Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1983 St. Thomas Culebii 2PR CZIC*11 St. John Vieques. PR C= ° VIRGIN ISLANDS St. Crola U.S. GEOLOGICAL SURVEY WATER DATA REPORT PR-83-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies CALENDAR FOR WATER YEAR 1983 1982 OCTOBER NOVEMBER DECEMBER SMTWTF S SMTW T F S SMTWTFS 1 2 1 2 3 4 5 6 1 2 3 4 3 4 5 6 7 8 9 7 8 9 10 11 12 13 5 6 7 8 9 10 11 10 11 12 13 14 15 16 14 15 16 17 18 19 20 12 13 14 15 16 17 18 17 18 19 20 21 22 23 21 22 23 24 25 26 27 19 20 21 22 23 24 25 24 25 26 27 28 29 30 28 29 30 26 27 28 29 30 31 31 1983 JANUARY FEBRUARY MARCH SMTWTF S SMTWTF S SMT W T F S 1 1 2 3 4 5 1 2 3 4 5 2 3 4 5 6 7 8 6 7 8 9 10 11 12 6 7 8 9 10 11 12 9 10 11 12 13 14 15 13 14 15 16 17 18 19 13 14 15 16 17 18 19 16 17 18 19 20 21 22 20 21 22 23 24 25 26 20 21 22 23 24 25 26 23 24 25 26 27 28 29 27 28 27 28 29 30 31 30 31 APRIL MAY JUNE SMTWTFS SMTWTF S SMTWTF S 1 2 1 2 3 4 5 6 7 1 2 3 4 3 4 5 6 7 8 9 8 9 10 11 12 13 14 5 6 7 8 9 10 11 10 11 12 13 14 15 16 15 16 17 18 19 20 21 12 13 14 15 16 17 18 17 18 19 20 21 22 23 22 23 24 25 26 27 28 19 20 21 22 23 24 25 24 25 26 27 28 29 30 29 30 31 26 27 28 29 30 JULY AUGUST SEPTEMBER SMTWTFS SMTW T F S SMTWTFS 1 2 1 2 3 4 5 6 1 2 3 3 4 5 6 7 8 9 7 8 9 10 11 12 13 4 5 6 7 8 9 10 10 11 12 13 14 15 16 14 15 16 17 18 19 20 11 12 13 14 15 16 17 17 18 19 20 21 22 23 21 22 23 24 25 26 27 18 19 20 21 22 23 24 24 25 26 27 28 29 30 28 29 30 31 25 26 27 28 29 30 31 Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1983 by Russell E. Curtis, Senen Guzman-Rios, and Pedro L. Diaz Culebra R St. Thomas C:ZZ (*I St. John Vieques, PR VIRGIN ISLANDS St. Cr. U.S. GEOLOGICAL SURVEY WATER DATA REPORT PR-83-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies II UNITED STATES DEPARTMENT OF THE INTERIOR WILLIAM P. CLARK, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information write to: Chief, Caribbean District, WRD U.S. Geological Survey GPO Box 4424 San Juan, PR 00936 (Telephone: (809) 753-4414) 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, and the 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 assem­ bled the report. In addition to the authors, who had primary responsibility for assuring that the information contained herein is accurate, complete and adheres to Geological Survey policy and established guidelines, the following personnel contributed significantly to the collection, processing and tabula­ tions of the data: Zaida Aquino de Diaz Ralph Gonzalez George Arroyo Felipe Hernandez Eloy ColOn-Dieppa Carlos Martinez Margarita ConcepciOn Rafael Pena-Cortes Rene Garcia Luis Santiago-Rivera Jose R. Gonzalez Pedro Vazquez Carmen A. Garcia typed the text of the report. Jose Alicea-Ortiz and Gilberto Pena-Cruz prepared the illustrations. This report was prepared in cooperation with agencies of the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and with other federal agencies, under the general supervision of Ferdinand Quinones, District Chief, Caribbean District, San Juan, Puerto Rico. IV 50272 - 1 1 1. REPORT NO. 2. I. Recipient's Accession No. REPORT DOCUMENTATION PAGE USGS/WRD/HD-84/027 4. Title and Subtitle S. Report Date April 1984 Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 1983. 6. 7. Author(s) S. Performing Organization Rept. No. Russell E. Curtis, Senen Guzmin-Rios and Pedro Diaz USGS-WDR-PR-83-1 9. Performing Organization Name and Address 10. Project/Task/Work Unit No. U.S. Geological Survey, Water Resources Division GPO Box 4424 11. Contract(C) or Grant(G) No. San Juan, Puerto Rico 00936 (C) (G) 12. Sponsoring Organization Name and Address 13. Type of Report & Period Covered U.S. Geological Survey, Water Resources Division Final. Oct. 1, 1982 to GPO Box 4424 Sept. 30, 1983 San Juan, Puerto Rico 00936 14. 15. Supplementary Notes Prepared in cooperation with the Commonwealth of Puerto Rico, the Territory of the U.S. Virgin Islands and other agencies. 16. Abstract (Limit 200 words) Water-resources data for surface-water, quality-of-water, and ground-water records for the 1983 water year for Puerto Rico and the U.S. Virgin Islands, consist of records of discharge, water quality of streams, and water levels of wells. This report contains discharge records for 46 gaging stations; stage only records for three lakes; water quality for 63 streamflow or lagoon sites, 13 partial-record sites, 6 miscellaneous sites, and 10 wells; and water levels for 97 observation wells. Also included are data for 131 low-flow and 1 crest-stage partial record-stations. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and cooperating local and federal agencies in Puerto Rico and the U.S. Virgin Islands. 17. Document Analysis a. Descriptors *Puerto Rico, *U.S. Virgin Islands, *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data, Sediments, Streamflow, Water analysis, Water levels, Water quality, Lakes. b. Identifier/Open•Ended Terms Puerto Rico, U.S. Virgin Islands, Sampling sites. c. COSATI Field/Group 18. Availability Statement No restriction on distribution. 19. Security Class (This Report) UNCLASSIFIED 21. No. of Pages 308 20. Security Class (This Page) UNCLASSIFIED 22. Price (See ANSI-Z39.18) See Instructions on Reverse OPTIONAL FORM 272 (4-77) (Formerly NTIS-351 Department of Commerce REPORT : PUBLIC WATER SUPPLIES IN PUERTO RICO, 1983, by Fernando aimez­ G6mez, Ferdinand Quinones, and Marisol Lopez - O.F. 84-126. ERRATA Please make the following change in the Conversion Table on page VI: Million gallons per year Cubic feet per second 3 (Mgal/yr) 0.00424 (ft /s) V CONTENTS Page Preface III Contents V Illustrations V Tables VI Introduction 1 Cooperation 1 Summary of hydrologic conditions 2 Definition of terms 12 Downstream order and station numbers 19 Numbering system for wells and miscellaneous sites 20 Special networks and programs 20 Explanation of stage and water-discharge records 21 Collection and computation of data 21 Accuracy of field data and computed results 24 Other data available 25 Explanation of water-quality records 25 Collection and examination of data 25 Water analysis 26 Water temperature 26 Sediment 27 Explanation of ground-water level records 27 Collection of the data 27 Surface- and quality-of-water records for Puerto Rico 29 Discharge at partial-record stations in Puerto Rico 195 Analyses of samples collected at water-quality partial-record stations in Puerto Rico 207 Ground-water records for Puerto Rico 237 Surface-water records for the U.S. Virgin Islands 267 Ground-Water records for the U.S. Virgin Islands 279 Index 297 ILLUSTRATIONS Figure 1. Graph showing comparison of average discharge for 1983 water year with median discharge for period of record for station 50038100 3 2. Graph showing comparison of average discharge for 1983 water year with median discharge for period of record for station 50071000 4 3. Graph showing comparison of average discharge for 1983 water year with median discharge for period of record for station 50112500 5 4. Graph showing comparison of average discharge for 1983 water year with median discharge for period of record for station 50144000 6 5. Map showing rainfall distribution during April 18, 1983 in the U.S. Virgin Islands 7 6. System for numbering wells and miscellaneous sites (latitude and longitude) 20 VI ILLUSTRATIONS--Continued Page Figure 7. Map showing location of continuous surface-water stations in Puerto Rico 30 8. Map showing location of water-quality stations in Puerto Rico 31 9. Map showing location of low-flow partial-record stations in Eastern Puerto Rico 32 10. Map showing location of partial-record stations in Central and Western Puerto Rico 33 11. Map showing Rio Guajataca basin 35 12. Map showing Rio Camuy basin 39 13. Map showing Rio Grande de Arecibo basin 41 14. Map showing Rio Grande de Manati basin 57 15. Map showing Rio Cibuco basin 71 16. Map showing Rio de la Plata basin 81 17. Map showing Rio Hondo to Rio Puerto Nuevo basins 89 18. Map showing Rio Grande de Loiza basin 101 19. Map showing northeastern river basins--Rio Herrera to Rio AntOn Ruiz basins 117 20. Map showing southeastern river basins--Rio Humacao to Rio Seco basins 133 21. Map showing south coast river basins--Rio Salinas to Rio Jacaguas basins 149 22. Map showing south coast river basins--Rio InabOn to Rio Loco basins 151 23. Map showing Rio Guanajibo basin 169 24. Map showing Rio Yagilez and Rio Grande de Afiasco basins 177 25. Map showing Rio Culebrinas basin 189 26. Map showing location of ground-water stations 238 27. Map showing location of surface-water stations in the U.S. Virgin Islands 268 28. Map showing location of ground-water stations in the U.S. Virgin Islands 280 TABLES Table 1. Flood data for April 18, 1983 in St. Thomas and St. John, U.S. Virgin Islands 8 2. Concentrations of dissolved inorganics of NASQAN 10 3. Factors for conversion of chemical constituents in milligrams or micrograms per liter to milliequivalents per liter 15 4. Degrees Celsius (°C) to degrees Fahrenheit (°F) 26 1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 INTRODUCTION Water resources data for the 1983 water year for Puerto Rico and the U.S. Virgin Islands consists of stage, discharge, and water quality of streams; stage and water quality of lakes and lagoons; and water levels and quality of ground water. This report contains discharge records for 46 gaging stations; stage only records for three lakes; water quality for 63 streamflow or lagoon sites, 13 partial-record sites, 6 miscellaneous sites, and 10 wells; and water levels for 97 observation wells. Also included are data for 131 low-flow and 1 crest-stage partial record-stations. These data represent that part of the National Water Data System collected by the U.S. Geological Survey and coopera­ ting local and federal agencies in Puerto Rico and the U.S. Virgin Islands. Water-resources data for Puerto Rico for calendar years 1958-67 were released in a series of reports entitled "Water Records of Puerto Rico". Water- resources data for the U.S. Virgin Islands for the calendar years 1962-69 were released in a report entitled "Water Records of U.S. Virgin Islands." Included were records of streamflow, ground-water levels, and water-quality data for both surface and ground water. Beginning with the 1968 calendar year, surface-water records for Puerto Rico were released separately on an annual basis. Ground-water level records and water-quality data for surface and ground water were released in companion reports covering periods of several years. Data for the 1973-74 reports were published under separate covers. Water-resources data reports for 1975-76, 1977, 1978, 1979-80 and 1981-82 water years consist of one volume each and contain data for streamflow, water quality and ground water. These official Survey reports carry 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 report is identified as "U.S. Geological Survey Water-Data Report PR-83-1." Water Data reports are for sale by the National Technical Information Service, U.S. Department of Commerce, Springfield, Virginia, 22161. 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 Survey are: Puerto Rico Environmental Quality Board Puerto Rico Aqueduct and Sewer Authority Puerto Rico Department of Agriculture Puerto Rico Industrial Development Company Puerto Rico Department of Public Works Puerto Rico Highway Authority Puerto Rico Department of Natural Resources Puerto Rico Department of Health Puerto Rico Electric and Power Authority 2 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Puerto Rico Rice Corporation Puerto Rico Administration for Agricultural Development Puerto Rico Land Administration Center for Energy and Environment Research, University of Puerto Rico Water Resources Institute, University of Puerto Rico Water Resources Institute, College of the Virgin Islands Department of Public Works of the U.S. Virgin Islands Funds were also provided by the Corps of Engineers, U.S. Army, for the collection of records at five gaging stations published in this report. Ground-water quality data at selected sites was collected with support from the U.S. Evironmental Protection Agency. SUMMARY OF HYDROLOGIC CONDITIONS Streamflow Streamflow in Puerto Rico during the 1983 water year was generally normal in the north and east but below normal to deficient in the south and west (figs. 1 to 4). The water year began with streamflows deficient in most parts of the Island. For many areas, this was the dryest October in the last 20 years. The rivers and streams gradually returned to normal during the winter months but by late February and early March, dry conditions returned and streamflow again became deficient. The rainy season began in mid-April, resulting in the wettest month of the year with island-wide monthly average of over eight inches, almost twice the normal. Streamflow increased to above normal over the entire Island and remained high in most areas throughout the summer. No flooding of consequence occured during the year. By late summer, unusually dry weather conditions prevailed throughout Puerto Rico and by September 1983, streamflow again became deficient island-wide. Many areas experienced the dryest September in the last 20 years. Streamflow conditions in the Virgin Islands usually follow the same general pattern as Puerto Rico. The 1983 water year was no exception except for the intense rains of April 1983. On April 18th, a low-pressure trough stalled over St. Thomas and St. John and produced one of the most intense rainfall events ever recorded in this area (fig. 5). Continuous-recording rain gages operated by National Oceanic Atmospheric Administration-National Weather Service recorded intensities of up to 2.5 inches in 1 hour and a total of 16.5 inches in 19 hours. Almost instantaneous runoff caused widespread flooding near the coastlines of St. Thomas and St. John. Parts of Charlotte Amalie in St. Thomas were inundated with four feet or more of flood water and mud. Harry S. Truman Airport was flooded for two days with two to three feet of ponded water. 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NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. Figure 1.--Comparison of monthly-mean discharges for the 1983 water year with long-term medians at Rio Grande de Manati at Highway 2 near Manati, Puerto Rico (50038100). 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NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. MONTHLY Figure 2.--Comparison of monthly-mean discharges for the 1983 water year with long-term medians at Rio Fajardo near Fajardo, Puerto Rico (50071000). 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NOV. DEC. JAN. FES. MAR. APR. MAY JUNE JULY AUG. SEPT. Figure 3.--Comparison of monthly-mean discharges for the 1983 water year with long-term medians at Rio Inabon at Real Abajo, Puerto Rico (50112500). 6 MONTHLY MEANDISCHARGE. INCUBIC 2000 IIIIIIIIMOUNIMUNUOINUIOUINUMIIIIIIIIIIIIINUmmumumummlinummonmsomummommommININIMIN 11111111111111111111111111111111111111111111M1111111111111M11111111111111111110111111111111111111111111111111M111111111111 11111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 IMMEMMIMMIMM1111111111111111111MUMMUMMOMMMEMENIMMEIMIMIIIMMELOMMin IMMEMEMEHOMMEMIHNIIMMOMMEMMEIMIMEMMEENEMMEMEMEMMEMOOMM 11111111111111111111111111111iiiiiiiMMIMMOMMIIIIIIIIIIIIIIM111111.1111101111111111111111111111111111111111 111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 11 1111111111111111111111111111111111111111111111M11111111111111111111111111111111111111111111111111111111111111111111111 0 1000 W 900 c 800 a. 700 1-w 600 mommaiommismimmommemommemommEmmommommomummommommEmmommommommommommommimmummommemminummommommeim mom MM e MM mommommommommummummommommmommommommommumwr-vre-mmirrorel-wirrornrrnr7mrrlr:nr.rmimmommumumm 11. 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NOV. DEC. JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT. Figure 4.--Comparison of monthly-mean discharges for the 1983 water year with long-term medians at Rio Grande de giasco near San Sebastian, Puerto Rico (50144000). 7 65605' 65°00' 55' 64°50' 18`24' 188 20' 64°50' 45' 64°40' 64°50' 45' 40' 64°35' ST. CROIX 17°45' 0 1 2 3 4 MILES 1 I I I 17°40' (Data from NOAA (NWS)5 EXPLANATION 6 6 LINE OF EQUAL RAINFALL - Contour interval 1 Inch. .4.34 NOAA WEATHER STATION - Number means precipitation In inches. £(3450) USGS GAGING STATION AND STATION NUMBER Figure 5.--Rainfall distribution during April 18, 1983 in the U.S. Virgin Islands. TABLE 1.--Peak discharges at gaging stations in St. Thomas and St. John, U.S. Virgin Islands. co Maximum previously Maximum discharge known discharge for April 18, 1983 Drainage Period Unit Fre- Station Station ar2a of Dischirge Unit dis- Discarge dis- quency number name (mi ) record Date (ft /s) charge Time (ft /s) charge (years) St. Thomas 50252000 Bonne Resolution 1963-64, Gut at Bonne 0.49 1979-83 9-4-79 218 445 1315 1,650 3,370 100+ Resolution 50276000 Turpentine Run 1963-69 at Mariendal 2.97 1979-83 9-4-79 2,500 840 - 9,700 3,270 100+ St. John 50295000 Guinea Gut at 1963-66, Bethany 0.37 1982-83 11-4-65 111 300 - 946 2,560 100+ 9 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Damages on St. Thomas and St. John were estimated by the Federal Emergency Management Administration at 12-13 million dollars and both islands were declared eligible for Federal Disaster Aid. In contrast, rainfall on St. Croix was not unusually heavy and almost no runoff occurred. The flood peaks at the two gaging stations on St. Thomas and the gage on St. John were much higher than any previously recorded peak, (table 1). The gage on Bonne Resolution Gut in St. Thomas was the only one of the three that was not damaged by the floods. The frequency of the April 18 floods in St. Thomas was estimated from unit discharges and flood-frequency data for stations in Puerto Rico. The estimates indicate that the flood frequency exceeded significantly the 100-year recurrence interval (1 percent probability of occurring in any year). Ground Water By the end of the 1982 water year the ground-water levels in Puerto Rico increased in response to the above average rainfall on September 12-13, 1982. In some areas a maximum rise of six feet was recorded. During the months of October and November 1982 the ground-water levels declined. This trend was reversed in response to above average precipitation during late November and December. From January through March, ground-water levels declined in response to below-average rainfall and increased ground-water withdrawals for public water supply, industries and irrigation. In April, a near-stationary trough produced above normal rainfall, causing a general increase in ground-water levels with a maximum rise of six feet in the south coast alluvial aquifers. Precipitation for May and June was generally normal maintaining the ground­ water levels on an increasing trend. After this period, the ground-water levels along the north coast limestone aquifers remained practically unchanged while the south coast alluvium aquifers showed some fluctuations probably in response to irrigation demands. Elsewhere in the island the declining trend was predominant. Above normal precipitation during late August reversed this trend islandwide. The rainfall for the last two months of the 1983 water year varied from below average to normal causing a decline during September. Ground-water levels in the U.S. Virgin Islands followed a pattern similar to to Puerto Rico. During April the ground-water levels increased significantly due to the intense rainfall of April 18. Ground-water levels at some wells in St. Thomas increased almost 20 feetin response to recharge from the April floods. The other two Virgin Islands, St. John and St. Croix, reflected lesser ground-water level increases. Water-Quality The results of the surface-water sampling program during water year 1983 indicate high concentrations of fecal coliform and fecal streptoccocal bacte­ rias and some contamination with trace organic compounds in the streams. In general, the water quality of the streams in Puerto Rico was essentially the same as the previous two years. 10 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Monitoring stations located close to urban zones, industrial parks and suburban zones not served by sewerage system showed the highest concentrations in bacteria population. Fecal coliform bacteria, a microorganism present in the intestines of warm-blooded animals, and which is often used as indication of the sanitary quality of the water, was found in concentrations in the thousands of colonies per hundred milliliters of sample in many streams. At some sites, concentrations were as high as millions of colonies per hundred milliliter of sample. Examples of this are: Quebrada Blasina near Carolina (station number 50050300); Rio Chico at Central Providencia (sta. 50091800), Rio Guayanilla at Central Rufina (sta. 50124700) and Rio Bairoa near Caguas (sta. 50055400). Septic tanks, cesspools, leaks in sewage systems, run-off from beef cattle feedlots, and percolation from waste ponds appear to be the main source of bacterias in streams throughout Puerto Rico. A considerable increase in the concentration of some inorganics serves as one of the important indexes of the pollution of a body of water. The inorganics which are normally absent or nearly so in the natural environment are arsenic, cadmium, chromium, lead, mercury, selenium, and silver. These inorganics have been designated as having a detrimental effect on human health. The National Interim Primary Drinking Water Regulations (Environmental Protection Agency, 1976) fixed the maxium permissible level for those inorganics in drinking water as follows: Concentration Constituent Micrograms per Liter Arsenic 50 Cadmium 10 Chromium 50 Lead 50 Mercury 2 Selenium 10 Silver 50 Mercury is one of the most dangerous of those inorganics. This metal is used widely in electronic devices and incandescent street lights. Water samples for analyses of these inorganics were collected twice during the water year at most of the monitoring sites. At the National Stream Quality Accounting Network (NASQAN) stations, a federal funded water-quality program, the dissolved inorganics were analyzed two times a year. Some results are listed in table 2. Table 2.--Concentrations of dissolved inorganics at NASQAN Stations, micrograms per liter (ug/L). Station name Chromium Lead Mercury Rio Grande de Manati 1 2 0.2 Rio de la Plata 3 3 1.0 Rio Grande de Patillas 1 4 .3 Rio Grande de Afiasco 1 4 .1 11 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Thousands of different toxic organics are used today to control undesirable insects, weeds, rodents and fungi. These synthetic-organic pesticides can contribute significantly to the contamination of a stream or a body of water by their direct discharge, spray drift, treated land runoff, treated land erosion, atmospheric precipitation, accidental spills and leachates from garbage dumps and sanitary landfills. Water bodies may receive not only the toxic chemicals, but also the intermediary and accessory products of their synthesis. Water samples were collected once at selected sites for analyses on the most common organics. Lindane or chlordane, two synthetic organics, were detected in over 20 % of the sampled sites. The rest of the organics for which labora­ tory analyses were performed, did not exceed the analytical detection limits. In the proposed mining area, the water quality did not change significantly during the water year. Samples from two stations (Numbers 50021000, 50023000) do not show significant changes in pH, alcalinity, or concentration of selected ions. The measurements of some physical and chemical parameters can help in the determination if a body of water is fresh, salty or saline. Specific conductance, dissolved solids and chlorides concentration are among them. Water with a specific conductance around 50,000 umhos/cm and a chloride concentration of 19,300 mg/1 is said to be seawater. Dissolved solids are chiefly the mineral constituents dissolved from weathering or rocks and soils. Water containing more than 1,000 mg/1 are unsuitable for many purposes. The U.S. Geological Survey classifies the degree of salinity of these more mineralized bodies of water as follows (Swenson and Baldwin, 1965): Dissolved Solids, mg/1 Degree of salinity Less than 1,000 nonsaline 1,000 to 3,000 slightly saline 3,000 to 10,000 moderately saline 10,000 to 35,000 very saline Chloride is found in large amounts in ancient brines, seawater, sewage and industrial brines. About 300 mg/1 chloride in combination with sodium gives a salty taste to water. The maximum chloride concentration permissible in drinking water is 250 mg/1 (EPA, 1976). At Rio Hondo at Flood Channel near Catalio (50047530), and Bahia de San Juan No. 5 (50049920) salinities can fluctuate between nonsaline and very saline. 12 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 DEFINITION OF TERMS Terms related to streamflow, water-quality, and other hydrologic data as used in this report, are defined below. See also the table for converting inch- pound units to the International System of units (SI) on the inside of the back cover. Acre-foot (AC-FT, acre-ft) is the quantity of water required to cover 1 acre to a depth of 1 foot and is equivalent to 43,560 cubic feet or about 326,000 gallons or 1,233 cubic meters. Algae are mostly aquatic single-celled, colonial, or multicelled plants containing chlorophyll and lacking roots, stems, and leaves. Aquifer is a geologic formation, group of formations, or part of a formation that contains sufficient saturated permeable material to yield significant quantities of water to wells and springs. Artesian means confined and is used to describe a well in which the water level stands above the top of the aquifer, tapped by the well. A flowing artesian well is one in which the water level is above the land surface. Bacteria are microscopic unicellular organisms, typically spherical, rodlike, or spiral and threadlike in shape, often clumped into colonies. Some bacteria cause disease, 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. Fecal coliform bacteria are bacteria that are present in the intestines or feces of warm-blooded animals. They are often used as indicators of the sanitary quality of the water. In the laboratory they are defined as all organisms which produce blue colonies within 24 hours when incubated at 44.5°C + 0.2°C on M-FC medium (nutrient medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Fecal streptococcal bacteria are bacteria found also in intestines of warm-blooded animals. Their presence in water is considered to verify fecal pollution. They are characterized as grampositive, coccie bacteria which are capable of growth in brain-heart infusion broth. In the laboratory they are definedas all the organisms which produce red or pink colonies within 48 hours at 35°C + 1.0°C on M-enterococcus medium (nutri- ent medium for bacterial growth). Their concentrations are expressed as number of colonies per 100 mL of sample. Total coliform bacteria are a particular group of bacteria that are used as indicators of possible sewage pollution. They are characterized as aerobic or facultative anaerobic, gram-negative, nonspore-forming, rod- shaped bacteria which ferment lactose with gas formation within 48 hours 13 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 at 35°C. In the laboratory these bacteria are defined as the organisms which produce colonies within 24 hours when incubated at 35°C + 1.0°C on M-Endo medium (nutrient medium for bacterial growth). Their concen­ trations are expressed as number of colonies per 100 mL of sample. Bed material is the unconsolidated material of which a streambed, lake, pond,reservoir, or estuary bottom is composed. Biochemical oxygen demand (BOD) is a measure of the quantity of dissolved oxygen, in milligrams per liter, necessary for the decomposition of organic matter by microorganisms, such as bacteria. Bottom material: See Bed material. Cells/volume refers to the number of cells of any organism which is counted by using a microscope and grid or counting cell. Many planktonic organisms are multicelled and are counted according to the number contained cells per sample, usually milliliters (mL) or liters (L). Cfs-day is the volume of water represented by flow or 1 cubic foot per second for 24 hours. It is equivalent to 86,400 cubic feet, approximately 1.9835 acre-feet, about 646,000 gallons or 2,447 cubic meters. Chlorophyll refers to the green pigments of plants. Chlorophyll a and b are the two most common pigments in plants. Control designates a feature downstream from the gage that determines the stage-discharge relation at the gage. This feature may be a natural constric­ tion of the channel, an artificial structure, or a uniform cross section over a long reach of the channel. Control structure as used in this report is a structure on a stream or canal that is used to regulate the flow or stage of the stream or to prevent the intrusion of saltwater. Crest-stage station is a special form of partial-record station that records the highest stage of the stream that occurred between periodic visits to the station. A stage-discharge relation for each gage may be developed from discharge measurements made by indirect methods or by current meter. Cubic feet per second per square mile (CFSM) is the average number of cubic feet or water flowing per second from each square mile of area drained, assuming that the runoff is distributed uniformly in time and area. Cubic foot per second (cu ft/s) is the rate of discharge representing a volume of 1 cubic foot passing a given point during 1 second and is equivalent to approximately 7.48 gallons per second or 448.8 gallons per minute or 0.02832 cubic meters per second. Discharge is the volume of water (or more broadly, volume of fluid plus suspended sediment), that passes a given point within a given period of time. 14 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Mean discharge (MEAN) is the arithmetic mean of individual daily mean discharges during a specific period. Instantaneous discharge is the discharge at a particular instant of time. Dissolved refers to the amount of substance present in true chemical solution. In practice, however, the term includes all forms of substance that will pass through a 0.45-micrometer membrane filter, and thus may include some very small (colloidal) suspended particles. Analyses are performed on filtered samples. Diversity index is a numerical expression of evenness of distribution of aquatic organisms. The formula for diversity index is: n -E i log7 ni i=1 n n Where n is the number of individuals per taxon, n is the total number of individuals, and s is the total number of taxa in the sample of the community. Diversity index values range from zero, when all the organisms in the sample are the same, to some positive number, when some or all of the organisms in the sample are different. Drainage area of a stream at a specific location is that area, measured in a horizontal plane, enclosed by a topographic divide from which direct surface runoff from precipitation normally drains by gravity into the river above the specified point. Figures of drainage area given herein include all closed basins, or noncontribution areas, within the area unless otherwise noted. Drainage basin is a part of the surface of the earth that is occupied by a drainage system, which consists of a surface stream or a body of impounded surface water together with all tributary surface streams and bodies of impounded surface water. Gage height (G.H.) is the water-surface elevation referred to some arbitrary gage datum. Gage height is often used interchangeably with the more general term "stage," although gage height is more appropriate when used with a reading on a gage. Gaging station is a particular site on a stream, canal, lake, or reservoir where systematic observations of hydrologic data are obtained. Ground-water station is a well at which observations of ground-water level are made, either continuously by recorder, or periodically by hand. In addition, various chemical or physical parameters may be obtained, usually on a periodic basis. Hardness of water is a physical-chemical characteristic that is commonly recognized by the increased quantity of soap required to produce lather. It is attributable to the presence of alkaline earths (principally calcium and magnesium) and is expressed as equivalent calcium carbonate (CaCO). 15 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Micrograms per gram (ug/g) is a unit expressing the concentration of a chem­ ical element as the mass (micrograms) of the element sorbed per unit mass (gram) of sediment. Micrograms per liter (UG/L, ug/L) is a unit expressing the concentration of chemical constituents in solution as mass (micrograms) of solute per unit volume (liter) of water. One thousand micrograms per liter is equivalent to one milligram per liter. Milligrams per liter (MG/L, mg/L) is a unit for expressing the concentration of chemical consitutents in solution. Milligrams per liter represent the mass of solute per unit volume (liter) of water. Concentration of suspended sediment also is expressed in mg/L, and is based on the mass of sediment per liter of water-sediment mixture. Conversion of chemical concentrations in Mg/L to milliequivalents per liter can be done by using the factors in table 3. TABLE 3.--Factors for conversion of chemical constituents in milligrams per liter to milliequivalents per liter. Ion Aluminum (A1+3) * Ammonia as NH4+1 Barium (Ba+2) Bicarbonate (HCO3-1) Bromide (Br-1) Calcium (Ca+2) Carbonate (CO3-2) Chloride (CI-1) Chromium (Cr+6 )* Cobalt (Co+2)* Copper (Cu+2)* Cyanide (CN-1)* Fluoride (F-1) Hydrogen (H+1 ) Hydroxide (OH-1) Multiply by 0.11119 .05544 .01456 .01639 .01251 .04990 .03333 .02821 .11539 .03394 .03148 .03844 .05264 .99209 .05880 Ion Multiply by Iodide (I-1) 0.00788 Iron (Fe+3)* .05372 Lead (Pb+2)* .00965 Lithium (Li+1)* .14411 Magnesium (Mg+2) .08226 Manganese (Mn+2)* .03640 Nickel (Ni+2)* .03406 Nitrate (NO3-1) .01613 Nitrite (NO2-1) .02174 Phosphate (PO4-3) .03159 Potassium (K+1) .02557 Sodium (Na+1 ) .04350 Strontium (Sr+2)* .02283 Sulfate (SO4-2) .02082 Zinc (Zn+2)* .03060 * Constituent reported in micrograms per liter; multiply by factor and divide results by 1,000. Organism is any living entity, such as an insect, phytoplankter, or zoo­ plankter. Organism count/area refers to the number of organisms collected nnd enumerated in a sample and adjusted to the number per area habitat, usually square meters (m ), acres, or hectares. Periphyton, benthic organisms, and macrophytes are expressed in these terms. Organism count/volume refers to the number of organisms collected and enu­ merated in a sample and adjusted to the number per sample volume, usually milliliters (mL) or liters (L). Numbers of planktonic organisms can be expressed in these terms. 2 16 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Total organism count is the total number of organisms collected and enumerated in any particular sample. Partial-record station is a particular site where limited streamflow and/or water-quality data are collected systematically over a period of years for use in hydrologic analyses. Particle-size is the diameter, in millimeters (mm), of suspended sediment or bed material determined by either sieve or sedimentation methods. Sedimen­ tation methods (pipet, bottom-withdrawal tube, visual-accumulation tube) determine fall diameter of particles in either distilled water (chemically dispersed) or in native water (the river water at the time and point of sampling). Particle-size classification used in this report agrees with recommendations made by the American Geophysical Union Subcommittee on Sediment Terminology. The classification is as follows: Classification Size (mm) Method of analysis Clay 0.00024 - 0.004 Sedimentation Silt .004 - .062 Sedimentation Sand .062 - 2.0 Sedimentation or sieve Gravel 2.0 - 64.0 Sieve The particle-size distributions given in this report are not necessarily representative of all particles in transport in the stream. Most of the organic material is removed and the sample is subjected to mechanical and chemical dispersion before analysis in distilled water. Chemical dispersion is not used for native water analysis. Percent composition is a unit for expressing the ratio of a particular part of a sample or population to the total sample or population, in terms of types, numbers, mass or volume. Pesticides are chemical compounds used to control undesirable plants and animals. Major categories of pesticides include insecticides, miticides, fungicides, herbicides, and rodenticides. Insecticides and herbicides, which control insects and plants, respectively, are the two categories reported. Plankton is the community of suspended, floating, or weakly swimming organisms that live in the open water of lakes and rivers. Phytoplankton is the plant part of the plankton. They are usually microscopic and their movement is subject to the water currents. Phytoplankton growth is dependent upon solar radiation and nutrient substances. Because they are able to incorporate as well as release materials to the surrounding water, the phytoplankton have a profound effect upon the quality of the water. They are the primary food producers in the aquatic environment, and are commonly known as algae. 