 38.7 21.0 19.6 24.0 23.9 17.0 29.1 16.1 15.5 24.1 33.2 (WY) (2002) (2003) (1998) (1998) (2001) (2003) (1997) (1997) (1997) (1997) (2003) (1997) 114 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1996 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 24,315 ANNUAL MEAN 66.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 727 LOWEST DAILY MEAN 21 ANNUAL SEVEN-DAY MINIMUM 22 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 48,230 ANNUAL RUNOFF (CFSM) 1.76 ANNUAL RUNOFF (INCHES) 23.84 10 PERCENT EXCEEDS 118 50 PERCENT EXCEEDS 44 90 PERCENT EXCEEDS 25 17,098 46.8 90.6 137 1998 46.8 2003 Apr 27 506 May 21 13,000 Sep 22, 1998 Mar 5 14 Aug 24 10 Jul 4, 1997 Mar 3 16 Aug 18 11 Jul 1, 1997 3,850 May 21 36,000 Sep 22, 1998 13.13 May 21 31.15 Sep 22, 1998 13 Jul 24 9.5 Jul 6, 1997 33,910 65,620 1.23 2.39 16.76 32.44 93 180 31 48 18 21 e Estimated 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 115 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- October 1995 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1995 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1996. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediments samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,800 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e952,000 tons (e864,000 tonnes) September 22, 1998; Minimum daily mean, 0.04 ton (0.03 tonne) December 29-30, 1998. EXTREMES FOR CURRENT YEAR 2003. SEDIMENT CONCENTRATION: Maximum daily mean, 1,640 mg/L May 21, 2003; Minimum daily mean, 2 mg/L February 22, 23, and May 11, 200 3. SEDIMENT LOADS: Maximum daily mean, 6,700 tons (6,078 tonnes) May 21, 2003; Minimum daily mean, 0.14 ton (0.13 tonne) March 15, 16, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 e36 e55 e8.5 e77 e77 e20 26 16 1.2 2 e71 e133 e26 e59 e44 e7.4 26 13 0.94 3 e97 e176 e83 e53 e46 e8.3 26 10 0.71 4 e90 e100 e29 e43 e31 e3.6 29 7 0.57 5 e58 e39 e6.5 e38 e28 e2.9 31 7 0.62 6 e42 e16 e1.9 e41 e28 e3.1 28 8 0.59 7 e65 e99 e46 e33 e27 e2.4 26 8 0.58 8 e77 e154 e94 e32 e26 e2.3 28 9 0.66 9 e93 e112 e36 e39 e30 e3.6 29 9 0.68 10 e85 e103 e36 e48 e43 e6.0 25 8 0.52 11 e61 e53 e8.8 e40 e35 e3.7 23 6 0.39 12 e48 e39 e5.1 e45 e43 e6.4 23 6 0.38 13 e44 e28 e3.3 e51 e43 e6.3 23 6 0.37 14 e83 e167 e91 e38 e34 e3.6 22 6 0.36 15 e152 e541 e417 45 34 4.1 22 6 0.35 16 e106 e137 e48 51 53 9.6 22 6 0.36 17 e94 e85 e24 40 24 2.6 65 182 141 18 e69 e31 e5.9 34 20 1.8 62 154 33 19 e59 e25 e4.0 32 17 1.4 29 79 6.3 20 e54 e25 e3.6 29 13 1.1 29 58 4.5 21 e125 e395 e320 32 13 1.1 24 36 2.4 22 e90 e99 e28 30 12 1.0 108 360 285 23 e61 e25 e4.2 29 12 0.95 75 82 20 24 e51 e22 e3.1 27 12 0.87 41 39 4.3 25 e46 e20 e2.5 26 11 0.77 32 35 3.0 26 e44 e17 e2.1 27 10 0.71 31 31 2.6 27 e39 e16 e1.6 30 8 0.67 32 28 2.4 28 e26 e17 e1.7 27 8 0.58 27 24 1.8 29 e34 e20 e1.8 32 11 1.3 25 14 0.99 30 e44 e22 e2.6 32 18 1.6 24 4 0.29 31 e51 e51 e14 24 4 0.23 TOTAL 2,095 1,359.2 1,160 109.75 1,037 517.09 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 116 RIO GRANDE DE ARECIBO BASIN 50026025 RIO CAONILLAS AT PASO PALMA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 23 4 0.22 23 7 0.46 22 15 0.92 2 24 6 0.37 69 223 164 22 6 0.34 3 23 8 0.51 162 655 603 21 6 0.32 4 21 11 0.61 127 260 94 20 7 0.40 5 22 13 0.74 177 693 687 20 9 0.46 6 22 13 0.75 127 281 121 19 8 0.40 7 23 12 0.77 69 56 11 19 6 0.33 8 21 12 0.68 53 18 2.5 19 5 0.26 9 21 12 0.66 44 15 1.7 18 4 0.20 10 23 11 0.72 39 17 1.8 18 4 0.19 11 27 11 0.82 36 19 1.9 17 4 0.19 12 22 11 0.64 34 21 2.0 17 4 0.19 13 21 8 0.47 32 19 1.7 17 4 0.17 14 20 6 0.33 32 16 1.4 16 3 0.15 15 20 5 0.25 30 13 1.0 16 3 0.14 16 20 6 0.34 29 10 0.77 16 3 0.14 17 19 9 0.45 29 8 0.61 16 5 0.19 18 19 11 0.57 28 6 0.44 16 6 0.25 19 20 12 0.68 27 4 0.29 18 7 0.33 20 19 10 0.52 25 3 0.23 19 6 0.30 21 18 8 0.40 25 3 0.20 18 5 0.24 22 18 6 0.30 24 2 0.16 17 4 0.18 23 19 7 0.37 23 2 0.15 17 3 0.15 24 28 10 0.96 23 4 0.26 16 3 0.15 25 88 203 105 23 6 0.39 16 4 0.16 26 119 285 156 23 11 0.69 44 49 15 27 38 32 3.3 23 33 2.0 83 103 29 28 29 28 2.1 23 27 1.7 58 32 6.5 29 24 23 1.5 44 17 2.2 30 24 17 1.1 39 10 1.0 31 23 12 0.77 24 10 0.66 TOTAL 858 282.90 1,379 1,702.35 742 61.11 APRIL MAY JUNE 1 e31 e10 e0.80 47 5 0.63 57 41 13 2 41 10 1.1 44 5 0.59 62 29 6.3 3 38 10 0.99 41 5 0.56 47 4 0.54 4 35 9 0.88 40 6 0.60 43 22 2.5 5 39 47 7.2 38 8 0.82 40 30 3.3 6 46 49 7.3 38 11 1.1 41 23 2.5 7 29 22 1.7 42 12 1.4 38 15 1.5 8 24 18 1.1 45 10 1.2 37 9 0.93 9 23 14 0.86 39 7 0.76 35 8 0.77 10 23 12 0.71 36 4 0.44 33 8 0.68 11 23 9 0.59 40 2 0.26 32 7 0.62 12 56 24 4.7 34 3 0.28 32 7 0.60 13 42 18 2.5 32 4 0.35 31 7 0.58 14 29 8 0.60 32 5 0.43 30 7 0.56 15 23 8 0.52 33 5 0.45 29 8 0.60 16 25 9 0.60 32 5 0.43 29 11 0.89 17 215 648 688 83 244 200 29 15 1.2 18 431 1,500 2,870 140 428 253 51 71 18 19 211 749 512 93 148 47 51 26 3.9 20 121 77 26 209 1,220 1,600 33 5 0.44 21 101 53 14 506 1,640 6,700 30 4 0.35 22 99 37 9.6 305 1,040 1,130 29 5 0.37 23 122 148 71 184 439 252 26 8 0.59 24 145 382 194 115 48 15 25 12 0.83 25 139 207 92 88 33 8.0 25 15 1.0 26 97 18 4.8 72 27 5.3 24 15 0.98 27 76 12 2.6 63 22 3.7 23 14 0.87 28 63 10 1.7 57 10 1.5 22 13 0.77 29 56 7 1.1 52 5 0.77 21 17 0.96 30 51 5 0.71 49 5 0.65 21 24 1.3 31 45 4 0.54 TOTAL 2,454 4,519.66 2,674 10,227.76 1,026 67.43 --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 117 50026025 RIO CAONILLAS AT PASO PALMA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 27 29 2.1 19 19 0.95 30 61 4.9 2 24 31 2.0 17 12 0.52 30 73 6.0 3 22 26 1.5 15 5 0.19 146 960 1,040 4 21 20 1.1 18 4 0.20 73 107 30 5 21 14 0.81 21 4 0.22 36 29 2.8 6 23 9 0.58 21 5 0.30 26 24 1.7 7 20 8 0.42 28 11 1.2 38 44 7.5 8 19 7 0.35 24 11 0.78 51 56 8.0 9 20 7 0.38 17 8 0.35 34 18 1.7 10 18 11 0.51 16 6 0.28 26 14 0.95 11 17 15 0.65 57 141 82 98 316 276 12 16 19 0.80 33 40 3.6 124 372 239 13 20 21 1.1 21 40 2.3 139 333 169 14 23 16 0.96 36 63 13 83 165 44 15 19 10 0.51 31 18 2.1 175 577 357 16 23 5 0.34 19 5 0.26 104 147 44 17 22 5 0.31 21 5 0.28 64 78 14 18 18 5 0.26 18 5 0.26 49 53 7.1 19 17 6 0.25 18 6 0.28 50 41 6.3 20 16 6 0.26 16 6 0.26 47 37 4.8 21 18 6 0.27 15 6 0.26 133 435 338 22 16 5 0.23 15 7 0.27 84 109 28 23 16 5 0.22 16 7 0.29 57 43 7.0 24 15 5 0.20 14 8 0.29 44 23 2.8 25 25 14 2.5 18 10 0.50 163 710 1,240 26 46 32 5.1 25 14 0.91 143 377 175 27 20 16 0.87 26 12 0.86 87 125 31 28 22 12 0.72 24 10 0.65 58 24 3.9 29 24 10 0.69 33 10 0.89 48 15 1.9 30 17 10 0.49 45 50 13 44 14 1.7 31 16 16 0.69 51 50 6.8 TOTAL 641 27.17 748 134.05 2,284 4,094.05 YEAR 17,098 23,102.52 e Estimated 118 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR LOCATION.--Lat 18q13'26", long 66q38'22", 300 ft (9 m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, 3.3 mi (5.3 km) northwest of Jayuya Plaza. DRAINAGE AREA.--40.4 mi2 (104.6 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 10... 1545 24 2.9 8.4 105 7.2 236 25.6 84 22.6 6.71 1.49 .6 MAR 20... 1100 17 3.4 8.6 -- 8.2 265 24.7 96 25.6 7.69 1.61 .7 MAY 21... 1300 111 24 7.3 -- 7.7 175 24.5 64 16.6 5.44 1.87 .5 AUG 20... 1130 14 4.7 9.1 -- 8.3 255 27.8 -- -- -- -- -­ SEP 15... 1320 E300 570 8.2 -- 7.7 146 24.5 53 14.6 4.08 1.95 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 10... 11.7 84 11.1 <.17 22.9 13.5 -- 140 9.06 <10 .20 <.01 -­ MAR 20... 15.4 88 15.2 .10 21.2 15.9 <.1 155 7.22 <10 <.20 .02 -­ MAY 21... 9.43 56 9.50 <.2 21.9 11.3 .2 109 32.9 <10 .30 .02 -­ AUG 20... -- 89 -- -- -- -- -- -- -- -- <.20 .02 -- SEP 15... 7.01 51 7.48 <.2 17.4 9.2 -- 92 74.6 488 1.6 .08 .48 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 10... .690 <.01 -- .05 .89 3.9 <10 E67 E80 -- -- -- -­ MAR 20... .380 <.01 -- .05 -- -- <10 94 -- E620 E1 27.4 E15 MAY 21... .960 <.01 .28 .08 1.3 5.6 10 E1,200 -- 6,200 <2 29.8 E13 AUG 20... .270 <.01 -- .04 -- -- -- 64 -- 300 -- -- -­ SEP 15... .510 .03 1.5 .44 2.1 9.3 40 15,000 -- E8,000 -- -- -­ 119 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 10... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 20... <.2 <.8 <10 <.01 90 <1 24.0 <.02 <3 <.3 <25 <.10 <16 MAY 21... <.2 E.4 10 <.01 770 M 59.6 <.02 <3 <.3 33 <.10 <16 AUG 20... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 15... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 120 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR LOCATION.--Lat 18q17'57", long 66q38'36", Hydrologic Unit 21010001, on left bank at Río Caonillas Tunnel 1.6 mi (2.6 km) downstream of Lago Caonillas Dam, 3.1 mi (5.0 km) southeast from Central Hidroelétrica of Lago Dos Bocas, 2.6 mi (4.2 km) west from Escuela Segunda Unidad de Mameyes. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage 295 ft (90 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 65 e47 69 36 74 59 50 15 22 32 33 390 2 67 110 69 36 36 59 52 3.8 16 32 33 380 3 66 139 69 36 36 59 52 1.6 6.5 32 33 375 4 64 88 69 36 36 59 52 1.7 3.9 32 36 372 5 63 39 72 36 37 60 51 1.5 3.0 32 37 370 6 62 5.1 76 36 36 60 51 1.4 3.3 32 34 368 7 77 5.1 76 36 34 60 51 1.3 2.7 32 34 367 8 74 4.2 76 36 33 60 51 1.6 2.3 32 33 365 9 67 3.7 76 36 33 60 51 4.5 1.9 32 33 363 10 69 3.6 75 36 33 55 50 4.4 1.7 32 33 362 11 70 3.6 75 36 32 86 50 2.1 1.6 32 33 361 12 66 3.4 75 36 32 61 49 1.6 1.5 31 34 359 13 67 32 75 36 33 61 49 1.5 1.5 32 124 359 14 134 18 75 36 31 61 49 1.4 1.4 32 287 356 15 70 15 75 35 28 61 49 1.4 1.3 32 254 354 16 52 12 75 71 13 61 49 1.3 1.4 32 253 352 17 42 8.1 75 35 12 142 49 4.2 2.7 32 253 351 18 39 6.4 68 35 26 51 63 3.4 14 32 172 336 19 39 5.5 74 35 29 150 64 9.0 8.4 32 3.8 288 20 38 4.9 74 35 30 65 62 21 3.8 32 63 7.8 21 35 4.7 73 35 29 71 63 13 2.7 32 163 12 22 34 4.6 74 35 41 60 276 5.0 2.3 32 159 5.0 23 36 4.5 55 35 55 60 12 3.5 1.9 32 165 3.0 24 e34 4.3 37 62 55 60 18 3.2 1.7 32 163 3.3 25 e32 4.1 37 48 50 123 31 2.6 5.4 44 122 4.6 26 e32 4.6 32 51 30 62 28 2.1 25 38 84 4.0 27 e31 36 36 42 66 61 23 1.9 32 34 266 3.2 28 e30 68 36 40 59 57 21 1.7 32 33 393 2.7 29 e31 70 36 40 58 21 1.5 32 34 391 2.4 30 e32 68 36 39 62 18 1.4 31 33 419 2.2 31 e41 36 40 54 1.3 33 455 TOTAL 1,659 822.4 1,956 1,217 1,039 2,118 1,555 120.9 266.9 1,016 4,595.8 6,878.2 MEAN 53.5 27.4 63.1 39.3 37.1 68.3 51.8 3.90 8.90 32.8 148 229 MAX 134 139 76 71 74 150 276 21 32 44 455 390 MIN 30 3.4 32 35 12 51 12 1.3 1.3 31 3.8 2.2 AC-FT 3,290 1,630 3,880 2,410 2,060 4,200 3,080 240 529 2,020 9,120 13,640 CFSM 1.05 0.54 1.24 0.77 0.73 1.34 1.02 0.08 0.18 0.65 2.92 4.51 IN. 1.21 0.60 1.43 0.89 0.76 1.55 1.14 0.09 0.20 0.74 3.37 5.04 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 69.9 64.7 111 70.7 48.0 65.5 130 141 94.6 92.1 139 156 MAX 86.3 102 158 104 60.8 68.3 250 287 148 127 164 229 (WY) (2002) (2002) (2002) (2002) (2002) (2003) (2002) (2002) (2001) (2001) (2001) (2003) MIN 53.5 27.4 63.1 39.3 37.1 63.0 51.8 3.90 8.90 32.8 106 95.3 (WY) (2003) (2003) (2003) (2003) (2003) (2001) (2003) (2003) (2003) (2003) (2002) (2002) 121 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2001 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 41,350.4 ANNUAL MEAN 113 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,140 LOWEST DAILY MEAN 3.4 ANNUAL SEVEN-DAY MINIMUM 4.1 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 82,020 ANNUAL RUNOFF (CFSM) 2.23 ANNUAL RUNOFF (INCHES) 30.28 10 PERCENT EXCEEDS 223 50 PERCENT EXCEEDS 75 90 PERCENT EXCEEDS 36 23,244.2 63.7 97.0 130 2002 63.7 2003 Apr 28 455 Aug 31 1,140 Apr 28, 2002 Nov 12 1.3 May 7 1.3 May 7, 2003 Nov 6 1.5 Jun 10 1.5 Jun 10, 2003 1,180 Aug 31 1,990 Apr 27, 2002 5.78 Aug 31 7.45 Apr 27, 2002 46,100 70,260 1.25 1.91 17.02 25.94 140 253 36 61 2.7 5.5 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 122 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--December 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: January 2001 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 268 mg/L November 8, 2001; Minimum daily mean, <1 mg/L several days during Water Year 2001. SEDIMENT LOADS: Maximum daily mean, 722 tons (655 tonnes) April 28, 2002; Minimum daily mean, 0.01 ton (0.01 tonne) several days during Water Year 2003. EXTREMES FOR CURRENT YEAR 2003.- SEDIMENT CONCENTRATION: Maximum daily mean, 129 mg/L August 14, 2003; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 112 tons (102 tonnes) August 14, 2003; Minimum daily mean, 0.01 ton (0.01 tonne) several day s. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 65 14 2.6 e47 e15 e1.8 69 19 3.5 2 67 29 5.3 110 7 2.2 69 12 2.3 3 66 28 5.0 139 9 3.3 69 7 1.2 4 64 27 4.7 88 11 2.5 69 6 1.1 5 63 26 4.4 39 13 1.3 72 7 1.3 6 62 26 4.3 5.1 15 0.21 76 7 1.4 7 77 26 5.5 5.1 17 0.23 76 7 1.4 8 74 21 4.2 4.2 19 0.21 76 7 1.4 9 67 20 3.6 3.7 21 0.21 76 7 1.4 10 69 19 3.6 3.6 23 0.22 75 8 1.6 11 70 19 3.6 3.6 25 0.24 75 14 2.9 12 66 19 3.3 3.4 27 0.25 75 22 4.5 13 67 18 3.3 32 25 2.0 75 30 6.0 14 134 18 6.9 18 10 0.46 75 37 7.4 15 70 16 3.0 15 9 0.37 75 35 7.2 16 52 16 2.2 12 9 0.28 75 33 6.6 17 42 15 1.8 8.1 8 0.18 75 31 6.2 18 39 15 1.6 6.4 8 0.13 68 33 6.0 19 39 15 1.6 5.5 8 0.12 74 35 7.1 20 38 14 1.5 4.9 21 0.27 74 38 7.6 21 35 14 1.3 4.7 35 0.45 73 40 8.0 22 34 18 1.7 4.6 39 0.49 74 40 8.0 23 36 21 2.0 4.5 42 0.51 55 23 4.2 24 e34 e21 e2.0 4.3 44 0.52 37 9 0.86 25 e32 e18 e1.7 4.1 47 0.52 37 8 0.81 26 e32 e18 e1.7 4.6 49 0.60 32 8 0.66 27 e31 e18 e1.7 36 44 4.2 36 7 0.72 28 e30 e18 e1.7 68 38 7.0 36 7 0.67 29 e31 e18 e1.7 70 31 6.0 36 7 0.63 30 e32 e18 e1.7 68 25 4.6 36 6 0.59 31 e41 e15 e1.8 36 6 0.53 TOTAL 1,659 91.0 822.4 41.37 1,956 103.77 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 123 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 36 5 0.47 74 5 1.4 59 5 0.80 2 36 4 0.41 36 4 0.38 59 5 0.80 3 36 4 0.35 36 4 0.38 59 5 0.80 4 36 3 0.30 36 4 0.37 59 5 0.80 5 36 3 0.29 37 4 0.37 60 5 0.81 6 36 3 0.29 36 4 0.36 60 5 0.81 7 36 3 0.29 34 4 0.34 60 5 0.81 8 36 3 0.29 33 4 0.33 60 5 0.81 9 36 3 0.29 33 4 0.31 60 5 0.74 10 36 3 0.29 33 3 0.31 55 4 0.61 11 36 3 0.29 32 3 0.30 86 6 1.7 12 36 3 0.29 32 3 0.29 61 6 0.91 13 36 3 0.29 33 3 0.30 61 5 0.83 14 36 3 0.29 31 3 0.27 61 5 0.75 15 35 3 0.29 28 3 0.24 61 4 0.68 16 71 4 1.3 13 3 0.11 61 4 0.66 17 35 5 0.48 12 3 0.10 142 7 3.6 18 35 5 0.48 26 3 0.32 51 8 1.1 19 35 5 0.48 29 3 0.24 150 9 4.1 20 35 5 0.47 30 3 0.24 65 9 1.6 21 35 5 0.47 29 3 0.23 71 9 1.7 22 35 5 0.47 41 6 0.74 60 9 1.4 23 35 5 0.47 55 9 1.3 60 9 1.4 24 62 6 1.1 55 8 1.3 60 8 1.3 25 48 5 0.63 50 8 1.0 123 9 3.2 26 51 5 0.64 30 3 0.23 62 10 1.6 27 42 4 0.50 66 4 1.1 61 10 1.6 28 40 4 0.46 59 5 0.80 57 10 1.5 29 40 4 0.43 58 10 1.5 30 39 4 0.43 62 9 1.6 31 40 4 0.43 54 9 1.4 TOTAL 1,217 13.96 1,039 13.66 2,118 41.92 APRIL MAY JUNE 1 50 9 1.2 15 7 0.28 22 5 0.41 2 52 9 1.3 3.8 7 0.07 16 4 0.19 3 52 9 1.2 1.6 7 0.03 6.5 4 0.07 4 52 7 0.98 1.7 6 0.03 3.9 4 0.04 5 51 5 0.71 1.5 6 0.03 3.0 4 0.03 6 51 3 0.47 1.4 6 0.02 3.3 4 0.04 7 51 3 0.47 1.3 6 0.02 2.7 4 0.03 8 51 4 0.54 1.6 5 0.02 2.3 4 0.02 9 51 4 0.53 4.5 5 0.06 1.9 4 0.02 10 50 4 0.52 4.4 5 0.06 1.7 4 0.02 11 50 4 0.50 2.1 5 0.03 1.6 4 0.02 12 49 4 0.48 1.6 5 0.02 1.5 4 0.01 13 49 3 0.46 1.5 5 0.02 1.5 4 0.01 14 49 3 0.45 1.4 5 0.02 1.4 3 0.01 15 49 3 0.43 1.4 5 0.02 1.3 3 0.01 16 49 3 0.42 1.3 5 0.02 1.4 3 0.01 17 49 3 0.41 4.2 5 0.05 2.7 4 0.03 18 63 4 0.68 3.4 5 0.04 14 6 0.23 19 64 5 0.83 9.0 5 0.11 8.4 7 0.16 20 62 5 0.75 21 5 0.26 3.8 9 0.09 21 63 4 0.72 13 4 0.16 2.7 8 0.06 22 276 16 18 5.0 4 0.06 2.3 7 0.04 23 12 15 0.51 3.5 4 0.04 1.9 5 0.03 24 18 13 0.63 3.2 4 0.04 1.7 5 0.02 25 31 12 0.97 2.6 4 0.03 5.4 8 0.14 26 28 10 0.78 2.1 4 0.02 25 12 0.85 27 23 9 0.54 1.9 4 0.02 32 16 1.4 28 21 8 0.45 1.7 4 0.02 32 18 1.6 29 21 8 0.42 1.5 4 0.02 32 20 1.7 30 18 7 0.36 1.4 4 0.02 31 21 1.8 31 1.3 4 0.01 TOTAL 1,555 36.71 120.9 1.65 266.9 9.09 --- --- --- --- --- --- 124 RIO GRANDE DE ARECIBO BASIN 50026200 RIO CAONILLAS BLW LAGO CAONILLAS TUNNEL, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 32 23 1.9 33 10 0.90 390 22 24 2 32 21 1.8 33 9 0.81 380 21 22 3 32 19 1.6 33 8 0.71 375 20 21 4 32 17 1.4 36 7 0.69 372 20 20 5 32 16 1.3 37 6 0.60 370 19 19 6 32 15 1.3 34 5 0.48 368 18 18 7 32 15 1.3 34 6 0.55 367 17 17 8 32 14 1.2 33 7 0.65 365 16 16 9 32 14 1.2 33 9 0.78 363 15 15 10 32 13 1.1 33 10 0.92 362 19 18 11 32 13 1.1 33 12 1.1 361 14 14 12 31 13 1.1 34 13 1.2 359 11 10 13 32 13 1.1 124 61 50 359 40 39 14 32 13 1.1 287 129 112 356 35 34 15 32 13 1.1 254 40 27 354 24 23 16 32 13 1.1 253 40 27 352 23 22 17 32 13 1.1 253 40 27 351 23 22 18 32 13 1.1 172 30 18 336 23 20 19 32 13 1.1 3.8 5 0.05 288 21 17 20 32 13 1.1 63 6 1.7 7.8 9 0.22 21 32 13 1.1 163 11 4.8 12 9 0.28 22 32 13 1.1 159 11 4.7 5.0 8 0.11 23 32 13 1.1 165 11 4.9 3.0 8 0.06 24 32 13 1.1 163 11 4.9 3.3 7 0.07 25 44 14 1.8 122 9 3.4 4.6 7 0.09 26 38 14 1.5 84 11 4.0 4.0 7 0.07 27 34 14 1.2 266 24 17 3.2 6 0.05 28 33 13 1.2 393 24 25 2.7 6 0.04 29 34 13 1.2 391 24 25 2.4 6 0.04 30 33 12 1.1 419 61 80 2.2 5 0.03 31 33 11 0.99 455 63 108 TOTAL 1,016 38.49 4,595.8 553.84 6,878.2 392.06 YEAR 23,244.2 1,337.52 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) AUG 13... 1816 389 97 176 185 --- --- --- --- --- --- --- 125 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR LOCATION.--Lat 18q19'27', long 66q35'13", Hydrologic Unit 21010002, on left bank, 600 ft downstream from bridge on Highway 140, 3.1 mi (4.9 km) southwest from Florida Plaza, 2.4 mi (3.9 km) northwest from Escuela Segunda Unidad de Frontón, 1.9 mi (3.1 km) northeast from Escuela Segunda Unidad de Mameyes. DRAINAGE AREA.--13.9 mi2 (36.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 492 ft (150 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 69 53 e24 13 12 9.4 e11 14 28 12 20 14 2 33 37 e19 15 12 9.3 22 13 34 13 9.4 12 3 25 34 e18 14 15 9.1 21 18 25 11 8.2 86 4 23 26 e22 12 49 8.9 15 13 e22 11 9.4 30 5 20 23 e20 12 77 8.8 15 11 e19 15 14 15 6 19 24 e18 12 39 8.7 12 11 e19 16 12 11 7 e142 22 e17 12 24 8.6 13 11 e18 13 10 12 8 e100 20 e17 11 19 8.5 10 12 e18 13 8.4 12 9 e54 19 e17 11 16 8.5 9.3 104 e17 12 7.7 9.8 10 e34 19 e16 11 15 8.2 8.8 34 e17 10 7.3 8.9 11 e31 18 e16 11 14 7.9 8.5 16 17 9.7 7.3 67 12 e35 17 e16 10 14 7.9 8.8 13 17 9.4 13 27 13 e80 70 e16 10 13 7.9 8.2 11 16 14 7.6 25 14 e70 e44 e15 10 13 7.8 7.7 11 15 12 7.4 28 15 e44 e75 e15 10 12 7.7 7.5 11 15 e10 11 14 16 e34 e35 e15 9.8 12 7.6 7.7 9.7 23 e11 7.9 12 17 e33 e27 e18 9.8 12 7.4 20 52 18 e9.8 7.1 11 18 e35 e25 e22 9.6 12 7.2 95 46 18 e8.8 6.9 10 19 e34 e23 15 9.6 11 22 43 131 20 e8.6 7.2 10 20 e29 e22 17 9.5 12 14 50 345 15 8.5 7.3 12 21 e27 e22 15 9.6 12 8.1 98 122 16 8.6 6.9 173 22 e25 e21 18 9.4 11 7.4 56 61 15 9.7 7.2 44 23 55 e20 18 9.8 10 7.3 157 52 14 9.3 12 31 24 32 e20 15 13 10 7.1 105 43 13 8.0 27 193 25 25 e19 14 72 10 6.9 116 32 13 18 28 52 26 24 e19 28 88 10 11 58 27 12 12 19 29 27 22 e18 23 23 9.9 25 31 24 12 14 11 23 28 20 e18 15 16 9.7 19 22 22 12 11 10 18 29 19 e18 14 14 15 18 21 11 12 12 16 30 19 e39 13 14 22 15 20 11 8.4 33 14 31 81 15 13 9.7 18 13 25 TOTAL 1,293 847 541 504.1 485.6 323.9 1,069.5 1,328.7 520 351.8 380.2 1,019.7 MEAN 41.7 28.2 17.5 16.3 17.3 10.4 35.6 42.9 17.3 11.3 12.3 34.0 MAX 142 75 28 88 77 25 157 345 34 18 33 193 MIN 19 17 13 9.4 9.7 6.9 7.5 9.7 11 8.0 6.9 8.9 AC-FT 2,560 1,680 1,070 1,000 963 642 2,120 2,640 1,030 698 754 2,020 CFSM 2.98 2.02 1.25 1.16 1.24 0.75 2.55 3.06 1.24 0.81 0.88 2.43 IN. 3.44 2.25 1.44 1.34 1.29 0.86 2.84 3.53 1.38 0.94 1.01 2.71 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 35.9 56.5 22.1 16.4 13.9 11.2 44.8 37.6 15.1 13.9 19.6 33.4 MAX 41.7 105 35.1 22.2 17.3 16.3 85.9 45.5 18.7 20.9 35.2 47.5 (WY) (2003) (2002) (2002) (2002) (2003) (2002) (2002) (2002) (2002) (2001) (2002) (2002) MIN 24.8 28.2 13.8 10.7 9.14 7.00 12.9 24.4 9.34 8.39 11.0 25.8 (WY) (2002) (2003) (2001) (2001) (2001) (2001) (2001) (2001) (2001) (2000) (2000) (2000) 126 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 11,834.4 ANNUAL MEAN 32.4 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 267 LOWEST DAILY MEAN 8.9 ANNUAL SEVEN-DAY MINIMUM 9.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 23,470 ANNUAL RUNOFF (CFSM) 2.32 ANNUAL RUNOFF (INCHES) 31.47 10 PERCENT EXCEEDS 60 50 PERCENT EXCEEDS 20 90 PERCENT EXCEEDS 13 8,664.5 23.7 27.3 38.8 2002 19.3 2001 Apr 29 345 May 20 1,660 Nov 8, 2001 Mar 26 6.9 Mar 25 4.7 Aug 12, 2000 Mar 21 7.2 Aug 16 5.2 Aug 12, 2000 4,080 May 20 5,070 Nov 8, 2001 11.57 May 20 12.37 Nov 8, 2001 6.2 Aug 20 4.4 Aug 12, 2000 17,190 19,770 1.70 1.95 23.04 26.51 45 51 15 16 8.5 7.7 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 127 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--June 2000 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: June 2000 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,940 mg/L November 8, 2001; Minimum daily mean, 1 mg/L several days during Water Year 2001. SEDIMENT LOADS: Maximum daily mean, 30,700 tons (27,850 tonnes) November 8, 2001; Minimum daily mean, 0.02 ton (0.02 tonne) seve ral days during Water Year 2001. EXTREMES FOR CURRENT YEAR 2003.- SEDIMENT CONCENTRATION: Maximum daily mean, 1,230 mg/L May 20, 2003; Minimum daily mean, 2 mg/L July 24, 2003. SEDIMENT LOADS: Maximum daily mean, 4,370 tons (3,960 tonnes) May 20, 2003; Minimum daily mean, 0.05 ton (0.04 tonne) July 24, 2 003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 69 237 217 53 123 26 e24 e32 e2.7 2 33 60 5.7 37 51 6.3 e19 e15 e0.76 3 25 18 1.2 34 34 3.5 e18 e15 e0.79 4 23 8 0.49 26 9 0.64 e22 e15 e0.79 5 20 8 0.43 23 8 0.48 e20 e15 e0.79 6 19 8 0.39 24 8 0.49 e18 e14 e0.68 7 e142 e461 e590 22 7 0.45 e17 e14 e0.68 8 e100 e275 e152 20 7 0.38 e17 e14 e0.68 9 e54 e317 e187 19 7 0.36 e17 e14 e0.68 10 e34 e100 e17 19 7 0.35 e16 e14 e0.55 11 e31 e47 e5.3 18 7 0.33 e16 e14 e0.55 12 e35 e15 e1.2 17 7 0.31 e16 e14 e0.55 13 e80 e15 e1.1 70 375 330 e16 e13 e0.52 14 e70 e232 e132 e44 e44 e5.3 e15 e13 e0.52 15 e44 e69 e8.8 e75 e103 e37 e15 e13 e0.52 16 e34 e17 e1.5 e35 e88 e11 e15 e14 e0.55 17 e33 e14 e1.0 e27 e40 e3.2 e18 e14 e0.55 18 e35 e10 e0.67 e25 e29 e2.1 e22 e15 e0.74 19 e34 e7 e0.55 e23 e18 e1.2 15 14 0.58 20 e29 e7 e0.42 e22 e15 e0.91 17 14 0.65 21 e27 e7 e0.38 e22 e15 e0.88 15 14 0.57 22 e25 e6 e0.34 e21 e15 e0.84 18 14 0.68 23 55 184 101 e20 e15 e0.79 18 14 0.68 24 32 33 3.1 e20 e15 e0.74 15 14 0.55 25 25 8 0.51 e19 e14 e0.73 14 14 0.52 26 24 7 0.44 e19 e14 e0.73 28 58 10 27 22 6 0.35 e18 e14 e0.70 23 28 2.0 28 20 6 0.31 e18 e14 e0.68 15 7 0.31 29 19 6 0.28 e18 e14 e0.77 14 5 0.19 30 19 5 0.26 e39 e71 e15 13 5 0.18 31 81 307 205 15 5 0.20 TOTAL 1,293 1,635.72 847 452.16 541 30.71 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 128 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 13 5 0.17 12 4 0.15 9.4 11 0.28 2 15 5 0.19 12 4 0.14 9.3 11 0.28 3 14 5 0.17 15 6 0.44 9.1 11 0.28 4 12 5 0.16 49 118 20 8.9 12 0.28 5 12 5 0.15 77 360 192 8.8 12 0.28 6 12 5 0.15 39 81 9.4 8.7 12 0.28 7 12 5 0.14 24 38 2.4 8.6 12 0.27 8 11 5 0.14 19 24 1.2 8.5 10 0.23 9 11 5 0.14 16 24 1.0 8.5 9 0.20 10 11 5 0.14 15 23 0.91 8.2 7 0.16 11 11 4 0.13 14 22 0.83 7.9 8 0.18 12 10 4 0.13 14 21 0.79 7.9 10 0.21 13 10 4 0.12 13 20 0.70 7.9 11 0.23 14 10 4 0.12 13 19 0.65 7.8 12 0.24 15 10 4 0.12 12 18 0.59 7.7 10 0.21 16 9.8 4 0.11 12 17 0.55 7.6 9 0.18 17 9.8 4 0.11 12 16 0.53 7.4 7 0.14 18 9.6 4 0.11 12 15 0.47 7.2 7 0.13 19 9.6 4 0.11 11 14 0.43 22 46 7.5 20 9.5 4 0.11 12 13 0.41 14 44 1.9 21 9.6 4 0.11 12 10 0.32 8.1 14 0.31 22 9.4 4 0.10 11 7 0.22 7.4 12 0.24 23 9.8 4 0.11 10 8 0.22 7.3 12 0.24 24 13 8 0.49 10 9 0.24 7.1 12 0.22 25 72 222 102 10 10 0.26 6.9 11 0.21 26 88 274 120 10 10 0.28 11 14 0.58 27 23 26 1.8 9.9 11 0.29 25 35 2.9 28 16 5 0.22 9.7 11 0.29 19 20 1.3 29 14 5 0.19 15 12 0.58 30 14 5 0.18 22 32 2.4 31 13 5 0.17 9.7 12 0.32 TOTAL 504.1 228.09 485.6 235.71 323.9 22.76 APRIL MAY JUNE 1 e11 e10 e0.28 14 6 0.21 28 44 6.9 2 22 10 0.60 13 5 0.18 34 34 3.7 3 21 10 0.55 18 22 1.9 25 16 1.0 4 15 11 0.43 13 17 0.63 e22 e15 e0.90 5 15 16 0.63 11 14 0.43 e19 e15 e0.83 6 12 21 0.65 11 12 0.37 e19 e15 e0.82 7 13 26 0.91 11 11 0.34 e18 e15 e0.79 8 10 30 0.82 12 10 0.31 e18 e15 e0.75 9 9.3 19 0.49 104 380 529 e17 e15 e0.72 10 8.8 7 0.16 34 85 9.9 e17 e17 e0.79 11 8.5 5 0.12 16 10 0.46 17 19 0.88 12 8.8 5 0.13 13 4 0.15 17 21 0.98 13 8.2 6 0.13 11 5 0.14 16 24 1.0 14 7.7 6 0.13 11 5 0.14 15 26 1.1 15 7.5 8 0.16 11 5 0.14 15 28 1.2 16 7.7 7 0.15 9.7 5 0.13 23 46 4.3 17 20 7 0.37 52 277 171 18 19 0.94 18 95 379 203 46 147 55 18 18 0.88 19 43 86 11 131 532 671 20 18 0.97 20 50 156 60 345 1,230 4,370 15 20 0.81 21 98 283 143 122 278 122 16 22 0.96 22 56 146 24 61 131 24 15 23 0.95 23 157 560 972 52 102 16 14 25 0.91 24 105 279 121 43 58 7.2 13 27 0.94 25 116 426 371 32 18 1.6 13 28 0.96 26 58 55 12 27 16 1.1 12 30 0.97 27 31 12 0.98 24 14 0.91 12 30 0.94 28 22 10 0.57 22 13 0.77 12 29 0.92 29 18 8 0.37 21 12 0.68 11 29 0.85 30 15 6 0.25 20 12 0.62 11 28 0.84 31 18 11 0.57 TOTAL 1,069.5 1,925.88 1,328.7 5,986.88 520 39.50 --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 129 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 12 28 0.90 20 43 3.0 14 16 0.60 2 13 27 0.96 9.4 6 0.15 12 14 0.48 3 11 27 0.80 8.2 6 0.13 86 643 692 4 11 26 0.80 9.4 9 0.41 30 80 8.8 5 15 26 1.0 14 10 0.50 15 17 0.70 6 16 25 1.1 12 6 0.20 11 11 0.32 7 13 25 0.86 10 7 0.18 12 10 0.33 8 13 24 0.87 8.4 7 0.15 12 9 0.31 9 12 24 0.80 7.7 7 0.14 9.8 9 0.23 10 10 25 0.69 7.3 7 0.13 8.9 8 0.19 11 9.7 26 0.69 7.3 6 0.12 67 502 357 12 9.4 28 0.70 13 6 0.21 27 57 4.8 13 14 29 1.1 7.6 6 0.12 25 35 3.2 14 12 30 1.0 7.4 6 0.12 28 46 4.8 15 e10 e25 e0.69 11 6 0.16 14 13 0.52 16 e11 e28 e0.70 7.9 6 0.12 12 8 0.26 17 e9.8 e26 e0.69 7.1 6 0.11 11 8 0.23 18 e8.8 e26 e0.69 6.9 5 0.10 10 9 0.24 19 e8.6 e26 e0.69 7.2 5 0.10 10 12 0.31 20 8.5 19 0.45 7.3 5 0.10 12 14 0.47 21 8.6 12 0.28 6.9 5 0.10 173 1,030 2,150 22 9.7 5 0.12 7.2 5 0.10 44 240 30 23 9.3 3 0.07 12 16 1.4 31 48 4.5 24 8.0 2 0.05 27 63 13 193 861 2,320 25 18 27 3.1 28 52 5.7 52 147 25 26 12 4 0.13 19 25 1.4 29 14 1.1 27 14 3 0.11 11 14 0.43 23 10 0.65 28 11 3 0.09 10 14 0.39 18 8 0.41 29 12 3 0.10 12 15 0.48 16 7 0.30 30 8.4 3 0.07 33 77 17 14 5 0.20 31 13 15 1.9 25 39 3.3 TOTAL 351.8 22.20 380.2 49.55 1,019.7 5,607.95 YEAR 8,664.5 16,237.11 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) NOV 13... 1715 392 97 3,590 3,800 JAN 25... 2130 236 95 801 510 APR 18... 1820 211 98 983 560 130 RIO GRANDE DE ARECIBO BASIN 50026400 RIO YUNES AT HWY 140 NEAR FLORIDA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus- Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve ment ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr concen­ dis­ charge, percent percent percent percent percent percent percent percent percent tration charge, Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm mg/L tons/d (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (80154) (80155) JAN 25... 2045 255 47 61 72 84 93 95 99 100 100 966 665 --- --- --- --- --- --- --- 131 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR LOCATION.--Lat 18q19'32", long 66q37'24", Hydrologic Unit 21010002, on right bank off Highway 146, 2.2 mi (3.5 km) northwest from Escuela Segunda Unidad de Mameyes, 3.0 mi (4.8 km) southwest from Lago Dos Bocas Dam, 3.8 mi (6.0 km) northeast from Lago Caonillas Dam. DRAINAGE AREA.--33.2 mi2 (86.0 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1999 to current year. GAGE.--Water-stage recorder. Datum of gage is 311.6 ft (94.9 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 150 99 61 36 38 27 e30 35 103 33 45 41 2 68 76 49 38 36 27 50 34 87 33 27 38 3 56 73 47 37 37 26 42 52 58 30 24 121 4 50 58 55 34 81 26 32 37 50 31 39 58 5 45 54 51 34 109 25 29 32 47 35 40 35 6 43 56 46 34 71 24 32 31 46 38 31 29 7 165 56 44 33 48 24 31 33 44 33 29 29 8 189 51 44 33 43 24 25 33 42 33 26 32 9 129 50 43 33 40 24 23 212 41 32 25 27 10 e82 49 42 33 38 23 22 63 40 28 23 26 11 e63 48 41 32 37 22 21 37 39 28 32 138 12 e60 46 41 31 36 22 21 33 39 27 35 58 13 64 e155 41 31 35 22 20 31 39 36 24 48 14 108 e93.0 40 31 35 21 19 30 37 32 24 59 15 99 e171 39 30 34 21 19 30 37 28 29 35 16 72 88 39 30 33 20 19 28 47 30 25 31 17 62 68 48 30 34 20 31 151 41 27 24 28 18 62 63 56 29 32 20 157 66 63 26 24 27 19 63 59 41 29 32 29 74 441 48 25 25 27 20 62 57 42 29 32 29 70 1,120 37 25 25 30 21 58 56 40 29 32 21 147 252 39 26 24 343 22 55 e54 46 28 31 20 92 128 37 27 25 107 23 108 e52 45 29 30 20 207 109 34 26 26 86 24 70 e51 39 31 30 19 148 92 34 23 59 311 25 59 49 38 119 30 19 216 73 32 57 67 110 26 57 49 64 152 29 20 95 64 32 36 49 71 27 54 48 52 49 29 42 58 59 31 37 33 61 28 52 47 39 40 29 38 47 56 31 31 31 49 29 51 46 37 37 39 41 53 29 32 33 44 30 51 97 36 37 48 38 51 29 25 71 41 31 125 37 37 e24 49 27 74 TOTAL 2,432 2,019.0 1,383 1,235 1,121 786 1,856 3,515 1,313 957 1,068 2,140 MEAN 78.5 67.3 44.6 39.8 40.0 25.4 61.9 113 43.8 30.9 34.5 71.3 MAX 189 171 64 152 109 48 216 1,120 103 57 74 343 MIN 43 46 36 28 29 19 19 28 29 23 23 26 AC-FT 4,820 4,000 2,740 2,450 2,220 1,560 3,680 6,970 2,600 1,900 2,120 4,240 CFSM 2.36 2.03 1.34 1.20 1.21 0.76 1.86 3.42 1.32 0.93 1.04 2.15 IN. 2.73 2.26 1.55 1.38 1.26 0.88 2.08 3.94 1.47 1.07 1.20 2.40 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 83.3 132 55.4 58.4 41.8 32.9 91.9 99.9 42.6 37.0 46.8 75.0 MAX 104 255 85.5 108 60.8 45.7 240 134 62.3 49.7 72.5 100 (WY) (2001) (2002) (2002) (2000) (2000) (2000) (2002) (2002) (2002) (2002) (2002) (2002) MIN 67.3 67.3 36.1 30.1 26.9 20.5 29.7 54.7 27.4 30.9 31.7 57.3 (WY) (2002) (2003) (2001) (2001) (2001) (2001) (2001) (2001) (2001) (2003) (2000) (2000) 132 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 29,911.0 ANNUAL MEAN 81.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 876 LOWEST DAILY MEAN 26 ANNUAL SEVEN-DAY MINIMUM 27 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 59,330 ANNUAL RUNOFF (CFSM) 2.47 ANNUAL RUNOFF (INCHES) 33.51 10 PERCENT EXCEEDS 140 50 PERCENT EXCEEDS 55 90 PERCENT EXCEEDS 36 19,825.0 54.3 67.0 99.9 2002 46.6 2001 Apr 29 1,120 May 20 3,990 Nov 8, 2001 Mar 25 19 Mar 24 14 Apr 18, 2001 Mar 21 20 Apr 10 16 Apr 15, 2001 10,200 May 20 11,500 Nov 8, 2001 15.14 May 20 15.63 Nov 8, 2001 18 Mar 25 13 Apr 18, 2001 39,320 48,510 1.64 2.02 22.21 27.40 92 117 38 42 25 23 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S RIO GRANDE DE ARECIBO BASIN 133 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--December 1999 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 09... 1445 44 5.0 8.8 106 7.2 205 24.1 77 21.0 5.89 1.96 .4 MAR 18... 1500 19 E1.7 8.5 -- 8.2 213 27.5 82 22.7 6.26 1.84 .5 MAY 20... 1500 120 30 8.0 -- 7.6 184 25.2 70 20.1 4.78 2.07 .4 AUG 19... 1300 22 2.6 8.8 -- 8.1 201 28.1 -- -- -- -- -­ SEP 18... 1350 27 3.8 8.4 -- 8.0 203 29.1 80 22.3 5.97 2.20 .4 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00630) DEC 09... 8.63 77 9.97 <.17 28.2 4.2 -- 126 14.9 <10 <.20 <.01 1.10 MAR 18... 9.73 84 10.6 .11 27.0 4.4 <.1 133 6.93 <10 <.20 .02 .480 MAY 20... 8.00 67 8.60 <.2 25.2 6.2 -- 115 37.3 10 -- -- -­ AUG 19... -- 78 -- -- -- -- -- -- -- <10 <.20 .01 .460 SEP 18... 8.29 79 10.1 <.2 27.9 4.6 -- 129 9.48 <10 <.20 .02 .660 Fecal Fecal Total Chrom- COD, coli- strep- coli- Barium, Boron, ium, Copper, Nitrite Phos- high form, tococci form, water, water, water, water, water, phorus, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd unfltrd Cyanide unfltrd water, water, 0.7u MF MF, immed, water recover recover water, recover recover water mg/L unfltrd unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, -able, unfltrd Date as N mg/L mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L ug/L mg/L (00615) (00665) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) (01042) (00720) DEC 09... <.01 .04 <10 84 266 -- -- -- -- -- -- -- -­ MAR 18... <.01 .02 <10 E9 -- E44 <2 41.7 <18 <.2 <.8 <10 <.01 MAY 20... -- -- <10 E510 -- E800 <2 42.7 22 <.2 E.7 <10 <.01 AUG 19... <.01 <.02 <10 14 -- 400 -- -- -- -- -- -- -­ SEP 18... <.01 .04 <10 190 -- 750 -- -- -- -- -- -- -­ 134 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, Selen- water, water, com­ unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover recover recover water, recover recover water, water, -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 09... -- -- -- -- -- -- -- -- -- MAR 18... 50 <1 8.2 <.02 <3 <.3 E25 <.10 <16 MAY 20... 590 <1 25.4 <.02 <3 E.2 <25 <.10 <16 AUG 19... -- -- -- -- -- -- -- -- -- SEP 18... -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- 135 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--December 1999 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2001 to current year INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 2000. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,420 mg/L November 8, 2001; Minimum daily mean, 1 mg/L several days during water year 2001. SEDIMENT LOADS: Maximum daily mean, 42,800 tons (38,830 tonnes) November 8, 2001; Minimum daily mean, 0.08 ton (0.07 tonne) Febr uary 6, 7, 2001. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,260 mg/L May 20, 2003; Minimum daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 31,500 tons (28,580 tonnes) May 20, 2003; Minimum daily mean, 0.14 ton (0.13 tonne) March 12, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 150 329 585 99 131 48 61 8 1.4 2 68 114 22 76 32 7.6 49 7 0.88 3 56 11 1.8 73 31 6.7 47 6 0.81 4 50 4 0.54 58 17 2.7 55 10 1.9 5 45 4 0.48 54 15 2.1 51 6 0.77 6 43 4 0.41 56 16 2.6 46 5 0.59 7 165 291 544 56 16 2.6 44 4 0.53 8 189 368 705 51 12 1.7 44 6 0.73 9 129 132 80 50 10 1.4 43 8 0.94 10 e82 e49 e12 49 9 1.1 42 10 1.1 11 e63 e27 e5.8 48 7 0.88 41 12 1.3 12 e60 e17 e3.0 46 5 0.58 41 10 1.2 13 64 22 4.1 e155 e468 e717 41 9 0.98 14 108 142 97 e93.0 e145 e82 40 8 0.84 15 99 67 21 e171 e158 e93 39 13 1.4 16 72 21 4.2 88 52 13 39 21 2.2 17 62 15 2.6 68 11 2.0 48 32 5.1 18 62 13 2.1 63 8 1.5 56 40 6.6 19 63 10 1.8 59 8 1.3 41 35 3.8 20 62 10 1.6 57 10 1.5 42 33 3.8 21 58 10 1.5 56 12 1.9 40 32 3.4 22 55 9 1.4 e54 e14 e2.1 46 26 3.1 23 108 129 101 e52 e13 e1.8 45 17 2.1 24 70 17 3.6 e51 e10 e1.4 39 10 1.1 25 59 9 1.4 49 7 0.97 38 10 0.97 26 57 8 1.2 49 5 0.62 64 37 12 27 54 7 1.1 48 4 0.51 52 10 1.4 28 52 7 0.92 47 4 0.50 39 12 1.2 29 51 6 0.81 46 4 0.54 37 14 1.4 30 51 5 0.75 97 79 39 36 16 1.6 31 125 204 170 37 13 1.4 TOTAL 2,432 2,378.11 2,019.0 1,038.60 1,383 66.54 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 136 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 36 2 0.22 38 21 2.1 27 8 0.59 2 38 3 0.27 36 21 2.0 27 8 0.58 3 37 3 0.29 37 20 2.0 26 8 0.57 4 34 4 0.36 81 45 12 26 8 0.56 5 34 5 0.45 109 138 73 25 8 0.53 6 34 6 0.52 71 23 4.8 24 7 0.48 7 33 5 0.44 48 18 2.3 24 7 0.45 8 33 4 0.36 43 16 1.9 24 6 0.40 9 33 3 0.28 40 15 1.6 24 5 0.33 10 33 2 0.20 38 13 1.4 23 4 0.26 11 32 2 0.21 37 12 1.2 22 3 0.19 12 31 3 0.26 36 10 1.0 22 2 0.14 13 31 4 0.31 35 9 0.82 22 4 0.22 14 31 4 0.35 35 7 0.66 21 6 0.33 15 30 5 0.39 34 5 0.50 21 8 0.43 16 30 5 0.38 33 6 0.55 20 9 0.51 17 30 4 0.35 34 8 0.69 20 11 0.60 18 29 4 0.31 32 7 0.63 20 13 0.68 19 29 3 0.26 32 6 0.55 29 17 1.7 20 29 3 0.21 32 6 0.50 29 9 0.79 21 29 2 0.17 32 5 0.43 21 7 0.39 22 28 3 0.19 31 4 0.37 20 6 0.33 23 29 3 0.25 30 9 0.74 20 5 0.29 24 31 4 0.36 30 16 1.3 19 5 0.26 25 119 107 70 30 22 1.8 19 5 0.23 26 152 142 109 29 17 1.4 20 4 0.23 27 49 3 0.42 29 5 0.39 42 14 1.7 28 40 2 0.24 29 6 0.45 38 17 1.8 29 37 2 0.25 39 18 2.4 30 37 6 0.65 48 26 4.3 31 37 21 2.1 e24 e12 e0.79 TOTAL 1,235 190.05 1,121 117.08 786 23.06 APRIL MAY JUNE 1 e30 e13 e1.0 35 8 0.80 103 108 95 2 50 20 3.0 34 11 1.0 87 44 15 3 42 16 1.9 52 25 6.6 58 5 0.77 4 32 10 0.85 37 7 0.73 50 5 0.62 5 29 7 0.55 32 6 0.54 47 4 0.51 6 32 9 0.94 31 5 0.43 46 3 0.43 7 31 11 0.91 33 4 0.37 44 3 0.38 8 25 9 0.63 33 4 0.32 42 4 0.46 9 23 8 0.50 212 405 1,330 41 5 0.54 10 22 7 0.42 63 46 10 40 6 0.62 11 21 6 0.36 37 11 1.2 39 6 0.61 12 21 6 0.32 33 7 0.63 39 6 0.58 13 20 5 0.27 31 4 0.30 39 5 0.55 14 19 5 0.24 30 4 0.34 37 5 0.51 15 19 6 0.30 30 6 0.44 37 5 0.50 16 19 8 0.40 28 7 0.51 47 11 1.9 17 31 7 0.61 151 277 459 41 25 2.7 18 157 195 198 66 45 9.6 63 47 13 19 74 47 11 441 1,070 6,010 48 8 1.1 20 70 49 19 1,120 2,260 31,500 37 6 0.56 21 147 179 154 252 611 498 39 4 0.45 22 92 99 29 128 60 22 37 5 0.53 23 207 355 839 109 49 16 34 7 0.61 24 148 236 105 92 35 9.0 34 8 0.70 25 216 312 532 73 24 4.7 32 7 0.63 26 95 62 18 64 17 2.9 32 6 0.53 27 58 26 4.2 59 10 1.6 31 5 0.44 28 47 8 0.97 56 4 0.68 31 5 0.42 29 41 5 0.61 53 4 0.53 29 5 0.40 30 38 6 0.59 51 3 0.46 29 5 0.40 31 49 3 0.40 TOTAL 1,856 1,924.57 3,515 39,889.08 1,313 141.45 --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 137 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 33 6 0.52 45 14 2.2 41 109 12 2 33 7 0.64 27 9 0.65 38 104 11 3 30 11 0.88 24 8 0.53 121 292 301 4 31 15 1.3 39 39 10 58 36 7.0 5 35 19 1.8 40 106 13 35 13 1.2 6 38 18 1.8 31 64 5.3 29 11 0.90 7 33 15 1.4 29 48 3.9 29 11 0.85 8 33 13 1.1 26 33 2.3 32 10 0.89 9 32 10 0.90 25 19 1.3 27 10 0.74 10 28 8 0.60 23 15 0.96 26 10 0.67 11 28 6 0.41 32 87 16 138 518 711 12 27 5 0.33 35 209 22 58 57 11 13 36 4 0.40 24 51 3.4 48 20 2.8 14 32 4 0.31 24 13 0.88 59 28 5.6 15 28 3 0.24 29 11 0.86 35 9 0.85 16 30 4 0.29 25 10 0.69 31 8 0.70 17 27 4 0.31 24 10 0.62 28 8 0.62 18 26 5 0.33 24 9 0.60 27 8 0.57 19 25 5 0.31 25 9 0.58 27 8 0.54 20 25 4 0.28 25 8 0.55 30 7 0.59 21 26 4 0.25 24 8 0.53 343 1,020 3,940 22 27 3 0.23 25 8 0.54 107 111 37 23 26 3 0.21 26 8 0.57 86 59 16 24 23 3 0.19 59 34 11 311 572 2,440 25 57 236 104 67 66 14 110 70 24 26 36 82 9.2 49 47 6.2 71 17 3.2 27 37 36 3.8 33 42 3.7 61 13 2.2 28 31 14 1.1 31 37 3.1 49 10 1.3 29 32 10 0.83 33 36 3.2 44 7 0.82 30 25 12 0.79 71 128 54 41 4 0.44 31 27 13 1.0 74 181 40 TOTAL 957 135.75 1,068 223.16 2,140 7,535.48 YEAR 19,825.0 53,662.93 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) NOV 13... 1910 426 99 1,810 2,090 138 RIO GRANDE DE ARECIBO BASIN 50027000 RIO LIMON ABOVE LAGO DOS BOCAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) NOV 13... 1710 1,170 48 60 73 89 94 98 99 100 100 100 2,920 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) NOV 13... 9,220 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 139 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR LOCATION.--Lat 18q20'16", long 66q40'05", Hydrologic Unit 21010001, on upstream side of road 146 over damsite, close to the center of dam, 10 mi (16 km) southeast of the city of Arecibo, 4.1 mi (6.6 km) north of Lago Caonillas Dam, 5.3 mi (8.53 km) northeast of Utuado Plaza, and 3.8 mi (6.1 km) southeast of Escuela Antonio S·nchez de Padilla. DRAINAGE AREA.--169.45 mi2 (438.87 km2). PERIOD OF RECORD.--March 1999 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Dos Bocas was completed in 1942. The dam is a concrete gravity structure with a total length of 1,317 ft (401.4 m ), a maximum height of 188 ft (57.3 m), and a maximum base width of 158 ft (48.2 m). No-overflow sections on each abutment have a total lenght of 957 f t (292 m). The dam and the powerplant comprise the Dos Bocas Hydroelectric Project, and provides 32,000 acre-feet (39.456 km 3). A three-unit powerplant is located on the right bank of the slitting basin. The dam is owned by Puerto Rico Electric Power Authority. The capacity of Lago Dos Bocas was computed to be 714.40 million ft3 (20.23 million m3) for June 1997. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 298.81 ft (91.08 m), November 8, 2001; minimum elevation, 283.88 ft (86.526 m), August 21, 2000. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 296.00 ft (90.221 m), May 20, 2003; minimum elevation, 285.32 ft (86.966 m), July 24. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 216 0 236 1,403 256 4,491 Elevation Contents 275 9,283 288 13,684 295 16,400 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 290.16 292.69 A A 291.17 289.49 290.98 291.67 293.95 286.32 286.82 293.15 2 291.31 292.30 A 290.94 291.83 290.03 291.75 292.06 293.02 286.06 287.20 290.81 3 291.18 292.95 292.69 A 293.16 289.13 290.64 292.60 293.20 286.55 286.59 289.37 4 291.38 291.27 292.59 A 293.83 289.07 291.22 292.16 293.03 287.03 287.21 289.26 5 291.38 292.05 292.29 A 294.91 289.52 292.02 292.50 294.10 287.46 286.52 291.05 6 291.20 291.78 A 292.46 293.92 290.01 291.95 291.70 292.56 286.30 286.93 291.04 7 292.47 291.47 A A 293.81 289.35 292.46 292.05 292.92 286.65 286.54 290.67 8 292.99 291.01 281.81 290.95 293.87 289.86 291.91 292.48 291.38 287.06 286.90 290.62 9 292.47 290.49 A A 293.83 289.23 292.33 292.69 291.76 286.71 286.81 289.94 10 292.47 290.69 291.61 A 293.80 289.70 292.43 293.45 292.14 287.13 287.14 289.52 11 290.96 290.31 291.45 A 293.27 289.21 291.56 293.92 291.84 286.54 A 290.64 12 291.52 290.91 289.96 A 293.77 289.64 292.03 292.97 292.11 286.95 286.25 291.56 13 A 294.25 A 290.99 293.28 289.36 292.47 293.08 291.64 286.51 286.99 292.20 14 292.94 293.37 290.23 A 292.91 289.19 291.58 292.29 291.43 286.97 288.36 293.74 15 292.98 293.06 289.95 290.97 292.42 288.89 291.77 292.38 291.67 287.40 288.50 293.54 16 291.63 291.52 289.78 291.08 292.77 289.29 292.18 292.89 290.44 286.59 289.26 292.38 17 290.60 291.64 290.75 291.52 292.41 288.99 291.61 294.29 290.92 287.22 289.77 291.06 18 290.28 290.50 292.33 291.96 291.75 289.35 293.80 293.58 292.58 285.68 288.93 290.61 19 290.73 289.44 292.17 291.56 291.67 289.42 292.92 294.92 292.01 286.10 287.93 292.29 20 291.01 292.00 292.00 291.12 289.98 292.37 295.68 290.38 286.50 287.40 291.77 21 291.48 288.42 292.06 291.53 290.51 289.72 292.52 293.38 288.45 285.78 288.12 292.80 22 290.90 A 292.88 292.02 289.92 290.16 291.17 292.21 285.63 286.19 289.16 291.39 23 290.28 A 293.83 292.47 289.63 289.45 290.73 293.24 286.09 286.55 290.13 289.94 24 289.27 A A 291.30 289.35 289.89 293.39 292.33 286.56 285.47 291.52 290.79 25 290.34 A 293.23 290.45 289.75 289.26 295.55 292.83 286.26 286.32 288.68 291.81 26 290.30 289.64 A 291.65 290.18 289.67 293.15 292.47 286.69 286.84 288.13 291.33 27 290.17 A 292.53 292.42 289.41 290.60 292.73 292.23 287.14 287.33 288.33 291.27 28 290.68 289.78 292.08 292.67 289.97 289.74 292.63 292.64 286.28 A 289.99 291.05 29 290.35 290.63 A 292.10 290.45 292.28 293.12 286.70 286.92 291.29 290.18 30 290.39 290.69 A 292.13 291.32 292.08 293.28 287.14 286.06 293.53 289.45 31 291.69 291.09 292.69 291.19 292.63 A 295.01 MAX 294.91 291.32 295.55 295.68 294.10 293.74 MIN 289.35 288.89 290.64 291.67 285.63 289.26 A No gage-height record 140 RIO GRANDE DE ARECIBO BASIN 50027100 LAGO DOS BOCAS AT DAMSITE NEAR UTUADO, PR—Continued O N D J F M A M J J A S 280 282 284 286 288 290 292 294 296 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 141 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR LOCATION.--Lat 18q20'50", long 66q40'02", at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6 km) west of Florida Plaza. DRAINAGE AREA.--169 mi2 (436 km2). This does not include 6.0 mi2 (15.5 km2) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 09... 1200 27 7.2 6.0 74 6.4 228 25.5 85 23.4 6.40 2.02 .5 MAR 18... 1200 32 E3.2 5.9 -- 7.5 234 26.0 90 24.1 7.13 2.13 .5 MAY 21... 1555 -- 370 5.8 -- 7.2 160 25.7 59 16.3 4.56 2.30 .4 AUG 19... 1048 -- 6.7 5.4 -- 7.2 216 27.7 -- -- -- -- -­ SEP 18... 1550 -- 18 4.7 -- 7.2 213 27.5 81 22.3 6.23 2.29 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 09... 9.73 81 10.5 <.17 24.6 11.0 -- 136 -- <10 .30 .03 .69 MAR 18... 11.5 89 11.5 .12 23.4 12.9 <.1 146 12.7 <10 .30 .13 .09 MAY 21... 7.58 57 7.65 <.2 17.5 9.0 <.1 99 -- 132 .90 .10 .60 AUG 19... -- 80 -- -- -- -- -- -- -- <10 .40 .23 .14 SEP 18... 9.16 78 9.95 <.2 21.1 11.1 -- 129 -- 10 .50 .02 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 09... .720 .03 .27 .03 1.0 4.5 <10 E16 121 -- -- -- -­ MAR 18... .100 .01 .17 <.02 .40 1.8 <10 E5 -- 300 <2 39.0 <18 MAY 21... .650 .05 .80 .22 1.6 6.9 10 2,800 -- E8,000 <2 87.0 E17 AUG 19... .160 .02 .17 <.02 .56 2.5 <10 E11 -- 240 -- -- -­ SEP 18... .920 <.01 .48 .02 1.4 6.3 <10 E66 -- 290 -- -- -­ 142 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 09... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 18... <.2 <.8 <10 M 90 <1 134 <.02 <3 <.3 <25 <.10 <16 MAY 21... <.2 4.9 20 <.01 5,270 3 220 .02 <3 E.2 27 <.10 <16 AUG 19... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 18... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 143 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR LOCATION.--Lat 18q23'55", long 66q41'29", Hydrologic Unit 21010002, on left side of old Highway 10, 7.2 mi (11.6 km) north of Lago Dos Bocas Dam, 5.4 mi (8.69 km) from Plaza Rosario at Arecibo town and 3.8 mi (6.11 km) east from La Esperanza School. DRAINAGE AREA.--173.7 mi2 (449 km2), approximately, of which an undetermined amount does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to February 1962 yearly measurements only, May 2001 to current year. GAGE.--Water-stage recorder. Elevation of gage is 49.2 ft (15 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Flow affected by Lago Dos Bocas Dam 7.2 mi (11.6 km) upstream from gage. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 244 187 e112 100 e502 235 210 243 308 295 67 1,020 2 172 565 e98 308 172 88 58 155 549 214 60 1,090 3 329 304 e277 123 65 e238 384 56 396 53 112 1,070 4 270 722 e210 193 100 e173 266 54 117 50 165 594 5 342 229 e297 75 206 e77 56 225 227 51 280 181 6 269 183 e203 53 611 57 274 286 680 333 54 350 7 583 277 e203 52 253 e311 60 60 117 111 88 531 8 581 288 e192 506 189 49 269 53 404 86 166 622 9 705 298 e181 173 194 276 60 348 174 205 125 632 10 742 281 265 70 178 48 91 74 78 68 51 549 11 791 295 272 e78 386 e277 349 56 111 245 339 567 12 306 132 596 e154 60 51 60 317 189 55 112 575 13 289 245 204 122 154 201 47 114 146 221 48 607 14 556 931 150 59 254 159 308 306 233 62 44 185 15 797 713 345 293 269 116 64 126 154 48 377 634 16 700 808 192 139 167 141 91 60 408 288 98 875 17 567 314 246 e78 91 268 324 129 139 55 154 803 18 451 494 168 e60 312 65 350 656 59 305 426 639 19 211 483 214 234 264 272 698 690 192 156 385 203 20 261 298 e221 55 148 57 501 1,420 707 47 238 404 21 350 409 e179 e47 286 197 599 1,670 468 243 64 452 22 478 319 e163 e54 279 59 993 979 733 55 48 690 23 607 127 e160 50 240 199 564 250 131 46 83 559 24 550 60 296 396 260 133 176 505 56 301 97 327 25 178 168 334 615 134 235 635 185 129 61 812 306 26 177 164 334 370 63 149 1,240 261 111 64 377 308 27 309 87 298 69 323 61 368 213 57 49 332 224 28 132 289 180 107 74 385 238 165 305 322 148 208 29 252 e177 e201 217 91 206 84 62 55 176 336 30 286 e122 293 257 46 264 59 52 267 191 306 31 353 255 e67 191 243 60 455 TOTAL 12,838 9,969 7,339 5,174 6,234 4,905 9,803 10,042 7,492 4,471 6,172 15,847 MEAN 414 332 237 167 223 158 327 324 250 144 199 528 MAX 797 931 596 615 611 385 1,240 1,670 733 333 812 1,090 MIN 132 60 98 47 60 46 47 53 52 46 44 181 AC-FT 25,460 19,770 14,560 10,260 12,370 9,730 19,440 19,920 14,860 8,870 12,240 31,430 CFSM 2.38 1.91 1.36 0.96 1.28 0.91 1.88 1.86 1.44 0.83 1.15 3.04 IN. 2.75 2.13 1.57 1.11 1.34 1.05 2.10 2.15 1.60 0.96 1.32 3.39 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 386 547 340 214 191 159 592 482 257 239 296 470 MAX 414 762 443 261 223 160 857 640 278 303 347 528 (WY) (2003) (2002) (2002) (2002) (2003) (2002) (2002) (2002) (2001) (2001) (2002) (2003) MIN 358 332 237 167 160 158 327 324 245 144 199 419 (WY) (2002) (2003) (2003) (2003) (2002) (2003) (2003) (2003) (2002) (2003) (2003) (2002) 144 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2001 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 132,280 ANNUAL MEAN 362 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2,850 LOWEST DAILY MEAN 50 ANNUAL SEVEN-DAY MINIMUM 113 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 262,400 ANNUAL RUNOFF (CFSM) 2.09 ANNUAL RUNOFF (INCHES) 28.33 10 PERCENT EXCEEDS 695 50 PERCENT EXCEEDS 264 90 PERCENT EXCEEDS 132 100,286 275 343 410 2002 275 2003 Apr 30 1,670 May 21 7,130 Nov 8, 2001 Feb 9 44 Aug 14 44 Aug 14, 2003 Feb 3 83 Jan 17 83 Jan 17, 2003 2,480 May 20 14,900 Nov 8, 2001 9.03 May 20 14.72 Nov 8, 2001 198,900 248,200 1.58 1.97 21.48 26.80 602 656 214 250 57 65 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 145 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--February 1959 to February 1962 yearly measurements only, May 2001 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2001 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 2001. REMARKS.-- Sediment samples were collected by local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 671 mg/L November 9, 2001; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 14,700 tons (13,336 tonnes) November 8, 2001; Minimum daily mean, 0.19 ton (0.17 tonne) July 27, 2002. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 166 mg/L April 26, 2003; Minimum daily mean, 2 mg/L November 24, 2002. SEDIMENT LOADS: Maximum daily mean, 679 tons (616 tonnes) April 26, 2003; Minimum daily mean, 0.39 ton (0.35 tonne) July 15, 200 3. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 244 23 34 187 7 11 e112 e7 e3.4 2 172 27 32 565 20 47 e98 e3 e0.70 3 329 39 82 304 14 22 e277 e12 e19 4 270 33 58 722 25 71 e210 e13 e11 5 342 33 62 229 12 14 e297 e12 e19 6 269 31 58 183 7 11 e203 e13 e11 7 583 53 158 277 14 20 e203 e13 e11 8 581 45 128 288 13 18 e192 e6 e5.4 9 705 41 127 298 15 22 e181 e6 e5.4 10 742 49 155 281 16 22 265 14 20 11 791 23 55 295 15 15 272 12 19 12 306 15 19 132 7 3.4 596 29 88 13 289 25 40 245 9 15 204 13 11 14 556 44 101 931 34 117 150 5 4.1 15 797 48 148 713 28 84 345 9 12 16 700 41 116 808 31 100 192 6 5.4 17 567 25 53 314 18 25 246 7 7.4 18 451 24 39 494 11 15 168 6 4.6 19 211 16 14 483 8 11 214 6 6.5 20 261 18 20 298 10 7.6 e221 e6 e6.5 21 350 21 29 409 16 30 e179 e6 e4.6 22 478 24 42 319 21 25 e163 e6 e4.6 23 607 47 119 127 8 5.1 e160 e6 e4.6 24 550 25 53 60 2 0.44 296 7 9.6 25 178 11 12 168 6 4.5 334 7 11 26 177 6 10 164 9 9.6 334 8 12 27 309 14 22 87 3 0.70 298 7 10 28 132 8 5.5 289 11 19 180 8 6.2 29 252 8 13 e177 e9 e9.6 e201 e7 e6.3 30 286 11 18 e122 e7 e3.4 293 8 11 31 353 12 17 255 7 8.8 TOTAL 12,838 1,839.5 9,969 758.34 7,339 359.10 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 146 RIO GRANDE DE ARECIBO BASIN 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 100 5 2.1 e502 e11 e20 235 6 5.2 2 308 7 11 172 8 5.9 88 6 1.6 3 123 6 3.2 65 6 0.96 e238 e7 e8.1 4 193 7 6.3 100 5 2.1 e173 e6 e3.4 5 75 4 0.79 206 7 5.1 e77 e6 e1.4 6 53 4 0.51 611 11 23 57 5 0.83 7 52 3 0.46 253 8 6.9 e311 e8 e11 8 506 9 22 189 7 4.8 49 7 0.88 9 173 8 7.1 194 7 5.1 276 9 10 10 70 5 0.89 178 7 4.7 48 7 0.86 11 e78 e5 e0.89 386 8 11 e277 e7 e6.5 12 e154 e6 e3.6 60 6 0.95 51 7 0.92 13 122 6 2.7 154 6 5.0 201 7 4.7 14 59 4 0.71 254 8 9.1 159 7 3.5 15 293 8 11 269 8 9.8 116 7 2.6 16 139 6 3.6 167 7 5.8 141 7 3.3 17 e78 e5 e0.89 91 5 1.9 268 8 6.7 18 e60 e4 e0.71 312 7 7.5 65 7 1.2 19 234 7 8.6 264 8 9.5 272 8 7.0 20 55 6 0.83 148 6 4.5 57 8 1.2 21 e47 e4 e0.55 286 8 10 197 8 5.2 22 e54 e6 e0.83 279 8 10 59 9 1.4 23 50 4 0.55 240 8 9.2 199 13 11 24 396 8 16 260 8 9.2 133 10 4.7 25 615 10 18 134 8 4.3 235 12 12 26 370 7 8.1 63 5 0.84 149 17 8.0 27 69 5 0.92 323 7 8.6 61 14 2.3 28 107 4 1.2 74 6 1.2 385 16 23 29 217 5 7.6 91 8 2.7 30 257 8 8.1 46 5 0.68 31 e67 e5 e0.92 191 10 8.6 TOTAL 5,174 150.65 6,234 196.95 4,905 160.47 APRIL MAY JUNE 1 210 9 8.6 243 47 64 308 60 101 2 58 6 0.95 155 39 32 549 85 183 3 384 11 19 56 16 2.5 396 103 167 4 266 16 14 54 11 1.6 117 59 23 5 56 13 1.9 225 43 37 227 67 47 6 274 17 21 286 33 49 680 50 88 7 60 11 1.8 60 10 1.6 117 20 6.3 8 269 16 21 53 9 1.4 404 25 44 9 60 4 0.73 348 29 60 174 49 25 10 91 3 0.77 74 17 3.6 78 44 9.3 11 349 11 25 56 12 1.8 111 42 14 12 60 7 1.1 317 27 49 189 43 26 13 47 6 0.73 114 13 4.0 146 35 14 14 308 16 24 306 27 44 233 44 30 15 64 18 3.2 126 12 4.6 154 46 20 16 91 19 4.5 60 15 2.5 408 41 49 17 324 76 195 129 16 15 139 35 13 18 350 81 223 656 72 145 59 36 5.8 19 698 116 287 690 71 162 192 38 22 20 501 92 159 1,420 68 291 707 29 69 21 599 122 276 1,670 94 436 468 19 48 22 993 163 528 979 43 121 733 23 71 23 564 73 155 250 31 28 131 34 12 24 176 103 59 505 38 63 56 31 4.7 25 635 78 194 185 29 17 129 28 9.4 26 1,240 166 679 261 32 32 111 25 7.6 27 368 65 98 213 33 32 57 22 3.4 28 238 48 61 165 31 26 305 30 32 29 206 41 39 84 32 7.1 62 36 6.1 30 264 47 68 59 44 6.9 52 35 4.9 31 243 45 73 TOTAL 9,803 3,169.28 10,042 1,813.6 7,492 1,155.5 --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 147 50027600 RIO GRANDE DE ARECIBO NEAR SAN PEDRO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 295 30 28 67 12 2.2 1,020 8 22 2 214 15 18 60 12 1.9 1,090 9 26 3 53 5 0.77 112 13 6.4 1,070 10 28 4 50 5 0.62 165 8 8.7 594 11 24 5 51 4 0.60 280 12 20 181 17 8.6 6 333 13 23 54 13 1.8 350 16 17 7 111 6 1.7 88 12 4.5 531 18 28 8 86 5 1.1 166 13 9.0 622 18 33 9 205 9 11 125 18 9.3 632 18 33 10 68 6 1.3 51 30 4.2 549 18 29 11 245 9 16 339 25 30 567 18 30 12 55 4 0.57 112 8 3.3 575 18 30 13 221 10 16 48 14 1.8 607 18 32 14 62 4 0.64 44 22 2.6 185 17 8.7 15 48 3 0.39 377 21 30 634 18 33 16 288 10 20 98 6 4.0 875 20 47 17 55 4 0.55 154 7 7.1 803 20 43 18 305 11 23 426 14 30 639 17 30 19 156 8 7.8 385 15 28 203 12 6.9 20 47 4 0.57 238 16 18 404 11 12 21 243 10 16 64 26 4.4 452 9 10 22 55 5 0.71 48 16 2.1 690 8 15 23 46 4 0.54 83 15 4.5 559 9 14 24 301 12 23 97 18 5.4 327 10 8.9 25 61 9 1.6 812 41 136 306 11 8.7 26 64 9 1.5 377 17 18 308 7 6.1 27 49 8 1.0 332 15 15 224 7 4.4 28 322 13 24 148 9 5.5 208 7 4.1 29 55 9 1.4 176 3 2.1 336 7 6.8 30 267 13 20 191 3 2.9 306 7 5.8 31 60 13 2.2 455 6 9.1 TOTAL 4,471 263.56 6,172 427.8 15,847 605.0 YEAR 100,286 10,899.75 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 26... 0439 1,620 93 430 1,880 --- --- --- --- --- --- --- 148 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR LOCATION.--Lat 18q18'02", long 66q46'58", Hydrologic Unit 21010001, on downstream side of left abutment of bridge on Highway 111, 1.2 mi (1.9 km) upstream from natural tunnel, 1.5 mi (2.4 km) northeast of Angeles, and 5.8 mi (9.3 km) northwest of Utuado. DRAINAGE AREA.--18.4 mi2 (47.7 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1944 to June 1958 (daily stage and two to four measurements per month by Puerto Rico Water Resources Authority), November 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 938.3 ft (286.0 m) above mean sea level. Datum of gage was increased by 3.0 ft (0.91 m) on October 1978. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 41 81 36 25 20 12 17 23 37 23 19 23 2 38 108 34 25 19 12 18 21 36 26 19 21 3 36 59 34 25 19 12 16 21 33 23 36 23 4 54 43 37 23 25 11 15 31 32 23 33 19 5 39 39 35 22 40 11 14 41 41 22 23 18 6 35 38 32 23 30 11 16 29 38 22 31 17 7 62 36 31 23 20 12 14 33 32 22 38 58 8 44 34 31 22 19 11 13 34 31 22 28 27 9 67 34 30 22 18 11 13 27 30 23 20 20 10 118 33 29 22 17 12 12 48 32 22 19 18 11 48 32 28 22 17 11 13 36 33 22 32 41 12 41 170 27 21 16 11 13 31 28 23 27 25 13 56 168 28 21 17 11 12 28 38 19 21 34 14 79 82 28 20 18 11 13 26 33 19 28 30 15 49 57 27 21 16 11 12 41 27 18 28 22 16 40 63 27 20 15 11 12 53 27 19 23 20 17 38 53 38 20 15 11 16 101 26 20 27 19 18 36 47 37 19 14 11 53 88 58 18 26 18 19 36 45 28 20 14 15 28 82 35 17 28 19 20 34 43 27 18 15 14 30 221 29 19 20 27 21 77 e41 26 19 13 12 52 124 27 18 18 24 22 42 e40 27 20 13 11 74 127 26 20 18 25 23 47 39 200 19 13 11 41 72 25 19 41 19 24 39 37 45 21 12 11 76 57 24 19 33 151 25 35 37 30 33 12 11 223 50 24 19 30 127 26 39 39 27 45 12 13 71 46 24 18 27 61 27 34 37 26 24 13 21 38 44 24 21 22 34 28 32 39 25 21 12 19 29 40 23 25 21 28 29 33 38 25 21 23 26 38 23 20 23 25 30 48 44 24 21 30 24 36 22 17 43 24 31 63 24 20 e14 34 19 36 TOTAL 1,480 1,656 1,103 698 484 408 1,004 1,683 918 637 838 1,017 MEAN 47.7 55.2 35.6 22.5 17.3 13.2 33.5 54.3 30.6 20.5 27.0 33.9 MAX 118 170 200 45 40 30 223 221 58 26 43 151 MIN 32 32 24 18 12 11 12 21 22 17 18 17 AC-FT 2,940 3,280 2,190 1,380 960 809 1,990 3,340 1,820 1,260 1,660 2,020 CFSM 2.59 3.00 1.93 1.22 0.94 0.72 1.82 2.95 1.66 1.12 1.47 1.84 IN. 2.99 3.35 2.23 1.41 0.98 0.82 2.03 3.40 1.86 1.29 1.69 2.06 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2003, BY WATER YEAR (WY) MEAN 80.9 70.2 43.6 30.2 25.8 24.8 38.2 58.3 44.0 36.0 47.2 77.2 MAX 195 159 121 71.0 50.8 71.2 151 193 117 65.7 110 208 (WY) (1990) (1969) (1966) (1997) (1996) (1972) (2002) (1963) (1999) (1981) (1979) (1998) MIN 25.4 25.1 18.1 14.7 13.2 11.0 9.70 12.4 15.6 9.18 15.9 25.0 (WY) (1963) (1995) (1998) (1998) (1965) (1984) (1984) (1977) (1994) (1994) (1994) (1994) RIO GRANDE DE ARECIBO BASIN 149 50028000 RIO TANAMA NEAR UTUADO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1960 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 21,088 ANNUAL MEAN 57.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 305 LOWEST DAILY MEAN 18 ANNUAL SEVEN-DAY MINIMUM 19 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 41,830 ANNUAL RUNOFF (CFSM) 3.14 ANNUAL RUNOFF (INCHES) 42.63 10 PERCENT EXCEEDS 111 50 PERCENT EXCEEDS 41 90 PERCENT EXCEEDS 23 11,926 32.7 48.1 71.7 1999 20.7 1994 Apr 27 223 Apr 25 3,260 Sep 22, 1998 Mar 25 11 Mar 4 5.4 Aug 4, 1994 Mar 1 11 Mar 11 6.4 Jul 29, 1994 1,960 Nov 12 23,500 Sep 22, 1998 10.24 Nov 12 21.24 Sep 22, 1998 10 Mar 16 5.4 Aug 4, 1994 23,660 34,840 1.78 2.61 24.11 35.52 53 87 26 34 13 16 e Estimated 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 150 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 11... 1000 29 4.2 8.9 100 6.6 170 20.1 59 14.3 5.64 1.68 .4 MAR 19... 1115 11 4.7 8.7 -- 8.0 167 24.2 61 15.0 5.77 1.58 .5 MAY 12... 1415 27 20 8.7 -- 8.5 164 26.5 59 15.5 5.04 2.15 .4 AUG 20... 1415 19 89 8.0 -- 8.0 150 27.9 -- -- -- -- -­ SEP 16... 0900 21 16 8.3 -- 7.7 169 23.9 63 16.3 5.42 2.12 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 11... 7.59 85 7.80 <.17 26.1 10.1 -- 124 9.88 <10 <.20 <.01 -­ MAR 19... 8.32 57 8.20 .07 23.5 12.3 <.1 109 3.12 <10 <.20 .02 -­ MAY 12... 7.59 52 8.04 <.17 23.1 10.0 <.1 103 7.37 <10 <.20 .01 -­ AUG 20... -- 48 -- -- -- -- -- -- -- 23 .30 .04 .83 SEP 16... 7.18 57 8.19 <.2 24.9 10.8 -- 109 6.10 <10 <.20 .01 .77 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 11... .950 <.01 -- <.02 -- -- <10 110 E535 -- -- -- -­ MAR 19... .600 <.01 -- <.02 -- -- <10 E61 -- 2,500 <2 24.7 <18 MAY 12... .700 <.01 -- <.02 -- -- <10 500 -- 3,000 <2 26.1 E10 AUG 20... .850 .02 .26 .03 1.1 5.1 10 E1,100 -- 7,500 -- -- -­ SEP 16... .780 .01 -- .02 -- -- 10 150 -- 3,300 -- -- -­ 151 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 11... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 19... <.2 <.8 <10 <.01 40 <1 13.2 <.02 <3 <.3 <25 <.10 <16 MAY 12... <.2 E.6 M <.01 350 <1 33.0 <.02 <3 <.3 E24 <.10 <16 AUG 20... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 16... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- 152 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. INSTRUMENTATION.--USDH-48 sediment sampler since October 1968. Automatic sediment sampler since 1990. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 20,400 mg/L November 27, 1968; Minimum daily mean, 1 mg/L several days during several years. SEDIMENT LOADS: Maximum daily mean, 240,000 tons (218,000 tonnes) September 22, 1998; Minimum daily mean, <0.01 ton ( <0.01 tonne) several days during several years. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 1,190 mg/L April 25, 2003; Minimum daily mean, 2 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 2,590 tons (2,350 tonnes) April 25, 2003; Minimum daily mean, 0.07 ton (0.06 tonne) April 15 , 16, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 41 34 3.9 81 197 116 36 9 0.88 2 38 7 0.72 108 338 277 34 7 0.61 3 36 7 0.68 59 93 17 34 5 0.50 4 54 61 19 43 25 2.9 37 6 0.56 5 39 12 1.3 39 20 2.1 35 6 0.59 6 35 7 0.66 38 17 1.7 32 7 0.58 7 62 98 37 36 14 1.4 31 6 0.47 8 44 101 12 34 14 1.3 31 4 0.32 9 67 151 46 34 15 1.3 30 4 0.31 10 118 465 699 33 15 1.3 29 6 0.49 11 48 56 7.5 32 15 1.3 28 7 0.50 12 41 40 4.4 170 635 1,970 27 7 0.50 13 56 82 26 168 682 1,290 28 7 0.52 14 79 180 104 82 152 40 28 7 0.52 15 49 55 7.5 57 59 9.2 27 7 0.50 16 40 42 4.6 63 85 18 27 7 0.50 17 38 39 3.9 53 45 6.4 38 28 7.1 18 36 32 3.1 47 18 2.3 37 21 3.0 19 36 25 2.4 45 11 1.3 28 6 0.44 20 34 17 1.6 43 8 0.91 27 5 0.37 21 77 148 71 e41 e5 e0.59 26 5 0.33 22 42 41 4.8 e40 e5 e0.54 27 4 0.32 23 47 36 6.5 39 5 0.53 200 1,180 2,200 24 39 25 2.8 37 5 0.51 45 172 24 25 35 8 0.76 37 5 0.50 30 64 5.2 26 39 8 0.84 39 5 0.49 27 36 2.6 27 34 8 0.72 37 4 0.44 26 12 0.83 28 32 8 0.70 39 17 2.4 25 8 0.54 29 33 8 0.72 38 31 3.4 25 7 0.46 30 48 39 18 44 32 4.3 24 13 0.81 31 63 96 29 24 15 0.98 TOTAL 1,480 1,121.10 1,656 3,775.11 1,103 2,255.33 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE ARECIBO BASIN 153 50028000 RIO TANAMA NEAR UTUADO, PR.—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 25 11 0.75 20 18 0.96 12 5 0.17 2 25 7 0.51 19 19 0.94 12 5 0.15 3 25 4 0.29 19 19 0.97 12 4 0.14 4 23 4 0.28 25 18 1.2 11 4 0.13 5 22 5 0.28 40 61 19 11 5 0.16 6 23 5 0.30 30 49 4.5 11 6 0.18 7 23 5 0.28 20 5 0.26 12 6 0.19 8 22 4 0.25 19 4 0.20 11 6 0.18 9 22 4 0.23 18 4 0.20 11 6 0.18 10 22 3 0.21 17 4 0.18 12 6 0.19 11 22 3 0.18 17 4 0.20 11 6 0.18 12 21 3 0.15 16 7 0.33 11 6 0.18 13 21 2 0.13 17 11 0.48 11 6 0.18 14 20 2 0.12 18 13 0.62 11 6 0.19 15 21 3 0.15 16 12 0.50 11 6 0.18 16 20 3 0.18 15 9 0.36 11 6 0.18 17 20 4 0.21 15 7 0.27 11 6 0.17 18 19 5 0.24 14 6 0.23 11 6 0.18 19 20 5 0.28 14 6 0.23 15 6 0.24 20 18 6 0.29 15 6 0.23 14 6 0.23 21 19 6 0.30 13 5 0.16 12 6 0.19 22 20 6 0.31 13 4 0.13 11 6 0.18 23 19 6 0.29 13 7 0.23 11 6 0.19 24 21 5 0.31 12 11 0.35 11 6 0.18 25 33 5 0.47 12 14 0.46 11 6 0.19 26 45 5 0.62 12 10 0.33 13 7 0.24 27 24 5 0.32 13 6 0.21 21 7 0.39 28 21 5 0.28 12 6 0.18 19 7 0.37 29 21 5 0.29 23 11 1.1 30 21 9 0.50 30 23 3.2 31 20 14 0.75 e14 e8 e0.31 TOTAL 698 9.75 484 33.91 408 10.12 APRIL MAY JUNE 1 17 7 0.31 23 12 0.72 37 6 0.59 2 18 7 0.34 21 9 0.49 36 6 0.58 3 16 7 0.31 21 6 0.34 33 6 0.53 4 15 7 0.28 31 27 5.0 32 6 0.48 5 14 7 0.28 41 46 7.5 41 31 5.0 6 16 8 0.34 29 51 4.2 38 33 3.6 7 14 8 0.32 33 25 3.2 32 20 1.8 8 13 9 0.31 34 29 2.8 31 14 1.1 9 13 11 0.38 27 19 1.4 30 13 1.0 10 12 7 0.23 48 131 80 32 12 1.0 11 13 3 0.11 36 32 3.7 33 12 1.1 12 13 3 0.10 31 24 2.1 28 12 0.92 13 12 3 0.09 28 20 1.6 38 35 7.8 14 13 2 0.08 26 17 1.1 33 7 0.65 15 12 2 0.07 41 60 15 27 8 0.56 16 12 2 0.07 53 138 56 27 9 0.65 17 16 2 0.08 101 282 213 26 10 0.69 18 53 78 17 88 207 101 58 85 26 19 28 35 3.3 82 198 98 35 35 3.4 20 30 32 3.8 221 690 1,420 29 22 1.7 21 52 76 19 124 301 157 27 17 1.3 22 74 139 58 127 377 303 26 13 0.96 23 41 51 6.3 72 226 44 25 10 0.66 24 76 228 150 57 169 26 24 7 0.47 25 223 1,190 2,590 50 116 16 24 12 0.76 26 71 130 32 46 63 7.7 24 17 1.1 27 38 36 3.7 44 18 2.2 24 8 0.54 28 29 20 1.6 40 9 0.98 23 4 0.22 29 26 14 0.98 38 17 1.7 23 4 0.25 30 24 12 0.76 36 12 1.1 22 5 0.27 31 34 6 0.55 TOTAL 1,004 2,890.14 1,683 2,577.38 918 65.68 --- --- --- --- --- --- 154 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR.—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 23 5 0.32 19 7 0.35 23 24 1.5 2 26 7 0.46 19 6 0.33 21 18 1.0 3 23 8 0.49 36 36 7.7 23 16 1.0 4 23 9 0.54 33 33 3.8 19 15 0.78 5 22 8 0.48 23 18 1.2 18 14 0.66 6 22 7 0.44 31 26 2.9 17 14 0.61 7 22 7 0.41 38 35 4.2 58 163 131 8 22 6 0.37 28 23 1.9 27 40 3.0 9 23 6 0.38 20 12 0.63 20 32 1.7 10 22 6 0.35 19 12 0.62 18 26 1.3 11 22 6 0.36 32 39 6.1 41 76 24 12 23 6 0.38 27 87 6.5 25 20 1.4 13 19 7 0.34 21 83 4.7 34 31 3.5 14 19 7 0.35 28 87 7.2 30 24 2.3 15 18 7 0.35 28 82 6.5 22 12 0.70 16 19 9 0.47 23 72 4.4 20 11 0.61 17 20 12 0.62 27 74 6.0 19 11 0.57 18 18 14 0.68 26 64 4.5 18 13 0.67 19 17 15 0.70 28 63 5.1 19 17 0.86 20 19 11 0.56 20 23 1.3 27 24 2.2 21 18 7 0.36 18 23 1.1 24 18 1.1 22 20 4 0.21 18 23 1.1 25 17 1.5 23 19 2 0.13 41 78 29 19 14 0.73 24 19 2 0.09 33 50 5.8 151 607 1,140 25 19 8 0.38 30 26 2.5 127 398 508 26 18 14 0.65 27 31 2.3 61 100 23 27 21 14 0.78 22 29 1.8 34 38 3.5 28 25 13 0.89 21 29 1.6 28 34 2.6 29 20 11 0.59 23 42 2.6 25 30 2.0 30 17 9 0.42 43 63 11 24 26 1.6 31 19 8 0.40 36 37 5.9 TOTAL 637 13.95 838 140.63 1,017 1,863.39 YEAR 11,926 14,756.49 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 25... 1919 1,170 84 6,260 19,800 155 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18q24'52", long 66q42'52", Hydrologic Unit 21010002, on right bank at abandoned power house at Charco Hondo, 1.5 mi (2.4 km) upstream from mouth, and 4 mi (6 km) south of Arecibo. DRAINAGE AREA.--22.2 mi2 (57.5 km2). PERIOD OF RECORD.--April 1969 to June 1971, October 1981 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 60 ft (18 m), from topographic map. REMARKS.--Records poor. Diversion 0.8 mi (1.3 km) upstream for municipal supply of Arecibo. Gage-height and precipitation satell ite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 126 169 e79 e65 e45 2 155 212 e75 e65 e44 3 155 198 e75 e64 47 4 173 123 e80 e57 54 5 134 107 e76 e56 62 30 e32 51 e74 47 43 102 29 39 50 e71 50 37 60 29 43 48 e66 53 40 63 30 38 45 e67 47 73 94 28 e47 71 e78 48 61 53 6 99 95 e70 e58 7 160 93 e69 e56 8 192 90 e67 e55 9 175 88 e66 e55 10 257 94 e63 e54 105 30 67 83 e75 47 43 45 50 30 e46 55 e67 45 64 64 44 29 e30 64 e65 45 64 91 41 29 e31 62 e64 44 41 51 42 28 32 80 e68 42 38 46 11 160 90 e63 e53 12 118 188 e60 e52 13 130 e306 e60 e54 14 186 327 e61 e52 15 233 270 e58 e52 40 28 31 108 e70 38 40 83 36 29 30 75 e61 42 80 123 39 27 31 60 62 39 43 74 40 29 39 54 83 40 46 71 38 30 28 94 63 38 78 50 16 185 280 e57 e50 17 136 209 e59 e51 18 132 162 99 e49 19 107 131 83 e50 20 98 114 74 e47 36 27 28 144 62 40 69 45 39 28 31 155 81 41 43 55 39 27 97 232 141 40 61 55 38 28 125 188 174 40 44 41 39 30 59 389 96 41 53 49 21 168 e96 72 e48 22 176 e92 71 e51 23 152 e90 253 e50 24 191 e88 161 e52 25 e123 e88 81 e72 39 28 119 440 79 41 40 107 35 28 182 e257 74 43 37 118 32 28 135 e183 64 39 59 135 32 28 163 123 56 38 83 209 33 29 375 e101 54 40 120 244 26 e112 e89 70 e99 27 e106 e84 67 e61 28 e104 e86 65 48 29 90 e84 63 46 30 e90 e94 61 47 31 e128 --- 59 46 33 29 294 e91 51 40 126 187 33 33 e119 e82 50 39 77 170 32 41 76 e77 47 51 51 124 --- 39 65 66 47 50 52 102 --- 63 55 e62 47 38 87 74 --- 32 --- e61 --- 37 213 --­ TOTAL 4,551 4,237 2,417 1,715 MEAN 147 141 78.0 55.3 MAX 257 327 253 99 MIN 90 84 57 46 AC-FT 9,030 8,400 4,790 3,400 CFSM 6.61 6.36 3.51 2.49 IN. 7.63 7.10 4.05 2.87 1,187 953 2,487 3,651 2,157 1,323 2,006 2,785 42.4 30.7 82.9 118 71.9 42.7 64.7 92.8 105 63 375 440 174 53 213 244 32 27 28 45 47 37 37 41 2,350 1,890 4,930 7,240 4,280 2,620 3,980 5,520 1.91 1.38 3.73 5.31 3.24 1.92 2.91 4.18 1.99 1.60 4.17 6.12 3.61 2.22 3.36 4.67 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2003, BY WATER YEAR (WY) MEAN 167 142 87.5 62.8 MAX 335 260 219 167 (WY) (1990) (1982) (1982) (1997) MIN 72.1 50.4 36.4 22.3 (WY) (1983) (1995) (1989) (1989) 51.0 44.4 73.2 128 91.7 66.1 84.9 139 106 76.1 232 371 236 120 168 448 (1996) (1999) (2002) (1986) (1999) (1969) (1998) (1998) 16.8 16.6 25.9 15.8 23.3 22.0 35.1 44.9 (1989) (1988) (1989) (1989) (1989) (1989) (1994) (1994) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1969 - 2003 ANNUAL TOTAL 39,645 ANNUAL MEAN 109 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 541 LOWEST DAILY MEAN 39 ANNUAL SEVEN-DAY MINIMUM 40 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 78,640 ANNUAL RUNOFF (CFSM) 4.89 ANNUAL RUNOFF (INCHES) 66.43 10 PERCENT EXCEEDS 206 50 PERCENT EXCEEDS 84 90 PERCENT EXCEEDS 48 29,469 80.7 93.5 133 1999 46.9 1994 Apr 8 440 May 21 6,400 Sep 22, 1998 Mar 1 27 Mar 13 4.2 May 28, 1989 Mar 21 28 Mar 13 5.4 May 22, 1989 2,080 Nov 12 15,000 May 18, 1985 10.35 Apr 25 24.56 Sep 22, 1998 58,450 67,720 3.64 4.21 49.38 57.21 162 180 61 65 32 30 e Estimated 156 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR—Continued O N D J F M A M J J A S 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 157 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR LOCATION.--Lat 18q27'20", long 66q42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 13.9 mi (22.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Río Tanamá junction, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to January 1965 (monthly measurements only), February 1965 to April 1969 (occasional measurements only), May 1969 to September 1983, October 1996 to current year. GAGE.--Water-stage recorder. Datum of gage is 3.73 ft (1.14 m) above mean sea level. REMARKS.--Records poor. Flow regulated by Lago Dos Bocas dam, 13.9 mi (22.4 km) upstream. Gage-height satellite telemetry at sta tion. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 299 204 119 150 88 51 e50 144 147 70 49 651 2 290 407 110 97 230 53 52 154 459 81 50 695 3 196 430 110 205 69 50 64 69 450 68 48 685 4 359 471 214 102 84 92 187 63 154 60 80 462 5 313 381 274 94 93 69 61 92 184 59 83 313 6 273 138 278 79 236 47 123 116 375 72 54 121 7 353 234 247 75 273 59 59 82 235 62 67 335 8 574 247 243 94 167 44 54 79 190 61 81 459 9 587 246 227 237 113 56 52 96 266 63 53 443 10 676 252 222 85 105 44 44 104 94 62 49 397 11 668 274 221 92 143 52 57 123 93 62 63 400 12 438 213 321 227 130 45 57 103 99 58 94 468 13 313 334 338 115 65 48 38 85 85 64 63 439 14 425 726 126 76 86 44 65 154 135 59 57 317 15 704 660 224 97 140 50 42 98 136 53 101 277 16 629 724 192 95 153 51 39 159 96 64 107 565 17 489 499 233 84 61 52 50 129 264 55 77 537 18 465 443 150 67 67 44 84 347 114 61 211 512 19 249 405 123 75 191 52 449 468 178 114 301 242 20 264 353 220 63 62 51 401 1,020 336 52 203 186 21 312 325 226 73 101 46 371 1,460 256 63 124 377 22 466 391 186 62 155 43 685 809 444 56 70 508 23 465 215 306 63 162 45 538 507 297 51 67 467 24 531 130 358 76 127 44 291 325 82 61 109 411 25 353 134 256 358 117 46 399 378 75 50 258 424 26 148 138 271 384 52 48 1,120 235 76 50 457 289 27 252 134 264 162 62 49 367 201 65 47 296 364 28 245 163 242 83 58 68 243 204 74 70 228 232 29 138 237 235 75 106 178 111 59 60 112 239 30 259 122 254 144 71 177 103 60 57 158 276 31 353 225 86 e49 102 58 338 TOTAL 12,086 9,630 7,015 3,775 3,390 1,669 6,397 8,120 5,578 1,923 4,108 12,091 MEAN 390 321 226 122 121 53.8 213 262 186 62.0 133 403 MAX 704 726 358 384 273 106 1,120 1,460 459 114 457 695 MIN 138 122 110 62 52 43 38 63 59 47 48 121 AC-FT 23,970 19,100 13,910 7,490 6,720 3,310 12,690 16,110 11,060 3,810 8,150 23,980 CFSM 1.95 1.60 1.13 0.61 0.61 0.27 1.07 1.31 0.93 0.31 0.66 2.02 IN. 2.25 1.79 1.30 0.70 0.63 0.31 1.19 1.51 1.04 0.36 0.76 2.25 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2003, BY WATER YEAR (WY) MEAN 763 725 510 329 270 280 378 529 429 346 415 664 MAX 1,577 1,529 1,327 651 425 627 1,022 1,192 1,220 854 1,269 1,866 (WY) (1971) (2000) (1982) (1997) (1997) (1972) (2002) (1980) (1979) (1979) (1979) (1979) MIN 331 201 150 108 85.4 53.8 89.7 188 139 62.0 133 271 (WY) (2002) (1998) (1998) (2001) (2001) (2003) (2001) (1977) (1977) (2003) (2003) (1997) 158 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1969 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 125,609 ANNUAL MEAN 344 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 3,140 LOWEST DAILY MEAN 38 ANNUAL SEVEN-DAY MINIMUM 56 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 249,100 ANNUAL RUNOFF (CFSM) 1.72 ANNUAL RUNOFF (INCHES) 23.36 10 PERCENT EXCEEDS 686 50 PERCENT EXCEEDS 247 90 PERCENT EXCEEDS 98 75,782 208 475 691 1979 208 2003 Apr 30 1,460 May 21 15,900 Aug 31, 1979 Mar 5 38 Apr 13 38 Mar 5, 2002 Mar 1 46 Mar 21 46 Mar 21, 2003 1,860 May 21 7.87 May 21 19.28 Sep 22, 1998 150,300 344,300 1.04 2.38 14.10 32.29 458 920 136 333 52 122 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 159 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR—Continued WATER-QUALITY RECORDS LOCATION.--Lat 18q27'20", long 66q42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 8.3 mi (13.4 km) downstream from Lago Dos Bocas, 1.9 mi (3.1 km) downstream from Río Tanamá, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA.--200 mi2 (520 km2), approximately, and excludes 6.0 mi2 (15.6 km2) above lago Garzas. PERIOD OF RECORD.--Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 12... 1500 -- 4.1 9.0 109 7.0 279 25.3 120 38.8 5.99 1.75 .4 MAR 13... 1045 43 3.3 10.7 -- 8.2 299 24.5 140 48.4 4.58 1.00 .2 MAY 06... 1230 93 23 8.2 -- 8.0 270 25.6 120 42.8 4.18 1.52 .3 AUG 11... 1230 48 5.8 10.0 -- 8.3 308 28.3 -- -- -- -- -­ SEP 11... 1100 248 7.3 8.0 -- 7.6 375 26.5 110 33.2 6.41 2.02 .4 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00630) DEC 12... 9.33 131 9.59 <.17 18.3 10.4 -- 173 -- <10 .40 <.01 .720 MAR 13... 6.63 131 9.25 .11 8.9 9.4 <.1 167 19.4 <10 <.20 <.01 .470 MAY 06... 6.53 109 7.76 <.17 12.4 9.2 <.1 150 37.5 <10 <.20 .03 .740 AUG 11... -- 123 -- -- -- -- -- -- -- <10 .30 .02 .520 SEP 11... 9.29 99 10.4 <.2 18.4 10.2 -- 149 100 <10 <.20 .02 .400 Total Fecal Fecal Total Organic Total nitro- COD, coli- strep- coli- Barium, Boron, Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd Date as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) DEC 12... <.01 -- <.02 1.1 5.0 <10 E64 E82 -- -- -- -- -­ MAR 13... <.01 -- <.02 -- -- <10 E18 -- 2,500 <2 18.2 <18 <.2 MAY 06... <.01 -- .02 -- -- <10 260 -- 5,000 <2 25.1 E9.0 <.2 AUG 11... <.01 .28 <.02 .82 3.6 <10 E22 -- 1,200 -- -- -- -­ SEP 11... <.01 -- <.02 -- -- <10 -- -- 5,000 -- -- -- -­ 160 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com­ unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover water recover recover recover recover water, recover recover water, water, -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 12... -- -- -- -- -- -- -- -- -- -- -- -- MAR 13... <.8 <10 <.01 30 <1 9.7 <.02 <3 <.3 <25 <.10 <16 MAY 06... 1.3 M <.01 540 M 47.0 <.02 <3 <.3 <25 <.10 <16 AUG 11... -- -- -- -- -- -- -- -- -- -- -- -- SEP 11... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAY 06... 1230 <.01 <.02 <.01 <.01 <.03 <.1 <.02 <.03 <.02 <.017 <.15 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAY 06... <.02 <.02 <.009 <.01 <.014 <.30 <.02 <.012 <.016 <.014 <.009 <.015 <.02 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAY 06... <.1 <.03 <.02 <1 <.03 < -- Less than 161 Figure 13. Río Grande de Manatí basin. 162 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR LOCATION.--Lat 18q13'25", long 66q23'34", Hydrologic Unit 21010001, on right bank, 0.4 mi (0.6 km) south of junction of Highways 155 and 156 in Orocovis, 2.1 mi (3.4 km) upstream from Río Botijas, and 250 ft (76 m) upstream from bridge on Highway 599. DRAINAGE AREA.--5.03 mi2 (13.0 km2). PERIOD OF RECORD.--April 1981 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 500 ft (152 m), from topographic map. REMARKS.--Records poor. Low flow affected by diversions for water supply. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.5 3.7 1.2 0.81 0.93 0.80 3.1 4.1 2.9 e1.8 1.9 1.5 2 6.2 2.3 1.0 0.76 0.89 0.87 3.8 3.9 2.9 e1.7 1.9 1.5 3 6.1 2.8 1.0 0.71 0.86 0.88 3.8 3.9 2.7 2.0 1.9 11 4 3.1 2.0 1.4 0.72 6.6 0.79 3.5 3.8 2.7 2.9 1.8 5.0 5 2.7 1.7 1.2 0.76 2.8 0.77 65 3.5 2.6 3.2 1.6 3.6 6 1.9 1.7 1.2 0.75 1.3 0.81 12 3.5 2.7 2.3 1.9 3.3 7 2.1 1.7 1.1 0.73 1.1 0.84 6.0 3.3 2.6 1.7 1.9 4.5 8 9.2 1.9 1.0 0.73 0.96 0.82 4.9 3.3 2.5 2.1 1.7 7.6 9 4.2 2.0 1.1 0.72 0.85 0.83 4.5 3.2 2.6 3.3 2.7 4.0 10 2.8 2.4 1.1 0.73 0.87 0.84 3.7 3.2 2.7 2.4 1.5 1.7 11 2.6 2.0 1.1 0.75 12 2.3 1.6 1.0 0.75 13 1.7 1.1 1.4 0.79 14 2.8 1.1 1.8 0.77 15 3.2 1.2 0.85 0.78 0.93 0.74 4.1 2.9 2.4 1.4 2.4 4.3 0.90 0.78 4.0 2.6 2.6 1.7 2.5 12 0.81 0.79 3.7 2.6 2.6 5.0 2.1 7.5 0.79 0.80 3.7 2.4 2.5 3.7 1.9 6.2 0.80 0.82 4.1 2.2 2.6 2.7 3.2 9.2 16 2.9 1.2 0.82 0.90 17 2.9 0.92 1.1 0.78 18 1.9 0.97 1.1 0.79 19 2.2 1.2 0.82 0.80 20 2.8 0.96 0.85 0.78 0.86 0.82 3.9 2.3 2.6 2.4 2.7 9.9 0.94 0.81 62 2.6 2.3 1.7 1.9 6.1 0.86 0.81 92 2.8 2.1 1.6 2.1 4.1 0.81 4.3 24 2.7 2.3 2.0 1.8 3.7 0.88 2.9 9.2 3.1 2.1 2.3 1.8 4.0 21 1.2 1.1 0.80 0.77 22 1.3 0.96 0.98 0.76 23 1.5 0.97 0.86 0.77 24 2.6 1.0 0.72 0.93 25 2.4 1.1 1.3 8.3 0.85 0.99 7.3 48 2.3 2.5 1.8 4.0 0.81 0.87 27 7.4 2.1 4.7 1.7 3.3 0.79 0.86 43 4.5 2.1 3.5 1.7 2.7 0.77 0.72 38 4.0 2.0 2.6 1.6 2.8 0.81 0.77 84 3.1 2.0 2.1 1.7 2.7 26 3.1 1.1 1.2 4.8 27 2.2 1.1 0.84 1.4 28 1.6 1.2 0.81 0.91 29 2.0 1.2 0.79 0.89 30 2.7 1.4 0.70 0.91 31 6.8 --- 0.71 0.91 0.83 45 21 3.2 1.9 2.0 3.1 2.4 0.80 23 7.2 3.0 1.9 2.3 2.1 2.4 0.80 10 5.2 3.2 1.9 2.7 3.2 2.4 --- 5.6 4.7 3.3 1.8 2.3 3.1 2.2 --- 5.4 4.3 3.0 1.8 1.9 1.5 1.7 --- 3.6 --- 2.9 --- 2.1 1.5 --­ TOTAL 93.5 45.58 31.85 36.66 MEAN 3.02 1.52 1.03 1.18 MAX 9.2 3.7 1.8 8.3 MIN 1.2 0.92 0.70 0.71 AC-FT 185 90 63 73 CFSM 0.60 0.30 0.20 0.24 IN. 0.69 0.34 0.24 0.27 32.20 118.63 562.7 147.5 70.8 76.6 64.2 137.3 1.15 3.83 18.8 4.76 2.36 2.47 2.07 4.58 6.6 45 92 48 2.9 5.0 3.2 12 0.77 0.72 3.1 2.2 1.8 1.4 1.5 1.5 64 235 1,120 293 140 152 127 272 0.23 0.76 3.73 0.95 0.47 0.49 0.41 0.91 0.24 0.88 4.16 1.09 0.52 0.57 0.47 1.02 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 2003, BY WATER YEAR (WY) MEAN 15.6 11.3 6.68 6.01 MAX 58.0 39.9 17.9 34.3 (WY) (1990) (2000) (2000) (1992) MIN 1.95 0.93 0.53 0.77 (WY) (1994) (1998) (1998) (1995) 4.11 2.26 6.82 12.2 4.57 3.02 4.39 21.5 15.7 5.02 21.5 45.9 17.1 9.07 12.3 83.0 (1996) (2002) (2002) (1995) (1999) (1996) (1989) (1998) 0.96 0.90 0.93 0.86 0.88 0.88 1.03 0.88 (1995) (1994) (1995) (1997) (1994) (1994) (1982) (1994) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1981 - 2003 ANNUAL TOTAL 1,991.63 ANNUAL MEAN 5.46 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 116 LOWEST DAILY MEAN 0.70 ANNUAL SEVEN-DAY MINIMUM 0.88 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 3,950 ANNUAL RUNOFF (CFSM) 1.08 ANNUAL RUNOFF (INCHES) 14.73 10 PERCENT EXCEEDS 9.7 50 PERCENT EXCEEDS 3.4 90 PERCENT EXCEEDS 1.2 1,417.52 3.88 8.11 13.3 1999 1.49 1994 Apr 25 92 Apr 18 1,570 Sep 10, 1996 Dec 30 0.70 Dec 30 0.20 Oct 4, 1992 Dec 18 0.73 Jan 3 0.33 Oct 11, 1992 699 Apr 5 8,890 Sep 10, 1996 8.86 Apr 5 17.38 Sep 10, 1996 2,810 5,880 0.772 1.61 10.48 21.91 5.1 13 2.0 2.2 0.80 0.85 e Estimated 163 RIO GRANDE DE MANATI BASIN 50030460 RIO OROCOVIS AT OROCOVIS, PR—Continued O N D J F M A M J J A S 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 164 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q14'20", long 66q22'58", at flat low bridge about 300 ft (91 m) northwest of Highway 568, 1.0 mi (1.6 km) north of Orocovis Plaza. DRAINAGE AREA.--10.1 mi2 (26.2 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 19... 0900 6.7 9.2 8.2 94 7.1 353 21.5 140 36.6 13.0 1.45 .5 MAR 20... 0850 9.6 85 7.2 -- 7.2 276 20.7 110 27.9 9.98 2.30 .5 MAY 07... 1300 14 -- 8.0 -- 8.4 297 25.2 120 29.0 11.4 1.96 .5 AUG 15... 1345 6.2 6.0 8.0 -- 8.3 334 27.0 -- -- -- -- -­ SEP 09... 1245 8.1 120 7.7 -- 8.0 291 -- 120 29.8 11.6 1.99 .5 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 19... 14.1 148 16.3 <.17 35.9 7.7 -- 214 3.85 <10 <.20 <.01 -­ MAR 20... 11.3 110 15.9 .10 27.0 9.0 .2 169 .65 30 .40 .03 .84 MAY 07... 12.2 115 16.3 <.17 31.9 7.9 <.1 180 6.97 32 .20 <.01 -­ AUG 15... -- 137 -- -- -- -- -- -- -- <10 .20 .02 -­ SEP 09... 11.6 110 15.9 <.2 29.8 8.6 -- 175 3.83 107 .50 .04 1.29 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 19... .970 <.01 -- .20 -- -- <10 590 510 -- -- -- -­ MAR 20... .860 .02 .37 .17 1.3 5.6 20 300 -- 2,900 <2 41.7 18 MAY 07... 1.20 <.01 -- .15 1.4 6.2 <10 E540 -- 34,000 <2 51.7 20 AUG 15... 1.10 <.01 .18 .16 1.3 5.8 <10 E90 -- 3,600 -- -- -­ SEP 09... 1.30 .01 .46 .23 1.8 8.0 10 E8,400 -- E90,000 -- -- -­ 165 RIO GRANDE DE MANATI BASIN 50030700 RIO OROCOVIS NEAR OROCOVIS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 19... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 20... <.2 1.8 <10 <.01 1,170 <1 53.5 <.02 <3 <.3 <25 <.10 <16 MAY 07... <.2 1.2 <10 <.01 700 <1 76.6 <.02 <3 <.3 E17 <.10 <16 AUG 15... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 09... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 166 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR LOCATION.--Lat 18q17'45", long 66q24'47", Hydrologic Unit 21010001, on right bank, 0.1 mi (0.2 km) downstream from Quebrada Perchas, 0.8 mi (1.3 km) upstream from Río Sana Muerto, and 2.2 mi (3.5 km) south of Morovis. DRAINAGE AREA.--55.2 mi2 (143.0 km2). PERIOD OF RECORD.--January 1965 to current year. WATER-DISCHARGE RECORDS GAGE.--Water-stage recorder and concrete control. Elevation of gage is 440 ft (134 m), from topographic map. February 2, 1966, to April 27, 1967, staff gage read twice daily. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Public water-supply pumpage, about 1,000 ft (305 m) upstream from the station, influences low-flow discharges. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 46 69 16 11 18 11 e17 e40 27 13 54 89 2 57 48 14 13 16 10 13 e40 27 18 24 42 3 106 30 15 14 15 10 18 40 27 14 20 71 4 89 31 18 13 147 10 18 43 29 12 15 96 5 51 31 21 11 134 9.4 e36 35 24 16 13 36 6 41 30 18 12 65 9.1 e22 31 23 25 13 21 7 102 26 15 12 37 8.4 e19 30 24 19 19 23 8 110 26 15 10 29 9.1 e17 29 27 21 15 43 9 120 28 17 11 24 8.3 e16 29 23 18 13 45 10 78 26 15 13 22 7.9 e16 26 22 14 14 20 11 56 25 14 13 20 8.6 e17 25 21 12 13 19 12 53 23 14 11 22 8.2 e19 23 20 11 60 194 13 41 25 16 11 20 8.5 e18 27 20 20 23 127 14 39 31 17 10 16 8.3 e17 23 20 40 18 104 15 54 23 15 9.9 15 7.5 e16 24 23 17 16 53 16 48 23 13 9.7 14 7.1 e18 22 22 24 16 68 17 36 21 13 9.8 15 6.9 e396 23 21 20 14 43 18 36 20 15 9.6 16 6.1 e253 21 19 15 13 28 19 38 20 16 9.9 15 6.2 e142 23 18 12 14 21 20 37 20 18 9.9 13 33 e336 67 18 11 13 19 21 35 20 16 9.7 14 12 e175 724 18 14 13 120 22 33 19 16 10 14 8.9 e469 262 18 15 25 139 23 30 18 24 9.9 12 8.3 e489 107 16 25 17 72 24 32 17 15 11 11 8.1 e512 70 15 14 13 38 25 34 16 13 146 11 8.0 e351 54 14 12 16 40 26 29 15 15 230 12 55 e188 46 15 13 30 69 27 31 15 13 64 11 82 e107 40 14 27 27 30 28 26 15 12 33 11 73 e78 37 13 21 17 23 29 28 15 11 23 34 e62 34 13 26 65 24 30 36 16 11 20 38 e49 32 13 16 36 25 31 44 12 18 e27 29 23 72 TOTAL 1,596 742 473 798.4 769 547.9 3,904 2,056 604 558 731 1,742 MEAN 51.5 24.7 15.3 25.8 27.5 17.7 130 66.3 20.1 18.0 23.6 58.1 MAX 120 69 24 230 147 82 512 724 29 40 72 194 MIN 26 15 11 9.6 11 6.1 13 21 13 11 13 19 AC-FT 3,170 1,470 938 1,580 1,530 1,090 7,740 4,080 1,200 1,110 1,450 3,460 CFSM 0.93 0.45 0.28 0.47 0.50 0.32 2.36 1.20 0.36 0.33 0.43 1.05 IN. 1.08 0.50 0.32 0.54 0.52 0.37 2.63 1.39 0.41 0.38 0.49 1.17 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1965 - 2003, BY WATER YEAR (WY) MEAN 143 144 108 79.9 62.3 59.8 101 144 57.9 43.0 51.4 107 MAX 1,037 491 522 228 179 226 412 915 173 157 435 432 (WY) (1971) (1971) (1966) (1997) (1969) (1972) (1969) (1985) (1987) (1979) (1979) (1996) MIN 20.9 11.4 8.65 10.4 15.3 12.7 8.80 15.7 6.75 5.54 9.70 6.87 (WY) (2002) (1995) (1995) (1995) (1994) (1984) (1995) (1994) (1994) (1994) (1984) (1994) 167 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1965 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 19,212 ANNUAL MEAN 52.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 515 LOWEST DAILY MEAN 11 ANNUAL SEVEN-DAY MINIMUM 12 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 38,110 ANNUAL RUNOFF (CFSM) 0.954 ANNUAL RUNOFF (INCHES) 12.95 10 PERCENT EXCEEDS 108 50 PERCENT EXCEEDS 36 90 PERCENT EXCEEDS 16 14,521.3 39.8 91.6 248 1971 24.2 1994 Apr 25 724 May 21 17,100 May 18, 1985 Dec 29 6.1 Mar 18 3.5 May 1, 1995 Dec 25 7.2 Mar 13 4.0 Jul 22, 1994 6,680 May 21 48,000 May 18, 1985 7.89 May 21 17.89 May 18, 1985 28,800 66,350 0.721 1.66 9.79 22.54 71 167 20 47 11 18 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 168 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 19... 1130 17 11 9.2 114 7.3 328 25.0 130 31.4 12.6 1.77 .5 MAR 20... 1130 38 17 8.1 -- 8.3 335 25.2 140 33.4 13.1 1.95 .6 MAY 07... 1025 29 -- 9.4 -- 8.3 303 25.8 120 29.0 11.7 2.28 .5 AUG 15... 1145 15 28 8.2 -- 8.0 258 28.3 -- -- -- -- -­ SEP 09... 1045 39 37 8.7 -- 8.0 287 26.0 120 28.9 11.8 2.16 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 19... 13.6 145 16.6 <.17 28.3 8.1 -- 199 -- <10 .20 .01 -­ MAR 20... 15.1 140 19.7 .13 26.9 8.7 <.1 203 20.9 20 <.20 .02 -­ MAY 07... 12.3 116 17.1 <.17 27.1 8.5 <.1 178 13.8 <10 <.20 .02 -­ AUG 15... -- 96 -- -- -- -- -- -- -- <10 .30 .03 -­ SEP 09... 11.4 110 15.7 <.2 25.5 8.0 -- 169 -- 25 .30 .03 .67 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 19... .600 <.01 .19 .07 .80 3.5 <10 E170 E127 -- -- -- -­ MAR 20... .170 <.01 -- .09 -- -- <10 E10,000 -- 30,000 <2 53.7 28 MAY 07... .300 <.01 -- .04 -- -- <10 E60 -- 591 <2 51.0 22 AUG 15... .740 <.01 .27 .05 1.0 4.6 <10 210 -- 2,900 -- -- -­ SEP 09... .680 .01 .27 .10 .98 4.3 <10 E1,300 -- E25,000 -- -- -­ 169 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 19... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 20... <.2 1.5 <10 <.01 540 M 47.7 <.02 <3 <.3 E19 <.10 <16 MAY 07... <.2 E.6 <10 <.01 140 <1 23.6 <.02 <3 <.3 <25 <.10 <16 AUG 15... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 09... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- 170 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1968 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2001 to current year. INSTRUMENTATION.-- USDH-48 and automatic sediment sampler since 2001. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 4,350 mg/L November 8, 2001; Minimum daily mean, 3 mg/L several days during Water Year 2003. SEDIMENT LOADS: Maximum daily mean, 60,000 tons (54,432 tonnes) November 8, 2001; Minimum daily mean, .09 ton (.08 tonne) July 1 2, 2003. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,370 mg/L May 21, 2003; Minimum daily mean, 3 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 20,300 tons (18,416 tonnes) May 21, 2003; Minimum daily mean, .09 ton (.08 tonne) July 12, 2 003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 46 194 24 69 66 15 16 17 0.74 2 57 97 16 48 42 8.7 14 17 0.65 3 106 118 45 30 21 1.7 15 17 0.71 4 89 93 25 31 21 1.7 18 17 0.82 5 51 45 6.3 31 21 1.8 21 17 0.96 6 41 44 4.9 30 21 1.6 18 17 0.80 7 102 137 71 26 20 1.4 15 16 0.67 8 110 118 42 26 20 1.4 15 16 0.65 9 120 130 44 28 20 1.5 17 16 0.72 10 78 70 15 26 20 1.4 15 16 0.64 11 56 46 7.0 25 20 1.3 14 16 0.60 12 53 41 6.0 23 20 1.2 14 16 0.60 13 41 35 3.9 25 20 1.3 16 16 0.66 14 39 32 3.4 31 19 1.6 17 15 0.69 15 54 50 11 23 19 1.2 15 15 0.61 16 48 37 5.0 23 19 1.2 13 15 0.54 17 36 23 2.3 21 19 1.1 13 15 0.51 18 36 21 2.0 20 19 1.0 15 15 0.61 19 38 21 2.1 20 19 1.0 16 15 0.62 20 37 21 2.1 20 19 0.99 18 15 0.71 21 35 21 2.0 20 19 0.98 16 15 0.65 22 33 21 1.8 19 18 0.93 16 14 0.63 23 30 21 1.7 18 18 0.88 24 14 0.94 24 32 21 1.8 17 18 0.82 15 14 0.57 25 34 20 1.9 16 18 0.77 13 14 0.49 26 29 20 1.6 15 18 0.75 15 14 0.57 27 31 20 1.7 15 18 0.74 13 14 0.50 28 26 20 1.4 15 18 0.72 12 14 0.46 29 28 20 1.5 15 17 0.70 11 14 0.41 30 36 20 2.0 16 17 0.74 11 13 0.40 31 44 34 5.5 12 13 0.44 TOTAL 1,596 360.9 742 56.12 473 19.57 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE MANATI BASIN 171 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 11 13 0.40 18 16 0.79 11 11 0.34 2 13 13 0.47 16 16 0.66 10 11 0.31 3 14 13 0.48 15 15 0.59 10 11 0.31 4 13 13 0.43 147 207 165 10 11 0.29 5 11 13 0.39 134 154 60 9.4 11 0.27 6 12 12 0.40 65 60 11 9.1 10 0.26 7 12 12 0.38 37 40 4.1 8.4 10 0.23 8 10 12 0.35 29 29 2.3 9.1 10 0.25 9 11 12 0.37 24 18 1.2 8.3 10 0.22 10 13 12 0.41 22 15 0.86 7.9 10 0.21 11 13 12 0.40 20 15 0.80 8.6 10 0.22 12 11 12 0.35 22 14 0.85 8.2 9 0.21 13 11 12 0.34 20 14 0.75 8.5 9 0.21 14 10 11 0.31 16 14 0.59 8.3 9 0.20 15 9.9 11 0.30 15 14 0.55 7.5 9 0.18 16 9.7 11 0.29 14 13 0.52 7.1 9 0.17 17 9.8 11 0.29 15 13 0.55 6.9 8 0.16 18 9.6 11 0.28 16 13 0.58 6.1 8 0.14 19 9.9 11 0.29 15 13 0.53 6.2 8 0.14 20 9.9 11 0.28 13 13 0.46 33 27 3.0 21 9.7 10 0.27 14 13 0.48 12 12 0.43 22 10 10 0.28 14 12 0.48 8.9 9 0.21 23 9.9 10 0.27 12 12 0.41 8.3 9 0.19 24 11 10 0.29 11 12 0.37 8.1 8 0.19 25 146 206 283 11 12 0.37 8.0 8 0.18 26 230 390 328 12 12 0.37 55 71 51 27 64 72 14 11 12 0.35 82 86 21 28 33 33 3.0 11 11 0.34 73 46 9.3 29 23 19 1.2 34 23 2.2 30 20 18 0.97 38 20 2.0 31 18 17 0.86 e27 e19 e1.3 TOTAL 798.4 639.35 769 255.85 547.9 95.32 APRIL MAY JUNE 1 e17 e19 e0.88 e40 e11 e1.2 27 9 0.63 2 13 19 0.66 e40 e9 e1.0 27 7 0.52 3 18 19 0.92 40 8 0.87 27 5 0.40 4 18 18 0.89 43 7 0.84 29 5 0.38 5 e36 e47 e12 35 7 0.63 24 5 0.29 6 e22 e19 e1.2 31 6 0.49 23 4 0.27 7 e19 e17 e0.86 30 5 0.41 24 4 0.27 8 e17 e16 e0.79 29 4 0.35 27 5 0.36 9 e16 e16 e0.66 29 4 0.29 23 6 0.39 10 e16 e16 e0.66 26 3 0.23 22 8 0.45 11 e17 e16 e0.66 25 5 0.34 21 9 0.48 12 e19 e18 e0.86 23 7 0.46 20 8 0.44 13 e18 e19 e0.86 27 9 0.68 20 7 0.40 14 e17 e16 e0.79 23 10 0.62 20 7 0.35 15 e16 e16 e0.66 24 10 0.65 23 6 0.36 16 e18 e17 e0.86 22 10 0.63 22 5 0.29 17 e396 e651 e923 23 11 0.65 21 4 0.22 18 e253 e468 e434 21 11 0.62 19 3 0.17 19 e142 e150 e63 23 11 0.68 18 4 0.19 20 e336 e900 67 63 22 18 5 0.27 21 e175 e398 e617 724 2,370 20,300 18 7 0.32 22 e469 e515 e1,140 262 468 434 18 7 0.34 23 e489 e515 e1,140 107 56 18 16 7 0.31 24 e512 e947 e1,450 70 19 3.6 15 7 0.28 25 e351 e651 e923 54 15 2.2 14 7 0.27 26 e188 e270 e149 46 14 1.8 15 7 0.27 27 e107 e56 e18 40 13 1.4 14 6 0.23 28 e78 e19 e3.6 37 12 1.2 13 6 0.21 29 e62 e15 e2.2 34 11 1.1 13 5 0.20 30 e49 e14 e1.8 32 11 0.92 13 4 0.14 31 29 10 0.79 TOTAL 3,904 7,788.81 2,056 20,798.65 604 9.70 172 RIO GRANDE DE MANATI BASIN 50031200 RIO GRANDE DE MANATI NEAR MOROVIS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean concen- Load discharge tration (tons/ Day (cfs) (mg/l) day) Mean Mean Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 13 3 0.10 2 18 4 0.19 3 14 5 0.20 4 12 6 0.22 5 16 8 0.32 54 47 7.7 89 99 31 24 22 1.4 42 33 3.7 20 19 1.0 71 93 49 15 18 0.71 96 96 29 13 17 0.60 36 28 2.8 6 25 7 0.49 7 19 6 0.32 8 21 5 0.28 9 18 4 0.21 10 14 4 0.14 13 16 0.58 21 20 1.2 19 16 0.79 23 20 1.3 15 16 0.62 43 34 4.7 13 15 0.53 45 49 6.7 14 15 0.59 20 31 1.7 11 12 3 0.11 12 11 3 0.09 13 20 8 0.94 14 40 28 3.4 15 17 15 0.67 13 15 0.53 19 27 1.6 60 60 12 194 398 617 23 27 1.7 127 150 63 18 18 0.87 104 116 40 16 17 0.73 53 44 6.6 16 24 14 0.91 17 20 12 0.64 18 15 9 0.36 19 12 6 0.20 20 11 11 0.32 16 17 0.75 68 60 11 14 15 0.54 43 46 5.3 13 11 0.41 28 37 2.8 14 8 0.30 21 27 1.5 13 5 0.17 19 17 0.88 21 14 19 0.70 22 15 27 1.1 23 25 35 2.4 24 14 32 1.3 25 12 24 0.78 13 5 0.18 120 171 118 25 6 0.40 139 165 68 17 7 0.32 72 112 22 13 7 0.25 38 85 8.7 16 7 0.31 40 80 10 26 13 17 0.57 27 27 16 1.2 28 21 20 1.1 29 26 24 1.7 30 16 27 1.1 31 23 31 2.4 30 7 0.58 69 81 18 27 9 0.62 30 57 4.7 17 8 0.38 23 56 3.5 65 60 12 24 56 3.7 36 36 3.4 25 56 3.8 72 99 42 --- --- --­ TOTAL 558 --- 24.46 731 --- 92.96 1,742 --- 1,141.18 YEAR 14,521.3 31,282.87 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) APR 23... 2255 984 49 58 64 74 79 85 89 94 99 99 3,340 Sus­ pended sedi­ ment load, Date tons/d (80155) APR 23... 8,870 --- --- --- --- --- --- --- --- --- 173 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR LOCATION.--Lat 18q09'41", long 66q31'36", Hydrologic Unit 21010001, at damsite on Río Toro Negro, 3.0 mi (4.8 km) northwest from Villalba Plaza and 1.9 mi (3.1 km) northeast of Cerro Maravillas. The reservoir itself fixes the territorial limits between the municipality of Ciales and Orocovis. DRAINAGE AREA.--1.64 mi2 (4.25 km2). PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago El Guineo at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago El Guineo was completed in 1931. It provides a maximum storage of approximately 2,180 acre-ft (2.688 hm3) for power and irrigation. Waters are discharged through an outlet power tunnel into the Río Toro Negro and conveyed to the head water works of Toro Negro Hydroelectric Plant No. 2, for energy generation at Toro Negro Hydroelectric plant No. 1, and are discharged into the Guayabal Reservoir to be laterused for irrigation at South Coast Irrigation System. The dam is rockfill with a vertical concrete corewall, rock toes, and riprap facing of upstream slope, with a total length of 565 ft (172 m), a maximum structural height of 125 ft (38 m) to top of corewall. At a maximum reservoir water surface elevation the unc ontrolled morning-glory tunnel spillway crest has an elevation of 2,960 ft (902 m) above mean sea level and a design capacity of 7,000 ft3/s. The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,964.40 ft (905.55 m), September 22, 1998; minimun elevation, 2,919.79 ft (899.95 m), May 27, 1988. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,961.01 ft (902.52 m), October 9; minimun elevation, 2,932.54 ft (893.84 m), September 15. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 2,872 0 2,919 361 2,925 491 2,943 1,029 Elevation Contents 2,950 1,308 2,961 1,852 2,966 2,180 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2,958.93 2,959.26 2,960.73 2,958.18 2,958.53 2,953.38 2,952.61 2,959.71 2,956.54 2,947.05 2,937.77 2,934.39 2 2,959.07 2,959.40 2,960.36 2,958.24 2,959.19 2,953.43 2,952.69 2,959.46 2,956.16 2,946.54 2,937.83 2,934.47 3 2,959.45 2,959.78 2,960.07 2,958.29 2,959.32 2,952.93 2,952.73 2,959.66 2,955.83 2,945.97 2,937.88 2,934.70 4 2,959.59 2,959.53 2,959.86 2,958.34 2,959.05 2,952.54 2,952.50 2,959.80 2,955.58 2,946.06 2,937.37 2,934.81 5 2,959.71 2,959.65 2,959.56 2,958.41 2,959.01 2,952.04 2,952.91 2,959.54 2,955.25 2,946.14 2,936.62 2,934.51 6 2,959.80 2,959.48 2,959.17 2,958.49 2,958.76 2,951.52 2,952.99 2,959.27 2,954.91 2,946.18 2,936.26 2,934.58 7 2,959.90 2,959.28 2,959.26 2,958.54 2,958.48 2,950.98 2,952.65 2,959.03 2,955.03 2,945.71 2,935.62 2,934.72 8 2,960.22 2,958.99 2,959.37 2,958.61 2,958.57 2,951.02 2,952.50 2,958.79 2,955.12 2,945.20 2,934.96 2,934.84 9 2,960.73 2,959.15 2,959.05 2,958.69 2,958.64 2,951.06 2,952.55 2,958.57 2,954.65 2,944.73 2,935.03 2,934.62 10 2,960.73 2,959.26 2,958.32 2,958.86 2,958.32 2,951.11 2,952.19 2,958.67 2,954.14 2,944.25 2,935.07 2,934.42 11 2,960.57 2,959.37 2,957.88 2,958.94 2,957.99 2,951.15 2,952.23 2,958.78 2,954.20 2,943.74 2,934.39 2,934.24 12 2,960.69 2,959.48 2,957.45 2,958.99 2,957.65 2,951.19 2,952.82 2,958.37 2,953.87 2,943.17 2,934.46 2,934.37 13 2,960.70 2,960.44 2,957.07 2,959.03 2,957.31 2,951.22 2,952.95 2,957.89 2,953.38 2,943.29 2,934.52 2,934.57 14 2,960.57 2,960.74 2,957.15 2,959.07 2,956.97 2,951.26 2,952.58 2,957.52 2,953.45 2,942.73 2,934.57 2,933.22 15 2,960.55 2,960.50 2,957.23 2,958.75 2,957.03 2,951.31 2,952.20 2,957.10 2,953.54 2,942.25 2,934.62 2,933.13 16 2,960.67 2,960.69 2,956.81 2,958.62 2,957.09 2,951.36 2,951.95 2,956.66 2,953.17 2,941.73 2,934.69 2,933.44 17 2,960.44 2,960.72 2,956.95 2,958.66 2,957.17 2,951.39 2,954.51 2,956.84 2,953.04 2,941.20 2,934.76 2,933.57 18 2,960.27 2,960.43 2,957.04 2,958.73 2,956.82 A 2,956.86 2,957.41 2,952.79 2,940.81 2,934.82 2,933.72 19 2,960.42 2,960.55 2,957.12 2,958.45 2,956.42 A 2,957.66 2,957.47 2,952.31 2,939.88 2,934.86 2,933.80 20 2,960.56 2,960.31 2,957.21 2,958.50 2,956.05 2,950.97 2,958.11 2,957.14 2,951.81 2,939.93 2,934.63 2,933.91 21 2,960.56 2,960.35 2,957.28 2,958.54 2,955.62 2,951.10 2,958.52 2,958.08 2,951.89 2,939.99 2,934.38 2,933.98 22 2,960.29 2,960.37 2,957.45 2,958.59 2,955.68 2,951.25 2,958.96 2,957.87 2,951.97 2,939.69 2,934.16 2,933.80 23 2,960.03 2,960.49 2,957.53 2,958.69 2,955.73 2,951.38 2,959.02 2,957.65 2,951.53 2,939.49 2,933.25 2,933.57 24 2,959.86 2,960.61 2,957.64 2,958.78 2,955.26 2,951.51 2,959.37 2,957.34 2,951.11 2,939.27 2,933.32 2,933.68 25 2,959.70 2,960.59 2,957.69 2,959.07 2,954.78 2,951.65 2,959.59 2,957.47 2,949.91 2,939.35 2,933.37 2,936.30 26 2,959.84 2,960.64 2,957.79 2,959.26 2,954.29 2,952.07 2,959.89 2,957.60 2,948.85 2,939.41 2,933.57 2,935.80 27 2,959.94 2,960.32 2,957.86 2,959.33 2,953.82 2,952.24 2,960.14 2,957.37 2,947.93 2,939.49 2,933.64 2,935.95 28 2,959.62 2,960.52 2,957.91 2,959.39 2,953.33 2,952.31 2,959.97 2,956.99 2,948.00 2,939.58 2,933.77 2,936.04 29 2,959.54 2,960.64 2,957.99 2,959.03 2,952.41 2,959.78 2,956.63 2,948.06 2,939.14 2,933.84 2,936.17 30 2,959.27 2,960.71 2,958.05 2,958.67 2,952.47 2,959.94 2,956.33 2,947.61 2,938.67 2,934.17 2,936.26 31 2,959.48 2,958.11 2,958.37 2,952.51 2,956.42 2,938.19 2,934.29 MAX 2,960.73 2,960.74 2,960.73 2,959.39 2,959.32 2,960.14 2,959.80 2,956.54 2,947.05 2,937.88 2,936.30 MIN 2,958.93 2,958.99 2,956.81 2,958.18 2,953.33 2,951.95 2,956.33 2,947.61 2,938.19 2,933.25 2,933.13 A No gage-height record 174 RIO GRANDE DE MANATI BASIN 50032290 LAGO EL GUINEO AT DAMSITE NEAR VILLALBA, PR—Continued O N D J F M A M J J A S 2,930 2,935 2,940 2,945 2,950 2,955 2,960 2,965 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 175 RIO GRANDE DE MANATI BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR LOCATION.--Lat 18q12'46", long 66q28'50", Hydrologic Unit 21010001, in shelter house at damsite, and 5.8 mi (9.3 km) southwest of Orocovis. DRAINAGE AREA.--4.46 mi2 (11.6 km2). PERIOD OF RECORD.--May 1988 to current year. Prior to October 1994, published as Lago de Matrullas at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Matrullas was completed in 1934. The dam is an earthfill structure about 120 ft (37 m) height, a top width of 30 ft (9 m) and a length of 710 ft (216 m), and has a maximum storage capacity of about 4,274 acre-ft (5.220 hm3) at top of dam elevation. The Matrullas Dam is owned by the Puerto Rico Electric Power Authority (PREPA) and is part of the Toro Negro Hydroelectric Project; a project developed by the PREPA for the primary purpose of generating electric power. Discharges from the power plants are collected by the Jacaguas River which flows into Guayabal Dam, at which are regulated for irrigation of lands served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 2,419.90 ft (737.58 m), September 10, 1996; minimum elevation, 2,375.55 ft (724.06 m), September 24 and 25, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 2,415.24 ft (736.16 m); October 4; minimum elevation, 2,413.54 ft (735.65 m) December 31. Capacity Table (based on data from the Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 2,338 2 2,360 302 Elevation Contents 2,399 1,845 2,420 3,331 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2,415.18 2,414.90 2,413.81 A 2 2,415.03 2,414.91 2,413.79 2,414.20 3 2,415.22 2,414.90 2,413.78 2,414.01 4 2,415.15 2,414.91 2,413.75 A 5 2,414.97 2,414.89 2,413.75 A A A 2,409.02 2,415.22 A 2,410.58 2,406.50 A A A 2,408.80 2,415.20 2,414.90 2,410.33 A 2,405.88 2,414.25 2,412.73 2,408.58 A 2,414.72 2,410.08 A 2,405.87 2,415.10 2,412.48 2,408.32 A 2,414.53 A 2,406.43 2,408.72 2,415.27 2,412.18 2,408.07 2,415.28 2,414.38 A 2,406.12 2,408.75 6 2,414.82 2,414.89 2,413.74 A 2,415.30 2,411.90 A 2,415.20 2,414.20 A 2,405.90 A 7 2,414.71 2,414.88 2,413.73 2,414.09 2,413.20 2,411.65 2,408.35 2,415.08 A 2,410.20 2,405.80 A 8 2,414.64 2,414.87 2,413.74 2,413.90 A A 2,408.10 2,415.05 A 2,409.89 2,405.68 2,408.90 9 2,414.59 2,414.86 2,413.74 2,413.60 A A 2,407.85 2,414.98 2,414.32 2,409.68 A 2,408.62 10 2,414.52 2,414.87 2,413.72 2,413.52 2,415.25 2,411.52 2,407.85 A 2,414.12 2,409.40 A 2,408.38 11 2,414.48 2,414.87 2,413.71 A 12 2,414.47 2,414.80 2,413.72 A 13 2,414.47 2,414.59 2,413.71 A 14 2,414.50 2,414.44 2,413.71 2,413.60 15 2,414.52 2,414.33 2,413.71 2,413.38 2,415.05 2,411.25 2,407.35 A 2,413.92 2,409.12 2,405.48 2,408.11 2,414.87 2,410.93 A 2,415.27 2,413.75 2,408.82 2,405.58 2,407.93 2,414.68 2,410.65 A 2,415.15 2,413.55 A 2,405.58 A 2,414.45 2,410.35 2,407.62 2,415.02 A 2,408.70 2,405.68 2,408.05 A A 2,407.35 2,414.90 A 2,408.55 2,405.77 2,407.60 16 2,414.54 2,414.24 2,413.71 2,413.18 17 2,414.56 2,414.16 2,413.70 2,413.00 18 2,414.59 2,414.11 2,413.69 A 19 2,414.62 2,414.06 2,413.71 A 20 2,414.65 2,414.00 2,413.70 A A A 2,407.32 2,414.75 2,413.58 2,408.42 A 2,407.62 A 2,410.22 2,407.30 A 2,413.38 A A 2,407.55 2,414.58 2,409.95 A A 2,413.17 2,407.93 2,406.03 2,407.38 2,414.35 2,409.67 A 2,415.02 2,413.02 2,407.70 2,406.12 2,407.15 2,414.10 2,409.48 A 2,414.88 2,412.83 A 2,406.18 2,406.92 21 2,414.69 2,413.97 2,413.69 2,413.05 2,413.87 2,409.20 A 2,415.28 A A 2,405.80 A 22 2,414.71 2,413.94 2,413.69 2,413.12 A 2,408.90 2,414.12 2,415.28 A 2,407.62 2,405.43 2,406.62 23 2,414.93 2,413.92 2,413.69 A A 2,408.62 2,414.32 2,415.20 2,412.50 2,407.30 2,405.06 2,406.32 24 2,414.92 2,413.89 2,413.67 2,413.30 2,413.78 2,408.42 2,414.70 2,415.28 2,412.28 2,406.92 A 2,405.98 25 2,414.90 2,413.86 2,413.65 A 2,413.53 2,408.12 2,415.22 A 2,412.08 A 2,404.72 2,405.78 26 2,414.91 2,413.88 2,414.05 A 2,413.28 2,407.82 27 2,414.92 2,413.85 2,414.15 2,414.50 2,413.03 2,409.73 28 2,414.91 2,413.84 2,413.61 2,414.60 2,412.82 2,409.10 29 2,414.90 2,413.83 2,413.58 2,414.70 --- A 30 2,414.73 2,413.83 2,413.93 2,414.45 --- A 31 2,414.92 --- A 2,413.90 --- 2,409.25 A A 2,411.82 A 2,404.83 2,405.32 A 2,415.20 2,411.03 A 2,405.02 A 2,415.30 2,415.03 A A 2,404.92 A 2,415.25 2,415.20 A 2,407.08 2,405.07 2,405.12 2,415.25 2,414.73 2,410.83 2,406.95 A 2,404.63 --- A --- 2,406.69 A --­ MAX 2,415.22 2,414.91 --- --- --- --- --- --- --- --- --- --­ MIN 2,414.47 2,413.83 --- --- --- --- --- --- --- --- --- --­ A No gage-height record 176 RIO GUAJATACA BASIN 50032590 LAGO DE MATRULLAS AT DAMSITE NEAR OROCOVIS, PR—Continued O N D J F M A M J J A S 2,404 2,406 2,408 2,410 2,412 2,414 2,416 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 177 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR LOCATION.--Lat 18q14'10", long 66q27'18", Hydrologic Unit 21010001, on left bank, at bridge on Highway 157 (12.1 km), and 4.2 mi (6.8 km) west of Orocovis. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--February 1959 to April 1966 (annual low-flow measurements only), February to September 1969 (occasional measurements only), October 1969 to September 1982, October 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 772.82 ft (235.556 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 44 10 8.0 11 6.0 10 31 14 9.4 9.7 13 2 12 26 11 8.6 8.7 5.9 11 28 14 9.4 8.4 11 3 15 22 12 8.2 9.9 5.9 11 27 14 8.4 8.0 56 4 17 20 12 7.7 56 5.7 11 25 13 8.7 7.6 30 5 12 18 12 7.8 50 5.6 299 23 13 9.5 7.5 13 6 10 18 11 8.0 34 5.5 87 22 13 11 8.5 9.2 7 9.4 15 11 8.0 15 5.5 30 22 12 8.8 8.9 10 8 129 14 11 7.9 11 5.5 19 21 12 8.5 7.7 11 9 88 13 11 8.1 9.1 5.5 15 20 12 9.1 7.3 9.3 10 43 14 11 8.3 8.6 5.5 13 20 11 8.0 7.0 7.8 11 30 15 11 8.1 8.4 5.5 15 19 12 7.6 19 16 12 21 14 11 7.9 8.7 5.5 18 18 12 7.4 14 42 13 19 17 11 8.0 7.8 5.4 15 17 11 10 8.3 57 14 33 23 10 8.0 7.5 5.3 13 18 11 9.8 8.1 35 15 30 26 9.9 8.0 7.3 5.3 12 17 12 9.4 7.8 26 16 69 29 9.8 8.2 7.4 5.3 11 16 12 11 8.3 32 17 70 20 10 8.4 7.5 5.0 266 16 11 10 7.2 21 18 33 16 12 8.2 7.4 5.0 475 16 11 9.3 7.8 14 19 26 15 11 8.6 7.1 25 208 16 11 9.0 7.6 12 20 21 14 13 8.0 7.0 19 79 55 11 9.2 6.9 11 21 20 14 10 6.4 7.0 7.9 81 141 12 9.0 7.4 23 22 18 14 13 6.2 6.8 6.0 100 71 11 12 8.0 16 23 34 14 10 6.5 6.4 5.7 229 30 10 10 7.2 12 24 25 13 9.2 7.8 6.2 5.3 277 23 9.8 8.8 8.3 13 25 19 12 9.3 45 6.3 5.3 491 19 9.6 8.4 8.1 12 26 21 11 9.0 38 6.2 180 217 17 9.2 8.3 15 19 27 18 12 8.8 11 6.2 98 88 16 8.8 9.2 12 21 28 18 11 8.4 8.6 6.2 37 55 16 8.8 11 12 13 29 19 11 8.4 7.9 18 41 15 8.5 10 15 11 30 17 11 8.4 7.8 19 35 15 e8.5 8.5 21 11 31 47 7.9 10 e12 14 9.8 19 TOTAL 955.4 516 323.1 317.2 340.7 537.1 3,232 824 338.2 288.5 308.6 587.3 MEAN 30.8 17.2 10.4 10.2 12.2 17.3 108 26.6 11.3 9.31 9.95 19.6 MAX 129 44 13 45 56 180 491 141 14 12 21 57 MIN 9.4 11 7.9 6.2 6.2 5.0 10 14 8.5 7.4 6.9 7.8 AC-FT 1,900 1,020 641 629 676 1,070 6,410 1,630 671 572 612 1,160 CFSM 1.85 1.03 0.62 0.61 0.73 1.04 6.45 1.59 0.68 0.56 0.60 1.17 IN. 2.13 1.15 0.72 0.71 0.76 1.20 7.20 1.84 0.75 0.64 0.69 1.31 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2003, BY WATER YEAR (WY) MEAN 78.9 56.5 29.7 21.2 16.8 15.3 32.5 47.9 20.1 15.0 20.9 106 MAX 392 205 108 83.4 43.5 59.9 119 179 78.6 104 152 1,104 (WY) (1971) (1971) (1971) (1992) (1998) (1972) (2002) (1981) (1979) (1979) (1979) (1996) MIN 12.6 7.12 4.29 3.66 5.70 4.18 4.92 4.24 3.59 3.22 3.97 3.55 (WY) (2002) (1995) (1995) (1995) (1994) (1994) (1995) (1994) (1994) (1994) (1994) (1994) 178 RIO GRANDE DE MANATI BASIN 50034000 RIO BAUTA NEAR OROCOVIS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1969 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 10,162.1 ANNUAL MEAN 27.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 525 LOWEST DAILY MEAN 7.8 ANNUAL SEVEN-DAY MINIMUM 8.3 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 20,160 ANNUAL RUNOFF (CFSM) 1.67 ANNUAL RUNOFF (INCHES) 22.64 10 PERCENT EXCEEDS 46 50 PERCENT EXCEEDS 15 90 PERCENT EXCEEDS 9.5 8,568.1 23.5 38.4 117 1996 6.56 1994 Apr 25 491 Apr 25 19,500 Sep 10, 1996 Jul 26 5.0 Mar 17 2.8 Jul 23, 1994 Jul 25 5.3 Mar 12 2.8 Jul 23, 1994 2,300 Apr 5 28,200 Sep 22, 1998 12.28 Apr 5 25.93 Sep 22, 1998 4.6 Mar 17 2.6 Jul 26, 1994 16,990 27,830 1.41 2.30 19.09 31.26 35 67 11 13 7.1 5.7 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 179 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR LOCATION.--Lat 18q19'26", long 66q27'36", Hydrologic Unit 21010001, on left bank, 1.6 mi (2.6 km) upstream from Highway 145 bridge, 0.8 mi (1.3 km) downstream from Quebrada Saliente, 0.9 mi (1.4 km) upstream from Quebrada Cojo Valés, and 1.2 mi (1.9 km) southeast of Ciales. DRAINAGE AREA.--128 mi2 (332 km2), excludes 6.0 mi2 (15.5 km2), the runoff from which is diverted through El Guineo and Matrullas reservoirs. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--September 1946 to September 1953, May 1956 to December 1957 (unpublished, available in files of Caribbean District Office, February 1959 to September 1960 (monthly discharge measurements only), October 1960 to current year. Equivalent record from January 1971 to December 1972 published as 50035200 Río Grande de Manatí at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 m i2 (342 km2). GAGE.--Water-stage recorder. Elevation of gage is 140 ft (43 m), from topographic map. Prior to April 1, 1962, staff gage, read twice daily, at site 100 ft (30 m) upstream at same datum. January 1971 to December 1972 at site 1.6 mi (2.6 km) downstream at different datum. Since October 1, 1997, 2.0 ft (0.6 m) were added to gage datum. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights of major floods, pointed out by local residents are as follows: Aug ust 1899, 50 ft (15 m), September 1928, 36 ft (11 m), and September 1932, 34 ft (10 m) at site 1.6 mi (2.6 km) upstream. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 105 206 53 40 e39 37 e78 144 e98 50 133 280 2 109 319 51 42 e37 36 69 133 e99 61 82 134 3 148 180 53 42 e36 36 79 130 e99 54 67 256 4 155 104 56 40 e169 36 80 133 e103 49 56 341 5 110 88 59 39 e156 35 498 121 e92 55 66 154 6 100 83 54 39 e86 34 222 109 e90 74 61 100 7 255 79 50 39 e61 34 102 103 e93 63 66 97 8 320 75 50 38 e51 34 84 106 107 69 60 139 9 382 74 51 38 e47 34 77 99 86 63 53 149 10 195 72 48 39 e44 34 77 96 78 54 52 97 11 152 70 46 39 e41 34 79 89 74 49 57 159 12 124 68 46 38 e45 34 90 87 64 47 134 568 13 115 81 45 37 e39 34 87 87 59 55 82 457 14 156 94 45 36 e39 34 84 82 59 91 68 379 15 186 141 44 36 e36 33 83 85 73 62 74 183 16 170 109 41 35 e36 33 83 80 71 74 70 209 17 151 80 43 35 e36 32 693 77 68 67 86 159 18 117 73 49 35 e38 31 1,210 105 66 50 84 116 19 107 69 47 35 e36 119 788 89 82 41 82 105 20 99 66 52 35 e34 97 463 544 67 43 86 113 21 97 64 49 35 41 50 1,030 1,170 63 49 98 443 22 95 62 48 35 41 42 557 709 75 54 138 401 23 107 61 64 34 39 41 1,420 278 64 72 142 258 24 120 59 47 37 37 42 1,480 188 73 57 123 170 25 96 57 43 208 37 43 1,540 151 73 47 115 163 26 90 56 44 553 37 382 847 132 68 50 136 256 27 90 56 45 79 37 452 361 118 62 71 131 186 28 82 55 41 54 37 127 245 104 68 71 89 136 29 80 53 40 e44 99 193 113 61 71 154 142 30 86 54 39 e39 102 163 95 54 61 135 140 31 193 41 e39 e99 e102 94 267 TOTAL 4,392 2,708 1,484 1,914 1,412 2,310 12,862 5,659 2,289 1,868 3,047 6,490 MEAN 142 90.3 47.9 61.7 50.4 74.5 429 183 76.3 60.3 98.3 216 MAX 382 319 64 553 169 452 1,540 1,170 107 94 267 568 MIN 80 53 39 34 34 31 69 77 54 41 52 97 AC-FT 8,710 5,370 2,940 3,800 2,800 4,580 25,510 11,220 4,540 3,710 6,040 12,870 CFSM 1.11 0.71 0.37 0.48 0.39 0.58 3.35 1.43 0.60 0.47 0.77 1.69 IN. 1.28 0.79 0.43 0.56 0.41 0.67 3.74 1.64 0.67 0.54 0.89 1.89 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1946 - 2003, BY WATER YEAR (WY) MEAN 411 355 259 191 162 132 256 390 154 102 146 308 MAX 2,422 1,029 1,296 679 1,393 477 1,174 2,293 512 438 1,212 1,295 (WY) (1971) (2000) (1966) (1952) (1950) (1969) (1969) (1985) (1999) (1979) (1979) (1996) MIN 66.7 34.7 29.7 26.2 41.6 29.7 28.5 29.6 17.8 14.1 27.0 23.9 (WY) (2002) (1995) (1995) (1995) (1957) (1994) (1984) (1994) (1994) (1994) (1994) (1994) 180 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1946 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 60,478 ANNUAL MEAN 166 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2,540 LOWEST DAILY MEAN 39 ANNUAL SEVEN-DAY MINIMUM 42 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 120,000 ANNUAL RUNOFF (CFSM) 1.29 ANNUAL RUNOFF (INCHES) 17.58 10 PERCENT EXCEEDS 267 50 PERCENT EXCEEDS 104 90 PERCENT EXCEEDS 59 46,435 127 240 520 1971 47.3 1994 Apr 25 1,540 Apr 25 42,700 May 18, 1985 Dec 30 31 Mar 18 8.5 Jul 28, 1994 Dec 25 33 Mar 12 9.5 Jul 24, 1994 6,470 May 21 128,000 Sep 10, 1996 8.57 May 21 25.20 Sep 10, 1996 30 Mar 18 8.5 Jul 27, 1994 92,100 173,600 0.994 1.87 13.50 25.44 214 440 74 113 37 50 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 181 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--September 1946 to September 1953, May 1956 to December 1957 (unpublished, available in files of Caribbean District Office), February 1959 to September 1960 (monthly discharge measurements only), October 1960 to current year. Equivalent record from January 1971 to December 1972 published as 50035200 Río Grande de Manatí at Highway 145 at Ciales at site 1.6 mi (2.6 km) downstream, drainage area 132 m i2 (342 km2). PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: December 2001 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 2001. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,890 mg/L April 25, 2002; Minimum daily mean, 1 mg/L several days during Water Years 2002 and 2003. SEDIMENT LOADS: Maximum daily mean, 35,300 tons (32,024 tonnes) April 25, 2002; Minimum daily mean, .15 ton (.14 tonne) July 18, 2003. EXTREMES FOR CURRENT YEAR 2003.- SEDIMENT CONCENTRATION: Maximum daily mean, 2,300 mg/L April 23, 2003; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 24,600 tons (22,317 tonnes) April 23, 2003; Minimum daily mean, .15 ton (.14 tonne) July 18, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 105 18 4.9 206 209 151 53 7 1.0 2 109 22 6.4 319 587 1,300 51 8 1.1 3 148 38 17 180 109 57 53 6 0.91 4 155 44 19 104 20 5.8 56 5 0.73 5 110 34 10 88 12 2.9 59 3 0.53 6 100 33 8.8 83 12 2.7 54 2 0.36 7 255 967 2,130 79 12 2.6 50 4 0.57 8 320 352 733 75 12 2.4 50 6 0.84 9 382 183 211 74 11 2.2 51 8 1.1 10 195 51 29 72 10 1.9 48 10 1.3 11 152 22 9.3 70 9 1.7 46 12 1.5 12 124 19 6.3 68 9 1.7 46 14 1.8 13 115 18 5.5 81 14 3.4 45 16 2.0 14 156 173 139 94 15 4.0 45 18 2.2 15 186 150 88 141 47 27 44 20 2.4 16 170 105 57 109 16 5.1 41 22 2.4 17 151 107 46 80 6 1.2 43 22 2.5 18 117 37 12 73 5 1.0 49 22 2.9 19 107 21 6.1 69 6 1.1 47 22 2.7 20 99 17 4.6 66 6 1.1 52 22 3.1 21 97 14 3.7 64 7 1.2 49 22 2.9 22 95 14 3.5 62 9 1.5 48 22 2.8 23 107 21 8.0 61 11 1.8 64 22 3.8 24 120 22 7.8 59 13 2.0 47 22 2.7 25 96 11 2.9 57 14 2.2 43 22 2.5 26 90 9 2.2 56 12 1.8 44 21 2.6 27 90 8 1.9 56 8 1.3 45 21 2.6 28 82 6 1.4 55 5 0.81 41 21 2.4 29 80 6 1.2 53 6 0.83 40 21 2.3 30 86 5 1.2 54 7 0.95 39 21 2.3 31 193 183 268 41 21 2.4 TOTAL 4,392 3,844.7 2,708 1,590.19 1,484 61.24 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 182 RIO GRANDE DE MANATI BASIN 50035000 RIO GRANDE DE MANATI AT CIALES, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 40 21 2.3 e39 e20 e2.0 37 7 0.66 2 42 21 2.4 e37 e20 e1.9 36 6 0.61 3 42 21 2.4 e36 e20 e1.9 36 6 0.59 4 40 21 2.3 e169 e105 e57 36 6 0.62 5 39 21 2.2 e156 e107 e46 35 7 0.63 6 39 21 2.2 e86 e12 e2.9 34 7 0.65 7 39 21 2.2 e61 e22 e3.8 34 7 0.64 8 38 21 2.1 e51 e22 e3.8 34 7 0.65 9 38 21 2.1 e47 e22 e2.7 34 7 0.65 10 39 21 2.2 e44 e22 e2.7 34 6 0.57 11 39 21 2.2 e41 e22 e2.4 34 5 0.48 12 38 21 2.1 e45 e22 e2.7 34 4 0.40 13 37 21 2.0 e39 e21 e2.2 34 4 0.39 14 36 21 2.0 e39 e21 e2.2 34 4 0.40 15 36 21 2.0 e36 e21 e2.0 33 5 0.41 16 35 20 2.0 e36 e21 e2.0 33 5 0.45 17 35 20 1.9 e36 e21 e2.0 32 6 0.51 18 35 20 1.9 e38 e21 e2.0 31 7 0.58 19 35 20 1.9 e36 e21 e2.0 119 51 56 20 35 20 1.9 e34 e6 e0.65 97 28 11 21 35 20 1.9 41 6 0.61 50 10 1.3 22 35 20 1.9 41 5 0.56 42 8 0.93 23 34 20 1.9 39 5 0.52 41 8 0.85 24 37 20 2.0 37 5 0.50 42 7 0.84 25 208 344 842 37 5 0.51 43 7 0.81 26 553 860 2,320 37 6 0.58 382 918 4,690 27 79 21 5.0 37 6 0.64 452 279 487 28 54 7 1.0 37 7 0.69 127 59 21 29 e44 e20 e2.0 99 34 9.7 30 e39 e20 e2.0 102 19 5.2 31 e39 e20 e2.0 e99 16 3.2 TOTAL 1,914 3,224.0 1,412 149.46 2,310 5,297.72 APRIL MAY JUNE 1 e78 e14 e2.6 144 26 10 e98 e5 e1.5 2 69 13 2.5 133 12 4.3 e99 e5 e1.5 3 79 12 2.6 130 9 3.5 e99 e5 e1.5 4 80 11 2.4 133 7 2.5 e103 e6 e1.7 5 498 432 2,090 121 7 2.1 e92 e5 e1.3 6 222 124 96 109 6 1.9 e90 e5 e1.3 7 102 80 22 103 6 1.7 e93 e5 e1.3 8 84 73 16 106 6 1.6 107 5 1.9 9 77 66 14 99 5 1.5 86 2 0.49 10 77 58 12 96 5 1.3 78 3 0.55 11 79 51 11 89 5 1.2 74 3 0.66 12 90 44 11 87 5 1.1 64 4 0.73 13 87 37 8.7 87 4 1.0 59 6 0.95 14 84 30 6.7 82 4 0.93 59 8 1.2 15 83 22 5.0 85 6 1.3 73 7 1.4 16 83 15 3.4 80 8 1.7 71 6 1.2 17 693 701 3,130 77 8 1.7 68 7 1.2 18 1,210 1,450 7,800 105 8 2.4 66 7 1.3 19 788 785 2,230 89 9 2.1 82 8 1.7 20 463 337 557 544 451 2,100 67 7 1.3 21 1,030 1,240 7,790 1,170 2,260 20,600 63 7 1.1 22 557 362 654 709 519 1,440 75 6 1.2 23 1,420 2,300 24,600 278 112 88 64 5 0.89 24 1,480 1,750 8,410 188 55 28 73 5 0.94 25 1,540 2,190 17,300 151 32 13 73 5 0.89 26 847 764 2,400 132 11 3.8 68 4 0.78 27 361 165 167 118 7 2.1 62 4 0.67 28 245 86 58 104 6 1.7 68 4 0.69 29 193 54 28 113 4 1.3 61 3 0.58 30 163 40 18 95 2 0.62 54 3 0.47 31 e102 e5 e1.2 TOTAL 12,862 77,447.9 5,659 24,323.55 2,289 32.89 RIO GRANDE DE MANATI BASIN 183 50035000 RIO GRANDE DE MANATI AT CIALES, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean concen- Load discharge tration (tons/ Day (cfs) (mg/l) day) Mean Mean Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 50 3 0.43 2 61 4 0.66 3 54 5 0.73 4 49 6 0.77 5 55 6 0.84 133 32 12 280 112 106 82 6 1.3 134 32 12 67 4 0.72 256 117 209 56 5 0.75 341 157 178 66 6 1.0 154 40 17 6 74 5 1.1 7 63 5 0.83 8 69 4 0.73 9 63 3 0.51 10 54 2 0.30 61 5 0.83 100 25 6.9 66 4 0.73 97 25 6.5 60 3 0.51 139 25 9.4 53 2 0.31 149 25 10 52 2 0.28 97 23 6.1 11 49 1 0.16 12 47 1 0.17 13 55 2 0.25 14 91 2 0.47 15 62 2 0.30 57 3 0.52 159 54 41 134 23 9.3 568 647 2,440 82 10 2.2 457 430 712 68 7 1.2 379 168 203 74 5 1.1 183 8 4.7 16 74 2 0.30 17 67 1 0.23 18 50 1 0.15 19 41 2 0.19 20 43 3 0.29 70 4 0.79 209 2 1.2 86 7 2.3 159 3 1.5 84 6 1.3 116 5 1.5 82 6 1.4 105 6 1.7 86 7 1.6 113 6 1.7 21 49 3 0.44 22 54 4 0.61 23 72 5 0.92 24 57 4 0.59 25 47 2 0.30 98 8 2.0 443 445 1,440 138 8 3.1 401 27 39 142 9 3.4 258 4 3.2 123 10 3.2 170 4 1.6 115 10 3.2 163 3 1.4 26 50 1 0.18 27 71 2 0.38 28 71 3 0.57 29 71 4 0.73 30 61 4 0.59 31 94 18 12 136 12 4.5 256 48 41 131 20 7.0 186 17 8.8 89 17 4.1 136 15 5.6 154 34 16 142 15 5.7 135 22 8.2 140 15 5.6 267 92 81 --- --- --­ TOTAL 1,868 --- 26.72 3,047 --- 175.84 6,490 --- 5,521.1 YEAR 46,435 121,695.31 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus- sedi- pended pended Instan- ment, sedi- sedi- taneous sieve ment ment dis- diametr concen- dis- charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) MAR 26... 2010 2,040 99 2,600 14,300 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus- Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve ment ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr concen­ dis­ charge, percent percent percent percent percent percent percent percent percent tration charge, Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm mg/L tons/d (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (80154) (80155) MAR 26... 2110 2,000 54 68 78 90 95 99 100 100 100 2,070 11,200 184 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, PR LOCATION.--Lat 18q20'46", long 66q28'06", at bridge on Highway 149, about 800 ft (244 m) upstream from confluence with Río Cialitos, 0.5 mi (0.8 km) north of Ciales Plaza. DRAINAGE AREA.--136 mi2 (352 km2) this excludes the 6 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas, flow from which is diverted to Río Jacaguas. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 21... 0915 76 5.0 7.5 91 6.9 275 25.0 100 25.9 9.05 1.66 .5 MAR 21... 0850 82 15 7.0 -- 7.7 260 25.5 100 25.3 9.10 2.09 .5 MAY 02... 1200 61 3.8 8.9 -- 8.1 234 26.2 92 23.3 8.09 1.93 .5 AUG 14... 1145 51 1.7 9.0 -- 8.1 264 28.3 -- -- -- -- -­ SEP 12... 1340 216 130 7.7 -- 7.8 235 28.3 95 23.7 8.64 2.20 .5 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 21... 11.6 103 13.4 <.17 25.6 8.9 -- 158 32.5 <10 .20 .02 -­ MAR 21... 12.5 100 13.1 .13 23.9 9.7 .2 156 34.7 <10 .30 .03 .50 MAY 02... 10.9 89 11.0 <.17 25.5 8.5 <.1 142 23.5 <10 <.20 <.01 -­ AUG 14... -- 101 -- -- -- -- -- -- -- <10 <.20 .01 -­ SEP 12... 10.3 90 11.7 <.2 24.0 8.1 -- 143 83.0 <10 .30 .06 .56 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 21... .360 <.01 .18 .05 .56 2.5 <10 E80 E54 -- -- -- -­ MAR 21... .510 .01 .27 .06 .81 3.6 <10 E610 -- 3,100 <2 50.9 <18 MAY 02... .450 <.01 -- .04 -- -- <10 E13 -- 450 3 41.1 E9.1 AUG 14... <.020 <.01 -- <.02 -- -- <10 E160 -- 3,600 -- -- -­ SEP 12... .590 .03 .24 .13 .89 3.9 10 3,700 -- 8,000 -- -- -­ 185 RIO GRANDE DE MANATI BASIN 50035500 RIO GRANDE DE MANATI AT HIGHWAY 149 AT CIALES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 21... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 21... <.2 <.8 <10 <.01 320 <1 34.3 <.02 <3 <.3 <25 <.10 <16 MAY 02... <.2 <.8 <10 <.01 160 <1 25.6 <.02 E2 <.3 <25 E.07 <16 AUG 14... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 12... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 186 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q20'18", long 66q28'28", 100 ft (30 m) upstream from bridge on Highway 649, 0.7 mi (1.1 km) upstream from mouth, and about 0.4 mi (0.6 km) west of Ciales Plaza. DRAINAGE AREA.--17.0 mi2 (44.0 km2). PERIOD OF RECORD.--Water years 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Instan- wat unf taneous lab, Dis- dis- Hach solved charge, 2100AN oxygen, Date Time cfs NTU mg/L (00061) (99872) (00300) pH, Specif. Hard- water, conduc- ness, Magnes- Potas- unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, field, wat unf ature, unfltrd water, water, water, adsorp- water, std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) NOV 19... 1415 22 16 8.3 7.2 257 25.2 99 29.0 6.54 1.70 .5 11.0 MAR 21... 1045 12 48 8.1 7.2 227 23.5 89 26.0 5.75 2.24 .4 9.42 MAY 02... 1400 20 4.0 8.2 8.2 245 27.9 95 27.9 6.24 1.89 .5 10.5 AUG 14... 1230 6.7 6.2 9.2 8.3 228 28.8 -- -- -- -- -- -­ SEP 12... 1150 29 92 8.1 7.8 197 26.5 79 23.6 4.93 2.35 .4 7.81 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) (00630) NOV 19... 96 10.6 <.17 28.5 7.1 -- 152 9.09 <10 <.20 .01 -- .890 MAR 21... 82 10.9 .11 21.9 8.4 .2 134 4.51 23 .40 .04 1.58 1.60 MAY 02... 97 10.4 <.17 29.6 6.9 <.1 151 7.98 <10 <.20 <.01 -- .670 AUG 14... 92 -- -- -- -- -- -- -- <10 <.20 .02 -- .390 SEP 12... 71 9.04 <.2 20.2 7.7 -- 118 9.19 47 .50 .05 1.07 1.10 Total Fecal Fecal Total Organic Total nitro- COD, coli- strep- coli- Barium, Boron, Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd Date as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) NOV 19... <.01 -- .08 -- -- <10 3,100 870 -- -- -- -- -­ MAR 21... .02 .36 .11 2.0 8.9 20 4,700 -- 24,000 <2 61.1 E16 <.2 MAY 02... <.01 -- .06 -- -- <10 E160 -- 2,800 <2 52.6 E9.1 <.2 AUG 14... <.01 -- .05 -- -- <10 E880 -- E18,000 -- -- -- -­ SEP 12... .03 .45 .11 1.6 7.1 20 E7,700 -- E85,000 -- -- -- -­ 187 RIO GRANDE DE MANATI BASIN 50035950 RIO CIALITOS AT HIGHWAY 649 AT CIALES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com­ unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover water recover recover recover recover water, recover recover water, water, -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 19... -- -- -- -- -- -- -- -- -- -- -- -- MAR 21... <.8 <10 <.01 630 <1 46.0 <.02 <3 <.3 E14 <.10 <16 MAY 02... <.8 <10 <.01 230 <1 17.7 <.02 <3 <.3 <25 <.10 <16 AUG 14... -- -- -- -- -- -- -- -- -- -- -- -- SEP 12... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 188 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR LOCATION.--Lat 18q25'52", long 66q31'37", Hydrologic Unit 21010002, at bridge on Highway 2, and 2.3 mi (3.7 km) west of Manatí. DRAINAGE AREA.--197 mi2 (510 km2), approximately, of which about 38 mi2 (98 km2) is partly or entirely noncontributing, excludes 6.0 mi2 (15.5 km2) upstream from Lago El Guineo and Lago de Matrullas. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1963-68 (annual maximum discharge only), February 1970 to current year. REVISED RECORDS.--WRD PR-86-1: 1970-71 (M), 1975, 1979, 1982-85 (P). GAGE.--Water-stage recorder. Elevation of gage is 14 ft (4 m), from topographic map. Prior to 1968 crest-stage gage at same site and datum 3.57 ft (1.09 m) lower. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. Possible water extraction about 500 ft (152.4 m) upstream of gage by unknown source affecting low flow. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate gage heights to gage datum of major floods, pointed out by local residents, are as follows: September 13, 1928, 36.6 ft (11.16 m), September 27, 1932, 36.3 ft (11.06 m), and August 4, 1945, 34.3 ft (10.45 m). DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 156 575 96 95 99 58 82 222 121 73 149 412 2 174 328 95 95 104 57 79 204 124 76 114 163 3 214 625 96 98 95 56 78 190 121 79 92 121 4 247 211 97 95 187 57 105 192 118 74 84 581 5 172 165 105 91 643 56 343 180 114 73 84 176 6 149 149 101 90 397 55 639 170 110 86 90 118 7 264 141 95 91 172 55 142 161 112 92 87 100 8 574 134 92 89 125 55 99 160 109 86 84 118 9 808 129 95 89 107 56 86 155 106 116 79 141 10 447 127 92 90 95 55 79 162 102 94 75 111 11 273 124 89 92 89 54 73 146 100 86 73 102 12 211 121 88 90 83 54 75 138 97 81 96 367 13 187 123 90 88 80 54 80 135 96 80 119 959 14 172 215 91 87 75 54 72 132 96 102 88 400 15 322 229 92 86 71 54 68 129 98 104 84 184 16 298 361 92 84 67 53 66 126 98 95 95 159 17 237 179 92 85 65 53 393 122 97 101 80 152 18 186 145 108 84 65 53 1,820 140 94 91 80 117 19 173 138 104 84 64 54 2,270 145 98 84 79 101 20 159 128 104 84 64 234 533 629 97 79 80 99 21 152 123 109 85 63 95 1,490 1,870 91 77 88 602 22 150 120 102 84 63 69 1,620 2,530 92 86 88 794 23 140 116 124 83 61 61 1,190 470 89 90 92 279 24 197 113 114 84 59 58 3,790 296 84 93 89 175 25 169 109 100 114 58 56 2,800 223 81 81 97 196 26 167 103 97 1,180 58 55 3,280 180 79 77 148 184 27 144 102 133 238 59 1,090 650 159 77 85 124 141 28 135 102 104 140 58 240 415 145 76 97 115 119 29 128 98 96 114 138 309 138 74 94 108 104 30 130 97 92 105 141 255 133 73 98 161 101 31 134 93 100 110 126 83 208 TOTAL 7,069 5,430 3,078 4,114 3,226 3,390 22,981 9,908 2,924 2,713 3,130 7,376 MEAN 228 181 99.3 133 115 109 766 320 97.5 87.5 101 246 MAX 808 625 133 1,180 643 1,090 3,790 2,530 124 116 208 959 MIN 128 97 88 83 58 53 66 122 73 73 73 99 AC-FT 14,020 10,770 6,110 8,160 6,400 6,720 45,580 19,650 5,800 5,380 6,210 14,630 CFSM 1.16 0.92 0.50 0.67 0.58 0.56 3.89 1.62 0.49 0.44 0.51 1.25 IN. 1.33 1.03 0.58 0.78 0.61 0.64 4.34 1.87 0.55 0.51 0.59 1.39 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1970 - 2003, BY WATER YEAR (WY) MEAN 686 634 410 263 203 176 371 612 234 150 205 595 MAX 2,958 2,383 1,717 879 444 521 1,187 3,178 815 577 1,644 3,732 (WY) (1971) (2002) (2000) (1997) (1988) (1972) (2002) (1985) (1999) (1979) (1979) (1998) MIN 130 71.0 55.1 59.1 72.0 56.2 49.9 93.7 63.8 53.0 67.9 67.4 (WY) (2002) (1995) (1998) (1995) (1994) (1994) (1995) (1989) (1994) (1994) (1984) (1994) 189 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1970 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 98,874 ANNUAL MEAN 271 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 6,810 LOWEST DAILY MEAN 76 ANNUAL SEVEN-DAY MINIMUM 86 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 196,100 ANNUAL RUNOFF (CFSM) 1.38 ANNUAL RUNOFF (INCHES) 18.67 10 PERCENT EXCEEDS 416 50 PERCENT EXCEEDS 140 90 PERCENT EXCEEDS 96 75,339 206 377 756 1971 96.5 1994 Apr 26 3,790 Apr 24 80,400 Sep 22, 1998 Aug 29 53 Mar 16 31 Jan 24, 1995 Aug 23 54 Mar 12 33 Jul 23, 1994 11,300 Apr 26 198,000 Sep 10, 1996 28.02 Apr 26 36.39 Sep 10, 1996 50 Mar 13 28 Jan 23, 1995 149,400 273,000 1.05 1.91 14.23 25.99 324 669 102 162 67 81 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 190 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 12... 1115 82 10 8.3 100 6.8 326 25.3 140 43.4 8.08 1.55 .4 MAR 13... 1500 55 9.3 11.3 -- 8.3 307 28.9 130 40.8 7.81 1.06 .4 MAY 06... 1600 167 15 7.6 -- 7.8 289 30.5 120 35.4 8.10 1.98 .5 AUG 18... 1145 82 11 7.4 -- 7.6 295 28.9 -- -- -- -- -­ SEP 11... 1425 93 12 8.9 -- 7.8 284 30.6 120 35.1 7.75 2.20 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 12... 11.4 189 12.5 <.17 20.0 7.7 -- 218 48.0 <10 .60 .07 -­ MAR 13... 11.6 131 14.4 .12 16.2 7.6 <.1 178 26.5 <10 .30 .02 -­ MAY 06... 11.6 112 13.1 <.17 22.4 8.3 <.1 168 76.0 14 <.20 .04 .48 AUG 18... -- 125 -- -- -- -- -- -- -- 11 .90 .29 -- SEP 11... 10.3 113 12.3 <.2 22.5 8.4 -- 166 41.5 11 .30 .05 .68 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 12... .410 <.01 .53 .14 1.0 4.5 <10 E9,000 48,000 -- -- -- -­ MAR 13... .100 <.01 .28 .09 .40 1.8 <10 3,100 -- 7,900 <2 35.2 25 MAY 06... .490 .01 -- .07 -- -- 10 E750 -- 3,800 <2 50.4 E14 AUG 18... .080 <.01 .61 .15 .98 4.3 20 3,300 -- 26,000 -- -- -­ SEP 11... .700 .02 .25 .10 1.0 4.4 10 E1,000 -- 2,900 -- -- -­ 191 RIO GRANDE DE MANATI BASIN 50038100 RIO GRANDE DE MANATI AT HIGHWAY 2 NEAR MANATI, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 12... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 13... <.2 E.8 <10 <.01 260 <1 32.6 <.02 <3 <.3 <25 <.10 <16 MAY 06... <.2 1.2 M <.01 710 M 70.4 <.02 <3 <.3 <25 <.10 <16 AUG 18... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 11... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAY 06... 1600 <.01 <.02 <.01 <.01 <.02 <.1 <.01 <.02 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAY 06... <.01 <.01 <.009 <.01 <.014 <.30 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAY 06... <.1 <.02 <.02 <1 <.02 < -- Less than 192 LAGUNA TORTUGUERO BASIN 50038200 LAGUNA TORTUGUERO OUTLET NEAR VEGA BAJA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q28'29", long 66q26'50", at bridge on Highway 686, 4.2 mi (6.8 km) northeast of Manatí, and 4.4 mi (7.1 km) northwest of Vega Baja Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1964-66, 1969-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 ANC, Residue Ammonia Nitrite Dis- pH, Specif. wat unf total + + Instan- solved water, conduc- fixed at 105 org-N, Ammonia nitrate taneous Dis- oxygen, unfltrd tance, Temper- end pt, Sulfide deg. C, water, water, water dis- solved percent field, wat unf ature, field, water sus- unfltrd unfltrd unfltrd charge, oxygen, of sat- std uS/cm water, mg/L as unfltrd pended, mg/L mg/L mg/L Date Time cfs mg/L uration units 25 degC deg C CaCO3 mg/L mg/L as N as N as N (00061) (00300) (00301) (00400) (00095) (00010) (00410) (00745) (00530) (00625) (00610) (00630) NOV 21... 1115 10 9.4 122 7.2 1,190 28.4 94 -- <10 3.3 .13 .850 MAR 10... 1115 5.6 6.0 -- 7.9 1,360 27.7 138 -- 12 1.3 .26 .450 MAY 01... 1325 5.0 6.3 -- 7.8 1,380 30.5 133 <.1 <10 1.3 .31 .480 AUG 07... 0950 5.7 6.4 -- 8.0 1,470 29.3 102 -- <10 .90 .16 .200 SEP 24... 1600 7.7 7.7 -- 8.0 1,460 31.6 109 -- <10 1.2 .16 .400 Total Fecal Fecal Total Mangan- nitro- COD, coli- strep- coli- Boron, Copper, Iron, ese, Zinc, Nitrite Phos- gen, high form, tococci form, water, water, water, water, water, water, phorus, water, level, M-FC KF M-Endo, unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd water, unfltrd water, 0.7u MF MF, immed, recover recover water recover recover recover mg/L unfltrd mg/L unfltrd col/ col/ col/ -able, -able, unfltrd -able, -able, -able, Date as N mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L mg/L ug/L ug/L ug/L (00615) (00665) (71887) (00340) (31625) (31673) (31501) (01022) (01042) (00720) (01045) (01055) (01092) NOV 21... <.01 <.02 18.4 10 E20 121 -- -- -- -- -- -- -­ MAR 10... .01 <.02 7.7 40 <10 -- E1,800 -- -- -- -- -- -­ MAY 01... .01 <.02 7.9 30 E12 -- 250 68 <10 M 20 E2.8 31 AUG 07... <.01 <.02 4.9 20 30 -- 320 -- -- -- -- -- -­ SEP 24... .01 <.02 7.1 30 E18 -- 76 -- -- -- -- -- -- Phen­ olic com- MBAS, pounds, water, water, unfltrd unfltrd Date mg/L ug/L (38260) (32730) NOV 21... -- -­ MAR 10... -- -­ MAY 01... <.10 <16 AUG 07... -- -­ SEP 24... -- -­ < -- Less than E -- Estimated value M -- Presence verified, not quantified 193 Figure 14. Río Cibuco basin. --- --- --- --- --- --- --- 194 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR LOCATION.--Lat l8q21'13", long 66q20'07", Hydrologic Unit 21010001, on right bank, 150 ft (46 m) downstream from junction with Río Corozal and 1.4 mi (2.3 km) northwest of Corozal. DRAINAGE AREA.--15.1 mi2 (39.1 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May 1969 to current year. GAGE.--Water-stage recorder. Elevation of gage is 195 ft (59 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. Daily discharge affected by sewage treatment plant about 0.6 mi (1.0 km) upstream from station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20 12 6.7 4.9 6.1 5.1 5.2 8.3 5.4 5.3 5.8 11 2 24 19 7.6 7.3 5.7 4.9 5.5 7.6 5.4 6.7 4.1 10 3 23 13 7.7 5.3 6.6 4.8 15 7.5 5.5 5.6 3.7 18 4 28 11 11 4.5 33 5.4 10 7.4 5.9 6.5 3.3 7.1 5 20 11 8.5 4.4 18 5.6 8.3 7.2 5.8 6.7 3.2 5.9 6 19 11 7.5 4.7 8.9 5.8 13 7.2 5.3 6.2 3.9 5.6 7 89 11 7.3 4.5 7.5 5.6 10 7.5 6.1 5.8 3.4 5.7 8 42 10 10 4.4 7.0 5.8 7.3 8.0 5.6 15 3.0 6.7 9 55 11 7.2 4.5 6.3 6.1 6.7 6.9 5.5 7.4 2.8 5.8 10 28 9.9 6.3 5.2 6.3 6.0 6.5 6.6 5.4 5.1 2.5 5.4 11 17 9.9 6.5 4.6 6.6 6.2 6.5 5.8 5.2 4.9 2.4 5.9 12 14 10 6.5 4.3 7.0 5.4 6.9 5.6 5.4 4.8 2.7 6.4 13 14 15 6.9 5.4 6.2 5.4 6.2 5.1 5.3 15 3.0 5.5 14 13 28 6.4 6.6 6.1 5.3 6.1 5.2 5.2 5.9 3.3 5.5 15 12 10 6.1 6.6 6.3 5.4 6.1 5.3 7.6 4.7 3.3 5.2 16 13 8.6 5.9 7.2 5.7 5.3 6.0 5.0 5.7 6.3 2.9 5.1 17 12 8.7 5.8 7.1 6.3 5.2 39 5.1 5.3 5.5 2.7 5.0 18 13 9.6 6.0 6.6 5.5 5.2 40 5.1 5.3 4.5 8.1 5.3 19 17 9.3 6.5 6.6 5.6 5.1 23 5.0 5.6 4.3 3.2 5.9 20 22 8.3 7.7 6.9 6.3 5.1 44 27 5.6 4.3 3.1 5.8 21 20 8.3 5.7 6.7 5.7 5.2 133 83 5.5 4.5 21 230 22 13 7.9 6.5 6.7 6.2 5.2 40 19 5.1 6.2 9.2 113 23 12 7.7 6.1 6.5 5.9 5.3 327 7.5 5.0 4.9 5.9 25 24 12 7.5 5.4 9.0 5.5 5.4 135 5.7 5.0 4.0 7.0 14 25 24 7.5 5.1 95 5.5 5.2 35 4.8 5.0 4.1 25 143 26 18 7.4 5.2 65 5.5 7.1 18 5.0 5.3 4.4 12 46 27 14 7.4 4.8 11 5.4 22 12 5.1 5.3 5.5 6.6 18 28 12 7.4 4.7 7.8 5.3 8.9 10 5.3 5.4 4.3 8.5 12 29 12 6.9 4.5 6.8 5.8 8.9 5.3 4.9 4.0 58 17 30 12 7.0 4.5 6.7 5.7 8.6 5.3 4.9 3.7 10 14 31 12 4.9 6.4 5.3 5.6 5.1 7.8 TOTAL 656 311.3 201.5 339.2 212.0 189.8 998.8 300.0 163.5 181.2 241.4 768.8 MEAN 21.2 10.4 6.50 10.9 7.57 6.12 33.3 9.68 5.45 5.85 7.79 25.6 MAX 89 28 11 95 33 22 327 83 7.6 15 58 230 MIN 12 6.9 4.5 4.3 5.3 4.8 5.2 4.8 4.9 3.7 2.4 5.0 AC-FT 1,300 617 400 673 421 376 1,980 595 324 359 479 1,520 CFSM 1.40 0.69 0.43 0.72 0.50 0.41 2.20 0.64 0.36 0.39 0.52 1.70 IN. 1.62 0.77 0.50 0.84 0.52 0.47 2.46 0.74 0.40 0.45 0.59 1.89 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1969 - 2003, BY WATER YEAR (WY) MEAN 40.6 50.6 39.1 24.5 20.8 19.7 31.2 40.9 14.6 12.0 15.7 33.3 MAX 135 155 169 69.6 51.3 65.1 111 157 44.4 35.6 50.8 191 (WY) (1991) (1971) (1971) (1992) (1988) (1981) (1973) (1986) (1987) (1999) (1979) (1996) MIN 8.05 5.63 1.94 6.93 7.57 4.36 3.32 3.20 1.63 2.19 3.44 3.88 (WY) (1979) (1998) (1998) (1995) (2003) (1984) (1984) (1977) (1994) (1994) (1978) (1994) 195 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1969 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 8,329.1 ANNUAL MEAN 22.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 440 LOWEST DAILY MEAN 4.5 ANNUAL SEVEN-DAY MINIMUM 4.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 16,520 ANNUAL RUNOFF (CFSM) 1.51 ANNUAL RUNOFF (INCHES) 20.52 10 PERCENT EXCEEDS 42 50 PERCENT EXCEEDS 12 90 PERCENT EXCEEDS 6.5 4,563.5 12.5 28.7 56.5 1971 7.47 1994 May 1 327 Apr 23 3,190 Nov 8, 2001 Dec 29 2.4 Aug 11 0.91 Jul 17, 1994 Dec 25 2.8 Aug 8 1.2 Jun 21, 1994 2,850 Apr 23 21,400 Nov 8, 2001 11.34 Apr 23 22.68 Nov 8, 2001 9,050 20,770 0.828 1.90 11.24 25.80 19 50 6.3 13 4.6 5.1 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 196 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969-76, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Instan- wat unf taneous lab, Dis- dis- Hach solved charge, 2100AN oxygen, Date Time cfs NTU mg/L (00061) (99872) (00300) pH, Specif. Hard- water, conduc- ness, Magnes- Potas- unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, field, wat unf ature, unfltrd water, water, water, adsorp- water, std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) NOV 22... 0930 8.2 4.0 8.0 7.3 428 24.6 160 40.3 13.5 3.26 .7 20.9 MAR 28... 0900 9.8 36 7.5 7.2 337 23.2 130 31.5 12.3 3.66 .7 17.8 MAY 08... 1015 7.9 5.6 8.1 7.8 422 25.7 160 41.2 14.1 3.92 .7 19.9 AUG 13... 1030 2.8 1.3 8.5 7.9 453 26.7 -- -- -- -- -- -­ SEP 24... 1045 16 21 7.7 7.7 372 25.3 140 36.5 12.8 4.22 .6 16.7 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) (00630) NOV 22... 141 27.4 <.17 31.1 14.1 -- 235 5.24 <10 .50 .10 2.64 2.70 MAR 28... 110 24.5 .13 26.0 17.7 <.1 199 5.27 22 .50 .05 1.48 1.50 MAY 08... 143 30.5 <.17 28.9 15.7 <.1 240 5.09 <10 .70 .33 1.75 1.90 AUG 13... 140 -- -- -- -- -- -- -- <10 .50 .10 3.42 3.50 SEP 24... 120 26.0 <.2 26.7 18.7 -- 213 8.94 10 .60 .12 1.67 1.70 Total Fecal Fecal Total Organic Total nitro- COD, coli- strep- coli- Barium, Boron, Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd Date as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) NOV 22... .06 .40 .41 3.2 14.2 <10 2,700 550 -- -- -- -- -­ MAR 28... .02 .45 .26 2.0 8.9 20 E17,000 -- E71,000 E2 47.1 25 <.2 MAY 08... .15 .37 .37 2.6 11.5 <10 2,400 -- 60,000 <2 58.9 35 <.2 AUG 13... .08 .40 .83 4.0 17.7 <10 E150 -- 28,000 -- -- -- -­ SEP 24... .03 .48 .20 2.3 10.2 10 2,100 -- 62,000 -- -- -- -­ 197 RIO CIBUCO BASIN 50038320 RIO CIBUCO BELOW COROZAL, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com­ unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover water recover recover recover recover water, recover recover water, water, -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 22... -- -- -- -- -- -- -- -- -- -- -- -- MAR 28... 3.5 <10 <.01 1,000 M 63.8 <.02 E2 <.3 <25 <.10 <16 MAY 08... <.8 <10 <.01 90 <1 58.1 <.02 <3 <.3 <25 <.10 <16 AUG 13... -- -- -- -- -- -- -- -- -- -- -- -- SEP 24... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 198 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR LOCATION.--Lat 18q26'53", long 66q22'29", Hydrologic Unit 21010002, on left bank, at bridge on Highway 2, 0.6 mi (1.0 km) downstream from Río Indio and 0.8 mi (1.3 km) east of Vega Baja. DRAINAGE AREA.--99.1 mi2 (256.7 km2), of which 25.4 mi2 (65.8 km2), does not contribute directly to surface runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is 7.79 ft (2.374 m) above mean sea level. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Flood of December 11, 1965, reached a stage of 26.2 ft (7.99 m), datum unknown, discharge ab out 28,000 ft3/s (793 m3/s). DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 49 87 24 27 31 21 18 45 23 21 70 158 2 61 70 24 28 33 21 19 41 23 e18 37 108 3 108 179 31 41 32 20 20 38 23 e17 38 62 4 96 65 40 26 175 19 87 37 23 19 26 94 5 93 49 55 24 247 18 35 37 23 21 23 44 6 51 48 32 24 78 18 31 37 22 28 24 35 7 277 48 29 24 49 19 72 40 20 28 35 31 8 e203 42 33 23 42 20 35 40 28 26 40 43 9 e171 40 51 22 41 20 26 38 22 94 24 63 10 e149 40 31 25 34 21 25 30 21 28 21 33 11 134 38 28 24 32 20 25 30 19 20 19 30 12 103 40 29 22 31 20 29 31 18 20 23 38 13 85 51 35 21 30 19 24 28 19 42 25 34 14 76 144 31 22 27 19 21 25 18 75 40 43 15 83 114 27 23 27 18 21 28 25 28 32 27 16 e78 44 27 22 27 19 22 25 29 33 24 23 17 69 54 26 23 29 18 139 25 21 46 21 21 18 59 53 25 21 26 18 265 22 21 25 28 20 19 66 57 25 20 25 21 287 29 21 19 81 20 20 92 38 39 21 25 19 145 21 22 18 34 23 21 107 34 34 22 26 19 526 68 22 17 86 580 22 84 33 32 21 25 19 488 364 22 53 214 837 23 59 29 39 19 e23 19 354 89 18 52 74 426 24 55 28 32 20 e22 19 799 51 16 26 40 164 25 100 28 27 134 e22 18 253 39 16 22 95 67 26 170 28 27 523 23 21 142 32 16 21 212 264 27 81 26 27 98 22 69 96 28 15 37 75 60 28 56 25 25 49 21 105 71 27 15 38 53 38 29 51 25 24 37 29 59 26 18 44 107 37 30 49 25 24 36 27 50 24 21 25 209 42 31 46 24 33 22 23 22 83 TOTAL 2,961 1,582 957 1,475 1,225 755 4,184 1,418 620 983 1,913 3,465 MEAN 95.5 52.7 30.9 47.6 43.8 24.4 139 45.7 20.7 31.7 61.7 116 MAX 277 179 55 523 247 105 799 364 29 94 214 837 MIN 46 25 24 19 21 18 18 21 15 17 19 20 AC-FT 5,870 3,140 1,900 2,930 2,430 1,500 8,300 2,810 1,230 1,950 3,790 6,870 CFSM 0.96 0.53 0.31 0.48 0.44 0.25 1.41 0.46 0.21 0.32 0.62 1.17 IN. 1.11 0.59 0.36 0.55 0.46 0.28 1.57 0.53 0.23 0.37 0.72 1.30 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 2003, BY WATER YEAR (WY) MEAN 155 200 200 104 86.6 76.4 141 171 68.8 55.4 75.1 141 MAX 559 523 1,316 339 190 339 667 655 239 235 461 690 (WY) (1986) (1980) (1982) (1997) (1988) (1990) (1987) (1985) (1987) (1999) (1979) (1996) MIN 45.9 28.3 12.9 30.2 27.2 20.5 16.2 24.7 12.5 14.0 21.2 26.7 (WY) (1974) (1998) (1998) (1995) (1994) (1994) (1984) (1977) (1994) (1994) (1978) (1994) RIO CIBUCO BASIN 199 50039500 RIO CIBUCO AT VEGA BAJA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1973 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 33,356 ANNUAL MEAN 91.4 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 905 LOWEST DAILY MEAN 24 ANNUAL SEVEN-DAY MINIMUM 25 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 66,160 ANNUAL RUNOFF (CFSM) 0.922 ANNUAL RUNOFF (INCHES) 12.52 10 PERCENT EXCEEDS 177 50 PERCENT EXCEEDS 55 90 PERCENT EXCEEDS 28 21,538 59.0 122 236 1982 38.5 1994 Apr 27 837 Sep 22 14,600 Dec 13, 1981 Aug 21 15 Jun 27 7.2 May 3, 1995 Nov 26 16 Jun 23 8.1 Apr 28, 1995 2,650 Sep 21 34,000 Apr 12, 1987 14.32 Sep 21 19.10 Apr 12, 1987 7.2 May 2, 1995 42,720 88,140 0.595 1.23 8.08 16.68 107 235 29 55 19 22 e Estimated 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 200 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 21... 1300 34 14 6.7 83 7.1 450 25.7 180 57.1 9.31 3.47 .5 APR 01... 0855 18 4.0 3.6 -- 7.3 428 26.8 -- -- -- -- -­ MAY 08... 1400 35 14 6.4 -- 7.8 408 27.5 170 53.1 8.21 3.69 .5 AUG 13... 1310 22 1.5 8.1 -- 7.9 437 28.4 -- -- -- -- -­ SEP 24... 1400 125 44 6.6 -- 7.8 439 26.6 190 65.1 7.22 4.50 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 21... 16.5 170 25.6 <.17 19.0 15.8 -- 249 23.0 <10 .40 .05 1.39 APR 01... -- 160 -- -- -- -- <.1 -- -- -- .20 .02 .87 MAY 08... 15.3 130 24.3 <.17 15.9 15.4 <.1 214 20.3 <10 .30 .06 1.18 AUG 13... -- 146 -- -- -- -- -- -- -- <10 .20 .01 1.09 SEP 24... 12.7 165 19.9 <.2 14.1 19.9 -- 242 82.0 50 .50 .07 1.78 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 21... 1.40 .01 .35 .15 1.8 8.0 <10 330 570 -- -- -- -­ APR 01... .880 .01 .18 .20 1.1 4.8 -- 500 -- 22,000 -- -- -­ MAY 08... 1.20 .02 .24 .20 1.5 6.6 <10 E780 -- E19,000 E2 46.3 35 AUG 13... 1.10 .01 .19 .26 1.3 5.8 10 E1,600 -- 35,000 -- -- -­ SEP 24... 1.80 .02 .43 .15 2.3 10.2 10 3,400 -- 47,000 -- -- -­ 201 RIO CIBUCO BASIN 50039500 RIO CIBUCO AT VEGA BAJA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 21... -- -- -- -- -- -- -- -- -- -- -- -- -- APR 01... -- -- -- -- -- -- -- -- -- -- -- <.10 <16 MAY 08... <.2 E.6 <10 <.01 200 <1 26.3 <.02 <3 <.3 E19 E.06 <16 AUG 13... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 24... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 202 THIS PAGE IS INTENTIONALLY BLANK 203 Figure 15. Río de la Plata basin. 204 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR LOCATION.--Lat 18q03'46", long 66q05'58", Hydrologic Unit 21010005, on top of a concrete tower at diversion tunnel on Carite Reservoir, 0.7 mi (1.1 km) northwest from Escuela Carite Chino, 1.2 mi (1.9 km) northeast from Central Hidroeléctrica de Carite Num. 1 and 1.8 mi (2.9 km) northeast from Escuela Segunda Unidad. DRAINAGE AREA.--8.20 mi2 (21.2 km2). PERIOD OF RECORD.--May 1989 to current year. Prior to October 1994, published as Lago Carite at Gate Tower. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Carite Dam was completed in 1913. The operation of the reservoir is controlled by the utilization of water to meet the demands for domestic, industrial, and agricultural purposes in the Guayama area. The dam is an earthfill with crest elevation of 1,806 ft (550 m) above mean sea level, with a structural height of 104 ft (32 m) and a length of 500 ft (152 m). The dam has a capacity of approximately 11,310 acre-feet (13.9 hm3). The Dam is operated by the Puerto Rico Electric and Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,789.62 ft (545.48 m), September 21, 1998; minimum elevation, 1,761.22 ft (536.81 m), May 28, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation 1,782.36 ft (543.26 m), September 16; minimum elevation, 1,774.37 ft (540.83 m), April 8. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 1,746 0 1,760 2,471 1,769 4,561 Elevation Contents 1,775 6,194 1,780 7,704 1,790 11,048 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1,778.11 1,778.78 1,778.30 1,777.74 1,777.15 1,776.74 1,774.94 1,779.88 1,779.32 1,779.33 1,780.68 1,781.44 2 1,778.11 1,778.74 1,778.36 1,777.79 1,777.11 1,776.69 1,774.86 1,779.86 1,779.34 1,779.39 1,781.61 1,781.42 3 1,778.11 1,778.82 1,778.35 1,777.78 1,777.06 1,776.65 1,774.81 1,779.84 1,779.37 1,779.37 1,781.52 1,781.86 4 1,778.18 1,778.79 1,778.33 1,777.73 1,777.05 1,776.63 1,774.79 1,779.82 1,779.33 1,779.36 1,781.46 1,781.61 5 1,778.15 1,778.76 1,778.34 1,777.78 1,776.99 1,776.58 1,774.79 1,779.80 1,779.28 1,779.44 1,781.41 1,781.51 6 1,778.09 1,778.75 1,778.32 1,777.79 1,776.95 1,776.52 1,774.75 1,779.76 1,779.27 1,779.52 1,781.49 1,781.47 7 1,778.10 1,778.71 1,778.28 1,777.76 1,776.96 1,776.46 1,774.65 1,779.73 1,779.29 1,779.50 1,781.57 1,781.43 8 1,778.94 1,778.66 1,778.23 1,777.72 1,776.92 1,776.42 1,774.49 1,779.75 1,779.25 1,779.61 1,781.53 1,781.42 9 1,778.92 1,778.62 1,778.22 1,777.67 1,776.93 1,776.40 1,774.49 1,779.70 1,779.23 1,779.62 1,781.57 1,781.39 10 1,778.95 1,778.61 1,778.22 1,777.64 1,776.96 1,776.27 1,774.45 1,779.65 1,779.16 1,779.59 1,781.50 1,781.37 11 1,778.90 1,778.62 1,778.22 1,777.59 1,776.94 1,776.27 1,774.79 1,779.60 1,779.12 1,779.55 1,781.46 1,781.36 12 1,778.93 1,778.56 1,778.20 1,777.55 1,776.89 1,776.18 1,774.84 1,779.55 1,779.09 1,779.54 1,781.42 1,781.35 13 1,778.91 1,778.56 1,778.16 1,777.52 1,776.85 1,776.15 1,774.92 1,779.53 1,779.02 1,780.45 1,781.39 1,781.33 14 1,778.86 1,778.53 1,778.15 1,777.48 1,776.83 1,776.05 1,774.96 1,779.59 1,779.00 1,780.47 1,781.42 1,781.37 15 1,778.84 1,778.52 1,778.10 1,777.41 1,776.77 1,776.03 1,775.04 1,779.61 1,779.11 1,780.46 1,781.40 1,781.96 16 1,778.89 1,778.62 1,778.11 1,777.39 1,776.75 1,775.93 1,775.06 1,779.59 1,779.09 1,780.51 1,781.40 1,781.86 17 1,778.90 1,778.67 1,778.13 1,777.35 1,776.85 1,775.96 1,777.14 1,779.56 1,779.05 1,780.49 1,781.39 1,781.61 18 1,778.90 1,778.66 1,778.12 1,777.33 1,776.85 1,775.82 1,779.02 1,779.59 1,779.00 1,780.47 1,781.60 1,781.51 19 1,778.87 1,778.65 1,778.09 1,777.32 1,776.84 1,775.80 1,779.39 1,779.57 1,779.50 1,780.44 1,781.50 1,781.46 20 1,778.85 1,778.62 1,778.05 1,777.27 1,776.84 1,775.62 1,779.50 1,779.53 1,779.51 1,780.40 1,781.45 1,781.45 21 1,778.82 1,778.59 1,778.07 1,777.23 1,776.95 1,775.60 1,779.56 1,779.75 1,779.65 1,780.39 1,781.54 1,781.71 22 1,778.80 1,778.58 1,778.05 1,777.18 1,776.96 1,775.65 1,779.68 1,779.75 1,779.65 1,780.51 1,781.54 1,781.55 23 1,778.74 1,778.55 1,778.01 1,777.23 1,776.93 1,775.49 1,779.71 1,779.72 1,779.62 1,780.49 1,781.49 1,781.48 24 1,778.75 1,778.52 1,777.99 1,777.21 1,776.91 1,775.38 1,779.94 1,779.71 1,779.61 1,780.45 1,781.44 1,781.45 25 1,778.83 1,778.48 1,777.97 1,777.35 1,776.90 1,775.40 1,779.96 1,779.68 1,779.57 1,780.42 1,782.23 1,781.43 26 1,778.95 1,778.50 1,777.95 1,777.36 1,776.85 1,775.36 1,779.95 1,779.63 1,779.53 1,780.40 1,781.76 1,781.40 27 1,778.95 1,778.45 1,777.91 1,777.33 1,776.83 1,775.30 1,779.95 1,779.58 1,779.49 1,780.51 1,781.59 1,781.38 28 1,778.91 1,778.41 1,777.88 1,777.26 1,776.78 1,775.18 1,779.95 1,779.53 1,779.45 1,780.69 1,781.60 1,781.37 29 1,778.87 1,778.39 1,777.81 1,777.23 --- 1,775.19 1,779.91 1,779.48 1,779.40 1,780.66 1,781.57 1,781.34 30 1,778.87 1,778.34 1,777.79 1,777.20 --- 1,775.07 1,779.93 1,779.43 1,779.36 1,780.64 1,781.50 1,781.32 31 1,778.81 --- 1,777.74 1,777.20 --- 1,774.98 --- 1,779.37 --- 1,780.66 1,781.47 --­ MAX 1,778.95 1,778.82 1,778.36 1,777.79 1,777.15 1,776.74 1,779.96 1,779.88 1,779.65 1,780.69 1,782.23 1,781.96 MIN 1,778.09 1,778.34 1,777.74 1,777.18 1,776.75 1,774.98 1,774.45 1,779.37 1,779.00 1,779.33 1,780.68 1,781.32 205 RIO DE LA PLATA BASIN 50039990 LAGO CARITE AT GATE TOWER NEAR CAYEY, PR—Continued O N D J F M A M J J A S 1,774 1,775 1,776 1,777 1,778 1,779 1,780 1,781 1,782 1,783 ELEVATION, IN FEET 2002 2003 206 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR LOCATION.--Lat 18q09'37", long 66q13'44", Hydrologic Unit 21010005, at upstream side of bridge on Highway 173, 0.4 mi (0.6 km) northeast of Proyecto La Plata, and 2.5 mi (4.0 km) upstream from Río Usabón. DRAINAGE AREA.--63.0 mi2 (163.2 km2), excludes 8.2 mi2 (21.1 km2) upstream from Lago Carite, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 20... 0945 15 2.5 7.5 95 7.5 480 25.5 140 34.3 13.5 3.82 1 FEB 20... 0915 20 4.5 6.6 -- 7.9 429 24.3 130 33.4 12.4 2.95 1 MAY 19... 1300 21 3.7 13.3 -- 8.4 498 29.0 160 37.8 15.0 4.19 1 AUG 12... 1330 41 11 10.1 -- 8.4 318 29.6 -- -- -- -- -­ SEP 10... 1500 31 4.7 10.2 -- 8.3 381 30.0 130 31.6 13.1 2.56 1 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 20... 36.4 146 39.8 <.17 24.3 17.2 -- 257 10.3 <10 .60 .07 3.13 FEB 20... 35.4 134 36.3 .12 24.8 16.1 <.0 242 13.0 <10 .70 .07 2.72 MAY 19... 38.8 143 45.8 <.2 22.9 21.4 <.1 271 15.1 <10 .60 .06 2.81 AUG 12... -- 105 -- -- -- -- -- -- -- <10 .40 .05 1.66 SEP 10... 25.8 125 28.9 <.2 25.9 13.1 -- 216 18.2 <10 .40 .05 2.15 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 20... 3.20 .07 .53 .19 3.8 16.8 <10 E80 E64 -- -- -- -­ FEB 20... 2.80 .08 .63 .15 3.5 15.5 20 E170 -- 2,700 <2 17.2 68 MAY 19... 2.90 .09 .54 .14 3.5 15.5 <10 E17 -- 450 <2 23.1 79 AUG 12... 1.70 .04 .35 .11 2.1 9.3 10 E20 -- 3,000 -- -- -­ SEP 10... 2.20 .05 .35 .14 2.6 11.5 20 64 -- 500 -- -- -­ 207 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 20... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 20... <.2 <.8 <10 <.01 130 <1 25.7 <.02 <3 E.1 <25 E.05 <16 MAY 19... <.2 <.8 <10 <.01 80 <1 23.1 <.02 <5 <.3 <25 E.06 <16 AUG 12... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 208 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR LOCATION.--Lat 18q13'23", long 66q13'30", Hydrologic Unit 21010005, on right bank 50 ft (15 m) upstream from bridge off Highway 167 in the Town of Comerío, 0.4 mi (0.6 km) southwest of Comerío High School, and 0.2 mi (0.3 km) northeast of Plaza de Comerío. DRAINAGE AREA.--109 mi2 (282 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 604.2 ft (184.160 m) above mean sea level. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Filtration plant more or less 500 feet upstream from station. Gage- height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 48 27 18 20 30 23 e18 75 23 60 67 154 2 41 26 20 24 26 25 17 59 23 173 406 76 3 42 25 31 28 19 29 17 45 26 60 316 185 4 52 25 36 30 231 29 22 44 36 30 104 443 5 48 37 42 23 211 26 21 33 37 74 61 185 6 41 30 56 42 81 25 42 32 25 90 50 101 7 74 25 45 48 43 24 25 31 68 87 99 80 8 59 23 31 28 32 15 16 32 54 37 83 61 9 172 22 40 21 26 13 15 32 41 58 84 47 10 155 20 29 24 29 12 18 29 28 46 157 39 11 62 18 28 20 52 13 19 25 23 25 74 285 12 53 20 28 17 59 14 148 22 22 17 74 1,720 13 42 22 32 14 54 12 91 22 20 681 46 886 14 38 25 33 14 31 10 58 30 26 421 36 267 15 38 22 31 16 25 11 35 35 22 91 36 244 16 38 20 27 16 21 11 34 40 27 72 39 1,200 17 37 23 38 23 23 9.4 5,020 30 33 134 35 707 18 36 41 266 23 65 9.1 5,710 23 21 43 63 239 19 39 40 76 17 56 10 2,270 27 325 30 162 125 20 33 29 40 15 45 48 689 87 249 24 84 86 21 28 38 35 16 37 42 534 3,230 75 22 55 2,020 22 31 28 37 16 65 19 726 1,240 69 65 388 1,130 23 29 23 59 15 58 14 1,560 231 41 283 201 278 24 29 21 50 20 36 11 4,360 109 29 66 82 139 25 28 19 33 113 32 9.0 1,660 68 25 35 52 91 26 37 20 28 324 31 59 493 46 23 50 1,970 71 27 62 20 30 111 30 200 245 36 18 73 456 57 28 47 20 23 47 27 96 145 30 18 155 231 49 29 31 18 19 27 34 110 30 19 139 355 44 30 27 17 17 24 91 92 28 15 64 194 47 31 25 18 22 e38 24 50 105 TOTAL 1,522 744 1,296 1,198 1,475 981.5 24,210 5,825 1,461 3,255 6,165 11,056 MEAN 49.1 24.8 41.8 38.6 52.7 31.7 807 188 48.7 105 199 369 MAX 172 41 266 324 231 200 5,710 3,230 325 681 1,970 2,020 MIN 25 17 17 14 19 9.0 15 22 15 17 35 39 MED 39 23 32 23 34 19 92 32 26 64 84 146 AC-FT 3,020 1,480 2,570 2,380 2,930 1,950 48,020 11,550 2,900 6,460 12,230 21,930 CFSM 0.45 0.23 0.39 0.36 0.49 0.29 7.44 1.73 0.45 0.97 1.83 3.40 IN. 0.52 0.26 0.44 0.41 0.51 0.34 8.30 2.00 0.50 1.12 2.11 3.79 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY) MEAN 208 248 125 126 89.2 46.4 120 90.9 82.3 81.6 135 400 MAX 866 1,264 457 732 268 75.7 807 263 292 291 563 1,433 (WY) (1991) (2000) (1999) (1992) (1998) (2002) (2003) (1992) (2002) (1993) (2000) (1996) MIN 40.6 19.0 17.1 21.3 24.4 20.6 22.3 19.7 13.2 10.4 12.7 26.2 (WY) (1992) (1995) (1995) (1995) (1990) (1993) (1991) (1994) (1994) (1994) (1994) (1997) 209 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1989 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 42,739 ANNUAL MEAN 117 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2,470 LOWEST DAILY MEAN 17 ANNUAL SEVEN-DAY MINIMUM 19 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 84,770 ANNUAL RUNOFF (CFSM) 1.08 ANNUAL RUNOFF (INCHES) 14.65 10 PERCENT EXCEEDS 237 50 PERCENT EXCEEDS 45 90 PERCENT EXCEEDS 25 59,188.5 162 145 267 2000 35.3 1994 Apr 21 5,710 Apr 18 32,400 Sep 10, 1996 Nov 30 9.0 Mar 25 5.8 Jun 25, 1994 Nov 25 10 Mar 13 7.3 Jul 31, 1994 25,300 Apr 17 127,000 Jan 5, 1992 15.46 Apr 17 29.22 Jan 5, 1992 117,400 105,200 1.49 1.34 20.29 18.18 244 217 37 41 18 17 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 210 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORDS.-- Water year 1989 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1989 to current year. INSTRUMENTATION.-- USD-77 sediment sampler since 1989. Automatic sediment sampler since 1989. REMARKS.--Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 8,800 mg/L January 05, 1992; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 950,000 tons (862,000 tonnes) January 05, 1992; Minimum daily mean, 0.04 tons (0.04 tonne) November 28, 1994. EXTREMES FOR WATER YEARS 2003.-- SEDIMENT CONCENTRATION: Maximun daily mean, 1,210 mg/L August 26, 2003; Minimun daily mean, 1 mg/L March 3,4, 2003. SEDIMENT LOADS: Maximun daily mean, 33,400 tons (30,300 tonnes) April 17, 2003; Minimun daily mean, 0.09 ton (0.08 tonne) March 4, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 48 13 1.6 27 9 0.63 18 8 0.38 2 41 12 1.3 26 9 0.60 20 8 0.44 3 42 11 1.3 25 9 0.58 31 8 0.67 4 52 11 1.5 25 9 0.58 36 8 0.78 5 48 10 1.3 37 9 0.86 42 8 0.91 6 41 10 1.1 30 9 0.68 56 13 2.0 7 74 19 6.0 25 8 0.58 45 11 1.4 8 59 15 2.6 23 8 0.53 31 9 0.74 9 172 41 30 22 8 0.50 40 9 0.95 10 155 36 18 20 8 0.46 29 9 0.69 11 62 18 3.0 18 8 0.42 28 9 0.66 12 53 16 2.2 20 8 0.46 28 9 0.64 13 42 13 1.5 22 8 0.50 32 8 0.73 14 38 11 1.1 25 8 0.55 33 8 0.73 15 38 9 0.92 22 8 0.48 31 8 0.70 16 38 9 0.92 20 8 0.45 27 8 0.59 17 37 9 0.89 23 8 0.52 38 8 0.82 18 36 9 0.87 41 8 0.91 266 82 80 19 39 9 0.95 40 8 0.90 76 26 5.8 20 33 9 0.78 29 8 0.64 40 11 1.2 21 28 9 0.67 38 8 0.84 35 10 0.95 22 31 9 0.73 28 8 0.62 37 10 1.0 23 29 9 0.69 23 8 0.50 59 15 2.6 24 29 9 0.69 21 8 0.45 50 12 1.7 25 28 9 0.67 19 8 0.41 33 9 0.80 26 37 9 0.87 20 8 0.44 28 9 0.67 27 62 9 1.5 20 8 0.44 30 9 0.71 28 47 9 1.1 20 8 0.44 23 9 0.53 29 31 9 0.73 18 8 0.39 19 9 0.45 30 27 9 0.62 17 8 0.37 17 9 0.38 31 25 9 0.59 18 8 0.40 TOTAL 1,522 86.69 744 16.73 1,296 111.02 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO DE LA PLATA BASIN 211 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 20 8 0.46 30 7 0.61 23 2 0.11 2 24 8 0.53 26 7 0.52 25 2 0.10 3 28 8 0.61 19 7 0.37 29 1 0.11 4 30 8 0.65 231 66 76 29 1 0.09 5 23 8 0.50 211 47 29 26 2 0.13 6 42 12 1.6 81 17 4.1 25 5 0.36 7 48 13 1.8 43 10 1.1 24 7 0.42 8 28 11 0.86 32 9 0.79 15 7 0.27 9 21 10 0.54 26 9 0.60 13 7 0.25 10 24 9 0.57 29 8 0.63 12 7 0.23 11 20 9 0.47 52 8 1.1 13 8 0.27 12 17 9 0.41 59 8 1.2 14 8 0.32 13 14 9 0.33 54 7 1.1 12 9 0.29 14 14 9 0.32 31 7 0.60 10 9 0.26 15 16 9 0.37 25 7 0.47 11 9 0.27 16 16 9 0.37 21 7 0.40 11 7 0.21 17 23 8 0.52 23 7 0.43 9.4 5 0.13 18 23 8 0.51 65 16 3.5 9.1 5 0.11 19 17 8 0.39 56 13 2.0 10 4 0.12 20 15 8 0.33 45 10 1.3 48 12 2.6 21 16 8 0.35 37 9 0.94 42 13 1.5 22 16 8 0.34 65 17 3.3 19 8 0.38 23 15 8 0.33 58 12 1.9 14 7 0.25 24 20 8 0.43 36 6 0.59 11 6 0.18 25 113 16 6.7 32 5 0.42 9.0 6 0.14 26 324 99 102 31 4 0.32 59 9 2.2 27 111 36 11 30 3 0.23 200 36 24 28 47 21 2.8 27 2 0.15 96 10 2.6 29 27 9 0.68 34 8 0.70 30 24 8 0.50 91 15 4.3 31 22 8 0.46 e38 e18 e1.8 TOTAL 1,198 137.73 1,475 133.67 981.5 44.70 APRIL MAY JUNE 1 e18 e18 e0.91 75 13 2.6 23 6 0.39 2 17 16 0.71 59 11 1.8 23 7 0.43 3 17 14 0.64 45 10 1.2 26 7 0.48 4 22 12 0.71 44 9 1.0 36 7 0.63 5 21 10 0.56 33 8 0.70 37 6 0.64 6 42 9 0.97 32 7 0.61 25 6 0.41 7 25 7 0.49 31 6 0.53 68 12 2.8 8 16 6 0.27 32 6 0.50 54 6 0.91 9 15 6 0.26 32 5 0.45 41 5 0.58 10 18 7 0.31 29 5 0.43 28 5 0.35 11 19 7 0.35 25 6 0.40 23 4 0.27 12 148 28 14 22 6 0.38 22 4 0.24 13 91 18 4.6 22 7 0.42 20 4 0.24 14 58 9 1.4 30 8 0.63 26 5 0.34 15 35 8 0.72 35 9 0.82 22 5 0.31 16 34 7 0.66 40 9 1.0 27 6 0.42 17 5,020 1,000 33,400 30 10 0.77 33 6 0.53 18 5,710 1,180 31,300 23 7 0.47 21 5 0.32 19 2,270 327 4,170 27 5 0.38 325 71 132 20 689 105 228 87 14 7.0 249 59 50 21 534 74 111 3,230 971 20,100 75 23 4.7 22 726 125 367 1,240 373 1,800 69 20 3.8 23 1,560 338 1,750 231 27 18 41 18 2.0 24 4,360 1,190 23,700 109 11 3.2 29 15 1.2 25 1,660 494 3,260 68 9 1.7 25 13 0.90 26 493 88 127 46 9 1.1 23 11 0.71 27 245 44 30 36 8 0.76 18 10 0.48 28 145 19 7.7 30 7 0.58 18 9 0.42 29 110 16 4.8 30 6 0.51 19 13 0.67 30 92 14 3.6 28 6 0.41 15 17 0.70 31 24 5 0.35 TOTAL 24,210 98,486.66 5,825 21,948.70 1,461 207.87 --- --- --- --- --- --- 212 RIO DE LA PLATA BASIN 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 60 28 9.9 67 27 4.9 154 34 17 2 173 43 33 406 129 330 76 19 3.9 3 60 16 2.7 316 104 110 185 45 58 4 30 12 0.97 104 33 9.5 443 105 132 5 74 22 7.9 61 25 4.1 185 77 39 6 90 22 6.0 50 20 2.7 101 67 18 7 87 15 3.7 99 21 5.8 80 57 12 8 37 12 1.2 83 14 3.2 61 53 8.7 9 58 11 1.8 84 13 3.3 47 50 6.4 10 46 11 1.4 157 34 16 39 49 5.2 11 25 10 0.70 74 15 2.9 285 116 312 12 17 10 0.47 74 17 3.3 1,720 402 5,390 13 681 475 2,800 46 20 2.4 886 191 643 14 421 202 316 36 23 2.2 267 93 78 15 91 29 7.7 36 25 2.4 244 49 39 16 72 18 4.4 39 22 2.3 1,200 250 1,110 17 134 31 14 35 16 1.5 707 159 347 18 43 12 1.4 63 11 2.0 239 77 50 19 30 10 0.82 162 35 16 125 63 22 20 24 10 0.63 84 20 4.8 86 50 12 21 22 9 0.53 55 11 1.6 2,020 508 10,600 22 65 14 4.2 388 75 112 1,130 294 1,360 23 283 67 63 201 39 22 278 66 52 24 66 37 6.7 82 24 5.5 139 33 13 25 35 28 2.7 52 16 2.2 91 12 3.1 26 50 27 4.1 1,970 1,210 8,080 71 10 1.9 27 73 31 6.3 456 147 203 57 9 1.4 28 155 37 17 231 74 46 49 9 1.1 29 139 33 13 355 80 77 44 8 0.94 30 64 29 5.0 194 23 13 47 7 0.87 31 50 28 3.7 105 16 4.5 TOTAL 3,255 3,340.92 6,165 9,096.1 11,056 20,337.51 YEAR 59,188.5 153,948.30 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 24... 1950 10,900 98 1,800 53,000 RIO DE LA PLATA BASIN 213 50043800 RIO DE LA PLATA AT COMERIO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMET Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) APR 17... 1420 15,500 50 62 73 85 90 94 98 99 100 100 4,530 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) APR 17... 190,000 214 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR LOCATION.--Lat 18q14'33", long 66q12'28", at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerío Plaza. DRAINAGE AREA.--139 mi2 (360 km2), excludes 8.2 mi2 (21.1 km2) upstream from Lago Carite, the flow of which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 18... 1030 41 5.4 9.4 118 7.5 472 26.3 160 36.8 16.0 3.19 1 MAR 19... 0840 15 E2.6 8.1 -- 8.0 468 24.6 160 36.8 16.9 3.03 1 MAY 05... 1145 42 1.4 10.1 -- 8.5 432 28.2 150 36.4 15.4 2.85 .7 AUG 08... 1450 79 7.5 8.3 -- 8.3 410 30.2 -- -- -- -- -­ SEP 10... 1210 52 7.6 8.0 -- 8.3 375 26.5 140 31.8 14.1 2.57 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 18... 32.5 154 38.9 <.17 28.1 18.1 -- 266 29.2 <10 .40 .02 -­ MAR 19... 35.0 160 44.7 .14 28.6 18.4 <.1 280 11.1 <10 .30 .02 .51 MAY 05... 20.3 153 29.8 <.17 24.1 24.9 <.1 246 28.2 <10 .20 .02 -­ AUG 08... -- 122 -- -- -- -- -- -- -- <10 .30 .02 1.29 SEP 10... 21.9 133 25.6 <.2 27.4 12.6 -- 216 30.1 <10 .30 .03 .73 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 18... 1.50 <.01 .38 .14 1.9 8.4 <10 210 240 -- -- -- -­ MAR 19... .520 .01 .28 .12 .82 3.6 E10 E100 -- 430 <2 38.8 83 MAY 05... .810 <.01 .18 .08 1.0 4.5 <10 E64 -- 800 4 54.2 36 AUG 08... 1.30 .01 .28 .11 1.6 7.1 10 30 -- 3,400 -- -- -­ SEP 10... .740 .01 .27 .10 1.0 4.6 10 E80 -- E1,900 -- -- -­ 215 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 18... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 19... E.2 <.8 <10 <.01 90 <1 17.7 <.02 <3 <.3 <25 <.10 <16 MAY 05... <.2 E.5 <10 <.01 40 <1 24.8 <.02 6 <.3 E17 <.10 E8 AUG 08... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 216 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NEAR GUADIANA, PR LOCATION.--Lat 18q13'42", long 66q18'05", Hydrologic Unit 21010005, at right bank 1.1 mi (2.1 km) east of Plaza de Naranjito, 0.9 mi (1.4 km) west from intersection of roads 167 and 164 at km 1.77 and 2.6 mi (4.2 km) northwest from Represa Comerío. DRAINAGE AREA.--8.60 mi2 (22.3 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 2001 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 229 ft (69.8 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.6 3.5 3.4 3.1 3.0 3.1 e3.2 4.4 3.2 3.4 6.1 6.3 2 3.7 3.2 3.8 3.2 2.7 3.0 3.4 4.2 3.3 3.3 8.4 6.5 3 4.0 3.2 3.5 2.2 2.6 2.9 6.0 4.2 3.5 3.2 5.0 5.4 4 3.9 3.1 4.6 2.3 24 3.0 3.5 4.0 3.3 3.2 4.4 4.8 5 3.5 3.2 3.6 2.5 7.6 3.0 3.3 4.1 3.2 3.6 4.2 4.8 6 4.0 3.3 3.4 2.6 4.4 2.9 3.4 4.1 3.2 3.3 5.4 4.9 7 4.3 3.1 3.1 2.5 3.9 2.9 3.3 4.5 3.6 3.0 5.5 5.0 8 4.5 3.0 3.7 2.5 3.7 2.9 3.3 4.3 3.3 5.0 4.4 7.4 9 7.4 3.3 3.5 2.4 3.5 2.8 3.1 4.1 3.2 3.1 4.1 4.9 10 4.2 3.2 3.1 2.3 3.3 2.9 3.4 4.1 3.1 2.9 4.1 4.6 11 3.5 2.9 2.7 2.3 3.1 2.9 3.6 3.8 3.1 2.9 4.4 7.1 12 3.3 3.5 2.8 2.2 3.2 2.9 3.7 4.1 3.0 2.8 4.4 5.3 13 3.1 5.2 3.4 2.1 3.4 3.0 3.3 3.7 3.2 10 5.0 21 14 3.3 4.2 3.2 2.3 3.3 3.0 3.1 3.9 3.1 4.5 4.9 12 15 3.3 3.4 2.9 2.2 3.3 3.1 3.3 3.8 3.7 4.7 4.4 9.6 16 3.2 3.3 2.9 2.2 3.4 2.9 3.3 3.6 3.3 5.6 4.2 9.9 17 3.4 3.1 2.8 2.2 3.4 3.0 12 3.7 3.2 4.5 4.1 10 18 3.5 3.2 2.8 2.1 3.4 2.8 32 3.8 3.3 4.0 5.5 11 19 5.9 3.4 3.2 2.3 3.4 2.8 12 3.7 3.6 4.0 4.2 12 20 5.7 e3.4 3.3 2.3 3.3 3.0 7.5 28 3.4 4.4 4.0 15 21 3.9 e3.7 3.3 1.8 3.4 2.9 23 59 3.8 4.0 9.1 161 22 3.6 e3.6 3.7 1.6 3.2 3.1 14 9.9 3.4 4.7 6.4 17 23 3.5 3.6 3.1 1.7 3.1 2.9 138 4.9 3.3 4.5 4.8 11 24 3.7 3.4 2.9 4.1 3.2 3.1 39 4.0 3.3 4.2 4.5 9.1 25 4.5 3.6 2.9 99 3.1 2.9 13 3.6 3.3 4.0 8.0 13 26 3.8 3.5 2.8 25 3.1 5.5 7.7 3.5 3.3 4.4 6.8 10 27 3.4 3.6 2.7 5.4 3.1 7.7 5.9 3.3 3.2 4.5 5.0 8.5 28 3.5 3.4 2.6 3.8 3.1 4.3 5.3 3.3 3.4 4.4 7.1 7.8 29 3.6 3.5 2.6 3.3 4.3 4.9 3.2 3.3 4.3 12 8.4 30 3.4 3.4 2.6 3.4 3.8 4.6 3.2 3.3 4.0 7.1 8.7 31 3.5 2.7 3.1 e3.4 3.1 7.1 6.5 TOTAL 121.7 103.0 97.6 200.0 117.2 102.7 375.1 205.1 99.4 131.5 174.0 422.0 MEAN 3.93 3.43 3.15 6.45 4.19 3.31 12.5 6.62 3.31 4.24 5.61 14.1 MAX 7.4 5.2 4.6 99 24 7.7 138 59 3.8 10 12 161 MIN 3.1 2.9 2.6 1.6 2.6 2.8 3.1 3.1 3.0 2.8 4.0 4.6 AC-FT 241 204 194 397 232 204 744 407 197 261 345 837 CFSM 0.49 0.43 0.39 0.80 0.52 0.41 1.55 0.82 0.41 0.53 0.70 1.75 IN. 0.56 0.48 0.45 0.92 0.54 0.47 1.73 0.95 0.46 0.61 0.80 1.95 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 5.73 33.4 12.0 9.40 7.37 6.31 12.6 11.2 4.82 4.53 5.29 7.51 MAX 7.54 63.5 20.9 12.4 10.6 9.31 18.6 16.1 6.91 5.33 6.15 14.1 (WY) (2002) (2002) (2002) (2002) (2002) (2002) (2002) (2002) (2002) (2002) (2001) (2003) MIN 3.93 3.43 3.15 6.45 4.19 3.31 6.68 6.62 3.31 4.02 4.11 2.65 (WY) (2003) (2003) (2003) (2003) (2003) (2003) (2001) (2003) (2003) (2001) (2002) (2001) 217 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NEAR GUADIANA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2001 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 3,021.3 ANNUAL MEAN 8.28 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 136 LOWEST DAILY MEAN 2.6 ANNUAL SEVEN-DAY MINIMUM 2.7 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 5,990 ANNUAL RUNOFF (CFSM) 1.03 ANNUAL RUNOFF (INCHES) 13.94 10 PERCENT EXCEEDS 14 50 PERCENT EXCEEDS 6.3 90 PERCENT EXCEEDS 3.3 2,149.3 5.89 10.5 15.0 2002 5.89 2003 May 1 161 Sep 21 1,570 Nov 8, 2001 Dec 28 1.6 Jan 22 1.6 Jan 22, 2003 Dec 25 2.0 Jan 17 2.0 Sep 28, 2001 4,570 Sep 21 8,280 Nov 8, 2001 9.93 Sep 21 12.69 Nov 8, 2001 4,260 7,580 0.731 1.30 9.92 17.63 7.9 14 3.5 4.8 2.8 2.9 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 218 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NR GUADIANA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--March 2001 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2001 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 2001. REMARKS.-- Sediment samples were collected by local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1,620 mg/L September 21, 2003; Minimum daily mean, 1 mg/L May 16-19, 2003. SEDIMENT LOADS: Maximum daily mean, e25,000 tons (e63,504 tonnes) November 8, 2001; Minimum daily mean, <0.01 ton (<0.01 tonne) May 16, 17, 19, 2003. EXTREMES FOR CURRENT YEAR 2003.- SEDIMENT CONCENTRATION: Maximum daily mean, 1,620 mg/L September 21, 2003; Minimum daily mean, 1 mg/L May 16-19, 2003. SEDIMENT LOADS: Maximum daily mean, 9,810 tons (4,360 tonnes) September 21, 2003; Minimum daily mean, <0.01 ton (<0.01 tonne) Ma y 16, 17, 19, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 3.6 11 0.11 3.5 9 0.08 3.4 7 0.06 2 3.7 11 0.11 3.2 9 0.08 3.8 7 0.07 3 4.0 10 0.11 3.2 9 0.08 3.5 7 0.07 4 3.9 9 0.09 3.1 9 0.07 4.6 7 0.09 5 3.5 8 0.07 3.2 9 0.07 3.6 7 0.07 6 4.0 7 0.07 3.3 9 0.08 3.4 7 0.06 7 4.3 6 0.07 3.1 8 0.07 3.1 7 0.06 8 4.5 5 0.06 3.0 8 0.07 3.7 7 0.07 9 7.4 18 0.73 3.3 8 0.07 3.5 7 0.06 10 4.2 10 0.11 3.2 8 0.07 3.1 7 0.06 11 3.5 10 0.09 2.9 8 0.06 2.7 7 0.05 12 3.3 10 0.09 3.5 8 0.08 2.8 7 0.05 13 3.1 10 0.08 5.2 24 0.90 3.4 7 0.06 14 3.3 10 0.09 4.2 13 0.19 3.2 7 0.06 15 3.3 10 0.09 3.4 7 0.07 2.9 7 0.05 16 3.2 10 0.08 3.3 7 0.07 2.9 7 0.05 17 3.4 10 0.09 3.1 7 0.06 2.8 7 0.05 18 3.5 10 0.09 3.2 7 0.06 2.8 7 0.05 19 5.9 20 0.49 3.4 7 0.07 3.2 7 0.06 20 5.7 16 0.30 e3.4 e7 e0.06 3.3 7 0.06 21 3.9 10 0.10 e3.7 e7 e0.07 3.3 7 0.06 22 3.6 10 0.09 e3.6 e7 e0.07 3.7 7 0.07 23 3.5 10 0.09 3.6 7 0.07 3.1 7 0.06 24 3.7 10 0.09 3.4 7 0.07 2.9 7 0.05 25 4.5 9 0.11 3.6 7 0.07 2.9 7 0.05 26 3.8 9 0.10 3.5 7 0.07 2.8 7 0.05 27 3.4 9 0.09 3.6 7 0.07 2.7 7 0.05 28 3.5 9 0.09 3.4 7 0.07 2.6 6 0.05 29 3.6 9 0.09 3.5 7 0.07 2.6 6 0.04 30 3.4 9 0.08 3.4 7 0.06 2.6 6 0.05 31 3.5 9 0.08 2.7 6 0.05 TOTAL 121.7 4.03 103.0 3.05 97.6 1.79 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO DE LA PLATA BASIN 219 50044810 RIO GUADIANA NR GUADIANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 3.1 6 0.05 3.0 75 0.59 3.1 8 0.07 2 3.2 6 0.05 2.7 58 0.42 3.0 10 0.08 3 2.2 6 0.04 2.6 41 0.29 2.9 10 0.08 4 2.3 6 0.04 24 158 28 3.0 9 0.07 5 2.5 6 0.04 7.6 88 1.9 3.0 9 0.07 6 2.6 6 0.04 4.4 76 0.91 2.9 8 0.06 7 2.5 6 0.04 3.9 68 0.72 2.9 9 0.07 8 2.5 6 0.04 3.7 60 0.59 2.9 10 0.08 9 2.4 6 0.04 3.5 51 0.48 2.8 11 0.08 10 2.3 6 0.04 3.3 43 0.39 2.9 12 0.09 11 2.3 6 0.04 3.1 34 0.28 2.9 11 0.09 12 2.2 6 0.04 3.2 26 0.22 2.9 11 0.08 13 2.1 6 0.03 3.4 18 0.16 3.0 10 0.08 14 2.3 6 0.04 3.3 10 0.09 3.0 9 0.07 15 2.2 6 0.04 3.3 9 0.08 3.1 8 0.07 16 2.2 6 0.04 3.4 8 0.07 2.9 8 0.06 17 2.2 6 0.04 3.4 7 0.07 3.0 7 0.06 18 2.1 6 0.03 3.4 7 0.07 2.8 7 0.05 19 2.3 6 0.04 3.4 8 0.07 2.8 6 0.05 20 2.3 6 0.04 3.3 8 0.08 3.0 6 0.05 21 1.8 6 0.03 3.4 9 0.08 2.9 5 0.04 22 1.6 6 0.03 3.2 8 0.07 3.1 5 0.04 23 1.7 6 0.03 3.1 7 0.06 2.9 5 0.04 24 4.1 17 0.43 3.2 5 0.05 3.1 4 0.03 25 99 766 864 3.1 4 0.04 2.9 4 0.03 26 25 230 26 3.1 5 0.04 5.5 25 0.87 27 5.4 160 2.3 3.1 6 0.05 7.7 45 2.0 28 3.8 143 1.5 3.1 7 0.06 4.3 36 0.42 29 3.3 126 1.1 4.3 30 0.35 30 3.4 109 1.0 3.8 24 0.25 31 3.1 92 0.77 e3.4 e21 e0.19 TOTAL 200.0 897.99 117.2 35.93 102.7 5.67 APRIL MAY JUNE 1 e3.2 e20 e0.18 4.4 15 0.18 3.2 3 0.03 2 3.4 20 0.18 4.2 15 0.17 3.3 4 0.04 3 6.0 36 0.96 4.2 15 0.17 3.5 5 0.05 4 3.5 22 0.21 4.0 15 0.16 3.3 6 0.05 5 3.3 18 0.16 4.1 15 0.16 3.2 5 0.05 6 3.4 16 0.14 4.1 14 0.16 3.2 5 0.04 7 3.3 14 0.12 4.5 14 0.17 3.6 4 0.04 8 3.3 12 0.11 4.3 14 0.17 3.3 3 0.03 9 3.1 10 0.08 4.1 14 0.16 3.2 3 0.02 10 3.4 8 0.07 4.1 14 0.16 3.1 2 0.02 11 3.6 6 0.06 3.8 14 0.14 3.1 2 0.02 12 3.7 4 0.04 4.1 11 0.13 3.0 3 0.02 13 3.3 5 0.04 3.7 8 0.08 3.2 3 0.02 14 3.1 6 0.05 3.9 5 0.05 3.1 3 0.03 15 3.3 8 0.07 3.8 2 0.02 3.7 3 0.03 16 3.3 9 0.08 3.6 1 <0.01 3.3 4 0.03 17 12 58 2.7 3.7 1 <0.01 3.2 4 0.04 18 32 210 48 3.8 1 0.01 3.3 5 0.05 19 12 50 2.3 3.7 1 <0.01 3.6 6 0.06 20 7.5 26 0.54 28 207 78 3.4 7 0.07 21 23 129 16 59 563 391 3.8 9 0.09 22 14 36 1.8 9.9 46 2.4 3.4 10 0.09 23 138 1,170 2,750 4.9 3 0.05 3.3 11 0.10 24 39 314 63 4.0 3 0.03 3.3 12 0.10 25 13 131 4.9 3.6 3 0.03 3.3 12 0.11 26 7.7 32 0.67 3.5 5 0.05 3.3 13 0.12 27 5.9 25 0.39 3.3 4 0.03 3.2 14 0.12 28 5.3 20 0.29 3.3 2 0.02 3.4 11 0.10 29 4.9 16 0.22 3.2 2 0.02 3.3 8 0.07 30 4.6 15 0.19 3.2 2 0.02 3.3 5 0.04 31 3.1 2 0.02 TOTAL 375.1 2,893.55 205.1 473.79 99.4 1.68 --- --- --- --- --- --- 220 RIO DE LA PLATA BASIN 50044810 RIO GUADIANA NR GUADIANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 3.4 4 0.04 6.1 36 0.62 6.3 22 0.41 2 3.3 5 0.04 8.4 43 1.2 6.5 15 0.27 3 3.2 5 0.04 5.0 33 0.45 5.4 14 0.20 4 3.2 5 0.04 4.4 30 0.36 4.8 12 0.16 5 3.6 5 0.05 4.2 27 0.31 4.8 10 0.12 6 3.3 5 0.05 5.4 26 0.37 4.9 8 0.10 7 3.0 5 0.04 5.5 26 0.38 5.0 7 0.09 8 5.0 20 0.52 4.4 26 0.30 7.4 16 0.55 9 3.1 5 0.05 4.1 26 0.29 4.9 7 0.09 10 2.9 6 0.05 4.1 26 0.28 4.6 7 0.09 11 2.9 7 0.05 4.4 25 0.30 7.1 24 1.0 12 2.8 8 0.06 4.4 25 0.30 5.3 11 0.16 13 10 32 2.7 5.0 25 0.34 21 122 28 14 4.5 7 0.08 4.9 25 0.34 12 19 0.77 15 4.7 5 0.07 4.4 25 0.30 9.6 9 0.24 16 5.6 8 0.18 4.2 25 0.28 9.9 9 0.24 17 4.5 4 0.05 4.1 25 0.27 10 9 0.25 18 4.0 4 0.04 5.5 33 0.66 11 9 0.26 19 4.0 3 0.03 4.2 30 0.34 12 9 0.29 20 4.4 5 0.05 4.0 28 0.31 15 31 1.4 21 4.0 7 0.07 9.1 57 3.2 161 1,620 9,810 22 4.7 9 0.11 6.4 38 0.66 17 136 6.5 23 4.5 11 0.13 4.8 33 0.43 11 88 2.5 24 4.2 13 0.15 4.5 30 0.36 9.1 70 1.7 25 4.0 15 0.16 8.0 36 1.1 13 64 3.9 26 4.4 17 0.20 6.8 25 0.47 10 19 0.53 27 4.5 16 0.19 5.0 19 0.25 8.5 12 0.29 28 4.4 14 0.17 7.1 28 0.63 7.8 10 0.21 29 4.3 13 0.15 12 44 2.2 8.4 9 0.20 30 4.0 12 0.13 7.1 18 0.36 8.7 8 0.19 31 7.1 27 1.2 6.5 22 0.47 TOTAL 131.5 6.89 174.0 18.13 422.0 9,860.71 YEAR 2,149.3 14,203.21 e Estimated < Actual value is known to be less than the value shown 221 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR LOCATION.--Lat 18q18'39", long 66q13'28", at steel-cross bridge 0.8 mi (1.3 km) northwest of Highway 164, 1.2 mi (1.9 km) upstream from mouth and about 2.0 mi (3.2 km) northeast of Naranjito Plaza. DRAINAGE AREA.--4.0 mi2 (10.3 km2). PERIOD OF RECORD.--Water year 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 18... 1215 4.0 2.9 7.3 95 7.3 407 28.1 150 36.2 15.1 2.27 .7 MAR 19... 1045 2.7 <1.0 6.8 -- 7.4 425 27.4 160 38.3 16.0 2.68 .9 MAY 05... 1345 5.2 <1.0 7.5 -- 8.1 397 30.0 160 38.0 15.7 3.45 1 AUG 08... 1245 4.8 8.6 7.2 -- 8.2 363 30.3 -- -- -- -- -­ SEP 10... 1000 12 21 8.0 -- 8.0 366 27.7 150 34.1 15.8 2.70 .6 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 18... 19.9 140 26.4 <.17 27.0 17.0 -- 228 -- <10 .40 .01 -­ MAR 19... 25.3 150 36.5 .15 26.7 19.1 <.1 255 1.85 <10 <.20 .01 .79 MAY 05... 27.6 130 33.5 <.17 26.7 17.4 <.1 240 3.38 <10 .20 .01 -­ AUG 08... -- 123 -- -- -- -- -- -- -- <10 <.20 .02 -­ SEP 10... 16.5 128 24.4 <.2 26.8 17.5 -- 214 -- 15 .30 .02 .95 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 18... 1.30 <.01 .39 .25 1.7 7.5 <10 300 690 -- -- -- -­ MAR 19... .800 .01 -- .28 -- -- <10 310 -- 3,700 2 54.9 39 MAY 05... .920 <.01 .19 .21 1.1 5.0 <10 E160 -- 3,700 E1 38.0 56 AUG 08... .950 <.01 -- .25 -- -- <10 E1,900 -- 25,000 -- -- -­ SEP 10... .960 .01 .28 .21 1.3 5.6 <10 E1,300 -- 23,000 -- -- -­ 222 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 18... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 19... <.2 E.4 <10 <.01 20 <1 17.4 <.02 <3 <.3 E19 <.10 <16 MAY 05... <.2 <.8 <10 <.01 50 <1 15.2 <.02 <3 <.3 39 <.10 <16 AUG 08... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- --- --- 223 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR LOCATION.--Lat 18q20'40", long 66q14'10", Hydrologic Unit 21010005, 2.9 mi (4.7 km) at northeast of Plaza de Naranjito, 2.7 mi (4.3 km) west of Road 167, km 15.3, Buena Vista, Bayamón, 5.2 mi (8.4 km) east of Plaza de Corozal. DRAINAGE AREA.--181 mi2 (469 km2). PERIOD OF RECORD.--February 1989 to current year. Prior to October 1994, published as Lago La Plata at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago La Plata first construction phase was completed in 1974 and the second construction phase to provide the spillway with bascule gates was completed in October 1989. The maximum storage is 37,000 acre-ft (45.6 hm3) and its purpose is the supply of water for domestic and industrial use. La Plata Dam is a concrete gravity structure located across the Río de la Plata, the dam has an overall length of 774 ft (236 m) and a maximum height of about 131 ft (40 m). The dam spillway is provided with six bascule gates. The spillway crest has a total clear length of 690 ft (210 m), an elevation of 155 ft (47 m). The Dam is owned and operated by the Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telem etry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 00-4045, October 1998. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 170.90 ft (52.09 m), September 10, 1996; minimum elevation, 107.95 ft (32.90 m), February 21, 1995. EXTREMES FOR CURRENT YEAR.--Maximum elevation, 167.98 ft (51.20 m), August 29; minimum elevation, 135.36 ft (41.26 m), January 2 4. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 00-4045, Puerto Rico, 1998) (Elevation in ft, capacity in acre-ft) Elevation Contents 82 0 105 1,873 125 5,943 Elevation Contents 144 12,915 164 24,021 171 28,748 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 161.91 157.96 150.63 142.96 139.96 140.36 136.92 167.14 166.35 162.70 164.44 167.13 2 161.78 157.74 150.37 142.71 139.87 140.21 136.77 167.09 166.14 162.95 164.99 167.18 3 161.65 157.51 150.10 142.42 139.76 140.07 136.69 166.99 166.01 162.89 165.47 167.16 4 161.55 157.31 149.95 142.11 141.05 139.91 136.54 166.90 165.84 162.78 165.54 166.90 5 161.39 157.09 149.73 141.79 141.93 139.73 136.45 166.78 165.69 162.76 165.47 167.04 6 161.21 156.87 149.50 141.51 142.13 139.58 136.41 166.68 165.53 162.85 165.46 167.00 7 161.22 156.62 149.27 141.30 142.14 139.42 136.33 166.59 165.44 162.85 165.52 166.94 8 161.27 156.37 149.05 141.01 142.09 139.26 136.18 166.54 165.36 162.95 165.48 166.89 9 161.32 156.14 148.80 140.72 142.00 139.10 136.03 166.47 165.24 162.85 165.42 166.80 10 161.47 155.91 148.53 140.37 141.92 138.93 135.91 166.36 165.08 162.77 165.45 166.66 11 161.36 155.64 148.27 140.04 141.89 138.74 135.81 166.27 164.89 162.61 165.44 166.58 12 161.20 155.37 148.02 139.68 141.92 138.57 135.90 166.17 164.71 162.42 165.39 167.44 13 161.03 155.17 147.76 139.33 141.93 138.39 136.05 166.07 164.52 163.59 165.50 167.16 14 160.85 155.00 147.49 138.98 141.83 138.20 136.03 166.01 164.36 164.33 165.40 166.82 15 160.67 154.76 147.23 138.61 141.72 138.02 135.96 165.90 164.30 164.39 165.27 166.90 16 160.48 154.52 146.93 138.24 141.64 137.81 135.80 165.81 164.13 164.41 165.14 166.89 17 160.29 154.33 146.66 137.86 141.52 137.62 148.20 165.75 163.99 164.49 164.98 167.31 18 160.12 154.12 146.80 137.45 141.43 137.40 160.16 165.65 163.83 164.40 165.46 167.15 19 159.98 153.93 146.72 137.07 141.42 137.14 164.07 165.56 163.96 164.27 165.52 166.78 20 159.91 153.71 146.52 136.72 141.39 136.88 164.88 166.46 164.31 164.11 165.50 166.77 21 159.80 A 146.28 136.33 141.30 136.66 166.44 166.83 164.28 163.95 166.52 166.91 22 159.61 153.18 146.06 135.98 141.20 136.42 166.58 166.98 164.19 163.92 167.18 167.27 23 159.44 152.96 145.83 135.61 141.17 136.20 166.53 167.20 164.07 164.24 167.35 166.90 24 159.28 152.69 145.62 135.52 141.09 135.92 166.42 167.28 163.89 164.21 167.32 167.00 25 159.21 152.39 145.38 138.33 140.95 135.67 167.10 167.26 163.72 164.07 167.47 167.03 26 159.04 152.10 145.09 139.95 140.82 135.80 167.17 167.18 163.55 163.98 167.02 166.97 27 158.89 151.82 144.77 140.21 140.68 136.68 167.02 167.09 163.34 164.09 167.46 166.86 28 158.73 151.53 144.43 140.19 140.52 136.97 167.16 166.96 163.16 164.24 167.90 166.71 29 158.56 151.23 144.07 140.19 137.01 167.19 166.83 162.96 164.36 166.67 166.63 30 158.35 150.93 143.70 140.14 137.04 167.20 166.69 162.77 164.31 166.92 166.53 31 158.15 143.31 140.06 137.04 166.48 164.40 167.01 MAX 161.91 150.63 142.96 142.14 140.36 167.20 167.28 166.35 164.49 167.90 167.44 MIN 158.15 143.31 135.52 139.76 135.67 135.80 165.56 162.77 162.42 164.44 166.53 A No gage-height record 224 RIO DE LA PLATA BASIN 50045000 LAGO LA PLATA AT DAMSITE NEAR TOA ALTA, PR—Continued O N D J F M A M J J A S 135 140 145 150 155 160 165 170 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 225 RIO DE LA PLATA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR LOCATION.--Lat 18q20'45", long 66q14'17", Hydrologic Unit 21010005, 2.8 mi (4.5 km) west of Road 167, km 15.3, Buena Vista, Bayamón, 5.0 mi (8.0 km) east of Plaza de Corozal, 3.0 mi (4.8 km) northeast of Plaza de Naranjito. DRAINAGE AREA.--173 mi2 (448 km2). PERIOD OF RECORD.--July 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage 66 ft (20 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by the Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. G age-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.6 0.44 0.33 0.78 0.14 0.37 e0.28 49 8.5 2.3 6.7 20 2 3.2 0.38 0.34 0.65 0.14 0.23 e0.42 83 24 2.4 4.8 25 3 2.9 0.28 0.34 0.58 0.15 0.22 e1.6 145 6.1 2.3 8.3 25 4 5.6 0.23 0.66 0.56 0.53 0.19 e2.3 178 6.1 2.4 7.9 309 5 2.7 0.20 0.49 0.58 0.31 0.18 e3.2 146 9.5 2.6 11 18 6 3.4 0.17 0.34 0.42 0.18 0.18 e1.5 118 4.9 3.7 4.2 22 7 3.0 0.17 0.30 0.38 0.16 0.19 e0.34 90 4.4 3.6 10 25 8 3.9 0.16 0.37 0.35 0.14 0.17 e0.22 78 3.9 3.3 5.3 19 9 3.0 0.19 0.36 1.1 0.18 0.17 e0.19 38 4.4 3.3 8.9 10 10 3.2 0.69 0.31 0.50 0.18 0.17 0.15 25 8.3 5.5 14 14 11 2.5 0.15 1.2 0.30 0.18 0.16 0.37 28 7.2 4.6 3.8 57 12 2.0 0.10 0.51 0.14 0.18 0.15 0.35 29 5.1 2.9 6.5 408 13 1.9 0.10 0.41 0.09 0.18 0.17 0.34 21 3.9 5.1 15 753 14 1.7 0.14 0.33 0.08 0.18 0.18 0.40 16 6.1 4.2 5.6 327 15 1.9 0.09 1.7 0.44 0.19 0.18 0.53 9.0 5.8 6.8 5.2 17 16 2.2 0.05 0.39 0.22 0.20 0.17 0.74 2.2 3.2 7.9 4.6 520 17 2.1 0.75 0.79 0.13 0.23 0.17 1.9 3.3 4.1 4.6 11 258 18 2.5 0.17 0.31 0.12 0.31 0.18 15 3.9 3.1 5.7 15 175 19 2.0 0.11 0.24 0.12 1.4 0.18 313 3.6 3.2 3.2 6.2 191 20 2.5 0.12 0.26 0.37 0.26 0.20 250 4.0 3.7 5.0 11 20 21 1.7 0.17 0.28 0.65 0.23 0.21 257 3,480 3.6 8.8 14 1,520 22 1.2 0.17 0.62 0.23 1.1 0.24 658 1,040 3.6 16 18 733 23 1.1 0.19 0.30 0.18 0.38 e0.25 2,850 107 3.5 3.7 26 297 24 1.4 0.16 0.31 0.76 0.17 e0.23 3,920 13 3.5 3.4 29 4.2 25 1.6 0.16 0.69 2.3 0.23 e0.42 1,180 8.4 e3.5 4.4 12 5.1 26 1.3 0.18 0.69 0.98 0.26 e0.29 377 18 e3.6 4.8 1,210 21 27 0.96 1.1 0.67 0.16 0.26 e1.2 247 16 3.2 2.0 82 18 28 0.76 0.70 0.67 0.13 1.0 e0.25 13 13 3.2 2.4 20 23 29 0.71 0.40 0.69 0.15 e0.48 33 5.6 2.8 9.4 956 17 30 0.58 0.35 0.70 0.14 e1.9 18 5.7 2.5 3.3 55 29 31 0.56 0.72 0.14 e0.32 8.3 3.5 22 TOTAL 67.67 8.27 16.32 13.73 9.05 9.60 10,145.83 5,785.0 158.5 143.1 2,609.0 5,880.3 MEAN 2.18 0.28 0.53 0.44 0.32 0.31 338 187 5.28 4.62 84.2 196 MAX 5.6 1.1 1.7 2.3 1.4 1.9 3,920 3,480 24 16 1,210 1,520 MIN 0.56 0.05 0.24 0.08 0.14 0.15 0.15 2.2 2.5 2.0 3.8 4.2 AC-FT 134 16 32 27 18 19 20,120 11,470 314 284 5,170 11,660 CFSM 0.01 0.00 0.00 0.00 0.00 0.00 1.96 1.08 0.03 0.03 0.49 1.13 IN. 0.01 0.00 0.00 0.00 0.00 0.00 2.18 1.25 0.03 0.03 0.56 1.27 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY) MEAN 165 242 162 172 45.7 10.7 58.9 92.2 33.7 52.6 57.0 774 MAX 1,107 1,368 926 1,581 241 83.2 338 494 220 384 322 8,046 (WY) (1991) (2000) (1999) (1992) (1998) (1990) (2003) (1993) (1993) (1993) (2000) (1996) MIN 0.05 0.00 0.00 0.19 0.14 0.02 0.01 0.00 0.00 0.04 0.02 0.00 (WY) (1992) (1995) (1995) (1990) (1995) (1995) (1995) (1994) (1994) (1994) (1989) (1991) 226 RIO GUAJATACA BASIN 50045010 RIO DE LA PLATA BELOW LA PLATA DAM, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1989 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 14,277.40 ANNUAL MEAN 39.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,810 LOWEST DAILY MEAN 0.01 ANNUAL SEVEN-DAY MINIMUM 0.15 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 28,320 ANNUAL RUNOFF (CFSM) 0.226 ANNUAL RUNOFF (INCHES) 3.07 10 PERCENT EXCEEDS 12 50 PERCENT EXCEEDS 2.1 90 PERCENT EXCEEDS 0.31 24,846.37 68.1 157 714 1996 8.62 1997 Apr 21 3,920 Apr 24 141,000 Sep 10, 1996 Aug 29 0.05 Nov 16 0.00 Jul 14, 1989 Nov 19 0.14 Jan 28 0.00 Jul 14, 1989 21,500 May 21 197,000 Sep 10, 1996 17.49 May 21 42.26 Sep 10, 1996 49,280 113,900 0.394 0.910 5.35 12.37 42 201 2.1 1.8 0.17 0.00 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 227 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR LOCATION.--Lat 18q24'41", long 66q15'39", Hydrologic Unit 21010005, on left bank at downstream side of bridge on Highway 2, 1.3 mi ( 2.1 km) downstream from Río Lajas and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--208 mi2 (539 km2), excludes 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. Area at site used prior to September 25, 1984, 200 mi2 (518 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. Prior to October 1984, published as Río de La Plata at Toa Alta, Puerto Rico; October 1984 to September 1988 published as 50046900. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 9.15 ft (2.789 m), above mean sea level. Prior to October 198 4, at site about 1.0 mi (1.6 km) upstream at mean sea level datum. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. Flow affected by water extraction for La Virgencita water treatment plant by the Puerto Rico Aqueduct and Sewer Authority of about 3.99 ft3/s (0.11 m3/s). Located about 1,000 feet upstream from station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations of major floods, as pointed out by local residents are as follows: September 13, 1928, 120,000 ft3/s (3,400 m3/s), gage height 37.4 ft (11.40 m); June 16, 1943, 82,000 ft3/s (2,322 m3/s), gage height 34.4 ft (10.48 m), at site 1.0 mi upstream and different datum. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 34 33 23 18 15 15 e11 37 30 15 31 75 2 32 32 20 18 16 13 12 41 33 17 27 60 3 30 28 18 19 19 11 19 36 34 16 28 49 4 76 25 49 17 211 11 32 e32 29 15 31 202 5 79 25 29 20 208 11 50 69 53 16 31 295 6 41 28 19 19 33 14 36 42 36 18 47 46 7 195 33 19 17 24 11 35 32 28 22 47 41 8 723 30 35 17 27 11 18 29 25 24 53 42 9 308 28 32 21 27 12 19 25 24 36 35 34 10 76 31 22 23 29 13 17 21 22 e22 31 28 11 45 35 19 19 26 11 25 27 23 26 34 41 12 37 75 20 17 18 9.0 20 23 24 24 37 49 13 36 65 20 18 15 9.0 13 21 23 155 71 1,490 14 35 46 19 18 15 10 14 22 22 54 80 452 15 37 45 18 18 19 11 21 24 31 27 36 133 16 38 31 17 18 18 7.5 22 26 41 31 38 127 17 29 83 16 20 19 8.1 132 25 25 26 34 909 18 28 46 15 18 16 8.8 110 25 29 21 136 69 19 28 34 15 17 15 8.3 214 21 36 20 159 411 20 31 25 21 20 25 11 422 123 26 20 47 e60 21 138 21 30 21 23 12 552 3,050 26 20 611 891 22 74 23 21 19 16 9.1 729 4,260 22 58 1,030 2,570 23 33 22 17 15 15 10 3,150 436 20 31 131 360 24 27 21 18 23 15 6.7 5,860 109 19 23 69 222 25 29 27 17 142 17 12 3,900 55 17 23 134 37 26 41 27 17 379 16 37 662 43 18 23 1,660 30 27 33 25 16 43 15 56 463 41 17 34 544 30 28 29 23 16 20 14 17 93 37 17 93 117 29 29 27 23 17 29 22 47 34 16 44 1,370 43 30 26 23 15 22 32 48 31 16 26 452 33 31 24 18 16 11 28 28 111 TOTAL 2,419 1,013 648 1,101 926 440.5 16,746 8,825 782 1,008 7,262 8,858 MEAN 78.0 33.8 20.9 35.5 33.1 14.2 558 285 26.1 32.5 234 295 MAX 723 83 49 379 211 56 5,860 4,260 53 155 1,660 2,570 MIN 24 21 15 15 14 6.7 11 21 16 15 27 28 AC-FT 4,800 2,010 1,290 2,180 1,840 874 33,220 17,500 1,550 2,000 14,400 17,570 CFSM 0.38 0.16 0.10 0.17 0.16 0.07 2.68 1.37 0.13 0.16 1.13 1.42 IN. 0.43 0.18 0.12 0.20 0.17 0.08 2.99 1.58 0.14 0.18 1.30 1.58 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2003, BY WATER YEAR (WY) MEAN 442 465 339 179 125 88.5 181 309 147 135 236 419 MAX 4,813 2,015 1,352 929 409 468 722 1,939 847 690 1,677 3,173 (WY) (1971) (1985) (1971) (1992) (1989) (1969) (1987) (1985) (1970) (1961) (1979) (1996) MIN 18.8 18.4 14.8 16.9 16.0 8.31 5.07 7.63 11.4 13.2 16.5 19.2 (WY) (1995) (1995) (1995) (1984) (1983) (1986) (1984) (1984) (1977) (1994) (1976) (1991) 228 RIO GUAJATACA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1960 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 38,200 ANNUAL MEAN 105 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 3,360 LOWEST DAILY MEAN 15 ANNUAL SEVEN-DAY MINIMUM 17 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 75,770 ANNUAL RUNOFF (CFSM) 0.503 ANNUAL RUNOFF (INCHES) 6.83 10 PERCENT EXCEEDS 173 50 PERCENT EXCEEDS 32 90 PERCENT EXCEEDS 19 50,028.5 137 254 824 1971 31.5 1994 Apr 21 5,860 Apr 24 68,100 Sep 10, 1996 Dec 18 6.7 Mar 24 2.7 Apr 17, 1984 Dec 24 9.0 Mar 13 2.9 Apr 15, 1984 18,000 May 21 160,000 Sep 10, 1996 17.53 May 21 27.33 Sep 10, 1996 99,230 183,700 0.659 1.22 8.95 16.56 147 468 27 72 15 18 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 229 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR--Continued WATER-QUALITY RECORDS LOCATION.--Lat 18q24'41", long 66q15'39", at Highway 2, 1.3 mi (2.1 km) downstream from Río Lajas, and 1.6 mi (2.6 km) northwest of Toa Alta, 11.3 mi (18.2 km) downstream from Lago La Plata. DRAINAGE AREA.--208 mi2 (539 km2), exclude 8.2 mi2 (21.2 km2) upstream from Lago Carite, flow from which is diverted to Río Guamaní. PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 22... 1200 23 1.4 11.6 149 7.4 474 28.3 180 53.9 10.1 2.74 .7 MAR 28... 1130 15 16 3.6 -- 7.0 366 27.8 140 43.3 7.13 4.40 .7 MAY 16... 1300 25 10 6.6 -- 7.5 518 28.5 200 57.8 12.8 3.60 .8 AUG 08... 0945 50 4.1 4.0 -- 7.3 407 29.1 -- -- -- -- -­ SEP 12... 0945 52 3.0 8.9 -- 7.4 455 29.4 180 52.1 12.2 3.35 .7 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 22... 22.4 166 30.2 <.17 17.5 15.3 -- 252 15.9 <10 .90 .04 .84 MAR 28... 17.9 130 24.6 .14 11.2 14.8 <.1 201 8.29 11 1.9 1.10 .24 MAY 16... 25.5 174 38.1 <.2 21.1 18.5 <.1 282 18.9 <10 .60 .27 .88 AUG 08... -- 141 -- -- -- -- -- -- -- <10 .50 .16 .80 SEP 12... 22.0 166 30.9 <.2 19.7 15.2 -- 255 36.1 <10 .80 .22 .66 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 22... .860 .02 .86 .04 1.8 7.8 <10 E60 <10 -- -- -- -­ MAR 28... .320 .08 .80 .12 2.2 9.8 20 E680 -- 36,000 E1 52.9 42 MAY 16... 1.00 .12 .33 .04 1.6 7.1 10 E12 -- 140 E1 70.6 56 AUG 08... .880 .08 .34 .05 1.4 6.1 20 84 -- 3,000 -- -- -­ SEP 12... .760 .10 .58 .05 1.6 6.9 10 270 -- 6,000 -- -- -­ 230 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT HIGHWAY 2 NEAR TOA ALTA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 22... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 28... <.2 <.8 <10 <.01 280 <1 381 <.02 <3 <.3 <25 E.05 <16 MAY 16... <.2 <.8 <10 <.01 160 <1 188 <.02 <3 <.3 E22 <.10 <16 AUG 08... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 12... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAY 16... 1300 <.01 <.02 <.01 <.01 <.02 <.1 <.01 E.01 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAY 16... <.01 <.01 <.009 <.01 <.014 <.10 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAY 16... <.1 <.02 <.02 <1 <.02 < -- Less than E -- Estimated value 231 Figure 16. Río Hondo to Río Puerto Nuevo basins. 232 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATAÑO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q26'13", long 66q09'36", at Río Hondo Channel, 800 ft (245 m) below junction with Río Hondo, 0.9 mi (1.5 km) downstream from bridge on de Diego Expressway and 1.1 mi (1.8 km) above mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- wat unf solved water, conduc- ness, Magnes- Potas- lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp- water, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, Date Time NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) DEC 17... 0920 11 7.0 105 7.8 41,300 28.6 4,600 298 939 275 50 7,840 MAR 10... 1420 12 16.3 -- 8.3 30,600 28.8 3,400 240 690 162 42 5,690 MAY 16... 1520 23 15.2 -- 8.5 43,200 33.0 4,500 302 906 322 47 7,200 AUG 07... 1300 -- 2.8 -- 7.4 33,600 29.1 -- -- -- -- -- -­ SEP 22... 1045 110 2.0 -- 7.2 1,430 28.0 170 30.0 21.9 10.1 6 170 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate Nitrite end pt, ide, ide, Silica, Sulfate Sulfide sum of deg. C, water, water, water water water, field, water, water, water, water, water consti- sus- unfltrd unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents pended, mg/L mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L mg/L as N as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (00530) (00625) (00610) (00620) (00630) (00615) DEC 17... 143 13,800 .75 6.0 1,830 -- 25,100 <10 .60 .21 .09 .120 .03 MAR 10... 157 10,100 .64 7.3 1,310 .5 18,300 31 1.0 .03 -- <.020 <.01 MAY 16... 125 13,300 .9 3.1 1,800 .2 23,900 67 .70 .01 -- <.020 <.01 AUG 07... 70 -- -- -- -- -- -- 32 .70 .38 .24 .270 .03 SEP 22... 79 331 <.2 6.2 47.1 -- 663 130 1.0 .52 .28 .320 .04 Total Organic Total nitro- COD, nitro- Phos- nitro- gen, high gen, phorus, gen, water, level, water, water, water, unfltrd water, unfltrd unfltrd unfltrd mg/L unfltrd Date mg/L mg/L mg/L as NO3 mg/L (00605) (00665) (00600) (71887) (00340) Fecal Fecal Total Chrom- coli- strep- coli- Barium, Boron, ium, form, tococci form, water, water, water, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd 0.7u MF MF, immed, water recover recover water, recover col/ col/ col/ unfltrd -able, -able, unfltrd -able, 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) DEC 17... .39 .09 .72 3.2 160 700 900 -- -- -- -- -- -­ MAR 10... .97 .13 -- -- 120 E130 -- E1,900 <6 28.1 2,040 <1.3 E1.2 MAY 16... .69 .09 -- -- 230 E100 -- E1,100 <8 45.9 3,360 E1.2 1.3 AUG 07... .32 .17 .97 4.3 10 30,000 -- E85,000 -- -- -- -- -­ SEP 22... .48 .19 1.3 5.8 20 E120,000 -- 230,000 -- -- -- -- -­ 233 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATAÑO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 17... -- -- -- -- -- -- -- -- -- -- -- MAR 10... <50 <.01 <80 E3 144 E.01 <8 .6 <125 .18 <16 MAY 16... 70 <.01 <20 E6 172 E.01 <10 .7 <25 E.08 19 AUG 07... -- -- -- -- -- -- -- -- -- -- -- SEP 22... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 234 RIO DE BAYAMON BASIN 50047535 RIO DE BAYAMON AT ARENAS, PR LOCATION.--Lat 18q10'11", long 66q07'18", Hydrologic Unit 21010005, at left bank, 2.6 mi (4.2 km) southeast of Plaza de Cidra, 0.6 mi (0.9 km) southwest from Escuela Segunda Unidad de Bayamón and 2.7 mi (4.3 km) northeast from Central Cayey. DRAINAGE AREA.--0.45 mi2 (1.16 km2). PERIOD OF RECORD.--July 1992 to September 1993, October 1995 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,378 ft (420 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 0.27 0.14 0.15 0.23 0.28 0.23 e0.43 0.22 0.16 1.3 1.2 0.82 2 0.27 0.15 0.15 0.24 0.25 0.20 0.22 0.21 0.22 3.6 3.1 0.75 3 0.21 0.19 0.14 0.18 0.65 0.19 0.26 0.22 0.56 0.62 0.67 0.39 4 0.21 0.14 0.16 0.16 1.9 0.17 0.25 0.21 0.41 0.47 0.39 0.27 5 0.19 0.13 0.28 0.61 0.92 0.16 0.55 0.19 0.28 0.44 0.28 0.21 6 0.19 0.12 0.15 0.47 0.48 0.15 0.22 0.22 0.66 0.96 0.33 0.17 7 0.20 0.11 0.16 0.27 0.80 0.15 0.19 0.22 0.52 0.51 0.29 0.15 8 0.20 0.11 0.20 0.20 0.47 0.15 0.17 0.30 0.31 0.42 0.27 0.16 9 0.21 0.11 0.20 0.19 0.31 0.15 0.24 0.25 0.22 0.39 0.31 0.15 10 0.22 0.11 0.16 0.22 0.59 0.15 0.38 0.25 0.17 0.23 0.26 0.26 11 0.21 0.13 0.16 0.18 0.48 0.15 1.2 0.23 0.15 0.16 0.31 0.21 12 0.21 0.14 0.15 0.17 0.38 0.15 0.91 0.22 0.21 0.14 0.22 0.19 13 0.22 0.13 0.16 0.15 0.35 0.14 0.53 0.21 0.18 7.5 0.19 0.18 14 0.20 0.11 0.15 0.15 0.27 0.15 0.26 0.24 0.15 0.98 0.15 0.17 15 0.19 0.12 0.15 0.15 0.21 0.15 0.19 0.21 0.21 0.50 0.15 0.29 16 0.18 0.14 0.18 0.13 0.22 0.15 0.21 0.19 0.20 1.1 e0.15 0.34 17 0.19 0.13 1.2 0.16 0.74 0.15 16 0.17 0.16 0.47 e0.45 0.20 18 0.20 0.12 0.64 0.36 0.56 0.15 16 0.29 0.15 0.26 e0.88 0.18 19 0.19 0.13 0.28 0.24 0.33 1.2 2.5 0.25 2.2 0.21 0.46 0.16 20 0.19 0.11 0.27 0.22 0.31 0.53 3.7 0.19 0.63 0.18 0.27 0.17 21 0.19 0.10 0.36 0.20 0.38 0.20 5.6 8.5 0.34 0.20 5.4 12 22 0.18 0.11 0.52 0.18 0.32 0.19 3.4 1.3 0.20 5.2 1.5 1.2 23 0.18 0.11 0.34 0.22 0.23 0.18 5.6 0.59 0.15 1.3 0.55 0.51 24 0.22 0.11 0.20 0.64 0.20 0.18 22 0.34 0.16 0.58 0.31 0.38 25 0.19 0.12 0.17 2.6 0.23 0.16 2.2 0.21 0.14 0.33 0.29 0.31 26 0.27 0.14 0.17 1.2 0.22 0.23 0.93 0.18 0.12 0.28 5.6 0.28 27 0.19 0.12 0.15 0.49 0.28 0.23 0.62 0.18 0.12 0.55 0.56 0.30 28 0.16 0.12 0.15 0.28 0.31 0.21 0.44 0.17 0.22 2.0 4.9 0.28 29 0.14 0.13 0.15 0.26 0.23 0.32 0.17 0.13 0.81 1.7 0.27 30 0.15 0.12 0.14 0.30 0.21 0.29 0.17 0.13 0.41 0.70 0.36 31 0.14 0.14 0.31 e0.18 0.17 0.80 0.44 TOTAL 6.16 3.75 7.58 11.36 12.67 6.82 85.81 16.47 9.46 32.90 32.28 21.31 MEAN 0.20 0.12 0.24 0.37 0.45 0.22 2.86 0.53 0.32 1.06 1.04 0.71 MAX 0.27 0.19 1.2 2.6 1.9 1.2 22 8.5 2.2 7.5 5.6 12 MIN 0.14 0.10 0.14 0.13 0.20 0.14 0.17 0.17 0.12 0.14 0.15 0.15 AC-FT 12 7.4 15 23 25 14 170 33 19 65 64 42 CFSM 0.44 0.28 0.54 0.81 1.01 0.49 6.36 1.18 0.70 2.36 2.31 1.58 IN. 0.51 0.31 0.63 0.94 1.05 0.56 7.09 1.36 0.78 2.72 2.67 1.76 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2003, BY WATER YEAR (WY) MEAN 0.59 1.08 1.09 0.59 0.57 0.26 0.66 0.49 0.59 0.73 0.96 2.05 MAX 1.73 3.82 4.63 1.17 2.38 0.65 2.86 2.02 1.79 2.12 1.87 6.52 (WY) (1998) (2000) (1999) (2000) (1998) (1998) (2003) (1993) (1996) (1993) (1996) (1998) MIN 0.20 0.12 0.05 0.34 0.16 0.10 0.09 0.10 0.10 0.09 0.46 0.20 (WY) (2003) (2003) (1998) (2002) (1993) (1993) (1997) (1999) (1998) (1998) (1992) (1997) RIO DE BAYAMON BASIN 235 50047535 RIO DE BAYAMON AT ARENAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1992 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 225.50 ANNUAL MEAN 0.62 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 28 LOWEST DAILY MEAN 0.10 ANNUAL SEVEN-DAY MINIMUM 0.11 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 447 ANNUAL RUNOFF (CFSM) 1.37 ANNUAL RUNOFF (INCHES) 18.64 10 PERCENT EXCEEDS 0.85 50 PERCENT EXCEEDS 0.21 90 PERCENT EXCEEDS 0.14 246.57 0.68 0.81 1.16 1996 0.31 1997 Sep 15 22 Apr 24 141 Sep 10, 1996 Mar 25 0.10 Nov 21 0.02 Jul 3, 1997 Nov 18 0.11 Nov 18 0.03 Jun 28, 1997 285 Apr 24 1,150 Sep 21, 1998 5.58 Apr 24 7.89 Sep 21, 1998 0.09 Nov 20 0.02 Jul 15, 1997 489 589 1.50 1.81 20.38 24.55 0.94 1.1 0.22 0.21 0.14 0.08 e Estimated 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 236 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR LOCATION.--Lat 18q11'57", long 66q08'29", Hydrologic Unit 21010005, at Lago de Cidra Dam on Río de Bayamón, 1.9 mi (3.0 km) northeast of Plaza de Cidra and 1.8 mi (2.9 km) northwest of Escuela Segunda Unidad de Bayamón. DRAINAGE AREA.--8.26 mi2 (21.39 km2). PERIOD OF RECORD.--January 1988 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago de Cidra was completed in 1946. The maximum storage is 5,300 acre-ft (6.53 hm3) and provides supplemental water to metropolitan San Juan. The dam is a concrete gravity and earthfill structure, approximately 541 ft (165 m) long between abutments with a maximum structural height of about 78.7 ft (24.0 m). The spillway portion of the dam, length 131 ft (40 m) and crest elevation 1,322 ft (403 m), is an ungated ogee crest located 131 ft (40 m) from the right abutment. This dam is owned by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 99-4144, November 1997. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 1,328.09 ft (404.80 m), September 10, 1996; minimum elevation 1,295.86 ft (394.98 m), April 22,1995. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,319.73 ft (402.25 m), May 24; minimum elevation, 1,304.37 ft (397.57 m ), March 19. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4144, 1997) (Elevation in ft, capacity in acre-ft) Elevation Contents 1,260 0 1,276 97 1,296 762 Elevation Contents 1,309 2,059 1,315 3,170 1,322 4,670 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1,317.33 1,313.39 1,310.44 1,307.59 1,306.47 1,306.21 1,305.21 1,318.87 1,319.39 1,316.52 1,313.76 1,312.69 2 1,317.19 1,313.29 1,310.38 1,307.56 1,306.40 1,306.06 1,305.19 1,318.88 1,319.24 1,316.58 1,313.95 1,312.66 3 1,317.07 1,313.19 1,310.26 1,307.53 1,306.28 1,305.94 1,305.29 1,318.90 1,319.25 1,316.44 1,313.73 1,312.57 4 1,316.99 1,313.09 1,310.24 1,307.45 1,307.16 1,305.79 1,305.28 1,318.90 1,319.19 1,316.29 1,313.51 1,312.47 5 1,316.88 1,312.96 1,310.23 1,307.49 1,307.20 1,305.68 1,305.44 1,318.90 1,319.14 1,316.27 1,313.27 1,312.37 6 1,316.80 1,312.84 1,310.12 1,307.46 1,307.20 1,305.60 1,305.56 1,318.91 1,319.13 1,316.20 1,313.07 1,312.26 7 1,316.69 1,312.74 1,310.01 1,307.39 1,307.26 1,305.44 1,305.53 1,318.90 1,319.10 1,316.02 1,312.85 1,312.15 8 1,316.59 1,312.66 1,309.96 1,307.30 1,307.26 1,305.33 1,305.48 1,318.91 1,319.03 1,315.82 1,312.61 1,312.07 9 1,316.49 1,312.56 1,309.85 1,307.18 1,307.27 1,305.23 1,305.52 1,318.88 1,318.95 1,315.63 1,312.37 1,312.02 10 1,316.39 1,312.46 1,309.73 1,307.12 1,307.28 1,305.14 1,305.56 1,318.84 1,318.87 1,315.43 1,312.13 1,312.06 11 1,316.29 1,312.37 1,309.64 1,307.07 1,307.32 1,305.09 1,306.07 1,318.78 1,318.80 1,315.23 1,311.87 1,312.08 12 1,316.20 1,312.27 1,309.54 1,307.03 1,307.32 1,304.99 1,306.33 1,318.71 1,318.66 1,315.03 1,311.61 1,312.09 13 1,316.07 1,312.19 1,309.45 1,306.98 1,307.28 1,304.84 1,306.50 1,318.67 1,318.52 1,315.77 1,311.42 1,312.05 14 1,315.96 1,312.07 1,309.34 1,306.77 1,307.24 1,304.71 1,306.61 1,318.71 1,318.41 1,315.63 1,311.23 1,312.01 15 1,315.85 1,311.97 1,309.23 1,306.53 1,307.24 1,304.61 1,306.74 1,318.70 1,318.32 1,315.48 1,311.02 1,312.02 16 1,315.72 1,311.90 1,309.14 1,306.30 1,307.24 1,304.57 1,306.84 1,318.68 1,318.21 1,315.41 1,310.87 1,312.00 17 1,315.61 1,311.88 1,309.13 1,306.13 1,307.32 1,304.52 1,309.42 1,318.66 1,318.11 1,315.23 1,310.72 1,311.97 18 1,315.49 1,311.80 1,309.10 1,306.00 1,307.33 1,304.41 1,311.79 1,318.68 1,318.05 1,315.05 1,310.64 1,311.97 19 1,315.36 1,311.70 1,309.11 1,305.83 1,307.34 1,304.85 1,312.11 1,318.67 1,318.14 1,314.88 1,310.48 1,311.95 20 1,315.22 1,311.59 1,309.12 1,305.67 1,307.30 1,304.96 1,312.58 1,318.76 1,318.00 1,314.70 1,310.37 1,311.94 21 1,315.08 1,311.50 1,309.06 1,305.51 22 1,314.92 1,311.41 1,309.09 1,305.37 23 1,314.74 1,311.31 1,309.00 1,305.30 24 1,314.61 1,311.20 1,308.83 1,305.87 25 1,314.45 1,311.10 1,308.71 1,306.51 A 1,305.03 1,313.82 1,319.65 1,317.90 1,314.53 1,310.91 1,314.16 A 1,305.02 1,314.09 1,319.70 1,317.77 1,314.94 1,310.98 1,314.22 A 1,305.00 1,315.41 1,319.71 1,317.62 1,314.78 1,311.03 1,314.22 A 1,305.00 1,318.57 1,319.71 1,317.43 1,314.54 1,311.05 1,314.21 A 1,304.96 1,318.77 1,319.70 1,317.21 1,314.31 1,311.17 1,314.20 26 1,314.31 1,310.97 1,308.57 1,306.64 1,306.66 1,305.04 1,318.87 1,319.69 1,316.99 1,314.45 1,312.11 1,314.17 27 1,314.14 1,310.86 1,308.39 1,306.68 1,306.55 1,305.21 1,318.93 1,319.66 1,316.78 1,314.37 1,312.16 1,314.14 28 1,313.98 1,310.77 1,308.19 1,306.68 1,306.38 1,305.20 1,318.95 1,319.64 1,316.61 1,314.52 1,312.56 1,314.10 29 1,313.81 1,310.67 1,307.99 1,306.70 --- 1,305.19 1,318.91 1,319.63 1,316.41 1,314.34 1,312.69 1,314.21 30 1,313.65 1,310.55 1,307.82 1,306.62 --- 1,305.21 1,318.88 1,319.58 1,316.19 1,314.10 1,312.68 1,314.22 31 1,313.50 --- 1,307.65 1,306.54 --- A --- 1,319.49 --- 1,313.92 1,312.67 --­ MAX 1,317.33 1,313.39 1,310.44 1,307.59 --- --- 1,318.95 1,319.71 1,319.39 1,316.58 1,313.95 1,314.22 MIN 1,313.50 1,310.55 1,307.65 1,305.30 --- --- 1,305.19 1,318.66 1,316.19 1,313.92 1,310.37 1,311.94 A No gage-height record 237 RIO DE BAYAMON BASIN 50047550 LAGO CIDRA AT DAMSITE NEAR CIDRA, PR—Continued O N D J F M A M J J A S 1,304 1,306 1,308 1,310 1,312 1,314 1,316 1,318 1,320 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 238 RIO DE BAYAMON BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR LOCATION.--Lat 18q12'04", long 66q08'26", Hydrologic Unit 21010005, 0.2 mi (0.3 km) downstream of Lago Cidra Dam on right bank, 2.1 mi (3.4 km) northwest of Plaza de Cidra. DRAINAGE AREA.--8.32 mi2 (21.5 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 1,279 ft (390 m), from topographic map. REMARKS.--Records poor. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22 20 12 13 e31 e28 e13 e13 19 27 24 e11 2 29 23 12 13 e21 e24 e14 e13 27 29 25 e10 3 23 19 13 9.6 e18 e23 e13 e13 20 29 21 e10 4 18 20 9.8 11 e30 e20 e19 e13 18 28 21 e10 5 18 22 11 13 e18 e18 e19 e13 17 29 22 e10 6 18 22 14 11 e16 e13 e14 12 17 31 21 e10 7 19 17 12 12 e15 e17 e27 12 17 31 22 e11 8 18 14 12 13 e15 e17 e21 13 18 34 22 e10 9 18 13 14 13 e14 e14 e34 17 21 34 22 e10 10 18 14 14 12 e16 e16 e30 20 22 35 21 e10 11 19 14 12 11 e16 e13 e17 18 19 29 21 e10 12 19 16 12 9.6 e15 e13 e18 15 23 26 24 e11 13 22 16 14 9.5 e16 e13 e20 16 26 32 16 e11 14 21 16 13 23 e16 e14 e18 15 26 26 13 e11 15 20 14 13 21 e15 e16 e20 15 25 28 12 e11 16 20 14 13 15 e14 e13 e20 15 23 28 11 e11 17 21 12 13 13 e18 e12 e11 15 20 21 11 e12 18 22 15 9.4 14 e21 e11 e12 13 17 16 11 e12 19 21 e16 5.4 15 e14 e9.6 e11 13 18 16 11 e12 20 22 e13 5.6 15 e18 e8.4 e10 15 18 17 9.6 e11 21 26 14 10 15 e20 e8.6 e12 14 18 17 9.1 e12 22 34 15 8.8 13 e20 e8.5 e10 13 16 20 9.0 e11 23 34 15 13 13 e20 e9.5 e12 13 18 24 7.9 e11 24 34 14 17 12 e19 e7.4 e14 12 29 29 8.3 e10 25 33 14 14 12 e16 e7.5 e11 11 28 29 9.8 e9.6 26 31 15 21 10 e17 e8.5 e9.3 11 29 30 10 e10 27 32 15 22 10 e20 e8.9 e10 12 30 22 10 e10 28 29 14 23 e10 e22 e8.6 e12 12 31 22 e9.7 e11 29 33 13 20 e11 e11 e12 12 28 23 e10 e10 30 33 14 19 e32 e12 e12 12 29 24 e11 e10 31 30 18 e35 e14 20 25 e11 TOTAL 757 473 420.0 439.7 511 417.5 475.3 431 667 811 466.4 318.6 MEAN 24.4 15.8 13.5 14.2 18.2 13.5 15.8 13.9 22.2 26.2 15.0 10.6 MAX 34 23 23 35 31 28 34 20 31 35 25 12 MIN 18 12 5.4 9.5 14 7.4 9.3 11 16 16 7.9 9.6 AC-FT 1,500 938 833 872 1,010 828 943 855 1,320 1,610 925 632 CFSM 2.94 1.90 1.63 1.70 2.19 1.62 1.90 1.67 2.67 3.14 1.81 1.28 IN. 3.38 2.11 1.88 1.97 2.28 1.87 2.13 1.93 2.98 3.63 2.09 1.42 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 2003, BY WATER YEAR (WY) MEAN 15.6 19.8 26.0 18.3 17.2 16.4 14.2 13.3 13.6 16.0 14.1 34.6 MAX 31.2 41.2 117 59.6 36.5 26.3 24.5 23.2 22.2 39.6 29.2 233 (WY) (1999) (1992) (2000) (1992) (1991) (1998) (1996) (1998) (2003) (1993) (1996) (1996) MIN 3.74 3.73 3.63 5.45 7.24 9.93 5.72 4.13 3.47 1.56 1.18 1.64 (WY) (1995) (2002) (2002) (1995) (1994) (2002) (1997) (1993) (1994) (1994) (1995) (1994) 239 RIO CAMUY BASIN 50047560 RIO DE BAYAMON BELOW LAGO CIDRA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1991 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 5,593.5 ANNUAL MEAN 15.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 81 LOWEST DAILY MEAN 3.6 ANNUAL SEVEN-DAY MINIMUM 4.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 11,090 ANNUAL RUNOFF (CFSM) 1.84 ANNUAL RUNOFF (INCHES) 25.01 10 PERCENT EXCEEDS 28 50 PERCENT EXCEEDS 13 90 PERCENT EXCEEDS 6.0 6,187.5 17.0 18.2 36.1 1996 5.93 1994 Jul 24 35 Jan 31 5,420 Sep 10, 1996 Mar 14 5.4 Dec 19 0.60 Aug 6, 1992 May 19 8.3 Mar 20 0.80 May 1, 1995 15,000 Sep 10, 1996 27.34 Sep 10, 1996 12,270 13,190 2.04 2.19 27.67 29.74 28 27 15 13 10 3.2 e Estimated 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 240 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR LOCATION.--Lat 18q14'39", long 66q08'39", at bridge on Highway 156 and 2.9 mi (4.7 km) west of Aguas Buenas Plaza. DRAINAGE AREA.--18.5 mi2 (47.9 km2). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Instan- wat unf taneous lab, Dis- dis- Hach solved charge, 2100AN oxygen, Date Time cfs NTU mg/L (00061) (99872) (00300) pH, Specif. Hard- water, conduc- ness, Magnes- Potas- unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, field, wat unf ature, unfltrd water, water, water, adsorp- water, std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) NOV 20... 1245 16 11 8.5 7.1 276 24.3 95 21.5 9.91 2.66 .7 16.0 FEB 20... 1320 19 4.9 8.9 8.4 301 23.9 110 25.9 11.3 2.00 .8 18.2 MAY 19... 1605 20 30 8.0 8.0 248 25.4 89 21.0 8.97 2.61 .6 13.4 AUG 12... 1615 36 10 7.8 8.2 258 27.7 -- -- -- -- -- -­ SEP 08... 1305 17 6.6 8.1 8.1 293 25.8 110 25.0 11.5 2.23 .6 13.9 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) (00630) NOV 20... 96 18.7 <.17 22.4 8.3 -- 157 6.69 <10 .30 .04 -- .470 FEB 20... 112 19.1 .09 25.4 9.8 <.0 179 9.15 <10 .70 .01 -- .580 MAY 19... 84 15.7 <.2 21.8 9.7 .2 143 7.63 <10 .30 .02 .45 .460 AUG 12... 90 -- -- -- -- -- -- -- <10 .40 <.01 -- .300 SEP 08... 