Water Resources Data Water Year 1984 Puerto Rico and the ntoLOGICAt s "4--isT ON, v4. U.S. Virgin Islands * SEP 2 5 1985 * a R By Russell E. Curtis, Sene'n Guzmdn-Rros, and Pedro L. Diaz Culebra, PR St. Thomas C b St. Johr Vieques, PR VIRGIN ISLANDS St Croix U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-84-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies , Water Resources Data Puerto Rico and the U.S. Virgin Islands Water Year 1984 By Russell E. Curtis, Senn Guzmdn-Rros, and Pedro L. D(az St. Thomas Culebra, PR C; e St. John Vieques, PR C= b VIRGIN ISLANDS St. Croix U.S. GEOLOGICAL SURVEY WATER-DATA REPORT PR-84-1 Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the U.S. Virgin Islands, and other agencies UNITED STATES DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information on the water resources investigation programs in Puerto Rico and the U.S. Virgin Islands write to: Chief, Caribbean District, Water Resources Division U.S. Geological Survey GPO Box 4424 San Juan, PR 00936 (Telephone: (809) 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, the U.S. Virgin Islands, and the other Trust Territories. These records of streamflow, ground-water levels, and quality of water provide the hydrologic information needed by state, local and Federal agencies, and the private sector for developing and managing our Nation's land and water resources. The report is the culmination of a concerted effort by dedicated personnel of the U.S. Geological Survey, Water Resources Division who collected, compiled, analyzed, verified, and organized the data, and who typed, edited, and 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 Gonzglez George Arroyo Felipe Herngndez Raul Calderiin Carlos Martinez Eloy ColOn-Dieppa Rafael Pena-Cortes Margarita ConcepciOn Luis Santiago-Rivera Rene Garcia Pedro Vgzquez Jose R. Gonzglez Carmen A. Garcia typed the text of the report. Jose Alicea-Ortiz 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 mnl 1. REPORT NO. 2. 3. Recipient's Accession No. REPORT DOCUMENTATION PAGE _ 4. Title and Subtitle 5. Report Date June 1985 Water Resources Data for Puerto Rico and the U.S. Virgin Islands, 6. 1984 7. Author(s) Russell E. Curtis, Senen Guzman-Rios, and Pedro Diaz 8. Performing Organization Rept. No. USGS-WDR-PR-84-1 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, 1983 to GPO Box 4424 Sept. 30, 1984 San Juan, Puerto Rico 00936 14. 15. Supplementary Notes Prepared in cooperation with the Commonwealth of Puerto Rico, the Government of the 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 1984 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 57 gaging stations; stage only records for four lakes; water quality for 63 streamflow or lagoon sites, 11 partial-record sites, and 17 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. Vigin Islands. 17. Document Analysis a. Descriptors *Surface water, *Water quality, *Ground water, Aquifers, Chemical analysis, Gaging stations, Hydrologic data, Sediments, Streamflow, Water analysis, Water levels, Lakes. b. Identifiers/Open-Ended Terms Puerto Rico, U.S. Virgin Islands, Sampling sites. c. COSATI Field/Group 18. Availability Statemen:. 19. Security Class (This Report) 21. No. of Pages NO RESTRICTION ON DISTRIBUTION UNCLASSIFIED 20. Security Class (This Page) 22. Price UNCLASSIFIED (See ANSI-239.18) OPTIONAL FORM 272 (4-77) See Instructions on Reverse (Formerly NTIS-35) Department of Commerce V CONTENTS Page Preface III Contents V Illustrations V Tables VI Introduction 1 Cooperation 1 Summary of hydrologic conditions 2 Definition of terms 9 Downstream order and station numbers 16 Numbering system for wells and miscellaneous sites 17 Special networks and programs 17 Explanation of stage and water-discharge records 18 Collection and computation of data 18 Accuracy of field data and computed results 21 Other data available 22 Explanation of water-quality records 22 Collection and examination of data 22 Water analysis 23 Water temperature 23 Sediment 24 Explanation of ground-water level records 24 Collection of the data 24 Surface- and quality-of-water records for Puerto Rico 27 Discharge at partial-record stations in Puerto Rico 267 Analyses of samples collected at water-quality partial-record stations in Puerto Rico 285 Ground-water records for Puerto Rico 297 Surface-water records for the U.S. Virgin Islands 337 Ground-Water records for the U.S. Virgin Islands 347 Index 369 ILLUSTRATIONS Figure 1. Graph showing comparison of 1984 water year monthly-mean discharges to long-term medians of monthly-mean discharges at selected stream-gaging stations 3 2. Graph showing ground-water levels at selected sites in Puerto Rico and the U.S. Virgin Islands during 1984 water year 5 3. Map showing location of maximum concentration of fecal coliform bacteria at sampled sites during water year 1984 6 4. Map showing location of maximum concentrations of fecal streptococci bacteria at sampled sites during water year 1984 7 5. System for numbering wells and miscellaneous sites (latitude and longitude) 17 VI ILLUSTRATIONS--Continued Page Figure 6. Map showing location of continuous surface-water stations in Puerto Rico 28 7. Map showing location of water-quality stations in Puerto Rico 29 8. Map showing location of low-flow partial-record stations in Eastern Puerto Rico 30 9. Map showing location of low-flow partial-record stations in Central and Western Puerto Rico 31 10. Map showing Rio Guajataca basin 33 11. Map showing Rio Camuy basin 43 12. Map showing Rio Grande de Arecibo basin 47 13. Map showing Rio Grande de Manati basin 69 14. Map showing Rio Cibuco basin 87 15. Map showing Rio de la Plata basin 101 16. Map showing Rio Hondo to Rio Puerto Nuevo basins 113 17. Map showing Rio Grande de Loiza basin 129 18. Map showing northeastern river basins--Rio Herrera to Rio Anton Ruiz basins 159 19. Map showing southeastern river basins--Rio Humacao to Rio Seco basins 185 20. Map showing south coast river basins--Rio Salinas to Rio Jacaguas basins 203 21. Map showing south coast river basins--Rio InabOn to Rio Loco basins 209 22. Map showing Rio Guanajibo basin 231 23. Map showing Rio Yagliez and Rio Grande de Aiiasco basins 243 24. Map showing Rio Culebrinas basin 259 25. Map showing location of ground-water stations 298 26. Map showing location of surface-water stations in the U.S. Virgin Islands 338 27. Map showing location of ground-water stations in the U.S. Virgin Islands 348 TABLES Table 1. Maximum concentrations of trace metals of NASQAN stations, water year 1984. (Concentrations in micrograms per liter (ug/L)) 8 2. Factors for conversion of chemical constituents in milligrams or micrograms per liter to milliequivalents per liter 12 3. Degrees Celsius (°C) to degrees Fahrenheit (°F) 23 1 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 INTRODUCTION Water resources data for the 1984 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 57 gaging stations; stage only records for four lakes; water quality for 63 streamflow or lagoon sites, 11 partial-record sites, and 17 wells; and water levels for 97 observa­ tion 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. Water-resources data for Puerto Rico for calendar years 1958-67 were released in a series of reports entitled "Water Records of Puerto Rico". Water- resources data for the U.S. Virgin Islands for the calendar years 1962-69 were released in a report entitled "Water Records of U.S. Virgin Islands." Included were records of streamflow, ground-water levels, and water-quality data for both surface and ground water. Beginning with the 1968 calendar year, surface-water records for Puerto Rico were released separately on an annual basis. Ground-water level records and water-quality data for surface and ground water were released in companion reports covering periods of several years. Data for the 1973-74 reports were published under separate covers. Water-resources data reports for 1975-76, 1977, 1978, 1979-80, 1981-82, and 1983 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-84-1." Water Data reports are for sale by the National Technical Information Service, U.S. Department of Commerce, Spring­ field, 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, 1984 Puerto Rico Rice Corporation Puerto Rico Administration for Agricultural Development Puerto Rico Land Administration Center for Energy and Environment Research, University of Puerto Rico Water Resources Research Institute, University of Puerto Rico Water Resources Research Institute, College of the Virgin Islands Department of Public Works of the U.S. Virgin Islands Funds were also provided by the Corps of Engineers, U.S. Army, for the collection of records at five gaging stations published in this report. Ground-water quality data at selected sites was collected with support from the U.S. Evironmental Protection Agency. SUMMARY OF HYDROLOGIC CONDITIONS Streamflow Streamflow in Puerto Rico during the 1984 water year was generally below normal. It increased considerably in October, but remained significantly below normal during the remainder of the water year throughout most of the island. The exception was in the west, where it was well above normal most of the time. The dry season experienced during the winter months became evident in reduced flows as recorded for the index stations (fig. 1). The unusually low stream- flow continued to decline through March. The drought that affected the island caused the lowest levels in at least 20 years establishing low flow records for various gaged sites. For the northern and eastern river basins, flows were about 50 percent of normal. This severe drought came to an end at mid May and streamflow returned to normal. By June, streamflow increased to two to three times normal in the west. At this time, the second highest monthly mean since records began in 1964 was recorded at the index station on Rio Grande de Afiasco. During August, streamflow declined islandwide to below normal. Deficiencies in runoff were the most significant on the north coast. This drought ended in September as streamflow increased dramatically. The most significant changes occurred in the north and west areas where at many gaging sites the maximum flows for the year were recorded. On the Rio Grande de Manati, located in the northern area, the average for September was the second highest recorded since records began in 1964. In the U.S. Virgin Islands, conditions were in general the same as in Puerto Rico. During the year most streams were dry or nearly so, particularly in St. Croix and St. John. 3 1000 RIO GRANDE DE ANASCO NEAR SAN SEBASTIAN (50144000) 500 •z 200 1964-83 0 Median • co cc / w 100 Current year LL' 50 0 op 40 o 30 83181 I 1 1 1 1 1 z 80, 1 ti11111111 RIO INABON AT REAL ABAJO (50112500) 50 I\ 20- 1965-83 Median / ' p 7 10- _Current year A • MONTHLY MEAN D ISCHARGE. 2000 RIO GRANDE DE MANATI AT HWY 2 NEAR MANATI (50038100) 1000 1961-83 Median 500- 74 a z O 7-, / s. , „1 cc 200- Current year -• a. I— LL 100-- ° 80- m D 83184 1 I I 11111 z 50 ui200 O CC C.)co 100 0 z 2 50 I— z 0 2 8318 14 iiit 1 1 itiii 3 JASONDJFMAMJJAS JASONDJFMAMJJAS Figure 1.--Comparison of 1984 water year monthly-mean discharges to long-term medians of monthly-mean discharges at selected stream-gaging stations. 4 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 Ground Water Ground-water levels along the north coast limestone aquifers of Puerto Rico remained nearly unchanged during the 1984 water year (October 1983 to September 1984). A slight declining trend was observed during the first half of the water year followed by a slow recovery during the last half of the year in response to seasonal rainfall patterns. These near equilibrium conditions are a typical response of the north coast aquifers to average rainfall conditions. Ground-water levels along the south coast alluvial aquifers followed a cyclic pattern associated with rainfall and ground-water withdrawals for public supply, industrial and irrigation uses. Above normal rainfall from October to November 1983 caused ground-water levels to increase. Scarce rainfall and increasing water demands for irrigation resulted in decreasing levels through the end of the 1984 water year. At the Alomar well a maximum decline of 7.5 feet in the ground-water levels was recorded (fig. 2). Ground-water levels in the U.S. Virgin Islands (St. Thomas, St. Croix and St. John) followed a pattern similar to the south coast aquifers of Puerto Rico (fig. 2). Early in November 1983, above normal rainfall resulted in an increase up to 8.0 feet in the ground-water levels. After this event, the ground-water levels declined significantly as rainfall was almost zero and ground-water withdrawals for public-water supply increased. In several areas of St. Thomas and St. Croix, a decline of 15 feet in the ground-water levels was recorded. Water-Quality The results of the surface-water quality sampling program during water year 1984 indicated the presence of fecal coliform bacterias in high concentrations and the presence of some organic compounds. Concentrations of fecal coliform, and fecal streptococci bacterias exceed 1 million colonies counts per one 6 hundred milliliters of raw water (10 col/100 ml) in many streams. Rio Hondo at Flood Channel near Catano (50047530), Quebrada Blasina near Carolina (50050300), Rio Caguitas near Caguas(50055250), Rio Bairoa near Caguas (50055400), Rio Chico at Central Providencia (50091800), and Rio Guayanilla at Central Rufina (50124700) are among them (fig. 3 and 4). These sites are located close to urban zones, industrial parks and surburban zones not served by sewage systems. Septic tanks, cesspools, leaks in sewage system, runoff from beef cattle feed lots, and percolation from waste ponds appear to be the main source of bacterias in streams throughout Puerto Rico. Drinking water standards recommend that the geometric mean of fecal coliform density in raw water for public supply should not exceed 2,000 colonies per 100 ml of water (EPA, 1975). The standard for contact and recreational purposes is 1,000 col/100 ml. 5 WATER LEVEL, INFEETBELOW LAND-SURFACE 282 I 1 - WELL 135, LEDERLE, PUERTO RICO 28 3 284 I 285 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 24 28 32 36 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 10 • 16 WELL 11, GUINEA GUT, ST. JOHN, U.S.V.I. II 22 OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 Figure 2.--Ground-water levels at selected sites in Puerto Rico and the U.S. Virgin Islands during 1984 water year. 0\ 67015' 67000' 45' 30' 15' 66°00' 45' •65°30'7 OCEAN() ATLANTIC0 0 \06.0 t‘o 4,ko e 906 ee qs9e I 8030'1- 01 e e‘ tt4 6A s Rio Cuiebrinas Rib Guayabo Rio Grander( Fajardo Rio Grande de Aitasco 16' Rio Vague to Daguao Quebrada Palma Rio Guanailbo 1 \ Rio Santiago Rio Blanco Rib Anto Ruiz Rio Humacao 'Rio Guayana's 18000 A - 1 , oc7x4; e 0 A e e AN-ov t . 14% FECAL COLIFORMS V 0 (5 to A,24 \ 1o 0,v * ,b . , ir ii. ,-, o C'• co e to ' o o 4,0 to Ck kko to ia. Jok o 4 --4, i,44) r • < 1000 • 1000-10,000 ...et' ; o kl•• r 10,000-100,000 to • 17°45' O 10 20 30 KILOMETERS II 100,000-1,000,000 O 10 20 MILES > 1,000,000 MAR CAR1BE Figure 3.--Location of maximum concentration of fecal coliform bacteria at sampled sites during water year 1984 in Puerto Rico. 11 670 e 30' 15' 66000' 45` $5°30' 18°30' 4-A cptG OCEANO ATLANTIC° tit'' o 4G 0% 0A 0 ,k'S• „c, ottk s o R, 0 0 ° .0 04. 1,000,000 Figure 4.--Location of maximum concentrations of fecal streptococci bacteria at sampled sites during water year 1984 in Puerto Rico. 8 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1983 A considerable increase in the concentration of key inorganic elements and/or compounds also is also an important index of the pollution of a body of water. Trace elements which are normally absent or nearly so in the natural environment are arsenic, cadmium, chromium, lead, mercury, selenium and silver. Water samples for analyses of those compounds were collected twice during the year at most of the monitoring sites. At the index National Stream Quality Accounting Network (NASQAN) stations, samples for analyses of trace metals were collected four times. Maximum concentrations of some of them are listed in table 1. TABLE 1 . Maximum concentrations of trace metals of NASQAN stations, Water Year 1984. (Concentrations in micrograms per liter( pg/L). Station number and name As Ba Cd Cr Pb Hg Se Ag 50038100 - Rio Grande de Manati at Hwy 2 near Manati 0.2 65 <1 <1 4 0.3 <1 2 50046000 - Rio de la Plata at Toa Alta .2 81 <1 <1 1 .6 <1 <1 50092000 - Rio Grande de Patillas on Patillas .1 24 <1 3 2 .2 <1 <1 50144000 - Rio Grande de Anasco near San Sebastign .2 49 <1 3 .1 <1 <1 Maximum permissible concentrations of these compounds in drinking water have been established by the Environmental Protection Agency (1976) as follows: Concentration Constituent Micrograms per liter (jig/L) Arsenic 50 Cadmium 10 Chromium 50 Lead 50 Mercury 2 Selenium 10 Silver 50 9 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 10 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 he 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. 11 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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: s n n. 7' i s a = _ E -IT log2 n i=1 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). 12 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 2. TABLE 2.--Factors for conversion of chemical constituents in milligrams per liter to milliequivalents per liter. Ion Multiply by Ion Multiply by Aluminum (AI+3) * 0.11119 Iodide (I-1) 0.00788 Ammonia as NH4+' .05544 Iron (Fe+3)* .05372 Barium (Ba+2) .01456 Lead (Pb+2)* .00965 Bicarbonate (HCO3-1) .01639 Lithium (L1+1)* .14411 Bromide (Br-1) .01251 Magnesium (Mg+2) .08226 Calcium (Ca+2) .04990 Manganese (Mn+2)* .03640 Carbonate (CO3-2) .03333 Nickel (Ni+2)* .0340G Chloride (Cl-1) .02821 Nitrate (NO3-1) .01613 Chromium (Cr+6 )* .11539 Nitrite (NO2-1) .02174 Cobalt (Co+2)* .03394 Phocphate (PO4-3) .03159 Copper (Cu+2)* .03148 Potassium (K+1) .02557 Cyanide (C/1-1)* .03844 Sodium (Na+1) .04350 Fluoride (F-1) .05264 Strontium (Sr+2)* .02283 Hydrogen (H+I) .99209 Sulfate (SO4-2) .02082 Hydroxide (OH-1) .05880 Zinc (Zn+2)* .03060 *Constituent reported in micrograms per liter; multiply by factor and divide results by 1,000. Organism is any living entity, such as an insect, phytoplankter, or zoo­ plankter. Organism count/area refers to the number of organisms collected and enumerated in a sample and adjusted to the number per area habitat, usually square 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 13 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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. 14 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 organocblorine 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. 15 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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. 16 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 Total load (tons) is the total quantity of any individual constituent, aE 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. 17 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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.5 , below). 66°53' 52' 51' 50' 49' 48' 66°47' 18°02 01' 134 132.4 X27 .74 COORDINATES FOR WELLS 27 (180150066474901), AND 74 (180110066473501). 131. COORDINATES FOR WELLS 132 (180133066503301), AND 134 (180120066503201). 18 0 00' 17°59 1.16 COORDINATES FOR WELL 131 (180058066502701) COORDINATES FOR WELL 16 (175922066495901). Figure 5.--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 18 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 19 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 20 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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. 21 WATER RSOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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. 22 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 tabl.,s 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. 23 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 on the Celcius scale. In addition, temperatures were taken during discharge measurements for water-discharge stations. Degrees Celsius can be converted to degrees Farenheit as shown in table 3. Large streams have a small daily 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 3.--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) 24 WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 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. WATER RESOURCES DATA FOR PUERTO RICO AND THE U.S. VIRGIN ISLANDS, 1984 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 or 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. 25 Surface and Quality-of-Water Records for Puerto Rico 67°1 67°00 45' 30' 66°00' 45' 65°30' OCEANO ATLANTIC° 6, 40 Nfo 0 $0 0 e c, ce 1/0 4 0 q ° '4) 4Z,db be z' 0 18°30' 0157 0114 3af° 4c 3a5 Rio Culebrina 112 os. 0284**027750 480 Rio Guayabo 1478 Rio Grande, 32 0870 I). • < 4 :1148( 666x)Rio Fajardo 0360 0818 1440 34 0 \, 0250 \ *071 Rio Grande 05!,40 0 '5\ ea 15' de Arlasco 0108) 14 1 '056 A0584 Rio Yaguez 14 6' 141 0 8 Rio Daguao 0558502 Quebrada Palma Rio Guanafibo 1 1360 1300 c„,1,428.4 0430A_LT0530504 051:_3, \ Rio Santiago I . l\- -2. Rio Blanco 16 05118 Rib Antall Ruiz •Rio Humacao 28 0' AS064, ;A128950 .7 Rio Guayana's :/\44.!9015 1800' 12 Ai121119 0 60 o 0csP Nc '0 4. 0,o „x4 00 14 EXPLANATION o4 3° 40 =1/0 4 41* ' .fe' 0 ik 1'10 % ) % (Z."' 4'4), SURFACE WATER STATIONS 0.0 0 An26 CONTINUOUS STREAMFLOW 4,‘ 17°45' O 10 20 30 KILOMETERS STATION r I O 10 20 MILES M1411 LAKE-ELEVATION STATION MAR CARIBE Figure 6.--Location of continuous surface-water stations in Puerto Rico. 67°15' 18030' Rio Culebrina Rio Guayabo Rio Grand Rk Grand'4' de Anasco 15' ft Rio Yagu Rio Guano/lb° 13 1800 1704 0 10 20 1- 0 10 67°00' 4 15' 66000' OCEANO ATLANTIC° t, o 0" Crt,S° IP b° ts 60 , ,% 0391 4,0 so.s 6, 00 600- e oct ‘ ,' 0o• so V z e 9 cp 6, ,N0 . 0 0395 4753 9...: p /170480 ' .i, 41. 9820 •4851 0470 00 *649 V-05 - IF" 31r0,59 \038320 ? 17',8 0 0358 „) t 0 t8 059 04414'- LTh 0588 044950 "54 0575 _, ...18525 0307 q *0478, 0430,,,,, 039954 ,f03-9 129,7 ' ‘ .1 ? it X ..., o o /P °. Ao to,„z,1,v A9 00 060 4,4 f• + OUALIT A 0 0 0 0 Clvso •s,3 0 S 0 10 b t 0 4.so 4§ 14, P CAP Oe V.0430 ' 4 ' p oto i% V 0820 30 KILOMETERS -V 0710 20 MILLS V-0910 MAR CARIBE Figure 7.--Location of water-quality stations in Puerto Rico. 4 65°30' cfr e , 0 eep Rib Fajardo Daguao Quebrada Palma Rio Santiago Rib Blanco Rib Anton Ruiz Rib Humacao Rio Guayan6 PLANATION Y-OF-WATER STATIONS BIOLOGICAL CHEMICAL SEDIMENT (DAILY) SEDIMENT (.BI-MONTHLY) 1 NO 0475.25 0475.04 18'15' 18-oce 66'00' 65°45' SAN JUAN 0496 0493.10 0485.10 15 0610 602 66 0638. 0 06 665 0690 0693.50 0 2 0.{5.40 Fajardo to Fajardo 0584 0570.15 0554.10 •553.1• 0566 a gua 0565.50 29 0527 0535 0775 0776 0735 eib 32 073 0511.40 0785.10 RIO Anton Ruiz Are HOMNIC10 0845 0857 0872 0650 0651 20 KILOMETERS 20 MILES A EXPLANATION SURFACE WATER STATIONS 0825 LOW-FLOW STATION /1159 CREST-STAGE GAGING STATION Figure 8.--Location of low-flow partial-record stations in Eastern Puerto Rico. 67°15' 67°00' 45' 30' 15' 6e.0o' 45' 65°30' OCEAN° ATLANTICO o siv i(4. A 6,4z'' 4Z 0 0 tr> i `.,0 0 C§ 4, 1 0 . 0 i? 6 N" e , 0 18°30' N q 0 ?° \)' (07 ko 4rk 4z, 41/4' Rio Culebrinas ,z,,p Rio Guayab Rio Grand Rio Fajardo R`to GrancMT IS de A fiasco Rio Yagu Rio Daguao Rio Guanailbo Quebrada Palma \ Rio Santiago R( Blanco Rib Anton Ruiz Rib Humacao Rto Guayands 18000'E a, 9,F 4irk, ‘0, \ tta 00 4$`# 4e4 sP 01? 0, .,??P• ,„ o -,5' 4, o 42, 00 N eq'Z' '° 4e '00 1% e 17°45' 0 10 20 30 KILOMETERS —H 0 10 20 MiLtS MAR CA RISE Figure 9.--Location of low-flow partial-record stations in Central and Western Puerto Rico. 33 OCEANO ArLANTICO 0070 \7",t1/4 ISABELA 01144e QUEBRADILLAS de Diversioh • 1 64 AGUADILLA • 165 112 0110 010790 Drainage boundaries indeterminate in limestone terrone Liuga,ocloeco 010720 Urnestone Igneous sedimentary rocks 0106 \s"- "\"\JL ARES Rio C. • f not , btn ( c`l : 0 PE(o Grisnd. Miasma W*0, '• EXPLANATION A0106 SURFACE—WATER STATION AND NUMBER V 0105 QUALITY—OF—WATER STATION AND NUMBER • 164 WELL AND WELL NUMBER Mop area vavourez %stow 61.1 40Astt ° FA C44104#,, ParfiCE r aliklethita 2 3 4 5 3 C? 4 7 xiLOIMET S 6 MILES Figure 10.--Rio Guajataca basin. 34 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 An6n, 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 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- SIRED- SPE- DTS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- 7,4 !JR- OXYGEN, (PER- ICAL 0.7 KF AGAR INISTAN- DUCT- (STAND- TEMPER- 5:0- DIS- CENT (HIGH 0M-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMMOS) UNITS) (DEG C) (NTU) (4G/L) ATION) (MS/L) 100 ML) 100 ML) OCT , 1933 23... 1140 10 214 1.0 23.0 2.Z i.9 95 16 K6900 6100 DEC 23... 1110 4.0 224 7.6 21.5 35 9.) 105 15 41000 7700 FE1 r 1934 03... 0740 2.3 226 7.5 19.5 1./ 7.1 •O 15 K16000 3300 APR 13... 1640 .45 275 3.3 26.) 1.1 9.1 116 12 3400 560 JUN 21... 1110 12 213 3.1 23.0 11 9.4 111 <10 3000 2500 AUG 16... 1345 11 223 3.0 24.5 1.0 7.3 07 13 21000 5300 HARD- mAr;NE- SODIUM POTAS- ALKA - CHLO- FLUO- HARD- NESS, CALCIUM SLUM, SODIUM, AD- SLUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- 015- FIELD DIS- DIS- DIS- (MG/L SONATE SOLVED SOLVED snLvED TzoN SOLVED oicaL 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 MA AS NA) AS <) CACO3) AS SO4) AS CL) AS F) OCT , 1933 28... 71 0 23 5.1 11 .6 2.1 30 6.0 10 <.10 DEC 23... 35 FEB , 1934 03... -- .... 9C - - APR 13... 100 0 70 6.6 14 .6 1.8 105 15 13 .33 JUN 21... - -- 79 AUG 16... 84 2 26 4.5 3.3 .4 2.7 82 13 10 .13 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 4' NITRO- SOLVED TUENTS, SOLVED DEG. C, NITRATE NITRITE NO2+403 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 NI) AS N) AS N) AS N) AS N) AS N) OCT , 1983 29... 23 130 2.6 3 2.1 .03 2.1 .17 .63 .80 2.9 DEC 23... -.. -- 68 1.7 .02 1.7 .16 .94 1.0 2.7 FE3 , 1934 03... --.. 6 .97 .03 1.0 <.01 .60 1.6 APR 18... 27 170 .21 4 <.01 .20 .03 .77 .30 1.0 JUN 21... -- 12 -- <.01 1.9 .01 <.10 AUG 16... 23 140 4.2 22 <.01 1.9 <.01 .10 2.0 K = non-ideal count RIO GUAJATACA BASIN 50010500 RIO GUAJATACA AT LARES, PR - -Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO- 3ARIUM, 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 CO) AS CR) AS P8) AS HG) AS SE) AS AG) OCT , 1983 28... 13 .05 1 100 1 <1 3 <.1 <1 <1 DEC 23... 12 .07 FEB , 1984 08... '.1 .10 APR 18... 4.4 .05 2 <100 1 <1 <1 .1 <1 <1 JUN 21... .06 AUG 16... 8.9 .11 35 36 RIO GUAJATACA BASIN 50010600 RIO GUAJATACA ABOVE LAGO DE GUAJATACA, PR LOCATION.--Lat 18°19'57", long 66°55'29", Hydrologic Unit 21010002, 125 ft (38.1 m) off road 451, 3 mi (4.8 km) south of Lago de Guajataca, 1.0 mi (1.6 km) east of Eneas and 2.0 mi (3.2 km) west of Piletas. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July to September, 1984. GAGE.--Water-stage recorder. REMARKS.--Records fair. EXTREMES FOR CURRENT PERIOD.--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) Aug. 15 1600 1,700 48.1 10.41 3.173 Sept. 15 1445 1,670 47.3 10.35 3.155 Sept. 13 1645 *1,910 54.1 10.82 3.298 Minimum discharge, 7.1 cu ft/s (0.201 cu m/s) Aug. 7. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 25 9.0 82 2 18 9.3 58 3 16 8.2 100 4 60 20 73 5 200 10 65 6 35 9.0 56 7 25 7.5 36 22 48 28 3 20 18 24 10 100 9.7 21 11 70 13 158 12 46 14 71 13 28 103 292 14 22 193 204 15 21 322 357 16 18 102 195 17 16 51 263 18 16 34 163 19 22 31 90 20 17 26 94 21 15 19 61 22 15 32 48 23 15 24 73 24 12 18 47 25 12 16 38 26 12 107 52 27 10 80 47 28 18 39 65 29 15 25 63 30 31 11 9.2 20 64 46 --- TOTAL 941.2 1481.7 2970 MEAN 30.4 47.8 99.0 MAX 200 322 357 MIN 9.2 7.5 21 AC-FT 1870 2940 5890 WATER QUALITY RECORDS PERIOD 0= RECORC. --AUGUST TO SEPTEMBER 1984 RATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 STREAMFLOWs SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS OUCTA10E TjRE DATE TIME INSTANTANEOUS DUCTANCE STREAmFLO4r SPECIFIC CON- TE1PERA- TURF. (CFS) (UMC3) (CEG C) (CFS) (UMHOS) (DEG C) AUG, 08 1328 9.7 71d 75.5 37 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'02", long 66°55'27", off Highway 476 at Lago Guajataca outlet, 3.0 mi (4.8 km) southwest of Segunda Unidad Baldorioty de Castro, and 5.3 mi (8.5 km) south of Quebradillas Plaza. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1958-64, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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- 310- OIS- 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) OCT , 1933 31... 1420 50 303 7.3 26.0 11 6.5 83 30 54 56 DEC 23... 1235 65 386 7.5 26.0 1.1 8.2 103 25 K65 72 FEB , 1984 10... 0840 58 273 7.8 25.0 1.1 7.3 96 <10 K109 K180 MAY 11... 1435 60 283 3.4 23.0 1.1 9.2 119 <10 K1 Kl JUL 05... 1650 60 333 7.6 25.0 1.1 2.0 25 <10 82 K170 AUG 20... 1415 45 310 7.7 26.0 .80 3.0 38 <10 K120 160 HARD- MAGNE- SOOIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DES- 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 504) AS CL) AS F) OCT , 1983 31... 150 8 53 3.4 5.3 .2 1.6 139 10 7.6 .20 DEC 23... 180 -... FEB , 1984 ..... 10... - 125 MAY 11... 130 9 46 4.2 6.5 .3 1.6 127 13 9.6 .20 JUL 05... - 139 AUG 20... 140 4 49 3.3 5.7 .2 1.7 134 15 9.1 .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. C, 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) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1983 31... 6.4 170 23 10 .02 <.10 .32 3.1 3.4 DEC 23... 1 <.01 .60 <.01 .50 1.1 FEB , 1984 10... 8 <.01 <.10 <.01 .60 MAY 11... 6.8 160 26 4 <.01 <.10 .27 2.2 2.5 JUL 05... -- 1 <.01 .40 <.01 .30 .70 AUG 20... 7.0 170 21 4 <.01 <.10 .17 .23 .40 RIO GUAJATACA BASIN 50011000 CANAL PRINCIPAL DE DIVERSIONES AT LAGO DE GUAJATACA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 ERA3LE ERA8LE ERABLE ERABLE ERABLE TOTAL ERABLE (MG/L (MGJL (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 CO) AS CR) AS P8) AS HG) AS SE) AS AG) OCT , 1983 31... .31 1 (100 1 <1 3 <.1 <1 <1 DEC 23... 