17 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Blue-green algae are a group of phytoplankton organisms having a blue pigment, in addition to the green pigment called chlorophyll. Blue-green often cause nuisance conditions in water. Diatoms are the unicellular or colonial algae having a siliceous shell. Their concentrations are expressed as number of cells/mL of sample. Green algae have chlorophyll pigments similar in color to those of higher green plants. Some forms produce algal mats or floating "moss" in lakes. Their concentrations are expressed as number of 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. Runoff in inches (IN, in) shows the depth to which the drainage area would be covered if all the runoff for a given time period were uniformly distributed on it. Sediment is solid material that originates mostly from disintegrated rocks and is transported by, suspended in, or deposited from water; it includes chemical and biochemical precipitates and decomposed organic material, such as humus. The quantity, characteristics, and cause of the occurrence of sediment in streams are influenced by environmental factors. Some major factors are degree of slope, length of slope, soil characteristics, land usage, and quantity and intensity of precipitation. Suspended sediment is the sediment that at any given time is maintained in suspension by the upward components of turbulent currents or that exists in suspension as a colloid. Suspended-sediment concentration is the velocity-weighted concentration of suspended sediment in the sampled zone (from the water surface to a point approximately 0.3 ft above the bed) expressed as milligrams of dry sediment per liter of water-sediment mixture (mg/L). Suspended-sediment discharge (tons/day) is the rate at which dry weight of sediment passes a section of a stream or is the quantity of sediment, as measured by dry weight or volume, that passes a section in a given time. It is computed by multiplying discharge times concentration times 0.0027. The suspended-sediment concentration (mg/L) and suspended-sediment discharge (tons/day) except in stations 50028000 and 50071000 are based on instantaneous discharge and do not necessarily represent the actual daily discharge of suspended sediment. Suspended-sediment load is quantity of suspended sediment passing a sec­ tion in a specified period. 18 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Total sediment discharge (tons/day) is the sum of the suspended-sediment discharge and the bed-load discharge. It is the total quantity of sedi­ ment, as measured by dry weight or volume, that passes a section during a given time. Mean concentration is the time-weighted concentration of suspended sediment passing a stream section during a 24-hour day. Solute is any substance derived from the atmosphere, vegetation, soil, or rocks that is dissolved in water. Specific conductance is a measure of the ability of a water to conduct an electric current. It is expressed in micromhos per centimeter at 25°C. Specific conductance is related to the type and concentration of ions in solution and can be used for approximating the dissolved-solids content of the water. Commonly, the concentration of dissolved solids (in milligrams per liter) is about 65 percent of the specific conductance (in micromhos). This relation is not constant from stream to stream, and it may vary in the same source with changes in the composition of the water. Stage-discharge relation is the relation between gage height (stage) and volume of water per unit of time, flowing in a channel. Streamflow is the discharge that occurs in a natural channel. Although the term "discharge" can be applied to the flow of a canal, the word "streamflow" uniquely describes the discharge in a surface stream course. The term "stream­ flow" is more general than "runoff" as streamflow may be applied to discharge whether or not it is affected by diversion or regulation. Surficial bed material is that part (0.1 to 0.2 ft) of the bed material that is sampled using U.S. Series Bed-Material Samplers. Suspended (as used in tables of chemical analyses) refers to the amount (concentration) of the total concentration in a water-sediment mixture. The water-sediment mixture is associated with (or sorbed on) that material re­ tained on a 0.45 micrometer filter. Time-weighted average is computed by multiplying the number of days in the sampling period by the concentrations of individual constituents for the corresponding period and dividing the sum of the products by the total number of days. A time-weighted average represents the composition of water that would be contained in a vessel or reservoir that had received equal quantities of water from the stream each day for the year. Tons per acre-foot indicates the dry mass of dissolved solids in 1 acre-foot of water. It is computed by multiplying the concentration in milligrams per liter by 0.00136. Tons per day is the quantity of substance in solution or suspension that passes a stream section during a 24-hour day. 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Total load (tons) is the total quantity of any individual constituent, as measured by dry mass or volume, that is dissolved in a specific amount of water (discharge) during a given time. It is computed by multiplying the total discharge, times the mg/L of the constituent, times the factor 0.0027, times the number of days. Taxonomy is the division of biology concerned with the classification and naming of organisms. The classification of organisms is based upon a hier­ archical 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, limbata is the following: Kingdom Animal Phylum Arthropoda Class Insecta Order Ephemeroptera Family Ephemeridae Genus Hexagenia Species....Hexagenia limbata Water year in Geological Survey reports dealing with surface water supply is the 12-month period, October 1 through September 30. The water year is designated by the calendar year in which it ends. Thus, the water year beginning October 1, 1976 and ending September 30, 1977 is called the "1977 water year." Weighted average is used in this report to indicate discharge-weighted average for days 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. WRD is used as an abbreviation for "Water-Resources Data" in the REVISED RECORDS paragraph to refer to State annual basic-data reports published before 1975. WSP is used as an abbreviation for "Water-Supply Paper" in references to previously published REPORTS. DOWNSTREAM ORDER AND STATION NUMBER Since October 1, 1950, the order of listing hydrologic-station records in Survey reports is in a downstream direction along the main stream. All stations on a tributary entering upstream from a main-stream station are listed before that station. A station on a tributary that enters between two main-stream stations is listed between them. A similar order is followed in listing stations in first rank, second rank, and other ranks of tributaries. 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 As an added means of identification, each hydrologic station and partial- record station has been assigned a station number. These are in the same downstream order used in this report. In assigning station numbers, no dis­ tinction is made between partial-record stations and other stations; there­ fore, the station number for a partial-record station indicates downstream order position in a list made up of both types of stations. Gaps are left in the series of numbers to allow for new stations that may be established; hence, the numbers are not consecutive. The complete 8-digit number for each station such as 50028000, which appears just to the left of the station name, includes the 2-digit part number "50" plus the 6-digit downstream order number "028000." 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 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. 6, below). 66°53' 52' 5" 50' 49' 48' 66°47' 18°02 01' 134 132.1 -70 131 \ • 27 .74 ...„ COORDINATES FOR WELLS 27 (180150066474901), AND 74 (180110066473501). COORDINATES FOR WELLS 132 (180133066503301), AND 134 (180120066503201). 18° 00' 17°59 •Ir 16 0 .*/ COORDINATES FOR WELL 131 (180058066502701) COORDINATES FOR WELL 16 (175922066495901). Figure 6.--System for numbering wells and miscellaneous sites (latitude and longitude). SPECIAL NETWORKS AND PROGRAMS National stream-quality accounting network (NASQAN) is a data collection net­ work designed by the U.S. Geological Survey to meet many of the information demands of agencies or groups involved in national or regional water-quality planning and management. Both accounting and broad-scale monitoring objectives 21 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 have been incorporated into the network design. Areal configuration of the network is based on river-basin accounting units (identified by 8-digit hydrologic-unit numbers) designated by the Office of Water Data Coordination in consultation with the Water Resources Council. Primary objectives of the network are (1) to depict areal variability of streamflow and water-quality conditions nationwide on a year-by-year basis and (2) to detect and assess long-term changes in streamflow and stream quality. Pesticide program is a network of regularly sampled water-quality stations where samples are collected to determine the concentration and distribution of pesticides in streams where potential contamination could result from the application of the commonly used insecticides and herbicides. Operation of the network is a Federal interagency activity. Tritium network is a network of stations which has been established to provide baseline information on the occurrence of tritium in the Nation's surface waters. In addition to the surface-water stations in the network, tritium data are also obtained at a number of precipitation stations. The purpose of the precipitation stations is to provide an estimate sufficient for hydrologic studies of the tritium input to the United States. EXPLANATION OF STAGE AND WATER-DISCHARGE RECORDS Collection and computation of data The base data collected at gaging stations consist of records of stage and measurements of discharge of streams. In addition, observations of factors affecting the stage-discharge relation or the weather records, and other information are used to supplement base data in determining the daily flow. Records of stage are obtained either from direct readings on a nonrecording gage or from a water-stage recorder that gives either a continuous graph of the fluctuations or a tape punched at selected time intervals. Measurements of discharge are made with a current meter, using the general methods adopted by the Geological Survey. These methods are described in standard textbooks, in Water-Supply Paper 2175, and in U.S. Geological Survey Techniques of Water Resources Investigations, book 3, chapter A6. For stream-gaging stations, rating tables giving the discharge for any stage are prepared from stage-discharge relation curves. If extensions to the rating curves are necessary to express discharge greater than measured, they are made on the basis of indirect measurements of peak discharge (such as slope-area or contracted-opening measurements, computation of flow over dams or 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 discharge are computed from the daily figures. If the stage-discharge relation is subject to change because of frequent or continual change in the physical features that form the control, the daily mean discharge is computed by the shifting-control method, in which correction factors based on individual discharge measurements and notes by engineers and observers are used in applying the gage heights to the rating tables. If the stage-discharge relation for a station is temporarily changed 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 by the presence of aquatic growth or debris on the control, the daily mean discharge is computed by what is basically the shifting-control method. At some stream-gaging stations the stage-discharge relation is affected by the backwater from reservoirs, tributary streams, or other sources. This neces­ sitates the use of the slope method in which the slope or fall in a reach of the stream is a factor in computing discharge. The slope or fall is obtained by means of an auxiliary gage set at some distance the base gage. At some stations the stage-discharge relation is affected by changing stage; at these stations the rate of change in stage is used as a factor in computing dis­ charge. For some gaging stations there are periods when no gage-height record is obtained or the recorded gage height is so faulty that it cannot be used to compute daily discharge or contents. This happens when the recorder stops or otherwise fails to operate properly, intakes are plugged, the float is loose in the well, or for various other reasons. For such periods the daily dis­ charges are estimated on the basis of recorded range in stage, prior and subsequent records, discharge measurements, weather records, and comparison with records for other stations in the same or nearby basins. The data in this report generally comprise a description of the station and tabulations of daily and monthly figures. For gaging stations on streams a table showing the daily discharge and monthly and yearly discharge is given. Records are published for the water year, which begins on October 1 and ends on September 30. The description of the gaging station gives the location, drainage area, period of record, notations of revisions of previously published records, type and history of gages, general remarks, average discharge, and extremes of discharge or elevation. The location of the gaging station and the drainage area are obtained from the most accurate maps available. River mileage, given under "LOCATION" for some stations, is that determined and used by the Corps of Engineers or other agencies. Periods for which there are published records for the present station or for stations generally equivalent to the present one are given under "PERIOD OF RECORD." Previously published streamflow records of some stations have been found to be in error on the basis of data or information later obtained. Revisions of such records are usually published along with the current records in one of the annual or compilation reports. In order to make it easier to find such revised records, a paragraph headed "REVISED RECORDS" has been added to the description of all stations for which revised records have been published. Listed therein are all the reports in which revisions have been published, each followed by the water years for which figures are revised in that report. In listing the water years only one number is given; for instance, 1965 stands for the water year October 1, 1964, to September 30, 1965. If no daily, monthly, or annual figures of discharge are affected by the revision, the fact is brought out by notations after the year dates as follows: "(M)" means that only the instantaneous maximum discharge was revised; "(m)" that only the instantaneous minimum was revised; and "(P)" that only peak discharges were revised. If the drainage area has been revised, the report in which the revised figure was first published is given. It should be noted that for all 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 stations for which cubic feet per second per square mile and runoff in inches are published, a revision of the drainage area necessitates corresponding revision of all figures based on the drainage area. Revised figures of cubic feet per second per square mile and runoff in inches resulting from a revision of the drainage area only are usually not published in the annual series of reports. The type of gage currently in use, the datum of the present gage above mean sea level, and a condensed history of the types, locations, and datums of previous gages used during the period of record are given under "GAGE." In references to datum of gage, the phrase "mean sea level" denotes "Sea Level Datum of 1929" as used by the Topographic Division of the Geological Survey unless otherwise qualified. Information pertaining to the accuracy of the discharge records and to condi­ tions which affect the natural flow of the gaging station is given under "REMARKS." For reservoir stations information on the dam forming the reser­ voir, the capacity, outlet works and spillway, and purpose and use of the reservoir is given under "REMARKS." The average discharge for the number of years indicated is given under "AVER­ AGE DISCHARGE"; it is not given for stations having fewer than 5 complete years of record or for stations where changes in water development during the period of record cause the figure to have little significance. In addition, the median of yearly mean discharges is given for stream-gaging stations having 10 or more complete years of record if the median differs from the average by more than 10 percent. Under "EXTREMES" are given first, the extremes for the period of record, second, information available outside the period of record, and last, those for the current year. Unless otherwise qualified, the maximum discharge (or contents) is the instantaneous maximum corresponding to the crest stage obtained by use of a water-stage recorder (graphic or digital), a crest-stage gage, or a nonrecording gage read at the time of the crest. If the maximum gage height did not occur on the same day as the maximum discharge (or contents), it is given separately. Similarly, the minimum is the instantaneous minimum unless otherwise qualified. For some stations peak discharges are listed with EXTREMES FOR THE CURRENT YEAR; if they are, all independent peaks including the maximum for the year, above the selected base with the time of occurrence and corresponding gage heights are published in tabular format. The base discharge, which is given in the table heading, is selected so that an average of about three peaks a year will be presented. Peak discharges are not published for any canals, ditches, drains, or for any stream for which the peaks are subject to substantial control by man. Time of day is expressed in 24-hour local standard time; for example, 12:30 a.m. is 0030, 1:30 p.m. is 1330. The minimums for these stations are published in a separate paragraph following the table of peaks. 24 WATER RSOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 The daily table for stream-gaging stations gives the mean discharge for each day and is followed by monthly and yearly summaries. In the monthly summary below the daily table, the line headed "TOTAL" gives the sum of the daily figures. The line headed "MEAN" gives the average flow in cubic feet per second during the month. The lines headed "MAX" and "MIN" give the maximum and minimum daily discharges, respectively, for the month. Discharge for the month also may be expressed in cubic feet per second per square mile (line headed "CFSM"), or in inches (line headed "IN"), or in acre-feet (line headed "AC-FT"). Figures for cubic feet per second per square mile and runoff in inches are omitted if there is extensive regulation or diversion, if the drainage area includes large noncontributing areas, or if the average annual rainfall over the drainage basin is usually less than 20 inches. In the yearly summary below the monthly summary, the figures shown are the appro­ priate daily discharges for the calendar and water years. Footnotes to the table of daily discharge are introduced by the word "NOTE." Footnotes are used to indicate periods for which the discharge is computed or estimated by special methods because of no gage-height record, backwater from various sources, or other unusual conditions. Periods of no gage-height record are indicated if the period is continuous for a month or more or in­ cludes the maximum discharge for the year. Period of backwater from an unusual source, or indefinite stage-relation, or of any other unusual condi­ tion at the gage site are indicated only if they are a month or more in length and the accuracy of the records is affected. The methods used in computing discharge for various unusual conditions have been explained in preceding paragraphs. Data collected at partial-record water-quality stations follows the informa­ tion for continuous-record sites. Data for partial-record discharge stations are presented in one table. This table shows the annual maximum stage and discharge at crest-stage stations. 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 dis­ charge measurements, and (2) the accuracy of observations of stage, measure­ ments of discharge, and interpretations of records. The station description under "REMARKS" states the degree of accuracy of the records. "Excellent" means that about 95 percent of the daily discharges are within 5 percent; "good," within 10 percent; and "fair" within 15 percent. "Poor" means that daily discharges have less than "fair" accuracy. Figures 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 cu ft/s; to tenths between 1.0 and 10 cu ft/s; to whole numbers between 10 and 1,000 cu ft/s; and to 3 significant figures above 1,000 cu ft/s. The number of signifi­ cant figures used is based solely on the magnitude of the figure. The same rounding rules apply to discharge figures listed for partial-record stations. 25 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Other data available Information of a more detailed nature than that published for most of the gaging stations such as observations of water temperatures, discharge measure­ ments, gage-height records, and rating tables is on file in the district office. Also, most 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. Access to WATSTORE Data The National WATer Data STOrage and REtrieval System (WATSTORE) was estab­ lished for handling water data collected through the activities of the U.S. Geological Survey and to provide for more effective and efficient means of releasing the data to the public. The system is operated and maintained on the central computer facilities of the Survey at its National Center in Reston, Virginia. WATSTORE can provide a variety of useful products ranging from simple data tables to complex statistical analyses. A minimal fee, plus the actual computer cost incurred in producing a desired product, is charged to the requester. Information about the availability of specific types of data, the acquisition of data or products, and user charges can be obtained locally from each of the Water Resources Division's Division's district offices (see address given on the back of the title page). General inquiries about WATSTORE may be directed to: Chief Hydrologist U.S. Geological Survey 437 National Center Reston, Virginia 22092 EXPLANATION OF WATER-QUALITY RECORDS Collection and examination of data Surface-water samples for analyses usually are collected at or near gaging stations. The quality-of-water records are given immediately following the discharge records at these stations. The descriptive heading for water-quality records gives the period of record for all water-quality data; the period of daily record for parameters that are measured on a daily basis (sediment discharge); extremes for the period of daily record; extremes for the current year; and general remarks. For ground-water records, no descriptive statements are given; however, the well number, date of sampling/and or other pertinent data are given in the table containing the chemical analyses of the ground water. 26 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Water analysis Most methods for collecting and analyzing water samples are described in the U.S. Geological Survey Techniques of Water-Resources Investigations. One sample can define adequately the water quality at a given time if the mixture of solutes throughout the stream cross sections 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. 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 possi­ ble, 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 were measured at all water-quality stations. In addition, temperatures were taken during discharge measurements for water-discharge stations. For stations where water temperatures are taken manually once or twice daily, the water temperatures are taken at about the same time each day. Large streams have a small diel 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. Table 4.--Conversion of Temperature Scales Degrees Celcius (°C) to Degrees Farenheit (°F) °C °F °C °F °C °F 15.0 59 21.0 70 27.0 81 15.5 60 21.5 71 27.5 82 16.0 61 22.0 72 28.0 82 16.5 62 22.5 72 28.5 83 17.0 63 23.0 73 29.0 84 17.5 64 23.5 74 29.5 85 18.0 64 24.0 75 30.0 86 18.5 65 24.5 76 30.5 87 19.0 66 25.0 77 31.0 88 19.5 67 25.5 78 31.5 89 20.0 68 26.0 79 32.0 90 20.5 69 26.5 80 °F = 9/5 (°C) + 32 or * °C = 5/9 (°F - 32) 27 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Sediment Suspended-sediment concentrations are determined from water-sediment samples collected by using depth-integrating or automatic 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, in some instances, hourly). The published sediment discharges for days of rapidly changing flow or concentration were computed by the subdivided day method (time-discharge weighted average). Therefore, for those days when the pub­ lished sediment discharge value differs from the value computed as the product of discharge times mean concentration times 0.0027, the reader can assume that the sediment discharge for that day was computed by the subdivided day method. For periods when no samples were collected, daily loads of suspended sediment were estimated on the basis of water discharge, sediment concentrations observed immediately before and after the periods, and suspended-sediment loads for other periods of similar discharge. At other stations, suspended-sediment samples were collected periodically at many verticals in the stream cross section. Although data collected period­ ically may represent conditions only at the time of observations, such data are useful in establishing seasonal relations between quality and streamflow in predicting long-term sediment-discharge characteristics of the stream. In addition to the records of the amounts of suspended sediment, records of the periodic measurements of the particle-size distribution of the suspended sediment and bed material are included. EXPLANATION OF GROUND-WATER LEVEL RECORDS Collection of the data 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. Each well is identified by means of (1) a 15-digit number that is based on latitude and longitude and (2) a local number that is provided for local needs. See figure 6. Measurements are made in many types of wells, under varying conditions of access and at different temperatures; hence, neither the method of measurement nor the equipment can be standardized. At each observation well, however, the equipment and techniques used are those that will ensure that measurements at each well are consistent. 28 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 Water-level measurements in this report are given in feet with reference either to mean sea level (msl) or land-surface datum (lsd). Mean sea level is the datum plane on which the national network of precise levels is based; land-surface datum is a datum plane that is approximately at land surface at each well. If known, the altitude of the land-surface datum is given in each well description. The height of the measuring point (M.P.) above or below low-surface datum is given in each well description. Water levels in wells equipped with recording gages are reported for every day. 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 in 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 are reported to a hun­ dredth of a foot, but some are given only to a tenth of a foot or a large unit. Surface and Quality-of--Water Records for Puerto Rico 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' OCEANO ATLANTICO Go „No ,00 oo 1, 4.; Gad 04' ..Ct ,oz1, ,z,s is C?aa O, t 1" 0 v bt 1/40 10 v 1,0 e b te 1/40.e e 18°30' 0 is.,be io to 8:r 0 038 • 395 Rio Culebrinas 027750 0460 Rio Guayabo 0284 1478 Rio Grand A (I t 832 0670 0350 655 Rio Fajardo 0618• 634 0 1440 0280 07 • Rio Grande 0570 15' de Aliasco 14 1 05 0564 Rio Yaguez 1 15 141 • 0 6 Rio Daguao Quebrada Palma Rio Guanafibo 1380 1425 1360 0430 0513 \ Rio Santiago 0.09 Rio Blanco 11 • 5 1 I5 • Rio Anton Ruiz Rio Humacao 26 5 • • _A128950 1 4 0 2 0905 Rio Guayands 18°00' 1293£ ft • to,‘0 4 i 1 j, 0 0 Abe'c, , ,z,e 6 c; o \f, 0 0 ,ocs ac. 0 0 o ote. 0 0,1°oes c• 0 ie 0 ea .0 so 0 G anti 0 * ic. 00 040 04 *0 0 Ne° A 0 4% EXPLANATION i1/4 1* 0 4/ 4 I* CPI' 4% ko .. ,0 1/40 143 0\0 ec'Z'ab C ,CP V ) r2 o SURFACE WATER STATIONS 41' 41* k0 (i‘ 8 0 0 4 \ q (2.0 1. 4/ t.„, i' R*% IS i s I •0* 11/0 4 I‘ 1%0 O CONTINUOUS STREAMFLOW -1125 17045' STATION O 10 20 30 KILOMETERS I • 1411 LAKE-ELEVATION STATION O 10 20 MILLS MAR CARIBE Figure 7.--Continuous surface-water stations in Puerto Rico. 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' T OCEAN° ATLANTICO cs0 .1. o o 0 ,9 , e. 4-039750 q i 0 0 0* so v 0 0A, o 0e cr et" 000 0 0397 , $ bil) ,0 \O 00be \O p 039650 6- e \e, 18°30' q`s 4q• be 00, ,.0R 0 ik` 0114 ,• 38 0290 0395 11 47530 Rio Culebrinas 4982 0381 0460 011• 0284 Rio Guayabo 1491 0491 04851 • 04799 59 Rio Grand 010790 06 010720 027250 0383 0 044 • 0 0 8 059 090 a 0725 b Fajardo 76 O "44 0588 144 • 116, 0280 03 554 251 0 A Rio Grande • 3 950 0575 07 0 4 10 15 de Afiasco 0 5525 • 02 0 025 47Er 1388 02 Ir0307 055 Rio Yaguez 3 66 7 to Daguao • - 15 Rio Guanafibo 136 02 • ir--0210 Quebrada Palma 0 = 2 ► \ Rio Santiago 13 0 0430 cy( 0.0 5 Rio Blanco 1 4 336 Rio Anton Ruiz 1 k 03995 •8 c 5 Rio Humacao 1965 ? 039 \ N 0 in f y 1 ,47 10 18°00' 1162 I . 1 IP 0 o04\ 6 0 • o EXPLANATION 00 2, +o 04 00 ,Qo 40 0 I. 0, ip ika.,0 eGo ‘P SOQ e s- 0 se, to QUALITY-OF-WATER STATIONS o 00A0v.cisoe 1)0‘00000v, o‘ 00-0-cp b vi 4z.‘ .0 0 Q. g.ilso e 1/40 0 Is IV 0430 BIOLOGICAL R.\ R. i'. 40 i1/0 4 i k cf 0820 CHEMICAL \O 'tik 17°45' • 110 20 30 KILOMETERS 1 0710 SEDIMENT (DAILY) O 10 20 MILES MAR CARIBE V-0910 SEDIMENT (MONTHLY) Figure 8.--Water-Quality stations in Puerto Rico. 66'00' 65'45' SAN JUAN 0475.25 0496 0493.10 665 0693.50 0485.10 0.15 0610 66 0690 602 0638 .0 06 0475.04 0; 2 0 5.40 Fajardo 0:94 to Fajardo 6 0720 . 0584 0570.15 07 0554.10 eib X 553.1 32 0566 Cagua 0565.50 29 0527 0535 555 0556 0770 0775 0776 073 0740.10 0511.40 0785.10 Rio Anton Ruiz Rio Humacao EXPLANATION SURFACE WATER STATIONS 0 19.50 0865 0857 0872 A0825 LOW-FLOW STATION 41159 CREST-STAGE GAGING STATION 18•00' 942.A 0943 A 0915 0910 0850 0851 10 20 KILOMETERS 10 20 MILES Figure 9.--Low-flow partial-record stations in Eastern Puerto Rico. 15 67°15' 67°00' 45' 30' 15' 66°00' 45' 65°30' OCEANI C) ATLANTIC° 66% 4e et. e 604' e 0,3 18°30' R. be p Rio Culebrinas Rio Guayab Rio Grand Rio Grande de Afiasco Rio Yaguez Rio Daguao Quebrada Palma Rio Guanallbo \ Rio Santiago Rio Blanco Rio Anton Ruiz Rio Humacao Rio Guayana's 18°00' 0 ,22#660 4 0 0 0* j,e,43 IkO'ilas oore 0 d&.A A so ok 1.•,, tO 1ov e ° AV \OW 4 W I Or 0if '0 OV vo A A + 0 ga* 40 4420 A%0 ‘.0 „N. 00 t S c,6 ko -6 011' 1/0 4 quto:n` r I. ko v. trip e p 1/0 4 q'he is` - i1/4 42. R• 0 so 0- 42. 424 40 17°45' 0 10 20 3:3 KILOMETERS 0 10 20 MILES MAR CARIBE Figure 10.--Partial-record stations in Central and Western Puerto Rico. 35 OCEANO ATLANTIC 0 ISABELA UE BRADILLAS 0114 A. oi rsioh • 164 AGUADILLA • 166 0110 010790 Drainage boundaries indeterminate in limestone terrane LaVfica 010720 Limestone Igneous sedimentary rocks LARES 0106-- Rio Culebrin basin Rio Grande de 1,.cti Artiasco basin • EXPLANATION A 0114 LOW-FLOW STATION AND NUMBER 11, 0105 QUALITY-OF-WATER STATION AND NUMBER • 164 WELL AND WELL NUMBER Map area 0 I 2 TKILOMETERS I i l l 1 0 SMILES Figure 11.--Rio Guajataca basin. 36 RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'01", long 66°52'24", at bridge on Highway 111 (km 32.9), 0.1 mi (0.2 km) upstream from Quebrada Anion, and 0.4 mi (0.6 km) northeast of Lares Plaza. DRAINAGE AREA.--3.16 sq mi (8.18 sq km). PERIOD OF RECORD.--Water years 1958-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- On- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 10... 1115 5.1 255 7.7 23.0 12 7.2 86 13 K66000 25000 JAN , 1983 31... 1425 1.5 243 7.3 21.0 1.6 9.4 108 12 540 1200 MAR 23... 1045 1.3 280 7.6 23.0 <1.0 7.0 84 14 5700 64000 MAY 11... 1300 3.6 245 7.5 25.0 3.4 7.8 98 <10 K1500 3500 AUG 24... 1130 2.7 234 8.0 24.0 1.9 11.2 137 16 K1300 570 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS. CALCIUM SIUM, SODIUM, AD- SIUMr LINITY SULFATE RIDE. RIDE, NESS NONCAR- DIS- DIS... DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1932 10... -- 87 JAN , 1983 31... 90 1 26 6.2 14 .7 2.0 90 9.0 9.2 .40 MAR 23... 130 MAY 11... 93 0 28 5.6 11 .5 2.9 93 15 11 .10 AUG 24... 95 2 28 6.0 12 .6 2.1 93 3.2 11 .20 SOLIDS. SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L 015- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV r 1982 10... 16 1.5 .020 1.5 <.010 1.3 1.30 2.8 JAN r 1933 31... 31 152 .62 5 1.1 .020 1.1 .020 .18 .20 1.3 MAR 23... 4 .75 .050 .80 .090 .21 .30 1.1 MAY 11... 25 154 1.5 8 1.1 (.010 1.1 <.010 .19 .20 1.3 AUG 24... 28 151 1.1 6 1.0 .060 1.1 .C3C .47 .50 1.6 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GIN, PHORUS, ASENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV 1982 10... 12 .110 JAN . 1983 31... 5.8 .100 2 ZOO 2 3 7 .4 <1 2 MAR 23... 4.9 .240 MAY 11... 5.8 .060 AUG 24... 7.1 .110 2 100 <1 <1 9 <.1 <1 K = non-ideal count RIO GUAJATACA BASIN 37 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'02", long 66°55'27", off Highway 476 at Lago Guajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND. FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (8G/L) ATION) (MG/L) 100 ML) 100 ML) OCT • 1982 01... 1020 50 322 7.1 25.0 1.5 .9 11 37 K10 K13 NOV 18... 1250 50 320 7.1 25.0 3.1 .0 0 23 K170 52 JAN . 1983 20... 1110 59 303 7.3 25.0 1.0 2.5 31 26 K5 K4 MAR 30... 1300 45 305 7.8 27.0 1.0 6.4 82 <10 K100 K100 MAY 23... 1420 40 323 7.1 255 1.9 2.0 2810 <10 92 310 AUG 26... 1005 55 309 7.5 27.0 2.2 2.1 27 20 500 260 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS. CALCIUM SLUM. SODIUM. AD- SIUM. LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD On- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) OCT . 1982 01... 150 43 56 3.1 4.4 .2 1.8 110 7.0 6.7 .10 NOV 18... 150 JAN , 1983 20... 140 0 49 3.6 5.4 .2 1.9 140 8.0 7.8 .10 MAR 30... 130 MAY 23... 150 9 54 3.4 4.8 .2 1.9 140 13 8.0 .10 AUG 26... 150 6 54 3.7 5.9 .2 1.4 143 12 8.5 .10 SOLIDS, SOLIDS. NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN. GEN• GEN. MONIA + SOLVED TUENTS. SOLVED DEG. Cs NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDEO (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NITRO- GEN. TOTAL (MG/L AS N) OCT r 1982 01... 6.3 151 20.4 3 <.010 <.10 .050 .45 .50 NOV 13... 6 <.010 <.10 .500 1.2 1.70 JAN , 1983 20... 1.7 161 25.8 2 .010 <.10 .040 .36 .40 MAR 30... 1 <.010 <.10 <.010 .30 MAY 23... 5.1 174 18.8 6 .47 .030 .50 .470 .63 1.10 1.6 AUG 26... 6.2 178 26.5 6 <.010 <.10 .150 .35 .50 NITRO- GEN, TOTAL (MG/L DATE AS NO3) CHRO- BARIUM, CADMIUM MIUM. LEAD, MERCURY PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS P) AS AS) AS BA) AS CD) AS CR) AS PS) AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) OCT • 1982 01... .030 3 100 1 <1 2 .2 <1 <1 NOV 18... .040 JAN . 1983 20... .060 3 <100 1 3 13 .3 <1 <1 MAR 30... <.010 MAY 23... 7.1 .010 AUG 26... .030 3 100 1 <1 7 <.1 <1 <1 K = non-ideal count 38 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°28'31", long 66°57'46", at ford, 1.7 mi (2.7 km) upstream from bridge on Highway 2, 2.1 mi (3.4 km) from the Atlantic Ocean, 6.6 mi (10.6 km) downstream from Lago Guajataca, and 1.6 mi (2.6 km) west of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAO. 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1982 01... 0825 11 533 7.2 24.0 <1.0 3.3 40 26 200 240 NOV 13... 1125 71 408 7.8 24.0 4.0 8.2 99 22 530 490 JAN , 1933 20... 0905 18 314 7.4 23.5 1.0 6.3 74 28 54 590 MAR 30... 1045 11 425 7.6 25.0 <1.0 7.1 86 16 K530 1300 MAY 12... 1510 11 510 7.6 26.0 .30 8.4 104 16 100 110 AUG 26... 0820 12 530 7.8 24.5 <1.0 3.8 46 20 60 550 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- ors- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) OCT , 1982 01... 230 18 77 8.6 13 .5 1.3 210 8.0 33 <.10 NOV 13... 170 JAN , 1983 20... 190 0 64 7.2 16 .5 1.3 190 9.0 23 <.10 MAR 30... 180 MAY 12... 210 1 71 3.1 13 .6 1.3 210 11 35 <.10 AUG 26... 230 20 78 9.0 20 .6 1.0 212 8.8 33 <.10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SCLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- HS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. C. NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (PG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1982 01... 5.7 278 8.2 4 1.7 .020 1.7 .040 .06 .10 1.8 NOV 18... 6 <.010 .70 .030 1.7 1.70 2.4 JAN , 1983 20... 5.6 240 11.7 2 <.010 1.6 .040 3.4 3.40 5.0 MAR 30... 2 1.3 .010 1.3 .010 .19 .20 1.5 MAY 12... 5.5 276 8.2 3 1.7 <.010 1.7 <.01C .09 .10 1.8 AUG 26... 6.4 283 9.2 4 2.1 .040 2.1 .020 .28 .30 2.4 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L GATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) OCT , 1982 01... 8.0 .010 2 100 1 <1 2 .2 <1 <1 NOV 18... 11 .020 JAN , 1983 20... 22 .010 2 <100 1 3 10 .2 <1 <1 MAR 30... 6.6 <.010 MAY 12... 8.0 .010 AUG 26... 11 .030 2 100 1 <1 5 <.1 <1 <1 K = non-ideal count I 39 OCEAN° ATLANTIC° QUEBRADILLAS E ARECIBO Drainage bounanries indeterminate esione terrune • Bayaney River underground Limestone Igneous and sedimen tar y rocks LARES Rfboain " Rio Tanana: R(o Grande de UTUADO I Arecibo basis Drainage boundary Atidsco desk, Gronds de EXPLANATION A 0158 LOW-FLOW STATION AND NUMBER TKILOmETERS 1 MILES Figure 12.--Rio Camuy basin. I  41 OCEANO ATLANTICO • HATILLO ARECIB BARCELONE TA 0284 027750 eBayaney eFlorida Drainage boundaries indeterminate in limestone terrane Limestone Logo UTUADO 0215 Logo Viv as .41PUYD Tu .. !!„. 02n Adjuntos Rio Grande du Alicia° basin cleADJUNTAS Rio inabon Rio Bucandbasin basin EXPLANATION A 0284 SURFACE-WATER STATION AND NUMBER Rio Guayonillo basin Rio Tallobo° basin • 0205 QUALITY-OF-WATER STATION AND NUMBER 161 WELL AND WELL NUMBER Map area SAN JUAN ?KILOMETERS SMILES Figure 13.--Rio Grande de Arecibo basin. 42 RIO GRANDE DE ARECIBO BASIN 50020500 RIO GRANDE DE ARECIBO NEAR ADJUNTAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°10'54", long 66°44'12", at Highway 135 bridge, 1.0 mi (1.6 km) upstream from Lago Adjuntas, and 1.5 mi (2.4 km) northwest of Adjuntas. DRAINAGE AREA.--12.7 sq mi (32.9 sq km) this does not include 6.0 sq mi (15.6 sq km) above Lago Garzas. PERIOD OF RECORD.--Water years 1969-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN. OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOM, CON- PH TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-Mc (COLS. TIME TANEOUS ANCE ARO ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMMOS) UNITS) (DEG C) (NTU) (MG/L) ATION) CMG/L) 100 ML) 100 ML) NOV r 1982 09... 0930 16 336 7.8 22.0 2.9 8.1 97 42 5000 4500 JAN • 1983 18... 0905 13 540 7.7 19.0 2.0 8.2 93 22 k16000 8600 MAR 17... 1435 15 320 7.6 26.0 7.2 7.1 93 29 k1800 5700 MAY 09... 1545 17 300 8.6 23.0 1.2 9.0 122 23 3200 3100 AUG 23... 0825 17 328 7.9 22.0 6.0 10.4 125 24 (14000 K12000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS. CALCIUM SIUM, SODIUM. AD- SIUM, LINITY SULFATE RIDE. RIDE. NESS NONCAR- DIS- ors- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS k) CAC03) AS SO4) AS CL) AS F) NOV • 1982 09... JAN .1983 18... 