98 21.1 <.2 24.1 8.8 -- 166 7.63 <10 .20 .01 -- .500 0;;; Total Fecal Fecal Total Organic Total nitro- COD, coli- strep- coli- Barium, Boron, Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd Date as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) NOV 20... <.01 .26 .02 .77 3.4 <10 510 410 -- -- -- -- -­ FEB 20... <.01 .69 <.02 1.3 5.7 20 E140 -- 3,000 <2 18.9 31 <.2 MAY 19... .01 .28 <.02 .76 3.4 10 E170 -- 2,500 <2 21.8 21 <.2 AUG 12... <.01 -- <.02 .70 3.1 10 98 -- 2,400 -- -- -- -­ SEP 08... <.01 .19 <.02 .70 3.1 10 E80 -- E6,400 -- -- -- -­ 241 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR—Continued ó WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com­ unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover water recover recover recover recover water, recover recover water, water, -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 20... -- -- -- -- -- -- -- -- -- -- -- -- FEB 20... <.8 <10 <.01 130 <1 31.3 <.02 <3 E.1 <25 <.10 <16 MAY 19... E.8 <10 <.01 560 <1 43.6 E.01 <5 <.3 <25 <.10 E11 AUG 12... -- -- -- -- -- -- -- -- -- -- -- -- SEP 08... -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 242 RIO DE BAYAMON BASIN 50047850 RIO DE BAYAMON NR BAYAMON, PR LOCATION.--Lat 18q20'08", long 66q08'13", Hydrologic Unit 21010005, on left bank, at rock quarry near Highway 174, 1.3 mi (2.1 km) south of colonia Santa Rosa and 4.7 mi (7.6 km) south of Bayamón. DRAINAGE AREA.--41.8 mi2 (108.3 km2). PERIOD OF RECORD.--September 1964 to October 1970, June 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98 ft (30 m), from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Diversion to the Guaynabo water treatment plant, for municipal supply, made upstream from station (at Represa de San Juan). Flow is regulated by storage and release of water at Lago de Cidra (capacity 5,220 acre-ft), 10.5 mi (16.9 km) upstream. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 7.6 5.6 6.0 7.0 5.7 e7.8 11 7.9 5.9 32 10 2 10 7.5 6.5 7.2 6.6 5.7 7.8 10 7.8 6.1 114 12 3 9.8 7.4 6.3 7.0 6.8 5.7 8.7 9.8 8.9 5.8 38 12 4 12 7.3 12 5.9 91 5.6 7.5 9.9 8.3 6.8 23 8.5 5 10 7.1 7.4 5.8 53 5.6 9.7 9.8 8.0 7.2 22 6.7 6 10 7.1 6.1 6.0 e12 5.5 8.1 10 7.7 7.3 25 6.0 7 9.6 6.9 6.0 5.6 e7.5 e5.3 e7.2 12 8.3 6.8 36 9.1 8 14 6.6 10 5.2 e6.8 e5.2 e6.7 14 9.3 9.7 23 9.6 9 12 6.9 7.8 5.2 e6.3 e5.2 e6.5 12 7.7 7.5 21 6.1 10 13 7.0 6.6 5.2 e6.1 e5.1 e6.3 9.3 7.4 6.2 19 5.7 11 10 6.6 6.7 4.9 e6.0 e5.1 e6.1 8.7 7.3 6.0 23 6.7 12 9.6 7.6 6.9 5.1 e5.9 e5.3 e6.0 8.6 7.1 5.7 19 5.8 13 9.3 8.3 7.3 5.7 e7.0 e5.4 e8.5 8.2 7.1 e20 37 7.6 14 9.7 6.8 6.9 5.0 e6.5 e5.4 e6.0 10 7.1 e15 18 6.6 15 9.3 6.6 6.3 4.9 e6.1 e5.3 e5.2 9.2 9.9 e13 14 5.2 16 9.2 6.7 6.0 4.9 e7.2 e5.2 5.2 7.7 8.1 21 10 5.0 17 8.3 6.8 5.8 4.8 e7.1 e5.1 194 7.5 7.7 19 8.9 4.8 18 8.9 7.2 5.9 4.8 e6.5 e5.2 261 8.8 7.5 11 61 4.7 19 10 9.7 6.0 5.0 e6.3 e5.2 150 9.1 9.4 9.3 16 4.8 20 12 6.7 6.4 5.1 e6.1 e5.1 72 90 7.8 8.7 9.5 5.3 21 9.9 6.6 6.4 4.9 e5.9 e5.1 183 198 7.3 9.3 152 43 22 8.7 6.3 7.3 4.9 e5.9 e5.2 188 83 7.0 13 50 30 23 9.6 6.4 9.2 5.3 e5.8 e5.2 884 35 6.6 21 20 12 24 9.8 6.2 6.9 12 e5.7 e5.3 524 16 6.5 12 13 9.0 25 11 6.1 6.8 113 e8.0 e5.2 121 11 6.3 12 18 8.1 26 12 6.0 6.9 87 e6.2 e50 43 9.4 6.1 12 47 8.3 27 8.9 5.8 6.3 12 e6.0 87 25 9.0 6.0 25 13 7.9 28 8.2 5.8 6.4 8.6 5.7 19 18 8.7 6.0 21 16 7.5 29 8.0 5.7 5.9 9.8 18 12 8.5 5.8 19 102 7.9 30 7.9 5.6 5.7 8.3 e11 11 8.5 5.8 13 26 8.8 31 8.3 6.0 8.1 e9.1 7.8 24 13 TOTAL 310.0 204.9 212.3 383.2 317.0 327.0 2,799.3 670.5 223.7 379.3 1,039.4 284.7 MEAN 10.0 6.83 6.85 12.4 11.3 10.5 93.3 21.6 7.46 12.2 33.5 9.49 MAX 14 9.7 12 113 91 87 884 198 9.9 25 152 43 MIN 7.9 5.6 5.6 4.8 5.7 5.1 5.2 7.5 5.8 5.7 8.9 4.7 AC-FT 615 406 421 760 629 649 5,550 1,330 444 752 2,060 565 CFSM 0.24 0.16 0.16 0.30 0.27 0.25 2.23 0.52 0.18 0.29 0.80 0.23 IN. 0.28 0.18 0.19 0.34 0.28 0.29 2.49 0.60 0.20 0.34 0.93 0.25 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 2003, BY WATER YEAR (WY) MEAN 38.0 59.7 53.6 35.9 22.7 16.9 26.0 33.8 19.0 22.1 42.1 59.3 MAX 129 232 263 159 75.3 52.9 93.3 131 60.8 79.2 137 360 (WY) (1991) (2000) (1966) (1969) (1989) (1990) (2003) (1966) (1970) (1999) (1970) (1996) MIN 4.30 6.83 3.45 5.30 4.75 3.58 5.36 4.85 3.68 4.01 7.47 6.02 (WY) (1969) (2003) (1998) (1968) (1965) (1965) (1965) (1994) (1994) (1994) (1994) (1967) 243 RIO DE BAYAMON BASIN 50047850 RIO DE BAYAMON NR BAYAMON, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1964 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 8,323.2 ANNUAL MEAN 22.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 388 LOWEST DAILY MEAN 5.6 ANNUAL SEVEN-DAY MINIMUM 5.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 16,510 ANNUAL RUNOFF (CFSM) 0.546 ANNUAL RUNOFF (INCHES) 7.41 10 PERCENT EXCEEDS 45 50 PERCENT EXCEEDS 12 90 PERCENT EXCEEDS 6.8 7,151.3 19.6 35.8 69.5 1999 10.9 1994 Apr 20 884 Apr 23 8,640 Sep 10, 1996 Nov 30 4.7 Sep 18 2.2 Apr 19, 1965 Nov 25 4.9 Jan 15 2.4 Apr 14, 1965 4,470 Apr 23 65,000 Sep 10, 1996 11.06 Apr 23 29.07 Sep 10, 1996 14,180 25,930 0.469 0.856 6.36 11.63 24 61 7.7 13 5.3 5.4 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 244 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q22'32", long 66q07'59", at bridge on Highway 833, 0.2 mi (0.3 km) upstream from Río de Bayamón, and 2.3 mi (3.7 km) southeast of Bayamón Plaza. DRAINAGE AREA.--73.2 mi2 (189.6 km2). PERIOD OF RECORD.--Water years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- wat unf solved water, conduc- ness, Magnes- Potas- lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp- water, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, Date Time NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) OCT 28... 1230 30 4.9 64 6.9 444 28.7 170 46.5 12.3 2.78 .8 25.0 JAN 28... 1355 4.8 6.0 75 7.5 494 26.9 180 50.2 12.9 3.42 .9 27.0 APR 01... 1238 3.9 6.4 -- 7.7 495 29.0 180 51.7 12.8 3.08 .9 27.7 JUN 04... 1245 5.8 7.0 -- 7.7 472 28.1 -- -- -- -- -- -­ SEP 22... 1315 29 6.8 -- 7.5 401 29.2 150 40.4 11.3 3.09 .7 18.5 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate Nitrite end pt, ide, ide, Silica, Sulfate Sulfide sum of deg. C, water, water, water water water, field, water, water, water, water, water consti- sus- unfltrd unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents pended, mg/L mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L mg/L as N as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (00530) (00625) (00610) (00620) (00630) (00615) OCT 28... 166 28.9 <.2 30.5 14.6 -- 260 22 .80 .36 .61 .700 .09 JAN 28... 169 34.9 .15 26.6 25.6 <.0 282 <10 .70 .36 1.03 1.10 .07 APR 01... 172 33.0 .15 30.0 19.5 <.1 281 <10 .40 .08 .67 .700 .03 JUN 04... 166 -- -- -- -- -- -- <10 -- -- -- -- -­ SEP 22... 158 25.3 <.2 23.7 18.6 -- 236 19 .40 .10 .95 .980 .03 Total Fecal Fecal Organic Total nitro- COD, coli- strep- nitro- Phos- nitro- gen, high form, tococci gen, phorus, gen, water, level, M-FC KF water, water, water, unfltrd water, 0.7u MF MF, unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ Date mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL (00605) (00665) (00600) (71887) (00340) (31625) (31673) Total Chrom- coli- Barium, Boron, ium, form, water, water, water, M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd immed, water recover recover water, recover col/ unfltrd -able, -able, unfltrd -able, 100 mL ug/L ug/L ug/L ug/L ug/L (31501) (01002) (01007) (01022) (01027) (01034) OCT 28... .44 .24 1.5 6.6 20 E800 200 -- -- -- -- -- -­ JAN 28... .34 .20 1.8 8.0 E10 1,700 -- 27,000 E2 108 53 <.2 <.8 APR 01... .32 .18 1.1 4.9 <10 320 -- 4,100 <2 94.9 50 <.2 <.8 JUN 04... -- -- -- -- <10 2,900 -- -- -- -- -- -- -­ SEP 22... .30 .14 1.4 6.1 20 6,000 -- E120,000 -- -- -- -- -­ 245 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 28... -- -- -- -- -- -- -- -- -- -- -- JAN 28... <10 <.01 230 <1 135 <.02 <3 <.3 <25 <.10 <16 APR 01... <10 <.01 200 <1 169 <.02 <3 <.3 <25 <.10 <16 JUN 04... -- -- -- -- -- -- -- -- -- -- -- SEP 22... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 246 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q24'29", long 66q09'04", at bridge on Highway 890, 1.0 mi (1.6 km) downstream from bridge on Highway 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 mi2 (186.2 km2). PERIOD OF RECORD.--Water years 1974 to current year. REMARKS.--Prior to 1979 sampling site was 0.8 mile (1.3 km) downstream but was changed because of flood channel construction. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 28... 0955 38 120 6.2 77 7.1 423 26.9 160 44.1 12.9 2.38 .8 JAN 28... 1130 18 17 6.1 73 7.4 431 24.4 160 43.4 13.0 2.83 .8 APR 01... 1100 -- 13 5.5 -- 7.5 450 27.0 170 45.7 13.6 2.60 .8 JUN 04... 1430 -- 13 8.1 -- 7.8 462 29.8 -- -- -- -- -­ SEP 22... 1520 86 170 7.0 -- 7.5 310 29.5 120 29.8 10.4 2.82 .6 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 28... 22.6 161 27.6 <.2 28.7 13.3 -- 248 -- 134 .80 .13 .58 JAN 28... 23.4 150 27.9 .13 25.7 20.6 <.0 247 12.3 21 .50 .22 1.04 APR 01... 22.6 161 28.1 .13 26.9 17.3 <.1 253 -- 13 .30 .12 .44 JUN 04... -- 165 -- -- -- -- -- -- -- 17 -- -- -- SEP 22... 13.8 110 18.8 <.2 21.3 12.3 -- 175 40.5 52 .70 .09 .76 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 28... .660 .08 .67 .28 1.5 6.5 <10 2,100 E1,820 -- -- -- -­ JAN 28... 1.10 .06 .28 .11 1.6 7.1 E10 2,100 -- 63,000 E1 74.1 37 APR 01... .470 .03 .18 .08 .77 3.4 <10 2,900 -- E17,000 <2 68.8 38 JUN 04... -- -- -- -- -- -- <10 E1,500 -- -- -- -- -­ SEP 22... .800 .04 .61 .17 1.5 6.6 <10 E18,000 -- E140,000 -- -- -­ 247 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 28... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 28... <.2 E.6 <10 <.01 700 M 159 <.02 <3 <.3 <25 <.10 <16 APR 01... <.2 E.5 <10 <.01 560 M 256 <.02 <3 <.3 <25 <.10 <16 JUN 04... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 22... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 01... 1100 <.01 E.02 <.01 <.01 <.02 <.1 <.01 E.01 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 01... <.01 <.01 <.009 <.01 <.014 <.10 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 01... <.1 <.02 <.02 <1 <.02 < -- Less than E -- Estimated value --- --- --- --- --- --- --- --- --- --- --- --- --- --- 248 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR LOCATION.--Lat 18q20'40", long 66q03'03", Hydrologic Unit 21010005, at Lago Las Curias Dam on Río Piedras, 4.15 mi (6.67 km) south of University of Puerto Rico Tower, 1.6 mi (2.57 km) northwest from Escuela José F. Díaz and 0.8 mi (1.28 km) north of Escuela Cupey Alto. DRAINAGE AREA.--0.97 mi2 (2.51 km2). PERIOD OF RECORD.--April 1997 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Las Curias was completed in 1946. The reservoir has a capacity of 1,135 acre-ft (1.40 hm 3) at spillway crest elevation 315.78 ft (96.25 m) for water supply. The dam is earthfill and has a crest elevation of 327.3 ft (99.75 m). Masonry parapet walls continous from abutment on each side of the 25 ft (7.62 m) wide crest. The dam is about 82.0 ft (25.0 m) high and 984.2 ft (300.0 m) long. The morning-glory inlet conduit spillway in located along the left abutment of the dam and has an uncontrolled capacity of about 5,000 ft3/s (141.6 m3/s) at reservoir elevation 321.5 ft (98.0 m). This dam is operated by Puerto Rico Aqueduct and Sewer Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 317.16 ft (96.67 m), August 21, 2003; minimum elevation, 313.04 ft (95.41 m), October 5, 1998. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 317.16 ft (96.67 m), August 21; minimum elevation, 315.47 ft (96.16 m), March 26. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 284.7 154 298.2 462 307.1 770 Elevation Contents 313.0 677 314.3 1,078 317.5 1,232 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 315.79 315.82 315.73 315.78 315.82 315.71 315.59 315.76 315.81 315.67 315.79 315.85 2 315.78 A 315.72 315.77 315.82 315.71 315.58 315.78 315.80 315.71 315.81 315.86 3 315.78 A 315.71 315.77 315.81 315.70 315.59 315.77 315.80 315.73 315.79 315.87 4 315.81 A 315.82 315.76 315.90 315.70 315.58 315.77 315.79 315.72 315.78 315.85 5 315.80 A 315.81 315.76 315.85 315.68 315.61 315.80 315.78 315.74 315.76 315.83 6 315.79 A 315.80 315.75 315.82 315.67 315.61 315.79 315.80 315.74 315.83 315.82 7 315.78 A 315.79 315.74 315.81 315.66 315.60 315.79 315.81 315.73 315.84 315.82 8 315.79 A 315.83 315.74 315.80 315.66 315.60 315.78 315.80 315.75 315.81 315.82 9 315.81 A 315.81 315.73 315.80 315.65 315.58 315.76 315.78 315.73 315.79 315.82 10 315.80 A 315.80 315.73 315.81 315.64 315.56 315.76 315.77 315.72 315.78 315.82 11 315.78 A 315.79 315.72 315.81 315.62 315.78 315.75 315.78 315.70 315.83 315.84 12 315.78 A 315.78 315.70 315.80 315.61 315.77 315.74 315.77 315.69 315.80 315.83 13 315.79 A 315.81 315.70 315.80 315.60 315.76 315.73 315.76 315.83 315.78 315.83 14 315.82 A 315.80 315.68 315.79 315.59 315.74 315.75 315.78 315.80 315.77 315.82 15 315.82 A 315.79 315.68 315.79 315.58 315.73 315.75 315.86 315.79 315.77 315.80 16 315.79 A 315.79 315.67 315.80 315.56 315.71 315.74 315.82 315.80 315.77 315.80 17 315.78 A 315.78 315.65 315.79 315.55 315.87 315.73 315.81 315.78 315.76 315.79 18 315.78 A 315.78 315.66 315.78 315.53 A 315.75 315.81 315.77 315.80 315.78 19 315.82 A 315.79 315.65 315.78 315.55 A 315.74 315.83 315.76 315.79 315.78 20 315.81 A 315.79 315.65 315.79 315.55 A 315.82 315.80 315.74 315.78 315.79 21 315.82 A 315.81 315.65 315.78 315.53 A 315.89 315.80 315.74 316.07 A 22 315.81 A 315.84 315.63 315.76 315.52 A 315.82 315.78 315.75 315.87 315.83 23 315.84 A 315.82 315.64 315.74 315.51 A 315.80 315.77 315.73 315.86 A 24 315.83 A 315.81 315.93 315.73 315.50 A 315.77 315.76 315.71 315.86 A 25 315.81 A 315.83 316.03 315.73 315.48 A 315.76 315.74 315.70 315.89 A 26 315.82 A 315.81 315.83 315.74 315.56 A 315.75 315.73 315.76 315.86 A 27 315.81 315.76 315.80 315.81 315.73 315.56 A 315.74 315.71 315.77 315.83 A 28 315.80 315.75 315.80 315.81 315.72 315.54 A 315.74 315.71 315.81 315.88 A 29 315.80 315.75 315.79 315.81 315.61 A 315.73 315.69 315.79 315.85 A 30 315.79 315.74 315.79 315.81 315.61 A 315.71 315.67 315.77 315.92 A 31 315.83 315.78 315.85 A 315.70 315.80 315.96 MAX 315.84 315.84 316.03 315.90 315.89 315.86 315.83 316.07 MIN 315.78 315.71 315.63 315.72 315.70 315.67 315.67 315.76 A No gage-height record 249 RIO PUERTO NUEVO BASIN 50048680 LAGO LAS CURIAS AT DAMSITE NEAR RIO PIEDRAS, PR—Continued O N D J F M A M J J A S 315.40 315.50 315.60 315.70 315.80 315.90 316.00 316.10 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 250 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR LOCATION.--Lat 18q20'44", long 66q03'15", Hydrologic Unit 21010005, at 0.2 miles (0.3 km) from Lago Las Curias Dam on Río Piedras, 4.1 mi (6.6 km) south of University of Puerto Rico Tower, 2.6 mi (4.1 km) northwest from Lago Loíza spillway crest and 0.8 mi (1.4 km) north of Escuela Cupey Alto. DRAINAGE AREA.--1.08 mi2 (2.79 km2). PERIOD OF RECORD.--August 1997 to current year. GAGE.--Water stage recorder. Elevation of gage is 262.47 ft (80.0 km), from topographic map. REMARKS.--Records poor. Flow completly regulated by Lago Las Curias Dam, 0.20 mi (0.32 km) from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 0.31 0.95 0.22 0.32 1.4 0.21 0.15 0.52 0.46 0.39 e0.80 8.5 2 0.30 0.76 0.25 0.34 0.67 0.24 0.14 0.39 1.0 0.51 e0.70 2.2 3 0.28 0.57 0.26 0.48 0.54 0.22 0.15 0.40 0.74 0.51 e0.60 1.1 4 0.68 0.47 0.72 0.33 11 0.25 0.13 0.37 0.51 0.58 e0.50 1.9 5 0.74 0.38 0.76 0.24 5.9 0.26 0.13 0.45 0.31 0.58 e2.5 1.8 6 0.33 0.31 0.33 0.34 1.9 0.27 0.12 0.64 0.53 0.59 e3.0 1.5 7 0.24 0.28 0.34 0.28 0.86 0.25 0.11 0.58 0.65 0.77 e3.5 2.3 8 0.30 0.31 0.82 0.24 0.54 0.27 0.11 0.73 0.62 0.64 e3.0 1.6 9 0.61 0.35 0.93 0.26 0.46 0.25 0.11 0.58 0.49 0.63 e2.0 1.5 10 0.78 0.34 0.44 0.31 0.59 0.25 0.11 0.58 0.44 0.66 e1.5 1.4 11 0.53 0.32 0.34 0.28 0.49 0.24 0.20 0.58 0.40 0.57 e2.0 2.8 12 0.30 0.53 0.37 0.27 0.69 0.24 0.33 0.59 0.46 0.55 e2.5 1.8 13 0.25 0.57 0.58 0.26 0.41 0.23 0.25 0.61 0.43 3.3 e3.0 1.3 14 0.46 0.56 0.42 0.26 0.39 0.23 0.27 0.59 0.52 1.9 e3.0 1.7 15 0.62 0.35 0.35 0.25 0.50 0.23 0.28 0.60 7.2 0.77 e2.5 2.2 16 0.79 0.31 0.32 0.26 0.46 0.24 0.36 0.64 2.3 0.79 e2.0 1.6 17 0.53 0.33 0.23 0.27 0.68 0.24 5.8 0.61 0.61 0.88 e2.0 1.5 18 0.35 1.3 0.22 0.28 0.40 0.23 12 0.66 0.66 0.59 e2.8 1.1 19 0.40 1.4 0.23 0.27 0.57 0.26 4.5 0.66 1.2 0.62 e4.0 1.1 20 0.98 0.39 0.41 0.27 0.46 0.24 4.2 1.1 1.0 0.61 e5.0 1.1 21 0.58 0.48 0.59 0.25 0.52 0.23 11 6.4 0.68 0.62 e7.0 16 22 0.53 0.45 2.4 0.26 1.0 0.21 6.2 2.7 0.74 e0.78 e13 5.3 23 1.8 0.28 1.2 0.27 0.58 0.20 5.8 0.71 0.48 e0.72 6.7 1.9 24 1.5 0.25 0.62 4.1 0.24 0.19 4.2 0.71 0.42 e0.66 4.0 1.4 25 1.1 0.25 0.71 17 0.23 0.18 1.1 0.41 0.42 e0.58 7.5 1.1 26 0.90 0.28 0.71 11 0.24 0.21 1.4 0.28 0.32 e0.68 8.6 1.1 27 0.75 0.30 0.34 1.3 0.27 0.19 0.67 0.25 0.38 e3.5 3.1 0.84 28 0.55 0.22 0.25 0.41 0.24 0.15 0.50 0.31 0.39 e2.5 5.4 0.74 29 0.43 0.22 0.29 0.49 0.18 0.38 0.40 0.43 e2.1 4.7 1.4 30 0.40 0.23 0.30 0.56 0.15 0.35 0.40 0.39 e2.0 17 2.1 31 1.3 0.32 3.9 0.15 0.31 e1.5 24 TOTAL 19.62 13.74 16.27 45.35 32.23 6.89 61.05 24.76 25.18 32.08 147.90 71.88 MEAN 0.63 0.46 0.52 1.46 1.15 0.22 2.04 0.80 0.84 1.03 4.77 2.40 MAX 1.8 1.4 2.4 17 11 0.27 12 6.4 7.2 3.5 24 16 MIN 0.24 0.22 0.22 0.24 0.23 0.15 0.11 0.25 0.31 0.39 0.50 0.74 AC-FT 39 27 32 90 64 14 121 49 50 64 293 143 CFSM 0.59 0.42 0.49 1.35 1.07 0.21 1.88 0.74 0.78 0.96 4.42 2.22 IN. 0.68 0.47 0.56 1.56 1.11 0.24 2.10 0.85 0.87 1.10 5.09 2.48 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2003, BY WATER YEAR (WY) MEAN 3.71 5.35 4.12 2.21 1.61 0.82 1.76 1.52 1.33 1.39 3.28 3.29 MAX 5.90 11.4 10.2 4.63 2.51 2.52 4.11 4.03 3.64 3.51 7.06 12.2 (WY) (1999) (2000) (1999) (1999) (1999) (1999) (2002) (2002) (1999) (1999) (1998) (1998) MIN 0.63 0.46 0.51 0.83 1.15 0.22 0.63 0.29 0.50 0.33 0.73 0.70 (WY) (2003) (2003) (1998) (1998) (2003) (2003) (2000) (1998) (2002) (2000) (2002) (2001) 251 RIO PUERTO NUEVO BASIN 50048690 QUEBRADA LAS CURIAS BELOW LAS CURIAS DAM, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1997 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 508.87 ANNUAL MEAN 1.39 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 29 LOWEST DAILY MEAN 0.18 ANNUAL SEVEN-DAY MINIMUM 0.22 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 1,010 ANNUAL RUNOFF (CFSM) 1.29 ANNUAL RUNOFF (INCHES) 17.53 10 PERCENT EXCEEDS 2.4 50 PERCENT EXCEEDS 0.44 90 PERCENT EXCEEDS 0.26 496.95 1.36 2.57 3.95 1999 1.36 2003 May 10 24 Aug 31 139 Nov 8, 2001 Sep 8 0.11 Apr 7 0.11 Apr 7, 2003 Sep 4 0.12 Apr 4 0.12 Apr 4, 2003 136 Aug 31 431 Aug 11, 1998 9.68 Aug 31 11.70 Aug 11, 1998 986 1,860 1.26 2.38 17.12 32.29 3.0 5.8 0.54 0.69 0.24 0.27 e Estimated 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 252 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR LOCATION.--Lat 18q21'51", long 66q03'56", Hydrologic Unit 21010005, on right bank, in the Riveras of Señorial Housing area, 0.6 mi (1.0 km) west of Highway 176 and 2.7 mi (4.3 km) southwest of Río Piedras Plaza. DRAINAGE AREA.--7.49 mi2 (19.4 km2). PERIOD OF RECORDS.--March 1988 to current year. WATER-DISCHARGE RECORDS GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 98.4 ft (30.0 m), from topographic map. REMARKS.--Records poor. Low flow is affected by discharges from water treatment plant of PRASA and others dispersed pollution po ints directly to the river. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10 8.5 4.8 6.0 7.0 4.8 e3.9 4.5 52 5.6 6.6 42 2 6.1 6.0 5.5 6.2 5.6 5.6 6.7 4.5 7.3 17 22 36 3 7.0 5.8 5.0 6.4 5.6 5.3 9.7 4.5 8.0 6.9 5.2 16 4 15 6.3 57 5.8 105 4.7 5.1 5.4 6.0 4.9 6.6 14 5 6.8 5.6 7.1 5.1 43 5.8 7.0 21 7.9 7.5 5.7 12 6 6.8 5.3 5.6 5.0 11 4.6 4.4 7.2 9.4 6.4 43 10 7 6.1 5.5 5.5 4.9 7.4 4.5 4.3 16 7.2 6.0 64 13 8 18 6.0 21 7.6 6.3 4.7 5.3 8.5 7.1 10 10 14 9 12 6.6 6.6 6.3 6.3 4.5 4.2 5.8 7.2 6.0 6.7 10 10 12 9.0 6.2 4.9 7.9 4.4 4.1 5.4 5.2 4.8 5.6 9.9 11 6.3 6.7 5.8 4.8 6.6 4.3 49 4.5 15 3.9 27 19 12 5.7 16 5.6 5.0 7.9 4.3 6.6 4.3 4.9 4.0 7.2 11 13 6.9 6.3 12 5.0 5.8 4.3 6.2 4.2 4.7 70 6.3 10 14 17 5.7 5.8 5.0 7.6 4.3 4.8 7.8 8.0 8.4 6.8 9.4 15 11 5.5 6.1 5.9 6.3 5.0 5.8 5.3 117 5.6 5.1 8.9 16 6.6 12 5.5 5.1 6.0 4.7 5.2 6.6 10 18 7.8 9.2 17 5.5 7.2 5.6 7.8 7.2 4.6 89 4.3 6.7 5.4 4.6 8.4 18 5.1 20 5.8 10 5.5 4.0 130 8.6 17 4.7 35 7.8 19 9.1 12 6.9 6.4 5.5 7.9 25 4.5 19 4.8 6.3 7.9 20 8.4 6.2 8.3 8.8 7.5 4.2 37 49 5.9 4.5 6.6 14 21 9.3 5.5 21 7.5 6.9 3.9 105 155 19 5.2 563 172 22 7.6 5.3 28 5.5 6.4 3.9 45 22 5.8 12 131 22 23 18 5.1 8.7 7.6 5.1 4.5 113 7.0 5.0 4.7 87 20 24 9.9 5.1 6.1 86 5.1 4.4 28 5.6 4.7 4.4 37 9.6 25 7.0 5.7 16 165 5.3 4.4 11 5.2 4.4 4.6 88 7.8 26 12 6.7 6.2 79 5.1 49 8.2 4.9 4.3 12 65 8.2 27 6.1 5.8 5.3 12 5.0 9.9 5.9 4.8 4.5 18 28 7.2 28 5.5 5.4 5.1 6.6 5.8 6.6 5.1 4.8 5.8 21 57 6.8 29 5.2 7.3 5.6 12 70 4.8 4.7 4.5 6.7 41 8.9 30 5.3 4.7 9.1 7.9 9.2 4.8 4.8 4.3 5.3 124 10 31 14 6.4 25 e6.0 4.3 20 147 TOTAL 281.3 218.8 309.2 536.1 315.7 268.3 744.1 405.0 387.8 318.3 1,656.1 555.0 MEAN 9.07 7.29 9.97 17.3 11.3 8.65 24.8 13.1 12.9 10.3 53.4 18.5 MAX 18 20 57 165 105 70 130 155 117 70 563 172 MIN 5.1 4.7 4.8 4.8 5.0 3.9 3.9 4.2 4.3 3.9 4.6 6.8 AC-FT 558 434 613 1,060 626 532 1,480 803 769 631 3,280 1,100 CFSM 1.21 0.97 1.33 2.31 1.51 1.16 3.31 1.74 1.73 1.37 7.13 2.47 IN. 1.40 1.09 1.54 2.66 1.57 1.33 3.70 2.01 1.93 1.58 8.23 2.76 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 2003, BY WATER YEAR (WY) MEAN 26.6 29.0 21.5 16.5 13.1 11.0 14.1 15.4 12.9 14.8 24.3 29.0 MAX 57.3 79.5 66.3 29.1 23.6 20.1 34.4 47.2 25.5 38.0 66.9 80.8 (WY) (1991) (2000) (1999) (2000) (1991) (1999) (2002) (1992) (1999) (1993) (1992) (1998) MIN 8.48 5.93 4.32 6.95 2.70 1.85 2.83 3.38 2.66 4.22 6.60 6.90 (WY) (1992) (1996) (1996) (1995) (1996) (1996) (1995) (1994) (1994) (1994) (1990) (1991) 253 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SEÑORIAL, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1988 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 5,523.4 ANNUAL MEAN 15.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 212 LOWEST DAILY MEAN 4.7 ANNUAL SEVEN-DAY MINIMUM 5.5 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 10,960 ANNUAL RUNOFF (CFSM) 2.02 ANNUAL RUNOFF (INCHES) 27.43 10 PERCENT EXCEEDS 26 50 PERCENT EXCEEDS 8.4 90 PERCENT EXCEEDS 5.5 5,995.7 16.4 18.9 28.6 1999 7.76 1994 May 10 563 Aug 21 1,650 Sep 10, 1996 Nov 30 3.9 Mar 21 0.84 Aug 13, 1995 Nov 27 4.4 Mar 8 0.97 Jun 30, 1996 5,140 Aug 21 5,390 Sep 10, 1996 15.20 Aug 21 15.46 Sep 10, 1996 11,890 13,720 2.19 2.53 29.78 34.35 31 39 6.6 8.3 4.5 3.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 254 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--March 1988 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: April 1988 to September 1998 and from October 2001 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler and automatic sediment sampler since 1988. REMARKS.-- Sediment samples were collected by local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 24,600 mg/L September 18, 1989; Minimum daily mean, 2 mg/L several years. SEDIMENT LOADS: Maximum daily mean, e165,000 tons (e150,000 tonnes) September 22, 1998; Minimum daily mean, 0.02 ton (0.02 tonne ) June 9, 1994. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 7,870 mg/L August 21, 2003; Minimum daily mean, 2 mg/L February 7-9, 2003. SEDIMENT LOADS: Maximum daily mean, 34,700 tons (31,480 tonnes) August 21, 2003; Minimum daily mean, 0.03 ton (0.03 tonne) Februry 8, 9, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 10 77 4.7 8.5 22 0.86 4.8 9 0.12 2 6.1 17 0.28 6.0 7 0.11 5.5 9 0.13 3 7.0 27 0.58 5.8 7 0.11 5.0 9 0.12 4 15 155 19 6.3 7 0.11 57 2,900 939 5 6.8 18 0.34 5.6 7 0.10 7.1 29 0.57 6 6.8 29 0.60 5.3 6 0.09 5.6 18 0.27 7 6.1 13 0.22 5.5 6 0.09 5.5 13 0.20 8 18 120 15 6.0 11 0.31 21 481 84 9 12 58 4.3 6.6 21 0.64 6.6 172 3.1 10 12 61 5.6 9.0 35 1.8 6.2 127 2.1 11 6.3 9 0.16 6.7 18 0.64 5.8 82 1.3 12 5.7 9 0.13 16 101 13 5.6 37 0.57 13 6.9 8 0.14 6.3 15 0.26 12 78 6.9 14 17 141 24 5.7 12 0.18 5.8 10 0.15 15 11 73 5.1 5.5 11 0.16 6.1 9 0.15 16 6.6 25 0.44 12 75 9.0 5.5 9 0.14 17 5.5 19 0.29 7.2 13 0.30 5.6 9 0.13 18 5.1 14 0.20 20 123 22 5.8 8 0.13 19 9.1 44 4.0 12 37 1.9 6.9 18 0.76 20 8.4 64 1.5 6.2 10 0.17 8.3 25 0.75 21 9.3 52 2.3 5.5 10 0.15 21 485 153 22 7.6 33 0.69 5.3 10 0.14 28 494 124 23 18 219 45 5.1 10 0.14 8.7 25 0.67 24 9.9 43 2.2 5.1 10 0.13 6.1 9 0.16 25 7.0 32 0.61 5.7 10 0.15 16 373 86 26 12 93 7.4 6.7 10 0.17 6.2 13 0.23 27 6.1 14 0.24 5.8 9 0.15 5.3 9 0.13 28 5.5 7 0.10 5.4 9 0.14 5.1 9 0.12 29 5.2 6 0.09 7.3 9 0.18 5.6 8 0.12 30 5.3 6 0.09 4.7 9 0.12 9.1 24 1.6 31 14 110 21 6.4 12 0.22 TOTAL 281.3 166.30 218.8 53.30 309.2 1,406.84 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO PUERTO NUEVO BASIN 255 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 6.0 9 0.15 7.0 7 0.13 4.8 19 0.25 2 6.2 19 0.43 5.6 5 0.07 5.6 20 0.31 3 6.4 9 0.16 5.6 3 0.05 5.3 21 0.30 4 5.8 9 0.14 105 1,710 1,140 4.7 22 0.27 5 5.1 9 0.12 43 279 69 5.8 22 0.35 6 5.0 9 0.12 11 3 0.10 4.6 23 0.29 7 4.9 8 0.11 7.4 2 0.04 4.5 24 0.29 8 7.6 10 0.32 6.3 2 0.03 4.7 25 0.31 9 6.3 12 0.23 6.3 2 0.03 4.5 25 0.31 10 4.9 10 0.13 7.9 6 0.18 4.4 26 0.31 11 4.8 10 0.13 6.6 5 0.09 4.3 27 0.31 12 5.0 10 0.13 7.9 6 0.13 4.3 28 0.32 13 5.0 10 0.13 5.8 7 0.11 4.3 28 0.33 14 5.0 10 0.13 7.6 8 0.17 4.3 29 0.34 15 5.9 9 0.15 6.3 9 0.16 5.0 27 0.37 16 5.1 9 0.13 6.0 10 0.17 4.7 25 0.33 17 7.8 9 0.19 7.2 12 0.23 4.6 24 0.30 18 10 9 0.25 5.5 13 0.19 4.0 22 0.24 19 6.4 9 0.16 5.5 14 0.20 7.9 48 3.8 20 8.8 19 0.55 7.5 24 0.85 4.2 9 0.10 21 7.5 7 0.14 6.9 14 0.25 3.9 7 0.07 22 5.5 7 0.11 6.4 14 0.25 3.9 7 0.07 23 7.6 7 0.15 5.1 15 0.21 4.5 7 0.08 24 86 409 471 5.1 16 0.22 4.4 6 0.08 25 165 989 883 5.3 17 0.24 4.4 6 0.07 26 79 417 184 5.1 17 0.24 49 791 825 27 12 33 1.1 5.0 18 0.24 9.9 14 0.39 28 6.6 6 0.10 5.8 19 0.29 6.6 11 0.19 29 12 41 4.2 70 1,250 1,110 30 7.9 5 0.11 9.2 14 0.41 31 25 43 9.3 e6.0 e8 e0.12 TOTAL 536.1 1,557.07 315.7 1,213.87 268.3 1,945.91 APRIL MAY JUNE 1 e3.9 e8 e0.08 4.5 9 0.11 52 1,020 839 2 6.7 7 0.13 4.5 9 0.11 7.3 9 0.18 3 9.7 20 1.2 4.5 8 0.10 8.0 28 1.2 4 5.1 7 0.10 5.4 8 0.11 6.0 9 0.15 5 7.0 7 0.13 21 359 110 7.9 8 0.17 6 4.4 7 0.08 7.2 7 0.14 9.4 21 1.6 7 4.3 7 0.08 16 154 21 7.2 8 0.16 8 5.3 6 0.09 8.5 35 2.2 7.1 8 0.15 9 4.2 6 0.07 5.8 7 0.11 7.2 8 0.16 10 4.1 6 0.07 5.4 7 0.10 5.2 8 0.11 11 49 654 296 4.5 7 0.09 15 141 32 12 6.6 10 0.17 4.3 7 0.08 4.9 10 0.13 13 6.2 9 0.16 4.2 7 0.07 4.7 9 0.12 14 4.8 9 0.12 7.8 67 3.3 8.0 9 0.20 15 5.8 9 0.14 5.3 7 0.10 117 2,310 2,590 16 5.2 8 0.12 6.6 7 0.12 10 33 1.3 17 89 1,890 2,150 4.3 6 0.07 6.7 9 0.16 18 130 4,170 4,520 8.6 62 4.9 17 223 52 19 25 288 33 4.5 7 0.08 19 504 175 20 37 998 415 49 1,020 604 5.9 13 0.22 21 105 1,740 1,010 155 2,520 5,200 19 471 193 22 45 336 59 22 217 29 5.8 10 0.16 23 113 1,810 2,660 7.0 23 0.44 5.0 10 0.13 24 28 179 25 5.6 10 0.14 4.7 10 0.12 25 11 17 0.51 5.2 9 0.13 4.4 9 0.11 26 8.2 12 0.28 4.9 8 0.11 4.3 9 0.11 27 5.9 12 0.19 4.8 8 0.10 4.5 9 0.11 28 5.1 11 0.15 4.8 8 0.10 5.8 19 0.47 29 4.8 11 0.14 4.7 8 0.10 4.5 9 0.11 30 4.8 10 0.13 4.8 8 0.10 4.3 9 0.10 31 4.3 8 0.09 TOTAL 744.1 11,172.14 405.0 5,977.10 387.8 3,888.43 --- --- --- --- --- --- 256 RIO PUERTO NUEVO BASIN 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 5.6 19 0.85 6.6 18 0.33 42 154 23 2 17 377 119 22 378 129 36 265 104 3 6.9 25 0.76 5.2 13 0.18 16 13 0.55 4 4.9 8 0.11 6.6 8 0.14 14 8 0.28 5 7.5 22 0.60 5.7 7 0.12 12 7 0.23 6 6.4 8 0.13 43 906 475 10 6 0.18 7 6.0 7 0.12 64 1,110 1,230 13 12 0.52 8 10 52 3.0 10 15 0.46 14 12 0.63 9 6.0 8 0.14 6.7 10 0.17 10 9 0.25 10 4.8 7 0.09 5.6 9 0.14 9.9 8 0.21 11 3.9 7 0.07 27 724 399 19 29 3.2 12 4.0 7 0.08 7.2 10 0.20 11 10 0.28 13 70 930 657 6.3 9 0.16 10 10 0.27 14 8.4 19 0.43 6.8 9 0.16 9.4 9 0.24 15 5.6 17 0.25 5.1 8 0.12 8.9 9 0.22 16 18 304 73 7.8 16 0.83 9.2 9 0.22 17 5.4 19 0.28 4.6 8 0.09 8.4 9 0.20 18 4.7 18 0.23 35 2,230 952 7.8 8 0.18 19 4.8 17 0.22 6.3 17 0.29 7.9 8 0.17 20 4.5 16 0.19 6.6 13 0.24 14 30 2.1 21 5.2 15 0.20 563 7,870 34,700 172 3,470 6,670 22 12 74 4.6 131 1,170 577 22 53 4.6 23 4.7 16 0.20 87 965 1,060 20 41 6.8 24 4.4 15 0.18 37 111 16 9.6 12 0.32 25 4.6 15 0.18 88 402 188 7.8 10 0.21 26 12 69 6.4 65 97 25 8.2 10 0.21 27 18 241 39 28 19 1.5 7.2 9 0.18 28 21 655 147 57 108 27 6.8 9 0.17 29 6.7 19 0.34 41 71 11 8.9 12 0.32 30 5.3 15 0.22 124 1,130 927 10 10 0.30 31 20 176 40 147 1,830 2,580 TOTAL 318.3 1,094.87 1,656.1 43,301.13 555.0 6,820.04 YEAR 5,995.7 78,597.00 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) DEC 04... 1455 221 79 7,650 4,560 SEP 21... 1500 363 21 25,900 25,400 RIO PUERTO NUEVO BASIN 257 50048770 RIO PIEDRAS AT EL SENORIAL, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) DEC 04... 1300 183 32 41 56 70 77 81 89 94 98 100 8,140 AUG 21... 1230 560 5 6 6 7 9 10 13 20 88 99 64,800 SEP 21... 1630 1,170 18 19 21 25 30 34 50 77 95 98 18,700 Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) DEC 04... 4,020 AUG 21... 97,900 SEP 21... 59,200 258 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR LOCATION.--Lat 18q22'15", long 66q03'40", at bridge on Winston Churchill Avenue in the El Señorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Río Piedras Plaza. DRAINAGE AREA.--8.17 mi2 (20.9 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 04... 1215 5.6 9.4 9.5 121 7.8 427 27.8 160 42.1 13.0 2.10 .9 JAN 27... 1240 13 67 7.6 91 7.6 400 24.2 140 37.6 12.2 3.00 1 MAR 31... 1000 7.9 8.2 7.6 -- 7.8 440 24.1 -- -- -- -- -­ JUN 03... 1300 8.4 17 7.2 -- 7.8 396 28.1 -- -- -- -- -­ SEP 23... 1140 9.5 4.6 6.2 -- 7.6 437 28.4 160 41.8 13.2 3.60 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 04... 25.4 156 32.2 <.17 33.1 14.0 -- 255 -- <10 .70 .03 -­ JAN 27... 26.3 140 33.2 .15 27.0 19.4 .0 243 8.20 58 .70 .13 .96 MAR 31... -- 148 -- -- -- -- <.1 -- -- -- .50 .29 .80 JUN 03... -- 134 -- -- -- -- -- -- -- <10 -- -- -­ SEP 23... 25.0 150 32.8 .2 29.2 17.8 -- 253 6.50 <10 1.7 1.20 .83 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 04... .740 <.01 .67 .10 1.4 6.4 <10 E1,700 E727 -- -- -- -­ JAN 27... .980 .02 .57 .14 1.7 7.4 <10 E12,000 -- E80,000 E1 93.9 45 MAR 31... .830 .03 .21 .13 1.3 5.9 -- E10,000 -- E98,000 -- -- -­ JUN 03... -- -- -- -- -- -- 20 35,000 -- -- -- -- -­ SEP 23... .930 .10 .50 .20 2.6 11.6 10 E95,000 -- 500,000 -- -- -­ 259 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 04... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 27... <.2 1.0 <10 <.01 2,070 M 132 E.01 <3 <.3 <25 <.10 <16 MAR 31... -- -- -- -- -- -- -- -- -- -- -- <.10 <16 JUN 03... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 23... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAR 31... 1000 <.01 E.02 <.01 <.01 <.02 <.1 <.01 E.01 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAR 31... <.01 <.01 <.009 <.01 <.014 <.10 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAR 31... <.1 <.02 <.02 <1 <.02 < -- Less than E -- Estimated value --- --- --- --- --- --- --- 260 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR LOCATION.--Lat 18q24'34", long 66q04'10", Hydrologic Unit 21010005, at bridge on Avenida Piñeiro near Expreso Las Américas (Luis A. Ferré) and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.2 mi2 (39.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June 1970 to December 1987 (discharge measurements only), 1972 to December 1982 (maximum discharge only), January 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 16 ft (5 m), from topographic map. REMARKS.--Records poor. Mean daily discharge affected by sewage discharges (approximately 2.0 ft 3/s (0.06 m3/s)), 20 ft (6 m) upstream from gaging station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 46 e30 e16 38 21 12 e13 14 56 22 32 70 2 37 e20 e18 23 16 13 15 15 39 32 53 70 3 36 e16 e18 16 16 12 44 15 24 20 27 32 4 42 e17 e120 15 e108 12 17 16 19 18 28 34 5 37 e15 e20 14 e220 13 15 25 20 19 28 27 6 38 e16 e16 13 e23 12 12 19 22 27 104 26 7 37 e14 e16 13 19 12 12 24 22 19 66 29 8 65 15 e40 15 17 12 13 19 21 32 34 28 9 106 18 e18 16 21 12 13 57 22 26 30 24 10 51 39 e16 13 24 12 13 17 20 20 27 23 11 31 16 e16 13 18 12 98 15 110 19 56 69 12 34 26 e16 13 18 11 18 15 19 19 31 24 13 28 e16 e28 13 15 10 16 21 19 123 31 27 14 188 e16 e16 13 17 9.8 16 34 21 25 29 22 15 166 e18 e16 13 15 10 21 17 258 24 85 21 16 40 e25 e18 13 16 10 15 16 32 52 28 21 17 32 e18 e18 15 18 9.8 144 17 23 23 25 20 18 28 e36 e16 21 15 9.4 275 19 28 22 60 20 19 30 e20 21 15 15 14 41 13 58 23 27 24 20 49 e17 21 18 17 10 93 72 23 22 31 147 21 34 e16 57 15 17 9.2 272 540 84 24 961 508 22 29 e15 45 12 15 9.6 77 65 20 84 255 42 23 e120 e15 20 14 14 10 415 40 17 23 133 34 24 e45 e15 17 133 19 9.7 53 35 16 23 68 23 25 e30 e16 30 211 16 9.8 27 33 16 24 136 20 26 e26 e20 18 136 14 181 22 32 17 31 100 22 27 e40 e15 16 24 15 20 18 29 17 46 60 19 28 e25 e16 15 18 13 19 17 28 19 37 111 18 29 e20 e25 15 22 425 16 26 17 27 89 27 30 e18 e16 40 56 24 16 26 18 26 428 24 31 e45 22 41 e16 22 56 383 TOTAL 1,553 577 779 1,005 772 961.3 1,837 1,336 1,097 988 3,556 1,495 MEAN 50.1 19.2 25.1 32.4 27.6 31.0 61.2 43.1 36.6 31.9 115 49.8 MAX 188 39 120 211 220 425 415 540 258 123 961 508 MIN 18 14 15 12 13 9.2 12 13 16 18 25 18 AC-FT 3,080 1,140 1,550 1,990 1,530 1,910 3,640 2,650 2,180 1,960 7,050 2,970 CFSM 3.30 1.27 1.65 2.13 1.81 2.04 4.03 2.84 2.41 2.10 7.55 3.28 IN. 3.80 1.41 1.91 2.46 1.89 2.35 4.50 3.27 2.68 2.42 8.70 3.66 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1972 - 2003, BY WATER YEAR (WY) MEAN 68.1 76.4 52.6 43.5 38.9 34.4 51.1 43.8 38.4 44.9 60.5 86.7 MAX 138 235 168 97.4 86.9 78.5 150 97.5 81.9 97.4 115 261 (WY) (1999) (1993) (1993) (1993) (1995) (1972) (1972) (1992) (1995) (1993) (2003) (1996) MIN 16.6 19.2 18.8 12.9 10.8 11.5 13.6 4.12 19.6 12.8 20.2 26.3 (WY) (1992) (2003) (1992) (1973) (1992) (1994) (1995) (1972) (2000) (1994) (1993) (1972) 261 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1972 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 13,999 ANNUAL MEAN 38.4 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 444 LOWEST DAILY MEAN 12 ANNUAL SEVEN-DAY MINIMUM 13 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 27,770 ANNUAL RUNOFF (CFSM) 2.52 ANNUAL RUNOFF (INCHES) 34.26 10 PERCENT EXCEEDS 67 50 PERCENT EXCEEDS 24 90 PERCENT EXCEEDS 16 15,956.3 43.7 52.6 84.0 1993 28.7 1994 Apr 20 961 Aug 21 4,550 Sep 10, 1996 Mar 26 9.2 Mar 21 1.2 Jun 28, 1972 Mar 21 10 Mar 12 1.2 Jul 5, 1972 7,260 Aug 21 10,500 Sep 10, 1996 19.15 Aug 21 22.11 Sep 10, 1996 31,650 38,090 2.88 3.46 39.05 47.00 84 109 21 23 13 11 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 262 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR—Continued WATER-QUALITY RECORDS LOCATION.--Lat 18q24'34", long 66q04'10", at bridge on Avenida Piñero at Expreso Las Americas, and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.4 mi2 (39.9 km2). PERIOD OF RECORD.--Water years 1971 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 05... 1545 15 4.5 4.2 55 7.1 530 29.3 170 47.3 11.5 3.65 1 JAN 27... 1630 23 19 5.6 70 7.5 437 26.5 150 43.4 10.8 3.90 1 MAR 31... 1300 17 7.7 6.2 -- 7.7 488 28.5 -- -- -- -- -­ JUN 03... 1030 19 20 5.3 -- 7.6 325 26.4 -- -- -- -- -­ SEP 23... 1420 24 9.2 5.8 -- 7.5 418 30.1 160 44.3 10.9 3.65 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 05... 31.5 171 41.1 <.17 31.0 14.0 -- 282 11.6 <10 2.8 2.10 .75 JAN 27... 29.1 152 35.0 .15 26.7 18.7 .0 259 16.1 14 2.4 1.40 1.03 MAR 31... -- 162 -- -- -- -- <.1 -- -- -- .90 .48 .93 JUN 03... -- 110 -- -- -- -- -- -- -- <10 -- -- -­ SEP 23... 24.0 147 30.9 <.2 25.7 15.6 -- 243 16.0 11 .70 .35 .83 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 05... .880 .13 .70 .34 3.7 16.3 10 E79,000 8,600 -- -- -- -­ JAN 27... 1.10 .07 1.0 .25 3.5 15.5 E20 E110,000 -- E960,000 E1 100 62 MAR 31... 1.00 .07 .42 .13 1.9 8.4 -- E16,000 -- E190,000 -- -- -­ JUN 03... -- -- -- -- -- -- 20 E15,000 -- -- -- -- -­ SEP 23... .890 .06 .35 .12 1.6 7.0 20 E11,000 -- 76,000 -- -- -­ 263 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 05... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 27... <.2 E.5 <10 <.01 680 <1 82.5 E.01 <3 <.3 35 .20 <16 MAR 31... -- -- -- -- -- -- -- -- -- -- -- .18 <16 JUN 03... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 23... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 264 RIO PUERTO NUEVO BASIN 50049820 LAGUNA SAN JOSE NO. 2 AT SAN JUAN, PR LOCATION.--Lat 18q25'46", long 66q02'10", 0.2 mi (0.3 km) east of Caño de Martin Peña, and 650 ft (200 m) south of Isla Guachinango. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 ANC, Residue Ammonia Nitrite Dis- pH, Specif. wat unf total + + Trans- solved water, conduc- fixed at 105 org-N, Ammonia nitrate Nitrite parency Dis- oxygen, unfltrd tance, Temper- end pt, deg. C, water, water, water water, Secchi solved percent field, wat unf ature, field, sus- unfltrd unfltrd unfltrd unfltrd disc, oxygen, of sat- std uS/cm water, mg/L as pended, mg/L mg/L mg/L mg/L Date Time inches mg/L uration units 25 degC deg C CaCO3 mg/L as N as N as N as N (00077) (00300) (00301) (00400) (00095) (00010) (00410) (00530) (00625) (00610) (00630) (00615) OCT 02... 0800 49.0 2.2 31 7.6 12,600 29.8 87 <10 2.3 .73 <.020 <.01 DEC 18... 0930 -- 2.9 -- 6.9 19,700 27.4 -- -- -- -- -- -­ MAR 05... 0915 -- 1.1 -- 7.2 7,000 25.7 71 <10 3.0 .85 <.020 .02 JUN 12... 0920 -- 5.0 -- 7.4 5,370 26.8 52 11 -- -- -- -­ Total Fecal Fecal nitro- coli- strep- Phos- gen, Organic form, tococci phorus, water, carbon, M-FC KF water, unfltrd water, 0.7u MF MF, unfltrd mg/L unfltrd col/ col/ Date mg/L as NO3 mg/L 100 mL 100 mL (00665) (71887) (00680) (31625) (31673) OCT 02... .22 -- 7.2 >6,000 -­ DEC 18... .33 7.6 6.5 -- <100 MAR 05... .45 -- 8.1 E600 -­ JUN 12... -- -- 7.7 190,000 -­ < -- Less than > -- Greater than E -- Estimated value 265 RIO PUERTO NUEVO BASIN 50049920 BAHIA DE SAN JUAN NO. 5 AT SAN JUAN, PR LOCATION--Lat 18q26'37", long 66q05'11", 0.4 mi (0.6 km) west of Puente de la Constitución, and 0.5 mi (0.8 km) south from U.S. Naval Reservation. DRAINAGE--Indeterminate. PERIOD OF RECORD--Water years 1974 to present. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 ANC, Residue Ammonia Nitrite Dis- pH, Specif. wat unf total + + Trans- solved water, conduc- fixed at 105 org-N, Ammonia nitrate Nitrite parency Dis- oxygen, unfltrd tance, Temper- end pt, deg. C, water, water, water water, Secchi solved percent field, wat unf ature, field, sus- unfltrd unfltrd unfltrd unfltrd disc, oxygen, of sat- std uS/cm water, mg/L as pended, mg/L mg/L mg/L mg/L Date Time inches mg/L uration units 25 degC deg C CaCO3 mg/L as N as N as N as N (00077) (00300) (00301) (00400) (00095) (00010) (00410) (00530) (00625) (00610) (00630) (00615) OCT 01... 0850 29.0 .6 8 6.8 29,500 29.7 170 44 2.8 2.00 <.020 .01 DEC 18... 0820 38.0 3.8 55 7.7 42,800 25.9 130 35 1.2 .71 .040 .02 MAR 04... 0855 29.4 2.7 39 7.6 42,100 26.8 140 <10 1.1 1.00 .060 .04 JUN 10... 0950 -- 4.1 -- 7.6 53,500 28.4 130 14 -- -- -- -­ Total Fecal Fecal nitro- coli- strep- Phos- gen, Organic form, tococci phorus, water, carbon, M-FC KF water, unfltrd water, 0.7u MF MF, unfltrd mg/L unfltrd col/ col/ Date mg/L as NO3 mg/L 100 mL 100 mL (00665) (71887) (00680) (31625) (31673) OCT 01... .34 -- 7.1 E88,000 -­ DEC 18... .13 5.5 3.7 E15,000 E500 MAR 04... .12 5.1 2.8 26,000 -­ JUN 10... -- -- 16.4 250,000 -­ < -- Less than E -- Estimated value 266 THIS PAGE IS INTENTIONALLY BLANK 267 Figure 17. Río Grande de Loíza basin. 268 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18q23'27", long 65q58'28", at bridge on Highway 3, 1.4 mi (2.3 km) south of Valle Arriba Heights housing area, and 1.2 mi (1.9 km) west-southwest of Carolina Plaza. DRAINAGE AREA.--2.96 mi2 (7.67 km2). PERIOD OF RECORD.--Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 05... 1315 5.2 4.7 5.3 68 7.2 612 28.0 210 65.3 10.7 3.97 1 JAN 28... 1615 7.3 14 6.2 77 7.5 526 26.6 190 59.2 10.5 3.62 1 APR 01... 1510 7.4 3.2 6.7 -- 7.8 564 27.1 200 62.5 10.4 3.51 1 JUN 04... 1040 4.1 12 6.6 -- 7.8 440 27.4 -- -- -- -- -­ SEP 23... 0945 11 14 6.0 -- 7.6 488 27.1 190 59.6 9.15 3.84 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 05... 34.3 221 42.5 <.17 30.7 11.9 -- 332 4.70 <10 4.8 4.20 .32 JAN 28... 30.6 192 40.1 .12 25.6 15.6 <.0 301 5.89 23 1.3 .67 1.14 APR 01... 33.5 191 45.0 .13 31.1 13.5 <.1 314 6.25 <10 1.8 1.20 1.12 JUN 04... -- 153 -- -- -- -- -- -- -- <10 -- -- -­ SEP 23... 25.4 176 29.2 <.2 21.5 24.5 -- 279 8.06 15 .80 .26 1.12 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 05... .410 .09 .60 .52 5.2 23.1 20 E11,000 E1,140 -- -- -- -­ JAN 28... 1.30 .16 .63 .17 2.6 11.5 E20 20,000 -- E100,000 E1 86.2 55 APR 01... 1.40 .28 .60 .23 3.2 14.2 20 E7,500 -- 73,000 <2 66.0 61 JUN 04... -- -- -- -- -- -- 10 4,600 -- -- -- -- -- SEP 23... 1.20 .08 .54 .14 2.0 8.9 20 E7,300 -- 67,000 -- -- -­ 269 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 05... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 28... <.2 <.8 <10 <.01 340 M 216 E.02 <3 <.3 26 <.10 <16 APR 01... <.2 <.8 <10 <.01 200 <1 51.6 E.01 <3 <.3 <25 .12 <16 JUN 04... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 23... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 270 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 18q07'10", long 65q59'22", Hydrologic Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) upstream from confluence with Río Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 mi2 (15.54 km2). PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder. Elevation of gage is 640 ft (195 m), from topographic map. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 8.5 14 11 13 9.0 9.6 16 11 12 41 30 2 12 8.4 20 14 18 9.1 7.8 15 18 62 149 20 3 11 14 16 13 12 9.1 7.7 15 35 25 22 17 4 14 11 14 12 12 8.6 12 14 19 20 16 15 5 11 8.6 33 106 11 8.3 41 14 14 37 15 14 6 11 8.3 15 29 10 8.1 11 14 21 33 45 14 7 10 8.2 12 15 11 8.1 9.1 19 97 19 36 14 8 12 8.0 11 13 11 9.4 9.6 35 24 22 20 14 9 12 8.2 12 12 11 8.5 18 16 18 20 21 13 10 12 9.0 11 12 29 10 32 13 14 15 16 12 11 12 10 12 11 14 8.4 320 14 13 13 15 12 12 12 11 13 11 13 7.8 125 13 25 13 14 12 13 11 9.1 15 10 10 7.6 106 12 14 351 13 11 14 9.9 8.4 13 11 9.7 7.5 31 40 13 29 17 11 15 13 8.1 12 9.9 9.5 7.8 20 18 52 20 16 19 16 13 158 28 9.5 10 7.8 48 16 25 37 39 54 17 13 24 60 9.4 44 8.6 755 35 16 20 77 29 18 11 22 22 11 22 7.6 408 36 43 16 140 16 19 9.5 17 13 10 13 7.4 123 38 292 15 24 13 20 9.8 12 12 9.2 17 7.3 57 16 32 14 17 13 21 9.4 13 16 9.0 51 7.0 39 242 43 15 23 163 22 9.2 13 22 8.7 17 7.1 191 37 22 41 58 22 23 8.8 11 13 11 12 7.1 53 21 18 20 21 14 24 16 10 12 10 11 7.0 37 26 19 14 17 12 25 28 10 31 41 13 6.7 27 17 16 13 26 11 26 36 10 14 24 11 6.5 24 15 15 17 50 11 27 14 11 12 13 9.7 6.8 22 14 14 26 20 11 28 11 9.7 11 11 9.3 6.5 19 13 15 25 39 9.8 29 9.7 9.3 11 10 9.5 18 12 13 15 124 9.3 30 9.1 8.9 10 12 7.5 17 12 12 13 30 9.1 31 8.8 10 16 6.7 11 18 22 TOTAL 390.2 477.7 520 504.7 434.2 244.4 2,597.8 829 983 1,010 1,183 625.2 MEAN 12.6 15.9 16.8 16.3 15.5 7.88 86.6 26.7 32.8 32.6 38.2 20.8 MAX 36 158 60 106 51 10 755 242 292 351 149 163 MIN 8.8 8.0 10 8.7 9.3 6.5 7.7 11 11 12 13 9.1 AC-FT 774 948 1,030 1,000 861 485 5,150 1,640 1,950 2,000 2,350 1,240 CFSM 2.10 2.65 2.80 2.71 2.58 1.31 14.4 4.46 5.46 5.43 6.36 3.47 IN. 2.42 2.96 3.22 3.13 2.69 1.52 16.11 5.14 6.09 6.26 7.33 3.88 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1978 - 2003, BY WATER YEAR (WY) MEAN 40.3 44.8 26.4 20.6 18.3 14.7 17.8 30.2 35.8 33.6 36.5 57.2 MAX 123 122 59.5 56.1 38.0 53.6 86.6 77.5 122 92.3 90.0 351 (WY) (1986) (1988) (1999) (1992) (1982) (1998) (2003) (1985) (1979) (1993) (1979) (1998) MIN 12.6 8.34 6.65 8.16 6.36 5.07 4.64 7.20 6.79 12.2 9.30 11.8 (WY) (2003) (1990) (1990) (1990) (1979) (1979) (1979) (1999) (2001) (2000) (1991) (1981) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1978 - 2003 ANNUAL TOTAL 9,614.8 9,799.2 ANNUAL MEAN 26.3 26.8 31.4 HIGHEST ANNUAL MEAN 62.7 1998 LOWEST ANNUAL MEAN 14.5 1990 HIGHEST DAILY MEAN 779 May 30 755 Apr 17 4,690 Sep 22, 1998 LOWEST DAILY MEAN 6.7 May 22 6.5 Mar 26 3.1 May 7, 1979 ANNUAL SEVEN-DAY MINIMUM 7.5 May 16 6.8 Mar 22 3.6 May 1, 1979 MAXIMUM PEAK FLOW 4,430 Jul 13 45,000 Sep 21, 1998 MAXIMUM PEAK STAGE 10.48 Jul 13 26.37 Sep 21, 1998 INSTANTANEOUS LOW FLOW 2.1 Mar 31 2.1 Mar 31, 2003 ANNUAL RUNOFF (AC-FT) 19,070 19,440 22,720 ANNUAL RUNOFF (CFSM) 4.39 4.47 5.23 ANNUAL RUNOFF (INCHES) 59.61 60.76 71.01 10 PERCENT EXCEEDS 33 40 50 50 PERCENT EXCEEDS 12 13 15 90 PERCENT EXCEEDS 8.3 8.7 7.2 271 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 272 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR LOCATION.--Lat 18q10'24", long 65q58'38", Hydrologic Unit 21010005, on right bank 50 ft upstream from bridge on Highway 181, 0.2 mi (0.3 km) upstream from Río Grande de Loíza, and 1.5 mi (2.4 km) southwest of San Lorenzo. DRAINAGE AREA.--3.74 mi2 (9.69 km2). PERIOD OF RECORD.--January 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 330 ft (100 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.5 1.0 1.0 2.2 1.6 0.79 e1.3 1.1 0.91 2.2 5.1 5.0 2 1.5 1.0 1.0 2.4 3.5 0.76 1.1 1.1 1.0 3.0 9.4 4.0 3 1.7 25 1.2 1.8 1.7 0.66 1.1 1.0 3.6 6.0 3.7 3.5 4 1.6 2.1 1.5 1.5 2.2 0.78 1.0 1.0 1.6 2.6 2.7 2.8 5 1.4 1.3 1.4 58 2.1 0.62 7.8 0.99 1.3 1.9 2.3 2.9 6 1.9 1.2 1.3 6.8 1.6 0.59 2.4 1.0 3.6 2.8 22 2.8 7 1.8 1.1 1.0 1.8 6.7 0.57 1.3 1.0 71 2.0 8.4 2.7 8 1.5 1.1 1.0 1.4 2.0 0.58 1.2 1.5 9.5 1.8 3.5 2.6 9 1.7 1.1 1.3 1.3 2.2 0.59 3.8 1.2 4.4 2.6 2.6 2.5 10 1.5 1.1 1.2 1.3 2.0 0.58 21 1.0 3.4 2.8 2.3 2.4 11 3.5 1.4 1.2 1.2 2.0 0.57 173 0.90 3.5 2.6 15 2.3 12 4.9 1.2 1.3 1.1 2.9 0.54 95 0.88 3.3 2.4 3.7 2.5 13 1.7 1.1 1.1 1.1 1.7 0.53 9.2 0.95 3.0 30 2.6 2.5 14 1.5 1.0 1.1 1.0 1.4 0.54 1.8 2.4 2.7 5.8 2.3 2.6 15 1.8 1.0 1.1 1.0 1.3 0.62 1.1 2.6 2.7 3.9 3.4 2.9 16 1.8 1.3 1.2 1.0 1.6 0.63 2.1 2.1 3.6 14 3.5 3.9 17 1.9 6.2 18 1.0 3.8 0.92 335 1.4 2.9 4.6 8.6 3.2 18 1.8 2.2 4.9 1.1 2.5 0.62 307 13 3.0 3.6 8.1 3.1 19 1.7 1.6 1.8 1.1 2.0 1.6 160 4.0 28 3.3 3.9 2.6 20 1.5 1.7 1.6 1.0 2.2 1.5 76 2.3 2.7 3.0 2.6 2.5 21 1.3 1.8 1.7 0.99 2.0 0.75 67 91 4.6 2.8 21 67 22 2.1 1.8 1.9 0.90 1.6 0.64 185 12 2.5 21 57 43 23 1.4 1.7 1.8 1.7 1.2 0.62 51 3.6 3.0 6.4 6.7 19 24 1.3 1.5 1.5 2.0 1.0 0.77 17 2.7 3.2 3.6 4.4 14 25 1.4 1.3 8.2 83 1.1 0.57 7.9 1.7 2.6 2.9 13 11 26 1.7 1.4 2.3 16 1.0 0.46 4.0 1.5 2.5 2.8 15 8.8 27 1.5 1.3 1.9 1.9 0.94 0.62 2.5 1.3 2.5 3.9 6.6 7.3 28 1.2 1.2 1.5 1.4 0.87 0.84 1.8 1.2 2.8 23 4.5 5.7 29 1.2 1.1 1.4 1.2 0.59 1.5 1.2 2.3 5.4 18 4.5 30 1.1 1.1 1.3 1.2 e0.81 1.2 0.99 2.1 3.4 6.7 4.6 31 1.0 1.4 3.9 e0.91 1.0 4.6 4.5 TOTAL 53.4 68.9 70.1 203.29 56.71 22.17 1,541.1 159.61 183.81 180.7 273.1 244.2 MEAN 1.72 2.30 2.26 6.56 2.03 0.72 51.4 5.15 6.13 5.83 8.81 8.14 MAX 4.9 25 18 83 6.7 1.6 335 91 71 30 57 67 MIN 1.0 1.0 1.0 0.90 0.87 0.46 1.0 0.88 0.91 1.8 2.3 2.3 AC-FT 106 137 139 403 112 44 3,060 317 365 358 542 484 CFSM 0.46 0.61 0.60 1.75 0.54 0.19 13.7 1.38 1.64 1.56 2.36 2.18 IN. 0.53 0.69 0.70 2.02 0.56 0.22 15.33 1.59 1.83 1.80 2.72 2.43 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 2003, BY WATER YEAR (WY) MEAN 8.92 11.8 5.69 4.87 3.28 3.09 5.05 5.33 5.55 5.08 7.36 15.3 MAX 36.2 33.4 22.8 23.4 10.3 17.4 51.4 35.8 17.5 20.5 14.5 76.5 (WY) (1986) (1988) (1988) (1992) (1984) (1989) (2003) (1985) (1996) (1993) (1996) (1996) MIN 1.72 2.30 1.17 1.16 1.23 0.72 0.66 0.86 0.75 0.99 1.51 1.39 (WY) (2003) (2003) (1990) (1990) (1990) (2003) (1995) (1995) (2001) (2001) (1994) (2001) RIO GRANDE DE LOIZA BASIN 273 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1984 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 1,477.96 ANNUAL MEAN 4.05 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 173 LOWEST DAILY MEAN 0.64 ANNUAL SEVEN-DAY MINIMUM 0.77 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 2,930 ANNUAL RUNOFF (CFSM) 1.08 ANNUAL RUNOFF (INCHES) 14.70 10 PERCENT EXCEEDS 3.1 50 PERCENT EXCEEDS 1.3 90 PERCENT EXCEEDS 0.83 3,057.09 8.38 6.77 12.4 1996 2.67 2001 Aug 31 335 Apr 17 1,750 Sep 10, 1996 Apr 14 0.46 Mar 26 0.25 Jul 22, 2001 Mar 31 0.56 Mar 8 0.28 Jul 17, 2001 1,420 Apr 22 15,000 Sep 10, 1996 10.47 Apr 22 20.87 Sep 10, 1996 0.43 Mar 26 0.23 Jul 21, 2001 6,060 4,910 2.24 1.81 30.41 24.60 11 9.5 1.9 2.0 0.97 0.89 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 274 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18q09'13", long 65q57'24", Hydrologic Unit 21010005, at downstream side of bridge on Highway 912, at Barrio Cerro Gordo, 2.8 mi (4.5 km) south of San Lorenzo. DRAINAGE AREA.--10.2 mi2 (26.4 km2). PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 490 ft (150 m), from topographic map. Prior to October 1, 1983, at site 2,000 ft (610 m) downstream at different datum. REMARKS.--Records poor. Sand removal at a commercial level is practiced at times during the year. This takes place about 100 ft (30.5 m) downstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 18 13 13 18 16 12 13 21 16 20 33 39 2 22 13 15 19 14 12 12 20 24 29 63 46 3 19 13 15 20 14 12 12 20 32 29 31 31 4 20 13 15 18 15 13 14 20 23 24 23 29 5 22 12 19 100 15 13 43 20 21 30 21 28 6 17 12 17 42 14 13 18 22 198 32 40 27 7 16 12 14 22 17 13 15 25 209 26 47 27 8 17 12 14 19 16 13 14 28 63 23 32 27 9 17 12 15 18 16 13 18 25 32 24 27 27 10 16 12 15 18 26 13 44 21 24 21 24 26 11 16 13 15 17 18 13 309 21 22 20 23 26 12 16 13 17 17 16 12 60 21 25 20 22 28 13 16 14 17 17 15 12 84 21 21 282 21 27 14 16 13 17 17 14 12 22 35 22 52 26 26 15 23 12 16 16 14 12 16 27 25 30 33 62 16 21 28 18 16 14 12 15 23 24 42 61 249 17 18 18 17 16 33 13 977 64 23 24 101 50 18 16 20 18 16 25 12 562 71 22 20 117 37 19 15 17 15 16 17 12 115 35 93 19 42 30 20 16 14 14 15 16 12 43 22 32 19 29 29 21 16 14 16 15 34 12 35 210 26 24 37 151 22 16 16 18 15 19 12 59 80 23 32 63 73 23 16 14 18 18 15 12 39 32 22 26 36 36 24 16 13 17 19 14 12 24 24 22 20 30 30 25 19 13 28 62 14 11 22 20 21 19 32 27 26 21 13 22 30 13 11 22 17 21 20 37 27 27 17 14 19 19 13 11 21 18 20 35 31 27 28 15 13 19 16 13 11 21 18 24 42 34 26 29 14 13 18 15 14 21 17 20 25 122 26 30 14 13 17 16 13 21 17 20 22 46 25 31 14 17 18 12 16 22 37 TOTAL 535 422 525 700 480 380 2,691 1,031 1,170 1,073 1,321 1,319 MEAN 17.3 14.1 16.9 22.6 17.1 12.3 89.7 33.3 39.0 34.6 42.6 44.0 MAX 23 28 28 100 34 14 977 210 209 282 122 249 MIN 14 12 13 15 13 11 12 16 16 19 21 25 AC-FT 1,060 837 1,040 1,390 952 754 5,340 2,040 2,320 2,130 2,620 2,620 CFSM 1.69 1.38 1.66 2.21 1.68 1.20 8.79 3.26 3.82 3.39 4.18 4.31 IN. 1.95 1.54 1.91 2.55 1.75 1.39 9.81 3.76 4.27 3.91 4.82 4.81 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1977 - 2003, BY WATER YEAR (WY) MEAN 60.8 69.0 45.8 33.8 29.1 23.1 24.2 43.5 42.8 41.4 52.0 75.2 MAX 176 196 163 99.5 74.1 64.1 89.7 155 140 118 202 330 (WY) (1986) (1988) (1988) (1998) (1997) (1998) (2003) (1985) (1979) (1979) (1979) (1998) MIN 14.4 14.1 12.5 14.6 11.0 11.3 10.7 9.68 10.9 15.4 14.5 16.9 (WY) (1992) (2003) (1992) (1990) (1992) (1992) (1980) (1990) (1994) (1994) (1991) (1980) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1977 - 2003 ANNUAL TOTAL 9,713 11,647 ANNUAL MEAN 26.6 31.9 45.1 HIGHEST ANNUAL MEAN 89.7 1979 LOWEST ANNUAL MEAN 18.6 1990 HIGHEST DAILY MEAN 543 May 30 977 Apr 17 5,120 Sep 10, 1996 LOWEST DAILY MEAN 11 Aug 28 11 Mar 25 7.1 Feb 4, 1981 ANNUAL SEVEN-DAY MINIMUM 12 Nov 4 11 Mar 22 8.5 Jun 19, 1994 MAXIMUM PEAK FLOW 3,750 Apr 17 14,200 Aug 22, 2001 MAXIMUM PEAK STAGE 14.99 Apr 17 24.21 Aug 22, 2001 ANNUAL RUNOFF (AC-FT) 19,270 23,100 32,670 ANNUAL RUNOFF (CFSM) 2.61 3.13 4.42 ANNUAL RUNOFF (INCHES) 35.42 42.48 60.06 10 PERCENT EXCEEDS 31 42 69 50 PERCENT EXCEEDS 19 20 24 90 PERCENT EXCEEDS 13 13 13 275 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR—Continued O N D J F M A M J J A S 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 276 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR LOCATION.--Lat 18q11'09", long 65q57'42", Hydrologic Unit 21010005, at downstream side of bridge on Highway 183 by-pass, 0.4 mi (0.6 km) south from Plaza de San Lorenzo, 1.4 mi (2.2 km), southwest from Escuela Rafael Colón García and 2.0 mi (3.2 km) northwest from Escuela Segunda Unidad de Carlos Zayas. DRAINAGE AREA.--25.0 mi2 (64.8 km2). PERIOD OF RECORD.--February 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 262 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated discharges, which are poor. Water purification plant located about 0.2 mi (0.3 km) upstream from gage. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 42 31 31 41 53 33 27 e57 49 56 111 90 2 50 30 38 46 42 35 28 e56 69 111 213 104 3 59 82 57 50 52 35 22 58 118 101 103 78 4 56 59 39 37 45 33 33 57 88 83 78 74 5 64 33 69 205 49 30 101 54 74 123 68 67 6 45 30 53 125 43 28 58 56 256 131 143 64 7 47 29 37 65 79 29 34 67 400 90 159 59 8 43 27 33 48 55 28 31 82 176 75 108 60 9 56 28 37 43 53 30 49 65 107 91 94 59 10 50 30 37 40 91 28 137 53 89 71 82 55 11 56 33 32 38 65 29 590 50 85 60 95 53 12 50 34 40 35 60 26 257 47 98 56 82 58 13 43 30 37 34 45 23 222 46 78 576 66 56 14 38 27 39 35 39 24 109 89 72 136 76 55 15 48 25 32 33 38 23 73 79 107 92 122 103 16 54 126 49 28 38 26 87 59 94 165 76 270 17 53 77 90 30 106 26 1,770 68 77 95 266 89 18 41 67 95 33 88 26 1,320 173 71 80 282 84 19 37 57 43 38 64 29 405 123 467 72 134 62 20 36 39 36 29 63 28 205 68 134 68 93 62 21 40 37 43 29 112 23 182 634 123 81 116 390 22 40 46 66 28 74 22 598 202 93 160 259 156 23 39 34 63 36 55 21 253 99 81 111 118 79 24 39 31 44 50 45 23 157 90 82 76 91 67 25 73 31 79 140 46 21 123 75 72 68 106 60 26 84 31 66 112 44 18 101 67 67 65 166 59 27 58 33 48 61 38 21 88 60 63 118 109 58 28 41 29 38 44 36 24 79 55 73 181 98 54 29 35 27 36 38 32 e72 53 63 101 253 51 30 35 26 32 40 35 e64 53 58 79 124 50 31 32 32 65 20 49 76 96 TOTAL 1,484 1,219 1,471 1,676 1,618 829 7,275 2,844 3,484 3,448 3,987 2,626 MEAN 47.9 40.6 47.5 54.1 57.8 26.7 242 91.7 116 111 129 87.5 MAX 84 126 95 205 112 35 1,770 634 467 576 282 390 MIN 32 25 31 28 36 18 22 46 49 56 66 50 AC-FT 2,940 2,420 2,920 3,320 3,210 1,640 14,430 5,640 6,910 6,840 7,910 5,210 CFSM 1.91 1.63 1.90 2.16 2.31 1.07 9.70 3.67 4.65 4.45 5.14 3.50 IN. 2.21 1.81 2.19 2.49 2.41 1.23 10.83 4.23 5.18 5.13 5.93 3.91 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 2003, BY WATER YEAR (WY) MEAN 137 142 103 98.7 73.9 52.8 60.6 69.4 99.3 85.9 113 183 MAX 340 298 253 192 160 158 242 186 290 208 196 631 (WY) (1999) (2000) (1999) (1992) (1998) (1998) (2003) (1992) (1992) (1993) (1996) (1996) MIN 47.9 40.6 47.5 43.6 21.0 17.4 16.8 25.2 22.5 40.2 39.3 59.7 (WY) (2003) (2003) (2003) (2001) (1992) (1992) (1992) (1995) (2001) (2001) (1994) (1990) 277 RIO GRANDE DE LOIZA BASIN 50051800 RIO GRANDE DE LOIZA AT HWY 183 NEAR SAN LORENZO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1990 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 25,146 ANNUAL MEAN 68.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 759 LOWEST DAILY MEAN 21 ANNUAL SEVEN-DAY MINIMUM 22 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 49,880 ANNUAL RUNOFF (CFSM) 2.76 ANNUAL RUNOFF (INCHES) 37.42 10 PERCENT EXCEEDS 103 50 PERCENT EXCEEDS 48 90 PERCENT EXCEEDS 30 31,961 87.6 103 154 1996 66.5 2001 Apr 20 1,770 Apr 17 10,000 Sep 10, 1996 Mar 25 18 Mar 26 6.3 Apr 29, 1992 Mar 20 21 Mar 21 7.4 Apr 25, 1992 7,810 Apr 17 56,800 Sep 10, 1996 16.86 Apr 17 35.62 Sep 10, 1996 63,390 74,790 3.50 4.13 47.56 56.11 136 178 58 63 29 27 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 278 RIO GRANDE DE LOIZA BASIN 50053025 RIO TURABO ABOVE BORINQUEN, PR LOCATION.--Lat 18q09'35", long 66q02'26", Hydrologic Unit 21010005, on left bank at Highway 765, 1.12 mi (1.8 km) south of Villa Borinquén, 1.35 mi (2.17 km), north from Mercedes Palma school and 0.83 mi (1.34 km) east from Atravezada school on Road 763. DRAINAGE AREA.--7.49 mi2 (18.5 km2). PERIOD OF RECORD.--January 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 492 ft (150 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 9.2 8.5 11 12 8.5 e9.9 16 18 13 24 21 2 12 9.6 11 13 11 8.4 10 15 20 28 62 19 3 11 13 12 12 11 8.2 11 14 24 16 26 17 4 13 11 9.5 9.8 13 7.9 13 13 20 20 19 16 5 13 9.3 18 40 14 7.4 19 13 19 21 17 15 6 11 8.9 11 20 11 7.3 15 13 70 35 24 15 7 12 8.6 9.4 13 16 7.0 13 14 70 19 31 15 8 11 8.6 9.5 11 15 7.1 14 14 30 21 21 15 9 12 8.9 11 10 13 e6.8 19 12 23 22 27 14 10 23 9.2 9.6 10 24 e7.1 24 12 21 16 19 14 11 14 9.0 13 9.5 16 6.6 90 11 21 15 31 13 12 11 8.5 11 9.2 16 6.4 48 11 23 14 20 13 13 11 8.2 11 9.2 12 6.2 58 11 21 140 17 13 14 11 7.9 10 8.9 11 6.0 27 17 20 30 18 12 15 11 8.0 9.3 8.6 11 6.1 23 14 27 20 19 18 16 11 15 13 8.5 12 6.1 26 12 25 52 17 18 17 11 11 21 8.5 32 6.4 370 13 22 21 55 13 18 10 12 16 11 24 6.0 258 23 22 17 61 12 19 9.6 10 11 9.8 16 8.3 92 19 154 16 28 12 20 9.9 9.0 10 8.7 15 7.2 45 13 31 14 20 13 21 10 9.3 13 8.4 26 6.3 35 143 26 18 57 145 22 15 9.3 24 7.9 16 5.8 136 48 20 72 56 42 23 11 8.4 15 11 12 7.2 63 30 18 30 29 25 24 11 8.3 12 11 11 6.0 90 26 18 19 22 22 25 17 8.4 17 98 12 5.8 46 21 16 16 26 20 26 21 8.3 14 31 10 5.9 30 21 15 15 57 20 27 14 8.4 12 17 9.3 6.3 24 19 14 33 25 19 28 11 8.0 10 13 8.9 6.7 20 17 18 54 26 18 29 10 7.8 9.4 12 10 19 16 14 28 34 18 30 9.9 7.7 9.0 13 9.1 17 16 13 20 22 18 31 9.8 9.1 15 e8.9 15 20 20 TOTAL 378.2 278.8 379.3 479.0 410.2 219.0 1,664.9 652 853 875 930 645 MEAN 12.2 9.29 12.2 15.5 14.7 7.06 55.5 21.0 28.4 28.2 30.0 21.5 MAX 23 15 24 98 32 10 370 143 154 140 62 145 MIN 9.6 7.7 8.5 7.9 8.9 5.8 9.9 11 13 13 17 12 MED 11 8.9 11 11 12 6.8 25 15 21 20 25 16 AC-FT 750 553 752 950 814 434 3,300 1,290 1,690 1,740 1,840 1,280 CFSM 1.71 1.30 1.71 2.16 2.05 0.99 7.77 2.95 3.98 3.95 4.20 3.01 IN. 1.97 1.45 1.98 2.50 2.14 1.14 8.67 3.40 4.44 4.56 4.85 3.36 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 2003, BY WATER YEAR (WY) MEAN 24.9 26.7 21.7 21.6 16.4 12.1 14.4 15.4 24.0 20.5 23.0 41.5 MAX 51.3 70.5 42.7 47.5 25.0 26.9 55.5 31.9 67.9 54.6 41.4 123 (WY) (1998) (2000) (1999) (1992) (1997) (1998) (2003) (1993) (1996) (1993) (1996) (1996) MIN 10.3 9.29 10.6 7.85 8.93 7.06 6.18 6.11 6.07 8.25 6.98 12.1 (WY) (1994) (2003) (1994) (1990) (1990) (2003) (1990) (1994) (2001) (2001) (1994) (2001) RIO GRANDE DE LOIZA BASIN 279 50053025 RIO TURABO ABOVE BORINQUEN, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1990 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 6,518.5 ANNUAL MEAN 17.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 237 LOWEST DAILY MEAN 6.2 ANNUAL SEVEN-DAY MINIMUM 6.4 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 12,930 ANNUAL RUNOFF (CFSM) 2.50 ANNUAL RUNOFF (INCHES) 33.96 10 PERCENT EXCEEDS 25 50 PERCENT EXCEEDS 12 90 PERCENT EXCEEDS 8.1 7,764.4 21.3 22.3 38.1 1996 12.1 1994 Sep 15 370 Apr 17 1,940 Sep 10, 1996 Mar 23 5.8 Mar 22 3.3 Aug 17, 1994 Mar 20 6.2 Mar 12 3.8 Aug 11, 1994 1,840 Sep 21 15,200 Sep 10, 1996 9.51 Sep 21 22.60 Sep 10, 1996 5.1 Mar 24 2.6 Jul 17, 1997 15,400 16,140 2.98 3.12 40.45 42.40 31 36 14 12 8.4 6.5 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 280 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR LOCATION.--Lat 18q14'33", long 66q00'34", Hydrologic Unit 21010005, on right bank 250 ft (76 m) upstream from bridge on Highway 189, 1.2 mi (1.9 km) downstream from Río Turabo, and 1.8 mi (2.9 km) east of Plaza de Caguas. DRAINAGE AREA.--89.8 mi2 (233 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1959 (low-flow measurement only), February to November 1959 (monthly measurements only), December 1959 to current year. GAGE.--Water-stage recorder. Datum of gage is 143.28 ft (43.672 m) above mean sea level. REMARKS.--Records good except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 86 58 42 53 83 43 e31 97 60 86 118 89 2 86 57 57 70 59 40 39 94 76 162 325 120 3 96 193 81 72 67 40 37 86 133 176 162 95 4 94 116 64 57 159 41 35 89 129 116 99 83 5 105 64 75 250 101 38 164 90 82 159 86 77 6 146 53 91 246 68 40 112 86 342 208 268 72 7 97 49 60 96 87 37 54 89 688 142 236 68 8 85 45 54 68 82 39 47 96 359 100 157 71 9 102 43 59 60 70 38 43 98 151 125 108 73 10 100 50 56 55 91 37 203 78 126 89 102 70 11 111 60 51 53 92 39 804 75 103 72 106 77 12 97 60 58 48 78 35 533 69 96 72 137 89 13 83 54 55 46 63 33 354 74 94 1,180 79 109 14 75 45 56 46 52 28 158 97 82 314 76 100 15 70 41 50 44 48 30 106 125 118 167 196 104 16 94 134 54 40 46 30 96 86 110 297 100 399 17 86 126 203 38 91 35 3,670 66 73 179 544 107 18 78 101 211 41 109 33 3,470 229 61 125 452 90 19 71 85 73 49 91 84 1,060 155 683 109 212 94 20 72 62 65 41 68 73 542 92 174 100 95 73 21 71 55 61 39 114 39 542 1,450 127 118 125 1,280 22 74 64 71 34 105 33 1,100 663 134 326 622 392 23 76 55 108 40 71 31 663 228 119 262 198 125 24 66 51 67 90 57 37 739 145 91 107 113 80 25 92 50 88 493 58 33 341 105 57 80 110 69 26 128 52 111 304 52 27 208 92 67 76 368 66 27 109 53 74 110 48 55 149 88 70 127 190 77 28 78 53 59 72 46 37 116 76 84 320 158 69 29 68 47 53 59 28 105 71 85 160 388 69 30 64 43 50 56 47 102 64 78 91 162 84 31 61 46 82 34 62 96 90 TOTAL 2,721 2,019 2,303 2,852 2,156 1,214 15,623 5,015 4,652 5,741 6,182 4,371 MEAN 87.8 67.3 74.3 92.0 77.0 39.2 521 162 155 185 199 146 MAX 146 193 211 493 159 84 3,670 1,450 688 1,180 622 1,280 MIN 61 41 42 34 46 27 31 62 57 72 76 66 AC-FT 5,400 4,000 4,570 5,660 4,280 2,410 30,990 9,950 9,230 11,390 12,260 8,670 CFSM 0.98 0.75 0.83 1.02 0.86 0.44 5.80 1.80 1.73 2.06 2.22 1.62 IN. 1.13 0.84 0.95 1.18 0.89 0.50 6.47 2.08 1.93 2.38 2.56 1.81 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2003, BY WATER YEAR (WY) MEAN 342 315 222 149 111 91.7 102 214 232 214 263 315 MAX 1,910 1,131 714 559 291 306 521 863 1,283 660 949 1,438 (WY) (1971) (1988) (1988) (1992) (1984) (1989) (2003) (1985) (1979) (1961) (1979) (1960) MIN 44.2 64.9 33.6 45.3 35.6 23.2 30.6 33.7 34.1 21.8 51.4 37.4 (WY) (1968) (1968) (1968) (1968) (1968) (1968) (1995) (1974) (1975) (1974) (1994) (1967) RIO GRANDE DE LOIZA BASIN 281 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1960 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 49,147 ANNUAL MEAN 135 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,950 LOWEST DAILY MEAN 27 ANNUAL SEVEN-DAY MINIMUM 29 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 97,480 ANNUAL RUNOFF (CFSM) 1.50 ANNUAL RUNOFF (INCHES) 20.36 10 PERCENT EXCEEDS 202 50 PERCENT EXCEEDS 84 90 PERCENT EXCEEDS 45 54,849 150 212 526 1979 82.3 1967 Apr 20 3,670 Apr 17 25,300 Sep 6, 1960 Mar 26 27 Mar 26 11 Apr 8, 1968 Mar 21 32 Mar 12 11 Apr 8, 1968 12,900 Apr 18 83,000 Sep 10, 1996 15.22 Apr 18 32.32 Sep 10, 1996 22 Mar 27 17 Aug 18, 1994 108,800 153,700 1.67 2.36 22.72 32.11 255 350 84 105 41 40 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 282 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 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 08... 1220 42 63 5.6 72 7.0 304 28.2 92 23.8 7.77 1.99 1 JAN 29... 1215 55 32 7.0 85 -- 278 25.5 82 21.2 7.09 2.33 1 APR 02... 1015 40 38 5.5 -- 7.4 325 27.5 96 25.4 7.98 1.89 1 JUN 05... 1145 88 74 7.0 -- 7.5 247 29.4 -- -- -- -- -­ SEP 03... 1015 97 -- 7.0 -- -- 222 29.1 72 18.4 6.23 1.74 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 08... 25.3 98 23.3 <.17 32.8 14.2 -- 188 21.5 55 .60 .14 .65 JAN 29... 20.6 86 20.3 .12 30.8 13.5 .0 168 -- 31 .80 .26 .69 APR 02... 27.7 98 24.9 .15 33.2 16.3 <.1 196 21.1 32 .40 .16 .54 JUN 05... -- 74 -- -- -- -- -- -- -- 15 -- -- -- SEP 03... 17.0 71 16.5 <.2 31.4 8.3 -- 142 37.0 31 .40 .10 .43 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 08... .690 .04 .46 .17 1.3 5.7 <10 E1,700 E180 -- -- -- -­ JAN 29... .730 .04 .54 .17 1.5 6.8 <10 3,100 -- 51,000 <2 39.3 36 APR 02... .580 .04 .24 .17 .98 4.3 10 2,600 -- 33,000 <2 37.4 36 JUN 05... -- -- -- -- -- -- <10 E8,600 -- E100,000 -- -- -­ SEP 03... .450 .02 .30 .10 .85 3.8 10 4,000 -- 40,000 -- -- -­ 283 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 08... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 29... <.2 <.8 <10 <.01 940 M 241 <.02 <3 <.3 E17 <.10 <16 APR 02... E.1 E.6 <10 <.01 1,220 M 289 <.02 <3 <.3 <25 <.10 <16 JUN 05... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 03... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- 284 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. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1983 to current year. INSTRUMENTATION.-- USDH-48 sediment sampler since October 1983. Automatic sediment sampler since 1984. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 14,500 mg/L November 27, 1987; Minimum daily mean, 5 mg/L September 30, 2001. SEDIMENT LOADS: Maximum daily mean, 396,000 tons (359,000 tonnes) September 10, 1996; Minimum daily mean, 0.65 ton (0.59 tonne) May 25, 1995. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 868 mg/L April 11, 2003; Minimum daily mean, 20 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 10,100 tons (9,163 tonnes) April 17, 2003; Minimum daily mean, 3.4 ton (3.1 tonne) March 26, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 86 20 4.6 58 108 17 42 151 17 2 86 20 4.7 57 108 17 57 153 23 3 96 20 5.2 193 169 170 81 155 34 4 94 20 5.1 116 152 49 64 157 27 5 105 20 5.7 64 108 19 75 159 32 6 146 109 68 53 92 13 91 160 39 7 97 196 52 49 89 12 60 156 25 8 85 135 31 45 89 11 54 151 22 9 102 122 33 43 89 10 59 146 23 10 100 132 37 50 89 12 56 141 21 11 111 144 44 60 89 14 51 136 19 12 97 126 33 60 88 14 58 132 21 13 83 121 27 54 88 13 55 127 19 14 75 117 24 45 88 11 56 122 19 15 70 113 21 41 88 9.8 50 117 16 16 94 111 28 134 145 81 54 112 16 17 86 111 26 126 153 53 203 175 147 18 78 110 23 101 137 38 211 200 131 19 71 110 21 85 127 29 73 117 23 20 72 110 21 62 129 22 65 111 20 21 71 110 21 55 131 19 61 110 18 22 74 110 22 64 133 23 71 111 22 23 76 109 23 55 135 20 108 139 41 24 66 109 19 51 137 19 67 109 20 25 92 120 30 50 139 19 88 125 33 26 128 152 53 52 141 20 111 143 44 27 109 144 43 53 143 20 74 110 22 28 78 120 25 53 145 21 59 101 16 29 68 110 20 47 147 18 53 98 14 30 64 109 19 43 149 17 50 98 13 31 61 109 18 46 97 12 TOTAL 2,721 807.3 2,019 810.8 2,303 949 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GRANDE DE LOIZA BASIN 285 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 53 96 14 83 100 22 43 55 6.5 2 70 95 18 59 100 16 40 54 5.8 3 72 94 18 67 99 18 40 53 5.8 4 57 94 14 159 161 79 41 53 5.9 5 250 188 230 101 118 33 38 53 5.4 6 246 223 165 68 108 20 40 53 5.7 7 96 140 37 87 107 25 37 52 5.3 8 68 115 21 82 107 24 39 52 5.5 9 60 115 19 70 106 20 38 52 5.3 10 55 115 17 91 116 30 37 51 5.2 11 53 115 16 92 112 29 39 51 5.3 12 48 115 15 78 102 21 35 51 4.9 13 46 115 14 63 97 17 33 50 4.5 14 46 115 14 52 93 13 28 50 3.8 15 44 115 14 48 88 11 30 50 4.0 16 40 114 12 46 83 10 30 50 4.0 17 38 114 12 91 108 34 35 49 4.7 18 41 114 13 109 98 30 33 49 4.3 19 49 114 15 91 77 19 84 105 34 20 41 114 13 68 76 14 73 109 22 21 39 114 12 114 109 40 39 72 7.7 22 34 114 11 105 106 32 33 50 4.5 23 40 114 12 71 77 15 31 49 4.1 24 90 132 39 57 73 11 37 48 4.8 25 493 309 521 58 70 11 33 47 4.2 26 304 247 231 52 66 9.3 27 46 3.4 27 110 144 43 48 62 8.1 55 80 18 28 72 115 23 46 59 7.3 37 90 9.0 29 59 103 16 28 88 6.8 30 56 101 15 47 87 11 31 82 101 22 34 85 7.6 TOTAL 2,852 1,636 2,156 618.7 1,214 229.0 APRIL MAY JUNE 1 e31 e83 e6.7 97 127 33 60 136 22 2 39 81 8.4 94 126 32 76 135 28 3 37 79 7.9 86 125 29 133 150 57 4 35 78 7.5 89 124 30 129 162 60 5 164 148 101 90 123 30 82 135 30 6 112 145 47 86 122 28 342 236 366 7 54 112 16 89 121 29 688 376 857 8 47 111 14 96 119 31 359 276 290 9 43 110 13 98 118 31 151 183 75 10 203 194 122 78 117 25 126 158 54 11 804 868 2,650 75 116 24 103 141 39 12 533 335 493 69 115 21 96 126 32 13 354 263 269 74 114 23 94 123 31 14 158 174 77 97 130 37 82 123 27 15 106 145 41 125 167 61 118 141 46 16 96 137 36 86 104 24 110 140 44 17 3,670 680 10,100 66 103 18 73 118 23 18 3,470 472 9,300 229 193 135 61 117 19 19 1,060 466 1,460 155 147 62 683 364 846 20 542 330 512 92 130 32 174 185 93 21 542 346 521 1,450 629 9,760 127 134 46 22 1,100 409 2,020 663 382 741 134 133 48 23 663 378 726 228 210 135 119 132 42 24 739 384 945 145 154 60 91 131 32 25 341 271 259 105 139 39 57 131 20 26 208 203 114 92 138 34 67 130 23 27 149 181 73 88 137 33 70 130 25 28 116 162 51 76 137 28 84 130 29 29 105 143 41 71 137 26 85 130 30 30 102 129 36 64 136 24 78 130 28 31 62 136 23 TOTAL 15,623 30,067.5 5,015 11,638 4,652 3,362 286 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean concen- Load discharge tration (tons/ Day (cfs) (mg/l) day) Mean Mean Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 86 130 30 118 2 162 168 83 325 3 176 183 89 162 4 116 138 43 99 5 159 160 76 86 138 44 89 58 14 239 264 120 58 19 168 77 95 58 15 130 35 83 58 13 127 29 77 58 12 6 208 201 115 7 142 162 63 8 100 137 37 9 125 154 52 10 89 126 31 268 210 209 72 58 11 236 208 146 68 58 11 157 171 77 71 58 11 108 131 38 73 58 11 102 126 35 70 58 11 11 72 124 24 12 72 123 24 13 1,180 421 3,020 14 314 245 217 15 167 173 78 106 135 41 77 58 12 137 159 62 89 58 14 79 121 26 109 58 17 76 116 24 100 58 16 196 186 107 104 58 16 16 297 225 215 17 179 180 88 18 125 150 51 19 109 149 44 20 100 149 40 100 135 36 399 257 378 544 323 553 107 66 20 452 300 410 90 58 14 212 194 120 94 57 15 95 128 33 73 57 11 21 118 148 47 22 326 240 265 23 262 219 167 24 107 137 40 25 80 134 29 125 142 65 1,280 606 7,010 622 363 621 392 289 369 198 203 114 125 164 56 113 144 44 80 124 27 110 144 44 69 114 21 26 76 135 28 27 127 152 55 28 320 251 227 29 160 177 81 30 91 138 34 31 96 138 36 368 261 280 66 114 20 190 182 109 77 114 24 158 164 83 69 113 21 388 273 304 69 113 21 162 111 57 84 113 25 90 58 14 --- --- --­ TOTAL 5,741 --- 5,429 6,182 --- 4,101 4,371 --- 8,235 YEAR 54,849 67,883.3 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus- sedi- pended pended Instan- ment, sedi- sedi- taneous sieve ment ment dis- diametr concen- dis- charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 17... 1225 5,390 96 2,120 30,800 22... 1810 4,180 97 1,260 14,200 -- -- -- -- -- -- -- -- -- RIO GRANDE DE LOIZA BASIN 287 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended Instan­ ment, ment, ment, ment, ment, ment, ment, ment, ment, ment, sedi­ taneous falldia falldia falldia falldia falldia sieve sieve sieve sieve sieve ment dis- nat wat nat wat nat wat nat wat nat wat diametr diametr diametr diametr diametr concen­ charge, percent percent percent percent percent percent percent percent percent percent tration Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L (00061) (70326) (70327) (70328) (70329) (70330) (70331) (70332) (70333) (70334) (70335) (80154) APR 17... 1140 5,060 50 58 65 77 89 97 99 100 100 100 4,470 MAY 21... 1807 9,420 52 60 67 79 91 3,430 SEP 21... 1903 5,830 68 78 83 75 96 98 3,160 WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Sus­ pended sedi­ ment dis­ charge, Date tons/d (80155) APR 17... 61,000 MAY 21... 87,300 SEP 21... 49,700 --- --- --- --- --- --- --- 288 RIO GRANDE DE LOIZA BASIN 50055100 RIO CAGÜITAS NEAR AGUAS BUENAS, PR LOCATION.--Lat 18q14'48", long 66q05'37", Hydrologic Unit 21010005, on right bank 450 ft (137 m) upstream from bridge on Highway 777, 1.0 mi (1.6 km) southeast from Aguas Buenas, 3.9 mi (6.3 km) northwest from Caguas, and 2.1 mi (3.4 km) southwest from Las Carolinas. DRAINAGE AREA.--5.30 mi2 (13.7 km2). PERIOD OF RECORD.--February 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.0 2.8 2.8 3.1 3.1 2.8 2.6 4.7 2.6 2.1 5.5 4.4 2 4.0 3.0 3.0 3.1 2.9 2.9 2.7 4.5 3.2 2.2 29 3.8 3 3.9 3.4 3.1 2.8 2.9 2.7 e7.4 4.2 4.1 3.4 6.7 3.5 4 4.3 3.2 4.0 2.6 30 2.8 e4.8 4.0 2.9 2.3 5.4 3.3 5 4.1 3.2 3.4 3.8 8.6 2.6 e17 4.9 2.6 4.2 4.7 3.1 6 4.1 3.2 3.1 3.4 4.4 2.6 e2.8 4.5 2.8 4.5 6.9 3.0 7 3.6 2.7 3.4 2.8 3.8 2.6 e2.1 3.4 6.6 2.7 7.3 3.7 8 3.9 2.8 3.8 2.9 3.5 2.6 e3.5 3.4 3.7 2.5 5.1 4.2 9 3.7 3.2 3.4 2.8 3.6 2.6 e4.8 3.3 3.1 2.4 4.8 3.9 10 3.7 3.2 3.1 2.8 3.5 2.8 e14 3.1 2.8 2.2 4.5 3.9 11 3.6 3.1 3.1 2.7 3.5 2.6 e39 3.0 2.7 2.1 4.5 4.0 12 3.7 3.0 3.2 2.6 3.5 2.5 e17 3.0 2.9 2.0 4.2 3.9 13 3.4 2.9 3.2 2.5 3.4 2.3 e4.8 2.9 2.6 24 3.8 4.3 14 3.2 2.9 3.0 2.6 3.2 2.3 e3.5 4.0 2.6 5.3 4.0 4.0 15 3.2 2.8 3.1 2.4 3.1 2.4 2.8 3.3 3.4 5.7 3.9 3.6 16 3.1 3.2 3.2 2.4 3.3 2.4 2.8 2.9 2.8 7.7 3.5 3.4 17 3.2 3.3 3.4 2.4 3.7 2.4 36 2.8 2.6 5.3 4.2 3.3 18 3.4 7.5 3.3 2.5 3.4 2.3 47 3.8 2.5 4.1 5.0 3.3 19 3.5 4.5 3.2 2.5 3.2 12 14 3.4 3.5 3.5 3.7 3.8 20 3.6 3.3 3.4 2.3 3.3 3.7 5.4 5.1 2.8 3.7 3.5 3.8 21 3.5 3.2 3.4 2.4 3.7 2.8 18 14 4.2 3.7 5.7 18 22 3.4 3.1 3.4 2.2 3.2 2.7 13 12 3.0 7.2 6.8 5.7 23 3.3 3.1 3.3 3.0 3.0 3.2 220 6.3 2.7 5.2 4.1 4.1 24 3.3 3.0 2.9 6.6 2.9 2.8 181 4.5 2.4 3.9 3.6 3.7 25 3.1 3.0 4.2 24 3.3 2.7 18 3.9 2.2 3.5 6.1 5.8 26 3.3 3.0 3.2 8.8 2.9 5.6 8.5 3.4 2.2 5.6 11 4.2 27 3.0 3.0 2.8 3.9 2.8 4.1 6.6 3.3 2.2 5.0 4.6 3.6 28 2.9 3.0 2.8 3.3 2.8 3.0 5.9 3.1 2.9 6.1 6.1 3.2 29 2.9 2.9 2.9 3.2 2.7 5.3 3.0 2.2 5.0 8.4 3.6 30 3.0 2.9 2.9 3.2 2.9 4.9 2.8 2.2 4.3 5.4 4.0 31 2.9 3.0 3.2 2.7 2.7 8.5 4.4 TOTAL 107.8 97.4 100.0 118.8 124.5 97.1 715.2 133.2 89.0 149.9 186.4 130.1 MEAN 3.48 3.25 3.23 3.83 4.45 3.13 23.8 4.30 2.97 4.84 6.01 4.34 MAX 4.3 7.5 4.2 24 30 12 220 14 6.6 24 29 18 MIN 2.9 2.7 2.8 2.2 2.8 2.3 2.1 2.7 2.2 2.0 3.5 3.0 AC-FT 214 193 198 236 247 193 1,420 264 177 297 370 258 CFSM 0.66 0.61 0.61 0.72 0.84 0.59 4.50 0.81 0.56 0.91 1.13 0.82 IN. 0.76 0.68 0.70 0.83 0.87 0.68 5.02 0.93 0.62 1.05 1.31 0.91 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 2003, BY WATER YEAR (WY) MEAN 9.01 11.2 10.4 8.47 5.99 4.88 6.91 5.24 4.83 6.08 7.52 13.1 MAX 20.9 32.7 39.2 16.7 10.1 8.87 23.8 18.0 12.1 18.6 18.9 52.9 (WY) (1991) (2000) (1999) (1992) (1999) (1990) (2003) (1993) (1999) (1993) (2000) (1996) MIN 3.17 2.66 2.34 2.48 2.96 2.09 1.84 2.00 1.84 1.86 1.85 2.43 (WY) (1996) (1995) (1995) (1995) (1995) (1996) (1995) (1997) (1997) (1994) (1994) (1997) RIO GRANDE DE LOIZA BASIN 289 50055100 RIO CAGÜITAS NEAR AGUAS BUENAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1990 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 2,159.7 ANNUAL MEAN 5.92 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 149 LOWEST DAILY MEAN 1.9 ANNUAL SEVEN-DAY MINIMUM 2.1 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 4,280 ANNUAL RUNOFF (CFSM) 1.12 ANNUAL RUNOFF (INCHES) 15.16 10 PERCENT EXCEEDS 8.8 50 PERCENT EXCEEDS 4.0 90 PERCENT EXCEEDS 2.8 2,049.4 5.61 7.91 14.5 1999 4.31 1997 Apr 20 220 Apr 23 1,260 Sep 10, 1996 Aug 27 2.0 Jul 12 1.0 Aug 1, 1997 Aug 21 2.3 Jun 25 1.2 Apr 30, 1996 1,920 Apr 23 4,490 Sep 10, 1996 16.27 Apr 23 21.22 Sep 10, 1996 1.8 Jul 11 0.82 Jul 29, 1997 4,060 5,730 1.06 1.49 14.38 20.28 6.6 12 3.3 4.7 2.6 2.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 290 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR LOCATION.--Lat 18q14'55", long 66q01'40", Hydrologic Unit 21010005, on left bank, at Calle 4 Villa Blanca housing area at Caguas, 1.8 mi (2.9 km) upstream from Río Grande de Loíza, and 0.95 mi (1.53 km) northeast from Caguas Plaza. DRAINAGE AREA.--11.7 mi2 (30.3 km2). PERIOD OF RECORD.--December 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. Low flow affected by pluvial discharges above 50 ft (15.24 m), upstream from station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 5.8 9.9 7.1 11 e7.0 e7.9 22 13 9.5 27 17 2 11 8.9 10 7.9 9.1 e6.9 8.1 23 21 9.7 123 17 3 8.8 6.7 12 7.2 8.6 e6.7 19 25 26 18 24 13 4 9.4 6.8 26 6.6 142 e6.5 11 24 15 13 17 12 5 8.3 6.6 15 26 e45 e6.4 43 24 12 26 15 11 6 14 6.6 9.8 13 e30 e6.3 15 28 15 e20 74 11 7 9.0 6.7 16 9.8 e25 e6.2 10 15 60 13 35 12 8 8.0 6.2 32 10 e15 e6.1 8.8 14 20 12 17 14 9 8.1 6.8 20 8.3 e16 e6.0 12 12 14 10 15 11 10 37 7.5 11 7.6 e18 e10 31 12 13 9.4 13 11 11 11 8.8 12 6.8 e15 e7.0 120 12 12 e9.5 13 11 12 9.3 9.4 9.5 6.9 e13 e6.0 49 12 11 e9.5 13 11 13 9.9 6.6 11 7.4 e10 e5.9 17 12 10 148 12 14 14 9.4 6.3 8.2 7.2 e8.0 e5.8 12 23 10 24 13 11 15 8.8 5.4 7.2 5.8 e6.0 e5.7 12 14 22 37 13 11 16 7.0 8.8 13 4.5 e6.0 e5.6 13 13 12 30 13 11 17 4.5 12 50 4.0 e15 e5.5 276 12 10 19 16 10 18 9.7 64 18 3.9 e11 e5.5 417 35 11 14 22 13 19 7.6 37 4.5 2.7 e7.0 e35 98 17 26 12 13 19 20 27 17 8.1 e2.8 e7.0 e25 70 16 14 11 10 11 21 12 12 7.9 e6.7 e18 13 106 146 e20 14 57 382 22 7.3 13 4.6 3.7 e10 8.6 68 175 11 35 76 65 23 6.5 12 3.7 9.6 e8.0 8.4 942 45 10 20 18 27 24 7.1 8.9 3.6 135 e7.0 12 621 24 9.5 13 13 22 25 6.4 8.7 21 238 e12 8.5 96 19 9.6 11 29 22 26 11 8.5 13 81 e9.0 7.7 42 16 9.1 21 43 28 27 6.4 8.2 9.1 24 e8.0 25 32 15 9.3 25 18 21 28 5.3 8.6 7.3 14 e6.0 11 27 14 16 33 47 19 29 4.6 9.3 6.9 16 9.2 24 13 9.5 17 25 37 30 5.3 9.7 6.5 12 8.7 21 12 8.7 13 24 22 31 5.8 6.6 14 e7.8 12 26 14 TOTAL 306.5 342.8 393.4 709.5 495.7 295.0 3,228.8 856 459.7 682.6 862 896 MEAN 9.89 11.4 12.7 22.9 17.7 9.52 108 27.6 15.3 22.0 27.8 29.9 MAX 37 64 50 238 142 35 942 175 60 148 123 382 MIN 4.5 5.4 3.6 2.7 6.0 5.5 7.9 12 8.7 9.4 10 10 MED 8.8 8.7 9.9 7.6 10 7.0 29 16 12 14 17 14 AC-FT 608 680 780 1,410 983 585 6,400 1,700 912 1,350 1,710 1,780 CFSM 0.84 0.98 1.08 1.95 1.51 0.81 9.19 2.36 1.31 1.88 2.37 2.55 IN. 0.97 1.09 1.25 2.25 1.57 0.94 10.26 2.72 1.46 2.17 2.74 2.85 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 2003, BY WATER YEAR (WY) MEAN 36.9 46.6 34.1 34.0 24.0 16.8 26.2 22.5 23.7 28.8 40.7 82.1 MAX 130 114 123 120 67.9 42.6 108 59.8 55.9 74.6 109 364 (WY) (1999) (1999) (1999) (1992) (1998) (1998) (2003) (1993) (1999) (1993) (1998) (1996) MIN 9.89 11.4 8.87 14.2 10.8 7.54 5.49 3.35 2.86 4.13 3.82 8.82 (WY) (2003) (2003) (1995) (1995) (1992) (1994) (1994) (1994) (1994) (1994) (1994) (1994) 291 RIO GRANDE DE LOIZA BASIN 50055225 RIO CAGÜITAS AT VILLA BLANCA AT CAGUAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1991 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 7,409.2 ANNUAL MEAN 20.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 413 LOWEST DAILY MEAN 3.6 ANNUAL SEVEN-DAY MINIMUM 6.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 14,700 ANNUAL RUNOFF (CFSM) 1.73 ANNUAL RUNOFF (INCHES) 23.54 10 PERCENT EXCEEDS 31 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 7.4 9,528.0 26.1 35.6 64.0 1998 11.9 1994 Apr 20 942 Apr 23 8,600 Sep 10, 1996 Dec 24 2.7 Jan 19 1.3 Jun 8, 1994 Oct 27 4.0 Jan 16 1.4 Jun 8, 1994 7,980 Apr 23 25,000 Sep 10, 1996 17.29 Apr 23 23.89 Sep 10, 1996 18,900 25,830 2.23 3.04 30.27 41.36 37 53 12 16 6.4 6.8 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 292 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGÜITAS AT HIGHWAY 30 AT CAGUAS, PR LOCATION.--Lat 18q15'11", long 66q01'26", at Highway 30 bridge, and 0.8 mi (1.3 km) east of Caguas Plaza. DRAINAGE AREA.--14.1 mi2 (36.5 km2). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 31... 1135 8.6 9.7 4.1 52 6.8 577 27.5 180 50.2 14.3 2.19 1 FEB 03... 1150 23 12 4.1 -- 7.7 577 25.4 200 54.0 15.0 2.67 1 APR 03... 1100 8.6 8.2 4.0 -- 7.4 564 25.8 190 52.4 14.0 2.36 1 JUL 01... 1350 8.1 5.8 4.7 -- 7.3 602 30.0 -- -- -- -- -­ SEP 05... 0930 9.4 17 2.1 -- 7.3 559 27.1 190 50.6 15.8 3.60 1 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 31... 34.0 154 39.8 <.2 36.4 52.2 -- 322 7.43 12 1.4 .89 .51 FEB 03... 35.9 171 41.5 .15 34.9 56.5 <.0 343 21.2 15 2.1 1.70 .38 APR 03... 35.5 151 40.5 .16 34.8 58.8 <.1 329 7.68 10 1.8 1.40 .36 JUL 01... -- 158 -- -- -- -- -- -- -- <10 3.2 3.00 .12 SEP 05... 33.6 169 41.0 <.2 33.0 44.1 -- 323 8.23 22 3.9 3.40 .08 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 31... .600 .09 .51 .27 2.0 8.9 <10 E6,700 E400 -- -- -- -­ FEB 03... .500 .12 .40 .31 2.6 11.5 20 E9,300 -- 74,000 E1 47.6 61 APR 03... .490 .13 .40 .32 2.3 10.1 10 E730 -- 52,000 <2 42.8 60 JUL 01... .200 .08 .20 .46 3.4 15.1 20 E10,000 -- -- -- -- -­ SEP 05... .120 .04 .50 .60 4.0 17.8 30 28,000 -- 220,000 -- -- -­ 293 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGÜITAS AT HIGHWAY 30 AT CAGUAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 31... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 03... <.2 E.6 <10 <.01 660 M 346 <.02 <3 <.3 <25 <.10 <16 APR 03... <.2 <.8 <10 <.01 120 M 321 <.02 <3 <.3 <25 <.10 <16 JUL 01... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 05... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 294 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR LOCATION.--Lat 18q15'28", long 66q02'13", at bridge on Highway 1, about 2.5 mi (4.0 km) upstream from Río Grande de Loíza, and 1.4 mi (2.3 km) north of Caguas Plaza. DRAINAGE AREA.--5.4 mi2 (14.0 km2). PERIOD OF RECORD.--Water years 1958, 1962-66, 1973-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 29... 0925 3.6 7.3 6.2 76 7.2 423 25.1 160 40.2 15.2 3.11 .7 FEB 03... 1500 15 360 4.1 -- 7.8 456 25.6 86 22.7 7.20 2.46 .6 APR 03... 0910 3.6 4.2 4.4 -- 7.4 456 24.4 160 40.1 15.4 3.33 .8 JUL 01... 1150 3.6 4.8 6.3 -- 7.6 438 28.7 -- -- -- -- -­ SEP 05... 1130 3.0 8.0 5.9 -- 7.4 418 27.8 160 38.1 15.4 3.60 .7 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 29... 21.8 148 32.1 <.2 32.0 14.4 -- 248 2.40 <10 .20 .06 .75 FEB 03... 12.2 127 16.7 .11 15.2 10.0 <.0 163 6.44 408 2.5 1.60 .58 APR 03... 24.0 151 33.4 .17 32.0 15.6 <.1 255 2.46 <10 .90 .69 .71 JUL 01... -- 139 -- -- -- -- -- -- -- <10 .70 .54 .68 SEP 05... 21.0 138 32.1 .2 28.1 13.4 -- 235 1.89 <10 .40 .14 .93 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 29... .770 .02 .14 .24 .97 4.3 <10 E220 310 -- -- -- -­ FEB 03... .670 .09 .90 .73 3.2 14.0 20 E150,000 -- E80,000 M 134 31 APR 03... .850 .14 .21 .38 1.8 7.7 10 E1,300 -- 8,000 2 76.8 34 JUL 01... .740 .06 .16 .32 1.4 6.4 10 E1,700 -- -- -- -- -­ SEP 05... 1.00 .07 .26 .28 1.4 6.2 10 E1,000 -- 32,000 -- -- -­ 295 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 29... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 03... <.2 33.6 70 <.01 13,000 6 633 .03 <3 <.3 76 E.07 <16 APR 03... <.2 <.8 <10 M 150 M 120 <.02 <3 <.3 <25 E.06 <16 JUL 01... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 05... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 296 RIO GRANDE DE LOIZA BASIN 50055750 RIO GURABO BELOW EL MANGO, PR LOCATION.--Lat 18q14'02", long 65q53'07", Hydrologic Unit 21010005, on left bank, 2.43 mi (3.91 km) northeast of Plaza de Juncos, 1.3 mi (2.1 km) southeast of Escuela La Placita and 0.35 mi (0.56 km ) southwest of El Mango. DRAINAGE AREA.--22.3 mi2 (57.8 km2). PERIOD OF RECORD.--March 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. Low flow is affected by sewage discharges from a water treatment plant, 0.60 mi (0.96 m) upstream from gaging station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 e8.5 e8.8 e7.2 11 e4.6 3.9 22 18 13 26 46 2 10 e7.9 e8.4 e9.5 103 e4.5 4.3 22 21 17 41 18 3 8.9 e8.5 e11 e8.2 26 e4.3 4.0 17 42 17 18 81 4 8.3 e9.0 e12 e8.3 137 e4.7 21 16 35 14 14 34 5 7.8 7.8 e24 e39 102 e4.6 310 17 21 14 12 18 6 7.4 7.6 e15 e34 41 e4.2 42 15 26 18 53 15 7 7.3 7.5 e12 e11 35 e4.0 21 15 91 15 43 14 8 8.5 7.3 e11 e8.1 16 e3.9 24 16 39 13 20 16 9 20 7.4 e15 e7.3 11 e3.8 74 15 25 13 16 17 10 10 13 e14 e8.3 24 e3.8 64 14 21 13 15 15 11 11 17 e10 e7.7 21 e4.2 1,430 12 22 12 44 13 12 16 15 e9.8 e6.8 15 e3.6 361 12 20 12 26 13 13 13 11 e9.3 e6.4 9.5 e3.6 177 40 19 58 16 49 14 9.3 8.4 e10 e6.5 7.3 e3.6 151 79 17 21 14 32 15 17 7.6 e9.3 e6.5 6.4 4.0 151 99 269 15 15 14 16 54 10 e11 e6.5 6.5 3.5 188 91 51 33 14 113 17 22 23 e50 e6.4 11 3.6 3,410 26 26 19 13 28 18 13 27 e34 e6.4 8.9 3.7 545 95 20 14 34 19 19 e11 e21 e11 e7.3 7.4 6.3 202 84 20 13 20 15 20 e10 e15 e9.6 e6.6 6.1 7.3 94 27 19 12 18 19 21 e13 e13 e11 e6.9 6.7 3.9 200 688 21 13 15 33 22 e13 23 e11 e6.2 7.7 3.7 261 75 18 16 285 21 23 e30 11 e10 e6.4 6.8 3.7 144 40 16 15 33 13 24 e22 e9.9 e12 e9.2 5.8 3.9 150 121 15 13 19 12 25 e22 e9.5 e9.8 e138 8.1 3.6 e57 34 14 12 18 11 26 e54 e13 e15 e62 7.4 3.2 e48 26 14 11 60 10 27 e24 e14 e14 e17 5.3 3.2 e33 22 13 13 26 10 28 e12 e10 e9.6 e12 4.8 6.3 e39 20 16 51 25 9.6 29 e8.9 e9.7 e8.2 e9.5 7.8 30 20 14 19 32 9.4 30 e8.4 e9.3 e7.0 e10 9.7 25 18 13 14 56 9.3 31 e8.5 e7.0 12 5.1 18 13 48 TOTAL 493.3 361.9 409.8 497.2 657.7 139.9 8,264.2 1,816 976 546 1,089 727.3 MEAN 15.9 12.1 13.2 16.0 23.5 4.51 275 58.6 32.5 17.6 35.1 24.2 MAX 54 27 50 138 137 9.7 3,410 688 269 58 285 113 MIN 7.3 7.3 7.0 6.2 4.8 3.2 3.9 12 13 11 12 9.3 AC-FT 978 718 813 986 1,300 277 16,390 3,600 1,940 1,080 2,160 1,440 CFSM 0.71 0.54 0.59 0.72 1.05 0.20 12.4 2.63 1.46 0.79 1.58 1.09 IN. 0.82 0.60 0.68 0.83 1.10 0.23 13.79 3.03 1.63 0.91 1.82 1.21 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 2003, BY WATER YEAR (WY) MEAN 51.8 78.7 44.8 34.2 25.5 10.8 31.1 31.0 38.3 36.1 42.3 77.6 MAX 161 252 166 103 66.7 18.1 275 123 117 147 110 196 (WY) (1991) (2000) (1999) (1996) (1995) (1991) (2003) (1992) (1992) (1993) (1998) (1998) MIN 4.01 12.1 10.7 6.34 8.90 4.51 5.29 4.83 9.65 6.64 10.2 21.4 (WY) (1993) (2003) (1998) (1995) (2001) (2003) (1995) (1990) (2000) (2000) (1993) (1997) 297 RIO CAMUY BASIN 50055750 RIO GURABO BELOW EL MANGO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1990 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 9,556.3 ANNUAL MEAN 26.2 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,790 LOWEST DAILY MEAN 4.5 ANNUAL SEVEN-DAY MINIMUM 4.7 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 18,950 ANNUAL RUNOFF (CFSM) 1.17 ANNUAL RUNOFF (INCHES) 15.94 10 PERCENT EXCEEDS 29 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 6.4 15,978.3 43.8 42.5 54.4 2000 22.0 1994 May 30 3,410 Apr 17 4,040 Sep 10, 1996 Mar 23 3.2 Mar 26 1.1 Oct 27, 1992 Mar 19 3.6 Mar 21 1.4 Oct 22, 1992 11,600 Apr 17 19,100 Sep 10, 1996 20.76 Apr 17 24.12 Sep 10, 1996 31,690 30,820 1.96 1.91 26.65 25.92 59 74 14 12 6.4 4.9 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 298 RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR LOCATION.--Lat 18q12'58", long 65q55'34", Hydrologic Unit 21010005, on left bank at Highway 919, 0.5 mi (0.8 km) upstream from Quebrada Don Víctor, 1.7 mi (2.7 km) upstream from Río Gurabo and 1.0 mi (1.6 km) south of Juncos Plaza. DRAINAGE AREA.--16.4 mi2 (42.5 km2). PERIOD OF RECORD.--January 1971 to current year. GAGE.--Water-stage recorder. Elevation of gage is 320 ft (98 m), from topographic map. REMARKS.--Records poor. Minor diversion from public water-supply tank, 0.5 mi upstream, during low flow. Gage-height and precipitation satellite telemetry at station. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges (no stages were recorded) of major floods are as follows: September 6, 1960, 37,100 ft3/s (1,050 m3/s), October 9, 1970, 18,200 ft3/s (515 m3/s). DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 17 4.8 5.2 16 19 5.5 e12 28 24 13 26 31 2 41 4.5 8.7 20 13 5.3 5.8 25 34 31 28 25 3 22 4.4 11 14 9.8 5.1 3.3 23 47 55 21 20 4 33 3.9 23 11 45 7.1 4.2 22 38 19 17 20 5 23 3.5 30 138 41 7.8 429 29 35 20 16 18 6 11 3.3 13 50 21 4.8 53 21 46 26 92 15 7 8.1 3.3 10 17 71 5.4 27 25 348 14 38 14 8 74 3.5 14 12 31 4.6 23 29 85 11 24 13 9 42 5.5 17 11 19 5.3 32 23 51 11 19 13 10 17 20 11 13 23 5.6 129 19 37 9.5 16 11 11 13 31 9.0 10 15 5.0 850 19 35 8.3 17 14 12 34 7.7 9.1 8.8 16 4.5 e120 19 34 8.5 13 32 13 16 5.8 9.2 8.4 10 5.7 e50 22 31 123 12 69 14 8.4 6.1 13 8.6 9.0 2.9 e20 35 24 23 12 31 15 14 3.9 8.3 8.1 8.0 2.9 e17 39 63 16 32 21 16 33 30 16 7.6 9.0 2.9 30 42 45 42 12 407 17 23 24 175 7.5 22 4.7 3,050 31 24 18 58 49 18 12 30 56 8.4 15 3.9 941 77 21 13 69 31 19 7.5 15 21 7.6 11 41 305 47 162 12 29 24 20 6.4 9.3 18 7.2 19 12 145 27 38 11 21 24 21 9.8 9.7 21 7.7 25 4.4 142 1,040 57 19 24 209 22 7.5 8.3 18 7.4 10 3.4 201 191 27 51 344 64 23 5.8 7.3 23 8.1 7.6 3.4 93 96 20 21 55 32 24 6.5 6.9 16 15 7.8 5.3 66 67 18 14 29 24 25 11 8.6 39 143 10 3.4 54 54 16 11 27 21 26 54 26 21 42 7.0 2.7 73 45 14 11 50 20 27 13 10 15 15 6.1 3.2 49 37 13 28 41 17 28 7.2 7.2 12 8.9 5.9 6.2 40 32 18 195 31 16 29 5.2 5.7 11 8.9 12 35 28 12 40 82 15 30 4.7 5.6 10 9.3 e18 30 24 11 26 47 15 31 4.8 10 45 e3.9 23 24 34 TOTAL 584.9 314.8 673.5 694.5 506.2 207.9 7,029.3 2,239 1,428 924.3 1,336 1,315 MEAN 18.9 10.5 21.7 22.4 18.1 6.71 234 72.2 47.6 29.8 43.1 43.8 MAX 74 31 175 143 71 41 3,050 1,040 348 195 344 407 MIN 4.7 3.3 5.2 7.2 5.9 2.7 3.3 19 11 8.3 12 11 AC-FT 1,160 624 1,340 1,380 1,000 412 13,940 4,440 2,830 1,830 2,650 2,610 CFSM 1.15 0.64 1.32 1.37 1.10 0.41 14.3 4.40 2.90 1.82 2.63 2.67 IN. 1.33 0.71 1.53 1.58 1.15 0.47 15.94 5.08 3.24 2.10 3.03 2.98 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1971 - 2003, BY WATER YEAR (WY) MEAN 72.7 88.0 52.6 26.9 19.6 17.5 22.7 45.1 47.3 43.3 60.4 83.6 MAX 293 461 550 79.6 47.9 39.7 234 268 188 163 231 285 (WY) (1986) (1988) (1988) (1998) (1984) (1973) (2003) (1985) (1979) (1981) (1979) (1998) MIN 18.9 10.5 11.0 11.4 7.21 6.04 5.17 5.02 3.86 4.61 4.71 10.8 (WY) (2003) (2003) (1990) (1976) (1974) (2000) (1995) (1990) (2001) (1994) (1994) (1987) 299 RIO GUAJATACA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1971 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 9,532.7 ANNUAL MEAN 26.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 619 LOWEST DAILY MEAN 3.3 ANNUAL SEVEN-DAY MINIMUM 3.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 18,910 ANNUAL RUNOFF (CFSM) 1.59 ANNUAL RUNOFF (INCHES) 21.62 10 PERCENT EXCEEDS 37 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 4.9 17,253.4 47.3 48.5 121 1988 17.1 1990 Apr 20 3,050 Apr 17 9,100 Dec 8, 1987 Nov 6 2.7 Mar 26 1.2 Jun 22, 2001 Nov 2 3.7 Mar 21 1.6 Jun 17, 2001 13,000 Apr 17 40,000 Dec 8, 1987 17.05 Apr 17 25.63 Dec 8, 1987 34,220 35,100 2.88 2.95 39.14 40.14 63 72 18 18 5.5 6.4 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 300 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR LOCATION.--Lat 18q15'30", long 65q58'05", Hydrologic Unit 21010005, on left bank, at bridge on Highway 181, 0.3 mi (0.5 km) east of Gurabo, and 4.5 mi (7.6 km) upstream from Río Grande de Loíza. DRAINAGE AREA.--60.2 mi2 (156 km2). PERIOD OF RECORD.--1958 (occasional low-flow measurements only), January to September 1959 (monthly measurements only), October 1959 to current year. GAGE.--Water-stage recorder and crest-stage gage. Datum of gage is 131.58 ft (40.106 m) above mean sea level. Prior to October 1, 1989 datum 5.0 ft (1.5 m) lower. REMARKS.--Records fair, except for March 20 to April 9, and estimated mean daily discharges, which are poor. Gage-height and pre cipitation satellite telemetry at station. Low flow affected by diversions for water supply about 400 ft (121 m) upstream from station by PRASA. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 37 31 30 20 51 23 e55 84 38 30 40 110 2 41 30 29 25 82 23 28 82 43 36 67 56 3 36 30 38 22 74 22 26 80 68 55 44 106 4 32 30 41 23 140 23 31 76 75 37 34 87 5 37 30 55 80 128 23 639 77 46 31 31 48 6 37 29 43 71 93 22 111 76 50 39 89 41 7 28 29 35 31 74 21 65 74 465 32 83 40 8 27 30 33 22 64 21 e94 76 123 28 48 39 9 79 30 48 20 46 20 e73 68 57 27 39 40 10 88 37 43 22 51 20 105 61 46 26 36 40 11 43 59 32 20 55 22 2,670 57 48 25 54 37 12 48 46 31 17 47 19 399 56 43 25 59 35 13 45 45 30 16 39 19 136 91 40 159 38 174 14 31 38 33 16 34 19 89 148 35 53 34 116 15 29 34 32 16 31 19 71 164 503 36 41 45 16 53 38 35 16 31 21 89 142 134 58 38 408 17 58 61 128 15 35 20 12,100 86 53 43 52 71 18 33 74 92 15 39 21 2,120 117 43 33 73 51 19 32 55 37 18 33 41 724 173 98 29 59 54 20 29 44 31 16 31 e86 347 67 54 28 45 46 21 38 42 36 17 37 e67 590 2,460 57 32 44 120 22 38 49 35 16 33 e48 635 335 46 43 258 78 23 80 41 34 15 28 22 314 96 37 41 89 42 24 62 38 39 24 27 24 436 227 35 30 57 36 25 61 36 36 374 30 24 166 72 33 28 52 33 26 134 48 46 170 32 23 143 59 31 28 103 30 27 67 52 40 56 25 24 115 51 30 33 73 29 28 40 38 25 42 24 24 108 46 35 136 57 27 29 33 34 21 36 25 97 43 32 55 85 28 30 31 31 19 38 35 89 41 29 37 103 26 31 30 19 53 e57 38 34 113 TOTAL 1,457 1,209 1,226 1,342 1,414 878 22,665 5,323 2,427 1,327 2,038 2,093 MEAN 47.0 40.3 39.5 43.3 50.5 28.3 756 172 80.9 42.8 65.7 69.8 MAX 134 74 128 374 140 86 12,100 2,460 503 159 258 408 MIN 27 29 19 15 24 19 26 38 29 25 31 26 AC-FT 2,890 2,400 2,430 2,660 2,800 1,740 44,960 10,560 4,810 2,630 4,040 4,150 CFSM 0.78 0.67 0.66 0.72 0.84 0.47 12.5 2.85 1.34 0.71 1.09 1.16 IN. 0.90 0.75 0.76 0.83 0.87 0.54 14.01 3.29 1.50 0.82 1.26 1.29 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1960 - 2003, BY WATER YEAR (WY) MEAN 212 214 145 63.6 47.1 37.6 57.8 133 120 105 156 224 MAX 1,414 1,045 863 204 131 97.5 756 746 468 376 610 1,225 (WY) (1971) (1988) (1988) (1992) (1989) (1985) (2003) (1985) (1970) (1993) (1979) (1960) MIN 16.0 23.7 10.7 16.4 12.6 11.2 13.1 12.7 16.8 14.9 24.8 8.76 (WY) (1968) (1996) (1968) (1968) (1968) (1965) (1995) (1990) (1972) (2000) (1967) (1967) 301 RIO CAMUY BASIN 50057000 RIO GURABO AT GURABO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1960 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 21,064.5 ANNUAL MEAN 57.7 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2,390 LOWEST DAILY MEAN 7.9 ANNUAL SEVEN-DAY MINIMUM 8.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 41,780 ANNUAL RUNOFF (CFSM) 0.959 ANNUAL RUNOFF (INCHES) 13.02 10 PERCENT EXCEEDS 76 50 PERCENT EXCEEDS 32 90 PERCENT EXCEEDS 16 43,399 119 127 286 1979 42.2 1967 May 30 12,100 Apr 17 26,200 Sep 10, 1996 Mar 21 15 Jan 17 3.7 May 27, 1996 Mar 17 16 Jan 12 5.2 May 25, 1996 43,500 Apr 17 62,100 Sep 10, 1996 29.15 Apr 17 31.44 Sep 10, 1996 86,080 91,660 1.98 2.10 26.82 28.56 121 199 40 46 23 16 e Estimated 100,000 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 302 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR LOCATION.--Lat 18q15'56", long 65q59'04", at bridge on Highway 941, 1.2 mi (1.9 km) west-northwest from gaging station 50057000, and 1.0 mi (1.6 km) northwest of Gurabo Plaza. DRAINAGE AREA.--62.8 mi2 (162.7 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- wat unf solved water, conduc- ness, Magnes- Potas- lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp- water, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, Date Time NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) OCT 31... 1020 19 3.2 41 6.6 361 28.2 100 24.5 10.3 4.42 1 22.4 FEB 18... 1400 12 4.2 -- 7.5 447 27.7 140 32.3 13.8 5.11 1 31.5 APR 03... 1240 28 3.8 -- 7.2 441 27.4 140 31.9 14.3 4.14 1 32.5 JUN 05... 1400 44 3.7 -- 7.8 345 28.5 -- -- -- -- -- -­ SEP 05... 1430 87 4.6 -- 7.3 192 31.0 62 14.5 6.18 3.66 .7 12.0 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate Nitrite end pt, ide, ide, Silica, Sulfate Sulfide sum of deg. C, water, water, water water water, field, water, water, water, water, water consti- sus- unfltrd unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents pended, mg/L mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L mg/L as N as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (00530) (00625) (00610) (00620) (00630) (00615) OCT 31... 111 24.1 <.2 28.0 11.1 -- 191 <10 1.3 .45 .89 .920 .03 FEB 18... 145 31.5 .16 32.2 13.3 <.0 247 14 1.2 .36 1.87 2.00 .13 APR 03... 144 34.8 .15 32.0 15.0 <.1 251 27 .80 .34 1.01 1.10 .09 JUN 05... 110 -- -- -- -- -- -- <10 -- -- -- -- -­ SEP 05... 58 13.1 <.2 16.7 6.5 -- 108 41 1.2 .35 .66 .790 .13 Total Fecal Fecal Total Chrom- Organic Total nitro- COD, coli- strep- coli- Barium, Boron, ium, nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, recover unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, Date mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) OCT 31... .85 .29 2.2 9.8 20 E1,400 230 -- -- -- -- -- -­ FEB 18... .84 .37 3.2 14.2 <10 E700 -- 4,100 <2 76.2 44 <.2 <.8 APR 03... .46 .29 1.9 8.4 20 4,800 -- 8,000 E2 93.7 54 <.2 E.8 JUN 05... -- -- -- -- 20 2,200 -- E19,000 -- -- -- -- -­ SEP 05... .85 .28 2.0 8.8 30 E1,300 -- 34,000 -- -- -- -- -­ 303 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 31... -- -- -- -- -- -- -- -- -- -- -- FEB 18... <10 <.01 410 <1 474 <.02 <3 <.3 <25 <.10 <16 APR 03... <10 <.01 1,190 M 1,050 <.02 <3 <.3 E19 <.10 <16 JUN 05... -- -- -- -- -- -- -- -- -- -- -- SEP 05... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 304 RIO GRANDE DE LOIZA BASIN 50058350 RIO CAÑAS AT RIO CAÑAS, PR LOCATION.--Lat 18q17'41", long 66q02'44", Hydrologic Unit 21010005, at right bank, off Road 798, upstream side of bridge on Highway 52, 0.5 mi (0.8 km) northeast from Escuela Segunda Unidad de Francisco Valdés, and 0.8 mi (1.3 km) north of La Barra. DRAINAGE AREA.--7.53 mi2 (19.5 km2). PERIOD OF RECORD.--March 1990 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 164 ft (50 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.0 15 4.7 3.4 4.1 3.6 2.8 4.4 3.9 3.0 e5.3 5.9 2 5.8 6.4 5.4 3.8 3.8 3.5 2.8 4.2 3.7 3.0 7.7 5.8 3 5.7 5.3 4.4 3.5 4.1 3.5 2.9 4.2 4.4 2.9 4.4 5.5 4 5.7 4.8 11 3.3 48 3.4 3.1 4.2 3.4 3.2 7.7 5.1 5 5.7 5.0 5.5 3.3 9.5 3.6 4.7 4.1 3.3 3.4 3.9 5.1 6 5.7 5.2 4.5 3.3 5.2 3.5 3.2 4.3 3.2 3.1 4.3 4.7 7 5.4 4.8 4.2 3.1 4.5 3.4 2.8 11 4.7 3.4 4.7 8.5 8 7.3 4.6 9.0 3.0 4.2 3.3 2.9 6.2 3.3 4.0 3.8 7.7 9 6.0 5.3 5.6 3.0 3.9 3.3 2.8 5.0 3.6 3.2 3.6 4.8 10 12 4.7 4.7 2.9 4.0 3.1 2.9 4.8 3.3 3.0 3.4 4.6 11 5.9 4.5 5.1 2.9 4.0 3.1 25 5.0 3.2 2.9 3.4 5.0 12 5.6 9.2 4.6 2.7 3.9 3.2 11 5.1 3.1 2.9 3.4 4.6 13 5.5 5.3 5.2 2.6 3.8 3.2 7.4 4.4 3.0 26 6.2 12 14 5.7 4.8 4.3 2.6 3.9 3.2 6.7 5.1 2.9 e3.7 9.0 5.5 15 6.5 4.7 4.2 2.5 3.7 3.1 6.3 4.6 5.2 e3.6 3.9 4.3 16 5.8 4.7 4.2 2.6 3.8 3.1 6.5 4.3 3.5 e6.4 3.5 4.7 17 5.4 4.7 4.2 2.7 4.1 3.2 47 4.2 3.2 e3.5 3.3 4.1 18 5.4 5.3 4.1 2.7 3.8 3.0 103 8.3 3.1 e3.0 16 4.1 19 7.3 5.2 4.0 2.7 3.7 3.0 26 5.3 4.2 e3.1 5.2 4.3 20 7.5 4.6 4.9 2.7 3.7 3.3 25 16 4.2 e3.4 4.1 4.2 21 12 4.6 4.5 2.8 3.7 3.1 48 25 3.2 e3.6 27 194 22 5.4 4.6 5.0 2.6 3.7 3.0 29 7.7 3.0 e5.4 21 e11 23 5.7 4.5 4.0 3.2 3.6 3.2 130 5.2 2.9 e3.7 6.5 e5.3 24 5.3 4.5 3.9 28 3.6 3.1 35 4.2 2.8 e3.2 5.3 e4.5 25 6.4 4.4 5.0 67 3.9 2.9 8.8 3.9 2.9 e3.1 17 e4.3 26 6.3 4.4 3.8 20 3.9 6.1 6.6 4.0 2.9 e3.6 11 e4.3 27 5.0 4.5 3.6 5.2 3.7 7.3 5.2 4.2 3.0 e3.9 5.4 e4.3 28 5.4 4.5 3.5 4.4 3.6 3.5 4.7 4.1 3.1 e5.4 9.0 e4.1 29 5.0 4.8 3.4 4.8 3.1 4.6 3.9 3.0 e3.9 94 e4.3 30 4.9 4.9 3.4 4.1 2.9 4.5 4.0 3.0 e3.4 10 e4.8 31 5.2 3.5 4.2 2.8 4.0 20 6.4 TOTAL 192.5 159.8 147.4 205.6 159.4 106.6 571.2 184.9 102.2 149.9 319.4 351.4 MEAN 6.21 5.33 4.75 6.63 5.69 3.44 19.0 5.96 3.41 4.84 10.3 11.7 MAX 12 15 11 67 48 7.3 130 25 5.2 26 94 194 MIN 4.9 4.4 3.4 2.5 3.6 2.8 2.8 3.9 2.8 2.9 3.3 4.1 AC-FT 382 317 292 408 316 211 1,130 367 203 297 634 697 CFSM 0.82 0.71 0.63 0.88 0.76 0.46 2.53 0.79 0.45 0.64 1.37 1.56 IN. 0.95 0.79 0.73 1.02 0.79 0.53 2.82 0.91 0.50 0.74 1.58 1.74 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1990 - 2003, BY WATER YEAR (WY) MEAN 19.6 19.4 18.1 12.8 10.2 6.19 7.94 8.38 9.07 8.79 15.3 23.9 MAX 51.0 53.8 50.7 24.5 18.8 12.0 23.7 19.5 35.2 25.9 36.8 81.6 (WY) (1999) (1999) (2002) (1992) (1995) (1999) (2002) (1992) (1999) (1999) (1996) (1996) MIN 4.60 5.33 4.75 4.48 4.29 2.48 3.24 2.50 1.78 3.40 4.36 4.25 (WY) (1992) (2003) (2003) (1994) (1994) (1994) (1995) (1994) (1994) (1990) (1990) (1997) RIO CAMUY BASIN 305 50058350 RIO CAÑAS AT RIO CAÑAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1990 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 3,843.4 ANNUAL MEAN 10.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 173 LOWEST DAILY MEAN 3.4 ANNUAL SEVEN-DAY MINIMUM 3.7 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 7,620 ANNUAL RUNOFF (CFSM) 1.40 ANNUAL RUNOFF (INCHES) 18.99 10 PERCENT EXCEEDS 18 50 PERCENT EXCEEDS 6.9 90 PERCENT EXCEEDS 4.3 2,650.3 7.26 13.6 24.8 1999 5.77 1994 Apr 26 194 Sep 21 1,670 Sep 10, 1996 Dec 29 2.5 Jan 15 1.1 Jun 8, 1994 Dec 25 2.6 Jan 12 1.2 Jun 8, 1994 2,080 Sep 21 7,500 Sep 10, 1996 17.35 Sep 21 24.60 Sep 10, 1996 2.4 Jan 15 1.0 Jun 21, 1994 5,260 9,870 0.964 1.81 13.09 24.57 9.0 26 4.3 6.2 3.0 3.0 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 308 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 ANC, Residue Ammonia Nitrite Dis- pH, Specif. wat unf total + + Instan- solved water, conduc- fixed at 105 org-N, Ammonia nitrate taneous Dis- oxygen, unfltrd tance, Temper- end pt, Sulfide deg. C, water, water, water dis- solved percent field, wat unf ature, field, water sus- unfltrd unfltrd unfltrd charge, oxygen, of sat- std uS/cm water, mg/L as unfltrd pended, mg/L mg/L mg/L Date Time Q cfs mg/L uration units 25 degC deg C CaCO3 mg/L mg/L as N as N as N (00061) (00300) (00301) (00400) (00095) (00010) (00410) (00745) (00530) (00625) (00610) (00630) OCT 29... 1135 93 93 .2 3 6.6 302 28.1 100 -- <10 .70 .24 <.020 JAN 29... 1525 155 155 .4 5 6.9 322 26.0 105 -- <10 .70 .29 .210 APR 23... 1350 154 -- 2.2 -- 6.8 176 28.1 49 <.1 32 .80 .10 .700 JUN 03... 1445 139 139 1.9 -- 7.0 208 29.2 65 -- 10 -- -- -­ SEP 03... 1215 174 179 2.0 -- 7.0 247 29.4 78 -- <10 .50 .16 .060 Total Fecal Fecal Total Mangan- nitro- COD, coli- strep- coli- Boron, Copper, Iron, ese, Zinc, Nitrite Phos- gen, high form, tococci form, water, water, water, water, water, water, phorus, water, level, M-FC KF M-Endo, unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd water, unfltrd water, 0.7u MF MF, immed, recover recover water recover recover recover mg/L unfltrd mg/L unfltrd col/ col/ col/ -able, -able, unfltrd -able, -able, -able, Date as N mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L mg/L ug/L ug/L ug/L (00615) (00665) (71887) (00340) (31625) (31673) (31501) (01022) (01042) (00720) (01045) (01055) (01092) OCT 29... <.01 .14 -- 10 E29 16 -- -- -- -- -- -- -­ JAN 29... .03 .10 4.0 -- E37 -- 208 -- -- -- -- -- -­ APR 23... .07 .18 6.6 20 E1,100 -- 650 20 20 <.01 3,140 108 E24 JUN 03... -- -- -- 20 50 -- -- -- -- -- -- -- -- SEP 03... .03 .07 2.5 10 40 -- 280 -- -- -- -- -- -- Phen­ olic com- MBAS, pounds, water, water, unfltrd unfltrd Date mg/L ug/L (38260) (32730) OCT 29... -- -­ JAN 29... -- -­ APR 23... <.10 <16 JUN 03... -- -­ SEP 03... -- -­ < -- Less than E -- Estimated value --- --- --- --- --- --- --- --- --- --- --- --- --- 306 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR LOCATION.--Lat 18q19'49", long 66q01'00", Hydrologic Unit 21010005, at pumpsite at damsite, and 1.9 mi (3.1 km) south of Trujillo Alto Plaza. DRANAIGE AREA.--208 mi2 (539 km2). ELEVATION RECORDS PERIOD OF RECORD.