4.9 .02 FEB , 1984 10... .05 MAY 11... <.01 2 <130 2 <1 <1 .1 <1 <1 JUL 05... 3.1 .01 - AUG 20... <.01 K = non-ideal count 38 39 RIO GUAJATACA BASIN 50011200 RIO GUAJATACA BELOW LAGO GUAJATACA, PR LOCATION.--Lat 18°24'01", long 66°55'40", Hydrologic Unit 21010002, on left bank, 250 ft (76.2 m) downstream from bridge on Highway 476, 1,000 ft (305 m) downstream from outlet tunnel, and 5.2 mi (8.4 km) southeast of Quebradillas. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--August 1969 to December 1970, April to September 1984. CAGE.--Water-stage recorder. Altitude of gage is 535 ft (163 m), from topographic map. REMARKS.--Records fair. Flow regulated by Lago Guajataca Dam. Low flows are from seepage through and under dam and nearby springs. EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 590 cu ft/s (16.7 cu m/s) Sept. 18, 1984, gage height, 9.94 ft (3.030 m), from rating curve extended above 400 cu ft/s (11.3 cu m/s) on basis of step-backwater analysis; minimum, 0.53 cu ft/s (0.015 cu m/s) May 31, June 1, 1984. EXTREMES FOR CURRENT PERIOD.--Maximum discharge, 590 cu ft/s (16.7 cu m/s) Sept. 18; minimum, 0.53 cu ft/s (0.015 cu m/s) May 31, June 1. DISCHARGE, IN CUBIC FEET PER SECOVD. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES OAT OCT NOV DEC JAN FEE MAR APR MAY JUN JUL AUG SEP 1 .97 .77 1.3 1.6 1.2 2 .99 1.1 1.6 1.3 1.0 3 .97 .94 1.3 5.5 .94 4 .88 1.1 1.1 1.1 .90 5 .88 1.1 2.2 1.1 1.6 6 .91 1.2 1.5 1.0 .94 7 .91 1.3 1.2 1.0 .95 8 .92 1.2 1.3 1.0 .91 9 .92 1.0 1.6 1.1 .87 10 .92 1.2 1.2 4.7 .88 11 .91 1.4 1.3 .90 1.3 12 .91 .98 .99 1.9 1.6 13 .89 2.5 1.1 3.1 1.3 14 .85 1.7 .90 1.3 1.5 15 .82 1.3 1.1 1.0 2.3 16 .86 1.2 1.4 .94 2.1 17 1.1 1.4 1.1 .92 8.2 18 1.8 1.9 1.1 .94 171 19 1.1 4.2 1.0 .98 492 20 1.2 1.9 1.0 .94 438 21 1.8 1.5 .86 .92 400 22 2.0 1.5 1.0 .96 385 23 1.6 1.3 1.3 .90 385 24 1.3 1.5 2.0 1.1 235 V-- 25 .95 1.3 1.7 1.7 1.0 2.0 26 .95 1.5 1.5 1.7 .94 2.6 27 .92 1.8 1.4 1.3 .90 2.1 28 .92 1.3 1.4 .95 .90 2.2 29 .91 1.3 1.4 1.2 1.0 40 30 .94 1.3 1.1 1.5 .92 2.4 ...... 31 .79 --- 1.2 .90 --- TOTAL 35.70 43.69 40.00 42.76 2585.79 MEAN 1.15 1.46 1.29 1.38 86.2 MAX 2.0 4.2 2.2 5.5 492 MIN .79 .77 .86 .90 .87 AC-FT 71 87 79 85 5130 WATER QUALITY RECORDS PERIOD OF RECORD.--APRIL TO SEPTEMBER 1934 WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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) APR, 25 1535 0.9 346 26.0 AUG, 08 1045 1.0 390 27.5 MAY, 30 1232 1.2 401 27.0 40 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR LOCATION.--Lat 18°28'31", long 66°57'46", Hydrologic Unit 21010002, on left bank at ford 1.7 mi (2.7 km) upstream from bridge on Highway 2, 1.6 mi (2.6 km) west of Quebradillas plaza, 2.1 mi (3.4 km) upstream from the Atlantic Ocean, and 6.6 mi (10.6 km) downstream from Lago de Guajataca. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--February to May 1969 (monthly measurements only), July 1969 to December 1970, April to September 1984. GAGE.--Water-stage recorder. Altitude of gage is at mean level from topographic map. REMARKS.--Records fair. Flow regulated by Lago de Guajataca 6.6 mi (10.6 km). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 3,090 cu ft/s (87.5 cu m/s) Sept. 19, 1984; minimum discharge, 6.2 cu ft/s (0.176 cu m/sec) Sept. 4, 9-12, 1984. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 1,000 cu ft/s (28.3 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Sept. 19 0300 *3,090 87.5 8.10 2.469 Minimum discharge, 6.2 cu ft/s (0.176 cu m/s) Sept. 4, 9-12. DISCHARGE. IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 7.1 6.8 8.4 7.6 6.8 2 7.3 7.8 8.6 8.4 6.6 3 7.3 8.2 9.1 8.2 6.5 4 7.3 8.1 9.7 8.8 6.6 5 7.4 11 86 8.2 6.6 6 7.7 19 27 8.1 6.4 7 7.7 14 12 8.1 6.9 8 7.5 14 9.9 8.0 6.6 9 7.7 12 9.6 7.8 6.4 10 7.7 12 9.1 7.8 6.3 11 7.8 10 9.7 8.0 6.2 12 7.7 9.3 8.6 7.8 9.0 13 7.4 8.9 8.3 7.6 8.1 14 7.4 30 8.2 9.2 7.9 15 7.4 12 8.2 9.2 29 16 7.4 10 8.6 8.7 52 17 - 7.5 11 8.5 8.1 170 18 18 75 8.2 8.2 580 19 16 145 8.0 9.0 1900 20 22 21 7.7 8.7 500 21 99 10 7.1 8.5 199 22 57 9.8 6.9 8.8 96 23 --- 14 9.7 7.3 8.4 129 24 8.4 9.8 10 7.7 8.7 90 25 8.5 8.9 9.5 9.0 8.2 20 26 8.5 19 9.1 8.3 7.9 30 27 8.6 31 9.1 8.3 7.7 20 28 8.6 11 8.9 7.3 7.4 25 29 8.9 11 8.6 7.3 7.1 70 30 14 9.2 8.7 7.1 7.2 25 31 --- 8.3 --- 7.5 7.0 --- TOTAL 461.5 538.5 357.2 252.4 4031.9 MEAN 14.9 18.0 11.5 8.14 134 MAX 99 145 86 9.2 1900 MIN 7.1 6.8 6.9 7.0 6.2 AC-FT 915 1070 709 501 8000 41 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1969 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI*.' STREP.. SPE- OIS•• DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM.... FECAL, FECAL, FLOW, CON- PH TJR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- 810- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARD ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMMOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT • 1983 31... 1225 13 484 7.5 25.0 1.2 7.2 87 30 K150 250 DEC 23... 1030 3.9 480 7.3 24.5 3.4 6.9 82 19 56 140 MAR , 1984 09... 1040 8.4 603 7.9 24.0 .80 12.6 149 <10 $(12 52 MAY 11... 1220 7.6 550 8.2 27.0 <1.0 9.9 123 <10 K30 K2 JUL 05... 1355 124 354 S.3 24.5 27 7.7 92 <10 K1100 3500 AUG 20... 1930 8.5 559 2.0 26.0 .30 10.4 128 <10 74 K140 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO.". HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- On- FIELD DIS- DIS- On.* (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 CACO3) CACO3) AS CA) AS MG) AS NA) AS 0 CAC03) AS SO4) AS CL) AS F) OCT , 1983 31... 220 18 77 7.3 15 .5 1.1 207 8.6 27 .10 DEC 28... -- 208 •. 0 .0 MAR , 1934 09... 228 MAY 11... 240 41 30 13 22 .6 1.0 226 7.3 41 .10 JUL M. 00 05... --. 154 AUG 20... 220 0 73 9.1 20 .6 1.2 258 9.6 38 .10 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO-. NITRO- NITRO- NITRO- GEN,A4- DI5- CONSTI- DIS- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO"' SOLVED TUENTS, SOLVED DEG. Co NITRATE NITRITE NO24-NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER PEN3E3 (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MGM AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1933 31... 6.4 270 9.4 4 2.0 .02 2.0 .27 .23 .50 2.5 DEC 28... <1 2.1 .03 2.1 .06 .64 .70 2.3 MAR , 1934 ..... 09... -- 5 -- <.01 2.4 <.01 1.0 3.4 MAY 11... 6.6 290 6.0 1 <.01 2.1 .34 1.8 2.1 4.2 JUL 05... 34 <.01 .70 <.01 .80 1.5 ..... ..... AUG 20... 6.4 310 7.1 1 <.01 1.8 <.01 .10 1.9 K = non-ideal count 42 RIO GUAJATACA BASIN 50011400 RIO GUAJATACA ABOVE MOUTH NEAR QUEBRADILLAS, PR--Continued WATER-QUAIITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO- BARIUM. CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- RHOS- TOTAL TOTAL TOTAL TOTAL TOTAL SELE- TOTAL GEN, PHORUS, ARSENIC RECOV- RECOV- RECOV- RECOV- RECOV- NIUM. RECOV- TOTAL TOTAL TOTAL ERAELE ERABLE ERA8LE 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 R) AS AS) AS SA) AS CO) AS CR) AS PS) AS 4G) AS SE) AS AG) OCT , 1983 31... 11 <.01 1 <100 1 21 2 <.1 <1 <1 DEC 28... 12 .02 MAR , 1934 09... 15 <.31 MAY 11... 19 (.01 1 <100 2 3 <1 .1 <1 <1 JUL 05... 6.6 .02 AUG 20... 3.4 <.01 STRE4MFLOW, 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. 19 0851 94 263 26.5 APR, 24 1320 8.8 550 25.5 I 43 OCEANO ATLANTIC 0 • aHATILLO CAMUY DOUEBRADILLAS 0158 ARECIBO 0157 0148 Drainage boundaries indeterminate in limestone terrone .Bayaney River underground Limestone Igneous and LARES sedimentary rocks Ri(),?.ojatac Rio Tononio'. Rio Grand. de UTUADO a Arecibo basin Rio Grande* Drainage boundary 'Masco oasis EXPLANATION A 0158 LOW—FLOW STATION AND NUMBER A0148 SURFACE—WATER STATION AND NUMBER \--Mop area CAN .Aawatoi0 •ARECI. MJAn00. CAOUA3. 6 7KILOMETERS • UAYANA 6MILES Figure 11.--Rio Camuy basin. 44 RIO CAMUY BASIN 50014800 RIO CAMUY NEAR BAYANEY, PR LOCATION .--Lat 18°23'48", long 66°49'04", Hydrologic Unit 21010002, on left bank at Highway 488, 1.4 mi (2.2 km) southeast of school at Santiago, 0.9 mi (1.4 km) northwest from Escuela Manuel A. Rivera at Bayaney and 9.1 mi (14.6 km) upstream from Atlantic Ocean. DRAINAGE AREA.--Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--May to September, 1984. GAGE.--Water-stage recorder. Altitude of gage is 330 ft (100 m), from topographic map. REMARKS.--Records fair. EXTREMES FOR CURRENT PERIOD.--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) June 21 2045 1,400 39.6 9.82 2.993 Sept. 15 1815 1,100 31.2 8.92 2.719 Sept. 4 2000 1,380 39.1 9.77 2.978 Sept. 18 2315 *2,040 57.8 11.53 3.514 Sept. 13 1945 1,800 51.0 10.93 3.331 Minimum discharge, 38 cu ft/s (1.076 cu m/s), Aug. 10, 11. DISCHARGE. IN CUBIC FEET PER SECOND, MATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 64 57 42 89 2 55 55 42 78 3 53 53 41 121 4 130 54 42 336 5 220 111 45 296 6 79 87 42 195 7 67 65 41 97 8 61 55 40 93 9 59 52 43 94 10 105 52 39 75 11 75 77 38 216 12 64 102 52 265 13 58 70 62 504 14 55 56 84 456 15 56 55 281 546 16 52 52 159 490 17 51 50 75 793 18 88 49 57 822 19 250 55 56 450 20 115 72 79 300 21 300 53 52 200 22 --- 256 50 52 160 23 236 130 55 49 170 24 149 86 49 46 220 25 193 124 47 44 130 26 114 112 46 49 130 27 162 79 45 117 210 28 128 73 45 79 140 29 81 66 52 55 270 30 76 61 45 50 230 31 62 --- 44 50 --- TOTAL 3044 1810 2003 8176 MEAN 101 58.4 64.6 273 MAX 300 111 281 822 MIN 51 44 38 75 AC-FT 6040 3590 3970 16220 WATER QUALITY RECORDS PERIOD CF RECORD.--JUNE TO SEPTEMBER 1184 WATER-QUALITY DATA, WATER YEAR OCTOBER 1783 TO SEPTEMBER 1984 STREAMFLOW. SPECIE': CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURF DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) ('U CS) (DEG C) (C=S) (UMMOS) (DEG C) JUN. 13 1320 09 2'9 27.5 SEP, 06 1152 194 322 AUG, 15 1179 153 306 24.0 24.0 45 RIO CAMUY BASIN 50015700 RIO CAMUY NEAR HATILLO, PR LOCATION.--Lat 18°27'44", long 66°49'56", Hydrologic Unit 21010002, 1.8 mi (2.90 km) southwest of Hatillo plaza, and 1.8 mi (2.9 km) southeast of Camuy plaza, 1.2 mi (1.9 km) south of Planta de Purificaci6n, and 3.3 mi (5.5 km) upstream from Atlantic Ocean. DRAINAGE AREA. - -Indeterminate. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--June to September 1984. GAGE.--Water-stage recorder. Altitude of gage is 15 ft (5.0 km), from topographic map. REMARKS.--Records fair. EXTREMES FOR CURRENT PERIOD.--Peak discharges above base of 1,800 cu ft/s (51.0 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) June 21 2315 1,810 51.2 13.16 4.011 Sept. 19 unknown *3,000 85 Unknown Sept. 13 Unknown 2,200 62 Unknown Minimum discharge, 42 cu ft/s (1.19 cu m/s) July 10, Aug. 6. DISCHARGE. IN CUBIC FEET PER SECOND• WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 63 52 100 2 60 52 90 3 56 51 130 4 58 51 400 5 119 56 350 6 117 51 203 7 78 51 122 8 62 49 90 9 56 53 119 10 54 52 83 11 76 50 186 12 122 61 380 13 80 69 700 14 63 70 400 15 60 350 300 16 56 258 500 17 55 83 1000 18 --- 54 61 1100 19 294 52 50 600 20 163 84 84 361 21 273 61 52 263 22 465 56 50 193 23 169 62 56 200 24 105 55 54 267 25 115 53 52 156 26 155 52 50 160 27 89 52 150 253 23 81 52 80 164 29 73 61 60 326 30 68 53 50 278 31 --- 52 50 --- TOTAL 2034 2358 9474 MEAN 65.6 76.1 316 MAX 122 350 1100 MIN 52 49 83 AC-FT 4030 4680 18790 WATER CjALITY RECORDS PERIOD OF RECORD.--AUGUST TO SEP7Fm3ER 1984 MATE;­ UALITY DATA, MATER YEAR OCTOBER 1983 TO SEPTEMBER 19E4 STREAMFL04, SPECIFIC CON- TEMP RA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME :NSTANTANEOUS CUCTANCI TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (jM40S) (DIG C) (CFS) ('JMHOS) (DEG C) AUG, 14 1416 36 311 ?5.5 SEP, 07 0626 126 336 24.5   47 OC AT-0 A, 0 HATILLO Colic boron. ARECibt 0290 BARCELONE TA 0135 • •161 284 • 027750 . Bayaney . Florida Drainage boundaries indeterminate in limestone t err ane 027250 ipr 027090 Logo Dos Boer 025110 r Limes,ane 250 igneous and sedimentary rocks \. 0280 R+b Comuy • basin ar L ugo Coonillo UT'UAfl0 :0 ti 02605. ./ C 4r 0 cx L090 SY . 123 YUYA 61. cx rotuyb L ago Perejo$ 0 1.ego ) :2 ..40fontes Gronde de S 0205 Ada.c.o basin 86 -6 ..ADJUNTAS Drainage boundary e,cand ot;sin Rio ea,irt Drainage "undwY7\„0050 Rta Per te9ue's EXPLANATION .1. 090 besEn Island divide ,— Of YOS ,„„, A 0284 SURFACE—WATER STATION AND NUMBER 0205 QUALITY—OF—WATER STATION AND NUMBER Ria Guayenitt Tallobon basin ° beam i • 161 WELL AND WELL NUMBER • ?-l Map area SA* Ailitt LAOWith., A Fa..PARDe AYAGS,t 6 iKiLOMETERS C461...% 4 6 i/i F.'.$ itAYA, Figure 12.--Rio Grande de Arecibo basin. 48 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 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, =LOW, CON- PH TiP- OXYGEN, (PER- ICAL 0.7 Go2,t ,/ 33 EXPLANAtrtrig CAYEY pr A0460 SURFACE—WATER STATION AND NUMBER A0458 LOW—FLOW STATION AM) NUMBER 039 0430 QUALITY O —F—WATER STATION AND NUMBER to'. Set: (Nip.) basin f `03995 ego arite a tats • 38 WELL AND WELL NUMBER 'rKit_Ciasf..TERS do F.a basin 1 1 60.4ILES RraAs TrnlInaa ikosm Figure 15.--Rio de la Plata basin. 102 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR LOCATION.--Lat 18°09'37", long 66°13'44", Hydrologic Unit 21010005, at upstream side of bridge on Highway 173, 0.4 mi (0.6 km) northeast of Proyecto La Plata, and 2.5 mi (4.0 km) upstream from Rio Usab6n. DRAINAGE AREA.--54.8 sq mi (142 sq km), excludes 8.2 sq mi (21.1 sq km) upstream from Carite Reservoir, the flow of which is diverted to Rio Guamani. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--1958 (occasional measurements only), February 1959 to March 1960 (monthly measurements only), April 1960 to current year. GAGE.--Water-stage recorder. Altitude of gage is 850 ft (259 m), from topographic map. Prior to Mar. 29, 1961, wire-weight gage read twice daily at same site and datum. REMARKS.--Records fair. The Puerto Rico Aqueduct and Sewer Authority operates a pumping plant about 5 mi (8 km) upstream which can divert as much as 23 cu ft/s (0.65 cu m/s) into Cidra Reservoir. AVERAGE DISCHARGE.--24 years (1961-84), 111 cu ft/s (3.144 cu m/s), 27.51 in/yr (699 mm/yr), 80,420 acre-ft/yr (99.2 cu hm/yr); median of yearly mean discharges, 84 cu ft/s (2.38 cu m/s), 60,900 acre-ft/yr (75 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 59,600 cu ft/s (1,688 cu m/s) Aug. 27, 1961, gage height, 32.21 ft (9.818 m), from rating curve extended above 7,000 cu ft/s (198 cu m/s) on basis of slope-area measurement; minimum daily, 2.6 cu ft/s (0.074 cu m/s) July 25, 1974. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 4,000 cu ft/s (113 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) Feb. 16 0100 4,220 120 10.47 3.191 July 5 0300 *5,370 152 10.92 3.328 Minimum discharge, 5.8 cu ft/s (0.164 cu m/s) July 26. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 48 38 26 58 28 19 17 20 886 502 26 91 58 28 26 23 18 13 13 15 12 12 11 12 15 15 14 13 13 13 16 15 12 12 12 12 11 10 8.2 7.4 20 12 11 9.1 8.4 10 30 20 15 400 10 15 20 12 27 7.3 7.4 26 20 46 6 7 8 9 10 23 21 21 22 25 310 189 101 76 60 27 31 24 21 17 19 16 13 13 13 15 12 11 11 59 14 13 13 15 16 13 16 16 14 13 7.5 8.2 7.8 8.0 7.7 76 115 49 25 324 100 50 30 25 20 14 12 9.8 7.1 7.1 160 20 12 9.6 10 11 12 13 14 15 22 24 29 24 20 50 100 50 30 27 20 19 20 18 18 14 13 15 183 42 33 21 499 241 90 13 12 12 13 13 16 16 14 14 16 7.2 7.5 8.9 18 20 128 37 37 44 29 18 17 16 100 50 11 11 11 9.9 9.4 56 31 25 31 20 16 17 18 19 20 31 28 25 21 22 25 24 23 24 24 21 19 15 17 17 24 19 21 26 34 1040 241 111 71 51 13 14 16 16 15 16 16 17 16 14 32 12 12 13 12 18 52 28 18 12 20 16 12 10 8.2 10 10 9.4 11 11 43 188 949 1010 956 21 22 23 24 25 27 36 51 38 24 23 21 19 18 16 17 16 18 17 14 44 24 21 17 17 39 33 30 27 25 9.9 9.9 10 11 13 14 13 13 12 12 11 11 12 15 15 10 10 9.0 9.0 9.0 6.8 10 14 11 7.6 9.3 9.4 8.4 7.4 7.5 661 178 68 39 28 26 27 28 29 30 31 22 20 22 20 23 22 17 19 19 23 25 --- 9.7 11 12 12 15 22 18 15 14 15 13 12 23 21 21 19 --- 14 15 14 13 15 16 11 11 20 15 13 --- 13 24 22 19 55 76 8.0 8.0 8.0 8.0 8.0 --- 6.2 7.8 8.0 7.0 15 17 11 74 16 8.0 7.6 6.8 21 27 15 13 13 --- TOTAL MEAN MAX MIN CFSM IN. AC-FT 861 27.8 58 20 .51 .58 1710 2757 91.9 886 16 1.68 1.87 5470 696.7 22.5 91 9.7 .41 .47 1380 757 24.4 183 12 .45 .51 1500 2806 96.8 1040 11 1.77 1.90 5570 416.8 13.4 16 9.9 .25 .28 827 428 14.3 20 11 .26 .29 849 503.4 16.2 76 7.2 .30 .34 998 1139.5 38.0 324 8.0 .69 .77 2260 1077.6 34.8 400 6.2 .64 .73 2140 403.1 13.0 74 6.8 .24 .27 800 4690.3 156 1010 7.3 2.85 3.18 9300 CAL YR 1983 WTR YR 1984 TOTAL TOTAL 28544.0 16536.4 MEAN 78.2 MEAN 45.2 MAX MAX 2920 1040 MIN 9.0 MIN 6.2 CFSM CFSM 1.43 .83 IN 19.38 IN 11.23 AC-FT AC-FT 56620 32800 103 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR--Continued WATER-QUALITY RECORDS PERIOD OF RECORD.--Water years 1958 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP­ SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TjR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- 3ID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARO ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) AT ION) (MG/L) 100 ML) 100 ML) OCT • 1933 07... 1405 21 382 8.4 30.5 17 19.0 138 27 300 230 DEC 15... 1125 13 444 8.2 24.5 3.1 13.2 126 <10 38 K30 MAR , 1934 14... 1335 13 440 8.8 23.3 4.5 11.3 149 12 250 170 MAY 03... 1255 10 427 8.2 23.0 3.4 13.3 171 16 K160 350 JUN 20... 1330 10 353 8.2 23.0 4. 2 19.4 136 K250 230 AUG 15... 1425 8.4 475 8.4 31.0 .40 11.4 157 12 K160 50 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARO- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- CIS- DIS- ors- SORP- OIS- 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 CO AS F) OCT , 1933 07... 130 0 32 12 29 1 2.3 131 17 30 .20 DEC 15... 166 -- MAR , 1934 14... 169 MAY 03... 160 0 39 16 34 1 2.7 166 24 32 .20 JUN 20... 136 AUG 15... 140 0 32 14 41 2 3.2 147 20 45 .30 SOLIDS, SOLIDS, NITRO... SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- OS- 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 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) OCT , 1983 07... 25 230 13 6 2.0 .02 2.0 .04 .66 .70 2.7 DEC 15... 8 2.3 .02 2.3 .03 .77 .80 3.1 MAR , 1984 14... 6 1.7 .02 1.7 .04 .56 .60 2.3 MAY 03... 24 270 7.3 8 .77 .03 .80 .07 .63 .70 1.5 JUN 20... 5 1.2 .02 1.2 .06 1.2 1.3 2.5 AUG 15... 25 270 6.1 2 <.01 <.10 .41 .29 .70 -- K = non-ideal count 104 RIO DE LA PLATA BASIN 50043000 RIO DE LA PLATA AT PROYECTO LA PLATA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO­ BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NI TRO- 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 (MGIL (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 P8) AS MG) AS SE) AS AG) OCT r 1933 07... 12 .52 200 1 12 4 (.1 <1 <1 DEC 15... 14 .66 MAR , 1934 14... 10 .35 MAY 03... 6.6 .57 2 <100 1 2 1 <.1 <1 <1 JUN 20... 11 .54 AUG 15... 1.1 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS OUCTANCE TURF DATE TIME INSTANTANEOUS DUCTANCE TURE (CPS) (UMHOS) (0EG C) (CFS) (UMHOS) (DEG C) NOV, 18 1223 24 413 27.5 MAR, 13 1300 13 440 26.0 JAN, 24 1343 13 317 25.5 105 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'33", long 66°12'28", at bridge on Highway 156, 0.56 mi (0.9 km) upstream from dam, about 2.0 mi (3.2 km) northeast of Comerio plaza. DRAINAGE AREA.--139 sq mi (360 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 (CFS) (UMHOS) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1933 18... 0945 103 301 7.8 25.0 323 7.4 92 58 K90000 K140000 DEC 20... 1105 33 407 8.2 24.5 11 11.0 134 <10 400 250 MAR , 1984 14... 1050 28 433 8.5 25.0 1.5 9.1 112 12 K950 950 MAY 04... 1150 24 409 8.1 23.0 5.0 11.5 150 16 K960 550 JUN 29... 1015 21 393 8.0 27.0 9.9 9.2 117 22 340 400 AUG 23... 0915 63 443 8.0 27.5 6.0 8.4 108 13 K1400 600 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AO* 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 (Mr/IL (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC031 CAC03) AS CA) AS MG) AS NA) AS K) CACO3) AS 504) AS CL) AS F) OCT • 1983 13... 100 1 24 10 20 .9 3.6 100 16 22 .20 DEC 20... 156 MAR , 1984 14... 165 MAY 04... 160 5 36 16 28 1 3.1 151 26 30 .20 JUN 29... -- ... .w.l. -.. 151 -- AUG 23... 150 0 34 15 38 1 4.0 150 28 44 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO.. NITRO- GEN,AM- D/S- 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 (4G/L DATE SI02) (MG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1983 18... 20 180 49 15 ...... <.01 <.10 .04 2.7 2.7 -- DEC 20... -- -.. 6 1.2 .04 1.2 .04 .56 .60 1.8 MAR • 1984 14... 5 .94 .06 1.0 .29 .21 .50 1.5 MAY 04... 28 260 17 11 .78 .12 .90 .25 1.2 1.4 2.3 JUN 29... -- 16 .65 .05 .70 .11 .19 .30 1.0 AUG 28... 25 280 47 6 1.4 .06 1.5 .02 .58 .60 2.1 K a non-ideal count DATE 106 RIO DE LA PLATA BASIN 50044000 RIO DE LA PLATA NEAR COMERIO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GEN, TOTAL (MG/L AS NO3) PROS- PMORUS, TOTAL (MG/L AS P) ARSENIC TOTAL (UG/L AS AS) BARIUM, TOTAL RECOV- ERA3LE (UGIL AS 3A) CADMIUM TOTAL RECOV- ERABLE (UG/L AS CO) CHRO- MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) LEAD, TOTAL RECOV- ERABLE (UG/L AS P3) MERCURY TOTAL RECOV- ERABLE (UG/L AS MG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) OCT r 1983 18... DEC 20... 3.0 MAR , 1984 14... 6.6 MAY 04... 10 JUN 29... 4.4 AUG 28... 9.3 .34 .48 .52 .55 .51 .90 1 2 100 100 1 1 37 3 16 3 <.1 <.1 1 <1 1 <1 107 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°18'39", long 66°13'28", at steel-cross-bridge 0.8 mi (1.3 km) northwest of Highway 164, 1.2 mi (1.9 km) upstream from mouth and about 2.0 mi (3.2 km) northeast of Naranjito plaza. DRAINAGE AREA.--4.0 sq mi (10.3 sq km). PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP­ SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, 7LOW. CON- PH TJR- OXYGEN, (PER- ICAL u.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- 015- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARC ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/0 100 ML) 100 ML) OCT , 1983 19... 1240 5.8 317 8.0 27.5 1.7 3.0 102 <10 <13000 K1100 DEC 20... 1315 4.6 342 8.0 25.0 2.1 8.3 107 13 K7000 K1100 MAR , 1924 20... 3855 2.8 307 7.8 21.0 23 9.2 104 10 <7000 K11000 MAY 09... 1255 1.4 353 8.2 29.0 1.0 13.0 170 <10 470 2800 JUN 29... 1225 2.5 363 8.0 27.5 3.0 3.6 109 17 <1000 K1400 AU5 28... 1230 3.3 351 8.0 30.0 1.5 3.2 108 13 K1100 520 HARD- ""ACNE- SOOIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- OIS- 01S- DIS- SORP- ()IS- FIELD OIS- DIS- OIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVE) (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MS/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS <) CAC03) AS 504) AS CL) AS F) OCT , 1983 18... 130 15 29 13 15 .6 2.2 111 15 21 .20 DEC 20... 121 -- MAR , 1984 20... 101 MAY 09... 140 19 32 14 21 .8 2.6 119 18 31 .20 JUN 29... 125 AUG 23... 130 15 32 13 19 .7 3.1 119 22 29 .20 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- OIS- 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) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1983 18... 27 190 3.0 <1 <.01 <.10 .01 2.8 2.9 DEC 20... 8 1.7 .01 1.7 .07 .53 .60 2.3 MAR , 1984 20... 4 2.1 .02 2.1 .21 .19 .40 2.5 MAY 09... 26 220 .82 2 2.1 .02 2.1 .34 .26 .60 2.7 JUN 29... 16 2.4 .02 2.4 .12 .28 .40 2.8 AUG 28... 23 210 1.9 7 <.01 1.4 <.01 -- .40 1.8 K = non-ideal count 108 RIO DE LA PLATA BASIN 50044850 RIO GUADIANA NEAR NARANJITO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GEN, TOTAL (MG/L AS NO3) PHOS- PHORUS, TOTAL (MG/L AS P) ARSENIC TOTAL (UG/L AS AS) 3ARIjM, TOTAL RECOV- ERASLE (UG/L AS 3A) CADMIUM TOTAL RECOV - ERABLE (UG/L AS CO) CHRO- MIUM, TOTAL RECOV - ERA3LE (UG/L AS CR) LEAD. TOTAL RECOV- ERABLE (UG/L AS P8) MERCURY TOTAL RECOV- ERA3LE (UG/L AS HG) SELF - NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) OCT , 1983 18... DEC 20... 10 MAR , 1934 20... 11 MAY 09... 12 JUN 29... 12 AUG 28... 3.0 .28 .41 .52 .37 .78 .50 1 2 100 100 <1 2 32 <1 1 1 <.1 <.1 <1 1 <1 <1 109 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT TOA ALTA, PR LOCATION.--Lat 18°23'50", long 66°15'17", Hydrologic Unit 21010005, on left bank, at upstream side of bridge on Highway 165, 800 ft (244 m) downstream from Rio Lajas, and 0.6 mi (1.0 km) northwest of Toa Alta, 10 mi (16 km) downstream from Puerto Rico Aqueduct and Sewer Authority reservoir. DRAINAGE AREA.--200 sq mi (518 sq km), excludes 8.2 sq km (21.2 sq km) upstream from Lago Carite, flow from which is diverted to Rio Guamani. WATER-DISCHARGE RECORDS PERIOD OF RECORD.--November 1959 (measurement only), January 1960 to current year. GAGE.--Water-stage recorder. Datum of gage is 8.55 ft (2.606 m) above mean sea level (levels by Puerto Rico Department of Public Works). Prior to Feb. 25, 1960, wire-weight gage at same site and datum. REMARKS.--Records fair. Regulation at all stages by Puerto Rico Aqueduct and Sewer Authority reservoir upstream from gage. AVERAGE DISCHARGE.--24 years (1961-84), 267 cu ft/s (7.561 cu m/s), 18.13 in/yr (461 mm/yr), 193,400 acre-ft/yr (238 cu hm/yr); median of yearly mean discharges, 218 cu ft/s (6.17 cu m/s), 158,000 acre-ft/yr (195 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 95,500 cu ft/s (2,704 cu m/s) Sept. 6, 1960, gage height, 36.35 ft (11.079 m), from floodmark, from rating curve extended above 12,000 cu ft/s (340 cu m/s) on basis of contracted-opening measurement of peak flow; minimum, 2.2 cu ft/s (0.062 cu m/s) Apr. 25, 1984. EXTREMES OUTSIDE PERIOD OF RECORD.--Approximate discharges and elevations to gage datum of major floods, as pointed out by local resi­ dents are as follows: Sept. 13, 1928, 120,000 cu ft/s (3,400 cu m/s), gage height, 37.4 ft (11.4 m); June 16, 1943, 82,000 cu ft/s (2,320 cu m/s), gage height, 34.4 ft (10.48 m). EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 6,000 cu ft/s (170 cu m/s) and maximum (*): Discharge Gage height Date Time (cu ft/s) (cu m/s) (ft) (m) Sept. 18 1430 *14,800 419 21.71 6.617 Minimum discharge, 2.2 cu ft/s (0.062 cu m/s) Apr. 25. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 65 100 33 23 14 25 11 5.2 12 12 30 20 2 59 90 48 19 11 19 11 5.6 13 13 54 17 3 53 80 37 19 11 16 9.9 5.2 12 15 37 17 4 52 300 31 19 11 15 9.9 4.2 11 17 101 17 5 51 500 27 18 10 14 8.8 4.0 14 249 89 39 6 48 200 31 18 9.9 15 7.5 4.2 39 48 43 63 7 39 100 24 26 11 15 6.7 4.7 23 26 35 27 8 36 80 24 26 11 14 6.3 5.0 16 20 31 21 9 47 70 25 25 9.4 14 5.7 4.3 12 17 28 19 10 39 100 22 20 15 14 5.1 3.9 11 28 27 19 11 36 200 24 17 51 13 4.7 4.0 12 29 26 88 12 52 100 23 13 16 13 4.1 3.3 14 22 26 125 13 101 80 22 16 48 13 3.6 3.6 288 18 31 99 14 63 65 22 15 32 17 3.3 3.6 148 37 25 93 15 51 64 22 15 15 14 3.1 3.8 31 42 24 55 16 51 60 23 15 107 13 3.1 4.1 64 20 70 57 17 320 58 26 14 138 12 2.7 4.3 53 18 50 706 18 192 56 27 16 78 12 2.7 4.6 27 18 30 2780 19 70 65 25 15 61 12 2.8 4.9 22 122 25 1420 20 59 65 23 15 56 11 2.9 5.4 19 106 23 2870 21 55 60 21 14 48 12 3.1 5.6 18 49 22 1810 22 67 46 24 13 42 12 3.4 6.7 17 68 25 649 23 83 41 25 13 38 13 3.7 8.3 15 88 50 305 24 206 39 21 16 60 13 3.1 11 15 51 22 184 25 160 39 20 17 238 12 2.7 15 14 37 20 107 26 130 37 20 15 77 12 3.1 15 13 32 30 101 27 110 37 20 14 73 12 4.1 20 13 28 80 93 28 100 35 20 14 79 11 4.7 11 11 38 40 90 29 95 33 20 13 38 11 4.7 15 13 44 20 81 30 90 35 20 14 --- 12 4.6 25 12 30 18 73 31 120 --- 42 14 11 --- 16 --- 28 17 --- TOTAL 2700 2835 792 525 1408.3 422 152.1 236.5 982 1370 1149 12045 MEAN 87.1 94.5 25.5 16.9 48.6 13.6 5.07 7.63 32.7 44.2 37.1 402 MAX 320 500 48 26 238 25 11 25 288 249 101 2870 MIN 36 33 20 13 9.4 11 2.7 3.3 11 12 17 17 CFSM .44 .47 .13 .09 .24 .07 .03 .04 .16 .22 .19 2.01 IN. .50 .53 .15 .10 .26 .08 .03 .04 .18 .25 .21 2.24 AC-FT 5360 5620 1570 1040 2790 837 302 469 1950 2720 2280 23890 CAL YR 1983 TOTAL 61338.0 MEAN 168 MAX 4720 MIN 6.9 CFSM .84 IN 11.41 AC-FT 121700 WTR YR 1984 TOTAL 24616.9 MEAN 67.3 MAX 2870 MIN 2.7 CFSM .34 IN 4.58 AC-FT 48830 . 110 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT TOA ALTA, PR--Continued (National stream-quality accounting network station) WATER-QUALITY RECORDS LOCATION.--Samples collected at bridge on Highway 2, 1.2 mi (1.9 km) downstream from discharge station. PERIOD OF RECORD.--Water years 1958 to current year WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, COLT- STREP- SPE- DIS- FORM, TOCOCCI STREAM- CIFIC SOLVED FECAL, FECAL, HARD- FLOW, CON- PH TOR- OXYGEN, (PER- 0.7 KF AGAR NESS INSTAN.... DUCT- (STAND- TEMPER- 810- DIS- CENT UM-MF (COLS. (MG/L TIME TANEOUS ANCE ARD ATURE ITT SOLVED SATUR- (COLS./ PER AS DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) 100 ML) 100 ML) CAC03) OCT , 1983 03... 1305 53 419 7.7 29.0 3.0 5.3 75 2200 2100 170 DEC 07... 1410 23 542 7.8 26.5 1.8 7.4 92 3200 2800 210 FEB , 1984 03... 1520 11 560 7.5 23.0 1.2 2.4 28 K17 230 230 APR 17... 1350 2.7 632 7.4 23.5 1.0 9.6 124 56 700 240 JUN 11... 1235 12 472 7.1 26.0 1.3 1.4 17 2100 510 200 AUG 2... 1700 60 504 7.4 26.5 2.5 2.1 26 K9200 5000 210 HARD- MAGNE- SODIUM POTAS- ALKA- CHU?'" FLUO- SILICA, NESS. CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, DIS- NONCAR- DIS- DIS... DIS- SORP- DIS- FIELD OIS- 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) OCT , 1933 3... 6 51 11 21 .7 2.7 167 14 30 .20 22 DEC 07... 19 65 11 25 .8 2.9 189 20 41 .30 19 FEB , 1984 03... 18 70 13 29 .9 .90 211 18 49 <.10 17 APR 17... 14 73 14 32 .9 .50 226 15 60 .10 20 JUN 11... 30 62 11 23 .7 3.1 171 31 41 .20 16 AUG 02... 16 67 9.7 20 .6 3.1 192 23 34 .10 17 SOLIDS, SOLIDS, NITRO- NITRO- NITRO.... NITRO- PHOS- RESIDUE SUM OF SOLIDS, GEN, GEN, GEN, GEN,AM- PHOS- PHORUS, AT 180 CONSTI- DIS-. NO2+NO3 AMMONIA AMMONIA MONIA + PHOS- PHORUS, ORTHO, DEG. C TUENTS, SOLVED DIS- DIS... DIS- ORGANIC PHORUS, DIS- DIS- D/S-. DIS- (TONS SOLVED SOLVED SOLVED TOTAL TOTAL SOLVED SOLVED DATE SOLVED (MG/L) SOLVED (MG/L) PER DAY) (MG/L AS N) (MG/L AS N) (MG/L AS NH4) (MG/L AS N) (MG/L AS P) (MG/L AS P) (MG/L AS P) OCT , 1983 03... 262 250 37 .56 .14 .18 .40 .14 .15 .15 DEC 07... 328 300 20 1.1 .11 .14 .40 .24 .22 .21 FEB , 1984 03... 344 320 10 .16 .02 .03 .70 .35 .33 .33 APR 17... 384 350 2.6 <.10 .10 .13 .60 .19 .18 .10 JUN 11... 334 290 11 <.10 .28 .36 .50 .52 .39 .37 AUG 02... 