120 MAR 17... MAY 09... 100 AUG 23... 110 110 5 23 11 65 2.8 2.9 110 10 89 .10 98 3 26 9.2 20 .9 2.3 100 12 28 <.10 4 29 10 20 .8 1.7 110 9.9 27 .10 SOLIDS. SOLIDS. NITRO- SILICA., SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN. GEN. GEN, MONIA + SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC (NG/L CIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE 5102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NITRO- GEN, TOTAL (MG/L AS N) NOV e 1932 09... 10 .71 .090 .80 .150 .95 1.10 1.9 JAN r 1983 18... 25 300 10.5 2 .80 .100 .90 .130 .42 .60 1.5 MAR 17... 8 .82 .080 .90 .390 .41 .80 1.7 MAY 09... 26 183 8.5 6 .66 .240 .90 .070 .63 .70 1.6 AUG 23... 30 194 8.9 12 1.1 .020 1.1 .200 .20 .40 1.5 C4R0- BARIUM, CADMIUM MIUM, LEAD, MERCURY NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL ERASLE ERABLE ERABLE ERABLE ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CO) AS CR) AS P3) AS MG) SELE- NIUM. TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) NOV e 1982 09... 3.4 .130 JAN r 1983 18... 6.6 .170 1 <100 1 5 22 .3 <1 <1 MAR 17... 7.5 .200 MAY 09... 7.1 .260 AUG 23... 6.6 .010 1 100 1 <1 8 <.1 <1 <1 K = non-ideal count 43 RIO GRANDE DE ARECIBO BASIN 50025000 RIO GRANDE DE ARECIBO NEAR UTUADO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'11", long 66°41'59", at bridge near Highway 10 at km 56.4, 0.5 mi (0.8 km)) downstream from Rio de Caguana, and 2.5 mi (4.0 km) north of Utuado plaza. DRAINAGE AREA.--66.0 sq mi (170.9 sq km) this excludes 6.0 sq mi (15.5 sq km) upstream from Lago Garzas, which is a diversion to Rio Guayan6s in the Rio Tallaboa basin. PERIOD OF RECORD.--Water years 1959-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND. FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, HARD- FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER AS DATE (C=S) (UMHOS) UNITS) MEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) NOV , 1982 03... 1415 59 289 8.0 23.0 6.5 7.4 95 17 3800 K1200 JAN , 1983 17... 1545 35 265 8.0 27.0 3.6 7.3 93 29 5800 K1500 98 MAR 18... 0910 38 258 8.0 23.0 2.9 8.1 96 17 4600 860 MAY 10... 1210 64 253 7.8 23.0 36 7.1 92 15 112000 27003 92 AUG 22... 1335 86 253 8.1 31.0 150 9.2 125 110 K150000 27000 92 HARD- NESS, UNGAR- 30NATE (MG/L DATE CACO3) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM, DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, AD- SIUM, LINITY SULFATE RIDE, RIDE, DIS- SORP- DIS- FIELD DIS- On- DIS- SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS AS K) CAC03) AS 504) AS CL) AS F) SI02) NOV , 1982 08... 87 JAN , 1983 17... 11 26 8.1 16 .7 2.4 87 20 11 .10 30 MAR 13... 52 MAY 10... 8 24 7.3 14 2.6 84 26 13 .10 26 AUG 22... 13 24 7.7 14 .7 2.0 79 21 15 .20 26 SOLIDS. SOLIDS, NITRO- SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GENtAM- CONSTI- DIS- AT 105 GEN, GEN. GEN, GEN, GEN, MCNIA + NITRO- NITRO- TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) NOV , 1932 03... 24 .93 .073 1.0 .070 .33 .90 1.9 8.4 JAN , 1933 17... 166 15.7 <1 1.4 .100 1.5 .040 .26 .30 1.8 8.0 MAR 18... (1 1.2 .020 1.2 .030 .17 .20 1.4 6.2 MAY 10... 164 28.3 54 1.1 .060 1.2 .200 .50 .70 1.9 8.4 AUG 22... 157 36.5 212 1.2 .110 1.3 .163 .24 .40 1.7 7.5 SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) CHRO* BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL SEDI- PHORUSt ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- MENT, TOTAL TOTAL ERABLE ERABLE ERASLE ERABLE ERASLE TOTAL ERABLE SUS- (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENDED DATE AS P) AS AS) AS 3A) AS CO) AS CR) AS P9) AS HG) AS SE) AS AG) (MG/L) NOV , 1982 08... .140 JAN , 1933 17... .190 1 100 1 5 13 .1 <1 <1 MAR 18... .120 MAY 10... .200 AUG 22... .090 1 200 1 <1 12 <.1 <1 <1 K = non-ideal count 96 10 RIO GRANDE DE ARECIBO BASIN 50026050 RIO CAONILLAS ABOVE LAGO CAONILLAS NEAR JAYUYA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°13'26", long 66°38'22", 300 ft (91.m) off Highway 531, 700 ft (213 m) upstream from Lago Caonillas, 3.3 mi (5.3 km) northwest of Jayuya plaza. DRAINAGE AREA.--40.4 sq mi (104.6 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, HARD- FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER AS DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CAC03) NOV , 1982 9... 1245 65 158 7.9 25.0 8.5 3.0 99 18 3000 K1500 JAN , 1983 18... 1310 35 208 8.5 21.0 1.2 3.9 103 31 470 200 76 MAR 17... 1045 53 207 8.0 24.0 34 8.1 100 11 K1700 6200 MAY 10... 0845 51 193 7.8 24.0 34 8.0 98 14 4000 540 70 AUG 23... 1205 32 215 8.2 27.5 6.7 10.6 138 20 K1000 K180 78 HARD- NESS, NONCAR- BONATE (MG/L DATE CAC03) CALCIUM DI S- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM, DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, AO.... SIUM, LINITY SULFATE RIDE, RIDE, DIS- SORP- DIS- FIELD DIS- DIS- DIS- SOLVED TION SOLVED (MG/L SOLVEC SOLVED SOLVED (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS AS K) CAC03) AS SO4) AS CL) AS F) SI02) NOV , 1982 9... 51 JAN , 1983 18... 2 19 7.0 14 .7 1.6 74 15 10 .10 22 MAR 17... 64 MAY 10... 1 18 6.0 10 .5 1.6 69 19 11 <.10 24 AUG 23... S 21 6.3 11 .6 1.4 70 14 11 <.10 24 SOLIOS, SOLIDS, NITRO- SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GENpAM- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+403 AMMONIA ORGANIC ORGANIC GEN, GEN, DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) NOV , 1952 09... 15 <.010 .40 .010 .49 .50 .90 4.0 JAN , 1983 13... 133 12.6 1 .49 .010 .50 .020 .28 .30 .80 3.5 MAR 17... 4 1.1 .020 1.1 .080 .12 .20 1.3 5.8 MAY 10... 131 18.0 2 .47 .030 .50 .030 .37 .40 .90 4.0 AUG 23... 131 11.3 <1 .39 .010 .40 .320 .58 .60 1.0 4.4 CMR0- SEDI- 9ARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, MENT, PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL SEDI- OIS- PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- NEWT, CHARGE, TOTAL TOTAL ERABLE ERABLE ERA3LE ERABLE ERABLE TOTAL ERABLE SUS- SUS- (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENOEC PENDED DATE AS P) AS AS) AS 3A) AS CO) AS CR) AS PS) AS HG) AS SE) AS AG) (MG/L) (T/DAY) NOV r 1982 09... .070 JAN 1983 18... .170 1 <100 1 6 11 <.1 10 <1 MAR 17... .090 96 14 MAY 10... .090 AUG 23... .110 K = non-ideal count 44 45 RIO GRANDE DE ARECIBO BASIN 50027250 RIO GRANDE DE ARECIBO BELOW LAGO DOS BOCAS NEAR FLORIDA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°20'50", long 66°40'02", at pedestrian bridge, 0.7 mi (1.1 km) downstream from Lago Dos Bocas and 6.6 mi (10.6 km) west of Florida plaza. DRAINAGE AREA.--169 sq mi (436 sq km) does not include 6.0 sq mi (15.6 sq km) above Lago Garzas. PERIOD OF RECORD.--Water years 1970-71, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 SPE- STREAM- CIFIC FLOW, CON- PH TUR- INSTAN- DUCT- (STAND- TEMPER- BID- TIME TANEOUS ANCE ARD ATURE ITY DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) NOV • 1982 08... 1150 136 203 7.4 26.0 3.2 JAN r 1983 17... 1450 187 204 7.3 25.0 3.1 MAR 18... 1210 23 212 7.6 25.0 2.7 MAY 10... 1400 E500 181 6.8 25.5 19 AUG 22... 1120 E700 222 7.3 27.5 13 OXYGEN. OXYGEN COLT- STREP- DIS- DEMAND. FORM. TOCOCCI SOLVED CHEM- FECAL, FECAL, OXYGEN. (PER- ICAL 0.7 KF AGAR DIS- CENT (HIGH UM-MF (COLS. SOLVED SATUR- LEVEL) (COLS./ PER (MG/L) ATION) (MG/L) 100 ML) 100 ML) 5.7 70 22 400 52 5.9 72 19 K36 160 7.1 87 12 80 70 5.1 63 16 270 310 3.4 43 16 370 550 HARD- MAGNE- SODIUM HARD- NESS., CALCIUM SIUMr SODIUM. AD- NESS NONCAR- DIS- DIS- DIS- SORP- (MG/L BONATE SOLVED SOLVED SOLVED TION AS (MG/L (MG/L (MG/L (MG/L RATIO DATE CAC03) CAC03) AS CA) AS MG) AS NA) POTAS- ALKA- SIUM, LINITY DIS- FIELD SOLVED (MG/L (MG/L AS AS K) CAC03) CHLO- FLUO- SULFATE RIDEr RIDE. DIS- DIS- DIS- SOLVED SOLVED SOLVED (MG/L (MG/L (MG/L AS SO4) AS CL) AS F) NOV • 1982 08... JAN • 1983 17... 73 MAR 18... MAY 10... 64 AUG 22... 76 69 1 19 6.1 12 .6 2.1 72 75 4 17 5.3 9.1 .5 2.2 60 1 20 6.4 11 .6 1.3 75 11 9.7 <.10 14 11 <.10 13 11 .10 SOLIDS, SOLIDS. NITRO- SILICA' SUM OF SOLIDS. RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- DIS- CONSTI- DIS- AT 105 GEN, GIN, GEN. GEN. GEN. MONIA + SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC (MG/L On- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENOED (MG/L (MG/L (MG/L (MG/L ' (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NITRO- GEN, TOTAL (MG/L AS N) NOV • 1982 08... JAN • 1983 17... MAR 18... MAY 10... AUG 22... 6 <.010 .20 .080 21 124 62.6 12 <.010 .60 .040 <1 .09 .010 .10 .090 17 112 15 .59 .010 .60 .020 18 126 <1 .040 <.10 .190 .92 1.00 1.2 .26 .30 .90 .01 .10 .20 .38 .40 1.0 .41 .60 CHRO- 3AR/UM, CADMIUM MIUM, LEAD, MERCURY NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL GEN/ PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL TOTAL TOTAL ERASLE ERASLE ERABLE ERABLE ERASLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CO) AS CR) AS P9) AS HG) NOV 1932 08... 5.3 .020 JAN t 1983 17... 4.0 .020 1 <100 1 3 11 .2 MAR 18... .89 .030 MAY 10... 4.4 .040 AUG 22... .050 1 100 4 <1 6 <.1 K = non-ideal count E . estimate SILVER, SELE- TOTAL NIUM, RECOV- TOTAL ERABLE (UG/L (UG/L AS SE) AS AG) <1 <1 <1 <1 46 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR LOCATION.--Lat 18°18'02", long 66°46'58", Hydrologic Unit 21010001, on downstream side of left abutment of bridge on Highway 111, 1.2 mi (1.9 km) uostream 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 sq mi (47.7 sq km). 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. Datum of gage is 938.32 ft (286.000 m) above mean sea level. Prior to Nov. 17, 1966, non-recording gage and Nov. 17, 1966 tc Sept. 30, 1978 recording gage, both at present site and datum 3.00 ft (0.914 m) higher. REMARKS.--Records fair. AVERAGE DISCHARGE.--23 years (1961-83), 48.4 cu ft/s (1.371 cu m/s), 35.72 in/yr (907 mm/yr), 35,070 acre-ft/yr (43.2 cu hm/yr); median of yearly mean discharges, 47 cu ft/s (1.33 cu m/s), 34,100 acre-ft/yr (42 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 8,950 cu ft/s (253 cu m/s) May 17, 1963, gage height, 13.29 ft (4.051 m) datum then in use, from floodmark, from rating curve extended above 500 cu ft/s (14.2 cu m/s) on basis of slope-area measurement of peak flow; minimum, 6.6 cu ft/s (0.187 cu m/s) June 12, 1977, gage height, 0.12 ft (0.037 m) datum then in use. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,000 cu ft/s (85.0 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 24 1715 *1,480 41.9 8.88 2.707 Minimum discharge, 8.0 cu ft/s (0.226 cu m/s) Apr. 9, 10. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27 28 37 39 19 15 9.8 29 27 19 22 22 2 29 26 35 34 19 14 9.7 22 25 22 21 21 3 26 26 34 31 18 15 9.3 21 59 16 58 21 4 25 25 35 30 18 14 9.5 45 47 19 72 20 5 25 25 32 30 19 24 9.6 37 31 21 33 22 6 29 24 31 29 18 17 10 56 27 19 23 86 7 80 24 30 29 17 14 9.5 60 24 16 20 40 3 52 24 30 24 16 14 9.1 57 24 15 25 24 9 36 45 33 27 17 14 8.6 39 25 53 33 20 10 32 57 30 25 17 13 8.3 36 23 34 55 20 11 31 53 29 25 16 13 8.8 66 21 60 35 39 12 30 52 29 25 16 20 8.7 43 21 31 24 28 13 29 54 50 25 16 18 14 76 20 21 25 21 14 41 36 35 24 16 14 15 51 20 19 58 19 15 46 41 53 24 16 13 48 39 19 18 47 19 16 32 52 41 22 16 13 32 33 19 42 34 18 17 33 92 35 22 16 12 13 64 19 57 79 59 13 71 89 32 21 16 12 12 92 24 42 48 45 19 75 55 30 21 16 12 12 57 19 25 33 29 20 52 44 39 24 16 12 15 33 18 23 29 23 21 38 38 39 21 25 11 118 35 18 21 41 21 22 33 S6 34 21 17 11 28 70 17 20 32 50 23 31 34 32 21 16 11 22 54 16 29 27 60 24 30 137 31 23 16 11 20 74 16 25 25 36 25 29 61 30 20 15 10 18 53 15 19 3C 27 26 29 47 30 21 15 10 17 56 16 19 34 24 27 28 59 41 21 15 11 16 39 16 19 39 22 28 28 53 44 23 15 10 16 33 16 20 30 21 29 29 42 67 20 --- 10 43 31 15 21 25 21 30 34 39 64 1? 10 35 31 17 21 24 20 31 29 --- 46 19 9.9 --- 21 --- 22 23 --- TOTAL 1138 1418 1157 751 472 407.9 634.9 1465 674 803 1104 393 MEAN 36.7 47.3 37.3 24.5 16.9 13.2 20.2 47.3 22.5 26.1 35.6 29.9 MAX 10 137 67 39 25 24 118 92 59 60 79 36 MIN 25 24 29 19 15 9.9 8.3 21 15 15 20 13 CFSM 2.00 2.57 2.03 1.33 .92 .72 1.10 2.57 1.22 1.42 1.94 1.63 IN. 2.30 2.87 2.34 1.53 .95 .82 1.22 2.96 1.36 1.63 2.23 1.82 AC-FT 2260 2810 2290 1500 936 809 1200 2910 1340 1600 2190 1780 CAL YR 1982 TOTAL 11912.0 MEAN 32.6 MAX 431 MIN 14 CFSM 1.77 IN 24.03 AC-FT 23630 WTR YR 1983 TOTAL 10904.8 MEAN 29.9 MAX 137 MIN 8.3 CFSM 1.63 IN 22.05 AC-FT 21630 47 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. PERIOD OF DAILY RECORD.-- SUSPENDED SEDIMENT DISCHARGE: January 1968 to current year. REMARKS.--Sediment samples were collected by a local observer on a weekly basis and during high flow events. Estimates for period of missing daily record were made from a sediment transport curve developed from a period of record of 10 years. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 20,400 mg/L November 27, 1968; minimum daily mean, 0.0 mg/L during many years. SEDIMENT LOADS: Maximum daily, 110,000 tons (100,000 tonnes) November 27, 1968, minimum daily, 0.0 ton (0.0 tonne) during many years. EXTREMES FOR CURRENT YEAR.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 1210 mg/L Apr. 21, 1983; minimum daily mean, 0.0 mg/L several days during 1983. SEDIMENT LOADS: Maximum daily, 1,470 tons (1,330 tonnes) Nov. 24, 1982; minimum daily, 0.0 ton (0.0 tonne) several days during 1983. WATER-QUALITY DATA, WATER YEARS OCTOBER 1980 TO SEPTEMBER 1982 OXYGEN. OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, HARD- FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER AS DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CAC03) NOV r 1982 15... 1315 29 160 7.8 24.0 14 8.3 103 <10 600 730 DEC 15... 1215 78 177 7.7 21.0 9.3 108 36 K190 40000 56 JAN , 1983 26... 1120 22 173 8.1 22.0 1.9 8.7 103 <10 K100 K150 62 FEB 16... 1225 17 172 8.3 21.5 2.1 9.0 105 2500 K160 63 MAR 28... 1320 10 170 8.7 24.5 <1.0 3.4 104 15 K130 280 MAY 11... 1020 37 136 7.4 23.0 270 8.3 100 61 K8300 47000 49 AUG 29... 1205 26 177 8.3 25.0 5.0 9.0 113 16 340 440 67 SOLIDS, HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, RESIDUE NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE. RIDE. DIS- AT 180 NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- GIS- 015- SOLVED DEG. C BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L On- (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS SOLVED DATE CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS 504) AS CL) AS F) SI02) (MG/L) NOV r 1982 15... 52 DEC 15... 0 16 3.9 7.7 .5 2.7 56 8.0 7.9 .10 18 JAN • 1983 26... 3 15 6.0 8.8 .5 1.5 59 12 7.6 <.10 27 FEB 16... 7 16 5.7 8.1 .5 1.4 57 13 7.9 <.10 25 110 MAR 28... 61 MAY 11... 3 13 4.0 6.9 .4 2.0 46 9.0 7.9 <.10 19 AUG 29... 8 17 6.0 8.1 .4 1.6 59 12 7.8 <.10 26 SOLIDS, SOLIDS. NITRO- NITRO- SUM OF SOLIDS. RESIDUE NITRO- NITRO- NITRO- GEN, NITRO- NITRO'''. GEN,AM- CONSTI- DIS- AT 105 GEN, GEN. GEN. NO2+NO3 GEN. GEN. MONT!. + NITRO"' TUENTS, SOLVED DEG. C. NITRATE NITRITE NO2+N O3 DIS- AMMONIA ORGANIC OKtiANIC GEN, DIS- (TONS SUS- TOTAL TOTAL TOTAL SOLVED TOTAL TOTAL TOTAL TOTAL SOLVED PER FENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV . 1982 15... 15 .69 .010 .70 <.010 .30 1.0 DEC 15... 98 20.6 .85 JAN 0 1983 26... 113 6.7 1 <.010 .70 .020 <.10 FEB 16... 111 5.0 <.010 .60 .04C .46 .50 1.1 MAR 28... 6 .29 .010 .30 <.010 .30 .60 MAY 11... 89 8.8 279 .91 .290 1.2 .600 .00 .50 1.7 AUG 29... 114 8.0 9 <.010 .50 <.010 .30 .80 K = non-ideal count 48 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 PHOS- BARIUM. PHORUS, ARSENIC BARIUM, SUS- CADMIUM NITRO- PHOS- ORTHO. SUS- ARSENIC TOTAL PENDED BARIUM, TOTAL CADMIUM GEN. PHORUS, DIS- ARSENIC PENDED On- RECOV- RECOV- CIS- RECOV- DIS- TOTAL TOTAL SOLVED TOTAL TOTAL SOLVED ERABLE ERABLE SOLVED ERABLE SOLVED (MG/L (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UGIL (UG/L (UG/L (UG/L DATE AS NO3) NOV , 1982 AS P) AS P) AS AS) AS AS) AS AS) AS BA) AS BA) AS BA) AS CD) AS CD) 15... 4.4 .090 DEC 15... <.010 JAN , 1983 26... .010 1 100 5 FEB 16... 4.9 .030 1 0 1 100 70 34 <1 1 MAR 28... 2.7 .030 MAY 11... 7.5 .250 AUG 29... 3.5 .020 1 <100 1 CHRO.. CHRO- CHRO- COBALT, COPPER, COPPER,' MIUM. MIUM. CHRO- MIUM, COBALT, SUS- COPPER, SUS- RECOV. TOTAL SUS- MIUM, RECOV. TOTAL PENDED COBALT, TOTAL PENDED COPPER., FM BOT- RECOV- FENDED On- FM BOT- RECOV- RECOV- DIS- RECOV- RECOV- DIS- TOM MA... ERASLE RECOV. SOLVED TOM MA- ERASLE ERABLE SOLVED ERABLE ERABLE SOLVED TERIAL (UG/L (UG/L (UG/L TERIAL (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/G DATE AS CR) AS CR) AS CR) (UG/G) AS CO) AS CO) AS CO) AS CU) AS CU) AS CU) AS CU) NOV r 1982 15... 3 19 DEC 15... JAN • 1983 26... <1 FEB 16... 20 0 20 1 0 1 8 4 4 MAR 28... MAY 11... AUG 29... <1 IRON., MANGA- MANGA- MERCURY IRON., TOTAL RECOV- SUS- PENDED RECOV- IRON, DIS- LEAD, TOTAL RECOV- LEAD, On- NESE, TOTAL RECOV- NESE. SUS- PENDED MANGA- NESE, DIS- MERCURY TOTAL RECOV- SUS- PENDED RECOV- MERCURY DIS- ERABLE ERABLE SOLVED ERABLE SOLVED ERABLE RECOV. SOLVED ERABLE ERABLE SOLVED (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS FE) AS FE) AS FE) AS PB) AS PB) AS MN) AS MN) AS MN) AS HG) AS HG) AS HG) NOV 1982 15... DEC 15... 68 17 JAN 1983 26... <1 .2 FEB 16... 490 480 14 <1 <1 30 20 7 .5 .3 .2 MAR 28... MAY 11... AUG 29... 4 <.1 NICKEL, NICKEL, NICKEL, SUS- RECOV. SELE- SILVER, ZINC, TOTAL PENDED NICKEL, FM BOT- SELE- NIUM, TOTAL SILVER, TOTAL ZINC. RECOV- RECOV- DIS- TOM MA- NIUM, DIS- RECOV- DIS- RECOV- On- ERABLE ERABLE SOLVED TERIAL TOTAL SOLVED ERABLE SOLVED ERABLE SOLVED (UG/L (UG/L (UG/L (UG/G (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NI) AS NI) AS NI) AS NI) AS SE) AS SE) AS AG) AS AG) AS ZN) AS ZN) RECOV. FM BOT- TOM MA- TERIAL (UG/G AS ZN) NOV , 1982 15... <10 DEC 15... JAN 1983 26... <1 2 FEB 16... 77 72 5 <1 <1 <1 MAR 28... MAY 11... AUG 29... <1 <1 <1 20 <3 24 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 4 9 STREAMFLOWr SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT' 04 1333 25 170 25.0 JUL, 12 1253 28 131 24.5 APR, 12 1200 8.5 207 24.5 SEP. 07 1022 214 186 26.0 JUN. 01 1315 25 179 -- CHLOR- DI- PCB. *LORIN, DANEr DOD, DDE. DDT. AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 03... 1240 (.10 <.01 (.10 <.01 <.01 <.01 <.01 HEPTA- METH- DI- ENDO- HEPTA- CHLOR MALA- OXY- ELDRIN SULFAN, ENDRIN. ETHION. CHLOR. EPDXIDE LINDANE THION. CHLOR, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN . 1983 03... <.01 <.10 <.01 <.01 <.01 <.01 <.01 <.01 <.01 NAPH- THA- METHYL METHYL LENES. PARA- TRI- PARA- POLY- PER- TOX- TOTAL THION, THION, MIREX. THION. CHLOR. THANE APHENE, TRI- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL THION DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 03... <.01 <.01 <.01 <.01 (.10 <.10 <1 (.01 SED. SED. SEQ. SEQ. SUSP. SUSP. SUSP. SUSP. STREAM- SEDI- FALL FALL FALL FALL FLOW, MENT, DIAM. DIAM. DIAM. DIAM. INSTAN- SUS- % FINER X FINER % FINER X FINER TIME TANEOUS FENDED THAN THAN THAN THAN DATE (CFS) (MG/L) .002 MM .004 MM .008 MM .016 MM AUG . 1983 10... 1750 E2860 3500 1 4 14 26 10... 1805 E3350 3960 3 6 17 31 10... 1820 E2780 3320 2 5 12 32 10... 1830 E2110 2660 2 3 7 24 SED. SEO. SED. SED. SEQ. SEO. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. % FINER % FINER % FINER B FINER % FINER % FINER THAN THAN THAN THAN THAN THAN DATE .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM AUG 10... 44 82 83 94 97 99 10... 53 34 92 96 98 99 10... 54 84 91 94 97 99 10... 43 79 90 93 95 99 SED. SED. SEQ. SED. SED. SEQ. BED SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. MAT. STREAM- FALL FALL FALL FALL FALL FALL FALL FLOW. D1AM. DIAM. DIAM. DIAM. DIAN. DIAM. QIAM. INSTAN- X FINER % FINER % FINER % FINER % FINER % FINER % FINER TIME TANEOUS THAN THAN THAN THAN THAN THAN THAN DATE (CFS) 002 MM .004 MM .003 MM .016 MM .031 MM .062 MM .004 MM DEC . 1982 15... 1215 78 0 1 1 1 2 2 1 JAN , 1983 26... 1120 22 0 0 0 1 1 1 0 FEB 16... 1225 17 0 0 0 0 1 1 0 BED BED BED BED BED BED BED BED MAT. MAT. MAT. MAT. MAT. MAT. MAT. MAT. FALL SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. QIAM. DIAM. DIAM. DIAM. % FINER % FINER X FINER I FINER X FINER % FINER % FINER % FINER THAN THAN THAN THAN THAN THAN THAN THAN DATE .062 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM 2.00 MM 4.00 MM DEC 15... 2 2 3 5 22 54 74 89 JAN 26... 1 1 1 3 7 25 52 68 FEB 16... 1 1 1 3 13 38 61 72 E = estimate 50 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO. PR--Continued WATER QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/I) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 27 10 .73 28 11 .83 37 211 22 2 29 99 8.7 26 19 1.3 35 164 15 3 26 64 4.6 26 69 4.8 34 152 14 4 25 24 1.6 25 9 .61 35 164 15 5 25 5 .34 25 36 2.4 32 123 11 6 29 104 13 24 22 1.4 31 7 .59 7 80 793 622 24 14 .91 30 96 7.8 8 52 590 96 24 25 1.6 30 96 7.8 9 36 89 8.7 45 268 79 33 151 16 10 32 17 1.5 57 457 142 30 115 9.3 11 31 10 .84 53 329 59 29 82 6.4 12 30 12 .97 52 333 70 29 82 6.4 13 29 22 1.7 54 372 69 50 320 133 14 41 235 63 36 135 20 35 226 24 15 46 359 51 41 236 47 53 348 65 16 32 21 1.8 52 416 77 41 218 25 17 33 133 13 92 845 414 35 164 15 18 71 533 583 89 932 309 32 123 11 19 75 911 263 55 549 86 30 96 7.8 20 52 392 58 44 326 40 38 203 24 21 38 23 2.4 38 207 21 39 222 23 22 33 43 3.8 36 112 11 34 152 14 23 31 20 1.7 34 152 14 32 123 11 24 30 8 .65 137 1170 1470 31 110 9.2 25 29 12 .94 61 648 116 30 96 7.8 26 29 3 .23 47 360 51 30 96 7.8 27 28 8 .60 59 470 85 41 262 37 28 28 14 1.1 53 432 62 44 300 36 29 28 148 11 42 145 16 67 542 146 30 34 15 1.4 39 231 25 64 582 125 31 29 11 .86 --- --- --- 46 336 43 TOTAL 1138 1818.16 1418 3296.85 1157 895.89 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 39 222 23 19 5 .26 15 0 .00 2 34 152 14 19 5 .26 14 0 .00 3 31 13 1.1 18 3 .15 15 0 .00 4 30 96 7.3 18 3 .15 14 0 .00 5 30 96 7.8 19 5 .26 24 123 28 6 29 82 6.4 18 3 .15 17 3 .15 7 29 82 6.4 17 30 1.4 14 45 1.7 8 28 69 5.2 16 1 .04 14 0 .00 9 27 58 4.2 17 2 .09 14 0 .00 10 25 60 4.1 17 2 .09 13 0 .00 11 25 36 2.4 16 1 .04 13 0 .00 12 25 36 2.4 16 1 .04 20 50 5.3 13 25 36 2.4 16 1 .04 18 10 .65 14 24 27 1.7 16 56 2.4 14 41 1.5 15 24 27 1.7 16 1 .04 13 0 .00 16 22 16 .95 16 1 .04 13 0 .00 17 22 60 3.6 16 1 .04 12 0 .00 18 21 11 .62 16 1 .04 12 0 .00 19 21 11 .62 16 1 .04 12 0 .00 20 24 27 1.7 16 1 .04 12 0 .00 21 21 11 .62 25 37 2.5 11 65 1.9 22 21 11 .62 17 2 .09 11 0 .00 23 21 11 .62 16 1 .04 11 0 .00 24 20 104 5.6 16 1 .04 11 0 .00 25 20 8 .43 15 0 .00 10 0 .00 26 21 11 .62 15 0 .00 10 0 .00 27 21 11 .62 15 0 .00 11 0 .00 28 20 8 .43 15 0 .00 10 37 1.0 29 20 8 .43 --- 10 0 .00 30 19 5 .26 10 0 .00 31 19 39 2.0 9.9 0 .00 TOTAL 758 110.34 472 8.28 407.9 40.20 51 RIO GRANDE DE ARECIBO BASIN 50028000 RIO TANAMA NEAR UTUADO, PR-Continued WATER QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (mG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 9.8 0 .00 29 110 16 27 58 4.2 2 9.7 0 .00 22 16 1.0 25 36 2.4 3 9.3 0 .00 21 16 1.0 59 533 372 4 9.5 27 .69 45 367 132 47 346 55 5 9.6 0 .00 37 200 25 31 110 9.2 6 10 0 .00 56 462 206 27 58 4.2 7 9.5 0 .00 60 552 164 24 27 1.7 8 9.1 0 .00 57 494 115 24 27 1.7 9 8.6 0 .00 39 226 26 25 36 2.4 10 8.3 0 .00 36 176 40 23 20 1.2 11 8.8 57 1.4 66 587 222 21 11 .62 12 8.7 0 .00 43 285 35 21 11 .62 13 14 30 2.3 76 730 228 20 8 .43 14 15 3 .16 51 406 56 20 8 .43 15 48 434 226 39 226 24 19 5 .26 16 32 161 28 33 137 12 19 5 .26 17 13 0 .00 64 526 209 19 5 .26 18 12 34 1.1 92 959 496 24 27 1.7 19 12 0 .00 57 498 84 19 5 .26 20 15 88 30 38 219 23 18 3 .15 21 118 1210 642 35 180 18 18 3 .15 22 28 69 5.5 70 651 268 17 2 .09 23 22 16 .95 54 445 68 16 1 .04 24 20 8 .43 74 701 241 16 1 .04 25 18 27 1.3 53 441 66 15 0 .00 26 17 2 .09 56 469 108 16 1 .04 27 16 1 .04 39 227 25 16 1 .04 28 16 1 .04 33 137 12 16 1 .04 29 43 385 181 31 110 9.2 15 0 .00 30 35 182 26 31 110 9.2 17 2 .09 31 --- --- --- 28 69 5.2 --- --- TOTAL 604.9 1147.50 1465 2944.6 674 459.52 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (M0/1) (TONS/DAY) JULY AUGUST SEPTEMBER 1 19 30 4.0 22 19 1.4 22 16 .95 2 22 37 3.3 21 14 .84 21 11 .62 3 16 1 .04 58 454 291 21 11 .62 4 19 36 3.7 72 643 250 20 8 .43 5 21 17 1.1 33 150 17 22 16 .95 6 19 8 .44 23 20 1.2 86 975 1330 7 16 1 .04 20 8 .43 40 249 33 8 15 0 .00 25 121 28 24 27 1.8 9 53 440 278 33 150 20 20 8 .43 10 34 167 24 55 540 355 20 8 .43 11 60 514 224 35 169 19 39 255 72 12 31 112 11 24 27 1.7 28 71 6.3 13 21 11 .62 25 49 4.4 21 11 .62 14 19 5 .26 58 544 284 19 5 .26 15 18 3 .15 47 353 55 19 5 .26 16 42 310 109 34 163 17 18 3 .15 17 57 522 184 79 725 299 59 479 253 18 42 270 39 48 361 51 45 313 56 19 25 36 2.4 33 128 11 29 86 7.5 20 23 20 1.2 29 83 7.0 23 20 1.2 21 21 11 .62 41 255 32 21 11 .62 22 20 8 .43 32 124 11 50 433 197 23 29 219 53 27 58 4.2 60 484 197 24 25 58 5.1 25 36 2.4 36 180 19 25 19 5 .26 30 116 22 27 58 4.2 26 19 5 .26 34 152 16 24 27 1.7 27 19 5 .26 39 235 49 22 16 .95 28 20 8 .43 30 90 7.6 21 11 .62 29 21 11 .62 25 36 2.4 21 11 .62 30 21 11 .62 24 27 1.7 20 8 .43 31 22 16 .95 23 20 1.2 --- --- --- TOTAL 808 948.80 1104 1863.47 898 2183.66 YEAR 10904.3 15722.27 52 RIO GRANDE DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR LOCATION.--Lat 18°24'52", long 66°42'52", on right bank of abandoned power house at Charco Hondo, 1.5 mi (2.4 km) upstream from mouth, and 4 mi (6 km) south of Arecibo. DRAINAGE AREA.--57.6 sq mi (149.2 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April 1969 to June 1971, October 1981 to current year. GAGE.--Water-stage recorder. Altitude of gage is 60 ft (18 m), from topographic map. REMARKS.--Records fair. Diversion 0.8 mi (1.3 km) upstream from municipal supply of Arecibo. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 4,120 cu ft/s (117 cu m/s) Apr. 21, 1969, gage height, 12.22 ft (3.725 m) from floodmark, from rating curve extended above 1,000 cu ft/s (28 cu m/s); minimum, 30 cu ft/s (0.850 cu m/s) Apr. 11-13, 1983. EXTREMES FOR WATER YEARS 1982-83.--Peak discharges above base of 1,000 cu ft/s (28.3 cu m/s) and maximums (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Oct. 25, 1981 1800 1,910 54.1 9.95 3.033 Nov. 9, 1981 1300 3,420 96.8 11.88 3.621 Nov. 3 1830 1,460 41.3 9.19 2.801 Dic. 14 0900 2,040 57.8 10.14 3.091 Nov. 5 1900 1,560 44.2 9.37 2.856 Sept. 13, 1982 0400 *3,970 112 12.45 3.795 Nov. 8 1830 1,840 52.1 9.83 2.996 Nov. 24 2030 *1,360 38.5 9.00 2.743 Nov. 9 0230 2,680 75.9 11.03 3.362 Minimum discharges, 46 cu ft/s (1.303 cu m/s) Apr. 24, 25, May 2, 3, 1982; 30 cu ft/s (0.850 cu m/s) Apr. 11-13, 1983. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1981 TC SEPTEMBER 1982 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 72 231 103 123 75 57 52 51 113 51 58 100 2 78 204 100 118 76 56 52 46 101 50 68 121 3 72 369 96 113 39 56 52 126 180 49 59 71 4 71 344 94 109 75 55 58 123 130 50 66 63 5 71 430 92 103 86 54 131 163 110 75 118 60 6 79 449 88 97 90 54 70 180 100 174 60 65 7 160 253 85 94 80 54 58 190 110 155 56 114 8 120 346 34 93 75 54 53 180 120 76 85 66 9 107 1270 82 92 70 54 52 120 101 61 112 60 10 91 530 30 89 67 54 53 110 85 104 117 71 11 155 360 175 86 67 53 72 200 76 59 146 85 12 155 264 166 86 64 54 54 130 65 53 78 123 13 119 186 490 82 67 53 53 240 60 53 89 336 14 97 168 1160 11 67 53 52 160 58 67 77 253 15 90 152 630 80 66 54 52 120 56 89 109 136 16 98 133 444 73 66 55 93 100 55 67 71 100 17 155 121 332 77 67 54 71 200 54 92 63 115 18 155 131 261 76 66 54 57 120 53 62 67 192 19 111 221 237 76 62 54 55 81 52 80 62 205 20 204 178 210 76 61 54 52 123 51 208 58 138 21 254 117 200 76 61 54 52 173 50 245 56 109 22 164 113 194 75 61 53 50 100 50 94 55 90 23 184 114 183 74 60 51 51 138 49 86 75 82 24 260 162 178 74 58 51 46 122 49 72 61 77 25 433 112 172 74 56 52 50 126 49 72 69 74 26 306 146 167 74 56 52 50 96 48 84 85 67 27 228 303 156 105 56 52 49 116 48 71 60 64 28 253 152 143 179 57 51 48 220 48 62 70 61 29 243 117 136 85 --- 51 52 194 51 61 144 60 30 234 109 128 90 51 54 153 53 62 33 81 31 260 --- 126 80 59 --- 130 --- 59 64 --- TOTAL 5129 7789 6792 2315 1901 1663 1744 4336 2225 2643 2441 3739 MEAN 165 260 219 90.9 67.9 53.6 58.1 140 74.2 85.3 78.7 125 MAX 433 1270 1160 179 90 59 131 240 130 245 146 336 MIN 71 109 80 74 56 51 46 46 48 49 55 60 CFSM 2.87 4.51 3.30 1.58 1.18 .93 1.31 2.43 1.29 1.43 1.37 2.17 IN. 3.31 5.03 4.39 1.82 1.23 1.07 1.13 2.80 1.44 1.71 1.58 2.41 AC-FT 10170 15450 13470 5580 3770 3300 3460 8600 4410 5240 4840 7420 WTR YR 1982 TOTAL 43217 MEAN 113 MAX 1270 MIN 46 CFSM 2.05 IN 27.91 AC-FT 85720 53 RIO GRIME DE ARECIBO BASIN 50028400 RIO TANAMA AT CHARCO HONDO, PR--Continued DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 71 53 95 100 51 40 33 63 69 39 43 45 2 58 51 90 90 51 39 32 91 52 45 44 45 3 76 50 35 85 50 35 31 47 68 39 41 44 4 74 50 86 81 49 41 31 52 117 39 122 44 5 93 49 31 76 48 43 31 118 70 49 92 43 6 76 43 72 76 49 65 32 137 94 43 49 81 7 92 41 70 72 49 42 32 193 38 39 46 112 3 125 43 69 67 48 40 31 164 64 38 45 60 9 85 82 67 64 48 39 31 161 61 40 64 50 10 60 169 71 62 48 33 31 87 60 109 62 47 11 58 134 64 61 48 33 30 1C3 62 76 90 50 12 58 145 66 60 48 37 30 181 60 83 59 76 13 57 136 62 57 48 47 34 272 52 50 50 51 14 56 88 100 55 47 39 50 376 50 44 65 46 15 81 76 75 58 47 38 40 173 48 43 103 45 16 80 190 110 56 47 36 116 116 46 52 60 45 17 59 128 90 55 47 36 48 177 46 81 156 66 18 58 185 75 55 47 35 40 219 48 100 156 106 19 150 183 70 55 46 34 43 185 46 54 69 87 20 104 133 70 55 46 35 45 104 45 48 57 55 21 74 96 35 52 53 35 241 86 44 45 62 52 22 64 88 35 51 49 34 70 138 43 44 68 68 23 62 81 75 51 45 34 47 163 41 42 53 86 24 60 217 70 51 44 34 42 143 40 67 50 77 25 59 330 70 51 43 33 38 157 40 45 48 65 26 58 135 70 50 42 34 36 166 38 41 59 63 27 62 110 70 50 41 33 34 204 38 40 62 53 23 57 135 90 51 40 33 33 123 38 40 76 63 29 56 120 95 51 --- 33 41 93 38 41 52 55 30 56 110 135 52 32 114 90 38 43 47 47 31 56 --- 110 52 33 --- 94 --- 44 48 --- TOTAL 2235 3473 2523 1902 1319 1163 1437 4486 1654 1608 2098 1323 MEAN 72.1 116 81.4 61.4 47.1 37.7 49.6 145 55.1 51.9 67.7 60.9 MAX 150 330 135 100 53 65 241 376 117 109 156 112 MIN 56 48 62 50 40 32 30 47 38 33 41 43 CFSM 1.25 2.01 1.41 1.07 .82 .66 .86 2.52 .96 .90 1.18 1.06 IN. 1.44 2.25 1.63 1.23 .85 .75 .96 2.90 1.07 1.04 1.35 1.18 AC-FT 4430 6900 5000 3770 2620 2320 2950 8900 3230 3190 4160 3630 CAL YR 1982 TOTAL 31743 MEAN 87.0 MAX 836 MIN 46 CFSM 1.51 IN 20.50 AC-FT 62960 WTR YR 1983 TOTAL 25786 MEAN 70.6 MAX 376 MIN 30 CFSM 1.23 IN 16.65 AC-FT 51150 WATER-2UALITY RECORDS PERIOD OF RECORD.--MARCH TO SEPTEMBER 1983 WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEM3ER 1913 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- OATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS OUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) MAR, 14 1322 39 311 24.0 JUL, 13 1003 49 265 24.0 APR, 05 1320 31 354 23.0 AUG, 09 1407 65 248 25.5 MAY, 16 1532 140 303 24.5 SEP, 01 1503 46 259 27.0 JUN, 02 1420 62 276 -- 54 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR LOCATION.--Lat 18°27'20", long 66°42'10", Hydrologic Unit 21010002, at bridge on unimproved road, about 500 ft (152 m) upstream from Central Cambalache, near Highway 2, 13.9 mi (22.4 km) downstream from Dos Bocas Reservoir, 1.9 mi (3.1 km) downstream from Rio Tanamg, and 1.6 mi (2.6 km) southeast of Arecibo. DRAINAGE AREA. --200 sq mi (520 sq km), approximately. 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 (discontinued). GAGE.--Water-stage recorder. Datum of gage is 3.73 ft (1.137 m) above mean sea level. REMARKS.--Records very poor. Flow regulated by Lago Dos Bocas dam, 13.9 mi (22.4 km) upstream. AVERAGE DISCHARGE.--14 years (1970-83), 510 cu ft/s (14.44 cu m/s), 369,500 acre-ft/yr (456 cu hm/yr); median of yearly mean discharges, 504 cu ft/s (14.27 cu m/s), 365,000 acre-ft/yr (450 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 26,100 cu ft/s (739 cu m/s) Aug. 31, 1979, gage height, 13.74 ft (4.188 m) from rating curve extended above 6,000 cu ft/s (170 cu m/s); minimum, 50 cu ft/s (1.416 cu m/s) Feb. 26, 1974, gage height, 4.25 ft (1.295 m). EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations above mean sea level of major floods at valley cross sections along Expressway PR-22 about 1.0 mi (1.6 km) above gage site are as follows: Aug. 8, 1899, 195,000 cu ft/s (5,520 cu m/s), gage height, 24.4 ft (7.44 m); Sept. 13, 1928, 105,000 cu ft/s (2,970 cu m/s), gage height, 21.6 ft (6.58 m); Oct. 13, 1954, 76,000 cu ft/s (2,150 cu m/s), gage height, 19.1 ft (5.82 m); and Nov. 26, 1968, 21,000 cu ft/s (595 cu m/s) gage height, 16.6 ft (5.06 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 4,350 cu ft/s (123 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 1345 8,680 246 11.66 3.554 Minimum daily discharge , 63 cu ft/s (1.784 cu m/s) Mar. 3. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 1020 465 283 150 850 114 138 320 400 210 267 240 2 319 277 270 700 169 90 270 500 183 133 137 193 3 279 403 169 110 99 63 208 250 560 135 103 36 4 222 289 453 300 85 191 252 400 532 144 169 97 5 598 184 222 300 156 151 124 1100 284 728 610 290 6 564 377 586 350 127 136 104 1200 45E 678 220 397 7 514 254 988 300 266 137 227 140 420 721 121 526 8 318 386 686 180 328 133 398 200 419 677 390 123 9 162 555 730 250 204 193 521 800 447 234 501 166 10 314 425 476 900 260 260 223 1200 494 590 541 129 11 333 602 553 1100 279 192 131 600 470 185 310 119 12 137 803 252 250 243 271 254 550 306 139 295 131 13 479 1930 374 550 133 642 143 2000 483 117 415 410 14 423 852 495 170 107 524 313 1300 460 143 314 753 15 305 952 265 110 173 162 314 1200 566 126 350 170 16 150 2110 489 95 233 153 323 400 292 100 291 369 17 176 '334 360 600 244 247 265 400 427 274 476 892 13 400 952 268 1200 177 252 380 1000 599 377 441 474 19 828 1110 114 1100 188 281 292 2000 480 276 217 673 20 766 453 330 400 234 627 229 2000 690 216 132 372 21 186 314 629 1200 322 346 7000 1100 161 415 250 777 22 578 827 449 450 130 196 2000 1200 264 410 574 297 23 417 717 336 400 165 376 1600 2500 120 137 309 178 24 358 951 150 1000 320 154 1300 1300 508 211 158 153 25 474 2410 100 150 174 213 600 1700 251 104 150 128 26 241 1430 120 130 222 154 200 1300 268 691 95 183 27 304 810 2000 220 133 186 120 2000 238 155 201 468 28 213 1263 1500 350 166 113 160 1000 401 242 270 330 29 535 1050 1000 200 --- 281 830 250 426 193 478 516 30 510 291 1800 250 361 300 1000 397 149 374 161 31 411 --- 600 600 165 --- 900 --- 102 477 --- TOTAL 12509 24283 17047 15065 6187 7379 19239 32310 12054 9122 9636 10356 MEAN 404 309 550 486 221 233 641 1042 402 294 311 362 MAX 1020 2410 2000 1200 850 642 7000 2500 690 723 610 892 MIN 137 184 100 95 35 63 104 140 120 100 95 86 AC-FT 24810 48170 33810 29380 12270 14640 35160 64090 23910 18090 19110 21530 CAL YR 1982 TOTAL 166790 MEAN 457 MAX 3200 MIN 60 AC-FT 330800 WTR YR 1983 TOTAL 175637 MEAN 481 MAX 7000 MIN 63 AC-FT 343500 RIO GRANDE DE ARECIBO BASIN 50029000 RIO GRANDE DE ARECIBO AT CENTRAL CAMBALACHE, PR--Continued 55 WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1963-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN. OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 11... 1300 E1460 257 7.1 25.5 49 7.1 87 18 22000 3500 FEB p 1983 1... 1400 147 247 7.7 24.0 4.3 10.3 122 12 2000 K140 MAR 25... 1245 86 290 8.0 23.0 <1.0 13.0 166 47 K50 K140 MAY 2... 1115 E300 245 7.4 25.0 12 7.6 92 12 K1700 3000 JUN 16... 1115 E235 253 8.2 27.0 AUG 12... 1125 118 255 7.9 27.0 65 7.6 96 27 2400 3200 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUMp LINITY SULFATE RIDE. RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1932 11... 92 FEB , 1933 1... 110 4 36 5.9 9.7 .4 1.4 110 10 9.8 1000000 MAY 10... 1430 6.4 478 7.2 30.0 4.5 .0 0 74 K1.0E+07 AUG 15... 1440 5.4 563 6.9 31.0 .0 0 220 5800000 STREP- TOCOCCI HARD- MAGNE- SODIUM POTAS- ALKA- FECAL, HARD- NESS, CALCIUM SLUM, SODIUM, AD- SIUM, LINITY SULFATE KF AGAR NESS NONCAR- DIS- DIS.". DIS- SORP- DIS- FIELD DIS- (COLS. (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED PER AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L DATE 100 ML) CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) NOV , 1982 08... K110000 190 JAN f 1983 14... K550000 150 0 47 8.4 43 1.6 7.1 170 21 MAR 09... >1000000 200 MAY 10... 6100000 160 0 51 8.6 47 1.7 6.5 200 23 AUG 15... K982000 170 10 55 8.8 40 1.4 6.0 164 14 SOLIDS, SOLIDS, CHLO- FLUO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. C, NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L DATE AS CL) AS F) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) NOV , 1982 08... 14 .020 (.10 12.0 .00 JAN , 1983 14... 54 .20 26 309 4.1 30 .030 <.10 13.0 47 MAR 09... 6 .010 <.10 11.0 5.0 MAY 10... 52 .20 26 334 5.8 <1 .020 <.10 6.30 3.0 AUG 15... 48 .20 25 295 4.3 13 .060 <.10 .040 13 NITRO- CHRO- GEN,AM- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, MONIA + PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL ORGANIC PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS N) AS P) AS AS) AS 8A) AS CD) AS CR) AS P8) AS HG) AS SE) AS AG) NOV r 1982 08... 12.0 2.50 JAN , 1983 14... 60.0 2.80 3 100 1 10 4 .2 <1 <1 MAR 09... 16.0 2.90 MAY 10... 9.30 3.10 AUG 15... 13.0 3 200 4 <1 8 1.0 <1 <1 K = non-ideal count; (1.0E+07 = 10000000) 103 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR LOCATION.--Lat 18°07'10", long 65°59'22", Hydrologic Unit 21010005, at intersection of Highways 181 and 9990, 0.2 mi (0.3 km) above con­ fluence with Rio Emajagua and about 7.1 mi (11.4 km) southwest of San Lorenzo. DRAINAGE AREA.--6.00 sq mi (15.54 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder. Altitude of gage is 175 ft (53.3 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--6 years (1978-83), 31.4 cu ft/s (0.889 cu m/s), 71.07 in/yr (1,810 mm/yr), 22,750 acre-ft/yr (28.1 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 8,950 cu ft/s (253 cu m/s) July 18, 1979, gage height 13.4 ft (4.08 m) from floodmark, from rating curve extended above 500 cu ft/s (14.2 cu m/s) on basis of step-backwater analysis; minimum, 2.8 cu ft/s (0.079 cu m/s) May 5,6, 1979. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,000 cu ft/s (56.6 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) June 16 0245 *2,660 75.3 8.92 2.719 June 18 0500 2,000 56.6 8.20 2.499 Minimum discharge, 4.9 cu ft/s (0.139 cu m/s) Apr. 8-13. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 25 38 94 20 10 6.9 5.9 7.6 13 25 134 23 2 19 24 46 18 10 6.4 5.9 8.1 12 46 63 41 3 17 22 33 16 9.8 6.6 5.6 8.8 10 41 32 28 4 16 23 40 21 11 6.4 5.4 7.4 11 291 27 24 5 15 53 30 44 11 5.9 5.4 8.0 11 174 33 21 6 15 40 26 29 10 5.3 5.9 16 20 91 24 19 7 14 33 24 22 10 6.2 5.4 10 12 88 21 18 3 14 39 22 22 9.8 12 5.1 7.7 12 48 20 18 9 14 29 21 84 9.2 17 4.9 7.0 26 38 19 17 10 13 34 20 31 8.9 6.6 4.9 6.6 13 33 20 16 11 12 42 20 23 8.5 6.4 4.9 5.8 11 30 25 17 12 11 66 19 29 8.2 64 4.9 6.0 11 27 31 18 13 34 42 17 20 8.7 22 5.4 6.4 21 26 32 16 14 14 26 17 17 9.9 12 6.2 11 92 25 33 15 15 12 23 26 16 8.5 11 5.9 10 95 23 31 18 16 13 24 18 17 7.8 9.2 5.6 8.7 296 25 72 25 17 56 23 16 16 8.5 8.1 13 13 60 26 188 18 18 30 52 15 14 7.7 7.8 30 14 192 34 78 16 19 53 61 14 13 7.2 7.6 12 97 39 29 43 14 20 67 136 22 12 7.2 7.4 18 27 34 30 38 16 21 55 39 16 12 8.5 7.2 115 13 27 23 178 102 22 31 28 22 11 7.2 7.2 16 10 23 21 43 39 23 167 30 15 11 6.8 7.0 9.8 23 22 81 28 38 24 32 25 16 11 6.9 7.1 8.1 172 20 52 25 48 25 28 24 14 15 6.9 6.7 7.1 44 19 22 59 65 26 25 22 14 19 6.9 5.9 6.6 24 18 19 54 128 27 21 22 13 13 7.5 5.8 8.8 18 31 18 36 38 28 27 28 13 12 7.5 5.8 16 16 20 62 92 37 29 20 27 12 11 --- 5.4 9.3 14 17 125 33 25 30 39 99 21 12 5.6 7.0 18 44 36 29 58 31 46 --- 78 11 5.9 --- 14 --- 36 25 --- TOTAL 955 1174 774 621 240.1 304.4 364.0 652.1 1232 1645 1566 976 MEAN 30.8 39.1 25.0 20.0 8.58 9.82 12.1 21.0 41.1 53.1 50.5 32.5 MAX 167 136 94 84 11 64 115 172 296 291 188 128 MIN 11 22 12 11 6.8 5.3 4.9 5.8 10 18 19 14 CFSM 5.13 6.52 4.17 3.33 1.43 1.64 2.02 3.50 6.85 8.85 8.42 5.42 IN. 5.92 7.28 4.30 3.35 1.49 1.89 2.26 4.04 7.64 10.20 9.71 6.05 AC-FT 1890 2330 1540 1230 476 604 722 1290 2440 3260 3110 1940 CAL YR 1982 TOTAL 10241.8 MEAN 28.1 MAX 304 MIN 5.6 CFSM 4.63 IN 63.49 AC-FT 20310 WTR YR 1983 TOTAL 10503.6 MEAN 28.8 MAX 296 MIN 4.9 CFSM 4.80 IN 65.11 AC-FT 20830 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 12 1345 11 132 29.0 MAY. 12 0915 6.4 157 26.0 NOV. 03 1350 20 140 26.5 JUN. 22 1330 23 129 29.0 DEC. 15 1200 17 -- 23.5 JUL, 13 1245 26 178 27.0 JAN. 18 1000 15 163 22.5 JUL, 27 0920 20 142 26.0 FEB, 10 1200 9.2 180 23.5 AUG. 02 1110 52 113 26.0 MAR, 01 1212 6.9 152 27.0 SEP. 08 1355 18 133 29.5 APR, 19 1200 3.8 165 28.0 -- 104 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18°09'27", long 65°57'29", Hydrologic Unit 21010005, on top of pumphouse at dam off Highway 912, at Barrio Cerro Gordo, 2.0 mi (3.2 km) south of San Lorenzo. DRAINAGE AREA.--10.2 sq mi (26.4 sq km). WATER DISCHARGE RECORDS PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder and concrete control. Altitude of gage is 150 ft (46 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--6 years (1978-83), 49.4 cu ft/s (1.399 cu m/s), 65.77 in/yr (1,671 mm/yr), 35,790 acre-ft/yr (44.1 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 13,200 cu ft/s (374 cu m/s), Aug. 31, 1979, gage height 9.44 ft (2.877 m), from rating curve extended above, 1,000 cu ft/s (28.3 cu m/s) on the basis of slope-area measurement; minimum discharge, 7.1 cu ft/s (0.201 cu m/s), Feb. 4, May 3, 1981, Apr. 12, 13, 16, 17, 1983. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,500 cu ft/s (70.8 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) June 18 0615 *5,920 168 7.27 2.216 Aug. 21 1230 3,250 92 6.01 1.832 Minimum discharge, 7.1 cu ft/s (0.201 cu m/s) Apr. 12, 13, 16, 17. DISCHARGE. IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 31 55 187 34 21 15 12 17 18 27 110 43 2 29 43 55 32 21 14 11 13 17 38 109 71 3 27 37 44 29 20 13 11 17 16 38 40 48 4 26 37 45 31 21 13 12 15 18 145 36 43 5 26 70 44 41 20 13 11 18 16 806 36 40 6 25 55 38 40 19 13 9.9 17 17 172 35 38 7 24 40 36 32 19 14 9.5 18 14 90 31 37 8 24 49 35 31 19 20 9.2 14 15 58 30 36 9 23 38 34 53 18 21 .8.3 13 24 47 28 35 10 23 43 33 42 18 15 8.3 13 17 41 29 34 11 22 54 32 34 18 15 8.5 12 14 38 27 35 12 23 43 32 42 18 119 8.2 11 16 37 25 33 13 29 51 31 31 18 42 8.5 13 14 35 25 31 14 28 37 32 29 19 26 10 17 24 34 30 30 15 24 34 37 23 19 23 11 19 27 32 25 32 16 24 44 33 23 17 22 8.3 18 134 34 35 38 17 51 38 31 26 17 22 9.7 17 51 47 218 33 18 47 46 31 26 17 21 39 16 702 58 70 31 19 86 88 29 25 17 20 19 21 47 41 39 30 20 178 105 39 25 17 19 23 25 36 35 34 30 21 51 65 31 24 18 17 87 15 34 33 476 47 22 49 42 31 23 17 16 29 14 29 31 78 44 23 209 43 29 23 16 15 21 22 27 36 51 43 24 50 37 30 23 17 16 19 168 26 83 47 86 25 44 37 27 30 17 16 17 62 24 32 88 44 26 40 35 28 32 17 15 16 34 21 29 104 92 27 37 33 28 24 16 14 17 27 34 28 57 39 28 38 38 28 23 16 14 33 25 25 32 91 35 29 33 40 27 22 --- 13 26 22 21 123 53 30 30 42 101 28 22 12 17 20 24 48 51 32 31 48 --- 73 21 12 --- 20 --- 46 45 --- TOTAL 1411 1483 1238 926 507 640 529.4 758 1552 2374 2153 1240 MEAN 45.5 49.4 39.9 29.9 18.1 20.6 17.6 24.5 51.7 76.6 69.5 41.3 MAX 209 105 187 53 21 119 87 168 702 806 476 92 MIN 22 33 27 21 16 12 8.2 11 14 27 25 30 CFSM 4.46 4.84 3.91 2.93 1.78 2.02 1.73 2.40 5.07 7.51 6.81 4.05 IN. 5.15 5.41 4.51 3.38 1.85 2.33 1.93 2.76 5.66 8.66 7.85 4.52 AC-FT 2800 2940 2460 1340 1010 1270 1050 1500 3080 4710 4270 2460 CAL YR 1982 TOTAL 14811.1 MEAN 40.6 MAX 741 MIN 7.8 CFSM 3.98 IN 54.01 AC-FT 29380 WTR YR 1983 TOTAL 14811.4 MEAN 40.6 MAX 306 MIN 8.2 CFSM 3.98 IN 54.01 AC-FT 29380 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TORE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT. 12 1030 24 121 25.5 MAY. 11 1330 12 136 30.0 NOV, 03 1040 36 128 24.0 JUN. 28 1216 26 28.5 DEC. 15 1000 31 112 22.0 JUL, 14 1240 34 133 27.5 JAN. 17 1320 27 156 23.0 JUL, 26 1350 29 126 30.0 FEB, 1C 0940 19 173 21.0 AUG, 18 1025 63 90 25.0 MAR. 01 0929 16 136 23.5 SEP. 07 1400 38 122 28.0 APR. 21 1615 97 175 28.0 105 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR LOCATION .--Lat 18°14'33", long 66°00'34", Hydrologic Unit 21010005, on right bank 250 ft (76 m) upstream from bridge on Highway 189, 1.2 mi (1.9 km) downstream from Rio Turabo, and 1.8 mi (2.9 km) east of Plaza de Caguas. DRAINAGE AREA.--89.8 sq mi (232.6 sq km). 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 (datum of 1941). REMARKS.--Records fair. AVERAGE DISCHARGES.--23 years (1961-83), 219 cu ft/s (6.202 cu m/s), 33.12 in/yr (841 mm/yr), 158,700 acre-ft/yr (196 cu hm/yr); median of yearly mean discharges, 210 cu ft/s (5.95 cu m/s), 152,000 acre-ft/yr (187 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 71,500 cu ft/s (2,025 cu m/s) Sep. 6, 1960, gage height, 31.17 ft (9.501 m), from rating curve extended above 6,000 cu ft/s (170 cu m/s) on basis of slope-area measurement; minimum daily discharge, 10 cu ft/s (0.283 cu m/s) Apr. 5, 10, 29, 1968. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 8,000 cu ft/s (227 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Mar. 12 1700 9,090 257 14.42 4.395 July 5 1400 *11,800 334 15.63 4.764 July 4 2130 9,090 257 14.42 4.395 Aug. 21 1330 10,200 289 14.95 4.557 Minimum discharge, 34 cu ft/s (0.963 cu m/s) Apr. 13. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1?82 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 235 491 873 223 84 59 46 69 80 118 194 208 2 160 236 381 162 86 53 45 75 73 281 550 420 3 142 185 281 140 33 53 44 77 71 178 199 260 4 131 169 239 152 81 51 44 75 72 1060 163 210 5 126 241 258 188 85 51 40 81 70 3940 167 180 6 120 255 190 216 75 50 45 71 117 1200 163 150 7 115 198 174 177 75 63 41 95 105 847 131 140 8 111 196 161 152 74 74 40 67 68 474 120 140 9 106 163 153 401 71 123 40 56 131 296 113 130 10 102 185 143 268 70 71 38 52 96 229 113 120 11 100 386 137 182 70 57 41 48 68 192 107 130 12 98 646 132 244 65 2060 40 47 73 171 134 140 13 562 779 128 166 70 532 36 67 66 157 175 124 14 235 235 124 142 72 161 49 193 203 146 131 115 15 125 183 331 132 74 113 52 136 171 132 121 129 16 114 186 202 130 66 94 35 92 1830 141 213 141 17 232 175 141 124 67 81 41 80 445 200 1710 130 18 296 190 127 122 68 74 300 609 1780 358 550 121 19 448 512 114 115 63 68 84 507 334 191 227 116 20 1020 758 293 115 65 66 115 460 228 155 162 106 21 408 467 158 114 128 64 979 415 170 141 2680 454 22 390 230 135 111 79 61 193 180 137 127 671 264 23 1100 219 123 106 67 57 101 181 125 118 393 208 24 366 183 122 102 65 60 82 717 110 431 279 286 25 266 188 119 101 65 64 66 498 104 150 612 282 26 212 201 294 162 64 55 56 231 93 131 509 565 27 190 304 240 110 63 51 147 153 130 119 344 247 28 183 330 162 98 64 52 175 125 133 140 657 195 29 173 266 132 94 --- 52 130 109 91 785 358 149 30 207 1510 115 96 46 78 97 121 351 264 206 31 301 --- 817 92 46 --- 90 --- 225 230 --- TOTAL 8374 10267 6989 4737 2059 4562 3223 5753 7295 13184 12440 6066 MEAN 270 342 225 153 73.5 147 107 186 243 425 401 202 MAX 1100 1510 873 401 128 2060 979 717 1830 3940 2680 565 MIN 98 163 114 92 63 46 35 47 66 118 107 106 CFSM 3.01 3.81 2.51 1.70 .82 1.64 1.19 2.07 2.71 4.73 4.47 2.25 IN. 3.47 4.25 2.90 1.96 .85 1.89 1.34 2.38 3.02 5.46 5.15 2.51 AC-FT 16610 20360 13860 9400 4080 9050 6390 11410 14470 26150 24670 12030 CAL YR 1982 TOTAL 82677 MEAN 227 MAX 3600 MIN 37 CFSM 2.53 IN 34.25 AC-FT 164000 WTR YR 1983 TOTAL 84949 MEAN 233 MAX 3940 MIN 35 CFSM 2.60 IN 35.19 AC-FT 168500 106 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 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP SPE'.. DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DIG C) (NTU) (MG/L) ATION) CMG/L) 100 ML) 100 ML) 1982 1320 164 192 7.3 27.5 20 8.0 102 18 K8500 270 1983 1300 116 220 7.1 25.0 22 8.4 102 30 3800 600 1125 71 231 7.5 26.5 320 6.8 85 54 K67000 15000 1045 78 223 7.6 27.5 35 7.1 91 10 580 6700 1215 109 212 7.4 29.0 20 7.6 99 180 K6800 310 HARD- NESS (MG/L AS DATE CAC03) HARD- NESS. NONCAR- BONATE (MG/L CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM. DIS- SOLVED (MG/L AS NA) SODIUM AD- SORP- TION RATIO POTAS- ALKA- CHLO- FLUO- SIUM, LINITY SULFATE RIDE. RIDE. DIS- FIELD DIS- DIS- DIS- SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L AS (MG/L (MG/L (MG/L AS K) CAC03) AS SO4) AS CL) AS F) NOV r 1982 9... JAN r 1983 19... 70 MAR 10... MAY 04... 72 AUG 11... 65 59 0 17 6.8 21 1.1 1.9 72 13 16 .10 71 o 13 6.6 20 1.1 2.1 75 17 20 .20 o 16 6.0 20 1.1 1.5 70 12 17 .20 SOLIDS, SOLIDS. NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + SOLVED TUENTS, SOLVED DEG. C. NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE 5102) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NITRO- GEN. TOTAL (MG/L AS N) NOV r 1982 9... 28 .48 .020 .50 .050 .55 .60 1.1 JAN r 1983 19... 33 152 47.6 6 .54 .060 .60 .220 .38 .60 1.2 MAR 10... 586 .67 .230 .90 .860 .34 1.20 2.1 MAY 04... 34 163 34.3 22 .60 .100 .70 .240 .36 .60 1.3 AUG 11... 34 149 43.8 16 .45 .050 .50 .200 .30 .50 1.0 NOV , 9... JAN • 19... MAR 10... MAY 04... AUG 11... BARIUM, CADMIUM NITRO- PHOS- TOTAL TOTAL GEN, PHORUS. ARSENIC RECOV- RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CO) NOV 1982 9... 4.9 .110 JAN r 1983 19... 5.3 .220 2 100 1 MAR 10... 9.3 .620 MAY 04... 5.8 .290 AUG 11... 4.4 .190 2 100 1 STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) OCT, 08 1320 113 197 29.0 DEC. 23 0950 123 247 23.5 FEB, 09 0950 67 280 24.0 APR, 06 1030 44 326 28.0 K = non-ideal count CHRO- MIUM, TOTAL LEAD, TOTAL MERCURY TOTAL SELE- SILVER. TOTAL RECOV- ERABLE RECOV- ERABLE RECOV- ERABLE NIUM, TOTAL RECOV- ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L AS CR) AS P8) AS HG) AS SE) AS AG) 5 11 .2 1 <1 6 <.1 <1 <1 DATE TIME STREAMFLOW, INSTANTANEOUS SPECIFIC CON- DUCTANCE TEMPERA- TURE (CFS) (UMHOS) (DEG C) JUN. 22 1055 140 .... 29.0 JUL, 28 1015 121 209 29.5 SEP. 12 1655 139 217 30.0 107 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGUITAS AT HIGHWAY 30 AT CAGUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'11", long 66°01'26", at Highway 30 bridge, and 0.8 mi (1.3 km) east of Caguas plaza. DRAINAGE AREA.--14.1 sq mi (36.5 sq km). PERIOD OF RECORD.--Water years 1972 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 83 OXYGEN, OXYGEN COLI- STREP- SPE- 015- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- MS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 23... 1350 16 463 6.8 26.0 7.5 .6 7 25 K610000 68000 JAN r 1983 18... 1510 12 528 7.1 27.0 5.0 5.0 63 69 39000 K13000 MAR 10... 1420 4.7 585 7.4 29.0 5.1 2.4 32 79 K6200000 215000 MAY 11... 1330 8.1 544 7.4 32.5 .90 2.0 28 38 560000 31000 AUG 16... 1240 14 385 7.4 29.0 3.6 47 63 43000 48000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUD- HARD- NESS, CALCIUM MIMI, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- On- SORP- DIS- FIELD DIS- 015- DIS- (MG/L 8ONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 23... 130 JAN , 1983 18... 180 42 48 15 39 1.3 3.3 140 66 40 .40 MAR 10... 150 MAY 11... 200 27 54 15 50 1.6 4.9 170 87 48 .60 AUG 16... 130 31 37 10 27 1.1 3.5 103 42 28 .30 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 23... 20 1.3 .220 1.5 1.90 1.6 3.50 5.0 JAN r 1983 18... 34 330 10.6 <1 1.5 .150 1.6 1.10 1.1 2.20 3.8 MAR 10... 11 .98 .220 1.2 2.80 2.3 5.10 6.3 MAY 11... 36 397 8.7 5 .81 .290 1.1 2.70 2.8 5.50 6.6 AUG 16... 25 235 8.9 42 .94 .160 1.1 .150 1.8 1.90 3.0 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS P3) AS HG) AS SE) AS AG) NOV , 1982 23... 22 .820 JAN , 1983 18... 17 .790 2 <100 5 13 6 .2 <1 <1 MAR 10... 28 1.70 MAY 11... 29 1.90 AUG 16... 13 2 <100 2 2 22 .4 <1 <1 K = non-ideal count 108 RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'28", long 66°02'13", at bridge on Highway 1, about 2.5 mi (4.0 km) upstream from Rio Grande de Loiza, and 1.4 mi (2.3 km) north of Caguas plaza. DRAINAGE AREA.--5.4 sq mi (14.0 sq km). PERIOD OF RECORD.--Water years 1958, 1962-66, 1973-74, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW. CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) NOV r 1982 02... 1435 3.6 358 7.3 25.5 29 6.6 81 22 72000 21000 JAN , 1933 05... 1435 7.5 418 6.8 24.0 25 3.3 45 59 280000 210000 MAR 16... 1120 2.6 485 7.8 26.5 1.1 7.0 88 23 27000 K2100 MAY 04... 1435 2.3 413 7.7 27.5 42 6.2 79 18 4300 77000 AUG 17... 1010 24 259 7.4 26.5 140 6.4 80 40 K730000 660000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM. SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- ()IS." (MG/L BONATE SOLVED SCLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MS/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 02... 110 JAN , 1983 05... 140 13 34 14 30 1.1 5.1 130 20 31 .20 MAR 16... 140 MAY 04... 160 11 38 16 31 1.1 4.9 150 22 51 .30 AUG 17... 78 0 20 6.9 16 .8 5.0 82 15 20 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- DIS- CONSTI- On* AT 105 GEN, GEN, GEN, GEN, GEN, MONZA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/t (MG/L (MG/L DATE 5IO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1932 02... 14 1.4 .090 1.5 .150 .75 .90 2.4 JAN , 1983 05... 29 241 4.9 12 1.3 .120 1.4 2.80 2.4 5.20 6.6 MAR 16... <1 1.8 .030 1.8 .120 .18 .30 2.1 MAY 04... 32 285 1.8 42 1.3 .050 1.3 .260 .44 .70 2.0 AUG 17... 6.3 139 9.0 26 .89 .110 1.0 1.10 2.6 3.70 4.7 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV TOTAL TOTAL TOTAL ERA8LE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 8A) AS CD) AS CR) AS P8) AS HG) AS SE) AS AG) NOV , 1982 02... 11 .610 JAN r 1983 05... 29 2.20 3 200 .6 <1 <1 MAR 16... 9.3 .540 MAY 04... 8.9 .770 AUG 17... 21 1.10 3 100 2 20 16 <.1 <1 K = non-ideal count --- RIO GRANDE DE LOIZA BASIN 50056400 RIO VALENCIANO NEAR JUNCOS, PR 109 LOCATION.--Lat 18°12'58", long 66°55'34", Hydrologic Unit 21010005, on left bank at Highway 919, 0.5 mi (0.8 km) upstream from Quebrada Don Victor, 1.7 mi (2.7 km) upstream from Rio Gurabo and 1.0 mi (1.6 km) south of Juncos. DRAINAGE AREA.--16.4 sq mi (42.5 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1971 to current year. GAGE.--Water-stage recorder. Altitude of gage is 320 ft (98 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--12 years (1972-83), 50.1 cu ft/s (1.419 cu m/s), 41.49 in/yr (1,054 mm/yr), 36,300 acre-ft/yr (44.8 cu hm/yr); median of yearly mean discharges, 51 cu ft/s (1.44 cu m/s), 36,900 acre-ft/yr (45 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 23,300 cu ft/s (660 cu m/s) Aug. 31, 1979, gage height, 20.17 ft (6.148 m), from rating curve extended above 100 cu ft/s (2.83 cu m/s) on basis of slope-area measurement and step-backwater analysis; minimum, 2.3 cu ft/s (0.065 cu m/s) July 10, 1977, gage height, 0.29 ft (0.088 m). EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges (no stages were recorded) of major floods are as follows: Sept. 6, 1960, 37,100 cu ft/s (1,050 cu m/s); Oct. 9, 1970, 18,200 cu ft/s (515 cu m/s). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,400 cu ft/s (96.3 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Mar 12 1630 4,200 119 8.42 2.566 Aug. 17 0615 4,020 114 8.26 2.518 July 5 1700 *7,340 208 11.23 3.423 Aug. 21 1830 6,890 195 10.87 3.313 Minimum discharge, 6.0 cu ft/s (0.170 cu m/s) Mar. 31, Apr. 1, 2. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 49 141 124 36 14 9.7 6.4 12 14 23 35 36 2 33 49 57 30 14 9.6 6.6 24 14 90 63 90 3 28 36 47 24 14 9.6 7.4 18 13 35 32 49 4 26 34 42 31 14 9.5 9.3 16 20 135 27 36 5 26 47 40 28 14 9.2 8.8 26 20 1340 26 32 6 25 83 35 38 13 9.3 10 19 27 252 33 29 7 24 41 33 32 13 9.6 8.3 18 24 129 23 27 8 23 42 29 29 13 13 7.7 14 16 70 21 26 9 22 41 28 43 13 32 7.3 13 57 51 21 24 10 21 33 27 31 12 12 7.1 12 25 42 21 23 11 21 76 27 24 12 12 7.2 18 17 33 19 27 12 20 74 26 25 12 764 7.3 10 43 35 18 40 13 27 70 25 22 12 89 7.2 11 19 32 19 25 14 25 39 24 21 13 29 31 17 24 30 23 23 15 21 36 34 20 12 21 14 23 54 28 19 29 16 20 74 28 19 12 16 9.1 17 256 31 83 27 17 35 49 24 19 12 15 9.6 28 67 56 702 25 18 57 69 22 19 12 14 70 17 220 54 104 26 19 188 229 22 18 11 12 15 29 51 31 40 24 20 166 64 83 17 11 10 24 25 34 29 32 22 21 98 56 32 13 13 9.4 440 16 29 26 1 860 34 22 122 45 28 17 11 9.1 43 13 23 25 30 23 110 62 27 17 11 3.9 22 47 21 30 59 23 24 42 46 27 17 11 9.5 17 167 20 59 44 47 25 40 42 27 17 11 11 14 60 20 27 159 65 26 33 35 43 26 11 8.1 13 41 20 24 131 67 27 31 34 42 17 10 7.6 14 25 65 22 157 33 28 66 40 33 17 10 7.6 17 22 37 21 100 26 29 34 38 32 16 7.3 14 21 20 197 67 23 30 53 598 28 16 7.0 17 18 24 52 64 26 31 100 --- 164 15 6.6 --- 16 --- 42 41 TOTAL 1586 2323 1260 725 341 1197.6 884.3 813 1294 3556 4213 1019 MEAN 51.2 77.4 40.6 23.4 12.2 38.6 29.5 26.2 43.1 115 136 34.0 MAX 188 598 164 48 14 764 440 167 256 1840 1860 90 MIN 20 33 22 15 10 6.6 6.4 10 13 21 18 22 CFSM 3.12 4.72 2.48 1.43 .74 2.35 1.80 1.60 2.63 7.01 8.29 2.07 IN. 3.60 5.27 2.86 1.64 .77 2.72 2.01 1.84 2.93 8.07 9.56 2.31 AC-FT 3150 4610 2500 1440 676 2380 1750 1610 2570 7050 8360 2020 CAL YR 1982 TOTAL 19192.1 MEAN 52.6 MAX 1470 MIN 6.7 CFSM 3.21 IN 43.53 AC-FT 38070 WTR YR 1983 TOTAL 19211.9 MEAN 52.6 MAX 1860 MIN 6.4 CFSM 3.21 IN 43.58 AC-FT 38110 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1932 TO SEPTEMBER 1983 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA­ DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT. 04 1520 26 216 28.5 APR, 20 1000 34 293 28.0 NOV. 04 1345 32 234 25.0 MAY, 11 0653 11 282 27.0 DEC. 22 0925 28 223 22.0 JUL, 14 1025 31 237 27.0 JAN, 13 1335 23 286 24.0 JUL, 26 1230 26 237 28.5 FEB. 08 1230 14 319 23.5 AUG, 10 1045 21 223 26.5 FEB. 28 1541 11 290 28.0 SEP. 06 1420 29 238 29.5 110 RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR LOCATION.--Lat 18°15'30", long 65°58'05", Hydrologic Unit 21010005, on left bank, at bridge on Highway 181, 0.3 mi (0.5 km) east of Gurabo, and 4.5 mi (7.6 km) upstream from Rio Grande de Loiza. DRAINAGE AREA.--60.2 sq mi (155.9 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1958 (occasional low-flow measurements only), January to September 1959 (monthly measurements only), October 1959 to current year. GAGE.--Water-stage recorder. Datum of gage is 136.58 ft (41.630 m) above mean sea level. REMARKS.--Records fair. AVERAGE DISCHARGE.--24 years (1960-83), 132 cu ft/s (3.738 cu m/s), 29.78 in/yr (756 mm/yr), 95,630 acre-ft/yr (118 cu hm/yr); median of yearly mean discharges, 127cu ft/s (3.60 cu m/s), 92,000 acre-ft/yr (113 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 74,600 cu ft/s (2,133 cu m/s) Sept. 6, 1960, gage height, 27.7 ft (8.44 m), from floodmark, from rating curve extended above 8,000 cu ft/s (227 cu m/s) on basis of slope-area measurement at gage height 21.6 ft (6.58 m), contracted opening, culvert and flow over road measurement at gage height 23.76 ft (7.242 m), and estimate of peak flow based on slope-area measurements of Rio Gurabo and Rio Valenciano, 7.0 mi (11.3 km) upstream, adjusted for channel storage and flow from intervening area; minimum, 4.5 cu ft/s (0.127 cu m/s) Feb. 21, 25, 1968. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate elevation to gage datum of the Aug. 4, 1945 flood, as pointed out by local residents, 26.6 ft (8.11 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,000 cu ft/s (85.0 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 30 0915 3,360 95.2 8.94 2.725 Aug. 17 0815 3,520 99.7 9.17 2.795 Mar. 12 2115 4,530 128 10.57 3.222 Aug. 21 1915 *32,300 915 22.32 6.803 Apr. 21 0745 4,880 138 11.02 3.359 Aug. 25 1730 3,500 99.1 9.14 2.786 July 5 2015 14,800 419 17.76 5.413 Aug. 27 2045 6,190 175 12.60 3.840 Minimum discharge, 15 cu ft/s (0.425 cu m/s) Apr 13. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 85 184 187 128 32 21 19 33 47 56 35 218 2 79 115 104 90 31 21 19 41 44 143 160 492 3 67 94 95 74 30 20 19 40 42 96 76 228 4 62 107 85 72 30 20 19 36 59 349 64 111 5 60 94 79 74 29 19 19 40 64 4710 62 97 6 57 119 71 110 29 19 19 52 65 1540 80 89 7 56 95 67 63 28 20 18 57 149 325 54 84 8 56 81 64 58 28 23 18 43 60 192 49 81 9 54 82 61 53 28 42 17 35 434 131 45 77 10 51 73 60 51 28 30 16 31 119 105 43 72 11 51 87 58 50 27 24 16 29 60 92 41 72 12 50 209 59 50 26 1040 16 23 86 84 39 86 13 77 285 56 49 26 268 15 28 51 77 39 68 14 86 97 56 49 26 59 40 36 50 71 41 63 15 55 82 72 48 28 41 39 97 328 66 36 64 16 58 155 92 48 26 32 26 72 1030 66 114 66 17 63 107 62 47 25 29 26 89 208 73 1270 62 18 114 i45 58 46 25 27 142 59 739 122 346 61 19 200 435 54 45 25 26 43 75 155 75 92 60 20 306 132 290 44 25 25 67 187 77 70 64 56 21 125 119 84 42 26 23 1270 80 90 66 8290 59 22 180 90 70 42 25 22 122 57 61 59 1170 73 23 247 184 62 40 24 22 72 317 53 57 248 72 24 128 96 61 40 22 21 48 410 46 138 186 77 25 100 89 82 39 22 23 38 178 45 68 774 104 26 95 79 233 38 23 22 35 119 42 55 410 128 27 86 97 275 37 22 20 269 114 73 50 1450 76 28 102 110 230 36 21 20 114 69 85 47 742 62 29 34 94 131 35 --- 20 56 67 49 336 306 59 30 94 920 84 34 20 44 53 55 155 450 81 31 123 --- 760 33 19 --- 52 --- 105 334 --- TOTAL 3051 4656 3852 1665 737 2038 2681 2639 4466 9579 17160 2998 MEAN 98.4 155 124 53.7 26.3 65.7 89.4 85.1 149 309 554 99.9 MAX 306 920 760 128 32 1040 1270 410 1030 4710 3290 492 MIN 50 73 54 33 21 19 15 28 42 47 36 56 CFSM 1.64 2.58 2.06 .89 .44 1.09 1.49 1.41 2.48 5.13 9.20 1.66 IN. 1.89 2.88 2.38 1.03 .46 1.26 1.66 1.63 2.76 5.92 10.60 1.85 AC-FT 6050 9240 7640 3300 1460 4040 5320 5230 8860 19000 34040 5950 CAL YR 1982 TOTAL 45253 MEAN 124 MAX 6830 MIN 14 CFSM 2.06 IN 27.96 AC-FT 89760 WTR YR 1983 TOTAL 55522 MEAN 152 MAX 8290 MIN 15 CFSM 2.53 IN 34.31 AC-FT 110100 -- RIO GRANDE DE LOIZA BASIN 50057000 RIO GURABO AT GURABO, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1963 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 04 1130 61 291 28.5 MAY, 05 0823 36 357 27.5 NOV' 04 1025 102 267 26.0 JUN. 22 1515 60 30.0 DEC, 23 1300 62 340 25.0 JUL, 26 1520 55 305 32.5 JAN, 17 1030 47 367 24.0 AUG, 11 0907 40 312 27.5 FEB, 09 1310 23 563 26.5 SEP. 07 1150 86 318 29.5 APR, 06 1430 19 439 28.0 111 112 RIO GRANDE DE LOIZA BASIN 50057025 RIO GURABO NEAR GURABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'56", long 65°59'04", at bridge on Highway 941, 1.2 mi (1.9 km) west-northwest from gaging station 50057000, and 1.0 mi (1.6 km) northwest of Gurabo plaza. DRAINAGE AREA.--62.8 sq mi (162.7 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN. OXYGEN COLI- STREP- SPE- DIS- DEMAND. FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOW. CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV . 1982 02... 1130 128 263 7.0 25.5 37 5.6 69 22 31000 5500 JAN , 1983 05... 1135 30 321 6.8 24.0 17 5.6 67 21 K10000 K1700 MAR 16... 1415 39 334 7.4 27.5 5.6 5.0 64 25 K1400 840 MAY 11... 1045 29 320 7.6 30.0 4.2 3.0 40 22 K76000 7500 AUG 16... 1040 42 357 7.4 29.0 11 4.2 55 24 K6000 7500 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS. CALCIUM SIUM. SODIUM. AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD CIS- DIS- DIS- (MG/L BON ATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CACO3) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 02... 78 JAN , 1983 05... 110 10 25 11 23 1.2 3.4 98 15 23 .10 MAR 16... 100 MAY 11... 110 0 25 12 24 1.2 4.9 120 25 31 .20 AUG 16... 110 0 25 12 29 1.2 3.3 115 19 29 .20 SOLIDS, SOLIDS. NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN. GEN, GEN, GEN, GEN. MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. C. NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDEO (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 02... 48 1.2 .200 1.4 .390 .71 1.10 2.5 JAN , 1953 05... 31 195 42.2 18 1.3 .130 1.4 .260 1.1 1.40 2.8 MAR 16... 12 1.4 .150 1.5 .540 .26 .80 2.3 MAY 11... 31 229 17.9 3 1.3 .160 1.5 .480 .82 1.30 2.8 AUG 16... 34 221 25.1 4 1.3 .190 1.5 .110 .69 .80 2.3 CHRO- BARIUM. CADMIUM MIUM, LEAD. MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN. PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NTUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 8A) AS CD) AS CR) AS P8) AS HG) AS SE) AS AG) NOV 1982 02... 11 .420 JAN r 1983 05... 12 .530 2 200 2 <1 5 .3 <1 <1 MAR 16... 10 .520 MAY 11... 12 .920 AUG 16... 10 .450 2 100 1 <1 2 <.1 <1 <1 K = non-ideal count RIO GRANDE DE LOIZA BASIN 50059000 LAGO LOIZA AT DAMSITE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°19'49", long 66°01'00", at pumphouse at damsite, and 1.9 mi (3.1 km) south of Trujillo Alto Plaza. DRAINAGE AREA.--208 sq mi (539 sq km). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI ALKA- STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, LINITY FLOW, CON- PH OXYGEN, (PER- ICAL 0.7 KF AGAR FIELD INSTAN- DUCT- (STAND- TEMPER- DIS- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE SOLVED SATUR- LEVEL) (COLS.! PER AS DATE (CFS) (UMHOS) UNITS) (DEG C) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CACO3) NOV , 1982 03... 1240 124 222 6.7 27.0 2.8 35 19 46 K41 62 JAN r 1983 14... 0850 124 718 6.4 24.0 1.2 14 K50 41 64 MAR 17... 1120 124 253 7.0 27.0 .8 10 <10 K1400 3500 80 MAY 13... 1135 124 232 6.8 28.0 .0 0 30 70 40 87 AUG 17... 1425 139 232 7.2 29.0 .0 0 27 96 120 72 SOLIDS, NITRO- RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA 4' NITRO- NITRO- PHOS- DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. GEN, PHORUS, SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL PENOED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) NOV , 1982 03... 11 .31 .090 .40 .120 .38 .50 .90 4.0 .170 JAN , 1983 14... 28 .48 .020 .50 .110 .69 .80 1.3 5.8 .360 MAR 17... <1 .48 .220 .70 .330 .07 .40 1.1 4.9 .200 MAY 13... 10 <.010 <.10 .390 .21 .60 .470 AUG 17... 10 .020 <.10 .200 .80 1.00 .160 K = non-idoal count 113 114 RIO GRANDE DE LOIZA BASIN 50059100 RIO GRANDE DE LOIZA BELOW TRUJILLO ALTO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°21'35", long 66°00'15", 100 ft (30 m) downstream of Highway 181 bridge, 0.4 mi (0.6 km) northwest of Trujillo Alto plaza, and 2.2 mi (3.5 km) northeast of Lago Loiza Reservoir. DRAINAGE AREA.--213 sq mi (552 sq km). PERIOD OF RECORD.--Water years 1981 to current year. REMARKS: Flow controlled by Lago Loiza reservoir. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 DATE STREAM- FLOW, INSTAN- T/ME TANEOUS (CFS) SPE- CIFIC CON- PH DUCT- (STAND- ANCE ARD (UMHOS) UNITS) TEMPER- ATURE (DEG C) OXYGEN. OXYGEN COLI- STREP- DIS- DEMAND. FORM, TOCOCCI SOLVED CHEM- FECAL. FECAL. TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR BID- DIS- CENT (HIGH UM-MF (COLS. ITY SOLVED SATUR- LEVEL) (COLS./ PER (NTU) (MG/L) ATION) CMG/L) 100 ML) 100 ML) NOV r 1982 03... 1020 JAN • 1983 14... 1105 MAR 17... 1000 MAY 13... 0930 AUG 17... 1220 16 235 7.2 27.5 5.7 6.4 81 240 K140 24 294 7.3 25.0 5.3 8.0 97 400 330 7.0 301 7.6 28.0 3.2 6.3 81 13 620 K170 9.4 289 8.0 29.0 3.5 7.4 97 28 600 K170 60 230 7.5 29.0 5.0 2.8 36 27 4800 4000 HARD- MAGNE- SODIUM HARD- NESS. CALCIUM SUM. SODIUM, AD- NESS NONCAR- DIS- DIS- DIS- SORP- (MG/L BONATE SOLVED SOLVED SOLVED TION AS (MG/L (MG/L (MG/L (MG/L RATIO DATE CAC03) CAC03) AS CA) AS MG) AS NA) POTAS- ALKA- SIUM, LINITY DIS- FIELD SOLVED (MG/L (MG/L AS AS K) CAC03) SULFATE DIS- SOLVED (MG/L AS 504) CHLO- FLUO- RIDE. RIDE. DIS- SOLVED SOLVED (MG/L (MG/L AS CL) AS F) NOV • 1982 03... JAN • 1983 14... 75 MAR 17... MAY 13... 110 AUG 17... 70 57 2 18 7.4 18 .9 3.2 74 15 19 .10 98 0 27 11 25 1.1 3.0 120 23 26 .20 0 17 6.7 18 1.0 2.7 73 12 17 .20 SOLIDS, SOLIDS, NITRO- SILICA. SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- BIS- CONSTI- DIS- AT 105 GEN. GEN, GEN, GEN. GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV r 1982 03... JAN I 1983 14... 24 MAR 17... MAY 13... 23 AUG 17... 25 14 .68 .020 .70 .030 .67 .70 1.4 149 9.8 16 .68 .020 .70 .030 2.5 2.50 3.2 <1 .98 .020 1.0 .030 .17 .20 1.2 210 5.3 4 .28 .020 .30 .010 .39 .40 .70 142 23.1 5 .030 <.10 .210 .59 .80 CHRO- BARIUM. CADMIUM MIUM. LEAD. MERCURY SILVER. NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN. PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CO) AS CR) AS PB) AS HG) AS SE) AS AG) NOV p 1982 03... 6.2 .220 JAN • 1983 14... 14 .450 2 100 1 10 3 .2 <1 <1 MAR 17... 5.3 .220 MAY 13... 3.1 .220 AUG 17... .180 2 200 1 <1 4 .1 <1 K = non-ideal count RIO GRANDE DE LOIZA BASIN 50061800 RIO CANOVANAS NEAR CAMPO RICO, PR 115 LOCATION.--Lat 18°19'08", long 65°53'21", Hydrologic Unit 21010005, at center pier on downstream side of bridge, on paved secondary road, 0.4 mi (0.6 km) northeast of junction of Highways 185 and 186, 1.5 mi (2.4 km) south of Campo Rico, and 4.4 mi (7.1 km) south of Loiza. DRAINAGE AREA.--9.84 sq mi (25.48 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1967 to current year. GAGE.--Water-stage recorder. Altitude of gage is 225 ft (68.6 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--16 years (1968-83), 28.2 cu ft/s (0.799 cu m/s), 38.92 in/yr (989 mm/yr), 20,430 acre-ft/yr (25.2 cu hm/yr); median of yearly mean discharges, 25 cu ft/s (0.71 cu m/s), 18,100 acre-ft/yr (22 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 15,000 cu ft/s (425 cu m/s) Sept. 13, 1982, gage height, 13.1 ft (3.993 m), from floodmarks, from rating curve extended above 350 cu ft/s (9.91 cu m/s) on basis of slope-area measurements and step-backwater analysis made in 1981; minimum daily, 0.80 cu ft/s (0.023 cu m/s) July 24, 1977. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,500 cu ft/s (70.8 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) July 5 1400 3,590 102 7.36 2.243 Aug. 21 1330 *6,910 196 977 2.978 Minimum discharge, 2.6 cu ft/s (0.074 cu m/s) Apr. 10, 14, 17. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 14 12 21 46 10 5.6 3.8 5.2 4.8 10 23 21 2 12 13 18 34 10 5.5 3.7 5.0 4.7 31 54 18 3 11 13 18 28 9.7 5.4 3.6 5.1 4.6 42 16 17 4 10 14 17 27 9.8 5.2 3.7 4.7 5.1 116 13 17 5 9.0 13 18 25 9.5 5.2 3.7 4.6 4.9 605 11 15 6 10 13 14 27 9.3 5.3 3.8 7.4 4.5 143 11 13 7 15 12 13 23 9.7 5.9 3.8 10 4.5 54 9.8 13 8 12 11 11 21 9.3 6.2 3.0 7.0 4.4 34 9.2 15 9 11 10 11 22 9.1 7.1 3.1 5.3 31 24 8.8 13 10 10 10 10 20 9.0 5.9 2.8 4.7 11 19 9.0 12 11 10 12 11 19 8.9 5.4 3.1 4.5 5.9 17 8.5 11 12 11 62 10 13 8.4 57 3.3 4.5 5.4 15 8.6 11 13 81 49 9.7 17 8.1 26 3.0 4.6 5.3 15 8.3 12 14 57 15 9.5 16 8.2 8.9 3.0 7.3 5.1 13 7.6 13 15 22 12 60 15 8.4 6.3 3.0 9.6 21 13 7.6 15 16 15 11 29 16 8.1 5.4 2.8 11 282 13 12 12 17 14 11 22 14 7.7 5.3 3.6 12 35 19 70 12 18 23 11 14 14 7.3 5.1 42 16 54 19 37 13 19 53 12 12 14 7.2 4.9 9.1 35 22 14 13 13 20 44 11 98 14 7.1 4.6 25 27 14 14 11 12 21 23 12 34 13 9.6 4.6 254 13 13 13 772 12 22 18 11 22 13 8.1 4.7 19 15 11 12 71 12 23 41 21 21 13 7.0 4.6 12 21 9.2 11 30 12 24 24 15 21 12 6.7 4.5 8.9 16 8.1 30 33 12 25 18 11 41 12 6.7 4.1 6.7 11 2.0 15 54 19 26 17 14 226 14 6.7 3.9 6.1 7.7 7.8 12 42 14 27 15 19 138 12 6.2 3.8 13 6.7 8.8 11 78 11 28 14 43 224 11 5.9 4.5 16 6.0 10 11 42 11 29 13 29 64 11 --- 4.4 6.9 5.7 7.7 35 30 11 30 12 43 37 11 4.3 5.6 5.4 11 13 34 20 31 14 --- 93 11 3.8 --- 5.0 --- 12 25 --- TOTAL 653.0 550 1347.2 563 231.7 233.4 481.1 303.0 623.8 1410 1559.4 412 MEAN 21.1 13.3 43.5 18.2 8.28 7.53 16.0 9.77 20.8 45.5 50.3 13.7 MAX 81 62 226 46 10 57 254 35 232 605 77' 21 MIN 9.0 10 9.5 11 5.9 3.8 2.8 4.5 4.4 10 7.6 11 CFSM 2.14 1.86 4.42 1.85 .34 .77 1.63 .99 2.11 4.62 5.11 1.39 IN. 2.47 2.03 5.09 2.13 .88 .83 1.82 1.15 2.36 5.33 5.89 1.56 AC-FT 1300 1090 2670 1123 460 463 954 601 1240 2300 3090 817 CAL YR 1982 TOTAL 9446.5 MEAN 25.9 MAX 1000 MIN 5.4 CFSM 2.63 IN 35.71 AC-FT 18740 WTR YR 1983 TOTAL 3367.6 MEAN 22.9 MAX 772 MIN 2.8 CFSM 2.33 IN 31.63 AC-FT 16600 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 21 1030 20 136 25.0 APR, 19 1345 11 181 26.0 NOV, 02 1030 13 220 24.0 MAY, 06 0812 4.6 254 25.0 DEC. 15 1020 13 239 23.0 JUN, 23 1205 182 29.0 JAN, 12 1330 18 235 24.0 JUL, 25 1045 14 167 27.0 FEB. 03 1225 9.8 265 23.0 AUG, 08 1224 9.3 223 28.5 MAR, 03 1626 5.5 246 23.5 SEP, 14 0923 12 212 25.0 117 OCEAN° AT LA NTIC 0 '0 CooeW basin RIO GRANDE 0649 0645 0638 A 0 °QUILL° 69350 062 06354 roforde Rib Grande de Loizo basin Drainage boundary 0732 07341--- LAS PIEDRAS 0777 I-.. Rib Art° A 0787 078 10 Rio Humacao basin '17:a0altmlin HUMACAO. EXPLANATION A0670 SURFACE-WATER STATION AND NUMBER A 0660 LOW-FLOW STATION AND NUMBER V0725 QUALITY-OF-WATER STATION AND NUMBER TKILOMETERS 1 6 MILES figure 19.--Northeastern rivers basin--Rio Herrera to Rio AntOn Ruiz basins. 118 RIO ESPIRITU SANTO BASIN 50063440 QUEBRADA SONADORA NEAR EL VERDE, PR LOCATION.--Lat 18°19'24", long 65°49'03", Hydrologic Unit 21010005, in Caribbean National Forest, at El Yunque, 0.55 mi (0.88 km) upstream from Rio Espiritu Santo, 0.23 mi (0.42 km) upstream from Highway 186, and about 1.2 mi (1.9 km) south of El Verde. DRAINAGE AREA.--1.01 sq mi (2.62 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March to September 1983. GAGE.--Water-stage recorder. Altitude of gage is 1,230 ft (375 m), from topographic map. REMARKS.--Records poor. EXTREMES FOR CURRENT PERIOD.--Peak discharges above base of 500 cu ft/s (14.2 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 0245 573 16.2 7.25 2.210 July 5 1400 586 16.6 7.28 2.219 June 17 2315 *1,210 34.3 8.35 2.545 Minimum discharge, 0.48 cu ft/s (0.014 cu m/s) Apr. 12-14. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.4 1.6 1.6 22 38 4.4 2 2.1 3.4 1.5 13 15 4.9 3 1.9 2.6 1.4 22 3.3 5.3 4 1.6 1.8 2.2 42 3.0 6.7 5 1.5 1.5 2.0 80 4.9 4.1 6 1.7 10 4.2 28 6.8 3.5 7 1.9 2.3 7.5 28 2.7 3.2 8 1.3 1.4 3.3 9.8 2.3 3.1 9 1.0 .80 8.3 7.1 2.1 3.0 10 .87 .72 2.2 5.8 2.5 3.0 11 1.6 .71 1.6 4.9 2.8 5.1 12 1.1 .91 1.3 4.5 3.0 4.5 13 .48 .77 5.5 4.1 3.0 3.0 14 .56 6.0 2.8 3.8 2.1 2.6 15 1.0 40 10 3.6 2.7 7.0 16 1.3 4.2 60 3.8 12 3.0 17 4.9 1.9 43 14 30 3.9 18 12 4.7 34 9.4 5.8 3.4 19 15 29 6.8 6.8 2.8 6.0 20 12 14 7.1 10 3.5 3.2 21 71 17 5.3 4.6 74 6.2 22 3.8 14 4.0 4.4 16 7.6 23 2.5 16 3.6 5.2 6.2 4.9 24 2.1 13 3.4 12 6.6 6.9 25 1.8 6.4 3.1 4.0 32 12 26 1.7 2.9 2.9 3.4 13 3.9 27 1.5 2.4 6.6 3.1 21 3.1 28 --- 1.6 2.1 15 3.5 14 2.0 29 3.0 2.2 2.5 3.5 21 13 1.8 30 2.7 1.5 1.9 17 5.1 7.3 4.4 31 2.6 --- 1.7 --- 4.0 6.1 --- TOTAL 155.91 208.21 270.7 397.9 357.5 140.7 MEAN 5.20 6.72 9.02 12.8 11.5 4.69 MAX 71 40 60 80 74 12 MIN .48 .71 1.3 3.1 2.1 1.8 CFSM 5.15 6.65 8.93 12.7 11.4 4.64 IN. 5.74 7.66 9.96 14.64 13.15 5.18 AC-FT 309 413 537 789 709 279 WATER-QUALITY RECORDS PERIOD OF RECORD.--APRIL TO SEPTEMBER 1983 WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS OUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) APR. 21 1135 18 86 21.5 JUL, 19 0950 9.1 45 23.0 MAY, 10 0947 .72 55 22.0 AUG. 09 0948 2.2 51 22.5 JUN. 15 1343 10 44 24.0 SEP, 14 1146 2.5 56 23.0 119 RIO ESPIRITU SANTO BASIN 50063500 QUEBRADA TORONJA AT EL VERDE, PR LOCATION.--Lat 18°19'43", long 65°49'14", Hydrologic Unit 21010005, in Caribbean National Forest, at downstream side of culvert on Highway 186, 0.22 mi (0.35 km) upstream from Rio Espiritu Santo, and about 0.9 mi (1.4 km) south of El Verde. DRAINAGE AREA.--0.064 sq mi (0.166 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--April to September 1983. GAGE.--Water-stage recorder and broad-V-notch crested weir. Altitude of gage is 876 ft (267 m), from topographic map. REMARKS.--Records poor. EXTREMES FOR CURRENT PERIOD.--Peak discharges above base of 50 cu ft/s (1.42 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) July 5 1400 *18.0 0.51 1.71 0.521 No flow for part of each day Apr. 10, 17. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .05 .04 .05 .83 1.3 .29 2 .05 .04 .05 .54 .89 .29 3 .02 .04 .04 .73 .25 .25 4 .02 .04 .07 2.7 .23 .24 5 .02 .04 .06 4.3 .24 .22 .02 .05 .20 2.4 .22 .20 7 .02 .03 .30 1.8 .15 .20 8 .02 .03 .10 .88 .13 .18 9 .02 .03 .40 .66 .12 .17 10 .01 .03 .07 .52 .12 .18 6 .01 .03 .05 .43 .13 .18 12 .01 .03 .04 .38 .12 .16 13 .01 .04 .20 .33 .12 .15 14 11 .01 .19 .10 .29 .10 .13 15 .01 1.3 .10 .27 .11 .17 16 .02 .19 1.6 .25 .14 .13 17 .06 .12 .77 .43 .46 .24 18 .24 .12 1.8 .31 .16 .47 19 .08 .57 .33 .26 .12 .19 20 .11 .42 .25 .23 .13 .24 21 1.9 .68 .21 .20 3.7 .26 22 .14 .52 .19 .19 1.1 .20 23 .09 .45 .17 .19 .47 .15 24 .09 .40 .16 .30 .41 .30 25 .05 .30 .15 .17 .97 .34 26 .05 .10 .15 .15 .55 .17 27 .05 .08 .22 .15 1.0 .13 28 .05 .07 .34 .15 .71 .09 29 .05 .08 .15 .42 .53 .08 30 .05 .06 .38 .16 .39 .14 31 --- .05 --- .15 .34 --- 3.33 6.17 8.70 20.77 15.41 6.14 TOTAL .20 .29 .67 .50 .20 MAX 1.9 1.3 1.8 MEAN .11 4.3 3.7 .47 MIN .01 .03 .04 .15 .10 .08 CFSM 1.33 3.33 4.33 11.2 3.33 3.33 IN. 1.91 3.53 4.98 11.89 8.82 3.51 AC-FT 6.6 12 17 41 31 12 WATER-QUALITY RECORDS PERIOD OF RECORD.--APRIL TO SEPTEMBER 1983 WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMgLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) APR, 21 1015 2.0 127 22.0 JUL, 19 1115 .30 100 24.0 MAY, 10 0753 .03 120 23.0 AUG, 09 0748 .13 104 23.0 JUN, 15 1155 .12 115 24.0 SEP, 14 1035 .11 118 23.5 120 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR LOCATION.--Lat 18°21'37", long 65°48'49", Hydrologic Unit 21010005, at left abutment, on downstream side of bridge on Highway 966, 0.1 mi (0.2 km) upstream from Quebrada Jimenez, and 1.9 mi (3.1 km) southeast of Rio Grande. DRAINAGE AREA.--8.62 sq mi (22.33 sq km). 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. Altitude of gage is 40 ft (12 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--17 years (1967-83), 57.0 cu ft/s (1.614 cu m/s), 89.80 in/yr (2,280 mm/yr), 41,300 acre-ft/yr (50.9 cu hm/yr); median of yearly mean discharges, 52 cu ft/s (1.47 cu m/s), 37,700 acre-ft/yr (46 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 11,800 cu ft/s (334 cu m/s) Oct. 26, 1978, gage height, 11.85 ft (3.612 m), from rating curve extended above 600 cu ft/s (17.0 cu m/s) on basis of step-backwater analysis; minimum, 4.0 cu ft/s (0.113 cu m/s) July 3-5, 1975, gage height 2.43 ft (0.741 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,000 cu ft/s (85.0 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 0300 5,350 152 8.84 2.694 July 5 1430 5,730 162 9.06 2.761 June 16 0145 3,380 95.7 7.51 2.289 Aug. 21 Unknown 5,400 153 8.87 2.704 June 17 2400 *7,460 211 9.97 3.039 Minimum discharge, 6.0 cu ft/s (0.170 cu m/s) Apr. 10. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 27 31 56 107 14 7.7 8.1 7.9 13 191 289 40 2 19 29 74 67 13 7.5 8.3 17 13 111 188 37 3 16 54 45 40 13 7.2 7.8 13 12 151 32 40 4 15 24 67 41 13 6.9 7.7 11 13 495 25 38 5 15 62 47 99 12 7.1 7.8 8.6 16 1060 31 35 6 15 71 24 122 11 10 8.2 66 17 299 30 28 7 13 23 29 53 11 22 8.1 22 52 247 31 27 8 13 16 22 59 11 60 7.8 14 16 73 27 37 9 13 17 19 53 11 31 7.2 9.4 62 51 35 28 10 12 16 17 42 11 14 7.2 8.1 20 40 57 23 11 13 17 17 41 10 11 6.8 7.7 14 34 31 25 12 13 137 15 53 9.8 206 7.2 9.0 13 31 54 23 13 14 74 15 34 9.6 47 6.7 8.1 26 28 41 22 14 12 57 15 20 9.8 16 6.7 37 26 25 31 20 15 11 37 173 27 10 12 7.0 328 84 22 49 25 16 12 97 42 31 9.3 10 9.8 39 559 23 76 24 17 26 31 70 25 8.7 9.6 8.6 15 189 78 155 38 18 62 28 20 24 8.6 9.1 115 35 457 56 55 49 19 40 23 17 23 8.3 8.5 68 145 40 34 34 40 20 43 19 233 22 8.0 9.3 73 96 28 47 33 35 21 72 32 133 21 20 12 718 176 27 27 490 30 22 23 19 120 21 14 11 27 99 20 23 103 37 23 51 27 89 21 10 9.8 15 103 18 27 49 35 24 27 18 91 20 9.2 9.2 12 85 16 78 41 46 25 31 15 86 20 10 8.7 10 45 15 24 215 66 26 33 33 281 24 9.7 8.3 9.5 23 14 20 121 29 27 35 63 122 20 8.6 7.9 8.9 18 24 18 136 24 28 15 233 196 15 8.0 12 8.7 16 62 19 151 19 29 13 105 75 14 --- 10 10 18 17 142 94 18 30 15 109 64 16 8.6 8.7 15 117 31 78 45 31 25 --- 269 15 8.0 --- 13 --- 24 50 --- TOTAL 744 1532 2543 1195 301.6 617.9 1214.8 1507.8 2000 3529 2832 983 MEAN 24.0 51.1 82.0 33.5 10.8 19.9 40.5 48.6 66.7 114 91.4 32.8 MAX 72 238 281 122 20 206 718 328 559 1060 490 66 MIN 11 15 15 14 8.0 6.9 6.7 7.7 12 18 25 18 CFSM 2.78 5.93 9.51 4.47 1.25 2.31 4.70 5.64 7.74 13.2 10.6 3.81 IN. 3.21 6.61 10.97 5.16 1.30 2.67 5.24 6.51 8.63 15.23 12.22 4.24 AC­FT 1480 3040 5040 2370 598 1230 2410 2990 3970 7000 5620 1950 CAL YR 1982 TOTAL 21048.7 MEAN 57.7 MAX 890 MIN 6.6 CFSM 6.69 IN 90.83 AC-FT 41750 WTR YR 1983 TOTAL 19000.1 MEAN 52.1 MAX 1060 MIN 6.7 CFSM 6.04 IN 81.99 AC-FT 37690 121 RIO ESPIRITU SANTO BASIN 50063800 RIO ESPIRITU SANTO NEAR RIO GRANDE, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958, 1961-66, 1968 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN• OXYGEN COL/- SPE- DIS- DEMAND, FORM, STREAM- CIFIC SOLVED CHEM- FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 INSTAN- DUCT- (STAND- TEMPER- BID- DIS.'. CENT (HIGH UM-MF TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 1982 1400 16 106 7.2 26.0 2.6 8.4 104 15 2400 1983 1020 14 128 7.8 23.0 1.0 8.4 98 <10 K110 1400 27 7 7.6 24.0 2.4 9.4 112 59 K820 1135 8.2 94 8.2 29.0 .80 8.0 104 17 290 1240 30 85 7.5 26.0 3.4 9.0 110 <10 4000 STREP- TOCOCCI HARD- MAGNE- SODIUM POTAS- ALKA- FECAL, HARD- NESS• CALCIUM SUM, SODIUM, AD- SIUM• LINITY SULFATE KF AGAR NESS NONCAR- DU- DIS- DIS- SORP- DIS- FIELD DIS- (COLS. (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED PER AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L DATE 100 ML) CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) NOV • 1982 8... 380 30 JAN , 1983 28... 210 39 0 8.2 4.4 8.6 .6 .4 43 <5.0 MAR 9... K1100 18 MAY 10... 3400 31 0 6.8 3.5 7.5 .6 .5 34 4.1 AUG 03... 2100 25 0 5.4 2.9 5.9 .5 .4 28 4.2 SOLIDS, SOLIDS, CHLO- FLUO- SILICA• SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- RIDE, RIDE, DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, DIS- DIS- SOLVED TUENTS, SOLVED DEG. Cr NITRITE NO2+NO3 AMMONIA ORGANIC SOLVED SOLVED (MG/L 01S- (TONS SUS- TOTAL TOTAL TOTAL TOTAL (MG/L (MG/L AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L DATE AS CL) AS F) SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) NOV , 1982 8... 8 (.010 (.10 <.010 JAN • 1983 28... 10 <.10 22 <1 <.010 <.10 .020 MAR 9... 6 (.010 <.10 .020 .28 MAY 10... 10 <.10 20 73 1.6 <1 .020 <.10 <.010 AUG 03... 8.8 (.10 15 59 4.8 2 <.010 <.10 .020 .08 NITRO- CHRO- GEN,AM- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, MONIA + PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL ORGANIC PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM• RECOV* TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS N) AS P) AS AS) AS BA) AS CD) AS CR) AS PS) AS HG) AS SE) AS AG) NOV , 1982 8... .70 -020 JAN , 1983 28... <.10 <.010 1 100 2 3 <1 .3 (1 2 MAR 9... .30 .020 MAY 10... (.10 .020 AUG 03... .10 .020 <1 <.1 <1 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW• SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 06 1025 14 95 25.5 JUL, 25 1145 23 93 27.5 MAR, 04 1145 7.0 123 30.5 SEP. 15 1212 60 77 24.5 K = non-ideal count DATE NOV , 8... JAN • 28... MAR 9... MAY 10... AUG 03... 122 RIO MAMEYES BASIN 50065500 RIO MAMEYES NEAR SABANA, PR LOCATION.--Lat 18°19'46", long 65°45'04", on left bank, at bridge on Highway 988, 1.4 mi (2.3 km) west of Sabana, 2.0 mi (3.2 km) down­ stream from Rio de la Mina, and 3.2 mi (5.1 km) southeast of Mameyes. DRAINAGE AREA.--6.88 sq mi (17.8 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1967 to December 1973. June to September, 1983. GAGE.--Water-stage recorder. Altitude of gage is 275 ft (83.8 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--6 years (1968-73), 59.9 cu ft/s (1.696 cu m/s), 118.23 in/yr (3,003 mm/yr), 43,400 acre-ft/yr (53.5 cu hm/yr). EXTREMES FOR CURRENT PERIOD.--Peak discharges above base of 4,000 cu ft/s (113 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) June 17 2315 *6,130 174 8.70 2.652 Minimum daily discharge, 24 cu ft/s (0.680 cu m/s) Aug. 8. DISCHARGE. IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 32 124 154 34 2 30 54 80 34 3 29 56 33 34 4 40 72 29 32 5 38 229 33 28 6 33 88 30 28 7 56 76 27 27 3 30 41 24 39 9 180 35 29 23 10 42 35 44 32 11 37 31 32 31 12 34 30 41 31 13 106 23 40 29 14 59 23 28 27 15 38 25 38 45 16 215 25 53 28 17 241 48 113 28 13 291 33 40 29 19 57 28 30 29 20 68 35 40 30 21 53 31 291 37 22 36 29 63 55 23 35 29 42 37 24 37 66 38 46 25 35 36 141 61 26 39 32 78 39 27 34 29 91 34 28 46 27 84 30 29 26 98 64 31 30 72 39 50 55 31 --- 31 39 --- TOTAL 2119 1568 1919 1048 MEAN 70.6 50.6 61.9 34.9 MAX 291 229 291 61 MIN 26 25 24 27 CFSM 10.3 7.36 9.00 5.07 IN. 11.46 8.48 10.37 5.67 AC-FT 4200 3110 3810 2080 WATER-QUALITY RECORDS PERIOD OF RECORD.--JUNE TO SEPTEMBER 1983 WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) JUN. 17 1005 53 73 25.0 AUG, 19 1213 39 121 24.5 JUL, 14 1625 27 93 26.0 SEP. 15 1212 60 77 24.5 --- --- 123 RIO MAMEYES BASIN 50065700 RIO MAMEYES AT HIGHWAY 191 AT MAMEYES, PR LOCATION.--Lat 18°22'03", long 65°46'14", Hydrologic Unit 21010005, on left bank, 0.2 mi (0.3 km) upstream from Quebrada Anon, 0.3 mi (0.5 km) downstream from Quebrada Tabonuco, and 0.3 mi (0.5 km) south of Mameyes. DRAINAGE AREA.--11.8 sq mi (30.6 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1966 to current year. GAGE.--Water-stage recorder. Altitude of gage is 22 ft (6.7 m), from topographic map. Prior to Jan. 1, 1974 at datum 4.88 ft (1.487 m) higher and Jan. 1, 1974 to Mar. 25, 1976 at datum 4.00 ft (1.219 m) higher. REMARKS.--Records poor. AVERAGE DISCHARGE.--17 years (1967-83), 73.2 cu ft/s (2.073 cu m/s), 84.24 in/yr (2,140 mm/yr), 53,030 acre-ft/yr (65.4 cu hm/yr); median of yearly mean discharges, 72 cu ft/s (2.04 cu m/s), 52,200 acre-ft/yr (64 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 26,200 cu ft/s (742 cu m/s), Oct. 24, 1974, gage height, 18.79 ft (5.727 m), present datum, from rating curve extended above 200 cu ft/s (5.66 cu m/s) on basis of slope-area measurement of peak flow; minimum, 5.0 cu ft/s (0.142 cu m/s) Apr. 28, 1975. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 5,300 cu ft/s (150 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Apr.- 21 0315 *16,200 459 17.17 5.233 June 17 2345 12,100 343 16.20 4.938 May 15 0915 5,460 155 12.96 3.950 Minimum daily discharge, 8.0 cu ft/s (0.226 cu m/s) Apr. 11. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 35 59 72 111 17 9.0 10 26 39 190 262 51 2 28 60 93 88 17 9.4 12 39 36 146 199 47 3 26 89 72 58 18 14 10 24 35 123 39 51 4 26 37 63 56 21 12 10 19 49 250 33 48 5 24 119 55 115 18 15 11 18 48 604 40 45 6 23 150 39 130 18 17 12 87 40 372 38 36 7 21 44 42 63 15 23 11 38 68 327 40 34 3 20 35 37 71 15 85 10 25 36 114 34 47 9 19 53 32 74 14 46 9.0 19 226 76 45 36 10 19 41 30 54 16 19 9.0 17 42 69 73 30 11 18 34 29 53 18 20 8.0 16 33 57 39 32 12 21 206 28 68 17 385 9.0 18 31 59 69 30 13 23 118 27 43 15 99 10 58 301 46 53 28 14 29 62 26 38 16 50 9.0 140 111 41 39 26 15 23 78 176 34 18 35 10 509 169 37 63 56 16 40 150 49 39 15 29 13 62 363 37 98 31 17 41 60 69 32 14 26 12 21 426 139 202 49 18 60 61 31 31 13 25 122 190 796 99 71 63 19 45 109 28 29 13 23 86 335 114 70 43 51 20 41 44 192 28 13 21 63 163 183 57 42 45 21 75 40 249 27 51 18 1160 182 129 37 642 38 22 33 36 162 27 27 15 45 110 64 38 133 47 23 53 99 93 27 15 13 31 218 52 38 63 45 24 41 36 64 26 13 12 25 175 44 86 53 59 25 30 43 59 25 13 12 21 87 38 34 284 85 26 55 65 179 31 10 13 19 45 33 27 158 37 27 49 114 103 25 9.6 11 18 45 53 31 176 31 28 23 229 145 22 9.5 17 22 42 92 48 198 24 29 20 128 85 21 --- 11 20 60 35 258 122 23 30 26 116 170 25 12 17 39 138 77 100 58 31 59 251 21 11 38 --- 52 64 --- TOTAL 1046 2515 2750 1492 469.1 1107.4 1824.0 2865 3824 3639 3515 1283 MEAN 33.7 83.8 88.7 48.1 16.8 35.7 60.8 92.4 127 117 113 42.8 MAX 75 229 251 130 51 385 1160 509 796 604 642 85 MIN 18 34 26 21 9.5 9.0 8.0 16 31 27 33 23 CFSM 2.86 7.10 7.52 4.08 1.42 3.03 5.15 7.83 10.8 9.92 9.58 3.63 IN. 3.30 7.93 3.67 4.70 1.48 3.49 5.75 9.03 12.05 11.47 11.08 4.04 AC-FT 2070 4990 5450 2960 930 2200 3620 5680 7580 7220 6970 2540 CAL YR 1982 TOTAL 24729.0 MEAN 67.8 MAX 907 MIN 11 CFSM 5.75 IN 77.95 AC-FT 49050 WTR YR 1983 TOTAL 26329.5 MEAN 72.1 MAX 1160 MIN 8.0 CFSM 6.11 IN 83.00 AC-FT 52220 WATER-QUALITY RECORDS PERIOD OF .RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOSER 1982 TO SEPTEMBER 1983 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA­ DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) .(CFS) (UMMOS) (DEG C) OCT, 06 1245 23 125 27.5 APR, 19 1055 24 140 25.0 NOV. 01 1220 52 110 25.5 MAY. 06 1216 18 134 28.0 DEC. 14 1325 27 160 25.0 JUN. 17 1005 57 69 25.0 JAN. 12 1035 102 136 22.5 JUL, 14 1155 41 132 28.0 FEB. 03 0945 18 201 22.0 JUL, 25 1510 32 130 30.0 MAR, 04 1148 12 158 28.0 AUG. 19 1430 44 132 28.0 124 RIO SABANA BASIN 50067000 RIO SABANA AT SABANA, PR LOCATION.--Lat 18°19'52", long 65°43'52", Hydrologic Unit 21010005, on right bank along Highway 988, 0.3 mi (0.5 km) north of junction of Highways 988 and 983 in Sabana, and 3.3 mi (5.3 km) south of Luquillo. DRAINAGE AREA.--3.96 sq mi (10.26 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1979 to current year. GAGE.--Water-stage recorder. Altitude of gage is 260 ft (80 m), from topographic map. REMARKS.--Records fair. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 9,010 cu ft/s (255 cu m/s) Apr. 21, 1983, gage height, 19.35 ft (5.898 m), from floodmark, from rating curve extended above 200 cu ft/s (5.66 cu m/s) on basis of step-backwater analysis and slope-area measurement; minimum discharge, 0.86 cu ft/s (0.024 cu m/s) Apr. 17, 1983. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,500 cu ft/s (42.5 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Dec. 21 2045 1,750 49.6 12.53 3.819 May 13 1600 4,730 134 16.00 4.877 Mar. 12 1330 1,500 42.5 12.13 3.697 June 17 1830 1,840 52 12.66 3.859 Apr. 21 0315 *9,010 255 19.35 5.898 June 18 0045 2,110 60 13.06 3.981 Minimum discharge, 0.86 cu ft/s (0.024 cu m/s) Apr. 17. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.8 11 10 19 4.2 1.5 1.2 22 11 97 97 13 2 3.2 13 17 15 4.1 1.3 1.2 17 10 28 49 12 3 2.9 14 13 13 3.8 1.3 1.2 7.4 9.6 18 13 12 4 2.7 6.2 13 14 3.9 1.3 1.2 5.2 12 20 12 12 5 2.9 67 11 23 3.6 1.3 1.1 7.1 8.9 96 12 11 6 3.4 35 9.2 19 3.5 2.3 1.1 5.5 9.4 53 9.9 10 7 2.4 11 8.8 12 3.7 2.9 1.0 33 9.3 41 9.1 10 8 2.4 12 8.5 12 3.2 26 1.0 12 7.9 22 8.6 11 9 2.1 27 7.9 13 3.0 8.7 .99 5.6 23 18 14 9.9 10 1.9 11 7.3 11 2.6 2.3 .96 4.4 7.6 16 22 9.3 11 1.9 12 7.1 10 2.4 1.8 .98 3.7 6.8 16 12 8.8 12 1.6 122 6.7 12 2.4 208 1.0 3.5 6.2 31 33 8.3 13 2.0 26 7.9 9.4 2.6 16 1.2 230 8C 16 18 5.4 14 8.6 10 7.0 3.7 2.7 7.2 1.8 60 38 14 11 8.0 15 2.3 20 29 9.1 2.4 4.8 1.2 153 66 13 12 11 16 8.0 20 10 3.5 2.3 3.8 1.2 23 124 13 13 8.8 17 13 10 10 7.7 1.9 3.4 12 44 243 17 23 13 18 12 10 7.2 7.6 2.0 2.9 29 120 194 13 15 14 19 6.8 50 6.9 7.0 1.9 2.4 62 151 33 12 10 11 20 8.6 12 135 6.7 1.6 2.3 14 47 40 11 10 8.3 21 15 9.2 190 6.9 8.5 2.4 545 31 27 11 199 3.7 22 6.4 8.3 38 6.5 3.0 2.0 19 24 21 11 21 9.6 23 18 77 17 6.2 2.4 2.2 11 43 19 11 14 8.2 24 12 11 12 6.0 1.9 1.3 8.7 37 17 17 12 9.7 25 6.9 9.7 12 6.0 2.7 2.1 7.4 27 16 10 53 13 26 12 14 21 6.0 2.3 1.7 6.2 19 15 9.3 22 3.9 27 11 15 16 5.4 2.0 1.6 5.6 18 24 9.1 37 8.7 28 5.2 39 17 5.0 1.8 1.9 6.4 15 26 9.2 42 7.4 29 4.5 17 16 5.2 --- 1.4 5.4 15 14 59 17 7.3 30 4.4 15 37 7.4 1.3 4.6 13 23 13 20 26 31 13 --- 59 5.0 1.3 --- 12 --- 11 14 --- TOTAL 200.9 714.4 767.5 303.3 82.4 321.2 754.63 1213.4 1141.7 735.6 854.6 317.8 MEAN 6.48 23.8 24.8 9.78 2.94 10.4 25.2 39.1 38.1 23.7 27.6 10.6 MAX 18 122 190 23 8.5 205 545 230 243 97 199 26 MIN 1.6 6.2 6.7 5.0 1.6 1.3 .96 3.5 6.2 9.1 8.6 7.3 CFSM 1.64 6.01 6.26 2.47 .74 2.63 6.36 9.87 9.62 5.99 6.97 2.68 IN. 1.89 6.71 7.21 2.85 .77 3.02 7.09 11.40 10.72 6.91 8.03 2.98 AC-FT 398 1420 1520 602 163 637 1500 2410 2260 1460 1700 630 CAL YR 1982 TOTAL 6451.80 MEAN 17.7 MAX 681 MIN 1.6 CFSM 4.47 IN 60.59 AC-FT 12800 WTR YR 1983 TOTAL 7407.43 MEAN 20.3 MAX 545 MIN .96 CFSM 5.13 IN 69.57 AC-FT 14690 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER QUALITY DATA. OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT' 05 1230 4.0 113 27.0 MAY. 09 1505 5.9 111 27.5 NOV' 05 1029 7.2 118 24.0 JUN, 16 1145 122 46 25.5 DEC. 13 1252 7.2 103 23.5 JUL, 15 1453 13 139 26.5 JAN, 11 1420 11 113 23.5 JUL' 25 1350 9.6 109 27.5 FEB. 04 1300 4.0 163 24.0 AUG, 18 0950 14 91 24.5 MAR, 03 0858 1.2 146 23.5 SEP. 15 1454 9.5 100 27.0 APR. 20 1255 12 118 23.5 125 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR LOCATION.--Lat 18°17'56", long 65°41'42", Hydrologic Unit 21010005, on left bank off Highway 976, 0.1 mi (0.2 km) upstream from Highway 977 bridge, 0.3 mi (0.5 km) downstream from Quebrada Pen6n, 1.1 mi (1.8 km) northeast of Colonia Parafso, and 3.3 mi (5.3 km) southwest of Fajardo. DRAINAGE AREA.--14.9 sq mi (38.6 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1960-61 (occasional low- and peak-flow measurements only), March 1961 to current year. GAGE.--Water-stage recorder. Datum of gage is 137.60 ft (41.940 m) above mean sea level. Due to flood damage, gage datum has had changes as follows: Mar. 24, 1961 to May 5, 1969, 138.95 ft (42.352 m); May 6, 1969 to Mar. 16, 1972, 135.05 ft (41.163 m); Mar. 17, 1972 to Mar 25, 1975, 138.60 ft (42.245 m). REMARKS.--Records fair. Low flow affected by diversions for water supply. AVERAGE DISCHARGE.--22 years (1962-83), 68.9 cu ft/s (1,951 cu m/s), 62.80 in/yr (1.595 mm/yr), 49,920 acre-ft/yr (61.6 cu hm/yr); median of yearly mean discharges, 69 cu ft/s, (1.95 cu m/s), 50,000 acre-ft/yr (62 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 19,600 cu ft/s (555 cu m/s), Oct. 24, 1974, gage height, 13.62 ft (4.151 m), datum then in use, from rating curve extended above 100 cu ft/s (2.83 cu m/s) on basis of step-backwater analyses and slope-area measurements of peak discharges; minimum, 1.5 cu ft/s (0.042 cu m/s) Apr. 3, May 13,14, 1977, gage height 1.57 ft (0.479 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,500 cu ft/s (99.1 cu m/s) and maximum (*): Discharge Gage height Discharge Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Dec. 20 0230 6,290 178 9.92 3.024 May 15 0945 5,040 143 9.01 2.746 Apr. 21 0400 *15,100 428 14.82 4.517 June 17 1930 9,920 281 12.17 3.701 May 13 1630 3,880 110 8.07 2.460 Minimum discharge, 3.7 cu ft/s (0.105 cu m/s) Apr. 10,11. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 29 31 38 69 14 6.1 5.8 43 44 72 162 46 2 18 26 63 57 13 5.4 5.6 62 40 86 167 50 3 15 50 48 47 12 5.1 5.0 33 37 100 37 53 4 14 13 48 42 12 5.4 4.6 24 47 135 34 42 5 15 143 41 79 11 5.3 4.8 24 37 373 31 33 6 14 106 35 79 10 31 5.3 68 35 222 25 23 7 12 26 32 42 10 42 4.9 117 62 132 20 25 8 12 34 28 49 9.7 164 4.7 46 37 66 17 31 9 11 150 25 44 9.8 53 4.1 29 66 53 49 25 10 10 43 22 33 9.8 14 3.9 24 33 46 81 21 11 9.8 127 20 32 11 17 4.3 21 28 45 27 23 12 9.6 335 18 42 9.3 664 4.9 19 32 75 60 27 13 30 126 17 27 8.8 97 4.4 500 79 44 68 20 14 41 33 16 23 8.8 31 12 179 99 39 25 17 15 13 80 115 22 11 21 13 533 197 35 40 25 16 17 150 35 22 9.2 16 14 117 371 34 38 16 17 49 35 36 22 3.3 14 100 81 668 46 132 15 18 59 38 18 20 8.0 14 169 243 282 43 46 19 19 21 180 16 13 7.4 11 221 4C5 77 42 28 25 20 31 4'5 533 17 7.0 11 68 201 138 40 33 15 21 31 34 423 16 36 10 1500 181 69 34 496 19 22 17 30 136 15 13 9.4 90 130 55 30 86 18 23 123 265 53 17 9.3 8.9 53 2C2 46 37 55 20 24 45 41 44 16 9.7 3.2 38 211 40 69 55 17 25 21 37 38 17 10 7.9 30 126 35 31 204 87 26 40 52 238 19 8.7 7.2 25 109 27 25 175 31 27 33 56 83 16 7.5 6.9 35 103 42 23 236 21 28 22 133 209 14 7.0 7.4 59 73 37 22 260 18 29 17 63 61 13 --- 7.3 28 75 25 216 106 17 30 14 56 86 21 6.2 19 55 150 41 93 72 31 24 --- 374 18 6.1 --- 51 --- 30 58 --- TOTAL 817.4 2551 2949 968 301.3 1317.3 2541.3 4090 2935 2296 2944 376 MEAN 26.4 85.0 95.1 31.2 10.8 42.5 84.7 132 97.8 74.1 95.0 29.2 MAX 123 335 533 79 36 664 1500 538 668 373 496 87 MIN 9.6 18 16 13 7.0 5.1 3.9 19 25 22 17 15 CFSM 1.77 5.71 6.38 2.09 .73 2.85 5.69 8.86 6.56 4.97 6.38 1.96 IN. 2.04 6.37 7.36 2.42 .75 3.29 6.34 10.21 7.33 5.73 7.35 2.19 AC-FT 1620 5060 5850 1920 598 2610 5040 8110 5820 4550 5840 1740 CAL YR 1982 TOTAL 23426.0 MEAN 64.2 MAX 851 MIN 3.9 CFSM 4.31 IN 58.48 AC-FT 46470 WTR YR 1983 TOTAL 24586.8 MEAN 67.4 MAX 1500 MIN 3.9 CFSM 4.52 IN 61.38 AC-FT 48770 126 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 current year. INSTRUMENTATION.--Automatic sediment sampler since January 1983. USD-49 Sediment sampler since February 1983. REMARKS.--Automatic sediment sampler set to collect samples above a streamflow of 100 ft3/sec. In addition to automatic sediment sampler, samples were collected by a local observer once daily during low flow and more than once daily during high flow events for concentration and particle size analyses. Discontinued as National Stream-Quality Accounting Network Station on September 1983 and continued operating as a regular pollution network station since that. EXTREMES FOR PERIOD OF DAILY RECORD.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 1,360 mg/L April 21; Minimum daily mean, 0.0 mg/L may 9. SEDIMENT LOADS: Maximum daily, 19,800 tons (17,960 tonnes) April 21; minimum daily, 0.0 tons (0.0 tonnes) May 9. EXTREMES FOR CURRENT YEAR.-- SEDIMENT CONCENTRATIONS: Maximum daily mean, 1,360 mg/L April 21; Minimum daily mean, 0.0 mg/L May 9. SEDIMENT LOADS: Maximum daily, 19,800 tons (17,960 tonnes) April 21; minimum daily, 0.0 tons (0.0 tonnes) May 9. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- SPE- DIS- DEMAND, FORM. STREAM- CIFIC SOLVED CHEM- FECAL, FLOW. CON- PH TUR- OXYGEN, (PER- ICAL 0.7 INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF TIME TANEOUS ANCE ARO ATURE ITT SOLVED SATUR- LEVEL) (COLS./ DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) STREP- TOCOCCI FECAL. KF AGAR (COLS. PER 100 ML) NOV , 1982 17... 1525 38 106 6.7 27.0 13 8.0 101 25 X680 200 JAN . 1983 4... 1325 41 113 7.0 25.0 3.5 9.0 109 14 210 360 MAR 07... 1230 30 105 7.6 25.5 4.1 9.4 116 47 800 830 MAY 03... 1200 36 92 8.2 27.0 1.7 10.2 128 <10 250 180 JUN 02... 1215 40 126 8.2 28.0 9.8 126 AUG 02... 1345 81 81 7.4 27.0 14 9.3 117 23 2100 3200 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM. AD- SIUM, LINITY SULFATE RIDE, RIDE. NESS NONCAR- On- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L 80NATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV r 1982 17... 23 JAN r 1983 04... 32 2 6.8 3.6 12 1.0 .9 30 4.0 11 <.10 MAR 07... 27 MAY 03... 27 0 5.9 2.9 11 1.0 1.1 30 5.4 11 <.10 JUN 03... 38 AUG 02... 21 0 4.6 2.3 6.8 .7 1.3 22 5.4 9.1 <.10 SOLIDS, SOLIDS, NITRO- SILICA. SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEM. GEN. GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 17... 12 .18 .020 .20 .030 1.1 1.10 1.3 JAN r 1983 04... 26 82 9.0 2 <.010 .20 .030 .07 .10 .30 MAR 07... 6 .37 .030 .40 .010 .29 .30 .70 MAY 3... 23 78 7.6 <1 <.010 <.10 <.010 <.10 JUN 03... AUG 02... 17 60 13.1 14 .29 .010 .30 .040 .16 .20 .50 K . non-ideal count <.01 <.01 <.01 <.10 <.10 <1 <.01 METHYL PARA- THION, TOTAL DATE (UG/L) METHYL TRI- THU/N. TOTAL (UG/L) MIREX. TOTAL (UG/L) PARA- THION. TOTAL (UG/L) NAPH- THA- LENES. POLY- PER- TOX- TOTAL CHLOR. THANE APHENEr TRI- TOTAL TOTAL TOTAL THION (UG/L) (UG/L) (UG/L) (UG/L) JUN. 0 1983 03... <.01 RIO FAJARDO BASIN 127 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- BARIUM. CADMIUM MIUM. LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELF- TOTAL GEN. PHORUS. ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV 1982 17... 5.8 .030 JAN e 1983 04... 1.3 .200 1 100 2 <1 7 .5 <1 <1 MAR 07... 3.1 .030 MAY 03... .010 JUN 03... AUG 02... 2.2 .040 <1 <.1 <1 STREAMFLOW, DATE TIME INSTANTANEOUS (CFS) 46 16 10 5.6 NOV, 01 1600 DEC. 13 0955 FEB. 07 1040 MAR, 04 0918 SPECIFIC CON- DUCTANCE (UMHOS) 110 123 155 138 TEMPERA- TURE (DEG C) 27.5 23.5 25.0 25.0 STREAMFLOW, DATE TIME INSTANTANEOUS (CFS) APR, 21 1315 375 JUL, 27 1150 24 SEP. 01 1030 46.9 SPECIFIC CON- DUCTANCE (UMHOS) 142 118 106 TEMPERA- TURE (DEG C) 28.0 30.0 28.5 CHLOR- DI- PCB. ALORINe DANE. ODD. DDE, DDT, AZINONe TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 03... 1215 <.10 <.01 <.10 <.01 <.01 <.01 <.01 LINDANE TOTAL (UG/L) DI- ELDRIN TOTAL DATE (UG/L) JUN r 1983 03... <.01 ENDO- SULFANe TOTAL (UG/L) HEPTA- HEPTA- CHLOR CHLOR, EPDXIDE TOTAL TOTAL (UG/L) (UG/L) METH- MALA- OXY- THION, CHLOR, TOTAL TOTAL (UG/L) (UG/L) ENDRIN, ETHION, TOTAL TOTAL (UG/L) (UG/L) <.10 <.01 <.01 <.01 <.01 <.01 <.01 <.01 SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. STREAM- SEDI- FALL FALL FALL FALL FLOW. MENT, DIAM. DIAM. DIAM. DIAM. INSTAN- SUS- % FINER I FINER % FINER % FINER TIME TANEOUS PENDED THAN THAN THAN THAN DATE (CFS) (MG/L) .002 MM .004 MM .008 MM .016 MM JUN ' 1983 13... 1615 E156 2350 11 20 33 50 13... 1630 E208 2030 9 17 32 60 13... 1645 E233 2370 16 22 38 61 13... 1700 E203 2000 18 24 40 58 SED. SED. SED. SED. SED. SED. SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. FALL SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. I FINER I FINER I FINER % FINER I FINER I FINER THAN THAN THAN THAN THAN THAN DATE .031 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM JUN 13... 74 93 95 98 99 99 13... 73 94 97 98 99 99 13... 76 88 95 98 100 100 13... 82 87 94 97 99 99 E = estimate 128 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued WATER QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) OCTOBER NOVEMBER DECEMBER 1 29 17 1.5 31 18 1.7 38 5 .27 2 18 5 .24 26 17 1.2 63 3 .24 3 15 8 .32 50 41 13 48 17 1.4 4 14 2 .08 13 7 .34 48 1 .08 5 15 3 .12 143 196 244 41 1 .05 6 14 1 .04 106 128 94 35 2 .11 7 12 5 .16 26 14 1.1 32 7 .38 8 12 14 .45 34 29 4.6 28 14 .76 9 11 2 .06 150 206 389 25 2 .11 10 10 8 .22 43 32 6.1 22 1 .05 11 9.8 7 .19 127 153 211 20 5 .23 12 9.6 5 .13 335 374 1500 18 6 .28 13 30 30 5.4 126 134 102 17 6 .28 14 41 32 5.0 33 20 1.8 16 6 .26 15 13 19 .67 80 36 113 115 209 31,6 16 17 7 .49 150 180 140 35 26 3.3 17 49 44 18 38 58 13 36 17 1.9 18 59 54 12 38 27 2.9 18 8 .39 19 21 11 .77 180 80 17 16 10 .43 20 31 18 1.8 45 18 1.9 533 618 5060 21 31 19 2.0 34 27 2.2 423 420 2120 22 17 13 .60 30 8 .43 136 176 142 23 123 163 204 265 108 29 53 7 1.0 24 45 38 7.9 41 27 2.2 44 10 1.2 25 21 16 .91 37 44 2.4 38 5 .51 26 40 25 3.5 52 36 2.9 238 292 340 27 33 22 2.3 56 20 1.6 33 36 22 28 22 24 1.4 138 24 4.5 209 294 427 29 17 7 .32 63 23 1.9 61 37 6.9 30 14 51 1.9 56 36 2.9 86 38 33 31 24 11 .98 --- --- --- 374 559 931 TOTAL 817.4 273.95 2551 2912.67 2949 9411.13 MEAN MEAN MEAN MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) CMG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JANUARY FEBRUARY MARCH 1 69 53 9.9 14 5 .19 6.1 10 .16 2 57 7 1.1 13 5 .18 5.4 1 .01 3 47 5 .63 12 13 .42 5.1 1 .01 4 42 4 .45 12 6 .19 5.4 1 .02 5 79 121 67 11 11 .33 5.3 1 .01 6 79 44 13 10 10 .27 31 22 5.1 7 42 9 1.0 10 10 .27 42 36 18 8 49 32 6.4 9.7 13 .34 164 223 220 9 44 34 4.0 9.8 11 .29 58 46 15 10 33 19 1.7 9.8 1 .03 14 4 .15 11 32 13 1.1 11 1 .03 17 7 .42 12 42 28 3.4 9.3 4 .10 664 641 3570 13 27 13 .95 8.8 3 .07 97 128 57 14 23 11 .68 8.8 5 .12 31 32 2.7 15 22 10 .59 11 4 .12 21 40 2.3 16 22 11 .65 9.2 3 .07 16 23 1.1 17 22 10 .59 8.3 1 .02 14 23 .87 18 20 8 .43 8.0 3 .06 14 31 1.2 19 18 7 .34 7.4 2 .04 11 21 .68 20 17 6 .28 7.0 5 .09 11 23 .68 21 16 6 .26 36 311 47 10 22 .59 22 15 5 .20 13 3 .11 9.4 56 1.4 23 17 6 .23 9.3 3 .08 8.9 53 1.3 24 16 6 .26 9.7 7 .18 8.2 51 1.2 25 17 6 .28 10 2 .05 7.9 43 .95 26 19 8 .41 8.7 1 .02 7.2 21 .42 27 16 6 .26 7.5 2 .04 6.9 51 .99 28 14 4 .15 7.0 4 .08 7.4 44 .38 29 13 4 .14 --- --- 7.3 34 .68 30 21 8 .57 6.2 44 .76 31 18 8 .41 6.1 34 .83 TOTAL 968 117.41 301.3 50.79 1317.8 3905.41 129 RIO FAJARDO BASIN 50071000 RIO FAJARDO NEAR FAJARDO, PR--Continued WINTER QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN MEAN MEAN MEAN CONCEN-SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) APRIL MAY JUNE 1 5.8 37 .60 43 37 10 44 16 1.9 2 5.6 25 .39 62 60 15 40 39 4.2 3 5.0 39 .54 33 12 1.1 37 9 .90 4 4.6 36 .44 24 3 .19 47 28 4.6 5 4.8 29 .38 24 4 .26 37 6 .60 6 5.3 31 .44 68 63 35 35 13 1.2 7 4.9 36 .50 117 133 67 62 29 5.2 8 4.7 34 .42 46 27 3.4 37 18 1.8 9 4.1 32 .35 29 0 .00 66 67 18 10 3.9 36 .38 24 4 .26 33 17 1.5 11 4.3 35 .40 21 4 .23 28 7 .53 12 4.9 28 .39 19 3 .15 32 7 .60 13 4.4 31 .38 500 671 3960 79 257 123 14 12 4 .16 179 326 199 99 70 23 15 18 8 .89 538 930 5740 197 276 432 16 14 7 I .36 117 65 27 371 481 615 17 100 232 1050 81 50 22 668 739 8040 18 169 277 $25 243 365 1010 282 483 670 19 221 318 405 458 1360 77 16 3.3 20 68 59 T 201 93 71 138 120 147 21 1500 1360 19800 181 192 111 69 7 1.3 22 90 29 7.0 130 135 50 55 1 .15 23 53 27 I 3.9 202 229 143 46 1 .12 24 38 35 3.6 211 293 231 40 5 .54 25 30 25 I 2.1 126 135 46 35 2 .19 26 25 17 I 1.5 109 123 62 27 18 1.3 27 35 24 5.1 103 130 45 42 31 5.3 28 59 64 117 73 8 1.6 37 25 2.7 29 28 22 1.5 75 12 2.4 25 12 .81 30 19 6 I .31 55 7 1.0 150 214 396 31 --- --- 51 12 1.7 --- --- --- TOTAL 2541.3 2206.03 4090 13216.29 2935 10502.74 MEAN MEAN MEAN MEAN CONCEN- ( SEDIMENT MEAN CONCEN- SEDIMENT MEAN CONCEN- SEDIMENT DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DISCHARGE TRATION DISCHARGE DAY (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) (CFS) (MG/L) (TONS/DAY) JULY AUGUST SEPTEMBER 1 72 65 31 162 220 457 46 11 1.4 2 86 94 28 167 186 184 50 2 .27 3 100 132 86 37 24 2.4 53 4 .57 4 135 214 145 34 25 2.3 42 1 .11 5 378 535 1720 31 13 1.1 33 7 .62 6 222 369 305 25 25 1.7 28 11 .83 7 132 74 26 20 10 .54 25 11 .74 8 66 13 2.8 17 9 .41 31 18 1.8 9 53 40 6.5 49 43 8.9 25 12 .81 10 46 4 .56 81 85 30 21 9 .51 11 45 46 5.6 27 17 1.2 23 8 .50 12 75 50 14 60 55 15 27 5 .36 13 44 20 2.4 68 65 15 20 6 .32 14 39 11 1.2 25 13 .88 17 16 .73 15 35 8 .76 40 24 3.9 25 12 .97 16 34 12 1.1 38 28 3.5 16 23 .99 17 46 10 1.2 132 156 95 15 15 .61 18 48 14 1.8 46 36 4.5 19 7 .36 19 42 9 1.0 28 6 .45 25 17 1.1 20 40 13 I 1.4 33 11 .98 15 7 .28 21 34 4 .37 496 723 2010 19 7 .36 22 30 11 .89 86 94 24 18 9 .44 23 37 6 .60 55 61 11 20 4 .22 24 69 46 11 55 50 8.8 17 2 .09 25 31 6 .50 204 290 439 87 121 74 26 25 1 .07 175 216 181 31 18 1.7 27 23 5 I .31 236 277 624 21 5 .28 28 22 10 1 .59 260 319 311 18 6 .29 29 216 314 1397 106 124 44 17 6 .28 30 41 7 .77 93 99 31 72 81 48 31 30 5 I .41 58 49 7.7 --- --- --- TOTAL 2296 p793.83 2944 4520.26 876 139.54 YEAR 24586.8 69950.05 130 RIO FAJARDO BASIN 50072500 RIO FAJARDO BELOW FAJARDO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°19'35", long 65°38'47", 1.2 mi (1.9 km) southwest of Playa de Fajardo, and 0.5 mi (0.8 km) east of Fajardo Plaza. DRAINAGE AREA.--23.4 sq mi (60.6 sq km). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- On- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (PG/L) 100 ML) 100 ML) NOV , 1982 17... 1050 67 139 6.7 25.5 15 8.4 102 23 52000 3900 JAN , 1983 21... 1415 25 192 7.6 23.0 5.5 10.6 135 31 90000 400 MAR 11... 1335 20 184 7.6 29.5 14 8.4 111 <10 1100 MAY 06... 1435 27 157 7.5 31.0 5.0 8.8 119 14 5600 3400 AUG 5... 1440 57 151 7.5 32.0 15 9.5 130 22 K13000 2000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- ors- SORP- On- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/"L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV r 1982 17... 26 JAN r 1983 21... 51 5 12 5.0 17 1.1 1.6 46 5.0 25 .10 MAR 11... 40 MAY 6... 47 6 12 4.2 17 1.1 1.4 41 6.5 24 .20 AUG 5... 45 3 11 4.3 14 .9 1.5 42 6.5 19 .10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GENrAM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L ors- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENOED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV r 1982 17... 12 <.010 .20 .120 .88 1.00 1.2 JAN r 1983 21... 22 115 7.8 1 .19 .010 .20 .320 .18 .50 .70 MAR 11... 18 .18 .020 .20 .140 .26 .40 .60 MAY 6... 21 111 8.1 <1 .010 <.10 .030 .07 .10 AUG 05... 21 103 15.8 24 .18 .020 .20 .120 .28 .40 .60 CHRO- BARIUM. CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV r 1982 17... 5.3 .040 JAN , 1983 21... 3.1 .090 1 <100 1 <1 11 .3 <1 <1 MAR 11... 2.7 .070 MAY 06... .030 AUG 05... 2.7 .070 <1 100 1 5 <.1 <1 <1 K = non-ideal count RIO BLANCO BASIN 50075000 RIO ICACOS NEAR NAGUABO, PR 131 LOCATION.--Lat 18°16'38", long 65°47'09", Hydrologic Unit 21010001, in Caribbean National Forest, off Highway 191, at El Yunque, 1.6 mi (2.6 km) upstream from confluence with Rio 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 sq mi (3.26 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1945 to March 1953 (operated by Puerto Rico Water Resources Authority), annual maximum, water years 1953-62, annual low-flow measurements 1962-66, October 1979 to current year. GAGE.--Water-stage recorder and broad-crested weir. Altitude of gage is 2,020 ft (616 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--11 years (1946-52, 1980-83), 15.7 cu ft/s (0.445 cu m/s), 169.21 in/yr (4,298 mm/yr), 11,370 acre-ft/yr (14.0 cu hm/yr); median of yearly mean discharges, 14 cu ft/s (0.40 cu m/s), 10,100 acre-ft/yr (12 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 2,860 cu ft/s (81.0 cu m/s) Apr. 21, 1983, gage height, 8.96 ft (2.731 m), from rating curve extended above 30 cu ft/s (0.850 cu m/s) on basis of step-backwater analysis; minimum daily, 1.5 cu ft/s (0.042 cu m/s) Mar. 22, Apr. 10, 1946. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 650 cu ft/s (18.4 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 0315 *2,860 81.0 8.96 2.731 July 5 1415 945 26.8 6.06 1.847 Minimum discharge, 3.1 cu ft/s (0.088 cu m/s) Apr. 26, 30. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 9.0 9.7 10 13 6.0 3.9 3.9 4.0 6.3 21 37 9.6 2 6.4 11 14 9.2 6.0 3.9 3.9 8.4 6.1 23 20 11 3 6.0 21 18 9.5 5.7 3.8 3.9 4.0 6.0 20 7.7 10 4 6.0 7.1 13 8.7 5.6 3.6 3.9 3.6 6.5 30 7.2 11 5 8.7 19 9.4 19 5.6 3.6 3.9 3.9 6.0 153 8.1 9.1 6 5.9 11 8.3 20 5.5 4.2 3.9 33 6.9 27 7.6 3.5 7 5.6 6.2 8.2 9.9 5.4 8.9 3.9 6.6 14 24 6.3 8.4 s 5.6 6.1 7.8 13 5.2 17 3.8 4.4 7.3 12 6.3 9.3 9 5.5 17 7.0 13 5.2 7.2 3.5 3.8 13 11 6.3 8.6 10 5.3 7.2 6.9 8.6 5.1 4.3 3.5 3.6 7.5 10 15 8.1 11 5.2 9.6 6.7 9.1 4.6 5.5 3.8 3.5 9.7 9.9 8.8 7.9 12 5.5 49 6.4 16 4.5 91 3.6 3.8 7.6 9.7 10 8.6 13 6.3 11 6.4 7.7 4.5 7.8 4.3 4.1 14 9.3 11 7.6 14 8.5 13 6.0 7.1 5.0 5.2 4.3 7.2 8.9 9.0 6.7 7.4 15 5.7 28 62 3.4 4.6 4.6 5.3 51 32 8.7 17 11 16 5.6 22 14 8.3 4.5 4.3 3.6 7.3 65 12 18 7.1 17 22 8.3 11 7.0 4.5 4.2 29 5.8 23 14 27 7.9 13 24 17 6.1 6.6 4.3 4.2 15 28 32 11 9.5 9.3 19 9.9 17 5.6 6.4 4.2 4.0 17 69 le 10 7.3 11 20 9.6 7.2 56 6.2 4.2 3.9 13 29 9.4 11 9.3 7.4 21 9.2 6.5 29 6.0 6.0 3.9 267 31 8.8 8.2 89 8.7 22 6.2 6.3 16 6.0 4.8 3.9 7.3 14 8.2 9.0 12 8.3 23 22 21 11 5.9 4.4 3.9 4.3 24 7.9 11 8.5 3.6 24 7.6 8.3 12 6.0 4.5 3.9 3.8 18 7.8 16 8.3 11 25 11 17 9.3 6.2 4.4 3.7 3.4 10 7.4 7.9 53 25 26 15 23 42 7.4 4.1 3.6 3.2 7.9 8.2 7.3 41 10 27 7.8 48 15 5.9 3.9 3.7 5.9 7.3 9.5 6.9 43 3.1 28 6.2 54 35 5.7 3.9 5.4 7.7 7.4 9.7 7.1 22 7.4 29 5.8 13 11 5.6 --- 4.2 3.8 3.0 7.3 38 22 7.3 30 6.5 29 22 6.3 4.0 3.3 6.4 3C 9.5 13 10 31 8.4 --- 64 6.0 4.0 --- 6.1 --- 8.5 10 --- TOTAL 272.0 524.0 549.1 277.7 136.2 239.3 446.7 424.1 396.0 565.0 567.9 283.7 MEAN 3.77 17.5 17.7 8.96 4.86 7.74 14.9 13.7 13.2 18.2 18.3 9.46 MAX 24 54 64 20 6.0 91 267 69 65 153 89 25 MIN 5.2 6.1 5.6 5.6 3.9 3.6 3.2 3.5 6.0 6.9 6.3 7.1 CFSM 6.96 13.9 14.0 7.11 3.86 6.14 11.8 10.9 10.5 14.4 14.5 7.51 IN. 8.02 15.46 16.20 8.19 4.02 7.07 13.18 12.51 11.68 16.67 16.75 8.37 AC-FT 540 1040 1090 551 270 476 886 841 795 1120 1130 563 CAL YR 1982 TOTAL 4926.8 MEAN 13.5 MAX 145 MIN 3.9 CFSM 10.7 IN 145.34 AC-FT 9770 WTR YR 1983 TOTAL 4632.2 MEAN 12.8 MAX 267 MIN 3.2 CFSM 10.2 IN 133.13 AC-FT 9290 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTO3ER 1982 TO SEPTEMBER 1933 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS OUCTANCE TURE DATE TIME INSTANTANEOUS OUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 05 1630 26 49 21.5 APR, 20 1035 9.7 88 20.0 NOV, 05 1400 7.5 66 21.0 MAY, 09 1211 3.9 59 21.0 DEC, 14 1040 5.3 66 20.0 JUN. 17 1220 11 51 22.0 JAN. 11 1140 8.3 60 20.0 JUL, 15 1204 8.4 95 21.0 FEB, 04 1005 5.6 78 19.5 AUG, 19 1115 7.5 80 22.0 MAR, 03 1156 4.0 66 20.0 SEP. 16 1106 6.3 61 21.5 132 RIO BLANCO BASIN 50076000 RIO BLANCO NEAR FLORIDA, PR LOCATION.--Lat 18°13'45", long 65°47'06", Hydrologic Unit 2101005, 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 sq mi (31.9 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1982 to September 1983. GAGE.--Water-stage recorder. Altitude of gage is 50 ft (15 m), from topographic map. REMARKS.--Records fair. Low flow affected by diversion for water supply. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 3,000 cu ft/s (85.0 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Dec. 20 0230 4,370 124 17.26 5.261 July 5 1445 3,880 110 16.68 5.084 Apr. 21 0330 *11,000 312 22.76 6.937 Aug. 21 1345 3,060 86.7 15.46 4.712 Minimum discharge, 8.8 cu ft/s (0.249 cu m/s) Apr. 10. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 58 57 50 82 20 14 11 27 24 73 300 53 2 36 51 52 60 19 13 11 38 26 131 100 84 3 30 106 39 47 18 13 11 32 22 142 80 66 4 28 41 56 48 19 12 11 23 23 204 70 61 5 30 50 42 85 18 12 11 33 33 766 60 50 6 26 46 30 91 17 23 11 125 23 204 50 45 7 25 26 39 53 17 50 11 85 43 136 40 43 8 24 25 30 73 16 112 10 37 38 69 35 43 9 23 65 26 54 16 4B 10 24 77 50 60 42 10 23 34 25 43 16 21 9.6 24 55 44 160 47 11 22 34 22 44 16 32 13 21 32 41 60 43 12 21 203 20 68 15 492 10 17 63 43 140 43 13 77 56 19 34 16 60 9.7 23 27 41 70 41 14 48 27 17 34 18 27 15 35 41 39 50 36 15 48 77 232 39 17 22 20 282 159 36 80 47 16 31 99 51 47 15 20 14 80 371 36 70 36 17 77 41 51 35 15 18 75 66 106 63 194 37 18 162 97 23 32 15 17 102 116 167 56 74 45 19 40 96 21 30 15 16 99 234 62 48 51 45 20 109 33 405 28 14 15 34 135 46 60 65 36 21 89 25 118 27 26 14 1220 158 46 40 610 43 22 39 23 85 26 18 14 96 91 30 35 98 44 23 148 136 76 25 15 14 42 206 31 38 61 52 24 61 57 91 24 15 13 38 153 31 105 63 69 25 44 57 92 23 18 13 31 75 30 45 214 91 26 64 110 346 26 16 13 27 76 41 37 181 50 27 46 202 154 23 15 12 154 74 35 35 248 37 28 34 186 230 21 14 25 98 42 43 44 152 37 29 28 65 69 21 --- 18 40 46 27 400 128 36 30 30 176 84 24 14 26 31 109 80 74 68 31 43 --- 332 21 12 --- 26 --- 60 58 --- TOTAL 1564 2301 2977 1292 469 1199 2320.3 2440 1861 3201 3696 1470 MEAN 50.5 76.7 96.0 41.7 16.8 38.7 77.3 78.7 62.0 103 119 49.0 MAX 162 203 405 91 26 492 1220 282 371 766 610 91 MIN 21 23 17 21 14 12 9.6 17 22 35 35 36 CFSM 4.11 6.24 7.81 3.39 1.37 3.15 6.29 6.40 5.04 8.37 9.68 3.98 IN. 4.73 6.96 9.00 3.91 1.42 3.63 7.02 7.38 5.63 9.68 11.18 4.45 AC-FT 3100 4560 5900 2560 930 2380 4600 4840 3690 6350 7330 2920 WTR YR 1983 TOTAL 24790.3 MEAN 67.9 MAX 1220 MIN 9.6 CFSM 5.52 IN 74.97 AC-FT 49170 WATER-QUALITY RECORDS PERIOD OF RECORD.--OCTOBER 1982 TO SEPTEMBER 1983 WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- OATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMMOS) (DEG C) (CFS) (UMNOS) (DEG C) OCT, 21 1345 107 83 26.0 MAR, 02 1340 13 115 28.0 NOV' 09 1159 23 107 27.5 MAY, 10 1307 25 105 29.0 DEC, 21 1240 65 93 23.5 JUN, 21 1600 47 -- 28.0 JAN, 13 1020 39 107 21.5 JUL. 26 1040 34 101 27.0 FEB, 07 1305 17 172 26.0 SEP, 01 1300 52 100 28.0 Rib Anton Rui. basin MACAO Drainage boundary-\ 820 Rio Grand• di Loira basin Rib de la Plato basin Island divide.\ Drainage boundary 0872. Rib Salinas (Nigua} basin t EXPLANATION 0820 SURFACE-WATER STATION AND NUMBER 0825 LOW-FLOW STATION AND NUMBER V0835 QUALITY-OF-WATER STATION AND NUMBER M A R CARIBE • 31 WELL AND WELL NUMBER 2 2 4 5 6 TKILOMETERS I I S MILES Figure 20.--Southeastern rivers basin--Rio Humacao to Rio Seco basins. 134 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR LOCATION.--Lat 18°08'49", long 65°49'37", at bridge on Highway 3, 300 ft (91 m) downstream from Quebrada Mariana, and 0.4 mi (0.6 km) south of Humacao. DRAINAGE AREA.--17.3 sq mi (44.8 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1982 to September 1983. GAGE.--Water-stage recorder and concrete control. Datum of gage 33.33 ft (10.16 m) above mean sea level. REMARKS.--Records fair. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,000 cu ft/s (56.6 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 19 0345 3,780 107 11.97 3.648 Aug. 17 0545 2,840 80.4 11.27 3.435 Apr. 21 0445 2,720 77.0 11.17 3.405 Aug. 21 1715 8,810 249 14.56 4.438 July 5 1700 *9,940 282 15.00 4.572 Minimum discharge, 10 cu ft/s (0.283 cu m/s) many days in March and April. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 74 87 190 40 27 14 11 21 23 41 53 56 2 56 64 101 40 23 13 12 41 23 84 78 83 3 47 55 68 31 21 15 10 31 22 64 49 61 4 43 49 66 35 22 14 11 28 29 102 48 50 5 43 161 59 42 22 14 12 37 27 1470 43 50 6 41 155 50 41 20 14 11 31 26 194 42 47 7 39 74 47 33 20 15 11 34 26 116 39 51 3 37 71 45 36 19 13 11 26 20 90 41 49 9 36 51 45 62 19 25 11 25 39 68 46 51 10 34 52 43 43 18 16 11 22 31 55 41 52 11 34 55 44 34 18 22 11 21 25 52 35 55 12 33 59 40 36 17 130 11 22 68 47 34 54 13 45 45 41 37 17 37 12 22 27 44 37 41 14 41 39 41 30 16 15 13 26 25 45 45 41 15 34 42 45 29 16 13 12 73 86 42 40 55 16 28 69 39 23 15 13 11 35 136 59 83 47 17 58 56 38 27 15 13 18 83 53 102 391 43 18 66 92 36 30 16 14 47 36 100 71 109 47 19 153 412 36 29 16 12 13 34 43 48 68 40 20 147 153 40 28 14 12 17 37 33 38 61 43 21 79 76 46 29 14 12 336 25 36 35 1760 72 22 72 74 42 28 14 13 37 27 37 35 151 54 23 65 149 37 23 14 12 25 40 33 45 107 52 24 49 71 36 28 16 13 24 274 34 74 100 118 25 47 72 35 28 15 13 23 75 34 37 138 125 26 45 52 52 32 14 12 23 67 33 33 124 102 27 43 58 46 27 13 12 24 35 85 32 98 64 28 93 73 57 26 13 11 42 31 47 35 110 55 29 49 52 49 26 --- 11 28 27 40 232 87 48 30 78 347 43 26 12 28 25 37 97 76 54 31 108 --- 105 27 11 --- 24 --- 123 60 --- TOTAL 1817 2870 1662 1016 484 571 866 1335 1278 3610 4194 1760 MEAN 58.6 95.7 53.6 32.8 17.3 18.4 28.9 43.1 42.6 116 135 58.7 MAX 153 412 190 62 27 130 336 274 136 1470 1760 125 MIN 28 39 35 26 13 11 10 21 20 32 34 40 CFSM 3.39 5.53 3.10 1.90 1.00 1.06 1.67 2.49 2.46 6.71 7.80 3.39 IN. 3.91 6.17 3.57 2.13 1.04 1.23 1.36 2.87 2.75 7.76 9.02 3.78 AC-FT 3600 5690 3300 2020 960 1130 1720 2650 2530 7160 8320 3490 WTR YR 1983 TOTAL 21463 MEAN 58.8 MAX 1760 MIN 10 CFSM 3.40 IN 46.15 AC- FT 42570 135 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°08'49", long 65°49'37", at bridge on Highway 3, 300 ft (91 m) downstream from Quebrada Mariana, and 0.4 mi (0.6 km) south of Humacao plaza. DRAINAGE AREA.--17.3 sq mi (44.8 sq km). PERIOD OF RECORD.--Water years 1958-66, 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW. CON- PH TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- 8ID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV r 1982 22... 1225 51 234 7.0 25.0 16 7.3 89 42 K130000 29000 JAN . 1983 21... 1100 28 282 7.1 25.5 6.5 9.0 109 26 260000 41000 MAR 11... 1000 29 274 7.6 26.0 65 6.8 0 <10 54000 K16000 APR 21... 1100 E257 146 25.0 21... 1105 E254 146 25.0 21... 1110 -- 146 25.0 21... 1115 E244 146 25.0 21... 1120 E231 -- -- MAY 06... 1110 31 235 7.7 27.0 75 6.8 86 18 270000 11000 AUG 05... 1040 45 236 7.4 29.0 16 7.6 98 29 K84000 26000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO-• HARD- NESS, CALCIUM STUN, SODIUM. AD- SIUMr LINITY SULFATE RIDE. RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 22... 68 JAN . 1983 21... 82 0 22 6.5 24 1.2 2.0 83 12 26 .20 MAR 11... 50 APR 21... 21... -- -- -- 21... 35 8 9.2 2.8 13 1.0 3.6 13 15 <.10 21... -- -- -- 21... -- MAY 06... 77 0 21 5.9 24 1.2 2.3 77 14 25 .20 AUG 05... 73 0 20 5.6 21 1.1 1.7 74 9.7 22 .20 SOLIDS, SOLIDS, NITRO- SILICA. SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- DIS- CONSTI- DIS- AT 105 GEN, GIN. GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS. SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV . 1982 22... 32 .68 .020 .70 .260 .14 .40 1.1 JAN r 1983 21... 39 181 13.7 1 .85 .050 .93 .440 .46 .90 1.8 MAR 11... 100 .04 .060 .10 .23C .97 1.20 1.3 APR 21... 21... -- 21... 19 92 21... -- 21... MAY 06... 35 174 14.5 104 .61 .090 .70 .39C .51 .90 1.6 AUG 05... 33 163 19.6 57 .73 .070 .80 .250 .55 .80 1.6 K = non-ideal count E = estimate 136 RIO HUMACAO BASIN 50082000 RIO HUMACAO AT HIGHWAY 3 AT HUMACAO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL SEDI- GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- MENT, TOTAL TOTAL T3TAL EPABLE ERASLE ERABLE ERA3LE ERAELE TOTAL ERABLE SUS- (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENDED DATE AS NO3) AS P) AS AS) AS FA) AS CD) AS CR) AS PS) AS HG) AS SE) AS AG) (MG/L) NOV , 1932 22... 4.9 .170 JAN 193' 21... 8.0 .310 2 <100 1 1 12 .3 <1 <1 MAR 11... 5.8 .370 APR 21... 863 21... 815 21... 21... 788 21... -- 15400 MAY 06... 7.1 .380 AUG 05... 7.1 .300 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURF DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMMOS) (DEG C) (CFS) (UMMOS) (DEG C) OCT, 21 1530 86 193 29.0 JUN, 21 1152 37 -- 29.5 DEC, 21 0955 44 268 23.5 JUL, 26 0855 34 243 28.0 FES, 08 0930 19 312 23.0 SEP, 06 1110 53 234 29.5 MAR, 02 1627 14 303 31.0 137 RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'33", long 65°54'03", at bridge on Highway 182, 1.4 mi (2.2 km) west-northwest of Yabucoa plaza. DRAINAGE AREA.--17.2 sq mi (44.6 sq km). PERIOD OF RECORD.--Water years 1958-62, 1968-70, 1980 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 DATE SPE- STREAM- CIFIC FLOW, CON- PH INSTAN- DUCT- (STAND- TIME TANEOUS ANCE ARD (CFS) (UMHOS) UNITS) OXYGEN, OXYGEN COLI- STREP- DIS- DEMAND, FORM, TOCOCCI SOLVED CHEM- FECAL, FECAL, HARD- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER AS (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CAC03) NOV • 1982 18... 1050 104 120 6.5 24.0 88 7.6 90 22 22000 45000 JAN e 1983 27... 1220 43 158 7.5 24.0 15 7.8 93 <10 2200 K1900 44 MAR 22... 1400 21 164 7.5 28.0 5.4 7.2 92 <10 K1400 5100 MAY 18... 1240 32 136 7.4 26.0 24 7.8 97 60 K1200 3800 44 JUN 03... 1240 30 166 7.4 28.0 7.3 100 AUG 22... 1045 139 106 7.2 26.0 8.4 103 4100 9500 HARD- NESS, NONCAR- 80NATE (MG/L DATE CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, SODIUM, AD- SIUM. LINITY SULFATE - RIDE, RIDE, DIS- DIS- SORP- Dn."' FIELD DIS- DIS- DIS- SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS AS NA) AS K) CAC03) AS SO4) AS CL) AS F) 5IO2) NOV , 1982 18... JAN •1983 27... 0 11 MAR 22... MAY 13... 0 11 JUN 03... AUG 22... 32 3.9 14 1.0 1.4 56 <5.0 11 .10 36 62 4.1 15 1.0 1.4 54 7.2 11 .10 37 61 34 SOLIDS, SOLIDS, NITRO- SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN.AM- CONSTI- ,DIS- AT 105 GEN. GEN, GEN, GEN, GEN, MCNIA + NITRO- NITRO- TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) DAY) CMG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) NOV • 1982 18... JAN r 1983 27... MAR 22... MAY 13... JUN 03... AUG 22... 162 .46 .040 .50 .070 1.2 1.30 1.8 8.0 7 <.010 .40 .080 .12 .20 .60 2.7 13 <.010 .20 .020 .28 .30 .50 2.2 119 10.3 28 <.010 .30 .060 .14 .20 .50 2.2 .25 .050 .30 .030 .27 .30 .60 2.7 K = non-ideal counts SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) SEDI- MENT, SUS- PENDED CMG/L) SEDI- MENT, DIS- CHARGE, SUS- PENDED (T/DAY) SELE- NIUM, TOTAL (UG/L AS SE) RIO GUAYANES BASIN 50083500 RIO GUAYANES AT YABUCOA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 138 PHOS- PHORUS, TOTAL (MG/L DATE AS P) CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY TOTAL TOTAL TOTAL TOTAL TOTAL ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) NOV , 1982 18... .150 JAN r 1983 27... .070 1 100 5 1 <1 .3 <1 2 MAR 22... .030 MAY 18... .080 JUN 03... AUG 22... .100 219 61 CHLOR- DI- PCB, ALORIN, DANE, DOD, DOE, DDT, AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN , 1983 03... 1240 <.10 <.01 <.10 <.01 <.01 <.01 <.01 HEPTA- METH- DI- ENDO- HEPTA- CHLOR PALA- OXY- ELDR IN SULFAN, ENDRIN, ETHIONe CHLOR, EPDXIDE LINDA NE THION, CHLOR, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (US/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 03... <.01 <.10 <.01 <.01 <.31 <.01 <.01 <.01 <.01 DATE METHYL PARA- THION, TOTAL (UG/L) METHYL TRI- THION, TOTAL (UG/L) MIREX, TOTAL (UG/L) PARA- THION, TOTAL (UG/L) NAPH- THA- LENES, POLY- CHLOR. TOTAL (UG/L) PER- THANE TOTAL (UG/L) TOX- APHENE, TOTAL (UG/L) TOTAL TRI- THICN (UG/L) JUN , 1983 03... <.01 <.01 <.01 <.01 <.10 <.10 <1 <.01 SED. SED. SEC. SED. SED. SED. BED SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. MAT. STREAM- FALL FALL FALL FALL FALL FALL FALL FLOW, DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. INSTAN- X FINER % FINER X FINER % FINER X FINER % FINER X FINER TIME TANEOUS THAN THAN THAN THAN THAN THAN THAN DATE (CFS) 002 MM .004 MM .003 MM .016 MM .031 MM .062 MM .004 MM JAN r 1983 27... 1220 43 0 0 0 0 0 0 0 BED 3ED BED BED BED BED BED BED MAT. MAT. MAT. MAT. MAT. MAT. MAT. MAT. FALL SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAN. DIAM. DIAM. DIAM. DIAM. DIAM. X FINER % FINER % FINER % FINER X FINER % FINER X FINER % FINER THAN THAN THAN THAN THAN THAN THAN THAN DATE .062 MM .062 MM .125 4M .250 MM .500 MM 1.00 MM 2.00 MM 4.00 MM JAN 27... 0 0 1 5 19 47 73 93 139 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'45", long 65°49'42", at old railroad crossing, 0.2 mi (0.3 km) from mouth, 0.4 mi (0.6 km) west of Playa de Guayanes, and 3.5 mi (5.6 km) northeast of Yabucoa Plaza. DRAINAGE AREA.--34.0 sq mi (88.1 sq km). PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL. HARD- FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS INSTAN- DUCT.. (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER AS DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CAC03) NOV , 1982 18... 1330 154 144 6.9 25.0 96 7.2 87 <10 30000 9800 JAN r 1983 27... 1025 62 167 7.6 23.0 14 7.8 91 10 K1500 K1800 47 MAR 22... 1135 31 189 7.8 30.0 9.4 3.0 106 <10 470 K110 MAY 18... 0945 121 145 7.3 26.5 35 7.0 37 43 45000 59000 41 AUG 22... 1400 425 113 7.0 28.0 95 8.0 102 24 5400 9800 28 HARD- MAGNE- SODIUM POTAS- ALKA- CHID- FLUO- SILICA, NESS, CALCIUM SIUMr SODIUM, AD- STUN, LINITY SULFATE RIDE, RIDE, ors- NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- SOLVED BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS DATE CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) SI02) NOV , 1982 18... 39 JAN , 1983 27... 0 12 4.2 16 1.0 1.7 56 6.0 14 .10 35 MAR 22... 70 MAY 18... 0 10 4.0 17 1.2 4.4 43 17 16 .10 28 AUG 22... 0 7.2 2.5 10 .8 2.5 30 10 10 <.10 21 SOLIDS, SOLIDS. NITRO- SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MCNIA + NITRO- NITRO- TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. GEN, DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/I) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) NOV , 1982 18... 161 .47 .030 .50 .080 1.6 1.70 2.2 9.7 JAN . 1983 27... 123 20.5 11 .49 .010 .50 .070 <.10 MAR 22... 22 .19 .010 .20 .060 .44 .50 .70 3.1 MAY 18... 122 39.9 77 .28 .020 .30 .060 .24 .30 .60 2.7 AUG 22... 81 93.1 109 .23 .070 .30 .040 .36 .40 .70 3.1 K = non-ideal count 140 RIO GUAYANES BASIN 50086500 RIO GUAYANES ABOVE MOUTH AT PLAYA DE GUAYANES, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO— SEDI— BARIUM, CADMIUM MIUM. LEAD. MERCURY SILVER, MENTe PHOS— TOTAL TOTAL TOTAL TOTAL TOTAL SELE— TOTAL SEDI— OIS— PHORUSe ARSENIC RECOV— RECOV— RECOV— RECOV— RECOV— NIUMe RECOV— MENTe CHARGE, TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE SUS— SUS— (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENDED PENDED DATE AS P) AS AS) AS BA) AS CD) AS CR) AS P3) AS HG) AS SE) AS AG) (MG/L) (T/DAY) NOV 1982 18... .100 207 86 JAN e 1983 27... .070 1 100 6 <1 <1 .5 <1 2 MAR 22... .050 MAY 18... .190 AUG 22... .150 1 <100 1 <10 5 <.1 <1 <1 SED. SED. SED. SED. SED. SED. BED SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. MAT. STREAM— FALL FALL FALL FALL FALL FALL FALL FLOW, DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. INSTAN— X FINER X FINER X FINER X FINER X FINER X FINER X FINER TIME TANEOUS THAN THAN THAN THAN THAN THAN THAN DATE (CFS) 002 MM .004 MM .008 MM .016 MM .031 MM .062 MM .004 MM JAN , 1983 27... 1025 62 0 0 0 0 0 0 0 BED BED BED BED BED BED BED BED MAT. MAT. MAT. MAT. MAT. MAT. MAT. MAT. FALL SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. X FINER 1 FINER X FINER X FINER X FINER X FINER X FINER % FINER THAN THAN THAN THAN THAN THAN THAN THAN DATE .062 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM 2.00 MM 4.00 MM JAN 27... 0 0 1 3 16 55 86 97 RIO MAUNABO BASIN 50090500 RIO MAUNABO AT LIZAS, PR 141 LOCATION.--Lat 18°01'38", long 65°56'24", Hydrologic Unit 21010005, on right bank, off Highway 759 at Lizas, about 1.0 mi (1.6 km) below Quebrada Coroco, and about 3.0 mi (4.8 km) northwest of Maunabo. DRAINAGE AREA.--5.38 sq mi (13.93 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1971 to current year. GAGE.--Water-stage recorder. Altitude of gage is 230 ft (70.1 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--12 years (1972-831 18.7 cu ft/s (0.530 cu m/s), 47.20 in/yr (1,199 mm/yr), 13,550 acre-ft/yr (16.7 cu hm/yr); median of yearly mean discharges, 16 cu ft/s (0.45 cu m/s), 11,600 acre-ft/yr (14 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 6,280 cu ft/s (178 cu m/s) Aug. 31, 1979, gage height, 14.57 ft (4.441 m), from rating curve extended above 50 cu ft/s (1.42 cu m/s) on basis of step-backwater analysis; minimum daily, 2.2 cu ft/s (0.062 cu m/s) Jul. 16, Aug. 7, 13, 1974. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 600 cu ft/s (17.0 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 18 2230 1,110 31.4 7.99 2.435 July 4 1845 *1,550 43.9 8.83 2.691 Nov. 30 0300 618 17.5 6.77 2.063 Aug. 16 2030 1,240 35.1 8.26 2.518 Minimum discharge, 2.5 cu ft/s (0.071 cu m/s) Apr. 16, 17. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19 17 23 21 7.6 5.6 3.3 4.4 7.2 12 31 28 2 16 13 21 16 7.5 5.5 3.3 6.4 6.9 35 29 44 3 15 12 19 15 7.4 5.2 3.1 6.8 6.6 36 23 31 4 14 12 19 16 7.5 5.1 3.3 6.3 7.1 97 24 27 5 21 14 16 18 7.4 5.0 3.3 8.4 7.4 73 34 24 6 13 11 14 23 7.0 5.4 3.4 7.1 11 79 23 23 7 12 11 14 17 7.0 6.4 3.2 5.9 7.6 61 19 22 8 12 13 13 17 6.8 11 3.0 4.8 6.5 31 18 21 9 12 13 13 23 6.7 14 2.9 4.5 23 25 17 20 10 12 14 12 18 6.7 6.2 2.7 4.4 9.0 22 17 19 11 11 13 12 16 6.5 6.0 2.8 4.1 7.6 20 17 20 12 10 14 12 15 6.2 6.7 2.6 4.3 6.7 21 25 25 13 10 13 11 14 6.1 6.6 2.9 4.1 8.2 17 35 19 14 10 10 11 14 7.2 5.7 2.9 6.4 8.3 16 23 17 15 10 11 12 13 6.9 5.6 3.2 7.8 33 15 23 17 16 11 15 11 15 6.5 5.3 2.6 6.2 61 15 102 17 17 18 11 10 12 6.5 5.1 4.4 21 19 41 127 17 18 19 70 9.6 9.6 6.7 5.0 27 20 77 26 43 17 19 14 79 9.4 9.4 6.2 4.9 7.0 50 17 21 26 15 20 37 32 9.8 9.1 6.0 4.7 11 13 13 13 24 17 21 18 17 11 9.0 6.3 4.6 54 7.1 11 17 139 25 22 15 13 12 9.0 6.0 4.6 11 11 9.9 16 47 19 23 54 16 12 9.1 5.8 4.5 6.7 83 9.2 46 33 26 24 19 13 16 9.0 6.4 4.3 5.3 93 8.8 39 28 20 25 16 11 15 9.2 6.5 4.0 4.6 25 8.2 18 54 22 26 16 11 17 9.3 6.2 3.7 4.6 16 8.1 15 40 110 27 14 11 18 3.7 6.2 3.5 4.2 13 19 15 38 53 28 13 11 17 8.2 5.8 3.8 5.7 10 15 15 56 26 29 12 46 16 8.2 --- 3.6 5.5 9.1 9.4 85 37 25 30 14 214 16 3.6 3.3 4.8 9.0 23 26 43 46 31 17 --- 58 7.9 3.3 --- 3.5 --- 22 31 --- TOTAL 504 766 479.8 407.8 185.6 168.2 204.3 485.6 464.7 995 1226 812 MEAN 16.3 25.5 15.5 13.2 6.63 5.43 6.81 15.7 15.5 32.1 39.5 27.1 MAX 54 214 58 23 7.6 14 54 98 77 97 139 110 MIN 10 10 9.4 7.9 5.8 3.3 2.6 4.1 6.5 12 17 15 CFSM 3.03 4.74 2.88 2.45 1.23 1.01 1.27 2.92 2.88 5.97 7.34 5.04 IN. 3.48 5.30 3.32 2.82 1.28 1.16 1.41 3.36 3.21 6.83 8.48 5.61 AC-FT 1000 1520 952 309 368 334 405 963 922 1970 2430 1610 CAL YR 1982 TOTAL 6403.5 MEAN 17.5 MAX 214 MIN 6.1 CFSM 3.25 IN 44.27 AC-FT 12700 WTR YR 1983 TOTAL 6699.0 MEAN 18.4 MAX 214 MIN 2.6 CFSM 3.42 IN 46.31 AC-FT 13290 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1932 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA, DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 13 1250 11 156 23.5 APR, 20 1245 12 189 23.0 NOV, 08 1405 11 188 26.5 MAY, 12 1221 4.4 177 23.5 DEC, 22 1400 11 245 26.0 JUN, 22 1105 10 152 29.0 JAN. 18 1235 9.6 297 25.5 JUL, 13 1025 17 167 27.0 FEB, 11 1030 6.7 233 22.0 JUL, 28 1335 14 167 29.0 MAR, 01 1212 7.0 152 27.0 AUG, 02 1325 25 151 29.0 MAR, 02 1116 5.7 175 27.0 142 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'24", long 65°54'19", at bridge on Highway 3, 0.4 mi (0.6 km) southwest of Maunabo plaza, and 1.3 mi (2.1 km) upstream from mouth. DRAINAGE AREA.--12.4 sq mi (32.1 sq km). PERIOD OF RECORD.--Water years 1958-66, 1975 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI-• STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEW.. FECAL, FECAL, HARD." FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS INSTAN- DUCT- (STAND- TEMPER- BID- On- CENT (HIGH UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARC ATURE ITV SOLVED SATUR- LEVEL) (COLS./ PER AS DATE (CFS) (UMMOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) CAC03) NOV e 1982 19... 1500 120 129 6.4 24.0 63 7.0 33 10 9200 14000 JAN r 1983 27... 1425 15 241 7.6 27.0 2.5 3.5 107 <10 8000 K1400 72 MAR 23... 1225 6.8 234 7.8 31.0 4.0 3.2 111 13 K200 K400 MAY 19... 1210 15 198 7.6 29.5 11 7.9 104 <10 3700 2200 69 AUG 23... 1100 69 194 7.4 27.0 2.0 3.2 102 58 4200 2800 58 HARD- NESS, NONCAR- BONATE (MG/L DATE CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM, DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, AD- SIUM, LINITY SULFATE RIDE, RIDE, DIS- SORP- DIS- FIELD DIS- DIS- DIS- SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS AS K) CAC03) AS 504) AS CL) AS F) SI02) NOV , 1982 19... JAN 1983 27... 0 17 MAR 23... MAY 19... 0 16 AUG 23... 0 14 27 7.2 20 1.1 1.0 84 10 16 .10 38 89 7.0 21 1.1 1.1 75 12 19 .20 37 5.5 17 1.0 1.1 61 10 15 <.10 35 SOLIDS, SOLIDS, SUM OF SOLIDS, RESIDUE NITRO- NITRO- CCNSTI- DIS- AT 105 GEN, GEN' TUENTS, SOLVED DEG. Cr NITRATE NITRITE DIS- (TONS SUS- TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L DATE (MG/L) DAY) (MG/L) AS N) AS N) NITRO- NITRO- NITRO- NITRO- GEN'AM- GEN, GEN, GEN, MONIA + NO2+NO3 AMMONIA ORGANIC ORGANIC TOTAL TOTAL TOTAL TOTAL (MG/L (MG/L (MG/L (MG/L AS N) AS N) AS N) AS N) NITRO- GEN, TOTAL (MG/L AS N) NITRO- GEN, TOTAL (MG/L AS NO3) NOV r 1982 19... 96 .57 .030 JAN • 1983 27... 160 6.3 <1 <.010 MAR 23... 16 .010 MAY 19... 158 6.4 6 <.010 AUG 23... 134 25.0 32 .38 .020 K = non-ideal count .60 .070 1.1 1.20 1.8 8.0 .30 .040 <.10 <.10 .010 .09 .10 .20 .070 .23 .30 .50 2.2 .40 .030 .17 .20 .60 2.7 RIO MAUNABO BASIN 50091000 RIO MAUNABO AT MAUNABO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- SEDI- BARIUM, CADMIUM MIUM. LEAD, MERCURY SILVER, MENT, PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL SEDI- DIS- PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM. RECOV- MENT, CHARGE, TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE SUS.. SUS- (MG/L (UG/L (UG/L (UG/L (UG/L (US/L (UG/L (UG/L (UG/L PENDED PENDED DATE AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) (MG/L) (T/DAY) NOV , 1982 19... .140 148 48 JAN 1983 27... .040 2 100 4 <1 <1 .3 <1 2 MAR 23... .050 MAY 19... .070 AUG 23... .100 1 100 1 <10 5 <.1 <1 <1 SED. SED. SED. SED. SED. SED. BED SUSP. SUSP. SUSP. SUSP. SUSP. SUSP. MAT. STREAM- FALL FALL FALL FALL FALL FALL FALL FLOW, DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. DIAM. INSTAN- X FINER X FINER X FINER I FINER X FINER X FINER X FINER TIME TANEOUS THAN THAN THAN THAN THAN THAN THAN DATE (CFS) 002 MM .004 MM .008 MM .016 MM .031 MM .062 MM .004 MM JAN r 1983 27... 1425 15 0 0 0 0 0 0 0 BED BED BED BED BED BED BED BED MAT. MAT. MAT. MAT. MAT. MAT. MAT. MAT. FALL SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE SIEVE DIAM. DIAM. DIAM. HAM. DIAM. DIAM. DIAM. DIAM. X FINER I FINER X FINER I FINER X FINER I FINER X FINER X FINER THAN THAN THAN THAN THAN THAN THAN THAN DATE .062 MM .062 MM .125 MM .250 MM .500 MM 1.00 MM 2.00 MM 4.00 MM JAW 27... 0 0 1 3 24 62 71 91 143 NITRO- GEN, TOTAL (MG/L AS N) NITRO- GEN, TOTAL (MG/L AS NO3) 144 RIO CHICO BASIN 50091800 RIO CHICO AT PROVIDENCIA, PR WATER-QUALITY RECORDS LOCATION.--Lat 17°59'16", long 66°00'18", at flat low bridge 200 ft (61 m) south of Highway 3, 0.5 mi (0.8 km) above mouth, and 1.5 mi (2.4 km) southeast of Patillas plaza. DRAINAGE AREA.--4.9 sq mi (12.8 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 SPE- STREAM- CIFIC FLOW. CON- PH INSTAN- DUCT- (STAND- TIME TANEOUS ANCE ARD DATE (CFS) (UMHOS) UNITS) OXYGEN, OXYGEN COLI STREP- DIS- DEMAND, FORM, TOCOCCI SOLVED CHEM- FECAL, FECAL, HARD- TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR NESS TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. (MG/L ATURE ITY SOLVED SATUR-• LEVEL) (COLS./ PER AS (DEG C) (NTU) (MG/L) ATION) CMG/L) 100 ML) 100 ML) CAC03) NOV , 1982 19... 1215 68 177 6.8 24.0 65 7.4 88 14 56000 30000 19... 1500 -- -- -- -- -- -- -- JAN , 1983 27... 1615 1.3 635 7.4 27.0 2.4 .0 0 71 2800000 430000 130 MAR 23... 1025 .53 773 7.4 29.0 .0 0 140 K6700000 K220000 MAY 19... 0930 .68 632 7.4 28.0 5.1 .0 0 100 K6300000 990000 130 AUG 23... 1300 19 278 7.6 23.0 11 7.2 92 20 420000 52000 80 HARD- NESS, CALCIUM NONCAR- DIS- BONATE SOLVED (MG/L (MG/L DATE CAC03) AS CA) MAGNE- SODIUM STUN, SODIUM, AD- DIS- DIS- SORP- SOLVED SOLVED TION (MG/L (MG/L RATIO AS MG) AS NA) POTAS- ALKA- CHLO- FLUO- SILICA, SIUM, LINITY SULFATE RIDE. RIDE, On- DIS- FIELD DIS- ors- DIS- SOLVED SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L (MG/L AS (MG/L (MG/L (MG/L AS AS K) CAC03) AS 504) AS CL) AS F) SI02) NOV , 1982 19... 19... JAN • 1983 27... 0 29 MAR 23... MAY 19... 0 32 AUG 23... 0 18 51 13 70 2.8 4.1 190 58 50 .80 33 220 12 78 3.1 6.5 210 69 87 .20 34 8.6 28 1.4 1.2 92 13 22 .10 33 SOLIDS, SOLIDS, NITRO- SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + TUENTS. SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NOV • 1982 19... <1 .74 .060 .30 .310 1.3 1.60 2.4 11 19... JAN .1983 27... 372 1.3 <1 .020 <.10 6.20 .10 6.30 MAR 23... 12 .030 <.10 14.0 ' 1.0 15.0 MAY 19... 445 .82 12 .030 <.10 8.40 8.6 17.0 AUG 23... 179 9.2 11 .36 .040 .40 .510 .59 1.10 1.5 6.6 CHRO- SEDI- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, MENT, PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL SERI- DIS- PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- MENT, CHARGE, TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE SUS- SUS- (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENDED PENDED DATE AS P) AS AS) AS BA) AS CO) AS CR) AS P3) AS HG) AS SE) AS AG) (MG/L) (T/DAY) NOV • 1982 19... .260 19... JAN ,1933 27... 2.20 MAR 23... 3.30 MAY 19... 2.70 AUG 23... .240 2 100 4 <1 <1 .5 <1 4 1 <100 1 <10 <.1 <1 <1 103 19 148 -- K = non-ideal count 145 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR LOCATION.--Lat 18°02'04", long 66°01'58", Hydrologic Unit 21010004, on left bank, at foot bridge, off Highway 184, 1.2 mi (1.9 km) up­ stream from Lago Patillas Dam and 2.2 mi (3.5 km) northwest of Patillas. DRAINAGE.--18.3 sq mi (47.4 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February 1959 to October 1965 (annual low-flow and occasional measurements only), January 1966 to current year. GAGE.--Water-stage recorder. Altitude of gage is 235 ft (71.6 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--17 years (1967-83), 60.9 cu ft/s (1.725 cu m/s), 45.19 in/yr (1,148 mm/yr), 44,120 acre-ft/yr (54.4 cu hm/yr); median of yearly mean discharges, 61 cu ft/s (1.728 cu m/s), 44,200 acre-ft/yr (54 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 14,800 cu ft/s (419 cu m/s) Sept. 16, 1975, gage height, 12.45 ft (3.795 m), from rating curve extended above 250 cu ft/s (7.08 cu m/s) on basis of slope-area measurement of peak flow; minimum, 4.6 cu ft/s (0.130 cu m/s) May 13-16, 1968, gage height, 3.55 ft (1.082 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,500 cu ft/s (70.8 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) June 16 0500 3,190 90.3 9.11 2.777 July 04 1945 *3,820 108 9.63 2.935 Minimum discharge, 10 cu ft/s (0.283 cu m/s) Apr. 16, 17. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 156 99 231 61 21 16 12 19 46 54 138 59 2 115 57 109 55 20 15 12 25 44 87 158 72 3 70 44 83 51 19 15 12 24 43 110 96 65 4 54 50 74 49 21 15 12 22 42 429 79 53 5 51 67 67 73 22 14 12 22 45 337 122 4B 6 41 49 55 78 20 21 12 30 113 258 94 44 7 37 43 47 65 20 18 11 26 57 235 76 42 8 34 46 44 61 19 22 11 21 47 144 75 40 9 31 72 41 109 19 28 11 19 69 104 77 39 10 29 63 39 68 19 19 11 19 51 86 76 36 11 27 113 37 57 19 17 11 18 44 72 67 36 12 26 146 35 55 19 92 11 17 41 67 62 42 13 80 238 35 50 19 33 11 17 47 61 66 36 14 36 98 33 46 20 21 11 22 70 55 60 36 15 26 71 41 44 20 20 11 24 243 49 62 38 16 27 63 37 41 19 18 10 22 1030 49 143 43 17 54 56 32 39 17 17 13 25 253 53 305 41 18 50 148 31 38 17 17 60 79 384 60 161 34 19 48 317 31 37 17 15 22 107 160 57 99 31 20 125 355 36 35 17 15 52 94 110 56 77 40 21 97 188 32 32 19 15 241 57 88 45 352 227 22 59 101 32 31 17 15 52 56 74 39 165 79 23 229 95 29 30 17 14 33 141 66 207 105 79 24 74 74 29 30 17 14 26 332 60 221 85 74 25 46 59 30 30 17 14 23 141 55 78 92 80 26 37 50 30 37 17 14 21 85 51 57 90 113 27 32 49 30 29 16 13 20 66 74 48 73 79 28 43 54 30 27 16 13 22 57 58 95 124 58 29 35 76 30 25 --- 13 20 50 50 322 81 50 30 50 332 36 24 13 18 55 55 131 73 70 31 95 --- 144 23 13 --- 49 --- 103 64 --- TOTAL 1914 3273 1590 1430 520 599 804 1741 3570 3769 3397 1784 MEAN 61.7 109 51.3 46.1 18.6 19.3 26.8 56.2 119 122 110 59.5 MAX 229 355 231 109 22 92 241 332 1030 429 352 227 MIN 26 43 29 23 16 13 10 17 41 39 60 31 CFSM 3.37 5.96 2.80 2.52 1.02 1.06 1.46 3.07 6.50 6.67 6.01 3.25 IN. 3.89 6.65 3.23 2.91 1.06 1.22 1.63 3.54 7.26 7.66 6.91 3.63 AC-FT 3800 6490 3150 2340 1030 1190 1590 3450 7080 7480 6740 3540 CAL YR 1982 TOTAL 22902 MEAN 62.7 MAX 839 MIN 15 CFSM 3.43 IN 46.55 AC-FT 45430 WTR YR 1983 TOTAL 24391 MEAN 66.8 MAX 1030 MIN 10 CFSM 3.65 IN 49.58 AC-FT 48380 146 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR--Continued (National stream-quality accounting network station) WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1960 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, COLI- STREP- SPE.' DIS- FORM. TOCOCCI HARD- STREAM- CIFIC SOLVED FECAL, FECAL, HARD- NESS, FLOW, CON- PH TUR- OXYGEN, (PER- 0.7 KF AGAR NESS NONCAR- INSTAN- DUCT- (STAND- TEMPER... BID- DIS- CENT UM-MF (COLS. (MG/L BONATE TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- (COLS./ PER AS (MG/L DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) 100 ML) 100 ML) CAC03) CAC03) OCT r 1932 06... 1235 43 168 8.1 26.0 1.1 8.4 105 320 K190 44 0 FEB r 1983 03... 1430 19 158 7.8 24.0 1.3 9.5 114 100 430 52 0 JUN 09... 1255 140 114 7.8 26.0 33 8.0 99 K12000 9500 AUG 02... 1315 131 113 7.5 26.0 11 3.6 106 220 340 33 0 CALCIUM DIS- SOLVED (MG/L DATE AS CA) MAGNE- SIUM. DIS- SOLVED (MG/L AS MG) SODIUM. DIS- SOLVED (MG/L AS NA) SOLIDS, SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, RESIDUE AD- SIUM, LINITY SULFATE RIDE, RIDE, DIS- AT 180 SORP- DIS- FIELD DIS- DIS- DIS- SOLVED DEG. C TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L ()IS- RATIO (MG/L AS (MG/L (MG/L (MG/L AS SOLVED AS K) CAC03) AS SO4) AS CL) AS F) SI02) (MG/L) OCT r 1982 06... 9.8 4.8 13 .9 <.1 52 11 11 .10 26 112 FEB , 1983 03... 12 5.3 15 .9 .4 52 11 9.6 .20 23 88 JUN 09... .6 36 8.6 9.6 .20 76 AUG 2... 7.5 3.4 10 .8 .4 33 8.4 9.6 <.10 21 79 SOLIDS, NITRO- NITRO- NITRO- NITRO- PHOS- PHOS- SUM OF SOLIDS, GEN' GEN. GEN, GEN,AM- PHOS- PHORUS. PRATE, CONSTI- DIS- NO2+NO3 AMMONIA AMMONIA MONIA + PHOS- PHDS- PHORUS, ORTHO. ORTHO, TUENTS, SOLVED DIS- DIS- DIS- ORGANIC PHORUS. PHORUS DIS- DIS- OIS- DIS- (TONS SOLVED SOLVED SOLVED TOTAL TOTAL TOTAL SOLVED SOLVED SOLVED SOLVED PER (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE CMG/L) DAY) AS N) AS N) AS NH4) AS N) AS P) AS PO4) AS P) AS P) AS PO4) OCT e 1982 06... 13.0 <.10 .020 .03 1.20 <.010 <.010 <.010 FEB . 1983 3... 108 4.5 .10 .020 .03 .70 .030 .09 .020 .010 .03 JUN 09... 28.6 .10 .020 .03 .50 .050 .15 .030 .010 .03 AUG 2... 81 27.9 .19 .040 .05 .30 .030 .09 .080 .020 .06 ALUM- BERYL- CHRO- INUM, ARSENIC BARIUM, LIUM , CADMIUM MIUM, COBALT, COPPER, IRON, LEAD, LITHIUM DIS- DIS- DIS- 015- DIS- DIS- DIS- DIS- DIS- DIS- DIS- SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS AL) AS AS) AS BA) AS BE) AS CO) AS CR) AS CO) AS CU) AS FE) AS PS) AS LI) OCT , 1932 06... 1 17 <1 <1 <1 <3 2 31 <1 <4 FEB r 1983 3... 10 1 16 <1 <1 <1 <3 5 28 1 <4 JUN 09... 10 1 <1 5 <1 AUG 02... 300 K = non-idoal count 1 15 <1 <1 <1 <3 9 100 4 <4 147 RIO GRANDE DE PATILLAS BASIN 50092000 RIO GRANDE DE PATILLAS NEAR PATILLAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 SEDI- MANGA- MOLY8- SELF- STRON- VANA- MENT, NESE, MERCURY DENUM, NICKEL. NIUM, SILVER, TIUM, DIUM. ZINC. SEDI- DIS- DIS- On- DIS- OIS- DIS- DIS- OIS- DIS- DIS- MENT, CHARGE, SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SUS- SUS- (UG/L (UG/L (UG/L (UG/L (UG/L (UG/1 (UG/L (UG/L (UG/L PENDED PENDED DATE AS MN) AS HG) AS MO) AS NI) AS SE) AS AG) AS SR) AS V) AS ZN) CMG/L) (T/DAY) OCT ' 1982 06... 10 <.1 <10 1 <1 <1 35 <6.0 <4 1 .12 FEB , 1983 03... 8 .3 <10 3 <1 <1 36 <6.0 15 5 .26 JUN 09... <.1 <1 <1 <1 73 28 AUG 02... 10 <.1 <10 3 <1 <1 27 <6.0 <3 12 4.2 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURF (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) NOV, 10 1510 54 135 27.5 MAY, 13 0722 17 164 25.5 DEC. 27 1025 31 214 21.5 JUL, 12 1220 67 152 28.0 MAR, 02 0814 16 173 23.5 JUL, 2i-.. 1540 58 142 29.5 APR, 05 1245 12 155 25.0 SEP. 13 1132 36 154 27.0 SED. SUSP. STREAM- SEDI- SIEVE FLOW, MENT, DIAM. INSTAN- SUS- 2 FINER TIME TANEOUS PENDED THAN DATE (CFS) (MG/L) .062 MM OCT . 1982 06... 1235 43 1 100 FEB , 1983 03... 1430 19 5 80 JUN 09... 1255 140 73 85 AUG 02... 1315 131 12 92 Rib Grande de Manoti basin AIBONITO N Rib tie la Plato basin • • \ r• • CAYEY E Riblnabob basin j• Logo Guayabal COAMO Drainage boundary Drainage boundary ,;?IUAN DIAZ • • 88 Coamo 1030 1020 SALIN S 8 Canal si GOAYAMA Bahra de Jobos SAN JUAN MAR CAR1BE EXPLANATION A1007 LOW-FLOW STATION AND NUMBER V1065 QUALITY-OF-WATER STATION AND NUMBER • 1 WELL AND WELL NUMBER 150 RIO COAMO BASIN 50106500 RIO COAMO NEAR COAMO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°03'52", long 66°22'10", on Highway 153 bridge, 0.4 mi (0.6 km) above Rio de la Mina, and 1.75 mi (2.8 km) south of Coamo plaza. DRAINAGE AREA.--46.0 sq mi (119.1 sq km). PERIOD OF RECORD.--Water years 1978 to current year. WATER-QUALITY RECORDS, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 01... 1040 6.7 595 7.8 27.0 2.0 4.2 54 24 K860 770 JAN , 1983 25... 0910 5.5 678 7.7 23.5 <1.0 5.3 63 48 K65000 8200 MAR 29... 1235 4.0 670 8.0 28.5 <1.0 3.6 112 10 430 400 MAY 09... 1115 16 615 8.1 27.5 1.5 8.4 108 26 5700 430 AUG 15... 1035 7.4 603 8.2 30.0 1.7 9.5 127 28 K830 260 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS 504) AS CL) AS F) NOV , 1982 01... 220 JAN , 1983 25... 260 0 66 22 42 1.2 3.2 260 33 45 .20 MAR 29... 250 MAY 09... 230 1 61 19 36 1.1 3.4 230 32 41 .20 AUG 15... 250 21 66 21 37 1.1 3.0 231 32 44 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO-. NITRO- GEN,AM- On- CONSTI- On- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDEO (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE St02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982b 01... 6 2.4 .180 2.6 .130 .57 .70 3.3 JAN .0, 1933 25... 32 399 5.9 <1 1.4 .230 1.6 1.60 .10 1.70 3.3 MAR 29... 2 2.4 .370 2.6 .470 .43 .90 3.7 MAY 09... 31 362 15.6 <1 1.8 .290 2.1 .390 .31 .70 2.8 AUG 15... 33 375 7.5 2 2.6 .150 2.7 .120 .48 .60 3.3 CHRO- SARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERA3LE ERASLE ERABLE ERABLE ERABLE TOTAL ERABLE DATE (MG/L AS NO3) (MG/L AS P) (UG/L AS AS) (UG/L AS BA) (UG/L AS CD) (UG/L AS CR) (UG/L AS PB) (UG/L AS HG) (UG/L AS SE) (UG/L AS AG) NOV , 1982 01... 15 JAN , 1983 25... 15 MAR 29... 16 MAY 09... 12 AUG 15... 15 .670 1.30 .900 .580 .580 1 2 <100 100 1 1 <1 2 11 7 .2 <.1 <1 <1 <1 <1 K = non-ideal count Rib Grande de Arecibo basin Island divide Rib Grande de Masco basin Drainage boundary Drainage boundary,. Rib Guonojibo basin? ..4c, L Logo SABANA GRANDE 41 o LOCO as JUANA DIAZ Logo Bronco GUAYANIILA 146 141 Bohl° di Guoyonillo elofteb de To/lobo° 1297 PLAYA DE ­PONCE ENSENADA GUANICA EXPLANATION A1125 SURFACE—WATER STATION AND NUMBER M A R CARIBE A1159 CREST—STAGE GAGING STATION A1220 LOW—FLOW STATION AND NUMBER V1140 QUALITY—OF—WATER STATION AND NUMBER • 74 WELL AND WELL NUMBER Map area Figure 22.--South coast rivers basin--Rio Inabon to Rio Loco basins. 152 RIO INABON BASIN 50112500 RIO INABON AT REAL ABAJO, PR LOCATION.--Lat 18°05'10", long 66°33'46", Hydrologic Unit 21010004, at bridge on private road, off Highway 511 at Hacienda La Concordia, 0.4 mi (0.6 km) upstream from diversion canal, 0.5 mi (0.8 km) north of Real Abajo, and 6.1 mi (9.8 km) northeast of Plaza Degetau in Ponce. DRAINAGE AREA.--9.70 sq mi (25.12 sq km). WATER-DISCHARGE RECORDS 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. Altitude of gage is 410 ft (125 m), from topographic map. Prior to April 1971 nonrecording gage and crest- stage gage at different datum. REMARKS.--Records fair. AVERAGE DISCHARGE.--17 years (1965-69, 72-83), 18.6 cu ft/s (0.527 cu m/s), 26.04 in/yr (661 mm/yr), 13,480 acre-ft/yr (16.6 cu hm/yr); median of yearly mean discharges, 18 cu ft/s (0.51 cu m/s), 13,000 acre-ft/yr (16 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 7,000 cu ft/s (198 cu m/s) Sept. 16, 1975, gage height, 18.6 ft (5.669 m) from flood- mark, from rating curve extended above 30 cu ft/s (0.850 cu m/s) on basis of contracted opening and flow-over-road measurements of peak flow; minimum daily, 0.80 cu ft/s (0.023 cu m/s) July 23, 1977. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 500 cu ft/s (14.2 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Mar. 12 1400 *691 19.6 8.24 2.512 May 22 1600 675 19.1 8.10 2.469 May 18 1445 663 18.8 8.00 2.438 Minimum daily discharge, 1.4 cu ft/s (0.040 cu m/s) Mar. 7. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 36 13 14 7.6 5.0 2.4 2.1 8.4 11 9.1 6.2 9.9 2 22 11 12 7.2 5.0 2.0 2.1 9.1 10 9.1 7.8 10 3 14 10 11 6.9 4.6 1.8 2.1 10 16 8.8 6.7 9.4 4 12 9.0 11 7.4 4.3 1.8 2.5 12 15 13 5.7 9.1 5 11 8.2 10 7.5 4.0 1.8 2.8 9.2 11 13 5.3 9.2 6 10 11 10 3.6 3.7 1.6 3.5 8.2 12 12 5.5 8.1 7 11 8.9 10 3.1 4.0 1.4 2.5 8.1 11 12 5.1 8.0 8 11 20 9.7 3.0 3.8 2.0 2.2 7.8 9.9 13 7.8 7.7 9 10 35 9.2 9.2 3.7 5.0 2.1 7.4 9.8 11 9.1 6.7 10 9.1 31 8.9 7.9 3.9 4.2 2.0 6.6 1C 11 9.3 5.9 11 7.8 21 8.7 7.8 3.2 2.5 2.2 6.0 10 12 6.4 5.7 12 8.0 41 8.7 8.1 2.8 92 2.6 5.1 9.3 11 5.0 10 13 18 46 9.9 8.3 2.8 25 2.8 6.4 10 10 5.0 5.8 14 18 27 10 9.0 3.4 12 3.1 10 9.9 10 4.7 4.8 15 17 29 10 9.3 3.8 8.0 14 10 17 9.6 4.5 7.1 16 44 28 11 3.2 3.1 6.1 13 13 107 9.7 4.0 6.8 17 26 21 8.8 7.3 3.3 4.8 9.3 10 91 11 17 9.3 13 16 21 8.2 7.1 3.4 4.1 22 61 88 11 12 13 19 14 19 7.9 6.8 2.9 3.5 7.6 53 49 9.3 5.8 14 20 10 17 8.1 6.6 3.1 3.3 35 30 33 7.7 4.3 6.2 21 11 15 7.8 5.8 3.2 3.1 126 34 26 8.5 16 5.2 22 11 28 7.5 5.7 2.3 2.6 40 81 22 7.9 14 14 23 15 47 7.0 5.8 2.1 2.5 22 44 21 8.1 7.2 13 24 13 25 6.9 5.7 2.3 2.4 18 22 19 10 5.5 7.5 25 10 20 7.0 5.7 3.3 3.4 13 22 18 8.4 4.5 9.0 26 8.1 17 7.3 5.3 3.6 2.9 10 22 17 8.4 10 13 27 7.8 15 9.9 5.8 2.6 2.0 16 17 16 6.5 18 6.0 28 20 14 7.6 5.7 2.5 2.0 20 14 13 6.6 21 3.8 29 24 13 11 5.4 --- 1.8 12 13 11 6.8 15 3.3 30 18 19 13 5.7 2.5 8.0 13 9.7 7.0 12 3.0 31 15 --- 8.5 5.2 2.4 --- 12 --- 6.2 12 --- TOTAL 477.8 640.1 290.6 219.7 95.7 212.9 420.5 585.3 712.6 297.7 272.4 249.5 MEAN 15.4 21.3 9.37 7.09 3.42 6.87 14.0 18.9 23.8 9.60 8.79 8.32 MAX 44 47 14 9.3 5.0 92 126 81 107 13 21 13 MIN 7.8 8.2 6.9 5.2 2.1 1.4 2.0 5.1 9.3 6.2 4.0 3.0 CFSM 1.59 2.20 .97 .73 .35 .71 1.44 1.95 2.45 .99 .91 .86 IN. 1.83 2.45 1.11 .84 .37 .82 1.61 2.24 2.73 1.14 1.04 .96 AC-FT 948 1270 576 436 190 422 834 1160 1410 590 540 495 CAL YR 1982 TOTAL 4735.1 MEAN 13.0 MAX 266 MIN 2.0 CFSM 1.34 IN 18.16 AC-FT 9390 WTR YR 1983 TOTAL 4474.8 MEAN 12.3 MAX 126 MIN 1.4 CFSM 1.27 IN 17.16 AC-FT 8880 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) --- 153 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR LOCATION.--Lat 18°04'15", long 66°34'51", Hydrologic Unit 21010004, on right bank off Highway 139, 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 sq mi (46.1 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to April 1964 (monthly measurements only), May 1964 to current year. GAGE.--Water-stage recorder. Datum of gage is 253.10 ft (77.145 m) above mean sea level, datum of 1929. Prior to Mar 22, 1977, at site 0.15 mi (0.24 km) upstream and datum 9.90 ft (3.018 m) higher. REMARKS.--Records fair. Some low-flow regulation by construction upstream. AVERAGE DISCHARGE.--19 years (1965-83), 35.8 cu ft/s (1.014 cu m/s), 27.31 in/yr (694 mm/yr), 25,940 acre-ft/yr (32.0 cu hm/yr); median of yearly mean discharges, 33 cu ft/s (0.93 cu m/s), 23,900 acre-ft/yr (29 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 22,400 cu ft/s (634 cu m/s) Sept. 16, 1975, gage height, 11.2 ft (3.41 m), from flood- marks, from rating curve extended above 150 cu ft/s (4.25 cu m/s) on basis of slope-area measurement of peak flow; minimum, 2.2 cu ft/s (0.062 cu m/s) May 28, 1967. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,200 cu ft/s (34.0 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 0445 *821 23.2 7.04 2.146 Minimum discharge, 5.6 cu ft/s (0.158 cu m/s) Mar. 20. DISCHARGE., IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 54 26 35 16 9.9 9.2 6.8 22 32 35 13 18 2 47 24 31 15 9.7 8.9 6.9 20 31 32 13 16 3 32 22 30 14 9.7 8.6 6.8 21 34 27 13 14 4 27 21 29 14 9.9 3.3 6.7 27 32 44 12 13 5 24 19 27 14 10 8.3 7.1 28 27 40 11 14 6 22 29 25 14 9.8 8.5 7.5 22 30 32 11 12 7 19 23 24 15 9.7 8.2 7.3 21 27 28 10 12 3 19 30 23 14 9.5 7.9 7.0 19 27 27 14 14 9 18 50 22 15 10 11 6.7 18 26 25 17 12 10 17 51 22 14 11 12 6.5 17 30 26 18 11 11 16 43 21 14 10 9.4 6.6 15 35 28 12 13 12 15 69 21 12 10 119 7.2 21 27 26 10 20 13 31 89 20 12 9.9 43 7.5 18 23 25 12 13 14 23 4? 22 12 9.7 17 20 22 22 24 15 11 15 18 41 21 13 10 12 66 23 34 22 14 11 16 58 53 22 13 10 9.8 58 25 124 22 12 12 17 38 67 19 13 9.8 9.0 24 25 120 24 49 18 18 30 88 18 12 9.5 8.5 66 63 149 22 33 53 19 36 72 18 12 9.2 8.2 33 91 92 21 20 34 20 28 56 19 12 8.8 7.6 115 52 62 19 17 18 21 27 50 18 10 9.1 7.4 206 69 52 13 34 14 22 30 76 17 10 9.3 7.6 68 113 45 16 33 22 23 53 103 16 10 9.1 7.6 75 105 39 15 21 25 24 60 63 16 11 9.0 7.3 66 69 35 18 18 18 25 34 51 16 10 9.4 7.8 42 61 32 16 17 22 26 25 43 16 11 9.7 7.9 33 58 37 17 34 24 27 21 38 16 11 9.7 7.1 39 48 39 15 40 16 28 52 37 16 10 9.3 7.1 40 43 41 15 25 14 29 57 34 20 10 --- 7.1 30 38 38 15 20 12 30 40 47 30 10 6.9 24 36 37 16 21 12 31 32 --- 18 11 7.1 --- 33 --- 14 24 TOTAL 1003 1469 668 384 270.7 415.3 1095.6 1243 1379 724 613 518 MEAN 32.4 49.0 21.5 12.4 9.67 13.4 36.5 40.1 46.0 23.4 19.8 17.3 MAX 60 108 35 16 11 119 206 113 149 44 49 53 MIN 15 19 16 10 8.8 6.9 6.5 15 22 14 10 11 CFSM 1.82 2.75 1.21 .70 .54 .75 2.05 2.25 2.58 1.32 1.11 .97 IN. 2.10 3.07 1.40 .80 .57 .87 2.29 2.60 2.38 1.51 1.28 1.08 AC-FT 1990 2910 1320 762 537 824 2170 2470 2740 1440 1220 1030 CAL YR 1982 TOTAL 10788.9 MEAN 29.6 MAX 450 MIN 6.0 CFSM 1.66 IN 22.55 AC-FT 21400 WTR YR 1983 TOTAL 9782.6 MEAN 26.8 MAX 206 MIN 6.5 CFSM 1.51 IN 20.44 AC-FT 19400 OCT, 19 1040 DEC. 07 1225 FEB. 08 1145 APR, 13 1030 32 246 25 230 9.6 234 7.4 332 JUN, 14 0950 22 JUL' 07 0820 28 SEPe 02 1320 16 260 27.0 282 26.0 257 30.0 32.0 24.5 26.0 28.0 154 RIO BUCANA BASIN 50114000 RIO CERRILLOS NEAR PONCE, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN. OXYGEN COLI- STREP- SPE- DIS- DEMAND. FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL. FLOW, CON- PH TUR- OXYGEN. (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARO ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) 1982 1230 24 285 8.1 27.0 1.1 7.5 96 11 K800 940 1983 1120 13 306 23.0 70 9.0 106 460 1000 1600 6.9 285 8.4 29.5 7.0 7.4 98 <10 K150 530 0830 23 275 7.9 23.5 63 3.9 106 16 K790 3600 1420 14 264 8.4 30.9 3.3 3.0 107 16 290 270 HARD- MAGNE- SODIUM POTAS-. ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SUM, SODIUM. AD- SIUMr LINITY SULFATE RIDE. RIDE, NESS NONCAR- DIS- On- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 02... 120 JAN , 1933 11... 130 0 42 7.0 11 .4 1.4 18 7.8 .10 MAR 29... 130 MAY 06... 120 4 39 6.5 12 .5 1.1 120 17 7.8 <.10 AUG 15... 120 6 38 6.5 11 .5 1.1 116 17 8.1 <.10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN. MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDEO (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE 5IO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 02... 4 <.010 .60 <.010 .40 1.0 JAN , 1933 11... 22 205 7.2 109 .47 .030 .50 .080 .72 .80 1.3 MAR 29... 4 .010 <.10 .010 <.10 MAY 06... 22 177 11.0 96 .37 .030 .40 .040 .16 .20 .60 AUG 15... 23 174 6.4 14 <.010 .20 <.010 .10 .30 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER. NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS. ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 3A) AS CD) AS CR) AS P3) AS HG) AS SE) AS AG) NOV r 1982 02... 4.4 .050 JAN r 1983 11... 5.8 .410 1 100 1 7 6 <.1 <1 MAR 29... .050 MAY 06... 2.7 .080 AUG 15... 1.3 .080 2 100 1 2 3 <.1 <1 <1 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOWe SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS OUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) NOV , 02... JAN ' 11... MAR 29... MAY 06... AUG 15... K = non-ideal count 155 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR LOCATION.--Lat 18°04'45", long 66°38'01", Hydrologic Unit 21010004, on right bank 30 ft 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 Rio Chiquito, and 4.7 mi (7.6 km) north of Plaza Degetau in Ponce. DRAINAGE AREA.--8.82 sq mi (22.84 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to June 1964 (monthly measurements only), July 1964 to current year. GAGE.--Water-stage recorder. Altitude of gage is 470 ft (143 m), from topographic map. Prior to Dec. 4, 1964, non-recording gage at same site and datum. REMARKS.--Records fair. Some low-flow regulation due to unknown activity upstream. AVERAGE DISCHARGE.--19 years (1965-83), 18.2 cu ft/s (0.515 cu m/s), 28.02 in/yr (712 mm/yr), 13,190 acre-ft/yr (16.3 cu hm/yr); median of yearly mean discharges, 18 cu ft/s (0.51 cu m/s), 13,000 acre-ft/yr (16 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 13,100 cu ft/s (371 cu m/s) Sept. 16, 1975, gage height, 10.1 ft (3.08 m), from flood- marks at downstream side of bridge, from rating curve extended above 150 cu ft/s (4.25 cu m/s) on basis of slope-area measurement of peak flow; minimum, 1.0 cu ft/s (0.028 cu m/s) May 29, 1973. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 800 cu ft/s (22.7 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 17 1700 838 23.7 5.67 1.728 May 18 1530 *1,550 43.9 7.28 2.219 Apr. 21 0545 1,030 29.2 6.15 1.874 May 21 1515 1,160 32.8 6.44 1.963 Minimum discharge, 3.4 cu ft/s (0.096 cu m/s) Mar 3-6. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 75 17 17 7.7 5.5 3.8 3.9 12 13 8.2 6.7 6.0 2 40 16 15 7.9 5.2 3.8 3.8 12 23 14 6.7 7.4 3 20 15 14 7.7 5.2 3.8 3.6 11 18 23 6.4 6.8 4 15 14 14 7.5 4.8 3.5 3.6 13 13 33 5.3 9.3 5 14 13 13 7.3 4.8 3.4 3.7 12 13 24 5.3 9.7 6 12 13 13 8.0 4.6 3.6 4.5 11 17 19 5.4 7.4 7 11 13 12 7.7 4.2 3.6 4.5 12 14 16 4.8 7.9 8 11 12 12 7.8 4.0 3.7 4.5 10 12 14 8.4 12 9 10 13 12 8.2 3.9 5.6 4.5 9.5 12 12 10 7.9 10 9.7 20 12 7.7 3.9 5.7 4.1 9.2 12 12 6.9 7.5 11 9.2 19 12 7.3 3.9 3.3 3.9 12 12 11 7.0 3.9 12 8.7 41 12 7.4 3.9 152 3.9 16 13 11 5.5 11 13 18 44 11 7.3 3.9 22 4.5 15 15 10 9.4 7.6 14 12 20 11 6.8 4.0 8.8 29 21 12 9.2 9.1 7.2 15 9.5 16 11 6.9 4.2 6.4 34 18 38 9.2 6.0 10 16 37 20 12 6.7 4.3 5.7 28 16 118 9.9 6.8 8.4 17 21 110 10 6.7 4.5 5.1 10 14 171 9.9 63 20 13 41 127 10 6.4 4.3 4.8 40 180 267 8.3 25 27 19 29 70 10 6.3 4.2 4.5 19 77 67 7.9 10 17 20 19 33 10 6.2 4.0 4.2 73 38 32 7.7 8.1 9.1 21 21 25 9.4 6.0 3.9 4.0 298 188 20 7.7 30 7.7 22 21 52 9.3 5.9 3.9 3.9 57 103 15 7.4 19 21 23 45 77 9.3 5.7 3.7 4.2 32 57 12 7.5 9.9 33 24 42 34 8.9 5.5 3.6 4.2 34 35 9.5 9.1 7.7 20 25 23 26 8.5 6.0 3.7 4.3 23 46 11 7.1 6.7 20 26 19 22 8.5 6.7 3.9 4.5 18 37 12 6.6 15 15 27 16 21 8.5 6.1 3.9 4.3 19 25 15 6.6 16 9.7 28 36 20 8.2 5.9 3.9 4.1 19 21 12 7.1 10 7.8 29 27 18 8.6 5.8 --- 3.9 15 15 9.1 7.4 8.3 7.0 30 23 21 11 6.0 3.9 13 15 8.5 7.7 6.7 6.2 31 19 --- 8.4 5.5 3.9 --- 14 --- 7.0 6.9 --- TOTAL 714.1 962 341.6 210.6 117.8 303.5 814.0 1074.7 1016.1 351.0 352.0 355.5 MEAN 23.0 32.1 11.0 6.79 4.21 9.79 27.1 34.7 33.9 11.3 11.4 11.9 MAX 75 127 17 8.2 5.5 152 298 188 267 33 63 33 MIN 8.7 12 8.2 5.5 3.6 3.4 3.6 9.2 8.5 6.6 4.8 6.0 CFSM 2.61 3.64 1.25 .77 .48 1.11 3.07 3.93 3.84 1.28 1.29 1.35 IN. 3.01 4.06 1.44 .89 .50 1.28 3.43 4.53 4.29 1.48 1.48 1.50 AC-FT 1420 1910 678 418 234 602 1610 2130 2020 696 698 705 CAL YR 1982 TOTAL 6738.7 MEAN 18.5 MAX 520 MIN 2.4 CFSM 2.10 IN 28.42 AC-FT 13370 WTR YR 1983 TOTAL 6612.9 MEAN 18.1 MAX 298 MIN 3.4 CFSM 2.05 IN 27.89 AC-FT 13120 156 RIO PORTUGUES BASIN 50115000 RIO PORTUGUES NEAR PONCE, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1964 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 01... 1410 JAN , 1983 25... 1340 MAR 16... 1210 MAY 06... 1210 AUG 16... 0925 16 282 3.3 26.0 1.5 7.8 99 23 K520 (560 5.6 309 8.4 25.0 <1.0 6.9 109 51 K13 130 5.7 276 1.2 25.0 <1.3 8.1 100 43 (150 510 Q.8 274 8.4 25.5 2.4 8.0 99 15 330 810 5.2 158 8.3 25.0 1.1 3.3 108 11 110 390 HARD- MAGNE- SODIUM POTAS- AL(A- CHLO- FLUO- HARD- NESS, CALCIUM srum, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- ors- 015- SORP- DIS- FIELD On- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 01... 130 JAN , 1983 25... 140 0 42 7.5 12 .5 1.0 140 8.0 8.7 .10 MAR 16... 120 MAY 06... 130 1 41 7.0 12 .5 1.3 130 8.1 8.7 .10 AUG 16... 140 4 45 7.4 11 .4 1.1 139 8.1 9.0 <.10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER FENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 01... 2 <.010 1.0 <.010 .90 1.9 JAN , 1983 25... 22 185 2.3 1 .39 .010 .90 .030 <.10 MAR 16... <1 <.010 1.4 .030 <.10 MAY 06... 22 178 4.7 6 <.010 .60 <.010 <.10 AUG 16... 22 187 2.6 4 <.010 .70 <.010 .20 .90 CHRO- BARIUM. CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERA3LE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS 9) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV , 1982 01... 3.4 .070 JAN 1983 25... .160 2 100 3 <1 9 .1 <1 <1 MAR 16... .050 MAY 06... .040 AUG 16... 4.0 .070 2 100 1 1 2 <.1 <1 <1 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 19 1330 23 213 24.0 JUN, 14 1235 10 267 27.0 DEC, 09 1345 12 260 23.0 JUL, 07 1040 14 275 26.0 FEB, 08 1410 4.0 295 25.5 SEP, 02 1000 6.3 286 30.0 APR, 13 1300 3.3 307 28.0 K = non-ideal count 157 RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'20", long 66°36'28", 1,300 ft (400 m) south of Las Americas Avenue Bridge, 1.2 mi (1.9 km) south of CSG 50115900, 0.8 mi (1.3 km) west of Highways 1 and 2 junction, and 0.7 mi (1.1 km) southeast of Ponce. DRAINAGE AREA.--18.9 sq mi (49.0 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN• OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM• TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL• FECAL, FLOM, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) NOV • 1982 02... 0850 14 415 8.1 25.0 7.0 8.9 108 11 51000 K11000 JAN • 1983 11... 1420 6.6 448 8.3 31.0 70 7.2 124 33000 3200 MAR 16... 1435 4.7 490 8.4 32.0 1.3 7.9 109 <10 2300 K170 MAY 19... 0805 107 249 7.8 22.5 55 3.9 103 11 29000 9500 JUN 07... 1340 14 403 8.6 33.0 11.8 165 AUG 16... 1220 5.4 458 8.0 33.0 43 6.0 33 45 52000 58000 HARD- NESS (MG/L AS DATE CAC03) HARD- NESS. NONCAR- 80NATE (MG/L CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM, DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALKA- CHLO- FLUO- AD- SIUM, LINITY SULFATE RIDE, RIDE. SORP- DIS- FIELD DIS- DIS- DIS- TION SOLVED (MG/L SOLVED SOLVED SOLVED RATIO (MG/L AS (MG/L (MG/L (MG/L AS K) CAC03) AS SO4) AS CL) AS F) NOV . 1982 02... 150 JAN • 1983 11... 160 23 47 11 37 1.3 2.2 140 60 34 .30 MAR 16... 130 MAY 19... 100 10 30 6.1 13 .6 1.5 90 20 11 .20 JUN 07... 130 AUG 16... 160 77 44 11 35 1.3 2.6 78 53 31 .40 SOLIDS, SOLIDS, NITRO- SILICA, SUM Of SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN•AM- DIS- CONSTI- DIS- AT 105 GEN. GEN, GEN, GEN, GEN. MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE S/02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV • 1982 02... 18 .58 .020 .60 .090 .61 .70 1.3 JAN • 1983 11... 20 295 5.3 100 .35 .050 .40 .230 .07 .30 .70 MAR 16... <1 .87 .030 .90 .120 .08 .20 1.1 MAY 19... 20 156 45.2 46 2.2 .020 2.2 .060 .54 .60 2.8 JUN 07... AUG 16... 17 241 3.5 69 .19 .110 .30 .870 1.3 2.20 2.5 K = non-idleal count RIO PORTUGUES BASIN 50116200 RIO PORTUGUES AT PONCE, PR--Continued WATER-QUALITY DATA, WATER YEARS OCTOBER 1982 TO SEPTEMBER 1983 CHRO- NITRO- PHOS- BARIUM, TOTAL CADMIUM TOTAL MIUM, TOTAL LEAD, TOTAL MERCURY TOTAL SELE- SILVER, TOTAL GEN, TOTAL PHORUS, TOTAL ARSENIC TOTAL RECOV- ERABLE RECOV- ERABLE RECOV- ERABLE RECOV- ERABLE RECOV- ERABLE NIUM, TOTAL RECOV- ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) NOV , 1982 AS P) AS AS) AS BA) AS CD) AS CR) AS PS) AS HG) AS SE) AS AG) 02... 5.8 .090 JAN , 1983 11... 3.1 .430 2 100 2 6 7 .2 <1 1 MAR 16... 4.9 .100 MAY 19... 12 .100 JUN 07... AUG 16... 11 .360 2 200 1 2 3 <.1 <1 <1 CHLOR- DI- PCB, ALDRIN, DANE, DOD, DDE, DDT, AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN , 1983 07... 1340 <.10 <.01 <.10 <.01 <.01 <.01 .11 HEPTA- METH- DI- ENDO- HEPTA- CHLOR MALA- OXY- ELDRIN SULFAN, ENORIN, ETHION, CHLOR, EPDXIDE LINDANE THION, CHLOR, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN 1983 07... <.01 <.01 <.01 <.01 <.01 <.01 <.01 (.01 (.01 NAPH- THA-. METHYL METHYL LENES, PARA- TRI- PARA- POLY- PER- TOX- TOTAL THION, THION, MIREX, THION, CHLOR. THANE APHENE, TRI- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL THION DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN 1983 07... <.01 (.01 <.01 <.01 <.10 <.10 <1 <.01 158 159 RIO GUAYANILLA BASIN 50124200 RIO GUAYANILLA NEAR GUAYANILLA, P.R. LOCATION.--Lat 18°02'40", long 66°47'53", Hydrologic Unit 21010004, on left bank, 0.7 mi (1.1 km) north of junction of Highways 2 and 132, 0.6 mi (1.0 km) downstream from Quebrada Consejo, 1.8 mi (2.9 km) north-northwest from Plaza de Guayanilla. DRAINAGE AREA.--18.9 sq mi (49.0 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1981 to current year. GAGE.--Water-stage recorder. Altitude of gage is 80 ft (24.4 m) from topographic map. REMARKS.--Records fair. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 14,700 cu ft/s (416 cu m/s) Sept. 12, 1982, gage height, 20.4 ft (6.21 m) from floodmarks, from rating curve extended above 100 cu ft/s (2.83 cu m/s) on basis of step-backwater analysis and indirect measurement of peak flow; minimum, 1.8 cu ft/s (0.051 cu m/s) Apr. 17-19, 1981. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 800 cu ft/s (22.7 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Apr. 21 0230 *2,010 56.9 11.55 3.520 Aug. 17 1645 970 27.5 9.69 2.954 Minimum discharge, 3.0 cu ft/s (0.085 cu m/s) Apr. 3-5, 9-13. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 17 16 15 13 19 11 11 11 11 11 35 26 24 22 20 9.3 3.9 8.6 3.5 8.7 5.2 4.9 4.8 4.7 5.0 4.9 4.9 4.9 4.3 4.7 3.3 3.4 3.3 3.0 3.1 16 14 14 14 13 17 17 19 16 15 18 21 20 16 24 6.4 6.7 6.4 6.0 6.0 5.9 5.5 5.6 15 11 6 7 8 9 10 16 18 18 14 14 11 9.9 9.2 9.2 9.2 19 18 17 17 18 3.5 3.5 3.3 5.9 3.2 4.8 4.5 4.4 4.5 4.5 5.2 5.4 6.3 6.5 7.3 5.3 3.8 4.2 3.5 3.0 12 11 11 12 11 14 14 14 14 13 19 14 13 11 11 6.0 6.0 17 12 8.6 7.4 6.3 6.8 6.0 5.5 11 12 13 14 15 13 12 16 17 15 9.2 50 43 31 26 17 15 15 15 14 7.9 7.8 7.4 7.7 7.8 4.6 4.4 4.4 4.8 5.3 5.7 92 22 3.5 6.5 3.0 3.1 3.4 8.9 13 12 12 17 18 16 13 12 12 18 16 12 12 11 11 11 8.7 7.6 7.5 10 7.4 6.0 6.7 5.3 5.0 18 16 17 18 19 15 14 14 14 34 97 79 54 14 13 12 18 7.5 7.3 7.1 7.1 4.7 4.6 5.0 4.8 5.6 5.2 5.0 4.7 5.9 4.6 24 12 14 14 35 70 33 40 71 32 13 13 12 12 10 122 31 11 9.5 7.2 10 6.1 20 15 47 17 7.1 4.8 4.6 28 109 18 11 8.0 5.5 21 22 23 24 25 14 23 26 29 19 43 42 38 29 30 12 12 11 11 11 7.1 6.5 6.5 6.2 5.6 5.1 5.0 5.1 4.9 5.1 4.2 4.0 4.8 4.4 4.1 327 52 36 29 22 183 115 48 36 47 15 14 13 12 13 11 10 8.9 8.8 8.3 23 14 9.2 13 7.8 5.2 7.6 14 9.2 6.6 26 27 15 14 24 21 11 10 5.6 5.5 5.1 4.9 4.0 3.9 19 61 43 29 14 16 7.6 7.2 6.7 6.6 5.8 5.4 28 29 30 31 14 14 13 11 62 30 48 --- 9.8 10 12 9.9 5.4 5.2 5.2 5.3 5.0 --- 4.0 4.0 3.5 3.5 63 27 19 --- 24 21 19 13 17 17 19 --- 7.2 7.4 8.4 7.4 6.8 6.6 6.3 6.4 5.1 5.0 5.6 --- TOTAL MEAN MAX MIN CFSM IN. AC-FT 497 16.0 29 11 .85 .98 986 940.7 31.4 97 9.2 1.66 1.85 1870 485.7 15.7 35 9.8 .83 .96 963 225.2 7.26 9.3 5.2 .33 .44 447 134.9 4.82 5.3 4.4 .26 .27 268 259.1 8.36 92 3.5 .44 .51 514 796.8 26.6 327 3.0 1.41 1.57 1580 1028 33.2 183 11 1.76 2.02 2040 568 18.9 71 12 1.00 1.12 1130 377.2 12.2 24 7.2 .65 .74 748 410.7 13.2 122 6.0 .70 .81 815 223.8 7.46 18 5.0 .40 .44 444 CAL YR 1982 TOTAL 5792.0 MEAN 15.9 MAX 500 MIN 3.7 CFSM .84 IN 11.40 AC-FT 1149J WTR YR 1983 TOTAL 5947.1 MEAN 16.3 MAX 327 MIN 3.0 CFSM .86 IN 11.70 AC-FT 11800 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 DATE TIME STREAMFLOW, INSTANTANEOUS SPECIFIC CON- DUCTANCE TEMPERA­ TURE DATE TIME STREAMFLOW. INSTANTANEOUS SPECIFIC CON­ DUCT ANCE TEMPERA­ TURE (CFS) CUMHOS) (DEG C) (CFS) (UMHOS) CDEG C) OCT, 13 1020 NOV, 12 1150 DEC. 09 1010 JAN. 17 1255 FEB. 02 1050 MAR, 16 1155 14 16 13 7.4 5.1 6.1 413 363 313 390 370 425 28.0 26.0 22.0 27.0 25.0 28.0 APR, 12 1300 MAY, 09 1030 JUN, 14 1250 JUL, 06 0950 AUG, 03 1500 SEP, 15 1028 3.0 12 13 17 6.2 5.1 387 446 -- 370 315 392 28.0 23.0 30.5 27.0 33.0 29.0 160 RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°00'40", long 66°46'49", at dirt road bridge, 0.7 mi (1.1 km) from mouth, 0.9 mi (1.4 km) east of Central Rufina and 0.9 mi (1.4 km) southeast of Guayanilla. DRAINAGE AREA.--22.8 sq mi (59.1 sq km). PERIOD OF RECORD.--Water years 1960-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COL/- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW. CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MGR) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 03... 0855 6.2 535 7.6 26.0 2.1 4.8 60 14 510000 93000 JAN , 12... 1983 0940 3.0 685 7.3 25.0 2.0 1.0 12 2500000 70000 MAR 31... 1100 1.2 960 7.6 27.0 6.5 1.6 20 66 2000000 190000 MAY 19... 1145 29 390 7.9 27.5 14 7.7 98 <10 K700000 98000 JUN 07... 1540 7.2 558 7.8 31.0 5.8 78 AUG 17... 0825 2.1 638 7.7 27.0 1.4 .8 10 53 K1900000 800000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS NESS, NONCAR- CALCIUM DIS- SLUM, DIS- SODIUM, DIS- AD- SORP- SIUM, DIS- LINITY FIELD SULFATE DIS- RIDE. DIS- RIDE, DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/I (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 03... 190 JAN , 1983 12... 240 11 65 19 37 1.1 3.9 230 73 37 .10 MAR 31... 350 MAY 19... 160 14 44 13 17 .6 1.9 150 36 17 .20 JUN 07... 190 AUG 17... 250 3 69 18 41 1.2 4.0 244 66 41 .10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN. GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN. (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 03... 6 .31 .090 .40 3.20 .30 3.50 3.9 JAN , 1983 12... 21 394 3.2 26 .06 .040 .10 6.30 8.7 15.0 15 MAR 31... <1 .03 .070 .10 14.0 15 29.0 29 MAY 19... 18 237 18.6 14 .38 .020 .40 1.30 .80 2.10 2.5 JUN 07... AUG 17... 21 406 2.3 8 .06 .040 .10 6.50 6.5 13.0 13 K = non-ideal count RIO GUAYANILLA BASIN 50124700 RIO GUAYANILLA AT CENTRAL RUFINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- BARIUM, CADMIUM MIUM. LEAD. MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV r 1982 03... 17 .770 JAN r 1983 12... 67 1.80 3 100 1 8 2 .1 <1 <1 MAR 31... 130 3.50 MAY 19... 11 .210 JUN 07... AUG 17... 58 1.50 2 200 1 9 5 .1 <1 <1 CHLOR- DI- PCB, ALORIN. DANE, ODD. DOE, DDT, AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN , 1983 07... 1540 <.10 <.01 <.10 <.01 <.01 <.01 .04 HEPTA- METH- DI- ENDO- HEPTA- CHLOR MALA- OXY- ELDRIN SULFAN. ENGRIN, ETHION, CHLOR. EPDXIDE LINDANE THION, CHLOR, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN 1983 07... <.01 <.01 <.01 <.01 <.01 <.01 <.01 .04 <.01 NAPH- THA- METHYL METHYL LINES. PARA- TRI- PARA- POLY- PER- TOX- TOTAL THION, THION, MIREX. THION, CHLOR. THANE APHENE. TRI- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL THION DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r, 1983 07... <.01 <.01 <.01 <.01 <.10 <.10 <1 <.01 161 162 RIO YAUCO BASIN 50126150 RIO YAUCO ABOVE DIVERSION MONSERRATE NEAR YAUCO, PR LOCATION.--Lat 18°02'58", long 66°50'30", 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 las Quebradas, 0.9 mi (1.4 km) downstream from Rio Duey, and 1.0 mi (1.6 km) northeast of Yauco Plaza. DRAINAGE AREA.--27.2 sq mi (70.4 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1976 to current year. GAGE.--Water-stage recorder. Altitude of gage is 115 ft (35 m), from topographic map. REMARKS.--Records poor. AVERAGE DISCHARGE.--6 years (1978-83), 22.7 cu ft/s (0.643 cu m/s), 11.33 in /yr (288 mm/yr), 16,450 acre-ft/yr (20.3 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 10,500 cu ft/s (297 cu m/s) Aug. 31, 1979, gage height, 9.83 ft (2.996 m) from flood- mark, from rating curve extended above 300 cu ft/s (8.50 cu m/s) on basis of step-backwater analysis; minimum daily discharge, 0.2 cu ft/s (0.006 cu m/s) June 30, 1978. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,000 cu ft/s (28.3 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Oct. 1 1630 1,010 28.6 4.11 1.253 Apr. 21 0230 *5,930 168 7.95 2.423 Minimum daily discharge, 1.5 cu ft/s (0.042 cu m/s) Feb. 8-10, 13, 14, 16, 17, 19, 20. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 174 3.3 135 6.6 1.6 1.3 3.4 10 11 15 3.5 5.4 2 152 8.0 70 7.3 1.6 1.3 3.8 9.1 1C 18 3.4 5.2 3 40 8.3 40 5.4 1.6 1.8 2.8 10 11 17 3.3 5.0 4 46 3.0 32 5.9 1.6 1.7 2.7 8.1 9.0 15 3.4 11 5 24 8.0 28 5.5 1.8 1.7 3.3 7.2 8.5 20 3.5 3.0 6 13 7.5 17 5.2 1.7 1.3 4.5 7.0 8.5 10 3.4 6.0 7 11 7.5 12 5.0 1.6 1.3 5.6 7.0 8.5 8.0 3.3 5.5 3 14 7.5 9.0 5.0 1.5 1.9 6.6 7.0 8.0 7.5 10 5.0 9 9.2 7.0 9.7 4.7 1.5 2.5 4.3 12 8.0 7.5 6.0 4.8 10 7.5 6.8 9.6 4.5 1.5 4.0 2.9 24 7.8 7.0 4.0 4.5 11 7.5 9.3 9.7 4.2 1.6 3.0 2.7 10 7.6 7.5 4.0 4.0 12 6.8 47 10 4.0 1.6 100 2.7 17 7.6 7.5 3.5 5.3 13 7.0 51 9.0 3.7 1.5 20 3.1 36 7.5 7.0 3.5 4.4 14 8.0 32 9.4 3.5 1.5 3.0 12 32 10 7.0 5.0 4.1 15 7.0 24 9.3 3.4 1.7 5.0 26 30 9.0 7.0 3.3 11 16 7.0 23 12 3.4 1.5 3.5 8.1 14 35 7.5 5.0 9.3 17 6.5 81 10 3.2 1.5 3.1 6.0 10 45 7.0 143 6.3 18 6.5 49 9.5 3.0 1.6 3.1 40 63 79 6.5 40 8.4 19 6.5 59 14 2.3 1.5 3.0 15 127 33 6.0 10 6.0 20 7.0 38 19 2.7 1.5 3.0 23 180 2C 6.0 7.0 5.5 21 6.5 55 12 2.5 1.6 2.9 735 232 16 5.5 20 5.2 22 19 30 10 2.3 1.6 2.6 86 190 14 5.5 11 10 23 23 25 9.0 2.2 1.6 2.7 28 47 12 5.0 8.0 37 24 25 30 8.5 2.1 1.6 2.3 15 20 11 5.0 10 19 25 15 22 8.0 2.0 1.6 4.5 10 61 12 5.0 7.0 10 26 12 18 7.5 2.0 1.7 5.2 8.7 75 13 4.5 6.0 6.6 27 11 16 7.2 1.9 1.7 4.4 121 23 13 4.0 5.8 6.4 28 10 53 6.8 1.3 1.7 3.9 140 17 14 4.0 5.6 5.2 29 10 15 6.7 1.3 --- 3.5 43 15 14 3.8 5.6 5.3 30 9.5 87 28 1.7 2.3 14 13 16 4.0 5.6 5.9 31 8.0 --- 7.6 1.7 3.1 --- 12 --- 3.7 5.5 --- TOTAL 709.5 845.6 535.5 111.1 44.6 210.9 1379.2 1330.4 479.0 244.0 358.2 235.3 MEAN 22.9 28.2 18.9 3.58 1.59 6.80 46.0 42.9 16.0 7.87 11.6 7.84 MAX 174 87 135 7.3 1.8 100 735 232 79 20 143 37 MIN 6.5 6.3 6.7 1.7 1.5 1.7 2.7 7.0 7.5 3.7 3.3 4.0 CFSM .84 1.04 .70 .13 .06 .25 1.69 1.58 .59 .29 .43 .29 IN. .97 1.16 .80 .15 .06 .29 1.89 1.82 .66 .33 .49 .32 AC-FT 1410 1680 1160 220 38 413 2740 2640 950 484 710 467 CAL YR 1982 TOTAL 6115.6 MEAN 16.8 MAX 784 MIN 1.8 CFSM .62 IN 8.36 AC-FT 12130 WTR YR 1983 TOTAL 6533.3 MEAN 17.9 MAX 735 MIN 1.5 CFSM .66 IN 8.93 AC-FT 12960 WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE GATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 12 1100 6.3 414 23.0 APR. 11 1145 2.9 519 28.0 NOV, 10 1250 6.3 385 29.0 MAY. 05 1110 7.2 423 28.0 DEC. 10 1045 9.7 321 24.0 SEP. 15 1238 4.3 400 29.0 MAR. 14 1030 6.3 392 26.0 163 RIO YAUCO BASIN 50128000 RIO YAUCO NEAR YAUCO, PR LOCATION.--Lat 17°59'19", long 66°49'55", Hydrologic Unit 21010004, on right bank at downstream side of bridge on Highway 335, 0.8 mi (1.3 km) northwest of Central San Francisco and 3.4 mi (5.5 km) southeast of junction of Highways 335 and 2 in Yauco. DRAINAGE AREA.--45.5 sq mi (117.8 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--October 1960 (discharge measurements only), May 1961 to December 1964, November 1976 to current year. GAGE.--Water-stage recorder. Datum of gage is 15.14 ft (4.615 m) above mean sea level, datum of 1929. Prior to Oct. 1, 1978, at same site at datum 4.0 ft (1.219 m) higher. REMARKS.--Records poor. Natural flow of stream is affected by transbasin diversions, storage reservoirs, power development, diversions for irrigation and municipal use, and return flow from irrigated areas. AVERAGE DISCHARGE.--6 years (1978-83), 18.5 cu ft/s (0.524 cu m/s), 5.52 in/yr (140 mm/yr), 13,400 acre-ft/yr (16.5 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 10,300 cu ft/s (292 cu m/s) Sept. 13, 1982, gage height, 15.0 ft (4.57 m), from floodmarks, from rating curve extended above 2,000 cu ft/s (56.6 cu m/s) on basis of step-backwater analysis and indirect measurement of peak flow; no flow many days in most years. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,000 cu ft/s (28.3 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Oct. 1 2015 1,320 37.4 10.93 3.331 Aug. 17 1900 1,550 43.9 11.42 3.481 Apr. 21 0730 *4,430 125 14.02 4.273 Minimum discharge, 0.50 cu ft/s (0.014 cu m/s) Apr. 11, 13. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 231 47 120 2.8 1.5 1.5 1.1 9.2 7.3 2.2 1.0 1.4 2 118 22 32 2.8 1.4 1.5 .88 7.9 6.8 2.2 .99 2.0 3 14 116 20 2.8 1.4 1.4 .94 7.5 6.5 2.1 1.0 1.6 4 8.1 36 15 2.8 1.4 1.4 .79 6.7 6.3 2.0 .95 1.5 5 14 6.3 15 2.7 1.4 1.4 .81 5.7 5.8 9.3 1.0 1.4 6 6.3 4.3 10 2.8 1.4 1.3 .32 5.6 4.2 5.3 1.0 1.3 7 5.6 3.4 8.4 2.7 1.5 1.3 .76 5.5 4.8 2.7 .95 1.3 8 5.9 3.2 7.1 2.7 1.4 1.3 .76 4.9 4.4 2.1 .94 1.2 9 5.2 3.2 5.3 2.6 1.5 1.4 .64 4.7 4.0 1.8 .98 1.3 10 4.8 3.0 4.9 2.6 1.4 1.4 .59 4.4 3.9 1.6 1.0 1.2 11 4.5 3.4 4.6 2.4 1.4 1.4 .53 4.4 3.9 1.6 .98 1.2 12 4.5 31 4.3 2.4 1.4 154 .53 4.2 3.5 1.5 .98 1.3 13 7.4 76 4.1 2.3 1.4 34 .54 5.2 3.4 1.4 .94 1.2 14 11 13 4.0 2.2 1.4 3.9 .59 10 3.5 1.3 .87 1.2 15 6.8 21 3.9 2.2 1.5 2.7 .57 9.3 4.6 1.3 .81 1.2 16 4.8 7.5 3.6 2.2 1.5 2.4 .66 6.7 4.5 1.3 .81 1.2 17 3.8 267 3.5 2.2 1.7 2.1 .67 5.8 9.0 1.3 223 1.2 18 4.9 127 3.5 2.0 1.6 1.9 3.1 45 21 1.2 73 1.2 19 18 247 6.5 2.0 1.5 1.8 4.6 109 13 1.2 4.4 1.2 20 11 183 11 1.9 1.5 1.7 2.1 157 6.7 1.2 2.5 1.2 21 6.7 263 5.3 1.9 1.5 1.6 1430 172 3.4 1.2 20 1.2 22 6.6 174 4.2 1.8 1.5 1.5 165 210 3.4 1.3 '9.5 1.2 23 6.6 73 3.9 1.8 1.5 1.5 65 41 3.2 1.3 2.7 12 24 11 66 3.9 1.7 1.5 1.5 33 22 3.0 1.3 1.9 6.8 25 6.3 17 3.4 1.7 1.6 1.4 20 26 2.7 1.1 2.0 2.3 26 4.5 12 3.5 1.7 1.6 1.3 15 56 2.6 1.2 1.7 1.6 27 5.3 20 3.3 1.6 1.4 1.2 88 21 2.5 1.2 1.7 1.6 28 3.5 73 3.2 1.6 1.4 1.1 112 15 2.5 1.2 1.6 1.6 29 3.3 36, 2.9 1.6 --- 1.1 43 11 2.4 1.2 1.6 1.6 30 3.3 61 3.3 1.6 1.1 13 9.3 2.4 1.2 1.5 1.7 31 75 --- 3.2 1.5 1.1 --- 8.5 --- 1.0 1.5 --- TOTAL 621.7 2015.3 326.8 67.6 41.2 234.2 2005.98 1010.5 155.2 57.8 363.80 57.9 MEAN 20.1 67.2 10.5 2.18 1.47 7.55 66.9 32.6 5.17 1.86 11.7 1.93 MAX 231 267 120 2.8 1.7 154 1430 210 21 9.3 223 12 MIN 3.3 3.0 2.9 1.5 1.4 1.1 .53 4.2 2.4 1.0 .81 1.2 CFSM .44 1.48 .23 .05 .03 .17 1.47 .72 .11 .04 .26 .04 IN. .51 1.65 .27 .06 .03 .19 1.64 .83 .13 .05 .30 .05 AC-FT 1230 4000 648 134 82 465 3980 2000 308 115 722 115 CAL YR 1982 TOTAL 5051.77 MEAN 13.8 MAX 1000 MIN .06 CFSM .30 IN 4.13 AC-FT 10020 WTR YR 1983 TOTAL 6957.98 MEAN 19.1 MAX 1430 MIN .53 CFSM .42 IN 5.69 AC-FT 13800 WATER-QUALITY RECORDS PERIOD OF RECORD.-- WATER YEAR AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS OUCTANCE TURE DATE TIME INSTANTANEOUS OUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 12 1330 4.4 964 23.0 APR. 11 1500 .53 1040 28.0 NOV, 09 1230 3.2 950 27.0 MAY. 05 1325 5.4 950 27.5 DEC. 10 1255 4.7 660 25.0 SEP. 14 1350 1.2 957 29.0 MAR. 14 1300 3.5 490 26.0 164 CANAL PRINCIPAL DE RIEGO VALLE DE LAJAS BASIN 50128950 LAJAS IRRIGATION CANAL NEAR BOQUERON, PR LOCATION.--Lat 18°02'14", long 67°08'22", Hydrologic Unit 21010004, on downstream side of wooden foot bridge near dirt levee road, 0.5 mi (0.8 km) north of intersection of Highways 101 and 103, 1.8 mi (2.9 km) northeast of Boquer6n. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1980 to current year. GAGE.--Water-stage recorder. Altitude of gage is shout 82 ft (25 m), from topographic map. REMARKS.--Records poor. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 34 cu ft/s (0.963 cu m/s) June 11, 1981, gage height, 2.56 ft (0.780 m) from rating curve extended above 10 cu ft/s (0.283 cu m/s) on basis of step-backwater analysis; no flow many days each year. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 23 cu ft/s (0.651 cu m/s) Apr. 21, gage height 1.80 ft (0.549 m); no flow many days. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR ASR MAY JUN JUL AUG SEP 1 .00 2.6 .00 .00 1.0 2.7 .06 .00 .00 2.4 2.1 2 .61 .27 .00 .00 1.4 .00 .30 .10 .00 .04 t 4.9 3 .13 2.4 .00 .00 .78 .24 .04 .82 .00 .02 A .02 4 .06 3.3 .00 .00 .80 1.2 .02 .74 .00 .06 .04 .02 5 .02 .01 .00 .13 .00 .00 .00 .39 .00 2.0 2.8 .58 6 .00 .00 .00 .11 .00 .02 1.7 .74 .00 2.3 .00 3.6 7 .00 .02 .00 .34 .00 2.0 .22 .02 2.5 3.3 .00 6.1 8 .00 .38 .00 .00 2.3 5.7 1.8 .00 .39 A .73 .45 9 .00 .88 .00 .00 .23 3.7 .00 .00 .02 4.6 .01 10 .00 .10 .00 1.3 .90 1.8 .00 .00 .00 3.2 .00 11 .07 3.4 .00 .00 .98 2.3 .00 .45 .00 4.1 .00 12 2.6 6.4 .00 .19 .00 2.9 1.4 1.2 .00 3.7 1.3 13 4.7 .50 .00 1.8 .00 .77 3.5 1.5 .00 .16 1.9 14 1.3 .21 1.0 4.3 1.2 1.4 1.6 5.7 .00 .01 1.8 15 1.2 3.2 1.8 .00 7.9 1.2 1.1 .22 .10 3.0 4.3 16 .00 2.0 1.4 .00 2.6 .02 .00 .22 2.0 6.0 6.6 17 .00 5.3 1.6 .12 .00 .02 .00 .00 2.9 2.1 .22 18 .94 .07 .43 1.6 .00 .00 1.6 4.9 1.4 4.4 .01 19 2.5 .00 1.3 1.0 .00 .00 .59 .40 1.1 .22 4.5 20 5.1 .50 .94 .00 .00 .00 2.0 .CO .52 .06 5.2 21 1.8 .20 .45 .33 .00 .00 11 1.1 2.1 5.0 5.4 22 .15 .00 .00 .00 .16 .00 .02 .37 2.6 .06 4.1 23 .45 .00 .14 .00 4.1 .00 .00 .00 1.8 3.0 1.9 24 .19 .00 .21 .56 1.3 .00 .00 .00 .02 6.7 .52 25 1.3 .01 .00 3.5 .00 .14 .00 .00 .00 1.6 .06 26 1.8 .01 .00 1.7 .00 .04 .00 .01 .00 1.8 5.2 27 1.1 .00 .00 1.1 .85 .00 .00 .00 .00 .30 7.1 28 1.2 .04 .14 3.6 3.1 .00 1.4 .00 1.2 .10 1.6 29 .38 .01 .09 .28 .16 1.9 .00 .39 1.6 1.4 30 .16 .00 .00 .34 .54 .04 .00 1.6 1.2 6.3 31 1.6 --- .00 1.4 .58 --- .00 --- 1.1 TOTAL 29.36 31.81 10.05 23.70 29.50 27.43 30.29 18.88 20.54 77.19 MEAN .95 1.06 .32 .76 1.05 .83 1.01 .61 .68 2.57 MAX 5.1 6.4 1.8 4.3 7.9 5.7 11 5.7 2.8 7.1 MIN .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 AC-FT 58 63 20 47 59 54 60 37 41 153 A No gage-height record. WATER-QUALITY RECORDS PERIOD OF RECORD.--JANUARY TO SEPTEMBER 1983 WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMMOS) (DEG C) (CFS) (UMMOS) (DEG C) JAN• 13 0345 2.2 306 24.0 MAY, 13 0320 1.7 288 27.0 APR, 15 0910 1.3 287 25.5 SEP, 07 1630 4.6 249 31.0 165 RIO LOCO BASIN 50129300 LAJAS DRAINAGE CANAL NEAR ENSENADA, PR LOCATION.--Lat 18°00'40", long 66°58'24", Hydrologic Unit 21010004, on upstream side of Cuesta Blanca Bridge on dirt road, 1.1 mi (1.8 km) north of Highway 116, 1.0 mi (1.6 km) below Quebrada Jicara, 3.9 mi (6.3 km) above Rio Loco, and 4.0 mi (6.4 km) northwest of Ensenada. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1979 to current year. GAGE.--Water-stage recorder. Altitude of gage is about 15.1 ft (4.602 m), from Hydrologic Atlas of Lajas Valley. REMARKS.--Records poor. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum discharge, 1,720 cu ft/s (48.7 cu m/s) Sept. 1, 1979, gage height, 16.44 ft (5.011 m), from rating curve extended above 600 cu ft/s (17 cu m/s); minimum daily, 1.0 cu ft/s (0.028 cu m/s) July 16, 1979, May 9, 16, 1982. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum discharge, 448 cu ft/s (12.7 cu m/s) Apr. 21,gage height, 9.05 ft (2.758 m); minimum daily, 1.2 cu ft/s (0.034 cu m/s) Dec. 18. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 3.0 9.3 A 3.1 A 2.6 2.5 3.5 4.6 3.3 B 2 3.9 9.7 2.9 3.1 2.4 4.0 6.8 3.2 3 3.3 13 2.5 3.4 2.1 3.6 2.7 2.6 4 2.9 8.8 2.0 3.6 2.1 2.9 2.5 2.2 5 3.3 11 2.0 3.7 2.3 3.1 2.2 2.6 6 3.6 4.1 1.8 2.4 2.5 2.9 4.5 4.6 7 3.8 2.4 2.2 3.0 2.6 2.9 3.6 5.3 8 3.1 3.4 2.1 2.9 3.2 2.7 3.0 6.9 9 3.0 A 2.5 A 3.4 3.2 2.9 8.4 3.1 10 2.9 2.8 3.6 4.1 2.5 3.0 4.4 2.5 11 2.8 2.4 3.9 4.0 2.4 3.1 7.1 2.9 12 3.3 2.7 3.2 36 2.7 8.6 5.3 13 2.4 A A 2.1 87 2.8 17 13 14 5.0 1.6 1.9 14 3.1 244 16 15 17 1.3 2.7 5.6 3.8 77 43 16 8.4 1.5 2.8 4.3 4.8 25 48 17 4.6 1.5 3.4 3.6 4.2 20 40 18 4.2 1.2 3.3 2.7 4.6 77 6.4 19 38 15 3.6 2.2 4.8 226 3.3 20 35 112 2.9 2.1 5.3 57 9.5 21 103 31 2.3 5.6 301 98 4.5 22 21 9.2 2.4 3.8 127 136 2.0 23 43 8.3 2.9 5.4 19 48 1.9 24 46 25 3.4 4.2 7.3 38 1.8 25 41 6.2 4.4 3.0 4.9 36 2.6 26 16 4.3 4.5 2.3 4.2 42 5.1 27 2.9 3.5 3.4 2.0 3.7 42 4.3 28 2.9 3.0 2.7 2.3 5.9 59 6.5 29 3.6 3.2 --- 2.5 9.4 19 6.4 30 3.6 3.2 2.5 4.4 3.6 4.0 31 5.2 A 3.3 A 2.7 --- 3.6 --- B TOTAL 441.7 230.0 550.7 1311.4 273.4 MEAN 14.2 7.42 18.4 42.3 9.11 MAX 103 87 301 244 48 MIN 2.4 2.0 2.1 2.7 1.8 AC-FT 876 456 1090 2600 542 A No gage-height record. B Discharge not determined but less than 50 cu ft/s. WATER-QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1932 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMNOS) (DEG C) (CFS) (UMMOS) (DEG C) OCT, 07 1300 5.0 927 30.0 APR, 15 1120 3.8 1190 27.5 NOV, 08 1105 2.2 783 30.5 MAY, 13 1057 5.7 1110 30.5 MAR, 18 1010 3.0 949 28.0 166 RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR WATER-QUALITY RECORDS LOCATION.--Lat 17 °58'33", long 66°54'52", 0.6 mi (1.0 km) northwest of Guanica 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 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL. FLOM, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 03... 1140 11.0 36600 7.9 26.0 4.4 7.6 108 23 4200 8300 JAN . 1983 12... 1200 11.0 36300 7.9 28.0 3.5 6.0 87 K47 460 MAR 31... 0835 1.00 28400 7.6 29.5 2.2 3.4 49 600 K33 280 MAY 18... 1400 E15 662 7.5 27.0 5.0 4.8 60 12 6000 2200 JUN 09... 0815 E.00 13800 7.7 28.0 5.4 72 AUG 17... 1020 1.00 12100 7.6 27.0 2.0 .6 8 240 2000 K1800 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUMe SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE. NESS NONCAR- DIS- DIS- DIS- SORP- On- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CACC3) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV , 1982 03... 130 JAN , 1983 12... 4900 4660 130 1100 8400 53 290 200 2300 15000 .60 MAR 31... 260 11000 MAY 18... 220 16 37 30 51 1.5 3.2 200 41 57 .20 JUN 09... 300 AUG 17... 1500 1270 120 300 2100 24 78 262 590 3900 .40 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GENeAM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + SOLVED TUENTS, SOLVED DEG. C. NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) NITRO- GEN. TOTAL (MG/L AS N) NOV . 1982 03... 12 .39 .010 .40 .050 .45 .50 .90 JAN , 1983 12... 7.1 27300 73.7 66 <.010 <.10 .150 .15 .30 MAR 31... 22 .020 <.10 .120 <.10 MAY 18... 26 365 6 .28 .020 .30 .060 .64 .70 1.0 JUN 09... AUG 17... 27 7270 8 <.010 <.10 .040 .56 .60 E = estimate K = non-ideal count RIO LOCO BASIN 50129700 RIO LOCO AT GUANICA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- BARIUM. CADMIUM MIUM. LEAD, MERCURY SILVER. NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS P8) AS MG) AS SE) AS AG) NOV r 1982 03... 4.0 .110 JAN r 1983 12... .130 1 100 2 20 3 <.1 <1 <1 MAR 31... .130 MAY 18... 4.4 .520 JUN 09... AUG 17... .220 2 100 1 7 3 .3 <1 <1 CHLOR- DI- PCB, ALORIN, DANE, Me DDEt DDT. AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN , 1983 09... 0815 <.10 <.01 <.10 <.01 <.01 <.01 <.01 HEPTA- METH- DI- ENDO- HEPTA- CHLOR MALA- OXY- ELDRIN SULFAN, ENCRIN, ETHION. MORA, EPDXIDE LINDANE THION, CHLOR, TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 09... <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 <.01 NAPH- THA- METHYL METHYL LINES, PARA- TRI- PARA- POLY- PER- TOX- TOTAL THIONr THIONr MIREXr THION, CHLOR. THANE APHENE, TRI- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL THION DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN , 1983 09... <.01 <.01 <.01 <.01 <.10 <.10 <1 <.01 167 Rio Grande de Anosco basin MARICAO Rosario Drainage boundary 1380 HORMIGU E r O.°" 11 Laguna Joy Rio .AOUADILLA najibo 1336 QED WC:OE PONCE. OUAYAMA. ABO ROJO 32010 Map area SAN GERMAN —onaii 0 • GRAND SNBA14A Rlo Loco basin LAJ EXPLANATION A1380 SURFACE-WATER STATION AND NUMBER 2,1300 LOW-FLOW STATION AND NUMBER v1297 QUALITY-OF-WATER STATION AND NUMBER 0143 WELL AN WELL NUMBER GUANICA ENSENADA M A R CARIBE Figure 23.--Rio Guanajibo basin. 170 RIO GUANAJIBO BASIN 50133600 RIO GUANAJIBO NEAR SAN GERMAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°07'18", long 67°03'56", at bridge on Highway 347, 2.2 mi (3.5 km) northwest of San German plaza. DRAINAGE AREA.--45.5 sq mi (117.8 sq km). PERIOD OF RECORD.--November 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLT- STREP* SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOM, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 04... 1330 32 419 7.9 27.0 19 6.5 83 14 50000 5600 JAN , 1983 13... 0905 18 582 7.8 24.0 1.4 3.4 41 K68000 48000 MAR 30... 1215 7.4 636 7.8 26.0 1.0 .0 0 49 K1800000 50000 MAY 04... 1345 21 543 7.6 27.0 6.2 5.8 73 24 57000 2000 AUG 18... 0930 40 440 7.9 27.0 3.5 3.2 40 28 K93000 22000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS 504) AS CL) AS F) NOV , 1932 04... 180 JAN , 1983 13... 260 11 27 47 23 .6 2.4 250 31 30 .40 MAR 30... 290 MAY 04... 260 20 28 46 22 .6 2.0 240 26 23 .30 AUG 18... 210 0 23 36 14 .4 1.8 230 19 18 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO." SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L On- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 04... 47 .47 .030 .50 .230 .57 .80 1.3 JAN , 1983 13... 35 346 16.8 5 .16 .040 .20 1.20 .70 1.90 2.1 MAR 30... 3 .020 <.10 2.90 1.8 4.70 MAY 04... 34 325 18.4 6 .13 .070 .20 .940 .16 1.10 1.3 AUG 18... 32 282 30.4 2 .17 .030 .20 .500 .80 1.30 1.5 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUMr RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 8A) AS CD) AS CR) AS P3) AS HG) AS SE) AS AG) NOV , 1982 04... 5.8 .230 JAN , 1983 13... 9.3 .900 2 <100 2 5 2 <.1 <1 1 MAR 30... 1.50 MAY 04... 5.8 .420 AUG 18... 6.6 .310 2 200 <1 5 5 <.1 <1 <1 K = non-ideal count RIO GUANAJIBO BASIN 171 50136000 RIO ROSARIO AT ROSARIO, PR LOCATION.--Lat 18°10'22", long 67°04'31", Hydrologic Unit 21010003, on left bank above low dam, 0.2 mi (0.3 km) below Quebrada Figueroa, 0.7 mi (1.1 km) northeast of Rosario, and 1.6 mi (8.6 km) below Quebrada Palma. DRAINAGE AREA.--16.4 sq mi (42.5 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1960 to June 1966 (gage-height records only) in files of Puerto Rico Water Resources Authority. June 1975 to current year. GAGE.--Water-stage recorder and concrete control. Altitude of gage is 230 ft (70 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--8 years (1976-83), 44.4 cu ft/s (1.257 cu m/s), 36.77 in/yr (934 mm/yr), 32,170 acre-ft/yr (39.7 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 33,800 cu ft/s (957 cu m/s) Sept. 16, 1975, gage height, 19.6 ft (5.97 m), from flood- marks, from rating curve extended above 60 cu ft/s (1.70 cu m/s) on basis of slope-area measurement of peak flow; minimum daily discharge, 2.4 cu ft/s (0.068 cu m/s) June 18, 21, 1977. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,500 cu ft/s (42.5 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Oct. 18 2115 2,340 66.3 6.60 2.012 May 7 1730 1,860 52.7 6.05 1.844 Nov. 16 1815 2,550 72.2 6.82 2.079 May 18 1515 *4,190 119 8.23 2.508 Minimum discharge, 7.8 cu ft/s (0.221 cu m/s) Apr. 4. DISCHARGE. IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 52 66 80 30 16 11 8.4 14 34 29 21 27 2 47 73 65 27 15 11 8.4 12 59 25 22 25 3 42 47 60 25 15 11 8.4 10 125 25 19 25 4 40 40 56 25 15 11 8.1 70 78 71 69 24 5 37 43 54 25 17 11 8.6 48 51 49 31 24 6 42 40 50 25 16 11 8.8 13 42 27 21 23 7 39 35 48 24 15 11 12 176 74 23 19 23 3 70 33 46 23 15 13 16 67 49 22 30 23 9 43 33 44 23 15 11 9.3 28 38 28 26 22 10 35 38 42 23 15 10 8.7 27 34 26 22 209 11 32 45 40 22 14 10 8.6 27 31 42 22 133 12 31 81 38 22 14 16 8.7 24 29 23 22 64 13 34 82 37 21 14 15 8.5 79 28 21 36 41 14 55 49 35 22 13 13 8.4 104 26 18 39 31 15 44 53 34 24 13 11 8.4 54 25 17 39 29 16 35 251 33 21 13 10 9.3 30 25 26 36 38 17 32 231 32 21 13 9.7 9.3 32 26 42 34 135 18 202 229 31 20 13 9.7 9.8 433 28 60 38 82 19 193 184 31 20 13 9.4 8.5 231 24 37 32 48 20 117 105 30 21 14 9.6 28 162 23 25 61 36 21 73 87 29 20 15 9.5 151 236 23 21 84 33 22 57 72 28 19 13 9.3 19 230 22 19 60 43 23 48 63 27 10 13 9.2 12 175 21 18 45 70 24 44 123 27 18 13 9.2 11 150 21 19 38 47 25 40 96 27 13 12 3.9 9.3 104 20 16 146 36 26 57 67 27 17 12 9.0 8.6 81 21 16 138 31 27 50 61 25 17 12 9.0 8.6 61 21 16 77 29 28 43 60 25 17 11 9.3 10 49 21 16 55 27 27 41 59 47 16 9.0 12 72 20 17 40 27 30 52 142 73 16 8.7 28 51 20 19 33 25 31 43 --- 43 16 8.5 --- 40 --- 23 30 --- TOTAL 1770 2593 1264 657 389 324.0 473.7 2895 1059 841 1385 1435 MEAN 57.1 86.4 40.8 21.2 13.9 10.5 15.8 93.4 35.3 27.1 44.7 47.8 MAX 202 251 80 30 17 16 151 433 125 71 146 209 MIN 31 33 25 16 11 8.5 8.1 10 20 16 19 22 CFSM 3.48 5.27 2.49 1.29 .35 .64 .96 5.70 2.15 1.65 2.73 2.92 IN. 4.01 5.88 2.37 1.49 .38 .73 1.07 6.57 2.40 1.91 3.14 3.25 AC-FT 3510 5140 2510 1300 772 643 940 5740 2100 1670 2750 2850 CAL YR 1982 TOTAL 16381.0 MEAN 46.2 MAX 452 MIN 10 CFSM 2.32 IN 38.29 AC-FT 33480 WTR YR 1983 TOTAL 15085.7 MEAN 41.3 MAX 433 MIN 8.1 CFSM 2.52 IN 34.22 AC-FT 29920 WATER-QUALITY RECORDS PERIOD OF RECORD. --OCTOBER 1982 TO SEPTEMBER 1983 WATER-QUALITY DATA. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA­ DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT' 07 1015 37 235 22.5 APR. 14 1325 3.4 289 26.0 NOV, 10 1320 37 210 25.0 MAY. 12 1257 17 285 29.0 DEC. 22 1157 29 234 23.0 JUN. 09 0915 39 221 24.0 JAN. 12 1410 22 265 24.0 SEP. 08 0950 24 269 25.0 MAR, 17 1400 9.7 302 28.5 172 RIO GUANAJIBO BASIN 50136400 RIO ROSARIO NEAR HORMIGUEROS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°09'36", long 67°05'08", at bridge on Highway 348, 0.5 mi (0.8 km) southwest of Rosario plaza. DRAINAGE AREA.--18.3 sq mi (47.4 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW• CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANtE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV r 1982 04... 