--December 1987 to current year. Prior to October 1994, published as Lago Loíza at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lake is formed by Loíza Dam, a concrete structure completed in 1954. Useable capacity of impoundment is 30,000 acre-ft (37.0 hm3). Out flow from lake is controlled by five slide gates in power plant and pump intake structure, four sluicegates, and concrete spillway wi th eight radial gates. Lake is used for municipal water supply and intermittent power generation. Gage-height satellite telemetry at station. New capacity table based on U.S. Geological Survey Water-Resources Investigations Report 97-4108, November 1994 . EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation 147.42 ft (44.93 m), September 18, 1989; minimum elevation, 108.52 ft (33.08 m), July 18, 1994. EXTREMES FOR CURRENT YEAR.--Maximum elevation 135.13 ft (41.19 m), April 17; minimum elevation, 126.85 ft (38.66 m), April 5. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 97-4108, 1994) (Elevation in ft, capacity in acre-ft) Elevation Contents 75 0 95 73 115 2,205 Elevation Contents 125 5,861 131 9,218 135 11,504 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 133.81 134.41 132.64 133.54 134.62 133.65 A 134.75 134.52 133.92 134.27 133.97 2 133.82 134.30 132.51 133.51 134.71 133.47 A 134.64 134.52 134.02 134.59 134.19 3 133.83 134.46 132.47 133.45 134.74 133.29 127.19 137.75 134.83 134.26 133.94 134.09 4 133.83 134.46 132.57 133.34 134.05 133.11 126.91 134.77 134.51 134.27 134.00 134.07 5 133.86 134.36 132.60 134.00 A 132.91 130.02 134.79 134.54 134.37 133.99 134.10 6 134.01 134.24 132.61 134.58 134.57 132.72 130.47 134.78 134.23 134.58 134.37 134.09 7 134.00 134.09 132.53 134.62 134.72 132.50 130.38 134.74 134.13 134.62 134.34 134.16 8 133.98 133.94 132.55 134.56 134.82 132.29 130.25 134.68 134.38 134.58 134.59 134.23 9 134.20 133.82 132.53 134.47 134.72 132.07 130.14 134.71 134.62 134.57 134.20 134.21 10 133.97 133.72 132.47 134.32 134.81 131.85 130.78 134.67 134.72 134.50 134.24 134.19 11 134.06 133.72 132.37 134.20 134.58 131.65 134.08 134.60 134.78 134.38 134.37 134.17 12 134.12 133.72 132.27 134.05 134.64 131.38 134.85 134.53 134.17 134.25 134.54 134.11 13 134.15 133.64 132.18 133.91 134.59 131.12 A 134.56 134.21 134.03 134.54 134.22 14 134.11 133.52 132.08 133.76 134.50 130.86 134.54 134.76 134.20 134.52 134.52 133.80 15 134.05 133.36 131.97 133.59 134.40 130.59 134.60 134.50 134.13 134.17 134.42 133.89 16 134.13 133.43 131.89 133.43 134.33 130.32 134.71 134.61 134.16 134.51 134.15 133.92 17 134.23 133.61 133.31 133.24 134.37 130.06 134.40 134.64 134.26 134.23 134.39 134.18 18 134.23 133.98 133.88 133.08 134.47 129.81 133.77 134.50 134.27 133.82 134.17 134.30 19 134.27 134.06 133.86 132.94 134.47 130.23 134.02 134.72 134.41 133.79 133.95 134.49 20 134.40 133.99 133.82 132.76 134.40 130.30 134.19 134.65 134.80 133.73 134.06 133.83 21 134.36 133.91 133.79 132.61 134.48 130.08 134.16 133.85 134.24 133.73 134.60 133.56 22 134.36 133.82 133.79 132.42 134.50 129.87 133.95 134.53 134.37 134.26 133.62 134.18 23 134.53 133.72 133.86 132.28 134.41 129.60 133.88 134.23 134.38 134.58 134.07 134.14 24 134.60 133.59 133.85 132.93 134.29 129.33 133.88 134.57 134.38 134.59 134.27 134.23 25 134.30 133.45 133.96 134.26 134.22 129.05 134.73 134.55 134.34 134.54 133.60 134.29 26 134.34 133.36 134.13 134.42 134.13 128.81 134.70 134.64 134.26 134.57 133.55 134.31 27 134.50 133.28 134.15 134.57 133.97 128.84 134.81 134.67 134.18 134.66 134.05 134.28 28 134.48 133.15 134.05 134.53 133.83 128.59 A 134.62 134.17 134.28 134.08 134.24 29 134.40 132.98 133.94 134.50 128.38 A 134.59 134.09 134.58 133.32 134.31 30 134.31 132.81 133.81 134.43 A 134.78 134.53 134.00 134.61 134.02 134.28 31 134.21 133.66 134.55 A 134.59 134.11 133.52 MAX 134.60 134.46 134.15 134.62 137.75 134.83 134.66 134.60 134.49 MIN 133.81 132.81 131.89 132.28 133.85 134.00 133.73 133.32 133.56 A No gage-height record 307 RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE NEAR TRUJILLO ALTO, PR—Continued O N D J F M A M J J A S 126 128 130 132 134 136 138 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 309 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE, PR LOCATION.--Lat 18q20'33", long 66q00'20", Hydrologic Unit 21010005, on left bank of Highway 175, 1.1 mi (1.8 km) downstream of Lago Loíza Dam. DRAINAGE AREA.--209 mi2 (541 km2). PERIOD OF RECORD.--December 1986 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 32 ft (10 m), from topographic map. REMARKS.--Records poor. Flow regulated by Lago Loíza Dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.2 1.9 2.8 2.4 7.0 1.3 e0.11 32 1.2 0.99 1.8 81 2 4.2 1.9 2.8 2.3 5.4 1.3 0.09 58 1.2 1.2 395 3.1 3 4.1 1.8 2.5 2.4 43 1.3 0.09 1.9 1.1 1.4 451 127 4 4.5 1.7 3.3 2.6 1,180 1.2 0.11 1.4 265 1.3 1.5 219 5 4.4 1.7 2.7 2.3 57 1.1 0.21 1.3 1.8 1.3 0.90 1.7 6 4.4 1.9 8.9 2.3 74 1.2 0.24 1.3 420 1.4 133 1.6 7 4.3 2.1 3.5 2.2 21 1.3 0.21 24 1,490 1.2 427 1.6 8 4.4 2.7 3.8 2.3 7.0 1.2 0.16 41 371 1.4 1.4 1.5 9 4.8 2.3 3.7 2.2 20 1.1 0.16 1.6 1.4 1.2 238 1.5 10 415 2.5 3.4 2.3 7.7 0.97 0.14 1.2 1.2 1.5 2.0 1.5 11 4.5 2.6 3.4 2.5 12 3.0 2.3 3.3 2.1 13 3.0 2.3 3.6 2.1 14 3.9 2.4 2.8 2.0 15 4.2 2.0 2.2 1.9 150 0.91 5,860 1.1 1.1 1.3 0.80 4.1 1.7 0.88 639 1.1 322 0.87 0.67 2.2 1.4 0.85 350 1.2 3.9 1,810 0.71 165 1.5 0.79 257 21 1.4 3.8 0.70 515 1.4 0.91 0.69 274 849 202 46 1.6 16 3.5 1.8 2.2 1.8 17 3.2 1.7 2.1 1.8 18 3.3 1.9 2.1 2.2 19 3.2 2.0 2.2 2.0 20 4.1 1.8 2.4 2.0 1.3 0.71 0.49 32 291 114 194 1,140 1.3 0.60 19,900 1.7 1.6 160 215 2.1 1.2 0.53 9,760 294 1.4 237 583 1.4 1.2 0.66 2,540 100 801 1.2 305 1.8 1.6 0.74 1,250 100 2.2 0.93 1.4 341 21 226 1.9 2.9 1.9 22 4.0 5.8 3.7 1.8 23 5.8 2.7 3.2 1.9 24 4.2 2.4 2.6 3.0 25 220 2.3 3.0 1,520 1.7 0.63 2,030 5,610 408 0.85 375 3,280 1.5 0.88 2,300 1,080 1.9 1.0 2,220 349 1.4 0.73 2,380 487 1.3 0.90 118 261 1.4 0.62 2,430 182 1.1 0.89 2.1 2.1 1.4 0.48 152 60 1.2 0.79 510 1.9 26 238 2.8 2.9 793 27 5.0 3.1 2.8 6.6 28 2.5 3.2 2.4 16 29 2.6 2.9 2.3 5.4 30 2.5 2.9 2.4 4.9 31 2.0 --- 2.4 11 1.4 0.92 285 1.8 1.3 1.2 558 2.4 1.7 0.88 94 1.1 1.1 1.8 7.9 1.7 1.5 0.22 97 15 1.1 705 124 1.6 --- 1.4 94 1.6 1.0 1.5 1,370 1.7 --- 0.51 35 0.99 1.0 0.91 104 1.8 --- e0.18 --- 1.1 --- 307 441 --­ TOTAL 1,202.8 71.3 94.3 2,409.2 MEAN 38.8 2.38 3.04 77.7 MAX 415 5.8 8.9 1,520 MIN 2.0 1.7 2.1 1.8 AC-FT 2,390 141 187 4,780 CFSM 0.19 0.01 0.01 0.37 IN. 0.21 0.01 0.02 0.43 1,596.7 27.00 50,455.70 8,430.39 5,247.5 3,565.83 8,828.88 6,516.9 57.0 0.87 1,682 272 175 115 285 217 1,180 1.4 19,900 5,610 1,490 1,810 2,220 3,280 1.2 0.18 0.09 0.99 1.0 0.79 0.67 1.4 3,170 54 100,100 16,720 10,410 7,070 17,510 12,930 0.27 0.00 8.05 1.30 0.84 0.55 1.36 1.04 0.28 0.00 8.98 1.50 0.93 0.63 1.57 1.16 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1987 - 2003, BY WATER YEAR (WY) MEAN 350 560 355 152 MAX 1,281 2,732 2,603 733 (WY) (1999) (1988) (1988) (1992) MIN 38.8 2.38 3.04 2.49 (WY) (2003) (2003) (2003) (1995) 70.5 41.2 149 102 162 132 265 741 242 299 1,682 367 784 672 718 4,255 (1989) (1989) (2003) (1992) (1987) (1993) (1988) (1996) 4.52 0.87 1.20 1.03 1.96 1.62 2.21 29.7 (1990) (2003) (1995) (1995) (1994) (1994) (1994) (1990) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1987 - 2003 ANNUAL TOTAL 51,770.4 ANNUAL MEAN 142 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 5,030 LOWEST DAILY MEAN 1.4 ANNUAL SEVEN-DAY MINIMUM 1.6 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 102,700 ANNUAL RUNOFF (CFSM) 0.679 ANNUAL RUNOFF (INCHES) 9.21 10 PERCENT EXCEEDS 307 50 PERCENT EXCEEDS 4.5 90 PERCENT EXCEEDS 2.2 88,446.50 242 257 652 1988 37.8 1994 Apr 20 19,900 Apr 17 110,000 Sep 10, 1996 Aug 28 0.09 Apr 2 0.09 Apr 2, 2003 Aug 23 0.15 Mar 31 0.15 Mar 31, 2003 59,300 Apr 17 223,000 Sep 10, 1996 28.88 Apr 17 49.31 Sep 10, 1996 175,400 186,500 1.16 1.23 15.74 16.74 383 442 2.3 8.1 0.89 2.1 e Estimated 310 RIO GRANDE DE LOIZA BASIN 50059050 RIO GRANDE DE LOIZA BELOW DAMSITE, PR—Continued DISCHARGE, 100,000 IN CUBIC FEET PER SECOND 50,000 20,000 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 2002 2003 O N D J F M A M J J A S 311 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR LOCATION.--Lat 18q21'35", long 66q00'15", 100 ft (30 m) downstream of Highway 181 bridge, 0.4 mi (0.6 km) northwest of Trujillo Alto Plaza, and 2.2 mi (3.5 km) northeast of Lago Loíza Reservoir. DRAINAGE AREA.--213 mi2 (552 km2). PERIOD OF RECORD.--Water years 1981 to current year. REMARKS: Flow controlled by Lago Loíza. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 29... 1335 5.8 3.9 10.2 138 7.6 433 31.2 160 40.9 13.8 2.75 1 JAN 29... 1715 7.8 4.1 8.6 108 7.6 467 27.1 160 41.0 13.8 2.89 1 APR 02... 1300 3.7 5.3 11.6 -- 8.0 502 30.0 170 43.7 15.8 2.68 1 JUN 06... 0950 5.2 34 6.2 -- 7.6 318 28.4 -- -- -- -- -­ SEP 03... 1400 11 -- 5.7 -- 7.7 478 32.3 190 46.8 16.8 2.71 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 29... 28.2 162 27.9 <.2 29.5 15.6 -- 256 4.01 <10 .30 .04 -­ JAN 29... 34.0 163 31.2 .15 28.9 19.4 <.0 269 5.71 <10 .40 .07 2.33 APR 02... 33.8 175 34.4 .17 29.5 18.0 <.1 283 2.82 <10 .60 .14 .43 JUN 06... -- 106 -- -- -- -- -- -- -- 59 -- -- -­ SEP 03... 28.3 175 27.7 <.2 29.2 19.0 -- 276 8.04 <10 .40 .04 .95 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 29... .480 <.01 .26 .10 .78 3.5 <10 E82 <10 -- -- -- -­ JAN 29... 2.40 .07 .33 .11 2.8 12.4 E10 E1,000 -- E8,600 E1 38.8 58 APR 02... .480 .05 .46 .12 1.1 4.8 20 110 -- 560 E1 36.1 68 JUN 06... -- -- -- -- -- -- 10 66 -- 4,400 -- -- -- SEP 03... .970 .02 .36 .08 1.4 6.1 10 280 -- 3,800 -- -- -­ 312 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 29... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 29... <.2 <.8 <10 <.01 100 <1 102 <.02 <3 <.3 E24 <.10 <16 APR 02... <.2 <.8 <10 <.01 130 <1 316 <.02 <3 <.3 <25 E.05 <16 JUN 06... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 03... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 313 RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR LOCATION.--Lat 18q19'08", long 65q53'21", Hydrologic Unit 21010005, at about 100 ft upstream from bridge, on paved secondary road, 0.4 mi (0.6 km) northeast of junction of Highways 185 and 186, 1.5 mi (2.4 km) south of Campo Rico, and 4.4 mi (7.1 km) south of Loíza. DRAINAGE AREA.--9.84 mi2 (25.5 km2). PERIOD OF RECORD.--March 1967 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 225 ft (68 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 9.5 5.8 5.5 9.6 5.1 e4.1 17 7.0 5.8 23 9.5 2 11 9.3 5.4 5.8 9.4 5.0 4.3 16 7.1 8.3 70 9.4 3 12 9.0 6.8 6.7 12 5.7 5.9 14 e7.2 8.9 15 77 4 9.8 9.2 15 6.8 116 5.3 8.1 14 e7.6 6.9 8.8 25 5 9.5 8.8 13 9.0 104 4.8 197 13 6.4 7.0 6.9 9.3 6 9.2 8.5 7.5 17 41 4.9 26 13 6.3 8.6 28 6.9 7 9.2 8.3 6.3 8.4 21 4.5 8.9 12 15 7.3 20 6.2 8 9.4 8.0 7.5 5.9 17 4.3 6.3 11 14 7.3 9.7 6.4 9 12 8.7 7.5 5.1 11 4.5 17 11 8.4 7.4 8.1 6.7 10 27 14 7.0 5.1 11 4.4 25 10 6.9 6.2 7.6 6.3 11 15 19 7.4 4.9 12 4.5 357 9.6 6.1 5.3 6.8 24 12 11 14 6.2 4.8 11 4.4 54 9.6 6.3 5.1 12 7.3 13 10 12 7.8 5.0 9.7 4.1 19 9.4 6.3 32 7.2 13 14 9.3 8.8 7.8 5.0 8.2 4.0 13 12 6.2 13 6.2 17 15 9.5 11 8.6 4.7 7.7 4.0 12 14 145 8.2 7.7 6.2 16 32 15 22 5.0 7.7 4.2 17 10 36 13 7.7 109 17 22 20 21 5.0 11 4.0 1,030 9.6 13 18 5.6 13 18 13 28 10 4.8 11 4.0 288 11 9.6 8.6 16 7.7 19 11 20 7.0 4.6 8.5 3.9 153 17 8.8 6.7 12 5.9 20 16 11 15 4.9 7.8 4.2 73 11 8.7 5.8 14 6.8 21 12 8.1 8.8 5.4 7.9 3.9 173 31 8.5 5.6 82 30 22 12 15 9.2 5.2 8.0 4.2 94 30 8.1 8.4 212 15 23 11 8.6 9.2 5.2 7.5 4.2 83 15 6.8 8.7 29 7.7 24 20 7.2 7.2 5.4 7.0 4.1 62 35 6.9 5.9 13 6.2 25 23 6.9 7.3 194 7.7 4.0 47 12 6.8 5.5 29 5.5 26 45 6.7 7.3 74 8.9 3.7 33 9.8 6.4 10 93 5.2 27 23 7.4 7.2 14 6.2 4.2 26 8.9 6.0 12 25 4.6 28 12 6.7 5.5 8.4 5.7 4.0 23 7.8 7.4 13 21 4.4 29 11 6.5 4.8 7.5 3.9 20 7.8 7.0 12 23 4.9 30 10 5.9 4.9 7.7 5.0 18 7.6 6.0 6.5 16 5.0 31 11 5.2 9.6 e4.6 7.2 11 12 TOTAL 460.9 331.1 271.2 460.4 505.5 135.6 2,897.6 416.3 401.8 288.0 847.3 461.1 MEAN 14.9 11.0 8.75 14.9 18.1 4.37 96.6 13.4 13.4 9.29 27.3 15.4 MAX 45 28 22 194 116 5.7 1,030 35 145 32 212 109 MIN 9.2 5.9 4.8 4.6 5.7 3.7 4.1 7.2 6.0 5.1 5.6 4.4 AC-FT 914 657 538 913 1,000 269 5,750 826 797 571 1,680 915 CFSM 1.51 1.12 0.89 1.51 1.83 0.44 9.82 1.36 1.36 0.94 2.78 1.56 IN. 1.74 1.25 1.03 1.74 1.91 0.51 10.95 1.57 1.52 1.09 3.20 1.74 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 2003, BY WATER YEAR (WY) MEAN 40.1 45.8 34.4 25.4 19.1 13.3 17.5 25.8 17.0 17.3 25.8 39.3 MAX 273 125 116 62.4 48.4 36.2 96.6 93.2 63.7 63.7 137 196 (WY) (1971) (1985) (1971) (1969) (1988) (1969) (2003) (1969) (1970) (1979) (1979) (1996) MIN 6.74 6.66 5.82 6.66 4.04 3.54 4.36 4.28 2.80 3.72 5.69 5.20 (WY) (1968) (1981) (1968) (1977) (1977) (1977) (1994) (1974) (1974) (1974) (1991) (1967) 314 RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1967 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 7,068.9 ANNUAL MEAN 19.4 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 752 LOWEST DAILY MEAN 4.6 ANNUAL SEVEN-DAY MINIMUM 6.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 14,020 ANNUAL RUNOFF (CFSM) 1.97 ANNUAL RUNOFF (INCHES) 26.72 10 PERCENT EXCEEDS 28 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 6.3 7,476.8 20.5 27.0 58.0 1971 10.5 1994 May 30 1,030 Apr 17 4,230 Sep 10, 1996 Aug 28 3.7 Mar 26 0.80 Jul 24, 1977 Dec 25 4.0 Mar 23 1.5 Jul 18, 1977 5,090 Apr 17 17,300 Sep 21, 1998 10.53 Apr 17 15.90 Sep 21, 1998 3.4 Mar 26 0.80 Jul 24, 1977 14,830 19,550 2.08 2.74 28.27 37.25 28 45 8.7 12 4.9 5.2 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 315 RIO ESPIRITU SANTO BASIN 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR LOCATION.--Lat 18q19'24", long 65q49'03", Hydrologic Unit 21010005, in Caribbean National Forest at El Yunque, 0.6 mi (1.0 km) upstream from Río Espíritu Santo, 0.2 mi (0.3 km) upstream from Highway 186, and about 1.2 mi (1.9 km) south of El Verde. DRAINAGE AREA.--1.01 mi2 (2.62 km2). PERIOD OF RECORD.--March 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 1,230 ft (375 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.4 2.3 e1.4 14 e2.9 1.2 2.5 2.5 1.4 1.1 5.8 5.0 2 22 2.1 e2.0 13 e1.6 1.2 1.6 2.4 2.6 6.4 21 14 3 5.0 12 e5.6 5.7 e2.0 1.3 17 2.1 12 4.0 3.2 19 4 3.1 3.0 e18 2.9 e25 1.2 10 2.0 2.9 5.3 2.1 5.9 5 2.6 2.2 e7.1 7.5 13 1.0 42 1.8 1.5 6.0 1.8 3.6 6 2.5 1.9 3.7 3.4 5.8 0.90 4.1 1.7 1.9 7.7 22 3.0 7 2.1 1.7 2.3 2.5 8.9 0.83 2.0 1.8 34 3.9 11 2.7 8 7.9 1.5 8.9 1.9 4.4 0.79 1.7 1.7 5.0 10 6.3 8.4 9 4.2 1.6 3.7 1.7 6.4 0.75 12 3.3 8.3 7.5 6.9 6.2 10 2.6 1.9 9.5 1.6 8.5 1.0 28 1.9 3.1 2.9 3.2 2.9 11 2.5 4.9 4.5 1.5 7.9 1.3 44 1.8 2.1 1.7 2.6 6.7 12 7.0 9.7 6.1 e1.4 9.3 1.6 6.0 1.5 8.0 1.4 2.0 2.7 13 3.8 2.4 17 e1.2 4.5 0.83 3.4 1.4 2.7 27 1.8 2.1 14 2.0 1.6 5.3 e1.0 3.2 0.73 3.9 14 3.8 3.4 2.8 1.9 15 2.6 1.4 4.0 0.96 2.8 0.72 30 4.9 28 2.2 5.6 4.7 16 2.4 4.9 3.0 e1.0 5.5 0.71 13 2.0 7.8 5.2 1.8 10 17 2.0 14 2.3 e0.98 24 0.80 146 3.5 3.5 5.3 1.4 2.4 18 1.7 14 1.9 e0.92 4.6 0.74 42 11 2.7 2.0 15 1.7 19 13 14 2.0 e1.3 3.4 1.0 32 4.8 9.5 2.0 3.9 2.6 20 14 e3.6 11 e0.99 4.9 0.96 9.4 2.0 3.2 1.5 15 15 21 9.5 e2.8 21 e1.3 4.1 0.63 19 14 19 1.6 55 33 22 10 e4.9 16 e0.98 2.8 0.81 9.7 16 3.5 22 35 6.9 23 3.9 e2.4 3.3 e0.93 2.2 1.3 19 26 2.4 3.4 6.1 3.0 24 22 e2.0 3.3 e0.99 1.7 1.3 17 23 2.1 1.9 3.9 2.4 25 19 e2.6 3.4 e50 3.9 0.78 6.0 3.8 1.8 1.5 29 2.0 26 21 e4.7 2.2 e4.0 1.9 0.56 7.3 2.7 1.6 1.6 30 2.2 27 5.6 e5.8 1.9 e1.4 1.4 0.66 4.5 2.2 1.4 3.4 5.9 2.1 28 3.6 e2.4 1.5 e1.4 1.3 0.74 3.8 1.8 3.5 24 14 1.6 29 4.2 e1.7 1.4 e1.1 0.48 3.2 1.6 1.5 3.2 12 2.5 30 2.8 e1.4 1.4 e3.7 1.3 2.8 1.4 1.2 1.9 16 6.8 31 2.7 2.2 e5.1 0.56 1.3 9.9 5.1 TOTAL 209.7 131.4 176.9 136.35 167.9 28.68 542.9 161.9 182.0 180.9 347.2 183.0 MEAN 6.76 4.38 5.71 4.40 6.00 0.93 18.1 5.22 6.07 5.84 11.2 6.10 MAX 22 14 21 50 25 1.6 146 26 34 27 55 33 MIN 1.7 1.4 1.4 0.92 1.3 0.48 1.6 1.3 1.2 1.1 1.4 1.6 AC-FT 416 261 351 270 333 57 1,080 321 361 359 689 363 CFSM 6.70 4.34 5.65 4.35 5.94 0.92 17.9 5.17 6.01 5.78 11.1 6.04 IN. 7.72 4.84 6.52 5.02 6.18 1.06 20.00 5.96 6.70 6.66 12.79 6.74 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 2003, BY WATER YEAR (WY) MEAN 5.66 9.26 9.36 7.22 5.79 4.48 5.68 6.95 5.49 5.83 7.38 7.47 MAX 16.8 19.8 22.3 14.1 11.9 14.3 18.1 14.3 13.7 12.7 14.2 23.2 (WY) (1986) (1985) (2000) (2002) (1988) (1990) (2003) (1992) (1987) (1983) (1988) (1998) MIN 0.22 2.47 0.92 3.42 1.56 0.93 0.90 2.00 0.98 1.90 0.50 2.45 (WY) (1993) (1991) (1990) (1985) (1992) (2003) (1997) (1999) (1985) (2000) (1993) (1986) 316 RIO ESPIRITU SANTO BASIN 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1983 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 2,702.80 ANNUAL MEAN 7.40 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 82 LOWEST DAILY MEAN 0.65 ANNUAL SEVEN-DAY MINIMUM 0.90 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 5,360 ANNUAL RUNOFF (CFSM) 7.33 ANNUAL RUNOFF (INCHES) 99.55 10 PERCENT EXCEEDS 19 50 PERCENT EXCEEDS 3.4 90 PERCENT EXCEEDS 1.4 2,448.83 6.71 6.67 9.74 2002 3.91 1994 May 30 146 Apr 17 346 Sep 10, 1996 Mar 26 0.48 Mar 29 0.00 Aug 14, 1993 Mar 20 0.73 Mar 25 0.01 Mar 31, 1994 1,410 Apr 17 2,230 Dec 7, 1987 8.82 Apr 17 9.42 Dec 7, 1987 0.20 Apr 1 0.00 Aug 13, 1993 4,860 4,840 6.64 6.61 90.19 89.79 17 16 3.0 2.7 1.2 0.59 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 317 Figure 18. Northeastern river basins -- Río Herrera to Río Antón Ruíz basins. --- --- --- --- --- --- --- 318 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR LOCATION.--Lat 18q21'37", long 65q48'49", Hydrologic Unit 21010005, on upstream left side of bridge on Highway 966, 0.1 mi (0.2 km) upstream from Quebrada Jiménez, and 1.9 mi (3.1 km) southeast of Río Grande. DRAINAGE AREA.--8.62 mi2 (22.33 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to April 1963 (annual low flow and occasional measurements only), August 1966 to current year. GAGE.--Water-stage recorder. Elevation of gage is 40 ft (12 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20 20 12 37 33 14 e13 22 16 19 41 37 2 123 18 15 38 21 14 15 21 19 37 104 61 3 37 48 29 28 18 16 31 20 41 27 27 78 4 26 23 81 17 132 15 43 19 24 31 20 46 5 23 18 34 33 63 14 419 19 17 31 18 30 6 22 17 26 22 32 13 55 19 18 42 76 27 7 20 17 21 16 34 12 18 19 124 29 54 27 8 31 16 37 15 25 12 14 19 36 39 35 41 9 32 19 31 14 30 12 23 23 37 50 41 39 10 26 22 37 13 32 13 93 19 25 27 25 27 11 22 19 27 13 33 15 293 17 19 22 20 39 12 26 42 31 12 38 17 39 17 29 20 19 25 13 25 17 56 12 23 12 22 17 21 254 18 23 14 18 14 33 12 19 11 22 42 20 31 19 27 15 32 12 27 12 18 11 113 32 103 22 28 27 16 26 20 25 12 19 11 64 18 49 36 18 54 17 20 42 22 12 83 11 2,100 18 28 45 17 24 18 17 58 20 11 29 10 377 40 24 23 42 20 19 48 64 19 19 24 12 188 30 42 21 27 21 20 81 21 43 13 27 12 65 18 27 19 53 74 21 45 18 62 19 24 10 346 45 73 21 402 174 22 52 26 56 13 23 10 75 61 30 82 245 52 23 36 16 33 11 19 11 88 87 24 31 43 26 24 160 15 31 11 17 14 69 78 23 21 31 22 25 85 17 34 527 24 11 42 26 21 19 217 20 26 92 25 25 100 19 9.1 39 21 21 19 174 20 27 35 29 24 27 16 9.2 33 19 20 31 46 21 28 25 16 20 21 15 9.3 30 18 29 77 66 19 29 33 14 19 18 8.4 26 17 21 29 83 24 30 23 12 17 40 15 24 17 20 21 69 36 31 22 20 55 e9.4 16 39 38 TOTAL 1,283 715 967 1,203 890 373.4 4,779 854 1,001 1,215 2,116 1,161 MEAN 41.4 23.8 31.2 38.8 31.8 12.0 159 27.5 33.4 39.2 68.3 38.7 MAX 160 64 81 527 132 17 2,100 87 124 254 402 174 MIN 17 12 12 11 15 8.4 13 16 16 19 17 19 AC-FT 2,540 1,420 1,920 2,390 1,770 741 9,480 1,690 1,990 2,410 4,200 2,300 CFSM 4.80 2.76 3.62 4.50 3.69 1.40 18.5 3.20 3.87 4.55 7.92 4.49 IN. 5.54 3.09 4.17 5.19 3.84 1.61 20.62 3.69 4.32 5.24 9.13 5.01 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 2003, BY WATER YEAR (WY) MEAN 61.0 87.5 78.9 56.0 49.3 37.4 47.5 62.7 44.3 50.6 63.2 62.5 MAX 202 196 248 119 117 153 159 185 120 114 126 235 (WY) (1971) (1985) (1999) (1969) (1982) (1990) (2003) (1979) (1970) (1983) (1998) (1998) MIN 12.3 23.8 16.8 18.5 10.8 9.53 6.27 14.9 10.0 11.1 18.5 17.7 (WY) (1969) (2003) (1994) (1977) (1983) (1996) (1984) (1973) (1975) (1975) (1994) (1971) 319 RIO GUAJATACA BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1966 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 16,107 ANNUAL MEAN 44.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 731 LOWEST DAILY MEAN 12 ANNUAL SEVEN-DAY MINIMUM 15 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 31,950 ANNUAL RUNOFF (CFSM) 5.12 ANNUAL RUNOFF (INCHES) 69.51 10 PERCENT EXCEEDS 72 50 PERCENT EXCEEDS 29 90 PERCENT EXCEEDS 17 16,557.4 45.4 58.5 98.6 1979 21.6 1994 May 30 2,100 Apr 17 2,600 Dec 7, 1987 Aug 28 8.4 Mar 29 3.6 Apr 2, 1996 Mar 20 10 Mar 25 4.0 May 28, 1999 15,600 Apr 17 21,200 Aug 13, 1990 13.96 Apr 17 16.62 Aug 13, 1990 32,840 42,380 5.26 6.79 71.45 92.21 74 122 24 26 13 10 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 320 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958, 1961-66, 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 05... 1045 19 3.7 8.3 101 6.7 108 25.0 35 7.41 4.03 .35 .6 FEB 18... 1100 28 6.2 8.9 -- 7.5 86 23.3 24 5.10 2.85 .41 .6 APR 11... 1210 241 28 8.5 -- 6.9 64 -- 16 3.36 1.77 .47 .5 JUL 14... 1140 30 7.2 8.2 -- 7.1 79 26.0 -- -- -- -- -­ SEP 04... 1540 40 8.6 7.8 -- 7.3 70 28.2 22 4.56 2.48 .39 .5 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 05... 7.53 35 7.74 <.17 17.3 1.9 -- 67 3.39 <10 .30 <.01 -­ FEB 18... 6.33 23 8.72 .01 12.7 1.9 <.0 52 3.88 <10 .20 .01 -­ APR 11... 4.95 13 7.91 .04 7.8 2.8 .2 37 24.0 16 .40 .02 .09 JUL 14... -- 22 -- -- -- -- -- -- -- <10 <.20 .01 -­ SEP 04... 5.30 20 7.07 <.2 12.5 1.6 -- 46 4.94 <10 .20 <.01 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 05... .080 <.01 -- <.02 .38 1.7 <10 360 E260 -- -- -- -­ FEB 18... .050 <.01 .19 <.02 .25 1.1 E20 E57 -- 2,700 <2 4.4 E12 APR 11... .100 .01 .38 .03 .50 2.2 20 E1,700 -- E8,000 <2 6.8 E14 JUL 14... .060 <.01 -- <.02 -- -- 10 240 -- 6,000 -- -- -­ SEP 04... .030 <.01 -- <.02 .23 1.0 20 260 -- 4,200 -- -- -­ 321 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 05... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 18... <.2 <.8 <10 <.01 210 <1 7.0 <.02 <3 <.3 <25 <.10 <16 APR 11... <.2 1.1 <10 <.01 720 <1 28.0 <.02 <3 <.3 <25 <.10 <16 JUL 14... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 322 RIO ESPIRITU SANTO BASIN 50064200 RIO GRANDE NEAR EL VERDE, PR LOCATION.--Lat 18q20'42", long 65q50'30", Hydrologic Unit 21010005, on left bank 250 ft (7.6 m) about 350 feet upstream side of bridge at Highway 960, 0.05 mi (0.08 km) southwest of junction of Highways 956 and 960, 1.1 mi (1.8 km) west of El Verde, and 2.7 mi (4.3 km) south of Río Grande. DRAINAGE AREA.--7.31 mi2 (18.9 km2). PERIOD OF RECORD.--May 1967 to December 1970, January 1972 to September 1982, August 1990 to current year. GAGE.--Water-stage recorder. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.4 7.4 6.4 12 20 e8.3 4.4 17 6.8 4.9 38 23 2 23 6.8 6.8 18 16 e8.4 4.8 16 7.7 17 134 37 3 12 8.9 13 19 15 e9.6 7.3 15 11 8.2 18 145 4 8.5 7.7 45 10 236 e8.5 20 14 9.2 13 11 45 5 7.6 6.5 15 17 140 e7.2 433 13 7.0 8.4 8.9 21 6 7.8 6.1 9.9 19 31 5.9 25 13 6.6 16 70 18 7 7.5 6.0 8.4 10 40 5.8 7.9 13 75 8.9 37 17 8 9.7 5.9 16 8.3 19 5.6 6.1 12 19 17 16 17 9 16 6.8 14 7.5 16 5.3 24 12 10 20 22 27 10 8.0 28 18 7.2 20 5.4 77 11 9.3 9.1 13 17 11 8.2 16 12 6.9 23 5.9 343 11 6.9 6.0 13 24 12 8.9 23 13 6.5 19 5.9 37 10 7.2 5.2 13 16 13 7.0 9.5 30 6.4 13 5.2 17 9.8 6.9 118 8.6 104 14 6.3 6.8 17 6.5 10 4.8 13 25 7.5 17 8.3 37 15 8.5 6.1 27 6.5 9.9 5.2 46 24 174 8.3 11 15 16 19 16 36 6.5 10 5.9 42 12 34 29 7.7 224 17 12 29 14 6.5 78 5.1 1,380 11 13 43 6.8 33 18 9.8 42 11 6.3 20 4.9 312 17 8.7 9.8 16 17 19 7.5 41 10 7.0 14 5.1 175 15 14 7.0 14 15 20 35 12 24 6.7 14 5.2 68 9.7 11 6.1 35 105 21 16 36 30 11 15 4.8 274 88 31 6.5 317 161 22 18 29 30 7.0 14 4.7 112 34 12 51 368 47 23 11 11 17 6.2 9.8 5.2 106 20 7.7 16 37 e21 24 94 8.6 16 6.2 8.6 5.9 56 25 6.5 8.0 19 e17 25 55 8.7 19 423 18 4.7 37 12 5.9 6.4 163 15 26 112 17 11 109 e13 4.6 30 8.8 5.6 8.2 212 14 27 20 14 13 16 e9.6 5.0 35 8.0 5.4 26 34 13 28 11 12 9.6 11 e9.2 5.1 29 7.5 9.4 64 76 12 29 13 7.6 8.7 10 4.6 23 7.2 6.5 18 73 14 30 8.5 6.6 8.4 19 6.0 19 6.9 5.1 9.2 61 20 31 8.0 8.9 23 4.9 6.7 71 30 TOTAL 597.2 442.0 518.1 835.2 861.1 178.7 3,763.5 504.6 539.9 656.2 1,891.3 1,291 MEAN 19.3 14.7 16.7 26.9 30.8 5.76 125 16.3 18.0 21.2 61.0 43.0 MAX 112 42 45 423 236 9.6 1,380 88 174 118 368 224 MIN 6.3 5.9 6.4 6.2 8.6 4.6 4.4 6.7 5.1 4.9 6.8 12 AC-FT 1,180 877 1,030 1,660 1,710 354 7,460 1,000 1,070 1,300 3,750 2,560 CFSM 2.64 2.02 2.29 3.69 4.21 0.79 17.2 2.23 2.46 2.90 8.35 5.89 IN. 3.04 2.25 2.64 4.25 4.38 0.91 19.15 2.57 2.75 3.34 9.62 6.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 2003, BY WATER YEAR (WY) MEAN 54.3 67.2 53.0 44.1 30.4 19.7 31.6 45.5 28.9 33.6 45.1 50.3 MAX 392 172 140 151 76.4 54.4 125 203 86.5 109 90.0 153 (WY) (1971) (1970) (1971) (1969) (1969) (1969) (2003) (1969) (1968) (1969) (1968) (1975) MIN 8.45 14.3 12.0 10.1 5.80 4.50 6.29 10.2 6.22 8.66 7.39 12.4 (WY) (1969) (1981) (1998) (1977) (1977) (1977) (1995) (1974) (1975) (1994) (1991) (1967) RIO GUAJATACA BASIN 323 50064200 RIO GRANDE NEAR EL VERDE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1967 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 12,018.6 ANNUAL MEAN 32.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 949 LOWEST DAILY MEAN 5.9 ANNUAL SEVEN-DAY MINIMUM 6.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 23,840 ANNUAL RUNOFF (CFSM) 4.50 ANNUAL RUNOFF (INCHES) 61.16 10 PERCENT EXCEEDS 57 50 PERCENT EXCEEDS 16 90 PERCENT EXCEEDS 8.4 12,078.8 33.1 40.7 87.1 1969 17.3 1994 May 30 1,380 Apr 17 3,470 May 21, 1969 Nov 8 4.4 Apr 1 2.2 Aug 15, 1991 Nov 2 4.9 Mar 26 2.5 Aug 10, 1991 14,800 Apr 17 22,000 Sep 21, 1998 17.44 Apr 17 19.30 Sep 21, 1998 4.1 Apr 1 1.6 Mar 13, 1977 23,960 29,480 4.53 5.57 61.47 75.63 62 80 13 17 6.0 6.7 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 324 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR LOCATION.--Lat 18q19'46", long 65q45'04", Hydrologic Unit 21010005, on left bank, at bridge on Highway 988, 1.4 mi (2.3 km) west of Sabana, 2.0 mi (3.2 km ) downstream from Río de la Mina, and 3.2 mi (5.1 km) southeast of Mameyes. DRAINAGE AREA.--6.88 mi2 (17.8 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1967 to December 1973, June 1983 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 275 ft (84 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24 e30 25 34 44 18 30 27 35 17 49 51 2 215 e28 43 38 31 18 18 25 42 58 139 52 3 45 e36 46 30 27 17 33 24 66 33 30 36 4 37 e29 92 23 155 16 47 23 36 33 22 31 5 30 e27 33 61 68 15 234 23 25 28 20 38 6 32 e25 27 28 41 15 42 22 35 31 100 29 7 27 e23 23 23 58 15 30 25 242 26 88 25 8 87 22 34 21 35 14 31 23 53 32 46 189 9 47 26 26 21 35 14 58 44 58 43 38 77 10 116 30 47 19 38 16 79 22 31 28 26 35 11 45 33 30 18 39 16 210 26 27 21 21 43 12 48 56 32 18 45 16 76 20 46 20 22 29 13 41 24 44 19 35 14 44 19 25 239 20 31 14 33 21 30 22 28 14 51 186 29 34 43 27 15 85 20 28 21 26 17 163 57 111 25 37 82 16 38 39 28 22 29 16 143 28 61 68 18 127 17 32 59 27 21 77 17 1,670 37 39 52 17 31 18 31 65 23 25 34 16 331 92 32 18 49 28 19 122 65 25 23 29 18 212 51 68 17 24 25 20 96 28 45 22 37 17 104 26 31 15 60 103 21 77 31 63 24 31 15 98 120 66 18 160 245 22 65 32 50 19 27 15 86 172 31 67 224 62 23 61 25 32 20 27 18 113 191 24 22 43 32 24 119 25 40 22 22 20 125 123 28 20 28 25 25 111 28 36 352 32 15 64 50 26 24 138 23 26 e106 33 39 116 22 14 91 48 22 21 186 23 27 e47 50 30 37 20 15 48 44 19 34 49 20 28 e40 26 25 31 19 14 38 44 31 108 73 18 29 41 22 22 32 15 32 52 19 25 65 27 30 33 21 21 62 20 29 42 17 26 78 45 31 e36 24 103 15 38 79 50 TOTAL 1,967 979 1,090 1,327 1,111 495 4,330 1,724 1,375 1,282 1,963 1,609 MEAN 63.5 32.6 35.2 42.8 39.7 16.0 144 55.6 45.8 41.4 63.3 53.6 MAX 215 65 92 352 155 20 1,670 191 242 239 224 245 MIN 24 20 21 18 19 14 18 19 17 15 17 18 AC-FT 3,900 1,940 2,160 2,630 2,200 982 8,590 3,420 2,730 2,540 3,890 3,190 CFSM 9.22 4.74 5.11 6.22 5.77 2.32 21.0 8.08 6.66 6.01 9.20 7.80 IN. 10.64 5.29 5.89 7.18 6.01 2.68 23.41 9.32 7.43 6.93 10.61 8.70 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 2003, BY WATER YEAR (WY) MEAN 63.5 80.2 63.6 54.3 40.7 34.8 45.3 61.5 52.0 47.9 56.0 61.8 MAX 240 191 164 105 68.0 79.7 144 147 112 93.4 85.2 166 (WY) (1971) (1985) (1971) (1969) (1988) (1990) (2003) (1970) (1970) (1969) (2000) (1989) MIN 20.3 32.6 16.6 25.0 21.7 16.0 14.5 18.7 12.4 20.3 20.4 26.6 (WY) (1969) (2003) (1990) (1985) (1968) (2003) (1984) (1973) (1985) (1994) (1994) (1986) RIO MAMEYES BASIN 325 50065500 RIO MAMEYES NEAR SABANA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1967 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 17,437 ANNUAL MEAN 47.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 597 LOWEST DAILY MEAN 11 ANNUAL SEVEN-DAY MINIMUM 12 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 34,590 ANNUAL RUNOFF (CFSM) 6.94 ANNUAL RUNOFF (INCHES) 94.28 10 PERCENT EXCEEDS 92 50 PERCENT EXCEEDS 31 90 PERCENT EXCEEDS 17 19,252 52.7 55.6 78.0 1971 33.1 1994 May 30 1,670 Apr 17 2,780 Sep 18, 1989 Mar 22 14 Mar 8 6.9 Apr 20, 1970 Mar 20 15 Mar 8 9.4 Jun 12, 1985 15,700 Apr 17 20,500 Sep 18, 1989 11.96 Apr 17 13.19 Sep 18, 1989 13 Mar 9 5.1 Apr 8, 1970 38,190 40,310 7.67 8.09 104.10 109.87 103 102 31 34 18 16 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 326 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.-- Water years 1992 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1992 to September 2003. INSTRUMENTATION.-- USDH-48 and automatic sediment samplers since 1993. REMARKS.-- During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 484 mg/L September 10, 1996; Minimum daily mean, 1 mg/L several days during several years. SEDIMENT LOADS: Maximum daily mean, 6,940 tons (6,296 tonnes) April 17, 2003; Minimum daily mean, 0.03 ton (0.03 tonne) October 05, 1994 and June 19, 2001. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 402 mg/L April 17, 2003; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 6,940 tons (6,296 tonnes) April 17, 2003; Minimum daily mean, 0.04 ton (.04 tonne) several d ays. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 24 2 0.15 e30 e5 e0.38 25 2 0.13 2 215 41 55 e28 e4 e0.37 43 5 0.84 3 45 6 0.74 e36 e4 e0.53 46 7 0.95 4 37 4 0.38 e29 e4 e0.32 92 15 5.9 5 30 4 0.29 e27 e4 e0.24 33 3 0.29 6 32 3 0.30 e25 e3 e0.22 27 3 0.22 7 27 3 0.23 e23 e3 e0.20 23 3 0.19 8 87 16 15 22 3 0.17 34 3 0.28 9 47 6 1.0 26 3 0.18 26 3 0.21 10 116 20 13 30 2 0.19 47 6 1.1 11 45 7 0.83 33 4 0.44 30 3 0.24 12 48 6 0.78 56 9 1.6 32 3 0.26 13 41 5 0.60 24 4 0.25 44 7 0.90 14 33 5 0.43 21 4 0.20 30 3 0.25 15 85 12 6.9 20 3 0.18 28 3 0.22 16 38 5 0.53 39 3 0.33 28 3 0.22 17 32 4 0.35 59 8 1.8 27 3 0.22 18 31 4 0.33 65 8 1.6 23 3 0.18 19 122 28 40 65 9 2.0 25 3 0.20 20 96 15 6.6 28 5 0.36 45 3 0.37 21 77 10 2.9 31 4 0.34 63 9 2.2 22 65 6 1.0 32 4 0.32 50 4 0.53 23 61 5 0.91 25 4 0.24 32 4 0.32 24 119 21 21 25 3 0.22 40 5 0.72 25 111 18 7.3 28 3 0.24 36 3 0.34 26 e106 e20 e7.4 33 3 0.26 39 5 0.58 27 e47 e7 e1.0 50 3 0.37 30 3 0.26 28 e40 e6 e0.64 26 3 0.18 25 3 0.20 29 41 5 0.61 22 2 0.14 22 3 0.17 30 33 5 0.47 21 2 0.12 21 3 0.15 31 e36 e5 e0.49 24 3 0.17 TOTAL 1,967 187.16 979 13.99 1,090 18.81 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO MAMEYES BASIN 327 50065500 RIO MAMEYES NEAR SABANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 34 4 0.45 44 6 0.73 18 4 0.20 2 38 2 0.24 31 4 0.35 18 4 0.17 3 30 2 0.18 27 3 0.21 17 3 0.14 4 23 2 0.13 155 25 14 16 2 0.10 5 61 9 2.5 68 8 1.7 15 2 0.07 6 28 3 0.23 41 5 0.51 15 1 0.05 7 23 3 0.18 58 7 1.4 15 1 0.04 8 21 3 0.16 35 4 0.37 14 1 0.04 9 21 3 0.15 35 4 0.37 14 1 0.04 10 19 3 0.13 38 4 0.41 16 1 0.04 11 18 2 0.12 39 4 0.42 16 1 0.04 12 18 2 0.11 45 4 0.48 16 1 0.04 13 19 2 0.11 35 4 0.38 14 1 0.04 14 22 2 0.13 28 4 0.29 14 1 0.04 15 21 2 0.11 26 4 0.25 17 1 0.05 16 22 2 0.11 29 3 0.25 16 1 0.04 17 21 2 0.10 77 11 2.9 17 1 0.05 18 25 2 0.11 34 3 0.29 16 1 0.04 19 23 2 0.10 29 4 0.27 18 1 0.05 20 22 1 0.09 37 4 0.40 17 1 0.05 21 24 1 0.09 31 4 0.36 15 1 0.04 22 19 1 0.07 27 5 0.34 15 1 0.04 23 20 1 0.06 27 5 0.36 18 1 0.05 24 22 1 0.06 22 5 0.31 20 1 0.05 25 352 74 130 32 6 0.49 15 1 0.04 26 116 14 6.6 22 6 0.35 14 1 0.04 27 37 6 0.64 20 5 0.30 15 1 0.04 28 31 6 0.47 19 5 0.25 14 1 0.04 29 32 5 0.40 15 1 0.04 30 62 9 2.6 20 1 0.06 31 103 15 6.5 15 1 0.04 TOTAL 1,327 152.93 1,111 28.74 495 1.81 APRIL MAY JUNE 1 30 2 0.13 27 2 0.15 35 1 0.09 2 18 2 0.11 25 1 0.08 42 1 0.11 3 33 5 0.66 24 1 0.07 66 9 2.3 4 47 6 0.86 23 1 0.07 36 5 0.52 5 234 56 192 23 1 0.08 25 3 0.20 6 42 10 1.2 22 1 0.08 35 2 0.16 7 30 6 0.51 25 2 0.10 242 81 147 8 31 2 0.17 23 2 0.10 53 10 1.6 9 58 4 1.5 44 6 1.1 58 11 1.9 10 79 11 2.6 22 2 0.11 31 4 0.31 11 210 21 16 26 2 0.13 27 2 0.18 12 76 7 1.4 20 2 0.11 46 7 1.0 13 44 5 0.59 19 2 0.10 25 3 0.21 14 51 5 0.68 186 39 50 29 3 0.23 15 163 20 20 57 7 1.3 111 16 5.3 16 143 22 11 28 4 0.30 61 7 1.2 17 1,670 402 6,940 37 6 0.86 39 5 0.50 18 331 71 105 92 13 3.2 32 4 0.37 19 212 39 32 51 7 1.1 68 9 1.9 20 104 20 5.8 26 5 0.32 31 5 0.45 21 98 18 5.6 120 36 42 66 10 2.0 22 86 9 2.0 172 55 88 31 4 0.30 23 113 17 6.6 191 48 57 24 3 0.19 24 125 68 49 123 19 8.8 28 2 0.18 25 64 27 4.8 50 7 0.93 26 2 0.14 26 91 17 5.2 48 5 0.65 22 2 0.12 27 48 7 0.96 44 4 0.47 19 2 0.10 28 38 5 0.55 44 3 0.34 31 2 0.17 29 32 4 0.36 52 2 0.27 19 2 0.10 30 29 3 0.24 42 1 0.12 17 2 0.09 31 38 1 0.10 TOTAL 4,330 7,407.52 1,724 258.04 1,375 168.92 --- --- --- --- --- --- 328 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 17 2 0.09 49 8 1.2 51 3 0.54 2 58 20 7.1 139 24 26 52 4 0.72 3 33 5 0.41 30 3 0.26 36 6 0.54 4 33 4 0.38 22 1 0.08 31 5 0.43 5 28 4 0.30 20 2 0.10 38 6 0.81 6 31 4 0.31 100 12 7.4 29 5 0.41 7 26 3 0.25 88 13 5.0 25 4 0.30 8 32 3 0.27 46 6 0.76 189 71 111 9 43 3 0.35 38 4 0.47 77 14 4.5 10 28 3 0.20 26 4 0.25 35 3 0.25 11 21 2 0.13 21 3 0.16 43 5 0.69 12 20 2 0.12 22 2 0.12 29 6 0.45 13 239 71 203 20 2 0.11 31 6 0.46 14 34 5 0.50 43 4 0.86 27 5 0.39 15 25 4 0.28 37 2 0.28 82 13 9.4 16 68 8 4.6 18 2 0.10 127 20 12 17 52 12 3.0 17 2 0.09 31 5 0.39 18 18 2 0.11 49 6 0.92 28 4 0.31 19 17 2 0.09 24 3 0.18 25 4 0.27 20 15 2 0.06 60 10 3.2 103 33 33 21 18 1 0.06 160 38 84 245 48 51 22 67 9 2.3 224 28 27 62 12 2.8 23 22 2 0.14 43 7 0.82 32 5 0.39 24 20 2 0.11 28 5 0.37 25 3 0.20 25 24 2 0.13 138 29 30 23 2 0.15 26 21 2 0.11 186 40 31 23 3 0.18 27 34 2 0.19 49 6 0.86 20 3 0.19 28 108 24 12 73 7 1.6 18 4 0.19 29 25 6 0.43 65 6 1.2 27 4 0.32 30 26 4 0.30 78 11 3.7 45 5 0.57 31 79 12 5.0 50 6 1.0 TOTAL 1,282 242.32 1,963 229.09 1,609 232.85 YEAR 19,252 8,942.18 e Estimated --- --- --- --- --- --- --- 329 RIO MAMEYES BASIN 50066000 RIO MAMEYES AT MAMEYES, PR LOCATION.--Lat 18q22'27", long 65q45'50", Hydrologic Unit 21010005, on right bank, at bridge on Highway 3, 3.1 mi (5.0 km), southwest from Luquillo, 0.4 mi (0.6 km) downstream from Quebrada Anón, and 2.9 mi (4.7 km) east from Escuela Juan González. DRAINAGE AREA.--13.5 mi2 (34.7 km2). PERIOD OF RECORD.--July 1997 to current year. GAGE.--Water-stage recorder. Elevation of gage is 16.4 ft (5.0 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Discharges above 5,000 ft3/s (141.6 m3/s), are based on a rating curve extension and are rated poor. Low flow affected by water supply intake about 1,000 ft (305 m), upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29 30 e19 43 55 16 e25 35 31 e23 47 63 2 371 26 e20 51 28 16 13 33 42 e71 108 58 3 90 99 e40 42 21 17 15 32 62 46 34 43 4 60 38 e80 23 205 e17 54 31 38 43 26 41 5 47 29 e42 87 99 e15 485 30 29 37 23 40 6 43 22 e37 37 45 e15 199 30 34 42 86 40 7 32 20 e28 23 63 e14 26 33 208 37 88 34 8 96 18 e45 17 35 15 19 29 67 41 48 201 9 85 21 e25 16 30 13 24 45 62 60 46 92 10 169 27 53 15 33 18 85 29 40 43 30 47 11 74 e20 30 13 38 15 310 31 35 31 27 69 12 67 e72 30 12 49 16 94 26 49 29 26 40 13 57 e22 60 12 35 10 39 25 34 229 27 39 14 36 16 36 12 24 9.1 40 152 34 43 40 39 15 92 e15 27 11 21 9.6 180 67 138 29 48 58 16 58 e48 28 13 21 10 263 34 73 43 26 175 17 34 e79 26 12 99 11 e2,000 35 47 70 28 48 18 32 e94 20 13 37 9.7 e650 89 43 28 74 42 19 130 e125 21 22 29 10 e300 59 91 27 40 36 20 164 e36 59 13 38 13 e140 32 45 24 71 78 21 117 e25 86 22 29 8.4 e120 96 81 27 127 533 22 99 e36 85 15 26 10 e110 236 45 80 244 156 23 116 e23 56 11 25 13 e130 214 36 32 71 95 24 172 e18 47 16 20 17 e140 148 38 24 44 80 25 159 e22 48 660 34 9.4 e70 59 34 23 152 72 26 145 e21 47 208 23 9.0 e100 47 30 22 263 72 27 70 e40 45 44 18 9.8 e53 41 30 33 74 66 28 49 e20 31 28 17 8.8 e43 37 40 96 87 60 29 56 e18 27 26 9.2 e40 35 e32 33 101 76 30 40 e17 23 61 14 e37 32 e30 25 88 97 31 42 22 105 e7.5 31 44 53 TOTAL 2,831 1,097 1,243 1,683 1,197 385.5 5,804 1,853 1,598 1,435 2,247 2,590 MEAN 91.3 36.6 40.1 54.3 42.8 12.4 193 59.8 53.3 46.3 72.5 86.3 MAX 371 125 86 660 205 18 2,000 236 208 229 263 533 MIN 29 15 19 11 17 7.5 13 25 29 22 23 34 AC-FT 5,620 2,180 2,470 3,340 2,370 765 11,510 3,680 3,170 2,850 4,460 5,140 CFSM 6.82 2.73 2.99 4.05 3.19 0.93 14.4 4.46 3.98 3.45 5.41 6.44 IN. 7.86 3.05 3.45 4.67 3.32 1.07 16.11 5.14 4.44 3.98 6.24 7.19 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2003, BY WATER YEAR (WY) MEAN 94.5 134 133 74.0 46.8 33.8 88.3 79.4 52.7 48.8 84.0 103 MAX 135 271 264 122 72.5 80.6 193 129 86.2 93.0 126 274 (WY) (1999) (2000) (1999) (1999) (2000) (1998) (2003) (1998) (1998) (1999) (2000) (1998) MIN 58.8 36.6 18.4 43.4 34.5 12.4 17.5 32.7 36.2 25.8 38.9 51.4 (WY) (2001) (2003) (1998) (2001) (2002) (2003) (2000) (1999) (2001) (2000) (2002) (2001) 330 RIO CAMUY BASIN 50066000 RIO MAMEYES AT MAMEYES, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1997 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 23,184.0 ANNUAL MEAN 63.5 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,230 LOWEST DAILY MEAN 9.1 ANNUAL SEVEN-DAY MINIMUM 11 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 45,990 ANNUAL RUNOFF (CFSM) 4.74 ANNUAL RUNOFF (INCHES) 64.36 10 PERCENT EXCEEDS 129 50 PERCENT EXCEEDS 35 90 PERCENT EXCEEDS 17 23,963.5 65.7 81.8 101 1998 52.3 2001 May 30 2,000 Apr 17 2,660 Sep 21, 1998 Mar 25 7.5 Mar 31 6.0 Apr 29, 2000 Mar 20 9.7 Mar 25 7.3 Apr 23, 2000 17,300 Apr 17 13.93 Apr 17 15.64 Aug 22, 2001 47,530 59,280 4.90 6.11 66.53 82.97 126 164 38 39 15 16 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 331 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR LOCATION.--Lat 18q19'52", long 65q43'52", Hydrologic Unit 21010005, on right bank along Highway 988, 0.3 mi (0.5 km) north of junction of Highways 988 and 983 in Sabana, and 3.3 mi (5.3 km) south of Luquillo. DRAINAGE AREA.--3.96 mi2 (10.3 km2). PERIOD OF RECORD.--October 1979 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (80 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Low flow affected by Puerto Rico Aqueduct and Sewer Authority Water Intake 1.0 mi (1.6 km) upstream, and purification plant 0.2 mi (0.32 km). Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.8 7.0 3.3 4.4 e4.0 1.9 3 9.4 7.0 3.3 e7.3 9.7 2 56 5.7 4.5 4.0 e3.2 2.0 1.2 9.0 9.9 7.0 e18 10 3 8.1 5.9 5.1 3.9 e3.0 1.8 1.3 8.2 7.8 5.3 e4.6 33 4 4.7 5.8 13 2.8 e11 1.6 2.3 7.8 6.5 4.7 e3.3 10 5 3.5 4.8 5.1 25 7.7 1.5 77 7.4 6.0 3.0 3.0 20 6 4.0 4.4 3.4 5.9 4.3 1.6 9.9 7.2 9.0 3.6 9.1 11 7 2.8 4.1 2.7 3.3 9.3 1.7 1.5 7.4 51 3.0 18 7.7 8 28 3.9 4.6 e2.5 4.2 1.6 1.2 6.9 14 3.9 9.4 146 9 14 4.4 3.4 e2.5 3.4 1.4 1.1 8.2 8.1 4.8 6.6 30 10 90 3.9 6.8 e2.3 3.5 2.9 2.4 6.5 6.6 e3.1 3.9 13 11 13 e4.9 4.9 e2.2 3.5 2.2 67 9.7 5.4 2.5 3.9 13 12 7.4 e9.1 4.6 e2.2 e4.0 1.7 12 6.4 5.8 e2.5 4.7 8.7 13 4.8 e3.6 7.2 e2.3 e3.4 1.6 3.0 5.8 4.9 e60 4.9 28 14 4.0 e3.0 3.9 e2.8 e3.0 1.6 4.4 89 4.9 e10 15 14 15 4.7 e2.8 2.9 e2.7 e2.9 1.4 84 22 18 e7.0 8.7 58 16 4.4 e6.3 5.1 3 e3.1 1.3 151 7.8 9.4 e15 4.0 102 17 2.9 e10 3.1 2.7 e6.4 1.2 1,120 27 6.3 13 3.6 21 18 2.8 e11 2.7 2.5 e3.4 1 217 26 5.5 4.8 9.3 15 19 55 e11 4.3 3.2 e2.4 e3.5 70 24 11 4.4 5.8 14 20 39 5.2 5.6 2.6 4.6 e2.8 37 9.3 5.7 3.5 15 24 21 12 3.9 6.4 2.9 3.3 e1.4 28 30 8.3 5.4 59 132 22 37 3.9 8.8 2.8 2.8 e1.5 23 75 5.3 11 83 31 23 65 4.7 5.2 2.9 2.4 e1.8 32 30 4.5 4.6 17 16 24 43 4.2 4.3 3.1 2.0 e3.5 54 18 4.9 3.7 7.9 13 25 20 3.7 4.7 e60 3.5 1.1 21 11 4.1 3.7 38 11 26 e50 3.2 14 e8.6 2.5 1.1 25 9.2 3.9 3.2 74 11 27 e23 11 6.0 e3.6 2.1 1.2 15 8.4 3.9 4.2 15 9.8 28 e12 4.3 3.5 e3.2 1.8 1.1 12 7.8 5.0 12 13 8.6 29 e15 2.9 2.9 e3.2 1.4 11 7.3 3.6 4.1 13 11 30 e8.0 2.8 2.5 e5.2 1.4 10 6.9 3.4 3.2 11 11 31 14 3.0 e7.9 1 6.5 e11 9.9 TOTAL 650.9 161.4 157.5 186.2 110.7 52.8 2,097.3 515.1 249.7 230.5 498.9 842.5 MEAN 21.0 5.38 5.08 6.01 3.95 1.70 69.9 16.6 8.32 7.44 16.1 28.1 MAX 90 11 14 60 11 3.5 1,120 89 51 60 83 146 MIN 2.8 2.8 2.5 2.2 1.8 1.0 1.1 5.8 3.4 2.5 3.0 7.7 AC-FT 1,290 320 312 369 220 105 4,160 1,020 495 457 990 1,670 CFSM 5.30 1.36 1.28 1.52 1.00 0.43 17.7 4.20 2.10 1.88 4.06 7.09 IN. 6.11 1.52 1.48 1.75 1.04 0.50 19.70 4.84 2.35 2.17 4.69 7.91 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1980 - 2003, BY WATER YEAR (WY) MEAN 22.7 33.9 26.3 15.7 11.8 9.93 13.9 28.2 18.3 14.6 17.9 23.8 MAX 66.4 82.2 64.1 48.5 23.2 36.0 69.9 63.9 50.6 36.0 39.9 74.2 (WY) (1986) (2000) (1982) (1996) (1997) (1987) (2003) (1982) (1987) (1996) (1995) (1996) MIN 6.48 5.38 3.92 6.01 2.94 1.70 2.20 4.65 3.64 2.82 3.09 7.23 (WY) (1983) (2003) (1990) (2003) (1983) (2003) (1984) (1994) (1997) (2000) (1994) (1987) 332 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1980 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 4,338.8 ANNUAL MEAN 11.9 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 204 LOWEST DAILY MEAN 1.7 ANNUAL SEVEN-DAY MINIMUM 2.0 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 8,610 ANNUAL RUNOFF (CFSM) 3.00 ANNUAL RUNOFF (INCHES) 40.76 10 PERCENT EXCEEDS 20 50 PERCENT EXCEEDS 5.5 90 PERCENT EXCEEDS 2.8 5,753.5 15.8 19.8 31.9 1996 7.85 1994 Apr 16 1,120 Apr 17 1,120 Apr 17, 2003 Sep 22 1.0 Mar 18 0.96 Apr 10, 1983 Mar 20 1.2 Mar 25 1.0 Apr 6, 1983 8,050 Apr 17 9,600 Jan 5, 1992 18.69 Apr 17 19.74 Jan 5, 1992 0.86 Apr 17, 1983 11,410 14,330 3.98 5.00 54.05 67.88 29 37 5.2 8.4 2.2 2.6 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 333 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR LOCATION.--Lat 18q17'56", long 65q41'42", Hydrologic Unit 21010005, on left bank off Highway 976, 0.1 mi (0.2 km) upstream from Highway 977 bridge, 0.3 mi (0.5 km) downstream from Quebrada Peñón, 1.1 mi (1.8 km) northeast of Colonia Paraíso, and 3.3 mi (5.3 km) southwest of F ajardo. DRAINAGE AREA.--14.9 mi2 (38.6 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1960-61 (occasional low and peak-flow measurements only), March 1961 to current year. GAGE.--Water-stage recorder. Datum of gage is 137.60 ft (41.940 m) above mean sea level. Due to flood damage, gage datum has had changes as follows: March 24, 1961, to May 5, 1969, 138.95 ft (42.352 m); May 6, 1969, to March 16, 1972, 135.05 ft (41.163 m); March 17, 1972, to M arch 25, 1975, 138.60 ft (42.245 m). REMARKS.--Records fair except those for estimated daily discharges, which are poor. Low flow affected by diversions for water supply about 0.25 mi (0.40 km) upstream from gaging station (estimated mean daily discharges is 9.0 ft3/s (0.255 m3/s)). Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12 32 13 e12 40 7.0 13 26 28 11 50 36 2 53 24 14 e14 28 6.7 10 23 36 66 134 29 3 22 23 24 e22 20 8.0 11 22 40 23 30 153 4 16 22 36 e23 63 6.1 24 20 43 25 19 41 5 15 19 21 e27 36 5.4 129 19 23 14 15 94 6 16 17 18 e22 24 4.5 59 18 103 12 68 47 7 13 17 15 e15 26 4.2 14 18 223 11 112 38 8 205 16 20 e13 17 3.9 12 18 59 12 34 371 9 104 20 17 e8.0 14 3.8 29 20 35 21 33 133 10 305 42 52 7.4 13 4.4 42 16 26 12 20 48 11 40 23 20 7.2 16 5.0 231 22 23 8.9 17 57 12 32 30 18 7.0 21 5.8 35 15 24 8.6 21 34 13 30 36 21 6.5 13 3.6 19 13 20 385 17 44 14 20 23 19 7.0 11 2.5 27 125 19 38 28 44 15 146 17 21 6.6 11 3.0 213 68 64 32 32 214 16 31 47 23 6.7 11 3.1 133 28 39 90 15 207 17 21 40 22 6.6 36 3.0 2,870 25 33 41 13 56 18 22 49 18 6.2 17 3.8 515 76 31 21 15 87 19 52 46 e18 8.0 13 28 202 35 49 18 22 48 20 85 25 e40 8.3 13 15 104 21 32 15 43 55 21 37 21 e38 7.9 12 6.7 82 255 46 15 37 538 22 96 25 e69 6.5 12 6.0 74 95 25 40 244 125 23 57 22 e58 7.1 9.7 5.7 78 82 19 20 44 70 24 180 19 e55 18 8.4 9.5 175 67 17 14 26 58 25 181 19 e68 607 21 5.5 63 39 15 13 94 53 26 321 19 e144 183 11 4.6 57 32 14 11 169 49 27 62 28 e41 24 8.3 4.2 42 29 13 25 48 44 28 39 17 e23 20 7.6 7.0 34 26 21 79 63 41 29 35 14 e18 16 4.1 30 24 14 23 48 47 30 32 13 e18 31 19 28 22 11 15 45 51 31 75 e14 128 6.2 22 45 34 TOTAL 2,355 765 996 1,282.0 533.0 205.3 5,355 1,321 1,145 1,164.5 1,590 2,912 MEAN 76.0 25.5 32.1 41.4 19.0 6.62 178 42.6 38.2 37.6 51.3 97.1 MAX 321 49 144 607 63 28 2,870 255 223 385 244 538 MIN 12 13 13 6.2 7.6 2.5 10 13 11 8.6 13 29 AC-FT 4,670 1,520 1,980 2,540 1,060 407 10,620 2,620 2,270 2,310 3,150 5,780 CFSM 5.10 1.71 2.16 2.78 1.28 0.44 12.0 2.86 2.56 2.52 3.44 6.51 IN. 5.88 1.91 2.49 3.20 1.33 0.51 13.37 3.30 2.86 2.91 3.97 7.27 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1961 - 2003, BY WATER YEAR (WY) MEAN 93.1 110 85.1 50.0 37.8 33.3 46.6 85.6 58.1 48.1 57.7 87.7 MAX 260 328 237 150 80.4 109 178 399 166 132 159 421 (WY) (1971) (2000) (1976) (1996) (1982) (1987) (2003) (1979) (1962) (1969) (1979) (1989) MIN 19.1 25.5 14.9 15.4 10.8 6.62 4.02 17.7 10.0 10.6 9.70 18.9 (WY) (1969) (2003) (1990) (1977) (1983) (2003) (1984) (1973) (1985) (2000) (1994) (1994) 334 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1961 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 18,169.9 ANNUAL MEAN 49.8 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 610 LOWEST DAILY MEAN 4.9 ANNUAL SEVEN-DAY MINIMUM 5.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 36,040 ANNUAL RUNOFF (CFSM) 3.34 ANNUAL RUNOFF (INCHES) 45.36 10 PERCENT EXCEEDS 105 50 PERCENT EXCEEDS 23 90 PERCENT EXCEEDS 12 19,623.8 53.8 66.5 140 1979 19.0 1994 Apr 16 2,870 Apr 17 8,800 Sep 18, 1989 Mar 26 2.5 Mar 14 1.0 May 6, 1984 Mar 20 3.5 Mar 12 1.5 Apr 18, 1984 14,500 Apr 17 21,700 Sep 18, 1989 14.14 Apr 17 20.00 Sep 18, 1989 0.86 May 3, 1984 38,920 48,160 3.61 4.46 48.99 60.62 99 130 23 31 7.3 10 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S RIO FAJARDO BASIN 335 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 07... 1445 17 2.7 8.7 115 6.9 130 29.4 33 7.15 3.71 .91 .9 JAN 30... 1445 53 15 8.5 -- 7.0 83 24.7 19 4.11 2.18 .88 .7 APR 14... 1130 18 4.1 9.3 -- 7.3 123 27.9 32 7.18 3.53 .95 .8 JUL 02... 1045 117 120 8.0 -- 6.8 78 25.8 -- -- -- -- -­ SEP 04... 1045 38 9.6 7.2 -- 7.0 105 27.4 28 6.07 3.20 1.34 .7 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 07... 11.4 38 11.8 <.17 25.8 3.6 -- 87 4.03 <10 <.20 .02 -­ JAN 30... 7.00 21 8.33 .03 17.7 3.1 .0 56 8.11 13 <.20 .01 -­ APR 14... 10.9 36 12.9 .09 23.4 3.7 <.1 84 4.05 <10 <.20 .01 -­ JUL 02... -- 16 -- -- -- -- -- -- -- 112 .40 .01 .14 SEP 04... 8.92 28 10.4 <.2 21.7 4.0 -- 72 7.39 <10 .30 <.01 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 07... .130 <.01 -- <.02 -- -- <10 210 E50 -- -- -- -­ JAN 30... .150 <.01 -- <.02 -- -- <10 E580 -- E9,800 <2 17.6 E14 APR 14... .080 <.01 -- <.02 -- -- <10 88 -- 2,800 <2 21.9 24 JUL 02... .150 .01 .39 .08 .55 2.4 30 3,300 -- -- -- -- -­ SEP 04... .290 <.01 -- <.02 .59 2.6 <10 890 -- 8,000 -- -- -­ 336 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 07... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 30... <.2 <.8 <10 <.01 520 <1 33.6 <.02 <3 <.3 <25 <.10 <16 APR 14... <.2 <.8 <10 <.01 250 <1 13.8 <.02 <3 <.3 37 <.10 E9 JUL 02... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 14... 1130 <.01 <.02 <.01 <.01 <.05 <.1 <.04 <.05 <.02 <.017 <.30 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 14... <.03 <.03 <.009 <.01 <.014 <.30 <.04 <.012 <.016 <.014 <.009 <.015 <.03 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 14... <.1 <.05 <.02 <1 <.05 < -- Less than --- --- --- --- --- --- 337 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1982 to September 1986 and October 1995 to current year. INSTRUMENTATION.--USDH-48 sediment sampler and automatic sediment sampler since October 1983. EXTREMES FOR PERIOD OF RECORD.-- SEDIMENT CONCENTRATION: Maximum daily mean, 2,210 mg/L October 6, 1985; Minimum daily mean, 1 mg/L several years. SEDIMENT LOADS: Maximum daily mean, 34,600 tons (31,390 tonnes) April 17, 003; Minimum daily mean,<0.01 tons (<0.01 tonnes) July 9, 2001. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATION: Maximum daily mean, 1850 mg/L April 17, 2003; Minimum daily mean, 1 mg/L several days. SEDIMENT LOADS: Maximum daily mean, 34,600 tons (31,390 tonnes) April 17, 2003; Minimum daily mean, 0.02 tons (0.02 tonnes) March 13, 14, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 12 5 0.16 32 16 1.4 13 3 0.11 2 53 28 6.2 24 12 0.82 14 3 0.11 3 22 13 0.81 23 11 0.67 24 3 0.19 4 16 9 0.41 22 10 0.59 36 14 1.9 5 15 8 0.35 19 9 0.46 21 10 0.59 6 16 8 0.34 17 8 0.36 18 8 0.38 7 13 7 0.24 17 7 0.31 15 5 0.23 8 205 59 247 16 6 0.25 20 8 0.64 9 104 60 103 20 5 0.26 17 8 0.37 10 305 166 369 42 18 3.6 52 30 6.1 11 40 24 2.6 23 8 0.47 20 14 0.75 12 32 19 1.6 30 6 0.45 18 13 0.61 13 30 14 1.2 36 15 2.6 21 12 0.67 14 20 10 0.53 23 4 0.28 19 12 0.60 15 146 68 153 17 4 0.18 21 11 0.64 16 31 26 2.5 47 21 3.2 23 11 0.68 17 21 9 0.52 40 18 2.2 22 11 0.63 18 22 7 0.45 49 25 3.6 18 10 0.50 19 52 20 23 46 20 2.7 e18 e10 e0.50 20 85 46 29 25 7 0.48 e40 e18 e2.2 21 37 11 1.1 21 3 0.20 e38 e18 e2.2 22 96 47 17 25 3 0.20 e69 e35 e5.9 23 57 31 5.5 22 3 0.18 e58 e31 e5.5 24 180 91 220 19 3 0.15 e55 e31 e5.5 25 181 94 63 19 3 0.16 e68 e35 e5.9 26 321 163 219 19 3 0.15 e144 e68 e153 27 62 35 5.9 28 3 0.22 e41 e18 e2.2 28 39 20 2.1 17 3 0.14 e23 e11 e0.68 29 35 13 1.2 14 3 0.11 e18 e13 e0.61 30 32 8 0.66 13 3 0.10 e18 e13 e0.61 31 75 35 9.9 e14 e3 e0.11 TOTAL 2,355 1,487.27 765 26.49 996 200.61 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 338 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 e12 e3 e0.11 40 29 3.4 7.0 4 0.08 2 e14 e3 e0.11 28 23 1.8 6.7 4 0.07 3 e22 e11 e0.63 20 22 1.2 8.0 4 0.09 4 e23 e11 e0.63 63 39 9.2 6.1 7 0.11 5 e27 e11 e0.63 36 26 2.6 5.4 9 0.13 6 e22 e11 e0.63 24 26 1.7 4.5 11 0.13 7 e15 e9 e0.62 26 26 1.8 4.2 9 0.11 8 e13 e9 e0.62 17 25 1.1 3.9 8 0.08 9 e8.0 e5 e0.12 14 25 0.91 3.8 6 0.07 10 7.4 5 0.10 13 24 0.87 4.4 5 0.06 11 7.2 5 0.10 16 24 1.0 5.0 4 0.05 12 7.0 5 0.09 21 24 1.3 5.8 3 0.05 13 6.5 5 0.09 13 23 0.82 3.6 2 0.02 14 7.0 5 0.09 11 23 0.70 2.5 3 0.02 15 6.6 5 0.08 11 23 0.68 3.0 4 0.03 16 6.7 5 0.08 11 22 0.67 3.1 5 0.04 17 6.6 5 0.08 36 24 3.0 3.0 6 0.05 18 6.2 4 0.07 17 5 0.21 3.8 6 0.06 19 8.0 4 0.09 13 4 0.14 28 17 4.0 20 8.3 4 0.10 13 4 0.14 15 7 0.32 21 7.9 4 0.09 12 4 0.13 6.7 6 0.11 22 6.5 4 0.07 12 4 0.12 6.0 6 0.10 23 7.1 4 0.08 9.7 3 0.09 5.7 6 0.09 24 18 9 0.62 8.4 3 0.07 9.5 6 0.16 25 607 323 975 21 8 0.69 5.5 7 0.11 26 183 101 134 11 4 0.12 4.6 8 0.10 27 24 32 2.1 8.3 4 0.09 4.2 9 0.10 28 20 26 1.4 7.6 4 0.08 7.0 9 0.16 29 16 25 1.1 4.1 8 0.09 30 31 31 4.2 19 12 0.81 31 128 73 56 6.2 5 0.08 TOTAL 1,282.0 1,179.73 533.0 34.63 205.3 7.48 APRIL MAY JUNE 1 13 4 0.13 26 9 0.64 28 9 0.83 2 10 3 0.08 23 10 0.64 36 8 1.0 3 11 4 0.16 22 11 0.66 40 10 1.6 4 24 8 0.62 20 12 0.66 43 11 1.8 5 129 61 92 19 13 0.67 23 4 0.25 6 59 25 7.6 18 14 0.68 103 41 47 7 14 3 0.12 18 15 0.72 223 107 154 8 12 3 0.11 18 15 0.73 59 13 2.4 9 29 8 3.1 20 13 0.66 35 7 0.62 10 42 14 3.8 16 10 0.42 26 5 0.36 11 231 124 151 22 7 0.41 23 5 0.31 12 35 8 0.76 15 4 0.17 24 5 0.33 13 19 5 0.26 13 4 0.15 20 5 0.27 14 27 5 0.37 125 56 42 19 5 0.25 15 213 97 196 68 24 8.1 64 32 6.2 16 133 67 42 28 2 0.16 39 20 2.2 17 2,870 1,850 34,600 25 1 0.10 33 18 1.6 18 515 174 524 76 13 3.9 31 14 1.3 19 202 39 22 35 1 0.11 49 24 3.8 20 104 20 5.9 21 1 0.06 32 12 1.1 21 82 12 2.7 255 107 237 46 24 3.8 22 74 9 1.9 95 35 11 25 14 0.94 23 78 17 5.0 82 29 8.1 19 13 0.65 24 175 77 103 67 18 4.2 17 10 0.46 25 63 13 2.5 39 8 0.83 15 8 0.33 26 57 14 2.5 32 8 0.66 14 7 0.26 27 42 5 0.62 29 11 0.82 13 11 0.36 28 34 4 0.41 26 14 0.97 21 15 0.86 29 30 6 0.48 24 16 1.0 14 19 0.72 30 28 8 0.57 22 13 0.75 11 22 0.69 31 22 9 0.50 TOTAL 5,355 35,769.69 1,321 327.47 1,145 236.29 RIO FAJARDO BASIN 339 50071000 RIO FAJARDO NEAR FAJARDO, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean concen- Load discharge tration (tons/ Day (cfs) (mg/l) day) Mean Mean Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 11 21 0.62 2 66 44 15 3 23 3 0.19 4 25 7 0.44 5 14 18 0.65 50 18 3.0 36 4 0.40 134 89 96 29 4 0.32 30 5 0.41 153 233 570 19 3 0.17 41 20 2.4 15 3 0.12 94 46 31 6 12 28 0.91 7 11 35 1.1 8 12 28 0.88 9 21 19 1.1 10 12 13 0.42 68 28 15 47 31 4.0 112 89 67 38 28 2.9 34 19 1.8 371 474 2,000 33 14 1.2 133 68 40 20 12 0.66 48 16 2.1 11 8.9 12 0.28 12 8.6 11 0.26 13 385 582 3,060 14 38 10 1.1 15 32 13 2.1 17 11 0.49 57 14 2.2 21 10 0.57 34 10 0.98 17 9 0.41 44 18 3.1 28 12 1.6 44 7 0.91 32 41 3.8 214 152 295 16 90 52 17 17 41 35 4.6 18 21 8 0.48 19 18 5 0.26 20 15 5 0.19 15 34 1.4 207 112 162 13 32 1.2 56 6 0.94 15 30 1.2 87 5 1.2 22 27 1.6 48 5 0.59 43 23 3.1 55 9 2.5 21 15 4 0.16 22 40 24 3.0 23 20 23 1.3 24 14 15 0.54 25 13 14 0.48 37 24 5.4 538 565 1,400 244 133 135 125 92 40 44 64 7.5 70 35 6.8 26 62 4.4 58 23 3.6 94 73 21 53 12 1.7 26 11 13 0.41 27 25 14 0.99 28 79 18 4.1 29 23 13 0.83 30 15 11 0.44 31 45 31 8.8 169 88 61 49 9 1.2 48 24 3.3 44 8 0.95 63 12 2.0 41 7 0.77 48 8 1.0 47 6 0.75 45 5 0.60 51 5 0.73 34 4 0.40 --- --- --­ TOTAL 1,164.5 --- 3,128.63 1,590 --- 442.33 2,912 --- 4,579.04 YEAR 19,623.8 47,419.66 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus- sedi- pended pended Instan- ment, sedi- sedi- taneous sieve ment ment dis- diametr concen- dis- charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) APR 17... 1115 6,790 69 6,700 123,000 SEP 21... 0655 1,470 91 1,890 7,510 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus- Sus- sedi- sedi- sedi- sedi- sedi- pended pended Instan- ment, ment, ment, ment, ment, sedi- sedi- taneous sieve sieve sieve sieve sieve ment ment dis- diametr diametr diametr diametr diametr concen- dis- charge, percent percent percent percent percent tration charge, Date Time cfs <.063mm <.125mm <.25mm <.5 mm <1 mm mg/L tons/d (00061) (70331) (70332) (70333) (70334) (70335) (80154) (80155) APR 17... 1455 7,290 76 94 100 100 100 6,720 132,000 340 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR LOCATION.--Lat 18q19'35", long 65q38'47", 1.2 mi (1.9 km) southwest of Playa de Fajardo, and 0.5 mi (0.8 km) east of Fajardo Plaza. DRAINAGE AREA.--23.4 mi2 (60.6 km2). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 07... 1210 20 3.4 9.8 127 7.5 157 28.5 41 8.72 4.56 .97 .9 JAN 30... 1145 35 22 8.8 -- 7.3 185 25.6 47 10.5 4.97 1.47 .9 APR 14... 1400 47 110 9.4 -- 8.0 156 29.3 51 12.2 5.04 1.17 1 JUL 02... 1315 136 68 7.6 -- 7.0 964 25.8 -- -- -- -- -­ SEP 04... 1300 45 16 8.9 -- 7.3 116 28.6 29 6.39 3.16 1.50 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 07... 13.5 42 14.9 <.17 23.8 4.0 -- 95 5.13 <10 <.20 .02 -­ JAN 30... 14.4 44 19.6 .08 23.5 5.4 .0 106 9.93 17 <.20 .01 -­ APR 14... 16.9 43 24.4 .10 22.5 6.0 <.1 114 14.5 106 .30 .02 .07 JUL 02... -- 21 -- -- -- -- -- -- -- 34 .20 .01 -- SEP 04... 10.0 30 10.9 <.2 19.7 4.3 -- 74 8.92 <40 .40 .02 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 07... .060 <.01 -- <.02 -- -- <10 200 E6 -- -- -- -­ JAN 30... .330 <.01 -- .02 -- -- 10 180 -- 6,300 <2 48.4 27 APR 14... .090 .02 .28 .09 .39 1.7 <10 E1,700 -- 42,000 <2 86.5 33 JUL 02... .130 <.01 .19 .04 .33 1.5 20 E910 -- -- -- -- -­ SEP 04... .250 <.01 .38 .03 .65 2.9 10 E740 -- 7,800 -- -- -­ 341 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 07... -- -- -- -- -- -- -- -- -- -- -- -- -- JAN 30... <.2 E.5 <10 <.01 840 M 64.8 E.01 <3 <.3 E14 <.10 <16 APR 14... <.2 1.7 <10 <.01 3,910 2 188 .03 <3 <.3 59 <.10 <16 JUL 02... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 342 RIO BLANCO BASIN 50074950 QUEBRADA GUABA NEAR NAGUABO, PR LOCATION.--Lat 18q17'02", long 65q47'20", Hydrologic Unit 21010005, on right bank, off Highway 191 at El Yunque Caribbean National Forest, 4.8 mi (7.7 km) southeast of Campamento Eliza Colberg, 1.3 mi (2.1 km) southeast of Mt. Britton, 2.0 mi (3.2 km) northwest of Pico del Este and 7.3 mi (11.7 km) southeast of Río Grande Plaza. DRAINAGE AREA.--0.12 mi2 (0.31 km2). PERIOD OF RECORD.--June 1992 to current year. GAGE.--Water-stage recorder. Elevation of gage is 2,100 ft (640 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 0.18 0.21 0.15 0.26 0.36 0.19 0.13 e1.5 e1.1 e0.42 e0.58 e0.66 2 0.47 0.20 0.18 0.33 0.31 0.20 0.11 e1.4 e0.50 e1.3 e2.4 e1.2 3 0.23 0.25 0.18 0.26 0.28 0.18 0.20 e1.6 e0.77 e0.57 e0.52 e0.72 4 0.21 0.20 0.35 0.26 1.4 0.16 0.17 e2.0 e0.86 e0.58 e0.50 e0.52 5 0.20 0.19 0.19 0.41 0.47 0.17 2.9 e2.3 e0.44 e0.45 e0.47 e0.52 6 0.20 0.18 0.18 0.30 0.36 0.16 e0.32 e2.5 e0.47 e0.46 e1.5 e0.50 7 0.18 0.17 0.16 0.30 0.46 0.16 e0.25 e3.0 e3.0 e0.40 e1.2 e0.49 8 0.49 0.17 0.22 0.28 0.33 0.15 e0.26 e2.6 e1.4 e0.54 e0.58 e0.91 9 0.26 0.17 0.16 0.27 0.30 0.15 e0.40 e1.6 e1.8 e0.58 e0.60 e1.0 10 0.41 0.39 0.30 0.25 0.36 0.17 e0.74 e2.2 e1.5 e0.41 e0.46 e0.49 11 0.24 0.24 0.18 0.28 0.33 0.17 e2.2 e1.3 e1.2 e0.40 e0.45 e0.58 12 0.22 0.31 0.17 0.26 0.32 0.16 e0.52 e0.64 e1.0 e0.40 e0.44 e0.46 13 0.21 0.21 0.19 0.26 0.28 0.15 e0.47 e0.63 e1.1 e2.9 e0.44 e0.84 14 0.20 0.19 0.16 0.26 0.28 0.15 e0.62 e1.6 e1.0 e0.44 e0.65 e0.49 15 0.77 0.19 0.17 0.27 0.26 0.15 e2.0 e1.4 e2.7 e0.44 e0.58 e1.0 16 0.25 0.35 0.28 0.27 0.28 0.14 e1.4 e2.0 e1.1 e1.3 e0.44 e1.3 17 0.22 0.34 0.23 0.25 0.71 0.14 e21 e1.4 e0.88 e0.65 e0.44 e0.49 18 0.21 0.37 0.18 0.30 0.34 0.14 e6.3 e3.0 e0.90 e0.50 e0.52 e0.58 19 0.64 0.29 0.19 0.27 0.28 0.14 e6.2 e2.2 e2.1 e0.47 e0.47 e0.84 20 0.32 0.22 0.32 0.33 0.31 0.13 e3.0 e1.2 e1.5 e0.44 e0.84 e1.6 21 0.37 0.38 0.38 0.28 0.30 0.14 e3.6 e2.4 e2.1 e0.47 e1.5 e2.1 22 0.35 0.25 0.32 0.28 0.27 0.14 e3.8 e1.8 e1.0 e1.1 e2.9 e0.72 23 0.27 0.22 0.28 0.31 0.25 0.14 e1.6 e2.8 e0.87 e0.50 e0.65 e0.52 24 1.0 0.21 0.36 0.30 0.27 0.12 e1.4 e2.2 e0.72 e0.46 e0.52 e0.46 25 0.56 0.20 0.29 4.2 0.37 0.12 e0.86 e0.90 e0.55 e0.44 e1.9 e0.42 26 0.69 0.26 0.32 0.62 0.25 0.12 e0.77 e0.90 e0.60 e0.44 e1.9 e0.42 27 0.29 0.21 0.29 0.40 0.23 0.11 e0.69 e1.2 e0.41 e0.84 e0.58 e0.41 28 0.25 0.18 0.28 0.34 0.20 0.11 e0.62 e0.82 e0.60 e1.6 e0.98 e0.41 29 0.24 0.17 0.26 0.33 0.14 e1.1 e0.53 e0.41 e0.50 e0.96 e0.49 30 0.22 0.15 0.25 0.41 0.12 e1.7 e0.58 e0.42 e0.43 e1.0 e0.78 31 0.23 0.26 0.75 0.11 e1.4 e1.4 e0.66 TOTAL 10.58 7.07 7.43 13.89 10.16 4.53 65.33 51.60 33.00 21.83 27.63 21.92 MEAN 0.34 0.24 0.24 0.45 0.36 0.15 2.18 1.66 1.10 0.70 0.89 0.73 MAX 1.0 0.39 0.38 4.2 1.4 0.20 21 3.0 3.0 2.9 2.9 2.1 MIN 0.18 0.15 0.15 0.25 0.20 0.11 0.11 0.53 0.41 0.40 0.44 0.41 AC-FT 21 14 15 28 20 9.0 130 102 65 43 55 43 CFSM 2.84 1.96 2.00 3.73 3.02 1.22 18.1 13.9 9.17 5.87 7.43 6.09 IN. 3.28 2.19 2.30 4.31 3.15 1.40 20.25 16.00 10.23 6.77 8.57 6.80 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1992 - 2003, BY WATER YEAR (WY) MEAN 0.47 0.58 0.57 0.49 0.41 0.24 0.47 0.50 0.41 0.44 0.48 0.60 MAX 0.89 1.19 1.24 0.67 0.71 0.32 2.18 1.66 1.10 1.18 0.89 1.42 (WY) (1998) (2000) (2000) (1997) (2000) (2001) (2003) (2003) (2003) (1992) (2003) (1996) MIN 0.25 0.24 0.22 0.28 0.28 0.15 0.20 0.13 0.18 0.22 0.19 0.34 (WY) (1993) (2003) (1994) (1994) (2002) (2003) (2000) (1999) (2000) (1994) (1993) (1993) 343 RIO BLANCO BASIN 50074950 QUEBRADA GUABA NEAR NAGUABO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1992 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 138.00 ANNUAL MEAN 0.38 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 8.5 LOWEST DAILY MEAN 0.09 ANNUAL SEVEN-DAY MINIMUM 0.10 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 274 ANNUAL RUNOFF (CFSM) 3.15 ANNUAL RUNOFF (INCHES) 42.78 10 PERCENT EXCEEDS 0.59 50 PERCENT EXCEEDS 0.28 90 PERCENT EXCEEDS 0.16 274.97 0.75 0.47 0.75 2003 0.32 1994 May 30 21 Apr 17 23 Sep 10, 1996 Mar 27 0.11 Mar 27 0.06 May 31, 1999 Mar 22 0.12 Mar 25 0.07 May 27, 1999 133 Apr 17 133 Apr 17, 2003 11.20 Apr 17 11.20 Apr 17, 2003 0.05 May 1, 1997 545 339 6.28 3.90 85.24 52.99 1.6 0.79 0.41 0.30 0.17 0.15 e Estimated 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 344 RIO BLANCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR LOCATION.--Lat 18q16'38", long 65q47'09", Hydrologic Unit 21010005, in Caribbean National Forest, at Highway 191, at El Yunque, 1.6 mi (2.6 km) upstream from confluence with Río Cubuy, 2.8 mi (4.5 km) north of Florida, and 5.3 mi (8.5 km) northwest of Naguabo Plaza. DRAINAGE AREA.--1.26 mi2 (3.26 km2). PERIOD OF RECORD.--July 1945 to March 1953 (operated by Puerto Rico Water Resources Authority), annual maximum, water years 1953 -62, annual low- flow measurements 1962-66, October 1979 to current year. REVISED RECORDS.--WDR PR-02-1: 1995-2001 (M). GAGE.--Water-stage recorder, crest-stage gage and sharp-crested weir. Elevation of gage is 2,020 ft (616 m), from topographic ma p. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e4.5 7.2 6.2 5.9 10 5.2 5.0 7.8 6.4 6.5 9.5 10 2 e9.9 6.9 8.3 8.2 7.8 6.0 4.6 7.6 8.0 19 38 19 3 e6.5 10 8.4 6.3 7.2 5.4 8.1 7.3 13 8.6 7.7 11 4 e6.0 6.7 18 5.3 38 5.2 7.3 7.2 11 8.9 6.7 8.4 5 4.8 6.2 7.2 10 16 5.0 59 7.1 6.2 6.4 6.4 8.5 6 5.3 6.1 6.4 5.8 8.2 4.9 7.9 6.9 9.1 6.8 21 8.1 7 4.5 7.1 5.9 5.3 12 4.8 6.3 7.2 41 5.9 18 7.4 8 18 6.4 9.4 5.1 7.1 4.8 7.4 7.0 9.6 8.8 8.7 14 9 6.9 6.1 6.2 5.0 7.3 4.7 16 8.1 15 9.3 10 16 10 13 13 12 4.9 10 5.2 26 6.8 7.6 6.1 7.3 7.8 11 6.3 6.7 7.7 4.8 9.3 5.5 54 6.9 6.9 5.8 6.7 9.5 12 6.9 11 7.1 4.7 9.0 4.9 8.3 6.3 8.4 5.6 6.4 7.1 13 6.1 5.8 9.4 4.7 6.6 4.6 6.4 6.2 6.6 44 6.4 12 14 5.0 e5.5 7.3 4.7 6.2 4.6 10 24 8.5 7.2 9.9 8.0 15 32 e5.5 7.4 4.6 6.0 4.8 41 11 33 7.3 8.3 16 16 8.7 e10 8.8 4.7 6.9 4.6 21 8.5 14 20 6.3 21 17 8.1 e10 7.1 4.6 22 4.5 e438 7.7 12 10 6.2 7.9 18 6.8 e11 5.8 6.1 8.5 4.7 56 19 8.5 6.5 7.3 9.4 19 25 11 7.1 4.9 6.7 4.6 37 7.9 12 6.0 6.7 13 20 15 5.8 13 6.0 8.8 4.4 16 6.9 9.4 5.8 12 25 21 17 13 15 5.0 7.9 4.3 28 30 22 6.2 24 32 22 12 9.3 11 4.5 6.4 4.3 20 14 8.2 16 44 11 23 7.6 7.3 7.1 4.9 5.9 5.0 15 18 7.1 6.8 8.5 7.7 24 32 6.8 13 4.6 6.6 4.5 12 18 6.8 5.9 7.2 7.1 25 25 6.5 7.3 86 11 4.3 10 7.9 6.4 5.7 29 6.8 26 32 11 7.4 20 6.0 4.3 12 7.1 6.2 5.7 29 6.6 27 9.9 8.3 6.2 9.0 5.7 4.2 9.5 6.7 6.0 13 8.8 6.4 28 8.1 6.2 5.6 7.7 5.5 4.2 8.9 6.4 8.2 23 15 6.1 29 7.8 5.2 5.3 11 5.9 8.3 6.2 5.9 7.2 13 7.7 30 7.4 5.4 5.2 15 5.7 8.1 6.0 5.8 6.1 16 12 31 8.3 5.9 30 3.6 5.9 21 10 TOTAL 366.4 237.0 257.7 309.3 268.6 148.7 967.1 303.6 328.8 321.1 414.0 342.5 MEAN 11.8 7.90 8.31 9.98 9.59 4.80 32.2 9.79 11.0 10.4 13.4 11.4 MAX 32 13 18 86 38 6.0 438 30 41 44 44 32 MIN 4.5 5.2 5.2 4.5 5.5 3.6 4.6 5.9 5.8 5.6 6.2 6.1 AC-FT 727 470 511 613 533 295 1,920 602 652 637 821 679 CFSM 9.38 6.27 6.60 7.92 7.61 3.81 25.6 7.77 8.70 8.22 10.6 9.06 IN. 10.82 7.00 7.61 9.13 7.93 4.39 28.55 8.96 9.71 9.48 12.22 10.11 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1945 - 2003, BY WATER YEAR (WY) MEAN 15.5 18.7 16.1 13.5 13.1 9.80 12.4 15.3 11.9 12.9 14.5 17.3 MAX 32.1 46.8 34.6 27.0 44.0 26.2 34.4 26.4 20.5 38.9 24.5 40.5 (WY) (1986) (1951) (1999) (1952) (1950) (1949) (1950) (1948) (1996) (1952) (1945) (1996) MIN 4.78 7.90 4.99 6.65 4.86 3.96 4.77 5.25 5.19 6.44 5.91 7.03 (WY) (1993) (2003) (1990) (1994) (1983) (1951) (1984) (1999) (1985) (1994) (1993) (1986) 345 RIO BLANCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1945 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 4,131.4 ANNUAL MEAN 11.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 203 LOWEST DAILY MEAN 4.5 ANNUAL SEVEN-DAY MINIMUM 4.9 MAXIMUM PEAK FLOW MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 8,190 ANNUAL RUNOFF (CFSM) 8.98 ANNUAL RUNOFF (INCHES) 121.97 10 PERCENT EXCEEDS 18 50 PERCENT EXCEEDS 7.8 90 PERCENT EXCEEDS 5.3 4,264.8 11.7 14.2 21.0 1952 7.92 1994 May 30 438 Apr 17 571 Sep 10, 1996 Oct 1 3.6 Mar 31 1.5 Mar 22, 1946 Jul 31 4.4 Mar 22 2.0 Apr 7, 1946 Not determined Apr 17 Not determined Apr 17, 2003 2,860 Apr 21, 1983 8.96 Apr 21, 1983 8,460 10,300 9.27 11.3 125.91 153.31 20 27 7.3 8.2 4.9 4.8 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 346 RIO BLANCO BASIN 50076000 RIO BLANCO NEAR FLORIDA, PR LOCATION.--Lat 18q13'45", long 65q47'06", Hydrologic Unit 21010005, on left bank of Highway 191, 0.5 mi (0.8 km) upstream from Quebrada Sonadora, 0.7 mi (1.1 km) upstream from intersection of Highway 191 and 31, 0.8 mi (1.3 km) south of Florida. DRAINAGE AREA.--12.3 mi2 (31.9 km2). PERIOD OF RECORD.--October 1982 to January 1985, July 2002 to current year. GAGE.--Water-stage recorder. Elevation of gage is 50 ft (15 m), from topographic map. REMARKS.-Records fair, except those for estimated daily discharges, which are poor. Low flow affected by diversion for water supply and hydroelectric power generation. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24 28 26 31 51 2 81 22 32 50 62 3 34 30 48 55 39 4 28 27 93 30 300 5 26 23 44 83 219 21 e48 39 38 45 78 82 30 32 42 44 113 185 90 30 40 41 60 49 58 94 25 167 40 59 79 50 64 23 540 39 37 46 43 53 6 27 21 35 44 7 24 20 28 35 8 136 20 51 29 9 61 18 44 25 10 128 105 82 24 69 22 63 38 64 47 162 60 104 21 36 40 233 41 118 58 46 17 38 38 63 47 60 73 37 19 88 39 61 58 68 122 45 24 184 35 43 39 51 55 11 54 41 38 20 12 61 65 36 21 13 42 23 61 21 14 29 21 38 25 15 186 19 47 22 50 21 405 37 40 36 48 64 55 22 90 33 44 34 47 50 33 20 47 34 40 247 43 88 30 19 56 145 46 54 52 63 26 18 198 101 336 57 57 77 16 71 76 81 22 17 e46 131 61 22 18 46 121 46 21 19 66 77 32 23 20 101 33 113 22 31 19 149 55 89 113 43 137 153 22 5,850 46 61 73 43 63 55 21 426 125 54 46 62 83 40 75 270 56 66 41 51 83 39 25 123 42 55 40 74 118 21 93 135 108 29 22 98 71 93 22 23 46 41 58 22 24 176 35 76 32 25 142 37 50 534 47 20 199 437 95 39 64 172 36 16 131 89 52 e33 187 85 29 22 91 118 45 e26 74 54 32 24 72 106 43 e31 54 42 78 19 60 52 38 36 105 42 26 314 43 84 159 27 53 53 48 37 28 32 33 35 29 29 31 29 31 28 30 29 27 33 61 31 36 --- 32 120 35 18 61 45 42 33 204 45 28 18 66 41 36 61 59 45 27 18 56 38 54 110 101 43 --- 20 50 36 38 51 79 49 --- 37 47 36 36 42 93 63 --- e53 --- 35 --- 107 81 --­ TOTAL 2,321 1,425 1,684 1,698 MEAN 74.9 47.5 54.3 54.8 MAX 314 135 113 534 MIN 24 18 26 20 AC-FT 4,600 2,830 3,340 3,370 CFSM 6.09 3.86 4.42 4.45 IN. 7.02 4.31 5.09 5.14 1,796 759 9,683 2,098 2,012 1,874 2,494 2,217 64.1 24.5 323 67.7 67.1 60.5 80.5 73.9 300 75 5,850 437 336 247 204 172 26 16 32 33 36 26 43 42 3,560 1,510 19,210 4,160 3,990 3,720 4,950 4,400 5.21 1.99 26.2 5.50 5.45 4.91 6.54 6.01 5.43 2.30 29.29 6.35 6.09 5.67 7.54 6.71 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1983 - 2003, BY WATER YEAR (WY) MEAN 69.7 97.2 69.3 48.3 MAX 89.3 190 96.0 54.8 (WY) (1985) (1985) (1983) (2003) MIN 50.5 47.5 54.3 41.7 (WY) (1983) (2003) (2003) (1983) 49.9 29.9 140 70.3 68.3 68.8 83.9 66.6 68.0 38.7 323 78.7 75.9 103 119 75.1 (1984) (1983) (2003) (1983) (1984) (1983) (1983) (2002) 16.8 24.5 20.2 64.5 62.0 50.0 49.4 49.0 (1983) (2003) (1984) (1984) (1983) (1984) (1984) (1983) 347 RIO GUAJATACA BASIN 50076000 RIO BLANCO NEAR FLORIDA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2003 WATER YEAR WATER YEARS 1983 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 30,061 ANNUAL MEAN 82.4 68.6 HIGHEST ANNUAL MEAN 82.4 2003 LOWEST ANNUAL MEAN 55.7 1984 HIGHEST DAILY MEAN 5,850 Apr 17 5,850 Apr 17, 2003 LOWEST DAILY MEAN 16 Mar 22 9.6 Apr 10, 1983 ANNUAL SEVEN-DAY MINIMUM 19 Mar 22 10 Apr 7, 1983 MAXIMUM PEAK FLOW 50,600 Apr 17 50,600 Apr 17, 2003 MAXIMUM PEAK STAGE 24.40 Apr 17 24.40 Apr 17, 2003 INSTANTANEOUS LOW FLOW 8.8 Apr 10, 1983 ANNUAL RUNOFF (AC-FT) 59,630 49,730 ANNUAL RUNOFF (CFSM) 6.70 5.58 ANNUAL RUNOFF (INCHES) 90.92 75.83 10 PERCENT EXCEEDS 124 128 50 PERCENT EXCEEDS 46 41 90 PERCENT EXCEEDS 22 18 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 348 THIS PAGE IS INTENTIONALLY BLANK Figure 19. Southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins. 349 --- --- --- --- --- --- --- 350 RIO HUMACAO BASIN 50081000 RIO HUMACAO AT LAS PIEDRAS, PR LOCATION.--Lat 18q10'27", long 65q52'11", Hydrologic Unit 21010005, on left bank at downstream side of bridge on Highway 921, 0.6 mi (1.0 km) southeast of junction with Highway 30, 0.8 mi (1.3 km) downstream from Quebrada Blanca and 0.8 mi (1.3 km) south of Las Piedras. DRAINAGE AREA.--6.65 mi2 (17.2 km2). PERIOD OF RECORD.--September 1958 to December 1967 (monthly discharge measurements), July 1974 to September 1977, October 1987 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 260 ft (79 m), from topographic map. Prior to July 1974, crest-stage gage at different datum. July 1974 to September 1977 at site 90 ft (27 m) upstream at present datum. REMARKS.--Records fair except those for estimated daily discharges and those for above 1,000 ft3/s (28.3 m3/s), which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e9.0 e6.9 e8.7 e8.1 e7.8 e5.1 e13 18 15 15 14 e17 2 e9.0 e6.6 e10 e13 e9.6 e5.1 e11 17 19 23 16 e22 3 e15 e17 e11 e11 e9.0 e5.1 e9.6 17 22 26 13 e18 4 e10 e10 e7.8 e8.7 e6.3 e4.8 e16 16 18 18 12 e16 5 e8.4 e10 e12 e15 e7.2 e4.8 e15 18 18 22 12 15 6 e8.4 e5.7 e11 e16 e6.3 e6.5 e13 17 51 20 30 15 7 e9.0 e5.7 e7.2 e10 e7.5 e4.8 e9.9 21 116 17 24 15 8 e20 e5.4 e6.6 e9.0 e6.3 e4.8 e9.6 25 31 15 18 14 9 e14 e5.4 e7.8 e7.8 e8.4 e4.8 e15 17 21 16 15 15 10 e15 e6.0 e10 e16 e9.6 e6.0 e17 15 19 15 14 14 11 e9.3 e6.0 e8.7 e7.2 e8.1 e7.3 e68 16 19 14 14 13 12 e8.7 e6.6 e9.9 e6.6 e8.4 e4.2 e39 15 18 14 13 13 13 e8.1 e5.7 e9.6 e6.3 e6.0 e3.9 e28 15 16 73 13 21 14 e7.5 e6.0 e10 e6.6 e5.1 e3.9 e30 24 18 19 13 27 15 e8.7 e5.7 e8.4 e6.0 e5.1 e3.9 e17 19 33 16 32 21 16 e8.4 e50 e11 e6.0 e5.7 e4.5 e16 17 24 25 21 93 17 e8.7 e18 e11 e6.0 e17 e5.7 e48 27 19 15 81 20 18 e9.3 e16 e14 e6.6 e9.6 e5.7 e80 39 18 14 61 17 19 e7.5 e13 e8.4 e6.6 e7.5 e7.5 e57 33 58 13 23 15 20 e7.2 e9.0 e7.5 e6.0 e8.7 e7.2 e28 18 24 13 19 16 21 e7.5 e8.1 e9.0 e5.7 e16 e5.7 e25 204 23 16 31 51 22 e6.9 e8.1 e9.6 e5.4 e10 e5.4 59 43 19 23 87 25 23 e6.9 e7.2 e8.7 e7.5 e7.5 e5.4 41 24 17 15 25 17 24 e8.4 e6.6 e7.5 e7.8 e6.6 e5.7 30 21 17 13 18 15 25 e14 e6.6 e7.2 e8.7 e7.2 e5.1 26 19 16 12 19 14 26 e31 e7.8 e7.8 e12 e6.3 e5.1 30 17 16 14 31 15 27 e16 e9.0 e7.5 e7.5 e5.7 e5.1 23 17 16 20 20 14 28 e8.4 e6.9 e6.6 e6.3 e5.4 e5.4 22 16 19 55 21 13 29 e7.8 e7.2 e6.3 e5.7 e6.3 20 16 15 17 33 13 30 e7.2 e7.8 e6.0 e6.3 e8.7 19 15 15 14 24 13 31 e7.2 e6.0 e8.4 e6.6 15 14 18 TOTAL 322.5 290.0 272.8 259.8 223.9 170.1 835.1 811 750 616 785 607 MEAN 10.4 9.67 8.80 8.38 8.00 5.49 27.8 26.2 25.0 19.9 25.3 20.2 MAX 31 50 14 16 17 8.7 80 204 116 73 87 93 MIN 6.9 5.4 6.0 5.4 5.1 3.9 9.6 15 15 12 12 13 AC-FT 640 575 541 515 444 337 1,660 1,610 1,490 1,220 1,560 1,200 CFSM 1.56 1.45 1.32 1.26 1.20 0.83 4.19 3.93 3.76 2.99 3.81 3.04 IN. 1.80 1.62 1.53 1.45 1.25 0.95 4.67 4.54 4.20 3.45 4.39 3.40 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1974 - 2003, BY WATER YEAR (WY) MEAN 30.6 37.7 29.3 19.9 15.7 11.3 11.2 15.6 17.6 18.4 20.8 34.9 MAX 77.5 126 112 37.5 22.2 16.4 27.8 42.2 41.1 38.1 34.7 121 (WY) (1999) (1988) (1988) (1999) (1997) (1989) (2003) (1992) (1996) (1993) (1996) (1996) MIN 10.4 9.67 8.80 8.38 8.00 5.49 5.88 7.26 5.91 7.02 9.45 10.0 (WY) (2003) (2003) (2003) (2003) (2003) (2003) (1977) (1990) (1977) (2001) (1974) (1990) 351 RIO GUAJATACA BASIN 50081000 RIO HUMACAO AT LAS PIEDRAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1974 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 6,044.1 ANNUAL MEAN 16.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 444 LOWEST DAILY MEAN 5.4 ANNUAL SEVEN-DAY MINIMUM 5.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 11,990 ANNUAL RUNOFF (CFSM) 2.49 ANNUAL RUNOFF (INCHES) 33.81 10 PERCENT EXCEEDS 20 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 7.6 5,943.2 16.3 22.0 37.6 1988 12.1 1990 May 30 204 May 21 2,010 Sep 10, 1996 Nov 8 3.9 Mar 13 2.2 Jul 15, 1974 Nov 6 4.5 Mar 12 2.8 Jul 19, 1974 1,090 May 21 20,800 Sep 6, 1960 4.49 May 21 34.40 Sep 6, 1960 11,790 15,950 2.45 3.31 33.25 44.99 27 33 13 14 5.7 7.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 352 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR LOCATION.--Lat 18q08'49", long 65q49'37", at bridge on Highway 3, 300 ft (91 m) downstream from Quebrada Mariana, and 0.4 mi (0.6 km) south of Humacao Plaza. DRAINAGE AREA.--17.3 mi2 (44.8 km2). PERIOD OF RECORD.--Water years 1958-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 06... 1410 11 14 6.5 85 6.8 314 28.6 99 26.3 8.02 1.69 1 FEB 19... 1400 12 15 6.6 -- 7.5 302 27.0 90 24.5 7.10 2.25 1 APR 23... 1100 55 98 7.1 -- 7.2 235 25.9 69 18.5 5.48 3.51 .8 JUL 14... 1445 26 22 7.5 -- 7.4 267 31.9 -- -- -- -- -­ SEP 02... 1622 30 -- 6.8 -- 7.2 272 30.6 89 24.6 6.66 2.57 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 06... 26.5 98 29.8 <.17 38.3 7.8 -- 197 5.84 10 .70 .47 .58 FEB 19... 22.0 96 29.2 .09 32.8 7.5 <.0 183 5.96 12 1.7 .96 .50 APR 23... 16.1 71 19.8 .11 25.7 8.1 .2 140 20.8 66 .90 .27 .55 JUL 14... -- 79 -- -- -- -- -- -- -- 11 .30 .05 .50 SEP 02... 19.2 83 24.4 <.2 30.6 6.9 -- 165 13.5 63 .60 .18 .48 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 06... .590 .01 .23 .09 1.3 5.7 <10 E18,000 880 -- -- -- -­ FEB 19... .520 .02 .74 .17 2.2 9.8 30 34,000 -- E80,000 <2 67.5 32 APR 23... .570 .02 .63 .12 1.5 6.5 20 E78,000 -- E80,000 <2 96.6 E15 JUL 14... .510 .01 .25 .08 .81 3.6 10 E76,000 -- 220,000 -- -- -­ SEP 02... .500 .02 .42 .10 1.1 4.9 20 36,000 -- 300,000 -- -- -­ 353 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 06... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 19... <.2 E.7 <10 <.01 650 2 158 E.01 <3 <.3 <25 E.09 <16 APR 23... <.2 <.8 10 <.01 2,330 2 319 E.01 <3 <.3 <25 <.10 <16 JUL 14... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 354 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR LOCATION.--Lat 18q03'33", long 65q54'03", at bridge on Highway 182, 1.4 mi (2.2 km) west-northwest of Yabucoa Plaza. DRAINAGE AREA.--17.2 mi2 (44.6 km2). PERIOD OF RECORD.--Water years 1958-62, 1968-70, 1980 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 30... 1010 17 9.5 7.4 90 6.6 188 25.1 53 13.3 4.80 1.51 .9 FEB 19... 0830 33 17 7.6 -- 7.5 163 23.4 46 11.3 4.26 1.82 .9 APR 22... 1430 59 21 7.2 -- 7.0 172 24.9 48 12.1 4.29 1.99 .9 JUL 18... 1500 35 33 6.8 -- 7.2 179 28.0 -- -- -- -- -­ SEP 02... 1415 50 -- 6.8 -- 7.1 163 27.5 43 11.0 3.90 1.99 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 30... 15.0 63 13.0 <.2 39.0 3.5 -- 128 5.82 <10 .20 .02 -­ FEB 19... 13.3 57 12.4 .10 34.5 4.0 <.0 116 10.5 12 .50 .01 -­ APR 22... 14.2 55 13.5 .11 33.3 4.8 .2 117 18.7 21 .20 .03 -­ JUL 18... -- 60 -- -- -- -- -- -- -- <10 .30 .02 -­ SEP 02... 12.3 52 12.4 <.2 31.8 4.2 -- 109 14.8 29 .30 .03 .46 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 30... .340 <.01 .18 .04 .54 2.4 <10 E130 420 -- -- -- -­ FEB 19... .380 <.01 .49 .04 .88 3.9 <10 220 -- 3,300 <2 46.2 E18 APR 22... .470 <.01 .17 .05 .67 3.0 <10 E1,100 -- 5,200 8 60.3 E11 JUL 18... .310 <.01 .28 .07 .61 2.7 <10 E770 -- -- -- -- -­ SEP 02... .470 .01 .27 .08 .77 3.4 20 E1,900 -- 23,000 -- -- -­ 355 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 30... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 19... <.2 <.8 <10 <.01 1,500 <1 77.9 <.02 <3 E.2 <25 <.10 <16 APR 22... <.2 <.8 M <.01 1,570 M 99.1 <.02 <3 <.3 <25 <.10 <16 JUL 18... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 22... 1430 <.01 <.02 <.01 <.01 <.02 <.1 <.01 <.02 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 22... <.01 <.01 <.009 <.01 <.014 <.30 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 22... <.1 <.02 <.02 <1 <.02 < -- Less than 356 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR LOCATION.--Lat 18q03'45", long 65q49'42", at old railroad crossing, 0.2 mi (0.3 km) from mouth, 0.4 mi (0.6 km) west of Playa de Guayanés, and 3.5 mi (5.6 km) northeast of Yabucoa Plaza. DRAINAGE AREA.--34.0 mi2 (88.1 km2). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 06... 1130 -- 6.8 8.1 100 7.0 215 26.0 60 15.0 5.39 1.78 1 FEB 19... 1130 45 19 6.9 -- 7.5 188 24.8 52 13.1 4.69 2.62 1 APR 22... 1125 130 36 8.7 -- 7.0 279 25.0 55 14.0 4.95 3.99 1 JUL 18... 1220 49 17 6.5 -- 7.3 204 27.4 -- -- -- -- -­ SEP 02... 1135 91 -- 4.2 -- 6.8 203 26.7 49 12.5 4.34 3.14 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 06... 20.0 64 17.2 <.17 38.4 5.1 -- 141 -- <10 .30 .08 -­ FEB 19... 16.5 57 15.9 .10 34.6 4.9 <.0 127 15.5 <10 .50 .04 .39 APR 22... 17.5 59 18.4 .12 29.9 7.0 <.1 131 46.0 28 .60 .07 .34 JUL 18... -- 59 -- -- -- -- -- -- -- 12 .40 .11 -- SEP 02... 15.0 66 16.6 <.2 29.9 3.8 -- 125 30.9 43 .70 .13 .26 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 06... .330 <.01 .22 .05 .63 2.8 <10 420 390 -- -- -- -­ FEB 19... .400 .01 .46 .06 .90 4.0 20 380 -- 3,600 <2 50.9 30 APR 22... .350 .01 .53 .37 .95 4.2 10 370 -- 6,200 10 96.2 28 JUL 18... .330 <.01 .29 .06 .73 3.2 <10 330 -- E8,400 -- -- -­ SEP 02... .270 .01 .57 .23 .97 4.3 20 510 -- 22,000 -- -- -­ 357 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 06... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 19... E.1 <.8 <10 <.01 1,180 <1 63.8 <.02 <3 E.1 <25 <.10 <16 APR 22... <.2 <.8 M <.01 3,120 1 661 <.02 <3 <.3 <25 <.10 <16 JUL 18... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 358 RIO MAUNABO BASIN 50090500 RIO MAUNABO AT LIZAS, PR LOCATION.--Lat 18q01'38", long 65q56'24", Hydrologic Unit 21010005, on right bank, off Highway 759 at Lizas, about 1.0 mi (1.6 km) downstream from Quebrada Coroco, and about 3.0 mi (4.8 km) northwest of Maunabo. DRAINAGE AREA.--5.38 mi2 (13.9 km2). PERIOD OF RECORD.--February 1971 to January 1985, February 1991 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 230 ft (70 m), from topographic map. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.6 e10 17 13 9.2 8.1 e5.9 e7.8 e21 e50 69 41 2 7.9 e9.7 21 18 9.1 8.3 6.3 e7.6 e19 e80 105 24 3 8.1 e9.5 19 14 9.2 8.1 5.5 e7.4 e45 e60 52 23 4 8.8 e9.3 15 12 10 7.8 8.7 e7.0 e30 e30 55 22 5 8.1 e9.0 20 24 11 7.4 9.3 e7.5 e20 e25 53 21 6 e9.2 e8.7 16 18 11 7 e7.8 e8.5 13 13 15 8 e20 e8.2 12 12 10 9 e13 e8.8 14 11 32 10 e10 e9.5 17 14 15 7.4 5.8 e7.5 e30 e62 71 20 7.5 5.6 e13 e56 e45 72 20 7.4 7.0 e15 e40 e80 47 20 7.9 9.7 e11 e28 e100 65 20 9.9 5.7 e16 e20 e60 45 19 11 9.0 e8.4 15 11 10 12 11 e9.8 14 11 10 13 9.8 e8.0 18 11 8.6 14 9.1 10 16 11 8.2 15 11 8.1 14 10 8.1 7.6 125 e25 e15 e30 48 18 7.0 21 e12 e20 e35 43 18 6.9 11 e15 e16 e120 39 18 6.6 78 e40 e14 e17 42 18 6.7 14 e15 e80 e20 42 20 16 11 63 44 10 9.6 17 10 23 65 10 30 18 10 31 32 11 19 19 10 e39 19 11 13 20 8.1 21 17 10 13 6.5 17 e12 e30 e18 40 54 8.5 306 e11 e20 e17 71 27 7.2 216 e18 e15 e16 100 22 7.7 34 e28 e140 e15 39 20 7.0 e30 e13 e50 e17 34 28 21 7.8 24 19 9.6 22 8.3 21 28 9.2 23 7.3 18 17 11 24 7.0 14 16 10 25 e28 14 15 23 25 6.1 e28 e45 e80 e20 34 25 14 6.0 e30 e25 e50 e35 54 21 11 6.0 e16 e17 e30 e22 35 19 10 5.7 e12 e50 e35 e18 33 18 11 5.9 e9.5 e20 e38 e16 35 17 26 e27 e21 14 16 27 e16 e25 13 11 28 e12 18 13 9.6 29 e11 15 12 9.4 30 e10 14 12 9.6 31 e11 --- 12 11 9.6 5.0 e8.0 e15 e45 e22 93 17 8.9 4.5 e10 e13 e50 e35 27 16 8.6 4.3 e11 e12 e48 e50 25 16 --- e4.7 e9.0 e10 e40 e35 31 16 --- e5.5 e8.0 e18 e30 e30 25 16 --- e5.4 --- e28 --- e45 24 --­ TOTAL 344.9 496.5 589 384.4 MEAN 11.1 16.6 19.0 12.4 MAX 28 63 65 24 MIN 7.0 8.0 12 9.2 AC-FT 684 985 1,170 762 CFSM 2.07 3.08 3.53 2.30 IN. 2.38 3.43 4.07 2.66 359.1 210.6 1,063.0 541.8 1,155 1,225 1,548 654 12.8 6.79 35.4 17.5 38.5 39.5 49.9 21.8 32 9.9 306 50 140 120 105 54 8.1 4.3 5.5 7.0 14 15 24 16 712 418 2,110 1,070 2,290 2,430 3,070 1,300 2.38 1.26 6.59 3.25 7.16 7.35 9.28 4.05 2.48 1.46 7.35 3.75 7.99 8.47 10.70 4.52 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1971 - 2003, BY WATER YEAR (WY) MEAN 27.3 31.8 20.1 15.1 MAX 52.6 88.9 48.1 40.2 (WY) (1979) (1978) (1999) (1998) MIN 10.4 7.46 8.74 7.79 (WY) (1994) (1982) (1994) (1981) 12.4 9.59 9.02 13.4 18.1 17.5 24.3 28.2 24.5 18.9 35.4 25.1 47.1 40.2 131 94.6 (1982) (1976) (2003) (1979) (1979) (1993) (1979) (1996) 6.10 4.32 3.92 4.46 4.40 3.70 6.18 7.99 (1979) (1979) (1979) (1999) (1974) (1974) (1974) (1980) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1971 - 2003 ANNUAL TOTAL 6,977.3 ANNUAL MEAN 19.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 371 LOWEST DAILY MEAN 5.6 ANNUAL SEVEN-DAY MINIMUM 5.9 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 13,840 ANNUAL RUNOFF (CFSM) 3.55 ANNUAL RUNOFF (INCHES) 48.24 10 PERCENT EXCEEDS 32 50 PERCENT EXCEEDS 12 90 PERCENT EXCEEDS 7.2 8,571.3 23.5 19.0 36.7 1979 10.8 1994 May 30 306 Apr 17 2,480 Aug 31, 1979 Apr 2 4.3 Mar 28 2.2 Jul 16, 1974 Mar 20 5.0 Mar 25 2.8 Jul 11, 1974 2,030 Apr 17 9,950 Sep 20, 1994 9.65 Apr 17 17.46 Sep 20, 1994 17,000 13,770 4.36 3.53 59.27 48.02 49 35 15 11 7.6 5.3 e Estimated 359 RIO CAMUY BASIN 50090500 RIO MAUNABO AT LIZAS, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 360 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR LOCATION.--Lat 18q00'24", long 65q54'19", at bridge on Highway 3, 0.4 mi (0.6 km) southwest of Maunabo Plaza, and 1.3 mi (2.1 km) upstream from mouth. DRAINAGE AREA.--12.4 mi2 (32.1 km2). PERIOD OF RECORD.--Water years 1958-66, 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) OCT 30... 1230 9.7 7.8 6.9 92 7.1 377 29.8 93 22.2 9.07 2.36 1 FEB 12... 0900 13 3.3 7.4 -- 7.6 276 24.4 78 18.5 7.61 1.38 1 APR 08... 1705 7.9 2.9 6.8 -- 7.5 276 28.3 82 19.3 8.15 1.46 1 JUL 15... 1445 20 3.2 7.1 -- 7.3 240 29.3 -- -- -- -- -­ SEP 10... 1120 18 6.3 7.3 -- 7.7 268 28.8 78 19.3 7.29 1.40 1 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) OCT 30... 29.5 102 32.8 <.2 39.2 12.8 -- 209 5.48 11 3.7 2.60 .25 FEB 12... 22.0 90 25.2 .12 38.7 9.7 <.0 177 6.25 <10 .60 .34 .60 APR 08... 23.8 89 26.3 .16 37.7 10.1 <.1 180 3.82 <10 1.1 .86 .61 JUL 15... -- 68 -- -- -- -- -- -- -- <10 1.2 .90 .41 SEP 10... 20.0 85 23.6 <.2 39.5 8.5 -- 171 8.19 <10 1.6 1.40 .29 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) OCT 30... .280 .03 1.1 .52 4.0 17.6 20 <100 E300 -- -- -- -­ FEB 12... .710 .11 .26 .03 1.3 5.8 <10 340 -- 5,300 <2 33.8 22 APR 08... .760 .15 .24 .17 1.9 8.2 10 470 -- E120,000 E1 31.8 42 JUL 15... .430 .02 .30 .17 1.6 7.2 10 E1,200 -- 1,000 -- -- -­ SEP 10... .340 .05 .20 .17 1.9 8.6 10 E650 -- 2,200 -- -- -­ 361 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) OCT 30... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 12... <.2 <1.6 <10 <.01 240 <1 22.4 <.02 <3 <.3 <25 <.10 <16 APR 08... <.2 <.8 <10 <.01 210 <1 11.7 <.02 <3 <.3 <25 E.07 E10 JUL 15... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 362 RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR LOCATION.--Lat 17q59'16", long 66q00'18", at flat low bridge 200 ft (61 m) south of Highway 3, 0.5 mi (0.8 km) above mouth, and 1.5 mi (2.4 km) southeast of Patillas Plaza. DRAINAGE AREA.--4.9 mi2 (12.8 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 12... 1445 1.0 7.0 2.0 28 7.0 534 31.8 76 18.4 7.29 7.24 3 FEB 12... 1200 1.4 7.0 2.9 -- 7.5 584 27.7 87 20.7 8.59 7.65 2 APR 08... 1430 1.3 80 .6 -- 7.1 650 30.5 76 18.0 7.47 8.96 3 JUL 15... 1630 1.9 2.6 5.8 -- 7.5 450 29.7 -- -- -- -- -­ SEP 10... 1000 1.7 7.2 3.3 -- 7.1 466 28.6 87 20.0 9.11 5.96 2 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 12... 50.8 149 49.6 <.17 28.3 20.8 -- 272 .75 <10 20 18.0 .18 FEB 12... 48.4 180 50.5 .12 30.3 17.8 <.1 292 1.10 10 21 21.0 .20 APR 08... 50.5 184 67.2 .12 27.2 15.4 .6 306 1.06 128 35 9.90 -­ JUL 15... -- 122 -- -- -- -- -- -- -- <10 12 11.0 .30 SEP 10... 43.3 139 42.0 <.2 30.2 20.5 -- 254 1.14 <10 11 9.70 .96 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 12... .960 .78 2.0 2.50 21 92.8 40 540 570 -- -- -- -­ FEB 12... .820 .62 .00 2.20 22 96.6 40 3,400 -- 7,700 <2 13.0 121 APR 08... <.020 .02 25 4.70 -- -- 210 E10,000 -- 320,000 M 46.3 153 JUL 15... .610 .31 1.0 1.20 13 55.8 30 E180 -- 3,200 -- -- -­ SEP 10... 1.40 .44 1.3 2.00 12 54.9 40 E900 -- 5,800 -- -- -­ RIO CHICO BASIN 363 50091800 RIO CHICO AT PROVIDENCIA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 12... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 12... <.2 <.8 M <.01 130 <1 33.3 E.01 <3 .4 <25 .48 <16 APR 08... .4 1.4 60 <.01 1,310 3 61.6 .20 <3 5.9 107 1.33 36 JUL 15... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 364 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR LOCATION.--Lat 18q02'04", long 66q01'58", Hydrologic Unit 21010004, on left bank, at old foot bridge abutment, off Highway 184, 1.2 mi (1.9 km) upstream from Lago Patillas Dam and 2.2 mi (3.5 km) northwest of Patillas. DRAINAGE AREA.--18.3 mi2 (47.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to October 1965 (annual low flow and occasional measurements only), January 1966 to current yea r. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 235 ft (72 m), from topographic map. REMARKS.--Records fair, except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 30 23 29 27 26 17 e43 28 54 78 131 61 2 30 22 35 44 32 17 36 27 66 131 220 53 3 29 58 37 38 30 17 32 25 101 101 108 107 4 32 34 26 29 21 16 53 24 72 67 100 77 5 28 21 39 49 24 15 50 26 54 61 148 54 6 28 19 31 54 21 15 42 26 70 104 205 45 7 30 19 24 35 25 15 33 30 122 90 225 41 8 67 18 22 30 21 15 32 42 74 144 175 38 9 46 18 26 26 28 15 51 33 63 149 210 36 10 35 20 34 27 32 20 58 38 55 100 154 33 11 31 20 29 24 27 15 226 48 49 78 120 31 12 29 22 33 e22 28 14 130 39 57 81 103 30 13 27 19 32 21 20 13 95 42 49 195 88 34 14 25 20 34 22 17 13 99 96 45 83 89 31 15 29 19 28 20 17 13 56 52 146 47 94 42 16 28 167 37 20 19 15 54 51 74 61 76 140 17 29 60 37 20 57 19 161 36 49 44 133 63 18 31 54 46 22 32 19 267 56 44 38 193 46 19 25 42 28 22 25 25 190 72 205 37 125 39 20 24 30 25 20 29 24 94 44 59 38 85 41 21 25 27 30 19 52 19 83 103 130 41 89 116 22 23 27 32 18 34 18 101 94 75 76 154 107 23 23 24 29 25 25 18 74 54 68 60 103 58 24 28 22 25 26 22 19 47 107 87 42 79 46 25 47 22 24 29 24 17 35 51 73 35 88 41 26 103 26 26 41 21 17 28 43 76 41 212 38 27 52 30 25 25 19 17 34 38 88 78 108 37 28 28 23 22 21 18 18 35 35 85 112 86 35 29 26 24 21 19 21 32 33 72 78 190 34 30 24 26 20 21 29 29 47 66 72 107 32 31 24 20 28 e22 67 87 76 TOTAL 1,036 956 906 844 746 547 2,300 1,507 2,328 2,449 4,074 1,586 MEAN 33.4 31.9 29.2 27.2 26.6 17.6 76.7 48.6 77.6 79.0 131 52.9 MAX 103 167 46 54 57 29 267 107 205 195 225 140 MIN 23 18 20 18 17 13 28 24 44 35 76 30 AC-FT 2,050 1,900 1,800 1,670 1,480 1,080 4,560 2,990 4,620 4,860 8,080 3,150 CFSM 1.83 1.74 1.60 1.49 1.46 0.96 4.19 2.66 4.24 4.32 7.18 2.89 IN. 2.11 1.94 1.84 1.72 1.52 1.11 4.68 3.06 4.73 4.98 8.28 3.22 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 2003, BY WATER YEAR (WY) MEAN 95.6 90.0 53.8 36.0 28.7 24.5 24.1 48.9 63.1 60.8 69.9 95.8 MAX 593 393 195 125 94.6 51.2 76.7 172 200 164 231 432 (WY) (1971) (1978) (1999) (1992) (1982) (1998) (2003) (1969) (1979) (1979) (1979) (1998) MIN 14.4 16.1 8.63 14.0 7.09 6.74 9.98 10.3 13.1 14.1 17.2 12.1 (WY) (1968) (1968) (1968) (1973) (1973) (1968) (1968) (1974) (1974) (1974) (1994) (1967) RIO GRANDE DE PATILLAS BASIN­ 365 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1966 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 17,232 ANNUAL MEAN 47.2 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 988 LOWEST DAILY MEAN 11 ANNUAL SEVEN-DAY MINIMUM 12 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 34,180 ANNUAL RUNOFF (CFSM) 2.58 ANNUAL RUNOFF (INCHES) 35.03 10 PERCENT EXCEEDS 63 50 PERCENT EXCEEDS 27 90 PERCENT EXCEEDS 17 19,279 52.8 57.2 117 1979 19.8 1994 May 30 267 Apr 18 4,780 Sep 16, 1975 Mar 26 13 Mar 13 4.8 May 9, 1968 Mar 20 15 Mar 11 5.0 Apr 10, 1968 667 Nov 16 30,900 Jan 5, 1992 6.87 Nov 16 0.00 Jan 5, 1992 12 Mar 15 4.6 May 13, 1968 38,240 41,430 2.89 3.13 39.19 42.46 107 96 35 28 19 13 e Estimated 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 366 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 12... 1205 21 2.6 6.2 77 7.7 163 26.7 48 11.1 4.99 .50 .8 FEB 12... 1445 27 5.5 8.5 -- 8.5 143 26.6 41 9.22 4.28 .47 .8 APR 08... 1215 30 1.9 8.7 -- 8.0 168 26.1 51 11.7 5.32 .44 .8 JUL 15... 1215 47 2.2 8.3 -- 7.8 150 25.7 -- -- -- -- -­ SEP 10... 0830 34 1.2 8.3 -- 7.0 164 25.0 55 13.1 5.36 .49 .7 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00630) NOV 12... 12.6 50 10.2 <.17 23.8 9.2 -- 102 5.80 <10 <.20 <.01 .080 FEB 12... 11.5 -- 10.6 .06 21.9 8.2 <.0 -- -- <10 <.20 .02 .060 APR 08... 13.1 54 10.4 .11 22.1 10.4 .4 106 8.73 <10 <.20 .01 .030 JUL 15... -- 42 -- -- -- -- -- -- -- <10 <.20 .01 .170 SEP 10... 12.5 56 12.2 <.2 24.4 9.2 -- 111 10.2 <10 <.20 .01 .130 Fecal Fecal Total Chrom- COD, coli- strep- coli- Barium, Boron, ium, Copper, Nitrite Phos- high form, tococci form, water, water, water, water, water, phorus, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd unfltrd Cyanide unfltrd water, water, 0.7u MF MF, immed, water recover recover water, recover recover water mg/L unfltrd unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, -able, unfltrd Date as N mg/L mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L ug/L mg/L (00615) (00665) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) (01042) (00720) NOV 12... <.01 <.02 <10 E170 E50 -- -- -- -- -- -- -- -­ FEB 12... <.01 <.02 <10 100 -- 320 <2 8.9 E16 <.2 <.8 <10 <.01 APR 08... <.01 <.02 <10 E12 -- 80 <2 11.8 24 <.2 <.8 <10 <.01 JUL 15... <.01 <.02 <10 300 -- 5,700 -- -- -- -- -- -- -­ SEP 10... <.01 <.02 <10 E140 -- 600 -- -- -- -- -- -- -­ 367 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, Selen- water, water, com­ unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover recover recover recover water, recover recover water, water, -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 12... -- -- -- -- -- -- -- -- -- FEB 12... 90 <1 10.2 <.02 <3 <.3 <25 <.10 <16 APR 08... 50 <1 8.1 <.02 <3 <.3 <25 <.10 <16 JUL 15... -- -- -- -- -- -- -- -- -- SEP 10... -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value 368 RIO GRANDE DE PATILLAS BASIN 50093000 RIO MARIN NEAR PATILLAS, PR LOCATION.--Lat 18q02'16", long 66q00'31", Hydrologic Unit 21010004, on left bank, 3.52 mi (5.66 km) southeast from Escuela Francisco Zenón Gedy, 1.45 mi (2.33 km) northeast from Lago Patillas Dam and 2.10 mi (3.38 km) north from Patillas town. DRAINAGE AREA.--4.45 mi2 (11.5 km2). PERIOD OF RECORD.--February 2000 to current year. GAGE.--Water-stage recorder. Elevation of gage is 295.3 ft (90 m), from topographic map. REMARKS.--Records fair. Gage-height satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.2 7.1 7.9 8.8 7.1 7.5 17 9.3 8.2 9.4 22 18 2 9.5 7.0 17 19 7.3 8.1 6.7 9.1 9.8 26 124 19 3 9.0 6.9 11 10 7.0 7.6 6.2 9.0 14 21 30 14 4 11 6.7 8.3 8.4 7.1 7.3 9.2 8.8 10 10 20 12 5 8.8 6.6 13 12 7.4 7.0 8.3 9.5 8.6 17 18 12 6 8.4 6.4 8.7 14 7.4 6.8 6.3 9.2 31 14 41 11 7 8.2 6.2 7.2 9.4 13 7.1 6.5 9.7 51 10 45 11 8 12 6.0 6.7 8.4 7.6 7.2 6.2 11 13 53 26 11 9 9.0 6.2 9.8 7.9 38 7.4 6.9 9.6 24 17 61 11 10 9.2 7.1 16 8.9 13 8.9 6.0 8.5 12 12 25 11 11 8.6 7.1 13 7.9 12 9.1 7.1 13 7.5 13 8.4 6.2 14 7.3 14 7.9 6.2 11 7.4 15 15 6.0 8.7 7.1 9.4 6.8 69 8.4 10 10 20 9.8 9.3 6.4 18 8.1 26 10 18 9.5 7.9 6.4 14 8.9 9.9 127 18 9.9 7.7 6.1 52 26 9.4 26 19 10 7.5 6.2 13 14 54 19 18 13 16 9.7 42 18 6.9 17 9.4 21 14 7.1 18 11 29 12 9.6 19 9.3 34 9.5 7.8 20 8.3 10 8.8 7.3 9.1 6.1 17 14 16 17 28 95 26 6.7 216 9.3 11 15 39 19 14 6.9 191 12 10 14 84 14 10 7.6 68 14 42 14 24 13 12 6.6 30 9.3 13 13 19 21 21 8.2 9.2 11 6.8 22 7.9 7.8 12 6.6 23 7.7 7.5 8.9 9.3 24 8.5 6.6 9.2 7.6 25 20 7.1 8.3 23 28 6.1 21 60 31 13 18 31 12 5.9 14 17 13 36 34 14 9.5 5.9 13 11 11 16 19 12 9.5 5.6 12 26 11 13 18 12 10 5.6 11 11 10 13 28 11 26 30 17 8.3 11 27 9.8 30 7.8 8.0 28 8.2 9.0 7.5 7.4 29 7.5 7.3 7.3 7.4 30 7.2 6.9 7.2 7.6 31 8.5 --- 7.6 8.0 8.8 5.3 11 9.6 9.7 19 107 11 8.3 5.3 11 9.2 9.4 42 19 11 7.9 5.3 10 8.9 10 53 16 10 --- 5.3 9.8 8.7 9.2 21 50 10 --- 8.0 9.5 8.5 9.1 16 17 10 --- 6.0 --- 8.3 --- 16 15 --­ TOTAL 314.5 343.2 322.7 285.4 MEAN 10.1 11.4 10.4 9.21 MAX 30 42 18 23 MIN 7.2 6.0 6.7 6.6 AC-FT 624 681 640 566 CFSM 2.28 2.57 2.34 2.07 IN. 2.63 2.87 2.70 2.39 321.8 205.0 889.6 395.9 506.3 712.4 1,040 476.2 11.5 6.61 29.7 12.8 16.9 23.0 33.5 15.9 38 8.9 216 60 54 127 124 95 7.0 5.3 6.0 8.1 8.2 9.4 15 9.5 638 407 1,760 785 1,000 1,410 2,060 945 2.58 1.49 6.66 2.87 3.79 5.16 7.54 3.57 2.69 1.71 7.44 3.31 4.23 5.96 8.69 3.98 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 16.1 13.1 17.0 8.93 MAX 20.5 14.4 26.4 11.4 (WY) (2002) (2002) (2002) (2002) MIN 10.1 11.4 10.4 6.19 (WY) (2003) (2003) (2003) (2001) 9.14 5.95 14.7 13.6 15.3 12.4 22.9 18.8 11.5 6.61 29.7 16.6 30.4 23.0 33.5 27.4 (2003) (2003) (2003) (2000) (2002) (2003) (2003) (2000) 7.10 4.80 5.87 10.6 4.77 7.16 15.3 14.7 (2001) (2000) (2000) (2001) (2001) (2000) (2000) (2002) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 ANNUAL TOTAL 4,957.0 ANNUAL MEAN 13.6 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 200 LOWEST DAILY MEAN 5.0 ANNUAL SEVEN-DAY MINIMUM 5.1 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 9,830 ANNUAL RUNOFF (CFSM) 3.05 ANNUAL RUNOFF (INCHES) 41.44 10 PERCENT EXCEEDS 19 50 PERCENT EXCEEDS 8.9 90 PERCENT EXCEEDS 6.1 5,813.0 15.9 14.5 16.1 2002 11.5 2001 May 30 216 Apr 17 269 Aug 22, 2001 Mar 25 5.3 Mar 26 4.0 Jun 21, 2001 Mar 22 5.5 Mar 23 4.2 Jun 17, 2001 2,700 Apr 17 4,970 Sep 1, 2001 10.80 Apr 17 13.28 Sep 1, 2001 5.1 Mar 26 3.7 Jun 22, 2001 11,530 10,510 3.58 3.26 48.59 44.30 28 24 9.9 9.0 6.8 5.4 369 RIO GRANDE DE PATILLAS BASIN 50093000 RIO MARIN NEAR PATILLAS, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 370 RIO PATILLAS BASIN 50093045 LAGO PATILLAS AT DAMSITE NEAR PATILLAS, PR LOCATION.--Lat 18q01'15", long 66q01'19", Hydrologic Unit 21010004, on right edge, in a concrete tower at damsite, 1.05 mi (1.69 km) northeast from Patillas Plaza, 0.45 mi (0.72 km) northeast from Escuela Segunda Unidad de Real and 2.30 mi (3.70 km) from Escuela Segunda Unidad de Jesús María Rodríguez. DRAINAGE AREA.--25.6 mi2 (66.3 km2). PERIOD OF RECORD.--March 1995 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Patillas was completed in 1914. The dam is a semihydraulic earthfill structure about 147 ft (45 m) height, a top width of 15 ft (4.6 m), maximum pool elevation of 230 ft (70.1 m), a base width of 625 ft (190 m), a crest length of 1,067 ft (325 m) and has maximum po ol storage of 17,073 acre-ft (21.05 hm3). The Patillas Dam is owned by the Puerto Rico Electric Power Authority (PREPA) and its primary purpose is for irrigation of la nds served by the Patillas irrigation canal. Gage-height and precipitation satellite telemetry at station. New capacity table based on U.S. Geological Survey Water- Resources Investigations Report 99-4030, April 1997. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 225.92 ft (68.86 m) September 10, 1996; minimum elevation, 211.19 ft (64.37 m), May 29, 1995, July 19, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximun elevation, 222.33 ft (67.77 m), August 26; minimum elevation, 218.61 ft (66.63 m), April 18. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4030, 1997) (Elevation in ft, capacity in acre-ft) Elevation Contents 147 0 163 819 179 2,294 Elevation Contents 192 4,281 209 7,629 222 11,220 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 221.04 221.05 221.30 221.09 221.11 221.35 220.27 221.26 221.16 221.48 221.90 221.43 2 221.04 221.01 221.36 221.25 221.15 221.32 220.26 221.30 221.22 221.79 221.15 221.65 3 221.08 221.14 221.32 221.30 221.15 221.28 220.23 221.30 221.47 221.76 221.11 221.69 4 221.12 221.17 221.30 221.31 221.14 221.20 220.30 221.29 221.56 221.54 221.31 221.44 5 221.15 221.10 221.37 221.46 221.16 221.15 220.32 221.30 221.56 221.46 221.45 221.70 6 221.13 221.05 221.37 221.65 221.14 221.09 220.29 221.33 221.71 221.45 221.99 221.86 7 221.16 220.98 221.29 221.62 221.20 221.03 220.29 221.33 221.70 221.46 221.82 221.93 8 221.36 220.94 221.20 221.56 221.17 220.98 220.25 221.41 221.00 221.92 221.73 221.92 9 221.46 220.90 221.20 221.47 221.39 220.98 220.26 221.44 221.09 221.80 221.82 221.90 10 221.50 220.91 221.25 221.41 221.45 220.95 220.33 221.43 221.14 221.65 221.23 221.84 11 221.50 220.89 221.28 221.29 221.51 220.93 221.86 221.39 221.18 221.66 221.21 221.73 12 221.50 220.88 221.36 221.19 221.53 220.88 221.70 221.38 221.26 221.70 221.39 221.71 13 221.48 220.85 221.45 221.12 221.48 220.79 221.07 221.34 221.28 221.15 221.55 221.78 14 221.41 220.82 221.51 221.08 221.41 220.75 221.18 221.74 221.29 221.32 221.70 221.82 15 221.41 220.83 221.49 221.04 221.35 220.71 221.03 221.81 221.91 221.59 221.84 221.94 16 221.37 221.59 221.61 221.02 221.36 220.66 221.05 221.87 221.80 221.81 221.97 221.94 17 221.41 221.56 221.59 221.00 221.64 220.63 221.80 221.79 221.54 221.89 221.86 221.76 18 221.43 221.58 221.62 221.03 221.67 220.60 219.74 221.85 221.49 221.90 221.45 221.91 19 221.37 221.48 221.55 221.02 221.59 220.68 221.47 221.78 221.91 221.90 221.66 221.94 20 221.34 221.41 221.40 220.98 221.09 220.66 221.97 221.50 221.77 221.85 221.88 221.63 21 221.26 221.45 221.34 220.91 221.38 220.63 221.66 222.00 221.77 221.79 221.94 222.03 22 221.26 221.46 221.29 220.83 221.43 220.60 221.52 221.66 221.06 222.01 221.58 221.83 23 221.23 221.45 221.27 220.87 221.46 220.50 221.63 221.72 221.04 221.75 221.09 222.04 24 221.22 221.40 221.27 220.88 221.46 220.47 221.89 221.87 221.22 221.64 221.11 222.01 25 221.37 221.36 221.28 221.05 221.50 220.42 221.87 221.53 221.29 221.66 221.55 221.85 26 221.60 221.42 221.25 221.17 221.48 220.36 221.66 221.29 221.33 221.79 221.95 221.72 27 221.32 221.54 221.22 221.16 221.45 220.29 221.44 221.24 221.36 221.88 221.61 221.56 28 221.18 221.51 221.20 221.10 221.41 220.22 221.24 221.22 221.41 221.85 221.68 221.43 29 221.14 221.44 221.15 221.10 220.19 221.19 221.20 221.42 221.82 221.37 221.39 30 221.11 221.35 221.12 221.05 220.18 221.24 221.20 221.40 221.92 221.11 221.45 31 221.07 221.06 221.11 220.09 221.19 221.97 221.30 MAX 221.60 221.59 221.62 221.65 221.67 221.35 221.97 222.00 221.91 222.01 221.99 222.04 MIN 221.04 220.82 221.06 220.83 221.09 220.09 219.74 221.19 221.00 221.15 221.09 221.39 371 RIO PATILLAS BASIN 50093045 LAGO PATILLAS AT DAMSITE NEAR PATILLAS, PR—Continued O N D J F M A M J J A S 219.5 220.0 220.5 221.0 221.5 222.0 222.5 ELEVATION, IN FEET 2002 2003 372 CANAL DE PATILLAS BASIN 50093075 CANAL DE RIEGO DE PATILLAS ABOVE GUAYAMA FILTRATION PLANT, PR LOCATION.--Lat 17q58'57", long 66q06'05", Hydrologic Unit 21010004, 0.85 mi (1.37 km) southeast from Guayama Plaza church, 1.8 mi (2.90 km) north northeast from Central Machete and 2.85 mi (4.58 km) northwest from Arroyo town church. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--February to September 2003. GAGE.--Water-stage recorder. Altitude of gage is about 98 ft (30 m) from topographic map. REMARKS.--Records fair. Controlled by Lago Patillas dam. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximum discharge undetermined April 17, gage height, 3.22 ft (0.98 m); minimum daily discharge 12 ft3/s (0.34 m3/s) May 8 and 9. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- --- --- --­ 2 --- --- --- --- --­ 3 --- --- --- --- --­ 4 --- --- --- --- --­ 5 --- --- --- --- --­ 18 A 15 15 16 17 17 18 17 15 15 17 17 16 17 17 14 14 17 17 16 16 18 15 14 17 16 15 15 A 14 14 17 16 16 6 --- --- --- --­ 7 --- --- --- --­ 8 --- --- --- --­ 9 --- --- --- --­ 10 --- --- --- --- --- 14 A 13 14 17 17 17 --- 15 A 13 16 16 17 17 --- 16 A 12 15 16 16 16 --- 17 A 12 15 16 16 15 --- 16 A 13 15 17 16 15 11 --- --- --- --­ 12 --- --- --- --­ 13 --- --- --- --­ 14 --- --- --- --­ 15 --- --- --- --- --- 15 19 13 15 17 16 15 --- 15 18 13 16 18 15 15 --- 14 18 14 15 21 15 16 --- 15 18 14 15 18 14 16 20 17 17 14 16 17 14 16 16 --- --- --- --­ 17 --- --- --- --­ 18 --- --- --- --­ 19 --- --- --- --­ 20 --- --- --- --­ 20 17 18 15 16 17 14 17 20 16 24 14 16 18 15 16 19 15 28 14 16 17 15 16 17 21 20 16 16 17 14 16 17 16 18 15 15 16 14 17 21 --- --- --- --­ 22 --- --- --- --­ 23 --- --- --- --­ 24 --- --- --- --­ 25 --- --- --- --­ 17 16 17 15 15 16 14 17 18 18 16 16 14 17 16 16 18 18 15 15 16 17 17 16 17 18 16 15 14 17 17 17 16 18 16 15 14 17 17 17 26 --- --- --- --­ 27 --- --- --- --­ 28 --- --- --- --­ 29 --- --- --- --­ 30 --- --- --- --­ 31 --- --- --- --­ 17 17 15 15 15 17 19 17 17 17 16 15 15 17 17 17 17 17 16 14 15 17 17 17 --- 18 15 15 17 17 17 16 --- 18 15 15 17 16 16 15 --- 17 --- 15 --- 16 17 --­ TOTAL --- --- --- --­ MEAN --- --- --- --­ MAX --- --- --- --­ MIN --- --- --- --­ MED --- --- --- --- AC-FT --- --- --- --- --- 515 --- 443 455 526 495 485 --- 16.6 --- 14.3 15.2 17.0 16.0 16.2 --- 21 --- 16 19 17 19 17 --- 14 --- 12 14 15 14 15 --- 17 --- 15 16 16 16 16 --- 1,020 --- 879 902 1,040 982 962 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2003 - 2003, BY WATER YEAR (WY) MEAN --- --- --- --­ MAX --- --- --- --- (WY) --- --- --- --­ MIN --- --- --- --- (WY) --- --- --- --- --- 16.6 --- 14.3 15.2 17.0 16.0 16.2 --- 16.6 --- 14.3 15.2 17.0 16.0 16.2 --- (2003) --- (2003) (2003) (2003) (2003) (2003) --- 16.6 --- 14.3 15.2 17.0 16.0 16.2 --- (2003) --- (2003) (2003) (2003) (2003) (2003) A No gage-height record 373 RIO CAMUY BASIN 50093075 CANAL DE RIEGO DE PATILLAS ABOVE GUAYAMA FILTRATION PLANT, PR—Continued O N D J F M A M J J A S 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 374 CANAL DE PATILLAS BASIN 50093078 CANAL DE RIEGO DE PATILLAS BELOW GUAYAMA FILTRATION PLANT, PR LOCATION.