315 290 51 .10 .36 .46 1.1 .27 .20 .20 K = non-ideal count 111 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT TOA ALTA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 PHOS- PHATE• ALUM- BERYL- CHRO- ORTHO• INUM• ARSENIC BARIUM, LIUM. CADMIUM MIUM, COBALT• COPPER• IRON• DIS- BIS'''. DIS- DIS- DIS- DIS- DIS- On- DIS- DIS- SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED SOLVED (MG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS PO4) AS AL) AS AS) AS BA) AS BE) AS CD) AS CR) AS CO) AS CU) AS FE) OCT • 1983 03... .46 <10 2 61 <.5 <1 <1 <3 1 19 DEC 07... .64 -- FEB • 1984 03... 1.0 <10 2 64 <.5 <1 <1 <3 2 6 APR 117• • • .31 -- JUN 11... 1.1 20 2 81 <.0 <1 1 <3 1 13 AUG 2... .61 <10 2 65 <.0 <1 1 <3 1 18 MANGA- MOLY3- SELE- STRON- VANA- LEAD, LITHIUM NESE, MERCURY DENUM, NICKEL, NIUM, SILVER• TIUM, OIUM• DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- DIS- 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 DATE AS P8) AS LI) AS MN) AS MG) AS MO) AS NI) AS SE) AS AG) AS SR) AS V) OCT • 1983 3... 1 <4 160 <.1 <10 2 <1 <1 220 <6 DEC 07... FEB • 1984 03... 1 <4 53 <.1 <10 4 <1 <1 340 <6 APR 17... -- JUN 11... <1 <4 710 .6 <10 3 <1 <1 350 <6 AUG 02... <1 <4 140 .2 <10 1 <1 <1 310 <6 STREAMFLOM. 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) NOV, 14 1530 65 410 26.0 MAY, 23 1037 8.6 680 26.0 JAN. 13 0925 16 568 24.5 JUL, 17 1236 18 421 30.0 MAR, 16 1240 12 510 26.0 SEP. 11 1321 30 520 26.5 DI- PC8• ALDRIN, DANEr 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 • 1984 11... 1235 <.1 <.01 <.1 <.01 <.01 <.01 .03 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 • 1984 11... <.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) LUG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN • 1984 11... <.01 <.01 <.01 <.01 <.10 <.1 <1 <.01 -- 112 RIO DE LA PLATA BASIN 50046000 RIO DE LA PLATA AT TOA ALTA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 SED. SUSP. STREAM- SEDI- SIEVE FLOW, MENT, DIAM. INSTAN- SUS- X FINER TIME TANEOUS PENDED THAN DATE (CFS) (MG/L) .062 MM OCT . 1983 03... 1305 526 15 93 DEC 07... 1410 23 FE8 , 1934 03... 1520 11 13 100 APR 17... 1350 2.7 42 60 JUN 11... 1235 100 15 100 AUG 02... 1700 60 212 100 SEP 19... 1820 267 75 19... 1835 169 78 19... 1845 171 30 19... 1850 158 85 19... 1855 139 38 19... 1900 144 36 19... 1905 159 82 19... 1910 153 84 19... 1915 154 74 19... 1925 155 77 113 OCEAN° A LANrico AN JUAN 049920 o o Drainage boundaries indeterminate 660 in iirnestant terrane 0496 0491 ageoe r, Jose 048519 049310 Limestone gneaus and seaimentor y rocks 80 \Th, ( I • 90 Represo ds 0 ftri, Piedras y047 vit 0488( Ga‘NABO k 1.ego Les Curios TRuJiLio ALTO • ( Drainage boundary /P— • 'q• 47 AGUAS BUENAS in Rt'c, de la Parts, be., fifil Grande de Lei. basin CIDRA EXPLANATION A 0490 LOW-FLOW STATION AND NUMBER V 0488 QUALITY-OF-WATER STATION AND NUMBER • 42 WELL AND WELL NUMBER „Map area mos Roo. 4 ri; 7 lc mETERS „cAo u e C3A4,1114. Figure 16.--Rio Hondo to Rio Puerto Nuevo basins. RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NEAR CATARO,PR WATER-QUALITY RECORDS LOCATION.--Lat 18°26'13", long 66°09'36", at Rio Hondo Channel, 800 ft (245 m) below junction with Rio Hondo, 0.9 mi (1.5 km) downstream from bridge on de Diego Expressway and 1.1 mi (1.8 km) above mouth. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI CIFIC SOLVED CHEM- FECAL, 'ECAL, SAM- CON- PH TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR PIING DUCT- (STAND- TEMPER- 313- DIS- CENT (HIGH UM-MF (COLS. TIME DEPTH ANCE ARO ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER (FEET) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 25... 1210 1.00 33100 8.4 31.0 6.4 15.0 226 1100 K11000 1200 DEC 06... 1250 1.00 7730 7.5 30.0 3.5 .0 0 290 K1100000 260000 MAR , 1984 22... 1305 1.00 36400 8.3 29.0 3.0 11.4 168 40 <100 APR 12... 0955 1.00 40000 '.4 30.0 5.0 6.6 100 32000 K110 JUL 12... 1125 1.00 565 7.6 30.0 50 4.0 53 16 K88000 2800 AUG 31... 1530 1.00 11000 7.7 32.5 3.2 .0 0 130 >600000 6400 HARD". MAGNE- SODIUM POTAS'." ALKA"" CHLO- FLUO- NESS, CALCIUM STUN, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, HARD- NONCAR- DIS- On- DIS- SORT,- 315- FIELD OIS." DIS- DIS- NESS, 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 DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS K) CAC03) AS 504) AS CL) AS F) OCT , 1983 25... 3900 3700 220 810 6800 48 240 139 1700 12000 .70 DEC 06... 158 2200 MAR , 1984 22... -- 173 19000 APR 12... 1400 1200 280 170 7300 87 220 189 1600 11000 .60 JUL 12... - 63 AUG 31... 1000 840 99 190 1600 22 65 188 390 3100 .40 SOLIDS, SOLIDS, NITRO- SILICA, SUM OF RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- AT 105 GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- SOLVED TUENTS, DEG. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L OM- SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1983 25... 6.8 22000 76 .06 .04 .10 .98 3.6 4.6 4.7 DEC 06... 19 .01 <.10 6.5 4.5 11 MAR , 1984 22... 81 .01 <.10 2.8 1.9 4.7 APR 12... 5.8 21000 43 .02 <.10 6.3 .20 6.5 JUL 12... 49 .17 .03 .20 .24 .76 1.0 1.2 AUG 31... 17 5600 5 .08 .02 .10 9.4 4.6 14 14 K = non-ideal count 114 115 RIO HONDO BASIN 50047530 RIO HONDO AT FLOOD CHANNEL NR CATASO, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GENE TOTAL (MG/L AS NO3) PHOS- PHORUS, TOTAL (MG/L AS P) ARSENIC TOTAL (UG/L AS AS) BARIUM, TOTAL RECOV- ERABLE (UG/L AS BA) CADMIUM TOTAL RECOV- ERABLE (UG/L AS CD) CHRO MIUM, TOTAL RECOV- ERABLE (UG/L AS CR) LEAD,. TOTAL RECOV- ERABLE (UG/L AS PB) MERCURY TOTAL RECOV- ERABLE (UG/L AS HG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERABLE (UG/L AS AG) OCT , 1983 25... 21 DEC 06... MAR , 1984 22... APR 12... JUL 12... 5.3 AUG 31... 62 .64 .24 2.6 2.3 .25 3.6 2 3 100 <100 -- 1 <1 2 <1 4 2 <.1 .6 <1 <1 <1 1 116 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°14'39", long 66°08'39", at bridge on Highway 156, and 2.9 mi (4.7 km) west of Aguas Buenas plaza. DRAINAGE AREA.--18.5 sq mi (47.9 sq km). PERIOD OF RECORD.--Water years 1958-65, 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP­ SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PM TJR­ OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STANO­ TEMPER- PIO­ DIG- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE A40 ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 07... 1010 28 242 8.0 24.5 15 3.5 105 160 390 DEC 15... 1400 21 250 8.4 23.5 2.0 9.3 119 <10 K160 220 MAR , 1934 14... 1620 26 235 8.7 24.5 3.5 3.3 139 12 K110 460 MAY 04... 0930 le 243 8.0 24.0 1.1 13.5 128 <10 200 700 JUL 10... 1040 12 279 7.8 25.0 4.4 8.6 107 320 630 AUG 15... 1030 26 213 7.8 25.5 3.5 3.3 110 <10 K730 300 MARC- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SLUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- ors- 01$- DIS- SORP- 3IS- 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) OCT , 1933 07... 92 0 21 9.5 17 .8 2.1 92 10 16 .10 DEC 15... 93 MAR , 1984 14... 90 MAY 04... 87 0 19 9.6 17 .8 1.9 93 9.4 17 .10 JUL 10... 107 AUG 15... 77 0 18 7.3 13 .7 3.0 80 11 16 .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. 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) (4G/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1933 07... 25 160 12 8 (.01 .40 <.01 .50 .90 DEC 15... 4 -..". <.01 .60 .04 .36 .40 1.0 MAR , 1984 14... 4 <.01 .20 .08 .32 .40 .60 MAY 04... 23 150 7.4 2 <.01 .20 <.01 .90 1.1 JUL 10... 5 .68 .02 .70 .01 .69 .70 1.4 AUG 15... 20 140 9.2 5 .19 .01 .20 .04 .36 .40 .60 K = non-ideal count' 117 RIO DE BAYAMON BASIN 50047600 RIO DE BAYAMON NEAR AGUAS BUENAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHR1- BARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- P'lOS- 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 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 P8) AS HG) AS SE) AS AG) OCT , 1983 07... 4.0 .06 2 200 1 3 4 .1 <1 <1 DEC 15... 4.4 .05 MAR . 1934 14... 2.7 .04 MAY 04... 4.9 .33 1 100 1 7 1 .1 <1 <1 JUL 10... 6.2 .04 AUG 15... 2.7 .08 118 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'32", long 66°07'59", at bridge on Highway 833, 0.2 mi (0.3 km) upstream from Rio de Bayamin, and 2.3 mi (3.7 km) southeast of BayamOn Plaza. DRAINAGE AREA.--73.2 sq mi (189.6 sq km). PERIOD OF RECORD.--Water years 1958, 1964, 1971-73, 1976, 1979 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP- SPE- ors- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TOR- OXYGEN, (PER- IC AL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- DIS- UM-MC (COLS. TIME TANEOUS ANCE ARD ATURE ITT (HIGH SOLVED SCATU TR- LEVEL) (COLS./ 0ER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 17... 1335 29 374 7.4 27.5 9.6 4.5 58 56 K8000 4700 DEC 19... 1220 19 435 7.3 25.5 23 1.4 17 27 4500 700 MAR , 1984 20... 1135 13 450 7.9 25.0 5.3 3.6 44 20 K7700 740 MAY 11... 1055 7.7 568 7.2 26.0 1.5 .0 0 56 >60000 3300 JUL 09... 1250 21 506 7.3 29.0 4.0 3.0 39 21 K1200 440 AUG 27... 1215 56 330 7.4 27.0 1.8 5.1 64 10 K550000 K93000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUD- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- 015- 015- On- SORP- DIS- cIELO On- DIS- OIS- (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 504) AS CL) AS F) OCT 1983 17... 140 DEC 19... MAR , 1934 20... MAY 11... 150 JUL 09... AUG Z7... 110 6 38 11 25 1 3.6 134 21 30 .20 161 154 0 41 12 42 2 5.9 187 23 51 .20 156 0 31 3.3 20 .8 3.7 113 26 25 .10 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. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (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 5102) (MG/L) DAY) CMG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1933 17... 27 240 18 35 .42 .08 .50 2.0 .40 2.4 2.9 DEC 19... 6 .07 .03 .10 3.2 .20 3.4 3.5 MAR ,1984 20... 4 .01 <.10 3.0 .70 3.7 MAY 11... 29 320 6.5 5 .02 <.10 8.1 .00 6.6 JUL 09... 8 .08 .02 .10 3.2 .60 3.8 3.9 AUG 27... 20 200 31 75 1.1 .09 1.2 1.4 1.2 2.6 3.8 K = non-ideal count 119 RIO DE BAYAMON BASIN 50047990 RIO GUAYNABO NEAR BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GEN, TOTAL (MG/L AS NO3) PROS- PMORUS, TOTAL (MG/L AS P) ARSENIC TOTAL (UG/L AS AS) 3ARIUM, TOTAL RECOV - ERA3LE (UG/L AS BA) CADMIUM TOTAL RECOV- ERABLE (UG/L AS CO) CHRO- MIUM, TOTAL RECOV- ERA3LE (UG/L AS CR) LEAD, TOTAL RECOV- ERABLE (UG/L AS P3) MERCURY TOTAL RECOV- ERABLE (UG/L AS MG) SELE- NIUM, TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERA3LE (UG/L AS AG) OCT . 1983 17... 13 DEC 19... 15 MAR , 1984 20... MAY 11... JUL 09... 17 AUG 27... 17 .58 1.0 .45 2.2 .92 .35 1 2 100 100 <1 2 <1 <1 1 1 <.1 .3 <1 <1 <1 <1 120 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'29", long 66°09'04", at bridge on Highway 890, 1.0 (1.6 km) downstream from bridge on Highway 2, and 3.2 mi (5.1 km) above mouth. DRAINAGE AREA.--71.9 sq mi (186.2 sq km). PERIOD OF RECORD.--Water years 1974 to current year. REMARKS.--Prior to 1979 sampling site was 0.8 mile (1.3 km) downstream but was changed because of flood channel construction. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN CCLI- STREP- SPE- 015- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOW, CON- PH TJR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- ors- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARC ATURE ITT SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1933 17... 1045 74 316 7.4 26.5 65 5.3 62 40 K113000 K44000 DEC 19... 0950 35 412 7.2 25.0 3.2 4.2 51 17 550 K600 MAR , 1984 22... 1035 20 476 7.8 26.5 5.6 7.8 97 13 K600 MAY 09... 1535 19 558 7.6 31.0 2.9 8.0 108 23 410000 36000 JUL 09... 1040 26 423 7.2 29.0 9.4 4.8 62 12 4600 990 AUG 28... 1525 50 356 7.4 30.5 7.5 5.0 66 13 30000 500 HARD- MANE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD-. NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- 015- DIS- SORP- DIS- FIELD DIS- DIS- DI'S- (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 C) OCT , 1983 17... 120 3 31 9.9 19 .8 2.9 115 17 22 .20 DEC 19... 153 MAR , 1984 22... 179 MAY 09... 160 0 41 13 38 1 5.0 187 24 48 .20 JUL 09... 152 AUG 28... 130 0 35 11 22 .9 3.3 133 27 27 .20 SOLIDS, SILICA, SUM OF SOLIDS, SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- DIS- CONSTI- SOLVED TUENTS, DIS- AT 105 GEN, GEN, SOLVED DEG. Cr NITRATE NITRITE GEN, NO2+NO3 GEN, GEN, MONIA + AMMONIA ORGANIC ORGANIC NITRO- GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE AS SI02) SOLVED (MG/L) PER DAY) PENDED (MG/L) (MG/L AS N) (M3/L AS N) (MG/L AS N) (MG/L AS N) (MG/L AS N) (MG/L AS N) (MG/L AS N) OCT • 1983 17... 23 190 39 110 .55 .15 .70 1.2 1.0 2.2 2.9 DEC 19... 6 .30 .10 .40 2.5 .60 3.1 3.5 MAR • 1984 22... .15 .15 .30 3.5 .80 4.3 4.6 MAY 09... 29 310 16 20 .11 .09 .20 9.4 .00 9.0 9.2 JUL 09... 24 .46 .14 .60 1.6 .00 1.6 2.2 AUG 28... 24 230 30 38 .40 .20 .60 .89 .61 1.5 2.1 K = non-ideal count 121 RIO DE BAYAMON BASIN 50048510 RIO DE BAYAMON AT FLOOD CHANNEL AT BAYAMON, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 PS) AS HG) AS SE) AS AG) OCT , 1983 17... 13 .42 1 <100 1 8 5 <.1 <1 <1 DEC 19... 15 .97 MAR , 1994 22... 20 .44 MAY 09... 41 1.7 2 100 2 1 3 .2 <1 (1 JUL 09... 9.7 .42 AUG 28... 9.3 .39 - - CHLOR- DI- PC 8, 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) JUL r 1984 09... 1040 <.1 <.01 <.1 <.01 <.01 (.01 .16 HEPTA- METH- DI- ENDO- HE'TA- CHLOR MALA- OXY- ELORIN 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) JUL 1984 09... <.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) JUL , 1984 09... <.01 <.01 <.01 <.01 .10 <.1 <1 <.01 122 RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°22'15", long 66°03'40", at bridge on Winston Churchill Avenue in the El Senorial Housing area, 0.5 mi (0.8 km) west of Highway 176, and 2.5 mi (4.0 km) southwest of Rio Piedras plaza. DRAINAGE AREA.--8.17 sq mi (20.9 sq km). PERIOD OF RECORD.--Water years 1972 to current year. WATER QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLT- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TJR- 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) OCT , 1983 12... 1235 5.8 328 7.7 27.0 ?.2 3.2 103 71 37000 K12000 DEC 12... 1125 5.0 376 7.4 23.5 2.4 6.1 71 15 50000 7200 MAR , 1984 20... 1445 4.5 382 7.9 25.3 16 5.6 105 23 K82000 40000 MAY 10... 0940 1.9 390 7.4 25.5 1.0 8.0 98 12 K1400 900 JUL 9... 1240 4.0 429 7.9 27.5 5.4 7.8 99 <10 4300 5900 AUG 24... 1210 3.6 352 7.8 27.0 .70 3.3 103 <10 3500 4500 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO-- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- CIS- On- SORP- DIS- FIELD DIS- DIS- DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MS/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) OCT , 1983 12... 120 3 31 9.4 20 .8 2.5 115 19 25 .10 DEC 12... 140 MAR , 1984 20... 143 MAY 10... 150 0 39 12 26 1 1.8 157 15 29 .20 JUL .... -- 09... 142 AUG 24... 130 0 35 11 22 .9 2.1 135 16 27 .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 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) OCT , 1983 12... 30 208 3.3 10 .79 .01 .80 .18 .42 .60 1.4 DEC ... 12... 26 1.1 .17 1.3 .75 .00 .70 2.0 MAR , 1984 20... 4 .77 .13 .90 .64 .26 .90 1.8 MAY 10... 35 250 1.3 4 .18 .02 .20 .61 4.4 5.0 5.2 JUL .... 09... 9 .47 .03 .50 .57 .00 .50 1.0 AUG 24... 35 230 2.2 14 <.01 .40 .12 .48 .60 1.0 K = non-ideal count RIO PUERTO NUEVO BASIN 50048800 RIO PIEDRAS NEAR RIO PIEDRAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO- 8ARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, NITRO- PROS- 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 P8) AS HG) AS SE) AS AG) OCT , 1983 12... 6.2 .21 3 300 1 4 3 <.1 <1 <1 DEC 12... 8.9 .34 MAR , 1984 20... 8.0 .37 - - MAY 10... 23 .23 2 100 2 <1 <1 .1 <1 <1 JUL 09... 4.4 .15 - - - - AUG 24... 4.4 .24 CHLOR- DI- PCB, ALDRIN, DANE, ODD, ODE, DDT, AZINON, TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/I) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUL , 1984 09... 1240 <.1 <.01 <.1 <.01 <.01 <.01 .01 HEPTA- D/- ENDO- HEPTA- CHLOR MALA- ELDRIN SULFAN, ENDRIN, ETHION, CHLOR, EPDXIDE LINOANE THION, 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) METH- OXY- CHLOR, TOTAL (UG/L) JUL 1984 09... <.01 <.01 <.01 <.01 <.01 <.01 <.01 .02 (.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) JUL , 1984 09... .01 (.01 <.01 <.01 <.10 <.1 <1 (.01 123 124 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'34", long 66°04'10", at bridge on Avenida Pifiero at Expreso Las Americas, and 0.8 mi (1.3 km) southwest of Hato Rey. DRAINAGE AREA.--15.4 sq mi (39.9 sq km). PERIOD OF RECORD.--Water years 1971 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN CDLI- 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 ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHas) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 12... 1455 14 372 7.6 30.5 23 5.6 75 67 333000 K15000 DEC 12... 1320 13 416 7.5 27.5 1.3 5.6 34 17 K120000 5000 MAR , 1984 19... 1355 11 411 8.2 30.5 2.5 6.7 89 15 K7900 K1300 MAY 10... 1215 10 432 7.6 30.0 7.8 7.5 130 15 29000 2100 JUL 09... 1555 11 436 7.9 30.0 5.1 4.6 61 18 380000 34000 AUG 24... 0945 9.4 387 7.4 27.5 3.0 4.6 58 24 K17000 9000 HARD- MAGNF- SODIUM POTAS- ALKA- CHIC- FLUO- HARD- NESS. CALCIUM SIUM, SODIUM, AD- SLUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- On- OIS- DIS- SORP- DIS- FIELD On... DIS- DIS- DATE (MG/L AS CAC03) 80NATE (MG/L CAC03) SOLVEO (MG/L AS CA) SOLVED (MG/L AS MG) SOLVED (MG/L AS NA) TION RATIO SOLVED (MG/L AS K) (MG/L AS CAC03) SOLVED (MG/L AS SO4) SOLVED (MG/L AS CL) SOLVED (MG/L AS F) OCT , 1983 12... 130 0 37 9.2 24 .9 3.4 131 17 28 .20 DEC 12... 148 MAR , 1984 19... 151 MAY 10... 140 0 41 11 34 1 3.6 161 20 38 .20 JUL 09... 153 AUG 24... 140 0 41 9.6 26 1 3.4 147 19 30 .20 SOLIDS, SOLIDS, NITRO.... SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO... NITRO- GEN,A4... 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 DATE AS SI02) SOLVED (MG/L) PER DAY) PENOED (MG/L) (MG/L AS N) (MG/L AS N) (MGIL AS 4) (MG/L AS N) (MG/L AS N) (MG/L AS N) (MG/L AS N) OCT , 1983 12... 27 224 8.5 12 1.1 .16 1.3 .88 .22 1.1 2.4 .EC 12... 24 1.5 .23 1.7 1.1 .40 1.5 3.2 MAR , 1984 19... 4 1.1 .11 1.2 .21 1.7 1.9 3.1 MAY 10... 28 270 7.3 18 .47 .13 .60 1.5 3.6 5.1 5.7 JUL 09... 14 .92 .18 1.1 .94 .56 1.5 2.6 AUG 24... 28 250 6.2 2 1.0 .16 1.2 .39 .81 1.2 2.4 K = non-idoal count 125 RIO PUERTO NUEVO BASIN 50049100 RIO PIEDRAS AT HATO REY, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 ERA8LE ERABLE ERA3LE TOTAL ERABLE (MG/L (MG/L (UG/L (UG/L (UG/L (UG/L CUG/L (UG/L (UG/L (UG/L DATE AS NO3) AS P) AS AS) AS 3A) AS CD) AS CR) AS P3) AS MG) AS SE) AS AG) OCT , 1983 12... 11 .52 3 200 2 4 9 <.1 <1 <1 DEC 12... 14 .95 MAR , 1984 19... 14 .52 MAY 10... 25 .80 2 100 2 3 14 1.1 <1 <1 JUL 09... 12 .54 AUG 24... 11 .47 126 RIO PUERTO NUEVO BASIN 50049820 LAGUNA SAN JOSE NO. 2 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°25'46", long 66°02'10", 0.2 mi (0.3 km) east of Cafio de Martin Pena, and 650 ft (200 m) south of Isla Guachinango. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, COLI- STREP- SOLIDS, SPE- DIS- FORM, TOCOCCI ALKA- RESIDUE CIFIC SOLVED FECAL, FECAL, LINITY AT 105 SAM- CON- PH OXYGEN, (PER- 0.7 KF AGAR FIELD DEG. Cr PLING DUCT- (STAND- TEMPER- DIS- JM-MF (COLS. (MG/L SUS- TIME ANCE ATURE CENT ?ENDED DEPTH ARD SOLVED SATUR- (COLS./ PER AS (FEET) (UMHOS) UNITS) (DEG C) (143/L) ATION) 100 ML) 100 ML) CACO3) (MG/L) OCT , 1933 25... 0850 1.00 15500 9.4 29.5 4.4 61 K740 2700 100 44 DEC 06... 1030 1.00 18403 7.9 23.0 2.0 27 110090 9500 137 62 MAR , 1984 21... 1040 1.00 25000 8.8 27.0 8.6 117 47000 540 149 50 APR 12... 1335 1.00 30000 9.0 30.0 18.0 264 600 K170 166 53 JUL 11... 1115 1.00 21500 9.1 29.0 10.2 142 9900 510 131 26 AUG 31... 1125 1.00 19000 8.9 30.5 10.0 140 20000 500 135 10 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GFN,AM- GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PROS- CARBON, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS, ORGANIC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS C) OCT , 1983 25... .08 .02 .10 .63 3.9 4.5 4.6 20 .39 6.7 DEC 06... .04 (.10 2.3 1.3 4.1 .61 14 MAR , 1984 21... .03 <.10 .31 3.5 3.8 .61 10 APR 12... .02 (.10 .14 5.1 5.2 .65 15 JUL 11... .05 .05 .10 .79 .81 1.6 1.7 7.5 .31 13 AUG 31... <.01 <.10 .08 2.6 2.7 .48 9.5 K = non-ideal count DATE 127 RIO PUERTO NUEVO BASIN 50049920 BAHIA DE SAN JUAN NO. 5 AT SAN JUAN, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°26 37", long 66°05'11", 0.4 mi (0.6 km) west of Puente de la Constituci6n, and 0.5 mi (0.8 km) south from U.S. Naval Reservation. DRAINAGE AREA.--Indeterminate. PERIOD OF RECORD.--Water years 1974 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, Coil- STREP- SOLIDS, SPE- OIS- FORM, TOCOCCI ALKA-. RESIDUE CIFIC SOLVED FECAL, FECAL, LINITY AT 105 SAM- CON- PH OXYGEN, (PER- 0.7 KF AGAR FIELD DEG. C, PLING DUCT- (STAND- TEMPER- On- CENT UM-MF (COLS. (MG/L SUS- TIME DEPTH ANCE ARO ATURE SOLVED SATUR- (COLS./ PER AS PENDED DATE (FEET) (UMHOS) UNITS) (DEG C) (MG/L) ATION) 100 ML) 100 ML) CAC03) (MG/L) OCT , 1983 25... 1035 1.00 44300 8.0 29.5 4.4 67 K7000 K1000 123 98 DEC 06... 1125 1.00 47400 8.0 23.5 5.2 79 2000 K600 124 222 MAR , 1934 21... 1215 1.00 45100 8.1 28.0 5.1 77 37000 K180 138 116 APR 12... 1155 1.00 44000 7.8 23.5 4.1 62 K2303000 41000 141 56 JUL 11... 1300 1.00 14600 7.4 28.3 1.5 20 230000 74000 145 30 AUG 31... 1350 1.00 15000 7.9 29.0 4.2 57 K180000 9800 91 24 NITRO- NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- GEN, GEN, GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- CARBON, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS, ORGANIC TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE AS N) AS N) AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) AS C) OCT , 1983 25... <.01 <.10 .57 .73 1.3 .28 4.0 DEC 06... .09 .01 .10 .42 .28 .70 .80 .20 4.0 MAR , 1984 21... .03 <.10 .75 .55 1.3 .35 3.8 APR 12... .05 .05 .10 1.4 .80 2.2 2.3 10 .57 4.0 JUL 11... <.01 <.10 .09 2.? 3.0 -- .45 7.4 AUG 31... .03 <.10 .49 .71 1.2 .30 K . non-ictal count 4.0 129 Coostoi Dosin Cocmiol lads:o 40620 RIO GRANDE a Rio Pierfros bdsin EE .'3 7- , , ',' I 11- Aeons, 57 •, :{."-c7 , --------- (, Ri`o floprs (fr----•-•-----644 \,., Ban+a bash, go I..o,:zo ', fl}' \ '') \ '- / 057 ( / i 05705 \ . ''''''"'' / a ....:111 1........„. 52 5i615 . ...- tr...00, Cif' / .-- •.. . ) 1 ,' 1.-- , 654 55310 '; AGUAS BUENAS 5a 250 ? ';';agb%cs , N't- N\ 05 0556. e765 05 it' 64 \ ....,. i 1 \ ( \ 051140 , 51 Reb de to Pkno basin rooms bosin EXPLANATION A0509 SURFACE—WATER STATION AND NUMBER Rki i7f,tneht A0619 LOW—FLOW STATION A Pat bosi AND NUMBER V 0564 QUALITY—OF—WATER Mop +area 7 6tioyones basis STATION AND NUMBER 52 WELL AND WELL NUMBER ?,,,tAYAGVEX A S Figure 17.--Rio Grande de Loiza basin. 1 130 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°23'27", long 65°58'28", at bridge on Highway 3, 1.4 mi (2.3 km) south of Valle Arriba Heights housing area, and 1.2 mi (1.9 km) west-southwest of Carolina plaza. DRAINAGE AREA.--2.96 sq mi (7.67 sq km). PERIOD OF RECORD.--Water years 1973 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP.. SPE". ors- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- PH TUR- 3XYGEN, (PER... ICAL 0.7 KF AGAR I4STAN.... DUCT- (STAND- TEMPER- BID- DIS-. CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARC ATURE ITY SOLVED SATUR... LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) CMG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 12... 0950 5.6 588 7.2 23.5 (1.0 .0 0 130 K6400000 5200000 DEC 08... 0905 7.6 588 7.2 25.0 5.3 .0 0 100 K1000000 2400000 MAR , 1984 15... 0935 5.2 556 7.7 25.5 53 .4 5 67 3700030 4300000 MAY 02... 1445 4.0 679 7.4 27.5 2.4 .0 0 100 11000000 4400000 JUN 23... 1410 6.9 605 7.2 30.0 3.3 3.0 106 83 2300000 28000 AUG 22... 1000 6.4 493 7.4 29.0 5.5 1.2 15 43 K1300000 K190000 HARD- MAGNE- SODIUM POTAS- ALKA-.. CHLO- FLUO- HARD.- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE. RIDE. NESS NONCAR- DIS- DM'. DIS." SOR0- DIS- FIELD DIS- DIS- DIS DATE (MG/L BONATE AS (MG/L CACO3) CACO3) SOLVED SOLVED (MG/L (MG/L AS CA) AS MG) SOLVED (MG/L AS NA) TION SOLVED (MG/L SOLVED SOLVED RATIO (MG/L AS (MG/L (MG/L AS K) C4CO3) AS SO4) AS CL) SOLVED (MG/L AS F) OCT • 1983 12... 150 0 48 3.4 45 2 5.7 134 19 49 .20 DEC OS... 174 MAR , 1984 15... .... 134 MAY 02... 150 0 46 9.1 56 2 6.5 201 24 74 .20 JUN 28... 174 AUG 22... 140 0 42 8.0 39 2 6.2 169 28 45 .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 lITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (TONS SUS- TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL AS SOLVED PER FENDED (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE SI02) (MG/L) DAY) (MGM AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT • 1933 12... 29 310 4.8 6 <.01 <.10 7.9 8.1 16 DEC 03... 22 .04 (.10 8.4 5.6 14 MAR • 1934 15... •...•. •....... 60 -- .02 <.10 8.0 3.0 11 MAY 02... 24 360 3.8 12 .02 <.10 8.8 6.2 16 JUN 23... 14 .09 .01 .10 9.9 2.1 12 12 AUG 22... 19 290 5.0 54 .77 .13 .90 6.0 2.5 8.5 9.4 K = non-ideal count 131 RIO GRANDE DE LOIZA BASIN 50050300 QUEBRADA BLASINA NEAR CAROLINA, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GEN, TOTAL (MG/L AS NO3) PHOS- PHORUS, TOTAL (MG/L AS P) CMR0- SARIUM, CADMIUM MIUM, LEAD, MERCURY SILVER, TOTAL TOTAL TOTAL TOTAL TOTAL SELF- TOTAL ARSENIC RECOV - RECOV- RECOV- RECOV- RECOV- NIUM, RECOV­ TOTAL ERA3LE ERA3LE ERA3LE ERABLE ERABLE TOTAL ERABLE (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L AS AS) AS 3A) AS CO) AS CR) AS P3) AS HG) AS SE) AS AG) OCT • 1983 12... DEC 08... MAR , 1984 15... MAY 02... JUN 28... 53 AUG 22... 42 .26 .22 1.6 3.3 3.0 . 1.7 4 2 200 <100 1 1 2 1 2 7 (.1 .3 <1 <1 <1 <1 132 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.--7 years (1978-84), 30.6 cu ft/s (0.866 cu m/s), 69.26 in/yr (1,759 mm/yr), 22,170 acre-ft/yr (27.3 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 11,700 cu ft/s (331 cu m/s) Nov. 5, 1983, gage height 14.78 ft (4.505 m), 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) Nov. 5 1845 *11,700 331 14.78 4.505 June 10 0815 2,590 73.3 8.85 2.697 Feb. 15 2030 4,410 125 10.46 3.188 Sept. 17 1345 2,600 73.6 8.86 2.700 June 10 0515 2,850 80.7 9.11 2.777 Sept. 20 0715 2,880 81.6 9.14 2.786 Minimum discharge, 4.2 cu ft/s (0.119 cu m/s) May 21. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 37 40 12 20 8.7 14 7.8 5.4 31 33 14 24 2 24 15 191 14 8.6 13 7.2 5.5 15 21 18 15 3 21 16 23 13 12 13 7.5 5.4 12 18 13 45 4 19 289 18 12 17 12 7.2 5.5 17 63 50 18 5 17 736 16 11 14 11 7.6 5.2 21 157 18 34 6 16 119 19 11 14 12 8.0 6.0 75 32 15 21 7 16 41 15 11 12 11 8.1 5.5 134 24 13 15 8 15 31 15 10 9.5 11 7.5 5.1 40 21 12 14 9 30 27 14 12 9.2 12 7.1 5.2 24 20 12 13 10 16 23 14 21 13 9.5 7.2 7.4 369 19 11 23 11 15 22 15 11 10 8.9 7.5 5.4 44 19 11 18 12 17 20 14 12 107 8.7 6.9 5.2 45 18 11 44 13 34 19 13 69 87 9.0 6.4 6.1 44 18 10 42 14 19 18 12 49 33 16 6.4 5.7 32 24 9.9 56 15 23 17 14 17 372 9.1 6.4 5.3 24 21 11 25 16 17 18 15 17 137 8.7 6.4 4.9 31 13 12 36 17 14 17 14 32 36 9.4 6.6 4.6 25 17 11 207 18 28 16 14 22 25 8.8 6.2 4.6 21 16 9.9 132 19 23 15 12 15 21 8.3 6.1 5.4 21 16 9.9 77 20 15 15 12 30 18 8.0 6.5 5.1 20 16 10 302 21 16 15 11 15 17 7.8 7.6 4.8 19 18 9.8 82 22 19 14 12 17 17 8.3 7.6 5.4 19 17 10 44 23 13 14 12 13 16 9.3 7.1 6.7 18 18 9.9 37 24 12 14 11 12 15 7.8 6.4 5.3 17 16 9.9 30 25 12 13 11 15 15 7.5 6.0 9.9 17 14 9.8 28 26 15 12 11 13 14 7.4 5.9 21 16 16 29 24 27 12 13 12 11 15 7.1 7.6 18 16 16 21 22 28 11 12 16 11 13 6.7 7.4 14 16 14 12 22 29 16 13 13 9.8 13 7.7 5.7 12 17 35 11 27 30 20 13 24 9.4 --- 7.1 5.5 106 21 19 13 31 31 13 --- 41 3.9 6.7 --- 26 --- 14 14 --- TOTAL 575 1647 646 544.1 1099.0 296.8 207.4 337.6 1221 788 431.1 1508 MEAN 18.5 54.9 20.8 17.6 37.9 9.57 6.91 10.9 40.7 25.4 13.9 50.3 MAX 37 736 191 69 372 16 8.1 106 369 157 50 302 MIN 11 12 11 8.9 8.6 6.7 5.5 4.6 12 14 9.8 13 CFSM 3.08 9.15 3.47 2.93 6.32 1.60 1.15 1.82 6.78 4.23 2.32 8.38 IN. 3.56 10.21 4.00 3.37 6.81 1.84 1.29 2.09 7.57 4.83 2.67 9.35 AC-FT 1140 3270 1280 1080 2180 589 411 670 2420 1560 855 2990 CAL YR 1983 TOTAL 10468.6 MEAN 28.7 MAX 736 MIN 4.9 CFSM 4.78 IN 64.89 AC-FT 20760 WTR YR 1984 TOTAL 9301.0 MEAN 25.4 MAX 736 MIN 4.6 CFSM 4.23 IN 57.66 AC-FT 18450 133 RIO GRANDE DE LOIZA BASIN 50050900 RIO GRANDE DE LOIZA AT QUEBRADA ARENAS, PR--Continued WATER QUALITY RECORDS PERIOD V' RECORD.--WAT.ER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 STREAMFLOW. SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA­ OATE TIME INSTANTANEOUS OUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UPiIOS) (DEG C) (CFS) (UMNOS) (DEG C) OCT, 12 1045 14 139 25.5 MAR. 21 1606 7.3 155 28.0 ?Olt, 07 15)8 39 172 26.0 APR, 11 1245 7.4 152 27.5 OEC, 14 1300 12 153 24.0 MAY, 21 1501 4.7 152 29.0 JAN. 13 1217 24 158 23.5 JUN. 14 1235 34 125 29.0 FES, 16 1308 79 39 22.5 AUG, 16 1030 12 145 28.0 MAR. 09 1023 16 145 22.0 134 RIO GRANDE DE LOIZA BASIN 50051180 QUEBRADA SALVATIERRA NEAR SAN LORENZO, PR LOCATION.--Lat 18°10'24", long 65°58'38", Hydrologic Unit 21010005, on left downstream side of bridge on Highway 181, 0.2 mi (0.3 km) upstream from Rio Grande de Loiza, and 1.5 mi (2.4 km) southwest of San Lorenzo. DRAINAGE AREA.--3.74 sq mi (9.69 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January to September, 1984. GAGE.--Water-stage recorder. Altitude of gage is 330 ft (100 m), from topographic map. REMARKS.--Records fair. EXTREMES FOR CURRENT PERIOD.--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) Feb. 15 1930 1,430 40.5 9.31 2.838 June 10 0700 *6,300 178 15.12 4.609 Minimum discharge, 0.69 cu ft/s (0.020 cu m/s) Apr. 9-13, 15,16. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 2.0 1.7 1.6 .86 .96 1.8 1.9 4.1 2.2 2 1.8 1.5 1.6 .86 .93 1.5 2.3 6.2 1.8 3 1.7 1.5 1.6 .86 .97 1.2 1.4 1.4 1.7 4 1.6 1.9 1.5 .31 1.0 1.3 30 6.6 1.9 5 1.5 1.6 1.5 .80 .93 1.2 64 2.3 16 6 1.5 1.5 1.5 .82 .93 10 6.2 1.3 5.4 7 1.5 1.5 1.5 .84 .97 26 2.8 1.1 2.7 8 1.5 1.5 1.4 .85 1.0 9.8 2.0 .99 2.1 9 1.6 1.9 1.4 .74 .97 5.3 1.7 .95 2.2 10 1.8 4.2 1.4 .71 1.1 295 1.8 .86 2.6 11 1.6 3.7 1.3 .72 1.2 15 1.5 .83 2.3 12 3.2 8.8 1.3 .71 1.1 7.0 1.3 .83 4.7 13 14 33 1.3 .72 1.8 20 1.1 .82 19 14 12 11 1.4 .74 2.1 9.9 1.5 .82 86 15 3.8 106 1.3 .74 1.4 5.9 1.5 .84 10 16 2.6 88 1.2 .73 1.3 5.9 1.2 1.0 11 17 2.0 6.6 1.2 .77 1.2 5.3 1.1 .92 24 18 1.7 3.3 1.2 .80 1.1 3.8 .97 .89 54 19 1.7 2.3 1.2 .79 1.1 3.2 1.0 .89 41 20 14 1.9 1.1 .80 1.1 2.6 1.1 1.1 95 21 3.5 1.7 1.1 .86 1.1 2.3 1.6 1.0 38 22 1.8 1.6 1.1 .93 1.0 2.1 1.3 .87 13 23 1.7 1.6 1.2 .93 1.1 1.8 1.2 .87 7.3 24 1.8 1.6 1.2 .93 1.1 1.7 1.0 .82 5.2 25 1.8 1.6 1.1 .90 2.0 1.6 .98 .34 4.2 26 1.7 1.6 1.0 .93 14 1.8 1.1 2.8 3.7 27 1.7 1.7 1.0 1.4 2.1 1.5 .98 3.8 3.4 28 1.9 1.7 .97 1.7 2.2 1.4 .99 2.4 3.7 29 1.7 1.6 .96 1.1 1.5 2.0 1.7 1.7 3.1 30 1.6 --- .91 1.0 18 1.6 2.3 16 5.0 31 1.6 .88 --- 3.1 --- 1.3 4.1 --- TOTAL 93.9 298.1 38.92 26.35 70.36 449.5 140.82 69.94 472.2 MEAN 3.03 10.3 1.26 .88 2.27 15.0 4.54 2.26 15.7 MAX 14 106 1.6 1.7 18 295 64 16 95 MIN 1.5 1.5 .88 .71 .93 1.2 .97 .82 1.7 CFSM .81 2.75 .34 .24 .61 4.01 1.21 .60 4.20 /N. AC-FT .93 186 2.96 591 .39 .26 .70 4.47 77 52 140 892 1.40 279 .70 139 4.70 937 WATER QUALITY RECDROS PERIOD OF RECORD.