1030 40 265 8.3 24.0 1.5 8.8 107 <10 K500 330 JAN P 1983 13... 1155 30 273 8.4 23.0 <1.0 9.6 113 K530 240 APR 4... 1545 7.9 296 8.0 25.5 8.1 100 <10 430 MAY 5... 1400 42 204 8.2 25.5 18 8.1 101 17 4100 3500 AUG 18... 1150 44 233 8.3 25.5 15 8.7 107 16 5100 3100 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUD.*. HARD- NESS• CALCIUM SIUM, SODIUM• AD- SION, LINITY SULFATE RIDEr RIDE, NESS NONCAR- DIS DIS- DES- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV p 1982 04... 120 JAN r 1983 13... 130 3 25 17 3.6 .3 1.2 130 7.0 8.3 <.10 APR 4... 170 MAY 5... 98 7 18 13 7.0 .3 1.1 92 8.7 7.3 <.10 AUG 18... 110 1 21 13 6.5 .3 1.1 105 8.2 6.0 <.10 SOLIDS, SOLIDS. NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DM- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN. GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Cr NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV s 1982 04... 4 <.010 .60 <.010 .30 .90 JAN r 1983 13... 31 176 14.3 12 <.010 .70 .020 .78 .80 1.5 APR 4... <.010 .10 .010 .39 .40 .50 MAY 5... 27 137 15.6 22 .79 .010 .80 .010 .19 .20 1.0 AUG 18... 27 146 17.5 16 .59 .010 .60 <.010 .20 .80 CHRO- BARIUM. CADMIUM MIUM. LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELF- TOTAL GEN, pHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L CMG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PB) AS HG) AS SE) AS AG) NOV r 1982 04... 4.0 .050 JAN , 1983 13... 6.6 .580 1 <100 2 24 2 <.1 <1 <1 APR 4... 2.2 .050 MAY 5... 4.4 .050 AUG 18... 3.5 .040 2 200 <1 11 6 <.1 <1 1 K = non-ideal count 173 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR LOCATION.--Lat 18°08'36", long 67°08'57", Hydrologic Unit 21010003, at bridge on Highway 100, 1.4 mi (2.3 km) west of Hormigueros, and 2.0 mi (3.2 km) downstream from Rio Rosario. DRAINAGE AREA.--120 sq mi (311 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--Annual low-flow measurements 1959, monthly measurements April 1959 to November 1967, January 1973 to current year. GAGE.--Water-stage recorder. Datum of gage is at mean sea level. Previous to Nov. 7, 1980, at site 0.3 mi (0.5 km) upstream at datum 7.36 ft (2.243 m) higher. REMARKS.--Records fair. AVERAGE DISCHARGE.--10 years (1974-83), 220 cu ft/s (6.230 cu m/s), 24.90 in/yr (632 mm/yr), 159,400 acre-ft/yr (197 cu hm/yr); median of yearly mean discharges, 204 cu ft/s (5.78 cu m/s), 148,000 acre-ft/yr (182 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 128,000 cu ft/s (3,625 cu m/s) Sept. 16, 1975, gage height, 28.50 ft (8.687 m), site and datum then in use, from rating curve extended above 100 cu ft/s (2.83 cu m/s) on the basis of contracted-opening measurement of peak flow; minimum, 4.6 cu ft/s (0.130 cu m/s) June 22, 1977. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 2,000 cu ft/s (56.6 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) May 19 0215 2,160 61.2 18.86 5.748 May 23 0545 *2,360 66.8 19.38 5.907 May 19 2330 2,090 59.2 18.66 5.688 Minimum discharge, 15 cu ft/s (0.425 cu m/s) Apr. 4. DISCHARGE• IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 162 419 437 73 39 23 17 82 172 54 41 76 2 206 504 230 70 38 23 16 75 162 86 49 71 3 144 377 192 65 36 22 16 62 209 80 37 66 4 126 288 170 63 35 22 16 67 207 150 102 70 5 122 385 158 61 36 24 16 141 145 208 74 78 6 112 290 143 58 35 28 17 68 126 111 41 70 7 112 180 131 57 35 30 17 201 156 77 35 66 8 112 200 123 55 33 30 33 225 192 64 33 62 9 115 400 159 53 32 25 44 98 138 57 54 57 10 90 600 129 51 32 23 25 74 122 64 53 209 11 85 300 115 43 31 21 20 70 109 71 67 311 12 80 250 106 47 30 83 19 61 99 90 43 160 13 79 300 102 46 29 99 18 166 90 60 144 109 14 99 200 98 47 29 65 18 692 83 51 158 93 15 112 166 92 61 29 42 16 243 79 48 106 86 16 88 420 92 50 29 32 17 153 77 48 64 105 17 72 1340 39 47 29 28 17 119 75 66 111 233 18 160 1520 85 45 29 25 20 540 82 85 153 199 19 933 990 97 44 29 23 19 1620 74 83 37 121 20 521 939 155 45 30 22 31 1480 68 59 221 100 21 314 620 98 42 35 22 1100 1180 65 51 380 92 22 220 422 92 42 30 21 219 2230 61 46 247 243 23 215 343 185 40 29 21 130 1310 59 43 158 351 24 174 353 143 39 28 21 143 783 56 42 168 226 25 148 540 113 38 28 20 95 687 54 38 423 173 26 460 353 105 37 27 20 78 573 52 34 381 150 27 570 276 97 36 25 19 66 354 53 33 206 134 28 222 286 89 36 24 19 146 281 51 34 152 123 29 186 246 92 37 --- 19 148 240 50 36 120 113 30 187 674 125 33 18 96 246 50 37 100 104 31 174 --- 106 42 17 --- 196 --- 41 86 --- TOTAL 6450 14186 4198 1518 871 907 2633 14327 3016 2047 4094 4051 MEAN 208 473 135 49.0 31.1 29.3 87.8 462 101 66.0 132 135 MAX 983 1520 487 78 39 99 1100 2230 209 208 423 351 MIN 72 166 35 36 24 17 16 61 50 33 33 57 CFSM 1.73 3.94 1.13 .41 .26 .24 .73 3.85 .34 .55 1.10 1.13 IN. 2.00 4.40 1.30 .47 .27 .28 .82 4.44 .93 .63 1.27 1.26 AC-FT 12790 28140 3330 3010 1730 1800 5220 28420 5980 4060 8120 8040 CAL YR 1982 TOTAL 66654 MEAN 183 MAX 6270 MIN 19 CFSM 1.53 IN 20.66 AC-FT 132200 WTR YR 1983 TOTAL 58298 MEAN 160 MAX 2230 MIN 16 CFSM 1.33 IN 18.07 AC-FT 115600 174 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 DATE STREAM FLOW. INSTAN- TIME TANEOUS (CFS) SPE- CIFIC CON- DUCT- ANCE (UMHOS) PH (STAND- ARD UNITS) TEMPER- ATURE (DEG C) TUR- BID- ITY (NTU) OXYGEN. DIS- SOLVED (MG/L) OXYGEN, OXYGEN COLI- STREP- DIS- DEMAND, FORM, TOCOCCI SOLVED CHEM- FECAL, FECAL, (PER- ICAL 0.7 KF AGAR CENT (HIGH UM-MF (COLS. SATUR- LEVEL) (COLS./ PER AT ION) (MG/L) 100 ML) 100 ML) NOV , 1982 05... 0915 207 394 7.5 24.0 16 5.5 66 14 27000 K12000 JAN • 1983 14... 1000 46 490 8.0 23.0 5.5 7.0 82 38000 K4000 APR 4... 1255 15 519 7.4 25.0 3.9 108 <10 K1700 MAY 5... 1050 134 286 7.5 25.0 150 7.5 91 57 35000 53000 JUN 08... 1540 172 355 7.6 26.0 5.6 70 AUG 17... 1330 58 218 8.2 28.0 18 5.9 75 200 K85000 7400 HARD- NESS (MGM. AS DATE CAC03) HARD- NESS. NONCAR- BONATE (MG/L CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM, DIS- SOLVED (MG/L AS MG) SODIUM. DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALKA- AD- SIUM, LINITY SORP- DIS- FIELD TION SOLVED (MG/L RATIO (MG/L AS AS K) CAC03) SULFATE DIS- SOLVED (MG/L AS SO4) CHLO- FLUO- RIDE, RIDE, DIS- DIS- SOLVED SOLVED (MG/L (MG/L AS CL) AS F) NOV • 1932 05... JAN • 1983 14... 210 APR 4... MAY 5... 130 JUN 08... AUG 17... 180 170 3 31 33 17 .5 2.0 210 22 20 .20 220 15 21 20 12 .5 1.8 120 14 11 .10 150 1 29 26 16 .5 1.8 179 15 15 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN. GEN' MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE 5IO2) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 OS... JAN e 1983 14... APR 4... MAY 5... JUN 08... AUG 17... 32 .37 .030 .40 .170 .23 .40 .80 32 283 35.2 22 .71 .090 .80 .350 .05 .40 1.2 .47 .030 .50 .520 .28 .80 1.3 25 177 64.0 307 .78 .120 .90 .360 .54 .90 1.8 31 241 37.8 22 .76 .040 .80 .230 .57 .80 1.6 K = non-ideal count 175 RIO GUANAJIBO BASIN 50138000 RIO GUANAJIBO NEAR HORMIGUEROS, PR - -Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 CHRO- BARIUM, CADMIUM MIUM. LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN. PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM. RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERA3LE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS BA) AS CD) AS CR) AS PS) AS HG) AS SE) AS AG) NOV 1982 05... 3.5 .290 JAN r 1983 14... 5.3 .520 1 100 1 15 4 .1 <1 <1 APR 4... 5.8 .570 MAY 5... 8.0 .300 JUN 08... AUG 17... 7.1 .440 2 100 1 10 4 <.1 <1 <1 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA­ DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 06 1355 113 428 27.5 FEB. OS 1450 32 452 25.0 DEC. 22 1530 92 495 25.0 SEP, 07 1510 66 422 28.0 CHLOR- DI- PCB, ALDRIN. DANE. ODD, DDE. DDT. AZINON. TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UM) (UG/L) (UG/L) (UG/L) JUN r 1983 08... 1540 (.10 <.01 <.10 <.01 <.01 <.01 .02 HEPTA- METH- DI- ENDO- HEPTA- CHLOR MALA- OXY­ ELDRIN SULFANe ENDRIN. ETHIONe CHLOR. EPDXIDE LINDANE THION. CHLOR. TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN e 1983 08... <.01 <.01 <.01 <.01 <.01 <.01 <.01 .02 <.01 NAPH­ THA­ METHYL METHYL LENESe PARA- TRI- PARA- POLY'. PER- TOX- TOTAL THION. THION. MIREX. THION. CHLOR. THANE APHENE. TRI­ TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL THION DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN r 1983 08... <.01 <.01 <.01 <.01 <.10 <.10 <.01 <1 Coastal bosi Drainage boundary Rio Culebrinas basin FLARES Rio GrOnd Rio Guajot000 basin Rio Camuy basin Rio Tanamd basin MAYA L•VO ranuoca 1410 ,e; /Orre Coastal basin Rio Guonojibo basin MARICAO al Drainage boundary as a 14 o 4. • ac § Rio Youco basin Guayimil basin \Island EXPLANATION A1410 SURFACE—WATER STATION AND NUMBER A1389 LOW—FLOW STATION AND NUMBER Y1385 QUALITY—OF—WATER STATION AND NUMBER • 45 WELL AND WELL NUMBER .A0UADIL L A eA.E. Map area___ '1.1.(*i,. 2 3 4 5 6 TKILOMETERS I hMILES Figure 24.--Rio Yaguez and Rio Grande de glasco basins. 178 RIO YAGUEZ BASIN 50138800 RIO YAGUEZ NEAR MAYAGUEZ, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°12'31", long 67°07'07", at steel-truss bridge on unnumbered paved road about 800 ft (244 m) south of Highway 106, 1.8 mi (2.9 km) west of Highways 106 and 352 junction, and 1.4 mi (2.3 km) east-northeast from Mayaguez plaza. DRAINAGE AREA.--6.7 sq mi (17.3 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS.". CENT (HIGH UM-MF (COLS. TIME TANEOUS JUICE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 4... 0745 9.3 318 8.0 22.0 2.5 7.9 92 19 20000 3300 JAN , 1983 13... 1445 6.0 311 8.3 23.5 <1.0 9.6 114 3500 520 MAR 30... 1510 1.1 305 8.2 26.5 <1.0 10.2 127 <10 K130 750 MAY 5... 0710 1.4 298 7.6 24.0 <1.0 7.4 88 16 530 10000 AUG 18... 1430 9.3 268 8.0 27.0 18 7.1 89 11 2300 5200 HARD- NESS (MG/L AS DATE CAC03) HARD- NESS, NONCAR- BONATE (MG/L CAC03) CALCIUM DIS- SOLVED (MG/L AS CA) MAGNE- SIUM' DIS- SOLVED (MG/L AS MG) SODIUM, DIS- SOLVED (MG/L AS NA) SODIUM POTAS- ALMA- CHLO- FLUO- AD- SIUM, LINITY SULFATE RIDE, RIDE, SORP- DIS- FIELD DIS- DIS- DIS- TION SOLVED (MG/L SOLVED SOLVED SOLVED RATIO (MG/L AS (MG/L (MG/L (MG/L AS K) CAC03) AS SO4) AS CL) AS - F) NOV , 1982 4... 140 JAN , 1983 13... 130 0 35 10 12 .5 2.4 140 9.0 9.7 .10 MAR 30... 140 MAY 5... 140 0 37 11 15 .6 2.4 140 11 11 .10 AUG 18... 110 0 30 8.7 9.4 .4 1.9 111 8.2 7.8 <.10 SOLIDS. SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- GENeAM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Co NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL- TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) CMG/L) AS N) AS N) AS N) AS N) AS N) AS N) NOV , 1982 4... 6 <.010 .80 <.010 .40 1.2 JAN , 1983 13... 31 193 3.1 10 <.010 .70 .010 <.10 MAR 30... <1 <.010 .10 .010 .09 .10 .20 MAY 5... 27 198 .77 <1 <.010 .30 <.010 <.10 AUG 18... 27 160 4.0 12 <.010 .60 <.010 .10 .70 CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER. NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, CHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV". RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERA3LE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 3A) AS CD) AS CR) AS PB) AS HG) AS SE) AS ...,G) NOV , 1982 4... 5.3 .050 JAN , 1983 13... .570 1 200 1 8 2 <.1 <1 <1 MAR 30... .89 .030 MAY 5... .030 AUG 18... 3.1 .010 1 100 <1 6 5 <.1 <1 <1 K = non-ideal count 179 RIO GRANDE DE ARASCO BASIN 50141000 RIO BLANCO NEAR ADJUNTAS, PR LOCATION.--Lat 18°12'19", long 66°48'01", Hydrologic Unit 21010003, on right bank near dirt road off Highway 129, 0.4 mi (0.6 km) north- northwest of Highways 129 and 135 junction, 2.5 mi (4 km) northeast of Castailer, 2.3 mi (3.7 km) east-southeast of Lago Guayo Dam, and 0.5 mi (0.8 km) upstream from Rio Limani. DRAINAGE AREA.--15.4 sq mi (40.1 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1946 to December 1966 in reports of the Puerto Rico Water Resources Authority as "Rio Yahuecas near Adjuntas"; June 1980 to current year. GAGE.--Water-stage recorder. Altitude of gage is about 1,530 ft (466 m) from USGS topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--23 years (1947-66, 81-83), 37.4 cu ft/s (1.059 cu m/s), 32.98 in/yr (838 mm/yr), 27,100 acre-ft/yr (33.4 cu hm/yr); median of yearly mean discharges, 37 cu ft/s (1.05 cu m/s), 26,800 acre-ft/yr (33 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 17,000 cu ft/s (481 cu m/s) Oct. 13, 1954, gage height unknown, minimum, 5.6 cu ft/s (0.158 cu m/s) Mar. 24, 1983. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,700 cu ft/s (48.1 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Oct. 14 1745 2,000 56.6 10.52 3.206 Apr. 21 0245 *5,350 152 13.37 4.075 Oct. 18 1945 5,010 142 13.13 4.002 Minimum discharge, 5.6 cu ft/s (0.158 cu m/s) Mar. 24. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 31 25 20 19 19 23 22 22 21 20 29 26 24 24 23 13 18 17 17 18 11 8.7 6.8 11 8.3 6.7 11 8.3 6.6 11 8.4 6.2 11 8.4 6.8 16 15 15 16 15 16 15 16 15 14 13 12 12 14 20 8.9 9.0 14 30 12 11 11 11 9.9 10 6 7 8 9 10 19 96 29 21 19 21 23 21 20 20 21 21 21 20 21 17 17 16 16 16 11 8.4 9.8 11 8.2 7.4 10 8.6 6.8 10 8.4 6.8 10 8.5 6.7 15 14 14 14 22 13 51 21 16 15 15 12 12 15 13 9.1 8.1 16 16 21 29 20 15 39 21 11 12 13 14 15 19 18 30 179 55 23 61 46 25 24 21 19 19 19 25 15 15 15 15 16 9.9 7.9 6.7 9.6 64 6.9 9.5 20 7.4 9.5 12 15 9.6 10 20 16 21 39 26 21 15 14 13 13 13 1,4 12 11 10 10 13 11 11 12 14 45 24 17 14 14 16 17 18 19 20 30 26 348 112 65 45 107 53 55 39 22 19 19 24 37 15 14 14 14 14 9.3 8.7 12 9.6 3.1 9.1 9.4 8.1 22 9.1 7.9 13 9.4 7.7 48 16 15 71 33 21 18 38 64 25 19 12 19 14 11 10 9.9 46 24 13 41 13 45 50 34 18 21 22 23 24 25 45 38 30 26 25 34 36 31 48 30 24 21 19 19 19 14 13 13 13 12 11 7.5 576 9.9 7.2 34 9.4 7.2 23 9.1 7.3 20 9.0 7.3 18 43 57 35 41 54 17 16 14 14 13 9.9 9.6 9.8 10 8.8 37 25 16 14 31 16 35 55 55 28 26 27 28 29 30 31 24 25 26 27 30 24 31 40 31 27 39 --- 25 25 20 23 20 19 12 12 12 12 12 11 9.1 7.5 16 9.1 7.4 16 9.0 7.6 15 --- 7.2 29 7.2 18 7.0 --- 42 26 22 20 19 17 13 13 13 12 12 --- 8.5 8.5 8.5 9.0 11 9.5 18 14 13 12 11 11 20 21 20 32 20 --- TOTAL MEAN MAX MIN CFSM IN. AC-FT 1500 48.4 348 18 3.14 3.62 2980 1043 34.8 107 20 2.26 2.52 2070 688 22.2 37 19 1.44 1.66 1360 453 14.6 18 11 .95 1.09 899 277.5 319.0 995.7 9.91 10.3 33.2 11 64 576 9.0 7.0 6.2 .64 .67 2.16 .67 .77 2.41 550 633 1970 316 26.3 71 14 1.71 1.97 1620 561 18.7 64 12 1.21 1.36 1110 364.1 11.7 20 8.5 .76 .88 722 541.0 17.5 46 8.1 1.14 1.31 1070 752.9 25.1 55 9.9 1.63 1.82 1490 CAL YR 1982 WTR YR 1983 TOTAL TOTAL 11759.2 8311.2 MEAN 32.2 MEAN 22.3 MAX MAX 1110 MIN 9.2 CFSM 2.09 576 MIN 6.2 CFSM 1.48 IN IN 28.40 20.08 AC-FT AC-FT 23320 16490 WATER-QUALITY RECORDS PERIOD OF RECORD.--MARCH 1946 TO DECEMBER 1966 IN REPORTS OF THE PUERTO RICO WATER RESOURCES AUTHORITY AS "RIO YAHUECAS NEAR ADJUNTAS"; JUNE 1980 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW. SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TORE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 04 0855 19 239 22.0 APR, 13 0850 7.2 269 19.0 NOV, 09 1030 20 254 22.0 MAY. 11 0945 16 232 19.0 DEC. 20 1255 38 180 20.0 JUN. 08 1100 21 207 25.0 JAN. 11 0945 15 232 19.0 SEP, 06 1105 10 262 26.5 MAR. 16 1032 9.0 257 22.5 180 RIO GRANDE DE ARASCO BASIN 50141100 LAGO YAHUECAS NEAR CASTARER, PR LOCATION.--Lat 18°13'20", long 66°49'15", Hydrologic Unit 21010003, at Yahuecas Dam on Rio Blanco, 1.1 mi (1.8 km) northeast of Lago Guayo, 2.8 mi (4.5 km) northeast of Castaiier, 3.8 mi (6.1 km) northeast of Lago Prieto, and about 4 mi (6 km) northwest of Adjuntas. DRAINAGE AREA.--17.4 sq mi (45.1 sq km). ELEVATION RECORDS PERIOD OF RECORD.--April 1980 to current year. GAGE.--Water-stage recorder. Datum of gage is 1,400.00 ft (426.720 m) above mean sea level. REMARKS.--Lago Yahuecas was completed in 1956. The dam is a unit of the southwestern Puerto Rico project and provides a maximum storage of 1,800 ac-ft (2.22 cu hm) for power and irrigation. The dam is a concrete gravity structure with a total length of 450 ft (137.2 m), a maximum structural height of 90 ft (27.4 m), and a maximum base width of 60 ft (18.3 m). The spillway is an ungated overflow type with a crest elevation of 71.00 ft (21.641 m) and a crest length of 200 ft (61.0 m); It was designed to pass a maximum flood of 38,000 cu ft/s (1,076 cu m/s) at a reservoir elevation of 84.00 ft (25.603 m). Timber flashboards, originally installed on the spillway crest, were subsequently removed and their use discontinued. Diversions are conveyed to Lago Guayo by an 11 ft (3.4 m) diameter, 6,470 ft (1,972 m) long tunnel, mostly unlined. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 76.61 ft (23.351 m) Sept. 13, 1982; minimum, 48.42 ft (14.758 m) Feb. 4, 1981. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 73.79 ft (22.491 m) Apr. 21; minimum, 51.36 ft (15.654 m) June 28. Capacity table (elevation, in feet, and contents, in acre-feet) (based on data from Puerto Rico Water Resources Authority) 30 0 65 1,000 49 393 71 1,308 60 778 75 1,540 ELEVATION (FEET NGV0), WATER YEAR OCTOBER 1932 TO SEPTEMBER 1983 INSTANTANEOUS OBSERVATIONS AT 2400 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 71.27 71.14 71.10 71.23 70.50 68.12 68.92 70.86 70.68 52.83 51.80 A 2 71.17 71.10 71.10 71.21 70.50 68.04 63.72 70.62 70.34 52.39 51.90 3 71.12 71.06 71.11 71.23 70.50 67.92 68.49 70.35 70.29 52.54 55.52 4 71.09 71.03 71.12 71.23 70.01 67.78 68.27 70.45 69.90 52.82 55.48 5 71.06 71.01 71.13 71.28 70.09 67.63 68.02 70.33 69.45 53.56 53.26 A 6 71.10 71.00 71.13 71.36 70.01 67.60 67.94 70.23 69.01 53.61 53.37 56.14 7 71.33 71.02 71.14 71.18 69.77 67.43 67.74 70.01 70.45 52.61 53.38 53.60 3 71.13 71.00 71.15 71.20 69.66 67.40 67.53 69.74 70.32 52.50 54.75 53.68 9 71.14 71.07 71.16 71.13 69.56 67.32 67.31 69.54 69.98 54.11 52.88 53.60 10 71.12 71.01 71.20 71.25 69.42 A 67.18 70.58 69.29 53.67 56.74 58.79 11 71.12 71.06 71.21 70.90 69.27 67.98 70.72 68.24 53.07 53:15 54.52 12 71.11 71.58 71.16 71.04 69.12 66.81 71.13 67.27 53.23 53.00 54.60 13 71.29 71.10 71.05 71.01 69.01 66.72 71.26 61.26 52.78 53.19 54.38 14 71.47 71.03 71.20 71.03 68.89 66.69 71.22 58.55 52.78 54.69 54.17 15 71.20 71.03 71.28 71.10 68.79 66.69 71.14 57.31 52.78 53.21 54.22 16 71.24 71.34 71.19 71.10 68.68 70.45 67.44 71.01 55.23 53.10 52.96 55.50 17 71.24 71.39 71.16 70.98 68.60 70.50 67.18 70.93 55.44 54.22 56.94 60.80 18 71.39 71.18 71.18 70.97 68.49 70.51 67.57 71.37 55.54 53.17 54.38 19 71.43 71.24 71.31 70.92 63.41 70.57 67.64 71.19 55.60 53.35 54.22 20 71.38 71.16 71.37 70.92 68.12 70.58 69.54 71.13 55.48 53.51 54.35 21 71.31 71.07 71.31 70.78 68.25 70.58 71.37 71.45 55.01 52.84 54.30 22 71.31 71.13 71.33 70.70 68.23 70.49 71.23 71.36 54.64 52.50 61.06 23 71.29 71.03 71.31 70.84 68.21 70.40 71.17 71.22 54.32 52.24 56.72 24 71.27 71.17 71.30 70.69 63.20 70.25 71.12 71.29 53.75 52.24 54.25 25 71.26 71.12 71.34 70.82 68.24 70.10 71.01 71.49 51.69 52.36 54.09 26 71.34 71.19 71.35 70.87 63.20 69.96 70.34 71.23 51.87 51.87 54.01 27 71.24 71.17 71.21 70.86 68.25 69.82 70.62 71.13 51.62 51.93 54.02 28 71.18 71.13 71.23 70.83 68.18 69.65 70.41 71.13 51.74 52.20 54.03 29 71.37 71.11 71.40 70.71 --- 69.47 71.07 71.14 51.81 51.79 54.23 30 71.18 71.19 71.33 70.71 69.27 71.08 71.13 51.88 52.14 54.16 31 71.17 --- 71.29 70.66 69.09 --- 70.96 --- 52.17 TOTAL 2208.82 2133.85 2207.85 2200.84 1933.16 2064.30 2197.39 1817.96 1636.91 MEAN 71.25 71.13 71.22 70.99 69.04 68.81 70.88 60.60 52.80 MAX 71.69 71.58 71.40 71.36 70.50 71.37 71.49 70.68 54.22 MIN 71.06 71.00 71.05 70.66 68.12 66.69 69.54 51.62 51.79 A No gage-height record. 181 RIO GRANDE DE ARASCO BASIN 50141500 LAGO GUAYO NEAR CASTARER, PR LOCATION.--Lat 18°12'46", long 66°50'06", Hydrologic Unit 21010003, at Guayo Dam on Rio 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 Castafier, and 6.0 mi (9.6 km) west of Adjuntas. DRAINAGE AREA.--9.60 sq mi (24.9 sq km). ELEVATION RECORDS PERIOD OF RECORD.--April 1980 to current year. GAGE.--Water-stage recorder. Datum of gage is 1,400.00 ft (426.720 m) above mean sea level. REMARKS.--Lago Guayo was completed in 1956. The dam is on Rio Guayo and is the largest in the southwestern Puerto Rico project. The maximum storage is 17,400 ac-ft (21.5 cu hm) for power and irrigation. The dam is a concrete gravity structure with a total length of 555 ft (169.2 m), a maximum structural height of 190 ft (57.9 m), and a maximum width at the base of 145 ft (44.2 m). The ungated overflow spillway with a crest elevation of 60.00 ft (18.288 m) and a crest length of 220 ft (67.1 m) was designed to pass a maximum flood of 30,200 cu ft/s (855 cu m/s) at a reservoir elevation of 70.00 ft (21.336 ft). Timber flashboards that were added to increase storage capacity were subsequently removed and their use discontinued. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 62.43 ft (19.029 m) May 27, 1980; minimum, 35.13 ft (10.708 m) Jan. 20, 1981. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 61.04 ft (18.605 m) Apr. 21; minimum, 45.95 ft (14.001 m) Nov. 5. Capacity table (elevation, in feet, and contents, in acre-feet) (based on data from Puerto Rico Water Resources Authority) 30 6,530 60 13,550 49 10,660 65 15,000 ELEVATION (FEET NGVO), WATER YEAR OCTOBER 1982 TO SEPTEMBER INSTANTANEOUS OBSERVATIONS AT 2400 1983 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 53.92 41.22 53.67 59.32 60.07 60.01 59.50 60.08 59.74 51.59 51.57 51.27 2 59.22 47.12 53.37 59.46 60.06 59.91 59.35 60.07 59.43 51.82 51.17 51.02 3 4 59.46 59.70 46.46 46.26 54.07 54.25 59.62 59.73 60.07 60.09 59.77 59.62 59.20 59.16 60.07 60.10 59.27 59.57 52.04 52.35 51.65 52.28 51.20 51.01 5 59.93 46.04 54.44 59.93 60.07 59.51 59.26 60.08 59.82 52.75 52.49 51.17 6 60.11 46.43 54.63 60.05 60.08 59.33 59.37 60.13 59.99 53.02 52.64 50.90 7 8 9 10 60.23 60.22 60.20 60.18 46.77 47.12 46.89 46.60 54.80 54.98 55.15 55.32 60.06 60.09 60.08 60.05 60.08 60.07 60.08 60.08 59.22 59.10 58.94 58.78 59.46 59.55 59.63 59.71 60.09 60.09 60.C7 60.20 59.85 59.82 59.43 58.38 52.10 52.31 52.56 52.80 52.78 52.21 52.00 52.29 50.39 49.70 49.53 51.21 11 60.16 46.83 55.48 60.03 60.06 58.65 59.81 59.93 59.15 53.05 52.69 52.03 12 13 14 15 60.17 60.28 60.47 60.20 47.81 49.47 48.87 48.56 55.66 55.84 56.01 56.23 60.03 60.08 60.10 60.09 60.07 60.07 60.07 60.08 58.77 58.67 58.54 58.47 59.88 59.99 60.05 60.12 59.70 59.63 60.04 60.13 59.40 59.31 58.58 57.31 53.26 52.66 52.79 52.52 52.53 52.73 53.01 52.14 52.33 51.94 50.58 49.49 16 17 18 19 20 60.14 60.13 60.35 60.30 60.17 49.37 49.26 49.44 49.98 50.65 56.41 56.59 56.74 56.99 57.22 60.09 60.03 60.08 60.10 60.09 60.08 60.08 60.09 60.11 60.09 58.54 53.60 58.69 58.76 58.83 60.08 60.08 60.09 60.08 60.37 60.08 60.05 60.30 60.64 59.41 55.20 54.16 55.11 55.49 55.38 52.76 53.14 53.13 53.32 53.49 51.62 52.27 52.99 52.32 52.98 48.73 48.62 48.35 47.62 47.04 21 22 23 24 25 60.16 59.61 53.64 57.65 56.11 51.19 51.57 51.79 52.06 52.31 57.37 57.54 57.72 57.88 58.05 60.09 60.08 60.09 60.07 60.08 60.08 60.08 60.08 60.07 60.07 58.91 58.99 59.07 59.16 59.23 60.20 60.10 60.10 60.08 60.07 60.49 60.27 60.16 59.23 59.80 55.04 54.63 54.30 53.58 51.39 52.76 52.03 52.27 52.44 52.59 53.69 53.17 52.69 52.09 52.53 47.00 48.07 48.99 49.58 49.77 26 27 54.28 53.56 52.53 52.77 58.32 58.50 60.07 60.07 60.07 60.06 59.30 59.40 60.07 60.07 59.83 59.48 51.53 51.50 52.07 52.22 51.42 51.67 49.55 48.97 28 52.47 53.00 58.66 60.06 60.05 59.48 60.07 58.81 51.53 52.36 51.91 47.90 29 30 31 51.27 50.22 49.25 53.21 53.46 --- 58.34 59.00 59.17 60.07 60.07 60.07 --- 59. 9659 59.66 60.08 60.07 --- 59.70 59.77 59.97 51.41 51.35 --- 51.86 52.09 52.11 52.11 51.75 51.22 48.04 47.43 --- TOTAL MEAN MAX MIN 1804.29 58.20 60.88 49.25 1481.09 49.37 53.46 46.04 1749.40 56.43 59.17 53.67 1860.16 60.01 60.10 59.32 1682.11 60.08 60.11 60.05 1833.22 59.14 60.01 58.47 1795.65 59.86 60.37 59.16 1858.40 59.95 60.64 58.81 1691.15 56.37 59.99 51.35 1628.31 52.53 53.49 51.59 1620.61 52.28 53.69 51.17 1489.43 49.65 52.33 47.00 CAL YR 1982 TOTAL 19010.20 MEAN 52.08 MAX 60.83 MIN 35.65 WTR YR 1983 TOTAL 20493.82 MEAN 56.15 MAX 60.83 MIN 46.04 182 RIO GRANDE DE MASCO BASIN 50142500 LAGO PRIETO NEAR CASTARER, PR LOCATION.--Lat 18°11'08", long 66°51'48", Hydrologic Unit 21010004, at dam on Rio Prieto, 2.0 mi (3.2 km) west of Castaner, 3.1 mi (5.0 km) southwest of Lago Guayo, 3.8 mi (6.1 km) southwest of Lago Yahuecas, and about 9 mi (14 km) west of Adjuntas. DRAINAGE AREA.--9.60 sq mi (24.9 sq km). ELEVATION RECORDS PERIOD OF RECORD.--May 1980 to current year. GAGE.--Water-stage recorder. Datum of gage is 1,400.00 ft (476.720 m) above mean sea level. REMARKS.--Lago Prieto was completed in 1955. It provides a maximum storage of approximately 700 ac-ft (0.863 cu hm) for power and irrigation. A power tunnel adit from the reservoir to the Lago Guayo tunnel allows for releases to Power Plant No. 1. Turbine releases are collected in Lago Antonio Lucchetti and are reused for power generation at Power Plant No. 2. The dam is a concrete gravity structure with a total length of 260 ft (79.2 m), a maximum structural height of 98 ft (29.9 m), and a maximum base width of 65 ft (19.8 m). The ungated overflow spillway, with a crest elevation of 85.00 ft (25.908 m), and a crest length of 170 ft (51.8 m) was designed to pass a maximum flood of 32,000 cu ft/s (906 cu m/s). Timber flashboards that were added after initial construction were subsequently removed, and their use discontinued. EXTREMES OBSERVED FOR PERIOD OF RECORD.--Maximum elevation, 87.49 ft (26.667 m) Sept. 13, 1982; minimum, less than 55.05 ft (16.779 m) many days. EXTREMES OBSERVED FOR CURRENT YEAR.--Maximum elevation, 83.10 ft (25.329 m) May 19; minimum, less than 52.60 ft (16.032 m) most days. Capacity table (elevation, in feet, and contents, in acre-feet) (based on data from Puerto Rico Water Resources Authority) 49 0 85 484 60 97 90 586 65 156 ELEVATION (FEET NGVD). WATER YEAR OCTO3ER 1982 TO SEPTEM3ER 1983 INSTANTANEOUS 03SERVATIONS AT 2400 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 59.38 62.96 C 2 59.36 60.99 3 59.60 62.26 4 59.78 60.75 5 59.95 60.63 6 60.03 60.28 53.58 7 60.20 60.10 53.66 8 60.18 59.86 53.23 9 10 60.22 60.15 59.43 59.04 52.64 C 57.54 11 60.18 60.27 59.10 54.00 54.20 12 13 60.22 60.52 65.62 69.28 59.55 59.46 53.96 53.87 54.16 53.01 14 15 60.94 60.14 71.78 71.92 57.69 54.29 52.96 16 60.15 55.17 71.85 52.61 17 18 19 60.16 71.09 60.35 69.53 68.77 79.89 60.05 54.04 52.75 20 60.11 63.91 55.38 21 22 23 24 25 60.14 57.32 56.92 55.88 A 74.79 66.88 66.33 64.98 66.54 53.58 54.87 53.96 54.08 52.62 52.61 62.12 53.71 54.05 52.98 26 65.64 52.70 52.62 27 28 29 30 B 62.10 62.42 63.55 63.00 52.61 52.61 52.61 52.61 52.61 31 63.32 C C TOTAL MEAN MAX MIN A No gage-height record. 8 Stage below elevation 55.05 ft. C Stage below elevation 52.60 ft. AS N) AS N) AS N) AS N) AS N) 1.6 .050 1.3 1.30 2.9 .50 .030 <.10 .40 .020 .18 .20 .60 .60 .050 .25 .30 .90 .60 .020 .48 .50 1.1 DATE SI02) (MG/L) DAT) (MG/L) AS N) AS N) NOV r 1982 10... JAN , 1983 31... MAR 23... MAY 11... AUG 24... 85 26 170 20.2 1 6 21 145 33.6 24 30 205 12.2 8 1.6 .040 <.010 .39 .010 .58 .020 .58 .020 AS NO3) AS 1982 13 1983 P) .090 AS AS) AS BA) .040 1 100 2.7 .030 4.0 .070 4.9 .040 2 100 AS CD) AS CR) AS P3) AS HG) AS SE) AS AG) 3 3 .3 <1 <1 <1 4 <.1 <1 <1 DATE NOV , 10... JAN , 31... MAR 23... MAY 11... AUG 24... 183 RIO GRANDE DE A1ASCO BASIN 50143000 RIO GRANDE DE A1ASCO NEAR LARES, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°15'26", long 66°55'00", at bridge on Highway 124, 0.7 mi (1.1 km) downstream from confluence of Rio Blanco and Rio Prieto, and 3.7 mi (6.0 km) southwest of Lares plaza. DRAINAGE AREA.--26.3 sq mi (68.1 sq km) this does not include 36.2 sq mi (93.8 sq km) which contributes only during high floods, and 3.5 sq mi (9.1 sq km) 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 1982 TO SEPTEMBER 1983 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL. FLOW, CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMMOS) UNITS) (DEC C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 10... JAN , 31... MAR 23... MAY 11... AUG 24... 85 2.3 1.1 30 4.5 1982 0845 63 223 7.8 22.0 1983 1720 44 282 7.9 24.0 0835 16 320 8.1 24.5 1520 86 232 8.2 29.0 0915 22 298 6.3 26.0 7.9 92 26 22000 K15000 8.2 99 16 K44 K88 8.6 105 18 K94 580 7.1 94 14 3300 2900 12.3 154 78 220 230 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- OIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) NOV • 1932 10... JAN • 1983 31... 120 10 32 9.8 12 .5 MAR 23... MAY 11... 96 3 26 7.5 9.4 .4 AUG 24... 120 0 34 9.4 13 .5 77 1.7 110 13 9.4 <.10 130 2.5 93 13 9.4 <.10 1.5 140 23 9.8 <.10 SOLIDS, SOLIDS. NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO-_ NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- DIS- AT 105 GEN, GEN, GEN. GEN, GEN, MONIA + NITRO- SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L CHRO- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM, RECOV- TOTAL TOTAL TOTAL ERABLE ERABLE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L K . non-ideal count 184 RIO GRANDE DE ARASCO BASIN 50144000 RIO GRANDE DE A8ASCO NEAR SAN SEBASTIAN, PR LOCATION.--Lat 18°17'05", long 67°03'05", Hydrologic Unit 21010003, on left bank, 200 ft (61 m) downstream from bridge on Highway 108, 0.4 mi (0.6 km) downstream from Quebrada La Zumbadora, 4.4 mi (7.1 km) northwest of Las Marias, 5.4 mi (8.7 km) southwest of San Sebastign. DRAINAGE AREA.--94.3 sq mi (244.2 sq km), does not include 36.2 sq mi (93.8 sq km) which contributes only during high floods, and 3.5 sq mi (9.1 sq km) which contributes only part of its storm runoff. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--March 1963 to current year. GAGE.--Water-stage recorder. Datum of gage is 103.72 ft (31.614 m) above mean sea level (Puerto Rico Department of Public Works bench mark). Previous to Oct. 30, 1975, a site 600 ft (180 m) upstream at same datum. REMARKS.--Records fair. Transbasin diversion (except during floods) to Rio Yauco basin for hydroelectric power and irrigation above Lago Guayo, Yahuecas, and Prieto, combined usable storage 17,300 acre-ft (21.3 cu hm). Limited storm runoff is contributed to basin by 3.5 sq mi (9.1 sq km) above Rio Toro Diversion dam. AVERAGE DISCHARGE.--20 years (1964-83), 304 cu ft/s (8.609 cu m/s), 43.78 in/yr (1,112 mm/yr), 220,200 acre-ft/yr (272 cu hm/yr); median of yearly mean discharges, 301 cu ft/s (8.52 cu m/s), 218,000 acre-ft/yr (269 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 140,000 cu ft/s (3,965 cu m/s) Sept. 16, 1975, gage height, 33.9 ft (10.33 m), from rating curve extended above 4,000 cu ft/s (113 cu m/s) on basis of slope-area measurement; minimum, 31 cu ft/s (0.878 cu m/s) Apr. 19-20, 1965, gage height, 0.88 ft (0.268 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 6,000 cu ft/s (170 cu m/s) and maximum (*): Discharge Gage height Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Date Time (cu ft/s) (cu m/s) (ft) (m) Nov. 18 1715 6,340 180 7.46 2.274 May 18 0830 6,710 190 7.67 2.338 Apr. 21 0815 *8,000 227 8.36 2.548 Minimum discharge, 53 cu ft/s (1.501 cu m/s) Apr. 4, 9-11. DISCHARGE. IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1982 TC SEPTEMBER 1983 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 292 191 322 167 114 85 56 108 219 162 98 124 2 302 182 258 159 114 83 56 98 236 182 88 110 3 258 175 243 151 113 75 56 96 865 106 82 107 4 216 167 237 150 111 73 54 138 668 102 147 102 5 283 162 228 150 116 71 56 265 390 194 111 93 6 326 168 220 146 116 83 58 143 272 128 97 95 7 325 190 214 151 114 75 57 477 236 100 81 168 3 387 172 210 160 111 72 55 300 243 91 127 112 9 306 447 206 157 108 72 54 172 204 86 190 333 10 269 692 203 154 105 70 53 131 265 179 121 169 11 230 277 203 149 105 69 56 232 192 297 234 389 12 218 243 198 147 100 100 58 148 178 191 201 193 13 210 348 192 145 100 199 58 183 155 109 220 131 14 278 204 190 143 100 104 62 251 143 92 579 107 15 726 356 192 157 102 85 102 209 136 83 355 107 16 358 985 204 164 102 73 206 170 128 125 196 102 17 304 1570 185 163 102 73 115 248 121 350 422 380 18 315 1800 175 164 103 70 100 1530 131 202 374 432 19 1760 776 194 153 100 69 106 877 118 132 179 274 20 634 539 299 146 103 63 117 802 112 105 141 143 21 395 428 262 136 115 67 2620 1260 110 92 211 122 22 323 383 179 134 102 63 311 1600 104 87 202 289 23 242 365 168 132 96 63 153 723 98 127 140 472 24 215 556 164 132 96 64 129 594 96 109 166 482 25 206 581 157 127 97 64 108 624 92 90 127 228 26 198 348 162 123 92 64 93 668 93 87 223 161 27 203 325 174 123 91 62 36 359 108 82 226 172 28 212 319 167 113 89 59 31 255 95 82 190 159 29 223 282 233 115 --- 59 121 344 103 144 143 273 30 245 295 359 116 53 132 491 174 116 128 163 31 215 --- 202 119 57 --- 270 --- 98 126 --- TOTAL 10674 13526 6599 4461 2917 2359 5369 13771 6085 4130 5925 6192 MEAN 344 451 213 144 104 76.1 179 444 203 133 191 206 MAX 1760 1800 359 163 116 199 2620 1600 865 350 579 482 MIN 198 162 157 115 89 57 53 96 92 82 31 93 CFSM 3.65 4.78 2.26 1.53 1.10 .81 1.90 4.71 2.15 1.41. 2.03 2.19 IN. 4.21 5.34 2.60 1.76 1.15 .93 2.12 5.43 2.40 1.63 2.34 2.44 AC-FT 21170 26830 13090 8350 5790 4680 10650 27310 12070 8190 11750 12280 CAL YR 1982 TOTAL 107145 MEAN 294 MAX 6630 MIN 79 CFSM 3.12 IN 42.27 AC-FT 212500 WTR YR 1983 TOTAL 82008 MEAN 225 MAX 2620 MIN 53 CFSM 2.39 IN 32.35 AC-FT 162700 185 RIO GRANDE DE ASASCO BASIN 50144000 RIO GRANDE DE ARASCO NEAR SAN SEBASTIAN, PR--Continued (National stream-quality accounting network station) WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1963 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 TIME DATE OXYGEN. COLT- STREP- SPE- On- FORM, TOCOCCI HARD- STREAM- CIFIC SOLVED FECAL, FECAL. HARD- NESS. FLOW, CON- PH TUR- OXYGEN, (PER- 0.7 KF AGAR NESS NONCAR- INSTAN- DUCT- (STAND- TEMPER- SID- DIS- CENT UM-MF (COLS. (MG/L BONATE TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- (COLS./ PER AS (MG/L (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) 100 ML) 100 ML) CAC03) CAC03) OCT . 1982 07... 1225 280 156 7.8 25.0 100 8.1 99 11800 6400 74 0 FEB . 1983 01... 0900 112 249 7.5 22.0 2.6 8.9 102 K100 330 110 1 JUN 16... 1130 129 253 8.4 29.0 6.6 7.8 102 K190 82 100 4 AUG 03... 1340 83 237 8.0 30.5 12 8.1 109 210 84 100 1 SOLIDS. MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, RESIDUE CALCIUM srum, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, DIS- AT 180 DIS- DIS- DIS- SORP- ors- FIELD DIS- DIS- DIS- SOLVED DEG. C SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L OIS- (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS SOLVED DATE AS CA) AS MG) AS NA) AS K) CAC03) AS SO4) AS CL) AS F) SI02) (MG/L) OCT r 1932 07... 18 7.0 7.7 .4 1.1 30 10 6.1 (.10 23 130 FEB . 1983 01... 28 10 12 .5 1.3 110 10 7.5 <.10 30 155 JUN 16... 26 9.4 10 .4 1.8 100 10 7.6 .10 30 157 AUG 03... 25 9.2 9.7 .4 1.7 100 11 7.2 .10 29 152 SOLIDS, SUM OF CONSTI- TUENTS, DIS- SOLVED DATE (MG/L) SOLIDS, DIS- SOLVED (TONS PER DAY) NITRO- GEN. NO2+NO3 DIS- SOLVED (MG/L AS N) NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS N) NITRO- GEN, AMMONIA DIS- SOLVED (MG/L AS NH4) NITRO- GEN/AM- MONIA + ORGANIC TOTAL (MG/L AS N) PHOS- PHORUS, TOTAL (MG/L AS P) PHOS- PHORUS TOTAL (MG/L AS PO4) PHOS- PHORUS. DIS- SOLVED (MG/L AS P) PHOS- PHORUS, ORTHO. DIS- SOLVED (MG/L AS P) PHOS- PHATE. ORTHOr DIS- SOLVED (MG/L AS PO4) OCT r 1982 07... 121 98.3 .93 .030 .04 .70 .070 .21 .030 .030 .09 FEB . 1983 01... 165 46.9 .60 .030 .04 <.10 .060 .18 .030 .030 .09 JUN 16... 155 5f..7 .39 .030 .04 .40 .020 .06 .020 .020 .06 AUG 03... 153 34.1 .23 .050 .06 .30 .040 .12 .060 .030 .09 ALUM- BERYL- CHRO- INUM, DIS- ARSENIC DIS- BARIUM, DIS- LIUM. DIS- CADMIUM DIS- MIUM, DIS- COBALT. DIS- COPPER. DIS- IRON. DIS- LEAD, DIS- LITHIUM DIS- SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS AL) AS AS) AS 8A) AS BE) AS CD) AS CR) AS CO) AS Cu) AS FE) AS PB) AS LI) OCT r 1982 07... <10 1 44 <1 <1 <1 <3 3 17 <1 <4 FEB r 1933 01... 10 1 50 <1 <1 <1 <3 6 <3 3 <4 JUN 16... 30 1 52 1 1 1 3 <1 3 <1 4 AUG 03... 200 K = non-ideal 1 count 50 <1 <1 <1 <3 6 12 4 <4 RIO GRANDE DE ARASCO BASIN 50144000 RIO GRANDE DE ARASCO NEAR SAN SEBASTIAN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 SEDI- MANGA- MOLYB- SELE- STRON- YANA- MENT, NESE, MERCURY DENUM, NICKEL, NIUM, SILVER, T/UM, DIUM, ZINC, SEDI- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- MENT, CHARGE, SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SUS- SUS- (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L PENDED PENDED DATE AS MN) AS HG) AS MO) AS NI) AS SE) AS AG) AS SR) AS V) AS ZN) (MG/L) (T/DAY) OCT 1982 07... 8 <.1 <10 2 <1 <1 99 <6.0 <4 154 116 FEB , 1983 01... 15 .1 <10 3 <1 <1 150 <6.0 16 9 2.7 JUN 16... 19 <.1 10 2 <1 <1 140 6.0 67 23 8.0 AUG 03... 26 <.1 <10 3 <1 <1 130 <6.0 <3 5 1.1 186 STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) ,(DEG C) NOV, 05 1235 60 284 26.0 DEC, 21 1512 202 252 24.0 JAN, 04 1100 148 283 23.0 FEB, 01 0845 112 248 22.0 STREAM-FLOW, SPECIFIC CON- DATE TIME INSTANTANEOUS DUCTANCE (CFS) (UMHOS) MAR, 10 1610 69 245 APR, 11 1300 53 250 MAY, 04 1120 87 312 SEP, 01 1150 117 331 TEMPERA- TURE (DEG C) 28.0 27.0 27.0 28.0 DATE STREAM- FLOW, INSTAN- TIME TANEOUS (CS) SED. SUSP. SEDI- SIEVE MENT, DIAM. SUS- X FINER PENDED THAN CMG/L) .062 MM OCT , 1932 07... 1225 280 154 96 FEB , 1983 01... 0900 112 9 78 JUN 16... 1130 129 23 94 AUG 03... 1340 33 5 100 BED MAT. STREAM- SIEVE FLOW, DIAM. INSTAN- FINER TIME TANEOUS THAN DATE (CFS) .062 MM AUG , 1983 03... 0955 E32 2 E = estimate 187 RIO GRANDE DE ARASCO BASIN 50146000 RIO GRANDE DE AIASCO NEAR ARASCO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°16'00", long 67°08'05", at bridge on Highway 430, 0.2 mi (0.3 km) south of Highway 109 at a El Espino and 1.4 mi (2.3 km) east-southeast from Aiiasco plaza. DRAINAGE AREA.--139 sq mi (360 sq km) this does not include 39.7 sq mi (102.8 sq km), flow is diverted to south coast. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1982 TO SEPTEMBER 1983 OXYGEN. OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC FECAL. FECAL, FLOW. SOLVED CHEM- CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS-CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) NOV , 1982 05... 1250 217 255 8.0 27.0 15 9.0 115 <10 400 K30 JAN . 1933 14... 1310 300 258 7.8 24.0 20 8.7 105 200 K88 MAR 30... 0905 59 235 8.2 25.5 1.2 8.4 103 <10 K47 150 MAY 12... 1140 179 240 7.6 25.5 38 7.8 96 13 2200 K700 JUN 08... 1215 256 234 8.0 27.0 AUG 19... 1000 600 225 7.4 26.0 50 7.6 93 24 K1500 3600 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS. CALCIUM SIUM, SODIUM. AD- SIUM, LINITY SULFATE RIDE, RIDE. NESS NONCAR- DIS- DIS- DIS- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L 80NATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CACO3) AS SO4) AS CL) AS F) NOV I 1982 05... JAN • 1983 14... 100 MAR 30... MAY 12... 97 JUN 03... AUG 19... 90 100 0 26 9.4 9.7 .4 1.7 110 9.0 7.5