--Lat 18q58'57", long 66q06'05", Hydrologic Unit 21010004, on downstream side of Guayama Filtration Plant intake 0.95 mi (1.53 km) southeast from Guayama town church, 1.8 mi (2.90 km) north northeast from Central Machete and 2.8 mi (4.50 km) northwest from Arroyo town church. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--February to September 2003. GAGE.--Water-stage recorder. Altitude of gage is 98 ft (30 m), from topographic map. REMARKS.--Records fair. Controlled by Lago Patillas dam. EXTREMES OBSERVED FOR CURRENT PERIOD.--Maximum discharge, undetermined April 17, gage height, 2.68 ft (0.816 m); minimum daily discharge 4.7 ft3/s (0.133 m3/s) May 8. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11 A 7.2 7.2 7.8 7.3 9.2 2 11 7.1 7.0 8.0 8.5 8.0 8.7 3 11 7.8 6.6 8.5 6.9 7.3 8.2 4 8.0 7.8 7.8 8.2 7.1 7.3 7.8 5 6.7 A 6.4 7.1 7.7 7.2 8.4 6 5.5 A 5.2 4.9 7.5 7.7 9.8 7 6.1 A 5.1 6.9 7.0 8.5 10 8 7.2 A 4.7 6.3 6.0 7.1 8.9 9 7.8 A 5.5 5.7 5.8 7.2 7.4 10 6.8 A 5.8 5.3 6.3 7.5 7.7 11 5.8 9.5 6.0 6.4 6.8 6.8 8.0 12 5.6 8.7 6.2 7.2 6.1 6.5 7.8 13 5.2 8.4 6.1 6.9 10 6.4 8.0 14 6.0 8.4 6.5 6.6 6.0 6.2 8.1 15 8.0 7.3 7.5 8.9 5.9 6.0 8.3 16 8.1 8.2 8.4 8.1 6.5 5.6 9.7 17 7.8 >15 8.7 7.0 6.8 6.1 8.7 18 6.6 >15 9.6 7.1 6.2 6.5 9.1 19 >15 12 11 8.5 5.7 6.1 9.4 20 8.3 11 8.8 6.8 5.6 7.2 10 21 9.4 8.2 10 7.5 6.9 5.7 8.4 10 22 10 8.7 8.1 7.7 5.9 6.5 8.5 9.8 23 9.8 9.0 7.4 7.4 8.5 6.8 8.7 9.7 24 8.6 9.5 8.2 7.3 5.7 6.2 8.6 10 25 7.5 8.6 8.3 7.2 5.3 6.1 8.5 10 26 7.9 7.0 8.5 7.2 5.9 6.3 13 10 27 9.1 6.4 8.8 6.9 6.2 6.7 9.2 10 28 10 6.7 8.3 6.1 6.6 6.8 9.2 10 29 7.6 7.5 6.9 8.1 6.5 9.3 9.3 30 7.2 7.4 7.3 8.5 6.3 8.7 8.6 31 6.7 7.2 6.4 9.1 TOTAL 243.1 218.8 209.2 206.5 239.7 270.6 MEAN 7.84 7.06 6.97 6.66 7.73 9.02 MAX 15 11 8.9 10 13 10 MIN 5.2 4.7 4.9 5.6 5.6 7.4 MED 7.6 7.2 6.9 6.5 7.3 9.2 AC-FT 482 434 415 410 475 537 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2003 - 2003, BY WATER YEAR (WY) MEAN 7.84 7.06 6.97 6.66 7.73 9.02 MAX 7.84 7.06 6.97 6.66 7.73 9.02 (WY) (2003) (2003) (2003) (2003) (2003) (2003) MIN 7.84 7.06 6.97 6.66 7.73 9.02 (WY) (2003) (2003) (2003) (2003) (2003) (2003) > Actual value is known to be greater than the value shown A No gage-height record 375 RIO CAMUY BASIN 50093078 CANAL DE RIEGO DE PATILLAS BELOW GUAYAMA FILTRATION PLANT, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD 2002 2003 376 THIS PAGE IS INTENTIONALLY BLANK Figure 20. South coast river basins -- Río Salinas to Río Jacaguas basins. 377 --- --- --- --- --- --- --- 378 RIO SALINAS BASIN 50100200 RIO LAPA NEAR RABO DEL BUEY, PR LOCATION.--Lat 18q03'36", long 66q14'28", Hydrologic Unit 21010004, on left bank, at bridge on Highway 1, km 9.7, 1.5 mi (2.4 km) north of Rabo del Buey, and 4.4 mi (7.1 km) northeast of Salinas Plaza. DRAINAGE AREA.--9.92 mi2 (25.7 km2). PERIOD OF RECORD.--1953-63 (annual low-flow measurements only), September 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 394 ft (120 m), from topographic map. REMARKS.--Records poor. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 0.63 0.17 0.14 0.21 0.26 0.17 e0.32 1.7 0.52 0.16 0.36 0.47 2 0.55 0.19 0.17 0.24 0.27 0.16 0.36 1.4 0.54 0.18 2.2 0.83 3 0.60 0.20 0.38 0.26 0.28 0.15 0.31 1.3 0.59 0.17 1.1 0.59 4 0.48 0.24 0.17 0.24 0.26 0.14 0.33 1.3 0.52 0.17 0.47 1.5 5 0.44 0.24 0.20 0.25 0.27 0.13 0.33 1.2 0.46 0.20 0.29 0.62 6 0.40 0.22 0.23 0.31 0.27 0.13 0.31 1.1 0.54 0.22 0.28 e0.45 7 0.39 0.21 0.21 0.29 0.30 0.12 0.30 1.1 0.75 0.11 0.36 e0.36 8 0.39 0.19 0.21 0.26 0.27 0.15 0.29 1.1 0.60 0.24 0.29 0.35 9 0.48 0.18 0.21 0.24 0.25 0.23 0.32 1.1 0.50 0.18 0.24 0.36 10 6.4 0.17 0.22 0.24 0.24 0.35 0.29 0.96 0.45 0.19 0.24 0.27 11 1.6 0.17 0.20 0.23 0.25 0.13 9.0 0.91 0.43 0.16 0.21 19 12 0.94 0.17 0.25 0.20 0.22 0.12 1.4 0.88 e0.40 0.16 0.21 23 13 0.70 0.17 0.27 0.19 0.21 0.11 0.88 0.85 0.37 23 0.16 12 14 0.64 0.17 0.26 0.18 0.20 0.11 0.62 e1.0 0.36 3.1 0.15 3.8 15 0.61 0.18 0.26 0.16 0.18 0.12 0.54 0.96 0.36 0.85 0.14 7.0 16 0.58 0.19 0.32 0.15 0.17 0.11 0.60 0.91 0.37 0.67 0.13 42 17 0.52 0.19 0.92 0.19 0.17 0.11 167 0.81 0.37 0.56 0.21 16 18 0.51 0.19 1.2 0.33 0.17 0.13 217 0.89 0.35 0.47 0.54 5.3 19 0.61 0.19 0.50 0.16 0.17 2.2 65 1.1 0.37 0.38 0.38 2.8 20 0.65 0.18 0.35 0.14 0.19 0.36 22 0.96 0.33 0.33 0.21 2.3 21 e7.0 0.17 0.30 0.14 0.31 0.26 17 2.7 0.31 0.30 0.23 2.1 22 e1.5 0.18 0.29 0.13 0.32 0.24 10 1.9 0.28 0.34 0.52 4.2 23 e0.50 0.17 0.29 0.21 0.25 0.24 6.5 1.1 0.25 0.17 0.37 2.6 24 e0.30 0.16 0.29 1.0 0.23 0.25 52 0.98 0.21 0.15 0.24 1.8 25 e0.27 0.16 0.29 1.0 0.22 0.25 27 0.86 0.20 0.15 0.32 1.4 26 0.26 0.16 0.28 1.0 0.20 0.30 7.8 0.76 0.22 0.13 99 1.2 27 0.22 0.16 0.29 0.51 0.20 0.34 4.5 0.69 0.18 0.54 4.6 1.1 28 0.19 0.15 0.26 0.39 0.19 0.28 3.1 0.64 0.17 0.69 2.2 0.93 29 0.19 0.15 0.24 0.32 0.30 2.4 0.58 0.17 0.35 1.5 0.83 30 0.18 0.15 0.22 0.30 e0.27 2.0 0.56 0.17 0.22 0.84 0.75 31 0.19 0.20 0.27 e0.27 0.53 0.34 0.60 TOTAL 28.92 5.42 9.62 9.74 6.52 8.23 619.50 32.83 11.34 34.88 118.59 155.91 MEAN 0.93 0.18 0.31 0.31 0.23 0.27 20.6 1.06 0.38 1.13 3.83 5.20 MAX 7.0 0.24 1.2 1.0 0.32 2.2 217 2.7 0.75 23 99 42 MIN 0.18 0.15 0.14 0.13 0.17 0.11 0.29 0.53 0.17 0.11 0.13 0.27 AC-FT 57 11 19 19 13 16 1,230 65 22 69 235 309 CFSM 0.09 0.02 0.03 0.03 0.02 0.03 2.08 0.11 0.04 0.11 0.39 0.52 IN. 0.11 0.02 0.04 0.04 0.02 0.03 2.32 0.12 0.04 0.13 0.44 0.58 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1988 - 2003, BY WATER YEAR (WY) MEAN 15.1 8.87 3.62 6.63 3.04 1.29 3.39 4.11 2.36 1.47 4.44 17.0 MAX 76.1 36.4 14.4 68.8 12.4 2.67 20.7 36.6 10.4 7.80 17.9 81.2 (WY) (1991) (2000) (1999) (1992) (1991) (2002) (2003) (1992) (1993) (1993) (2000) (1996) MIN 0.93 0.18 0.31 0.31 0.23 0.27 0.28 0.09 0.04 0.01 0.00 0.05 (WY) (2003) (2003) (2003) (2003) (2003) (2003) (1990) (1994) (1994) (1994) (1994) (1997) RIO GUAJATACA BASIN 379 50100200 RIO LAPA NEAR RABO DEL BUEY, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1988 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 999.21 ANNUAL MEAN 2.74 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 130 LOWEST DAILY MEAN 0.14 ANNUAL SEVEN-DAY MINIMUM 0.15 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 1,980 ANNUAL RUNOFF (CFSM) 0.276 ANNUAL RUNOFF (INCHES) 3.75 10 PERCENT EXCEEDS 2.8 50 PERCENT EXCEEDS 0.72 90 PERCENT EXCEEDS 0.21 1,041.50 2.85 5.94 14.1 1998 0.57 1994 Jun 5 217 Apr 18 1,900 Sep 10, 1996 Dec 1 0.11 Mar 13 0.00 Jun 24, 1994 Nov 25 0.12 Mar 11 0.00 Jul 21, 1994 817 Apr 17 18,100 Sep 10, 1996 8.84 Apr 17 18.65 Sep 10, 1996 0.06 Jul 7 0.00 Jun 24, 1994 2,070 4,310 0.288 0.599 3.91 8.14 2.1 8.1 0.30 1.1 0.16 0.18 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 380 RIO SALINAS BASIN 50100450 RIO MAJADA AT LA PLENA, PR LOCATION.--Lat 18q02'40", long 66q12'27", Hydrologic Unit 21010004, on right bank, upstream side of bridge on Highway 712, about 0.3 mi (0.5 km) southwest of La Plena. DRAINAGE AREA.--16.7 mi2 (43.3 km2). PERIOD OF RECORD.--January 1973 to April 1979 (monthly measurements only), September 1988 to current year. GAGE.--Water-stage recorder. Elevation of gage is 410 ft (125 m), from topographic map. REMARKS.-Records poor. Some regulation at low flow upstream from station by local residents for agricultural purposes. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 0.83 0.33 0.50 0.34 e0.29 0.48 e0.39 1.6 e0.34 e0.02 1.0 2.0 2 0.75 0.32 0.43 0.64 e0.30 0.38 0.48 1.4 0.39 e0.70 4.1 2.2 3 0.77 0.33 0.99 0.92 e0.35 0.42 0.46 1.2 0.55 0.67 3.9 2.9 4 0.91 0.33 0.93 0.50 e0.21 0.53 0.44 1.1 0.72 0.45 1.4 2.7 5 0.74 0.37 0.77 0.35 0.21 0.52 0.69 1.1 0.48 0.51 0.83 2.2 6 0.64 0.31 0.93 0.96 0.24 0.41 0.82 0.93 1.2 0.91 0.73 2.0 7 0.67 0.27 0.74 0.75 0.27 0.51 0.60 0.93 1.8 0.76 1.4 1.5 8 0.64 e0.27 0.58 e0.47 0.47 0.38 0.45 1.1 1.1 0.97 2.2 1.4 9 1.8 e0.25 0.50 e0.40 0.36 0.46 0.48 1.3 0.77 2.7 1.3 1.6 10 1.8 0.21 0.65 e0.37 0.44 0.58 0.84 0.97 0.64 1.3 0.97 1.7 11 1.3 0.19 0.94 e0.35 12 0.98 0.21 0.89 e0.33 13 0.87 0.22 0.94 e0.32 14 0.82 0.21 0.92 e0.30 15 0.78 0.22 0.84 e0.29 0.35 0.76 3.1 0.85 0.57 0.55 0.76 3.7 0.30 0.65 5.4 0.71 0.39 0.30 5.8 16 0.27 0.47 1.5 0.68 0.35 42 1.3 17 0.24 0.35 1.1 0.99 0.33 11 0.90 7.0 0.23 0.31 1.1 1.4 0.59 2.5 0.75 e9.1 16 1.3 0.29 1.0 e0.30 17 1.4 0.65 1.6 e0.45 18 1.1 0.71 2.5 e0.80 19 0.98 0.57 0.94 e0.35 20 0.89 0.49 0.62 e0.30 0.21 0.33 0.91 1.0 0.93 1.3 0.65 e60 0.28 0.41 58 0.86 0.58 1.2 1.0 e22 0.45 0.58 131 0.91 0.39 0.80 5.2 e10 0.32 3.7 59 2.8 0.39 0.75 4.3 e7.3 0.29 5.7 20 1.5 0.55 0.44 1.4 6.1 21 0.78 0.47 0.56 e0.28 22 0.63 0.48 0.65 e0.25 23 0.56 0.49 0.78 e0.50 24 0.58 0.46 0.77 e1.2 25 0.65 0.43 0.64 e1.8 0.78 1.2 15 1.9 0.49 0.37 1.8 5.1 0.98 0.77 10 3.5 0.32 0.97 4.7 8.4 0.43 0.58 6.8 1.6 0.23 1.9 2.7 6.1 0.30 0.49 16 1.1 0.15 0.98 1.4 4.8 0.31 0.41 19 0.93 0.12 0.70 1.2 4.1 26 1.2 0.32 0.81 e1.8 27 1.1 0.35 2.2 e1.1 28 0.60 0.54 0.84 e0.55 29 0.44 0.62 0.56 e0.38 30 0.37 0.54 0.43 e0.35 31 0.34 --- 0.38 e0.33 0.32 0.47 8.8 0.75 0.09 0.54 137 3.9 0.33 0.43 5.2 0.59 0.06 1.2 12 4.0 0.61 0.38 3.6 0.49 0.05 4.2 6.4 3.3 --- e0.37 2.7 0.47 0.04 4.2 4.1 2.9 --- e0.34 2.0 0.42 0.01 e1.6 2.6 2.5 --- e0.33 --- 0.39 --- 0.95 2.6 --­ TOTAL 27.22 11.45 26.83 18.03 MEAN 0.88 0.38 0.87 0.58 MAX 1.8 0.71 2.5 1.8 MIN 0.34 0.19 0.38 0.25 AC-FT 54 23 53 36 CFSM 0.05 0.02 0.05 0.03 IN. 0.06 0.03 0.06 0.04 10.14 23.70 375.86 35.47 14.62 87.44 216.39 223.5 0.36 0.76 12.5 1.14 0.49 2.82 6.98 7.45 0.98 5.7 131 3.5 1.8 42 137 60 0.21 0.31 0.39 0.39 0.01 0.02 0.65 1.4 20 47 746 70 29 173 429 443 0.02 0.05 0.75 0.07 0.03 0.17 0.42 0.45 0.02 0.05 0.84 0.08 0.03 0.19 0.48 0.50 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 2003, BY WATER YEAR (WY) MEAN 14.9 14.9 5.86 8.21 MAX 76.4 82.8 21.4 68.8 (WY) (1991) (2000) (1999) (1992) MIN 0.88 0.38 0.62 0.37 (WY) (2003) (2003) (1995) (1995) 3.40 2.19 3.12 4.49 3.36 2.79 4.79 21.9 12.1 4.42 12.5 25.5 12.1 12.9 23.4 109 (1991) (1999) (2003) (1992) (1992) (1993) (1998) (1996) 0.36 0.59 0.30 0.21 0.04 0.01 0.01 0.01 (2003) (1990) (1995) (1994) (1994) (1997) (1994) (1997) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1973 - 2003 ANNUAL TOTAL 859.01 ANNUAL MEAN 2.35 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 129 LOWEST DAILY MEAN 0.19 ANNUAL SEVEN-DAY MINIMUM 0.22 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 1,700 ANNUAL RUNOFF (CFSM) 0.141 ANNUAL RUNOFF (INCHES) 1.91 10 PERCENT EXCEEDS 3.4 50 PERCENT EXCEEDS 0.91 90 PERCENT EXCEEDS 0.41 1,070.65 2.93 7.49 18.7 1998 0.81 1994 Jun 5 137 Aug 26 2,270 Sep 10, 1996 Nov 11 0.01 Jun 30 0.00 Oct 3, 1994 Nov 9 0.06 Jun 25 0.00 Oct 8, 1994 1,430 Aug 26 17,700 Sep 10, 1996 8.01 Aug 26 19.69 Sep 10, 1996 2,120 5,430 0.176 0.449 2.38 6.10 4.2 12 0.74 2.0 0.30 0.30 e Estimated 381 RIO CAMUY BASIN 50100450 RIO MAJADA AT LA PLENA, PR—Continued O N D J F M A M J J A S 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 382 RIO COAMO BASIN 50106100 RIO COAMO AT HWY 14 AT COAMO, PR LOCATION.--Lat 18q05'00", long 66q21'16", Hydrologic Unit 21010004, on Highway 14 bridge, 0.8 mi (1.3 km) northeast from Parque Atlético, 1.2 mi (1.9 km) southeast from (WCPR) Antena de Radio. DRAINAGE AREA.--43.5 mi2 (113 km2). PERIOD OF RECORD.--January 1987 to current year. Prior to September 2000, published as Río Coamo at Coamo, PR. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 335 ft (110 m), from topographic map. REMARKS.--Records poor. Low flow is affected by domestic discharges about 200 ft (65.6 m), upstream from gaging station. Gage-he ight and precipitation satellite telemetry at station. The gage height recovered for the instantaneous peak stage produced by Hurricane Georges was affected by backwater caused by the Highway 14 old bridge which is about 100 ft (30.40 m) downstream from gage. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 4.6 4.6 3.2 2.4 3.1 2.3 4.3 22 e3.9 2.4 e1.4 8.6 2 4.5 117 3.2 2.9 3.5 2.1 4.1 14 e4.7 e3.0 e1.3 6.0 3 4.3 13 3.3 2.4 2.9 2.3 3.9 12 e5.2 e2.6 e1.2 28 4 4.2 6.8 3.2 2.3 5.1 2.2 4.0 10 e3.8 e2.6 e1.1 e8.2 5 4.1 5.5 3.8 2.4 5.8 3.9 6.9 9.9 e3.2 e2.2 e1.6 e4.3 6 4.0 5.0 3.5 3.0 4.7 1.8 9.8 9.4 e3.3 e2.1 e1.5 e3.1 7 3.9 4.9 3.1 2.9 4.3 1.8 5.4 8.7 e5.3 e1.8 e1.4 e2.6 8 4.0 4.5 3.1 2.1 3.7 2.0 4.6 9.1 e4.1 e2.0 1.3 e2.3 9 5.1 4.5 3.5 1.9 3.3 1.8 3.9 8.1 e4.1 e2.0 1.3 e1.8 10 17 4.6 3.2 2.1 3.3 1.9 3.4 4.1 3.2 e1.8 1.4 e1.6 11 7.8 4.1 3.1 2.0 3.2 1.8 9.3 3.9 2.9 e1.6 60 e31 12 5.2 3.9 3.2 1.9 3.4 1.9 11 2.6 2.6 e1.7 10 e18 13 4.7 3.8 3.3 2.4 2.7 1.8 7.1 2.0 2.7 e2.0 5.6 e25 14 4.8 20 3.0 2.0 2.8 1.9 5.2 2.2 2.3 e1.9 4.9 e13 15 5.8 11 3.2 1.9 2.5 1.8 4.6 2.4 2.4 e2.3 4.8 e18 16 5.5 7.1 3.4 1.8 2.3 1.9 4.3 e2.0 2.6 e10 4.3 e20 17 4.7 5.1 4.1 1.9 2.5 1.9 434 e2.3 2.5 e4.0 4.2 e8.2 18 4.3 4.4 4.4 1.9 2.6 1.8 365 e2.3 2.3 e2.0 3.9 e4.9 19 3.9 4.0 3.2 2.8 2.5 50 423 e2.2 2.9 e2.5 3.3 e3.7 20 3.7 3.7 2.9 2.0 2.6 12 139 e2.2 2.5 e2.0 3.2 e3.1 21 3.9 3.8 3.0 2.0 2.8 4.0 144 e140 2.4 e1.9 3.2 e7.8 22 3.6 3.8 3.5 1.9 2.4 3.3 144 e9.8 e5.2 e1.9 3.3 e11 23 182 3.6 3.5 2.4 2.0 3.0 e152 e4.5 3.3 e1.9 3.8 e5.1 24 25 3.4 3.0 8.2 2.4 2.9 e99 e2.8 3.0 e2.1 3.2 e4.4 25 3.9 3.5 3.2 3.9 2.1 2.6 e49 e4.1 2.9 e1.9 3.2 e3.7 26 3.5 3.3 3.4 4.0 2.0 28 e27 e5.2 e4.8 e1.9 25 e3.1 27 3.9 3.3 3.2 3.2 2.5 32 e23 e4.9 e3.6 e1.5 11 e3.3 28 3.9 3.2 2.6 2.7 2.6 15 e23 e3.5 2.5 1.3 7.5 e3.4 29 3.8 3.2 2.6 2.7 26 24 e5.2 2.4 1.2 5.6 e2.9 30 4.4 3.2 2.5 2.6 13 23 e5.4 2.3 e1.5 4.0 e2.9 31 5.1 2.3 2.5 5.6 e4.3 e1.5 6.0 TOTAL 349.1 271.8 99.7 81.1 85.6 234.3 2,160.8 321.1 98.9 71.1 193.5 259.0 MEAN 11.3 9.06 3.22 2.62 3.06 7.56 72.0 10.4 3.30 2.29 6.24 8.63 MAX 182 117 4.4 8.2 5.8 50 434 140 5.3 10 60 31 MIN 3.5 3.2 2.3 1.8 2.0 1.8 3.4 2.0 2.3 1.2 1.1 1.6 AC-FT 692 539 198 161 170 465 4,290 637 196 141 384 514 CFSM 0.26 0.21 0.07 0.06 0.07 0.17 1.66 0.24 0.08 0.05 0.14 0.20 IN. 0.30 0.23 0.09 0.07 0.07 0.20 1.85 0.27 0.08 0.06 0.17 0.22 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1987 - 2003, BY WATER YEAR (WY) MEAN 54.1 38.2 20.9 17.3 10.4 6.98 12.9 18.3 15.1 6.78 10.6 48.0 MAX 274 142 83.8 79.0 25.5 16.1 37.7 69.6 76.1 15.5 29.7 291 (WY) (1991) (2000) (1988) (1992) (1998) (2000) (2002) (1992) (1987) (1988) (1998) (1998) MIN 10.3 4.91 3.72 2.71 3.16 3.09 2.49 1.66 1.99 0.78 1.28 1.61 (WY) (1989) (1995) (1989) (1995) (2002) (1987) (1995) (1989) (1989) (1989) (1994) (1994) 383 RIO CAMUY BASIN 50106100 RIO COAMO AT HWY 14 AT COAMO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1987 - 2003 IN CUBIC FEET PER SECOND ANNUAL MEAN HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 228 LOWEST DAILY MEAN 1.4 ANNUAL SEVEN-DAY MINIMUM 1.6 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) ANNUAL RUNOFF (CFSM) ANNUAL RUNOFF (INCHES) 10 PERCENT EXCEEDS 50 PERCENT EXCEEDS 90 PERCENT EXCEEDS 21.4 40.9 1998 4.52 1994 Apr 26 4,530 Sep 22, 1998 Aug 21 0.67 Aug 2, 1989 Aug 20 0.70 Jul 27, 1989 4,460 Apr 17 52,700 Sep 21, 1998 10.66 Apr 17 25.94 Sep 21, 1998 15,530 0.493 6.70 43 7.6 2.4 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 384 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR LOCATION.--Lat 18q03'52", long 66q22'10", Hydrologic Unit 21010004, on Highway 153 bridge, 0.4 mi (0.6 km) above Río de la Mina, and 1.8 mi (2.9 km) south of Coamo Plaza. DRAINAGE AREA.--46.0 mi2 (119.1 km2). PERIOD OF RECORD.--Water years 1978 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 13... 1545 4.0 1.3 6.0 80 7.5 616 30.5 250 66.9 21.3 2.33 .9 FEB 13... 1230 4.2 2.0 10.1 -- 8.3 587 27.1 240 62.3 19.7 1.93 .9 APR 09... 0935 6.1 1.2 8.0 -- 8.0 579 26.2 230 60.3 18.4 1.88 .9 JUL 21... 1205 3.3 <1.0 9.5 -- 8.2 595 30.7 -- -- -- -- -­ SEP 03... 1115 7.9 1.1 7.9 -- 8.0 554 31.0 220 57.1 18.3 2.31 .9 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 13... 34.4 221 38.7 .17 31.2 33.0 -- 361 3.87 <10 <.20 <.01 -­ FEB 13... 32.8 225 35.9 .17 31.9 31.5 <.0 351 3.98 <10 .30 .03 -­ APR 09... 30.0 214 32.3 .18 31.6 28.3 .6 331 5.49 <10 <.20 .03 1.39 JUL 21... -- 207 -- -- -- -- -- -- -- <10 <.20 .02 1.49 SEP 03... 30.4 198 33.7 .2 32.7 28.7 -- 322 6.88 <10 .20 .02 1.39 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 13... 2.50 <.01 -- .14 -- -- <10 E170 210 -- -- -- -­ FEB 13... 1.70 <.01 .27 .09 2.0 8.9 <10 E30 -- 3,000 <2 28.8 72 APR 09... 1.40 .01 -- .11 -- -- <10 E160 -- 5,900 E1 38.2 E12 JUL 21... 1.50 .01 -- .10 -- -- <10 E120 -- 4,800 -- -- -­ SEP 03... 1.40 .01 .18 .14 1.6 7.1 10 E960 -- E1,800 -- -- -­ 385 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 13... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 13... <.2 <.8 <10 <.01 E10 <1 E2.4 <.02 <3 <.3 <25 <.10 <16 APR 09... <.2 <.8 <10 <.01 120 <1 10.7 <.02 <3 <.3 E14 <.10 E8 JUL 21... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 03... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 386 RIO DESCALABRADO BASIN 50108000 RIO DESCALABRADO NEAR LOS LLANOS, PR LOCATION.--Lat 18q03'08", long 66q25'34", Hydrologic Unit 21010004, at bridge on Highway 14, 1.5 mi (2.4 km) west of Los Llanos, and 5.3 mi (8.5 km) east of Juana Díaz. DRAINAGE AREA.--12.9 mi2 (33.4 km2). PERIOD OF RECORD.--1959-65 (annual low-flow measurements only), 1965 (annual maximum discharge), January 1966 to June 1969, July to December 1969 (maximum discharge only), February 1984 to current year. GAGE.--Water-stage recorder. Elevation of gage is 220 ft (67 m), from topographic map. REMARKS.--Records poor. Some regulation at low flow by local resident upstream from station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1.4 e5.7 0.20 0.60 e0.21 0.79 0.08 e1.7 e0.33 0.10 e1.0 0.49 2 0.82 e5.7 0.20 0.35 e0.21 0.51 0.08 e1.5 e0.24 e0.11 e0.64 0.38 3 0.56 e6.2 0.29 0.17 e0.22 0.41 0.09 e1.5 1.5 e0.11 e0.70 0.16 4 0.58 e4.6 0.20 0.25 e0.23 0.34 0.08 e1.4 e1.1 e0.10 e0.37 0.19 5 0.51 e4.6 0.39 0.34 e0.24 0.31 0.08 e1.3 e0.69 e0.10 e0.34 0.15 6 0.44 e5.7 0.12 0.68 0.23 0.33 0.08 e1.4 0.44 0.12 e0.67 0.12 7 0.49 e1.8 0.11 0.34 0.22 0.28 5.3 e1.4 e0.36 e0.09 e1.5 0.13 8 0.53 1.2 0.11 0.25 0.25 0.24 0.21 e1.5 e0.27 e0.08 e0.52 0.95 9 0.58 e0.70 0.11 0.18 0.21 0.17 0.09 e1.3 e0.21 0.11 e0.43 0.14 10 5.7 0.69 0.09 0.18 0.19 0.24 0.09 1.1 e0.16 0.08 e0.37 0.09 11 0.93 0.63 0.09 0.18 0.17 0.18 1.0 1.1 0.12 e0.06 128 0.12 12 0.69 0.75 0.09 0.24 0.16 0.17 9.7 1.0 0.11 e0.07 7.6 7.4 13 0.82 0.56 0.10 0.28 0.15 0.16 0.31 1.0 0.10 0.11 1.9 5.8 14 0.88 0.50 0.09 0.28 e0.14 0.16 0.12 1.6 e0.10 0.10 1.0 0.32 15 1.1 0.78 0.09 0.37 0.14 0.16 0.10 1.3 e0.10 0.17 1.3 19 16 1.4 3.3 0.11 0.37 0.14 0.18 0.09 0.98 e0.10 0.56 1.8 26 17 0.93 0.25 0.81 0.74 0.13 0.16 374 0.87 e0.11 e0.39 2.6 1.6 18 1.1 0.12 0.25 0.52 0.14 0.37 298 0.76 e0.12 e0.42 5.2 0.53 19 0.72 0.17 0.12 0.77 0.14 4.8 26 0.77 e0.16 e0.33 0.65 0.41 20 1.1 1.2 0.09 0.45 0.43 0.31 11 0.73 e0.13 e0.33 1.3 3.8 21 6.6 0.34 0.09 0.45 0.88 0.32 6.0 51 e0.11 e0.26 0.97 148 22 1.6 0.32 0.11 1.0 0.77 0.07 98 5.9 e0.15 e0.20 1.8 5.9 23 103 0.57 0.11 0.62 0.86 0.11 28 e1.4 e0.12 e0.51 2.1 1.0 24 3.7 0.34 0.12 0.57 0.79 0.09 5.4 e0.85 e0.11 e0.30 0.79 0.60 25 1.4 0.21 0.12 0.44 0.78 0.13 5.2 0.80 e0.10 e0.34 0.19 7.2 26 0.81 0.16 0.16 0.36 0.66 0.09 5.1 e0.68 e0.10 e0.34 4.7 2.9 27 0.21 0.20 0.14 0.40 0.82 0.06 e2.9 e0.53 e0.08 e1.5 0.71 0.76 28 0.37 0.17 0.16 e0.37 0.85 0.06 e2.5 e0.46 0.08 e2.1 0.55 0.19 29 0.32 0.14 0.13 e0.31 1.7 e2.2 e0.38 0.08 e3.6 0.47 0.07 30 32 0.28 0.14 e0.26 1.3 e1.9 e0.33 0.08 e1.6 0.28 0.09 31 e5.3 0.30 e0.20 0.09 0.87 e0.49 0.16 TOTAL 176.59 47.88 5.24 12.52 10.36 14.29 883.70 87.41 7.46 14.78 170.61 234.49 MEAN 5.70 1.60 0.17 0.40 0.37 0.46 29.5 2.82 0.25 0.48 5.50 7.82 MAX 103 6.2 0.81 1.0 0.88 4.8 374 51 1.5 3.6 128 148 MIN 0.21 0.12 0.09 0.17 0.13 0.06 0.08 0.33 0.08 0.06 0.16 0.07 AC-FT 350 95 10 25 21 28 1,750 173 15 29 338 465 CFSM 0.44 0.12 0.01 0.03 0.03 0.04 2.28 0.22 0.02 0.04 0.43 0.61 IN. 0.51 0.14 0.02 0.04 0.03 0.04 2.55 0.25 0.02 0.04 0.49 0.68 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1966 - 2003, BY WATER YEAR (WY) MEAN 25.3 14.9 5.54 4.45 3.25 1.97 6.03 12.5 4.66 2.30 3.94 33.0 MAX 117 41.0 24.5 36.4 23.9 8.93 29.5 62.2 25.2 10.5 13.1 395 (WY) (1986) (1985) (1988) (1992) (1995) (1996) (2003) (1985) (1987) (1991) (1996) (1996) MIN 2.02 1.04 0.17 0.06 0.02 0.01 0.00 0.03 0.00 0.00 0.19 0.06 (WY) (1968) (1995) (2003) (1968) (1968) (1968) (1968) (1968) (1967) (1967) (1990) (1967) 387 RIO CAMUY BASIN 50108000 RIO DESCALABRADO NEAR LOS LLANOS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1966 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 1,405.45 ANNUAL MEAN 3.85 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 211 LOWEST DAILY MEAN 0.09 ANNUAL SEVEN-DAY MINIMUM 0.09 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 2,790 ANNUAL RUNOFF (CFSM) 0.298 ANNUAL RUNOFF (INCHES) 4.05 10 PERCENT EXCEEDS 5.7 50 PERCENT EXCEEDS 0.90 90 PERCENT EXCEEDS 0.27 1,665.33 4.56 10.2 41.7 1996 1.69 1994 Jun 5 374 Apr 17 10,000 Sep 10, 1996 Dec 10 0.06 Mar 27 0.00 Jun 22, 1966 Dec 9 0.08 Mar 31 0.00 Jun 22, 1966 2,940 Apr 17 30,000 Oct 7, 1985 9.78 Apr 17 24.37 Oct 7, 1985 0.00 Jun 22, 1966 3,300 7,390 0.354 0.791 4.80 10.75 4.6 16 0.37 1.7 0.10 0.13 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 388 RIO JACAGUAS BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR LOCATION.--Lat 18q07'37", long 66q27'24", Hydrologic Unit 21010004, on right bank, off a dirt road about 0.3 mi (0.5 km) from Road 553, 2.4 mi (3.9 km) southeast from Villalba Plaza, and 0.2 mi (0.3 km) downstream from confluence with Quebrada Limón. DRAINAGE AREA.--14.2 mi2 (36.8 km2). PERIOD OF RECORD.--April 1989 to current year. GAGE.--Water-stage recorder. Elevation of gage is 525 ft (160 m ), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 15 e3.7 e4.3 e2.6 e6.6 e1.7 e2.8 15 e4.3 2.6 2.7 18 2 9.3 e13 e4.2 e2.3 e6.5 e1.4 2.3 13 e3.7 2.8 2.5 6.3 3 10 e5.8 e4.5 e2.4 e2.6 e1.4 2.0 12 e13 2.9 2.6 7.3 4 12 e5.1 e4.7 e2.2 e2.6 e1.3 2.0 12 e11 2.8 2.3 8.6 5 8.4 e8.5 e4.1 e2.1 e2.4 e1.4 2.2 11 e8.8 2.8 2.3 4.6 6 7.0 e5.1 e3.9 e2.2 e2.4 e1.1 5.0 10 e6.3 3.2 2.5 3.6 7 e6.2 e5.9 e4.2 e2.3 e2.6 e1.3 3.0 10 e4.5 2.9 3.0 3.4 8 12 e4.7 e3.6 e2.3 2.4 e1.2 2.8 9.8 e4.0 2.7 2.5 2.9 9 18 e4.2 e3.3 e2.6 2.2 e1.3 2.7 9.3 e3.5 2.9 2.2 2.7 10 14 e4.3 e3.0 e2.3 2.3 e1.2 2.1 9.1 e3.2 2.5 2.2 2.5 11 9.2 e8.5 e2.8 e2.3 2.2 e1.3 4.8 8.7 3.0 2.4 26 2.8 12 7.0 e8.5 e2.8 e2.3 2.1 e1.3 6.0 8.0 3.0 2.3 7.9 3.1 13 28 e4.8 e2.8 e2.3 2.0 e1.1 3.8 7.8 3.0 3.2 3.3 4.0 14 13 e5.3 e2.7 e2.0 2.0 e1.2 2.9 9.0 2.9 3.8 2.8 3.5 15 15 e8.5 e2.4 e2.1 1.9 e1.2 2.5 8.3 3.0 3.2 2.6 11 16 22 e8.3 e2.4 e2.0 1.9 e1.3 2.3 7.5 3.0 3.3 2.6 26 17 20 e9.0 e2.2 e2.3 1.9 e1.2 205 7.3 3.1 3.1 2.5 13 18 12 e5.9 e2.2 e2.3 1.9 e1.2 237 7.5 3.3 2.7 2.7 6.8 19 8.8 e5.3 e5.1 e2.0 1.8 e1.9 65 7.7 4.0 2.6 e3.6 4.9 20 7.6 e4.8 e5.1 e2.0 1.7 4.1 34 7.5 3.4 2.5 e2.7 4.2 21 7.5 e4.5 e4.5 e1.9 1.7 2.0 40 41 3.2 2.4 e2.1 6.4 22 5.9 e4.5 e8.1 e2.0 1.6 1.9 39 25 3.8 2.4 e2.7 6.4 23 25 e3.9 e8.4 e1.9 1.6 1.9 75 12 3.4 2.5 e2.2 4.7 24 e11 e3.9 e16 e1.8 e1.7 1.5 120 8.0 3.1 2.4 2.7 4.4 25 e6.2 e3.6 e9.6 e1.8 e1.7 1.5 84 e7.8 3.0 2.3 2.2 7.3 26 e5.3 e3.5 e3.9 e2.3 e1.4 6.6 51 e6.8 2.9 2.3 11 5.1 27 e5.3 e3.4 e2.8 e2.0 e1.5 14 32 e5.8 2.7 3.0 5.6 4.8 28 e4.5 e10 e2.4 e1.9 e1.5 9.8 24 e5.3 2.7 3.4 3.1 4.4 29 e4.1 e6.1 e7.7 e1.9 4.3 19 e4.8 2.5 4.4 3.1 4.0 30 e3.7 e4.6 e3.5 e1.8 5.1 17 e4.5 2.6 2.8 3.7 4.0 31 e4.5 e2.8 e3.5 e3.0 e6.0 2.5 33 TOTAL 337.5 177.2 140.0 67.7 64.7 80.7 1,091.2 317.5 123.9 87.6 152.9 190.7 MEAN 10.9 5.91 4.52 2.18 2.31 2.60 36.4 10.2 4.13 2.83 4.93 6.36 MAX 28 13 16 3.5 6.6 14 237 41 13 4.4 33 26 MIN 3.7 3.4 2.2 1.8 1.4 1.1 2.0 4.5 2.5 2.3 2.1 2.5 AC-FT 669 351 278 134 128 160 2,160 630 246 174 303 378 CFSM 0.77 0.42 0.32 0.15 0.16 0.18 2.56 0.72 0.29 0.20 0.35 0.45 IN. 0.88 0.46 0.37 0.18 0.17 0.21 2.86 0.83 0.32 0.23 0.40 0.50 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY) MEAN 37.4 20.4 8.75 7.93 5.15 4.08 12.9 19.1 12.2 5.91 8.89 38.0 MAX 109 55.7 20.4 43.1 12.6 8.93 37.0 76.1 35.4 14.4 36.4 152 (WY) (1991) (2000) (2002) (1992) (1996) (2002) (2002) (1995) (1992) (1992) (1998) (1998) MIN 4.61 2.19 1.42 1.79 2.31 1.67 1.46 1.42 1.23 0.71 2.74 3.21 (WY) (1992) (1992) (1992) (1995) (2003) (1990) (1990) (1997) (1990) (1990) (1990) (1994) 389 RIO CAMUY BASIN 50110900 RIO TOA VACA ABOVE LAGO TOA VACA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1989 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 4,023.7 ANNUAL MEAN 11.0 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 319 LOWEST DAILY MEAN 2.2 ANNUAL SEVEN-DAY MINIMUM 2.5 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 7,980 ANNUAL RUNOFF (CFSM) 0.776 ANNUAL RUNOFF (INCHES) 10.54 10 PERCENT EXCEEDS 20 50 PERCENT EXCEEDS 5.8 90 PERCENT EXCEEDS 3.6 2,831.6 7.76 15.2 29.3 1998 4.02 1994 Apr 26 237 Apr 18 2,050 Sep 10, 1996 Dec 17 1.1 Mar 6 0.45 Aug 7, 1990 Dec 12 1.2 Mar 12 0.61 Jul 9, 1990 1,680 Apr 17 3,000 Sep 21, 1998 7.51 Apr 17 20.60 Sep 21, 1998 0.42 Jul 14, 1997 5,620 10,990 0.546 1.07 7.42 14.51 12 32 3.4 5.1 1.9 1.7 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 390 RIO TOA VACA BASIN 50111210 LAGO TOA VACA AT DAMSITE NEAR VILLALBA, PR LOCATION.--Lat 18q06'07", long 66q29'23", Hydrologic Unit 21010004, in a concrete gate tower at Damsite on Río Toa Vaca, 0.45 mi (0.7 km) northwest from Escuela Higüero, 2.0 mi (3.2 km) south from Villalba Plaza. DRAINAGE AREA.--22.0 mi2 (57.9 km2). PERIOD OF RECORD.--August 1997 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Toa Vaca was completed in 1972. The dam is located in the Toa Vaca river just upstream from Guayabal reservoir. T he Toa Vaca dam is a zoned earth and rockfill embankment structure. At crest elevation 555.00 ft (169.2 m) (top of dam), the dam is approximately 1,740 ft (530.3 m) long, about 215 ft (65.53 m) height, and has a maximum storage capacity of about 67,759 acre-ft (83.55 hm3) at top of dam elevation. The Toa Vaca dam is owned by the Puerto Rico Aqueduct and Sewer Authority and its primary purpose is to provide water for municipal and industrial use, an d for irrigation of some of the lands served by the South Coast irrigation district through the Juana Díaz canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 535.24 ft (163.14 m) November 13, 1998; minimum elevation, 463.63 ft (141.31 m), August 19, 2001. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 488.63 ft (148.93 m), October 1; minimum elevation, 466.11 ft (142.07 m), March 26. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 345.00 0 488.70 23,259 Elevation Contents 489.80 23,756 531.20 48,362 570.00 81,991 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 A A A 470.93 466.98 466.76 466.45 476.54 476.10 474.31 472.19 471.67 2 488.37 A A 470.69 467.10 466.73 466.43 476.53 476.05 474.24 472.13 471.65 3 488.20 A A 470.43 467.13 466.70 466.41 476.52 476.00 474.17 472.05 471.61 4 488.03 A A 470.18 467.16 466.67 466.39 476.51 475.95 474.10 471.98 471.59 5 A A A 469.92 467.18 466.64 466.36 476.49 475.89 474.05 471.91 471.54 6 A A A 469.67 467.20 466.61 466.36 476.47 475.83 473.98 471.86 471.48 7 A A A 469.41 467.21 466.58 466.35 476.46 475.81 473.91 471.80 471.47 8 A A A 469.16 467.20 466.54 466.33 476.43 475.76 473.84 471.73 471.41 9 A A A 468.90 467.19 466.50 466.32 476.41 475.70 473.77 471.66 471.36 10 A A A 468.65 467.17 466.48 466.30 476.38 475.64 473.70 471.59 471.30 11 A A A 468.38 467.15 466.44 466.34 476.34 475.58 473.62 A 471.27 12 A A 475.39 468.12 467.13 466.41 466.43 476.31 475.53 473.54 A 471.26 13 A A 475.16 467.85 467.11 466.37 466.42 476.27 475.47 473.52 A 471.22 14 A A 474.91 467.58 467.09 466.33 466.40 476.25 475.40 473.45 A 471.16 15 A A 474.68 467.31 467.07 466.30 466.37 476.21 475.35 473.38 A 471.24 16 A A 474.48 467.05 467.06 466.27 466.37 476.17 475.28 473.32 A 471.45 17 A A 474.30 467.01 467.03 466.24 469.62 476.13 475.22 473.25 A 471.46 18 A A 474.09 467.00 467.01 466.23 472.40 476.10 475.18 473.19 A 471.46 19 A A 473.84 466.98 466.99 466.24 472.99 476.06 475.13 473.13 A 471.42 20 A A 473.60 466.97 466.96 466.25 473.22 476.03 475.07 473.05 A 471.37 21 A A 473.35 466.96 466.96 466.23 473.55 476.33 475.00 472.98 A 471.53 22 A A 473.14 466.94 466.93 466.22 473.87 476.46 474.94 472.91 A 471.50 23 A A 473.13 466.92 466.90 466.19 474.47 476.47 474.88 472.82 A 471.44 24 A A 472.89 466.97 466.88 466.17 475.47 476.45 474.82 472.74 A 471.39 25 A A 472.66 466.98 466.85 466.14 476.03 476.42 474.74 472.66 471.51 471.38 26 A­ A 472.44 466.97 466.83 466.20 476.30 476.39 474.67 472.59 471.57 471.33 27 A A 472.18 466.95 466.82 466.31 476.42 476.35 474.61 472.54 471.54 471.29 28 A A 471.94 466.93 466.79 466.40 476.48 476.29 474.53 472.48 471.48 471.23 29 A A 471.69 466.91 466.46 476.52 476.25 474.45 472.41 471.48 471.17 30 A A 471.43 466.91 466.47 476.54 476.20 474.37 472.35 471.43 471.12 31 A 471.18 466.89 A 476.15 472.27 471.55 MAX 470.93 467.21 476.54 476.54 476.10 474.31 471.67 MIN 466.89 466.79 466.30 476.03 474.37 472.27 471.12 A No gage-height record 391 RIO GUAJATACA BASIN 50111210 LAGO TOA VACA AT DAMSITE NEAR VILLALBA, PR—Continued O N D J F M A M J J A S 465 470 475 480 485 490 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 392 RIO JACAGUAS BASIN 50111300 LAGO GUAYABAL AT DAMSITE NEAR JUANA DIAZ, PR LOCATION.--Lat 18q05'17", long 66q30'09", Hydrologic Unit 21010004, at Damsite, 2.30 mi (3.70 km) northeast from Juana Díaz Plaza, 0.70 mi (1.13 km) northeast from Escuela Salvador Bousquets and 2.45 mi (3.94 km) southeast from Escuela Zoilo Gracia. DRAINAGE AREA.--43.3 mi2 (42.1 km2). PERIOD OF RECORD.--April 1995 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guayabal was completed in 1913. The dam is a reinforced concrete, flatslab and buttress-type structure about 130 ft (40 m) height, a net crest length at the right side of the dam of 693 ft (211 m) and a crest elevation of 331 ft (101 m). It has a maximum storage capacity of 7,600 acre-feet (9.37 hm3). The Guayabal dam is owned by the Puerto Rico Electric Power Authority (PREPA) and its primary purpose is for irrigation of la nds served by the Juana Díaz Canal. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 342.89 ft (104.51 m), April 26, 2002; minimum elevation, 325.99 ft (99.36 m), September 29, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 341.33 ft (104.04 m), April 24; minimum elevation, 335.55 ft (102.28 m), March 26. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 305 366 321 2,010 Elevation Contents 330 3,885 341 7,360 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 341.03 340.89 339.95 A 336.79 337.29 336.12 340.33 339.56 338.89 337.87 338.34 2 340.88 340.76 340.04 338.56 337.04 337.11 336.10 340.25 339.62 338.91 337.68 338.39 3 340.84 340.77 340.07 338.52 337.14 337.15 336.10 340.11 339.61 338.97 337.50 338.37 4 340.82 340.80 340.13 338.40 337.29 337.13 336.11 340.06 339.59 338.88 337.49 338.33 5 340.68 340.81 340.17 338.29 337.47 337.13 336.12 340.17 339.58 338.81 337.46 338.37 6 340.56 340.81 340.19 A 337.59 337.12 336.04 340.26 339.56 338.75 337.41 338.25 7 340.53 340.81 340.04 338.21 337.66 337.12 336.12 340.33 339.39 338.74 337.45 338.28 8 340.65 340.82 339.91 338.15 337.53 336.92 336.21 340.26 339.25 338.71 337.41 338.34 9 340.93 340.68 339.88 338.08 337.41 336.71 336.27 340.25 339.29 338.69 337.23 338.37 10 341.00 340.58 339.94 338.06 337.48 336.62 336.35 340.09 339.30 338.65 337.06 338.50 11 340.91 340.49 339.96 337.95 337.51 336.52 336.59 339.93 339.21 338.63 337.87 338.99 12 340.78 340.46 339.93 337.85 337.56 336.43 336.81 339.98 339.21 338.58 337.79 339.36 13 340.93 340.66 339.90 A 337.62 336.31 336.85 339.98 339.21 338.48 337.65 339.38 14 340.93 340.81 339.71 337.73 337.71 336.21 337.03 340.02 339.02 338.49 337.51 339.61 15 341.05 340.83 339.55 337.75 337.70 336.03 337.10 340.01 338.87 338.46 337.40 339.39 16 340.92 340.70 339.60 337.74 337.68 335.85 337.24 340.00 338.89 338.44 337.37 340.40 17 340.90 340.65 A 337.68 337.68 335.77 341.00 339.82 338.84 338.46 337.30 340.35 18 340.87 340.73 339.45 337.56 337.86 335.65 340.85 339.71 338.87 338.42 337.27 A 19 340.74 340.59 A 337.49 337.98 335.69 340.80 339.79 338.93 338.45 337.13 340.51 20 340.73 340.64 A A 337.91 335.75 340.77 339.86 338.94 338.30 337.09 340.51 21 340.88 340.60 A 337.29 337.93 335.76 340.76 A 338.89 338.14 337.05 340.83 22 340.86 340.57 A A 337.74 335.73 340.94 340.24 338.72 338.15 337.07 340.74 23 340.85 340.44 A A 337.55 335.65 341.01 340.26 338.77 338.13 337.37 340.65 24 340.82 340.31 339.34 A 337.57 335.62 340.84 340.27 338.77 338.17 337.28 340.60 25 340.81 340.29 339.25 A 337.53 335.60 340.89 340.10 338.80 338.09 337.16 340.81 26 340.72 340.28 339.22 A 337.50 335.89 340.76 339.95 339.09 338.02 337.37 340.75 27 340.63 340.32 339.17 A 337.47 336.16 340.71 339.95 339.19 338.00 337.43 340.63 28 340.68 340.26 339.04 336.79 337.47 336.24 340.60 339.95 339.01 337.96 337.49 340.50 29 340.81 340.16 338.91 336.83 336.23 340.53 339.92 338.85 337.97 337.57 340.47 30 340.80 340.04 338.87 336.87 336.14 340.39 339.90 338.88 337.95 337.75 340.43 31 340.86 338.73 336.91 336.13 339.72 337.91 338.14 MAX 341.05 340.89 337.98 337.29 341.01 339.62 338.97 338.14 MIN 340.53 340.04 336.79 335.60 336.04 338.72 337.91 337.05 A No gage-height record 393 RIO JACAGUAS BASIN 50111300 LAGO GUAYABAL AT DAMSITE NEAR JUANA DIAZ, PR—Continued O N D J F M A M J J A S 335 336 337 338 339 340 341 342 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 394 RIO JACAGUAS BASIN 50111500 RIO JACAGUAS AT JUANA DIAZ, PR LOCATION.--Lat 18q03'16", long 66q30'40", Hydrologic Unit 21010004, on Highway 14 bridge, 0.4 mi (0.6 km) west of Juana Díaz Plaza, and 4.0 mi (6.4 km) downstream from Lago Guayabal. DRAINAGE AREA.--49.8 mi2 (129 km2). PERIOD OF RECORD.--March 1984 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 131 ft (40 m), from topographic map. REMARKS.--Records poor. Flow regulation from Lago Guayabal. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 52 43 13 8.5 5.9 7.0 5.2 35 17 11 7.3 13 2 67 41 13 8.6 8.2 6.8 4.9 31 16 11 7.6 13 3 28 23 13 8.2 8.0 6.3 5.2 30 16 11 7.6 14 4 22 22 13 8.0 6.4 5.8 5.5 28 16 11 7.5 13 5 19 21 13 8.0 6.5 3.4 4.1 27 16 11 7.6 13 6 16 26 13 8.1 6.7 5.8 3.9 26 16 10 8.0 12 7 15 24 13 7.6 7.3 5.6 4.6 25 16 9.7 8.0 13 8 15 22 13 7.4 7.9 5.6 4.6 24 15 9.2 7.7 13 9 33 22 13 7.3 7.8 5.5 5.2 23 14 9.0 7.3 12 10 83 16 13 8.1 7.6 4.7 5.0 22 13 8.7 7.4 21 11 78 16 13 7.3 7.3 2.7 5.2 21 6.6 8.5 23 15 12 38 16 13 7.2 7.1 4.9 4.3 20 7.7 8.4 14 17 13 33 15 13 7.1 7.1 4.7 6.3 20 14 8.9 9.5 21 14 57 16 12 6.9 7.4 4.6 6.3 20 14 8.8 9.4 18 15 78 25 12 6.9 8.9 4.6 6.4 18 13 8.5 8.9 21 16 106 27 6.3 6.8 9.1 4.5 6.9 18 13 8.5 8.6 34 17 56 17 12 6.8 9.3 4.2 272 20 13 8.3 8.9 32 18 42 16 12 6.8 9.2 4.2 774 20 13 8.4 8.6 33 19 31 17 11 6.7 9.3 9.5 239 19 13 8.5 9.0 28 20 20 16 10 6.4 8.5 6.0 97 19 13 8.5 7.8 27 21 28 15 10 6.4 8.5 4.6 71 19 13 8.3 8.1 49 22 40 15 9.7 6.8 8.3 4.7 83 15 13 8.0 8.4 61 23 32 15 11 7.1 7.9 4.5 172 20 12 7.5 8.1 35 24 28 15 11 11 7.4 4.1 530 21 12 6.9 8.4 28 25 22 14 9.8 8.2 5.1 3.8 230 20 12 7.0 8.2 28 26 20 14 9.9 6.6 7.1 3.7 135 20 12 7.0 11 59 27 16 14 9.7 6.4 7.3 4.0 68 19 12 7.1 9.3 38 28 16 14 9.6 6.2 7.3 4.5 52 19 12 7.6 10 26 29 16 14 9.2 5.8 8.6 44 18 12 7.3 11 25 30 23 13 9.0 5.8 10 40 18 11 7.1 10 25 31 24 8.9 5.8 5.7 18 7.2 9.9 TOTAL 1,154 584 352.1 224.8 214.4 164.6 2,890.6 673 396.3 267.9 286.1 757 MEAN 37.2 19.5 11.4 7.25 7.66 5.31 96.4 21.7 13.2 8.64 9.23 25.2 MAX 106 43 13 11 9.3 10 774 35 17 11 23 61 MIN 15 13 6.3 5.8 5.1 2.7 3.9 15 6.6 6.9 7.3 12 AC-FT 2,290 1,160 698 446 425 326 5,730 1,330 786 531 567 1,500 CFSM 0.75 0.39 0.23 0.15 0.15 0.11 1.93 0.44 0.27 0.17 0.19 0.51 IN. 0.86 0.44 0.26 0.17 0.16 0.12 2.16 0.50 0.30 0.20 0.21 0.57 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1984 - 2003, BY WATER YEAR (WY) MEAN 119 93.1 34.3 21.8 9.19 5.64 21.0 62.2 41.3 20.3 26.9 82.3 MAX 445 287 151 144 21.2 12.0 96.4 215 198 82.4 136 667 (WY) (1986) (1988) (1988) (1992) (2000) (2000) (2003) (1985) (1987) (1987) (1998) (1998) MIN 4.31 7.57 6.20 1.71 1.97 1.95 1.84 1.46 0.93 1.04 1.59 0.76 (WY) (1995) (1995) (1998) (1998) (1994) (1994) (1994) (1994) (1994) (1994) (1994) (1997) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1984 - 2003 ANNUAL TOTAL 12,435.2 7,964.8 ANNUAL MEAN 34.1 21.8 45.7 HIGHEST ANNUAL MEAN 93.1 1998 LOWEST ANNUAL MEAN 6.23 1994 HIGHEST DAILY MEAN 1,140 Jun 5 774 Apr 18 8,530 Sep 22, 1998 LOWEST DAILY MEAN 2.3 Mar 10 2.7 Mar 11 0.24 Jan 3, 1992 ANNUAL SEVEN-DAY MINIMUM 2.5 Mar 4 4.2 Mar 22 0.51 Aug 31, 1997 MAXIMUM PEAK FLOW 4,360 Apr 24 40,000 Oct 7, 1985 MAXIMUM PEAK STAGE 13.03 Apr 24 29.42 Oct 7, 1985 ANNUAL RUNOFF (AC-FT) 24,670 15,800 33,140 ANNUAL RUNOFF (CFSM) 0.684 0.438 0.918 ANNUAL RUNOFF (INCHES) 9.29 5.95 12.48 10 PERCENT EXCEEDS 70 33 102 50 PERCENT EXCEEDS 14 11 11 90 PERCENT EXCEEDS 6.0 5.8 2.9 395 RIO JACAGUAS BASIN 50111500 RIO JACAGUAS AT JUANA DIAZ, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 100 200 500 1,000 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 396 THIS PAGE IS INTENTIONALLY BLANK Figure 21. South coast river basins -- Río Inabón to Río Loco basins. 397 --- --- --- --- --- --- --- 398 RIO INABON BASIN 50112500 RIO INABON AT REAL ABAJO, PR LOCATION.--Lat 18q05'10", long 66q33'46", Hydrologic Unit 21010004, at bridge on private road, off Highway 511 at Hacienda La Concordia, 0.4 mi (0.6 km) upstream from diversion canal, 0.5 mi (0.8 km) north of Real Abajo, and 6.1 mi (9.8 km) northeast of Plaza Degetau in P once. DRAINAGE AREA.--9.70 mi2 (25.1 km2). PERIOD OF RECORD.--1962-63 (annual low-flow measurements only), February to June 1964 (monthly measurements only), July 1964 to July 1970, April 1971 to current year. GAGE.--Water-stage recorder. Elevation of gage is 410 ft (125 m), from topographic map. Prior to April 1971 non-recording gage and crest-stage gage at different datum. REMARKS.--Records fair. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 33 24 9.8 8.3 13 4.9 9.2 25 14 4.9 2.1 11 2 18 18 9.5 9.5 26 4.5 10 24 15 4.6 2.4 13 3 21 24 9.2 8.3 25 4.7 9.0 25 13 4.2 2.2 8.6 4 23 22 11 7.0 19 4.5 6.4 25 13 3.5 2.5 6.9 5 20 21 10 6.8 18 3.9 6.6 26 13 5.2 2.5 5.5 6 18 21 9.3 9.0 15 4.0 6.9 25 14 6.2 4.7 6.4 7 16 18 8.5 8.2 11 4.4 5.3 28 12 6.1 5.4 14 8 40 16 8.3 7.0 8.6 3.9 5.5 32 9.5 7.2 4.0 16 9 61 15 8.0 6.5 7.5 3.7 6.4 31 8.8 7.7 2.9 12 10 41 15 7.8 13 7.2 3.4 6.1 35 8.1 5.9 2.8 21 11 28 14 7.4 12 6.4 3.3 10 28 7.2 6.3 5.0 29 12 18 14 7.7 7.5 6.0 3.3 20 23 7.9 5.4 8.0 25 13 14 15 7.8 6.3 6.2 3.1 13 20 7.2 7.3 6.0 20 14 13 20 7.0 7.1 7.3 3.0 9.0 21 5.9 6.8 6.1 13 15 22 23 12 7.2 6.0 3.3 8.3 20 5.3 3.8 4.5 37 16 30 20 13 7.5 5.8 3.5 9.8 18 7.0 4.0 11 41 17 29 17 23 7.7 6.2 3.0 99 61 4.5 5.1 18 23 18 19 15 14 8.1 5.4 3.9 94 80 5.8 4.9 19 22 19 15 14 6.4 8.7 4.7 7.7 41 62 9.9 4.5 19 21 20 18 12 6.9 7.7 5.4 5.9 21 47 5.8 3.9 15 17 21 18 12 7.7 7.6 6.4 4.1 16 78 4.2 2.2 14 26 22 15 12 21 7.3 5.7 3.6 17 70 3.9 2.4 15 20 23 13 11 27 8.5 4.8 3.4 31 57 3.8 2.5 18 14 24 12 10 16 20 4.5 3.3 46 50 4.3 2.0 15 13 25 10 11 12 18 4.3 2.9 32 41 3.9 2.2 10 32 26 11 18 13 18 4.4 5.6 18 35 4.2 3.3 11 30 27 13 15 12 13 5.6 11 22 31 2.8 3.0 6.1 20 28 17 13 10 11 6.0 7.4 32 23 3.3 3.4 5.7 15 29 21 12 8.6 10 6.4 29 17 3.6 3.2 6.2 13 30 16 10 7.7 9.4 7.3 27 14 4.2 2.5 10 12 31 26 7.2 9.6 5.2 14 2.1 16 TOTAL 669 482 338.8 295.8 251.4 142.1 666.5 1,086 225.1 136.3 270.1 557.4 MEAN 21.6 16.1 10.9 9.54 8.98 4.58 22.2 35.0 7.50 4.40 8.71 18.6 MAX 61 24 27 20 26 11 99 80 15 7.7 19 41 MIN 10 10 6.4 6.3 4.3 2.9 5.3 14 2.8 2.0 2.1 5.5 AC-FT 1,330 956 672 587 499 282 1,320 2,150 446 270 536 1,110 CFSM 2.22 1.66 1.13 0.98 0.93 0.47 2.29 3.61 0.77 0.45 0.90 1.92 IN. 2.57 1.85 1.30 1.13 0.96 0.54 2.56 4.16 0.86 0.52 1.04 2.14 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1964 - 2003, BY WATER YEAR (WY) MEAN 44.7 32.3 12.4 8.47 5.90 5.98 9.82 19.5 16.0 11.7 17.7 35.2 MAX 148 77.9 26.5 45.5 13.1 16.4 35.9 76.7 49.8 32.7 46.1 119 (WY) (1986) (1978) (1966) (1992) (1996) (1972) (1998) (1969) (1969) (1979) (1979) (1975) MIN 14.5 8.32 4.43 4.11 3.05 1.85 2.76 1.94 2.75 1.77 4.47 6.16 (WY) (1994) (1977) (1977) (1989) (1977) (1977) (1975) (1967) (1967) (1990) (1974) (1997) SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1964 - 2003 ANNUAL TOTAL 4,540.8 5,120.5 ANNUAL MEAN 12.4 14.0 18.2 HIGHEST ANNUAL MEAN 30.9 1969 LOWEST ANNUAL MEAN 7.44 1994 HIGHEST DAILY MEAN 143 Jun 5 99 Apr 17 2,500 Sep 16, 1975 LOWEST DAILY MEAN 2.1 Mar 6 2.0 Jul 24 0.80 Jul 23, 1977 ANNUAL SEVEN-DAY MINIMUM 2.3 Mar 4 2.3 Jul 30 1.1 Mar 31, 1977 MAXIMUM PEAK FLOW 647 Oct 9 19,000 Oct 7, 1985 MAXIMUM PEAK STAGE 7.87 Oct 9 25.30 Oct 7, 1985 ANNUAL RUNOFF (AC-FT) 9,010 10,160 13,190 ANNUAL RUNOFF (CFSM) 1.28 1.45 1.88 ANNUAL RUNOFF (INCHES) 17.41 19.64 25.51 10 PERCENT EXCEEDS 24 27 40 50 PERCENT EXCEEDS 8.3 10 9.2 90 PERCENT EXCEEDS 3.8 3.8 3.3 399 RIO CAMUY BASIN 50112500 RIO INABON AT REAL ABAJO, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND 2002 2003 --- --- --- --- --- --- --- 400 RIO BUCANA BASIN 50113800 RIO CERRILLOS ABOVE LAGO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18q07'01", long 66q36'17", Hydrologic Unit 21010004, on right bank, 0.3 mi (0.5 km) downstream from confluence with Río San Patricio, 0.1 mi (0.2 km) southwest of Highway 139 and 2.4 mi (3.7 km) northwest of Maragüez. DRAINAGE AREA.-- 11.9 mi2 (30.8 km2). PERIOD OF RECORD.--December 1988 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 720 ft (210 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e19 e30 e20 e11 12 9.2 e9.9 19 18 e11 9.0 15 2 e28 e27 e21 e12 68 9.1 11 19 20 e10 9.1 16 3 48 39 e19 e11 30 9.1 50 18 18 e10 8.9 12 4 57 e27 e18 e11 18 8.9 18 18 17 e10 8.8 9.3 5 34 e30 e19 e11 51 8.7 33 18 28 e11 8.9 8.2 6 22 e26 e17 e11 30 8.6 21 19 25 e11 9.9 9.0 7 20 e24 e16 e10 18 8.5 14 22 19 e10 9.9 26 8 77 e24 e15 e10 14 8.4 12 26 17 e10 9.2 16 9 73 39 e14 e10 13 8.3 13 21 16 e11 8.8 11 10 105 39 e14 e11 12 8.3 13 22 16 e10 8.8 13 11 55 e26 e14 e11 11 8.3 17 19 15 e10 10 64 12 33 e28 e14 e10 11 8.5 34 17 15 e9.8 11 45 13 27 39 e13 e9.9 11 8.5 25 17 14 e9.6 15 32 14 26 39 e13 e9.8 11 8.6 16 18 14 e9.5 12 16 15 56 41 e12 e9.8 9.9 8.5 14 17 14 9.4 11 94 16 43 e30 e12 e9.6 9.7 8.7 15 18 14 10 20 50 17 e35 e28 e58 e9.4 10 8.7 175 54 14 9.8 13 22 18 48 e26 25 e9.4 9.9 9.2 252 53 e16 9.1 11 20 19 e34 e25 14 e11 9.7 9.7 75 32 e16 9.0 9.9 52 20 e38 e25 12 e10 9.6 9.2 38 25 e15 9.1 9.0 30 21 60 e23 11 e9.8 9.9 8.2 32 144 e14 9.0 8.3 18 22 e45 e23 29 e9.6 9.3 7.7 27 64 e14 8.9 9.0 15 23 e30 e22 14 e9.4 9.2 7.5 31 36 e13 8.9 8.5 13 24 e28 22 12 e15 9.4 7.2 107 29 e13 8.6 8.1 12 25 e28 21 11 e26 9.4 6.9 56 25 e12 11 7.8 58 26 e25 41 12 e26 9.2 16 32 23 e12 11 e8.5 25 27 e24 26 12 e12 9.6 18 26 22 e12 9.6 e9.7 17 28 e22 21 11 e12 9.5 11 23 21 e11 10 9.0 14 29 e25 19 11 e11 11 21 20 e11 9.7 8.8 12 30 e22 e19 11 e11 9.5 20 19 e11 9.0 9.5 12 31 54 11 e12 e8.2 19 9.1 12 TOTAL 1,241 849 505 361.7 444.3 286.2 1,230.9 894 464 304.1 312.4 756.5 MEAN 40.0 28.3 16.3 11.7 15.9 9.23 41.0 28.8 15.5 9.81 10.1 25.2 MAX 105 41 58 26 68 18 252 144 28 11 20 94 MIN 19 19 11 9.4 9.2 6.9 9.9 17 11 8.6 7.8 8.2 AC-FT 2,460 1,680 1,000 717 881 568 2,440 1,770 920 603 620 1,500 CFSM 3.36 2.38 1.37 0.98 1.33 0.78 3.45 2.42 1.30 0.82 0.85 2.12 IN. 3.88 2.65 1.58 1.13 1.39 0.89 3.85 2.79 1.45 0.95 0.98 2.36 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1989 - 2003, BY WATER YEAR (WY) MEAN 65.0 36.9 17.6 14.8 11.9 10.4 18.4 25.0 22.6 15.9 33.1 68.6 MAX 154 75.0 29.6 59.0 26.1 27.5 41.0 68.2 46.4 26.7 83.3 196 (WY) (1991) (2000) (2002) (1992) (1996) (1989) (2003) (1993) (1996) (1991) (1998) (1998) MIN 24.6 9.77 8.10 6.59 6.34 4.77 5.01 4.58 4.14 3.37 10.1 13.1 (WY) (1992) (1994) (1995) (1995) (1990) (1990) (1997) (1990) (1997) (1994) (2003) (1997) 401 RIO GUAJATACA BASIN 50113800 RIO CERRILLOS ABOVE LAGO CERRILLOS NEAR PONCE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1989 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 6,956.1 ANNUAL MEAN 19.1 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 105 LOWEST DAILY MEAN 6.0 ANNUAL SEVEN-DAY MINIMUM 6.5 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 13,800 ANNUAL RUNOFF (CFSM) 1.60 ANNUAL RUNOFF (INCHES) 21.75 10 PERCENT EXCEEDS 39 50 PERCENT EXCEEDS 13 90 PERCENT EXCEEDS 8.7 7,649.1 21.0 28.3 43.9 1998 9.94 1994 Oct 10 252 Apr 18 2,510 Sep 22, 1998 Mar 25 6.9 Mar 25 3.0 Jul 6, 1994 Mar 21 8.1 Mar 19 3.2 Jul 27, 1994 1,460 Apr 18 16,200 Sep 21, 1998 6.00 Apr 18 12.42 Sep 21, 1998 6.8 Mar 24 3.0 Jul 6, 1997 15,170 20,470 1.76 2.37 23.91 32.26 39 64 14 14 9.0 5.5 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 402 RIO BUCANA BASIN 50113950 LAGO CERRILLOS AT DAMSITE NEAR PONCE, PR LOCATION.--Lat 18q04'41", long 66q34'38", Hydrologic Unit 21010004, on left bank west from intake house of dam, 0.7 mi (1.1 km) southwest from Iglesia San Mateo at Real Abajo, 3.2 mi (5.1 km) northeast from Hospital de Distrito de Ponce, and 2.2 mi (3.5 km) northwest from Escuel a Yuca. DRAINAGE AREA.--17.4 mi2 (45.1 km2). PERIOD OF RECORD.--October 1992 to current year. REVISED RECORDS.--WDR PR-94-1, 1993, 1994. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lake is formed by Cerrillos Dam, a rockfilled ungated structure completed in 1992. Elevation of crest is 611 ft (186 m ) above mean sea level, with a structural height of 323 ft (98 m) and a length of 1,555 ft (474 m). The dam has a capacity of approximately 47,900 acre-ft (59.1 hm3). The dam is operated by the U.S. Army Corps of Engineers and its purpose is for flood control, water supply, power generation, and recreation. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 602.84 ft (183.74 m), September 22, 1998; minimum elevation, 416.63 ft (126.99 m), October 1, 1992 (Revised). EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 532.74 ft (162.38 m), January 16; minimum elevation, 503.42 ft (153.44 m), September 10. Capacity Table (based on data from U.S. Army Corps of Engineers) (Elevation in ft, capacity in acre-ft) Elevation Contents 328 0 426 3,206 492 10,621 Elevation Contents 525 16,990 558 25,786 590 37,509 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 509.51 522.61 528.26 531.71 529.62 525.37 517.53 526.95 526.62 520.33 512.27 504.74 2 509.80 522.74 528.36 531.80 530.09 525.12 517.15 526.82 526.47 520.10 511.99 504.78 3 510.55 523.19 528.34 531.86 530.12 524.87 517.57 526.72 526.32 519.86 511.70 504.60 4 511.26 523.44 528.32 531.91 530.02 524.60 517.45 526.57 526.14 519.62 511.41 504.34 5 511.58 523.76 528.62 531.98 530.32 524.35 517.28 526.42 526.07 519.41 A 504.05 6 511.73 523.97 528.63 532.06 530.34 524.09 517.17 526.35 525.99 519.18 A 503.80 7 511.95 524.09 528.54 532.12 530.25 523.82 517.14 526.20 525.85 518.90 510.65 503.92 8 512.86 524.16 528.64 532.17 530.08 523.55 516.75 526.14 525.67 518.67 A 503.82 9 514.19 524.36 528.64 532.22 529.89 523.29 516.79 526.04 525.49 518.42 A 503.59 10 515.47 524.58 528.77 532.42 529.70 523.02 516.39 525.96 A 518.16 A 503.55 11 516.04 524.78 528.94 532.52 529.50 522.75 516.39 525.78 525.10 517.90 A 504.24 12 516.09 525.05 528.71 532.57 529.28 522.48 516.27 525.67 524.91 517.64 A 504.58 13 516.32 525.39 528.37 532.62 529.08 522.20 516.17 525.53 524.71 517.42 A 504.74 14 516.68 525.64 528.77 532.66 528.87 521.92 516.32 525.37 524.51 517.07 508.86 504.59 15 517.28 526.02 529.24 532.70 528.65 521.64 515.78 A 524.30 516.80 508.59 505.89 16 517.62 526.22 529.01 532.73 528.42 521.36 515.56 525.52 524.09 516.53 508.57 506.59 17 517.86 526.75 532.50 528.21 521.08 519.08 525.72 523.90 516.26 508.37 506.60 18 518.41 526.90 529.99 532.25 527.99 A 523.37 525.97 523.69 516.00 A 506.62 19 518.58 526.61 530.09 532.01 527.75 A 524.26 525.96 523.53 515.73 A 507.17 20 519.17 A 530.17 531.76 527.52 A 524.45 525.87 523.30 515.47 A 507.32 21 519.73 A 530.23 531.51 527.30 A 524.54 527.37 523.08 515.20 A 507.86 22 520.05 527.68 530.52 531.25 527.05 A 524.72 527.76 522.86 514.93 507.04 507.81 23 520.30 527.71 531.02 531.04 526.81 A 525.06 527.79 522.63 514.65 506.78 507.65 24 520.48 527.77 531.13 531.17 526.58 A 526.51 527.74 522.40 514.37 506.50 507.82 25 520.73 527.85 531.21 531.08 526.33 519.55 527.01 527.65 521.72 514.11 506.21 508.32 26 520.81 528.02 531.32 530.94 526.09 518.77 527.14 527.53 521.49 513.87 506.13 508.34 27 520.97 528.16 531.40 530.73 525.86 518.35 527.24 527.41 521.24 513.62 505.89 508.22 28 521.09 528.08 531.47 530.51 525.61 518.33 527.20 527.25 521.01 513.38 505.68 508.08 29 521.38 528.19 531.53 530.28 518.32 527.16 527.10 520.76 513.11 505.44 507.87 30 521.75 528.26 531.59 530.06 517.89 527.04 526.95 520.52 512.84 505.16 507.66 31 522.45 531.65 529.83 526.78 512.57 504.92 MAX 522.45 532.73 530.34 527.24 520.33 508.34 MIN 509.51 529.83 525.61 515.56 512.57 503.55 A No gage-height record 403 RIO GUAJATACA BASIN 50113950 LAGO CERRILLOS AT DAMSITE NEAR PONCE, PR—Continued O N D J F M A M J J A S 500 505 510 515 520 525 530 535 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 404 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18q04'24", long 66q34'53", Hydrologic Unit 21010004, on right bank off Highway 139, 0.8 mi (1.3 km) below Lago Cerrillos Dam, 2.3 mi (3.7 km) upstream from Quebrada Ausubo, and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--17.8 mi2 (46.1 km2), excludes 17.4 mi2 (45.1 km2) upstream from Lago Cerrillos Dam. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to April 1964 (monthly measurements only), May 1964 to June 1985, July 1985 to April 1991 (semi-monthly measurements only), May 1991 to current year. GAGE.--Water-stage recorder. Datum of gage is 253.10 ft (77.145 m), above mean sea level. Prior to March 22, 1977, at site 0.15 mi (0.24 km) upstream and datum 9.90 ft (3.018 m) higher. REMARKS.--Records poor. Flow regulated by Lago Cerrillos Dam since May 1991. Gage-height and precipitation satellite telemetry at station. Prior to June 1985, some low-flow regulation by construction upstream. Maximum discharge prior to regulation, 22,400 ft 3/s (634 m3/s), September 16, 1975, gage height, 11.2 ft (3.41 m), site and datum then in use from floodmarks, from rating curve extended above 150 ft3/s (4.25 m3/s), on basis of slope-area measurements of peak flow; minimum discharge prior to regulation, 2.2 ft3/s (0.062 m3/s), May 28, 1967. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.4 2.2 3.1 2.6 1.9 1.1 e1.5 2.4 5.1 2.8 2.5 3.0 2 2.2 2.2 3.2 2.6 2.0 1.1 1.6 2.2 5.2 2.7 2.5 3.7 3 2.2 4.0 3.8 2.3 1.8 1.1 e2.3 2.5 6.6 2.6 2.5 2.6 4 2.2 2.4 3.9 2.4 2.0 1.0 1.7 2.6 5.1 2.7 2.5 2.6 5 2.4 2.4 3.4 2.3 2.0 1.0 1.7 2.9 4.9 2.9 2.5 2.6 6 2.4 2.4 2.9 2.5 1.9 1.0 1.9 3.3 5.1 2.7 2.7 2.6 7 2.4 2.4 3.0 2.4 1.9 0.94 2.4 3.8 5.5 2.7 2.6 3.0 8 2.3 2.4 3.2 2.5 1.8 0.87 2.8 3.8 5.4 2.7 2.6 2.6 9 2.4 2.5 2.9 2.6 1.8 0.85 2.5 3.8 5.5 2.7 2.7 3.1 10 2.4 2.5 2.9 2.7 1.7 0.84 2.4 3.8 4.7 2.7 2.8 4.3 11 2.4 2.6 3.0 2.7 1.7 0.78 2.7 3.8 4.7 2.7 2.6 3.2 12 2.6 2.7 3.0 2.7 1.6 0.77 2.6 3.8 4.8 2.6 2.6 4.9 13 3.2 3.0 3.1 2.5 1.6 0.77 2.5 3.8 4.8 2.7 2.7 5.0 14 5.0 2.8 3.1 2.4 1.5 0.95 2.9 3.9 4.9 2.7 2.7 3.1 15 3.8 3.9 3.3 2.3 1.5 1.1 2.6 3.8 5.0 2.7 2.7 3.1 16 3.8 2.8 3.2 2.3 1.5 1.0 2.2 3.8 5.1 2.7 2.6 3.9 17 3.2 2.9 4.5 2.3 1.4 1.0 11 3.9 5.1 2.7 2.6 2.9 18 2.4 2.9 3.4 2.4 1.4 0.94 6.9 3.9 4.9 2.6 2.6 3.1 19 2.5 3.1 3.3 2.4 1.4 0.80 3.5 3.9 5.5 2.6 2.5 4.6 20 2.6 2.9 3.4 2.3 1.4 e0.75 2.9 3.8 5.5 2.6 4.8 3.7 21 2.9 3.0 3.4 2.1 1.3 e0.75 2.1 4.3 5.6 2.5 10 10 22 2.6 3.2 4.2 2.5 1.2 0.79 2.9 4.1 5.8 2.6 4.9 3.8 23 2.3 3.0 14 2.2 1.2 e0.83 2.8 4.4 5.6 2.5 2.4 3.5 24 2.4 2.9 2.6 2.1 1.2 0.82 2.1 5.0 8.0 2.6 2.4 3.4 25 2.6 2.9 2.4 2.1 1.2 0.87 1.8 6.1 61 2.6 2.5 4.1 26 2.8 2.9 2.7 2.0 1.2 0.95 1.9 6.0 3.4 2.6 3.1 3.6 27 2.5 3.1 2.7 2.0 1.1 1.1 2.1 5.7 3.0 2.6 2.9 3.4 28 2.2 3.0 2.9 1.9 1.1 1.1 2.6 5.7 2.9 2.6 3.4 3.2 29 2.5 3.0 3.1 1.9 1.5 2.4 4.9 2.9 2.5 3.9 2.8 30 2.4 3.1 3.4 2.0 1.4 2.6 5.1 2.8 2.5 3.1 2.9 31 2.2 2.7 1.8 e1.4 5.3 2.5 2.6 TOTAL 82.2 85.1 109.7 71.8 43.3 30.17 83.9 126.1 204.4 81.9 95.5 108.3 MEAN 2.65 2.84 3.54 2.32 1.55 0.97 2.80 4.07 6.81 2.64 3.08 3.61 MAX 5.0 4.0 14 2.7 2.0 1.5 11 6.1 61 2.9 10 10 MIN 2.2 2.2 2.4 1.8 1.1 0.75 1.5 2.2 2.8 2.5 2.4 2.6 AC-FT 163 169 218 142 86 60 166 250 405 162 189 215 CFSM 0.15 0.16 0.20 0.13 0.09 0.05 0.16 0.23 0.38 0.15 0.17 0.20 IN. 0.17 0.18 0.23 0.15 0.09 0.06 0.18 0.26 0.43 0.17 0.20 0.23 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1991 - 2003, BY WATER YEAR (WY) MEAN 57.3 35.8 9.07 12.6 6.28 7.24 9.35 33.8 23.8 18.6 40.6 81.1 MAX 221 137 20.5 74.2 14.7 17.9 31.0 127 107 94.3 195 316 (WY) (2001) (2000) (1999) (1992) (1992) (1997) (1999) (2001) (1999) (2001) (2001) (2001) MIN 2.65 2.84 3.54 2.32 1.55 0.97 2.80 3.16 3.69 2.41 2.41 2.11 (WY) (2003) (2003) (2003) (2003) (2003) (2003) (2003) (2002) (1995) (2002) (2002) (2002) 405 RIO GUAJATACA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1991 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 1,106.7 ANNUAL MEAN 3.03 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 14 LOWEST DAILY MEAN 1.8 ANNUAL SEVEN-DAY MINIMUM 1.9 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 2,200 ANNUAL RUNOFF (CFSM) 0.170 ANNUAL RUNOFF (INCHES) 2.31 10 PERCENT EXCEEDS 4.0 50 PERCENT EXCEEDS 2.9 90 PERCENT EXCEEDS 2.2 1,122.37 3.07 28.8 92.8 2001 3.07 2003 Dec 23 61 Jun 25 900 Jan 6, 1992 Sep 17 0.75 Mar 20 0.64 Aug 19, 1992 Sep 17 0.80 Mar 19 0.80 Mar 19, 2003 1,270 Jun 25 1,320 Sep 10, 1996 5.84 Jun 25 7.74 Sep 10, 1996 2,230 20,830 0.173 1.62 2.35 21.95 4.9 80 2.6 5.5 1.4 2.9 e Estimated 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S 2002 2003 406 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR—Continued WATER-QUALITY RECORDS LOCATION.--Lat 18q04'15", long 66q34'51", Hydrologic unit 21010004, on right bank off Highway 139, 2.3 mi (3.7 km) upstream from Quebrada Ausubo and 4.6 mi (7.4 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--17.8 mi2 (46.1 km2) PERIOD OF RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 14... 0910 2.7 27 6.5 78 7.3 369 25.0 160 53.4 5.66 .83 .5 FEB 04... 1130 1.8 7.8 8.1 -- 8.1 351 26.3 140 48.9 5.31 .65 .5 APR 09... 1250 5.2 1.5 7.6 -- 7.8 334 26.7 140 47.4 4.95 .73 .4 JUL 16... 1430 1.9 50 7.7 -- 7.7 341 26.5 -- -- -- -- -­ SEP 02... 1025 2.7 4.6 7.6 -- 7.8 350 26.5 150 50.5 5.17 .74 .5 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00630) NOV 14... 14.3 136 7.40 .22 22.7 39.9 -- 226 1.66 38 .30 <.01 .200 FEB 04... 13.8 133 6.48 .23 23.6 36.7 .0 215 1.06 16 <.20 .01 .140 APR 09... 12.0 125 6.48 .22 21.6 30.6 .3 199 2.80 <10 <.20 .03 .110 JUL 16... -- 139 -- -- -- -- -- -- -- 60 <.20 .02 .140 SEP 02... 13.8 138 7.87 .2 23.2 30.8 -- 215 1.59 <10 <.20 .07 .080 Total Fecal Fecal Total Chrom- Total nitro- COD, coli- strep- coli- Barium, Boron, ium, Nitrite Phos- nitro- gen, high form, tococci form, water, water, water, water, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd unfltrd water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, recover mg/L unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, Date as N mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L (00615) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) NOV 14... <.01 .04 .50 2.2 <10 E640 460 -- -- -- -- -- -­ FEB 04... <.01 <.02 -- -- <10 E20 -- 2,400 <2 38.3 29 <.2 <.8 APR 09... <.01 <.02 -- -- <10 E28 -- 3,000 <2 37.6 22 E.1 <.8 JUL 16... <.01 .04 -- -- <10 220 -- 5,400 -- -- -- -- -­ SEP 02... <.01 <.02 -- -- <10 E140 -- 550 -- -- -- -- -­ 407 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 14... -- -- -- -- -- -- -- -- -- -- -- FEB 04... <10 <.01 360 <1 71.5 <.02 E1 <.3 <25 <.10 <16 APR 09... <10 <.01 120 <1 9.8 <.02 <3 <.3 E22 <.10 <16 JUL 16... -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 408 RIO PORTUGUES BASIN 50114900 RIO PORTUGUES NEAR TIBES, PR LOCATION.--Lat 18q06'00", long 66q38'34", Hydrologic Unit 21010004, 1.6 mi (2.6 km), north from Escuela Segunda Unidad of Corral Viejo, 0.3 mi (0.50 km) south from Hacienda Burenes and 6.0 mi (9.6 km) northeast from Peñuelas Plaza church. DRAINAGE AREA.--7.27 mi2 (18.8 km2). PERIOD OF RECORD.--October 1997 to current year. GAGE.--Water-stage recorder. Elevation of gage is 918 ft (280 m), from topographic map. REMARKS.--Records poor. Some low-flow regulation due to PRASA intakes (2) 0.85 mi (1.36 km) upstream from station. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 16 13 e9.2 e8.9 8.6 10 8.8 12 6.9 5.2 3.6 21 2 19 11 e9.4 e9.7 31 10 8.6 11 7.6 4.7 3.6 22 3 29 13 e9.0 e9.1 18 10 46 11 6.8 4.6 3.6 16 4 69 10 e8.8 e9.0 16 9.9 28 10 6.6 4.5 3.5 11 5 64 9.9 e9.4 e8.9 31 9.8 32 12 9.3 5.9 3.5 9.1 6 53 9.7 8.9 e8.9 28 9.8 24 11 10 4.9 4.7 11 7 44 9.2 8.6 e8.3 20 9.8 12 19 8.6 4.3 4.3 21 8 101 8.5 9.1 e8.3 17 9.8 9.6 18 7.6 4.5 3.8 15 9 91 16 8.7 e8.5 16 9.8 e9.5 14 7.3 4.4 3.6 10 10 49 12 8.1 e19 15 9.9 e9.9 12 6.9 4.2 3.4 9.4 11 37 9.8 8.0 e13 14 9.8 e10 11 6.7 4.2 5.5 18 12 31 13 8.3 e8.1 14 9.6 e14 10 7.2 4.2 4.4 30 13 28 15 8.1 e7.9 13 9.5 e13 10 6.8 4.6 7.4 32 14 26 13 8.2 e7.9 13 9.3 e11 14 6.5 4.4 6.1 18 15 26 11 7.9 e7.8 13 9.4 e11 11 6.4 4.5 5.1 73 16 23 13 8.3 e7.7 12 9.3 e11 10 6.4 4.6 16 45 17 23 11 44 e7.6 13 9.2 e37 13 6.3 4.5 8.2 29 18 30 10 e21 e7.5 12 9.4 e88 14 6.2 4.2 7.0 31 19 22 e11 e12 e8.9 12 10 e21 11 6.1 4.1 6.3 56 20 23 e10 e11 e7.3 12 9.9 e17 11 5.8 3.8 5.7 43 21 20 e10 e9.9 7.4 12 9.4 e15 60 5.6 3.8 6.3 31 22 17 e9.9 e26 e8.8 12 9.2 e25 24 5.5 3.8 6.7 25 23 15 e9.8 e14 e10 12 9.1 22 13 5.4 3.7 6.6 21 24 14 e9.8 e10 16 12 8.9 46 11 5.4 3.6 6.3 23 25 13 e9.6 e9.6 16 12 8.7 37 9.6 5.2 3.6 6.8 24 26 13 e13 e9.6 14 11 16 23 9.0 5.1 3.7 15 20 27 12 e10 e10 10 11 16 18 8.3 4.9 4.1 7.9 17 28 11 e9.5 e9.0 9.1 11 10 16 7.8 4.8 4.7 8.0 16 29 12 e9.4 e8.6 8.8 9.9 14 7.5 4.7 4.2 8.1 16 30 10 e9.3 e8.7 8.6 9.1 13 7.2 4.7 3.7 6.9 16 31 14 e8.9 8.5 8.8 7.0 3.6 6.4 TOTAL 955 329.4 350.3 299.5 421.6 309.3 650.4 409.4 193.3 132.8 194.3 729.5 MEAN 30.8 11.0 11.3 9.66 15.1 9.98 21.7 13.2 6.44 4.28 6.27 24.3 MAX 101 16 44 19 31 16 88 60 10 5.9 16 73 MIN 10 8.5 7.9 7.3 8.6 8.7 8.6 7.0 4.7 3.6 3.4 9.1 AC-FT 1,890 653 695 594 836 613 1,290 812 383 263 385 1,450 CFSM 4.24 1.51 1.55 1.33 2.07 1.37 2.98 1.82 0.89 0.59 0.86 3.34 IN. 4.89 1.69 1.79 1.53 2.16 1.58 3.33 2.09 0.99 0.68 0.99 3.73 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1998 - 2003, BY WATER YEAR (WY) MEAN 31.0 20.9 10.9 6.65 6.84 5.51 13.4 12.7 10.4 8.96 19.3 53.4 MAX 46.4 45.0 14.8 9.66 15.1 9.98 21.7 17.6 17.6 16.1 34.5 147 (WY) (2001) (2000) (2000) (2003) (2003) (2003) (2003) (2000) (1999) (1998) (1999) (1998) MIN 13.3 6.91 3.98 3.07 4.34 3.52 5.78 5.96 6.44 4.28 6.27 9.79 (WY) (1998) (1998) (1998) (1998) (2002) (1998) (2001) (1999) (2003) (2003) (2003) (2002) 409 RIO CAMUY BASIN 50114900 RIO PORTUGUES NEAR TIBES, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1998 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 4,116.5 ANNUAL MEAN 11.3 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 101 LOWEST DAILY MEAN 2.4 ANNUAL SEVEN-DAY MINIMUM 2.6 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 8,170 ANNUAL RUNOFF (CFSM) 1.55 ANNUAL RUNOFF (INCHES) 21.06 10 PERCENT EXCEEDS 23 50 PERCENT EXCEEDS 7.4 90 PERCENT EXCEEDS 4.0 4,974.8 13.6 16.6 22.2 1998 10.0 2002 Oct 8 101 Oct 8 3,000 Sep 22, 1998 Jul 19 3.4 Aug 10 1.1 Oct 6, 1997 Jul 18 3.6 Jul 30 1.7 Oct 1, 1997 701 Feb 2 10,000 Sep 21, 1998 10.09 Feb 2 22.46 Sep 21, 1998 9,870 12,060 1.87 2.29 25.46 31.11 25 35 9.9 8.6 4.7 4.0 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 410 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR LOCATION.--Lat 18q04'45", long 66q38'01", Hydrologic Unit 21010004, on right bank 30 ft (9 m) upstream from bridge on Highway 504, 0.2 mi (0.3 km) upstream from small unnamed tributary, 4.4 mi (7.1 km) upstream from Río Chiquito, and 4.7 mi (7.6 km) north of Plaza Degetau in Ponce. DRAINAGE AREA.--8.82 mi2 (22.84 km2). PERIOD OF RECORD.--Water year 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 13... 1200 13 8.8 6.5 77 7.6 296 24.1 140 42.9 7.24 1.01 .3 FEB 04... 1445 14 5.0 8.0 -- 8.5 295 24.8 130 41.5 6.92 1.31 .3 APR 09... 1505 9.4 1.1 7.8 -- 8.3 379 26.0 170 53.0 8.98 1.34 .4 JUL 17... 0845 5.3 1.4 8.7 -- 8.3 366 24.5 -- -- -- -- -­ SEP 02... 1210 12 2.1 7.7 -- 8.3 324 27.0 150 48.1 7.68 1.23 .4 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00630) NOV 13... 9.25 133 6.30 <.17 20.0 9.2 -- 176 6.15 <10 <.20 <.01 .980 FEB 04... 8.98 135 5.72 .11 19.9 9.2 .0 175 6.84 <10 <.20 <.01 1.20 APR 09... 10.6 160 6.75 .11 20.5 20.2 <.1 217 5.53 <10 <.20 .17 1.10 JUL 17... -- 158 -- -- -- -- -- -- -- <10 <.20 .01 .610 SEP 02... 10.2 149 7.49 <.2 19.5 14.1 -- 198 6.51 <40 .20 <.01 1.10 Total Fecal Fecal Total Chrom- Total nitro- COD, coli- strep- coli- Barium, Boron, ium, Nitrite Phos- nitro- gen, high form, tococci form, water, water, water, water, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd unfltrd water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, recover mg/L unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, Date as N mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L (00615) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) NOV 13... <.01 .05 -- -- <10 460 740 -- -- -- -- -- -­ FEB 04... <.01 .04 -- -- <10 390 -- 5,300 <2 33.8 E13 <.2 <.8 APR 09... <.01 .04 -- -- <10 140 -- 4,600 <2 43.4 E10 E.1 <.8 JUL 17... <.01 .02 -- -- <10 40 -- 480 -- -- -- -- -­ SEP 02... <.01 .05 1.3 5.8 <10 E630 -- 2,000 -- -- -- -- -­ 411 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 13... -- -- -- -- -- -- -- -- -- -- -- FEB 04... <10 <.01 160 <1 6.8 <.02 <3 <.3 <25 <.10 <16 APR 09... <10 <.01 80 <1 5.2 <.02 <3 <.3 E20 <.10 E15 JUL 17... -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 412 RIO PORTUGUES BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR LOCATION.--Lat 18q01'09", long 66q36'26", Hydrologic Unit 21010004, on right bank upstream from bridge on Highway 14, 1.70 mi (2.74 km) downstream from Río Chiquito, and 0.6 mi (0.96 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--18.6 mi2 (48.17 km2). PERIOD OF RECORD.--Occasional measurements 1963, annual maximum discharge and peaks above base at different datum, from 1965 to 1972. June 1997 to current year. REVISED RECORDS.--WRD PR-02-1, 2001. GAGE.--Water-stage recorder. Elevation of gage is 67.2 ft (20.48 m), from topographic map. Prior to June 18, 1997 non-recording gage crested-stage gage at same site and different datum. REMARKS.--Records poor. Some low-flow regulation due to Río Portugués dam construction activity upstream. Gage-height and precip itation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10 83 16 11 7.1 4.2 11 e24 26 21 7.1 38 2 34 30 13 17 37 5.6 14 e22 32 10 7.5 103 3 37 51 20 13 131 4.9 93 e20 32 8.2 6.2 119 4 83 40 21 9.2 34 6.1 132 e19 23 10 6.6 49 5 153 18 19 9.2 43 5.5 32 e18 21 15 6.1 20 6 33 18 16 13 99 5.3 54 e20 49 20 7.4 12 7 33 21 16 11 30 e5.0 15 e25 39 9.1 17 66 8 69 16 22 10 20 e4.7 53 51 28 11 8.6 148 9 398 23 23 13 12 e5.0 92 56 25 11 6.6 53 10 266 53 25 20 16 e4.5 17 37 28 8.8 6.6 37 11 130 19 12 46 11 e4.0 23 70 25 7.8 12 27 12 57 22 14 18 12 e3.8 24 46 24 8.0 37 92 13 45 47 11 19 12 e3.6 68 32 22 12 7.5 226 14 35 52 12 16 13 e3.5 24 19 21 11 43 85 15 30 16 15 9.6 12 e3.4 12 22 18 11 12 265 16 30 16 18 11 8.1 e3.2 48 13 18 13 32 329 17 25 24 46 9.5 8.5 e3.1 768 12 20 11 88 141 18 31 25 203 9.8 6.7 e4.0 859 26 19 8.4 17 98 19 63 19 42 11 4.8 e3.5 286 16 26 8.0 16 187 20 42 20 26 11 4.3 e6.0 120 12 21 7.6 7.9 278 21 58 20 16 9.8 5.8 3.6 95 99 16 6.9 23 228 22 46 23 29 12 9.5 5.7 222 227 15 8.2 12 206 23 32 22 49 13 9.6 4.2 185 79 14 6.9 8.0 89 24 41 18 31 49 9.1 3.3 e130 60 13 6.3 11 75 25 28 16 20 101 5.1 2.7 e90 50 10 5.8 16 212 26 26 33 18 38 14 9.8 e60 45 9.3 5.8 114 101 27 26 65 18 16 10 44 e40 38 8.6 6.6 75 79 28 34 20 13 13 5.3 49 e35 36 7.4 8.9 40 64 29 26 20 11 9.4 18 e30 37 7.1 11 70 54 30 31 20 11 8.3 33 e26 33 7.0 6.5 41 57 31 31 10 6.6 12 28 6.5 19 TOTAL 1,983 870 816 563.4 589.9 274.2 3,658 1,292 624.4 301.3 781.1 3,538 MEAN 64.0 29.0 26.3 18.2 21.1 8.85 122 41.7 20.8 9.72 25.2 118 MAX 398 83 203 101 131 49 859 227 49 21 114 329 MIN 10 16 10 6.6 4.3 2.7 11 12 7.0 5.8 6.1 12 AC-FT 3,930 1,730 1,620 1,120 1,170 544 7,260 2,560 1,240 598 1,550 7,020 CFSM 3.44 1.56 1.42 0.98 1.13 0.48 6.56 2.24 1.12 0.52 1.35 6.34 IN. 3.97 1.74 1.63 1.13 1.18 0.55 7.32 2.58 1.25 0.60 1.56 7.08 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1997 - 2003, BY WATER YEAR (WY) MEAN 80.8 51.6 22.7 14.1 13.3 9.71 45.8 30.2 29.1 16.8 48.1 113 MAX 128 129 31.1 21.7 21.1 17.4 122 46.1 60.4 36.8 112 314 (WY) (2001) (2000) (2000) (1999) (2003) (1999) (2003) (2000) (1999) (1999) (1998) (1998) MIN 31.8 15.1 6.00 6.09 7.60 5.33 12.1 15.9 17.7 3.90 6.79 12.5 (WY) (2002) (1998) (1998) (1998) (2002) (1998) (2001) (1999) (2000) (2000) (1997) (1997) 413 RIO CAMUY BASIN 50115900 RIO PORTUGUES AT HIGHWAY 14 AT PONCE, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1997 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 10,224.9 ANNUAL MEAN 28.0 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 398 LOWEST DAILY MEAN 3.0 ANNUAL SEVEN-DAY MINIMUM 4.8 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 20,280 ANNUAL RUNOFF (CFSM) 1.51 ANNUAL RUNOFF (INCHES) 20.45 10 PERCENT EXCEEDS 59 50 PERCENT EXCEEDS 15 90 PERCENT EXCEEDS 6.9 15,291.3 41.9 41.8 57.8 1998 24.9 2002 Oct 9 859 Apr 18 5,580 Sep 22, 1998 Jul 24 2.7 Mar 25 0.97 Jun 18, 1997 Jul 21 3.5 Mar 13 1.6 Jul 27, 1997 5,050 Apr 17 16,300 Sep 22, 1998 14.32 Apr 17 19.73 Sep 22, 1998 30,330 30,260 2.25 2.25 30.58 30.51 92 88 20 17 6.5 6.2 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 414 RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR LOCATION.--Lat 18q00'20", long 66q36'28", 1,300 ft (400 m) south of Las Americas Avenue bridge, 0.8 mi (1.3 km) west of Highways 1 and 2 junction, and 0.7 mi (1.1 km) southeast of Ponce. DRAINAGE AREA.--18.9 mi2 (49.0 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 13... 0830 29 58 4.3 51 7.1 341 23.9 140 43.1 8.23 1.31 .6 FEB 13... 0845 11 7.9 6.0 -- 7.8 465 23.0 180 54.7 10.8 1.18 .9 APR 10... 1330 15 11 9.7 -- 8.6 459 29.5 170 48.7 10.8 1.59 1 JUL 17... 1120 7.5 5.4 -- -- 8.0 491 28.5 -- -- -- -- -­ SEP 02... 1345 19 16 7.9 -- 8.2 365 30.7 150 43.8 9.15 1.65 .7 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 13... 15.7 132 11.1 <.17 18.4 19.9 -- 197 15.6 16 .30 .01 -­ FEB 13... 28.0 176 21.3 .13 13.8 42.5 <.0 278 8.25 10 .30 .04 .35 APR 10... 28.6 140 23.3 .12 17.6 51.4 5.0 266 11.0 12 .30 .05 .23 JUL 17... -- 137 -- -- -- -- -- -- -- 11 .90 .37 .27 SEP 02... 19.0 134 15.5 <.2 18.4 29.8 -- 218 11.3 12 .50 .09 .32 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 13... .730 <.01 .29 .10 1.0 4.6 <10 E9,800 E14,100 -- -- -- -­ FEB 13... .360 .01 .26 .03 .66 2.9 <10 E100 -- 4,800 <2 43.1 68 APR 10... .240 .01 .25 .09 .54 2.4 10 E1,100 -- 41,000 E2 44.0 75 JUL 17... .380 .11 .53 .17 1.3 5.7 20 33,000 -- E100,000 -- -- -­ SEP 02... .340 .02 .41 .11 .84 3.7 20 E15,000 -- 42,000 -- -- -­ 415 RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 13... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 13... <.2 <.8 <10 <.01 240 <1 23.6 <.02 <3 <.3 <25 <.10 <16 APR 10... <.2 1.2 <10 <.01 1,850 2 106 <.02 <3 <.3 <25 <.10 E13 JUL 17... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 02... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 10... 1330 <.01 <.02 <.01 <.01 <.04 <.1 <.03 E.01 <.02 <.017 <.20 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 10... <.03 <.02 <.009 <.01 <.014 <.30 <.03 <.012 <.016 <.014 <.009 <.015 <.02 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 10... <.1 <.04 <.02 <1 <.04 < -- Less than E -- Estimated value --- --- --- --- --- --- --- 416 RIO GUAYANILLA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, PR LOCATION.--Lat 18q02'40", long 66q47'53", Hydrologic Unit 21010004, on left bank, 0.7 mi (1.1 km) north of junction of Highways 2 and 132, 0.6 mi (1.0 km) downstream from Quebrada Consejo, 1.8 mi (2.9 km) north-northwest from Plaza de Guayanilla. DRAINAGE AREA.--18.9 mi2 (49.0 km2). PERIOD OF RECORD.--March 1981 to current year. GAGE.--Water-stage recorder. Elevation of gage is 80 ft (24 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 22 19 13 7.1 7.4 5.4 20 16 8.3 17 6.5 13 2 22 17 13 7.7 44 5.2 12 15 10 7.5 6.2 7.2 3 23 50 13 7.8 32 4.8 76 14 8.0 6.5 5.8 6.4 4 28 39 14 6.9 30 4.8 37 13 7.8 6.8 5.5 5.5 5 35 24 13 6.8 13 4.9 14 13 7.8 10 5.4 3.7 6 61 19 12 7.0 10 4.9 10 14 9.8 8.7 5.6 3.2 7 47 17 12 7.0 8.7 4.9 8.8 15 8.7 5.9 6.6 59 8 48 16 14 6.8 7.9 4.8 8.8 37 8.1 5.4 5.7 25 9 72 20 13 7.1 7.0 5.1 9.8 38 8.1 6.0 4.5 6.5 10 178 20 12 9.9 6.6 5.3 8.7 18 8.5 5.5 4.6 23 11 72 16 12 10 6.3 5.4 9.7 15 8.1 5.3 4.4 57 12 36 21 12 7.3 6.1 5.5 10 14 7.9 5.4 4.0 59 13 26 57 11 6.8 6.0 5.7 9.1 13 8.6 5.6 4.3 80 14 25 63 11 6.7 6.1 5.1 8.4 14 8.9 5.8 5.1 40 15 21 38 11 6.6 5.7 5.2 8.0 13 8.2 5.5 3.9 86 16 22 22 11 6.7 5.6 5.6 12 13 8.6 5.9 3.6 34 17 20 18 37 6.5 5.8 5.5 74 16 8.4 5.5 4.0 16 18 33 38 26 6.5 5.7 5.7 188 20 8.5 4.9 4.2 e60 19 35 32 11 7.6 5.6 8.6 82 18 9.0 5.1 3.9 e83 20 31 20 9.0 6.5 5.6 7.0 40 19 7.9 5.2 4.2 40 21 33 17 8.3 8.6 5.6 6.1 29 57 7.2 6.2 11 20 22 32 20 10 7.8 5.4 5.9 57 46 7.3 5.1 3.8 14 23 23 14 19 6.8 5.3 6.3 53 23 6.6 5.2 3.2 10 24 27 14 9.4 9.3 5.4 6.8 60 18 6.2 4.9 3.2 8.8 25 24 14 8.2 12 5.3 6.9 61 17 6.4 5.3 9.7 8.2 26 20 20 7.8 8.1 5.1 11 46 15 6.4 8.8 6.5 7.6 27 17 15 7.6 6.8 5.7 14 31 14 6.5 12 4.3 6.9 28 16 13 7.4 6.6 5.8 11 24 12 6.5 7.6 40 6.1 29 16 13 7.4 6.4 28 20 11 6.8 6.1 27 16 30 17 14 8.5 6.3 12 18 10 8.3 5.8 e18 14 31 22 7.2 6.5 7.8 9.8 6.5 4.6 TOTAL 1,104 720 380.8 230.5 268.7 225.2 1,045.3 580.8 237.4 207.0 229.3 819.1 MEAN 35.6 24.0 12.3 7.44 9.60 7.26 34.8 18.7 7.91 6.68 7.40 27.3 MAX 178 63 37 12 44 28 188 57 10 17 40 86 MIN 16 13 7.2 6.3 5.1 4.8 8.0 9.8 6.2 4.9 3.2 3.2 AC-FT 2,190 1,430 755 457 533 447 2,070 1,150 471 411 455 1,620 CFSM 1.88 1.27 0.65 0.39 0.51 0.38 1.84 0.99 0.42 0.35 0.39 1.44 IN. 2.17 1.42 0.75 0.45 0.53 0.44 2.06 1.14 0.47 0.41 0.45 1.61 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1981 - 2003, BY WATER YEAR (WY) MEAN 58.3 45.1 17.9 10.2 7.55 6.29 12.7 26.3 14.0 11.4 20.0 45.7 MAX 167 110 41.9 27.5 11.6 13.2 34.8 80.4 41.0 25.9 50.5 124 (WY) (1986) (1988) (1988) (1992) (1996) (1989) (2003) (1985) (1987) (1986) (2000) (1998) MIN 12.7 15.2 4.78 4.06 3.10 2.85 2.76 2.33 2.35 2.45 5.14 3.62 (WY) (2002) (1998) (1998) (1998) (1990) (1981) (1995) (1994) (1997) (1994) (1997) (1997) 417 RIO GUAJATACA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1981 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 6,448.7 ANNUAL MEAN 17.7 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 178 LOWEST DAILY MEAN 2.6 ANNUAL SEVEN-DAY MINIMUM 2.6 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 12,790 ANNUAL RUNOFF (CFSM) 0.935 ANNUAL RUNOFF (INCHES) 12.69 10 PERCENT EXCEEDS 36 50 PERCENT EXCEEDS 11 90 PERCENT EXCEEDS 3.8 6,048.1 16.6 22.7 34.7 1999 8.94 1994 Oct 10 188 Apr 18 1,500 Oct 7, 1985 Mar 7 3.2 Aug 23 0.77 Jul 30, 1994 Mar 21 4.1 Aug 14 1.1 Sep 4, 1994 1,810 Oct 10 18,700 May 6, 2001 11.22 Oct 10 21.89 May 6, 2001 0.70 Apr 19, 1995 12,000 16,480 0.877 1.20 11.90 16.35 37 50 9.0 10 5.3 3.6 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S 418 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR LOCATION.--Lat 18q00'40", long 66q46'49", at dirt road bridge, 0.7 mi (1.1 km) from mouth, 0.9 mi (1.4 km) east of Central Rufina and 0.9 mi (1.4 km) southeast of Guayanilla. DRAINAGE AREA.--22.8 mi2 (59.1 km2). PERIOD OF RECORD.--Water years 1960-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 14... 1315 40 32 8.1 103 7.7 310 27.6 130 36.5 9.55 1.59 .4 FEB 06... 1330 10 7.1 8.3 -- 8.3 433 27.6 180 48.6 13.3 2.19 .5 APR 10... 1055 4.3 3.6 8.1 -- 7.8 496 27.2 -- -- -- -- -­ JUL 16... 1145 1.7 3.5 6.1 -- 7.6 630 29.0 -- -- -- -- -­ SEP 03... 0900 3.8 3.4 5.0 -- 7.6 545 27.1 220 60.1 17.3 2.92 .8 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 14... 9.46 110 9.30 <.17 16.1 26.4 -- 175 19.0 28 .50 .05 -­ FEB 06... 16.0 146 16.7 .10 17.2 39.3 .0 241 6.62 <10 <.20 .03 2.18 APR 10... -- 156 -- -- -- -- <.1 -- -- -- .30 .06 2.29 JUL 16... -- 163 -- -- -- -- -- -- -- 10 1.8 .06 5.87 SEP 03... 27.4 184 29.4 <.2 20.2 51.2 -- 319 3.30 <10 .50 .33 .79 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 14... 1.60 <.01 .45 .12 2.1 9.3 <10 E1,000 680 -- -- -- -­ FEB 06... 2.20 .02 -- .25 -- -- <10 530 -- 6,100 <2 52.0 36 APR 10... 2.30 .01 .24 .47 2.6 11.5 -- E1,200 -- 80,000 -- -- -­ JUL 16... 5.90 .03 1.7 .54 7.7 34.1 10 400 -- 24,000 -- -- -­ SEP 03... .970 .18 .17 .08 1.5 6.5 10 510 -- E2,000 -- -- -­ 419 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 14... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 06... <.2 E.7 <10 <.01 290 <1 31.8 <.02 <3 <.3 <25 <.10 <16 APR 10... -- -- -- -- -- -- -- -- -- -- -- -- -- JUL 16... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 03... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 10... 1055 <.01 .04 <.01 <.01 <.02 <.1 <.01 E.01 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 10... <.01 <.01 <.009 <.01 <.014 <.30 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 10... <.1 <.02 <.02 <1 <.02 < -- Less than E -- Estimated value --- --- --- --- --- --- --- --- --- 420 RIO YAUCO BASIN 50125780 LAGO LUCCHETTI AT DAMSITE NEAR YAUCO, PR LOCATION.--Lat 18q05'37", long 66q51'54", Hydrologic Unit 21010004, at Antonio Lucchetti Dam on Río Yauco, 3.9 mi (6.3 km) north of Yauco. DRAINAGE AREA.--17.4 mi2 (45.1 km2). PERIOD OF RECORD.--December 1989 to current year. Prior to October 1994, published as Lago Lucchetti at Damsite. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Lucchetti was completed in 1952. The dam is on Río Yauco and is a unit of the Southwestern Puerto Rico Project. I t provides 16,500 acre- feet (20.3 hm3) of usable storage for power generation and irrigation. The dam is a concrete gravity structure with a total length of 591 ft (180 m), a maximum height of 178 ft (54 m), and a maximum width at the base of 150 ft (46 m). An ungated, overflow tupe spillway with a clear length of 171 ft (52 m), and a maximum capacity of 62,800 ft3/s (1,778 m3/s) at a design head of 20 ft (6 m). The dam is owned by Puerto Rico Electric Power Authority. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 577.56 ft (176.04 m), September 22, 1998; minimum elevation, 512.09 ft (156.08 m), September 9, 1994. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 561.67 ft (171.20 m), December 26, minimum elevation, 526.91 ft (160.60 m), August 18. Capacity Table (based on data from Puerto Rico Water Resources Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 512 1,505 520 2,385 525 2,965 527 3,255 530 3,695 532 3,975 Elevation Contents 540 5,165 550 7,020 561 9,600 563 10,125 571 12,125 573 12,645 578 14,061 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 548.05 551.48 556.87 560.31 554.37 555.77 546.50 558.02 551.13 538.89 531.80 529.65 2 546.88 552.03 556.67 560.27 554.88 555.50 546.92 558.07 551.43 538.63 530.56 529.53 3 546.86 553.31 557.50 560.16 555.39 555.26 547.23 558.30 551.58 538.33 529.71 531.06 4 546.52 554.00 A 560.11 555.67 555.02 547.16 558.00 550.89 538.01 531.30 530.63 5 545.27 554.83 557.45 560.00 556.09 554.90 547.32 558.08 550.20 537.77 531.15 531.70 6 544.89 555.64 557.77 559.89 556.39 554.83 547.55 558.00 550.01 537.47 530.79 533.47 7 544.24 556.70 557.79 560.03 555.54 554.90 547.87 557.90 549.89 537.19 530.57 536.43 8 544.36 558.07 557.94 559.81 555.34 555.20 548.70 558.39 550.20 536.94 530.58 536.93 9 543.94 558.29 558.47 559.77 555.19 555.52 549.10 557.82 549.58 535.88 530.24 536.79 10 547.45 558.43 559.12 559.64 555.19 554.96 550.50 557.26 547.54 536.19 529.88 537.45 11 547.54 558.70 559.82 559.55 554.95 554.50 550.43 557.23 546.73 536.43 528.34 538.79 12 548.81 559.17 560.26 559.41 555.61 554.32 551.21 555.58 544.71 536.83 527.92 541.73 13 549.31 559.25 560.24 559.27 555.46 553.90 550.70 554.62 543.38 536.51 527.79 544.26 14 549.86 559.41 560.02 559.10 555.50 553.68 550.58 552.86 543.17 535.86 528.03 544.78 15 549.03 559.57 560.65 559.02 555.79 553.01 550.92 551.30 543.17 537.40 527.86 545.27 16 547.48 559.02 560.24 558.82 555.60 552.37 551.02 550.41 542.94 537.40 527.46 545.47 17 546.02 559.77 560.43 558.61 555.48 551.60 551.23 548.67 542.69 537.72 527.06 545.57 18 545.42 560.01 559.80 558.40 555.38 551.39 552.47 548.54 542.53 536.54 529.57 547.59 19 545.94 560.11 560.41 558.20 555.24 550.56 552.62 548.36 542.60 536.15 531.07 548.46 20 546.67 560.34 560.59 557.97 555.12 549.28 552.93 548.31 542.38 535.78 530.78 548.14 21 548.93 560.35 560.59 556.84 555.08 548.94 553.21 549.19 542.11 536.01 530.83 548.37 22 549.40 559.37 560.98 556.66 555.84 548.58 554.54 550.42 541.86 535.63 530.71 548.62 23 549.65 559.19 561.11 555.21 556.56 548.22 555.45 550.50 541.62 535.41 530.50 548.29 24 550.05 559.12 561.38 555.19 556.89 547.87 556.42 550.26 541.34 535.01 531.07 547.39 25 549.57 559.02 561.67 555.04 556.69 547.29 557.48 550.52 541.23 534.72 531.06 546.21 26 549.20 558.31 561.60 554.84 555.95 546.82 557.73 550.89 540.95 534.87 530.54 545.18 27 549.34 558.20 561.35 554.62 556.01 546.69 557.66 551.41 540.63 534.56 530.21 544.32 28 549.31 557.62 560.75 554.44 555.48 546.62 557.78 551.09 540.32 534.23 529.91 542.94 29 551.03 557.38 560.21 554.46 545.84 557.78 550.46 540.45 534.07 529.75 543.17 30 551.16 557.13 560.15 554.24 546.18 557.62 550.45 540.57 534.06 529.58 542.59 31 550.77 560.45 554.11 546.47 551.11 533.82 529.26 MAX 551.16 560.35 560.31 556.89 555.77 557.78 558.39 551.58 538.89 531.80 548.62 MIN 543.94 551.48 554.11 554.37 545.84 546.50 548.31 540.32 533.82 527.06 529.53 A No gage-height record 421 RIO YAUCO BASIN 50125780 LAGO LUCCHETTI AT DAMSITE NEAR YAUCO, PR—Continued O N D J F M A M J J A S 525 530 535 540 545 550 555 560 565 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 422 RIO YAUCO BASIN 50126150 RIO YAUCO ABOVE DIVERSION MONSERRATE NEAR YAUCO, PR LOCATION.--Lat 18q02'58", long 66q50'30", Hydrologic Unit 21010004, on right bank off Highway 375, about 300 ft (91 m) upstream from diversion Monserrate, 0.1 mi (0.2 km) downstream from Quebrada de la Quebradas, 0.9 mi (1.4 km) downstream from Río Duey, and 1.0 mi (1.6 km) northeast of Yauco Plaza. DRAINAGE AREA.--27.2 mi2 (70.4 km2). PERIOD OF RECORD.--November 1976 to January 1985, October 2002 to September 2003. GAGE.--Water-stage recorder. Elevation of gage is 115 ft (35 m), from topographic map. REMARKS.--Records poor. Flow affected by numerous diversions into and out of the basin. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.3 10 2.8 1.6 0.94 0.64 1.1 2.6 0.95 0.00 0.09 7.2 2 3.2 9.7 2.6 1.7 19 0.86 2.9 2.3 1.0 0.82 0.01 11 3 3.5 53 2.8 2.3 18 0.95 3.5 2.0 1.2 0.75 0.00 14 4 3.8 34 e2.4 1.5 4.4 0.57 7.8 1.6 0.97 0.58 0.00 13 5 5.4 12 e3.1 1.2 2.6 0.82 2.0 1.5 0.72 0.62 0.00 2.1 6 16 9.1 e2.4 1.6 1.9 0.86 1.4 1.9 0.80 1.4 0.00 0.90 7 11 7.8 1.7 1.5 1.6 0.67 1.3 1.7 0.89 0.88 0.00 25 8 13 6.9 2.0 1.2 1.3 0.44 2.0 7.8 0.77 0.72 0.00 20 9 13 6.9 2.8 1.1 1.1 0.40 e2.3 11 0.77 0.72 0.00 3.0 10 87 7.2 2.1 1.3 0.97 0.60 e7.3 2.8 0.73 0.69 0.00 1.2 11 24 5.8 e1.4 2.8 0.79 0.43 e5.6 1.8 0.71 0.52 0.00 29 12 8.8 6.4 e1.3 1.5 0.95 0.39 e3.9 1.8 0.73 0.41 0.00 77 13 6.6 21 1.6 1.2 0.79 0.34 e2.1 1.6 0.70 0.34 0.00 75 14 4.9 18 1.9 1.1 0.72 0.29 e1.3 1.5 0.64 0.31 0.00 32 15 4.5 8.1 1.4 0.91 0.89 0.28 1.1 1.7 0.61 0.31 0.12 69 16 5.8 6.8 1.5 0.83 0.68 0.26 0.77 1.4 0.61 0.41 0.19 22 17 6.9 5.8 9.0 0.91 0.59 0.25 61 1.8 0.69 0.39 0.10 8.4 18 21 9.8 14 0.81 0.54 0.23 123 2.1 0.65 0.30 0.08 129 19 21 8.1 3.9 0.97 0.49 0.32 42 1.6 0.48 0.23 0.10 68 20 33 6.3 2.7 0.80 0.48 0.35 12 1.4 0.29 0.13 3.1 39 21 26 5.2 2.1 0.82 0.86 0.52 6.3 50 0.05 0.04 5.2 16 22 14 5.6 2.1 0.97 0.82 0.51 51 28 0.06 0.00 1.6 10 23 8.4 4.6 13 0.79 0.79 0.43 32 6.6 0.02 0.00 0.82 6.0 24 13 4.2 2.9 1.3 0.74 0.38 35 3.4 0.00 0.00 0.54 4.2 25 12 3.7 2.4 4.8 0.50 0.40 29 2.5 0.00 0.00 2.6 3.5 26 7.1 3.7 2.0 2.5 0.48 1.1 11 1.9 0.00 0.00 5.3 2.8 27 5.6 4.3 2.0 1.3 0.66 5.0 6.2 1.6 0.00 0.00 2.0 2.8 28 4.7 3.2 1.7 1.1 0.50 5.6 4.4 1.5 0.00 0.55 7.0 2.0 29 10 2.9 1.4 0.89 2.6 3.4 1.3 0.00 0.45 12 6.7 30 11 3.6 1.8 0.87 2.8 3.0 1.1 0.00 0.27 11 12 31 11 1.6 0.80 1.6 1.1 0.19 1.5 TOTAL 418.5 293.7 96.4 42.97 64.08 30.89 465.67 150.9 15.04 12.03 53.35 711.80 MEAN 13.5 9.79 3.11 1.39 2.29 1.00 15.5 4.87 0.50 0.39 1.72 23.7 MAX 87 53 14 4.8 19 5.6 123 50 1.2 1.4 12 129 MIN 3.2 2.9 1.3 0.79 0.48 0.23 0.77 1.1 0.00 0.00 0.00 0.90 AC-FT 830 583 191 85 127 61 924 299 30 24 106 1,410 CFSM 0.50 0.36 0.11 0.05 0.08 0.04 0.57 0.18 0.02 0.01 0.06 0.87 IN. 0.57 0.40 0.13 0.06 0.09 0.04 0.64 0.21 0.02 0.02 0.07 0.97 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1977 - 2003, BY WATER YEAR (WY) MEAN 32.5 38.7 12.1 7.47 6.54 4.72 11.7 23.6 15.3 12.5 23.2 45.0 MAX 62.9 94.3 19.7 13.9 11.4 8.64 46.0 66.1 95.1 54.1 131 133 (WY) (1979) (1985) (1979) (1979) (1984) (1979) (1983) (1980) (1979) (1979) (1979) (1979) MIN 13.5 5.64 3.11 1.39 1.59 1.00 3.06 4.10 0.50 0.39 1.72 5.97 (WY) (2003) (1981) (2003) (2003) (1983) (2003) (1977) (1977) (2003) (2003) (2003) (1978) 423 RIO CAMUY BASIN 50126150 RIO YAUCO ABOVE DIVERSION MONSERRATE NEAR YAUCO, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2003 WATER YEAR WATER YEARS 1977 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 2,355.33 ANNUAL MEAN 6.45 19.9 HIGHEST ANNUAL MEAN 50.9 1979 LOWEST ANNUAL MEAN 6.45 2003 HIGHEST DAILY MEAN 129 Sep 18 2,690 Aug 31, 1979 LOWEST DAILY MEAN 0.00 Jun 24 0.00 Sep 30, 1977 ANNUAL SEVEN-DAY MINIMUM 0.00 Jun 24 0.00 Jun 24, 2003 MAXIMUM PEAK FLOW 1,540 Sep 18 10,500 Aug 31, 1979 MAXIMUM PEAK STAGE 7.71 Sep 18 9.83 Aug 31, 1979 ANNUAL RUNOFF (AC-FT) 4,670 14,410 ANNUAL RUNOFF (CFSM) 0.237 0.731 ANNUAL RUNOFF (INCHES) 3.22 9.94 10 PERCENT EXCEEDS 14 37 50 PERCENT EXCEEDS 1.6 6.9 90 PERCENT EXCEEDS 0.13 1.8 e Estimated 1,000 500 200 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- 424 RIO LOCO BASIN 50128900 LAGO LOCO AT DAMSITE NEAR YAUCO, PR LOCATION.--Lat 18q02'41", long 66q53'16", Hydrologic Unit 21010004, at Damsite, 2.60 mi (4.18 km) northwest from Yauco Plaza, 0.45 mi (0.72 km) northeast from Escuela Río Cañas and 0.95 mi (1.53 km) northwest from Escuela Susúa Alta. DRAINAGE AREA.--8.35 mi2 (21.6 km2). PERIOD OF RECORD.--May 1995 to current year. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Loco was completed in 1951. The dam is a concrete gravity structure with a total length of 600 ft (183 m), maximu m structural height of 72 ft (21.9 m), the ungated overflow spillway is 150 ft (47.7 m) long with crest at elevation of 230 ft (70.1 m). It has a normal storage capacity of 1,950 acre-feet (2.40 hm3) as for May 4, 1979. The Loco Dam is owned by the Puerto Rico Electric Power Authority (PREPA) and its part of the Southwestern Puerto Rico Project which was developed for electric power generation and irrigation of the lands in the Lajas Valley, some of t he project waters are used for water supply in the Lajas area. The maximum drawdown of the dam is from 230 ft (70.1 m) to 220 ft (67.1 m) and the Capacity Table provided by PREPA includes only that portion of the storage for the dam. Gage-height and precipitation satellite telemetry at station. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 235.71 ft (71.84 m), May 6, 2001; minimum elevation, 217.77 ft (66.4 m), June 10, 1997. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 231.41 ft (70.53 m), October 29; minimum elevation, 222.02 ft (67.67 m), March 3. Capacity Table (based on data from Puerto Rico Electric Power Authority) (Elevation in ft, capacity in acre-ft) Elevation Contents 220 0 225 299 Elevation Contents 230 639 232 787 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 230.33 230.60 229.97 229.44 230.05 224.03 225.35 230.51 230.45 227.74 229.93 230.18 2 230.28 230.24 229.58 230.15 229.80 222.77 225.01 230.55 230.40 226.47 230.17 230.13 3 229.84 230.43 229.17 230.69 228.91 225.01 225.04 230.27 229.72 225.40 229.83 230.37 4 230.04 230.31 228.34 230.78 227.55 226.15 225.83 230.09 230.50 225.30 228.47 230.03 5 230.69 229.80 227.95 230.30 225.94 226.61 226.50 230.31 230.26 225.69 228.57 230.02 6 230.32 230.29 227.70 230.14 224.46 226.80 226.71 230.29 230.51 225.61 226.59 230.28 7 230.32 230.33 228.62 230.33 229.21 226.49 227.23 230.29 230.02 224.84 223.61 230.28 8 230.60 230.21 228.40 230.32 230.16 225.53 228.88 230.13 230.77 224.95 226.88 230.06 9 230.38 230.36 227.99 230.00 230.31 223.78 228.84 230.29 230.59 227.49 227.04 230.01 10 230.45 230.36 227.34 230.32 230.19 226.80 229.06 230.32 230.22 226.35 226.65 230.02 11 230.37 230.33 227.09 230.30 229.15 227.56 229.26 230.29 230.36 225.42 228.50 229.97 12 230.10 230.28 226.35 230.32 227.98 225.26 229.20 230.63 230.69 224.93 226.79 230.54 13 230.10 230.33 226.21 230.32 228.92 227.45 230.15 230.65 230.17 224.40 224.83 230.13 14 230.43 230.32 227.71 229.83 230.04 225.45 230.30 230.30 229.99 226.47 225.00 230.09 15 230.05 230.84 227.13 229.73 230.24 226.17 230.41 230.27 229.68 224.90 226.46 230.35 16 230.39 230.52 228.38 228.25 229.63 226.70 230.25 230.39 229.54 225.92 225.76 230.36 17 230.32 230.30 228.59 226.79 230.37 226.93 230.14 230.31 227.95 224.27 225.04 230.47 18 230.05 230.28 230.13 225.72 230.26 224.24 230.51 230.21 225.89 226.05 226.07 230.49 19 230.26 230.32 229.78 224.49 229.18 225.49 230.41 229.66 226.67 225.93 224.25 230.47 20 230.15 230.10 229.93 223.04 229.59 228.46 230.22 230.49 225.97 225.83 225.74 230.36 21 230.09 230.21 230.17 227.01 230.18 227.23 229.99 230.22 225.55 225.85 224.26 230.42 22 230.38 230.34 230.23 225.26 229.34 226.72 230.35 230.24 226.95 224.90 226.32 230.36 23 230.40 230.30 230.21 229.40 228.54 226.18 230.22 230.38 226.64 225.61 227.55 230.37 24 230.13 230.38 230.25 228.67 227.40 225.40 230.26 230.18 224.97 223.91 228.04 230.50 25 230.18 229.90 230.42 228.36 225.38 226.08 230.25 230.38 229.07 223.22 228.34 230.84 26 230.35 230.53 230.27 227.97 226.00 227.63 230.35 230.19 227.51 225.76 228.99 230.74 27 230.37 229.79 230.32 227.10 223.63 225.61 230.45 230.10 226.11 225.10 228.91 230.38 28 230.28 230.32 230.27 226.52 224.98 224.23 230.38 230.27 225.31 224.37 228.84 230.39 29 230.53 229.98 230.26 225.19 228.03 230.52 230.08 224.44 225.56 228.88 230.38 30 230.35 229.98 229.96 229.17 227.42 230.41 230.23 225.26 225.34 229.29 230.35 31 230.14 230.05 230.26 226.41 230.19 224.77 229.47 MAX 230.69 230.84 230.42 230.78 230.37 228.46 230.52 230.65 230.77 227.74 230.17 230.84 MIN 229.84 229.79 226.21 223.04 223.63 222.77 225.01 229.66 224.44 223.22 223.61 229.97 425 RIO DE BAYAMON BASIN 50128900 LAGO LOCO AT DAMSITE NEAR YAUCO, PR—Continued O N D J F M A M J J A S 222 224 226 228 230 232 ELEVATION, IN FEET 2002 2003 426 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128905 CANAL DE RIEGO DE LAJAS BELOW LAGO LOCO DAM, YAUCO, PR LOCATION.--Lat 18q02'35", long 66q53'18", Hydrologic Unit 21010004, on right side of irrigation conduit outlet upstream from Cipolletti Weir, located downstream from Lago Loco Dam 0.05 mi (0.08 km), 5.4 mi (8.67 km) south east from Sabana Grande Plaza and 0.35 mi (0.56 km) north east from Escuela Río Cañas. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--March 2000 to current year. GAGE.--Water-stage recorder. Altitude of gage is 197 ft (60 m), from topographic map. REMARKS.--Records fair. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 105 ft3/s (2.974 m3/s) March 27, 2000, gage height, 2.15 ft (0.655 m) from rating curve extended above 70 ft3/s (1.98 m3/s) on basis of step-backwater analysis; no flow many days during the year 2000. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 94 ft3/s (2.662 m3/s), March 20, gage-height 2 ft (0.610 m); minimum daily discharge, 6.3 ft3/s (0.178 m3/s), September 16. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 31 32 33 39 2 33 29 42 40 3 38 29 50 35 4 35 38 49 29 5 28 45 47 29 30 52 50 28 40 79 57 19 29 52 35 28 54 76 39 21 48 64 28 26 67 51 39 23 59 70 26 26 65 29 61 21 59 70 25 34 64 28 74 20 6 28 46 41 29 7 34 42 37 33 8 35 34 37 42 9 29 28 41 43 10 24 28 46 33 51 72 25 39 56 28 75 20 38 66 27 39 43 44 77 19 29 59 27 41 42 52 58 21 29 59 28 36 56 53 41 22 41 71 30 28 69 54 32 22 11 21 28 46 26 12 A 39 49 26 13 A 41 46 26 14 A 35 39 42 15 A 33 38 57 50 80 28 28 76 48 38 24 54 85 26 33 78 37 68 24 54 85 26 39 58 37 67 20 45 71 26 40 40 48 64 19 35 58 28 39 40 62 50 22 16 A 29 44 64 17 33 29 49 59 18 29 34 58 48 19 25 36 57 48 20 23 38 40 48 36 58 25 31 60 65 39 6.3 36 77 23 26 70 60 39 9.0 46 89 23 26 70 46 50 31 54 88 23 37 70 32 59 21 59 91 23 46 51 31 58 17 21 36 35 34 55 22 33 32 34 61 23 21 29 38 59 24 29 29 40 45 25 32 35 40 34 54 70 22 47 36 31 54 17 44 49 23 48 36 48 34 22 44 50 24 39 55 65 18 24 60 56 24 32 64 60 26 25 72 76 25 32 68 39 39 23 26 22 42 36 34 27 23 40 26 45 28 37 36 22 49 29 41 34 21 50 30 38 33 33 56 31 35 --- 39 41 77 88 25 32 71 39 28 19 73 80 26 46 61 39 27 17 62 56 26 65 45 39 29 18 --- 42 26 68 45 61 24 20 --- 41 25 60 65 74 19 22 --- 51 --- 40 --- 75 19 --­ TOTAL --- 1,038 1,252 1,325 MEAN --- 34.6 40.4 42.7 MAX 46 58 64 77 MIN 28 21 26 29 AC-FT --- 2,060 2,480 2,630 1,368 2,076 798 1,179 1,715 1,530 1,402 608.3 48.9 67.0 26.6 38.0 57.2 49.4 45.2 20.3 91 50 68 78 79 77 31 41 22 26 36 28 18 6.3 2,710 4,120 1,580 2,340 3,400 3,030 2,780 1,210 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 28.4 32.2 33.1 45.6 MAX 34.0 34.8 40.4 50.1 (WY) (2002) (2002) (2003) (2002) MIN 22.7 27.2 25.7 42.7 (WY) (2001) (2001) (2002) (2003) 55.5 59.7 33.2 28.7 42.2 47.2 43.2 28.5 63.6 67.0 38.1 38.0 57.2 53.2 45.2 36.1 (2002) (2003) (2002) (2003) (2003) (2002) (2003) (2001) 48.9 52.4 26.6 18.6 31.7 38.7 40.6 20.3 (2003) (2002) (2003) (2001) (2001) (2001) (2000) (2003) A No gage-height record 427 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128905 CANAL DE RIEGO DE LAJAS BELOW LAGO LOCO DAM, YAUCO, PR—Continued SUMMARY STATISTICS WATER YEARS 2000 - 2003 ANNUAL MEAN 41.0 HIGHEST ANNUAL MEAN 41.0 2002 LOWEST ANNUAL MEAN 41.0 2002 HIGHEST DAILY MEAN 98 Mar 28, 2000 LOWEST DAILY MEAN 4.9 Apr 2, 2000 ANNUAL SEVEN-DAY MINIMUM 15 May 13, 2001 MAXIMUM PEAK FLOW 105 Mar 27, 2000 MAXIMUM PEAK STAGE 2.15 Mar 27, 2000 ANNUAL RUNOFF (AC-FT) 29,720 10 PERCENT EXCEEDS 62 50 PERCENT EXCEEDS 39 90 PERCENT EXCEEDS 24 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD --- --- --- --- --- --- --- --- --- --- 428 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128920 CANAL DE RIEGO DE LAJAS ABOVE MAJINAS FILTRATION PLANT, PR LOCATION.--Lat 18q02'41", long 66q56'59", Hydrologic Unit 21010003, 0.1 mi (0.2 km) south of intersection of Highways 2 and 117, 2.1 mi, (3.4 km) northeast of Escuela Thomas A. Edison, 0.5 mi (0.8 km) southeast of Escuela Dr. Santiago Veve, and 2.6 mi (4.2 km) southeast of Plaza de Sabana Grande. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--February 2000 to current year. GAGE.--Water-stage recorder. Altitude of gage is about 164 ft (50 m) from topographic map. REMARKS.--Records fair. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge 199 ft3/s (5.64 m3/s) May 6, 2001, gage height 5.43 ft (1.66 m) from rating curve extended above 60 ft3/s (1.70 m3/s) on basis of step-backwater analysis; minimum daily discharge 1.6 ft3/s (0.045 m3/s) October 23, 2002. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge 186 ft3/s (5.27 m3/s) March 26, gage height 5.29 ft (1.61 m); minimum daily discharge 1.6 ft3/s (.045 m3/s) October 23, 2002. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13 27 19 38 44 57 47 27 39 63 51 24 2 25 21 30 39 45 57 37 29 45 61 41 25 3 33 21 44 37 50 59 31 29 52 48 41 27 4 37 38 41 32 54 60 28 27 48 30 50 26 5 22 58 40 33 55 59 26 29 50 29 56 26 6 21 56 38 33 52 62 25 A 48 29 58 25 7 28 43 34 33 47 62 28 A 41 37 59 24 8 30 25 35 34 45 59 29 A 42 44 51 25 9 18 13 36 38 45 59 28 34 46 45 43 27 10 12 13 40 37 47 63 28 29 54 46 37 28 11 5.8 13 44 31 50 65 27 29 58 44 32 28 12 6.6 25 43 31 54 67 27 31 60 36 52 31 13 8.1 31 45 31 55 67 27 34 51 36 57 27 14 14 18 39 40 52 65 27 34 39 40 55 26 15 28 20 39 53 48 59 29 34 39 46 48 25 16 35 17 43 61 49 58 28 32 47 48 42 14 17 29 16 48 60 49 62 29 28 54 48 42 5.5 18 25 20 54 55 52 65 30 28 54 43 46 36 19 12 18 55 56 56 66 26 31 55 34 51 26 20 8.6 25 44 56 56 70 25 36 48 32 51 21 21 34 28 36 56 55 62 24 37 37 33 48 21 22 36 23 36 56 53 49 25 39 36 41 35 24 23 1.6 14 38 56 53 48 26 37 45 53 23 26 24 12 15 36 53 57 49 27 33 51 54 27 26 25 30 23 36 48 61 64 27 33 57 40 40 26 26 7.8 36 36 47 62 64 26 33 61 40 33 23 27 7.7 33 29 53 61 68 27 37 56 40 31 21 28 28 21 23 55 59 52 27 48 44 40 34 22 29 36 21 23 52 42 27 51 43 50 29 23 30 32 20 31 54 42 26 51 53 59 24 26 31 30 37 49 46 40 59 23 TOTAL 666.2 752 1,172 1,407 1,466 1,827 844 1,453 1,348 1,310 734.5 MEAN 21.5 25.1 37.8 45.4 52.4 58.9 28.1 48.4 43.5 42.3 24.5 MAX 37 58 55 61 62 70 47 61 63 59 36 MIN 1.6 13 19 31 44 42 24 36 29 23 5.5 AC-FT 1,320 1,490 2,320 2,790 2,910 3,620 1,670 2,880 2,670 2,600 1,460 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 24.6 29.5 33.9 45.3 51.4 49.2 32.6 24.7 39.8 46.7 40.4 25.6 MAX 31.4 36.6 37.8 46.5 58.6 58.9 36.7 26.8 48.4 49.3 42.3 29.2 (WY) (2002) (2002) (2003) (2001) (2002) (2003) (2002) (2002) (2003) (2000) (2003) (2001) MIN 20.9 25.1 29.8 44.0 43.4 43.3 28.1 22.6 34.6 43.5 38.5 23.0 (WY) (2001) (2003) (2002) (2002) (2001) (2001) (2003) (2001) (2001) (2003) (2000) (2000) SUMMARY STATISTICS WATER YEARS 2000 - 2003 HIGHEST DAILY MEAN 77 Jul 25, 2000 LOWEST DAILY MEAN 1.6 Oct 23, 2002 ANNUAL SEVEN-DAY MINIMUM 13 Oct 9, 2002 MAXIMUM PEAK FLOW 199 May 6, 2001 MAXIMUM PEAK STAGE 5.43 May 6, 2001 A No gage-height record 429 RIO GUAJATACA BASIN 50128920 CANAL DE RIEGO DE LAJAS ABOVE MAJINAS FILTRATION PLANT, PR—Continued O N D J F M A M J J A S 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 430 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128925 CANAL DE RIEGO DE LAJAS BELOW MAJINAS FILTRATION PLANT, PR LOCATION.--Lat 18q02'41", long 66q57'01", Hydrologic Unit 21010004, on upstream side from iron platform used as cross way and reference point, downstream of Majinas Filtration Plant intake, 0.08 mi (0.12 km) east of new Highway 2, 0.10 mi (0.16 km) south of Highway 121, and 2.6 mi (4.2 km) southeast of Plaza de Sabana Grande. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--February 2000 to current year. GAGE.--Water-stage recorder. Altitude of gage is 164 ft (50 m), from topographic map. REMARKS.--Records fair, except those above 50 ft3/s (1.46 m3/s), which are poor. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 197 ft3/s (5.58 m3/s) May 6, 2001, gage height, 5.39 ft (1.64 m) from rating curve extended above 50 ft3/s (1.416 m3/s) on basis of logarithmic extension using gage height and flow comparison with upstream station 50128920 Canal de Riego de Lajas above Majinas Filtration Plant, Sabana Grande, PR; minimum daily discharge .01 ft3/s (0.00 m3/s) September 17, 2003. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 165 ft3/s (4.67 m3/s) March 12, gage height, 4.97 ft (1.51 m); minimum daily discharge .01 ft3/s (0.00 m3/s) September 17. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13.2 23.5 19.9 34.3 37.6 48.3 44.6 20.9 34.8 57.9 46.1 22.2 2 24.1 18.9 28.6 34.9 37.6 48.5 35.3 24.6 38.9 55.0 35.1 23.5 3 30.5 18.3 37.9 34.8 44.2 51.5 28.8 22.5 49.3 45.2 35.1 24.5 4 33.9 33.7 35.3 30.8 50.8 54.4 27.6 22.3 42.5 23.9 41.6 23.6 5 23.2 50.1 35.7 31.2 54.2 52.5 25.3 22.9 46.4 24.1 49.6 22.0 6 21.8 48.7 35.3 31.4 50.0 55.4 25.1 26.6 46.1 23.9 50.5 20.9 7 27.0 40.9 33.1 31.7 42.6 60.1 26.3 27.8 35.8 29.9 52.7 19.8 8 28.1 25.7 32.9 30.4 36.6 52.9 27.0 31.1 36.2 37.1 47.0 20.6 9 17.7 15.2 33.3 33.6 36.2 52.5 25.8 31.1 39.6 36.7 36.5 23.1 10 12.1 14.9 34.8 34.5 39.1 57.8 26.2 25.9 49.0 35.4 34.7 23.5 11 7.07 14.5 38.5 30.3 43.8 62.4 25.8 26.8 52.7 35.9 21.3 24.5 12 8.01 25.4 37.1 30.5 48.5 70.8 24.5 27.2 55.3 28.4 44.8 27.4 13 9.01 28.4 39.4 30.7 50.1 71.7 24.3 30.0 49.3 28.1 50.6 22.9 14 15.4 18.6 36.2 33.6 47.2 64.8 24.5 29.2 33.7 30.9 50.6 21.1 15 25.0 22.3 36.1 43.6 38.8 53.1 25.8 30.4 34.0 36.1 45.0 20.7 16 29.2 20.3 37.2 57.4 39.0 50.1 25.7 29.3 39.9 38.4 36.5 12.1 17 26.5 19.5 39.8 61.2 38.5 53.4 24.9 24.4 49.5 38.5 36.6 0.011 18 22.0 23.7 44.0 52.4 41.9 63.6 24.6 24.5 48.5 36.3 39.7 30.2 19 10.5 20.1 45.6 52.5 48.9 64.9 21.7 26.9 49.9 26.4 46.7 20.5 20 8.28 26.3 39.2 52.3 49.3 70.0 22.6 31.6 44.9 25.0 47.8 17.9 21 26.2 28.9 33.4 50.9 49.6 63.4 21.6 32.4 31.1 25.5 47.2 17.2 22 27.6 25.1 33.5 51.3 43.9 46.8 21.1 34.4 31.1 30.7 37.4 19.2 23 2.92 16.9 33.9 51.0 43.9 45.9 20.8 32.8 38.1 42.0 22.9 22.5 24 11.7 17.8 32.6 49.8 48.8 47.3 21.9 29.0 44.8 47.5 23.6 22.3 25 26.5 26.1 32.7 41.0 58.7 60.4 22.3 29.1 49.1 32.7 37.8 22.5 26 10.0 36.8 33.1 42.4 60.5 67.6 22.5 28.9 55.2 33.0 33.2 20.3 27 10.0 31.4 28.8 47.6 56.4 63.6 22.5 30.9 52.8 32.8 29.2 17.2 28 24.8 20.9 23.1 51.3 54.6 52.2 22.9 43.1 36.7 33.3 33.8 17.1 29 28.5 20.5 23.0 49.0 38.3 24.1 46.3 36.5 39.0 29.8 19.2 30 25.3 20.2 26.9 55.1 37.9 21.5 49.3 44.3 49.7 21.3 21.2 31 25.1 34.0 47.6 42.6 34.9 49.7 21.0 TOTAL 611.19 753.6 1,054.9 1,309.1 1,291.3 1,724.7 757.6 927.1 1,296.0 1,109.0 1,185.7 619.711 MEAN 19.7 25.1 34.0 42.2 46.1 55.6 25.3 29.9 43.2 35.8 38.2 20.7 MAX 33.9 50.1 45.6 61.2 60.5 71.7 44.6 49.3 55.3 57.9 52.7 30.2 MIN 2.92 14.5 19.9 30.3 36.2 37.9 20.8 20.9 31.1 23.9 21.0 0.011 AC-FT 1,210 1,490 2,090 2,600 2,560 3,420 1,500 1,840 2,570 2,200 2,350 1,230 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2000 - 2003, BY WATER YEAR (WY) MEAN 21.8 23.5 29.2 41.6 44.1 45.5 29.3 24.8 31.5 38.7 34.5 25.0 MAX 30.1 33.1 34.0 42.2 46.1 55.6 33.7 29.9 43.2 41.2 38.2 31.1 (WY) (2002) (2002) (2003) (2003) (2003) (2003) (2000) (2003) (2003) (2001) (2003) (2002) MIN 15.6 12.4 25.4 41.0 42.2 39.8 25.3 18.2 24.2 35.8 27.9 19.1 (WY) (2001) (2001) (2002) (2001) (2001) (2000) (2003) (2001) (2000) (2003) (2001) (2000) 431 RIO GUAJATACA BASIN 50128925 CANAL DE RIEGO DE LAJAS BELOW MAJINAS FILTRATION PLANT, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2003 WATER YEAR WATER YEARS 2000 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 12,639.900 ANNUAL MEAN 34.6 32.1 HIGHEST ANNUAL MEAN 34.6 2003 LOWEST ANNUAL MEAN 29.6 2001 HIGHEST DAILY MEAN 71.7 Mar 13 86.5 Aug 2, 2002 LOWEST DAILY MEAN 0.010 Sep 17 0.010 Sep 17, 2003 ANNUAL SEVEN-DAY MINIMUM 13 Oct 9 10 Nov 7, 2000 MAXIMUM PEAK FLOW 165 Mar 12 197 May 6, 2001 MAXIMUM PEAK STAGE 4.97 Mar 12 5.39 May 6, 2001 ANNUAL RUNOFF (AC-FT) 25,070 23,260 10 PERCENT EXCEEDS 52 49 50 PERCENT EXCEEDS 33 32 90 PERCENT EXCEEDS 20 15 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- 432 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128935 CANAL DE RIEGO DE LAJAS ABOVE LAJAS FILTRATION PLANT AT LAJAS, PR LOCATION.--Lat 18q02'45", long 66q03'16", Hydrologic Unit 21010003, on upstream side of Lajas Filtration Plant intake 2.8 mi (4.4 km) south of San Germán Plaza, 2.6 mi (4.2 km) east of Cerro Quemado and 1.5 mi (2.4 km) northeast of Universidad de Puerto Rico, Estación Experimental Agrícola and 0.6 mi (0.96 km) northwest from Lajas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--January 2001 to current year. GAGE.--Water-stage recorder. Altitude of gage is 131.2 ft (40 m), from topographic map. REMARKS.--Records fair. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 64 ft3/s (1.812 m3/s) August 1, 2003, gage height, 3.34 ft (1.018 m) from rating curve extended above 23 ft3/s (0.651 m3/s) on basis of step-backwater analysis, but could be higher during period of no gage-height record; no flow many days each year. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge 64 ft3/s (1.812 m3/s) August 1, gage height 3.34 ft (1.018 m); no flow many days. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.6 15 17 24 14 23 26 11 A 34 45 A 2 13 12 18 23 15 23 20 14 24 31 28 A 3 14 13 20 23 19 23 16 13 31 27 28 A 4 19 14 15 17 21 25 15 13 20 8.8 36 A 5 17 20 17 17 22 24 13 A 23 7.9 48 A 6 15 20 19 18 21 28 14 A 25 8.3 50 A 7 13 18 20 18 16 32 13 A 19 12 54 A 8 14 18 21 17 13 31 12 A 21 19 47 A 9 12 12 19 20 14 34 12 A 21 20 34 A 10 11 13 17 23 13 34 14 A 25 22 33 A 11 8.3 13 24 17 16 30 15 A 27 24 33 A 12 9.7 14 24 17 22 36 14 A 31 18 41 A 13 12 18 25 18 25 38 15 A 29 19 51 A 14 13 13 19 16 24 41 13 A 17 18 52 A 15 13 15 21 21 23 38 13 A 18 24 50 A 16 16 15 21 27 24 41 15 A 20 33 40 A 17 16 17 24 30 24 39 19 A 29 32 42 A 18 16 18 27 29 20 38 21 A 25 33 40 A 19 9.0 16 31 30 22 32 16 A 26 20 46 A 20 7.9 16 28 32 22 31 16 A 24 21 A A 21 11 16 24 27 22 31 14 A 16 22 A A 22 18 16 25 22 21 24 11 A 16 22 A A 23 0.00 10 24 24 25 27 9.9 A 21 35 A A 24 0.00 11 20 25 24 28 11 A 22 43 A A 25 0.11 13 19 19 30 31 11 A 21 24 A A 26 8.2 16 19 20 28 31 13 A 29 24 A A 27 9.7 18 18 21 24 29 12 A 32 24 A A 28 11 16 14 20 27 25 11 A 22 25 A A 29 14 16 14 19 20 12 A 23 31 A A 30 13 16 15 27 20 12 A 25 44 A A 31 15 22 21 22 A 43 A TOTAL 358.51 458 641 682 591 929 428.9 769.0 MEAN 11.6 15.3 20.7 22.0 21.1 30.0 14.3 24.8 MAX 19 20 31 32 30 41 26 44 MIN 0.00 10 14 16 13 20 9.9 7.9 AC-FT 711 908 1,270 1,350 1,170 1,840 851 1,530 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 15.3 18.8 20.7 22.0 21.3 30.0 14.3 24.3 7.09 MAX 19.0 22.4 20.7 22.0 21.5 30.0 14.3 24.8 7.09 (WY) (2002) (2002) (2003) (2003) (2002) (2003) (2003) (2003) (2002) MIN 11.6 15.3 20.7 22.0 21.1 30.0 14.3 23.7 7.09 (WY) (2003) (2003) (2003) (2003) (2003) (2003) (2003) (2002) (2002) SUMMARY STATISTICS WATER YEARS 2001 - 2003 HIGHEST DAILY MEAN 54 Aug 7, 2003 LOWEST DAILY MEAN 0.00 Oct 23, 2002 ANNUAL SEVEN-DAY MINIMUM 3.4 Aug 15, 2002 MAXIMUM PEAK FLOW 64 Aug 1, 2003 MAXIMUM PEAK STAGE 3.34 Aug 1, 2003 A No gage-height record 433 RIO GUAJATACA BASIN 50128935 CANAL DE RIEGO DE LAJAS ABOVE LAJAS FILTRATION PLANT AT LAJAS, PR—Continued 100 50 20 10 5 2 1 0.5 0.2 0.1 O N D J F M A M J J A S DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD 2002 2003 --- --- --- --- --- --- --- 434 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128940 CANAL DE RIEGO DE LAJAS BELOW LAJAS FILTRATION PLANT AT LAJAS, PR LOCATION.