--FEBRUARY TO SEPTEMBER 1984 WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 STREAMFLOW, SPECI.IC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS OUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UMHOS) (DEG C) FEB. 09 1125 1.4 463 23.0 JUN, 14 1011 18 24 28.0 MAR, 08 1000 1.4 412 23.5 AUG, 15 1320 0.9 243 30.5 MAY, 17 113C 1.2 414 29.0 135 \ RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR LOCATION.--Lat 18°09'13", long 65°57'20", Hydrologic Unit 21010005, at downstream side on bridge on Highway 912, at Barrio Cerro Gordo, 2.8 mi (4.5 km) south of San Lorenzo. DRAINAGE AREA.--10.2 sq mi (26.4 sq km). WATER DISCHARGE RECORDS PERIOD OF RECORD.--October 1977 to current year. GAGE.--Water-stage recorder. Altitude of gage is 490 ft (150 m), from topographic map. Prior to Oct. 1, 1983, at site 2,000 ft (610 m) downstream at different datum. REMARKS. - -Records fair. AVERAGE DISCHARGE.--7 years (1978-84), 47.9 cu ft/s (1.356 cu m/s), 63.77 in/yr (1,620 mm/yr), 34,700 acre-ft/yr (42.8 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) site and datum then in use, 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) Nov. 5 1915 2,940 83.3 13.83 4.215 June 10 0800 3,030 85.8 13.97 4.258 Feb. 15 2045 *4,530 128 15.98 4.871 Minimum daily discharge, 11 cu ft/s (0.312 cu m/s) Apr. 30, May 1-5, 7-9, 11,12, 15-20. DISCHARGES IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 53 188 29 35 27 22 16 11 51 35 32 19 2 33 54 306 26 26 22 15 11 26 34 43 18 3 29 29 52 24 29 22 15 11 21 27 28 18 4 27 440 39 23 32 21 15 11 27 126 105 27 5 27 478 36 22 29 21 15 11 20 167 33 46 6 27 194 39 22 31 22 15 12 44 38 23 43 7 29 74 34 22 30 21 15 11 195 29 24 21 8 29 52 28 21 27 22 14 11 74 26 23 21 9 41 42 25 24 27 26 14 11 42 25 22 18 10 31 37 26 38 30 24 13 13 542 24 20 22 11 27 35 26 22 29 22 13 11 99 24 21 47 12 27 33 24 24 100 23 13 11 62 24 21 39 13 31 32 23 130 129 25 13 12 72 24 21 64 14 31 32 23 85 48 37 13 12 47 26 25 155 15 31 33 26 40 567 29 13 11 34 26 22 41 16 33 32 33 35 464 31 13 11 66 24 25 29 17 25 30 31 33 52 36 14 11 48 23 19 118 18 23 30 31 33 32 30 13 11 37 23 19 89 19 37 30 29 31 25 25 13 11 37 24 21 70 20 22 30 32 49 23 23 12 11 33 25 18 332 21 22 30 25 33 23 21 13 12 32 27 19 94 22 25 29 23 37 22 20 13 12 30 30 16 46 23 21 29 23 32 22 22 13 17 29 31 17 37 24 20 29 22 31 22 19 12 13 28 26 14 33 25 20 28 22 38 22 18 12 26 26 24 14 31 26 24 28 22 34 22 17 12 30 27 24 17 31 27 20 29 23 32 23 17 13 19 27 24 51 30 28 19 28 29 33 23 17 17 27 27 23 22 36 29 25 28 25 29 22 18 13 27 28 27 18 32 30 31 27 40 28 --- 17 11 132 34 34 20 40 31 21 --- 75 27 16 --- 39 --- 25 18 --- TOTAL 861 2190 1221 1093 1958 706 406 579 1865 1069 791 1647 MEAN 27.8 73.0 39.4 35.3 67.5 22.8 13.5 18.7 62.2 34.5 25.5 54.9 MAX 53 478 306 130 567 37 17 132 542 167 105 332 MIN 19 27 22 21 22 16 11 11 20 23 14 18 CFSM 2.73 7.16 3.86 3.46 6.62 2.24 1.32 1.83 6.10 3.38 2.50 5.38 IN. 3.14 7.99 4.45 3.99 7.14 2.57 1.48 2.11 6.80 3.90 2.88 6.01 AC-FT 1710 4340 2420 2170 3880 1400 805 1150 3700 2120 1570 3270 CAL YR 1983 TOTAL 14951.4 MEAN 41.0 MAX 806 MIN 8.2 CFSM 4.02 IN 54.52 AC-FT 29660 NTR YR 1984 TOTAL 14386.0 MEAN 39.3 MAX 567 MIN 11 CFSM 3.85 IN 52.46 AC-FT 28530 136 RIO GRANDE DE LOIZA BASIN 50051310 RIO CAYAGUAS AT CERRO GORDO, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1911 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1934 DATE TIME STREA0FLO4, INSTANTANEOUS (CFS) SPECIFI: CC'- DUCTANCE (UmHOS) TEMPERA- TUBE (DEG C) DATE TIME STREAMFLOW, INSTANTANEOUS (CFS) SPECIFIC CON- DUCTANCE (UM1OS) TEMPERA- TURF (DEG C) OCT, NOV, DEC, JAN, =F.°, MAR, 12 07 14 1R 16 09 1236 1244 1030 0937 1343 1320 27 73 24 32 130 28 125 104 140 219 61 128 27.0 25.5 22.0 22.0 21.5 26.0 MAR, APR, MAY, JUN, AUG, 23 1400 11 1610 21 1246 13 1173 16 1310 17 14 12 93 26 132 135 143 93 123 29.0 29.0 30.0 28.5 29.5 137 RIO GRANDE DE LOIZA BASIN 50053050 RIO TURABO AT BORINQUEN, PR LOCATION.--Lat 18°10'10", long 66°02'37", Hydrologic Unit 21010005, at right upstream end of bridge on Highway 765, 0.5 mi (0.8 km) south of Villa Borinquen, and 7.3 mi (11.7 km) upstream from Rio Grande de Loiza. DRAINAGE AREA.--7.89 sq mi (20.4 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1983 to September 1984. GAGE.--Water-stage recorder. Altitude of gage is 430 ft (130 m) , from topographic map. REMARKS.--Records fair. EXTREMES FOR CURRENT PERIOD.--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) Feb. 15 2145 *2,650 75.0 9.75 2.972 July 5 0130 1,740 49.3 8.52 2.597 June 10 0600 2,180 61.7 9.14 2.786 Minimum discharge, 5.9 cu ft/s (0.167 cu m/s) Apr. 28,29. DISCHARGE, IN CUBIC FEET PER SECOMD, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10 11 7.4 13 11 7.3 31 19 6.4 10 2 140 9.1 7.1 13 11 8.1 26 17 16 10 3 30 3.5 7.6 12 12 8.5 20 12 10 19 4 15 3.5 9.8 12 13 7.7 16 110 28 15 5 13 8.4 7.4 13 15 7.4 14 396 19 69 6 18 9.6 7.0 13 14 7.3 25 41 17 31 7 14 8.8 7.4 13 11 7.0 53 29 16 15 8 12 8.8 6.6 13 9.9 7.0 43 26 16 11 9 11 9.2 18 13 9.7 8.6 29 25 15 13 10 11 9.3 27 13 9.3 9.8 430 24 14 11 11 12 9.1 20 12 9.7 8.7 50 23 14 11 12 10 11 116 12 8.4 9.3 33 22 10 14 13 9.5 89 184 12 8.2 18 44 20 11 14 14 9.0 36 50 14 9.1 9.9 28 22 9.9 25 15 9.0 23 325 12 9.0 9.4 21 20 11 19 16 9.5 19 208 12 8.6 8.8 96 18 11 23 17 9.5 25 33 13 8.8 8.9 29 17 9.1 96 18 10 29 23 12 8.0 7.2 19 18 8.2 87 19 9.0 22 19 12 7.7 7.0 26 16 8.2 74 20 8.5 48 17 12 8.2 8.0 17 18 8.9 128 21 8.2 28 16 12 9.0 8.8 15 23 8.9 49 22 8.6 24 16 13 9.6 10 14 22 7.4 25 23 8.4 15 15 16 12 22 13 24 7.4 19 24 8.1 9.2 14 15 11 20 11 17 6.9 17 25 7.8 24 14 13 11 26 11 17 6.8 16 26 7.8 11 14 16 7.7 52 11 15 27 15 27 7.8 8.4 14 18 14 38 10 12 20 15 28 7.9 12 14 17 7.3 36 10 10 11 14 29 9.2 8.1 14 17 6.3 37 11 16 8.1 14 30 16 7.9 --- 16 6.6 101 13 16 10 15 31 16 7.6 12 37 8.0 10 TOTAL 475.8 557.5 1231.3 416 296.1 561.7 1169 1073.0 382.2 894 MEAN 15.3 18.0 42.5 13.4 9.87 18.1 39.0 34.6 12.3 29.8 MAX 140 89 325 18 15 101 430 396 28 128 MIN 7.8 7.6 6.6 12 6.3 7.0 10 8.0 6.4 10 CFSM 1.94 2.28 5.39 1.70 1.25 2.29 4.94 4.39 1.56 3.78 IN. 2.24 2.63 5.80 1.96 1.40 2.65 5.51 5.06 1.80 4.21 AC-FT 944 1110 2440 825 587 1110 2320 2130 758 1770 138 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.--24 years (1961-84), 218 cu ft/s (6.174 cu m/s), 32.97 in/yr (837 mm/yr), 157,900 acre-ft/yr (195 cu hm/yr); median of yearly mean discharges, 208 cu ft/s (5.89 cu m/s), 151,000 acre-ft/yr (186 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 71,500 cu ft/s (2,025 cu m/s) Sept. 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) Nov. 5 unknown *29,100 824 21.72 6.620 June 10 0845 24,300 688 20.26 6.175 Feb. 15 2215 14,500 411 16.77 5.111 Sept. 20 0900 8,080 229 13.79 4.203 Minimum discharge, 26 cu ft/s (0.736 cu m/s) May 17-19,22. DISCHARGE• IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 340 187 100 124 66 89 48 34 158 120 94 90 2 131 193 1330 83 67 85 44 33 124 142 247 93 3 277 110 219 73 67 82 46 33 85 90 100 84 4 165 2390 139 75 85 82 44 34 97 380 277 148 5 122 6500 122 74 82 77 47 34 72 1900 172 408 6 110 1700 165 70 81 81 50 33 262 276 100 283 7 110 400 127 70 77 76 51 36 668 171 87 113 8 109 286 114 71 72 74 46 35 343 138 77 87 9 150 225 105 72 109 78 43 35 198 132 74 93 10 122 194 103 93 137 81 44 44 4100 121 72 131 11 104 175 108 74 125 70 46 42 443 110 68 178 12 108 160 98 67 293 66 45 36 239 102 65 176 13 115 150 90 354 951 67 41 67 445 92 62 319 14 137 141 86 340 307 86 38 71 255 116 61 957 15 117 136 87 143 1830 72 38 50 173 131 61 253 16 150 140 91 107 2300 70 35 39 270 92 73 322 17 110 131 91 131 324 70 35 32 264 83 65 781 18 103 124 94 122 211 75 35 30 153 79 58 983 19 151 122 86 115 166 63 34 31 150 76 56 716 20 99 116 82 207 142 58 34 30 131 79 61 1720 21 113 110 32 135 129 56 38 30 116 86 66 673 22 137 107 80 109 119 59 42 30 105 102 57 326 23 94 103 88 98 110 71 35 63 95 104 55 243 24 84 102 79 86 104 63 34 55 90 85 53 197 25 81 102 75 107 100 55 31 80 87 77 50 173 26 87 100 75 87 98 53 40 202 86 73 128 157 27 79 97 80 87 97 52 80 136 81 82 300 146 28 74 96 82 83 94 49 104 139 77 71 111 152 29 86 93 82 77 91 48 46 102 95 89 76 135 30 136 103 100 71 --- 48 37 713 103 172 436 177 31 121 --- 114 68 47 --- 245 --- 93 149 --- TOTAL 3972 14593 4374 3473 3434 2103 1331 2574 9565 5464 3411 10314 MEAN 128 486 141 112 291 67.8 44.4 83.0 319 176 110 344 MAX 340 6500 1330 354 2300 89 104 713 4100 1900 436 1720 MIN 74 93 75 67 66 47 31 30 72 71 50 84 CFSM 1.43 5.41 1.57 1.25 3.24 .76 .49 .92 3.55 1.96 1.23 3.83 IN. 1.65 6.05 1.81 1.44 3.49 .87 .55 1.07 3.96 2.26 1.41 4.27 AC-FT 7880 28950 8680 6890 16730 4170 2640 5110 18970 10840 6770 20460 CAL YR 1983 TOTAL 82258 MEAN 225 MAX 6500 MIN 35 CFSM 2.51 IN 34.08 AC-FT 163200 WTR YR 1984 TOTAL 69608 MEAN 190 MAX 6500 MIN 30 CFSM 2.12 IN 28.84 AC-FT 138100 139 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 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI". STREP'' SPE'. DIS- DEMAND, FORM. TOCOCCI STREAM- CIFIC SOLVED CHEM-. FECAL, FECAL, FLOW, CON- PH TJR- OXYGEN, (PER". ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND". TEMPER-. RID- DIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANC! ARD ATURE ITY SOLVED SATUR.... LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) AT ION) (MG/L) 100 ML) 100 ML) OCT , 1933 04... 1300 156 209 7.4 27.0 60 7.6 96 13 20000 6000 DEC 13... 1105 91 243 7.4 24.5 3.9 R.6 104 <10 41000 590 MAR , 1934 13... 1210 64 245 7.9 26.0 7.5 3.0 99 12 600 K50 APR 24... 1050 40 253 7.4 27.5 13 7.9 100 <10 K1300 120 JUN 25... 1220 19 226 7.6 30.0 7.9 7.4 98 <10 K2000 40 AUG 14... 1315 61 239 7.6 31.5 2.5 8.7 117 <10 260 230 HARD- MAGNE.. SODIUM POTAS- ALKA... 'CMLO- FLUO- HARD- NESS, CALCIUM SLUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR... DIS- DIS- DIS- SORP- DIS- FIELD DIS- HS." DIS- (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED DATE AS CAC03) (MG/L CAC03) (MG/L AS CA) (MG/L AS MG) (MG/L AS NA) RATIO (MG/L AS K) AS CAC03) (MG/L AS SO4) (MG/L AS CL) (MG/L AS F) OCT , 1983 04... 61 0 15 5.3 17 1 2.3 65 12 15 .20 DEC 13... 74 MAR , 1984 13... 77 APR 24... 70 0 18 6.1 23 1 2.0 75 19 22 .20 JUN 25... 73 AUG 14... 67 0 17 6.0 22 1 2.0 71 20 21 .20 SOLIDS, SOLIDS, NITRO'". SILICA, SUM OF DIS.... CONSTI... SOLIDS, DIS.... RESIDUE AT 105 NITRO- GEN, NITRO- GEN, NITRO. . GEN, NITRO- GEN, NITRO- GEN,A*". GEN, MONIA + NITRO'". DATE SOLVED TUENTS, (MG/L DIS- AS SOLVED 5IO2) (MG/L) SOLVED DEG. Cr (TONS SUS- PER PENDED DAY) (MG/L) NITRATE NITRITE TOTAL TOTAL (MG/L (MS/L AS N) AS N) 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) GEN, TOTAL (MG/L AS N) OCT , 1933 04... 32 140 58 98 .58 .02 .60 .11 1.3 1.4 2.0 DEC 13... ...... 25 .72 .08 .80 .15 .05 .20 1.0 MAR , 1984 13... 9 .52 .08 .60 .28 .42 .70 1.3 APR 24... 32 170 18 21 .52 .08 .60 .32 1.2 1.5 2.1 JUN 25... 14 .31 .09 .40 .06 .04 .10 .50 AUG 14... 31 160 27 11 .45 .05 .50 .14 .56 .70 1.2 K = non-ideal count 140 RIO GRANDE DE LOIZA BASIN 50055000 RIO GRANDE DE LOIZA AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO- BARIUM, CADMIUM M/UM, 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 ERA3LE 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 PS) AS HG) AS SE) AS AG) OCT , 1983 04... 8.9 .22 4 100 4 4 7 <.1 <1 <1 DEC 13... 4.4 .16 -- MAR , 1984 13... 5.8 .24 -- APR 24... 9.3 .38 1 <100 1 3 4 .2 <1 <1 JUN 25... 2.2 .04 AUG 14... 5.3 .22 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) JAN, 13 1333 86 279 28.0 APR, 24 1021 40 244 28.0 MAR, 08 1247 73 235 26.0 MAY, 18 0935 34 293 29.0 APR, 13 1540 54 259 30.5 JUL, 26 1304 70 223 29.5 141 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 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP- SPE- ors- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- P4 TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- BID- OIS- CENT (HIGH UM-MF (COLS. TIME TANEOUS ANCE ARO ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT , 1983 13... 1450 9.0 528 7.6 30.0 3.4 7.0 93 14 K200000 K9100 DEC 13... 1345 12 725 7.6 27.5 16 .6 3 80 2300000 220000 MAR , 1984 12... 1255 8.3 720 7.7 27.5 9.3 7.8 99 97 K740000 220000 APR 25... 1440 3.5 718 7.6 27.5 2.5 6.6 87 15 310000 K11000 JUN 26... 1425 5.8 654 7.6 32.0 2.1 15.2 209 22 250000 5300 AUG 23... 1245 6.7 651 7.6 30.5 1.7 6.8 91 22 230000 K8000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- HARD- NESS, CALCIUM SIUM, SODIUM, AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DU- DIS- 01S- SORP- On- FIELD ors- ors- OIS- (MG/L BORATE SOLVED SOLVED SOLVED TIDN 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) OCT , 1983 13... 190 56 51 15 33 1 3.0 133 63 37 .20 DEC 13... - 194 MAR , 1984 12... 175 APR 25... 230 78 71 14 47 1 3.4 157 140 54 .40 JUN ..• .0. 26... 153 AUG 23... 210 52 60 14 44 1 4.4 156 100 50 .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. 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 (MUL (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) OCT r 1983 13... 36 320 7.7 3 .54 .06 .60 .29 .31 .60 1.2 DEC II 0 .M. alb 010 3... 1 -- 34 2.0 .48 2.5 7.8 4.2 12 15 MAR • 1984 -.. •I10 alb 12... -- 18 2.2 .14 2.3 4.0 4.0 8.0 10 APR 25... 33 460 .65 6 .10 .10 .20 2.6 2.4 5.0 5.2 JUN 26... -- -- -- 6 .92 .18 1.1 1.9 2.0 3.9 5.0 AUG 23... 32 400 7.2 4 .14 .06 .20 3.30 .90 4.2 4.4 A a non-idoal count 142 RIO GRANDE DE LOIZA BASIN 50055250 RIO CAGUITAS AT HIGHWAY 30 AT CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER. 1983 TO SEPTEMBER 1984 GATE NITRO- GEN, TOTAL (MG/L AS M03) PM0S­ PHORUS, TOTAL (MG/L AS ') ARSENIC TOTAL (UG/L AS AS) 3ARIUM, TOTAL RECOV­ ERA3LE (UG/L AS 3A) CADMIUM TOTAL RECOV­ ERAPLE (UG/L AS CO) CIRO- MIUm, TOTAL RECOV­ ERA3LE (UG/L AS :R) LEAD, TOTAL RECOV­ ERAELE (UG/L AS P3) MERCURY TOTAL RECOV­ ERA3LE (UG/L AS MG) SELE- NIOM• TOTAL (UG/L AS SE) SILVER, TOTAL RECOV- ERA3LE (UG/L AS AG) OCT • 1483 13... 5.3 DEC 13... 64 MAR , 1434 12... 46 APR 25... 23 JUN 26... 22 AUG 23... 14 .49 .35 1.2 .?1 .49 .44 1 <100 103 <1 1 7 3 2 2 <.1 <.1 <1 <1 <1 <1 143 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 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP- SPE- DIS- DEMAND, FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL, FECAL, FLOW, CON- P4 TOR- OXYGEN, (PER- ICAL 0.7 AF AGAR INSTAN- DUCT- (STAND- TEMPER- 310- DIS- CENT (HIGH UM-ME (COLS. TIME TANEOUS ANCE A'0 ATURE ITY SOLVED SATUR- LEVEL) (COLS./ PER DATE (CFS) (UMHOS) UNITS) (DEG C) (NTU) (MG/L) ATION) (MG/L) 100 ML) 100 ML) OCT . 1933 14... 10)0 2.3 447 7.6 25.3 2.4 5.2 63 27 54000 5700 DEC 16... 1255 3.3 433 7.6 25.D 4.1 7.0 35 10 K190000 9700 MAR , 1934 12... 1110 3.3 603 7.7 25.i 11 5.7 64 130 K2200000 460000 APR 26... 1020 1.2 466 7.4 26.0 1.5 3.3 41 17 24000 7200 JUN 25... 1530 2.0 479 7.4 31.3 5.2 6.6 116 13 24000 2300 AUG 22... 1305 2.5 436 7.6 2F.0 1.5 5.0 64 57 K123030 7400 HARD- mAGNE- SCJIUM POTAS- ALKA.- CHLO - FLUO- HARD- NESS, CALCIUM S!UM, SODIUM, AD- SLUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- CIS- DIS- SORP- DIS- FIELD CIS- DIS." ors- (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/1 (MG/L (MG/L DATE CAC03) CAC03) AS CA) AS MG) AS NA) AS () CAC03) AS SO4) AS CL) AS OCT , 1983 14... 153 15 35 15 28 1 4.5 134 17 46 .30 DEC 16... 143 MAR , 1934 12... 179 APR 26... 160 2 37 17 30 1 5.5 161 1 7 47 .30 JUN 25... 153 AUG 22... 153 10 35 15 33 1 7.1 139 25 45 .30 SOLIDS, SOLIDS, NITRO'. SILICA, SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO- NITRO- NITRO- GEN,AM- °IS". CONSTI- OIS- AT 105 GEN, GEN, GEN, GEN, GEN. MONIA + NITRO- SOLVED TUENTS, SOLVE) 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 OWL (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L DATE S102) CMG/L) DAY) (MG/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT , 1983 14... 33 260 1.6 4 2.0 .05 2.0 .25 .35 .60 2.6 DEC 16... 8 2.5 .08 2.6 .38 .72 1.1 3.7 MAR , 1984 12... 19 .94 .06 1.0 7.0 1.5 3.5 9.5 APR 26... 33 280 .92 2 .95 .05 1.0 .16 .92 1.1 2.1 JUN 25... 13 1.8 .07 1.9 .14 .36 .50 2.4 AUG 22... 31 270 1.9 10 2.4 .09 2.5 .57 .73 1.3 3.8 K = non-ideal count RIO GRANDE DE LOIZA BASIN 50055400 RIO BAIROA NEAR CAGUAS, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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 ERASLE ERASLE ERASLE ERA3LE TOTAL ERASLE (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 RA) AS CD) AS CR) AS PS) AS HG) AS SE) AS AG) OCT , 1933 14... 12 .78 3 190 <1 4 3 60000 8900 APR 19... 1525 17 475 1.2 21.0 13 8.3 113 27 X7400 350 JUN 22... 1900 299 309 8.1 25.0 34 7.7 95 <10 25000 4700 AUG 17... 1130 170 242 1.0 25.5 25) 3.0 98 <10 K140000 24000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO.". HARD- NESS, CALCIUM SUM, SODIUM, AO- SUM, L/NITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS- DIS- SORP- On- FIELD DIS- DIS- BIS.'" (MG/L BONATE SOLVED SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED AS (MG/L (MG/L (MI/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) OCT r 1983 27... 120 2 40 4.9 10 .4 1.8 117 12 10 .10 DEC 21... 37 FE8 • 1984 08... 114 ...... APR 19... 140 0 44 7.5 32 1 13 175 23 24 <.10 JUN 22... 123 AUG 17... 99 1 34 3.5 6.7 .3 2.2 98 16 7.9 .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. C, NITRATE NITRITE NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, (MG/L DIS- (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 5102) (MG/L) DAY) (MS/L) AS N) AS N) AS N) AS N) AS N) AS N) AS N) OCT • 1953 27... 23 180 72 18 1.4 .03 1.4 .15 .25 .40 1.8 DEC 21... 8 1.5 .04 1.5 .02 .08 .10 1.6 FEB 1984 08... 21 .19 .01 .20 .08 2.6 2.7 2.9 APR 19... 38 290 13 20 .75 .15 .90 .64 .86 1.5 2.4 JUN 22... 50 1.2 .02 1.2 .02 <.10 AUG 17... 15 140 68 320 1.1 .07 1.2 .13 .97 1.1 2.3 K = non-ideal count 261 RIO CULEBRINAS BASIN 50147600 RIO CULEBRINAS NEAR SAN SEBASTIAN, PR--Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE NITRO- GEN, TOTAL (MG/L AS NO3) PMCS­ PHORUS. TOTAL (MG/L AS P) ARSENIC TOTAL (UG/L AS AS) WZIUM. TOTAL RECOV­ ERABLE (UG/L AS AA) CADMIUM TOTAL RECOV­ ERABLE (UG/L AS CI) CHRO­ MIUM, TOTAL RECOV­ ERA3LE (UG/L AS CR) LEAD, TOTAL RECOV­ ERA:3LE (UG/L AS P3) MERCURY TOTAL RECOV­ ERASLE (UG/L AS HG) SELE - NIUM, TOTAL (UG/L AS SE) SILVER' TOTAL RECOV­ ERA3LE (UG/L AS AG) OCT , 1485 27... 8.0 DEC 21... 7.1 FEB , 1984 08... 13 APR 19... 11 JUN 22... AUG 17... 10 .04 .13 .16 .59 .37 .12 1 3 (100 10) 1 1 1 <1 3 1 (.1 .5 <1 <1 <1 <1 262 RIO CULEBRINAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR LOCATION.--Lat 18°21'42", long 67°05'33", Hydrologic Unit 21010003, on right bank, at bridge on Highway 404, 0.3 mi (0.5 km) downstream from Quebrada Yagruma, and 2.8 mi (4.5 km) southeast of Moca. DRAINAGE AREA.--71.2 sq mi (184.4 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--July 1967 to current year. GAGE.--Water-stage recorder. Altitude of gage is 45 ft (13.7 m), from topographic map. REMARKS.--Records fair. AVERAGE DISCHARGE.--17 years (1968-84), 300 cu ft/s (8.496 cu m/s), 57.22 in/yr (1,453 mm/yr), 217,400 acre-ft/yr (268 cu hm/yr); median of yearly mean discharges, 286 cu ft/s (8.10 cu m/s), 207,000 acre-ft/yr (255 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 69,000 cu ft/s (1,954 cu m/s) Sept. 16, 1975, gage height, 36.6 ft (11.16 m) from slope-area measurement, but may have been exceeded by flood of Oct. 23, 1974, from rating curve extended above 2,600 cu ft/s (73.6 cu m/s) on basis of slope-area and contracted-opening measurements of peak flow; minimum, 16 cu ft/s (0.453 cu m/s) Apr. 17-19, 1979. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 11,300 cu ft/s (320 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. 7 1845 14,300 405 23.81 7.257 Sept. 15 1930 *26,700 756 28.03 8.544 Oct. 8 1915 12,000 340 22.80 6.949 Sept. 16 1615 13,900 394 23.65 7.208 June 5 1900 24,400 691 27.36 8.339 Sept. 17 1845 14,300 405 23.79 7.251 June 19 1830 12,400 351 22.96 6.998 Sept. 18 1800 16,800 476 24.82 7.565 Sept. 1 1830 12,000 340 22.78 6.943 Sept. 26 2400 12,500 354 22.98 7.004 Sept. 14 2200 12,300 348 22.93 6.989 Minimum discharge, 21 cu ft/s (0.595 cu m/s) Apr. 25,26. DISCHARGE, IN CUBIC FEET PER SECONIOr WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 179 173 123 74 48 43 38 30 126 224 94 2250 2 234 165 114 66 47 60 41 26 104 165 94 314 3 176 242 106 64 46 47 39 29 95 151 89 460 4 170 531 100 63 46 45 35 55 340 831 105 810 5 374 312 98 66 47 40 35 101 5320 1810 143 292 6 325 535 95 63 47 40 33 50 1550 335 99 249 7 2690 733 93 64 57 37 37 39 1830 243 35 195 8 2280 303 95 84 54 40 49 32 744 213 88 179 9 924 280 90 85 49 41 33 67 1050 192 196 166 10 409 221 89 63 44 40 33 44 451 548 114 293 11 305 214 87 58 44 38 31 41 328 303 105 568 12 597 199 85 56 44 34 30 55 243 227 204 533 13 458 172 85 91 58 35 29 41 481 185 344 601 14 279 375 82 143 108 35 72 70 291 168 251 2530 15 235 313 81 89 74 34 95 45 196 160 374 6920 16 275 171 78 79 66 34 43 81 324 151 388 4720 17 221 158 75 77 61 33 32 475 262 143 421 3940 18 1600 153 75 68 56 35 34 416 1840 146 198 4360 19 1030 162 73 63 53 33 31 236 2320 156 148 942 20 852 328 86 61 52 29 33 282 522 406 166 564 21 442 185 138 62 48 54 33 1770 1500 201 133 441 22 555 175 81 60 50 83 30 476 534 143 141 368 23 338 141 74 59 48 99 27 257 321 133 144 1510 24 323 134 77 56 46 86 25 161 449 123 119 410 25 265 129 72 57 47 43 26 153 430 116 110 303 26 228 124 73 55 51 44 135 493 402 110 625 1190 27 296 120 116 54 46 45 227 506 331 105 339 1570 28 204 116 89 53 45 43 55 410 242 108 183 731 29 404 111 73 51 44 39 40 285 201 121 141 443 30 246 109 69 50 --- 39 32 172 180 105 130 334 31 212 --- 76 50 36 --- 151 --- 98 443 --- TOTAL 17126 7094 2748 2089 1526 1389 1433 7049 23057 8125 6214 38191 MEAN 552 236 88.6 67.4 52.6 44.8 47.8 227 769 262 200 1273 MAX 2690 738 138 148 108 99 227 1770 5320 1810 625 6920 MIN 170 109 69 50 44 29 25 26 95 98 85 166 CFSM 7.75 3.32 1.24 .95 .74 .63 .67 3.19 10.8 3.68 2.81 17.9 IN. 8.95 3.71 1.44 1.09 .80 .73 .75 3.68 12.05 4.25 3.25 19.95 AC-FT 33970 14070 5450 4140 3030 2760 2840 13980 45730 16120 12330 75750 CAL YR 1983 TOTAL 81893 MEAN 224 MAX 3880 MIN 19 CFSM 3.15 IN 42.79 AC-FT 162400 MIR YR 1984 TOTAL 116041 MEAN 317 MAX 6920 MIN 25 CFSM 4.45 IN 60.63 AC-FT 230200 RIO CULEBRINAS BASIN 50147800 RIO CULEBRINAS AT HIGHWAY 404 NEAR MOCA, PR--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--WATER YEARS AUGUST 1981 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMMOS) (DEG C) (CFS) (UMHOS) (DEG C) OCT, 05 0952 152 227 24.5 MAR, 06 0937 38 276 23.0 NOV, 08 1407 195 254 25.5 APR, 05 1011 38 265 25.0 DEC. 07 0940 91 241 23.0 MAY, 03 1257 28 318 27.0 JAN, 12 0920 58 232 23.5 JUL. 11 1338 246 224 26.5 FEB' 08 1413 58 242 24.5 AUG, 08 1802 90 224 28.0 263 264 RIO CULEBRINAS BASIN 50149100 RIO CULEBRINAS NEAR AGUADA, PR WATER-QUALITY RECORDS LOCATION.--Lat 18°24'03", long 67°09'40", at bridge on Highway 2, and 2.3 mi (3.7 km) northeast of Aguada plaza. DRAINAGE AREA.--97.0 sq mi (251.2 sq km). PERIOD OF RECORD.--Water years 1958, 1970 to current year. WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 OXYGEN, OXYGEN COLI- STREP- SPE- OIS- DEMAND. FORM, TOCOCCI STREAM- CIFIC SOLVED CHEM- FECAL. FECAL, FLOW, CON- P4 TUR- OXYGEN, (PER- ICAL 0.7 KF AGAR INSTAN- DUCT- (STAND- TEMPER- SID- 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) OCT , 1983 27... 1345 280 318 7.8 25.5 33 7.2 38 10 K15000 K10300 DEC 21... 1230 236 295 7.7 24.5 203 7.2 86 10 3800 2500 FES , 1984 09... 1225 68 364 6.7 27.0 11 4.5 56 130 35000 K1200000 MAY 13... 1450 47 385 7.9 23.0 3.8 6.1 12 30000 K16000 JUN 21... 1950 1230 259 7.9 25.0 203 6.7 81 20 50000 29000 AUG 17... 1830 498 244 3.0 26.0 283 6.7 83 21 >60000 K110000 HARD- MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO." HARD.- NESS. CALCIUM SIUM, SODIUM. AD- SIUM, LINITY SULFATE RIDE, RIDE, NESS NONCAR- DIS- DIS." ()TS- SORP- DIS- FIELD DIS- DIS- On- (MG/L SONATE 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) CACO3) AS CA) AS MG) AS NA) AS K) CAC03) AS 504) AS CL) AS F) OCT , 1983 27... 130 2 45 5.4 12 .5 2.1 133 10 11 .10 DEC 21... 116 FEB , 1984 9... 146 MAY 10... 140 0 47 6.4 20 .8 4.3 150 21 17 .20 JUN 21... 103 AUG 17... 94 0 32 3.4 7.2 .3 2.2 108 18 9.9 .10 SOLIDS, SOLIDS, NITRO... SILICA. SUM OF SOLIDS, RESIDUE NITRO- NITRO- NITRO... NITRO- NITRO- GENsAM- 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) OCT , 1983 27... 27 190 146 62 1.1 .03 1.1 .34 .36 .70 1.8 DEC 21... 5 1.2 .04 1.2 .05 .45 .50 1.7 FEB ' 1984 9... 28 .37 .03 .40 .29 1.8 2.1 2.5 MAY 10... 31 230 34 .74 .06 .80 .59 2.8 3.4 4.2 JUN 21... 1270 .64 .06 .70 .14 .26 .40 1.1 AUG 17... 14 150 204 1800 .64 .16 .80 .25 2.1 2.3 3.1 K = non-idoal count 265 RIO CULEBRINAS BASIN 50149100 RIO CULEBRINAS NEAR AGUADA, PR - -Continued WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 CHRO- BARIUM, CADMIUM MIUM• LEAD• MERCURY SILVER, NITRO- PROS- 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 (MGIL (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L (UG/L DATE AS NO3) AS a) AS AS) AS BA) AS CO) AS CR) AS P3) AS HG) AS SE) AS AG) OCT • 1983 27... 8.0 .07 1 <100 1 2 6 <.1 <1 <1 DEC 21... 7.5 .10 FES • 1984 9... 11 .18 MAY 10... 19 .23 2 10J 2 <1 10 .1 <1 <1 JUN 21 ... 4.9 .09 AUG 17... 14 .17 CHLOR- DI- PCB, ALDRIN, ANE, DOD, DDE, DOT• AIINON• TIME TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL DATE (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) (UG/L) JUN • 1984 21... 1950 <.1 (.01 <.1 <.01 (.01 <.01 <.01 HEPTA... METH- DI- ENDO- HEPTA- CHLOR MALA- OXY••• ELORIN 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 • 1984 21... <.01 <.01 <.01 (.01 <.01 (.01 <.01 <.01 <.01 NAPH..- THA- METHYL METHYL LENES, PARA-. TRI- PARA- POLY- PER- TO)fr TOTAL THION• THION• MIREEX• 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 • 1984 21... <.01 (.01 <.01 <.01 <.10 <.1 <1 (.01 267 DISCHARGE AT PARTIAL-RECORD STATIONS As the number of streams on which streamflow information is likely to be desired far exceeds the number of stream-gaging stations feasible to operate at one time, the Geological Survey collects limited streamflow data at sites other than stream-gaging stations. When limited streamflow data are collected on a systematic basis over a Period of years for use in hydrologic analyses, the site at which the data are collected is called a partial-record station. Data collected at these partial-record stations are useable in low-floe or floodflow analyses, depending on the type of data collected. In addition, discharge measurements are made at other sites not included in the partial- record program. These measurements are generally made in times of drought or flood to give better areal coverage to those events. Those measurements and others collected for some special reason are called measurements at miscellane­ ous sites. Records collected at partial-record stations are presented in two tables. The first is a table of dis­ charge measurements at low-flow partial-record stations and the second is a table of annual maximum stage and dis­ charge at crest-stage stations. Low-flow partial-record stations Measurements of streamflow in the areas covered by this report made at low-flow partial-record stations are given in the following table. These measurements were made during periods of base flow when streamflow is pri­ marily from ground-water storage. These measurements, when correlated with the simultaneous discharge of nearby stream when continuous records are available, will give a picture of the low-flow potentiality of stream. Discharge measurements made at low-flow oartial-records stations during water year 1984 PUBLICATION RECORD STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- TEMPER- FLOW CIFIC CONDUC- ATURE cfs TANCE (cms) umhos deg C Quebrada de los Cedros basin 50007000 Quebrada de los Cedros near Isabela, PR Lat 13 30 46, long 67 05 47 Hydrologic unit 21010002. On dirt road, 4.7mi (7.6km) west of Isabela, and 3.5 mi (0.8 km) upstream from mouth. 6.91 (17.90) 3/27/84 DRY Rio Guajataca basin 50011400 Rio Guajataca above Let 13 28 31, long 66 57 46 mouth near Quebradillas, Hydrologic unit 21010)02. PR At ford, 1.7 mi (2.7 km) up- stream from bridge on Hwy 2, 2.1 mi (3.4 km) from the 23.7 3/27/84 1340 8.01 564 26.0 Atlantic Ocean, 6.6 mi (61.4) (0.23) (10.6 km) downstream from Lego Guajataca, and 1.6 mi (2.6 km) west of Quebradi- llas. Rio Camuy basin 50015800 Rio Camuy at Capaez, PR Lat 13 27 49, long 66 49 58 Hydrologic unit 21010002. At 1.1 iii (1.7 km) south of Purification Plant of Heti- 22.0 3/26/84 No Meas llo, about 1.4 mi (2.2 km) (57.0) south of Hwy 2, and 1.8 mi (2.9 km) upstream from mouth. Rio Cibuco basin 50039000 Rio Indio near Vega Baja, Lat 18 26 19, long 66 22 13 PR Hydrologic unit 21010002. At bridge on Hwy 160, 0.6 mi 26.7 3/23/54 1450 6.86 456 27.0 (1.0 km) upstream from Rio (69.2) (0.19) Cibuco, and 1.2 mi (1.9 km) southeast of Vega Baja. Rio de la Plata basin 50045800 Rio Lajas at Toe Alta, Let 18 23 39, long 66 15 16 PR Hydrologic unit 21010005. At bridge on Hwy 165, 0.2 mi (0.3 km) upstream from 8.60 3/29/84 1128 1.39 649 25.5 Rio de la Plata, and 3.5 mi (22.27) (0.04) (0.8 km) northwest of Toe Alta. 268 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPEC- TEMPER- NUMBER NAME AND AREA sq mi DATE TIME FLOW cfs CIFIC CONDUC- TANCE ATURE BASIN (sq km) (cms) umhos deg C Rio Hondo basin 50047502 Rio Hondo at Bayamon, PR Let 18 23 51, long 66 )9 22 Hydrologic unit 21010005. At bridge on Hwy 2, 700 ft (213 m) east of Hwy 2 and Calle Parque intersection, and 3.7 mi (1.2 km) south of sewage treatment plant. 