--Lat 18q02'44", long 66q03'17", Hydrologic Unit 21010003, on downstream side of Lajas Filtration Plant intake 2.8 mi (4.4 km) south of San Germán town plaza, 2.6 mi (4.2 km) east of Cerro Quemado and 1.5 mi (2.4 km) northeast of Universidad de Puerto Rico, Estación E xperimental Agrícola and 0.6 mi (0.96 km) northwest from Lajas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--January 30 to current year. GAGE.--Water-stage recorder. Altitude of gage is 131.2 ft (40 m), from topographic map. REMARKS.--Records fair. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 190 ft3/s (5.381 m3/s) May 6, 2001, gage height, 3.64 ft (1.109 m) from rating curve extended above 23 ft3/s (0.651 m3/s) on basis of step-backwater analysis; no flow many days each year. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 67.7 ft3/s (1.917 m3/s) September 2, gage height, 2.57 ft (0.783 m); no flow many days. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10.3 11.4 13.3 17.8 10.4 17.9 22.2 8.84 19.2 28.8 28.6 10.0 2 11.7 8.57 15.3 17.5 11.1 18.8 16.4 12.0 19.3 26.0 16.6 12.5 3 11.8 8.86 19.1 16.9 15.2 18.7 12.4 10.6 25.4 22.6 15.9 8.65 4 14.0 10.1 7.87 11.0 16.9 20.7 12.2 10.7 18.0 5.26 21.2 9.37 5 12.8 16.5 11.1 11.8 17.5 19.9 10.2 9.81 20.2 4.62 30.8 8.77 6 12.2 15.7 13.4 12.7 16.9 22.4 10.3 12.6 21.8 4.96 31.5 10.5 7 10.9 14.4 13.6 13.0 12.3 25.7 10.0 10.9 17.1 8.25 34.3 10.5 8 11.4 14.2 14.7 11.6 8.52 25.3 9.23 13.8 18.1 15.3 29.5 9.08 9 10.3 8.75 13.3 14.2 9.36 28.3 8.92 13.8 18.4 15.8 19.5 10.7 10 10.1 8.87 11.0 17.3 9.24 26.8 10.9 12.4 22.3 17.8 18.6 12.5 11 8.40 8.87 17.8 11.3 11.5 23.9 11.9 11.6 23.3 19.2 4.08 12.4 12 9.07 10.0 17.8 11.1 17.2 28.9 11.8 13.4 26.9 13.0 23.2 16.9 13 10.2 14.4 18.0 12.1 19.8 30.6 12.3 15.9 25.3 12.7 29.8 13.9 14 10.5 10.4 12.8 11.4 18.6 32.5 10.0 14.3 14.3 11.6 30.4 11.7 15 10.8 15.3 14.4 16.7 17.2 28.3 10.3 12.9 15.3 16.6 28.0 11.6 16 11.7 16.0 14.4 21.9 18.5 30.6 12.8 11.4 17.4 22.4 20.8 8.52 17 11.6 17.1 17.4 24.9 19.6 29.0 15.8 8.80 25.2 20.9 21.8 0.070 18 11.5 19.5 19.6 23.0 15.5 30.1 17.2 8.98 22.3 20.8 21.0 15.9 19 5.04 14.5 22.8 24.8 17.6 26.3 12.6 9.36 22.8 11.1 26.9 10.9 20 3.96 15.4 21.0 26.4 17.7 25.4 12.1 13.3 20.5 10.8 28.4 8.50 21 7.03 15.9 18.0 22.0 17.2 25.5 10.3 14.7 12.7 11.5 26.9 8.91 22 12.9 13.7 18.6 18.0 16.5 19.4 7.81 16.5 13.1 12.2 19.7 9.63 23 0.000 2.17 17.5 19.5 20.5 22.3 6.63 16.5 17.1 22.7 6.57 12.1 24 0.000 2.95 13.7 20.6 19.2 22.7 8.41 15.6 19.0 29.5 7.92 10.9 25 7.33 7.27 13.6 15.8 24.2 25.9 8.83 15.8 17.8 15.0 23.5 11.3 26 4.58 13.9 13.0 15.9 22.4 25.7 10.3 16.1 24.9 14.6 14.2 9.33 27 5.76 17.1 12.1 16.8 19.6 24.5 9.46 15.0 27.5 13.9 10.0 4.51 28 7.20 10.4 8.85 16.3 21.7 21.1 9.49 22.7 18.7 14.9 14.2 6.65 29 9.93 11.2 8.77 14.0 16.2 10.0 23.2 19.8 18.8 12.8 9.44 30 9.23 12.2 9.33 22.2 16.7 9.06 27.0 21.1 29.2 8.45 11.7 31 11.6 16.2 17.0 19.0 19.1 27.7 8.00 TOTAL 283.830 365.61 458.32 525.5 461.92 749.1 339.84 437.59 604.8 518.49 633.12 307.430 MEAN 9.16 12.2 14.8 17.0 16.5 24.2 11.3 14.1 20.2 16.7 20.4 10.2 MAX 14.0 19.5 22.8 26.4 24.2 32.5 22.2 27.0 27.5 29.5 34.3 16.9 MIN 0.000 2.17 7.87 11.0 8.52 16.2 6.63 8.80 12.7 4.62 4.08 0.070 AC-FT 563 725 909 1,040 916 1,490 674 868 1,200 1,030 1,260 610 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 12.3 15.0 13.9 16.4 17.4 19.3 12.8 10.6 14.2 17.4 15.5 12.1 MAX 15.5 17.9 14.8 17.0 20.2 24.2 14.8 14.1 20.2 22.3 20.4 14.0 (WY) (2002) (2002) (2003) (2003) (2002) (2003) (2002) (2003) (2003) (2002) (2003) (2001) MIN 9.16 12.2 12.9 15.9 15.4 15.9 11.3 8.26 8.28 13.1 11.5 10.2 (WY) (2003) (2003) (2002) (2002) (2001) (2001) (2003) (2002) (2001) (2001) (2002) (2003) 435 RIO CAMUY BASIN 50128940 CANAL DE RIEGO DE LAJAS BELOW LAJAS FILTRATION PLANT AT LAJAS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2003 WATER YEAR WATER YEARS 2001 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 5,685.550 ANNUAL MEAN 15.6 15.6 HIGHEST ANNUAL MEAN 15.6 2003 LOWEST ANNUAL MEAN 15.6 2003 HIGHEST DAILY MEAN 34.3 Aug 7 45.0 May 6, 2001 LOWEST DAILY MEAN 0.000 Oct 23 0.000 Oct 23, 2002 ANNUAL SEVEN-DAY MINIMUM 5.0 Oct 23 2.5 Aug 15, 2002 MAXIMUM PEAK FLOW 68 Sep 2 98 Sep 15, 2002 MAXIMUM PEAK STAGE 2.57 Sep 2 2.94 Sep 15, 2002 ANNUAL RUNOFF (AC-FT) 11,280 11,280 10 PERCENT EXCEEDS 25 25 50 PERCENT EXCEEDS 14 14 90 PERCENT EXCEEDS 8.8 8.8 100 50 20 10 5 2 1 0.5 0.2 0.1 0.05 0.02 0.01 O N D J F M A M J J A S 2002 2003 --- --- --- --- --- --- --- --- --- --- --- -- -- -- -- --- --- --- --- --- --- --- 436 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128945 CANAL DE RIEGO DE LAJAS AT BO. PALMAREJO NR LAJAS, PR LOCATION.--Lat 18q02'14", long 67q04'44", Hydrologic Unit 21010004, 0.2 mi (0.32 km) south from Palmarejo school, 1.6 mi (2.57 km) southwest from Lajas Plaza Church and 0.5 mi (.80 km) northwest from Universidad de Puerto Rico Estación Agrícola. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--January to current year. GAGE.--Water stage recorder. Altitude of gage is about 98 ft (30 m) from topographic map. REMARKS.--Records fair. Controlled by Lago Loco dam. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge 97 ft3/s (2.75 m3/s) May 6, 2001, gage height, 3.32 ft (1.01 m); no flow many days each year. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 60 ft 3/s (1.70 m3/s) September 2, gage height, 2.65 ft (0.81 m); no flow many days. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.3 10 11 17 7.0 12 A 6.4 18 29 24 4.9 2 10 7.7 9.7 15 7.6 13 9.7 9.5 17 23 10 8.3 3 11 8.0 11 15 12 11 7.6 8.4 26 23 9.5 4.6 4 18 7.7 6.3 8.7 12 13 7.1 8.6 16 4.0 12 4.8 5 15 13 8.5 9.1 10 12 5.4 7.3 18 3.1 21 4.3 6 14 13 10 9.7 9.7 14 6.0 8.7 20 3.5 21 4.7 7 9.8 12 10 9.4 5.4 18 6.7 8.1 14 5.8 27 5.2 8 12 13 12 7.0 2.9 17 6.6 12 15 13 22 4.4 9 8.4 7.8 11 9.9 2.4 23 5.4 12 16 14 10 6.4 10 8.5 7.9 8.7 13 2.6 21 6.2 10 22 14 11 8.6 11 5.4 7.8 15 8.6 3.1 16 6.9 9.2 21 16 2.5 8.6 12 6.5 8.8 14 8.3 7.4 21 6.9 11 25 10 16 12 13 8.8 13 16 9.2 11 20 7.5 14 24 9.6 24 11 14 8.0 8.8 8.5 8.4 11 22 6.0 9.2 10 8.2 25 7.9 15 7.7 11 10 11 12 16 6.1 9.0 11 13 21 7.9 16 9.9 11 11 15 13 18 8.5 5.5 14 16 7.6 6.7 17 9.4 11 15 21 15 14 12 6.0 28 18 8.3 0.00 18 9.7 14 16 21 11 20 15 6.3 23 19 9.6 14 19 4.5 11 20 24 13 16 8.0 5.1 24 8.5 A 8.2 20 3.6 11 16 27 13 17 7.8 7.7 19 8.1 20 6.0 21 5.8 11 17 22 12 18 6.5 9.1 9.2 8.5 21 6.4 22 13 11 18 13 11 11 4.8 12 9.3 9.1 13 6.9 23 0.06 5.4 17 17 16 15 4.2 12 15 19 3.8 8.9 24 0.00 5.9 12 19 14 14 5.4 11 16 25 5.6 8.6 25 6.0 7.4 11 12 20 17 5.5 11 13 11 27 8.8 26 3.8 11 11 12 18 17 7.0 11 22 10 13 7.2 27 5.5 13 9.9 13 12 17 6.2 8.7 25 9.9 8.4 3.0 28 6.1 9.7 6.8 13 17 13 6.3 19 15 11 12 4.8 29 8.4 10 6.7 11 8.6 7.0 22 17 11 11 7.1 30 7.7 11 7.0 21 9.1 6.7 28 18 22 5.9 8.4 31 10 14 15 13 19 21 5.0 TOTAL 252.86 302.9 370.1 435.3 301.1 486.7 336.8 540.5 416.3 208.60 MEAN 8.16 10.1 11.9 14.0 10.8 15.7 10.9 18.0 13.4 6.95 MAX 18 14 20 27 20 23 28 28 29 14 MIN 0.00 5.4 6.3 7.0 2.4 8.6 5.1 9.2 3.1 0.00 AC-FT 502 601 734 863 597 965 668 1,070 826 414 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 2001 - 2003, BY WATER YEAR (WY) MEAN 10.6 12.7 10.7 13.3 11.9 13.7 8.32 12.1 16.3 11.9 9.53 MAX 13.1 15.3 11.9 14.0 14.1 15.7 10.9 18.0 20.0 13.6 11.3 (WY) (2002) (2002) (2003) (2003) (2002) (2003) (2003) (2003) (2002) (2001) (2001) MIN 8.16 10.1 9.51 12.6 10.8 11.7 5.78 7.35 13.4 10.3 6.95 (WY) (2003) (2003) (2002) (2002) (2003) (2001) (2001) (2001) (2003) (2002) (2003) SUMMARY STATISTICS WATER YEARS 2001 - 2003 HIGHEST DAILY MEAN 36 May 6, 2001 LOWEST DAILY MEAN 0.00 Apr 13, 2001 ANNUAL SEVEN-DAY MINIMUM 2.8 May 14, 2001 MAXIMUM PEAK FLOW 97 May 6, 2001 MAXIMUM PEAK STAGE 3.32 May 6, 2001 A No gage-height record 437 RIO CAMUY BASIN 50128945 CANAL DE RIEGO DE LAJAS AT BO. PALMAREJO NR LAJAS, PR—Continued O N D J F M A M J J A S 0.01 0.02 0.05 0.1 0.1 0.2 0.5 1 2 5 10 10 20 50 100 DISCHARGE, IN CUBIC FEET PER SECOND GAP INDICATES MISSING RECORD 2002 2003 438 RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR LOCATION.--Lat 17q58'33", long 66q54'52", 0.6 mi (1.0 km) northwest of Guánica Plaza and 1.2 mi (1.9 km) northeast of Ensenada. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- wat unf solved water, conduc- ness, Magnes- Potas- lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium Sodium, Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp- water, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion fltrd, Date Time NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio mg/L (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) (00930) NOV 14... 1525 13 7.5 98 7.0 422 29.0 150 35.2 14.1 2.97 1 27.4 FEB 06... 1045 4.2 3.4 -- 7.4 7,960 26.1 900 82.7 168 49.9 19 1,330 APR 10... 0850 2.8 1.6 -- 7.1 10,700 27.0 -- -- -- -- -- -­ JUL 16... 0950 1.8 3.2 -- 7.3 10,700 27.4 -- -- -- -- -- -­ SEP 03... 0730 66 .8 -- 7.2 931 26.9 180 38.9 20.2 8.97 4 118 ANC, Residue Residue Ammonia Nitrite wat unf water, total + + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate nitrate Nitrite end pt, ide, ide, Silica, Sulfate Sulfide sum of deg. C, water, water, water water water, field, water, water, water, water, water consti- sus- unfltrd unfltrd unfltrd unfltrd unfltrd mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents pended, mg/L mg/L mg/L mg/L mg/L Date CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L mg/L as N as N as N as N as N (00410) (00940) (00950) (00955) (00945) (00745) (70301) (00530) (00625) (00610) (00620) (00630) (00615) NOV 14... 151 29.2 <.17 21.7 17.1 -- 238 <10 .40 .02 -- .300 <.01 FEB 06... 195 2,360 .38 22.8 329 .0 4,460 <20 .50 .06 -- <.020 <.01 APR 10... 144 -- .37 -- -- .3 -- -- .60 .07 -- <.020 <.01 JUL 16... 203 -- -- -- -- -- -- <10 .30 .03 -- <.020 <.01 SEP 03... 157 173 .2 18.4 41.3 -- 514 27 1.0 .03 .11 .140 .03 Total Fecal Fecal Total Chrom- Organic Total nitro- COD, coli- strep- coli- Barium, Boron, ium, nitro- Phos- nitro- gen, high form, tococci form, water, water, water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd Cadmium unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover water, recover unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, unfltrd -able, Date mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L ug/L ug/L (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) (01027) (01034) NOV 14... .38 .11 .70 3.1 <10 340 270 -- -- -- -- -- -­ FEB 06... .44 .10 -- -- 30 E1,000 -- 37,000 <2 72.5 644 .8 E1.2 APR 10... .53 .25 -- -- -- E160 -- 6,500 -- -- -- -- -­ JUL 16... .27 .04 -- -- 40 E55 -- 3,000 -- -- -- -- -­ SEP 03... .97 .20 1.1 5.0 30 3,000 -- 21,000 -- -- -- -- -­ 439 RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Mangan- Phen- Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, Selen- water, water, com­ unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, recover water recover recover recover recover water, recover recover water, water, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 14... -- -- -- -- -- -- -- -- -- -- -- FEB 06... <10 <.01 60 20 128 <.02 <3 E.2 <25 <.10 <16 APR 10... -- -- -- -- -- -- -- -- -- -- -- JUL 16... -- -- -- -- -- -- -- -- -- -- -- SEP 03... -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 10... 0850 <.01 <.02 <.01 <.01 <.02 <.1 <.01 E.01 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 10... <.01 <.01 <.009 <.01 <.014 <.30 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 10... <.1 <.02 <.02 <1 <.02 < -- Less than E -- Estimated value 440 THIS PAGE IS INTENTIONALLY BLANK Figure 22. Río Guanajibo basin. 441 442 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR LOCATION.--Lat 18q07'18", long 67q03'56", at bridge on Highway 347, 2.2 mi (3.5 km) northwest of San Germán. DRAINAGE AREA.--45.5 mi2 (117.8 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 03... 1700 25 5.8 7.3 96 7.6 539 28.8 240 25.1 43.7 1.94 .5 FEB 06... 0815 8.3 2.7 3.2 -- 7.8 588 24.4 240 25.6 42.6 3.32 .7 APR 15... 1515 9.6 3.1 6.2 -- 7.8 647 29.4 260 26.5 46.5 3.56 .8 JUL 21... 1735 5.6 6.4 7.7 -- 8.0 627 30.7 -- -- -- -- -­ SEP 04... 1230 77 39 5.9 -- 7.7 398 28.0 190 22.0 31.8 2.43 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 03... 18.4 230 22.6 <.17 33.1 17.0 -- 300 20.3 <10 .40 .11 1.32 FEB 06... 26.0 238 33.3 .10 30.8 22.0 <.0 326 7.34 <10 1.5 1.00 1.72 APR 15... 29.7 245 41.9 .13 34.4 24.4 <.1 354 9.14 <10 2.5 1.10 1.51 JUL 21... -- 134 -- -- -- -- -- -- -- <10 .60 .24 1.50 SEP 04... 11.5 172 16.2 <.2 31.4 16.3 -- 235 49.1 40 1.1 .37 1.14 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 03... 1.40 .08 .29 .39 1.8 8.0 <10 E40 3,100 -- -- -- -­ FEB 06... 2.00 .28 .50 .53 3.5 15.5 10 540 -- 7,200 <2 54.1 72 APR 15... 1.80 .29 1.4 .66 4.3 19.0 20 E1,700 -- 52,000 M 65.3 111 JUL 21... 1.60 .10 .36 .76 2.2 9.7 10 84 -- 620 -- -- -­ SEP 04... 1.20 .06 .73 .25 2.3 10.2 20 3,900 -- 22,000 -- -- -­ 443 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 03... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 06... <.2 1.7 <10 <.01 60 <1 43.1 <.02 <3 .4 <25 <.10 <16 APR 15... <.2 1.8 <10 <.01 200 M 73.7 <.02 <3 <.3 <25 E.08 E13 JUL 21... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 444 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR LOCATION.--Lat 18q09'36", long 67q05'08", Hydrologic Unit 21010003, at bridge on Highway 348, 0.5 mi (0.8 km) southwest of Rosario Plaza. DRAINAGE AREA.--18.3 mi2 (47.4 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1985 to current year. GAGE.--Water-stage recorder. Elevation of gage is 50.0 ft (15.2 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27 144 43 e24 17 13 17 16 32 28 26 75 2 27 111 44 e23 17 12 23 16 32 25 24 80 3 41 171 40 e22 38 12 58 15 30 20 26 49 4 35 161 39 e18 27 12 45 22 31 32 30 38 5 28 118 37 e18 24 11 16 88 34 35 34 21 6 25 100 36 e18 25 11 12 99 43 24 31 19 7 61 91 35 e18 19 12 15 123 35 20 48 28 8 50 83 36 e18 18 12 11 156 31 20 39 40 9 45 100 36 e18 18 11 12 105 74 29 28 22 10 119 97 33 e20 17 e11 9.9 76 44 41 25 36 11 65 81 32 e23 16 e11 9.4 81 39 46 24 44 12 46 117 31 e23 16 e11 9.3 72 53 55 24 144 13 39 195 31 e22 16 e11 23 69 53 57 37 121 14 48 119 30 e22 16 e10 36 51 60 47 72 43 15 51 96 29 20 16 e10 30 43 39 49 56 31 16 36 83 e30 20 15 e10 15 53 47 88 36 28 17 30 80 e47 19 15 e10 18 67 55 70 91 23 18 77 75 e120 19 15 e10 93 58 56 45 69 23 19 82 75 e29 18 15 e10 58 72 58 38 36 36 20 92 69 e26 18 15 10 26 76 75 41 27 77 21 155 65 e25 18 14 11 43 85 66 18 22 77 22 81 62 e23 18 14 10 49 61 39 16 21 68 23 175 60 e73 20 14 9.9 47 59 25 17 21 46 24 128 57 e65 23 14 9.6 30 50 33 16 20 52 25 183 55 e40 27 14 9.6 39 49 39 20 20 212 26 97 53 e38 22 14 14 44 43 34 31 27 107 27 70 51 e40 20 13 18 27 45 44 31 20 82 28 221 48 e29 19 13 19 21 35 33 27 18 86 29 286 46 e23 18 24 18 34 30 24 95 113 30 179 44 e23 18 18 17 32 27 63 64 97 31 176 e21 17 13 36 42 49 TOTAL 2,775 2,707 1,184 621 485 376.1 871.6 1,887 1,291 1,115 1,160 1,918 MEAN 89.5 90.2 38.2 20.0 17.3 12.1 29.1 60.9 43.0 36.0 37.4 63.9 MAX 286 195 120 27 38 24 93 156 75 88 95 212 MIN 25 44 21 17 13 9.6 9.3 15 25 16 18 19 AC-FT 5,500 5,370 2,350 1,230 962 746 1,730 3,740 2,560 2,210 2,300 3,800 CFSM 4.89 4.93 2.09 1.09 0.95 0.66 1.59 3.33 2.35 1.97 2.04 3.49 IN. 5.64 5.50 2.41 1.26 0.99 0.76 1.77 3.84 2.62 2.27 2.36 3.90 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1986 - 2003, BY WATER YEAR (WY) MEAN 107 75.7 36.8 24.2 19.6 20.2 26.5 45.8 44.3 42.3 62.1 100 MAX 206 150 80.9 39.7 37.8 77.0 60.1 122 127 75.2 102 308 (WY) (1986) (2000) (2002) (1997) (1995) (1989) (2002) (1993) (1999) (1989) (1989) (1998) MIN 33.2 16.1 9.92 15.1 8.55 10.1 11.0 14.8 12.0 20.6 25.1 32.7 (WY) (1992) (1992) (1992) (1994) (1992) (1992) (1998) (1997) (1992) (2002) (1991) (1986) RIO GUANAJIBO BASIN 445 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1986 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 17,283 ANNUAL MEAN 47.4 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 286 LOWEST DAILY MEAN 12 ANNUAL SEVEN-DAY MINIMUM 14 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 34,280 ANNUAL RUNOFF (CFSM) 2.59 ANNUAL RUNOFF (INCHES) 35.13 10 PERCENT EXCEEDS 100 50 PERCENT EXCEEDS 32 90 PERCENT EXCEEDS 16 16,390.7 44.9 50.6 75.9 1999 30.8 1992 Oct 29 286 Oct 29 4,420 Sep 22, 1998 Jul 4 9.3 Apr 12 3.9 May 9, 1992 Jun 29 10 Mar 14 4.2 May 6, 1992 2,710 Sep 25 13,700 Sep 22, 1998 9.32 Sep 25 18.66 Sep 22, 1998 8.8 Mar 25 3.7 May 9, 1992 32,510 36,620 2.45 2.76 33.32 37.53 91 114 32 30 14 12 e Estimated 300 250 200 150 100 50 0 2002 2003 O N D J F M A M J J A S 446 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS 1979 TO CURRENT YEAR. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 15... 0900 93 16 8.4 97 7.2 232 22.2 100 19.6 12.8 1.43 .2 FEB 05... 1435 18 5.2 8.8 -- 8.5 264 23.8 120 24.3 13.2 1.31 .3 APR 16... 0950 15 4.3 8.7 -- 8.1 279 25.0 130 24.7 15.7 1.16 .3 JUL 22... 1120 17 6.3 8.5 -- 8.1 298 27.0 -- -- -- -- -­ SEP 04... 0800 26 42 7.7 -- 7.8 239 24.0 120 23.2 13.9 1.46 .2 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 15... 5.78 102 5.46 <.17 27.9 5.5 -- 139 35.1 <10 .30 <.01 -­ FEB 05... 7.33 120 6.83 .06 27.0 6.3 .0 158 7.76 <10 <.20 <.01 -­ APR 16... 7.85 122 8.53 .05 28.0 <.2 .6 -- -- <10 <.20 .02 -­ JUL 22... -- 238 -- -- -- -- -- -- -- <10 <.20 .01 -­ SEP 04... 6.04 116 6.77 <.2 24.7 5.6 -- 152 10.6 12 .30 .02 .76 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 15... 1.00 <.01 -- .04 1.3 5.8 <10 E850 720 -- -- -- -­ FEB 05... .930 <.01 -- .03 -- -- <10 250 -- 3,600 <2 34.8 E16 APR 16... .680 <.01 -- .03 -- -- <10 E150 -- 2,300 <2 40.8 <18 JUL 22... .630 <.01 -- .04 -- -- <10 100 -- 2,000 -- -- -­ SEP 04... .770 .01 .28 .05 1.1 4.7 10 6,000 -- E14,000 -- -- -­ 447 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 15... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 05... <.2 2.5 <10 <.01 120 <1 9.3 <.02 <3 <.3 <25 <.10 <16 APR 16... <.2 2.6 <10 <.01 180 M 14.4 <.02 <3 <.3 <25 <.10 E11 JUL 22... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- 448 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1979 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 1985 to current year. INSTRUMENTATION.--USDH-48 sediment sampler since October 1985. Automatic sediment sampler since 1986. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 15,900 mg/L September 22, 1998; Minimum daily mean, 1 mg/L several days during several years. SEDIMENT LOADS: Maximum daily mean, 356,000 tons (323,000 tonnes) September 22, 1998; Minimum daily mean, 0.05 ton (0.04 tonne) several days during several years. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 681 mg/L September 25, 2003; Minimum daily mean, 2.0 mg/L February 17, 18, 2003. SEDIMENT LOADS: Maximum daily mean, 2,470 tons (2,241 tonnes) September 25, 2003; Minimum daily mean, e0.08 ton (e0.07 tonne) se veral days. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 27 12 0.88 144 101 46 43 6 0.75 2 27 17 1.2 111 46 14 44 6 0.67 3 41 27 4.0 171 236 284 40 5 0.55 4 35 14 1.4 161 155 116 39 6 0.58 5 28 10 0.79 118 47 15 37 6 0.59 6 25 8 0.57 100 18 5.0 36 6 0.59 7 61 73 36 91 13 3.2 35 6 0.57 8 50 23 4.5 83 11 2.5 36 6 0.58 9 45 23 3.0 100 52 27 36 6 0.56 10 119 110 96 97 56 16 33 6 0.51 11 65 42 7.9 81 27 6.0 32 6 0.47 12 46 25 3.0 117 101 80 31 5 0.45 13 39 24 2.5 195 425 570 31 5 0.43 14 48 47 7.0 119 70 25 30 5 0.42 15 51 61 8.4 96 43 12 29 7 0.54 16 36 55 5.3 83 28 6.3 e30 e9 e0.69 17 30 50 4.1 80 26 5.8 e47 e7 e0.87 18 77 107 52 75 15 3.0 e120 e46 e14 19 82 65 15 75 26 5.5 e29 e7 e0.54 20 92 84 28 69 69 13 e26 e7 e0.52 21 155 231 314 65 50 8.9 e25 e7 e0.52 22 81 39 8.5 62 29 4.8 e23 e4 e0.21 23 175 291 360 60 18 3.0 e73 e26 e5.5 24 128 138 65 57 11 1.7 e65 e29 e4.8 25 183 244 239 55 5 0.73 e40 e5 e0.55 26 97 62 16 53 5 0.72 e38 e5 e0.55 27 70 42 8.0 51 6 0.82 e40 e5 e0.55 28 221 518 1,180 48 7 0.90 e29 e5 e0.42 29 286 592 1,270 46 8 0.96 e23 e4 e0.22 30 179 194 109 44 7 0.87 e23 e4 e0.22 31 176 207 149 e21 e4 e0.22 TOTAL 2,775 4,000.04 2,707 1,278.70 1,184 38.64 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO GUANAJIBO BASIN 449 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR.—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 e24 e4 e0.22 17 7 0.32 13 3 0.11 2 e23 e4 e0.22 17 7 0.33 12 3 0.09 3 e22 e4 e0.22 38 22 4.3 12 6 0.19 4 e18 e4 e0.21 27 17 1.3 12 10 0.30 5 e18 e4 e0.21 24 16 1.2 11 13 0.41 6 e18 e4 e0.21 25 17 1.2 11 16 0.49 7 e18 e4 e0.21 19 13 0.65 12 12 0.38 8 e18 e4 e0.21 18 12 0.56 12 8 0.24 9 e18 e4 e0.21 18 10 0.50 11 3 0.11 10 e20 e4 e0.21 17 9 0.41 e11 e3 e0.08 11 e23 e4 e0.22 16 8 0.35 e11 e3 e0.08 12 e23 e4 e0.22 16 7 0.29 e11 e3 e0.08 13 e22 e4 e0.22 16 5 0.23 e11 e3 e0.08 14 e22 e4 e0.23 16 4 0.18 e10 e3 e0.08 15 20 4 0.22 16 3 0.14 e10 e3 e0.08 16 20 4 0.22 15 3 0.11 e10 e3 e0.08 17 19 4 0.21 15 2 0.09 e10 e3 e0.08 18 19 5 0.25 15 2 0.10 e10 e3 e0.08 19 18 6 0.32 15 3 0.12 e10 e5 e0.15 20 18 10 0.48 15 3 0.14 10 7 0.19 21 18 14 0.64 14 4 0.15 11 8 0.24 22 18 17 0.82 14 4 0.17 10 6 0.16 23 20 15 0.81 14 5 0.17 9.9 3 0.09 24 23 11 0.64 14 5 0.19 9.6 3 0.08 25 27 7 0.52 14 5 0.21 9.6 3 0.09 26 22 4 0.21 14 6 0.21 14 3 0.13 27 20 4 0.21 13 6 0.20 18 4 0.18 28 19 5 0.23 13 5 0.16 19 4 0.19 29 18 5 0.26 24 4 0.25 30 18 6 0.29 18 4 0.19 31 17 7 0.33 13 4 0.12 TOTAL 621 9.68 485 13.98 376.1 5.10 APRIL MAY JUNE 1 17 3 0.14 16 7 0.31 32 4 0.38 2 23 3 0.16 16 7 0.28 32 4 0.32 3 58 66 37 15 6 0.26 30 3 0.26 4 45 30 4.7 22 10 0.81 31 3 0.25 5 16 19 0.80 88 96 47 34 3 0.27 6 12 17 0.56 99 60 19 43 3 0.34 7 15 15 0.61 123 240 129 35 3 0.29 8 11 12 0.38 156 173 91 31 3 0.25 9 12 9 0.28 105 73 26 74 71 28 10 9.9 6 0.15 76 48 14 44 15 2.0 11 9.4 5 0.13 81 37 8.7 39 10 1.1 12 9.3 5 0.13 72 17 3.7 53 9 1.3 13 23 12 1.2 69 32 6.0 53 9 1.2 14 36 21 3.2 51 22 3.1 60 8 1.3 15 30 19 2.0 43 15 1.8 39 7 0.78 16 15 12 0.48 53 32 9.5 47 7 0.85 17 18 11 0.52 67 30 6.3 55 6 0.90 18 93 82 30 58 10 1.7 56 25 6.6 19 58 35 7.1 72 35 9.3 58 7 1.2 20 26 6 0.39 76 56 18 75 52 29 21 43 19 3.4 85 56 16 66 37 8.9 22 49 24 3.3 61 16 2.6 39 15 1.6 23 47 16 2.0 59 13 2.0 25 12 0.83 24 30 13 1.0 50 11 1.4 33 12 1.1 25 39 30 7.3 49 9 1.2 39 12 1.3 26 44 26 3.5 43 7 0.84 34 12 1.1 27 27 9 0.63 45 7 0.81 44 12 1.4 28 21 8 0.45 35 6 0.59 33 10 0.89 29 18 8 0.37 34 6 0.53 30 8 0.64 30 17 7 0.34 32 5 0.46 27 5 0.39 31 36 5 0.47 TOTAL 871.6 112.22 1,887 422.66 1,291 94.74 --- --- --- --- --- --- 450 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR.—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 28 5 0.38 26 43 3.0 75 215 89 2 25 5 0.34 24 37 2.3 80 50 13 3 20 5 0.27 26 31 2.2 49 18 2.4 4 32 5 0.43 30 34 3.7 38 17 1.7 5 35 19 2.7 34 18 2.1 21 16 0.91 6 24 15 0.93 31 9 0.76 19 15 0.74 7 20 26 1.4 48 37 9.6 28 21 2.8 8 20 5 0.29 39 32 4.0 40 22 2.9 9 29 12 1.6 28 21 1.5 22 12 0.73 10 41 22 2.5 25 18 1.2 36 30 7.8 11 46 18 2.2 24 15 1.0 44 33 7.5 12 55 28 7.2 24 10 0.68 144 334 657 13 57 31 5.4 37 18 3.9 121 140 80 14 47 22 2.8 72 99 32 43 27 3.1 15 49 20 2.7 56 29 4.8 31 17 1.4 16 88 86 41 36 17 1.7 28 8 0.61 17 70 28 5.7 91 437 414 23 7 0.43 18 45 21 2.5 69 70 18 23 6 0.41 19 38 18 1.9 36 20 2.0 36 6 0.61 20 41 16 1.7 27 13 0.98 77 76 29 21 18 13 0.64 22 11 0.63 77 79 25 22 16 10 0.44 21 11 0.63 68 24 4.5 23 17 8 0.36 21 12 0.67 46 23 4.0 24 16 5 0.23 20 13 0.69 52 34 16 25 20 5 0.25 20 11 0.63 212 681 2,470 26 31 27 5.1 27 10 0.73 107 151 45 27 31 12 1.1 20 8 0.44 82 33 7.5 28 27 10 0.71 18 8 0.38 86 16 3.7 29 24 9 0.60 95 600 532 113 12 3.7 30 63 91 50 64 47 8.5 97 9 2.4 31 42 70 8.9 49 10 1.4 TOTAL 1,115 152.27 1,160 1,056.12 1,918 3,483.84 YEAR 16,390.7 10,667.99 e Estimated --- --- --- --- --- --- --- 451 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR LOCATION.--Lat 18q08'36", long 67q08'57", Hydrologic Unit 21010003, at bridge on Highway 100, 1.4 mi (2.3 km) west of Hormigueros, and 2.0 mi (3.2 km) downstream from Río Rosario. DRAINAGE AREA.--120 mi2 (311 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Annual low-flow measurements 1959, monthly measurements April 1959 to November 1967, January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is at mean sea level. Previous to November 7, 1980, at site 0.3 mi (0.5 km) upstream at datum 7.36 ft (2.243 m) higher. REMARKS.--Records fair, except those for estimated daily discharges which are poor. Gage-height and precipitation satellite telemetry at station. Daily discharges affected by sewage treatment plant about 2.1 mi (3.4 km) upstream from gage. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 e110 e360 e100 e49 31 e9.8 62 57 45 38 33 97 2 e113 e305 e83 e53 33 e10 101 52 44 51 29 245 3 e112 e335 e70 e62 41 e9.6 121 49 41 29 29 e298 4 e110 e270 e90 e48 56 e11 255 47 39 27 26 e221 5 e120 e190 e75 e45 41 e9.3 81 267 40 67 38 e90 6 e200 e135 e63 e43 41 8.2 56 258 38 43 26 e130 7 e145 e120 e61 e42 27 7.5 55 245 47 29 36 231 8 e240 e112 e64 e43 25 8.5 49 302 36 26 52 188 9 e415 e135 e62 e45 24 8.2 44 391 60 31 29 104 10 e590 e115 e60 e46 22 7.3 40 130 63 35 23 89 11 e350 e110 e58 e51 22 7.3 40 123 44 32 24 152 12 e190 e240 e57 e44 21 7.6 40 105 37 35 25 259 13 e135 e295 e57 e42 22 6.9 39 102 35 47 33 759 14 e114 e270 56 e41 25 7.5 53 80 36 33 66 314 15 e112 e235 54 e40 16 7.7 64 71 32 31 79 163 16 e108 e190 54 e41 15 7.5 38 70 30 47 41 135 17 e106 e130 55 e38 15 7.9 88 99 31 71 51 117 18 e120 e175 82 e36 14 8.5 361 95 39 42 93 120 19 e265 e140 65 e39 13 10 366 89 47 35 43 258 20 e240 e95 59 e35 13 15 180 83 34 41 41 306 21 e335 e87 60 e34 13 10 414 106 66 71 65 221 22 e470 e85 63 e33 13 11 328 139 35 40 83 212 23 e375 e80 90 33 12 12 250 149 29 31 45 150 24 e270 e76 87 43 11 13 302 85 27 27 37 141 25 e290 e78 e67 57 e13 12 281 71 26 29 41 224 26 e185 e80 e58 43 e10 17 189 63 24 28 64 179 27 e155 e74 e80 38 e9.8 46 114 60 30 45 49 117 28 e135 e72 e63 34 e11 50 87 55 37 34 44 97 29 e335 e85 e52 33 78 74 51 26 30 108 95 30 e345 e70 e60 32 68 65 47 24 31 102 107 31 e390 e55 31 e40 45 70 81 TOTAL 7,180 4,744 2,060 1,294 609.8 532.3 4,237 3,586 1,142 1,226 1,536 5,819 MEAN 232 158 66.5 41.7 21.8 17.2 141 116 38.1 39.5 49.5 194 MAX 590 360 100 62 56 78 414 391 66 71 108 759 MIN 106 70 52 31 9.8 6.9 38 45 24 26 23 89 AC-FT 14,240 9,410 4,090 2,570 1,210 1,060 8,400 7,110 2,270 2,430 3,050 11,540 CFSM 1.93 1.32 0.55 0.35 0.18 0.14 1.18 0.96 0.32 0.33 0.41 1.62 IN. 2.23 1.47 0.64 0.40 0.19 0.17 1.31 1.11 0.35 0.38 0.48 1.80 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1973 - 2003, BY WATER YEAR (WY) MEAN 446 374 128 60.3 49.7 44.6 77.7 177 107 97.8 210 457 MAX 1,254 1,518 422 112 119 244 316 698 504 240 757 2,075 (WY) (1986) (1978) (1976) (1997) (1996) (1989) (1989) (2001) (1979) (1984) (1988) (1975) MIN 97.5 42.7 15.4 13.8 13.9 10.6 16.1 12.7 9.23 26.4 42.3 78.5 (WY) (1992) (1992) (1992) (1973) (1977) (1977) (1977) (1977) (1977) (1976) (1976) (1997) 452 RIO GUAJATACA BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1973 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 38,216 ANNUAL MEAN 105 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 1,120 LOWEST DAILY MEAN 25 ANNUAL SEVEN-DAY MINIMUM 27 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 75,800 ANNUAL RUNOFF (CFSM) 0.873 ANNUAL RUNOFF (INCHES) 11.85 10 PERCENT EXCEEDS 264 50 PERCENT EXCEEDS 61 90 PERCENT EXCEEDS 34 33,966.1 93.1 187 402 1979 69.6 1994 Apr 24 759 Sep 13 35,000 Sep 16, 1975 Mar 6 6.9 Mar 13 5.0 Jun 18, 1977 Mar 3 7.4 Mar 10 5.5 Jun 17, 1977 1,350 Sep 13 128,000 Sep 16, 1975 18.00 Sep 13 28.50 Sep 16, 1975 4.6 Jun 22, 1977 67,370 135,800 0.775 1.56 10.53 21.22 247 409 56 78 15 23 e Estimated 1,000 500 200 100 50 20 10 5 2 1 2002 2003 O N D J F M A M J J A S RIO GUANAJIBO BASIN 453 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) NOV 15... 1145 237 35 7.2 87 7.3 338 24.8 160 23.4 24.5 1.49 .3 FEB 05... 0830 41 24 7.3 -- 8.0 385 23.0 170 26.2 24.3 1.89 .5 APR 15... 1245 56 36 7.7 -- 7.8 333 25.9 150 24.8 20.8 1.83 .4 JUL 21... 1545 64 81 5.6 -- 7.5 308 27.6 -- -- -- -- -­ SEP 05... 0830 89 28 6.2 -- 7.6 396 27.4 180 28.0 27.9 2.87 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) NOV 15... 8.71 149 8.84 <.17 29.6 10.5 -- 196 126 36 .30 .03 .84 FEB 05... 13.5 166 15.2 .09 26.4 12.9 <.0 220 24.4 21 <.20 .04 .98 APR 15... 10.9 134 13.1 .07 25.7 11.4 .5 189 28.4 22 .50 .03 1.18 JUL 21... -- 108 -- -- -- -- -- -- -- 53 .70 .10 .78 SEP 05... 13.2 174 14.8 <.2 30.1 16.9 -- 238 57.3 29 .60 .11 1.05 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) NOV 15... .850 .01 .27 .15 1.1 5.1 <10 E890 830 -- -- -- -­ FEB 05... 1.00 .02 -- .19 -- -- <10 2,800 -- 33,000 <2 51.8 28 APR 15... 1.20 .02 .47 .16 1.7 7.5 10 E1,100 -- 20,000 <2 50.9 31 JUL 21... .830 .05 .60 .29 1.5 6.8 20 E11,000 -- 51,000 -- -- -­ SEP 05... 1.10 .05 .49 .22 1.7 7.5 20 2,800 -- E19,000 -- -- -­ 454 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) NOV 15... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 05... <.2 3.5 <10 <.01 620 <1 52.4 <.02 <3 E.2 <25 <.10 <16 APR 15... <.2 5.8 <10 <.01 1,040 M 69.1 <.02 <3 <.3 <25 <.10 E9 JUL 21... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 05... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) APR 15... 1245 <.01 .04 <.01 <.01 <.03 <.1 <.02 <.03 <.02 <.017 <.30 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) APR 15... <.02 <.02 <.009 <.01 <.014 <.30 <.02 <.012 <.016 <.014 <.009 <.015 <.02 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) APR 15... <.1 <.03 <.02 <1 <.03 < -- Less than Figure 23. Río Yagüez to Río Grande de Añasco basins. 455 456 RIO YAGÜEZ BASIN 50138800 RIO YAGÜEZ NEAR MAYAGÜEZ, PR LOCATION.--Lat 18q12'31", long 67q07'07", at steel-truss bridge on unnumbered paved road about 800 ft (244 m) south of Highway 106, 1.8 mi (2.9 km) west of Highways 106 and 352 junction, and 1.4 mi (2.3 km) east-northeast from Mayagüez Plaza. DRAINAGE AREA.--6.7 mi2 (17.3 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 03... 1400 15 4.8 8.7 104 7.5 307 24.6 130 36.4 10.2 1.77 .4 FEB 05... 1130 7.4 14 8.6 -- 8.2 273 23.1 110 31.1 8.94 1.86 .4 APR 16... 1205 6.1 20 8.3 -- 7.7 263 26.2 110 28.8 8.81 2.04 .4 JUL 22... 0830 9.1 9.2 8.4 -- 7.9 302 24.5 -- -- -- -- -­ SEP 04... 1020 11 9.5 7.9 -- 7.9 286 25.4 130 37.7 9.70 2.52 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 03... 10.4 139 8.91 <.17 33.4 6.0 -- 191 7.87 <10 .20 <.01 -­ FEB 05... 9.15 120 7.86 .08 29.3 7.0 <.0 167 3.34 10 <.20 .06 .99 APR 16... 10.2 105 10.1 .08 27.9 7.7 .3 159 2.62 12 <.20 .02 -­ JUL 22... -- 131 -- -- -- -- -- -- -- <10 <.20 <.01 -­ SEP 04... 11.2 126 9.70 <.2 29.8 6.0 -- 182 5.33 <40 .30 .02 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 03... 1.00 <.01 -- .05 1.2 5.3 <10 24,000 E1,110 -- -- -- -­ FEB 05... 1.00 .01 -- .05 -- -- <10 2,200 -- 40,000 <2 52.5 20 APR 16... .830 <.01 -- .04 -- -- <10 E120 -- 4,800 E1 136 29 JUL 22... .780 <.01 -- .04 -- -- <10 280 -- 4,400 -- -- -­ SEP 04... .820 <.01 .28 .04 1.1 5.0 <10 E1,400 -- 2,900 -- -- -­ 457 RIO YAGÜEZ BASIN 50138800 RIO YAGÜEZ NEAR MAYAGÜEZ, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 03... -- -- -- -- -- -- -- -- -- -- -- -- -- FEB 05... <.2 E.6 <10 <.01 200 <1 18.0 <.02 <3 E.1 <25 <.10 <16 APR 16... <.2 E.5 <10 <.01 400 M 26.4 <.02 <3 <.3 <25 <.10 E10 JUL 22... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 04... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- --- --- 458 RIO GRANDE DE AÑASCO BASIN 50141500 LAGO GUAYO AT DAMSITE NEAR CASTAÑER, PR LOCATION.--Lat 18q12'46", long 66q50'06", Hydrologic Unit 21010003, at Guayo Dam on Río Guayo, 1.1 mi (1.8 km) southwest of Lago Yahuecas, 2.6 mi (4.2 km) southwest of Lago Prieto, 2.1 mi (3.4 km) north of Castañer, and 6.0 mi (9.6 km) west of Adjuntas. DRAINAGE AREA.--9.60 mi2 (24.9 km2). PERIOD OF RECORD.--April 1980 to January 1985, June 1989 to current year. Prior to October 1994, published as Lago Guayo near Ca stañer. GAGE.--Water-stage recorder. Datum of gage is mean sea level. REMARKS.--Lago Guayo was completed in 1956. The dam is on Río Guayo and is the largest in the Southwestern Puerto Rico Project. The maximum storage is 17,400 acre-ft (21.5 hm3) for power and irrigation. The dam is a concrete gravity structure with a total length of 555 ft (169 m), a maximum structural height of 190 ft (58 m), and a maximum width at the base of 145 ft (44 m). The ungated overflow spillway with a crest elevation of 60 ft (18.29 m) and a crest length of 220 ft (67 m) was designed to pass a maximum flood of 30,200 ft3/s (855 m3/s), at a reservoir elevation of 70 ft (21.34 m). Timber flashboards that were added to increase storage capacity were subsequently removed and their use discontinued. Gage-height and precipitation satellite telemetry at station. New capacity table based U.S. Geological Survey Water-Resources Investigations Report 99-4053, October 1997. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation,1,465.35 ft (446.64 m), September 22, 1998; minimum elevation recorded, 1,415.43 ft (431.42 m), June 2, 1990, but may have been less during period of no gage-height record June 2-5, 1990. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 1,457.83 ft (444.35 m), November 15; minimum elevation 1,436.93 ft (437. 98 m), May 12. Capacity Table (based on data from U.S. Geological Survey Water-Resources Investigations Report 99-4053, 1997) (Elevation in ft, capacity in acre-ft) Elevation Contents 1,333 0 1,353 241 1,373 820 Elevation Contents 1,400 2,745 1,440 8,622 1,460 13,436 ELEVATION ABOVE NGVD 1929, FEET WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 2400 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1,447.95 1,454.52 1,457.19 1,455.18 1,454.05 1,450.92 1,449.71 1,443.90 1,445.59 1,439.13 1,438.14 1,439.56 2 1,447.28 1,454.61 1,457.54 1,455.08 1,454.60 1,451.09 1,449.65 1,443.44 1,444.80 1,439.18 1,438.35 1,440.09 3 1,447.38 1,455.07 1,457.00 1,454.80 1,455.21 1,450.71 1,449.63 1,442.26 1,444.49 1,439.40 1,438.54 1,439.31 4 1,447.66 1,455.78 1,457.00 1,454.27 1,455.32 1,450.36 1,449.77 1,442.02 1,443.89 1,439.64 1,437.90 1,439.58 5 1,447.83 1,455.85 1,456.93 1,454.02 1,455.33 1,450.02 1,449.60 1,440.71 1,443.88 1,439.81 1,437.51 1,439.03 6 1,448.05 1,455.36 1,456.81 1,454.16 1,455.33 1,449.66 1,449.46 1,439.71 1,442.62 1,440.08 1,437.78 1,438.86 7 1,448.24 1,454.50 1,456.73 1,453.53 1,455.21 1,449.31 1,449.20 1,438.61 1,441.91 1,440.26 1,438.13 1,439.91 8 1,448.38 1,453.56 1,456.77 1,453.10 1,455.19 1,448.90 1,448.23 1,437.78 1,440.05 1,440.18 1,437.17 1,440.38 9 1,448.56 1,453.03 1,456.51 1,453.11 1,455.02 1,448.59 1,447.94 1,437.85 1,438.78 1,440.07 1,437.15 1,440.76 10 1,448.76 1,452.47 1,456.10 1,452.64 1,454.85 1,448.22 1,446.72 1,437.35 1,439.15 1,439.89 1,437.33 1,440.62 11 1,448.97 1,451.56 1,455.53 1,452.21 1,454.92 1,448.02 1,446.76 1,437.08 1,438.07 1,439.92 1,437.75 1,440.99 12 1,448.34 1,452.35 1,455.25 1,452.08 1,454.34 1,448.11 1,446.15 1,437.10 1,438.39 1,439.73 1,437.99 1,441.98 13 1,448.20 1,456.01 1,454.81 1,451.77 1,454.12 1,447.55 1,446.34 1,437.38 1,438.81 1,439.98 1,438.45 1,442.31 14 1,447.55 1,457.24 1,454.79 1,451.86 1,453.76 1,447.70 1,445.55 1,437.23 1,439.11 1,439.77 1,438.35 1,442.84 15 1,447.85 1,457.26 1,454.34 1,451.75 1,453.25 1,447.84 1,444.79 1,437.51 1,439.19 1,438.86 1,438.08 1,442.17 16 1,448.16 1,457.34 1,454.46 1,451.98 1,453.47 1,447.99 1,444.40 1,439.87 1,439.20 1,438.77 1,438.36 1,441.47 17 1,448.47 1,456.85 1,455.88 1,452.20 1,453.14 1,448.12 1,444.80 1,441.32 1,439.52 1,438.84 1,440.46 1,440.71 18 1,448.95 1,456.39 1,457.00 1,452.42 1,453.03 1,448.22 1,446.41 1,442.44 1,439.87 1,439.12 1,439.21 1,440.62 19 1,449.95 1,455.96 1,456.14 1,452.64 1,453.08 1,448.39 1,446.85 1,443.22 1,439.31 1,439.35 1,438.52 1,440.82 20 1,450.86 1,455.63 1,456.09 1,452.86 1,452.87 1,448.38 1,446.86 1,443.36 1,439.62 1,439.57 1,438.12 1,440.42 21 1,451.25 1,455.09 1,455.97 1,453.13 1,452.50 1,448.52 1,447.64 1,447.20 1,439.91 1,439.36 1,438.33 A 22 1,450.61 1,455.01 1,455.87 1,453.35 1,451.85 1,448.66 1,448.47 1,448.20 1,439.78 1,439.57 1,437.93 1,442.46 23 1,450.42 1,455.12 1,455.94 1,453.56 1,451.23 1,448.80 1,448.88 1,448.51 1,439.82 1,439.15 1,437.80 1,441.75 24 1,450.84 1,455.03 1,455.55 1,453.85 1,450.94 1,448.90 1,449.08 1,448.75 1,440.08 1,439.34 1,437.38 1,441.47 25 1,451.22 1,455.15 1,454.93 1,454.36 1,451.08 1,448.79 1,449.07 1,448.89 1,438.84 1,439.46 1,437.40 1,442.23 26 1,451.41 1,455.31 1,454.79 1,454.81 1,451.27 1,448.50 1,447.77 1,448.36 1,439.08 1,438.81 1,437.74 1,441.94 27 1,451.09 1,455.63 1,454.48 1,455.12 1,451.26 1,448.89 1,447.67 1,447.64 1,439.34 1,439.02 1,438.02 A 28 1,451.04 1,456.01 1,454.79 1,455.24 1,451.25 1,449.24 1,446.55 1,447.08 1,439.57 1,439.26 1,438.26 1,441.32 29 1,451.70 1,456.37 1,455.08 1,455.28 1,449.52 1,446.00 1,446.94 1,439.46 1,438.80 1,438.63 1,441.68 30 1,452.96 1,456.83 1,455.21 1,454.53 1,449.50 1,445.29 1,446.55 1,438.89 1,438.61 1,438.93 1,440.52 31 1,454.00 1,454.87 1,454.27 1,449.31 1,446.06 1,438.55 1,439.20 MAX 1,454.00 1,457.34 1,457.54 1,455.28 1,455.33 1,451.09 1,449.77 1,448.89 1,445.59 1,440.26 1,440.46 MIN 1,447.28 1,451.56 1,454.34 1,451.75 1,450.94 1,447.55 1,444.40 1,437.08 1,438.07 1,438.55 1,437.15 A No gage-height record. 459 RIO GRANDE DE AÑASCO BASIN 50141500 LAGO GUAYO AT DAMSITE NEAR CASTAÑER, PR—Continued O N D J F M A M J J A S 1,435 1,440 1,445 1,450 1,455 1,460 ELEVATION, IN FEET GAP INDICATES MISSING RECORD 2002 2003 460 RIO GRANDE DE AÑASCO BASIN 50143000 RIO GRANDE DE AÑASCO NEAR LARES, PR LOCATION.--Lat 18q15'26", long 66q55'00", at bridge on Highway 124, 0.7 mi (1.1 km) downstream from confluence of Río Blanco and Río Prieto, and 3.7 mi (6.0 km) southwest of Lares Plaza. DRAINAGE AREA.--26.3 mi2 (68.1 km2) this does not include 36.2 mi2 (93.8 km2) which contributes only during high floods, and 3.5 mi2 (9.1 km2) which contributes only part of its storm runoff. PERIOD OF RECORD.--Water years 1959-68, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 05... 1130 41 7.1 9.4 111 7.5 281 23.1 120 33.5 9.60 1.74 .5 MAR 25... 0945 12 5.2 11.4 -- 8.4 317 24.7 -- -- -- -- -­ MAY 13... 1335 73 32 8.9 -- 8.1 245 26.5 99 27.0 7.57 1.70 .4 JUN 24... 1415 33 -- 8.6 -- 8.5 292 30.1 -- -- -- -- -­ AUG 21... 1200 30 19 8.6 -- 8.2 277 28.5 -- -- -- -- -­ SEP 16... 1320 30 14 9.4 -- 8.3 264 30.0 110 29.7 8.57 1.75 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 05... 11.6 107 8.42 <.17 32.8 20.5 -- 183 20.0 <10 <.20 <.01 -­ MAR 25... -- 116 -- -- -- -- <.1 -- -- -- <.20 .02 -­ MAY 13... 9.73 87 7.83 <.17 29.3 18.4 <.1 154 30.4 17 <.20 .02 -­ JUN 24... -- -- -- -- -- -- -- -- -- 7 <.20 .02 -­ AUG 21... -- 102 -- -- -- -- -- -- -- 18 .30 .03 -- SEP 16... 10.1 102 8.50 <.2 31.9 18.3 -- 170 13.7 14 <.20 .03 .61 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 05... 1.20 <.01 -- .05 -- -- <10 330 570 -- -- -- -­ MAR 25... .240 <.01 -- .02 -- -- -- E11 -- E540 -- -- -­ MAY 13... .950 <.01 -- .04 -- -- <10 280 -- E14,000 <2 22.0 <18 JUN 24... .690 <.01 -- .03 -- -- -- E35 -- 60 <1 -- -­ AUG 21... .650 <.01 .27 .03 .95 4.2 <10 500 -- 7,000 -- -- -­ SEP 16... .620 .01 -- .05 -- -- 20 98 -- 3,000 -- -- -­ 461 RIO GRANDE DE ANASCO BASIN 50143000 RIO GRANDE DE ANASCO NEAR LARES, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 05... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 25... -- -- -- -- -- -- -- -- -- -- -- <.10 <16 MAY 13... <.2 <.8 10 <.01 520 <1 39.3 <.02 <3 <.3 E22 <.10 <16 JUN 24... -- -- 2 -- -- <2 -- <.1 -- -- -- -- -­ AUG 21... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 16... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value --- --- --- --- --- --- --- 462 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR LOCATION.--Lat 18q17'05", long 67q03'05", Hydrologic Unit 21010003, on left bank, at downstream side of bridge on Highway 108, 0.4 mi (0.6 km) downstream from Quebrada La Zumbadora, 4.4 mi (7.1 km) northwest of Las Marías, 5.4 mi (8.7 km) southwest of San Sebastián. DRAINAGE AREA.--94.3 mi2 (244.2 km2), does not include 36.2 mi2 (93.8 km2) which contributes only during high floods, and 3.5 mi2 (9.1 km2) which contributes only part of its storm runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1963 to current year. REVISED RECORDS.--WDR PR-2,000-1: 1999. Revised maximum discharge and revised daily discharges, in cubic feet per second, for wa ter year 1999, are given below. These figures supersede those published in the report for 1999. GAGE.--Water-stage recorder. Datum of gage is 103.72 ft (31.614 m) above mean sea level (Puerto Rico Department of Public Works bench mark). Previous to October 30, 1975, at site 600 ft (180 m) upstream at same datum. REMARKS.--Records fair. Transbasin diversion (except during floods) to Río Yauco basin for hydroelectric power and irrigation ab ove Lago Guayo, Yahuecas, and Prieto, combined useable storage 17,300 acre-ft (21.3 hm3). Limited storm runoff is contributed to basin by 3.5 mi2 (9.1 km2) above Río Toro Diversion dam. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 187 695 367 183 115 72 76 104 664 154 109 285 2 218 662 279 185 137 71 112 97 521 158 130 328 3 194 584 245 183 163 70 104 145 324 153 150 383 4 349 625 235 169 158 69 115 391 498 148 339 293 5 237 356 230 165 200 67 103 806 898 144 375 225 6 167 314 218 163 149 66 101 459 500 147 142 192 7 272 270 209 159 128 66 87 484 398 138 155 549 8 375 246 201 156 113 67 72 481 364 134 227 532 9 451 385 198 156 107 66 75 660 334 148 177 249 10 373 374 190 158 103 66 73 1,000 290 134 121 205 11 410 298 182 162 98 63 69 782 354 332 266 463 12 269 447 178 146 97 62 71 502 268 219 197 407 13 354 802 174 142 95 62 179 638 243 193 578 742 14 445 898 170 140 115 60 269 449 272 140 1,030 479 15 517 771 165 138 99 59 214 612 253 129 538 275 16 344 679 161 136 91 59 95 2,570 220 129 517 225 17 338 658 213 134 89 58 87 3,430 234 172 562 300 18 276 575 484 129 87 56 372 1,570 400 268 591 201 19 320 502 186 127 85 55 437 1,390 342 148 379 404 20 316 474 161 125 86 70 184 1,170 235 125 283 530 21 465 422 154 122 84 65 413 1,050 253 121 204 396 22 498 397 149 124 82 63 625 1,120 207 114 181 411 23 470 371 399 141 79 57 638 1,030 192 111 211 291 24 556 356 472 129 78 56 309 655 184 116 215 790 25 321 358 245 183 78 55 268 479 177 356 265 2,690 26 277 378 237 198 75 62 498 446 171 130 229 1,030 27 224 332 239 174 81 80 219 442 166 116 251 480 28 218 363 202 132 76 110 148 341 164 123 192 338 29 267 346 193 122 100 127 305 158 111 165 283 30 553 374 187 119 112 113 281 154 103 732 260 31 553 181 119 90 263 140 623 TOTAL 10,814 14,312 7,104 4,619 2,948 2,134 6,253 24,152 9,438 4,854 10,134 14,236 MEAN 349 477 229 149 105 68.8 208 779 315 157 327 475 MAX 556 898 484 198 200 112 638 3,430 898 356 1,030 2,690 MIN 167 246 149 119 75 55 69 97 154 103 109 192 AC-FT 21,450 28,390 14,090 9,160 5,850 4,230 12,400 47,910 18,720 9,630 20,100 28,240 CFSM 3.70 5.06 2.43 1.58 1.12 0.73 2.21 8.26 3.34 1.66 3.47 5.03 IN. 4.27 5.65 2.80 1.82 1.16 0.84 2.47 9.53 3.72 1.91 4.00 5.62 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1963 - 2003, BY WATER YEAR (WY) MEAN 679 462 230 143 116 106 172 405 301 265 373 682 MAX 1,514 1,297 482 286 345 271 1,045 1,084 939 657 936 3,505 (WY) (1999) (2000) (1966) (1997) (1996) (1972) (2002) (1986) (1999) (1979) (1979) (1998) MIN 344 182 103 82.4 62.3 54.4 49.3 63.7 71.2 111 152 206 (WY) (1983) (1998) (1992) (1998) (1992) (1965) (1968) (1967) (1977) (1990) (1967) (1983) 463 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1963 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 130,290 ANNUAL MEAN 357 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 4,670 LOWEST DAILY MEAN 83 ANNUAL SEVEN-DAY MINIMUM 99 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 258,400 ANNUAL RUNOFF (CFSM) 3.79 ANNUAL RUNOFF (INCHES) 51.40 10 PERCENT EXCEEDS 630 50 PERCENT EXCEEDS 226 90 PERCENT EXCEEDS 129 110,998 304 328 556 1999 189 1967 Apr 27 3,430 May 17 69,900 Sep 22, 1998 Mar 23 55 Mar 19 32 Apr 18, 1965 Mar 21 58 Mar 13 35 Apr 14, 1965 13,100 May 16 163,000 Sep 22, 1998 10.67 May 16 34.50 Sep 22, 1998 31 Apr 19, 1965 220,200 237,600 3.22 3.48 43.79 47.26 580 683 207 189 79 75 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S 464 RIO GRANDE DE AÑASCO BASIN 50144000 RIO GRANDE DE AÑASCO NEAR SAN SEBASTIAN, PR—Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1963 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 04... 0945 232 8.5 8.8 103 7.2 241 23.2 98 24.8 8.64 1.55 .4 MAR 25... 1245 60 10 10.7 -- 8.6 246 27.1 97 23.9 9.01 1.36 .5 MAY 13... 1015 516 94 8.4 -- 7.7 195 24.4 79 20.3 6.96 1.69 .3 AUG 25... 1415 177 87 7.9 -- 7.9 212 28.2 -- -- -- -- -­ SEP 17... 1000 190 13 9.1 -- 7.9 234 26.2 100 25.3 10.0 1.55 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 04... 8.92 97 6.63 <.17 32.0 8.3 -- 149 93.4 <10 <.20 <.01 -­ MAR 25... 10.2 102 6.58 .10 31.2 9.9 <.1 153 25.0 <10 <.20 .02 -­ MAY 13... 7.15 75 5.85 <.17 25.2 8.5 <.1 120 168 68 .30 .02 .88 AUG 25... -- 84 -- -- -- -- -- -- -- 43 <.20 .03 .63 SEP 17... 8.43 98 6.64 <.2 32.2 8.1 -- 151 77.7 17 <.20 <.01 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 04... .860 <.01 -- .04 -- -- <10 210 350 -- -- -- -­ MAR 25... .170 <.01 -- .03 -- -- <10 E10 -- E590 <2 28.6 E11 MAY 13... .890 .01 .28 .07 1.2 5.3 10 E1,300 -- 55,000 <2 42.5 E13 AUG 25... .640 .01 -- .05 -- -- 20 E1,100 -- 35,000 -- -- -­ SEP 17... .700 <.01 -- .04 -- -- <10 E170 -- 3,700 -- -- -­ 465 RIO GRANDE DE ANASCO BASIN 50144000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 04... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 25... <.2 <.8 <10 <.01 90 <1 23.8 <.02 <3 <.3 <25 <.10 <16 MAY 13... <.2 .9 10 <.01 1,490 M 96.5 <.02 <3 <.3 26 <.10 <16 AUG 25... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 17... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified 466 RIO GRANDE DE AÑASCO BASIN 50146000 RIO GRANDE DE AÑASCO NEAR ANASCO, PR LOCATION.--Lat 18q16'00", long 67q08'05", at bridge on Highway 430, 0.2 mi (0.3 km) south of Highway 109 at El Espino and 1.4 mi (2.3 km) east-southeast from Añasco Plaza. DRAINAGE AREA.--139 mi2 (360 km2) this does not include 39.7 mi2 (102.8 km2), flow is diverted to south coast. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 04... 1300 292 17 8.6 104 6.9 240 24.9 96 24.1 8.77 1.56 .4 MAR 26... 0930 72 7.2 7.5 -- 7.9 249 26.6 98 23.5 9.51 1.23 .5 MAY 14... 1320 409 220 7.8 -- 7.5 177 25.9 69 17.5 6.17 1.81 .4 JUN 26... 0930 260 -- 8.0 -- 7.6 249 27.3 -- -- -- -- -­ AUG 25... 1715 266 60 7.1 -- 7.5 224 29.1 -- -- -- -- -­ SEP 17... 1315 284 22 7.3 -- 7.6 234 29.3 97 24.8 8.53 1.71 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 04... 9.02 95 7.25 <.17 32.5 7.7 -- 148 117 17 <.20 <.01 -­ MAR 26... 10.2 104 6.68 .11 31.2 8.9 <.1 154 29.9 <10 <.20 .02 -­ MAY 14... 6.77 66 5.70 <.17 23.7 8.5 <.1 110 121 139 .50 .04 .75 JUN 26... -- 98 -- -- -- -- -- -- -- 27 <.20 .02 -­ AUG 25... -- 91 -- -- -- -- -- -- -- 52 .20 .03 -- SEP 17... 8.04 98 6.68 <.2 31.5 7.3 -- 147 113 23 .20 .01 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 04... .790 <.01 -- .05 -- -- <10 430 200 -- -- -- -­ MAR 26... .070 <.01 -- <.02 -- -- <10 E40 -- 400 <2 33.3 <18 MAY 14... .780 .03 .46 .13 1.3 5.7 <10 5,300 -- 47,000 E1 55.3 E14 JUN 26... .450 <.01 -- .02 -- -- -- E140 -- 400 <1 -- -­ AUG 25... .590 <.01 .17 .06 .79 3.5 <10 1,100 -- 7,500 -- -- -­ SEP 17... .620 <.01 .19 .05 .82 3.6 10 E120 -- 3,500 -- -- -­ 467 RIO GRANDE DE ANASCO BASIN 50146000 RIO GRANDE DE ANASCO NEAR ANASCO, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 04... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 26... <.2 <.8 <10 <.01 130 <1 58.9 <.02 <3 <.3 <25 <.10 <16 MAY 14... <.2 1.6 20 <.01 2,870 1 190 E.01 <3 <.3 <25 <.10 <16 JUN 26... -- -- 3 -- -- <2 -- <.1 -- -- -- -- -­ AUG 25... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 17... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAY 14... 1320 <.01 1.94 <.01 <.01 <.02 <.1 <.01 <.02 <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAY 14... <.01 <.01 <.009 <.01 <.014 M <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAY 14... <.1 <.02 <.02 <1 <.02 < -- Less than M -- Presence verified, not quantified 468 THIS PAGE IS INTENTIONALLY BLANK Figure 24. Río Culebrinas basin. 469 470 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR LOCATION.--Lat 18q20'51", long 67q02'40", at bridge on Highway 423, 1.3 mi (2.1 km) south of Quebrada El Salto Bridge on Highway 111, and 2.1 mi (3.4 km) west of Central La Plata. DRAINAGE AREA.--58.2 mi2 (150.7 km2). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 05... 0830 125 60 8.3 96 6.9 274 22.7 120 38.7 4.75 2.53 .4 MAR 25... 1540 18 10 10.3 -- 8.4 280 26.6 99 31.4 4.97 2.36 .7 MAY 13... 1650 167 140 7.1 -- 7.7 249 25.4 97 31.7 4.37 2.61 .4 AUG 21... 0925 104 60 7.2 -- 7.8 253 26.3 -- -- -- -- -­ SEP 16... 1550 109 7.4 8.2 -- 8.0 396 28.5 130 42.2 5.25 2.39 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 05... 9.01 110 8.07 <.17 25.2 9.0 -- 163 55.0 34 .40 .02 1.09 MAR 25... 15.4 106 14.3 .10 36.0 8.4 <.1 176 8.56 <10 .30 .04 .84 MAY 13... 9.37 91 8.82 <.17 25.6 10.7 <.1 148 66.6 152 .70 .06 .98 AUG 21... -- 118 -- -- -- -- -- -- -- 33 .30 .05 1.08 SEP 16... 9.86 123 10.2 <.2 28.6 11.2 -- 184 54.1 <10 <.20 .04 -­ Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 05... 1.10 .01 .38 .08 1.5 6.6 <10 E9,900 E23,000 -- -- -- -­ MAR 25... .860 .02 .26 .16 1.2 5.1 <10 E910 -- E910 <2 28.9 33 MAY 13... 1.00 .02 .64 .14 1.7 7.5 10 5,300 -- 50,000 E1 47.8 26 AUG 21... 1.10 .02 .25 .05 1.4 6.2 10 5,100 -- 56,000 -- -- -­ SEP 16... .340 <.01 -- .05 -- -- <10 E600 -- 6,000 -- -- -­ 471 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 05... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 25... <.2 <.8 <10 <.01 130 <1 20.0 <.02 <3 <.3 <25 <.10 <16 MAY 13... <.2 1.5 10 <.01 2,730 M 160 E.02 <3 <.3 <25 <.10 <16 AUG 21... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 16... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value M -- Presence verified, not quantified --- --- --- --- --- --- --- 472 RIO CULEBRINAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR LOCATION.--Lat 18q21'42", long 67q05'33", Hydrologic Unit 21010003, on right bank, 1.0 mi (1.6 km) below Quebrada Los Morones confluence, 1.1 mi (1.8 km) above Quebrada Las Marías confluence, 2.8 mi (4.5 km) southeast of Moca Plaza, at bridge 404 road over Culebrina river. DRAINAGE AREA.--71.2 mi2 (184 km2). PERIOD OF RECORD.--July 1967 to current year. REVISED RECORDS.--WDR PR-99-1: (M). GAGE.--Water-stage recorder. Elevation of gage is 45 ft (14 m), from topographic map. REMARKS.--Records fair except those for estimated daily discharges, which are poor. Gage-height and precipitation satellite telemetry at station. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 549 610 692 93 79 49 64 86 1,540 110 65 349 2 356 1,220 221 94 81 47 71 78 631 225 95 256 3 392 473 184 95 84 46 43 72 314 864 69 269 4 410 284 198 91 196 45 73 527 237 208 140 226 5 259 244 198 89 343 44 379 300 4,120 144 126 352 6 164 221 165 89 150 44 327 202 666 127 78 246 7 209 203 156 87 85 43 136 134 474 117 87 180 8 728 181 149 84 75 42 70 126 479 109 89 264 9 3,660 267 148 85 70 43 283 261 322 106 76 675 10 530 832 142 84 68 42 144 275 266 100 63 265 11 703 275 138 83 65 42 96 236 381 101 183 534 12 527 451 134 82 63 40 70 196 260 114 212 494 13 717 5,710 131 80 60 40 425 307 203 92 195 305 14 494 1,520 130 79 69 39 431 269 563 90 135 267 15 5,060 1,420 131 79 60 39 293 951 305 85 354 179 16 701 554 126 79 58 38 124 4,160 201 83 188 160 17 1,380 707 133 78 57 37 94 e4,310 185 79 98 307 18 516 368 146 77 56 36 643 3,980 294 142 83 226 19 354 275 120 77 55 35 753 1,040 957 111 1,290 154 20 307 241 115 74 55 35 448 1,310 259 78 433 142 21 335 222 111 74 54 38 899 601 487 207 200 202 22 306 215 110 75 54 35 386 357 221 93 170 156 23 1,980 192 133 84 52 33 167 290 194 75 439 263 24 412 180 158 74 52 32 1,270 367 177 70 304 446 25 301 170 107 107 52 32 470 230 158 150 262 226 26 280 369 104 127 51 32 532 196 145 90 295 510 27 255 231 104 94 50 49 274 177 137 104 1,450 244 28 229 168 101 80 49 62 138 160 131 91 356 152 29 215 157 98 76 92 113 149 123 74 227 133 30 228 1,400 97 74 82 98 139 116 69 1,570 123 31 3,270 94 79 43 130 66 905 TOTAL 25,827 19,360 4,774 2,623 2,243 1,356 9,314 21,616 14,546 4,174 10,237 8,305 MEAN 833 645 154 84.6 80.1 43.7 310 697 485 135 330 277 MAX 5,060 5,710 692 127 343 92 1,270 4,310 4,120 864 1,570 675 MIN 164 157 94 74 49 32 43 72 116 66 63 123 AC-FT 51,230 38,400 9,470 5,200 4,450 2,690 18,470 42,880 28,850 8,280 20,310 16,470 CFSM 11.7 9.06 2.16 1.19 1.13 0.61 4.36 9.79 6.81 1.89 4.64 3.89 IN. 13.49 10.12 2.49 1.37 1.17 0.71 4.87 11.29 7.60 2.18 5.35 4.34 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1967 - 2003, BY WATER YEAR (WY) MEAN 625 352 156 93.9 77.0 73.8 141 457 389 290 351 558 MAX 1,086 799 630 530 371 319 621 2,054 773 847 831 1,651 (WY) (1973) (1982) (2002) (1997) (1996) (1981) (1986) (1986) (1998) (1979) (1979) (1998) MIN 231 108 72.1 51.2 37.0 30.4 26.4 96.7 73.1 66.7 119 145 (WY) (1968) (1979) (1992) (1979) (1992) (1979) (1970) (1973) (1997) (1994) (1970) (1986) RIO CULEBRINAS BASIN 473 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1967 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 124,195 ANNUAL MEAN 340 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 5,710 LOWEST DAILY MEAN 41 ANNUAL SEVEN-DAY MINIMUM 42 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE INSTANTANEOUS LOW FLOW ANNUAL RUNOFF (AC-FT) 246,300 ANNUAL RUNOFF (CFSM) 4.78 ANNUAL RUNOFF (INCHES) 64.89 10 PERCENT EXCEEDS 704 50 PERCENT EXCEEDS 157 90 PERCENT EXCEEDS 54 124,375 341 299 457 1986 179 1977 Nov 13 5,710 Nov 13 17,000 Sep 22, 1998 Mar 4 32 Mar 24 19 Apr 16, 1979 Feb 27 34 Mar 20 20 Apr 13, 1979 Not determined May 17 41,200 Sep 16, 1975 29.92 May 17 36.60 Sep 16, 1975 31 Mar 23 16 Apr 17, 1979 246,700 216,500 4.79 4.20 64.98 57.04 652 605 154 136 54 43 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- --- 474 RIO CULEBRINAS BASIN 50148890 RIO CULEBRINAS AT MARGARITA DAM NEAR AGUADA, PR LOCATION.--Lat 18q23'40", long 67q09'04", Hydrologic Unit 21010003, on right bank 40 ft upstream of Margarita Dam spillway 0.2 mi (0.32 km) upstream of Highway 2 at Aguadilla Filtration Plant water intake at Río Culebrinas, 1.05 mi (1.69 km) northeast of Central Coloso and 2.5 5 mi (4.10 km) southeast from Aguadilla Plaza. DRAINAGE AREA.--94.6 mi2 (245 km2). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1998 to current year. GAGE.--Water-stage recorder and crest-stage gage. Elevation of gage is 48.6 ft. (14.8 m), from topographic map. For mean sea level elevations add 3.0 ft to gage-height readings. REMARKS.--Records poor. Gage-height and precipitation satellite telemetry at station. There are water extraction activities at t he reservoir by PRASA. DISCHARGE, CUBIC FEET PER SECOND WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 616 1,340 1,270 107 100 56 e68 156 472 169 99 e585 2 584 690 319 107 84 49 152 139 1,200 362 129 281 3 522 967 230 108 105 47 69 112 501 1,020 135 291 4 672 314 221 103 304 46 84 310 349 458 132 256 5 567 320 268 100 474 46 412 513 1,130 251 258 320 6 283 244 195 102 392 41 582 286 1,570 186 158 475 7 257 260 187 97 134 41 326 140 732 155 176 e227 8 708 203 179 97 101 41 125 127 638 143 203 529 9 1,630 247 179 99 87 40 263 398 525 141 186 696 10 992 787 169 103 82 43 327 315 364 137 119 465 11 908 531 157 93 76 43 223 309 542 154 326 608 12 816 376 153 88 67 38 114 333 499 173 331 698 13 655 1,300 149 82 66 36 205 196 312 128 330 514 14 796 1,950 145 84 88 41 654 491 381 123 308 331 15 1,280 1,330 145 82 70 38 549 509 671 114 777 211 16 1,520 1,060 134 87 67 39 258 1,660 284 110 487 190 17 1,080 760 151 80 70 36 210 2,240 260 105 216 295 18 1,040 687 190 75 68 38 930 2,620 498 139 e161 377 19 395 383 145 77 62 34 854 1,660 e1,040 224 617 192 20 316 335 139 71 61 31 801 1,340 e424 115 905 172 21 292 307 137 70 68 43 839 1,180 929 408 228 208 22 362 295 132 70 64 39 938 534 402 210 179 235 23 1,050 254 178 89 60 32 325 406 280 122 469 188 24 868 224 251 70 56 31 775 621 278 105 475 449 25 356 213 140 128 55 27 1,140 360 242 236 353 464 26 308 414 142 178 54 26 736 288 217 176 406 552 27 295 424 143 134 57 51 660 254 205 169 996 453 28 238 223 135 88 54 115 269 235 196 180 654 248 29 221 214 131 76 135 208 211 187 122 241 192 30 216 396 128 82 140 176 199 180 104 612 190 31 1,190 119 102 e60 176 100 1,430 TOTAL 21,033 17,048 6,361 2,929 3,026 1,523 13,272 18,318 15,508 6,339 12,096 10,892 MEAN 678 568 205 94.5 108 49.1 442 591 517 204 390 363 MAX 1,630 1,950 1,270 178 474 140 1,140 2,620 1,570 1,020 1,430 698 MIN 216 203 119 70 54 26 68 112 180 100 99 172 AC-FT 41,720 33,810 12,620 5,810 6,000 3,020 26,330 36,330 30,760 12,570 23,990 21,600 CFSM 7.17 6.01 2.17 1.00 1.14 0.52 4.68 6.25 5.46 2.16 4.12 3.84 IN. 8.27 6.70 2.50 1.15 1.19 0.60 5.22 7.20 6.10 2.49 4.76 4.28 STATISTICS OF MONTHLY MEAN DATA FOR WATER YEARS 1998 - 2003, BY WATER YEAR (WY) MEAN 656 577 223 119 75.8 101 243 379 380 296 523 645 MAX 778 792 392 207 108 318 442 591 632 408 949 970 (WY) (2000) (2000) (2002) (1999) (2003) (1999) (2003) (2003) (1999) (2001) (1998) (1998) MIN 588 252 92.7 71.6 52.1 35.5 89.8 257 156 204 213 363 (WY) (2001) (2001) (2001) (2001) (2001) (2000) (2000) (2000) (2002) (2003) (2000) (2003) 475 RIO CULEBRINAS BASIN 50148890 RIO CULEBRINAS AT MARGARITA DAM NEAR AGUADA, PR—Continued DISCHARGE, SUMMARY STATISTICS FOR 2002 CALENDAR YEAR FOR 2003 WATER YEAR WATER YEARS 1998 - 2003 IN CUBIC FEET PER SECOND ANNUAL TOTAL 122,513 ANNUAL MEAN 336 HIGHEST ANNUAL MEAN LOWEST ANNUAL MEAN HIGHEST DAILY MEAN 2,110 LOWEST DAILY MEAN 32 ANNUAL SEVEN-DAY MINIMUM 40 MAXIMUM PEAK FLOW MAXIMUM PEAK STAGE ANNUAL RUNOFF (AC-FT) 243,000 ANNUAL RUNOFF (CFSM) 3.55 ANNUAL RUNOFF (INCHES) 48.18 10 PERCENT EXCEEDS 897 50 PERCENT EXCEEDS 179 90 PERCENT EXCEEDS 56 128,345 352 340 362 1999 308 2001 Aug 10 2,620 May 18 3,860 Sep 22, 1998 Mar 23 26 Mar 26 17 Apr 18, 2000 Mar 19 33 Mar 20 26 Apr 13, 2000 3,750 May 18 5,480 Sep 22, 1998 15.00 May 18 18.28 Sep 22, 1998 254,600 246,200 3.72 3.59 50.47 48.81 845 843 216 200 63 53 e Estimated 10,000 5,000 2,000 1,000 500 200 100 50 20 10 2002 2003 O N D J F M A M J J A S --- --- --- --- --- --- 476 RIO CULEBRINAS BASIN 50148890 RIO CULEBRINAS AT MARGARITA DAM NEAR AGUADA, PR—Continued WATER-QUALITY RECORD PERIOD OF RECORD.--July 1998 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED-SEDIMENT DISCHARGE: October 2001 to current year. INSTRUMENTATION.--USDH-48 and automatic sediment sampler since 2001. REMARKS.-- Sediment samples were collected by a local observer on a weekly basis. During high flow events sediment samples were collected with automatic sediment sampler. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 3,680 mg/L May 18, 2003; Minimum daily mean, 5 mg/L February 3-6, 2002. SEDIMENT LOADS: Maximum daily mean, 29,200 tons (26,490 tonnes) May, 2003; Minimum daily mean, 0.79 ton (0.61 tonne) March 6, 20 02. EXTREMES FOR CURRENT YEAR 2003.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 3,680 mg/L May 18, 2003; Minimum daily mean, 6 mg/L January 20, 21, 2003. SEDIMENT LOADS: Maximum daily mean, 29,200 tons (26,490 tonnes) May 18, 2003; Minimum daily mean, 0.79 ton (0.72 tonne) March 26, 2003. SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY) WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) OCTOBER NOVEMBER DECEMBER 1 616 367 1,340 1,340 1,190 6,860 1,270 1,760 9,980 2 584 549 1,130 690 540 1,650 319 552 486 3 522 496 861 967 857 3,900 230 342 215 4 672 648 1,400 314 209 178 221 159 95 5 567 417 857 320 196 177 268 159 132 6 283 113 87 244 159 105 195 78 41 7 257 111 88 260 139 98 187 70 35 8 708 494 1,640 203 121 66 179 64 31 9 1,630 574 3,260 247 155 164 179 53 26 10 992 346 1,300 787 590 2,220 169 42 19 11 908 666 2,490 531 443 983 157 33 14 12 816 879 2,020 376 343 585 153 39 16 13 655 733 1,600 1,300 936 6,190 149 49 19 14 796 815 2,120 1,950 1,910 12,800 145 58 23 15 1,280 900 5,570 1,330 1,300 6,450 145 48 19 16 1,520 1,260 7,350 1,060 1,150 3,780 134 22 7.9 17 1,080 337 1,490 760 769 1,930 151 29 12 18 1,040 414 1,430 687 518 1,390 190 41 21 19 395 185 200 383 174 181 145 36 14 20 316 116 100 335 152 137 139 24 9.1 21 292 90 74 307 159 131 137 37 14 22 362 154 193 295 134 107 132 58 21 23 1,050 655 4,750 254 97 67 178 125 86 24 868 720 2,790 224 62 38 251 230 182 25 356 196 191 213 52 30 140 74 28 26 308 150 124 414 332 706 142 55 21 27 295 125 100 424 262 515 143 36 14 28 238 101 65 223 57 34 135 25 8.9 29 221 91 54 214 54 31 131 17 6.1 30 216 87 51 396 375 1,340 128 32 11 31 1,190 871 6,390 119 54 17 TOTAL 21,033 51,115 17,048 52,843 6,361 11,624.0 --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- RIO CULEBRINAS BASIN 477 50148890 RIO CULEBRINAS AT MARGARITA DAM NEAR AGUADA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JANUARY FEBRUARY MARCH 1 107 76 22 100 51 15 56 38 5.7 2 107 97 28 84 24 5.4 49 81 11 3 108 114 33 105 40 12 47 135 17 4 103 76 21 304 312 351 46 178 22 5 100 27 7.2 474 675 1,870 46 108 13 6 102 23 6.2 392 1,040 1,460 41 23 2.5 7 97 32 8.4 134 432 157 41 13 1.4 8 97 40 10 101 280 77 41 15 1.7 9 99 39 10 87 129 31 40 26 2.9 10 103 36 10 82 40 8.8 43 38 4.4 11 93 37 9.2 76 38 7.8 43 28 3.1 12 88 38 9.1 67 36 6.5 38 12 1.2 13 82 38 8.4 66 35 6.2 36 15 1.5 14 84 30 6.8 88 33 8.0 41 22 2.4 15 82 24 5.4 70 35 6.7 38 19 1.9 16 87 33 7.8 67 38 6.8 39 15 1.5 17 80 41 8.8 70 40 7.6 36 11 1.1 18 75 27 5.5 68 43 7.9 38 10 1.1 19 77 10 2.1 62 47 7.9 34 11 1.0 20 71 6 1.2 61 52 8.6 31 12 0.99 21 70 6 1.2 68 56 10 43 13 1.5 22 70 7 1.3 64 48 8.3 39 13 1.3 23 89 7 1.7 60 37 6.0 32 12 1.0 24 70 7 1.3 56 34 5.1 31 13 1.1 25 128 56 25 55 32 4.8 27 13 1.0 26 178 130 64 54 25 3.6 26 11 0.79 27 134 92 35 57 17 2.6 51 32 8.7 28 88 52 12 54 24 3.5 115 68 28 29 76 28 5.9 135 80 36 30 82 26 6.4 140 112 48 31 102 41 16 e60 e29 e4.7 TOTAL 2,929 389.9 3,026 4,105.1 1,523 229.48 APRIL MAY JUNE 1 e68 e34 e6.6 156 82 35 472 387 2,420 2 152 104 53 139 64 24 1,200 2,500 10,300 3 69 51 9.6 112 44 14 501 495 820 4 84 47 12 310 471 1,590 349 134 125 5 412 526 1,210 513 1,080 2,870 1,130 1,430 11,200 6 582 807 1,630 286 379 386 1,570 2,620 13,700 7 326 368 452 140 155 59 732 990 2,170 8 125 74 25 127 151 52 638 872 1,750 9 263 271 653 398 586 1,300 525 525 888 10 327 368 517 315 351 532 364 269 266 11 223 146 101 309 236 515 542 941 2,370 12 114 72 22 333 236 356 499 1,410 2,310 13 205 223 523 196 126 189 312 166 140 14 654 932 2,530 491 563 1,280 381 422 988 15 549 724 1,590 509 633 2,600 671 818 2,890 16 258 319 253 1,660 2,250 14,000 284 182 140 17 210 251 142 2,240 2,790 20,000 260 174 123 18 930 1,150 3,610 2,620 3,680 29,200 498 593 1,370 19 854 1,220 3,820 1,660 2,170 12,200 e1,040 e1,460 e6,850 20 801 1,100 3,200 1,340 1,660 8,540 e424 e555 e800 21 839 1,020 3,690 1,180 1,540 7,090 929 1,310 5,920 22 938 1,390 4,980 534 325 475 402 332 445 23 325 343 303 406 190 210 280 92 69 24 775 852 4,450 621 591 1,590 278 82 62 25 1,140 1,470 6,410 360 97 101 242 72 47 26 736 830 2,240 288 76 59 217 63 37 27 660 811 2,060 254 71 49 205 53 29 28 269 163 120 235 65 41 196 43 23 29 208 114 64 211 59 33 187 34 17 30 176 95 45 199 53 28 180 25 12 31 176 50 24 TOTAL 13,272 44,721.2 18,318 105,442 15,508 68,281 --- --- --- --- --- --- 478 RIO CULEBRINAS BASIN 50148890 RIO CULEBRINAS AT MARGARITA DAM NEAR AGUADA, PR—Continued SEDIMENT DISCHARGE, SUSPENDED (TONS/DAY)—CONTINUED WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Mean Mean Mean Mean concen- Load Mean concen- Load Mean concen- Load discharge tration (tons/ discharge tration (tons/ discharge tration (tons/ Day (cfs) (mg/l) day) (cfs) (mg/l) day) (cfs) (mg/l) day) JULY AUGUST SEPTEMBER 1 169 24 11 99 201 54 e585 e723 e1,430 2 362 336 872 129 222 90 281 437 333 3 1,020 1,450 7,380 135 276 105 291 407 347 4 458 592 1,070 132 263 105 256 332 230 5 251 255 174 258 371 294 320 496 780 6 186 137 71 158 280 123 475 808 1,500 7 155 108 45 176 178 85 e227 e286 e179 8 143 99 38 203 174 134 529 439 937 9 141 91 35 186 113 66 696 510 1,540 10 137 83 31 119 68 22 465 676 957 11 154 115 58 326 532 1,240 608 713 1,340 12 173 159 75 331 819 951 698 724 1,600 13 128 147 51 330 730 777 514 519 853 14 123 138 46 308 486 438 331 293 304 15 114 129 40 777 1,010 3,170 211 185 106 16 110 120 36 487 1,360 1,870 190 182 94 17 105 111 31 216 260 157 295 243 316 18 139 145 82 e161 e166 e72 377 444 535 19 224 233 185 617 683 3,750 192 346 179 20 115 129 40 905 1,500 6,350 172 353 164 21 408 545 1,570 228 122 75 208 369 216 22 210 236 170 179 111 54 235 410 273 23 122 117 39 469 840 2,100 188 381 220 24 105 97 28 475 899 1,450 449 515 782 25 236 377 459 353 658 644 464 506 885 26 176 277 137 406 641 831 552 872 2,550 27 169 216 96 996 1,290 8,000 453 864 1,400 28 180 204 99 654 1,290 3,640 248 137 98 29 122 203 67 241 378 247 192 94 49 30 104 203 57 612 929 3,780 190 86 44 31 100 202 54 1,430 2,140 10,700 TOTAL 6,339 13,147 12,096 51,374 10,892 20,241 YEAR 128,345 423,512.68 e Estimated WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 SILT AND CLAY PERCENT OF SUSPENDED SEDIMENT Suspnd. Sus- Sus­ sedi­ pended pended Instan­ ment, sedi­ sedi­ taneous sieve ment ment dis­ diametr concen­ dis­ charge, percent tration charge, Date Time cfs <.063mm mg/L tons/d (00061) (70331) (80154) (80155) JUL 25... 1935 715 96 1,160 2,240 SEP 11... 1740 1,190 97 873 2,800 12... 0310 1,090 95 1,040 3,050 WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 PARTICLE SIZE DISTRIBUTION OF SUSPENDED SEDIMENT Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Suspnd. Sus- Sus­ sedi­ sedi­ sedi­ sedi­ sedi­ sedi­ pended pended Instan­ ment, ment, ment, ment, ment, ment, sedi­ sedi­ taneous falldia falldia falldia falldia falldia sieve ment ment dis- nat wat nat wat nat wat nat wat nat wat diametr concen­ dis­ charge, percent percent percent percent percent percent tration charge, Date Time cfs <.002mm <.004mm <.008mm <.016mm <.031mm <.063mm mg/L tons/d (00061) (70326) (70327) (70328) (70329) (70330) (70331) (80154) (80155) AUG 11... 1912 1,120 60 68 74 87 91 96 3,250 9,830 RIO CULEBRINAS BASIN 479 50149100 RIO CULEBRINAS NEAR AGUADA, PR LOCATION.--Lat 18q24'03", long 67q09'40", at bridge on Highway 2, 2.3 mi (3.7 km) northeast of Aguada Plaza. DRAINAGE AREA.--97.0 mi2 (251.1 km2). PERIOD OF RECORD.--Water years 1958, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 Turbid­ ity, Dis- pH, Specif. Hard- Instan- wat unf solved water, conduc- ness, Magnes- Potas- taneous lab, Dis- oxygen, unfltrd tance, Temper- water, Calcium ium, sium, Sodium dis- Hach solved percent field, wat unf ature, unfltrd water, water, water, adsorp­ charge, 2100AN oxygen, of sat- std uS/cm water, mg/L as fltrd, fltrd, fltrd, tion Date Time cfs NTU mg/L uration units 25 degC deg C CaCO3 mg/L mg/L mg/L ratio (00061) (99872) (00300) (00301) (00400) (00095) (00010) (00900) (00915) (00925) (00935) (00931) DEC 04... 1615 -- 42 7.4 89 7.1 326 24.5 140 46.6 5.70 2.67 .4 MAR 26... 1150 4.2 12 7.4 -- 7.9 325 27.1 130 40.7 5.91 2.22 .5 MAY 14... 1535 -- 490 7.1 -- 7.6 257 25.6 110 36.7 4.29 2.68 .3 AUG 26... 0855 -- 380 7.2 -- 7.6 303 25.9 -- -- -- -- -­ SEP 17... 1530 -- 38 6.6 -- 7.7 340 28.2 140 46.8 5.79 2.38 .4 ANC, Residue Residue Ammonia wat unf water, total + fixed Chlor- Fluor- fltrd, at 105 org-N, Ammonia Nitrate Sodium, end pt, ide, ide, Silica, Sulfate Sulfide sum of Residue deg. C, water, water, water water, field, water, water, water, water, water consti- water, sus- unfltrd unfltrd unfltrd fltrd, mg/L as fltrd, fltrd, fltrd, fltrd, unfltrd tuents fltrd, pended, mg/L mg/L mg/L Date mg/L CaCO3 mg/L mg/L mg/L mg/L mg/L mg/L tons/d mg/L as N as N as N (00930) (00410) (00940) (00950) (00955) (00945) (00745) (70301) (70302) (00530) (00625) (00610) (00620) DEC 04... 10.5 136 9.99 <.17 29.8 7.4 -- 194 -- 44 .30 .02 -­ MAR 26... 13.9 134 12.9 .11 36.2 6.1 <.1 198 2.25 <10 .40 .05 -­ MAY 14... 7.79 112 8.46 <.17 15.9 9.9 <.1 153 -- 440 1.2 .05 .68 AUG 26... -- 134 -- -- -- -- -- -- -- 420 1.2 .04 .69 SEP 17... 10.3 148 11.9 <.2 30.4 8.9 -- 205 -- 53 .20 .03 .71 Nitrite Total Fecal Fecal Total + Organic Total nitro- COD, coli- strep- coli- Barium, Boron, nitrate Nitrite nitro- Phos- nitro- gen, high form, tococci form, water, water, water water, gen, phorus, gen, water, level, M-FC KF M-Endo, Arsenic unfltrd unfltrd unfltrd unfltrd water, water, water, unfltrd water, 0.7u MF MF, immed, water recover recover mg/L mg/L unfltrd unfltrd unfltrd mg/L unfltrd col/ col/ col/ unfltrd -able, -able, Date as N as N mg/L mg/L mg/L as NO3 mg/L 100 mL 100 mL 100 mL ug/L ug/L ug/L (00630) (00615) (00605) (00665) (00600) (71887) (00340) (31625) (31673) (31501) (01002) (01007) (01022) DEC 04... .930 <.01 .28 .07 1.2 5.4 <10 E620 9,200 -- -- -- -­ MAR 26... .320 <.01 .35 .07 .72 3.2 <10 E110 -- E1,000 <2 32.4 E17 MAY 14... .720 .04 1.1 .22 1.9 8.5 20 E6,400 -- 200,000 2 80.6 19 AUG 26... .710 .02 1.2 .21 1.9 8.5 30 24,000 -- E150,000 -- -- -­ SEP 17... .720 .01 .17 .05 .92 4.1 10 E880 -- 7,000 -- -- -­ 480 RIO CULEBRINAS BASIN 50149100 RIO CULEBRINAS NEAR AGUADA, PR—Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003—CONTINUED Chrom- Mangan- Phen- ium, Copper, Iron, Lead, ese, Mercury Silver, Zinc, olic water, water, water, water, water, water, Selen- water, water, com- Cadmium unfltrd unfltrd Cyanide unfltrd unfltrd unfltrd unfltrd ium, unfltrd unfltrd MBAS, pounds, water, recover recover water recover recover recover recover water, recover recover water, water, unfltrd -able, -able, unfltrd -able, -able, -able, -able, unfltrd -able, -able, unfltrd unfltrd Date ug/L ug/L ug/L mg/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L mg/L ug/L (01027) (01034) (01042) (00720) (01045) (01051) (01055) (71900) (01147) (01077) (01092) (38260) (32730) DEC 04... -- -- -- -- -- -- -- -- -- -- -- -- -- MAR 26... <.2 <.8 <10 <.01 250 <1 62.1 <.02 <3 <.3 E17 <.10 <16 MAY 14... <.2 4.1 20 <.01 6,530 3 362 .04 <3 <.3 <25 <.10 <16 AUG 26... -- -- -- -- -- -- -- -- -- -- -- -- -- SEP 17... -- -- -- -- -- -- -- -- -- -- -- -- -- < -- Less than E -- Estimated value PESTICIDE ANALYSES Chlor- alpha- Carbo- dane, Di- Endo- pheno- tech- Chlor- Diazi- chlor- Diel- Disul- 2,4,5-T 2,4-D Aldrin, sulfan, thion, nical, pyrifos non, prop, drin, foton, Endrin, water water water, water, water, water, water water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date Time ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39740) (39730) (39330) (39388) (39786) (39350) (38932) (39570) (82183) (39380) (39011) (39390) MAY 14... 1535 <.01 .44 <.01 <.01 <.02 <.1 <.01 M <.02 <.017 <.10 <.02 p,p-' Hepta- Methyl Meth­ chlor Hepta- Mala- para- p,p-' p,p-' p,p-' oxy- Para- Ethion, Fonofos epoxide chlor, Lindane thion, thion, Mirex, DDD, DDE, DDT, chlor, thion, water, water water water, water, water, water, water, water, water, water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L ug/L (39398) (82614) (39420) (39410) (39340) (39530) (39600) (39755) (39360) (39365) (39370) (39480) (39540) MAY 14... <.01 <.01 <.009 <.01 <.014 <.10 <.01 <.012 <.016 <.014 <.009 <.015 <.01 Toxa- Tribu- PCBs, Phorate Silvex, phene, phos, water, water water, water, water, unfltrd unfltrd unfltrd unfltrd unfltrd Date ug/L ug/L ug/L ug/L ug/L (39516) (39023) (39760) (39400) (39040) MAY 14... <.1 <.02 <.02 <1 <.02 < -- Less than M -- Presence verified, not quantified 481 482 GROUND-WATER LEVELS RIO GUAJATACA BASIN 182422067015100. Local number, 165. LOCATION.--Lat 18q24'22", long 67q01'51", Hydrologic Unit 21010003, 5.6 mi northeast of Moca plaza, 4.7 mi southeast of Aguadilla US Naval Reservation radio antenna, and 1.63 mi northwest of La Virgen del Rosario Church, Name: Saltos 1 Well, Isabela. AQUIFER.--Cibao Formation. Aguada Limestone. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 16 in (0.4 m), cased 16 in (0.4 m) 0-40 ft (0-12.2 m), case d 12 in (0.30 m) 40­ 200 ft (12.2-61 m). Depth 158 ft (48.2 m), sounded depth measured on October 4,2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 689 ft (210 m), above mean sea level. Measuring point: Hole on pump base, 0.5 f t (0.15 m), above land- surface datum. Prior to October 6, 1988, hole on top of pipe on top of pump base, 0.8 ft (0.24 m), above land-surface datum. Pri or to November 1985, hole on top of pump base, 1 ft (0.3 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recoder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. Formerly published as 182421067015000. Well is affected by nearby pumping. PERIOD OF RECORD.--January 1982 to March 1985, November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 35.17 ft (10.7 m), below land-surface datum, June 6, 2002; lowest water level measured, 70.6 ft (21.5 m), below land-surface datum, June 18, 1982. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 35.44 35.99 37.72 39.45 2 35.39 35.84 37.73 39.32 3 35.44 35.77 37.75 39.90 4 35.44 35.71 37.75 39.75 5 35.45 35.69 37.98 39.60 39.45 39.83 40.56 39.78 39.75 40.29 40.05 40.10 39.49 39.78 40.35 40.30 39.70 40.03 40.00 40.13 39.49 39.76 40.20 40.08 39.62 39.95 39.99 40.01 39.64 39.76 40.04 39.93 39.61 39.89 39.89 39.94 40.10 39.75 40.00 39.87 39.57 39.85 39.83 40.60 6 35.39 35.59 38.03 39.52 7 35.33 35.51 38.06 39.46 8 35.37 36.25 38.09 39.46 9 35.39 36.00 38.13 39.45 10 35.28 36.22 38.18 39.43 39.89 39.73 39.96 39.83 40.16 39.78 39.80 40.36 39.82 39.72 39.89 39.80 40.01 39.77 39.80 40.18 39.80 39.68 39.83 40.38 39.89 40.31 40.39 40.11 39.75 39.59 39.82 40.15 39.82 40.09 40.24 40.03 39.69 39.57 40.43 40.02 39.81 39.99 40.15 39.98 11 35.55 36.27 38.20 39.41 12 35.52 36.44 38.87 39.36 13 35.47 36.48 38.64 39.30 14 35.35 36.53 38.54 39.29 15 35.32 36.58 38.50 39.29 39.64 39.62 40.19 39.95 39.75 39.94 40.77 40.52 39.60 39.66 40.10 39.88 39.68 39.88 40.48 40.28 39.62 39.65 40.11 39.81 40.22 39.85 40.37 40.13 39.61 39.61 40.05 39.77 40.05 39.83 40.26 40.04 40.18 39.59 39.95 39.74 39.88 40.35 40.16 40.02 16 35.67 36.94 38.48 39.29 17 35.62 36.92 38.49 39.26 18 35.80 36.95 39.85 39.27 19 35.67 36.93 41.00 39.34 20 35.62 37.52 41.32 39.30 39.99 39.69 39.85 39.67 39.87 40.16 40.09 40.09 39.89 40.35 39.79 40.16 39.80 40.08 40.83 40.69 39.87 40.07 39.80 39.91 39.78 40.02 40.58 40.44 39.84 40.02 39.79 39.83 39.77 39.96 40.43 40.28 39.78 39.98 39.76 39.77 39.77 39.87 40.27 40.15 21 35.54 37.47 40.86 39.24 22 35.53 37.48 40.50 39.18 23 35.47 37.51 40.27 39.18 24 35.82 37.51 40.04 39.20 25 35.69 37.51 39.92 39.25 39.65 39.94 39.69 39.71 39.71 39.81 40.13 40.10 39.58 39.86 39.67 39.73 39.63 39.80 40.03 40.04 39.65 39.81 39.78 39.74 39.60 40.42 40.64 39.92 39.72 39.79 39.86 39.69 40.14 40.16 40.42 39.89 40.14 39.77 39.80 39.69 39.96 40.07 40.27 39.82 26 35.60 37.56 39.84 39.23 27 35.52 37.51 39.77 39.21 28 35.48 37.57 39.67 39.87 29 35.45 37.63 39.59 39.74 30 35.41 37.70 39.53 39.61 31 35.37 --- 39.49 39.49 39.91 39.76 39.79 39.69 39.87 40.03 40.19 40.34 39.87 39.86 39.79 39.68 39.83 39.93 40.14 40.13 39.84 39.86 39.76 40.20 39.81 39.87 40.11 40.01 --- 39.84 39.78 39.95 39.80 39.83 40.02 39.95 --- 39.79 39.80 39.82 39.77 40.51 39.99 39.84 --- 39.80 --- 39.79 --- 40.23 39.95 --­ MEAN 35.50 36.72 39.06 39.41 39.77 39.79 39.94 39.88 39.82 40.02 40.20 40.14 WTR YR 2003MEAN39.18 HIGHEST 35.27 OCT 10, 2002 LOWEST 41.44 DEC 20, 2002 35 36 37 38 39 40 41 42 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 483 GROUND-WATER LEVELS RIO GUAJATACA BASIN—Continued 182647066552400. Local number, 202. LOCATION.--Lat 18q26'47", long 66q55'24", Hydrologic Unit 21010002, 2.22 mi southeast of Quebradillas plaza, 1.29 mi north of José de Diego School , and 1.99 mi northwest of El Calvario Church, Name: Carmelo Barreto García Well, Quebradillas. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-296 ft (0-90.2 m), diameter 13 in (0.33 m), cased 13 in (0.33 m) 0-550 ft (0-168 m), perforated 270-529 ft (82.3-161 m). Depth 550 ft (168 m). INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 475 ft (145 m), above mean sea level, from topographic map. Measuring point: Ho le in horizontal steel plate, 1.11 ft (0.34 m), above land-surface datum. Priot to February 18, 1998, hole on side of casing, 1.5 ft (0.46 m), above land-surface datum. Prior July 25, 1986, top of shelter floor, 3.3 ft (1 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. PERIOD OF RECORD.--November 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 401.9 ft (122 m), below land-surface datum, February 6, 1999; lowest water level recorded, 453.9 ft (138 m), below land-surface datum, May 14, 15, 16, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- 432.02 433.88 2 --- --- 432.06 433.93 3 --- --- 432.11 433.98 4 --- --- 432.19 434.04 5 --- --- 432.24 434.12 435.89 437.44 439.51 439.17 437.96 439.15 440.87 442.33 435.97 437.53 439.58 439.00 437.96 439.21 440.93 442.33 436.05 437.60 439.64 438.87 437.96 439.27 441.02 442.33 436.11 437.65 439.67 438.73 437.99 439.34 441.04 442.34 436.15 437.73 439.74 438.63 438.00 439.40 441.08 442.36 6 --- --- 432.28 434.16 7 --- --- 432.33 434.23 8 --- --- 432.39 434.32 9 --- --- 432.46 434.40 10 --- --- 432.50 434.47 436.19 437.79 439.80 438.54 438.02 439.45 441.14 442.36 436.24 437.86 439.85 438.45 438.06 439.51 441.20 442.36 436.29 437.92 439.88 438.40 438.08 439.56 441.25 442.39 436.30 437.97 439.92 438.35 438.10 439.62 441.32 442.41 436.32 438.04 439.96 438.31 438.19 439.66 441.38 442.43 11 --- --- 432.56 434.52 12 --- --- 432.61 434.60 13 --- --- 432.66 434.64 14 --- 431.48 432.69 434.71 15 --- 431.53 432.76 434.80 436.35 438.13 --- 438.29 438.20 439.72 441.40 442.46 436.40 438.20 --- 438.27 438.24 439.77 441.47 442.49 436.45 438.26 --- 438.23 438.29 439.83 441.52 442.49 436.52 438.33 --- 438.27 438.33 439.88 441.57 442.48 436.55 438.38 --- 438.27 438.33 439.92 441.67 442.45 16 --- 431.57 432.82 434.85 17 --- 431.61 432.89 434.91 18 --- 431.64 432.96 434.98 19 --- 431.62 433.05 435.08 20 --- 431.63 433.10 435.13 436.62 438.45 --- 438.26 438.41 439.99 441.73 442.42 436.67 438.51 --- 438.26 438.44 440.05 441.79 442.39 436.75 438.56 --- 438.30 438.49 440.11 441.85 442.37 436.82 438.65 --- 438.32 438.54 440.16 441.88 442.35 436.86 438.74 --- 438.31 438.61 440.21 441.89 442.36 21 --- 431.65 433.16 435.18 22 --- 431.69 433.23 435.23 23 --- 431.73 433.30 435.30 24 --- 431.74 433.34 435.38 25 --- 431.77 433.42 435.46 436.90 438.79 --- 438.30 438.63 440.27 441.94 442.38 436.95 438.84 --- 438.27 438.67 440.34 441.99 442.40 437.05 438.91 --- 438.24 438.72 440.39 442.06 442.40 437.13 438.97 440.12 438.17 438.78 440.43 442.09 442.39 437.16 439.04 440.03 438.13 438.82 440.50 442.14 442.38 26 --- 431.80 433.47 435.53 27 --- 431.81 433.54 435.57 28 --- 431.87 433.60 435.66 29 --- 431.90 433.66 435.71 30 --- 431.96 433.74 435.77 31 --- --- 433.80 435.82 437.23 439.10 439.91 438.12 438.87 440.57 442.19 442.38 437.32 439.19 439.80 438.07 438.93 440.61 442.23 442.39 437.37 439.28 439.63 438.03 439.02 440.67 442.24 442.38 --- 439.32 439.47 437.98 439.06 440.71 442.26 442.39 --- 439.37 439.31 437.96 439.11 440.79 442.28 442.37 --- 439.44 --- 437.95 --- 440.82 442.31 --­ MEAN --- --- 432.87 434.85 436.59 438.45 --- 438.34 438.43 440.00 441.67 442.39 WTR YR 2003MEAN437.91 HIGHEST 431.45 NOV 14, 2002 LOWEST 442.52 SEPT 12, 2003 400 410 420 430 440 450 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 484 GROUND-WATER LEVELS RIO CAMUY BASIN 182723066511200. Local number, 1026. LOCATION.--Lat 18q27'23", long 66q51'12", Hydrologic Unit 21010002, 1.6 mi south of the intersection of Hwy 119 with Hwy 2, 1.35 mi east of Hwy 119 of, and 0.01 mi east of Hwy 486, Name: Zanja 4 Well, Camuy. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.3 m). Depth 585 ft (178 m). DATUM.--Elevation of land-surface datum is about 360 ft (110 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4 in (0.1 m) casing, 3 ft (0.91 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--February 25, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 161.8 ft (49.3 m), below land-surface datum, September 22, 1998; lowest water level recorded, WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 14 321.50 JAN 09 328.91 MAR 06 340.68 MAY 15 318.74 JULY 24 338.94 SEPT 11 329.13 DEC 04 333.65 FEB 12 335.03 APR 16 338.34 JUNE 10 329.31 AUG 15 336.27 WATER YEAR 2003 HIGHEST 318.74 MAY 15, 2003 LOWEST 338.94 JULY 24, 2003 180 200 220 240 260 280 300 320 340 360 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 485 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN 182756066454700. Local number, 1051 LOCATION.--Lat 18q27'56", long 66q45'47", Hydrologic Unit 21010002, 0.04 mi north of Hwy 653, 1.86 mi west of Hwy 129, and 1.55 mi west of the University of Puerto Rico, Arecibo Campus, Name: Barreto 1 Well, Arecibo. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m). Depth 300 ft (91.4 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 164 ft (50 m), above mean sea level, from topographic map. Measuring point: Top of white PVC cap 3.37 ft (1.03 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on October 24, 1997. Well is affected by marine ti des. PERIOD OF RECORD.--October 24, 1997 to January 21, 2003, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 159.4 ft (48.6 m), below land-surface datum, November 1, 2, 3, 1998; lowest water level recorded, 161.4 ft (49.2 m), below land-surface datum, January 6, 1998. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 160.79 160.78 160.91 160.98 2 160.79 160.77 160.91 160.99 3 160.74 160.75 160.92 160.99 4 160.68 160.74 160.89 160.99 5 160.66 160.73 160.91 161.01 --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 6 160.67 160.74 160.92 161.01 7 160.66 160.77 160.92 161.02 8 160.63 160.80 160.95 161.03 9 160.64 160.82 160.94 161.01 10 160.66 160.84 160.94 161.00 --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 11 160.70 160.84 160.93 160.98 12 160.71 160.86 160.93 161.00 13 160.69 160.86 160.94 161.00 14 160.67 160.82 160.91 161.03 15 160.67 160.78 160.88 161.03 --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 16 160.62 160.79 160.87 161.03 17 160.59 160.81 160.87 161.06 18 160.60 160.82 160.87 161.07 19 160.61 160.83 160.91 161.07 20 160.64 160.85 160.91 161.08 --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 21 160.66 160.86 160.93 --­ 22 160.65 160.87 160.95 --­ 23 160.64 160.89 160.97 --­ 24 160.67 160.93 160.97 --­ 25 160.69 160.95 160.99 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 26 160.71 160.95 160.99 --­ 27 160.71 160.94 160.99 --­ 28 160.74 160.94 160.99 --­ 29 160.77 160.93 160.98 --­ 30 160.78 160.91 160.97 --­ 31 160.78 --- 160.97 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ MEAN 160.68 160.84 160.93 --- --- --- --- --- --- --- --- --­ WTR YR 2003MEAN160.85 HIGHEST 160.58 OCT 17, 2002 LOWEST 161.14 JAN 18, 2003 159.0 159.5 160.0 160.5 161.0 161.5 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 486 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued 182737066370900. Local number, 204. LOCATION.--Lat 18q27'37", long 66q37'09", Hydrologic Unit 21010002, 5.26 mi west of Barceloneta plaza, 1.58 mi north of Hwy 2 km 63.7, and 3.67 mi southwest of Escuela Agustín Balseiro, Name: Gilberto Rivera Well, Arecibo. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Abandoned unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 57 ft (17.4 m). INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is 48 ft (14.63 m), above mean sea level. Measuring point: Top of shelter floor, 3.06 ft (0.93 m), avobe land-surface datum. Prior to August 8, 2003, air hole on pump base, 0.5 ft (0.15 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 7, 1997. Well is affected by marine tides. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 50 ft (15.2 m), below land-surface datum, May 14, 1986; lowest water level recorded, 53.1 ft (16.2 m), below land-surface datum, January 29, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 51.74 51.75 51.83 51.88 2 51.76 51.72 51.82 51.90 3 51.73 51.66 51.81 51.90 4 51.66 51.65 51.77 51.89 5 51.62 51.62 51.78 51.90 51.91 51.92 51.89 51.79 51.95 51.90 51.81 51.94 51.91 51.92 51.88 51.81 51.96 51.87 51.81 51.99 51.93 51.92 51.92 51.80 51.97 51.86 51.82 52.01 51.94 51.89 51.96 51.80 51.96 51.84 51.85 52.02 51.96 51.89 51.93 51.79 51.96 51.86 51.88 52.03 6 51.60 51.63 51.79 51.91 7 51.58 51.67 51.80 51.91 8 51.52 51.72 51.83 51.92 9 51.50 51.76 51.83 51.91 10 51.53 51.78 51.83 51.91 51.98 51.91 51.94 51.84 51.95 51.86 51.93 52.07 51.98 51.94 51.95 51.87 51.97 51.86 52.03 52.04 52.00 51.95 51.99 51.87 51.98 51.86 52.00 52.01 51.99 51.93 51.97 51.89 51.97 51.86 51.96 51.93 51.99 51.91 51.96 51.89 51.98 51.87 51.94 51.90 11 51.58 51.81 51.82 51.90 12 51.62 51.86 51.84 51.91 13 51.64 51.83 51.82 51.92 14 51.64 51.80 51.81 51.94 15 51.62 51.76 51.74 51.92 51.98 51.89 51.95 51.88 51.97 51.88 51.90 51.88 51.97 51.88 51.91 51.88 51.97 51.86 51.83 51.87 51.96 51.92 51.89 51.88 51.98 51.82 51.82 51.84 51.95 51.93 51.89 51.84 51.97 51.82 51.83 51.83 51.96 51.91 51.91 51.83 51.94 51.79 51.88 51.82 16 51.59 51.76 51.73 51.93 17 51.58 51.76 51.73 51.94 18 51.59 51.76 51.74 51.95 19 51.61 51.75 51.78 51.94 20 51.62 51.75 51.80 51.95 51.97 51.86 51.91 51.86 51.96 51.76 51.89 51.82 51.95 51.82 51.84 51.87 51.97 51.76 51.91 51.83 51.95 51.79 51.78 51.87 51.97 51.77 51.96 51.90 51.94 51.74 51.77 51.87 51.94 51.82 52.00 51.93 51.93 51.76 51.82 51.87 51.95 51.85 52.02 51.94 21 51.62 51.75 51.83 51.97 22 51.63 51.75 51.86 51.94 23 51.65 51.79 51.88 51.91 24 51.66 51.85 51.90 51.86 25 51.69 51.87 51.90 51.87 51.93 51.82 51.86 51.85 51.96 51.86 52.06 51.91 51.92 51.86 51.77 51.85 51.94 51.87 52.06 51.82 51.90 51.88 51.79 51.89 51.96 51.89 52.03 51.81 51.91 51.87 51.77 51.91 51.93 51.88 52.00 51.80 51.96 51.87 51.79 51.91 51.92 51.92 51.98 51.78 26 51.70 51.88 51.90 51.83 27 51.71 51.86 51.90 51.82 28 51.73 51.86 51.91 51.82 29 51.73 51.85 51.91 51.83 30 51.75 51.83 51.88 51.85 31 51.75 --- 51.87 51.90 51.97 51.88 51.80 51.90 51.93 51.96 51.97 51.78 51.92 51.88 51.79 51.91 51.92 51.98 51.93 51.78 51.92 51.89 51.78 51.93 51.91 51.92 51.92 51.78 --- 51.90 51.79 51.94 51.90 51.88 51.90 51.78 --- 51.91 51.78 51.94 51.91 51.86 51.89 51.79 --- 51.92 --- 51.94 --- 51.85 51.91 --­ MEAN 51.64 51.77 51.83 51.90 51.95 51.88 51.87 51.87 51.95 51.86 51.93 51.89 WTR YR 2003MEAN51.86 HIGHEST 51.47 OCT 9, 2002 LOWEST 52.11 FEB 16, 2003 50.5 51.0 51.5 52.0 52.5 53.0 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 487 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued 182616066364100. Local number, 1052. LOCATION.--Lat 18q26'16", long 66q36'41", Hydrologic Unit 21010002, 3 mi west of the intersection of Hwy 140 with Hwy 2 at Cruce Dávila, 0.32 mi southwest of Hwy 22, 0.15 mi north of Hwy 2, and 0.22 mi northeast of the intersection of Hwy 2 with Hwy 639, Name: Encantada Well, Arecibo. AQUIFER.--Aguada Limestone.AQUIFER.--Tertiary Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m). DATUM.--Elevation of land-surface datum is about 312 ft (95 m), above mean sea level, from topographic map. Measuring point: On shelter floor 3.4 ft (1.04 m), above land-surface datum. REMARKS.--Observation well. Well is affected by marine tides. PERIOD OF RECORD.--August 23, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 312.23 ft (95.2 m), below land-surface datum, September 13, 14, 1996; lowest water level recorded, 313.84 ft (95.7 m), below land-surface datum, April 3, 1998. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 01 313.12 JAN 09 313.36 APR 16 313.20 JUNE 10 313.41 AUG 08 313.37 SEPT 15 313.17 DEC 13 313.31 FEB 19 313.41 MAY 15 313.09 JULY 28 313.35 WATER YEAR 2003 HIGHEST 313.09 MAY 15, 2003 LOWEST 313.41 FEB 19, JUNE 10, 2003 312.40 312.60 312.80 313.00 313.20 313.40 313.60 313.80 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 488 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued 182626066345100. Local number, 1053. LOCATION.--Lat 18q26'26", long 66q34'51", Hydrologic Unit 21010002, 1.45 mi south of Hwy 682, 1.15 mi northwest of the intersection of Hwy 140 with Hwy 2 (Cruce Dávila), 0.48 mi north of Hwy 2, and approximately 100 ft (30.48 m) south of Hwy 22, Name: Tiburones Well, Barceloneta. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 12 in (0.3 m). Depth 320 ft (97.5 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 295 ft (89.9 m), above mean sea level, from topographic map. Measuring point: Hole on floor of instrument shelter, 3.15 ft (0.96 m), above land-surface datum. Prior October 27, 1997, top of 4 in (0.1 m) PVC cap, above shelter floor, 3.4 ft (1.04 m), above land- surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), re-installed on October 27, 1997. Well is affected by marine tides. PERIOD OF RECORD.--May 14, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 283.58 ft (86.43 m), below land-surface datum, October 1, 2002; lowest water level measured, 292.34 ft (89.1 m), below land-surface datum, April 13, 14, 2001. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 291.75 291.89 291.96 2 --- 291.72 291.89 292.00 3 --- 291.69 291.89 292.01 4 --- 291.69 291.89 292.00 5 --- 291.68 291.93 292.01 291.99 292.00 291.83 --- --- 291.92 291.86 291.99 292.00 292.01 291.82 --- --- 291.91 291.86 292.02 292.01 292.00 291.84 --- --- 291.89 291.87 292.03 292.03 291.97 291.89 --- --- 291.88 291.89 292.03 292.04 291.96 291.88 --- --- 291.89 291.91 292.04 6 --- 291.71 291.93 292.02 7 --- 291.76 291.94 292.00 8 --- 291.80 291.97 292.00 9 --- 291.84 291.96 291.98 10 --- 291.85 291.95 291.97 292.05 291.97 291.87 --- --- 291.89 291.94 292.05 292.05 291.99 291.87 --- --- 291.89 291.99 292.04 292.04 291.99 291.89 --- --- 291.88 292.01 292.01 292.04 291.97 291.89 --- --- 291.87 291.99 291.96 292.04 291.93 291.88 --- --- 291.87 291.98 291.93 11 291.58 291.86 291.94 291.95 12 291.61 291.90 291.95 291.96 13 291.63 291.87 291.92 291.97 14 291.62 291.84 291.88 292.00 15 291.59 291.80 291.83 292.00 292.04 291.91 291.86 --- --- 291.88 291.94 291.90 292.02 291.89 291.84 --- --- 291.86 291.90 291.89 292.00 291.92 291.81 --- --- 291.85 291.89 291.88 292.00 291.95 291.81 --- --- 291.84 291.90 291.87 292.03 291.93 291.81 --- --- 291.83 291.93 291.85 16 291.56 291.79 291.82 292.00 17 291.54 291.81 291.83 292.03 18 291.56 291.82 291.84 292.05 19 291.58 291.84 291.88 292.06 20 291.61 291.85 291.91 292.07 292.04 291.88 --- --- --- 291.82 291.95 291.83 292.03 291.83 --- --- --- 291.82 291.97 291.85 292.03 291.81 --- --- --- 291.83 292.01 291.89 292.01 291.75 --- --- --- 291.86 292.05 291.92 292.05 291.76 --- --- --- 291.89 292.07 291.93 21 291.62 291.85 291.95 292.08 22 291.65 291.86 291.97 292.04 23 291.67 291.90 292.01 291.98 24 291.72 291.95 292.02 291.93 25 291.75 291.99 292.01 291.91 292.04 291.80 --- --- --- 291.90 292.09 291.88 292.03 291.84 --- --- --- 291.90 292.08 291.79 292.01 291.84 --- --- --- 291.92 292.06 291.75 291.99 291.83 --- --- --- 291.92 292.01 291.72 292.02 291.82 --- --- --- 291.93 292.00 291.68 26 291.76 291.99 291.99 291.87 27 291.77 291.97 291.97 291.86 28 291.77 291.95 291.98 291.86 29 291.77 291.92 291.96 291.86 30 291.77 291.89 291.94 291.92 31 291.76 --- 291.94 291.97 292.04 291.83 --- --- --- 291.95 292.00 291.66 292.01 291.81 --- --- --- 291.97 291.96 291.65 292.00 291.83 --- --- --- 291.96 291.96 291.66 --- 291.84 --- --- --- 291.91 291.94 291.68 --- 291.85 --- --- 291.93 291.89 291.93 291.72 --- 291.85 --- --- --- 291.88 291.95 --­ MEAN --- 291.84 291.93 291.98 292.02 291.89 --- --- --- 291.89 291.96 291.87 WTR YR 2003MEAN291.90 HIGHEST 283.58 OCT 1, 2002 LOWEST 292.13 JAN 18, 2003 290.80 291.00 291.20 291.40 291.60 291.80 292.00 292.20 292.40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 489 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 01 291.72 DEC 13 291.92 APR 16 291.83 JUNE 30 291.93 JUNE 17 292.07 AUG 08 291.94 11 291.56 FEB 19 292.00 WATER YEAR 2003 HIGHEST 291.56 OCT 11, 2002 LOWEST 292.07 JUNE 17, 2003 490 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued 182639066385200. Local number, 1056. LOCATION.--Lat 18q26'39", long 66q38'52", Hydrologic Unit 21010002, 0.19 mi south of Hwy 2, 1.14 mi west of intersection of Hwy 2 with Hwy 22, 1.18 mi east southeast of Escuela Federico Degetau, Name: Santana 1 Well. AQUIFER.--Upper Aquifer. WELL CHARACTERISTICS.--Abandoned production well, diameter 12 in (0.3 m), open screened 175-220 ft (53.34-60.96 m). Depth 220 ft (60.96 m). DATUM.--Elevation of land-surface datum is about 131 ft (39.92 m), above mean sea level, from topographic map. Measuring point: Lower point 13/8 in slanted access pipe, 0.5 ft (0.15 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--August 10, 1995 to July 20, 2000, discontinued, October 25, 2002 to September 30, 2003. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 101.29 ft (30.87 m), below land-surface datum, January 7, 2000; lo west water level measured, 107.54 ft (32.78 m), below land-surface datum, June 3, 1998. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 25 102.68 JAN 09 103.03 MAR 06 103.10 MAY 1 5102.89 JULY 24 103.07 SEPT 11 103.08 DEC 13 102.94 FEB 12 103.12 APR 11 103.04 JUNE 1 0103.04 AUG 15 103.10 WATER YEAR 2003 HIGHEST 102.68 OCT 25, 2002 LOWEST 103.12 FEB 12, 2003 101.0 101.5 102.0 102.5 103.0 103.5 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 491 GROUND-WATER LEVELS RIO GRANDE DE ARECIBO BASIN—Continued 182209066340600. Local number, 1057. LOCATION.--Lat 18q22'09", long 66q34'06", Hydrologic Unit 21010002, 0.2 north of the intersection of Hwy 140 with Hwy 642, 1.15 mi south of the intersection of Hwy 140 with Hwy 641, and approximately 100 ft (30.48 m) west of Hwy 140, Name: PRASA Florida 1 Well, Florida. AQUIFER.--Cibao Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 12 in (0.3 m), Depth 200 ft (61 m). INSTRUMENTATION.--Pressure transducer with integrated data logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 607 ft (185 m), above mean sea level from topographic map. Measuring point: Hol e in concrete base 1.1 ft (0.33 m), above land-surface datum. Prior to September 20, 1996, shelter floor 4 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on August 12, 1996. PERIOD OF RECORD.--August 12, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 137.07 ft (41.8 m), below land-surface datum, November 8, 2001; lowest water level recorded, 157.63 ft (48 m), below land-surface datum, August 14, 1996. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 149.14 147.44 150.01 151.12 2 149.47 147.52 150.13 151.21 3 149.76 147.49 150.23 151.24 4 149.99 147.64 150.31 151.28 5 150.20 147.77 150.16 151.32 150.15 152.74 151.98 147.72 147.89 151.91 152.73 152.38 149.19 152.79 151.55 148.23 148.14 151.95 152.61 152.55 147.94 152.84 150.32 148.67 148.21 152.01 152.71 152.72 147.37 152.87 149.43 149.02 148.45 152.07 152.82 152.88 147.80 152.92 150.30 149.36 148.67 152.13 152.91 153.08 6 150.38 147.92 150.03 151.35 7 150.55 148.05 150.02 151.37 8 147.39 148.27 150.01 151.41 9 143.08 148.50 149.83 151.47 10 143.78 148.64 149.62 151.53 147.60 152.96 149.83 149.66 148.89 152.14 152.95 153.25 148.30 153.00 150.34 149.81 149.10 152.15 152.90 153.41 148.88 153.04 150.84 149.95 149.28 152.12 152.97 153.54 149.37 153.07 151.24 150.17 149.49 151.02 153.05 152.87 149.84 153.09 149.43 148.48 149.72 151.35 153.12 153.09 11 144.89 148.75 149.69 151.58 12 143.14 148.89 149.84 151.67 13 143.81 149.06 149.91 151.76 14 144.78 148.97 149.93 151.85 15 145.40 149.01 150.06 151.94 150.23 153.12 150.08 148.90 149.91 151.57 153.18 153.28 150.59 153.16 150.54 149.35 150.11 151.74 153.24 152.89 150.88 153.19 150.95 149.79 150.29 151.89 153.30 152.60 151.11 153.23 150.73 150.17 150.47 151.98 153.35 152.72 151.32 153.26 151.10 150.49 150.62 152.08 153.40 152.94 16 145.74 147.51 150.21 152.03 17 145.98 147.73 150.36 152.11 18 146.19 148.01 150.08 152.18 19 146.34 148.26 150.16 152.25 20 146.60 148.46 150.21 152.32 151.52 153.28 151.30 150.73 150.75 151.92 153.45 153.16 151.68 153.32 151.05 150.93 150.84 151.33 153.51 153.35 151.84 153.35 148.94 151.13 150.95 151.61 153.55 153.48 151.97 153.39 147.45 148.65 150.92 151.84 153.58 153.60 152.07 153.39 147.63 147.24 151.03 152.03 153.61 153.48 21 146.83 148.66 150.28 152.39 22 147.05 148.88 150.12 152.45 23 147.24 149.06 149.89 152.50 24 147.11 149.20 149.79 152.52 25 147.35 149.33 150.01 149.19 152.17 153.41 148.13 142.63 151.14 152.18 153.62 152.31 152.25 153.42 145.58 143.57 151.06 151.65 153.52 150.86 152.36 153.45 146.07 144.21 151.20 151.59 153.61 151.40 152.44 153.48 146.48 145.02 151.32 151.88 153.67 151.78 152.51 153.51 147.31 145.58 151.43 152.10 153.48 152.04 26 146.41 149.46 150.29 147.09 27 146.64 149.55 150.46 147.57 28 147.01 149.66 150.65 148.25 29 147.33 149.77 150.79 148.83 30 147.60 149.88 150.88 149.30 31 147.80 --- 151.00 149.76 152.58 153.54 147.38 145.95 151.52 152.29 152.13 152.29 152.64 153.57 147.46 146.31 151.62 152.37 152.44 152.52 152.69 153.16 145.89 146.67 151.70 152.47 152.38 152.75 --- 150.58 146.33 146.98 151.79 152.38 152.26 152.92 --- 151.18 147.08 147.29 151.85 152.54 152.18 153.06 --- 151.62 --- 147.60 --- 152.65 152.53 --­ MEAN 146.93 148.58 150.16 151.06 150.69 153.00 149.09 148.07 150.28 151.97 153.06 152.77 WTR YR 2003MEAN150.47 HIGHEST 142.61 MAY 21, 2003 LOWEST 153.70 AUG. 25, 2003 135 140 145 150 155 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 492 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182544066341500. Local number, 205. LOCATION.--Lat 18q25'44", long 66q34'15", Hydrologic Unit 21010002, 300 ft (91.4 m) west of Hwy 140, 0.5 mi southwest of Cruce Dávila, and 1.3 mi southwest of intersection of Hwy 140 with Hwy 22, Name: NC-5 Cruce Dávila Well, Barceloneta. AQUIFER.--Montebello/Cibao Limestone. WELL CHARACTERISTICS.--Deep test well, diameter 2.5 in (0.06 m) 0-1,070 ft (0-326.1 m), open screened 1,070-2,564 ft (326.1-781. 5 m). Depth 2,564 ft (781.5 m). DATUM.--Elevation of land-surface datum is about 312 ft (95.1 m), above mean sea level, from topographic map. Measuring point: T op of black PVC pipe, 1.25 ft (0.38 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--December 1986 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.16 ft (2.79 m), below land-surface datum, August 18, 1987; lowest water level measured, 104.78 ft (31.93 m), below land-surface datum, September 15, 2003. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 01 97.27 DEC 13 98.35 FEB 19 99.92 MAY 15 101.45 JULY 16 103.42 SEPT 15 104.74 01 97.26 JAN 09 98.92 APR 11 100.88 JUNE 10 102.65 AUG 08 104.19 WATER YEAR 2003 HIGHEST 97.26 OCT 01, 2002 LOWEST 104.74 SEPT 15, 2003 85 90 95 100 105 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 493 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN—Continued 182549066304300. Local number, 166. LOCATION.--Lat 18q25'49", long 66q30'43", Hydrologic Unit 21010002, 0.95 mi east of the Rio Grande de Manatí Hwy 2 bridge, 0.4 mi southwest of Central Monserrate, 1.07 mi east of the intersection of Hwy 666 with Hwy 2, 1.2 mi west of the intersection of Hwy 685 with Hwy 2, 0.01 mi north of Hwy 2, Name: PRASA 166 USGS Observation Manatí Well, Manatí. AQUIFER.--Alluvial deposits. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 0-100 ft (0-39.49 m), diameter 14 in (0.36 m), cased 0-140 ft (0-42.7 m), slotted 80-90 ft (24.7-27.4 m), and 130-140 ft (39.6-42.7 m). Depth 101 ft (30.8 m). DATUM.--Elevation of land-surface datum is about 29.5 ft (9 m), above mean-sea level, from topographic map. Measuring point: A hole in the side of the 20 in (0.51 m) diameter well casing, 1.65 ft (0.5 m) above land-surface datum. Prior May 31, 1996, top of 14 in (0.36 m) casing, 0. 8 ft (0.24 m), above land- surface datum. REMARKS.--Observation well. Formerly published as 182542066305200. Station was flooded by Río Grande de Manatí on September 1998 and November 2001. PERIOD OF RECORD.--January 1982 to December 1984, discontinued, May 31, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.38 ft (6.52 m), below land-surface datum, November 21, 1999; lowest water level measured, 26.36 ft (8.04 m), below land-surface datum, February 3, 1983. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 10 23.68 JAN 09 24.31 APR 16 24.33 JUNE 17 24.42 AUG 08 24.34 SEPT 15 24.10 DEC 16 24.25 FEB 19 24.30 MAY 15 24.26 JULY 28 24.31 WATER YEAR 2003 HIGHEST 23.68 OCT 10, 2002 LOWEST 24.42 JUNE 17, 2003 21.0 21.5 22.0 22.5 23.0 23.5 24.0 24.5 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 494 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN—Continued 182506066280200. Local number, 1076. LOCATION.--Lat 18q25'06", long 66q28'02", Hydrologic Unit 21010002, 0.72 mi southwest of the intersection of Hwy 686 with Hwy 670, 0.73 mi southeast of intersection of Hwy 149 with Hwy 670, and 0.78 mi northeast of Escuela Sabana Seca, Name: Piezometer Hill 2, Manatí. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), screened 360-410 ft (110-125 m). Depth 410 ft (12 5 m). INSTRUMENTATION.--Pressure transducer with integrated electronic data logger--60 minutes interval. DATUM.--Elevation of land-surface datum is about 312 ft (95 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 3.76 ft (1.15 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on May 28, 1996. PERIOD OF RECORD.--May 28, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 249.79 ft (76.1 m), below land-surface datum, December 5, 1998; lowest water level recorded, 293.09 ft (89.3 m), below land-surface datum, September 5, 6, 1996. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 289.23 289.65 290.37 291.13 2 289.17 289.67 290.36 291.09 3 289.13 289.72 290.39 291.08 4 289.16 289.71 290.42 291.11 5 289.24 289.77 290.45 291.13 291.26 291.84 291.88 291.86 292.09 292.12 292.49 292.25 291.37 291.80 291.97 291.81 292.03 292.04 292.55 292.15 291.42 291.82 291.99 291.79 292.01 292.07 292.60 292.08 291.44 291.88 291.95 291.82 292.04 292.11 292.57 292.01 291.41 291.89 292.01 291.88 292.10 292.12 292.56 292.03 6 289.23 289.74 290.48 291.18 7 289.23 289.75 290.49 291.19 8 289.32 289.83 290.53 291.23 9 289.14 289.87 290.54 291.31 10 289.03 289.83 290.58 291.32 291.44 291.82 292.03 291.94 292.17 292.08 292.59 291.99 291.42 291.77 292.02 291.98 292.21 292.10 292.66 291.90 291.42 291.80 291.94 292.00 292.23 292.08 292.63 291.91 291.40 291.75 292.03 292.02 292.28 292.07 292.71 291.85 291.41 291.76 292.03 292.04 292.35 292.07 292.67 291.86 11 289.03 289.86 290.60 291.36 12 289.08 289.87 290.60 291.36 13 289.11 289.85 290.56 291.34 14 289.07 289.92 290.52 291.34 15 289.11 289.97 290.55 291.38 291.44 291.84 292.06 292.12 292.28 292.10 292.51 291.78 291.49 291.92 292.09 292.03 292.25 292.19 292.48 291.78 291.51 291.92 292.10 291.96 292.25 292.29 292.53 291.75 291.55 291.89 292.03 291.97 292.26 292.33 292.51 291.73 291.57 291.89 291.95 291.94 292.18 292.29 292.45 291.72 16 289.14 290.03 290.68 291.40 17 289.23 290.08 290.73 291.39 18 289.27 290.09 290.78 291.33 19 289.32 290.03 290.85 291.39 20 289.35 290.01 290.89 291.33 291.60 291.92 291.91 291.90 292.21 292.37 292.43 291.74 291.62 291.86 291.95 291.87 292.19 292.43 292.48 291.76 291.67 291.85 292.05 291.85 292.19 292.50 292.49 291.77 291.72 291.86 292.06 291.89 292.24 292.51 292.42 291.75 291.69 291.99 292.05 291.85 292.22 292.48 292.35 291.66 21 289.40 290.04 290.92 291.23 22 289.46 290.09 290.93 291.19 23 289.45 290.15 290.94 291.17 24 289.49 290.16 290.90 291.25 25 289.50 290.16 290.96 291.35 291.62 291.97 291.97 291.91 292.16 292.43 292.36 291.73 291.60 291.96 291.90 292.03 292.13 292.49 292.37 291.56 291.69 291.96 291.88 292.15 292.11 292.53 292.45 291.50 291.77 291.95 291.83 292.13 292.12 292.50 292.47 291.47 291.72 291.95 291.82 292.18 292.12 292.51 292.43 291.45 26 289.45 290.19 290.99 291.35 27 289.44 290.15 291.01 291.29 28 289.50 290.19 291.02 291.35 29 289.51 290.23 291.04 291.37 30 289.52 290.29 291.09 291.37 31 289.55 --- 291.11 291.23 291.64 291.98 291.84 292.20 292.12 292.52 292.41 291.36 291.74 292.00 291.84 292.15 292.13 292.46 292.44 291.34 291.79 292.07 291.81 292.09 292.16 292.48 292.38 291.28 --- 292.02 291.79 292.08 292.20 292.51 292.25 291.27 --- 291.93 291.85 292.11 292.16 292.57 292.26 291.21 --- 291.91 --- 292.11 --- 292.55 292.28 --­ MEAN 289.29 289.96 290.72 291.28 291.55 291.90 291.95 291.99 292.17 292.32 292.48 291.72 WTR YR 2003MEAN291.44 HIGHEST 288.98 OCT 11, 2002 LOWEST 292.76 AUG 9, 2003 250 260 270 280 290 300 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 495 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN—Continued 182308066260400. Local number, 210. LOCATION.--Lat 18q23'01", long 66q25'52", Hydrologic Unit 21010002, 4.88 mi southeast of Manatí plaza, 5.24 mi southwest of Vega Baja plaza, and 2.25 mi west of Escuela Evaristo Camacho, Name: Gelo Martínez Well, Vega Baja. AQUIFER.--Lares Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.2 m), cased 8 in (0.2 m). Depth 83 ft (25.3 m). DATUM.--Elevation of land-surface datum is about 574 ft (174.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.3 ft (1.01 m), above land-surface datum. Prior to January 14, 1993, hole on side of casing, 2 ft (0.61 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 40.56 ft (12.4 m), below land-surface datum, May 22, 1986; lowest water level recorded, 85.5 ft (26.1 m), below land-surface datum, October 14, 15, 1994. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 25 63.87 JAN 09 66.27 MAR 10 65.66 MAY 15 63.35 JULY 28 70.00 SEPT 15 68.80 DEC 16 62.00 FEB 21 65.65 APR 16 69.58 JUNE 17 66.19 AUG 11 70.17 WATER YEAR 2003 HIGHEST 62.00 DEC 16, 2002 LOWEST 70.17 AUG 11, 2003 45 50 55 60 65 70 75 80 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 496 GROUND-WATER LEVELS RIO CIBUCO BASIN 182712066251700. Local number, 1102. LOCATION.--Lat 18q27'12", long 66q25'17", Hydrologic Unit 21010002, 0.6 mi north of the intersection of Hwy 687 with Hwy 2, 0.55 mi southeast of the eastern shoreline of Laguna Tortuguero, 0.32 mi east of Laguna Rica, and 0.12 mi west of Hwy 687, Name: Piezometer Tortuguero 3, Vega Baja. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), screened 68-218 ft (20.7-66.4 m). Depth 218 ft (6 6.4 m). INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 30 ft (9 m), above mean sea level, from topographic map. Measuring point: Shelt er floor on top of 4 in (0.1 m) casing, 3.42 ft (1.04 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n June 10, 1999. PERIOD OF RECORD.--May 31, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.13 ft (7.05 m), below land-surface datum, December 7, 8, 1999; lowest water level recorded, 25.26 ft (7.7 m), below land-surface datum, June 21, 22, 23, 1996. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 24.51 24.52 24.70 24.77 2 24.52 24.52 24.71 24.78 3 24.49 24.50 24.72 24.80 4 24.46 24.50 24.73 24.80 5 24.46 24.50 24.74 24.81 24.75 24.89 24.87 24.76 24.95 25.03 24.86 24.86 24.75 24.90 24.86 24.78 24.96 25.02 24.86 24.87 24.77 24.89 24.87 24.79 24.98 25.02 24.86 24.87 24.74 24.87 24.90 24.79 24.98 25.00 24.87 24.86 24.71 24.88 24.91 24.80 24.98 25.01 24.88 24.87 6 24.46 24.51 24.74 24.81 7 24.46 24.54 24.74 24.81 8 24.46 24.57 24.76 24.83 9 24.31 24.60 24.76 24.81 10 24.30 24.60 24.76 24.80 24.72 24.88 24.88 24.83 24.98 25.00 24.90 24.88 24.75 24.89 24.90 24.85 24.99 25.00 24.92 24.87 24.77 24.90 24.92 24.85 24.99 24.98 24.94 24.87 24.77 24.90 24.93 24.85 24.99 24.98 24.94 24.84 24.78 24.88 24.93 24.87 25.01 24.98 24.94 24.84 11 24.32 24.62 24.76 24.80 12 24.35 24.64 24.78 24.80 13 24.38 24.64 24.76 24.81 14 24.38 24.63 24.74 24.84 15 24.37 24.61 24.71 24.85 24.79 24.88 24.93 24.86 25.01 24.98 24.94 24.84 24.79 24.88 24.93 24.87 25.00 24.98 24.92 24.83 24.78 24.90 24.91 24.88 25.02 24.96 24.92 24.82 24.79 24.91 24.91 24.87 25.02 24.96 24.92 24.79 24.80 24.92 24.92 24.87 25.01 24.94 24.94 24.78 16 24.35 24.61 24.69 24.86 17 24.35 24.61 24.70 24.88 18 24.35 24.61 24.70 24.90 19 24.37 24.63 24.73 24.90 20 24.39 24.63 24.73 24.91 24.81 24.88 24.92 24.88 25.02 24.93 24.95 24.77 24.81 24.86 24.92 24.90 25.03 24.92 24.95 24.78 24.82 24.84 24.88 24.90 25.03 24.93 24.98 24.79 24.82 24.82 24.79 24.91 25.03 24.94 25.00 24.80 24.84 24.82 24.79 24.89 25.01 24.95 25.01 24.82 21 24.42 24.63 24.75 24.91 22 24.45 24.64 24.75 24.89 23 24.46 24.67 24.76 24.86 24 24.48 24.70 24.76 24.84 25 24.51 24.72 24.78 24.82 24.84 24.84 24.79 24.88 25.01 24.97 25.02 24.80 24.84 24.86 24.70 24.85 25.00 24.94 25.00 24.69 24.83 24.85 24.70 24.86 25.01 24.92 24.99 24.65 24.84 24.85 24.69 24.87 25.00 24.93 24.96 24.60 24.85 24.85 24.70 24.87 25.00 24.93 24.94 24.60 26 24.48 24.73 24.77 24.71 27 24.47 24.73 24.77 24.68 28 24.49 24.72 24.78 24.69 29 24.50 24.70 24.77 24.69 30 24.51 24.69 24.76 24.70 31 24.51 --- 24.76 24.73 24.88 24.87 24.72 24.87 25.01 24.94 24.90 24.59 24.88 24.84 24.71 24.89 25.00 24.94 24.88 24.59 24.89 24.84 24.72 24.90 25.00 24.94 24.87 24.59 --- 24.86 24.73 24.92 25.01 24.89 24.86 24.61 --- 24.86 24.75 24.94 25.03 24.88 24.84 24.64 --- 24.88 --- 24.95 --- 24.87 24.85 --­ MEAN 24.43 24.62 24.74 24.81 24.80 24.87 24.84 24.86 25.00 24.96 24.92 24.77 WTR YR 2003MEAN24.80 HIGHEST 24.28 OCT 10, 2002 LOWEST 25.07 JUNE 17, 2003 23.0 23.5 24.0 24.5 25.0 25.5 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 497 GROUND-WATER LEVELS RIO CIBUCO BASIN—Continued 182615066235300. Local number, 211. LOCATION.--Lat 18q26'07", long 66q23'32", Hydrologic Unit 21010002, 4.46 mi southeast of Manatí plaza, 5.48 mi southwest of Vega Baja plaza, and 1.22 mi east of Hwy 155 km 58.3, Name: Rosario 2 Well, Vega Baja. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 14 in (0.36 m) 0-200 ft (0-61 m), diameter 12 in (0.3 m), 200-2 50 ft (61-76.2 m), cased 12 in (0.3 m) 0-250 ft (0-76.2 m), perforated 210-250 ft (64-76.2 m), diameter 10 in (0.25 m) 250-270 ft (76.2-82.3 m), open hole; concrete sealed 0­ 200 ft (0-61 m). Depth 270 ft (82.3 m). DATUM.--Elevation of land-surface datum is about 230 ft (70.1 m), above mean sea level, from topographic map. Measuring point: T op of shelter floor, 3.1 ft (0.94 m), above land-surface datum. Prior to April 11, 1994, hole on side of casing, 1.15 ft (0.35 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 191.29 ft (58.3 m), below land-surface datum, May 16, 1986; lowest water level recorded, 194.1 ft (59.2 m), below land-surface datum, Mar. 31, April 1 to 7, 1995. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 25 193.00 JAN 09 193.32 MAR 10 193.40 MAY 15 193.28 JULY 28 193.51 SEPT 15 193.23 DEC 16 193.22 FEB 21 193.33 APR 23 193.11 JUNE 17 193.57 AUG 11 193.45 WATER YEAR 2003 HIGHEST 193.00 OCT 25, 2002 LOWEST 193.57 JUNE 17, 2003 191.5 192.0 192.5 193.0 193.5 194.0 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 498 GROUND-WATER LEVELS RIO CIBUCO BASIN—Continued 182647066201700. Local number, 70. LOCATION.--Lat 18q26'47", long 66q20'17", Hydrologic Unit 21010002, 1.52 mi north of Vega Alta plaza, 4.78 mi southwest of Dorado plaza, and 2.01 mi northwest of Escuela Industrial para Mujeres Penitenciary, Name: Sabana Hoyos Well, Vega Alta. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled unused water table well, diameter 8 in (0.2 m), cased 0-90 ft (0-27.4 m), perforated. Depth 88 ft (26.8 m), sounded depth measured on October 1, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. 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, 1.2 ft (0.36 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 1998. Only monthly tapedown measurements published on water years 2000 and 2001, and from October 1 to December 23, 2001. PERIOD OF RECORD.--February 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.33 ft (6.5 m), below land-surface datum, October 26, 1976; lowest water level recorded, 31.12 ft (9.48 m), below land-surface datum, May 12, 13, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29.80 --- --- 29.52 2 29.67 --- --- 29.53 3 29.61 --- --- 29.55 4 29.57 --- --- 29.55 5 29.60 --- --- 29.54 29.40 29.27 29.66 29.71 30.15 30.59 30.46 30.43 29.37 29.28 29.67 29.71 30.17 30.69 30.44 30.42 29.37 29.30 29.69 29.73 30.19 30.68 30.46 30.45 29.33 29.31 29.73 29.74 30.22 30.67 30.45 30.48 29.30 29.33 29.70 29.76 30.17 30.66 30.46 30.50 6 29.59 --- --- 29.54 7 29.55 --- --- 29.53 8 29.57 --- --- 29.53 9 29.61 --- --- 29.52 10 29.71 --- --- 29.59 29.29 29.34 29.73 29.78 30.25 30.66 30.48 30.51 29.24 29.36 29.73 29.80 30.28 30.62 30.49 30.50 29.22 29.39 29.76 29.84 30.30 30.53 30.52 30.50 29.23 29.38 29.75 29.86 30.32 30.59 30.52 30.51 29.21 29.40 29.76 29.87 30.34 30.57 30.52 30.51 11 29.73 --- --- 29.60 12 29.71 --- --- 29.57 13 29.73 --- --- 29.56 14 29.73 --- --- 29.56 15 29.73 --- --- 29.57 29.21 29.41 29.75 29.90 30.38 30.57 30.51 30.50 29.22 29.41 29.77 29.91 30.39 30.58 30.50 30.50 29.17 29.43 29.77 29.92 30.40 30.57 30.48 30.50 29.15 29.44 29.78 29.95 30.42 30.60 30.46 30.51 29.14 29.45 29.78 29.97 30.46 30.61 30.45 30.52 16 29.72 --- --- 29.58 17 29.71 --- --- 29.59 18 29.70 --- --- 29.60 19 29.73 --- --- 29.61 20 29.79 --- --- 29.62 29.14 29.45 29.78 29.98 30.47 30.61 30.44 30.52 29.17 29.46 29.77 30.00 30.48 30.61 --- 30.52 29.16 29.46 29.77 30.01 30.50 30.63 30.42 30.52 29.18 29.48 29.82 30.04 30.50 30.64 30.41 30.51 29.19 29.50 29.85 30.07 30.52 30.64 --- 30.51 21 29.82 --- --- 29.64 22 29.81 --- --- 29.64 23 --- --- 29.55 29.63 24 --- --- 29.53 29.62 25 --- --- 29.52 29.59 29.18 29.52 29.87 30.09 30.52 30.66 30.41 30.46 29.19 29.53 29.88 30.09 30.55 30.64 30.38 30.48 29.19 29.56 29.90 30.07 30.56 30.61 30.34 30.50 29.18 29.56 29.90 30.05 30.58 30.59 30.30 30.52 29.20 29.58 29.85 30.05 30.58 30.58 30.25 30.54 26 --- --- 29.51 29.53 27 --- --- 29.50 29.48 28 --- --- 29.50 29.49 29 --- --- 29.49 29.48 30 --- --- 29.51 29.47 31 --- --- 29.53 29.42 29.22 29.58 29.82 30.05 30.59 30.55 30.25 30.54 29.23 29.61 29.79 30.07 30.61 30.54 30.27 30.54 29.25 29.62 29.74 30.08 30.64 30.52 30.29 30.54 --- 29.64 29.71 30.10 30.64 30.51 30.32 30.54 --- 29.63 29.71 30.11 30.65 30.47 30.35 30.54 --- 29.64 --- 30.14 --- 30.46 30.40 --­ MEAN --- --- --- 29.56 29.23 29.46 29.77 29.95 30.43 30.60 --- 30.50 WTR YR 2003MEAN29.96 HIGHEST 29.10 FEB 16, 17, 2003 LOWEST 30.70 JULY 2, 2003 25 26 27 28 29 30 31 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 499 GROUND-WATER LEVELS RIO CIBUCO BASIN—Continued 182330066185700. Local number, 213. LOCATION.--Lat 18q23'30", long 66q18'57", Hydrologic Unit 21010002, 1.82 mi southeast of Vega Alta plaza, 4.23 mi west of Toa Alta plaza, and 1.27 mi northwest off the intersection of Hwy 820 with Hwy 823, Name: Pampano 2 Well, Vega Alta. AQUIFER.--Río 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 (0.3 m) 0-220 ft (0-67.1 m); open hole 220-330 ft (67.6-101 m). Depth 330 ft (101 m). DATUM.--Elevation of land-surface datum is about 394 ft (120 m), above mean sea level, from topographic map. Measuring point: To p of plexiglass plate, 9.34 ft (2.84 m), above land-surface datum. Prior April 27, 1993, hole on side of casing, 2.95 ft (0.9 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 26.27 ft (8.01 m), below land-surface datum, January 25, 2000; lowest water level recorded, 65.68 ft (20 m), below land-surface datum, August 20, 1995. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 01 44.97 JAN 10 49.30 MAR 10 50.64 MAY 19 52.50 JULY 28 53.33 SEPT 15 50.49 DEC 16 48.11 FEB 21 50.18 APR 23 52.19 JUNE 17 52.56 AUG 11 53.24 WATER YEAR 2003 HIGHEST 44.97 NOV 01, 2002 LOWEST 53.33 JULY 28, 2003 25 30 35 40 45 50 55 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 500 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182526066165001. Local number, 1127. LOCATION.--Lat 18q25'26", long 66q16'50", Hydrologic Unit 21010005, 1.03 mi north of Hwy 2, 0.93 mi west of the intersection of Hwy 659 with Hwy 693, and 0.03 mi north of Hwy 659, Name: Piezometer Santa Rosa USGS 2, Dorado. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m) 0-140 ft (0-42.7 m), screened 120-130 ft (36.6-39.6 m). Depth 140 ft (42.7 m). DATUM.--Elevation of land-surface datum is about 91.8 ft (28 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 3.31 ft (1.01 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--February 2, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 57.63 ft (17.56 m), below land-surface datum, December 11-14, 1999; lowest water level recorded, 64.9 ft (19.8 m), below land-surface datum, May 2-5, 10-15, 1995. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 01 62.72 JAN 10 63.38 MAR 10 63.58 MAY 19 64.25 JULY 28 64.51 SEPT 15 63.86 DEC 17 63.18 FEB 21 62.98 APR 03 64.09 JUNE 03 64.33 AUG 11 64.59 WATER YEAR 2003 HIGHEST 62.72 NOV 01, 2002 LOWEST 64.59 AUG 11, 2003 57 58 59 60 61 62 63 64 65 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 501 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 182548066164401. Local number, 1128. LOCATION.--Lat 18q25'48", long 66q16'44", Hydrologic Unit 2101005, 1.47 mi north of Hwy 2, 0.6 mi south of Hwy 695, 0.04 mi south of the intersection of Hwy 694 with 659, and 0.02 mi east of Hwy 659, Name: Piezometer Maguayo USGS 2, Dorado. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m) 0-110 ft (0-33.5 m), screened 95-105 ft (29-32 m). Depth 115 ft (35.1 m), sounded depth measured on August 3, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 39.4 ft (12 m), above mean sea level, from topographic map. Measuring point: On shelter floor, 3.66 ft (1.12 m), above land-surface datum. Prior to April 12, 2002, metal bar on pulley, 3.8 ft (1.16 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n February 6, 1997. PERIOD OF RECORD.--June 22, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 24.02 ft (7.32 m), below land-surface datum, December 11, 12, 1998 ; lowest water level recorded, 29.49 ft (8.99 m), below land-surface datum, July 21, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27.38 27.32 27.62 27.87 2 27.36 27.33 27.62 27.87 3 27.38 27.29 27.62 27.87 4 27.38 27.29 27.63 27.87 5 27.38 27.30 27.63 27.87 27.81 27.70 28.52 28.33 28.86 29.46 29.15 28.58 27.76 27.78 28.55 28.33 28.86 29.43 29.16 28.47 27.76 27.80 28.57 28.33 28.92 29.41 29.18 28.43 27.75 27.84 28.59 28.33 28.97 29.38 29.18 28.39 27.66 27.84 28.63 28.34 28.99 29.33 29.22 28.42 6 27.36 27.35 27.63 27.88 7 27.36 27.39 27.63 27.91 8 27.33 27.41 27.65 27.89 9 27.29 27.45 27.65 27.88 10 27.24 27.47 27.66 27.91 27.61 27.87 28.59 28.49 29.01 29.27 29.23 28.42 27.58 27.90 28.58 28.50 29.04 29.23 29.24 28.44 27.55 27.91 28.59 28.54 29.07 29.23 29.24 28.46 27.46 27.91 28.59 28.58 29.10 29.23 29.26 28.46 27.40 27.92 28.59 28.65 29.12 29.23 29.27 28.46 11 27.22 27.47 27.66 27.93 12 27.12 27.46 27.68 27.93 13 27.16 27.46 27.68 27.93 14 27.18 27.46 27.68 27.93 15 27.14 27.46 27.68 27.94 27.36 28.02 28.60 28.66 29.12 29.26 29.27 28.46 27.36 28.04 28.60 28.70 29.13 29.38 29.25 28.47 27.36 28.07 28.61 28.74 29.17 29.39 29.24 28.47 27.37 28.11 28.61 28.77 29.18 29.39 29.16 28.42 27.43 28.16 28.65 28.77 29.19 29.44 29.16 28.43 16 27.14 27.46 27.68 27.96 17 27.17 27.46 27.68 27.98 18 27.19 27.46 27.68 28.00 19 27.15 27.45 27.68 28.02 20 27.08 27.46 27.68 28.03 27.44 28.19 28.67 28.77 29.18 29.46 29.16 28.43 27.44 28.15 28.68 28.81 29.20 29.44 29.16 28.43 27.47 28.23 28.68 28.83 29.22 29.45 29.16 28.44 27.51 28.26 28.62 28.86 29.24 29.46 29.14 28.44 27.54 28.28 28.58 28.87 29.27 29.47 29.10 28.47 21 27.07 27.46 27.68 28.04 22 27.12 27.47 27.68 28.06 23 27.18 27.47 27.68 28.06 24 27.25 27.51 27.69 28.08 25 27.26 27.51 27.73 28.08 27.55 28.33 28.56 28.88 29.32 29.48 29.08 28.47 27.63 28.37 28.54 28.66 29.32 29.48 28.98 28.43 27.67 28.38 28.53 28.66 29.32 29.47 28.94 28.42 27.69 28.39 28.33 28.66 29.36 29.42 28.91 28.42 27.68 28.40 28.24 28.68 29.37 29.36 28.89 28.40 26 27.26 27.51 27.77 27.97 27 27.26 27.53 27.82 27.92 28 27.28 27.55 27.85 27.90 29 27.28 27.57 27.86 27.86 30 27.28 27.60 27.87 27.81 31 27.28 --- 27.87 27.81 27.69 28.43 28.25 28.71 29.42 29.33 28.84 28.41 27.69 28.45 28.30 28.74 29.43 29.27 28.72 28.41 27.69 28.49 28.34 28.78 29.43 29.23 28.72 28.41 --- 28.49 28.33 28.79 29.44 29.15 28.69 28.41 --- 28.50 28.33 28.80 29.46 29.15 28.58 28.35 --- 28.50 --- 28.84 --- 29.15 28.58 --­ MEAN 27.24 27.45 27.70 27.94 27.57 28.15 28.53 28.66 29.19 29.35 29.06 28.44 WTR YR 2003MEAN28.28 HIGHEST 27.06 OCT 12, 2002 LOWEST 29.49 JULY 21, 2003 24 25 26 27 28 29 30 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 502 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 182620066163403. Local number, 1130. LOCATION.--Lat 18q26'20", long 66q16'34", Hydrologic Unit 2101005, 1.85 mi south of Dorado plaza, 0.7 mi southwest of Laboratorio Dorado, 0.65 mi northwest of the intersection of Hwy 695 with Hwy 693, and 0.09 mi north of Hwy 695, Name: Piezometer Higuillar USGS 4, Dorado. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m) 0-100 ft (0-30.5 m), screened 80-90 ft (24.4-27.4 m). Depth 90 ft (30.5 m), sounded depth measured on October 19, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 49.2 ft (15 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 3.6 ft (1.1 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n February 6, 1997. From October 1 2001 to February 19, 2002, tapedowns measurements only. PERIOD OF RECORD.--January 23, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 29.58 ft (9.02 m), below land-surface datum, December 8, 9, 1999; lowest water level recorded, 36.33 ft (11.07 m), below land-surface datum, June 29, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 34.18 34.04 34.34 34.52 2 34.19 34.05 34.35 34.49 3 34.21 34.04 34.35 34.50 4 34.20 34.03 34.35 34.57 5 34.18 34.05 34.36 34.58 34.40 34.54 35.25 35.10 35.85 36.31 35.98 --- 34.39 34.60 35.26 35.11 35.82 36.19 36.01 --- 34.39 34.63 35.27 35.13 35.85 36.13 36.06 --- 34.35 34.67 35.28 35.15 35.88 36.04 36.04 --- 34.25 34.67 35.32 35.15 35.91 35.98 36.10 --­ 6 34.17 34.12 34.36 34.60 7 34.17 34.17 34.36 34.61 8 34.17 34.18 34.36 34.60 9 34.03 34.22 34.39 34.59 10 33.95 34.23 34.39 34.64 34.24 34.69 35.24 35.20 35.90 35.90 36.09 --- 34.24 34.71 35.23 35.29 35.92 35.89 36.11 --- 34.23 34.76 35.26 35.34 35.95 35.92 36.11 --- 34.20 34.74 35.27 35.39 35.98 35.90 36.11 --- 34.10 34.71 35.27 35.53 35.99 35.93 36.08 --­ 11 33.89 34.22 34.40 34.67 12 33.84 34.21 34.42 34.61 13 33.89 34.20 34.42 34.61 14 33.91 34.21 34.41 34.65 15 33.89 34.21 34.38 34.71 34.09 34.76 35.26 35.53 35.99 36.06 35.98 --- 34.11 34.78 35.26 35.59 35.99 36.16 35.96 --- 34.14 34.89 35.27 35.65 36.07 36.17 35.94 --- 34.21 34.92 35.27 35.65 36.08 36.14 35.88 --- 34.22 34.95 35.28 35.65 36.01 36.21 35.84 --­ 16 33.88 34.26 34.40 34.73 17 33.89 34.26 34.41 34.74 18 33.91 34.24 34.41 34.75 19 33.97 34.23 34.46 34.78 20 33.91 34.24 34.46 34.78 34.24 34.96 35.29 35.65 35.99 36.24 35.83 --- 34.24 34.94 35.29 35.68 36.07 36.20 35.83 --- 34.24 34.98 35.18 35.70 36.11 36.22 35.82 --- 34.26 35.00 35.05 35.73 36.13 36.23 35.78 --- 34.27 35.02 35.02 35.77 36.14 36.24 35.74 --­ 21 33.91 34.26 34.45 34.78 22 33.91 34.27 34.45 34.82 23 33.91 34.28 34.44 34.83 24 33.99 34.31 34.44 34.85 25 33.99 34.31 34.49 34.71 34.28 35.05 35.01 35.76 36.18 36.27 35.73 --- 34.30 35.08 34.99 35.65 36.14 36.26 --- --- 34.37 35.10 35.00 35.65 36.18 36.15 --- --- 34.36 35.09 34.73 35.65 36.20 36.06 --- --- 34.39 35.10 34.65 35.65 36.19 35.96 --- --­ 26 33.98 34.31 34.52 34.50 27 33.97 34.31 34.55 34.46 28 33.98 34.32 34.57 34.44 29 33.98 34.34 34.58 34.42 30 33.98 34.34 34.58 34.39 31 33.99 --- 34.57 34.39 34.42 35.17 34.93 35.65 36.22 35.91 --- --- 34.50 35.17 34.98 35.69 36.29 35.86 --- --- 34.53 35.17 34.99 35.75 36.29 35.84 --- --- --- 35.17 34.98 35.71 36.32 35.84 --- --- --- 35.17 35.01 35.77 36.28 35.90 --- --- --- 35.20 --- 35.81 --- 35.94 --- --­ MEAN 34.00 34.22 34.43 34.62 34.28 34.92 35.14 35.54 36.06 36.07 --- --­ WTR YR 2003MEAN35.00 HIGHEST 33.79 OCT 11, 12, 2002 LOWEST 36.33 JUNE 29, 2003 29 30 31 32 33 34 35 36 37 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 503 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 182657066162701. Local number, 1132. LOCATION.--Lat 18q26'57", long 66q16'27", Hydrologic Unit 21010005, 20 ft (6.1 m) north of San Antonio 1, Name: Piezometer San Antonio USGS 3, Dorado. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-80 ft (0-24.4 m), screened 65-75 ft (19.8-22.9 m). Depth 80 ft (24.4 m). INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 19.6 ft (6 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m), casing, 3.32 ft (1.01 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n February 6, 1997, removed on January 10, 2003. PERIOD OF RECORD.--October 19, 1994 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 12.93 ft (3.94 m), below land-surface datum, December 8, 1999; low est water level recorded, 19.05 ft (5.8 m), below land-surface datum, April 21, 2001. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 16.95 16.80 17.09 17.20 2 16.94 16.81 17.08 17.15 3 16.94 16.83 17.13 17.16 4 16.93 16.82 17.13 17.18 5 16.87 16.82 17.08 17.22 --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 6 16.85 16.84 17.11 17.25 7 16.85 16.88 17.13 17.27 8 16.85 16.92 17.14 17.29 9 16.79 16.94 17.15 17.29 10 16.61 16.94 17.15 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 11 16.66 16.93 17.15 --­ 12 16.64 16.97 17.17 --­ 13 16.66 16.93 17.14 --­ 14 16.68 16.91 17.10 --­ 15 16.66 16.93 17.07 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 16 16.64 17.00 17.05 --­ 17 16.67 17.00 17.07 --­ 18 16.75 16.95 17.10 --­ 19 16.76 16.95 17.14 --­ 20 16.78 16.99 17.13 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 21 16.76 17.03 17.15 --­ 22 16.76 17.06 17.16 --­ 23 16.79 17.10 17.16 --­ 24 16.82 17.09 17.16 --­ 25 16.78 17.08 17.16 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ 26 16.75 17.06 17.16 --­ 27 16.74 17.09 17.17 --­ 28 16.74 17.13 17.23 --­ 29 16.77 17.09 17.24 --­ 30 16.77 17.11 17.21 --­ 31 16.80 --- 17.20 --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ --- --- --- --- --- --- --- --­ MEAN 16.77 16.97 17.14 --- --- --- --- --- --- --- --- --­ WTR YR 2003MEAN16.98 HIGHEST 16.55 OCT 11, 2002 LOWEST 17.32 JAN 10, 2003 12 13 14 15 16 17 18 19 20 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 504 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 182654066150600. Local number, 1133. LOCATION.--Lat 18q26'54", long 66q15'06", Hydrologic Unit 21010005, 0.92 mi southeast of the Dorado bridge, 0.66 mi east of Hwy 693, 0.09 mi north of the intersection of Hwy 165 with Hwy 867, and 0.01 mi east of Hwy 165, Name: Piezometer USGS 1, Toa Baja. AQUIFER.--Tertiary Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-165 ft (0-50.3 m), screened 25-165 ft (7.62-50.3 m). Depth 161 ft (49.1 m), sounded depth measured on October 4, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 7 ft (2.1 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor on top of 4 in (0.1 m) casing, 3.6 ft (1.1 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 25, 1997. Water levels affected by marine tides. PERIOD OF RECORD.-- November 16, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.04 ft (0.93 m), below land-surface datum, September 10, 1996; lowest water level recorded, 11.19 ft (3.41 m), below land-surface datum April 19, 20, 2001. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.30 9.40 9.50 9.48 9.14 9.84 10.21 9.94 10.81 10.23 10.11 10.44 2 9.30 9.23 9.47 9.37 9.21 9.84 10.07 10.06 10.75 10.31 10.10 10.37 3 9.30 9.18 9.50 9.41 9.17 9.89 10.15 10.07 10.75 10.33 9.95 10.43 4 9.28 9.14 9.33 9.46 9.11 9.91 9.99 10.09 10.76 10.44 9.89 10.36 5 9.21 9.12 9.32 9.53 9.08 9.82 10.11 10.04 10.71 10.46 9.77 10.27 6 9.18 9.15 9.33 9.55 9.16 9.83 9.98 10.09 10.72 10.53 9.79 10.13 7 9.17 9.22 9.38 9.66 9.19 9.83 10.10 10.23 10.79 10.55 9.82 10.13 8 9.11 9.40 9.51 9.73 9.22 9.88 10.08 10.32 10.67 10.61 9.73 10.26 9 9.03 9.45 9.56 9.62 9.22 9.82 10.03 10.48 10.64 10.52 9.74 10.21 10 8.93 9.48 9.56 9.69 9.19 9.82 10.01 10.40 10.55 10.43 9.94 10.20 11 9.03 9.48 9.60 9.81 12 9.10 9.42 9.68 9.82 13 9.17 9.39 9.60 9.83 14 9.18 9.39 9.49 9.83 15 9.16 9.36 9.40 9.85 9.16 9.74 9.93 10.41 10.61 10.30 9.99 10.28 9.16 9.80 9.89 10.50 10.61 10.24 10.03 10.27 9.17 9.87 9.88 10.46 10.56 10.24 10.13 10.42 9.24 9.98 9.92 10.51 10.56 10.30 10.18 10.30 9.25 10.02 9.93 10.51 10.59 10.29 10.19 10.15 16 9.12 9.44 9.39 9.80 17 9.14 9.37 9.37 9.78 18 9.18 9.31 9.38 9.76 19 9.18 9.30 9.50 9.66 20 9.19 9.31 9.39 9.76 9.26 9.99 9.95 10.64 10.68 10.26 10.17 10.10 9.19 10.02 9.85 10.63 10.55 10.33 10.09 10.11 9.24 10.02 9.68 10.57 10.49 10.23 10.12 9.98 9.29 10.01 9.67 10.56 10.50 10.11 10.13 9.97 9.29 10.15 9.67 10.68 10.47 10.11 10.14 9.95 21 9.16 9.40 9.44 9.70 22 9.14 9.42 9.49 9.73 23 9.17 9.44 9.49 9.77 24 9.20 9.58 9.55 9.68 25 9.10 9.52 9.52 9.50 9.32 10.28 9.68 10.58 10.50 10.05 10.12 10.02 9.46 10.31 9.66 10.18 10.49 10.13 10.25 10.42 9.46 10.30 9.67 10.33 10.37 10.17 10.28 10.26 9.58 10.19 9.38 10.38 10.36 10.24 10.31 10.17 9.65 10.20 9.38 10.38 10.28 10.30 10.36 10.14 26 9.09 9.52 9.57 9.11 27 9.07 9.59 9.62 9.14 28 9.11 9.68 9.65 9.14 29 9.14 9.57 9.64 9.07 30 9.16 9.59 9.47 9.07 31 9.40 --- 9.45 9.14 9.65 10.24 9.62 10.52 10.27 10.34 10.39 10.14 9.77 10.00 9.63 10.64 10.13 10.49 10.56 10.19 9.76 9.97 9.70 10.73 10.15 10.48 10.49 10.18 --- 10.07 9.70 10.82 10.13 10.42 10.56 10.23 --- 10.07 9.89 10.81 10.10 10.24 10.62 10.16 --- 10.13 --- 10.81 --- 10.17 10.53 --­ MEAN 9.16 9.39 9.49 9.56 9.31 9.99 9.85 10.43 10.52 10.32 10.14 10.21 WTR YR 2003MEAN9.87 HIGHEST 8.88 OCT 10, 2002 LOWEST 10.92 JUNE 4, 2003 7 8 9 10 11 12 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 505 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 182530066135400. Local number, 216. LOCATION.--Lat 18q25'30", long 66q13'54", Hydrologic Unit 21010005, 2.61 mi northeast of Toa Alta plaza, 2.73 mi southwest of Sabana Seca US Naval Radio Station, and 1.76 mi southeast of Hwy 2 km 17.7, Name: Campanilla Navy Well, Toa Baja. AQUIFER.--Aguada Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m) 0-106 ft (0-32.3 m), cased 16 in (0.41 m) 0-20 f t (0-6.1 m), cased 12 in (0.3 m) 0-106 ft (0-32.3 m), perforated 20-106 ft (6.1-32.3 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 104 ft (31.7 m), sounded depth measured on October 4, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 13 ft (3.96 m), above mean sea level, from topographic map. Measuring point: To p of shelter floor, 3.27 ft (0.99 m), above land-surface datum. Prior to August 6, 2001, hole on side of casing, 1.8 ft (0.55 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on November 6, 1998. Water levels affected by nearby pumping well. From October 2000 to August 6, 2001, tapedowns measurements only. PERIOD OF RECORD.--October 1985 to June 29, 2000. Shelter found destroyed on June 29, 2000, replaced on August 6, 2001 to curren t year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.38 ft (2.86 m), below land-surface datum, June 23, 1987; lowest water level recorded, 18.4 ft (5.61 m), below land-surface datum, September 24, 1994. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.91 14.90 15.44 16.71 2 14.87 15.03 15.30 15.83 3 14.91 15.06 15.40 15.74 4 14.96 14.95 15.39 15.77 5 15.03 14.96 15.27 15.75 14.01 14.08 14.74 13.89 14.20 14.03 13.71 14.14 13.99 14.10 14.59 13.92 14.19 14.00 13.74 14.09 13.98 14.13 14.68 13.94 14.20 13.94 13.84 14.06 13.89 14.15 14.64 13.95 14.20 13.93 13.89 14.07 13.75 14.14 14.65 13.97 14.21 13.92 13.92 14.13 6 15.04 15.10 15.29 15.75 7 15.21 15.06 15.42 15.75 8 15.04 15.12 15.40 15.83 9 14.94 14.60 15.38 15.83 10 14.74 15.24 15.26 15.83 13.72 14.12 14.58 13.97 14.08 13.92 14.01 14.21 13.69 14.11 14.55 14.01 14.04 13.90 13.83 14.29 13.68 14.14 14.55 14.05 14.04 13.85 13.78 14.28 13.67 14.14 14.53 14.07 14.05 13.77 13.78 14.32 13.66 14.13 14.50 14.08 14.05 13.79 13.73 14.38 11 14.76 15.18 15.16 15.91 12 14.81 14.84 15.33 15.91 13 14.78 14.83 15.38 15.94 14 14.72 14.74 15.45 15.87 15 14.65 15.16 15.48 16.17 13.64 14.13 14.45 14.09 14.02 13.84 14.53 14.38 13.65 14.15 14.44 14.11 14.00 13.94 14.64 14.42 13.65 14.20 14.44 14.14 14.02 13.94 14.27 14.45 13.66 14.24 14.44 14.16 14.04 13.92 14.71 14.47 13.70 14.31 14.48 14.19 14.05 13.92 14.71 14.51 16 14.47 15.21 14.84 15.83 17 14.50 15.04 15.34 16.02 18 14.85 14.84 15.39 16.10 19 14.91 14.91 15.48 15.83 20 14.90 14.99 15.46 15.76 13.72 14.34 14.48 14.21 14.02 13.92 14.79 14.53 13.72 14.36 14.41 14.20 14.05 13.86 14.81 14.56 13.72 14.37 14.28 14.19 14.06 13.91 14.81 14.66 13.75 14.38 14.17 14.18 14.13 13.96 14.74 14.62 13.75 14.45 14.10 14.25 14.09 13.97 14.71 14.61 21 14.91 15.03 15.54 15.50 22 14.80 15.10 15.51 15.69 23 14.84 15.27 15.55 15.61 24 15.03 15.30 15.58 15.99 25 14.80 15.31 15.47 15.37 13.75 14.49 14.07 14.20 14.03 13.98 14.66 14.67 13.77 14.51 14.02 14.03 13.94 14.01 14.53 14.55 13.83 14.51 14.03 14.02 13.93 13.89 14.50 14.52 14.29 14.49 13.83 14.00 13.92 13.85 14.45 14.51 13.93 14.49 13.74 13.98 13.94 13.78 14.35 14.57 26 14.83 15.24 16.41 14.58 27 14.82 15.38 16.57 14.36 28 14.71 15.47 16.74 14.25 29 14.70 15.38 16.79 14.15 30 14.38 15.43 16.79 14.07 31 14.96 --- 16.85 14.04 14.04 14.52 13.75 14.01 13.96 13.75 14.27 14.57 14.03 14.43 13.74 14.01 14.01 13.72 14.22 14.59 14.05 14.51 13.73 14.08 14.04 13.68 14.15 14.63 --- 14.60 13.78 14.11 14.05 13.65 14.11 14.61 --- 14.66 13.86 14.14 14.07 13.67 14.10 14.60 --- 14.70 --- 14.18 --- 13.69 14.13 --­ MEAN 14.83 15.09 15.63 15.54 13.81 14.33 14.28 14.08 14.05 13.87 14.27 14.43 WTR YR 2003MEAN14.52 HIGHEST 13.62 JULY 29, 2003 LOWEST 16.89 DEC 31, 2002 9 10 11 12 13 14 15 16 17 18 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 506 GROUND-WATER LEVELS RIO DE LA PLATA BASIN—Continued 180649066095500. Local number, 1134. LOCATION.--Lat 18q06'49", long 66q09'55", Hydrologic Unit 21010005, 0.1 mi southeast of Cayey plaza, 0.5 mi northwest of the intersection of Hwy 1 with Hwy 15, and 1.3 mi west of Cayey exit from Hwy 52, Name: Minima. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Abandoned production well, diameter 13 in (0.34 m), screened 40-90 ft (12.2-27.4 m). Depth 125 ft (38.1 m). DATUM.--Elevation of land-surface datum is about 1,296 ft (395 m), above mean sea level, from topographic map. Measuring point: On highest part of motor support, 1.86 ft (0.57 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--February 28, 1998 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 15.39 ft (4.69 m), below land-surface datum, December 27, 1999; lowest water level measured, 19.03 ft (5.8 m), below land-surface datum, June 11, 1998. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 28 18.36 JAN 30 18.83 MAR 14 18.95 MAY 01 17.37 JULY 02 18.15 SEPT 05 16.94 DEC 11 18.96 FEB 20 18.70 APR 21 17.40 JUNE 13 17.90 AUG 01 17.66 WATER YEAR 2003 HIGHEST 16.94 SEPT 05, 2003 LOWEST 18.96 DEC 11, 2002 15.0 15.5 16.0 16.5 17.0 17.5 18.0 18.5 19.0 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 1998 1999 2000 2001 2002 2003 507 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 182441066082600. Local number, 219. LOCATION.--Lat 18q24'41", long 66q08'26", Hydrologic Unit 21010005, 0.47 mi west of Fort Buchanan main gate, 1.74 mi northeast of Bayamón plaza, and 1.88 mi southwest of PR National Cementery, Name: Buchanan Park Well, Bayamón. 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 46-68.5 ft (14-20.7 m), 88-120 ft (26.8-36.6 m), 160-191 ft (48.8-58.2 m), 240-270 ft (73.2-82.3 m). Depth 270 ft (82.3 m). DATUM.--Elevation of land-surface datum is about 66 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.--Observation well. PERIOD OF RECORD.--December 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.9 ft (10.7 m), below land-surface datum, November 12, 13, 14, 1989; lowest water level recorded, 55.67 ft (17 m), below land-surface datum, May 13, 1995. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 18 38.53 JAN 10 40.16 MAR 10 40.87 MAY 19 40.47 JULY 28 40.09 SEPT 11 39.84 DEC 06 39.34 FEB 07 40.23 APR 03 41.30 JUNE 03 39.92 AUG 20 40.39 WATER YEAR 2003 HIGHEST 38.53 OCT 18, 2002 LOWEST 40.47 MAY 19, 2003 36 38 40 42 44 46 48 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 508 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS—Continued 182531066075900. Local number, 652. LOCATION.--Lat 18q25'31", long 66q06'59", Hydrologic Unit 21010005, 0.07 mi north of Hwy 22, 0.32 mi southwest of the intersection of Hwy 165 with Hwy 28, and 1.4 mi south of the Cataño ferry building, Name: Piezometer USGS Building 652, Guaynabo. AQUIFER.--Aymamón Limestone. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.1 m), cased 0-192 ft (0-58.5 m). Depth 130 ft (39.62 m), sounded depth measured on October 20, 2004. INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minutes interval. 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 the 4 in (0.1 m) casing, 3.27 ft (1 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on May 14, 1997. Water level affected by marine ti des. PERIOD OF RECORD.--May 14, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 3.1 ft (0.94 m), below land-surface datum, September 24, 2001; low est water level recorded, 9.16 ft (2.79 m), below land-surface datum, October 1, 1998. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 8.07 8.19 --- 7.69 7.24 7.78 7.88 8.15 8.34 8.10 7.57 6.99 2 8.33 8.09 --- 7.46 7.32 7.71 7.97 8.16 8.28 7.95 7.53 7.24 3 8.41 7.82 --- 7.11 7.36 7.66 8.09 8.02 --- 7.86 7.57 7.60 4 8.15 7.61 --- 6.80 7.42 7.76 8.05 7.95 --- 7.77 7.64 7.98 5 7.95 7.21 --- 6.82 7.20 7.84 8.02 7.97 --- 7.90 7.97 8.56 6 7.68 7.08 --- 7.07 7.31 7.90 8.15 8.07 --- 7.91 8.29 8.63 7 7.26 7.00 --- 7.49 7.49 8.04 8.28 8.10 --- 8.04 8.67 8.73 8 7.05 7.17 --- 7.69 7.68 8.08 8.20 8.04 --- 8.22 8.62 8.54 9 6.98 7.39 --- 7.84 7.76 7.94 8.19 8.15 --- 8.40 8.67 8.25 10 7.06 7.62 7.93 8.03 7.97 7.89 8.39 8.24 --- 8.44 8.61 8.06 11 7.37 8.00 8.03 8.13 12 7.68 8.14 8.20 8.25 13 7.98 8.22 8.24 8.16 14 8.06 8.35 8.21 8.08 15 6.97 8.29 8.03 8.13 7.82 8.00 8.24 8.29 --- 8.40 8.31 7.89 8.03 8.20 8.46 8.45 --- 8.40 8.17 7.72 8.05 8.22 8.49 8.47 --- 8.29 7.93 7.51 7.96 8.07 8.59 8.43 --- 8.03 7.84 7.44 8.00 8.03 8.59 8.38 --- 7.62 4.39 7.49 16 7.91 8.24 8.06 7.90 17 7.90 --- 7.86 7.64 18 7.85 --- 7.74 7.59 19 7.80 --- 7.71 7.49 20 7.67 --- 7.66 7.45 7.83 7.79 8.46 8.39 --- 7.65 7.50 7.69 7.59 7.74 8.18 8.20 --- 7.37 7.48 7.74 7.49 7.64 8.05 8.08 --- 7.45 7.59 7.82 7.40 7.21 8.03 7.98 --- 7.57 7.72 8.11 7.53 7.46 7.99 7.97 --- 7.65 7.91 8.22 21 7.43 --- 7.53 7.51 22 7.32 --- 7.59 7.46 23 7.25 --- 7.45 7.62 24 7.24 --- 7.54 7.77 25 7.08 --- 7.71 8.09 7.65 7.78 7.95 7.88 --- 7.87 8.34 8.20 7.85 8.14 7.82 7.92 --- 7.93 8.04 8.47 8.04 8.20 7.97 8.13 --- 8.15 7.88 8.41 8.11 8.18 7.78 8.29 --- 8.00 8.19 8.28 8.19 8.29 7.88 8.38 --- 8.13 6.74 8.03 26 7.03 --- 7.95 8.27 27 7.24 --- 8.10 8.13 28 7.35 --- 8.43 7.90 29 7.52 --- 8.45 7.76 30 7.82 --- 8.34 7.72 31 7.99 --- 8.23 7.43 8.21 8.29 7.93 8.37 --- 8.27 8.09 7.71 8.09 8.33 8.09 8.48 --- 8.43 7.97 7.44 7.99 8.35 8.15 8.50 8.46 8.31 7.91 7.19 --- 8.15 8.14 8.48 8.43 8.20 7.59 7.05 --- 8.10 8.09 8.50 8.27 8.07 7.33 7.29 --- 7.94 --- 8.46 --- 7.82 4.63 --­ MEAN 7.59 --- --- 7.69 7.74 7.96 8.14 8.22 --- 8.01 7.70 7.88 WTR YR 2003MEAN7.89 HIGHEST 3.59 AUG 15, 2003 LOWEST 8.95 DEC 21, 2002 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 509 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS—Continued 182435066052700. Local number, 1153. LOCATION.--Lat 18q24'35", long 66q05'27", Hydrologic Unit 21010005, 2.94 mi southeast of Cataño plaza, 0.44 mi north of Escuela Superior Gabriela Mistral, and 1.19 mi northeast of WAPA TV radio anthena, Name: Piezometer Salud Mental 1, San Juan. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-83 ft (0-25.3 m), perforated 73-83 ft (22.2-25.3 m). Depth 83 ft (25.3 m). DATUM.--Elevation of land-surface datum is about 85 ft (25.9 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 2.85 ft (0.87 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--April 1989 to July 1, 1998, discontinued, February 17, 1999 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 21.97 ft (6.69 m), below land-surface datum, December 8, 9, 1999; lowest water level recorded, 32.82 ft (10 m), below land-surface datum, September 25-28, 1994. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 18 26.09 JAN 27 27.72 APR 03 28.37 JUNE 17 27.12 JULY 29 27.14 SEPT 05 25.75 DEC 06 26.53 FEB 24 27.71 MAY 19 27.34 WATER YEAR 2003 HIGHEST 25.75 SEP 05, 2003 LOWEST 28.37 APR 03, 2003 21 22 23 24 25 26 27 28 29 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 510 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS—Continued 182445066043401. Local number, 1154. LOCATION.--Lat 18q24'45", long 66q04'34", Hydrologic Unit 21010005, 0.28 mi northeast of Dr. Pedreira School, 3.52 mi southeast of Cataño plaza, and 0.53 mi south of Hiram Bithorn Stadium main gate, Name: Piezometer Alsacia 2, San Juan. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-27 ft (0-8.23 m), perforated 21-27 ft (6.4-8.23 m). Depth 27 ft (8.23 m). DATUM.--Elevation of land-surface datum is about 13 ft (3.96 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 3.58 ft (1.09 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1989 to November 27, 1991, Temporary discontinued, September 9, 1993 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.6 ft (0.79 m), below land-surface datum, November 25, 1999; lowe st water level recorded, 13.65 ft (4.16 m), below land-surface datum, October 6, 7, 1994. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 18 6.03 JAN 27 7.78 APR 03 8.14 JUNE 1 37.41 JULY 29 7.83 SEPT 02 6.22 DEC 18 7.51 FEB 10 7.44 MAY 19 7.46 WATER YEAR 2003 HIGHEST 6.03 OCT 18, 2002 LOWEST 8.14 APR 03, 2003 3 4 5 6 7 8 9 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 511 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS—Continued 182406066034700. Local number, 1158. LOCATION.--Lat 18q24'06", long 66q03'47", Hydrologic Unit 21010005, 4.65 mi southeast of Cataño plaza, 0.89 mi south of Escuela J.J. Osuna, and 0.78 mi southwest of University of Puerto Rico main gate, Name: Piezometer Jardín Botánico 3, San Juan. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.1 m) cased 4 in (0.1 m), 0-48 ft (0-14.6 m), perforated 38-48 ft (11.6-14.6 m). Depth 48 ft.(14.6 m). DATUM.--Elevation of land-surface datum is about 32 ft (9.75 m), above mean sea level, from topographic map. Measuring point: Hole on well shaft, 2.91 ft (0.88 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--June 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.05 ft (0.62 m), below land-surface datum, December 4, 1998; lowest water level recorded, 13.43 ft (4.09 m), below land-surface datum, November 8, 9, 1994. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 18 3.71 JAN 24 6.71 APR 03 7.36 JUNE 13 6.59 AUG 04 7.85 SEPT 02 4.33 DEC 18 6.26 FEB 20 7.34 MAY 13 6.92 JULY 09 7.57 WATER YEAR 2003 HIGHEST 3.71 OCT 18, 2002 LOWEST 7.85 AUG 04, 2003 2 4 6 8 10 12 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 512 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS—Continued 182451066080200. Local number, 1159. LOCATION.--Lat 18q24'50", long 66q08'05", Hydrologic Unit 21010005, 1.7 mi west of Fort Buchanan main gate, 0.2 mi southeast of oil refinery, and 0.9 mi east of Goya Products plant, Name: Piezometer Ft. Buchanan 1, Bayamón. AQUIFER.--Mucarabones Sand. WELL CHARACTERISTICS.--Drilled water-table well, diameter 4 in (0.1 m), screened 209-249 ft (63.7-75.89 m). Depth 249 ft (75.89 m). DATUM.--Elevation of land-surface datum is about 46 ft (14 m), about mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.33 ft (1.01 m), above land-surface datum. REMARKS.--Observation well. Well is affected by nearby pumping. PERIOD OF RECORD.--September 12, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 24.91 ft (7.59 m), below land-surface datum, September 11, 2003; lowest water level recorded, 44.38 ft (13.53 m), below land-surface datum, July 28, 29, 2000. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 18 25.44 JAN 27 25.28 MAR 10 25.84 MAY 19 25.43 JULY 29 25.09 SEPT 11 24.93 DEC 06 25.25 FEB 07 25.38 APR 03 25.77 JUNE 17 25.25 AUG 15 25.11 WATER YEAR 2003 HIGHEST 24.93 SEP 11, 2003 LOWEST 25.84 MAR 10, 2003 20 25 30 35 40 45 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 513 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181352066025300. Local number, 1176. LOCATION.--Lat 18q13'52", long 66q02'53", Hydrologic Unit 21010005, 0.96 mi southwest of Caguas plaza, 1.02 mi northwest of Escuela Antonio S. Pedreira, and 0.3 mi southeast of Hwy 156 km 59.1, Name: Piezometer CJ 19A, Caguas. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-67 ft (0-20.4 m), screened 50-65 ft (15.2-19.8 m). Depth 67 ft (20.4 m). DATUM.--Elevation of land-surface datum is about 262 ft (79.8 m), above mean sea level, from topographic map. Measuring point: Top of casing 3.48 ft (1.06 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.-- June 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 20.75 ft (6.32 m), below land-surface datum, November 20, 21, 1999; lowest water level recorded, 25.7 ft (7.83 m), below land-surface datum, May 31, 1995. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 28 24.42 JAN 30 24.62 APR 21 24.01 JUNE 13 23.93 AUG 01 24.16 SEPT 05 23.88 DEC 12 24.72 FEB 20 24.45 MAY 01 23.41 JULY 23 24.19 WATER YEAR 2003 HIGHEST 23.41 MAY 01, 2003 LOWEST 24.72 DEC 12, 2002 20 21 22 23 24 25 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 514 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN—Continued 181311066022500. Local number, 1177. LOCATION.--Lat 18q13'11", long 66q02'25", Hydrologic Unit 21010005, 1.13 mi south of the intersection of Hwy 156 with Hwy 52, 0.15 mi southeast of the inserction of Hwy 172 with Hwy 1, and 0.2 mi northeast of Escuela Antonio S. Pereira, Name: Piezometer Caguas-Juncos 11, Caguas. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), 0-110 ft (0-33.5 m), screened 66-96 ft (20.1-29.3 m). Depth 110 ft (33.5 m). DATUM.--Elevation of land-surface datum is about 282 ft (85.9 m), above mean sea level. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 3.04 ft (0.24 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--May 2, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.34 ft (5.59 m), below land-surface datum, December 6, 7, 8, 199 8; lowest water level recorded, 28.73 ft (8.76 m), below land-surface datum, August 22, 1997. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 28 26.22 JAN 30 27.54 APR 21 26.29 JUNE 13 25.47 AUG 01 26.02 SEPT 05 25.67 DEC 11 27.50 FEB 20 27.39 MAY 01 25.29 JULY 23 26.08 WATER YEAR 2003 HIGHEST 25.29 MAY 01, 2003 LOWEST 27.54 JAN 30, 2003 18 20 22 24 26 28 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 515 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN—Continued 181539066014500. Local number, 1179. LOCATION.--Lat 18q15'39", long 66q01'45", Hydrologic Unit 21010005, 0.55 mi southeast of the intersection of Hwy 1 with Hwy 30, 0.75 mi southeast of the inserction of Hwy 1 with Hwy 52, and 0.06 mi north of Hwy 796, Name: Piezometer Caguas-Juncos 15, Caguas. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), 0-70 ft (0-21.3 m), screened 25-70 ft (7.62-21.3 m). Depth 70 ft (21.3 m). DATUM.--Elevation of land-surface datum is about 167.3 ft (51 m), above mean sea level, from topographic map. Measuring point: S helter floor on top of 4 in (0.1 m) casing, 3.75 ft (1.14 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--May 5, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 4.92 ft (1.5 m), below land-surface datum, December 3, 1998; lowest water level recorded, 11.11 ft (3.39 m), below land-surface datum, August 11, 22, 2000. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 07 7.28 JAN 30 6.96 APR 28 6.05 JUNE 13 7.21 AUG 01 7.05 SEPT 05 6.10 DEC 12 7.51 FEB 20 7.15 MAY 19 7.02 JULY 23 7.10 WATER YEAR 2003 HIGHEST 6.05 APR 28, 2003 LOWEST 7.51 DEC 12, 2002 5 6 7 8 9 10 11 12 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 516 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN—Continued 182515065594100. Local number, 222. LOCATION.--Lat 18q25'15", long 65q59'41", Hydrologic Unit 21010005, 3.56 mi northwest of Carolina plaza, 1.21 mi northwest of Extensión El Comandante School, and 0.74 mi southwest of Vistamar School, Name: Piezometer Campo Rico TW-1, Carolina. AQUIFER.--Surficial Deposits. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m). Depth 100 ft (30.5 m). DATUM.--Elevation of land-surface datum is about 10 ft (3.05 m), above mean sea level, from topographic map. Measuring point: Ho le on side of casing, 0.9 ft (0.27 m), above land-surface datum. Prior July 28, 1986, top of shelter floor, 3.1 ft (0.94 m), above land-surface datum. REMARKS.--Observation well. Well level affected by marine tides. PERIOD OF RECORD.--February 1986 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 4.33 ft (1.32 m), below land-surface datum, September 6, 1995; low est water level recorded, 7.42 ft (2.26 m), below land-surface datum, February 9, 1986. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 12 5.53 JAN 27 5.41 APR 29 5.49 JUNE 16 5.87 AUG 18 5.44 SEPT 02 5.30 DEC 18 5.26 FEB 10 5.58 MAY 13 5.64 JULY 09 5.52 WATER YEAR 2003 HIGHEST 5.26 DEC 18, 2002 LOWEST 5.87 JUNE 16, 2003 4.80 5.00 5.20 5.40 5.60 5.80 6.00 6.20 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 517 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 181217065453000. Local number, 1203. LOCATION.--Lat 18q12'17", long 65q45'30", Hydrologic Unit 21010005, 0.01 mi south of Hwy 927 at Km 8 and 0.62 mi south of Hwy 31, Name: Piezometer Carlos Arroyo 1, Naguabo. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), screened 29-32 ft (8.84-9.75 m). Depth 30 ft (9.1 4 m), sounded depth measured on October 18, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 16 ft (4.87 m), above mean sea level, from topographic map. Measuring point: Sh elter floor, 4.8 ft (1.46 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on October 26, 1997. Well is affected by stage in nearby Ro Blanco. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on September 27, 1999. PERIOD OF RECORD.--October 26, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.55 ft (0.47 m), below land-surface datum, April 17, 2003; lowest water level recorded, 12.2 ft (3.72 m), below land-surface datum, August 21, 22, 2000. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.85 9.70 10.07 10.05 9.63 10.25 10.99 8.97 9.22 9.95 9.66 9.39 2 9.90 9.79 10.14 10.05 9.78 10.29 10.93 9.11 9.26 9.15 8.53 9.54 3 9.79 9.86 10.03 9.91 9.76 10.25 11.00 9.17 9.24 9.81 9.82 9.72 4 9.91 9.90 9.98 10.01 8.76 10.34 9.99 9.25 9.12 9.65 10.02 9.44 5 9.97 9.96 9.93 10.07 9.20 10.40 10.70 9.32 9.39 9.94 10.20 9.77 6 10.00 10.03 10.02 9.80 7 10.05 10.09 10.07 9.88 8 10.11 10.14 10.12 9.95 9.15 10.43 9.31 9.37 9.48 9.93 10.29 9.90 9.41 10.47 9.68 9.42 8.93 10.04 9.08 9.87 9.46 10.50 9.83 9.44 9.02 10.13 9.73 10.00 9 9.59 10.19 9.93 9.97 9.60 10.56 9.84 9.47 9.28 10.00 9.83 9.62 10 9.60 10.00 9.75 10.05 9.64 10.58 9.64 9.54 9.43 10.12 9.95 9.78 11 9.38 9.97 9.85 10.12 12 9.22 9.80 9.95 10.16 13 9.35 10.12 10.03 10.21 14 9.45 10.20 9.99 10.24 15 9.52 10.26 10.05 10.28 9.61 10.59 8.50 9.58 9.58 10.24 10.01 9.87 9.55 10.64 8.66 9.69 9.59 10.28 10.09 9.95 9.72 10.67 9.22 9.72 9.66 8.72 10.20 10.08 9.81 10.70 9.45 9.39 9.84 9.53 10.26 9.81 9.85 10.75 9.42 8.64 9.25 9.76 10.14 9.96 16 9.20 10.22 10.02 10.30 17 9.34 9.92 10.01 10.34 18 9.40 9.63 9.95 10.36 19 9.35 9.66 10.12 10.39 20 9.14 9.88 9.72 10.40 9.91 10.77 8.96 8.97 8.24 9.06 10.36 9.24 9.24 10.78 2.36 9.01 8.70 9.42 10.42 9.73 9.69 10.77 5.01 8.59 8.90 9.76 10.37 9.50 9.80 10.81 5.31 8.61 9.08 9.91 10.32 9.85 9.90 10.52 6.16 8.81 9.13 10.00 10.16 9.71 21 9.37 9.86 9.73 10.44 22 9.21 9.44 9.92 10.44 23 9.45 9.68 9.80 10.49 24 9.31 9.70 9.87 10.50 25 9.13 9.81 9.80 8.91 9.91 10.60 6.92 8.95 8.89 10.04 10.34 9.27 9.88 10.65 6.99 6.79 9.26 9.78 7.98 9.13 9.97 10.71 7.23 7.24 9.44 9.96 9.18 9.49 10.04 10.76 7.57 7.22 9.51 10.12 9.48 9.72 9.97 10.79 7.94 7.93 9.66 10.20 9.53 9.86 26 8.52 9.87 9.95 9.01 27 9.01 9.80 9.70 9.58 28 9.29 9.90 9.84 9.81 29 9.43 9.96 9.94 9.93 30 9.52 10.03 9.97 9.95 31 9.58 --- 10.05 9.91 10.00 10.84 8.16 8.26 9.70 10.27 8.61 9.92 10.10 10.88 8.39 8.51 9.77 10.27 9.28 9.99 10.20 10.92 8.47 8.72 9.61 9.66 9.31 10.06 --- 10.94 8.65 8.88 9.79 9.88 9.24 10.12 --- 10.84 8.80 9.01 9.83 9.92 9.32 10.10 --- 10.92 --- 9.13 --- 10.03 9.44 --­ MEAN 9.48 9.91 9.95 10.05 9.70 10.64 8.47 8.86 9.33 9.86 9.71 9.75 WTR YR 2003MEAN9.64 HIGHEST 1.55 APR 17, 2003 LOWEST 11.02 APR 3, 2003 2 4 6 8 10 12 14 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 518 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS—Continued 182131065421100. Local number, 1205. LOCATION.--Lat. 18q21'31", long. 65q42'11", Hydrologic Unit 21010005, 1.39 mi southeast of the intersection of Hwy 992 with Hwy 3, 0.4 mi southeast of the intersection of Hwy 983 with Hwy 3, 0.12 mi northwest of the intersection with Hwy 940 with Hwy 983, and 0.03 mi southwest of Hwy 983, Name: Piezometer USGS RP-4, Luquillo. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m) 0-39 ft (0-11.9 m), screened 4 -39 ft (1.2-11.9 m). Depth 39 ft (11.9 m). DATUM.--Elevation of land-surface datum is about 14 ft (4.27 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 4.42 ft (1.35 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--August 15, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.32 ft (0.09 m), below land-surface datum, December 10, 1998; low est water level recorded, 14.05 ft (4.28 m), below land-surface datum, August 21, 1997. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 24 2.17 JAN 29 1.41 APR 04 3.45 JUNE 16 3.65 AUG 18 5.32 SEPT 02 4.03 DEC 12 2.58 FEB 10 1.77 MAY 13 2.11 JULY 09 4.53 WATER YEAR 2003 HIGHEST 1.41 JAN 29, 2003 LOWEST 5.32 AUG 18, 2003 0 2 4 6 8 10 12 14 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 519 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS—Continued 181917065382701. Local number, 1207. LOCATION.--Lat 18q19'17", long 65q38'27", Hydrologic Unit 2101005, 1.2 mi northwest of Punta Barrancas, 0.81 mi east of Hwy 3, 0.82 mi south of Hwy 195, and 0.61 mi east of Hwy 194, Name: Piezometer RF-12, Fajardo. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m) 0-34 ft (0-10.4 m), screened 3 .75-34 ft (1.14-10.4 m). Depth 35 ft (10.7 m), sounded depth measured on October 18, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is 13.7 ft (4.18 m), above mean sea level, from topographic survey. Measuring point: She lter floor on top of 4 in (0.1 m) casing, 4.16 ft (1.27 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n May 14, 1999. PERIOD OF RECORD.--August 11, 1995 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.58 ft (0.18 m), below land-surface datum, December 3, 1999; lowest water level recorded, 13.74 ft (4.19 m), below land-surface datum, April 15, 2002. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- 8.71 9.25 10.87 2 --- 8.70 9.27 10.92 3 --- 8.72 9.27 10.97 4 --- 8.75 9.24 11.01 5 --- 8.76 9.26 11.03 8.68 9.63 11.02 6.39 9.77 10.80 12.33 9.35 8.68 9.64 11.13 6.52 9.79 10.88 12.34 9.30 8.66 9.68 11.23 6.64 9.82 11.00 12.34 9.29 8.65 9.71 11.33 6.78 9.85 11.09 12.35 9.28 8.60 9.74 11.34 6.91 9.88 11.19 12.36 9.29 6 --- 8.79 9.26 11.02 7 --- 8.79 9.27 11.02 8 --- 8.83 9.28 11.02 9 --- 8.84 9.28 11.03 10 --- 8.85 9.29 11.11 8.59 9.77 10.42 6.99 9.90 11.28 12.37 9.28 8.58 9.80 10.32 7.07 9.91 11.35 12.37 9.29 8.57 9.83 10.42 7.12 9.88 11.44 12.38 9.08 8.57 9.87 10.53 7.24 9.89 11.48 12.37 8.53 8.57 9.89 10.58 7.38 9.91 11.54 12.37 8.26 11 --- 8.88 9.37 11.21 12 --- 8.87 9.46 11.28 13 --- 8.85 9.54 11.37 14 --- 8.82 9.66 11.43 15 --- 8.85 9.74 11.51 8.57 9.93 10.15 7.43 9.91 11.61 12.36 7.94 8.57 9.95 9.46 7.54 9.93 11.68 12.36 7.48 8.57 9.98 9.19 7.70 9.95 11.55 12.39 7.29 8.58 10.01 9.07 7.86 9.97 11.27 12.36 7.39 8.60 10.05 9.00 7.97 9.89 11.46 11.90 7.46 16 --- 8.89 9.73 11.60 17 --- 8.96 9.70 11.67 18 --- 9.06 9.75 11.76 19 --- 9.06 9.87 11.82 20 --- 9.17 10.01 11.89 8.66 10.08 8.96 8.11 9.72 11.58 12.06 7.46 8.75 10.09 6.82 8.26 9.74 11.66 12.20 7.44 8.89 10.12 4.05 8.40 9.77 11.73 12.28 7.40 9.02 10.14 3.65 8.46 9.80 11.79 12.25 7.47 9.11 10.16 3.84 8.49 9.82 11.84 12.28 7.48 21 --- 9.29 10.12 11.93 22 --- 9.05 10.18 11.99 23 --- 9.14 10.20 12.07 24 --- 9.17 10.22 12.14 25 8.68 9.20 10.23 11.42 9.24 10.17 4.25 8.62 9.82 11.88 12.31 5.35 9.35 10.19 4.58 8.69 9.84 11.93 11.89 4.75 9.45 10.21 4.83 8.84 9.87 11.95 11.59 5.12 9.51 10.26 5.07 8.96 9.93 11.99 11.33 5.32 9.51 10.27 5.28 9.09 10.05 12.04 11.17 5.31 26 8.74 9.22 10.24 10.09 27 8.75 9.22 10.26 9.01 28 8.77 9.23 10.37 8.84 29 8.78 9.24 10.48 8.68 30 8.79 9.25 10.62 8.67 31 8.72 --- 10.75 8.69 9.53 10.34 5.44 9.24 10.16 12.09 10.45 5.40 9.56 10.42 5.63 9.38 10.27 12.16 9.89 5.59 9.59 10.52 5.81 9.52 10.41 12.20 9.65 5.73 --- 10.65 6.04 9.62 10.54 12.24 9.55 5.84 --- 10.76 6.24 9.68 10.67 12.27 9.45 5.95 --- 10.88 --- 9.74 --- 12.30 9.39 --­ MEAN --- 8.97 9.78 10.94 8.90 10.09 7.86 8.09 9.96 11.65 11.70 7.34 WTR YR 2003MEAN9.57 HIGHEST 3.04 APR 18-19, 2003 LOWEST 12.41 AUG 14, 2003 0 2 4 6 8 10 12 14 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 520 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS—Continued 182234065440000. Local number, 1208. LOCATION.--Lat 18q22'34", long 65q44'00", Hydrologic Unit 2101005, 0.7 mi south of Balneario de Luquillo, 1.1 mi west of Luquillo, and 1 mi northwest of intersectin of Hwy 991 with Hwy 992, Name: Piezometer Quebrada Mata de Platanos 1, Luquillo. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--PVC cased ran levels, diameter 4 in (0.1 m) screened 5-25 ft (1.52-7.62 m). Depth 25 ft (7.62 m). DATUM.--Elevation of land-surface is about 2.39 ft (0.73 m), about mean sea level, from topographic map. Measuring point: Floor of shelter, 5.6 ft (1.71 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 17, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +3.02 ft (+0.92 m), above land-surface datum, September 18, 2002; lowest water level measured, 6.03 ft (1.84 m), below land-surface datum, August 19-22, 2001. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM (READINGS ABOVE LAND-SURFACE INDICATED BY "+"), WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 24 0.68 JAN 29 +0.01 APR 04 3.67 JUNE 16 2.70 AUG 18 4.98 SEPT 02 0.63 DEC 12 2.24 FEB 10 0.42 MAY 13 2.28 JULY 09 4.15 WATER YEAR 2003 HIGHEST +0.01 JAN 29, 2003 LOWEST 4.98 AUG 18, 2003 -1 0 1 2 3 4 5 6 7 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 521 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS 180415065513900. Local number, 96. LOCATION.--Lat 18q04'15", long 65q51'39", Hydrologic Unit 21010005, 2.44 mi northwest of Escuela Eugenio María de Hostos 4.67 mi southwest of Escuela Segunda Unidad Luciano, and 3.93 mi southwest of Escuela Asunción López, Name: Yabucoa 7 Well, Yabucoa. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 16 in (0.41 m), cased 0-1 ft (0-3.05 m), diameter 6 in (0. 15 m), cased about 0­ 183 ft (0-55.8 m), perforated 56-81 ft (17.1-24.7 m), 102-123 ft, (31.1-37.5 m), 144-181 ft (43.9-55.2 m). Depth 181 ft (55.2 m). DATUM.--Elevation of land-surface datum is about 25 ft (7.62 m), above mean sea level, from topographic map. Measuring point: To p of shelter floor, 4 ft (1.22 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--April 25, 1978 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.74 ft (2.05 m), below land-surface datum, June 7, 2002; lowest water level recorded, 28.29 ft (8.62 m) below land-surface datum, September 20, 1980. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 21 13.69 JAN 29 14.03 APR 04 14.67 JUNE 16 11.99 AUG 18 13.26 SEPT 02 13.09 DEC 12 14.11 FEB 10 14.12 MAY 13 10.71 JULY 09 12.76 WATER YEAR 2003 HIGHEST 10.71 MAY 13, 2003 LOWEST 14.67 APR 04, 2003 6 8 10 12 14 16 18 20 22 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 522 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175855066050500. Local number, 1228. LOCATION.--Lat 17q58'55", long 66q05'05", Hydrologic Unit 21010004, 1.97 mi east-southeast of the intersection of Hwy 16 with Hwy 3, 1 mi west of the intersection of Hwy 3 with Hwy 178, and 0.04 mi south of Hwy 3, Name: Algarrobos Domestic Well, Guayama. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 9 in (0.23 m). Depth 57 ft (17.4 m). DATUM.--Elevation of land-surface datum is about 89 ft (27.1 m), above mean sea level. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 2.95 ft (0.9 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--May 24, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18.19 ft (5.54 m), below land-surface datum, June 26, 1997; lowest water level measured, 34.62 ft (10.55 m), below land-surface datum, December 9, 2002. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 30 32.01 JAN 29 34.49 MAR 14 33.32 MAY 14 30.81 JULY 02 32.70 SEPT 09 33.22 DEC 09 34.61 FEB 20 33.87 APR 21 30.77 JUNE 12 30.77 AUG 05 34.10 WATER YEAR 2003 HIGHEST 30.77 JUNE 12, APR 21, 2003 LOWEST 34.61 DEC 09, 2002 20 25 30 35 40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 523 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175728066072200. Local number, 1229. LOCATION.--Lat 17q57'28", long 66q07'22", Hydrologic Unit 21010004, 0.65 mi west of Central Machete. 0.75 mi northwest of Playita Machete, 2 mi south of the intersection of Hwy 15 with Hwy 3, and 1.13 mi southeast of intersection of Hwy 710 with Hwy 3, Name: Barranca Dug Well, Guayama. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Hand-dug unused water-table well, diameter 9 in (0.23 m). Depth 38 ft (11.7 m). DATUM.--Elevation of land-surface datum is about 59.1 ft (18 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 5 ft (1.52 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--April 3, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 13.66 ft (4.16 m), below land-surface datum, November 25, 26, 27, 1999; lowest water level measured, 24.69 ft (7.52 m), below land-surface datum, March 14, 2003. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 30 23.28 JAN 29 24.33 MAR 14 24.69 MAY 14 24.28 JULY 02 24.05 SEPT 09 94.21 DEC 09 23.78 FEB 06 24.41 APR 21 24.65 JUNE 12 24.31 AUG 05 23.98 WATER YEAR 2003 HIGHEST 23.28 OCT 30, 2002 LOWEST 24.69 MAR 14, 2003 12 14 16 18 20 22 24 26 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 524 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175719066085500. Local number, 1230. LOCATION.--Lat 17q57'20", long 66q09'02", Hydrologic Unit 2101004, 1 mi east of the intersection of Hwy 3 with Hwy 707, 0.28 mi south of Hwy 3, and 0.25 mi northwest of the Phillips Petroleum oil refinery, Name: Phillips Petroleum 13 Well, Guayama. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m). Depth 99 ft (30.2 m). DATUM.--Elevation of land-surface datum is about 33 ft (10.1 m), above mean sea level, from topographic map. Measuring point: To p of 4 in (0.1 m) casing, 2.83 ft (0.86 m), above land-surface datum. Prior September 18, 2002, shelter floor on top of 4 in (0.1 m) casing, 3.21 ft (0.98 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 25, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 14.47 ft (4.41 m), below land-surface datum, March 22, 24, 1993; lowest water level recorded, 31.22 ft (9.52 m), below land-surface datum, August 24, 1998. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DEC 09 28.15 FEB 06 29.30 APR 21 27.99 JUNE 12 27.56 AUG 05 28.15 SEPT 10 25.64 JAN 08 28.87 MAR 14 30.10 MAY 14 25.87 JULY 02 26.69 WATER YEAR 2003 HIGHEST 25.64 SEPT 10, 2003 LOWEST 30.10 MAR 14, 2003 16 18 20 22 24 26 28 30 32 1998 1999 2000 2001 2002 2003 WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 525 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175858066100200. Local number, 6. LOCATION.--Lat 17q58'58", long 66q10'02", Hydrologic Unit 21010004, 4.23 mi northeast of Central Aguirre Church, 4.08 mi northeast of Colegio del Perpetuo Socorro Church, and 1.77 mi northwest of Hwy 3 km 144.2, Name: Juana 5 Well. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (0.41 m). Depth 173 ft (52.74 m) reported, 110 ft (33.54 m) measured. DATUM.--Elevation of land-surface datum is about 127 ft (38.7 m), above mean sea level, from topographic map. Measuring point: Inner steel pipe, 3 ft (0.91 m), above land-surface datum. After August 7, 1981, top of 16 in (0.41 m) casing, 1.55 ft (0.47 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--November 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 26.2 ft (7.99 m), below land-surface datum, Decenber 10, 1979; lowest water level recorded, 65.95 ft (20.1 m), below land-surface datum, June 2, 1968. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 30 59.08 JAN 08 63.20 MAR 14 63.79 MAY 14 63.80 JULY 02 63.18 SEPT 10 63.46 DEC 09 61.96 FEB 06 63.73 APR 28 64.20 JUNE 12 62.99 AUG 05 62.32 WATER YEAR 2003 HIGHEST 59.08 OCT 30, 2002 LOWEST 64.20 APR 28, 2003 35 40 45 50 55 60 65 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 526 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175947066130601. Local number, 1233. LOCATION.--Lat 17q59'47", long 66q13'06", Hydrologic Unit 21010004, 2.7 mi northeast of Central Aguirre Church, 6.16 mi northwest of Guayama School, and 2.7 mi northeast of Hwy 3 km 151.3, Name: Piezometer Aguirre HW 5B, Salinas. 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 (0.1 m), 0-51 ft (0-15.5 m), screened 41-46 ft (12.5-14 m). Depth 51 ft (15.54 m), sounded depth measured on October 13, 2004. INSTRUMENTATION.--Data collector platform--60-minutes interval. DATUM.--Elevation of land-surface datum is about 145 ft (44.2 m), above mean sea level. Measuring point: Hole on side of casing, 3 ft (0.91 m), above land- surface datum. Prior October 13, 1989 top of shelter floor, 3.47 ft (1.06 m), above land-surface datum. REMARKS.--Recording observation well. Electronic Data Logger (EDL), installed on April 15, 1998, replaced by a Data Collector Platform (DCP), installed on August 3, 2000. PERIOD OF RECORD.--April 13, 1988 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 5.55 ft (1.69 m), below land-surface datum, November 13, 1999; lowest water level recorded, 28.55 ft (8.7 m), below land-surface datum, August 14, 15, 1996. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.24 19.74 20.51 21.04 2 19.24 19.78 20.53 21.05 3 19.24 19.80 20.55 21.08 4 19.30 19.82 20.57 21.21 5 19.33 19.84 20.59 21.23 21.80 22.31 22.33 18.51 19.66 20.73 22.11 22.59 21.81 22.32 22.33 18.56 19.70 20.77 22.15 22.59 21.81 22.34 22.34 18.60 19.73 20.79 22.16 22.58 21.82 22.36 22.36 18.64 19.80 20.83 22.17 22.58 21.82 22.37 22.38 18.69 19.84 20.86 22.22 22.58 6 19.38 19.86 20.61 21.24 7 19.39 19.90 20.63 21.24 8 19.41 19.92 20.65 21.26 9 19.45 19.95 20.67 21.27 10 19.46 19.98 20.67 21.29 21.81 22.38 22.40 18.73 19.88 20.91 22.24 22.57 21.82 22.39 22.40 18.78 19.96 20.96 22.24 22.57 21.82 22.38 22.40 18.82 19.96 21.02 22.25 22.58 21.83 22.39 22.42 18.85 19.97 21.02 22.29 22.59 21.83 22.40 22.46 18.89 19.98 21.12 22.37 22.61 11 19.48 20.01 20.67 21.40 12 19.49 20.05 20.68 21.42 13 19.55 20.07 20.70 21.42 14 19.56 20.12 20.70 21.45 15 19.58 20.16 20.73 21.46 21.84 22.44 22.46 18.92 20.01 21.21 22.39 22.65 21.85 22.44 22.40 18.96 20.02 21.25 22.40 22.67 21.88 22.45 22.00 19.00 20.06 21.28 22.42 22.70 21.88 22.48 21.86 19.03 20.09 21.28 22.51 22.73 21.90 22.52 21.77 19.06 20.17 21.36 22.56 22.74 16 19.64 20.19 20.76 21.47 17 19.66 20.23 20.76 21.49 18 19.68 20.25 20.77 21.61 19 19.70 20.27 20.79 21.61 20 19.72 20.29 20.79 21.62 21.91 22.52 21.75 19.10 20.24 21.41 22.57 22.75 21.93 22.51 21.66 19.13 20.29 21.44 22.60 22.76 21.94 22.55 20.62 19.17 20.33 21.48 22.62 22.77 21.96 22.56 19.05 19.20 20.39 21.55 22.63 22.76 21.99 22.56 18.63 19.23 20.42 21.61 22.63 22.77 21 19.74 20.31 20.81 21.62 22 19.75 20.34 20.83 21.64 23 19.77 20.36 20.86 21.64 24 19.78 20.38 20.87 21.64 25 19.69 20.40 20.91 21.65 22.02 22.51 18.43 19.27 20.45 21.64 22.63 22.87 22.08 22.45 18.38 19.30 20.47 21.67 22.67 22.89 22.10 22.38 18.35 19.33 20.50 21.73 22.67 22.90 22.17 22.36 18.33 19.37 20.53 21.78 22.70 22.93 22.18 22.33 18.35 19.40 20.56 21.80 22.73 22.96 26 19.68 20.42 20.93 21.66 27 19.68 20.44 20.93 21.66 28 19.68 20.46 20.93 21.78 29 19.69 20.47 20.98 21.78 30 19.70 20.49 21.01 21.79 31 19.72 --- 21.02 21.80 22.21 22.32 18.36 19.43 20.59 21.81 22.73 22.96 22.25 22.32 18.36 19.47 20.62 21.92 22.69 23.01 22.28 22.32 18.37 19.50 20.65 21.93 22.64 23.07 --- 22.33 18.41 19.54 20.68 21.95 22.61 23.08 --- 22.32 18.44 19.56 20.71 22.01 22.60 23.15 --- 22.32 --- 19.62 --- 22.06 22.59 --­ MEAN 19.56 20.14 20.76 21.47 21.95 22.41 20.66 19.09 20.21 21.39 22.48 22.77 WTR YR 2003MEAN21.07 HIGHEST 18.33 APR 24, 2003 LOWEST 23.15 SEPT 30, 2003 5 10 15 20 25 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 527 GROUND-WATER LEVELS RIO HUMACAO TO QUEBRADA AGUAS VERDES BASINS—Continued 175814066102200. Local number, 1239. LOCATION.--Lat 17q58'14", long 66q10'22", Hydrologic Unit 21010004, 1 mi northwest of Jobos community, 3.8 mi east of Colegio del Perpetuo Socorro, and 3.5 mi northeast of Central Aguirre, Name: Jobos Well, Guayama. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 11 in (0.24 m). Depth 63 ft (19.2 m). DATUM.--Elevation of land-surface datum is about 59 ft (18 m), above mean sea level, from topographic map. Measuring point: On shelter floor, 2.86 ft (0.87 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--April 2, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 6.14 ft (1.87 m), below land-surface datum, October 18, 1998; lowest water level measured, 37.39 ft (11.4 m), below land-surface datum, September 10, 2003. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 30 32.96 JAN 08 33.93 MAR 14 35.61 MAY 14 34.89 JULY 02 36.16 SEPT 10 37.39 DEC 09 33.58 FEB 06 34.73 APR 28 34.60 JUNE 12 35.52 AUG 05 36.86 WATER YEAR 2003 HIGHEST 32.96 OCT 30, 2002 LOWEST 37.39 SEP 10, 2003 10 15 20 25 30 35 40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 528 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175809066133100. Local number, 1251. LOCATION.--Lat 17q58'09", long 66q13'31", Hydrologic Unit 21010004, 0.49 mi southwest of the intersection of Hwy 706 with Hwy 3, 0.3 mi south of Hwy 3, and 0.12 mi east of Hwy 705, Name: Coqui Battery 1 Well, Salinas. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 18 in (0.46 m). Depth 200 ft (60.96 m), sounded depth measured on October 13, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is 16.4 ft (5 m), above mean sea level, from topographic map. Measuring point: Top of sh elter floor, 1.33 ft (0.41 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on March 6, 1997. Automated Digital Recorder ( ADR), replaced by an Electronic Data Logger (EDL), installed on September 27, 1999. Well is affected by nearby pumping. From October 1 2001 to Feb ruary 12, 2002, tapedowns measurements only. PERIOD OF RECORD.--March 6, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.04 ft (0.32 m), below land-surface datum, November 10, 1999; lowest water level recorded, 19.97 ft (6.09 m), below land-surface datum, September 23, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 15.17 15.42 15.50 16.92 2 14.32 15.30 15.45 17.07 3 14.42 15.28 15.01 17.03 4 14.64 15.46 15.26 16.99 5 14.78 15.44 15.52 16.85 17.71 17.95 17.83 16.92 16.75 17.38 18.24 18.02 17.67 17.99 17.87 16.72 16.55 17.24 18.29 17.90 17.24 17.82 17.98 16.34 16.88 17.21 18.10 17.95 17.46 17.77 17.90 16.26 16.69 17.40 18.12 17.92 17.64 17.72 17.82 16.23 16.69 17.82 18.45 17.85 6 14.67 15.46 15.47 15.44 7 14.78 16.04 15.29 16.38 8 13.21 16.20 15.56 16.79 9 12.82 15.75 15.89 17.42 10 12.85 15.85 15.64 16.88 17.27 17.78 18.27 16.79 16.74 17.54 18.44 17.87 17.32 17.78 18.03 16.65 16.67 17.40 18.21 17.68 17.49 17.93 17.84 16.49 16.65 17.57 18.27 18.02 17.39 18.29 17.85 16.43 17.24 17.49 18.79 17.50 17.45 19.10 17.84 16.47 16.93 18.10 18.35 17.58 11 14.63 16.07 15.92 17.09 12 14.76 16.09 15.56 15.53 13 14.87 15.58 15.55 16.02 14 14.54 15.69 15.65 16.18 15 14.94 15.65 15.69 16.74 17.52 18.20 17.84 16.58 16.85 17.83 18.44 17.43 17.29 18.42 17.76 16.88 17.03 17.79 18.66 17.36 17.79 18.31 17.58 16.92 16.95 17.72 18.62 17.09 17.56 18.10 17.50 16.77 16.90 17.59 18.55 17.49 17.47 18.02 17.56 16.72 16.96 17.52 18.67 19.26 16 14.77 15.52 15.68 16.96 17 15.28 15.46 15.52 16.96 18 14.39 15.42 15.51 16.86 19 14.96 15.74 15.47 16.82 20 14.73 15.61 15.51 16.83 17.62 18.02 17.58 16.77 17.27 17.65 18.86 17.39 17.78 19.06 17.54 16.73 15.76 16.27 18.46 17.17 17.61 18.22 17.07 16.72 16.94 18.15 18.84 19.04 17.75 18.09 16.62 16.60 16.75 17.95 18.35 18.90 17.85 17.93 16.54 16.56 16.82 18.17 18.25 19.23 21 14.87 15.37 15.53 16.82 22 14.74 15.47 15.50 17.11 23 15.05 15.44 15.50 17.32 24 14.76 15.53 15.58 17.38 25 14.90 15.77 15.70 17.45 17.63 17.85 16.63 16.55 17.08 17.80 18.37 18.86 17.58 17.80 16.61 16.48 17.19 17.88 18.13 18.72 17.90 17.75 16.71 16.71 17.04 17.86 18.04 19.82 17.89 17.68 16.71 17.72 17.59 17.93 18.03 19.01 17.77 17.99 16.81 16.84 17.50 18.32 18.04 19.02 26 14.98 15.78 15.75 17.36 27 14.91 15.40 16.12 17.69 28 15.21 15.06 16.52 17.56 29 15.31 15.28 16.76 18.13 30 15.32 15.29 14.89 17.85 31 15.31 --- 17.01 17.89 17.77 18.40 16.84 16.96 17.56 18.61 17.94 19.29 17.43 18.01 16.75 17.02 17.51 18.29 18.00 19.24 17.37 17.95 16.73 16.94 17.26 18.16 18.08 18.87 --- 17.63 16.69 16.96 17.61 18.43 17.89 19.02 --- 17.44 16.72 17.30 17.53 18.60 18.09 19.10 --- 18.02 --- 16.93 --- 18.24 18.14 --­ MEAN 14.67 15.58 15.66 16.98 17.58 18.03 17.33 16.74 17.00 17.80 18.31 18.32 WTR YR 2003MEAN17.00 HIGHEST 12.40 OCT 10, 2002 LOWEST 19.90 SEPT 23, 2003 0 5 10 15 20 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 529 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 180104066152300. Local number, 1253. LOCATION.--Lat 18q01'04", long 66q15'23", Hydrologic Unit 21010004, 8 mi southeast of Coamo plaza, 1.07 mi northeast of Coco School, and 0.7 mi southwest of Sabana Llana School. Owner: US Geological Survey, WRD, Name: Piezometer RM 10, Salinas. AQUIFER.--Quaternary alluvium. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 4 in (0.1 m), cased 4 in (0.1 m), 0-37 ft (0-11.3 m), screened 27-37 ft (8.23-11.3 m). Depth 37 ft (11.3 m). DATUM.--Elevation of land-surface datum is about 164 ft (50 m), above mean sea level. Measuring point: Top of shelter floor, 3.6 2 ft (1.1 m), above land- surface datum. REMARKS.--Observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on June 3, 1998, removed on September 30, 2002. PERIOD OF RECORD.--March 13, 1989 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 18 ft (5.49 m), below land-surface datum, November 9, 1990; lowest water level recorded, well dray from September 14 to October 5, 1994. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 07 30.93 JAN 08 33.66 MAR 05 35.39 MAY 14 29.66 JULY 02 31.51 SEPT 05 31.15 NOV 07 30.95 FEB 20 35.11 MAR 05 35.35 JUNE 11 30.35 AUG 01 32.06 SEPT 05 31.09 DEC 09 32.66 FEB 20 35.13 APR 24 31.16 JULY 02 31.50 SEPT 05 31.10 WATER YEAR 2003 HIGHEST 29.66 MAY 14, 2003 LOWEST 35.35 MAR 05, 2003 15 20 25 30 35 40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 530 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175910066155500. Local number, 1254. LOCATION.--Lat 17q59'10", long 66q15'55", Hydrologic Unit 21010004, 0.55 mi south of Hwy 52, 0.92 mi north of the Salinas Speedway, and 2.27 mi northeast of the intersection of Hwy 1 with Hwy 3, Name: Piezometer USGS, Salinas. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), 0-86 ft (0-26.2 m). Depth 77 ft (23.5 m), sounded depth measured on October 6, 2004. INSTRUMENTATION.--Pressure transducer with integrated electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 73 ft (22.3 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 3.4 ft (1.04 m), above land-surface datum. REMARKS.--recording observation well. Automated Digital Recorder (ADR), installed on February 19, 1997. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on August 17, 1999. PERIOD OF RECORD.--February 19, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 19.7 ft (6 m), below land-surface datum, January 24, 25, 1999; lowest water level recorded, 52.19 ft (15.9 m) below land-surface datum, April 7, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 46.87 47.83 48.60 49.08 2 46.85 47.63 48.70 49.22 3 46.92 47.60 48.99 49.18 4 46.92 47.78 48.61 49.17 5 47.33 47.91 48.52 49.19 50.32 51.12 51.84 51.56 50.83 50.90 51.06 51.53 50.21 51.13 51.88 51.66 51.10 50.92 50.98 51.33 50.21 51.41 51.91 51.37 51.06 50.96 50.93 51.28 50.21 51.29 52.12 51.33 50.91 50.65 51.24 51.28 50.28 51.32 51.98 51.60 51.09 50.72 51.33 51.24 6 47.07 47.95 48.48 49.20 7 47.25 48.02 48.46 49.35 8 47.32 47.88 48.52 49.40 9 47.57 47.93 48.60 49.49 10 47.33 47.96 48.76 49.52 50.34 51.51 51.92 51.76 50.88 50.65 51.20 51.27 50.42 51.54 52.19 51.67 50.70 50.71 51.23 51.28 50.38 51.40 52.00 51.82 50.62 50.65 51.18 51.33 50.40 51.35 51.97 51.66 50.62 50.84 51.28 51.56 50.48 51.44 51.97 51.53 50.58 50.82 51.22 51.53 11 47.20 48.13 48.93 49.41 12 47.16 48.37 48.95 49.42 13 47.09 48.07 48.92 49.74 14 47.18 48.22 48.83 49.66 15 47.52 48.26 48.81 49.71 50.46 51.70 51.97 51.41 50.78 50.86 51.49 51.45 50.53 51.76 51.95 51.41 51.01 50.66 51.58 51.52 50.58 51.62 51.91 51.75 50.85 50.57 51.64 51.48 50.66 51.83 51.87 51.46 50.70 50.49 51.48 51.50 50.70 51.60 51.85 51.66 50.57 50.78 51.73 51.49 16 47.42 48.18 48.79 49.74 17 47.32 48.20 48.77 49.80 18 47.35 48.23 48.89 49.73 19 47.32 48.13 48.74 49.75 20 47.30 48.19 48.69 49.85 50.78 51.68 51.84 51.66 50.87 50.63 51.57 51.48 50.81 51.73 51.81 51.33 50.99 50.70 51.51 51.56 50.82 51.97 51.77 51.28 50.98 50.77 51.49 51.52 51.05 51.73 51.69 51.52 50.78 50.81 51.42 51.73 51.10 51.69 51.60 51.30 50.58 50.75 51.48 51.53 21 47.52 48.38 48.65 49.90 22 47.58 48.43 48.63 49.96 23 47.66 48.31 48.78 49.98 24 47.45 48.28 48.76 50.02 25 47.42 48.62 48.78 49.99 50.88 51.62 51.52 51.18 50.53 51.07 51.62 51.48 50.96 51.57 51.46 51.03 50.39 50.90 51.54 51.55 50.87 51.54 51.43 51.02 50.38 50.94 51.48 51.82 50.94 51.55 51.38 50.91 50.62 51.17 51.49 51.91 51.20 51.61 51.34 50.86 50.75 50.97 51.61 51.88 26 47.44 48.53 48.97 50.02 27 47.40 48.54 48.98 50.04 28 47.83 48.39 48.92 50.14 29 47.62 48.55 48.92 50.20 30 47.97 48.66 49.06 50.19 31 47.74 --- 49.17 50.22 51.29 51.88 51.32 51.12 50.79 50.99 51.54 51.94 51.34 51.61 51.28 51.26 50.61 51.01 51.48 51.61 51.20 51.79 51.34 50.99 50.52 51.09 51.37 51.61 --- 51.75 51.38 51.30 50.56 51.32 51.34 51.71 --- 51.84 51.42 51.25 50.86 51.37 51.30 51.96 --- 51.87 --- 50.94 --- 51.41 51.29 --­ MEAN 47.35 48.17 48.78 49.69 50.69 51.60 51.73 51.37 50.75 50.87 51.39 51.55 WTR YR 2003MEAN50.32 HIGHEST 46.75 OCT 1-2, 2002 LOWEST 52.19 APR 7, 2003 15 20 25 30 35 40 45 50 55 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 531 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175903066165000. Local number, 1256. LOCATION.--Lat 17q59'03", long. 66q16'50", Hydrologic Unit 21010004, 0.42 mi north of Hwy 3, 0.6 mi southeast of the intersection of Hwy 1 with Hwy 52, and 1.56 mi northeast of Punta Salinas, Name: Godreau 7 Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 20 in (0.51 m) 0-120 ft (0-36.6 m), perfo rated 30-120 ft (9.1- 36.6 m). Depth 166 ft (50.6 m), sounded depth measured on October 6, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 54 ft (16.5 m), above mean sea level, from topographic map. Measuring point: Sh elter floor on top of 20 in (0.5 m) casing, 3.63 ft (1.11 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n June 3, 1998. PERIOD OF RECORD.--September 25, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 16.46 ft (5.02 m), below land-surface datum, January 27, 28 1999; lowest water level recorded, 36.96 ft (11.26 m), below land-surface datum, August 25 to September 6, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 34.33 34.69 35.25 35.50 2 34.33 34.69 35.25 35.52 3 34.33 34.74 35.32 35.52 4 34.33 34.77 35.33 35.53 5 34.33 34.77 35.33 35.55 35.85 36.14 36.56 35.42 35.51 36.07 36.70 36.95 35.87 36.15 36.59 35.39 35.51 36.09 36.70 36.96 35.89 36.17 36.60 35.39 35.53 36.12 36.70 36.96 35.89 36.19 36.61 35.38 35.55 36.14 36.70 36.96 35.89 36.21 36.63 35.36 35.58 36.15 36.73 36.96 6 34.33 34.77 35.33 35.55 7 34.33 34.80 35.34 35.55 8 34.34 34.81 35.36 35.55 9 34.34 34.82 35.37 35.57 10 34.35 34.83 35.37 35.60 35.89 36.23 36.64 35.34 35.60 36.16 36.75 36.95 35.88 36.25 36.65 35.33 35.61 36.16 36.77 36.94 35.89 36.27 36.66 35.33 35.62 36.19 36.79 36.94 35.89 36.28 36.65 35.32 35.62 36.20 36.80 36.92 35.90 36.29 36.65 35.33 35.64 36.22 36.82 36.92 11 34.36 34.83 35.38 35.60 12 34.36 34.85 35.40 35.61 13 34.37 34.87 35.41 35.62 14 34.37 34.88 35.42 35.63 15 34.37 34.88 35.43 35.66 35.92 36.32 36.64 35.31 35.66 36.26 36.83 36.92 35.93 36.34 36.61 35.31 35.65 36.29 36.84 36.92 35.93 36.35 36.57 35.32 35.67 36.31 36.84 36.93 35.96 36.37 36.55 35.32 35.70 36.30 36.84 36.93 35.98 36.40 36.52 35.33 35.73 36.31 36.86 36.93 16 34.38 34.97 35.43 35.67 17 34.38 34.98 35.43 35.69 18 34.38 34.98 35.43 35.70 19 34.43 35.00 35.44 35.73 20 34.47 35.01 35.44 35.74 36.00 36.42 36.51 35.33 35.75 36.33 36.87 36.92 36.01 36.42 36.51 35.32 35.78 36.36 36.87 36.90 35.99 36.44 36.51 35.33 35.81 36.39 36.88 36.89 35.99 36.46 36.41 35.33 35.84 --- 36.88 36.89 36.01 36.47 36.27 35.33 35.84 --- 36.90 36.88 21 34.48 35.02 35.44 35.77 22 34.50 35.05 35.44 35.78 23 34.51 35.08 35.44 35.79 24 34.55 35.10 35.44 35.80 25 34.55 35.10 35.44 35.81 36.02 36.47 36.05 35.34 35.84 --- 36.92 36.87 36.04 36.47 36.05 35.34 35.86 --- 36.93 36.84 36.06 36.47 36.05 35.35 35.87 --- 36.94 36.84 36.06 36.46 35.75 35.35 35.89 --- 36.95 36.86 36.08 36.46 35.70 35.36 35.91 --- 36.95 36.87 26 34.55 35.13 35.44 35.81 27 34.55 35.14 35.44 35.81 28 34.65 35.17 35.46 35.81 29 34.65 35.21 35.48 35.81 30 34.66 35.24 35.48 35.82 31 34.68 --- 35.49 35.84 36.09 36.49 35.63 35.37 35.95 --- 36.96 36.87 36.11 36.50 35.58 35.37 35.98 --- 36.96 36.89 36.13 36.51 35.56 35.39 36.01 --- 36.96 36.90 --- 36.52 35.46 35.43 36.04 --- 36.96 36.90 --- 36.54 35.44 35.45 36.04 --- 36.95 36.91 --- 36.55 --- 35.49 --- --- 36.95 --­ MEAN 34.44 34.94 35.40 35.68 35.97 36.37 36.29 35.36 35.75 --- 36.85 36.91 WTR YR 2003MEAN35.83 HIGHEST 34.33 OCT 1 TO 7, 2002 LOWEST 36.96 AUG 25 TO SEPT 6, 2003 15 20 25 30 35 40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 532 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175943066224800. Local number 1257. LOCATION.--Lat 17q59'43", long 66q22'48", Hydrologic Unit 2101004, 0.74 mi east of Hwy 153, 1.45 mi northeast of Estación Santa Isabel, and 1.98 mi north of Hwy 1, Name: Paso Seco 7 Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter is 15 in (0.38 m). Depth 244 ft (74.37 m), sounded depth measured on October 6, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 89 ft (27.1 m) above mean sea level, from topographic map. Measuring point: Hole in horizontal steel pipe, 0.8 ft (0.24 m) above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n September 17, 1997. Water levels affected by nearby pumping wells. For water years 2001 and 2002, tapedowns measurements only. PERIOD OF RECORD.--March 27, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 81.11 ft (24.72 m) below land-surface datum, December 3, 4, 6, 7, 1992; lowest water level recorded, 101.28 ft (30.87 m) below land-surface datum, September 13, 1994. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- 88.58 89.29 2 --- --- 88.58 89.34 3 --- --- 88.61 89.36 4 --- --- 88.61 89.46 5 --- --- 88.69 89.49 90.12 90.62 91.15 90.48 --- --- 89.71 90.21 90.14 90.65 91.15 90.43 --- --- 89.72 90.21 90.18 90.67 91.14 90.40 --- --- 89.74 90.20 90.20 90.70 91.14 90.35 --- --- 89.78 90.20 90.21 90.72 91.15 90.32 --- --- 89.80 90.21 6 --- --- --- 89.50 7 --- 88.19 --- 89.52 8 --- 88.20 --- 89.53 9 --- 88.22 --- 89.55 10 --- 88.23 --- 89.56 90.21 90.74 91.15 90.28 --- --- 89.81 90.20 90.22 90.77 91.14 90.25 --- --- 89.83 90.20 90.22 90.80 91.13 90.21 --- --- 89.85 90.20 90.22 90.82 91.13 --- --- --- 89.88 90.20 90.22 90.85 91.12 --- --- --- 89.89 90.20 11 --- 88.24 --- 89.58 12 --- 88.24 --- 89.60 13 --- 88.33 --- 89.63 14 --- 88.33 --- 89.64 15 --- 88.35 --- 89.66 90.23 90.88 91.12 --- --- --- 89.91 90.20 90.24 90.90 91.11 --- --- --- 89.93 90.20 90.25 90.92 91.10 --- --- --- 89.94 90.20 90.28 90.95 91.08 --- --- --- 89.96 90.21 90.30 90.98 91.06 --- --- --- 89.98 90.21 16 --- 88.37 --- 89.67 17 --- 88.38 --- 89.75 18 --- 88.38 88.92 89.78 19 --- 88.39 88.94 89.83 20 --- 88.40 88.94 89.85 90.31 91.00 91.04 --- --- --- 90.00 90.22 90.33 91.03 91.02 --- --- --- 90.02 90.22 90.35 91.06 90.99 --- --- 89.57 90.04 90.21 90.38 91.09 90.96 --- --- 89.57 90.06 90.20 90.40 91.12 90.93 --- --- 89.57 90.08 90.21 21 --- 88.41 88.97 89.86 22 --- 88.42 89.09 89.90 23 --- 88.43 89.10 89.94 24 --- 88.44 89.12 89.97 25 --- 88.51 89.14 90.00 90.41 91.13 90.88 --- --- 89.57 90.09 90.20 90.44 91.14 90.85 --- --- 89.58 90.10 90.20 90.46 91.14 90.81 --- --- 89.60 90.13 90.20 90.49 91.15 90.77 --- --- 89.60 90.15 90.20 90.51 91.14 90.73 --- --- 89.62 90.16 90.19 26 --- 88.51 89.16 90.04 27 --- 88.53 89.20 90.06 28 --- 88.53 89.20 90.08 29 --- 88.54 89.21 90.09 30 --- 88.57 89.22 90.09 31 --- --- 89.23 90.10 90.54 91.13 90.68 --- --- 89.64 90.17 90.20 90.56 91.13 90.65 --- --- 89.64 90.19 90.19 90.59 91.12 90.60 --- --- 89.66 90.19 90.19 --- 91.12 90.56 --- --- 89.66 90.20 90.19 --- 91.14 90.52 --- --- 89.68 90.21 90.18 --- 91.15 --- --- --- 89.69 90.21 --­ MEAN --- --- --- 89.73 90.32 90.96 90.96 --- --- --- 89.99 90.20 WTR YR 2003MEAN90.02 HIGHEST 88.17 NOV 6, 2002 LOWEST 91.17 APR 1, 2003 80 82 84 86 88 90 92 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 533 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL NOV 06 88.16 JAN 22 89.91 FEB 13 90.25 MAY 08 90.20 JULY 18 89.57 DEC 05 88.68 JAN 28 90.05 APR 02 91.14 JUNE 11 89.62 AUG 04 89.76 WATER YEAR 2003 HIGHEST 88.16 NOV 06, 2002 LOWEST 90.25 FEB 13, 2003 534 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175829066232200. Local number, 87. LOCATION.--Lat 17q58'29", long 66q23'22", Hydrologic Unit 21010004, 1.1 mi northeast of Santa Isabel plaza, 3.69 mi southeast of Playita Cortada School, and 1.07 mi southeast of Estación Experimental Santa Isabel, Name: Alomar 1 Well. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), iron cased. Depth 105 ft (32 m), sounded depth measured on October 6, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 35.3 ft (10.8 m), above mean sea level. Measuring point: Bottom of clean-out shelter door, 2.5 ft (0.76 m), above land-surface datum. Prior August 1981, top of recorder shelter floor, 4 ft (1.22 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on December 16, 1997. PERIOD OF RECORD.--April 1967 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 8.45 ft (2.58 m), below land-surface datum, December 10, 1970; low est water level recorded, 49.18 ft (14.99 m) below land-surface datum, July 27, 1974. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 43.85 45.42 46.07 45.24 2 43.73 45.67 45.85 46.00 3 44.11 45.54 46.00 46.20 4 44.58 45.45 46.11 46.38 5 43.32 45.48 46.02 45.64 45.28 46.48 47.38 45.95 44.83 44.64 46.77 46.19 45.46 46.57 47.37 46.09 46.60 44.48 45.39 46.32 45.27 45.42 47.39 45.12 46.63 44.38 46.94 45.75 45.26 46.33 45.59 46.08 46.74 44.27 46.94 46.27 44.12 46.51 46.50 46.09 46.68 44.37 46.96 46.39 6 44.49 45.48 45.93 46.23 7 44.61 45.48 46.28 46.45 8 44.69 46.23 46.14 46.39 9 44.77 45.92 46.15 46.29 10 44.71 45.94 44.45 45.36 45.44 46.88 47.17 46.22 46.63 44.28 47.13 46.50 45.86 46.75 47.29 46.14 46.69 44.26 46.97 46.47 46.10 47.10 47.08 46.32 46.67 44.35 46.98 46.35 45.98 46.83 45.39 46.54 46.78 44.44 47.34 46.47 46.00 46.68 45.06 46.80 46.79 46.21 47.23 46.40 11 42.84 45.65 45.64 45.33 12 42.59 45.80 45.97 45.26 13 42.44 45.72 46.42 45.59 14 44.09 45.56 46.73 46.08 15 44.49 45.73 46.41 46.12 46.05 47.02 44.90 47.14 46.79 46.37 47.03 44.98 46.41 46.97 44.72 46.81 46.95 46.71 47.06 46.25 46.43 47.02 44.71 46.70 46.77 44.96 47.15 46.83 46.49 46.56 46.25 46.74 46.79 45.91 47.03 46.70 46.51 48.46 46.58 46.56 45.55 46.43 46.98 46.38 16 42.81 45.89 44.51 46.22 17 42.70 46.03 45.79 46.39 18 44.51 45.78 45.82 46.56 19 44.49 45.86 45.86 46.26 20 44.83 45.70 46.05 46.40 46.44 48.47 44.79 46.73 46.87 46.44 47.36 46.39 46.31 47.13 44.57 46.84 46.80 46.48 45.31 46.56 46.20 47.21 44.41 46.77 46.77 46.57 44.98 46.48 46.41 46.69 44.27 46.80 46.65 47.39 46.63 46.51 46.56 46.28 45.77 46.64 46.68 46.51 46.84 47.35 21 44.78 45.81 46.62 46.47 22 44.99 45.75 46.67 46.43 23 44.79 45.85 46.45 46.58 24 45.69 45.80 46.34 46.61 25 46.02 45.64 46.34 45.25 45.25 47.15 44.26 46.75 46.89 46.60 46.88 46.94 46.29 47.15 44.09 46.58 46.86 46.67 45.01 47.14 46.48 46.65 44.61 44.78 46.69 46.66 44.90 47.21 46.42 46.95 45.84 46.33 46.69 46.84 44.68 45.86 46.55 46.97 44.74 46.43 46.80 46.94 44.56 47.10 26 45.41 45.77 46.23 45.30 27 45.24 45.96 46.36 45.27 28 45.24 45.89 46.39 45.28 29 45.29 45.78 46.46 45.93 30 45.30 45.75 46.25 46.12 31 45.30 --- 46.42 46.34 46.65 47.06 44.86 46.53 46.46 47.14 44.52 47.09 46.57 46.90 44.22 46.45 46.78 47.24 44.45 47.70 46.50 46.91 44.74 46.60 45.14 47.07 46.14 47.58 --- 47.40 45.84 46.60 44.77 47.03 46.25 47.45 --- 46.95 45.54 46.63 44.64 47.08 44.53 47.39 --- 46.98 --- 46.67 --- 47.18 46.22 --­ MEAN 44.41 45.74 46.09 46.00 46.05 46.92 45.53 46.43 46.45 46.00 46.23 46.63 WTR YR 2003MEAN46.04 HIGHEST 42.13 OCT 1, 2002 LOWEST 48.64 MAR 15, 2003 36 38 40 42 44 46 48 50 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 535 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 180020066261500. Local number, 1258. LOCATION.--Lat 18q00'20", long 66q26'15", Hydrologic Unit 21010004, 1.04 mi north of the intersection of Hwy 536 with Hwy 1, 0.6 mi northwest of Central Cortada, and 0.1 mi west of Hwy 536, Name: Cabrera 1 Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 18 in (0.46 m). Depth 71 ft (21.6 m). DATUM.--Elevation of land-surface datum is about 65.6 ft (20 m), above mean sea level, from topographic map. Measuring point: Hole in horizontal plexiglass plate, 3.14 ft (0.95 m), above land-surface datum. Prior October 4, 1999, 3.12 ft (0.95 m), above land-surface datum. REMARKS.--Observation well. Well level affected by nearby pumping well. PERIOD OF RECORD.--March 18, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 31.93 ft (9.73 m), below land-surface datum, December 1, 1999; low est water level recorded, 55 ft (16.8 m), below land-surface datum, April 14, 1998. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 02 42.66 FEB 13 46.09 MAR 20 48.70 JUNE 03 46.73 AUG 13 48.21 DEC 05 43.50 FEB 26 48.08 APR 09 47.71 JULY 23 47.78 SEPT 09 48.43 JAN 08 47.56 MAR 05 46.84 MAY 08 46.03 WATER YEAR 2003 HIGHEST 42.66 OCT 02, 2002 LOWEST 48.70 MAR 20, 2003 30 35 40 45 50 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 536 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 180602066133100. Local number, 1260. LOCATION.--Lat 18q06'02", long 66q13'31", Hydrologic Unit 21010004, 130 ft (39.62 m) north of Hwy 1 km. 68.9, 0.1 mi east of Hwy 162, and 4 mi west southwest of Cayey plaza, Name: Bauzá 1 Well. AQUIFER.--Fractured rock Limestone. WELL CHARACTERISTICS.--Unused production well, diameter 10 in (0.25 m), open screen 220-320 ft (67.1-97.5 m). Depth 320 ft (97.5 m). DATUM.--Elevation of land-surface datum is about 2,178 ft (664 m), above mean sea level, from topographic map. Measuring point: Top of access hole, 0.49 ft (0.15 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 20, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 201.2 ft (61.32 m), below land-surface datum, May 18, 1999; lowest water level measured, 232.84 ft (70.1 m), below land-surface datum, August 1, 2003. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 28 221.15 JAN 30 224.67 FEB 20 225.57 APR 21 227.95 MAY 01 228.69 JULY 02 231.60 JAN 30 224.66 FEB 20 225.56 MAR 14 226.56 APR 21 227.98 JUNE 13 230.72 AUG 01 232.84 WATER YEAR 2003 HIGHEST 221.15 OCT 28, 2002 LOWEST 232.94 AUG 01, 2003 200 205 210 215 220 225 230 235 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 537 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175833066145800. Local number, 1261. LOCATION.--Lat 17q58'33", long 66q14'58", Hydrologic Unit 21010004, 0.3 mi north of Hwy 3, 1.3 mi west of Colegio del Perpetuo Socorro, and 2.2 mi northwest of Central Aguirre, Name: Piezometer A RASA. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), cased 0-154 ft (0-46.94 m). Depth 75 ft (22.9 m), sounded depth measured on October 15, 2004. INTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 56 ft (17.07 m), above mean sea level, from topographic map. Measuring point: T op of shelter floor 3.83 ft (1.17 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n June 2, 1998. PERIOD OF RECORD.--September 17, 1992 to May 17, 1994, discontinued, January 15, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 36.75 ft (11.2 m), below land-surface datum, January 20, 1999; low est water level recorded, 70.28 ft (21.42 m), below land-surface datum, October 1-7, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 65.27 65.86 66.64 67.66 2 65.29 65.88 66.68 67.67 3 65.32 65.90 66.71 67.69 4 65.34 65.94 66.77 67.70 5 65.38 65.96 66.80 67.73 68.33 68.54 68.69 --- --- 67.47 67.50 --- 68.35 68.54 68.70 --- --- 67.47 67.49 --- 68.35 68.55 --- --- --- 67.47 67.49 --- 68.36 68.55 --- --- --- 67.48 67.49 --- 68.36 68.55 --- --- --- 67.50 67.50 --­ 6 65.39 66.00 66.82 67.74 7 65.42 65.98 66.83 67.76 8 65.45 66.00 66.85 67.77 9 65.48 66.03 66.94 67.78 10 65.50 66.06 66.97 67.79 68.36 68.57 --- --- --- 67.50 67.50 --- 68.36 68.57 --- --- --- 67.51 67.50 --- 68.36 68.58 --- --- --- 67.52 67.50 --- 68.37 68.58 --- --- --- 67.52 67.49 --- 68.37 68.58 --- --- --- 67.52 67.49 --­ 11 65.51 66.08 66.99 67.81 12 65.53 66.10 66.98 67.85 13 65.56 66.12 67.00 67.91 14 65.57 66.14 67.02 67.96 15 65.60 66.16 67.03 67.98 68.38 68.59 --- --- --- 67.53 67.49 --- 68.38 68.61 --- --- 67.46 67.53 67.49 --- 68.38 68.61 --- --- 67.45 67.54 67.49 --- 68.38 68.62 --- --- 67.45 67.53 67.49 --- 68.39 68.62 --- --- 67.44 67.53 67.49 --­ 16 65.61 66.19 67.07 68.00 17 65.63 66.21 67.11 68.01 18 65.65 66.24 67.16 68.02 19 65.67 66.28 67.18 68.02 20 65.68 66.29 67.27 68.04 68.40 68.62 --- --- 67.44 67.53 67.49 --- 68.41 68.62 --- --- 67.45 67.53 67.48 --- 68.43 68.62 --- --- 67.45 67.53 67.48 --- 68.44 68.62 --- --- 67.46 67.53 67.48 --- 68.44 68.63 --- --- 67.46 67.53 67.48 --­ 21 65.71 66.31 67.32 68.06 22 65.72 66.35 67.36 68.14 23 65.72 66.39 67.37 68.16 24 65.74 66.41 67.38 68.17 25 65.79 66.44 67.40 68.22 68.45 68.63 --- --- 67.46 67.52 67.48 --- 68.47 68.63 --- --- 67.46 67.52 67.48 --- 68.47 68.65 --- --- 67.46 67.52 67.48 --- 68.48 68.65 --- --- 67.47 67.52 67.48 --- 68.50 68.65 --- --- 67.47 67.52 67.48 --­ 26 65.80 66.48 67.41 68.24 27 65.81 66.50 67.44 68.26 28 65.82 66.53 67.47 68.26 29 65.82 66.57 67.50 68.27 30 65.83 66.60 67.58 68.28 31 65.84 --- 67.63 68.29 68.50 68.65 --- --- 67.46 67.52 67.48 --- 68.50 68.66 --- --- 67.45 67.51 67.48 --- 68.52 68.66 --- --- 67.46 67.51 67.48 --- --- 68.66 --- --- 67.46 67.51 67.48 --- --- 68.67 --- --- 67.46 67.51 67.48 --- --- 68.68 --- --- --- 67.50 67.48 --­ MEAN 65.60 66.20 67.12 67.98 68.41 68.61 --- --- --- 67.51 67.49 --­ WTR YR 2003MEAN67.37 HIGHEST 65.24 OCT 1, 2002 LOWEST 68.78 APR 2, 2003 35 40 45 50 55 60 65 70 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 538 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175735066151800. Local number, 1262. LOCATION.--Lat 17q57'35", long 66q15'18", Hydrologic Unit 21010004, 1 mi southeast of Salinas Speedway, 1.3 mi northeast of dock at Las Mareas, and 3.1 mi southeast of Salinas plaza, Name: Piezometer C RASA. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.1 m), screen cased 22-82 ft (6.7-24.99 m). Depth 16 ft (4.87 m), sounded depth measured on October 15, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 20 ft (6.1 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 4.15 in (0.1 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on September 24, 1991, replaced by an Electron ic Data Logger (EDL), installed on June 2, 1998. Well is affected by nearby pumping. PERIOD OF RECORD.--September 24, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 6.36 ft (1.94 m), below land-surface datum, November 22, 1999; lowest water level recorded, 14.58 ft (4.44 m), below land-surface datum, June 25, 1998. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 11.06 11.14 11.56 11.25 2 11.01 11.13 11.38 11.25 3 11.01 11.09 11.35 11.29 4 11.03 11.08 11.36 11.30 5 10.98 11.04 11.41 11.29 11.56 11.65 11.64 11.50 11.65 11.68 11.79 11.84 11.59 11.62 11.67 11.52 11.63 11.62 11.76 11.81 11.58 11.62 11.73 11.54 11.65 11.64 11.72 11.81 11.52 11.58 11.74 11.52 11.67 11.64 11.73 11.83 11.53 11.62 11.74 11.49 11.70 11.66 11.72 11.85 6 11.03 11.12 11.35 11.26 7 11.02 11.19 11.37 11.22 8 11.10 11.19 11.36 11.27 9 11.11 11.18 11.33 11.27 10 11.14 11.16 11.26 11.24 11.60 11.69 11.78 11.51 11.70 11.66 11.71 11.83 11.57 11.70 11.81 11.55 11.72 11.65 11.74 11.81 11.57 11.65 11.83 11.57 11.77 11.67 11.76 11.72 11.54 11.61 11.79 11.59 11.75 11.64 11.78 11.72 11.54 11.57 11.76 11.63 11.70 11.68 11.74 11.70 11 11.05 11.13 11.31 11.22 12 11.05 11.16 11.29 11.27 13 11.03 11.11 11.28 11.26 14 11.01 11.12 11.23 11.29 15 10.96 11.13 11.21 11.28 11.56 11.63 11.57 11.59 11.71 11.67 11.74 11.72 11.53 11.59 11.67 11.60 11.70 11.64 11.73 11.73 11.52 11.65 11.72 11.61 11.68 11.62 11.77 11.74 11.60 11.62 11.72 11.47 11.64 11.60 11.78 11.72 11.56 11.62 11.72 11.47 11.61 11.64 11.81 11.69 16 11.93 11.13 11.17 11.33 17 12.10 11.12 11.20 11.32 18 12.30 11.13 11.18 11.30 19 11.33 11.14 11.21 11.31 20 11.19 11.16 11.19 11.33 11.57 11.59 11.65 11.56 11.59 11.58 11.85 11.65 11.50 11.62 11.58 11.58 11.61 11.64 11.88 11.66 11.51 11.64 11.55 11.50 11.59 11.73 11.89 11.67 11.49 11.60 11.43 11.48 11.56 11.73 11.90 11.67 11.50 11.60 11.42 11.47 11.57 11.74 11.97 11.68 21 11.15 11.73 11.21 11.33 22 11.15 11.39 11.25 11.27 23 11.15 12.21 11.29 11.20 24 11.23 12.48 11.27 11.21 25 11.19 12.14 11.21 11.30 11.49 11.55 11.44 11.46 11.58 11.75 11.96 11.61 11.53 11.61 11.40 11.45 11.55 11.74 11.94 11.58 11.58 11.58 11.39 11.45 11.56 11.75 11.97 11.59 11.61 11.51 11.37 11.50 11.59 11.82 11.96 11.63 11.67 11.60 11.43 11.52 11.65 11.91 11.99 11.62 26 11.19 12.05 11.24 11.27 27 11.21 11.53 11.24 11.20 28 11.20 12.37 11.24 11.27 29 11.24 12.51 11.22 11.39 30 11.20 12.30 11.18 11.43 31 11.15 --- 11.17 11.47 11.65 11.64 11.48 11.57 11.66 11.86 11.88 11.61 11.68 11.60 11.47 11.62 11.65 11.87 11.88 11.64 11.69 11.64 11.48 11.64 11.59 11.86 11.84 11.71 --- 11.67 11.53 11.65 11.63 11.88 11.81 11.73 --- 11.65 11.52 11.65 11.66 11.84 11.78 11.76 --- 11.65 --- 11.68 --- 11.83 11.82 --­ MEAN 11.21 11.45 11.27 11.29 11.57 11.62 11.60 11.55 11.64 11.72 11.83 11.71 WTR YR 2003MEAN11.54 HIGHEST 10.92 OCT 14-15, 2002 LOWEST 12.53 NOV 30, 2002 6 7 8 9 10 11 12 13 14 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 539 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175734066233300. Local number, 146. LOCATION.--Lat 17q58'43", long 66q24'43", Hydrologic Unit 21010004, 1 mi southeast of Santa Isabel plaza, 0.5 mi south of airport, 1.1 mi northeast of dock at Santa Isabel, Name: Pozo PRASA Alomar Oeste Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water table well, diameter 8 in (0.2 m). Constructed depth 70 ft (21.3 m). Depth 61 ft (18 .6 m), sounded depth measured on October 6, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land surface is about 19 ft (5.79 m) above mean sea level from topographic map. Measuring point: hole in si de of steel casing, 2.19 ft (0.67 m) above land-surface datum. REMARKS.--Abandoned production well being used as recording observation well. Automated Digital Recorder (ADR), installed on September 27, 1991, replaced by an Electronic Data Logger on January 14, 1998. PERIOD OF RECORD.--June 1981 to March 1985, discontinued, September 27, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 7.43 ft (2.26 m), below land-surface datum, October 18, 1984; lowest water level recorded, 19.75 ft (6.02 m) below land-surface datum, December 17, 1997. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 16.22 16.29 16.52 16.69 2 16.23 16.28 16.54 16.71 3 16.20 16.20 16.53 16.77 4 16.16 16.22 16.61 16.76 5 16.12 16.26 16.65 16.77 16.83 --- --- 16.15 16.46 16.50 16.56 16.70 16.78 --- 16.67 16.19 16.43 16.46 16.56 16.73 16.74 --- 16.68 16.18 16.42 16.44 16.56 16.74 --- --- 16.66 16.18 16.44 16.40 16.61 16.74 --- --- 16.59 16.14 16.51 16.41 16.65 16.80 6 16.12 16.37 16.65 16.73 7 16.10 16.45 16.66 16.71 8 16.18 16.50 16.67 16.79 9 16.24 16.48 16.63 16.73 10 16.25 16.45 16.56 16.66 --- --- 16.65 16.17 16.45 16.45 16.67 16.78 --- --- 16.69 16.19 16.47 16.44 16.69 16.75 --- --- 16.69 16.21 16.51 16.45 16.72 16.69 --- --- 16.66 16.23 16.47 16.47 16.73 16.70 --- --- 16.68 16.27 16.48 16.52 16.69 16.68 11 16.22 16.44 16.61 16.65 12 16.16 16.50 16.63 16.69 13 16.18 16.45 16.59 16.72 14 16.17 16.43 16.57 16.72 15 16.09 16.43 16.55 16.75 --- --- 16.63 16.26 16.52 16.55 16.68 16.72 --- --- 16.60 16.24 16.50 16.53 16.68 16.73 --- --- 16.60 16.30 16.51 16.46 16.65 16.74 --- --- 16.61 16.20 16.49 16.45 16.63 16.72 --- --- 16.62 16.18 16.47 16.45 16.68 16.71 16 16.07 16.46 16.51 16.81 17 16.07 16.43 16.57 16.83 18 16.11 16.45 16.57 16.77 19 16.08 16.49 16.65 16.78 20 16.11 16.52 16.61 16.85 --- --- 16.60 16.24 16.47 16.42 16.71 16.69 --- --- 16.49 16.30 16.52 16.46 16.73 16.67 --- --- 16.33 16.22 16.48 16.53 16.75 16.71 --- --- 16.21 16.20 16.45 16.53 16.74 16.71 --- --- 16.22 16.24 16.49 16.52 16.78 16.72 21 16.14 16.53 16.63 16.85 22 16.21 16.55 16.69 16.76 23 16.24 16.58 16.73 16.71 24 16.35 16.61 16.75 16.73 25 16.26 16.58 16.65 16.67 --- --- 16.21 16.29 16.52 16.55 16.75 16.65 --- --- 16.15 16.27 16.49 16.55 16.72 16.62 --- --- 16.20 16.31 16.54 16.55 16.67 16.64 --- --- 16.21 16.36 16.50 16.58 16.67 16.66 --- --- 16.24 16.41 16.50 16.61 16.69 16.65 26 16.27 16.57 16.69 16.59 27 16.25 16.58 16.67 16.53 28 16.31 16.57 16.67 16.63 29 16.35 16.57 16.67 16.77 30 16.38 16.54 16.63 16.78 31 16.31 --- 16.68 16.83 --- --- 16.23 16.39 16.54 16.62 16.66 16.62 --- --- 16.21 16.43 16.52 16.64 16.66 16.62 --- --- 16.24 16.45 16.46 16.60 16.66 16.66 --- --- 16.26 16.50 16.46 16.58 16.64 16.66 --- --- 16.22 16.45 16.50 16.56 16.63 16.69 --- --- --- 16.46 --- 16.60 16.68 --­ MEAN 16.20 16.46 16.62 16.73 --- --- --- 16.28 16.49 16.51 16.67 16.70 WTR YR 2003MEAN16.51 HIGHEST 15.97 OCT 16, 2002 LOWEST 16.89 FEB 1, 2003 14.5 15.0 15.5 16.0 16.5 17.0 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 540 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS—Continued 175843066244100. Local number, 1263. LOCATION.