7.59 (19.66) 3/29/84 1330 6.29 888 (0.18) 27.0 50047504 Quebrada Santa Catalina at Bayamon, PR Lat 18 24 05, long 65 )9 43 Hydrologic unit 21010005. 700 ft (213 m) downstream from bridge on Hwy 2 and 0.2 mi (0.3 km) upstream from mouth. 2.50 (6.47) 3/30/84 0939 1.35 987 (0.04) 26.5 50047503 Cano de Quebrada Catalina at Bayamon. PR Lat 18 24 27. long 66 09 33 Hydrologic unit 210100)5. At bridge on new Hay 167. 0.7 mi (1.1 km) north of Hwy 2 and Calle Parque intersec- tion, and 0.2 mi (0.3 km) upstream from sewage treat- ment plant. 0.65 (1.68) 3/29/84 No Flow 50047525 Rio Hondo II near Bayamon. PR Lat 18 25 19. long 66 10 38 Hydrologic unit 21010005. At bridge on Hwy 872 and 0.7 mi (1.1 km) downstream from bridge on Hwy 22. 3.18 (3.24) 3/30/84 1024 1.43 658 (0.04) 27.5 Rio de Bayamon basin 50048510 Rio de Bayamon at Flood Channel at Bayamon. PR Lai 18 24 29, long 66 39 04 Hydrologic unit 21010005. At bridge on Hwy 890, 1.0 mi (1.6 km) downstream from bridge on Hwy 2. and 3.2 mi (5.1 km) upstream from mouth. 73.2 (189.6) 3/30/84 0343 18.2 (0.52) 470 26.0 Rio Puerto Nuevo basin 50049000 Rio Piedras at Rio Piedras, PR Let 18 23 48, long 66 03 24 Hydrologic unit 21010005. On left bank, at bridge on Hwy 1, 0.3 mi (0.5 km) southwest of Rio Piedras Plaza, and 0.4 mi (0.6 km) downstream from diversion 12.5 (32.4) 3/29/84 1153 5.96 (0.17) 437 27.5 for water supply. 50049310 Quebrada Josefina at Pinero Avenue, PR Lat 18 24 33, long 66 04 36 Hydrologic unit 21010005. At bridge on Pinar° Ave, and 0.4 mi (0.6 km) upstream from junction with Rio Pie- dram. 19.0 (49.2) 3/29/84 1321 8.50 (0.24) 426 32.0 50049600 Quebrada Margarita at Caparra Heights, PR Let 18 24 33, long 66 06 18 Hydrologic unit 21010095. At bridge on Franklin 0. Roosevelt Ave, at San Pa- tricio Plaza and Fort Bu- channan interchange with Hwy 2, and 0.1 mi (0.2 km) south of Caparra Heights. 1.82 (4.71) 3/29/84 No Naas 269 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- FLOW CIFIC CONDUC- cfs TANCE (cms) umhos TEMPER- ATURE deg C Quebrada Blasina basin 50050300 Quebrada Blasina near Carolina, PR Lat 18 23 27, long 65 58 23 Hydrologic unit 21010005. At bridge on Hwy 3, 1.4 mi (2.3 km) south of Valle A­ rriba Heights, and 1.2 mi (1.9 km) west-southeast of Carolina. 2.96 (7.67) 3/26/84 1000 5/07/84 1134 4.71 533 (0.13) 4.97 710 (0.14) 27.5 29.0 Rio Grande de Loiza basin 50051010 Rio Grande de Loiza Let 18 07 23, long 65 59 18 3/27/84 1020 15.8 141 25.5 below Rio Emajagua, PR Hydrologic unit 21010015. 12.2 (0.45) 200 ft (61 m) below junc­ (31.6) tion with Rio Emajagua and 400 ft (122 m) north of Hwy 181 and Hwy 745 intersection. 5/09/84 1034 11.4 163 (0.32) 27.0 50051140 Rio Grande de Loiza at Lat 18 09 29, long 65 58 48 Jagual, PR Hydrologic unit 21010035. 200 ft (61 m) east of Jagual 17.8 3/27/84 1138 19.2 157 (0.54) 26.0 School on Hwy 181 and 1.7 mi (2.8 km) above junction with Rio Cayaguas. (46.1) 5/09/84 1152 14.7 172 (0.42) 29.5 50052300 Rio Grand. die Loiza at Lat 18 11 39, long 65 57 46 San Lorenzo North, PR Hydrologic unit 21010005. 3/27/84 1342 37.1 182 30.5 Above sewage treatment plant 46.0 (1.05) on north side of San Lorenzo, (119.1) 0.2 mi (0.3 km) northwest of the plaza, and 1.6 mi (2.6 km) downstream from Rio Cayaguas. 5/08/84 1352 18.7 277 (0.53) 33.0 50052700 Rio Grande de Loiza at Hwy 183, PR Lat 18 12 22. long 65 59 23 Hydrologic unit 21010035. 2.1 mi (3.4 km) northwest of 50.9 3/27/84 1446 39.0 211 (1.10) 31.0 Plaza de San Lorenzo and 1.8 mi (2.9 km) downstream from bridge on Hwy 181. (131.8) 5/08/84 1213 22.2 232 (0.63) 28.5 50052900 Quebrada las Bambuas at mouth, PR Lat 18 13 31. long 66 00 58 Hydrologic unit 21010005. 2.33 3/26/84 1407 0.33 545 (0.01) 24.0 300 ft (91 m) upstream from bridge on Hwy 183 and 900 ft (275 m) above junction with (6.03) 5/08/84 1043 0.07 539 (0.002) 26.0 Rio Grande de Loiza. 50053050 Rio Turabo at 8orinquen, Lat 18 10 11, long 66 32 37 PR Hydrologic unit 21010005. At bridge on Hwy 765 and 7.79 3/26/84 1036 3.42 172 (0.24) 24.5 50053300 Quebrada Beatriz above 1.2 mi (1.9 km) north of Escuela Anon. Lat 18 11 15, long 66 33 04 (20.19) 5/07/84 1230 8.34 183 (0.24) 28.5 Rio Turabo, PR Hydrologic unit 21010005. 1,400 ft (425 m) downstream from bridge on Hwy 765 and 400 ft (120 m) above junction with Rio Turabo. 5.65 (14.63) 3/26/84 1140 5/07/84 1412 2.56 258 (0.07) 2.81 268 (0.08) 27.0 29.5 50053500 Rio Turabo below Lat 18 11 22, long 66 03 02 Quebrada Beatriz, PR Hydrologic unit 21010005. 0.9 mi (1.4 km) downstream 17.3 from bridge on Hwy 765 and (44.8) 400 ft (120 m) below junction with Quebrada Beatriz. 3/26/84 1220 12.7 206 (0.36) 5/07/84 1506 9.00 220 (0.25) 28.0 30.5 270 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER- AREA FLOW CIFIC NUMBER NAME AND sq mi DATE TIME CONDUC- ATURE cfs TANCE BASIN (sq km) (cms) umhos deg C Rio Grande de Loiza basin 50054500 Rio Turabo at Caguas, PR Lat 18 13 36, long 66 01 40 3/26/84 1334 6.83 256 29.0 Hydrologic unit 21010005. 29.3 (0.19) At bridge on Hwy 183, 0.9 mi (75.9) (1.5 km) southeast of the 5/08/84 0940 3.89 359 26.5 plaza in Caguas, and 1.3 mi (0.11) (2.1 km) upstream from Rio Grande de Loiza. 50055310 Rio Caguitas above mouth, Lat 18 15 22, long 66 01 06 3/29/84 1157 15.3 696 28.5 PR Hydrologic unit 21010005. 13.0 (0.43) 0.5 mi (3.7 km) downstream (46.6) from bridge on Hwy 30 and 5/10/84 1430 16.4 480 31.0 0.4 mi (0.7 km) above junc- (0.461 tion with Rio Grande de Loiza. 50055410 Rio Sairoa at mouth, PR Lat 18 15 47, long 66 31 09 3/29/84 13031.36 489 29.0 Hydrologic unit 21010005. 7.51 (0.05) 0.8 mi (1.2 km) downstream (19.45) from bridge on Hwy 30 and 5/10/84 1521 2.63 440 31.0 0.4 mi (0.6 km) above junc- (0.07) tion with Rio Grande de Loiza. 50055500 Quebrada Honda at Las Lat 18 13 15, long 65 49 57 Torras, PR Hydrologic unit 21010005.At 3/30/84 1130 0.11 408 26.5 bridge on Hwy 31, 100 ft 1.15 (0.003) (30 m) east of Hwy 31 and (2.98) Hwy 936 intersection, and 5/07/84 1310 DRY 1.8 mi (2.9 km) abova junc- tion with Rio Gurabo. 50055600 Rio Gurabo at Ceiba Let 18 13 29, long 65 51 34 Norte, PR Hydrologic unit 21010005. 3/30/84 1225 3.25 322 32.0 0.4 mi (0.6 km) downstream 12.0 (0.09) from bridge on Hwy 31 and (31.1) 0.2 ci (0.4 km) below junc- 5/07/84 1235 1.08 400 28.0 tion with Quebrada Honda. (0.03) 50055700 Rio Gurabo at El Mango, Let 18 13 56, long 65 52 52 3/28/84 1110 3.23 376 24.0 PR Hydrologic unit 21010035. 16.5 (0.09) 1.2 mi (2.0 km) upstream (42.7) from bridge on Hwy 31 and 5/09/84 1456 1.25 387 32.0 0.2 mi (0.4 km) above junc- (0.04) tion with Quebrada Grande. 50056000 Rio Valenciano near Las Lat 18 10 37, long 65 54 21 3/28/84 1004 6.22 203 24.0 Piedras, PR Hydrologic unit 21010005. 6.35 (0.18) At bridge on Hwy 133 (km (17.74) 17.3), and 3.2 mi (5.1 km) 5/09/84 1326 4.17 221 32.5 west of Las Piedras. (0.12) 50056550 Rio Valenciano at mouth, Lat 18 14 13, long 65 55 13 3/28/84 1240 10.9 354 28.0 PR Hydrologic unit 21010035. 19.0 (0.31) 0.6 ci (1.0 km) downstream (49.2) from bridge on Hwy 31 and 5/09/84 1629 7.61 413 32.0 1,000 ft (305 m) above junc- (0.22) tion with Rio Gurabo. 50056600 Rio Gurabo near Juncos, Lat 18 14 38, long 65 55 25 PR Hydrologic unit 21010005. 3/28/84 1338 13.7 348 29.5 At bridge on Hwy 185 and 50.0 (0.39) 0.4 mi (0.6 km) below junc- (129.5) tion with Rio Valenciano. 5/08/84 1521 7.79 357 32.5 (0.22) 50057015 Rio Gurabo below Hwy 943, Lat 18 15 50, long 65 58 41 PR Hydrologic unit 21010005. 3/29/84 1412 15.8 382 29.0 0.6 mi (0.9 km) northeast of 62.4 (0.45) Plaza de Gurabo and 0.7 mi (161.6) (1.2 km) downstream from 5/10/84 1220 12.0 432 29.0 bridge on Hwy 181. (0.34) I 271 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations-Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- FLOW CIFIC C0NDUC- cfs TANCE (cms) umhos TEMPEk ATURE deg C Rio Grande de Loiza basin 50058400 Rio Canas above Lago Loiza. PR Lat 18 17 34. long 66 32 33 Hydrologic unit 21010005. At bridge about 2000 ft (610 m) off Hwy 1. 1.0 mi (1.6km) upstream from Lago Loiza. 1.0 mi (1.6 km) north of La Barra, and 4.0 mi (6.4 km) north of Caguas. 7.63 (19.76) 3/29/84 1021 5/10/84 1054 2.20 (0.06) 1.49 (0.04) 338 362 26.0 28.0 50059000 Lago Loiza at Dam Site, PR Let 18 19 49, long 66 01 00 Hydrologic unit 21010005. At pumphouse at damsite and 1.9 mi (3.1 km) south of Trujillo Alto Plaza. 203 (539) 3/29/84 0926 5/10/84 0955 2.00 210 26.0 (0.06) 1.37 338 28.0 (0.04) 50059200 Quebrada Grande at La Gloria, PR Lat 18 20 28, long 65 59 20 Hydrologic unit 21010005, 400 ft (122 m) downstream from bridge on Hwy 131, 200 ft (61 m) below junction with Quebrada Grande, and 1.5 mi (2.4 km) above junc­ tion with Rio Grande de Loi- 12.0 (31.1) 3/26/84 1445 5/09/84 1021 2.25 559 (0.06) 0.64 630 (0.02) 30.0 25.0 za. 50060000 Rio Grand. de Loiza above Carolina. PR Lat 18 22 10, long 65 57 50 Hydrologic unit 21010005. 0.5 mi (0.3 km) west of Tru- 230 jillo Bajo and 0.2 mi (0.3 (596) km) northwest of intersection of Hays 853 and 858. 3/26/84 1335 5/09/84 NO FLOW 367 DEEP POOL NO MEAS 30.5 50060200 Quebrada Maracuta at Trujillo 8ajo. PR Lai 18 22 11. long 65 57 28 Hydrologic unit 21010005. At bridge on Hwy 853 and 0.3 mi (0.5 km) above junc­ tion with Rio Grande da Loi­ za. 10.2 (26.4) 3/26/84 1255 5/09/84 1305 1.30 569 32.0 (0.04) 0.58 680 30.0 (0.02) 50061000 Rio Grande de Loiza at Carolina. PR Lat 18 22 39, long 65 57 08 Hydrologic unit 21010005. 243 At bridge on Hwy 3, 0.5 (629) mi (3.8 km) southeast of Ca­ rolina Plaza. and 9.1 mi (14.6 km) upstream from mouth. 3/26/84 1130 5/07/84 1322 43.3 (1.23) 11.7 (0.33) 365 437 30.0 29.0 50061200 Rio Canovanillas at Carruzos. PR Lat 18 19 03, long 65 54 16 Hydrologic unit 21010005. At bridge on road 500 ft (152 m) off Hwy 185, and 0.7 mi (1.1 km) east of Jesus T. Pinero School. 9.10 (23.57) 3/28/84 1145 5/09/84 1436 2.52 564 27.5 (0.07) 1.45 652 28.5 (0.04) 50061500 Rio Canovanillas at Loiza. PR Lat 18 22 44. long 65 55 00 Hydrologic unit 21010005.At bridge on Hwy 3. 0.9 mi (1.4 km) upstream from Rio Gran- do Loiza, and 1.0 mi (1.6 km) west of Loiza. 16.5 (42.7) 3/28/84 0920 5/07/84 1440 4.50 583 26.0 (0.13) 2.99 592 30.5 (0.08) 50061900 Rio Canovanas at La Marina, PR Lat 18 21 01. long 65 53 51 Hydrologic unit 21010005. 100 ft (30 m) east of Hwy 185 and 0.9 mi (1.5 km) downstream from bridge on H y 957. 14.6 (37.8) 3/28/84 1255 5/09/ 84 1548 8.58 293 28.0 (0.24) 4.67 387 27.5 (0.13) 50062000 Rio Canovanas at Loiza. PR Lat 18 22 53. long 65 53 33 Hydrologic unit 21010005.At bridge on Hwy 958 and 0.3 mi (0.5 km) east of Loiza. 17.0 (44.0) 3/28/84 1010 5/07/84 1518 0.50 317 25.5 (0.01) 0.32 378 23.5 (0.01) 272 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER- NUMBER NAME AND AREA sq mi DATE TIME FLOW cfs CIFIC CONDUC- TANCE ATURE BASIN (sq km) (cms) umhos deg C Rio Herrera basin 50062500 Rio Herrera near Colonia Let 18 21 02, long 65 52 00 Dolores, PR Hydrologc unit 21010)05. On right bank, at bridge on on Hwy 958, 2.0 mi (3.2 km) south of Goiania Dolores, and 3.2 mi (5.1 km) south­ west of Rio Grande. 2.75 (7.12) 3/29/84 1025 5/08/84 1543 3.58 232 (0.10) 1.09 300 (0.03) 25.0 27.5 50062800 Rio Herrera near Loiza, PR Lat 18 22 48, long 65 51 33 Hydrologic unit 21010005-At bridge on Hwy 3, 1.9 mi (3.1 km) west of Rio Gran­ de, and 2.8 mi (4.5 km) east of Loiza. 3.86 (10.00) 3/29/84 0930 5/07/84 1614 2.94 257 (0.08) 2.83 317 (0.08) 25.5 29.0 50063000 Quebrada Cambalacha near Loiza, PR Lat 18 22 49, long 65 52 04 Hydrologic unit 21019005.At bridge on Hwy 3, 2.2 mi (3.5 km) east of Loiza, and 2.5 mi (4.3 km) west of Rio Grande. 1.32 (3.42) 3/29 / 8 4 0840 5/07/84 1654 0.27 602 (0.01) 0.32 730 (0.01) 25.5 27.5 Rio Espiritu Santo basin 50063540 Rio Espiritu Santo at Camp Eliza Colberg, PR Lat 18 20 22, long 65 49 42 Hydrologic unit 21010035. 3.1 mi (4.9 km) northeast of Pico El Yunque and 0.3 mi (1.3 km) below junction with Quebrada Sonadora. 5.27 (13.65) 3/27 / 8 4 1010 5/08/84 1407 6.36 (0.19) 4.61 (0.13) 79 94 23.0 27.5 50063850 Quebrada Jimenez near Rio Grande, PR Let 18 21 36, long 65 48 47 Hydrologic unit 21010005. 300 ft (91 m) upstream from Rio Espiritu Santo and 1.9 mi (3.1 km) southeast of Rio Grande. 3.63 (9.40) 3/27/84 1125 5/08/84 1305 3.31 150 (0.09) 3.75 107 (0.11) 25.0 26.5 50064200 Rio Grande near El Verde, Lat 18 20 43, long 65 50 30 PR Hydrologic unit 21010015.On left bank, 400 ft (120 m) upstream from bridge on Hwy 960, 500 ft (150 m) south­ west of junction of Hays 956 & 960, 1.1 mi (1.8 km) west of El Verde, and 2.7mi (4.3km) south of Rio Grande. 7.31 (18.93) 3/29/84 1345 5/08/84 1504 6.16 155 (0,17) 4.25 202 (0.12) 29.5 31.5 50064500 Rio Grande at Rio Grande, Let 18 22 40, long 65 49 28 PR Hydrologic unit 21010005.At bridge on Hwy 3, 0.5 mi (0.8 10.4 km) southeast of Rio Grande, (26.9) and 0.8 mi (1.3km) upstream from Rio Espiritu Santo. 3/29 / 8 4 1115 5/08 / 8 4 0916 1.96 (0.06) 4.92 (0.14) 207 248 27.0 27.0 50064900 Quebrada Juan Gonzalez near Rio Grande, PR Lat 18 22 37, long 65 48 04 Hydrologic unit 21010005.At bridge on Hwy 955, 800 ft (244 m) upstream from bridge on Hwy 3, and 1.5 mi (2.4 km) above junction with Rio Es­ pirutu Santo. 2.17 (5.62) 3/27/84 1355 5/08/84 1017 1.43 287 (0.04) 0.72 367 (0.02) 25.0 25.0 273 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER- AREA FLOW CIFIC NUMBER NAME AND sq mi DATE TIME CONDUC- ATURE cfs TANCE BASIN (sq km) (cms) umhos deg C Rio Mameyes basin 50066000 Rio Mameyes at Mamoyes. La! 18 22 30, long 65 45 50 PR Hydrologic unit 21010005. At bridge on Hwy 3, 0.5 mi (0.8 km) downstream from Quebrada Anon. 0.5 mi (0.9 km) east of Mameyes (Palmer Post Office), and 3.1 Ai (5.0 km) east of Luquillo. 3/27/84 1525 16.7 159 28.0 13.5 (0.47) (35.0) 5/08/84 1124 12.3 143 26.0 (0.35) Quebrada Mate de Platano basin 50066500 Quebrada Mata do Platen() Let 18 22 52, long 65 43 16 near Luquillo. PR Hydrologic unit 21010005. At bridge on Hwy 3, 0.4 mi (0.6 km) northwest of Lu- quillo Plaza, and 0.3 mi (0.5 km) above mouth. Rio Sabana basin 50068000 Rio Sabana at Luquillo, Let 18 22 15, long 65 42 51 PR Hydrologic unit 21010005.At Hwy 3 bridge and 0.4 mi (0.6 km) southwest of Luquillo. 2.38 3/26/84 1110 NO FLOW 12400 26.5 (6.16) 5/07/84 1134 NO FLOW 17400 28.0 7.05 (18.26) 3/26/84 1208 4.17 171 26.0 (0.12) 5/07/84 1239 3.28 168 27.0 (0.09) 50069000 Rio Pitahaya near Luquillo, PR Rio Pitahaya basin Let 18 21 32, long 65 42 03 Hydrologic unit 21010005.At bridge on Hwy 3. 1.6 mi (2.6 km) southeast of Luquillo, and 1.7 mi (2.7 km) upstream from Rio Sabana. Rio Juan Martin basin 4.51 (11.68) 3/26/84 1248 NO FLOW 171 26.5 5/07/84 1351 3.25 178 27.0 (0.09) 50069300 Tributary to Rio Juan Lat 18 21 14, long 65 40 59 Martin at Hwy 3, PR Hydrologic unit 21010005.At bridge on Hwy 3 and 200 ft (61 m) above junction with Rio Juan Martin. 50069350 Rio Juan Martin above Lett 18 21 44, long 65 40 35 mouth, PR Hydrologic unit 21010005. 0.8 mi (1.2 km) downstream from bridge on Hwy 3 and 0.4 mi (0.7 km) above south. Quebrada Fajardo basin 50069400 Quebrada Fajardo at Hwy Lat 18 20 49, long 65 39 55 194, PR Hydrologic unit 21010005. At bridge on Hwy 194, 0.5 mi (0.8 km) east of Hwy 194 and Hwy 3 intersection, and 1.5 mi (2.4 km) above mouth. Rio Fajardo basin 3/26/84 1321 0.04 611 27.5 0.53 (0.001) (1.37) 5/07/84 1410 0.01 578 30.0 (0.000) 3/26/84 1446 0.28 425 29.0 2.41 (0.01) (6.24) 5/08/84 0945 0.15 435 27.5 (0.004) 3/26/84 1346 0.06 465 35.0 1.16 (0.002) (3.00) 5/07/84 1428 0.01 520 33.0 (0.000) 50071200 Rio Fajardo at Vapor below Confluence, PR Let 18 18 28. long 65 40 10 Hydrologic unit 21010035. 19.4 1.7 mi (2.8 km) southwest of (50.2) Plaza do Fajardo and 1.4 mi (2.3 km) upstream from bridge on Hwy 3. 3/27/84 1059 6.87 125 29.0 (0.19) 5/07/84 1556 2.31 127 25.0 (0.07) 274 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER- AREA FLOW CIFIC NUMBER NAME AND sq mi DATE TIME CONDUC- ATURE cfs TANCE BASIN (sq km) (cms) umhos deg C Rio Fajardo basin 50072000 Rio Fajardo at Fajardo, Let 18 19 11, long 65 39 07 3/27/84 0959 8.72 150 26.5 PR Hydrologic unit 21010005. (0.25) At bridge on Hwy 3, 0.5 mi 21.6 (0.8 km) south of Fajardo, (55.9) and 2.5 mi (4.9 km) upstream 5/07 / 8 4 1650 3.18 175 25.0 from mouth. (0.09) 50072600 Quebrada Mata Redonda Lat 18 19 34, long 65 39 00 near Fajardo, PR Hydrologic unit 21010035-At 3/27/84 1205 0.85 125 29.5 bridge on Hwy 3, 1.2 mi (2.0 (0.02) km) south of Plaza de Fa- 1.34 jardo, and 1.7 mi (2.7 km) (3.47) 5/07/84 DRY above junction with Rio Fa­ jardo. Rio Oemajagua basin 50072700 Rio Oemajagua at Lat 18 17 10, long 65 38 21 Oemajagua, PR Hydrologic unit 21010005. 3/27/84 1326 0.16 324 28.0 At bridge on Hwy 3, 203 ft 1.61 (0.005) (61 m) south of Hwy 3 and (4.17) Hwy 982 intersection, and 5/08/84 1106 0.01 415 28.0 0.3 mi (0.5 km) above mouth. (0.000) Quebrada Ceiba basin 50072800 Quebrada Ceiba at Ceiba, Lat 1E 16 25, long 65 38 25 PR Hydrologic unit 21010035.At 3/28/84 0826 1.18 415 26.5 bridge on Hwy 3, 0.8 mi (1.3 2.15 (0.03) km) northeast of Plaza de (5.57) Ceiba, and 0.8 mi (1.3 km) 5/08/84 1229 1.00 480 30.0 above mouth. (0.03) Quebrada Aguas Claras basin 50072900 Quebrada Aguas Claras Lat 18 16 03, long 65 38 20 near Ceiba, PR Hydrologic unit 21010005.At 3/27/84 1349 0.25 376 31.0 bridge on Hwy 979 and 0.6 mi 0.83 (0.01) (0.9 km) above mouth. (2.15) 5/08/84 1136 0.24 285 32.0 (0.01) Rio Daguao basin 50073200 Rio Daguao at Daguao, PR Lat 18 13 42, long 65 40 39 3/28/84 0903 0.40 508 25.0 At railroad bridge, 0.1 mi (0.01) (0.2 km) downstream from 2.26 bridge on Hwy 3. 0.3 mi (0.5 (5.85) 5/08/84 1325 0.25 505 28.0 km) east of Daguao, and 2.8 (0.01) mi (4.5 km) upstream from mouth. 50073300 Rio Oaguao above mouth. Lat 18 13 36, long 65 39 31 PR Hydrologic unit 21010005. At bridge 650 ft (200 m) 3/27/84 1411 NO FLOW 1130 30.0 downstream from bridge on 4.29 Langley Drive and 0.9 vi (11.11) 5/08/84 1148 NO FLOW 1320 28.5 (1.4 km) above mouth. Quebrada Palma basin 50073400 Quebrada Palma at Daguao, Lat 18 13 16, long 65 41 30 3/28/84 0937 0.99 329 25.0 PR Hydrologic unit 21010005. (0.03) At bridge on Hwy 3. 0.8 mi 4.84 (1.3 km) southwest of 0a- (12.54) guao, and 1.7 mi (2.7 km) 5/08/84 1350 0.36 345 26.5 upstream from mouth. (0.01) 275 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND DRAINAGE AREA so mi BASIN (31:4 km) Quebrada 3otija basin 50073500 Quebrada Botija at 31, PR Hwy, Let 18 12 55, long 65 42 25 Hydrologic unit 21010035. At bridge on Hwy 31, 5)0 ft (152 m) upstream from bridge on Hwy 3, and 1.6 mi (2.6 km) above mouth. 1.10 (2.85) Rio Santiago basin 50074000 Rio Santiago at Naguabo, Let 18 12 57, long 65 43 41 PR Hydrologic unit 21010005.At bridge on Hwy 31, 0.3 mi 4.99 (0.5 km) northeast of Nagua- (12.92) bo, 0.4 mi (0.5 km) downstream from Quebrada Grande, and 2.2 mi (3.5 km) upstream from mouth. 50074010 Tributary to Rio Let 18 12 04, long 65 43 33 Santiago at Hwy 192, PR Hydrologic unit 21010035. At bridge on Hwy 192 and 1.03 0.7 mi (1.1 km) above junc- (2.80) tion with Rio Santiago. Rio Blanco basin 50077000 Rio Blanco at Rio Blanco, Lat 18 13 09, long 65 46 57 PR Hydrologic unit 21010005. At bridge on Hwy 31 and 0.4 mi 17.6 (0.6 km) east of Rio Slane°. (45.6) 50077500 Rio Blanco below La Fe, Lat 18 12 17, long 65 45 31 PR Hydrologic unit 21010005. 20.3 1.9 mi (3.0 km) downstream (53.9) from bridge on Hwy 31 and 0.7 mi (1.1 km) south of Huy 31 and Hwy 970 intersec- tion. 50077600 Quebrada Vaca below La Lat 18 12 25, long 65 45 04 Fe, PR Hydrologic unit 21010005. 1.1 mi (1.8 km) downstream 3.47 from bridge on Hwy 31 and (8.99) 0.3 mi (1.4 km) southeast of Hwy 31 and Hwy 970 intersec­ tion. 50077700 Rio Blanco at mouth, PR Lat 18 11 17, long 65 41 47 Hydrollcrc unit 21010005.At bridge on Hwy 3, at mouth, 27.2 and 0.8 mi (1.2 km) south- (70.4) west of Hwy 3 and Hwy 192 intersection. Rio Anton Ruiz basin 50078510 Rio Anton Ruiz at Pasto Lat 18 10 26, long 65 47 05 Viejo, PR Hydrologic unit 21010005.At 5.75 bridge on unimproved road, (14.89) 300 ft (91 m) north of Hwy 925, and 1.5 mi (2.4 km) north of Hwy 3 and Hwy 925 intersection. STREAM- SPE- TEMPER- FLOW CIFIC DATE TIME CONOUC- ATURE cfs TANCE (cms) umhos deg C 3/28/84 1000 0.14 359 25.5 (0.004) 5/08/84 1427 0.02 457 27.0 (0.001) 3/23/84 1102 1.33 204 30.5 (0.04) 5/08/84 1523 0.45 226 33.5 (0.01) 3/28/84 1149 NO FLOW 526 25.5 5/08/84 1535 NO FLOW 348 29.5 3/29/84 1345 3.88 173 28.0 (0.11) 5/07/84 1410 9.47 165 30.0 (0.27) 3/29/84 1255 4.69 219 29.0 (0.13) 5/08/84 1119 2.01 340 29.0 (0.06) 3/30/84 1015 NO FLOW 354 27.5 5/08/84 1020 NO FLOW 403 28.0 3/28/84 1155 2.67 5830 30.0 (0.08) 5/08/14 1540 NO FLOW 38400 31.0 3/29/84 1150 0.96 340 30.5 (0.03) 5/08/84 1258 0.11 430 32.0 (0.003) 276 DISCHARGE AT PARTIAL -RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER­ NUM3ER NAME AND AREA sq mi DATE TIME FLOW cfs CIFIC CONDUC- TANCE ATURE BASIN (sq km) (cms) umhos deg C Rio Anton Ruiz basin 50078700 Rio Anton Ruiz at mouth, Lat 18 10 35, long 65 44 23 PR Hydrologic unit 21010005. At bridge on Hwy 3, 1.8 mi (2.9 krs) southwest of Hwy 3 and Hwy 192 intersection, and 200 ft (61 m) above mouth. a 7.99 (20.69) 3/28/84 1241 PONDED 13800 5/08/84 1543 PONDED 28200 29.0 29.0 Rio Humacao basin 50031000 Rio Humacao at Las Piedras, PR Lat 18 10 27, long 65 52 11 Hydrologic unit 21010005. On left bank about 60ft (18.3 m) off bridge on Hwy 921 (km 1.1), 0.6mi (1.0km) south -east of junction with Hwy 30, 0.8 mi (1.3 km) down­ stream from Ouebrada Blanca. and 0.3mi (1.3km) south of Las Piedras. 6.65 (17.22) 3/28/84 1400 5/08/84 1515 9.04 159 (0.26) 7.04 218 (0.20) 28.0 31.0 50081500 Rio Humacao near Humacao, Lat 18 0? 37, long 65 50 41 PR Hydrologic unit 21010005.At bridge on Hwy 914 and 1.3 mi (2.1 km) northwest of Humacao. 9.23 (23.91) 3/29/84 1450 5/09/84 1022 6.25 209 (0.18) 1.63 360 (0.05) 27.0 28.0 50031900 Ouebrada Mariana at Patagonia, PR Lat 18 03 46, long 65 49 40 Hydrologic unit 21010035-At bridge on Hwy 908 and 450 ft (137 m) above junction with Rio Humacao. 5.76 (14.92) 3/29/84 1105 5/08/84 1405 5.09 261 (0.14) 4.03 315 (0.11) 29.0 33.0 50032500 Rio Humacao Flood Channel near mouth. PR Lat 18 07 28, long 65 47 23 Hydrologic unit 21010005. 3.1 mi (4.9 km) southeast of Plaza de Humacao and 0.6 mi (0.9 km) above mouth. 25.1 (65.3) 3/28/84 1250 21.6 484 (0.61) 5/09/84 1227 16.1 540 (0.46) 33.0 30.0 Rio Candelero basin 50082600 Rio Candelero PR at Hwy 906, Lat 18 06 17, long 65 48 54 Hydrologic unit 21010005.At bridge on Hey 906. 1.4 mi (2.2 km) downstream from bridge on Hwy 3. and 1.7 mi (2.7 km) above mouth. 3.65 (9.45) 3/28/84 1140 5/09/84 1337 0.66 269 (0.02) 0.44 372 (0.01) 33.0 30.0 50082700 Rio Candelero at mouth. PR Lot 18 06 09, long 65 47 43 Hydrologic unit 21010005.At bridge on unimproved road, 1.3 mi (2.1 km) downstream from bridge on Hwy 906. and 0.4 mi (0.7 km) above mouth. 4.77 (12.35) 3/28/84 1100 5/09/84 1410 0.44 295 (0.01) DRY 34.0 Rio Guayanes basin 50082800 Rio Guayanes near Colonia Laura. PR Lat 18 04 55, long 65 57 32 Hydrologic unit 21010005.0n left bank, 1000 ft (305 m) 4.69 south of Hay 182. 4.5 xi (12.15) (7.2km) west of Colonia Laura. and 5.8 mi (9.3 km) north- northwest of Yabucoa. 3/29/84 0930 12.3 153 (0.35) 5/10/84 1336 9.05 152 (0.26) 24.0 27.5 277 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION NUMBER NAME AND BASIN Rio Guayanes basin 50032810 Rio Guayanas below Rio Arenas, PR Lat 18 04 44. long 65 56 54 Hydrologic unit 21010035. 100 ft (30 m) below junction with Rio Arenas and 2.3 mi (4.6 km) above junction with Quebrada Guayabo. 50083400 Rio Guayanes at Calahazas. PR Lat 18 03 33, long 65 54 03 Hydrologic unit 21010005.At bridge on Hwy 132 and 1.4 mi (2.2 km) above junction with Rio Limones. 50034000 Rio Limones near Yabucoa. Lat 18 04 35, long 65 53 42 PR Hydrologic unit 21010005-At bridge on Hwy 904. 1.2 mi (2.0 km) upstream from Rio Guayanas, and 2.0 mi (3.2 km) northwest of Yabucoa. 50085000 Rio Guayanes at Yabucoa. Lat 18 03 42, long 65 52 33 PR Hydrologic unit 21010005.At bridge on 4ry 3. 0.5 mi (0.8 km) downstream from Rio Li- mones, and 0.7 mi (1.1 km) north of Yabucoa. 50035100 Rio Guayanes at Central Let 18 03 57, long 65 52 22 Roig, PR Hydrologic unit 21010005. At abandonend lake control structure, 0.2 mi (0.3 km) northeast of Central Roig. 1.0 mi (1.6 km) downstream from Rio Limones. and 1.0 mi (1.6 km) northeast of Yabucoa. 50085700 Rio Guayanes near mouth Lat 18 04 16. long 65 50 14 near Playa de Guayanes. Hydrologic unit 21010005. PR At dirt road crossing, south of Hwy 906. and 3.1 mi (5.0 km) northeast of Yabucoa. 50086000 Rio del Ingenio near Let 18 05 03. long 65 51 27 Yabucoa. PR Hydrologic unit 21010005.At bridge on Hwy 3. 0.2 mi (0.3 km) upstream from Quebrada Cortadera and Aguacate, and 2.6 mi (4.2 km) northeast of Yabucoa. 50086300 Rio del Ingenio near Lat 18 04 20. long 65 50 02 Playa de Guayanes• PR Hydrologic unit 21010005. 1.8 mi (2.9 km) downstream from bridge on Hwy 3 and 0.6 mi (1.0 km) above junc­ tion with Rio Guayanas. 50086500 Rio Guayanes at Playa de Lat 18 03 45, long 65 49 42 Guayanes, PR Hydrologic unit 21010005. At old railroad crossing. 0.2 mi (0.3 km) from mouth. 0.4 mi (0.6km) west of Pla­ ya de Guayanes. and 3.5 mi (5.6 km) northeast of Yabu­ coa. DRAINAGE AREA sq mi (sq km) 7.44 (19.27) 17.2 (44.5) 7.89 (12.70) 25.5 (63.6) 26.6 (68.9) 27.6 (71.5) 2.46 (6.37) 11.5 (29.8) 34.0 (88.1) STREAM- SPE- TEMPER- FLOW CIFIC DATE TIME CONOUC- ATURE cfs TANCE (cms) umhos deg C 3/29/84 NO MEAS 5/08/84 - NO MEAS 3/29/84 1052 22.2 169 25.5 (0.63) 5/08/84 1105 16.4 173 27.0 (0.46) 3/29/84 1312 12.4 169 29.0 (0.35) 5/08/84 0814 9.12 174 24.5 (0.26) 3/29/ 84 1212 35.6 175 26.5 (1.01) 5/10/84 1632 30.2 172 31.0 (0.86) 3/27/ 84 1010 31.1 169 23.5 (0.88) 5/10/84 1427 26.5 177 26.5 (0.75) 3/27/84 1245 28.5 151 29.0 (0.81) 5/10/84 1236 29.7 152 30.5 (0.84) 3/27/84 1140 2.64 190 28.5 (0.07) 5/09/34 1556 1.87 220 28.5 (0.05) 3/27/84 1315 5.18 248 32.0 (0.15) 5/10/84 1134 2.95 373 32.5 (0.08) 3/28/84 0915 40.6 182 26.5 (1.15) 5/10/84 1020 22.4 210 28.0 (0.63) 278 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- TEMPER- FLOM CIFIC CONDUC- ATURE cfs TANCE (cms) umnos deg C Cano Santiago basin 50087100 Cano Santiago at Hwy 3. PR Lat 18 03 25. long 55 52 33 Hydrologic unit 21010105.At 3.81 bridge on Hwy 3. 0.5 si (0.8 (9.87) km) north of Plaza de Yabucoa, and 0.3 mi (0.5 km) below junc- tion with Quebrada Aguas Largas. 3/29/14 1358 5/05/34 0937 1.79 (0.05) 0.90 (0.03) 289 287 27.0 26.0 50037200 Cano Santiago near Central Roig, PR Lat 13 03 18, long 65 50 59 Hydrologic unit 21010305. At service road and railroad bridge. 1.8 mi (2.9 km) east of Central Roig. and 2.0 mi (3.2 km) east of Yabucoa. 6.04 (1 5.64) 3/27/84 1055 5/10/84 1536 4.18 370 (0.12) 2.40 475 (0.07) 26.0 30.0 Rio Maunabo basin 50091000 Rio Maunabo at Maunabo. PR Let 18 00 24, long 65 54 19 Hydrologic unit 21010305. At bridge on Hwy 3, 0.4 mi (0.6 km) southwest of Mau­ nabo, and 1.3 mi (2.1 km) upstream from mouth. 12.4 (32.1) 3/2 8 / 84 0937 5/08/84 1426 9.61 244 (0.27) 6.05 243 (0.17) 25.5 34.0 Rio Jacaboa basin 50091500 Rio Jacaboa at Hacienda San Isidro, PR Let 17 58 48, long 65 53 03 Hydrologic unit 21010004. At bridge on Hwy 3, 0.4 mi (0.6km) upstream from mouth, 0.4 mi (0.6 km) east of Ha­ cienda San Isidro, and 4.3 mi (7.7 km) southwest of Maunabo. 5.23 (13.5) 3/28/84 1046 5/08/84 1555 0.68 301 (0.02) 0.08 356 (0.002) 28.0 33.0 Rio Chico basin 50091800 Rio Chico at Providencia, Lat 17 59 16, long 66 00 18 PR Hydrologic unit 21010004. At flat low bridge 20) ft (61 m) south of Hwy 3, 0.5 mi (0.8 km) above mouth, and 1.5 mi (2.4 km) south­ east of Patillas. 4.93 (12.77) 3/28/84 1117 5/03/84 1715 0.07 1110 (0.002) 0.43 995 (0.01) 34.0 30.5 Rio Grande de Patillas basin 50091950 Rio Grande de Patillas below Quebrada Sonadora, PR Lat 18 03 43. long 66 02 57 Hydrologic unit 21010004. 1.300 ft (395 m) downstream from bridge on Hwy 184 and 1,000 ft (305 m) below junc­ tion with Quebrada Sonadora. 8.75 (22.66) 3/23/84 1242 5/08/34 1132 8.62 136 (0.24) 9.14 156 (0.26) 24.5 25.0 50094200 Rio Grande de Patillas at Patillas, PR Lat 18 00 15, long 66 01 27 Hydrologic unit 21010104. At bridgo on Hwy 3. 0.7 mi (1.1 km) west of Patillas, and 1.9 mi (3.1km) upstream from mouth. 27.9 (72.3) 3/23/84 5/08/84 1840 DRY 1.45 243 (0.04) 28.0 50094300 Rio Grande de Patillas at Providencia, PR Lat 17 59 20, long 66 00 47 Hydrologic unit 21010004. At abandoned railroad bridge. 29.0 0.5 mi (0.8 km) above mouth, (75.1) and 0.6 mi (1.0 km) west of Providencia. 3/27/84 1312 5/09 / 9 4 1325 1.56 338 (0.04) 1.01 412 (0.03) 30.0 33.0 279 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- FLOW CIFIC CONDUC- cfs TANCE (cms) umhos TEMPER- ATURE deg C Rio Nigua basin 50094500 Rio Nigua at Arroyo. PR Lat 17 53 10. long 66 03 41 Hydrologic unit 21010034. At bridge on Hwy 178, 0.2 mi (0.3 km)north of Arroyo. and 3.7 mi (6.0 km) east of Guayama. 3.04 (20.82) 3/27/84 1105 5/09/84 1410 0.12 1230 (0.003) 0.03 750 (0.301) 35.0 37.0 Quebrada Salads basin 50094510 Quebrada Salada near Arroyo, PR Lat 18 53 50. long 66 04 23 Hydrologic unit 21010034. At bridge on Hwy 3 and 0.9 mi (1.4 km) upstream from mouth. 0.76 (1.97) 3/27/84 1025 5/09/84 1448 0.04 2230 (0.001) 0.06 1460 (0.002) 27.5 33.0 Quebrada Corazon basin 50094520 Quebrada Corazon near Arroyo, PR Lat. 18 58 53. long 66 04 41 Hydrologic unit 21010004.At bridge on Hwy 3 and 1.0 mi (1.6 km) above mouth. 4.29 (11.11) 3/27 / 8 4 0955 5/09/84 1530 0.66 738 (0.02) 1.12 440 (0.03) 25.5 27.5 Rio Guamani basin 50095500 Rio Guamani near Guayama, Lat 17 57 30. long 66 08 20 PR Hydrologic unit 21010004. At railroad bridge, 0.5 mi (0.8 km) downstream from Hwy 3. 1.2 mi (1.9 km) up- stream from mouth. and 2.5 mi (4.0 km) southwest of Guayama. 12.3 (31.9) 3/30/84 DRY Rio Melania basin 50095900 Rio Melania near Jobos. PR Lat 17 57 51. long 66 59 30 Hydrologic unit 21010004. 0.6 mi (1.0 km) upstream from bridge on Hwy 3. 3.51 (9.09) 3/30/84 1445 0.55 (0.02) 592 23.0 Rio Seco basin 50097800 Rio Seco near Central Guamani, PR Lat 17 58 06. long 66 10 52 Hydrologic unit 21010004.At bridge on Hwy 3. 0.2 mi (0.3 km) north of Central Guamani. and 1.2 mi (1.9 km) northwest of Jobos. 11.1 (28.7) 3/30/84 DRY Rio Salinas (Nigua) basin 50100700 Rio Majada at Rabo del Buoy, PR Lat 18 02 17. long 66 14 27 Hydrologic unit 21010004.At 22.2 bridge on Hwy 1. at Rabo del (57.5) Buoy. 200 ft (61 m) upstream from Rio Lapa. and 5.6 mi (9.0 km) northeast of Sali- nas. 3/30/84 NO FLOW 50102000 Rio Salinas at Salinas. PR Lat 17 58 42. long 66 18 17 Hydrologic unit 21010004.At bridge on Hwy 1 and 0.4 mi (0.6 km) west of Salinas Plaza. 52.4 (135.7) 3/29/84 DRY 280 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- SPE- TEMPER- FLOW CIFIC CONDUC- ATURE cfs TANCE (cms) umhos deg C Rio Jueyas basin 50103000 Rio Jueyes near Jauca, PR Lat 17 53 45, long b6 20 20 Hydrologic unit 21010004.At bridge on Hwy 1, 1.8 mi (2.9 km) east of Jauca, and 2.7 mi (4.3 km) west of Salinas Plaza. 3.56 (22.17) 3/29 / 8 4 DRY Rio Coamo basin 50107000 Rio Coamo near Santa Isabel, PR Let 17 53 36, long 66 25 10 Hydrologic unit 21010004.At bridge on Hwy 1, at Yelaz- quez, and 1.1 mi (1.8 km) northwest of Santa Isabel Plaza. 69.0 (178.7) 3/29184 DRY Rio Descalabrado basin 50108500 Rio Descalabrado near Santa Isabel, PR Lat 17 59 34, long 66 26 35 Hydrologic unit 21010034.At bridge on Hwy 1, 0.9 mi (1.4 13.1 km) upstream from mouth, and (46.9) 3.1 mi (5.3 km) northwest of Santa Isabel. 3/29/84 DRY Rio Canas basin 50109500 Rio Canas near Santa Isabel, PR Lat 17 59 39, long 66 28 35 Hydrologic unit 21010004.At bridge on Hwy 1, 0.5 mi (0.8 km) from mouth, 0.6 ci (1.0 km) east of Pastillo, and 5.1 mi (3.2 km) northwest of Santa Isabel Plaza. 6.38 (16.52) 3/29/84 DRY Rio Jacaguas basin 50112000 Rio Jacaguas at Arus, PR Lat 18 00 05, long 66 31 50 Hydrologic unit 21010004.At bridge on Hwy 1, at Arus. and 59.3 4.0 mi (6.4 km) south of (153.6) Juana Diaz. 3/29/84 DRY Rio Inabon basin 50113450 Rio Inabon near Arus, PR Lat 18 00 22, long 66 33 13 Hydrologic unit 21010004. At bridge on Hwy 1. 0.9 mi (1.4 km) east of Ponce Mu- nicipal Airport terminal, and 1.7 ci (2.7 km) west of Arus. 30.2 (78.2) 3/29/84 NO FLOW Rio Bucana basin 50114600 Rio Bucana at Ponce, PR Let 18 00 28, long 66 35 36 Hydrologic unit 21010004. At bridge on Hay 1, 0.2mi (0.3 27.3 km) east of intersection of (70.7) Hays 1 and 2, 1.5mi (2.4km) oast of Plaza Degetau in Ponce. and 3.1mi (5.0km) upstream from mouth. 3/29/84 1715 0.73 (0.02) 517 29.0 281 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION NUMBER STATION NAME LOCATION AND BASIN DRAINAGE AREA sq mi (sq km) DATE TIME STREAM- FLOW cfs (cms) SPE- TEMPER- CIFIC CONDUC- ATURE TANCE umhos deg C Rio Portugues basin 50116500 Rio Portugues at Hwy 2 by pass at Ponce. PR Lat 17 59 52. long 66 36 52 Hydrologic unit 21010004. On pier at bridge on Hwy 2 by pass. 1.1 mi (1.8 km) south of Plaza Oegetau. and 2.0 mi (3.2 km) upstream from mouth. 20.5 (53.1) 3/29/84 1410 1.29 592 (0.04) 34.0 Rio Matilde basin 50116970 Rio Canas below Las Americas Avenue, PR Let 13 00 37. long 66 38 23 Hydrologic unit 21010004. 0.5 mi (0.8 km) upstream from junction with Rio Pas- tillo. 3.39 (21.73) 3/29/84 1615 5.46 (0.15) 780 31.0 50119200 Quebrada dal Agua at Playa de Ponce, PR Lat 17 59 13, long 66 33 22 Hydrologic unit 21010004. 700 ft (213 m) upstream from junction with Rio Matilda. 6.45 (16.71) 3/29 / 8 4 DRY Rio Tallaboa basin 50122000 Rio Tallaboa at Tallaboa, Lat 13 00 31, long 66 43 49 PR Hydrologic unit 21010004.At bridge at Hacienda Dolores. 700 ft (213 m) upstream from Hwy 2. 0.8 mi (1.3 km) north- west of Tallaboa, and 7.6 mi (12.2 km) west of Plaza 0e- getau in Ponce. 31.50 (81.6) 3/29/84 1140 3.48 (0.10) 318 29.5 Rio Macana basin 50122900 Rio Macana at Magas Arriba, PR Lat 18 01 00. long 66 45 57 Hydrologic unit 21010004. 1.8 mi (2.8 km) east of Pla­ za de Guayanilla, 200 ft (60 m) upstream from bridge on Hwy 2. and 0.6 mi (1.0 km) upstream from mouth. 8.96 (23.21) 3/29 / 8 4 DRY Rio Yauco basin 50126500 Rio Yauco at Pueblo Sur at Yauco, PR Let 18 02 08, long 66 50 51 Hydrologic unit 21010004.At bridge on 4wy 2, 0.1 mi (0.2 km) east of Yauco. and 0.6 mi (1.0 km) upstream from Quebrada 3errenchin. 33.0 (85.5) 3/28/84 DRY Rio Loco basin 50129200 Quebrada Susua at Palomas, PR Lat 18 01 19, long 66 52 28 Hydrologic unit 21010004.At bridge on Hwy 2. 0.5 mi (0.8 km) north of Palomas, and 1.9 mi (3.1 km) southwest of Yauco. 3.23 (8.37) 3/28/84 DRY 50129500 Rio Loco near Guanica, PR Last 17 59 38, long 66 54 59 Hydrologic unit 21010004. 90 ft (27 m) upstream from sheet piling drop structu- re, 900 ft (274 m) upstream from Lajas Drainage Canal. 7.2 mi (11.6 km) downstream from Lago Loco. and 1.5 mi (2.4 km) north of Guanica. 21.0 (54.4) 3/28/84 1540 1.68 (0.05) 412 30.0 282 DISCHARGE AT PARTIAL-RECORD STATIONS Low-flow partial-record stations--Continued STATION STATION LOCATION DRAINAGE STREAM- SPE- TEMPER- AREA FLOW CIFIC NUMBER NAME AND sq mi GATE TIME CONDUC- ATURE cfs TANCE BASIN Csq km) (cms) umhos dog C Quebrada Boqueron basin Lat 18 01 40, long 67 09 35 Hydrologic unit 21013094.At bridge on Hwy 101 and 0.9 mi (1.4 km) above mouth. 50130000 CIuebrada Boqueron at Boqueron, PR Rio Guanajibo basin 50132010 Rio Guanajibo below San Lot 18 05 28. long 67 02 33 German, PR Hydrologic unit 21010003. 0.5 mi (0.3 km) north of Plaza de San German and 1,500 ft (457 m) downstream from bridge on Hwy 360. Rio Yaguaz basin 4.35 3/28/84 1325 6.81 291 26.5 (11.27) (0.19) 36.1 3/28/84 1110 3.95 517 28.0 (93.5) (0.11) 50138900 Rio Yaguez at Balboa, PR Lat 18 12 13, long 67 07 55 Hydrologic unit 21010003. 1,200 ft (366 m) upstream 12.2 3/27/84 1740 6.53 320 26.0 from bridge on Balboa St. (31.6) (0.18) and 1.6 mi (2.5 km) up- stream from mouth. Rio Grande de Anasco basin 50146070 Rio Grande de Anasco at Lat 18 16 21. long 66 08 33 Anasco Arriba, PR Hydrologic unit 21010003. 0.8 mi (1.2 km) south of Anasco and 3.0 mi (4.8 km) upstream from mouth. Rio Grande basin 176 3/27/84 NO MEAS (456) 50146200 Rio Grande near Rincon. Lat 13 22 06, long 67 13 56 PR Hydrologic unit 21010003. At bridge on Hwy 115, 1.2 mi 2.83 3/27/84 1320 0.41 649 25.0 (1.9 km) upstream from mouth, (7.33) (0.01) and 2.2 mi (3.5 km) northeast of Rincon. Rio Ingenio basin 50146400 Rio Ingenio near Aguada. Lat 18 22 50. long 67 12 34 PR Hydrologic unit 21010003. At 6.22 3/27/84 1155 3.57 470 25.0 bridge on unimproved road, (16.11) (0.10) 0.3 xi (0.5 km) upstream from confluence with Rio Culebra, 0.7 ci (1.1 km) upstream from mouth of Rio Guayabo. and 1.4 ci (2.3 km) west of Aguada. Rio Culebra basin 50146600 Rio Culebra near Aguada. Lat 18 22 26. long 67 11 35 PR Hydrologic unit 21010003. At bridge on Hwy 411. 0.6 mi 3.70 3/27/84 1020 1.67 388 24.5 (1.0 km) south of Aguada, 1.5 (9.58) (0.05) mi (2.4 km) upstream from confluence with Rio Ingenio, and 1.9 mi (3.1 km) upstream from mouth of Rio Guayabo. Rio Culebrinas basin 50149100 Rio Culebrinas near Aguada. PR Lot 18 24 03. long 67 09 40 Hydrologic unit 21010003. At bridge on Hwy 2 and 2.3 97.0 3/27/84 NO MEAS mi (3.7 km) northeast of (251.2) Aguada Plaza. a Drainage area does not include coastal undefined drainage. 283 DISCHARGE AT CREST-STAGE PARTIAL-RECORD STATIONS The following table contains annual maximum discharge for crest-stage stations. A crest-stage gage is a device which mill register the peak stage occurring between inspections of the gage . A stage-discharge relation for each gage is developed from discharge measurements made by indirect measurements of peak flow or by current meter. The date of the maximum discharge is not always certain but is usually determined by comparison with nearby continuous- record stations, weather record, or local inquiry. Only the maximum discharge for each water year is given. Infor­ mation on some lower floods may have been obtained, and discharge measurements may have been made for purposes of establishing the stage-discharge relation, but these are not published herein. The years given in the period of rec­ ord represent years for which the annual maximum has been determined. Annual maximum discharge at crest-stage partial-record stations during water year 1934 Annual maximum Station number Station name Location Drainage area sq mi (sq km) Period of record Date Gage height ft (5) Dis­ charge cu ft/s (cu m/s) Rio Portuguas basin 50115900 Rio Portugues at Highway 14 at Ponce, PR Let 18 01 09, long 66 36 26, on left downstream side of Highway 14 bridge, 1.7 mi (2.7 km) downstream from Rio Chiquito, and 0.6 mi (0.97 km) northeast of Degetau Plaza in Ponce. 13.6 (48.2) 1963­84 < 8.82 (<2.688) < 1,700 (<48.1) -- -- 284 ANALYSES OF SAMPLES COLLECTED AT WATER-QUALITY PARTIAL-RECORD STATIONS WATER-QUALITY DATA,' WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 NITRO- BIOMASS CHLOR-A CHLOR-3 NITRO- NITRO- NITRO- GEN,AM- CHLORO- PHYTO- PHYTO- GEN, GEN, GEN, MONIA + NITRO- NITRO- PHOS- PHYLL PLANK- PLANK- NO2+NO3 AMMONIA ORGANIC ORGANIC GEN, GEN, PHORUS, RATIO TON TON TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL PLANK- CHROMO CHROMO (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L (MG/L TON FLUOROM FLUOROM DATE AS N) AS N) AS N) AS N) AS N) AS NO3) AS P) (UNITS) (UG/L) (UG/L) RIO GUAJATACA BASIN--CONTINUED 50010720 - LAGO GUAJATACA NO.3 NR MOUTH Ng EBRADILLAS,PR (LAT 18 22 05 LONG 066 54 36) OEC , 1983 01... <.10 <.01 .70 .02 .00 2.8 .60 APR , 1984 09... .40 .08 .62 .70 1.1 4.9 .03 .00 12 <.10 JUL 23... <.10 <.01 .20 .02 .00 2.6 <.10 SOLIDS. SOLIDS. MAGNE- SODIUM POTAS- ALKA- CHLO- FLUO- SILICA, SUM OF RESIDUE NITRO- STUN, SODIUM, AD- SIUMs LINITY SULFATE RIDE, RIDE, DIS- CONSTI- AT 105 GEN, DIS- DIS- SORP- On- FIELD DIS- DES- DES- SOLVED TUENTS, DEG. Co NITRATE SOLVED SOLVED TION SOLVED (MG/L SOLVED SOLVED SOLVED (MG/L DIS- SUS- TOTAL (MG/L (MG/L RATIO (MG/L AS (MG/L (MG/L (MG/L AS SOLVED PENDED (MG/L DATE AS MG) AS NA) AS K) CACO3) AS 504) AS CL) AS F) SI02) (MG/L) (MG/L) AS N) 50010790 LAGO GUAJATACA NO.1 NR DAM NR QUEBRADILLAS•PR (LAT 18 23 56 LONG 066 55 23) DEC • 1983 01... 3.6 5.9 .2 1.4 125 11 3.0 .20 6.1 160 4 01... 3.8 6.0 .2 1.5 125 11 8.0 .20 9.1 160 APR • 1984 09... 4.0 6.2 .3 1.5 121 11 8.9 .10 6.4 150 <1 09... 4.1 6.4 .2 1.6 138 8.8 8.9 .10 7.7 170 JUL 23... 3.8 5.7 .2 1.3 111 15 9.2 .10 4.5 150 4 23... 3.4 5.1 .2 1.7 144 15 5.9 .10 6.5 180 -- RIO GRANDE DE ARECIBO BASIN--CONTINUED 50020050 - LAGO GARZAS NO.1 NR DAM NR ADJUNTAS,PR (LAT 18 08 21 LONG 066 44 35) NOV • 1983 30... 4.3 6.3 .4 1.1 62 4.7 .10 17 8 30... 4.4 5.8 .3 1.4 91 12 5.6 .10 17 120 APR , 1984 04... 5.0 6.4 .4 1.0 71 2.7 3.7 <.10 19 98 8 04... 4.6 6.0 .3 1.1 75 1.0 5.7 -(I) 4.1 I -J Z La 283 3 285 SONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 303 GROUND-WATER LEVELS RIO GRANDE DE MANATI BASIN 182454066315300. Local number, 142. LOCATION.--Lat 18°24'54", long 66°31'53". Owner: P.R. Aqueduct and Sewer Authority. Name: Morgn Sim6. AQUIFER.--Aymamiin Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m) 0-147 ft (0-44.82 m), cased 20 in (0.51 m) 0-100 ft (0-30.49 m), diameter 16 in (0.41 m) 147-211 ft (44.82-64.33 m), diameter 12 in (0.30 m) 211-320 ft (64.33-97.56 m), cased 12 in (0.30 m) 0-320 ft (0-97.6 m), perforated 248-320 ft (75.6-97.6 m), diameter 10 in (0.25 m) 320-517 ft (97.6-158 m), cased 8 in (0.20 m) 300-517 ft (91.46-158 m), perforated 480-517 ft (146-158 m). Depth 517 ft 158 m). DATUM.--Altitude of land-surface datum is 492 ft (150 m) above mean sea level. Measuring point: top of 1.75 in (0.04 m) hole on top of 3 in (0.08 m) casing, 1.0 ft (0.30 m) above land surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--August 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 226.5 ft (69.05 m) below land-surface datum, May 21, 1982; lowest water level measured, 229.9 ft (70.09 m) below land-surface datum, May 29, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 Nov. 23 Dec. 15 228.5 226.6 229.0 Jan. 23 Feb. 21 Mar. 23 228.9 228.8 229.1 Apr. 17 May 29 June 11 229.3 229.9 229.9 July 18 Aug. 8 Sept. 5 229.0 229.0 229.1 182542066305100. Local number, 166. LOCATION.--Lat 18°25'42", long 66°30'51". Owner: P.R. Aqueduct and Sewer Authority. Name: Manati (New well). AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), cased 0-100 ft (0-39.49 m), diameter 14 in (0.36 m), cased 0-140 ft (0-42.68 m), slotted 80-90 ft (24.39-27.44 m) and 130-140 ft (39.63-42.68 m). Depth 140 ft (42.68 m). DATUM.--Altitude of land-surface datum is 29.52 ft (9.0 m) above mean-sea level. Measuring point: Top of 14 in (0.36 m) casing, 0.80 ft (0.24 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--January 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 22.90 ft (6.98 m) below land-surface datum, Mar. 3, 1983; lowest water level measured, 26.36 ft (8.04 m) below land-surface datum, Feb. 3, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 25.34 Jan. 23 26.05 Apr. 17 25.55 July 18 25.98 Nov. 23 25.17 Feb. 21 25.55 May 29 25.41 Aug. 8 25.96 Dec. 15 25.43 Mar. 23 25.78 June 11 25.53 Sept. 10 25.85 304 GROUND-WATER LEVELS RIO CIBUCO BASIN 182446066194801. Local number, 62. LOCATION.--Lat 18°24'46", long 66°19'48". Owner: P.R. Aqueduct and Sewer Authority. Name: Vega Alta 1. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 16 to 12 in (41 to 30 cm), cased 16 in (41 cm) 0-50 ft (0-15.2 m), 12 in (30 cm) 0-110 ft (0-33.54 m). Depth 210 ft (64.02 m). DATUM.--Altitude of land-surface datum is about 102 ft (31.10 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe in pump base, 1.0 ft (0.30 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--January 1961 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, a75.88ft (a23.13 m) below land-surface datum, Feb. 21, 1984; lowest measured, 137.9 ft (42.04 m) below land-surface datum, Mar. 3, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 a98.58 Jan. 23 a97.00 Apr. 17 a95.52 July 18 al06.4 Nov. 23 a112.6 Feb. 21 a75.88 May 29 al02.4 Aug. 8 a108.3 Dec. 15 al10.5 Mar. 23 a82.10 June 12 al00.1 Sept. 5 al08.0 a Pumping. 305 GROUND-WATER LEVELS RIO CIBUCO BASIN 182647066201701. Local number, 70. LOCATION.--Lat 18°26'47", long 66°20'17". Owner: P.R. Aqueduct and Sewer Authority. Name: Sabana Hoyos. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled unused artesian well, diameter 8 in (20 cm), cased 0-90 ft (0-27.43 m), perforated. Depth 90 ft (27.43 m). DATUM.--Altitude of land-surface datum is about 49 ft (14.9 m) above mean sea level. Measuring point: Top of casing wooden cover, 1.30 ft (0.40 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--February 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 21.33 ft (6.50 m) below land-surface datum, Oct. 26, 1976; lowest, 31.10 ft (9.48 m) below land-surface datum, July 31, 1975. WATER LEVEL, IN CEET BELOW LAND-SUR'ACE DATUM, W4TE2 YEAR OCTOBER 1983 TO SEPTEMSER 1984 INSTANTANEOUS OBSERVATIONS AT 1230 DAY OCT N3V DEC JAN FES MAR APR MAY JUN JUL 4UG SEP 1 28.9? 28.96 29.18 29.41 29.13 29.65 33.93 30.03 29.71 29.60 2/.68 2 29.00 213.96 24.18 29.40 21.15 29.66 30.31 30.02 29.73 29.60 29.'0 3 29.01 23.96 29.18 29.41 21.03 29.67 30.02 30.02 29.74 29.60 29.71 4 29.01 28.96 29.18 29.43 29.11 29.63 30.33 30.03 29.73 29.61 29.72 5 29.01 28.37 21.19 29.43 29.13 29.70 30.03 39.03 29.73 29.53 29.74 6 29.03 21.19 29.44 29.14 29.71 30.33 29.99 29.71 29.55 29.73 7 29.01 29.20 29.45 21.17 29.74 30.03 29.95 21.71 29.55 29.73 8 29.02 21.21 29.44 29.19 29.76 30.37 29.92 29.70 29.55 29.72 9 29.03 29.22 29.45 21.22 29.77 39.36 29.91 29.70 29.54 29.72 10 29.03 21.23 29.45 29.25 29.77 30.07 29.83 29.70 29.55 29.72 11 29.04 24.24 29.41 29.27 29.73 33.08 29.86 29.66 29.55 29.72 12 29.05 21.24 29.36 29.31 29.79 30.10 29.35 29.62 29.55 29.71 13 14 29.05 29.07 /9.24 29.25 29.31 29.11 21.33 29.35 29.79 29.80 31.11 30.13 29.84 29.84 29.61 27.60 29.55 29.56 29.70 29.57 15 29.07 29.04 29.26 29.12 24.37 29.81 30.13 29.34 29.59 29.56 29.64 16 29.05 29.05 21.27 29.06 21.38 29.32 31.14 29.85 29.55 29.53 29.50 17 29.05 29.05 29.28 29.01 29.39 29.53 30.15 29.74 29.55 29.59 29.57 18 29.02 29.05 29.30 23.95 29.41 29.83 33.14 29.72 29.53 29.59 29.28 19 29.01 29.06 29.31 23.91 29.42 29.35 33.14 29.69 29.55 29.59 29.14 20 28.99 29.05 29.32 28.89 29.45 29.86 33.13 29.67 29.58 29.60 29.04 21 28.99 29.07 29.33 28.90 21.46 29.87 30.13 29.66 29.58 29.62 23.96 22 28.99 29.08 29.33 25.89 29.45 29.90 30.11 29.66 29.56 29.62 23.39 23 28.93 29.09 29.33 28.90 29.50 29.91 30.11 29.65 29.55 29.63 28.33 24 28.97 29.10 29.34 28.91 29.52 29.93 30.09 29.65 29.55 29.63 28.79 25 28.97 29.12 21.34 28.94 24.54 29.93 30.37 29.64 29.55 29.64 28.76 26 28.96 29.13 29.35 28.95 29.55 29.94 33.06 29.64 29.55 29.65 23.76 27 28.95 29.14 29.36 28.97 29.58 29.96 30.05 29.64 29.56 29.66 23.77 28 28.96 29.15 29.36 28.99 27.60 29.98 30.04 29.65 29.57 29.66 28.79 29 28.97 29.16 29.37 29.01 27.61 30.00 30.03 29.67 29.57 29.66 23.31 30 28.98 29.17 29.39 --- 27.62 30.02 30.02 29.69 29.57 27.65 23.32 31 28.97 29.13 29.40 29.64 --- 30.01 --- 29.59 29.66 --- LOW 29.07 29.40 29.45 27.64 30.02 30.15 30.03 29.74 29.66 29.74 HIGH 29.95 20.18 28.39 29.03 29.65 30.01 29.64 29.55 29.54 23.76 20 3 22 0 -J LkJ 03 F- 1- < 24 Lao z< - 26 -J Jo 28 La< 3 30 32 ASONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 306 GROUND-WATER LEVELS RIO CIBUCO BASIN 182705066213500. Local number, 151. LOCATION.--Lat 18°27'05", long 66°21'35". Owner: AFDA - P.R. Department of Agriculture. Name: Rice Program #3. AQUIFER.--AymamEin Limestone. WELL CHARACTERISTICS.--Drilled agricultural water-table well, diameter 18 in (0.46 m) cased 0-80 ft (0-24.39 m), diameter 16 in (0.41 m), open hole 80-160 ft (24.39-48.78 m). Depth 160 ft (48.78). DATUM.--Altitude of land-surface datum is about 19.7 ft (6 m) above mean sea level; Measuring point: Hole 1 in (0.02 m) side of casing, 2.40 ft (0.73 m) above land-surface datum. REMARKS.--Observation well. Irrigation water supply. PERIOD OF RECORD.--January 13, 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 3.72 ft (1.13 m) below land-surface datum, Jan. 13, 1982; lowest water level, measured, a41.78 ft (a12.74 m) below land-surface datum, Aug. 17, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 20 6.30 Jan. 23 6.80 June 12 7.03 Aug. 3 6.88 Nov. 18 6.32 Feb. 24 6.68 July 9 6.96 Sept. 5 6.62 Dec. 15 6.48 May 4 7.39 182612066225400. Local number, 155. LOCATION.--Lat 18°26'54", long 66°22'54". Owner: P.R. Aqueduct and Sewer Authority. Name: La Trocha. AQUIFER.--Aymam6n Limestone. WELL CHARACTERISTICS:--Drilled unused water-table well, diameter 20 in (0.51 m), cased 0-70 ft (0-21.34 m), diameter 16 in (0.41 m), cased 0-100 ft (0-30.49), perforated 100-200 ft (30.49-60.97 m). Depth 200 ft (61.0 m). DATUM.--Altitude of land-surface datum is about 49.20 ft (15.0 m) above mean sea level. Measuring Point: Top of 20 in (0.51 m) casing, 2.10 ft (0.64 m) above land-surface datum. REMARKS.--Observation well. Never used as water supply well due to high concentrations of chlorides. PERIOD OF RECORD.--January 14, 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 32.23 ft (9.83 m) below land-surface datum, Jan. 14, 1982; lowest water level, 34.62 ft (10.55 m) below land-surface datum, May 29, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 34.10 Jan. 23 34.40 Apr. 17 34.60 July 18 34.51 Nov. 23 34.02 May 21 33.26 May 12 33.95 Aug. 15 34.32 Mar. 17 34.38 June 16 33.48 June 27 34.08 Sept. 6 34.60 182652066241400. Local number, 156. LOCATION.--Lat 18°26'52", long 66°24'14". Owner: P.R. Aqueduct and Sewer Authority. Name: El Criollo #1. AQUIFER.--AymamOn Limestone. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 20 in (0.51 m), cased 0-98 ft (0-29.88 m), diameter 16 in (0.41 m), perforated 88-120 ft (26.83-36.58 m). Depth 120 ft (36.58 m). DATUM.--Altitude of land-surface datum is about 49.20 ft (15 m) above mean sea level. Measuring point: Upper edge of 2 in (0.05 m) pipe on pump base, 1.80 ft (0.55 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--January 14, 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 40.52 ft (12.35 m) below land-surface datum, Feb. 16, 1982; lowest water level a47.30 ft (a14.42 m) below land-surface datum, Apr. 5, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 a42.95 Jan. 23 a41.89 Apr. 17 a42.89 July 18 a43.95 Nov. 23 a43.95 Feb. 21 a43.67 May 29 a43.00 Aug. 8 a43.75 Dec. 15 a43.94 Mar. 23 a44.02 June 11 a43.88 Sept. 5 a43.65 a Pumping. 307 GROUND-WATER LEVELS RIO CIBUCO BASIN 182654066211600. Local number, 167. LOCATION.--Lat 18°26'54", long 66°21'16". Owner: P. R. Land Authority, AFDA. Name: U.S.G.S. Observation Well #3. AQUIFER.--Aymamein Limestone. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m) 0-228 ft (0-69.51 m), open hole 228-238 ft (69.51-72.56 m). Depth 238 ft (72.56 m). DATUM.--Altitude of land-surface datum is 65.6 ft (20.0 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 3.10 ft (0.94 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by nearby pumpage. PERIOD OF RECORD.--January 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 13.07 ft (3.98 m) below land-surface datum, Jan. 13, 1982; lowest water level measured, c16.90 ft (5.15 m) below land-surface datum, Aug. 18, 1983. WATER LEVELS IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 14 15.13 Jan. 23 14.42 June 12 15.52 Aug. 3 15.54 Nov. 10 14.95 Feb. 24 15.19 July 9 15.60 Sept. 5 15.96 Dec. 15 15.14 May 4 15.92 182751066221600. Local number, 168. LOCATION.--Lat 18°27'51", long 66°22'16". Owner: AFDA. P.R. Department of Agriculture. Name: Rice Program #4. AQUIFER.--AymamOn Limestone. WELL CHARACTERISTICS.--Drilled agricultural water-table well, diameter 16 in (0.41 m), cased 16 in (0.41 m) 0-156 ft (0-32.3 m), slotted 56-106 ft (17.07-32.31 m), open hole 106-150 ft (32.31-45.73 m). Depth 150 ft (45.73 m). DATUM.--Altitude of land-surface datum is about 9.84 ft (3 m) above mean sea level. Measuring point: Top of 16 in (0.41 m) casing, 0.80 ft (0.24 m) above land-surface datum. REMARKS.--Observation well. Irrigation water supply well. PERIOD OF RECORD.--March 17, 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 4.88 ft (1.49 m) below land-surface datum, Mar. 17, 1982; lowest water level measured, a53.85 ft (16.42 m) below land-surface datum, July 26, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 14 a49.90 Jan. 23 5.90 June 12 5.77 Aug. 3 a42.65 Nov. 17 a46.77 Feb. 24 a43.22 July 9 5.76 Sept. 5 a24.17 Dec. 15 a43.90 May 4 6.15 182740066223100. Local number, 169. LOCATION.--Lat 18°27'40", long 66°22'31". Owner: AFDA. P.R. Department of Agriculture. Name: Rice Program #5. AQUIFER.--Aymamon Limestone. WELL CHARACTERISTICS.--Drilled agricultural water-table well, diameter 16 in (0.41 m), cased 16 in (0.41 m) 0-80 ft (0-24.39 m), open hole 80-140 ft (24.39-42.68 m). Depth 140 ft (42.68 m). Datum.--Altitude of land-surface datum is about 13.10 ft (4.0 m) above mean sea level. Measuring point: Top of 16 in (0.41 m) casing, 0.10 ft (0.03 m) above land-surface datum. REMARKS.--Observation well. Irrigation water supply well. PERIOD OF RECORD.--March 17, 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 6.15 ft (1.88 m) below land-surface datum, Mar. 17, 1982; lowest water level measured, a15.60 ft (4.76 m) below land-surface datum, July 26, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 14 6.33 Jan. 23 al2.10 June 12 6.35 Aug. 3 7.37 Nov. 17 al1.37 Feb. 24 al0.87 July 9 7.44 Sept. 5 7.62 Dec. 15 al1.10 May 4 al2.05 a Pumping. c Pumping nearby well 308 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 180707066084201. Local number, 33. LOCATION.--Lat 18°07'07", long 66°08'42". Owner: P.R. Aqueduct and Sewer Authority. Name. Cayey 10. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 16 to 12 in (41 to 30 cm), cased 16 in (41 cm) 0-30 ft (0-9.14 m), 12 in (30 cm) 0-200 ft (0-60.97 m), perforated 30-200 ft (9.14-60.97 m), gravel packed 0-190 ft (0-57.92 m). Depth 220 ft (67.07 m). DATUM.--Altitude of land-surface datum is about 1,280 ft (390 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe in pump base, 1.20 ft (0.37 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 1.49 ft (0.45 m) below land-surface datum, Jan. 18, 1961; lowest measured, a169.2 ft (a51.58 m) below land-surface datum, Dec. 10, 1976. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water WATER Water Date level Date level Date level Date level Oct. 13 al00.4 Jan. 24 a85.49 Apr. 10 a58.50 July 16 a79.50 Nov. 18 a 90.30 Feb. 24 a75.90 May 22 a67.97 Aug. 7 a70.75 Dec. 12 al02.1 Mar. 30 a112.0 June 19 a75.65 Sept. 11 a86.26 180853066095401. Local number, 37. LOCATION.--Lat 18°08'53", long 66°09'54". Owner: P.R. Aqueduct and Sewer Authority. Name: Barrio Rinc6n de Cidra. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled water supply water-table well, diameter 16 to 8 in (41 to 20 cm), cased 16 in (41 cm) 0-30 ft (0-9.15 m), 12 in (30 cm) 0-43 ft (0-13.10 m), perforated 0-43 ft (0-13.10 m). Depth 200 ft (60.97 m). DATUM.--Altitude of land-surface datum is about 1,180 ft (359.7 m) above mean sea level. Measuring point: Lower edge at 0.75 in (1.90 cm) pipe, 1.90 ft (0.58 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--June 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 14.38 ft (4.38 m) below land-surface datum, July 20, 1979; lowest measured, 62.87 ft (19.16 m) below land-surface datum, Jul. 5, 1961. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 13 22.25 Jan. 24 23.94 Apr. 11 25.34 July 16 24.00 Nov. 18 22.26 Feb. 24 23.27 May 22 25.47 Aug. 7 24.40 Dec. 12 23.00 Mar. 30 25.02 June 19 24.50 Sept. 11 24.98 180823066154601. Local number, 38. LOCATION.--Lat 18°08'23", long 66°15'46". Owner: P.R. Aqueduct and Sewer Authority. Name: Barrio Robles. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 10 in (25 cm). Depth 82 ft (25.0 m). DATUM.--Altitude of land-surface datum is about 1,980 ft (603 m) above mean sea level. Measuring point: Top of clean-out door sill, 1.80 ft (0.55 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1959 to current year; changed to a partial site on Sept. 2, 1981. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 3.60 ft (1.10 m) above land-surface datum, Sept. 6, 1960; lowest, 51.47 ft (15.69 m) below land-surface datum, Sept. 30, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 13 10.14 Jan. 24 10.30 Apr. 10 12.40 July 16 10.57 Nov. 18 9.12 Feb. 24 10.75 May 22 12.60 Aug. 7 11.12 Dec. 12 9.72 Mar. 30 11.82 June 19 11.12 Sept. 11 11.33 a Pumping. 309 GROUND-WATER LEVELS RIO DE LA PLATA BASIN 182518066144201. Local number, 67. LOCATION.--Lat 18°25'18", long 66°14'42". Owner: P.R. Aqueduct and Sewer Authority. Name: Campanilla. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 12 in (30 cm). Depth 300 ft (91.46 m). DATUM.--Altitude of land-surface datum is about 390 ft (119 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe, 1.00 ft (0.30 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--March 1959 to December 19, 1983 (discontinued). EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 27.91 ft (8.51 m) below land-surface datum, Dec. 16, 1981; lowest measured, 49.90 ft (15.21 m) below land-surface datum, June 6, 1967. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Date level Date level Oct. 31 34.31 Dec. 19 34.12 182636066164201. Local number, 69. LOCATION.--Lat 18°26'36", long 66°16'42". Owner: P.R. Aqueduct and Sewer Authority. Name: Higuillar. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 10 in (25 cm). Depth 200 ft (60.97 m). DATUM.--Altitude of land-surface datum is about 60 ft (18.3 m) above mean sea level. Measuring point: Airline hole in pump base, 1.10 ft (0.34 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1958 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 41.21 ft (12.56 m) below land-surface datum, July 3, 1958; lowest measured, 58.89 ft (17.95 m) below land-surface datum, Oct. 26, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Date Water level Date Water level Date Water level Date Water level Oct. 7 Nov. 8 Dec. 15 a54.07 a53.98 a54.17 Jan. 31 Feb. 21 Mar. 23 a49.70 a53.30 a52.70 Apr. 17 May 29 June 12 a51.26 a45.15 a51.26 July 18 Aug. 8 Sept. 5 a54.26 a53.56 a54.15 182623066181400. Local number, 150. LOCATION.--Lat 18°26'23", long 66°18°14". Owner: Department of Agriculture, Land Authority; loaned to Puerto Rico Aqueduct and Sewer Authority. Name: Monterey Forestal. AQUIFER.--AymamOn Limestone. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 12 in. (0.30 m), cased 12 in. (0.30 m) 0-300 ft (0-91.46 m), open hole 300-400 ft (91.46-122 m). Depth 400 ft (122 m). DATUM.--Altitude of land-surface datum is 131.2 ft (40 m) above mean sea level. Measuring point: Bottom edge of 1 in. (2.54 cm) pipe on top of pump concrete base, 1.00 ft (0.30 m) above land-surface datum. REMARKS.--Irrigation supply observation well. PERIOD OF RECORD.--January 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, a183.8 ft (56.04 m) below land-surface datum, Nov. 8, 1983; lowest water level measured, a210.9 ft (64.29 m) below land-surface datum, Apr. 15, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEARS OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 a184.2 Jan. 31 184.6 Apr. 17 al93.3 July 18 184.7 Nov. 8 a183.8 Feb. 21 184.0 May 29 185.6 Aug. 8 195.4 Dec. 15 184.2 Mar. 23 184.6 June 12 185.1 Sept. 5 196.5 a Pumping. 310 GROUND-WATER LEVELS RIO HONDO TO RIO PUERTO NUEVO BASINS 181047066091701. Local number, 42. LOCATION.--Lat 18°10'47", long 66°09'17". Owner: P.R. Aqueduct and Sewer Authority. Name: Cidra 2. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 13 in (33 cm), cased 0-64 ft (0-19.51 m), perforated 16-64 ft (4.88-19.51 m). Depth 92 ft (28.05 m). DATUM.--Altitude of land-surface datum is about 1,340 ft (408 m) above mean sea level. Measuring point: Airline hole in pump base, 1.40 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.30 ft (3.75 m) below land-surface datum, Dec. 27, 1979; lowest measured 56.32 ft (17.17 m) below land-surface datum, Apr. 1, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 13 17.00 Jan. 24 20.34 Apr. 11 25.95 July 16 19.99 Nov. 18 17.93 Feb. 24 21.00 May 22 26.01 Aug. 7 19.15 Dec. 12 19.71 Mar. 30 24.52 June 19 26.13 Sept. 11 21.93 182506066030801. Local number, 65. LOCATION.--Lat 18°25'06", long 66°03'08". Owner: P.R. Aqueduct and Sewer Authority. Name: Hato Rey Central, McCracken well. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 15 in (38 cm), cased 0-205 ft (0-62.50 m), perforated 64-205 ft (19.51-62.50 m). Depth 205 ft (62.50 m). DATUM.