--Lat 17q58'43", long 66q24'43", Hydrologic Unit 21010004, 0.4 mi east of new Hwy 1 bridge over RÌo Coamo, 0.9 mi northwest of Santa Isabel plaza, and 1.6 miles north-northwest of dock at Santa Isabel, Name: Jobitos Battery Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water table well, diameter 6 in (0.15 m). Depth 198 ft (60.35 m), sounded depth measured o n October 7, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land surface is about 39 ft (11.9 m) above mean sea level from topographic map. Measuring point: Top of shelter floor, 2.7 ft (0.82 m) above land-surface datum. Prior to February 1997, 1.41 ft (0.43 m) above land-surface datum. REMARKS.--Abandoned production well being used as recording observation well. Automated Digital Recorder (ADR), installed on September 26, 1991, replaced by an Electronic Data Logger on September 9, 1997. PERIOD OF RECORD.--September 26, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 34.86 ft (10.62 m), below land-surface datum, October 16, 2000; lowest water level recorded, 45.81 ft (13.96 m) below land-surface datum, March 15, 16, 2003. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 41.95 42.65 43.25 44.10 2 41.97 42.64 43.33 44.11 3 42.12 42.49 43.45 44.27 4 42.21 42.32 43.41 44.20 5 42.35 42.38 43.56 44.11 44.87 45.12 45.26 43.65 43.79 44.09 44.59 43.93 44.78 45.13 45.15 43.57 43.72 43.99 44.52 43.92 44.72 45.13 45.15 43.64 43.82 43.87 44.57 43.78 44.78 45.26 45.03 43.58 43.71 43.87 44.59 43.80 44.77 45.34 44.99 43.58 43.78 43.82 44.72 43.72 6 42.19 42.51 43.52 44.04 7 42.04 42.62 43.48 44.14 8 42.18 42.76 43.36 44.20 9 42.14 42.76 43.46 44.32 10 42.21 42.58 43.52 44.31 44.62 45.64 44.97 43.75 43.82 43.83 44.68 43.61 44.66 45.50 44.97 43.76 43.75 43.87 44.58 43.57 44.69 45.46 45.00 43.71 43.57 44.04 44.66 43.50 44.64 45.33 44.99 43.63 43.69 44.17 44.84 43.48 44.64 45.33 44.93 43.59 43.68 44.17 44.97 43.56 11 42.18 42.50 43.43 44.21 12 42.17 42.81 43.59 44.13 13 42.02 42.83 43.67 43.98 14 41.96 42.84 43.67 44.20 15 41.97 42.83 43.56 44.27 44.73 45.44 44.77 43.53 43.74 44.07 44.87 43.62 44.81 45.48 44.70 43.50 43.72 44.23 44.88 43.56 44.95 45.62 44.58 43.70 43.75 44.14 44.80 43.55 45.07 45.59 44.52 43.66 43.88 44.05 44.80 43.50 45.10 45.71 44.45 43.53 43.81 43.99 44.72 43.34 16 41.83 42.81 43.52 44.40 17 42.00 42.68 43.64 44.59 18 42.00 42.82 43.69 44.52 19 42.13 42.95 43.80 44.46 20 41.97 42.88 43.74 44.48 45.05 45.72 44.42 43.40 43.75 44.03 44.82 43.26 44.86 45.69 44.40 43.49 43.88 44.00 44.78 43.22 45.09 45.58 44.40 43.61 43.77 44.36 44.59 43.32 45.06 45.53 44.31 43.67 43.67 44.34 44.45 43.36 45.19 45.61 44.10 43.68 43.72 44.29 44.45 43.30 21 41.95 43.06 43.78 44.61 22 42.07 42.96 43.72 44.72 23 42.22 42.98 43.76 44.68 24 42.26 42.95 44.04 44.79 25 42.40 42.95 43.91 44.83 45.26 45.35 43.98 43.84 43.86 44.16 44.45 43.23 45.11 45.31 43.98 44.03 43.71 44.35 44.46 43.18 45.13 45.27 43.85 43.87 43.71 44.50 44.34 43.22 45.09 45.10 43.76 43.77 43.76 44.50 44.33 43.31 45.20 45.14 43.76 43.68 43.88 44.48 44.27 43.58 26 42.33 43.04 43.93 44.58 27 42.15 43.15 44.15 44.42 28 41.99 43.13 44.00 44.49 29 42.24 42.99 43.94 44.60 30 42.25 43.17 43.95 44.65 31 42.31 --- 44.14 44.85 45.28 45.38 43.71 43.62 44.02 44.46 44.27 43.91 45.27 45.42 43.65 43.86 44.08 44.57 44.27 43.69 45.14 45.37 43.58 43.86 44.07 44.55 44.06 43.38 --- 45.30 43.69 43.93 44.18 44.52 44.06 43.36 --- 45.11 43.78 43.92 44.10 44.54 44.05 43.49 --- 45.10 --- 43.84 --- 44.53 44.00 --­ MEAN 42.12 42.80 43.68 44.40 44.95 45.39 44.43 43.69 43.81 44.21 44.53 43.51 WTR YR 2003MEAN43.95 HIGHEST 41.82 OCT 16-17, 2002 LOWEST 45.81 MAR 15-16, 2003 34 36 38 40 42 44 46 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE 541 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 175950066354200. Local number, 141. LOCATION.--Lat 17q59'50", long 66q35'42", Hydrologic Unit 21010004, 1.71 mi southeast of Plaza Degetau at Ponce, 1.31 mi southeast of the intersection between Hwy 10 and Hwy 2, and 2.6 mi notheast of Muellle de Ponce, Name: Restaurada 8A Well. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused public supply well, diameter 16-10 in (0.41-0.25 m), cased 16 in (0.41 m) 2-20 ft (0.6-6.1 m), perforated 20­ 130 ft (6.1-39.6 m), 10 in (0.25 m) 128-165 ft (39-50.3 m), perforated. Depth 151 ft (46.02 m), sounded depth measured on Octobe r 7, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 24 ft (7.3 m), above mean sea level, from topographic map. Measuring point: Bottom edge of hole on side of casing 3.54 ft (1.08 m), above land-surface datum, 26.2 ft (7.67 m), above mean sea level. REMARKS.--Recording observation well. Discontinued on Novenber 8, 1994 due to apparent collapsed casing, repair on August 7, 199 6. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 12, 1998. PERIOD OF RECORD.--October 1981 to March 1, 1986, discontinued, November 18, 1991 to November 8, 1994, discontinued, August 7, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 11.2 ft (3.41 m), below land-surface datum, October 9, 1985; lowest water level recorded, 28.6 ft (8.71 m), below land-surface datum, July 9, 1982. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.53 23.99 24.60 24.72 2 23.63 24.05 24.65 24.76 3 23.69 23.98 24.71 24.67 4 23.66 23.99 24.85 24.73 5 23.62 24.14 24.85 24.63 23.70 24.44 24.93 23.07 23.72 22.22 23.42 24.29 23.52 24.36 24.90 23.21 23.89 22.03 23.61 22.98 23.43 24.35 24.95 23.14 23.80 21.98 23.43 22.84 23.31 24.42 24.91 23.17 23.83 21.94 23.74 23.01 23.18 24.48 24.89 23.04 23.84 21.95 23.87 22.91 6 23.67 24.04 24.92 24.44 7 23.66 23.96 24.93 24.61 8 23.57 23.28 24.88 24.62 9 23.54 23.14 24.90 24.61 10 23.55 23.11 25.04 24.57 23.47 24.65 24.87 23.24 23.52 22.01 24.01 24.48 24.14 24.69 24.91 23.06 23.49 21.81 23.99 24.47 24.16 24.76 24.94 22.96 23.25 21.99 24.27 24.67 24.38 24.70 24.86 23.00 23.47 22.01 24.21 --- 24.45 24.83 24.95 23.00 23.30 21.96 24.03 --­ 11 23.63 23.08 25.13 24.51 12 23.61 23.08 24.93 24.50 13 23.60 23.04 25.25 24.51 14 23.62 23.05 25.33 24.52 15 23.57 22.98 25.36 24.50 24.52 24.76 24.93 22.86 23.70 22.14 24.23 24.57 24.41 24.88 24.88 22.82 23.52 22.03 24.17 24.61 24.57 24.97 24.90 22.90 23.70 22.05 24.35 24.76 24.60 24.89 24.95 22.85 23.76 22.02 24.22 24.61 24.65 24.89 25.00 22.97 23.67 22.01 24.32 24.54 16 23.52 23.00 25.34 24.59 17 23.58 22.88 25.33 24.65 18 23.65 22.99 25.32 24.51 19 23.60 23.00 25.32 24.54 20 23.57 22.90 25.31 24.48 24.71 24.87 24.90 22.93 23.80 21.99 24.25 24.45 24.65 24.88 24.36 22.82 23.82 22.00 24.20 24.58 24.75 24.94 24.42 22.96 23.79 21.85 24.38 24.58 24.96 24.91 24.11 23.08 23.71 21.98 24.41 24.56 24.93 24.69 23.91 23.23 23.51 21.83 24.44 24.29 21 23.52 22.88 25.27 24.61 22 23.45 23.18 25.19 24.62 23 23.68 23.82 25.29 24.68 24 23.62 23.86 25.38 24.65 25 23.62 24.01 25.22 24.55 24.88 24.71 23.80 23.26 23.58 21.97 24.62 24.13 24.82 24.66 23.76 23.20 23.70 21.91 24.57 24.00 24.80 24.58 23.59 23.07 23.84 21.86 24.39 23.94 24.78 24.66 23.47 23.01 24.03 22.11 24.46 23.88 24.68 24.76 23.35 22.89 23.86 22.12 24.55 23.91 26 23.81 24.05 25.32 24.52 27 23.81 24.26 25.15 24.53 28 23.89 24.25 24.92 24.53 29 23.96 24.26 24.95 24.55 30 23.95 24.39 24.81 24.49 31 23.98 --- 24.86 24.18 24.72 24.84 23.29 22.94 23.09 22.12 24.36 23.98 24.73 24.68 23.17 23.08 22.55 22.00 24.32 24.19 24.59 24.82 23.19 22.84 22.28 22.09 24.35 24.18 --- 24.85 23.09 22.92 22.04 22.19 24.34 24.06 --- 24.82 23.10 23.10 22.19 22.26 24.23 24.04 --- 24.87 --- 23.66 --- 22.28 24.19 --­ MEAN 23.66 23.55 25.07 24.57 24.37 24.73 24.31 23.04 23.48 22.02 24.19 --­ WTR YR 2003MEAN23.92 HIGHEST 21.64 JULY 23, 2003 LOWEST 25.41 DEC 24, 2002 16 18 20 22 24 26 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 542 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS—Continued 175934066364800. Local number, 1276. LOCATION.--Lat 17q59'34", long 66q36'48", Hydrologic Unit 21010004, 0.35 mi southeast of the intersection of Hwy 10 with Hwy 2, 0.32 mi south of Hwy 2, 0.1 mi southwest of Plaza del Caribe Mall, and 1.9 mi north of Punta Carenero, Name: Constancia 3 Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 13 in (0.33 m). Depth 83 ft (25.3 m), sounded depth measured on October 7, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is 16 ft (4.9 m), above mean sea level, from topographic map. Measuring point: Hole in horizontal steel plate, 1.59 ft (0.48 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL,) installed o n March 19 to April 9, 1997. Automated Digital Recorder (ADR), re-installed on April 9, 1997, replaced by an Electronic Data Logger (EDL), installed on June 4, 1998. PERIOD OF RECORD.--May 30, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.13 ft (2.78 m), below land-surface datum, September 28, 29, 2000 ; lowest water level recorded, 17.96 ft (5.47 m), below land-surface datum, July 19, 20, 21, 1997. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 13.53 13.29 13.39 13.35 2 --- 13.29 13.40 13.34 3 13.52 13.29 13.41 13.32 4 13.53 13.28 13.41 13.30 5 13.53 13.27 13.44 13.29 13.68 13.78 13.05 9.88 11.17 --- --- 12.29 13.69 13.76 13.04 9.91 11.21 --- --- 12.27 13.69 13.75 13.03 9.95 11.25 --- --- 12.25 13.70 13.74 12.99 9.98 11.29 --- --- 12.24 13.62 13.74 12.98 10.02 --- --- --- 12.23 6 13.54 13.26 13.45 13.27 7 13.45 13.26 13.46 13.24 8 13.45 13.27 13.47 13.23 9 13.37 13.28 13.48 13.23 10 13.37 13.28 13.49 13.23 13.63 13.75 12.97 10.08 --- --- --- 12.22 13.64 13.76 12.97 10.13 --- --- --- 12.22 13.64 13.76 12.97 10.18 --- --- --- 12.22 13.64 13.76 12.75 10.20 --- --- --- 12.22 13.64 13.76 12.70 10.24 --- --- --- 12.21 11 13.37 13.29 13.50 13.25 12 13.36 13.30 13.52 13.27 13 13.35 13.31 13.53 13.29 14 13.34 13.31 13.55 13.31 15 13.32 13.31 13.57 13.33 13.65 13.76 12.60 10.28 --- --- --- 12.21 13.67 13.77 12.56 10.31 --- --- --- 12.21 13.67 13.79 12.55 10.33 --- --- --- 12.22 13.68 13.80 12.53 10.34 --- --- 12.74 12.24 13.70 13.81 12.52 10.40 --- --- 12.74 12.25 16 13.31 13.32 13.57 13.37 17 13.30 13.32 13.58 13.39 18 13.29 13.33 13.60 13.42 19 13.29 13.29 13.49 13.44 20 13.29 13.30 13.50 13.46 13.73 13.81 12.19 10.42 --- --- 12.74 12.22 13.74 13.81 12.04 10.46 --- --- 12.75 12.20 13.75 13.81 11.09 10.51 --- --- 12.77 12.20 13.77 13.82 10.15 10.58 --- --- 12.78 12.13 13.79 13.40 10.09 10.62 --- --- 12.78 12.13 21 13.29 13.30 13.50 13.48 22 13.26 13.30 13.50 13.50 23 13.26 13.30 13.50 13.53 24 13.26 13.31 13.50 13.54 25 13.27 13.32 13.48 13.56 13.81 13.43 10.05 10.65 --- --- 12.79 12.13 13.81 13.41 10.05 10.71 --- --- 12.74 11.96 13.81 13.22 9.60 10.78 --- --- 12.73 11.97 13.81 13.23 9.60 10.83 --- --- 12.73 11.97 13.80 13.23 9.65 10.88 --- --- 12.73 11.97 26 13.27 13.33 13.46 13.57 27 13.27 13.35 13.43 13.58 28 13.27 13.37 13.42 13.60 29 13.28 13.37 13.40 13.62 30 13.28 13.37 13.38 13.64 31 13.28 --- 13.37 13.66 13.80 13.21 9.69 10.92 --- --- 12.52 11.97 13.80 13.18 9.73 10.96 --- --- 12.51 11.97 13.78 13.16 9.75 11.00 --- --- 12.51 11.95 --- 13.14 9.78 11.03 --- --- 12.32 11.94 --- 13.07 9.82 11.08 --- --- 12.32 11.94 --- 13.07 --- 11.13 --- --- 12.31 --­ MEAN --- 13.31 13.48 13.41 13.72 13.56 11.52 10.48 --- --- --- 12.14 WTR YR 2003MEAN12.74 HIGHEST 9.60 APR 23-24, 2003 LOWEST 13.83 MAR 19, 2003 9 10 11 12 13 14 15 16 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 543 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS—Continued WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 02 13.51 DEC 05 13.42 FEB 13 13.69 APR 09 12.76 JUNE 04 11.30 AUG 13 12.71 WATER YEAR 2003 HIGHEST 11.30 JUNE 04, 2003 LOWEST 13.69 FEB 13, 2003 544 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASIN 180045066381600. Local number 1277. LOCATION.--Lat 18q00'45", long 66q38'16", Hydrologic Unit 21010004, 0.27 mi east of the intersection of Hwy 10 with Hwy 132, 0.6 mi northwest of Parque Paquito Montaner, and 0.04 mi south of Hwy 132, Name: Albergue de Niños Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 10 in (0.25 m). Depth is 126 ft (38.4 m), sounded depth measured on October 7, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 49 ft (14.9 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of 4 in (0.1 m) casing, 5.42 ft (1.65 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 12, 1998. PERIOD OF RECORD.--March 30, 1992 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 23.83 ft (7.26 m), below land-surface datum, June 4, 2003; lowest water level recorded, 51.88 ft (15.81 m), below land-surface datum, August 30, 1994. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29.25 27.89 28.89 28.72 2 29.24 28.12 29.07 28.71 3 29.33 28.27 29.08 28.68 4 29.31 28.32 29.09 28.67 5 29.29 28.06 29.33 28.67 28.93 29.66 30.22 24.18 --- 25.25 26.91 27.75 28.98 29.68 30.33 --- --- 25.24 26.96 27.72 29.01 29.72 30.23 --- --- 25.27 27.02 27.71 29.03 29.76 30.14 --- --- 25.31 27.06 27.70 29.05 29.78 30.08 --- 23.89 25.37 27.09 27.74 6 29.29 28.06 29.36 28.66 7 29.24 27.93 29.19 28.64 8 29.24 27.90 29.07 28.65 9 29.08 27.88 29.02 28.66 10 28.97 27.87 29.00 28.66 29.15 29.80 30.04 --- 23.91 25.43 27.16 27.77 29.16 29.82 29.97 --- 23.89 25.48 27.21 27.80 29.19 29.83 29.94 --- 23.89 25.54 27.23 27.81 29.20 29.85 29.77 --- 23.95 25.57 27.31 27.76 29.22 29.88 29.63 --- 24.03 25.63 27.35 27.60 11 29.45 27.86 29.59 28.66 12 28.73 27.85 28.97 28.66 13 28.65 27.93 28.92 28.66 14 28.51 28.13 28.91 28.67 15 28.45 28.07 28.95 28.67 29.25 29.92 29.53 --- 24.07 25.71 27.35 27.53 29.29 29.96 29.39 --- 24.13 25.77 27.37 27.47 29.32 29.99 29.29 --- 24.18 25.86 27.38 27.40 29.38 30.03 29.18 --- 24.23 25.94 27.41 27.36 29.40 29.93 29.08 --- 24.26 25.95 27.43 27.32 16 28.40 28.07 28.92 28.66 17 28.27 28.10 28.92 28.66 18 28.21 28.15 28.90 28.67 19 28.14 28.12 28.79 28.68 20 28.09 28.14 28.73 28.68 29.46 30.04 28.99 --- 24.32 25.99 27.49 27.25 29.95 30.05 28.49 --- 24.57 26.27 27.56 27.19 29.53 30.07 27.88 --- 24.44 26.39 27.70 27.12 29.53 30.10 27.20 --- 24.51 26.32 27.77 27.08 29.54 30.06 26.75 --- 24.53 26.29 27.82 27.04 21 28.06 28.17 28.74 28.66 22 28.04 28.20 28.75 28.66 23 27.98 28.24 28.77 28.67 24 27.93 28.22 28.74 28.68 25 27.94 28.25 28.74 28.70 29.53 30.02 26.37 --- 24.59 26.30 27.88 27.00 29.55 29.98 26.10 --- 24.64 26.35 27.93 26.91 29.58 29.95 25.69 --- 24.72 26.40 27.99 26.82 29.61 29.96 25.40 --- 24.79 26.45 28.02 26.78 29.59 29.96 25.13 --- 24.85 26.53 28.07 26.76 26 27.81 28.27 28.74 28.74 27 27.41 28.28 28.74 28.75 28 27.40 28.30 28.74 28.79 29 27.59 28.33 28.74 28.82 30 27.71 28.53 28.72 28.84 31 27.75 --- 28.74 28.88 29.60 29.98 24.78 --- 24.92 26.57 28.06 26.70 29.64 30.01 24.77 --- 24.97 26.60 27.99 26.71 29.65 30.01 24.57 --- 25.06 26.69 27.94 26.72 --- 30.02 24.39 --- 25.13 26.75 27.87 26.75 --- 29.98 24.27 --- 25.18 26.81 27.84 26.77 --- 30.00 --- --- --- 26.85 27.79 --­ MEAN 28.48 28.12 28.93 28.70 29.37 29.93 27.92 --- --- 26.03 27.55 27.27 WTR YR 2003MEAN27.91 HIGHEST 23.83 JUNE 4, 2003 LOWEST 30.33 APR 2, 2003 22 24 26 28 30 32 34 36 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 545 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180156066434000. Local number, 1278. LOCATION.--Lat 18q01'56", long 66q43'40", Hydrologic Unit 21010004, 1.23 mi north of Hwy 2, 0.1 mi west of Hwy 385, and 0.14 mi east of Río Tallaboa, Name: Luciano Ventura Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well. Depth 74 ft (22.5 m). DATUM.--Elevation of land-surface datum is about 66 ft (20.1 m), above mean sea level, from topographic map.. Measuring point: H ole in horizontal plexiglass plate, 3.02 ft (0.92 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 5, 1997 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 16.65 ft (5.07 m), below land-surface datum, September 23, 1998; lowest water level recorded, 28.87 ft (8.8 m), below land-surface datum, September 28, 1997. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 02 23.44 JAN 08 23.55 MAR 05 24.78 MAY 14 23.41 JULY 23 23.81 SEPT 10 24.57 DEC 05 23.41 FEB 13 24.15 APR 09 23.39 JUNE 05 23.92 AUG 13 23.90 WATER YEAR 2003 HIGHEST 23.39 APR 09, 2003 LOWEST 24.78 MAR 05, 2003 18 19 20 21 22 23 24 25 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 546 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS—Continued 180133066503300. Local number, 132. LOCATION.--Lat 18q01'33", long 66q50'33", Hydrologic Unit 21010004, 0.9 mi southeast of Yauco plaza, 3.46 mi west of Guayanilla plaza, and 1.32 mi north of Segunda Unidad Barinas School, Name: Pittsburg Plate Glass 4 Well, Yauco. 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 (0.3 m) perforated pipe 20-84 ft (6.1-25.6 m), 10 in (0.25 m) perforated pipe 84-190 ft (25.6-57.9 m). Depth 190 ft (57.9 m). DATUM.--Elevation of land-surface datum is about 75 ft (22.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.8 ft (1.16 m), above land-surface datum. REMARKS.--Observation well. [+, above land-surface datum]. PERIOD OF RECORD.--July 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, +0.12 ft (+0.04 m), above land-surface datum, July 19, 1979; lowest water level recorded, 36.91 ft (11.25 m), below land-surface datum, June 27, 1974. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 02 17.04 JAN 08 16.69 MAR 05 20.91 MAY 14 15.97 JULY 23 23.04 SEPT 11 21.74 DEC 05 14.83 FEB 13 18.55 APR 09 22.08 JUNE 05 17.19 AUG 13 25.88 WATER YEAR 2003 HIGHEST 14.83 DEC 05, 2002 LOWEST 25.88 AUG 13, 2003 5 10 15 20 25 30 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 547 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180132067033800. Local number, 143. LOCATION.--Lat 18q01'33", long 67q03'25", Hydrologic Unit 21010003, 1.86 mi south of Lajas plaza, 1.27 mi southeast of the Estación Experimental Agrícola, and 1.3 mi northwest of the intersection of Hwy 116 with Hwy 305, Name: Vivoni-Col Amistad Well, Lajas. AQUIFER.--Limestone of unknown age. WELL CHARACTERISTICS.--Drilled unused irrigation well, diameter 12 in (0.3 m). Depth 200 ft (60.98 m). DATUM.--Elevation of land-surface datum is about 52.5 ft (16 m), above mean sea level, from topographic map. Measuring point: Ho le side of casing, 0.8 ft (0.24 m), above land-surface datum. REMARKS.--Observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on January 14, 1998 and removed on December 5, 2002. From July 27, 1998 to March 18, 1999, tapedown measurements only. PERIOD OF RECORD.--December 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 37.4 ft (11.4 m), below land-surface datum, November 20, 1985; lowest water level measured, 41.17 ft (12.55 m) below land-surface datum, July 7, 1987. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 02 40.69 JAN 08 40.84 MAR 05 41.09 MAY 14 40.33 JULY 23 40.67 SEPT 11 40.73 DEC 05 40.82 FEB 13 41.04 APR 09 40.92 JUNE 05 40.47 AUG 14 40.80 WATER YEAR 2003 HIGHEST 40.33 MAY 14, 2003 LOWEST 41.09 MAR 05, 2003 39.0 39.5 40.0 40.5 41.0 41.5 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 1998 1999 2000 2001 2002 2003 548 GROUND-WATER LEVELS RIO GUANAJIBO BASIN—Continued 180542067084000. Local number, 1301. LOCATION.--Lat 18q05'42", long 67q08'40", Hydrologic Unit 21010003, 0.35 mi east of Hwy 311, 0.3 mi north of Hwy 102 in Central Cabo Rojo, and 0.5 mi norhwest of the intersection of Hwy 102 with hwy 103, Name: PRASA 1, Cabo Rojo Well. AQUIFER.--Coquí Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.3 m). Depth 116 ft (35.36 m), sounded depth measured on October 8, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. DATUM.--Elevation of land-surface datum is about 39 ft (11.9 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 1.3 ft (0.4 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), installed on May 25, 1996. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on April 9, 1999. From May 12 to September 30, 2002, tapedowns measurements only. PERIOD OF RECORD.--May 25, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.37 ft (2.86 m), below land-surface datum, September 27, 1998; lowest water level recorded, 35.91 ft (10.94 m) below land-surface datum, May 3, 4, 2000. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 --- --- --- --- --­ 2 --- --- --- --- --­ 3 --- --- --- --- --­ 4 --- --- --- --- --­ 5 --- --- 20.39 --- --- 30.31 --- 23.58 --- --- 30.59 31.78 30.35 --- 23.63 --- --- 30.63 31.84 30.62 --- 23.63 --- --- 30.72 31.91 30.86 --- 23.64 --- --- 30.87 31.75 31.00 --- 23.69 --- --- 31.07 31.43 6 --- --- 20.53 --­ 7 --- --- 20.57 --­ 8 --- --- --- --­ 9 --- --- --- --­ 10 --- --- --- --- --- 31.17 --- 23.84 --- --- 31.27 31.39 --- 31.23 --- 23.94 --- --- 31.32 31.29 --- 31.34 --- 23.91 --- --- 31.36 31.32 --- 31.36 --- 23.79 --- --- 31.37 31.42 --- 31.38 32.68 23.71 --- --- 31.37 31.43 11 --- --- --- --­ 12 --- --- --- --­ 13 --- --- --- --­ 14 --- --- --- --­ 15 --- --- --- --- --- 31.42 32.67 23.59 --- --- 31.41 31.33 --- 31.43 32.76 23.51 --- --- 31.63 30.76 28.92 --- 32.86 23.59 --- --- 31.82 30.09 28.95 --- 32.93 23.68 --- --- 31.88 29.52 28.88 --- 32.99 24.00 --- --- 31.82 28.96 16 --- --- --- --­ 17 --- --- --- --­ 18 --- --- --- --­ 19 --- --- --- --­ 20 --- --- --- --- 28.80 --- 33.01 --- --- --- 31.71 28.70 28.81 --- 33.02 --- --- --- 31.78 28.36 29.00 --- 32.66 --- --- --- 31.66 28.11 29.04 --- 30.94 --- --- --- 31.80 27.93 29.20 --- 29.65 --- --- --- 31.94 27.81 21 --- --- --- --­ 22 --- --- --- --­ 23 --- --- --- --­ 24 --- --- --- --­ 25 --- --- --- --- 29.32 --- 28.62 --- --- --- 31.95 27.59 29.37 --- 27.56 --- --- --- 31.82 27.54 29.38 --- 26.67 --- --- --- 31.60 27.50 29.66 --- 26.05 --- --- 30.38 31.52 27.52 29.74 --- 25.69 --- --- 30.18 31.58 27.51 26 --- --- --- --­ 27 --- --- --- --­ 28 --- --- --- --­ 29 --- --- --- --­ 30 --- --- --- --­ 31 --- --- --- --- 29.96 --- 25.15 --- --- 30.09 31.76 27.41 30.20 --- 24.78 --- --- 30.04 31.74 27.49 30.22 --- 24.41 --- --- 30.03 31.77 27.63 --- --- 24.19 --- --- 30.17 31.77 27.85 --- --- 23.93 --- --- 30.43 31.71 27.98 --- --- --- --- --- 30.63 31.71 --­ MEAN --- --- --- --- --- --- --- --- --- --- 31.51 29.44 WTR YR 2003MEAN29.22 HIGHEST 20.28 DEC 5, 2002 LOWEST 33.03 APR 16-17, 2003 10 15 20 25 30 35 40 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 549 GROUND-WATER LEVELS RIO GUANAJIBO BASIN—Continued WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 03 20.89 FEB 12 28.87 APR 10 32.67 JUNE 05 25.98 AUG 14 31.87 DEC 04 20.35 WATER YEAR 2003 HIGHEST 20.89 OCT 03, 2002 LOWEST 32.67 APR 10, 2003 550 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182017067143300. Local number, 1352. LOCATION.--Lat 18q20'17", long 67q14'33", Hydrologic Unit 21010003, 0.63 mi southeast of the intersection of Hwy 412 with Hwy 115, 1.13 mi south of the intersection of Hwy 413 with Hwy 115, and 0.01 mi north of Hwy 411, Name: Rincón 4 Well. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (0.3 m), cased 0-69 ft (0-21 m). Depth 102 ft (31.1 m). DATUM.--Elevation of land-surface datum is about 39 ft (11.9 m), above mean sea level, from topographic map. Measuring point: Shelter floor on top of the 4 in (0.1 m) casing, 3.53 ft (1.08 m), above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--May 30, 1996 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 20.8 ft (6.34 m), below land-surface datum, September 27, 1998; lowest water level recorded, 36.71 ft (11.19 m), below land-surface datum, August 5, 2002. WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 03 30.74 JAN 09 31.33 MAR 06 33.18 MAY 15 30.14 JULY 23 28.84 SEPT 11 30.00 DEC 04 28.71 FEB 12 32.79 APR 10 32.94 JUNE 05 28.16 AUG 14 29.45 WATER YEAR 2003 HIGHEST 28.16 JUNE 05, 2003 LOWEST 33.18 MAR 06, 2003 22 24 26 28 30 32 34 36 38 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 551 GROUND-WATER LEVELS RIO CULEBRINAS BASIN—Continued 182442067091700. Local number, 200. LOCATION.--Lat 18q24'42", long 67q09'17", Hydrologic Unit 21010002, 1.4 mi south of Aguadilla plaza, 3.04 mi northeast of Aguada plaza, and 0.2 mi north of Hwy 2 km 146.4, Name: Aguadilla Cement North Well. AQUIFER.--Alluvial deposits. WELL CHARACTERISTICS.--Abandoned water-table industrial well, diameter 4 in (0.1 m), cased 0-20 ft (0-6.1 m), perforated 11-20 ft (3.35-6.1 m). Depth 10 ft (3.05 m), sounded depth measured on October 8, 2004. INSTRUMENTATION.--Electronic water level logger--60-minutes interval. 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 (0.1 m) casing, 3.25 ft (0.99 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 18, 1998. Water levels affected by nearby pumping well. PERIOD OF RECORD.--October 1985 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 1.61 ft (0.49 m), below land-surface datum, September 22, 1998; lowest water level recorded, 9.6 ft (2.93 m), below land-surface datum, February 20, 1992. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 6.77 --- 5.89 7.07 7.09 7.67 8.04 6.97 5.95 5.06 6.12 6.41 2 6.77 --- 5.95 7.10 7.16 7.69 7.92 7.00 5.86 5.14 6.12 6.45 3 6.84 --- 6.01 7.14 7.23 7.72 7.94 7.05 5.95 4.77 6.16 6.50 4 6.84 --- 6.05 7.15 7.23 7.74 7.97 7.10 6.01 4.37 6.22 6.54 5 6.68 --- 6.05 7.18 7.19 7.78 7.88 7.16 6.08 4.53 6.01 6.60 6 6.70 --- 6.10 7.21 6.93 7.80 7.75 7.19 5.73 4.67 6.13 6.28 7 6.82 --- 6.14 7.24 6.94 7.83 7.75 7.19 5.53 4.82 6.19 6.33 8 6.86 --- 6.18 7.28 6.96 7.83 7.74 7.22 5.26 4.88 6.19 6.42 9 6.69 --- 6.24 7.31 7.02 7.85 7.77 7.27 5.30 4.98 6.09 6.45 10 6.50 --- 6.33 7.33 7.09 7.89 7.66 6.88 5.40 5.08 6.17 6.35 11 6.52 --- 6.36 7.35 12 6.50 --- 6.40 7.38 13 6.36 --- 6.46 7.45 14 6.37 --- 6.48 7.43 15 6.42 5.03 6.53 7.47 7.14 7.91 7.66 6.91 5.51 5.17 6.23 6.44 7.20 7.92 7.47 6.99 5.57 5.21 6.29 6.00 7.27 7.95 7.46 7.06 5.07 5.30 6.34 6.02 7.28 7.96 7.43 6.90 5.13 5.38 6.08 6.09 7.31 7.98 7.47 6.76 5.16 5.45 6.17 6.18 16 6.19 5.09 6.58 7.49 17 6.08 5.16 6.59 7.52 18 --- 5.12 6.64 7.53 19 --- 5.24 6.68 7.55 20 --- 5.32 6.73 7.56 7.34 8.00 7.51 6.34 5.31 5.51 6.02 6.27 7.39 8.02 7.37 6.08 5.44 5.59 6.12 6.34 7.41 8.04 6.93 5.79 5.52 5.65 6.24 6.39 7.44 8.06 6.76 5.35 4.49 5.70 6.27 6.46 7.50 8.12 6.63 5.20 5.07 5.75 6.19 6.49 21 --- 5.40 6.76 7.61 22 --- 5.47 6.79 7.59 23 --- 5.55 6.86 7.61 24 --- 5.62 6.76 7.63 25 --- 5.74 6.82 7.63 7.49 8.10 6.63 4.87 5.17 5.83 6.29 6.54 7.50 8.11 6.57 4.95 4.41 5.51 6.35 6.59 7.52 8.13 6.64 5.09 4.41 5.64 6.38 6.63 7.56 8.16 6.73 5.19 4.46 5.74 6.28 6.36 7.63 8.18 6.81 5.17 4.55 5.92 6.22 6.42 26 --- 5.78 6.88 7.32 27 --- 5.66 6.91 7.35 28 --- 5.63 6.94 7.31 29 --- 5.76 6.98 7.38 30 --- 5.84 7.02 7.39 31 --- --- 7.05 7.10 7.60 8.21 6.55 5.37 4.61 5.95 6.18 6.48 7.67 8.24 6.61 5.45 4.70 6.02 6.29 6.18 7.65 8.17 6.71 5.56 4.79 5.67 6.27 6.14 --- 8.18 6.81 5.68 4.88 5.85 6.33 6.22 --- 7.97 6.89 5.77 4.97 5.99 6.39 6.03 --- 8.01 --- 5.86 --- 6.06 6.40 --­ MEAN --- --- 6.52 7.38 7.31 7.97 7.27 6.24 5.21 5.39 6.22 6.35 WTR YR 2003MEAN6.53 HIGHEST 3.64 JULY 3, 2003 LOWEST 8.25 MAR 27, 2003 3 4 5 6 7 8 9 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 552 THIS PAGE IS INTENTIONALLY BLANK 553 554 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174225064472000. Local number, 2. LOCATION.--Lat 17q42'25", long 64q47'20", Hydrologic Unit 21020002, 0.9 mi southeast of the Experimental Station, 6.0 mi southwest of Christiansted Plaza, and 0.18 mi northeast of the Alexander Hamilton Airport entrance on Hwy 64. Owner: US Virgin Islands Water and Power Authority, Name: USGS­ 10, Fairplains 2 Well. AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 20 ft (6.1 m), above mean sea level, from topographic map. Measuring point: Top of shelter floor, 3.76 ft (1.15 m), above land-surface datum. Prior November 19, 1999, top of 0.5 in (0.01 m), hole at concrete base wall, 3 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Water level affected by nearby pumping well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on October 27, 1999. PERIOD OF RECORD.--June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 15.86 ft (4.83 m), below land-surface datum, January 24, 2000; lowest water level recorded, 26.46 ft (8.06 m), below land-surface datum, August 25, 1990. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.78 20.04 20.15 20.95 2 19.74 20.07 20.14 20.95 3 19.80 20.10 20.14 21.02 4 19.77 20.13 20.22 21.00 5 19.76 20.10 20.30 21.00 20.92 20.76 21.93 21.29 21.31 21.75 21.66 22.12 20.86 20.77 22.00 21.26 21.35 21.75 21.65 22.12 20.91 20.87 22.02 21.25 21.41 21.76 21.62 22.18 20.90 20.89 22.06 21.20 21.40 21.74 21.61 22.17 20.92 21.01 22.09 21.23 21.39 21.75 21.66 22.16 6 19.71 20.11 20.34 21.01 7 19.70 20.16 20.35 21.04 8 19.74 20.19 20.37 21.06 9 19.71 20.14 20.39 21.04 10 19.80 20.09 20.46 21.02 20.97 21.07 22.05 21.24 21.39 21.76 21.72 22.18 21.02 21.11 22.06 21.30 21.40 21.76 21.86 22.16 20.94 21.14 22.08 21.19 21.37 21.82 21.92 22.17 20.82 21.13 22.09 21.13 21.39 21.87 22.00 22.16 20.86 21.17 22.08 21.07 21.37 21.93 21.99 22.25 11 19.91 20.06 20.60 20.90 12 19.84 20.03 20.59 20.80 13 19.81 20.04 20.53 20.75 14 19.80 20.05 20.55 20.71 15 19.74 20.07 20.58 20.76 20.77 21.26 22.08 20.92 21.46 21.91 22.04 22.24 20.75 21.34 22.08 20.87 21.46 21.95 22.11 22.27 20.68 21.39 22.03 20.87 21.48 21.92 22.13 22.26 20.71 21.43 22.02 20.84 21.50 21.95 22.21 22.22 20.71 21.45 22.00 20.80 21.47 22.02 22.20 22.21 16 19.74 20.12 20.57 20.71 17 19.75 20.18 20.58 20.64 18 19.77 20.22 20.60 20.61 19 19.73 20.28 20.65 20.56 20 19.70 20.29 20.74 20.50 20.62 21.45 21.96 20.77 21.48 21.99 22.19 22.29 20.59 21.49 21.96 20.86 21.53 22.03 22.18 22.16 20.62 21.53 21.88 20.84 21.61 22.05 22.20 22.10 20.64 21.58 21.79 20.90 21.64 22.07 22.24 22.01 20.67 21.60 21.71 20.95 21.68 22.04 22.31 21.94 21 19.69 20.33 20.69 20.46 22 19.71 20.32 20.70 20.48 23 19.69 20.33 20.71 20.48 24 19.69 20.34 20.73 20.51 25 19.70 20.35 20.75 20.50 20.66 21.67 21.66 20.97 21.63 22.10 22.29 21.86 20.67 21.66 21.62 20.98 21.60 22.15 22.26 21.78 20.59 21.64 21.54 21.01 21.61 22.14 22.25 21.72 20.65 21.62 21.48 21.00 21.59 22.12 22.19 21.71 20.67 21.73 21.46 21.00 21.67 21.97 22.18 21.66 26 19.76 20.39 20.76 20.42 27 19.71 20.30 20.85 20.43 28 19.73 20.24 20.82 20.56 29 19.84 20.20 20.85 20.73 30 19.90 20.19 20.87 20.72 31 19.99 --- 20.97 20.80 20.65 21.75 21.39 20.99 21.70 21.91 22.25 21.66 20.65 21.79 21.34 21.14 21.75 21.83 22.22 21.61 20.67 21.92 21.31 21.22 21.73 21.82 22.20 21.54 --- 21.92 21.32 21.31 21.67 21.81 22.17 21.50 --- 21.88 21.29 21.38 21.72 21.73 22.19 21.45 --- 21.89 --- 21.38 --- 21.68 22.14 --­ MEAN 19.76 20.18 20.57 20.75 20.75 21.42 21.81 21.07 21.53 21.91 22.06 22.00 WTR YR 2003MEAN21.15HIGHEST19.69 OCT 7 , 20-25, 27, 28, 2002LOWEST22.31 AUG 20, 2003 15 16 17 18 19 20 21 22 23 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 555 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS—Continued 174243064475100. Local number, 3. LOCATION.--Lat 17q42'43", long 64q47'51", Hydrologic Unit 21020002, 0.75 mi northwest of the Alexander Hamilton Airport entrance on Hwy 64, 6.45 mi southwest of Christiansted plaza, and 0.57 mi southwest of the Experimental Station. Owner: US Virgin Islands Government, Name: Golden Grove 6 Well. AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.2 m), cased 8 in (0.2 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 40 ft (12.2 m), above mean sea level, from topographic map. Measuring point: Upper edge of hole at 8 in (0.2 m) casing, 4.2 ft (1.28 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n October 27, 1999. From Febraury 21, 2001 to May 21, 2002, tapedowns measurements only. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 9.68 ft (2.95 m), below land-surface datum, November 19, 20, 1999; lowest water level recorded, 41.05 ft (12.5 m), below land-surface datum, September 15, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 23.63 25.79 25.98 27.86 2 23.72 25.85 25.90 27.91 3 23.81 25.96 25.95 27.96 4 23.93 25.76 26.38 28.01 5 24.02 25.96 26.52 28.07 28.16 28.96 30.66 28.89 29.14 --- --- 32.52 28.27 29.10 30.70 28.93 29.18 --- --- 32.58 28.37 29.22 30.77 28.99 29.23 --- --- 32.64 28.44 29.32 30.82 29.02 29.27 --- --- 32.71 28.51 29.36 30.88 29.09 29.31 --- --- 32.77 6 24.10 25.97 26.61 28.11 7 24.22 25.91 26.67 28.15 8 24.29 25.62 26.75 28.20 9 24.56 25.55 26.81 28.23 10 25.13 25.50 26.89 28.14 28.67 29.49 30.93 29.14 29.34 --- --- 32.85 28.76 29.59 30.98 29.23 29.38 --- --- 32.91 28.75 29.61 31.02 29.02 29.41 --- --- 32.97 28.65 29.69 31.06 28.95 29.49 --- --- 33.03 28.64 29.74 31.08 28.83 29.52 --- --- 33.08 11 25.34 25.48 26.94 28.05 12 24.80 25.46 26.99 27.97 13 24.68 25.46 27.02 27.89 14 24.59 25.47 27.05 27.82 15 24.58 25.48 27.08 27.75 28.64 29.81 31.11 28.77 29.55 --- --- 33.13 28.63 29.85 31.13 28.70 29.58 --- --- 33.18 28.62 29.93 31.16 28.62 29.61 --- --- 33.22 28.62 30.05 31.17 28.58 29.63 --- 31.21 33.27 28.62 30.09 31.17 28.53 29.66 --- 31.27 33.33 16 24.57 26.06 27.11 27.69 17 24.57 26.20 27.15 27.62 18 24.53 26.26 27.19 27.56 19 24.51 26.35 27.23 27.52 20 24.52 26.45 27.28 27.46 28.61 30.12 31.13 28.52 29.70 --- 31.32 33.38 28.62 30.13 31.02 28.65 29.72 --- 31.36 33.40 28.63 30.15 30.89 28.72 29.75 --- 31.40 33.40 28.64 30.14 30.69 28.79 29.81 --- 31.49 33.41 28.63 30.14 30.33 28.81 29.85 --- 31.60 33.42 21 24.51 26.50 27.33 27.37 22 24.51 26.56 27.38 27.36 23 24.53 26.63 27.43 27.35 24 24.51 26.67 27.48 27.36 25 24.50 26.73 27.53 27.35 28.62 30.13 29.93 28.87 29.87 --- 31.69 33.42 28.63 30.13 29.62 28.97 29.91 --- 31.77 33.42 28.64 30.12 29.44 29.02 29.94 --- 31.86 33.42 28.66 30.13 29.20 29.04 29.98 --- 31.94 33.42 28.64 30.17 29.04 29.05 30.01 --- 32.01 33.41 26 24.52 26.69 27.57 27.35 27 24.52 26.34 27.60 27.36 28 24.72 26.20 27.64 27.68 29 25.33 26.11 27.70 27.84 30 25.52 26.04 27.75 27.95 31 25.66 --- 27.81 28.06 28.64 30.25 28.93 29.06 30.04 --- 32.09 33.41 28.65 30.32 28.86 29.08 30.07 --- 32.17 33.40 28.67 30.39 28.82 29.09 30.11 --- 32.24 33.34 --- 30.51 28.81 29.10 30.12 --- 32.31 33.33 --- 30.57 28.82 29.10 30.16 --- 32.38 33.23 --- 30.60 --- 29.12 --- --- 32.44 --­ MEAN 24.55 26.03 27.06 27.77 28.59 29.93 30.34 28.91 29.68 --- --- 33.17 WTR YR 2003MEAN28.77 HIGHEST23.57 OCT 1, 2002LOWEST33.42 SEPT 19 TO 24, 2003 5 10 15 20 25 30 35 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 556 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS—Continued 174316064480800. Local number, 13. LOCATION.--Lat 17q43'16", long 64q48'08", Hydrologic Unit 21020002, 5.25 mi east of Fort Frederick at Frederickstead, 0.95 mi southeast of Holy Cross Church, and 0.65 mi northeast of Adventure Ruins. Owner: US Virgin Islands Water and Power Authority, Name: WAPA-17 Well. AQUIFER.--Kingshill Limestone. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.1 m), cased 0-95 ft (0-29 m), screened 10-40 ft (3.05-12.2 m). Depth 95 ft (29 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 75 ft (22.9 m), above mean sea level, from topographic map. Measuring point: To p of shelter floor, 2.33 ft (0.71 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed o n October 27, 1999. From October 1, 2000 to March 26, 2001, tapedowns measurements only. PERIOD OF RECORD.--February 28, 1990 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 0.27 ft (0.08 m), below land-surface datum, September 10, 1996; lowest water level recorded, 27.88 ft (8.5 m), below land-surface datum, September 6, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 12.26 --- --- --- --­ 2 12.32 --- --- --- --­ 3 12.38 --- --- --- --­ 4 12.41 --- --- --- --­ 5 12.45 --- --- --- --- --- --- 15.18 16.24 --- --- 19.13 --- --- 15.21 16.29 --- --- 19.17 --- --- 15.22 16.35 --- --- 19.24 --- --- 15.22 16.40 --- --- 19.30 --- --- 15.22 16.45 --- --- 19.35 6 12.47 --- --- --­ 7 --- --- --- --­ 8 --- --- --- --­ 9 --- --- --- --­ 10 --- --- --- --- --- --- --- 15.22 16.50 --- --- 19.39 --- --- --- 15.32 16.54 --- --- 19.43 --- --- 19.37 15.35 16.57 --- --- 19.49 --- --- 16.54 15.34 16.64 --- --- 19.52 --- --- 16.60 15.29 16.69 --- --- 19.56 11 --- --- --- --­ 12 --- --- --- --­ 13 --- --- --- --­ 14 --- --- --- --­ 15 --- --- --- --- --- --- 15.57 15.25 16.74 --- --- 19.61 --- --- 14.92 15.22 16.80 --- --- 19.65 --- --- 15.50 15.16 16.86 --- --- 19.68 --- --- 16.12 15.13 16.91 --- 18.70 19.73 --- --- 15.60 15.11 16.96 --- 18.78 19.76 16 --- --- --- --­ 17 --- --- --- --­ 18 --- --- --- --­ 19 --- --- --- --­ 20 --- --- --- --- --- --- 15.04 15.11 17.01 --- 18.84 19.79 --- --- 15.69 15.14 17.07 --- 18.88 19.85 --- --- 14.13 15.18 17.11 --- 18.93 19.85 --- --- 13.67 15.24 17.15 --- 18.95 19.85 --- --- 13.93 15.32 17.20 --- 18.98 19.82 21 --- --- --- 14.13 22 --- --- --- 14.13 23 --- --- --- --­ 24 --- --- --- --­ 25 --- --- --- --- --- --- 14.31 15.42 17.25 --- 19.04 19.77 --- --- 14.65 15.51 17.27 --- 18.99 18.67 --- --- 14.82 15.57 17.28 --- 18.61 18.94 --- --- 14.93 15.66 17.32 --- 18.85 19.08 --- --- 15.00 15.75 17.35 --- 18.93 19.13 26 --- --- --- --­ 27 --- --- --- --­ 28 --- --- --- --­ 29 --- --- --- --­ 30 --- --- --- --­ 31 --- --- --- --- --- --- 15.05 15.80 17.41 --- 18.90 19.13 --- --- 15.07 15.91 17.48 --- 18.90 19.14 --- --- 15.11 15.95 17.53 --- 18.99 19.14 --- --- 15.13 15.99 17.59 --- 19.01 19.14 --- --- 15.15 16.12 17.64 --- 19.03 19.14 --- --- --- 16.18 --- --- 19.08 --­ MEAN --- --- --- --- --- --- --- 15.43 16.95 --- --- 19.41 WTR YR 2003MEAN16.89 HIGHEST12.03 NOV 20, 2002LOWEST19.85 SEPT 17 TO 20, 2003 4 6 8 10 12 14 16 18 20 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD 557 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS—Continued WATER LEVELS IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 WATER WATER WATER WATER WATER DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL DATE LEVEL OCT 07 12.48 JAN 21 14.13 APR 08 16.37 JUNE 3 017.64 SEPT 3 019.14 NOV 20 12.03 MAR 04 15.17 MAY 31 16.18 AUG 1 318.67 WATER YEAR 2003 HIGHEST 12.03 NOV 20, 2002 LOWEST 19.14 SEPT 30, 2003 558 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182038064550300. Local number, 6. LOCATION.--Lat 18q20'38", long 64q55'03", Hydrologic Unit 21020001, 1.12 mi east of Charlotte Amalie, 0.75 mi southwest of Winterberg Peak, and 1.08 mi southeast of Canaan. Owner: US Virgin Islands Government, Name: Grade School 3 Well. AQUIFER.--Volcanic breccia. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 70 ft (21.3 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 52 ft (15.8 m), above mean sea level, from topographic map. Prior to June 30, 1 999, is about 60 ft (18.3 m), above mean sea level. Measuring point: Top of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 3.3 ft (1 m), above land-surface datum. Prior to June 30, 1999, top of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.3 ft (0.4 m), above land-surface datum. Prior to June 27, 1983, top of 6 in (0.15 m) casing, 2.9 ft (0.88 m), above land-surface datum. REMARKS.--Recording observation well. Automated Digital Recording (ADR), replaced by an Electronic Data Logger (EDL), installed on October 28, 1999. A datum correction was required after land-surface elevation in the area, changed from 60 ft (18.3 m) to 52 ft (15.8 m) on June 29, 1999. PERIOD OF RECORDS.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORDS.--Highest water level recorded, 1.53 ft (0.47 m), below land-surface datum, October 1, 1989; lowest water level recorded, 35.38 ft (10.8 m), below land-surface datum, July 21, 1982. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 20.15 22.77 22.57 24.24 2 20.38 22.83 22.68 24.14 3 20.36 22.91 22.80 24.24 4 20.60 22.94 22.94 24.31 5 20.81 23.04 23.04 23.43 22.63 23.58 --- 16.96 22.71 23.59 --- 23.06 22.73 23.68 --- 17.42 22.69 --- --- 23.06 22.80 23.78 --- 17.88 22.75 --- --- 23.11 22.56 23.87 --- 18.32 22.79 --- --- 23.08 22.52 23.97 --- 18.74 22.79 --- --- 23.08 6 21.02 23.14 23.14 23.25 7 21.21 23.21 23.23 23.52 8 21.47 23.28 23.30 23.70 9 21.63 23.34 23.30 23.87 10 21.74 23.38 23.36 24.01 22.10 24.01 --- 19.15 22.80 --- --- 23.12 22.27 24.06 --- 19.53 22.82 --- --- 23.18 22.41 24.10 --- 19.83 22.72 --- --- 23.21 22.55 24.12 --- 20.17 22.76 --- --- 23.21 22.64 24.13 --- 20.46 22.82 --- --- 23.24 11 21.90 23.43 23.40 24.11 12 19.69 23.48 23.44 24.24 13 20.14 22.85 23.48 24.34 14 20.44 22.95 23.47 24.42 15 20.75 22.93 23.47 24.44 22.65 24.13 --- 20.73 22.87 --- --- 23.24 22.65 24.15 23.00 20.98 22.92 --- --- 23.25 22.63 24.19 23.17 21.25 22.98 --- --- 23.25 22.66 24.21 23.33 21.43 23.08 --- --- 23.28 22.74 24.23 23.54 21.58 23.15 --- 23.57 23.10 16 21.01 22.56 23.46 24.49 17 21.24 22.58 21.75 24.52 18 21.47 22.80 20.83 24.51 19 21.66 22.78 20.97 24.41 20 21.84 21.55 20.83 24.41 22.78 24.27 23.72 21.70 23.19 --- 23.59 23.09 22.83 24.30 23.89 21.80 23.23 --- 23.62 23.10 22.84 24.34 19.52 21.92 23.25 --- 23.64 23.14 22.92 24.37 17.85 22.03 23.29 --- 23.62 23.22 22.92 24.37 17.34 22.12 23.59 --- 23.59 23.28 21 21.85 20.97 20.95 24.47 22 21.99 21.22 21.07 24.53 23 22.06 21.44 22.84 22.86 24 22.13 21.60 23.08 22.86 25 22.24 21.71 23.20 22.90 22.93 24.37 16.66 22.11 23.88 --- 23.56 22.94 23.00 24.41 16.33 22.06 23.89 --- 23.57 22.58 23.08 24.44 15.31 21.99 23.83 --- 23.57 22.49 23.18 --- 15.26 22.00 23.77 --- 23.56 22.54 23.20 --- 14.58 22.08 23.73 --- 23.53 22.62 26 22.28 21.80 23.36 21.99 27 22.39 21.83 23.55 22.21 28 22.48 21.93 23.68 22.31 29 22.57 22.00 23.83 22.42 30 22.63 22.21 24.02 22.50 31 22.68 --- 24.15 22.55 23.24 --- 14.75 22.21 23.69 --- 23.31 22.74 23.32 --- 15.15 22.36 23.66 --- 23.26 22.83 23.45 --- 15.55 22.47 23.67 --- 23.26 22.87 --- --- 16.01 22.55 23.65 --- 23.25 22.93 --- --- 16.48 22.58 23.63 --- 23.07 23.05 --- --- --- 22.65 --- --- 23.08 --­ MEAN 21.45 22.52 22.88 23.68 22.79 --- --- 20.94 23.22 --- --- 23.03 WTR YR 2003MEAN22.47 HIGHEST 14.57 APR 25, 2003 LOWEST 24.53 JAN 17, 18, 2003 12 14 16 18 20 22 24 26 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 559 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS—Continued 182038064580000. Local number, 8. LOCATION.--Lat 18q20'38", long 64q58'00", Hydrologic Unit 21020001, 2.08 mi northwest of Charlotte Amalie, 0.5 mi northeast of Harry S. Truman Airport entrance on Hwy 302, and 1.15 mi southwest of Dorothea. Owner: US Virgin Islands Water and Power Authority, Name: Kirwan Terrace , VIEO-6 Well. AQUIFER.--Alluvial deposits, volcanic rock. WELL CHARACTERISTICS.--Drilled observation well, diameter 4 in (0.1 m), cased 0-56 ft (0-17.1 m), screened 56-76 ft (17.1-23.2 m). Depth 76 ft (23.2 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 35 ft (10.7 m), above mean sea level, from topographic map. Measuring point: To p of shelter floor, 3 ft (0.91 m), above land-surface datum. REMARKS.--Recording observation well. Drilled on July 1, 1991. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on October 29, 1999. PERIOD OF RECORD.--October 2, 1991 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 14.3 ft (4.37 m), below land-surface datum, December 6, 7, 1996; lowest water level recorded, 33.97 ft (10.35 m), below land-surface datum, July 29, 30, 2001. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29.60 27.61 27.80 28.07 2 29.36 27.61 27.83 28.09 3 29.17 27.63 27.88 28.14 4 29.04 27.62 27.94 28.16 5 28.96 27.63 28.00 28.18 29.30 30.38 31.89 24.35 25.63 27.71 --- 30.00 29.37 30.47 31.89 24.40 25.66 --- --- 30.01 29.42 30.54 31.88 24.45 25.70 --- --- 30.05 29.44 30.57 31.88 24.47 25.75 --- --- 30.10 29.45 30.64 31.81 24.48 25.82 --- --- 30.15 6 28.89 27.64 28.04 28.18 7 28.86 27.66 28.08 28.19 8 28.88 27.67 28.13 28.19 9 28.88 27.69 28.16 28.21 10 28.87 27.72 28.20 28.24 29.47 30.71 31.68 24.52 25.89 --- --- 30.20 29.48 30.75 31.56 24.55 26.00 --- --- 30.27 29.50 30.73 31.42 24.60 26.02 --- --- 30.32 29.51 30.79 31.12 24.65 26.02 --- --- 30.44 29.56 30.83 30.73 24.68 26.03 --- --- 30.52 11 28.87 27.75 28.24 28.31 12 28.79 27.79 28.32 28.34 13 28.64 27.76 28.36 28.37 14 28.51 27.77 28.38 28.40 15 28.33 27.73 28.44 28.43 29.60 30.87 30.40 24.76 26.06 --- --- 30.58 29.65 30.91 30.08 24.80 26.14 --- --- 30.68 29.67 30.97 29.79 24.83 26.21 --- --- 30.82 29.68 31.02 29.42 24.86 26.27 --- --- 30.94 29.73 31.08 28.89 24.92 26.33 --- 29.23 31.03 16 28.21 27.72 28.49 28.46 17 28.16 27.73 28.50 28.51 18 28.09 27.72 28.43 28.59 19 28.06 27.69 28.36 28.68 20 28.02 27.74 28.28 28.71 29.78 31.12 28.38 24.98 26.37 --- 29.28 31.12 29.86 31.17 27.86 25.03 26.43 --- 29.34 31.24 29.91 31.22 26.77 25.11 26.53 --- 29.38 31.37 29.95 31.30 26.94 25.14 26.71 --- 29.57 31.50 30.01 31.35 27.01 25.20 26.75 --- 29.61 31.58 21 27.95 27.69 28.21 28.75 22 27.89 27.68 28.13 28.81 23 27.83 27.66 28.05 28.89 24 27.77 27.65 28.00 28.97 25 27.74 27.61 27.98 29.08 30.05 31.41 26.91 25.22 26.81 --- 29.63 31.67 30.10 31.49 26.58 25.25 26.89 --- 29.66 31.69 30.18 31.53 25.70 25.28 26.98 --- 29.70 31.68 30.24 31.56 25.14 25.29 27.05 --- 29.72 31.68 30.28 31.55 24.76 25.31 27.12 --- 29.77 31.68 26 27.69 27.62 27.97 29.13 27 27.67 27.65 27.97 29.14 28 27.64 27.69 27.99 29.15 29 27.63 27.74 28.02 29.17 30 27.62 27.78 28.03 29.22 31 27.61 --- 28.05 29.26 30.30 31.56 24.52 25.32 27.19 --- 29.86 31.68 30.34 31.61 24.40 25.34 27.28 --- 29.89 31.68 30.37 31.67 24.30 25.38 27.36 --- 29.95 31.67 --- 31.73 24.28 25.45 27.44 --- 29.98 31.75 --- 31.79 24.33 25.51 27.61 --- 29.99 31.91 --- 31.86 --- 25.59 --- --- 30.00 --­ MEAN 28.36 27.69 28.14 28.58 29.79 31.13 28.41 24.96 26.47 --- --- 31.00 WTR YR 2003MEAN29.80 HIGHEST 24.27 APR 29, 2003 LOWEST 31.92 SEPT 30, 2003 15 20 25 30 35 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE GAP INDICATES MISSING RECORD 560 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 181956064464500. Local number, 11. LOCATION.--Lat 18q19'56", long 64q46'45", Hydrologic Unit 21020001, 1.05 mi southeast of Cruz Bay plaza, 0.25 mi southeast of Bethany Church, and 0.48 mi southeast of Margaret Hill. Owner: US Virgin Islands Government, Name: Guinea Gut Well. AQUIFER.--Louisenhoj Formation (Donnelly, 1959). WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 85 ft (25.9 m). INSTRUMENTATION.--Electronic water level logger--60-minutes punch. DATUM.--Elevation of land-surface datum is about 280 ft (85.36 m), above mean sea level, from topographic map. Measuring point: Bottom of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.5 ft (0.46 m), above land-surface datum. Prior to June 28, 1983, top of 6 in (0.15 m) casing, 1.8 ft (0.55 m), above land- surface datum. REMARKS.--Recording observation well. Automated Digital Recorder (ADR), replaced by an Electronic Data Logger (EDL), installed on February 17, 2000. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level recorded, 2.34 ft (0.71 m), below land-surface datum, December 7, 1998; lowest water level recorded, 34.18 ft (10.4 m), below land-surface datum, September 6, 1995. DEPTH TO WATER LEVEL, FEET BELOW LAND SURFACE WATER YEAR OCTOBER 2002 TO SEPTEMBER 2003 DAILY OBSERVATION AT 1200 HOURS DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14.46 14.58 17.04 19.47 2 14.27 14.68 17.16 19.51 3 13.99 14.76 17.29 19.56 4 13.99 14.73 17.41 19.62 5 14.02 14.76 17.52 19.66 20.41 21.50 23.05 9.37 14.98 19.20 21.47 22.90 20.41 21.55 23.08 9.67 15.06 19.29 21.56 22.94 20.41 21.62 23.11 9.94 15.19 19.41 21.61 22.99 20.40 21.67 23.11 10.19 15.36 19.50 21.64 23.07 20.40 21.74 23.10 10.46 15.54 19.59 21.67 23.13 6 14.02 14.80 17.62 19.68 7 14.04 14.84 17.73 19.70 8 14.10 14.93 17.84 19.71 9 14.12 15.03 17.90 19.72 10 14.09 15.12 17.96 19.73 20.40 21.81 23.07 10.69 15.66 19.65 21.71 23.20 20.41 21.87 23.02 10.92 15.71 19.75 21.77 23.29 20.45 21.92 23.00 11.15 15.81 19.85 21.83 23.29 20.49 21.96 22.98 11.35 15.96 19.92 21.90 23.28 20.52 22.02 22.98 11.57 16.16 20.03 22.00 23.28 11 14.11 15.24 18.02 19.77 12 14.11 15.32 18.09 19.82 13 14.06 15.32 18.18 19.89 14 14.01 15.47 18.24 19.96 15 14.01 15.62 18.35 20.02 20.53 22.08 22.97 11.76 16.30 20.13 21.98 23.28 20.53 22.13 22.95 11.97 16.47 20.23 22.07 23.27 20.52 22.17 22.93 12.13 16.66 20.30 22.06 23.26 20.53 22.23 22.89 12.26 16.86 20.34 22.05 23.26 20.55 22.29 22.88 12.47 17.02 20.35 22.07 23.27 16 14.03 15.77 18.45 20.10 17 14.06 15.89 18.55 20.16 18 14.10 16.00 18.58 20.21 19 14.15 16.07 18.59 20.28 20 14.18 16.11 18.63 20.34 20.60 22.34 22.86 12.63 17.12 20.38 22.12 23.27 20.68 22.40 22.83 12.73 17.28 20.41 22.19 23.29 20.77 22.45 18.79 12.80 17.45 20.46 22.25 23.28 20.88 22.49 14.85 12.87 17.62 20.51 22.29 23.28 20.95 22.54 12.70 12.98 17.75 20.60 22.35 23.30 21 14.18 16.17 18.71 20.38 22 14.13 16.21 18.75 20.44 23 14.11 16.26 18.80 20.48 24 14.10 16.35 18.85 20.51 25 14.12 16.45 18.93 20.51 21.03 22.59 11.58 13.10 17.87 20.67 22.40 23.29 21.08 22.64 10.90 13.17 18.01 20.74 22.45 23.25 21.16 22.67 9.13 13.22 18.16 20.81 22.51 23.20 21.22 22.71 8.42 13.37 18.31 20.88 22.55 23.14 21.29 22.77 8.11 13.52 18.45 20.95 22.60 23.08 26 14.15 16.55 19.01 20.47 27 14.24 16.63 19.09 20.46 28 14.31 16.72 19.16 20.44 29 14.39 16.81 19.24 20.42 30 14.45 16.91 19.32 20.41 31 14.47 --- 19.39 20.41 21.33 22.81 7.97 13.70 18.60 21.04 22.64 23.02 21.37 22.85 7.96 13.90 18.73 21.11 22.69 22.99 21.41 22.89 8.13 14.13 18.89 21.17 22.74 22.96 --- 22.94 8.56 14.33 19.02 21.23 22.78 22.94 --- 22.97 9.02 14.55 19.11 21.30 22.82 22.91 --- 23.01 --- 14.78 --- 21.39 22.85 --­ MEAN 14.15 15.67 18.34 20.06 20.74 22.31 17.56 12.31 17.04 20.36 22.18 23.16 WTR YR 2003MEAN18.64 HIGHEST 7.91 APR 27, 2003 LOWEST 23.31 SEPT 20, 2003 0 5 10 15 20 25 1998 1999 2000 2001 2002 2003 O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S O N D J F M A M J J A S WATER LEVEL, IN FEET BELOW LAND SURFACE TREND LINE GAP INDICATES MISSING RECORD INDEX 561 A Access to U.S. Geological Survey Water Data . . . . . . . . . . . . . . 30 Accuracy of field data and computed results . . . . . . . . . . . . . . . . 24 Acid neutralizing capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Acre-foot, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Adenosine triphosphate, definition of . . . . . . . . . . . . . . . . . . . . . 31 Adjuntas, Lago Garzas near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Adjuntas, Río Grande de Arecibo near . . . . . . . . . . . . . . . . . . . . 72 Adjusted discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 31 Aguada, Río Culebrinas at Margarita Dam near . . . . . . . . . . . . 474 Aguada, Río Culebrinas near . . . . . . . . . . . . . . . . . . . . . . . . . . . 479 Aguas Buenas, Río Cagüitas near . . . . . . . . . . . . . . . . . . . . . . . 288 Aguas Buenas, Río de Bayamón near . . . . . . . . . . . . . . . . . . . . 240 Algae, Blue-green, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Fire, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Green, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Algal growth potential, definition of . . . . . . . . . . . . . . . . . . . . . . 31 Alkalinity, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Annual runoff, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Annual 7-day minimum, definition of . . . . . . . . . . . . . . . . . . . . . 31 Aquifer Confined, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Unconfined, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Water table, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Arenas, Río de Bayamón at . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 Aroclor, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Arrangement of records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Artificial substrate, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 31 Ash mass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Aspect, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B Bacteria, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Enterococcus, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 35 Escherichia coli, definition of . . . . . . . . . . . . . . . . . . . . . . . 35 Fecal coliform, definition of . . . . . . . . . . . . . . . . . . . . . . . . 36 Fecal streptococcal, definition of . . . . . . . . . . . . . . . . . . . . . 36 Total coliform, definition of . . . . . . . . . . . . . . . . . . . . . . . . 46 Bahía de San Juan No. 5 at San Juan . . . . . . . . . . . . . . . . . . . . . 265 Bairoa near Caguas, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 Bankfull stage, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Base discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Base flow, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Bauta near Orocovis, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Bayamón at Arenas, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 Bayamón at Flood Channel at Bayamón, Río de . . . . . . . . . . . . 246 Bayamón below Lago de Cidra, Río de . . . . . . . . . . . . . . . . . . . 238 Bayamón near Aguas Buenas, Rio de . . . . . . . . . . . . . . . . . . . . 240 Bayamón near Bayamón, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 242 Bayamón, Río Guaynabo near . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Bayaney, Río Camuy near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Bed material, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Bedload, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Bedload discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 32 Benthic organisms, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 32 Biochemical oxygen demand, definition of . . . . . . . . . . . . . . . . . 32 Biomass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Biomass pigment ratio, definition of . . . . . . . . . . . . . . . . . . . . . . 32 Blasina near Carolina, Quebrada . . . . . . . . . . . . . . . . . . . . . . . . 268 Blue-green algae, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Boriquén, Río Turabo above . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Bottom material, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Bulk electrical conductivity, definition of . . . . . . . . . . . . . . . . . . 32 C Caguas, Río Bairoa near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 Caguas, Río Cagüitas at Highway 30 at . . . . . . . . . . . . . . . . . . 292 Caguas, Río Cagüitas at Villa Blanca at . . . . . . . . . . . . . . . . . . 290 Caguas, Río Grande de Loíza at . . . . . . . . . . . . . . . . . . . . . . . . 280 Cagüitas at Highway 30 at Caguas, Río . . . . . . . . . . . . . . . . . . 292 Cagüitas at Villa Blanca at Caguas, Río . . . . . . . . . . . . . . . . . . 290 Cagüitas near Aguas Buenas . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Campo Rico, Río Canóvanas near . . . . . . . . . . . . . . . . . . . . . . . 313 Camuy near Bayaney, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Canadian Geodetic Vertical Datum 1928, definition of . . . . . . . 32 Canal de Riego de Lajas above Majinas Filtration Plant . . . . . . 428 Canal de Riego de Lajas at . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 Canal de Riego de Lajas below Lago Loco Dam . . . . . . . . . . . 426 Canal de Riego de Lajas below Lajas Filtration Plant at Lajas . 434 Canal de Riego de Lajas below Majinas Filtration Plant . . . . . 430 Canal de Riego de Patillas above Guayama Filtration Plant . . . 372 Canal Principal de Diversiones at Lago Guajataca . . . . . . . . . . . 60 Canal Principal de Riego Valle de Lajas Basin . . . . . . . . . . . . . 432 Cañas at Río Cañas, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Canóvanas near Campo Rico, Río . . . . . . . . . . . . . . . . . . . . . . . 313 Caonillas above Lago Caonillas near Jayuya, Río . . . . . . . . . . . 118 Caonillas at Paso Palma, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Caonillas below Lago Caonillas Tunnel, Río . . . . . . . . . . . . . . 120 Carolina, Quebrada Blasina near . . . . . . . . . . . . . . . . . . . . . . . . 268 Castañer, Lago Guayo at Damsite near . . . . . . . . . . . . . . . . . . . 458 Cataño, Río Hondo at Flood Channel near . . . . . . . . . . . . . . . . 232 Cayaguas at Cerro Gordo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Cayey, Lago Carite at Gate Tower near . . . . . . . . . . . . . . . . . . 204 Cell volume, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Cells/volume, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Central Cambalache, Río Grande de Arecibo at . . . . . . . . . . . . 157 Central Pellejas, Río Pellejas above . . . . . . . . . . . . . . . . . . . . . . 80 Central Rufina, Río Guayanilla at . . . . . . . . . . . . . . . . . . . . . . . 418 Cerrillos above Lago Cerrillos near Ponce, Río . . . . . . . . . . . . 400 Cerrillos near Ponce, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 Cerro Gordo, Río Cayaguas at . . . . . . . . . . . . . . . . . . . . . . . . . . 274 Cfs-day, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Channel bars, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Charco Hondo, Río Tanamá at . . . . . . . . . . . . . . . . . . . . . . . . . 155 Chemical oxygen demand, definition of . . . . . . . . . . . . . . . . . . . 33 Chico at Providencia, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 Ciales, Río Cialitos at Highway 649 at . . . . . . . . . . . . . . . . . . . 186 Ciales, Río Grande de Manatí at . . . . . . . . . . . . . . . . . . . . . . . . 179 Ciales, Río Grande de Manatí at Highway 149 at . . . . . . . . . . . 184 Cialitos at Highway 649 at Ciales, Río . . . . . . . . . . . . . . . . . . . 186 Cibuco at Vega Baja, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Cibuco below Corozal, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 Cidra, Lago de Cidra at Damsite near . . . . . . . . . . . . . . . . . . . . 236 Classification of records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Clostridium perfringens, definition of . . . . . . . . . . . . . . . . . . . . . 33 Coamo at Hwy 14 at Coamo, Río . . . . . . . . . . . . . . . . . . . . . . . 382 Coamo near Coamo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 Coliphages, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Color unit, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Comerío, Río de la Plata at . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 Comerio, Río de la Plata near . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Conductivity, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Confined aquifer, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 33 562 INDEX—Continued Contents, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Continuous-record station, definition of . . . . . . . . . . . . . . . . . . . 33 Control, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Control structure, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Cooperation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Corozal, Río Cibuco below . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 Cubic foot per second, definition of . . . . . . . . . . . . . . . . . . . . . . 34 Cubic foot per second-day, definition of . . . . . . . . . . . . . . . . . . . 34 Cubic foot per second per square mile, definition of . . . . . . . . . . 34 Culebrinas at Highway 404 near Moca, Río . . . . . . . . . . . . . . . 472 Culebrinas at Margarita Dam near Aguada, Río . . . . . . . . . . . . 474 Culebrinas near San Sebastián, Río . . . . . . . . . . . . . . . . . . . . . . 470 Curias Dam, Quebrada Las Curias below . . . . . . . . . . . . . . . . . 250 D Daily mean suspended-sediment concentration, definition of . . . 34 Daily record station, definition of . . . . . . . . . . . . . . . . . . . . . . . . 34 Data collection and computation . . . . . . . . . . . . . . . . . . . . . . . . . 19 Data collection platform, definition of . . . . . . . . . . . . . . . . . . . . 34 Data logger, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Data presentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20, 27 Data table of daily mean values . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Definition of terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Descalabrado near Los Llanos, Río . . . . . . . . . . . . . . . . . . . . . . 386 Diatoms, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Diel, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Dissolved, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Dissolved oxygen, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Dissolved solids concentration, definition of . . . . . . . . . . . . . . . 35 Diversity index, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Drainage area, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Drainage basin, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Dry mass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Dry weight, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 E El Mango, Río Gurabo below . . . . . . . . . . . . . . . . . . . . . . . . . . 296 El Señorial, Río Piedras at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 El Verde, Quebrada Sonadora near . . . . . . . . . . . . . . . . . . . . . . 315 El Verde, Río Grande near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Embeddedness, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Enterococcus bacteria, definition of . . . . . . . . . . . . . . . . . . . . . . 35 EPT Index, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Escherichia coli (E. coli), definition of . . . . . . . . . . . . . . . . . . . . 35 Espíritu Santo near Río Grande, Río . . . . . . . . . . . . . . . . . . . . . 318 Estimated (E) value, definition of . . . . . . . . . . . . . . . . . . . . . . . . 36 Euglenoids, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Explanation of records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Extractable organic halides, definition of . . . . . . . . . . . . . . . . . . 36 F Fajardo near Fajardo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 Fecal coliform bacteria, definition of . . . . . . . . . . . . . . . . . . . . . 36 Fecal streptococcal bacteria, definition of . . . . . . . . . . . . . . . . . . 36 Fire algae, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Florida, Río Blanco near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Florida, Río Grande de Arecibo below Lago Dos Bocas near . . 141 Florida, Río Yunes at Hwy 140 near . . . . . . . . . . . . . . . . . . . . . 125 Flow, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Flow-duration percentiles, definition of . . . . . . . . . . . . . . . . . . . 36 G Gage datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Gage height, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Gage values, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Gaging station, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Gas chromatography/flame ionization detector, definition of . . . 36 Geomorphic channel units, definition of . . . . . . . . . . . . . . . . . . . 36 Grande de Añasco near Lares, Río . . . . . . . . . . . . . . . . . . . . . . 460 Grande de Arecibo below Lago Dos Bocas near Florida, Río . 141 Grande de Arecibo near Adjuntas, Río . . . . . . . . . . . . . . . . . . . . 72 Grande de Arecibo near San Pedro, Río . . . . . . . . . . . . . . . . . . 143 Grande de Arecibo near Utuado, Río . . . . . . . . . . . . . . . . . . . . 100 Grande de Arecido at Central Cambalache, Río . . . . . . . . . . . . 157 Grande de Loíza at Caguas, Río . . . . . . . . . . . . . . . . . . . . . . . . 280 Grande de Loíza at Highway 183 near San Lorenzo . . . . . . . . . 276 Grande de Loíza at Quebrada Arenas, Río . . . . . . . . . . . . . . . . 270 Grande de Loíza below Damsite . . . . . . . . . . . . . . . . . . . . . . . . 309 Grande de Loíza below Trujillo Alto, Río . . . . . . . . . . . . . . . . . 311 Grande de Manati near Morovis, Río . . . . . . . . . . . . . . . . . . . . 170 Grande de Manatí at Highway 149 at Ciales, Río . . . . . . . . . . . 184 Grande de Manatí at Highway 2 near Manatí, Río . . . . . . . . . . 188 Grande de Manatí, Río near Morovis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Grande de Manatí, Río, at Ciales . . . . . . . . . . . . . . . . . . . . . . . . 179 Grande de Patillas near Patillas, Río . . . . . . . . . . . . . . . . . . . . . 364 Grande near El Verde, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Green algae, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Grid showing system for numbering wells and miscellaneous sites (latitude and longitude) . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Ground water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Ground-water levels at selected wells in Puerto Rico and the U.S. Virgin Islands, graphs showing . . . . . . . . . . . . . . . . . . . . . 7 Ground-water levels, records of . . . . . . . . . . . . . . . . . . . . . . . . . 28 Ground-water records for Puerto Rico . . . . . . . . . . . . . . . . . . . 481 Ground-water records for USVI . . . . . . . . . . . . . . . . . . . . . . . . 553 Ground-water stations in Puerto Rico, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Ground-water stations in the U.S. Virgin Islands, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18, 55 Ground-water stations in the U.S. Virgin Islands, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Guabá near Naguabo, Quebrada . . . . . . . . . . . . . . . . . . . . . . . . 342 Guadiana near Guadiana, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 216 Guadiana near Naranjito, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 221 Guajataca above mouth near Quebradillas, Río . . . . . . . . . . . . . 62 Guanajibo near Hormigueros, Río . . . . . . . . . . . . . . . . . . . . . . . 451 Guanajibo near San Germán, Río . . . . . . . . . . . . . . . . . . . . . . . 442 Guánica, Río Loco at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 Guayanés above mouth at Playa de Guayanés, Río . . . . . . . . . . 356 Guayanés at Yabucoa, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Guayanilla at Central Rufina, Río . . . . . . . . . . . . . . . . . . . . . . . 418 Guayanilla near Guayanilla, Río . . . . . . . . . . . . . . . . . . . . . . . . 416 Guaynabo near Bayamón, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Gurabo at Gurabo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Gurabo below El Mango,Río . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 Gurabo near Gurabo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 H Habitat, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Habitat quality index, definition of . . . . . . . . . . . . . . . . . . . . . . . 37 563 INDEX—Continued Hacienda El Progreso, Río Viví below . . . . . . . . . . . . . . . . . . . . 92 Hardness, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Hato Rey, Río Piedras at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 Hato Rey, Río Piedras at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 High tide, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Highest ground-water levels recorded during 2003 water year and previous high ground-water levels at selected wells in Puerto Rico, table showing . . . . . . . . . . . . . . . . . . . . . . 8 Hilsenhoff’s Biotic Index, definition of . . . . . . . . . . . . . . . . . . . . 37 Hondo at Flood Channel near Cataño, Río . . . . . . . . . . . . . . . . 232 Horizontal datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Hormigueros, Río Guanajibo near . . . . . . . . . . . . . . . . . . . . . . . 451 Hormigueros, Río Rosario near . . . . . . . . . . . . . . . . . . . . . . . . . 444 Humacao at Highway 3 at Humacao, Río . . . . . . . . . . . . . . . . . 352 Humacao at Las Piedras, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 Hydrologic index stations, definition of . . . . . . . . . . . . . . . . . . . 37 Hydrologic unit, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 I Icacos near Naguabo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 Identification numbers, stations . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Identifying estimated daily discharge . . . . . . . . . . . . . . . . . . . . . 24 Inabón at Real Abajo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 Inch, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Instantaneous discharge, definition of . . . . . . . . . . . . . . . . . . . . . 37 International Boundary Commission Survey Datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Island, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Islandwide monthly rainfall for the water year 2001 and annual averages for the 30-year reference period, 1961-1990, table showing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 J Jacaguas at Juana Díaz, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 Jauca at Paso Palma, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Jayuya, Río Caonillas above Lago Caonillas near . . . . . . . . . . . 118 Jayuya, Río Saliente at Coabey near . . . . . . . . . . . . . . . . . . . . . 102 Juana Díaz, Lago Guayabal at Damsite near . . . . . . . . . . . . . . . 392 Juana Díaz, Río Jacaguas at . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 Juncos, Río Valenciano near . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 L La Plata at Comerío, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 La Plata at Highway 2 near Toa Alta . . . . . . . . . . . . . . . . . . . . . 227 La Plata at Proyecto La Plata, Río de . . . . . . . . . . . . . . . . . . . . 206 La Plata below La Plata Dam, Río . . . . . . . . . . . . . . . . . . . . . . . 225 La Plena, Río Majada at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 Laboratory measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Laboratory reporting level, definition of . . . . . . . . . . . . . . . . . . . 38 Lago Caonillas Tunnel, Río Caonillas below . . . . . . . . . . . . . . 120 Lago Carite at Gate Tower near Cayey . . . . . . . . . . . . . . . . . . . 204 Lago Cerrillos at Damsite near Ponce . . . . . . . . . . . . . . . . . . . . 402 Lago Cerrillos near Ponce, Río Cerrillos above . . . . . . . . . . . . 400 Lago de Cidra at Damsite near Cidra . . . . . . . . . . . . . . . . . . . . . 236 Lago de Cidra, Río de Bayamón below . . . . . . . . . . . . . . . . . . . 238 Lago de Guajataca, Canal Principal de Diversiones at . . . . . . . . 60 Lago de Matrullas at Damsite near Orocovis . . . . . . . . . . . . . . 175 Lago Dos Bocas at Damsite near Utuado . . . . . . . . . . . . . . . . . 139 Lago Dos Bocas, Río Limón above . . . . . . . . . . . . . . . . . . . . . . 131 Lago El Guineo at Damsite near Villalba . . . . . . . . . . . . . . . . . 173 Lago Garzas near Adjuntas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 Lago Guajataca at Damsite near Quebradillas . . . . . . . . . . . . . . . 58 Lago Guayabal at Damsite near Juana Díaz . . . . . . . . . . . . . . . 392 Lago Guayo at Damsite near Castañer . . . . . . . . . . . . . . . . . . . 458 Lago La Plata at Damsite near Toa Alta . . . . . . . . . . . . . . . . . . 223 Lago Las Curias at Damsite near Río Piedras . . . . . . . . . . . . . . 248 Lago Loco at Damsite near Yauco . . . . . . . . . . . . . . . . . . . . . . 424 Lago Loíza at Damsite near Trujillo Alto . . . . . . . . . . . . . . . . . 306 Lago Lucchetti at Damsite near Yauco . . . . . . . . . . . . . . . . . . . 420 Lago Patillas at Damsite near Patillas . . . . . . . . . . . . . . . . . . . . 370 Lago Toa Vaca at Damsite near Villalba . . . . . . . . . . . . . . . . . . 390 Lago Toa Vaca, Río Toa Vaca above . . . . . . . . . . . . . . . . . . . . 388 Laguna Tortuguero outlet near Vega Baja . . . . . . . . . . . . . . . . . 192 Lajas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 Lajas, Canal de Riego de Lajas . . . . . . . . . . . . . . . . . . . . . . . . . 436 Lajas, Canal de Riego de Lajas below Lajas Filtration Plant at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 Lajas, Canal de Riego de Lajas Filtration Plant at . . . . . . . . . . . 432 Land-surface datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . 38 Lapa near Rabo del Buey, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 378 Lares, Río Grande de Añasco near . . . . . . . . . . . . . . . . . . . . . . 460 Las Piedras, Río Humacao at . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 Latent heat flux, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Light-attenuation coefficient, definition of . . . . . . . . . . . . . . . . . 38 Limón above Lago Dos Bocas, Río . . . . . . . . . . . . . . . . . . . . . . 131 Lipid, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Lizas, Río Maunabo at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 Location of ground-water stations in Puerto Rico . . . . . . . . . . . . 17 Location of maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico. . . 10 Location of maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico. . . 11 Location of Río Cibuco basin . . . . . . . . . . . . . . . . . . . . . . . . . . 193 Location of Río Culebrinas basin . . . . . . . . . . . . . . . . . . . . . . . 469 Location of Río de la Plata basin . . . . . . . . . . . . . . . . . . . . . . . . 203 Location of Río Grande de Arecibo basin . . . . . . . . . . . . . . . . . . 69 Location of Río Grande de Loíza basin . . . . . . . . . . . . . . . . . . . 267 Location of Río Grande de Manatí basin . . . . . . . . . . . . . . . . . . 161 Location of Río Guanajibo basin . . . . . . . . . . . . . . . . . . . . . . . . 441 Location of Río Hondo to Río Puerto Nuevo basins . . . . . . . . . 231 Location of Río Yagüez to Río Grande de Añasco basins . . . . 455 Location of south coast river basins -- Río Inabón to Río Loco basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 Location of south coast river basins -- Río Salinas to Río Jacaguas basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 377 Location of southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins . . . . . . . . . . . . . . . . . . . . . . . 349 Location of surface-water stations in Puerto Rico. . . . . . . . . . . . 15 Location of surface-water stations in the U.S. Virgin Islands. . . 18 Location of water-quality stations in PR . . . . . . . . . . . . . . . . . . . 16 Locations of Northeastern river basins -- Río Herrera to Río Antón Ruíz basins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 317 Long-term method detection level, definition of . . . . . . . . . . . . . 38 Los Llanos, Río Descalabrado near . . . . . . . . . . . . . . . . . . . . . . 386 Low flow, 7-day, 10-year, definition of . . . . . . . . . . . . . . . . . . . 43 Low tide, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Lowest ground-water levels recorded during 2003 water year and previous high ground-water levels at selected wells in Puerto Rico, table showing . . . . . . . . . . . . . . . . . . . . . 8 M Macrophytes, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Majada at La Plena, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 564 INDEX—Continued Majinas Filtration Plant, Canal de Riego de Lajas above . . . . . 428 Majinas Filtration Plant, Canal de Riego de Lajas below . . . . . 430 Mameyes at Mameyes, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Mameyes near Sabana, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 Mameyes, Río Mameyes at . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 Manatí, Río Grande de Manatí at Highway 2 near . . . . . . . . . . 188 Marín near Patillas, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Maunabo at Lizas, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 Maunabo at Maunabo, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 360 Maximum concentrations of fecal coliform bacteria at the water-quality sampling sites in Puerto Rico, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Maximum concentrations of fecal streptococci bacteria at the water-quality sampling sites in Puerto Rico, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Mean concentration of suspended sediment, definition of . . . . . 38 Mean discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Mean high tide, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Mean low tide, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Mean sea level, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Measuring point, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Megahertz, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Membrane filter, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Metamorphic stage, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 39 Method detection limit, definition of . . . . . . . . . . . . . . . . . . . . . . 39 Method of Cubatures, definition of . . . . . . . . . . . . . . . . . . . . . . . 39 Methylene blue active substances, definition of . . . . . . . . . . . . . 39 Micrograms per gram, definition of . . . . . . . . . . . . . . . . . . . . . . . 39 Micrograms per kilogram, definition of . . . . . . . . . . . . . . . . . . . 39 Micrograms per liter, definition of . . . . . . . . . . . . . . . . . . . . . . . 39 Microsiemens per centimeter, definition of . . . . . . . . . . . . . . . . . 39 Milligrams per liter, definition of . . . . . . . . . . . . . . . . . . . . . . . . 39 Minimum reporting level, definition of . . . . . . . . . . . . . . . . . . . . 39 Miscellaneous site, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 39 Moca, Río Culebrinas at Highway 404 near . . . . . . . . . . . . . . . 472 Monthly-mean discharge of selected streams in Puerto Rico. . . . . 5 Morovis, Río Grande de Manatí near . . . . . . . . . . . . . . . . . . . . 166 Most probable number, definition of . . . . . . . . . . . . . . . . . . . . . . 39 Multiple-plate samplers, definition of . . . . . . . . . . . . . . . . . . . . . 39 N Naguabo, Quebrada Guabá near . . . . . . . . . . . . . . . . . . . . . . . . 342 Naguabo, Río Icacos near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 344 Nanograms per liter, definition of . . . . . . . . . . . . . . . . . . . . . . . . 40 Naranjito, Río Guadiana near . . . . . . . . . . . . . . . . . . . . . . . . . . 221 National Geodetic Vertical Datum of 1929, definition of . . . . . . 40 Natural substrate, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Nekton, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Nephelometric turbidity unit, definition of . . . . . . . . . . . . . . . . . 40 Networks and programs, special . . . . . . . . . . . . . . . . . . . . . . . . . 13 North American Datum of 1927, definition of . . . . . . . . . . . . . . 40 North American Datum of 1983, definition of . . . . . . . . . . . . . . 40 North American Vertical Datum of 1988, definition of . . . . . . . 40 Northeastern river basins -- Río Herrera to Río Antón Ruíz basins, map showing locations of . . . . . . . . . . . . . . . . . . . . . 317 Numbering system for wells and miscellaneous sites . . . . . . . . . 19 O On-site measurements and sample collection . . . . . . . . . . . . . . . 25 Open interval, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Organic carbon, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Organic mass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Organism count, Area, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Total, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Volume, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Organochlorine compounds, definition of . . . . . . . . . . . . . . . . . . 40 Orocovis, Lago de Matrullas at Damsite near . . . . . . . . . . . . . . 175 Orocovis, Río Bauta near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Orocovis, Río Orocovis at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 Orocovis, Río Orocovis near . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 P Parameter code, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Partial-record station, definition of . . . . . . . . . . . . . . . . . . . . . . . 40 Particle size, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Particle-size classification, definition of . . . . . . . . . . . . . . . . . . . 41 Paso Palma, Río Caonillas at . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Paso Palma, Río Jauca at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Patillas, Lago Patillas at Damsite near . . . . . . . . . . . . . . . . . . . 370 Patillas, Río Grande de Patillas near . . . . . . . . . . . . . . . . . . . . . 364 Patillas, Río Marín near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 Peak flow, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Peak stage, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Pellejas above Central Pellejas, Río . . . . . . . . . . . . . . . . . . . . . . 80 Percent composition, definition of . . . . . . . . . . . . . . . . . . . . . . . . 41 Percent of total, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Percent shading, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Periodic-record station, definition of . . . . . . . . . . . . . . . . . . . . . . 41 Periphyton, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Pesticides, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 pH, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Phytoplankton, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Picocurie, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Piedras at El Señorial, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 Plankton, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Polychlorinated biphenyls, definition of . . . . . . . . . . . . . . . . . . . 42 Polychlorinated naphthalenes, definition of . . . . . . . . . . . . . . . . 42 Ponce, Lago Cerrillos at Damsite near . . . . . . . . . . . . . . . . . . . 402 Ponce, Río Cerrillos above Lago Cerrillos near . . . . . . . . . . . . 400 Ponce, Río Cerrillos near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 Ponce, Río Portugués at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 Ponce, Río Portugués at Highway 14 at . . . . . . . . . . . . . . . . . . 412 Ponce, Río Portugués near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410 Pool, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Portugués at Highway 14 at Ponce, Río . . . . . . . . . . . . . . . . . . 412 Portugués at Ponce, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 Portugues at Tibes, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Portugués near Ponce, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 410 Precipitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii Primary productivity, definition of . . . . . . . . . . . . . . . . . . . . . . . 42 Carbon method, definition of . . . . . . . . . . . . . . . . . . . . . . . . 42 Oxygen method, definition of . . . . . . . . . . . . . . . . . . . . . . . 42 Programs, special networks and . . . . . . . . . . . . . . . . . . . . . . . . . 13 Providencia, Río Chico at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 362 Proyecto La Plata, Río de la Plata at . . . . . . . . . . . . . . . . . . . . . 206 Publications on Techniques of Water-Resources Investigations . 49 Q Quality-of-Water Records for Puerto Rico, surface-and . . . . . . . 53 Quebrada Arenas, Río Grande de Loíza at . . . . . . . . . . . . . . . . 270 Quebrada Las Curias below Las Curias Dam . . . . . . . . . . . . . . 250 Quebradillas, Lago Guajataca at Damsite near . . . . . . . . . . . . . . 58 565 INDEX—Continued Quebradillas, Río Guajataca above mouth near . . . . . . . . . . . . . . 62 R Rabo del Buey, Río Lapa near . . . . . . . . . . . . . . . . . . . . . . . . . . 378 Radioisotopes, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Reach, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Real Abajo, Río Inabón at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 398 Records of Ground-Water Levels . . . . . . . . . . . . . . . . . . . . . . . . 28 Records of stage and water discharge . . . . . . . . . . . . . . . . . . . . . 19 Records of surface-water quality . . . . . . . . . . . . . . . . . . . . . . . . . 25 Records, explanation of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Recoverable from bed (bottom) material, definition of . . . . . . . . 42 Recurrence interval, definition of . . . . . . . . . . . . . . . . . . . . . . . . 43 Replicate samples, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Return period, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Ri . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 Riffle, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Río Blanco near Florida . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 346 Rio Camuy basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 Río Cañas, Río Cañas at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 Río Cibuco basin, map showing location of . . . . . . . . . . . . . . . 193 Río Culebrinas basin, map showing location of . . . . . . . . . . . . 469 Río de la Plata basin, map showing location of . . . . . . . . . . . . . 203 Río de la Plata near Comerio . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Río Grande de Arecibo above Utuado . . . . . . . . . . . . . . . . . . . . . 86 Río Grande de Arecibo basin, map showing location of . . . . . . . 69 Río Grande de Arecibo below Utuado . . . . . . . . . . . . . . . . . . . . . 94 Río Grande de Loíza basin, map showing location of . . . . . . . . 267 Río Grande de Manatí basin, map showing location of . . . . . . . 161 Río Grande, Río Espíritu Santo near . . . . . . . . . . . . . . . . . . . . . 318 Rio Guajataca basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Río Guanajibo basin, map showing location of . . . . . . . . . . . . . 441 Río Hondo to Río Puerto Nuevo basins, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 Río Limón above Lagos Dos Bocas . . . . . . . . . . . . . . . . . . . . . 133 Río Loco at Guánica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 Río Piedras at Hato Rey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 Río Piedras, at Hato Rey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 Río Piedras, Lago Las Curias at Damsite near . . . . . . . . . . . . . 248 Río Saliente at Coabey near Jayuya . . . . . . . . . . . . . . . . . . . . . . 102 Río Yagüez to Río Grande de Añasco basins, map showing locations of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 Río Yauco above Diversion Monserrate near Yauco . . . . . . . . 422 River mileage, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Rosario near Hormigueros, Río . . . . . . . . . . . . . . . . . . . . . . . . . 444 Run, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Runoff, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 S Sabana at Sabana, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Sabana, Río Mameyes near . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 Salvatierra near San Lorenzo, Quebrada . . . . . . . . . . . . . . . . . . 272 San Germán, Río Guanajibo near . . . . . . . . . . . . . . . . . . . . . . . 442 San Juan, Bahía de San Juan No. 5 at . . . . . . . . . . . . . . . . . . . . 265 San Lorenzo, Quebrada Salvatierra near . . . . . . . . . . . . . . . . . . 272 San Lorenzo, Río Grande de Loíza at Highway 183 near . . . . . 276 San Pedro, Río Grande de Arecibo near . . . . . . . . . . . . . . . . . . 143 San Sebastián, Río Culebrinas near . . . . . . . . . . . . . . . . . . . . . . 470 Screened interval, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Sea level, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Sediment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Sediment, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Sensible heat flux, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Seven-day, 10-year low flow, definition of . . . . . . . . . . . . . . . . . 44 Shelves, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Sodium adsorption ratio, definition of . . . . . . . . . . . . . . . . . . . . . 44 Soil heat flux, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Soil-water content, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 44 Sonadora near El Verde,Quebrada . . . . . . . . . . . . . . . . . . . . . . 315 South coast river basins -- Río Inabón to Río Loco basins, map showing locations of . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 South coast river basins -- Río Salinas to Río Jacaguas basins, map showing locations of . . . . . . . . . . . . . . . . . . . . . 377 Southeastern river basins -- Río Humacao to Quebrada Aguas Verdes basins, map showing locations of . . . . . . . . . . 349 Special Networks and programs . . . . . . . . . . . . . . . . . . . . . . . . . 13 Specific electrical conductance (conductivity), definition of . . . 44 Stable isotope ratio, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 44 Stage, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Stage-discharge relation, definition of . . . . . . . . . . . . . . . . . . . . . 44 Station Identification Numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Station manuscript . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Statistics of montly mean data . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Streamflow, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Substrate, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Artificial, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Natural, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Substrate embeddedness class, definition of . . . . . . . . . . . . . . . . 44 Summary of Hydrologic Conditions . . . . . . . . . . . . . . . . . . . . . . . 3 Summary statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Surface and Quality-of-Water Records for Puerto Rico . . . . . . . 53 Surface area of a lake, definition of . . . . . . . . . . . . . . . . . . . . . . . 44 Surface water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Surface-water quality, records of . . . . . . . . . . . . . . . . . . . . . . . . . 25 Surface-water stations in Puerto Rico, map showing location of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Surficial bed material, definition of . . . . . . . . . . . . . . . . . . . . . . . 44 Surrogate, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Suspended, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Recoverable, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Total, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Suspended sediment, definition of . . . . . . . . . . . . . . . . . . . . . . . . 45 Suspended-sediment concentration, definition of . . . . . . . . . . . . 45 Suspended-sediment discharge, definition of . . . . . . . . . . . . . . . 45 Suspended-sediment load, definition of . . . . . . . . . . . . . . . . . . . 45 Suspended solids, total residue at 105 °C concentration, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Synoptic studies, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 T Tanamá at Charco Hondo, Río . . . . . . . . . . . . . . . . . . . . . . . . . 155 Tanamá near Utuado Río . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Taxa (Species) richness, definition of . . . . . . . . . . . . . . . . . . . . . 45 Taxonomy, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Techniques of Water-Resources Investigations, publications on 49 Thalweg, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Thermograph, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Tibes, Río Portugues at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 408 Time-weighted average, definition of . . . . . . . . . . . . . . . . . . . . . 46 Toa Alta, Lago La Plata at Damsite near . . . . . . . . . . . . . . . . . . 223 Toa Alta, Río de la Plata at Highway 2 near . . . . . . . . . . . . . . . 227 Toa Vaca above Lago Toa Vaca, Río . . . . . . . . . . . . . . . . . . . . 388 Tons per acre-foot, definition of . . . . . . . . . . . . . . . . . . . . . . . . . 46 Tons per day, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 566 V INDEX—Continued Total, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Total coliform bacteria, definition of . . . . . . . . . . . . . . . . . . . . . . 46 Total discharge, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Total in bottom material, definition of . . . . . . . . . . . . . . . . . . . . . 46 Total length, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Total load, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Total organism count, definition of . . . . . . . . . . . . . . . . . . . . . . . 47 Total recoverable, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Total sediment discharge, definition of . . . . . . . . . . . . . . . . . . . . 47 Total sediment load, definition of . . . . . . . . . . . . . . . . . . . . . . . . 47 Transect, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Trujillo Alto, Lago Loíza at Damsite near . . . . . . . . . . . . . . . . . 306 Trujillo Alto, Río Grande de Loíza below . . . . . . . . . . . . . . . . . 311 Turabo above Borinquén, Río . . . . . . . . . . . . . . . . . . . . . . . . . . 278 Turbidity, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 U U.S Geological Survey Water Data, Access to . . . . . . . . . . . . . . 30 Ultraviolet (UV) absorbance (absorption), definition of . . . . . . . 47 Unconfined aquifer, definition of . . . . . . . . . . . . . . . . . . . . . . . . 47 Utuado, Lago Dos Bocas at Damsite near . . . . . . . . . . . . . . . . . 139 Utuado, Río Grande de Arecibo above . . . . . . . . . . . . . . . . . . . . 86 Utuado, Río Grande de Arecibo below . . . . . . . . . . . . . . . . . . . . 94 Utuado, Río Grande de Arecibo near . . . . . . . . . . . . . . . . . . . . . 100 Utuado, Río Tanamá near . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 Valenciano near Juncos, Río . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 Vega Baja, Laguna Tortuguero outlet near . . . . . . . . . . . . . . . . 192 Vega Baja, Río Cibuco at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 Vertical datum, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Villalba, Lago El Guineo at Damsite near . . . . . . . . . . . . . . . . . 173 Villalba, Lago Toa Vaca at Damsite near . . . . . . . . . . . . . . . . . 390 Viví below Hacienda El Progreso, Río . . . . . . . . . . . . . . . . . . . . 92 Volatile mass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Volatile organic compounds, definition of . . . . . . . . . . . . . . . . . 47 W Water quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Water table, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Water-table aquifer, definition of . . . . . . . . . . . . . . . . . . . . . . . . 48 Water temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Water year, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Water-discharge, records of stage and . . . . . . . . . . . . . . . . . . . . . 19 Water-quality stations in PR, map showing location of . . . . . . . 16 Water-Resources Investigations, publications on Techniques of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Watershed, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 WDR, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Weighted average, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Wells - Puerto Rico Camuy Basin, Río Well 1026 - Zanja 4 . . . . . . . . . . . . . . . . . . . . . . . 484 Cibuco Basin, Río Well 1102 - Piezometer Tortuguero 3 . . . . . . . . . . 496 Well 211 - Rosario 2 . . . . . . . . . . . . . . . . . . . . . . 497 Well 213 - Pampano 2 . . . . . . . . . . . . . . . . . . . . . 499 Well 70 - Sabana Hoyos . . . . . . . . . . . . . . . . . . . . 498 Grande de Arecibo Basin, Río Well 1051 - Barreto 1 . . . . . . . . . . . . . . . . . . . . . 485 Well 1052 - Encantada . . . . . . . . . . . . . . . . . . . . . 487 Well 1053 - Tiburones . . . . . . . . . . . . . . . . . . . . . 488 Well 1057 - PRASA Florida 1 . . . . . . . . . . . . . . . 491 Well 204 - Gilberto Rivera . . . . . . . . . . . . . . . . . . 486 Grande de Arecibó Basin, Río Well 1056 - Santana 1 . . . . . . . . . . . . . . . . . . . . . 490 Grande de Manatí Basin, Río Well 1076 - Piezometer Hill 2 . . . . . . . . . . . . . . . 494 Well 205 - NC-5 Cruce Dávila . . . . . . . . . . . . . . . 492 Well 210 - Gelo Martínez . . . . . . . . . . . . . . . . . . 495 Guajataca Basin, Río Well 165 - Saltos 1 . . . . . . . . . . . . . . . . . . . . . . . 482 Well 202 - Carmelo Barreto García . . . . . . . . . . . . 483 Hondo to Río Puerto Nuevo Basins, Río Well 1153 - Piezometer Salud Mental 1 . . . . . . . . 509 Well 1154 - Piezometer Alsacia 2 . . . . . . . . . . . . . 510 Well 1158 - Piezometer Jardín Botánico 3 . . . . . . . 511 Well 1159 - Piezometer Ft. Buchanan 1 . . . . . . . . 512 Well 219 - Buchanan Park Well . . . . . . . . . . . . . . 507 Well 652 - Piezometer USGS Building 652 . . . . . . 508 Humacao to Quebrada Aguas Verdes Basins, Río Well 1228 - Algarrobos Domestic . . . . . . . . . . . . 522 Well 1229 - Barranca Dug . . . . . . . . . . . . . . . . . . 523 Well 1230 - Phillips Petroleum 13 . . . . . . . . . . . . 524 Well 1233 - Piezometer Aguirre HW 5B . . . . . . . . 526 Well 1239 - Jobos . . . . . . . . . . . . . . . . . . . . . . . . 527 Well 6 - Juana 5 . . . . . . . . . . . . . . . . . . . . . . . . . 525 Inabón to Río Loco Basins, Río Well 1276 - Constancia 3 . . . . . . . . . . . . . . . . . . . 542 Well 141 - Restaurada 8A . . . . . . . . . . . . . . . . . . 541 La Plata Basin, Río de Well 1127 - Piezometer Santa Rosa USGS 2 . . . . . 500 Well 1128 - Piezometer Maguayo USGS 2 . . . . . . 501 Well 1130 - Piezometer Higuillar USGS 4 . . . . . . 502 Well 1132 - Piezometer San Antonio USGS 3 . . . . 503 Well 1133 - Piezometer USGS 1, Toa Baja . . . . . . 504 Well 216 - Campanilla Navy Well . . . . . . . . . . . . 505 Salinas to Río Jacaguas Basins, Río Well 1251 - Coqui Battery 1 . . . . . . . . . . . . . . . . 528 Well 1254 - Piezometer USGS D . . . . . . . . . . . . . 530 Well 1256 - Godreau 7 . . . . . . . . . . . . . . . . . . . . 531 Well 1257 - Paso Seco 7 . . . . . . . . . . . . . . . . . . . 532 Well 1261 - Piezometer A RASA . . . . . . . . . . . . . 537 Well 1262 - Piezometer C RASA . . . . . . . . . . . . . 538 Well 87 - Alomar 1 . . . . . . . . . . . . . . . . . . . . . . . 534 Wells - U.S. Virgin Islands St. Croix Well 13 - WAPA-17 . . . . . . . . . . . . . . . . . . . . . . 556 Well 2 - USGS-10, Fairplains 2 . . . . . . . . . . . . . . 554 Well 3 - Golden Grove 6 . . . . . . . . . . . . . . . . . . . 555 St. John Well 11- Guinea Gut . . . . . . . . . . . . . . . . . . . . . . 560 St. Thomas Well 6 - Grade School 3 . . . . . . . . . . . . . . . . . . . 558 Well 8 - Kirwan Terrace, VIEO-6 . . . . . . . . . . . . . 559 Wells Puerto Rico Culebrinas Basin, Río Well 1352 - Rincón 4 . . . . . . . . . . . . . . . . . . . . . 550 Well 200 - Aguadilla Cement North . . . . . . . . . . . 551 Grande de Loíza Basin, Río Well 1176 - Piezometer CJ 19A . . . . . . . . . . . . . . 513 Well 1177 - Piezometer Caguas-Juncos 11 . . . . . . 514 Well 1179 - Piezometer Caguas-Juncos 15 . . . . . . 515 Well 222 - Piezometer Campo Rico TW-1 . . . . . . 516 567 INDEX—Continued Guanajibo Basin, Río Well 1258 - Cabrera 1 . . . . . . . . . . . . . . . . . . . . . 535 Well 1301 - PRASA 1 Cabo Rojo . . . . . . . . . . . . . 548 Well 1260 - Bauzá 1 . . . . . . . . . . . . . . . . . . . . . . 536 Well 143 - Vivoni-Col Amistad . . . . . . . . . . . . . . 547 Well 1263 - Jobitos Battery . . . . . . . . . . . . . . . . . 540 Herrera to Río Antón Ruiz Basins, Río Well 146 - Alomar Oeste . . . . . . . . . . . . . . . . . . . 539 Well 1203 - Piezometer Carlos Arroyo 1 . . . . . . . . 517 Wet mass, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Well 1205 - Piezometer USGS RP-4 . . . . . . . . . . . 518 Wet weight, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Well 1207 - Piezometer RF-12 . . . . . . . . . . . . . . . 519 WSP, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Well 1208 - Piezometer Quebrada Mata de Platanos 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520 Y Humacao to Quebrada Aguas Verdes Basins, Río Yabucoa, Río Guayanés at . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 354 Well 96 - Yabucoa 7 . . . . . . . . . . . . . . . . . . . . . . 521 Yauco, Canal de Riego de Lajas below Lago Loco Dam . . . . . 426 Inabón to Río Loco Basins, Río Yauco, Lago Loco at Damsite near . . . . . . . . . . . . . . . . . . . . . . 424 Well 1277 - Albergue de Niños . . . . . . . . . . . . . . . 544 Yauco, Lago Lucchetti at Damsite near . . . . . . . . . . . . . . . . . . 420 Well 1278 - Luciano Ventura . . . . . . . . . . . . . . . . 545 Yauco, Río Yauco above Diversion Monserrate near . . . . . . . . 422 Well 132 - Pittsburg Plate Glass 4, Yauco 2 . . . . . . 546 Yunes at Hwy 140 near Florida, Río . . . . . . . . . . . . . . . . . . . . . 125 La Plata Basin, Río de Well 1134 - Minima . . . . . . . . . . . . . . . . . . . . . . 506 Z Salinas to Río Jacaguas Basins, Río Zooplankton, definition of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Well 1253 - Piezometer RM 10 . . . . . . . . . . . . . . . 529