--Altitude of land-surface datum is about 33 ft (10.1 m) above mean sea level. Measuring point: Top of casing 3.40 ft (1.04 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1958 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 22.40 ft (6.83 m) below land-surface datum, Aug. 12, 1976; lowest measured, 42.40 ft (12.92 m), below land-surface datum, May 13, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 11 31.24 Feb. 17 30.33 Apr. 11 30.75 July 18 31.46 Nov. 17 31.05 Mar. 19 30.66 May 31 31.25 Aug. 8 31.48 Dec. 19 30.35 23 30.80 June 5 31.46 Sept. 11 31.30 Jan. 13 30.43 182547066110801. Local number, 66. LOCATION.--18°25'47", long 66°11'08". Owner: P.R. Aqueduct and Sewer Authority. Name: Sabana Seca. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well. Depth 130 ft (39.63 m). DATUM.--Altitude of land-surface datum is about 75 ft (22.87 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe in pump base, 1.20 ft (0.37 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--June 1958 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, a39.23 ft (a11.96 m) below land-surface datum, Dec. 17, 1981; lowest measured, 57.75 ft (17.60 m), below land-surface datum, Aug. 13, 1976. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 7 a43.63 Feb. 21 a44.02 May 29 45.36 Aug. 8 44.87 Dec. 15 a44.30 Mar. 23 a44.55 June 12 45.14 Sept. 6 44.92 Jan. 31 a46.87 Apr. 17 44.96 July 18 44.77 a Pumping. 311 GROUND-WATER LEVELS RIO GRANDE DE LOIZA BASIN 181550065593201. Local number, 50. LOCATION.--Lat 18°15'50", long 65°59'32". Owner: Gurabo Agricultural Experimental Station. Name: Gurabo. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 13 in (33 cm). Depth 145 ft (44.21 m). DATUM.--Altitude of land-surface datum is about 148 ft (45.12 m) above mean sea level. Measuring point: Top of 12 in (30 cm) casing, 0.80 ft (0.24 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--December 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.65 ft (3.86 m) below land-surface datum, Sept. 9, 1975; lowest measured, 44.38 ft (13.53 m) below land-surface datum, June 18, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 13 29.83 Jan. 12 29.44 Apr. 10 31.34 July 30 26.96 Nov. 22 28.99 Feb. 16 28.86 May 29 34.33 Aug. 13 30.20 Dec. 19 29.55 Mar. 8 29.17 June 14 30.15 Sept. 17 30.45 181538066021301. Local number, 52. LOCATION.--Lat 18°15'38", long 66°02'13". Owner: P.R. Aqueduct and Sewer Authority. Name: Bairoa. AQUIFER.--Unconsolidated deposits of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 to 10 in (41 to 25 cm) 0-69 ft (0-21.04 m), 79-100 ft (24.08-30.49 m), 110-116 ft (33.54-35.37 m), perforated 79-100 ft (24.08-30.49 m), screened 69-79 ft (21.04-24.08 m) and 100-110 ft (30.49-33.54 m); gravel packed to 113 ft (34.45 m). Depth 116 ft (35.37 m). DATUM.--Altitude of land-surface datum is about 200 ft (60.98 m) above mean sea level. Measuring point: Airline hole in pump base, 1.4 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, +0.92 ft (+0.28 m) below land-surface datum, Nov. 15, 1979; lowest measured, a115.1 ft (a35.09 m) below land-surface datum, June 18, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 13 a73.51 Jan. 13 a74.08 Apr. 10 a80.08 July 30 a73.12 Nov. 11 a73.76 Feb. 17 a75.53 May 29 a78.85 Aug. 13 a76.22 Dec. 12 a73.16 Mar. 8 a79.85 June 14 a73.01 Sept. 13 26.23 + Above land-surface datum. a Pumping. 312 GROUND-WATER LEVELS RIO HERRERA. TO RIO ANTON RUIZ BASINS 181217065453000. Local number, 171. LOCATION.--Lat 18°12'17", long 65°45'30". Owner: Carlos Arroyo and Roberto Ramirez. Name: Arroyo well #1. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Test well drilled by the USGS, diameter 4 to 2 in (10.16-5.08 cm), cased 4 in (10.16 cm) 0-29 ft (0-8.84 m), 2 in (5.08 cm) 29-32 (8.84-9.76 m), 2 in (5.08 cm) slotted PVC screen 29-32 ft (8.84-9.76 m). Depth 32 ft (9.76 m). DATUM.--Altitude of land-surface datum is about 19.10 ft (5.82 m) above mean sea level. Measuring point: Mark on shelf of gage house, 6.00 ft (1.83 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 2.72 ft (0.83 m) below land-surface datum, Nov. 6, 1983; lowest measured, 10.87 ft (3.31 m) below land-surface datum, May 17, 1984. WATER LEVEL, IN FEET 3FLCW LAND-SURFACE DATum, WATER INSTANTANEOUS 05SERVATIONS AT TZAR 1230 OCTOBER 1183 TO SEPTEMBER 1984 DAY OCT NOV JEC JAN .83 mAP APR MAY JUN JUL AUG SEP 1 2 3 4 5 5.51 8.81 3.94 8.14 9.01 3.'6 2.77 1.30 5.63 5.67 1.97 5.23 °.22 3.4) 9.50 3.99 9.00 7.37 2.92 3.72 3.91 3.10 1.03 1.07 1.11 9.93 9.9 - 9.92 10.01 10.03 10.52 10.62 10.56 12.68 13.71 9.75 9.93 10.09 10.20 10.30 .6.5 9 3.72 3.61 3.36 7.44 9.13 7.84 8.44 8.59 3.54 3.52 3.61 3.72 3.77 3.35 6 7 8 9 10 9.27 9.03 9.07 8.14 8.76 3.37 5.47 7.13 7.45 7.73 7.77 8.27 8.41 3.56 3.67 9.06 9.73 1.13 1.14 3.33 3.37 8.54 3.36 3.35 7.73 9.14 1.22 7.24 1.25 7.76 10.06 10.07 10.10 10.15 10.17 10.75 10.77 13.79 10.32 10.65 9.13 6.99 7.81 1.21 7.69 3.26 3.56 3.73 1.36 3.35 R.70 3.85 3.93 9.05 9.12 3.57 3.72 3.33 3.16 3.36 11 12 13 14 15 8.58 8.36 8.72 8.93 8.93 7.35 3.02 3.12 3.20 1.29 8.64 2.51 8.74 8.R4 8.86 3.99 3.17 3.76 4.49 3.57 7.31 P.29 3.03 8.06 7.45 4. 1 5 1.39 /.47 1.24 1.75 10.19 10.15 13.22 10.24 10.30 11.32 10.35 10.36 13.73 10.31 7.49 d.2) 7.97 8.74 8.56 9.02 9.07 7.18 9.21 9.11 9.25 9.31 9.34 9.42 9.44 2.91 7.91 3.25 6.43 7.34 16 17 18 19 20 8.75 8.94 8.74 8.15 8.05 3.40 3.45 5.53 3.46 8.60 °.50 2.35 5.64 3.30 1.02 6.78 7.63 7.93 8.13 F.30 1.45 1.28 1.34 9.49 7.55 10.33 10.37 10.39 10.41 10.43 13.36 10.34 10.79 13.71 13.40 9.71 3.53 8.7° 3.82 8.49 9.28 4.37 9.26 1.43 9.49 9.49 9.49 9.56 9.64 9.65 8.39 6.93 5.73 7.04 4.66 21 22 23 24 25 3.23 Q.43 8.52 8.63 8.75 8.60 9.68 9.74 8.76 3.69 1.48 3.59 3.22 3.56 1.11 8.39 8.51 8.55 3.67 8.70 7.62 1.64 1.64 1.55 9.70 10.45 10.45 10.53 10.54 10.56 10.59 10.77 10.69 10.50 10.72 3.70 8.91 9.07 9.11 9.19 9.53 7.43 9.34 9.50 9.52 9.70 9.65 9.68 9.75 9.84 6.14 7.07 7.46 7.81 7.97 26 27 28 29 30 31 8.70 8.85 8.90 8.95 8.70 8.00 3.14 3.92 3.96 3.99 3.97 --- 2.51 5.66 3.77 3.34 3.39 3.93 3.75 8.90 8.80 8.88 --- 1. 75 9.73 7.30 7.81 1.36 9.90 10.58 10.59 10.03 10.33 10.48 --- 3.92 10.33 5.15 9.84 7.91 9.18 9.32 9.35 9.45 9.34 8.44 --- 9.53 7.64 9.64 9.45 3.79 9.35 9.33 7.40 7.95 3.35 8.52 3.63 8.11 3.27 3.16 3.34 8.45 --- LOw HIGH 9.03 8.00 8.99 3.37 9.07 6.7! 3.90 3.90 10.59 9.93 10.96 7.91 10.30 6.97 9.64 7.44 9.84 7.40 8.91 4.66 313 GROUND-WATER LEVELS RIO HERRERA TO RIO ANTON RUIZ BASINS 180908065475000. Local number, 173. LOCATION.--Lat 18°09'08", long 65°47'50". Owner: Squibb Manufacturing, Inc. Name: Squibb observation well #3. AQUIFER.--Alluvium. WELLS CHARACTERISTICS.--Drilled unused water-table industrial well, diameter 10 in (0.25 m), cased 10 in (0.25 cm), perforated 60-110 ft (18.29-33.54 m). Depth 110 ft (33.54 m) DATUM.--Altitude of land-surface datum is about 21.00 ft (6.40 m) above mean sea level. Measuring point: Mark on shelf of gage house, 3.00 ft (0.91 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--July 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 3.73 ft (1.14 m) below land-surface datum, Sept. 29, 1984; lowest measured, 10.44 ft (3.18 m) below land-surface datum, May 19-20, 1984. )48TER LEVEL, IN FEET 3EL01r LANG-suRFAcE 0ATum, 'WATER YEAR OCTOBER 1933 TO SEFTE41Ep 1984 INSTANTANEOUS 013SERvATicms AT 1200 Our OCT NOV DEC JAN FE1 mAR IPR MAY JUN JUL Au; SEP 1 6.89 6.67 7.84 5.78 4.33 3.28 9.91 10.07 9.53 7.79 6.36 2 6.91 5.66 7.77 5.76 4.44 3.55 9.15 10.11 9.43 7.32 6.36 3 7.01 6.64 7.70 5.53 4.35 3.44 7.67 10.13 9.45 7.35 6.36 4 7.00 6.53 7.66 5.59 4.26 3.51 9.87 10.15 9.44 7.91 6.32 5 7.02 5.46 7.65 5.55 3.31 3.60 9.95 10.17 9.44 7.78 6.34 6 7.05 6.44 7.65 5.70 2.63 3.67 9.93 10.13 9.06 7.69 6.74 7 7.07 6.52 7.65 5.32 2.24 3.77 10.0' 10.19 8.34 7.67 6.67 8 7.07 6.60 7.45 5.87 2.64 3.35 10.16 10.19 5.76 7.71 6.61 9 7.07 6.61 7.25 5.94 3.63 3.39 10.24 10.20 6.76 7.74 5.56 10 7.07 6.58 7.21 5.90 3.92 3.99 10.21 10.23 5.64 7.72 6.49 11 7.07 6.70 7.13 5.90 4.72 1.04 10.14 10.25 8.54 7.78 6.34 12 7.06 6.86 7.03 5.94 5.39 9.10 10.13 10.26 8.41 7.77 6.43 13 7.06 6.96 7.32 5.97 5.79 1.15 10.14 10.22 8.23 7.76 6.07 14 7.03 7.01 7.55 5.14 6.21 1.18 10.16 10.24 8.21 7.78 5.78 15 7.02 7.09 7.71 5.98 4.47 1.24 10.17 10.25 1.19 7.81 5.78 16 17 18 6.19 6.87 6.35 7.11 7.12 7.18 7.81 7.80 7.47 5.98 5.71 5.91 6.64 6.34 6.92 4.30 9.34 1.36 10.10 10.20 10.23 10.27 10.33 10.33 8.19 8.21 8.12 7.35 7.93 7.97 5.79 5.29 5.26 19 6.84 7.23 7.53 5.94 7.07 4.22 10.26 10.39 7.95 3.02 4.38 20 6.14 7.27 7.12 5.33 7.13 9.28 10.23 10.42 7.35 3.03 4.57 21 6.85 7.33 6.34 5.56 7.33 7.40 10.29 10.27 7.82 3.07 4.31 22 23 24 25 6.85 6.86 6.86 6.84 7.38 7.45 7.53 7.60 6.66 6.56 6.39 6.29 5.39 5.17 5.04 5.00 7.43 7.64 7.74 7.89 7.45 9.48 9.52 9.55 10.24 10.13 10.16 10.11 10.13 13.11 10.10 10.06 7.80 7.81 7.83 7.79 7.35 7.75 --- 4.19 4.08 4.00 3.90 26 27 28 29 30 31 6.82 6.82 6.76 6.76 6.76 6.67 7.65 7.68 7.71 7.78 7.82 --- 6.20 6.11 6.04 5.97 5.33 5.82 4.32 4.74 4.67 4.62 4.38 4.39 8.03 8.08 8.16 8.23 --- 4.58 9.52 9.65 9.68 9.72 3.78 10.08 10.09 10.10 10.12 10.14 --- 10.35 10.06 10.06 10.04 9.85 9.67 7.45 7.47 7.61 7.72 7.74 --- 7.05 7.00 6.94 6.87 3.35 3.32 3.76 3.74 3.76 LOW HIGH 7.07 6.67 7.82 6.44 7.84 5.82 5.98 4.38 8.23 2.29 7.78 3.28 10.29 9.81 10.42 9.67 9.53 7.45 6.36 3.74 314 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 175735066095901. Local number, 2. LOCATION.--Lat 17°57'35", long 66°09'59". Owner: P.R. Aqueduct and Sewer Authority. Name: Puente Jobos. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 21 in (53 cm). Depth 148 ft (45.12 m). DATUM.--Altitude of land-surface datum is about 26 ft (7.93 m) above mean sea level. Measuring point: Bottom edge of 0.88 in (2.24 cm) pipe, 1.70 ft (0.52 m) above land-surface datum. REMARKS.--Observation well. Lowest water level is a pumping level. PERIOD OF RECORD.--February 1961 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 2.85 ft (0.87 m) below land-surface datum, July 24, 1979; lowest measured, 61.78 ft (18.83 m) below land-surface datum, Aug. 6, 1964. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 7.25 Jan. 13 7.04 Apr. 6 6.91 July 9 6.51 Nov. 22 6.94 Feb. 17 6.49 May 5 7.20 Aug. 6 7.15 Dec. 9 7.20 Mar. 23 6.75 June 12 5.87 Sept. 26 6.10 175734066100401. Local number, 3. LOCATION.--Lat 17°57'34", long 66°10'04". Owner: P.R. Aqueduct and Sewer Authority. Name: Jobos. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Bored unused artesian well, diameter 4 in (10 cm). Depth 16 ft (4.88 m). DATUM.--Altitude of land-surface datum is about 25 ft (7.62 m) above mean sea level. Measuring point: Top of 5 in (13 cm) fitting, 0.50 ft (0.15 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--November 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 0.01 ft (0.30 m) below land-surface datum, Jan. 3, 1963; lowest measured, dry at 16 ft (4.88 m) below land-surface datum, many days during 1968 and 1969. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 2.90 Jan. 13 2.59 Apr. 6 2.55 July 9 2.08 Nov. 22 2.58 Feb. 17 1.81 May 3 2.94 Aug. 6 2.86 Dec. 9 2.85 Mar. 23 2.21 June 12 0.83 Sept. 26 1.62 315 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 175858066100201. Local number, 6. LOCATION.--Lat 17°58'58", long 66°10'02". Owner: Doctor Bruno. Name: Juana 5. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 in (41 cm). Depth 173 ft (52.74 m) reported, 110 ft (33.54 m) measured. DATUM.--Altitude of land-surface datum is about 127 ft (38.72 m) above mean sea level. Measuring point: Top of shelter floor, 3.00 ft (0.91 m) above land-surface datum. After Aug. 7, 1981, top of 16" casing, 1.55 ft (0.47 m) above land-surface datum. REMARKS.--Recorder installed Jan. 25, 1962. PERIOD OF RECORD.--November 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 26.20 ft (7.99 m) below land-surface datum, Dec. 10, 1979; lowest measured, 65.95 ft (20.10 m) below land-surface datum, June 2, 1968. WATER LEV1L, IN FEET 3FL0W LAND-SURFACE DATUM, WATER YEAR CCTO8ER 1983 TO SEPTEMBER 1984 INSTANTANEOUS 03SERVATIONS AT 1200 DAY OCT NOV DEC JAN FE3 MAR APR MAY JUN JUL AUG SEP 1 55.25 43.26 44.74 43.49 46.41 53.24 52.23 50.47 50.67 52..1 54.33 54.15 2 55.17 47.55 44.39 41.49 46.35 53.50 52.21 50.71 50.70 52.57 54.36 54.31 3 55.11 46.34 44.17 43.53 46.32 53.75 52.21 50.31 50.75 52.71 54.39 54.45 4 55.04 45.35 43.3' 47.58 46.31 53.97 51.97 50.55 50.81 52.52 54.43 54.55 5 54.77 45.70 43.94 43.50 46.36 51.18 51.14 50.33 50.81 52.48 54.47 54.54 6 54.93 46.12 44.42 43.53 46.45 51.40 53.55 59.23 50.80 52.7,0 54.50 54.73 7 54.85 46.78 44.82 43.52 46.69 51.54 49.92 50.13 50.86 52.92 54.52 54.81 8 54.81 47.48 44.97 43.50 46.77 51.33 43.80 49.97 50.93 52.95 54.53 54.97 9 10 54.79 54.77 46.05 45.27 44.72 44.67 4'.58 43,36 46.66 46.52 5).94 53.43 43.40 49.12 49.72 49.74 50.90 50.90 52.99 53.04 54.54 54.55 54.90 54.39 11 54.76 44.86 44.83 44.28 46.33 53.33 49.55 49.51 50.89 53.10 54.55 54.32 12 54.74 44.'8 44.93 44.36 46.25 53.58 49.23 49.70 50.91 53.18 54.55 54.72 13 54.70 44.99 45.11 44.33 46.12 53.91 49.28 49.99 50.93 53.25 54.52 54.59 14 54.63 45.14 45.06 44.30 46.17 51.26 49.73 50.25 50.98 53.33 54.47 54.51 15 54.65 45.57 45.19 44.36 46.67 51.51 49.85 50.26 51.04 53.41 54.48 54.53 16 53.73 45.32 45.18 44.53 46.75 51.71 49.90 50.24 51.09 53.48 54.48 54.63 17 52.14 46.41 44.68 44.67 46.32 51.35 49.85 50.16 51.13 53.57 54.45 54.76 18 50.93 46.41 44.04 44.51 46.77 51.16 50.00 50.02 51.17 53.65 54.37 54.33 19 50.23 46.41 43.63 44.54 46.71 52.14 50.08 49.90 51.23 53.72 54.27 54.97 20 49.23 46.37 43.81 44.60 46.63 52.12 49.82 49.86 51.33 53.30 54.10 55.05 21 49.07 45.33 44.31 44.59 46.77 52.20 49.37 49.83 51.33 53.36 53.91 55.08 22 48.95 44.83 44.51 44.73 47.01 52.25 48.93 50.02 51.47 53.90 53.77 55.04 23 48.16 45.11 44.10 44.33 47.51 52.23 48.84 50.13 51.62 53.95 53.66 54.93 24 47.93 45.23 44.14 45.47 48.05 52.09 49.31 53.32 51.69 54.01 53.59 54.30 25 48.59 45.67 43.90 46.36 43.60 52.16 49.24 50.55 51.71 54.07 53.52 54.68 26 48.03 46.13 43.35 45.17 49.09 52.26 48.93 50.63 51.73 54.16 53.43 54.59 27 47.79 46.06 44.11 45.96 49.43 52.34 48.39 50.55 51.80 54.25 53.49 54.53 28 48.76 45.70 43.84 45.96 49.32 52.43 49.34 50.56 51.94 54.29 53.54 54.52 29 43.51 45.73 43.59 45.76 50.01 52.49 49.81 59.68 52.10 54.28 53.66 54.50 30 48.53 45.40 43.72 45.97 --- 52.45 30.17 50.63 52.25 54.30 53.81 54.49 31 48.60 --- 43.56 46.35 52.37 --- 50.69 --- 54.30 53.98 --- LOW 55.25 43.26 45.19 45.35 50.01 52.49 52.28 50.71 52.25 54.30 54.55 55.03 HIGH 47.79 44.78 43.56 43.49 46.12 50.24 48.40 49.61 50.67 52.41 53.45 54.15 WTR YR 1934 MEAN 49.68 LOW 55.25 HIGH 43.48 40 3 LaD 45 CD 41 4.1 4- (-)< L- 50 LI W-ICI Z < 55 3 ASONDJFMAMJJASQNDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 60 316 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 175944066033601. Local number, 15. LOCATION.--Lat 17°59'44", long 66°03'36". Owner: P.R. Aqueduct and Sewer Authority. Name: Pitahaya 1. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (30 cm). Depth 181 ft (55.18 m). DATUM.--Altitude of land-surface datum is about 130 ft (39.63 m) above mean sea level. Measuring point: Bottom of inspection door, 1.10 ft (0.34 m) above land-surface datum. REMARKS.--Recording observation well. Water levels affected by pumping of nearby well. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 3.00 ft (0.91 m) below land-surface datum, Oct. 7, 1970; lowest, 43.90 ft (13.38 m) below land-surface datum, May 20, 1968. WATER LEVFL, IN FEET ?ELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 DAY OCT NOV -DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 10.75 14.56 14.46 13.31 15.26 20.24 23.44 19.27 16.99 22.12 27.45 2 10.79 15.04 14.54 13.55 15.19 20.03 22.45 19.07 16.68 22.01 25.54 3 11.06 15.21 13.63 18.75. 17.20 19.73 23.67 18.15 13.04 22.17 27.16 4 5 11.35 11.60 13.35 9.32 13.71 14.01 19.19 19.04 /7.38 13.24 19.5.1 19.83 24.36 24.73 17.21 16.29 18.69 18.11 22.31 22.37 27.45 27.45 6 11.33 3.93 14.55 12.52 13.77 20.15 24.38 15.46 10.37 22.24 25.35 7 11.9? 8.72 15.01 19.03 14.19 20.46 24.44 14.62 9.46 22.17 27.44 s 12.15 3.94 15.33 17.55 14.55 20.47 24.40 13.90 9.61 21.81 27.44 9 11.95 9.24 15.63 17.75 14.44 20.32 24.51 12.97 10.07 21.61 27.44 10 11.44 4.55 16.09 13.00 20.02 20.24 24.50 12.13 10.53 21.33 27.44 11 12 13 14 11.61 11.93 12.1 7 12.36 4.37 13.16 13.44 10.70 16.52 13.45 18.62 18.20 13.33 2).04 2).36 2).17 27.38 20.33 20.66 20.73 21.09 24.92 25.06 25.30 25.11 11.30 10.48 9.65 8.82 10.37 11.26 11.63 12.10 20.79 20.24 20.22 20.33 27.24 27.29 27.19 27.00 15 12.56 10.97 12.57 23.09 21.16 25.18 9.03 12.50 20.61 27.22 16 12.29 11.22 10.45 20.10 21.34 25.14 9.38 13.11 20.97 26.01 17 12.30 11.42 9.32 20.11 20.9? 25.18 9.69 13.61 21.04 20.72 13 12.55 11.55 9.34 23.13 21.18 25.18 9.96 14.42 24.86 10.57 19 20 12.43 12.24 11.75 11.97 13.39 9.65 10.04 2).14 23.15 21.27 21.23 25.18 25.18 10.12 10.47 15.39 17.55 25.42 25.60 8.75 8.39 21 22 12.43 12.51 12.19 12.39 14.)9 14.70 10.42 10.34 2).15 23.43 21.61 21.59 25.18 25.17 10.85 11.19 18.32 13.33 26.35 26.40 7.25 7.63 23 24 12.62 12.93 12.62 12.35 15.39 15.35 11.25 11.65 2).53 20.72 21.37 21.61 25.05 25.12 11.49 11.86 19.38 19.80 26.73 26.97 7.88 3.06 25 13.07 13.13 16.74 12.10 23.43 21.81 25.18 12.29 23.31 26.95 2.19 26 27 28 13.23 13.15 13.41 13.31 13.49 13.67 17.24 1 7.57 1 7.96 12.53 12.97 13.49 2).12 2).12 20.11 21.75 21.80 22.17 25.18 25.18 25.13 12.32 13.40 13.80 23.28 21.37 21.35 27.45 26.70 27.13 3.32 3.48 8.65 29 13.73 13.85 1?.05 13.97 14.96 22.35 25.17 14.36 21.83 27.22 8.32 30 13.94 14.10 18.02 --- 19.33 22.03 24.58 15.64 21.83 27.31 3.92 31 14.09 --- 13.32 23.20 --- 20.76 --- 21.97 26.53 --- LOW 14.04 15.21 19.19 23.72 22.35 25.18 19.27 21.97 27.45 27.45 HIGH 10.75 3.72 9.32 15.26 19.73 20.76 8.82 9.46 20.22 7.25 • 10 -J LJ 0 co o­w 1L -0 wo 15 Z.ct _J D > 20 41 -J 1=1 IX 7 41 --1 • 25 30 ASONDJFMAMJ JASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 317 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 180338065523301. Local number, 31. LOCATION.--Lat 18°03'38", long 65°52'33". Owner: P.R. Aqueduct and Sewer Authority. Name: Central Roig. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 20 in (51 cm), 0-120 ft (0-36.58 cm), 12 in (30 cm) 120-125 ft (36.58-38.11 m), cased 0-125 ft (0-38.11 m), perforated 40-125 ft (12.20-38.11 m). Depth 125 ft (38.11 m). DATUM.--Altitude of land-surface datum is about 41 ft (12.50 m) above mean sea level. Measuring point: Airline hole in pump base, 4.00 ft (1.22 m) above land-surface datum. REMARKS.--Observation well. Drilled 5 ft (1.52 m) into rock. Affected by nearby pumping. PERIOD OF RECORD.--July 1959 to August 1973; April 1975 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 5.86 ft (1.79 m) below land-surface datum, Sept. 20, 1960; lowest measured, a50.57 ft (a15.41 m) below land-surface datum, July 7, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a34.98 Jan. 17 a34.81 Apr. 12 a36.97 July 18 a27.10 Nov. 22 a33.77 Feb. 15 a34.91 May 21 a35.93 Aug. 16 a40.25 Dec. 13 a33.91 Mar. 12 a38.54 June 14 a32.84 Sept. 26 a40.60 175641066085101. Local number, 89. LOCATION.--Lat 17°56'41", long 66°08'51". Owner: Phillips Puerto Rico Core, Inc. Name: Phillips observation well 3. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled test well, diameter 4 in (10 cm). Depth 114 ft (34.75 m). DATUM.--Altitude of land-surface datum is about 6 ft (1.8 m) above mean sea level. Measuring point: Top of casing, 2.25 ft (0.69 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 1968 to current year; changed to a partial site on Oct. 1, 1981. EXTREMES FOR PERIOD OF RECORD.--Highest water level, +2.70 ft (+0.82 m) above land-surface datum, Jan. 9, 1973; lowest, 4.32 ft (1.32 m) below land-surface datum, June 5, 1981. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 0.98 Jan. 13 0.79 Apr. 6 1.22 July 9 +0.41 Nov. 22 0.50 Feb. 17 0.95 May 3 1.45 Aug. 6 1.60 Dec. 9 0.82 Mar. 23 1.34 June 14 1.13 Sept. 26 0.64 + Above land-surface datum. a Pumping. 318 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 180416065514101. Local number, 96. LOCATION.--Lat 18°04'16", long 65°51'41". Owner: P.R. Aqueduct and Sewer Authority. Name: USGS TW-2 or Yabucoa 7. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled observation water-table well, diameter 16 in (41 cm) cased 0-10 ft (0-3.05 m), diameter 6 in (15 cm), cased about 0-183 ft (0-55.79 m), perforated 56-81 ft (17.07-24.70 m), 102-123 ft (31.10-37.50 m), 144-181 ft (43.90-55.18 m). Depth 181 ft (55.18 m). DATUM.--Altitude of land-surface datum is about 25 ft (7.62 m) above mean sea level. Measuring point: Top of shelter floor, 4.00 ft (1.22 m) above land-surface. REMARKS.--Observation recording well. PERIOD OF RECORD.--April 25, 1978 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 15.52 ft (4.73 m) below land-surface datum, Jan. 15, 1982; lowest, 28.29 ft (8.62 m) below land-surface datum, Sept. 20, 1980. WATER LEVEL, IN =ET 1EL0W LAND-SURFACE OATuM, HATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1210 DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 19.07 19.53 18.61 19.62 22.54 23.17 22.60 23.19 21.96 21.27 21.57 22.31 2 18.80 18.61 18.12 13.41 22.51 23.56 22.47 23.38 21.92 21.28 21.73 22.44 3 18.51 19.27 18.31 13.25 22.77 21.44 22.11 23.48 21.87 21.A7 21.32 22.63 4 18.73 19.75 17.96 13.44 23.02 21.30 22.37 23.66 21.73 21.45 21.93 22.32 5 18.95 20.08 17.63 13.55 23.13 21.95 22.56 23.59 21.65 21.31 21.94 22.95 6 19.58 19.98 11.16 23.23 21.91 22.71 23.55 21.65 21.29 21.95 22.92 7 19.80 19.94 1A.94 23.47 22.20 22.85 23.34 21.40 21.27 21.98 22.96 8 19.89 23.10 13.99 23.59 22.28 22.89 22.79 21.33 21.16 22.04 23.09 9 19.70 20.24 13.93 23.45 22.22 22.90 22.50 21.20 23.84 22.01 23.16 10 19.04 20.22 13.35 23.36 22.30 22.97 22.60 20.95 20.70 21.93 23.04 11 18.92 19.99 11.73 23.25 21.96 22.96 22.57 20.76 20.20 21.87 22.92 12 18.96 19.91 13.31 23.05 20.55 22.86 22.33 20.63 19.99 . 21.80 22.86 13 19.05 20.38 --- 13.93 22.32 23.66 22.73 22.42 20.50 20.66 21.53 22.86 14 19.29 20.15 17.98 11.78 22.77 21.28 22.93 22.56 20.43 20.55 21.41 22.98 15 19,57 19.88 18.34 13.66 20.14 23.75 23.09 22.91 20.42 20.15 21.52 23.05 16 19.29 19.20 18.23 13.55 20.71 21.50 23.19 23.26 20.51 19.99 21.53 23.99 17 19.17 13.79 18.12 13.60 20.92 21.73 23.37 23.41 20.66 19.95 21.42 22.91 18 19.33 13.94 17.93 21.74 20.72 21.77 23.44 23.45 20.72 20.03 21.43 22.64 19 19.60 18.80 17.94 21.09 20.53 22.05 23.61 23.50 20.81 20.16 21.64 22.43 20 19.59 13.68 18.17 21.46 20.33 22.33 23.69 23.56 20.74 20.09 21.77 22.20 21 19.79 13.64 18.60 21.67 20.32 22.54 23.43 23.60 20.77 20.19 21.90 21.16 22 20.09 13.63 18.78 21.59 20.23 22.73 23.17 23.67 20.79 20.05 22.06 21.69 23 20.13 13.73 18.66 21.62 20.21 22.68 22.91 23.53 20.75 19.95 22.21 21.46 24 20.01 11.71 18.79 21.95 20.58 22.66 22.93 23.39 20.73 20.05 22.34 21.18 25 20.22 19.64 18.91 22.15 20.81 22.62 23.12 23.15 20.63 20.26 22.44 20.99 26 20.33 13.62 18.05 22.37 20.75 22.53 23.31 22.96 20.56 20.38 22.45 20.90 27 20.33 18.45 19.13 22.59 20.50 22.56 23.44 22.74 20.59 20.57 22.48 20.13 28 20.02 18.6 7 19.26 22.49 19.53 22.64 23.52 22.58 20.83 20.34 22.56 20.73 29 20.72 13.90 19.22 22.18 19.30 22.63 23.15 22.48 21.10 21.06 22.50 20.68 30 21.13 18.82 19.07 21.95 --- 22.67 23.02 22.25 21.23 21.11 22.41 20.79 31 20.25 --- 18.87 22.06 22.73 --- 22.11 --- 21.29 22.33 --- LOW 21.13 20.24 22.59 23.58 22.73 23.69 23.67 21.96 21.45 22.56 23.16 HIGH 18.61 18.45 13.25 19.30 23.17 22.11 22.11 20.42 19.95 21.41 20.68 14 0 La n 17 m F 1- 4 Lac La w LL. L) Z.< 20 W v I) Ld < 23 aJ 26 ONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 319 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASINS 180026065544301. Local number, 122. LOCATION.--Lat 18°00'26", long 65°54'43". Owner: P.R. Aqueduct and Sewer Authority. Name: Maunabo Calzada. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled exploration well, diameter 4 in (10 cm). Depth 70 ft (21.3 m). DATUM.--Altitude of land-surface datum is about 28.5 ft (8.7 m) above mean sea level. Measuring point: Top of shelter floor, 1.4 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--December 1971 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 2.24 ft (0.68 m) below land-surface datum, July 8, 1976; lowest measured, 12.38 ft (3.77 m) below-land surface datum, Aug. 12, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 c 8.90 Jan. 17 c 9.14 Apr. 12 c10.60 July 18 c10.45 Nov. 22 c 8.78 Feb. 15 c10.10 May 21 c11.33 Aug. 16 c10.79 Dec. 13 c 9.42 Mar. 12 c10.00 June 14 c 8.13 Sept. 26 7.83 180010066004501. Local number, 125. LOCATION.--Lat 18°00'10", long 66°00'45". Owner: P.R. Aqueduct and Sewer Authority. Name: Patillas STP. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 in (41 cm), cased 0-45 ft (0-13.7 m); cased 12 in (30 cm) 0-49 ft (0-14.9 m); perforated 49-81 ft (14.9 -24.7 m). Depth 90 ft (27.4 m). DATUM.--Altitude of land-surface datum is about 48 ft (14.6 m) above mean sea level. Measuring point: Bottom edge of 0.75 in (1.90 cm) pipe in concrete pump base 1.0 ft (0.30 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping nearby well. PERIOD OF RECORD.--January 1976 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.83 ft (3.91 m) below land-surface datum, June 17, 1981; lowest measured, a52.98 ft (a16.15 m) below land-surface datum, May 24, 1979. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a48.83 Jan. 20 a48.90 Apr. 11 a48.16 July 10 a51.33 Nov. 22 a48.87 Feb. 15 a48.76 May 14 a52.10 Aug. 6 a48.72 Dec. 5 a50.10 Mar. 21 a48.90 June 14 a50.63 Sept. 17 20.58 a Pumping. c Pumping nearby well 320 GROUND-WATER LEVELS RIO HUMACAO TO RIO SECO BASIN 180849065502400. Local number, 172. LOCATION.--Lat 18°08'49", long 65°50'24". Owner: U.S. Geological Survey, City of Humacao. Name: Rio Humacao Ground-Water Station. AQUIFER.--Alluvium. WELL CHARACTERISTICS.--Test well drilled by USGS, diameter 4 to 2 in (10.16-5.08 cm), cased 4 in (10.16 cm) 0-40 ft (0-12.20 m), 2 in (5.08 cm) 40-43 ft (12.20-13.11 m), 2 in (5.08 slotted PVC screen 40-43 ft (12.20-13.11 m), 2 in (5.08) slotted PVC screen 40-43 ft (12.20-13.11 m). Depth 43 ft (13.11 m). DATUM.--Altitude of land-surface datum is about 57.40 ft (17.50 m) above mean sea level. Measuring point: Mark on shelf of gage house, 3.30 ft (1.01 m) above land surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--November 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 15.73 ft (4.80 m) below land-surface datum, Sept. 14, 1984; lowest measured 18.22 ft (5.55 m) below land-surface datum, May 9-11, 1984. WATER LEVEL. IN FEET !FLOW LAND-SURFACE DATUM. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 DAY OCT NOV DEC JAN FES MAR APR MAY JUN JUL AUG SEP 1 2 3 17.71 17.53 17.40 17.61 17.56 17.70 17.79 17.80 17.81 17.78 17.77 17.78 18.05 18.06 18.07 13.18 18.19 18.20 17.42 17.50 17.60 17.17 17.13 17.21 17.17 16.95 17.12 17.15 17.21 17.24 4 17.45 17.71 17.81 17.80 18.09 18.15 17.62 17.24 16.77 17.18 5 17.52 17.71 17.82 17.80 18.07 18.15 17.70 16.93 16.99 17.23 6 17.51 17.71 17.82 17.82 18.06 18.18 17.08 17.10 17.10 16.92 7 17.51 17.71 17.84 17.83 17.99 18.18 16.73 17.17 17.14 17.05 8 9 17.55 17.63 17.73 17.74 17.77 17.79 17.14 17.84 18.04 18.06 18.19 18.19 16.94 17.03 17.22 17.25 17.21 17.22 17.11 17.18 10 17.64 17.56 17.80 17.84 18.06 18.22 16.73 17.17 17.26 17.08 11 17.22 17.65 17.65 17.75 17.85 18.07 18.21 16.67 17.22 17.28 17.13 12 17.27 17.66 17.69 17.76 17.87 18.08 13.13 16.90 17.26 17.31 17.08 13 17.32 17.69 17.71 17.61 17.38 18.10 18.11 16.66 17.29 17.34 16.79 14 17.36 17.70 17.62 17.49 17.89 18.09 18.10 16.82 17.29 17.35 15.97 15 17.40 17.61 17.63 17.52 17.39 18.12 18.11 16.92 17.25 17.37 16.55 16 17.41 17.70 17.56 17.02 17.91 18.13 18.15 17.01 17.28 17.32 16.69 17 18 17.44 17.47 17.72 17.71 17.69 17.69 17.15 17.30 17.94 17.93 18.13 18.15 18.15 18.18 17.08 17.00 17.34 17.35 17.31 17.40 16.57 16.31 19 17.50 17.70 17.70 17.41 17.94 18.17 13.20 16.71 1.7.36 17.42 16.30 20 17.52 17.73 17.66 17.43 17.96 18.07 13.12 16.86 17.30 17.42 16.17 21 17.56 17.75 17.62 17.54 17.1 18.08 13.11 16.95 17.34 17.44 16.09 22 23 24 17.57 17.59 17.62 17.76 17.75 17.76 17.65 17.67 17. 71 17.60 17.64 17.67 13.00 17.98 17.97 18.03 18.09 18.12 18.02 17.88 17.96 16.98 17.04 17.03 17.20 17.16 17.21 17.44 17.46 17.48 16.28 16.42 16.55 25 17.64 17.75 17.67 17.69 17.99 18.12 17.72 17.11 17.26 17.49 16.58 26 17.66 17.76 17.67 17.72 13.00 18.15 17.62 17.14 17.30 17.49 16.65 27 17.67 17.76 17.71 17.74 11.01 18.16 17.87 17.19 17.32 16.79 16.70 28 17.67 17.74 17.72 17.74 13.01 18.09 17.77 17.17 17.37 16.98 16.74 29 17.59 17.74 17.73 17.77 13.01 18.14 17.79 17.15 17.21 17.08 16.81 30 17.70 17.72 17.75 --- 13.02 18.17 17.22 17.15 16.95 17.12 16.86 31 --- 17.67 17.77 13.03 --- 17.30 --- 17.09 17.13 --- LOW 17.76 17.71 17.34 13.03 11.17 18.22 17.70 17.37 17.49 17.24 HIGH 17.40 17.61 17.02 17.77 17.99 17.22 16.66 16.93 16.77 15.97 321 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175658066155401. Local number, 1. LOCATION.--Lat 17°56'58", long 66°15'54". Owner: P.R. Aqueduct and Sewer Authority. Name: Mar Negro. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Bored unused artesian well, diameter 3 in (8 cm). Depth 23 ft (7.0 m). DATUM.--Altitude of land-surface datum is about 3 ft (0.91 m) above mean sea level. Measuring point: Top of 1.5 in (3.8 cm) pipe fitting, 3.2 ft (0.98 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by nearby pumping well. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, +1.83 ft (+0.56 m) above land-surface datum, Dec. 2, 1970; lowest measured, 3.60 ft (1.10 m) below land-surface datum, July 7, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 +0.20 Jan. 13 +0.31 Apr. 6 0.69 July 19 +0.05 Nov. 22 +0.11 Feb. 17 +0.36 May 3 1.05 Aug. 6 0.31 Dec. 9 +0.12 Mar. 23 0.30 June 12 0.03 Sept. 27 +0.78 175851066174601. Local number, 8. LOCATION.--Lat 17°58'51", long 66°17'46". Owner: P.R. Aqueduct and Sewer Authority. Name: Salinas 1. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 in (41 cm) to 13 in (33 cm); cased 16 in (41 cm) 0-32 ft (0-9.8 m), 13 in (33 cm) 25-120 ft (7.6-36.6 m); perforated 25-120 ft (7.6-36.6 m). Depth 125 ft (38.1 m). DATUM.--Altitude of land-surface datum is about 29 ft (8.8 m) above mean sea level. Measuring point: Top of 1.0 in (2.54 cm) pipe in pump base, 1.2 ft (0.37 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 11.95 ft (3.64 m) below land-surface datum, Dec. 14, 1960; lowest measured, 42.95 ft (13.09 m) below land-surface datum, Dec. 9, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 a28.15 Jan. 13 a26.26 Apr. 6 a27.07 July 9 a32.73 Nov. 4 a21.60 Feb. 17 a36.78 May 3 a36.55 Aug. 6 a27.52 Dec. 8 a25.85 Mar. 23 a27.10 June 12 a22.65 Sept. 28 a27.28 + Above land-surface datum. a Pumping. 322 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180044066153401. Local number, 18. LOCATION.--Lat 18°00'44", long 66°15'34". Owner: P.R. Aqueduct and Sewer Authority. Name: Cocos. AQUIFER.--Alluvium of Quaternary Age and undifferentiated rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 to 12 in (41 to 30 cm), cased 16 in (41 cm) 0-40 ft (0-12-2 m), 12 in (30 cm) 0-53 ft (0-16.2 m), perforated 32-53 (9.8-16.2 m). Depth 125 ft (38.1 m). DATUM.--Altitude of land-surface datum is about 140 ft (42.7 m) above mean sea level. Measuring point: Top of 1.0 in (2.54 cm) pipe in pump base, 1.25 ft (0.38 cm) above land-surface datum. REMARKS.--Observation well. Water level affected by nearby pumpage. PERIOD OF RECORD.--September 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 14.67 ft (4.47 m) below land-surface datum, Sept. 20, 1960; lowest measured, 79.17 ft (24.13 m) below land-surface datum, June 19, 1968. WATER LEVEL, IN FEET BELOW LAND SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 24.61 Jan. 13 28.40 Apr. 6 32.45 July 9 35.88 Nov. 4 25.75 Feb. 17 32.37 May 3 33.90 Aug. 6 36.58 Dec. 8 24.07 Mar. 23 31.52 June 6 35.24 Sept. 25 27.14 180023066175301. Local number, 19. LOCATION.--Lat 18°00'23", long 66°17'53". Owner: U.S. Army. Name: Theater 1. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 16 to 11 in (41 to 28 cm), cased 16 in (41 cm) 0-64 ft (0-19.5 m), 11 in 0-80 ft (0-24.4 m), perforated 16-64 ft (4.9-19.5 m). Depth 150 ft (45.7 m) reported, 86 ft (26.2 m) measured. DATUM.--Altitude of land-surface datum is about 140 ft (42.7 m) above mean sea level. Measuring point: Top of 1.0 in (2.54 cm) casing liner, 0.85 ft (0.26 m) above land-surface datum. After Apr. 8, 1983, top of 4.0 in (10.1 cm) flat cap on new concrete slab, 3.6 ft (1.10 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--December 1958 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 39.38 ft (12.00 m) below land-surface datum, Oct. 15, 1979; lowest, measured, 79.15 ft (24.12 m) below land-surface datum, Oct. 10, 1973. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 50.24 Jan. 13 45.16 Apr. 6 47.70 July 9 52.83 Nov. 4 50.20 Feb. 17 46.73 May 3 55.57 Aug. 6 53.90 Dec. 8 47.62 Mar. 23 47.72 June 6 51.52 Sept. 25 52.11 323 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175829066232201. Local number, 87. LOCATION.--Lat 17°58'29", long 66°23'22". Owner: Francisco Alomar. Name: Alomar 1. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 20 in (0.51 m), iron cased. Depth 112 ft (34.14 m). DATUM.--Altitude of land-surface datum is about 35.32 ft (10.77 m) above mean sea level. Measuring point: Bottom of clean-out shelter door, 2.50 ft (0.76 m) above land-surface datum. Prior to August 1981, top of recorder shelter floor, 4.00 ft (1.22 m) above land- surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--April 1967 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 8.45 ft (2.58 m) below land-surface datum, Dec. 10, 1970; lowest 49.18 ft (14.99 m) below land-surface datum, July 27, 1974. WATER LEVEL, IN FEET 3ELOW LANG-SURgACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEASER 1984 INSTANTANEOUS JeSERVATIONS AT 1270 DAY OCT NOV OEC JAN xE3 MAR APR MAY JUN JUL AU; SEP 1 27.44 26.53 25.69 27.29 27.44 23.68 30.05 30.53 11.57 31.18 30.65 32.66 2 26.88 26.32 26.14 27.24 27.49 23.69 29.30 30.74 71.31 31.13 30.63 32.62 3 26.49 26.44 26.21 27.28 27.53 23.73 29.83 30.79 31.13 31.43 30.76 32.05 4 26.33 26.65 26.26 27.39 27.55 23.31 29.98 30.77 31.21 31.55 30.81 31.65 5 26.16 26.96 26.25 27.73 27.47 23.19 30.12 30.38 31.44 31.43 30.82 31.40 6 7 26.24 26.34 25.34 23.02 26.29 26.31 26.37 26.97 27.30 27.39 23.75 24.05 30.19 30.23 31.55 30.43 31.57 31.45 3).80 30.57 30.86 31.19 31.13 31.15 8 26.47 25.02 26.35 27.28 27.10 29.25 30.03 30.79 31.59 30.41 31.37 31.16 9 26.81 25.13 26.31 26.07 27.44 24.18 30.02 30.97 31.35 30.33 31.50 31.54 10 26.90 25.28 26.33 26.36 27.55 29.19 30.26 31.04 31.17 33.25 31.55 31.62 11 27.27 25.30 26.27 27.21 27.55 24.20 30.33 31.13 31.10 33.23 31.53 31.99 12 27.51 25.42 26.14 25.29 27.06 23.73 30.46 31.21 30.64 30.27 31.33 32.32 13 14 27.56 27.75 25.48 25.41 26.19 26.22 25.15 25.23 26.93 27.10 2).18 24.26 30.35 30.54 31.00 30.95 30.51 30.41 30.26 33.27 31.44 31.63 31.52 31.60 15 27.77 25.50 26.23 25.96 27.54 29.26 30.31 31.22 30.33 30.27 31.74 31.58 16 27.30 25.53 26.14 26.65 27.53 24.46 30.20 31.35 30.32 30.45 31.74 31.55 17 27.07 25.48 26.06 25.97 27.78 24.63 30.38 31.40 30.29 30.70 32.00 31.47 18 27.08 25.33 25.74 26.74 27.37 29.51 30.45 31.43 30.43 30.64 32.07 31.34 19 27.13 25.36 25.41 27.16 27.27 29.44 30.23 31.26 30.73 30.58 31.85 30.81 20 27.08 25.38 25.31 25.77 27.61 24.72 30.26 30.92 30.79 30.50 31.96 30.38 21 22 26.91 26.84 25.42 25.48 25.57 25.67 26.49 26.55 27.64 28.00 2).69 29.73 30.23 30.22 30.95 31.28 30.84 30.84 30.49 30.43 32.14 32.42 29.63 29.42 27 26.90 25.56 25.72 26.77 27.79 24.76 30.15 31.44 30.87 30.59 32.51 29.19 24 26.83 25.58 25.88 26.36 28.13 29.70 30.14 31.53 30.83 30.50 32.66 28.94 25 26.95 25.66 26.72 26.97 28.23 29.73 30.57 31.50 30.66 30.36 32.61 29.72 26 27.06 25.70 26.85 27.09 28.33 29. 73 70.53 31.63 31.03 30.21 32.28 28.69 27 28 27.13 27.19 25.70 25.68 26.87 27.00 27.15 27.23 28.02 28.43 2).38 33.10 30.55 30.54 31.56 31.29 31.28 31.42 29.38 30.10 32.25 32.58 23.64 23.63 29 27.20 25.69 27.17 27.22 23.57 33.21 30.49 31.52 31.30 29.88 32.78 28.78 30 26.77 25.73 27.25 27.20 --- 31.30 30.42 31.54 31.24 30.20 32.90 28.58 31 26.51 --- 27.29 27.34 33.16 --- 31.27 --- 30.35 32.62 --- LOW 27.77 25.94 27.29 27.73 23.57 33.30 30.53 31.63 31.59 31.55 32.90 32.66 HIGH 26.16 25.02 25.31 25.96 26.98 21.19 29.30 33.43 30.29 29.88 30.65 23.58 WTR YR 1984 MEAN 23.93 LOW 32.90 HIGH 24.98 20 3 0 Lin 24 CO I-- 6.1 CI 0 b- 28 > N Li-10 cez w< 32 ASONDJFMAMJJ ASONDJFMAMJJASONDJFMAMJJ AS 1981 1982 1983 1984 36 324 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 180052066305001. Local number, 88. LOCATION.--Lat 18°00'52", long 66°30'50". Owner: Luce and Co. Name: Hacienda Potala. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 19 in (48 cm). Depth 143 ft (43.6 m). DATUM.--Altitude of land-surface datum is about 42.65 ft (13 m) above mean sea level. Measuring point: Top of shelter floor, 2.20 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumpage of nearby well. Station discontinued, Jan. 1,1973. Reactivated, Apr. 15, 1976. PERIOD OF RECORD.--May 1968, January 1973; April 1976 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 4.50 ft (1.37 m) below land-surface datum; Feb. 26, 1971; lowest measured, 37.89 ft (11.55 m) below land-surface datum, July 16, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 17.00 Jan. 13 c21.23 Apr. 10 17.06 July 9 21.20 Nov. 4 15.60 Feb. 17 15.44 May 3 18.49 Aug. 7 28.80 Dec. 8 13.35 Mar. 23 16.68 June 6 c27.18 Sept. 5 21.43 175822066134801. Local number, 124. LOCATION.--Lat 17°58'22", long 66°13'48". Owner: P.R. Aqueduct and Sewer Authority. Name: Coqul 2. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 to 12 in (40 to 30 cm), cased 16 in (40 cm) 20-40 ft (6.1-12.2 m), 12 in (30 cm) 2-20 ft (0.61-6.1 m); perforated 20-118 ft (6.1-36.0 m). Depth 118 ft (36.0 m). DATUM.--Altitude of land-surface datum is about 26 ft (7.9 m) above mean sea level. Measuring point: Airline hole in pump base, 2.2 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--April 24, 1975 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, a9.25 ft (a2.82 m) below land-surface datum, Nov. 29, 1979; lowest measured, a54.70 ft (a16.67 m) below land-surface datum, July 7, 1977. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 a13.99 Jan. 13 a14.02 Apr. 6 a38.70 July 9 a39.34 Nov. 22 a13.22 Feb. 17 a32.37 May 3 a45.63 Aug. 6 a20.05 Dec. 9 a12.80 Mar. 23 a33.47 June 12 a37.54 Sept. 27 a13.35 175750066225800. Local number, 144. LOCATION.--Lat 17°57'50", long 66°22'58". Owner: P.R. Aqueduct and Sewer Authority. Name: Jauca south well, site 1. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-50 ft (0-15.2 m), perforated 45-50 ft (13.7-15.2 m). Depth 50 ft (15.2 m). DATUM.--Altitude of land-surface datum is about 15.98 ft (4.87 m) above mean sea level. Measuring Point: Hole side of 8 in (20 cm) casing, 3.2 ft (0.98 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1980 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 9.48 ft (2.89 m).below land-surface datum, Jan. 20, 1982; lowest measured, 11.90 ft (3.63 m) below land-surface datum, Feb. 9, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 10.58 Jan. 13 10.03 Apr. 10 10.93 July 9 10.90 Nov. 4 10.37 Feb. 17 10.75 May 3 11.00 Aug. 7 11.87 Dec. 8 10.02 Mar. 23 11.15 June 6 10.79 Sept. 27 10.40 a Pumping. c Pumping nearby well. 325 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175750066225801. Local number, 145. LOCATION.--Lat 17°57'50", long 66°22'58". Owner: P.R. Aqueduct and Sewer Authority. Name: Jauca north well, site 1. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-250 ft (0-76.2 m), perforated 245-250 ft (74.7-76.2 m). Depth 250 ft (76.2 m). DATUM.--Altitude of land-surface datum is about 16.11 ft (4.91 m) above mean sea level. Measuring point: Hole side of 8 in (20 cm) casing, 1.5 ft (0.46 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1980 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 9.50 ft (2.90 m) below land-surface datum, Jan. 20, 1982; lowest measured, 13.23 ft (4.03 m) below land-surface datum, Jan. 6, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTA/,.'EOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 10.68 Jan. 13 10.66 Apr. 10 11.50 July 9 11.43 Nov. 4 10.47 Feb. 17 9.98 May 3 11.53 Aug. 7 12.04 Dec. 8 10.18 Mar. 23 11.36 June 6 11.39 Sept. 27 10.62 175734066233300. Local number, 146. LOCATION.--Lat 17°57'34", long 66°23'33". Owner: P.R. Aqueduct and Sewer Authority. Name: Hacienda Alomar west well, site 3. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-70 ft (0-21.3 m), perforated 65-70 ft (19.8-21.3 m). Depth 70 ft (21.3 m). DATUM.--Altitude of land-surface datum is about 18.74 ft (5.71 m) above mean sea level. Measuring point: Hole side of 8 in (20 cm) casing, 2.5 ft (0.76 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--June 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 8.32 ft (2.54 m) below land-surface datum, June 3, 1981; lowest measured, 12.49 ft (3.81 m) below land-surface datum, Aug. 17, 1981. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 11.13 Jan. 13 9.27 Apr. 10 10.50 July 9 10.30 Nov. 4 9.23 Feb. 17 10.00 May 3 10.69 Aug. 7 11.56 Dec. 8 9.07 Mar. 23 10.29 June 6 9.74 Sept. 27 9.04 175734066233301. Local number, 147. LOCATION.--Lat 17°57'34", long 66°23'33". Owner: P.R. Aqueduct and Sewer Authority. Name: Hacienda Alomar east well, site 3. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-250 ft (0-76.2 m), perforated 245-250 ft (74.7-76.2 m). Depth 250 ft (76.2 m). DATUM.--Altitude of land-surface datum is about 18.80 ft (5.73 m) above mean sea level. Measuring point: Top of 8 in (20 cm) casing, 3.60 ft (1.10 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--June 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 13.37 ft (4.08 m) below land-surface datum, January 13, 1984; lowest measured, 15.05 ft (4.59 m) below land-surface datum, August 7, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 13.86 Jan. 13 13.37 Apr. 10 14.22 July 9 14.30 Nov. 4 13.69 Feb. 17 14.00 May 3 14.40 Aug. 7 15.05 Dec. 8 13.50 Mar. 23 14.31 June 6 14.26 Sept. 27 13.66 326 GROUND-WATER LEVELS RIO SALINAS TO RIO JACAGUAS BASINS 175756066244000. Local number, 148. LOCATION.--Lat 17°57'56", long 66°24'40". Owner: P.R. Aqueduct and Sewer Authority. Name: Playa Santa Isabel east well, site 2. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-250 ft (0-76.2 m), diameter 2 in (5 cm), cased 0-200 ft (0-61.0 m), perforated 195-200 ft (59.4-61.0 m), concreted 200-250 ft (61.0-76.2 m). Depth 200 ft (61.0 m). DATUM.--Altitude of land-surface datum is about 21.20 ft (6.46 m) above mean sea level. Measuring point: Hole side of 8 in (20 cm) casing, 2.8 ft (0.85 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--January 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.82 ft (3.91 m) below land-surface datum, Dec. 23, 1981; lowest measured, 29.45 (8.98 m) below land-surface datum, Jan. 13, 1981. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 14.13 Jan. 13 14.66 Apr. 10 16.19 July 9 16.85 Nov. 4 15.29 Feb. 17 15.20 May 3 16.20 Aug. 7 17.42 Dec. 8 14.20 Mar. 23 16.20 June 6 17.60 Sept. 5 18.61 175756066244001. Local number, 149. LOCATION.--Lat 17°57'56", long 66°24'40". Owner: P.R. Aqueduct and Sewer Authority. Name: Playa Santa Isabel west well, site 2. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (20 cm), cased 0-250 ft (0-76.2 m), diameter 2 in (5 cm), cased 0-250 ft (0-76.2 m), perforated 245-250 ft (74.7-76.2 m), concreted 200-250 ft (61.0-76.2 m). Depth 250 ft (76.2 m). DATUM.--Altitude of land-surface datum is about 21.20 ft (6.46 m) above mean sea level. Measuring point: Hole side of 8 in (20 cm) casing, 2.8 ft (0.85 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--January 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 12.07 ft (3.68 m) below land-surface, Dec. 23, 1981; lowest measured, 26.92 ft (8.21 m) below land-surface datum, Jan. 13, 1981. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 13.44 Jan. 13 13.09 Apr. 10 14.64 July 9 15.00 Nov. 4 13.09 Feb. 17 13.50 May 3 15.62 Aug. 7 16.34 Dec. 8 13.07 Mar. 23 14.54 June 6 15.85 Sept. 5 17.81 327 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 175922066495901. Local number, 16. LOCATION.--Lat 17°59'22", long 66°49'59". Owner: SucesiOn Lluveras. Name: Central San Francisco. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused artesian well, diameter 20 in (51 cm). Depth 185 ft (54'.4). DATUM.--Altitude of land-surface datum is about 30 ft (9.1 m) above mean sea level. Measuring point: Top of shelter's wooder Lase, 4.06 ft (1.24 m) above land-surface datum. REMARKS.--Recording observation well (Nov. 9, 1960 to Mar. 23, 1965). Water levels affected by pumpage of nearby wells. PERIOD OF RECORD.--November 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 1.43 ft (0.44 m) below lend-surface datum, Dec. 22, 1960; lowest measured, 35.76 ft (10.90 m) below land-surface datum, Mar. 7, 1975. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 6.23 Jan. 17 5.98 Apr. 3 6.62 July 2 1.85 Nov. 1 6.15 Feb. 15 4.94 May 1 6.75 Aug. 2 7.34 Dec. 6 6.30 Mar. 20 6.44 June 4 5.91 Sept. 5 8.28 180057066361101. Local number, 21. LOCATION.--Lat 18°00'57", long 66°36'11". Owner: P.R. Aqueduct and Sewer Authority. Name: Alhambra. AQUIFER.--Ponce Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 20 in (51 cm), cased 300 ft (91.4 m), perforated 80-300 ft (24.4-91.4 m). Depth 300 ft (91.4 m). DATUM.--Altitude of land-surface datum is about 53 ft (16.2 m) above mean sea level. Measuring point: Bottom edge 1.5 in (3.8 cm) pipe in concrete pump base, 0.7 ft (0.21 m) below land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--November 1958 to August 10, 1972; January 17, 1975 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 17.43 ft (5.31 m) below land-surface datum, Dec. 14, 1960; lowest measured, 97.61 ft (29.75 m) below land-surface datum, Aug. 8, 1967. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 a80.35 Jan. 18 a72.58 Apr. 4 a75.82 July 5 a81.70 Nov. 2 a73.00 Feb. 16 a72.80 May 2 a80.30 Aug. 3 a83.39 Dec. 7 a72.84 Mar. 21 a77.32 June 6 a80.00 Sept. 5 a82.94 180150066474901. Local number, 27. LOCATION.--Lat 18°01'50", long 66°47'49". Owner: P.R. Aqueduct and Sewer Authority. Name: Quebradas. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 to 12 in (41 to 30 cm), cased 16 in (41 cm) 0-40 ft (0-12.2 m), 12 in (30 cm) 0-120 ft (0-36.6 m), perforated 40-120 ft (12.2-36.6 m). Depth 120 ft (36.6 m). DATUM.--Altitude of land-surface datum is about 59 ft (18.0 m) above mean sea level. Measuring point: Top of 1.0 in (2.54 cm) pipe in pump base, 1.1 ft (0.34 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--November 1958 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 25.72 ft (7.84 m) below land-surface datum, Oct. 8, 1959; lowest measured, 75.1 ft (22.89 m) below land-surface datum, June 27, 1972. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 a30.90 Jan. 18 a33.38 Apr. 4 a36.35 July 3 a42.60 Nov. 2 a32.59 Feb. 16 a32.81 May 2 a39.86 Aug. 2 a40.81 Dec. 7 a34.10 Mar. 20 a35.39 June 4 a37.44 Sept. 5 a40.36 a Pumping. 328 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180110066473501. Local number, 74. LOCATION.--Lat 18°01'10", long 66°47'35". Owner: P.R. Aqueduct and Sewer Authority. Name: Guayanilla. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 16 in (41 cm), cased 0-103 ft (0-31.4 m), perforated 39-103 ft (11.9-31.4 m). Depth 102 ft (31.1 m). DATUM.--Altitude of land-surface datum is about 34 ft (10.4 m) above mean sea level. Measuring point: Airline hole in pump base, 3.0 ft (0.91 m) above land-surface datum. REMARKS.--Observation well. Drilled to 195 ft (59.44 m), plugged back to 102 ft (31.1 m). PERIOD OF RECORD.--August 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 8.56 ft (2.61 m) below land-surface datum, Oct. 21, 1960; lowest measured, 90.50 ft (27.58 m) below land-surface datum, Aug. 13, 1976. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 a15.87 Jan. 18 a15.25 Apr. 4 a15.76 July 3 a57.45 Nov. 2 al5.80 Feb. 16 a15.33 May 2 al6.50 Aug. 2 18.40 Dec. 7 a15.75 Mar. 20 a15.53 June 4 a20.55 Sept. 5 a48.55 180058066502701. Local number, 131. IOCATION.--Lat 18°00'58", long 66'50'27". Owner: Union Carbide Corporation. Name: Yauco 1 or UCC 2. AQUIFER.--Alluvium of Quaternary Age and limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled observation well, casing slotted 20-145 ft (6.1-44.2 m), open hole below 145 ft (44.2 m). Depth 156 ft (47.6 m). DATUM.--Altitude of land-surface datum is about 66 ft (20.1 m) above mean sea level. Measuring point: Top of 3 in (0.08 m) pipe, 2.5 ft (0.76 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--August 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 0.46 ft (0.14 m) below land-surface datum; June 14, 1979; lowest measured, 44.95 ft (13.70 m) below land-surface datum, May 20, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 9.60 Jan: 17 8.08 Apr. 3 10.38 July 2 12.24 Nov. 1 9.14 Feb. 15 8.67 May 1 11.59 Aug. 2 12.13 Dec. 6 8.22 Mar. 19 9.72 June 4 11.50 Sept. 5 12.18 a Pumping. 329 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180133066503301. Local number, 132. LOCATION.--Lat 18°01'33", long 66°50'33". Owner: Pittsburg Plate Glass 4. Name: Yauco 2. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled observation well, cased 20 in (51 cm) 0-20 ft (0-6.1 m), 12 in (30 cm) perforated pipe 20-84 ft (6.1-25.61 m), 10 in (25 cm) perforated pipe 84-190 ft (25.61-57.93 m). Depth 190 ft (57.93 m). Datum.--Altitude of land-surface datum is about 75 ft (22.87 m) above mean sea level. Measuring point: Top of shelter floor, 2.35 ft (0.72 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--July 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, +0.12 ft (+0.04 m) below land-surface datum, July 19, 1979; lowest, 36.91 ft (11.25 m) below land-surface datum, June 27, 1974. WATER LEVEL, IN FEET .FLCW LAND-SURFACE DATUM, WATER YEAR OCTCEER 1985 TO SEPTEHS5R 1934 INSTANTANEOUS O?..iERVATIONS AT 1230 DAY OCT NOV DEC JAN FEE MAR APR MAY JUN JUL AUG SEP 1 2 3 4 5 8.7o 8.77 8.91 9.97 9.05 3.12 8.16 9.13 7.68 7.15 6.96 7.04 6.99 7.0! 7.22 '.59 '.61 !.05 8.04 7.93 7.97 1. 92 3.37 1.94 3. 9A 7. 09 12.34 12.43 12.63 12.65 12.70 12.45 12.50 12.53 12.49 12.47 12.07 12.07 12.08 12.10 12.15 13.77 14.01 14.14 14.26 13.55 13.15 13.21 13.20 13.22 13.15 14.33 14.67 14.47 14.27 14.25 6 7 8 9 10 9.09 9.13 9.13 9.10 9.21 7.07 6.97 6.84 5.98 6.99 7.20 7.09 7.15 7.15 6.99 7.51 7.45 7.46 7.61 7.59 3.13 8.17 3.22 3.22 8.05 7.33 7.64 0.65 7.66 4.69 12.71 12.53 12.51 12.55 12.62 12.47 12.50 12.54 12.56 12.62 12.19 12.23 12.26 12.23 12.31 12.74 12.87 12.34 12.37 12.32 13.22 13.34 13.41 13.50 13.61 14.14 14.30 13.39 13.78 13.75 11 12 13 14 1.5 9.32 9.39 9.23 9.16 1.32 6.78 6.31 6.33 6.83 5.93 6.94 7.09 7.31 7.50 7.59 7.52 6.97 6.77 *.01 7.09 7.97 7.91 8.00 8.01 8.03 9.70 4. 73 7.79 9.90 13.00 12.65 12.68 12.70 12.61 12.52 12.67 12.70 12.76 12.85 12.75 12.37 12.51 12.62 12.63 12.74 12.30 1'.32 12.33 12.15 12.37 13.6! 13.67 13.76 13.89 13.97 13.34 13.86 13.78 13.75 13.59 16 17 18 19 20 8.72 8.76 8.63 9.45 8.35 6.94 7.07 7.16 6.99 6.98 7.64 7.52 7.22 --- 7.15 7.19 7.23 7.28 7.43 8.02 8.02 3.02 8.02 8.02 13.11 10.22 13.32 17.43 13.57 12.60 12.65 12.69 12.58 12.53 12.59 12.52 12.48 12.48 12.53 12.72 12.69 12.80 12.86 12.92 12.90 12.94 12.96 12.93 12.34 14.20 14.37 14.55 14.53 14.71 13.44 13.30 13.04 12.24 10.79 21 22 23 24 25 8.23 8.10 8.05 8.04 8.02 7.18 7.18 7.21 7.18 7.18 '.35 7.35 7.49 7.29 7.53 8.19 3.21 8.29 8.35 8.43 10.71 13.86 11.31 11.16 11.30 12.51 12.43 12.47 12.47 12.46 12.56 12.51 12.63 12.50 12.23 12.95 13.00 13.03 12.93 13.12 12.80 12.76 12.30 12.90 12.85 14.87 14.97 15.13 15.27 15.23 9.66 9.38 9.25 9.14 9.04 26 27 28 29 30 31 8.00 8.17 8.27 8.20 7.97 8.04 7.05 5.93 6.98 6.77 6.95 --- 7.70 7.76 7.57 7.71 7.76 7.92 8.43 1.57 8.81 8.81 --- 11.45 11.50 11.75 11.89 12.04 12.19 12.45 12.42 12.36 12.34 12.37 --- 12.23 12.19 12.15 12.14 12.12 12.08 13.24 13.36 13.49 13.69 13.84 --- 12.95 13.03 13.08 12.98 13.05 13.10 15.11 15.19 15.21 15.23 15.25 15.25 8.93 1.91 3.80 8.74 8.68 --- LOW HIGH 9.39 7.97 3.16 6.78 8.81 7.93 12.17 3.82 12.71 12.34 12.75 12.08 13.84 12.07 14.26 12.76 15.27 13.15 14.83 8.68 4 4\„ I SONDJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 + Above land-surface datum. 16 330 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 180120066503201. Local number, 134. LOCATION.--Lat 18°01'20", long 66°50'32". Owner: Union Carbide Corporation. Name: Yauco 4 or UCC 1. AQUIFER.--Alluvium of Quaternary Age and limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled observation well, casing slotted 20-140 ft (6.1-42.7 m) open hole 140-163 ft (42.7-49.7 m). Depth 163 ft (49.7 m). DATUM.--Altitude of land-surface datum is about 87 ft (26.5 m) above mean sea level. Measuring point: Top of 3 in (0.08 m) pipe, 3.4 ft (1.04 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1972 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 7.90 ft (2.41 m) below land-surface datum; June 14, 1979; lowest measured, 37.84 ft (11.53 m) below land-surface datum, June 27, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 3 11.95 Jan. 17 11.28 Apr. 3 14.15 July 8 16.94 Nov. 1 12.01 Feb. 15 11.66 May 1 15.39 Aug. 2 16.58 Dec. 6 11.50 Mar. 19 13.22 June 4 15.28 Sept. 5 17.80 331 GROUND-WATER LEVELS RIO INABON TO RIO LOCO BASINS 175950066354201. Local number, 141. LOCATION.--Lat 17°59'50", long 66°35'42". Owner: P.R. Aqueduct and Sewer Authority. Name : Restaurada 8A. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused public supply well, diameter 16 to 10 in (41 to 25 cm), cased 16 in (41 cm) 2-20 ft (0.61-6.10 m), perforated 20-130 ft (6.10-39.63 m), 10 in (25 cm) 128-165 ft (39.02-50.30 m), perforated. Depth 165 ft (50.30 m). DATUM.--Altitude of land-surface datum is about 24 ft (7.32 m) above mean sea level. Measuring Point: Bottom edge of hole on side of casing, 1.90 ft (0.58 m) above land-surface datum, 26.15 ft (7.97 m) above mean sea level. REMARKS.--Recording observation well. PERIOD OF RECORD.--Oct. 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 15.65 ft (4.77 m) below land-surface datum, Aug. 30, 1983; lowest, 28.59 ft (8.714 m) below land-surface datum, July 9, 1982. WATER LEVEL, TN FEET 3ELDW LAND-SURF ACE DATUM, WATEI YEAR OCTISER 1983 TO SEPTEMBER 1984 NSTANTANEOUS OSSERVATTONS AT 1230 DAY OCT NOV DEC JAN ;Ca MAR APR MAY JUN JUL AUG SEP 1 16.55 17.50 18.27 1 7.34 17.59 17.43 17.51 13.33 13.27 17.43 20.22 2 16.49 17.40 18.44 17.29 17.63 17.45 17.66 18.7! 13.19 17.44 20.34 3 16.41 17.33 17.71 15.10 17.61 17.63 13.01 13.97 13.50 17.46 19.52 4 16.47 16.61 17.42 17.23 17.64 17.70 18.01 11.23 13.68 17.49 11.47 5 16.90 16.25 17.83 17.37 17.53 17.75 17.75 19.39 13.55 17.44 19.45 6 16.61 15.29 18.02 17.43 17.33 17.55 17.52 19.57 19.90 13.68 17.38 15.87 7 16.64 15.90 11.13 17.51 17.27 17.91 17.39 19.70 19.03 13.58 17.40 13.07 8 16.65 15.96 18.12 16.15 17.27 13.15 17.25 19.38 19.19 13.56 17.44 16.28 9 16.66 16.03 13.13 16.92 17.29 13.22 17.27 20.06 19.92 13.71 17.46 18.15 10 17.49 16.10 17.57 17.40 17.22 13.41 17.39 20.22 19.62 13.80 17.46 17.91 11 12 17.6) 17.66 16.22 15.19 17.82 17.32 1'.52 17.78 16.96 16.71 17.92 17.95 17.49 17.59 20.45 23.95 19.81 19.91 19.48 11.77 17.48 17.44 17.94 17.98 13 17.60 16.12 17.82 17.11 16.59 13.36 17.70 21.05 20.01 19.45 18.32 13.01 14 17.63 16.11 17.68 17.99 16.93 13.51 17.93 21.06 20.05 19.41 18.91 13.35 15 17.66 16.15 17.67 1 7.90 17.03 13.19 18.35 21.11 20.10 19.27 19.31 18.08 16 17.62 15.77 17.57 13.11 17.09 13.2P 18.51 20.72 20.05 19.19 19.43 19.77 17 17.57 16.59 17.49 13.27 17.1? 12.16 18.65 23.33 19.68 19.61 19.54 19.63 18 17.63 16.58 17.43 13.36 17.07 17.35 11.75 20.58 19.4 7 19.69 19.65 19.53 19 17.71 17.21 17.37 13.44 16.95 17.93 18.82 20.47 19.36 19.68 19.75 13.26 20 17.79 17.45 17.35 13.52 16.97 1 7.89 18.87 20.24 13.30 19.66 19.75 17.80 21 17.91 17.12 17.35 18.59 17.9? 17.94 18.87 20.07 19.13 19.59 19.86 16.79 22 18.53 17.14 17.66 13.71 17.11 11.07 18.81 20.01 19.05 19.41 19.98 16.33 23 18.26 17.53 17.72 13.76 17.15 13.05 18.77 19.96 19.02 19.35 20.11 16.07 24 18.27 17.84 17.67 11.21 17.18 14.05 18.77 --- 18.95 19.38 20.25 15.84 25 18.65 17.96 17.58 13.25 17.17 17.96 18.77 18.86 18.93 20.33 15.86 26 18.71 18.10 17.49 17.90 17.20 17.91 18.73 18.83 19.12 20.33 16.03 27 18.50 13.17 17.44 11.02 17.22 13.26 18.73 18.59 17.00 20.33 16.20 28 18.31 13.15 17.40 13.02 17.20 13.39 18.76 13.44 17.32 20.37 16.42 29 18.20 18.23 17.41 13.00 17.23 18.41 18.80 18.17 17.32 20.37 17.02 30 17.80 11.33 17.42 17.65 --- 18.43 18.23 18.37 17.30 20.37 16.88 31 17.54 --- 17.40 17.11 13.44 --- --- 17.38 20.31 --- LOW 18.71 18.33 18.44 18.76 17.69 13.51 18.37 19.77 20.37 20.22 HIGH 16.41 15.90 17.35 16.90 16.59 17.43 17.26 17.00 17.38 15.34 14 30 w, 18 m F F a L.,.1 6.1 LJ IJ Z < L- 22 -JD CC fryviNti '4y > La-J 0Z Lai < 26 30 ONDJFMAMJJASONDJEMAMJJASONDJEMAMJJ AS 1981 1982 1983 1984 332 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180933067050801. Local number, 40. LOCATION.--Lat 18°09'33", long 67°05'08". Owner: P.R. Aqueduct and Sewer Authority. Name: Rosario. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 16 to 12 in (41 to 30 cm), cased 16 in (41 cm) 0-30 ft (0-9.1 m) 12 in (30 cm) 0-60 ft (0-18.3 m); perforated 12 (30 cm) 10-60 ft (3.0-18.3 m). Depth 105 (32.0 m). DATUM.--Altitude of land-surface datum is about 164 ft (50.0 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe, 2.7 ft (0.82 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--July 1960 to November 1971; May 1973; March 1974 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 0.20 ft (0.06 m) below land-surface datum, Aug. 3, 1983; lowest measured, 37.30 ft (11.37 m) below land-surface datum, May 7, 1973. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 a14.31 Jan. 13 a14.43 Apr. 5 a14.84 Aug. 27 al4.25 Nov. 30 a14.28 Feb. 9 a14.71 June 7 12.52 Sept. 13 11.30 Dec. 8 a14.43 Mar. 6 a14.74 July 12 13.80 181018067091601. Local number, 43. LOCATION.--Lat 18°10'18", long 67°09'16". Owner: Mayaguez Sugar Co. Name: Central Rochelaise. AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (30 cm), cased 0-45 ft (0-13.7 m), perforated 0-45 ft (0-13.7 m). Depth 80 ft (24.4 m). DATUM.--Altitude of land-surface datum is about 7 ft (2.1 m) above mean sea level. Measuring point: Top of 12 in (30 cm) casing, 1.9 ft (0.58 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--August 1959 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, +0 59 ft (+0.18 m) above land-surface datum, June 6, 1984; lowest measured, 2.70 ft (0.82 m) below land-surface datum, Apr. 15, 1970. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 6 +0.50 Jan. 12 +0.45 Apr. 6 +0.47 July 11 +0.24 Nov. 3 +0.53 Feb. 8 +0.55 May 3 0.22 Aug. 10 0.53 Dec. 7 +0.53 Mar. 5 +0.42 June 6 +0.59 Sept. 12 +0.58 + Above land-surface datum. a Pumping. 333 38 GROUND-WATER LEVELS RIO GUANAJIBO BASIN 180132067033801. Local number, 143. LOCATION.--Lat 18°01'32", long 67°,03'38". Owner: Pedro P. Vivoni. Name : Vivoni, Hacienda Amistad. AQUIFER.--Limestone of unknown age. WELL CHARACTERISTICS.--Drilled unused irrigation well, diameter 12 in (30 cm). Depth 200 ft (60.98 m). DATUM.--Altitude of land-surface datum is about 52.5 ft (16.0 m) above mean sea level. Measuring Point: Hole side of casing, 0.80 ft (0.24 m) above land-surface datum. REMARKS.--Recording observation well. PERIOD OF RECORD.--Dec. 1981 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level, 38.00 ft (11.58 m) below land-surface datum, Sept. 19-20, 1982; lowest, 39.34 ft (11.99 m) below land-surface datum, Apr. 10, 1983. WATER LEVEL, IN FEET 9'ELCW LANO -SUR'ACE C.ATUM, WATER YEAR CCTOEER 1183 TO SEPTEMEER 1914 INSTANTANEOUS 03SE9VATI0NS AT 1200 011Y OCT NOV )EC JAN cca AR APR MAY JUN XJL AUG SEP 1 39.34 39.34 38.90 72.90 33.85 31.46 39.29 39.56 39.53 39.67 39.44 39.49 2 39.33 39.01 38.91 31.38 33.85 33.99 39.30 31.56 39.54 39.70 30.45 39.49 3 39.33 33.99 38.90 33.90 3.8.34 39.00 39.31 39.55 39.52 39.69 39.45 39.50 4 39.37 33.59 38. 9 3 33.91 33.31 39.00 39.30 37.54 39.50 39.64 39.44 19.52 5 39.39 33.22 33.90 3 2.90 19.84 31.00 39.29 31.54 39.51 37.31 39.49 39.50 39.40 33.79 38.81 33.90 38.34 34.31 39.31 39.56 39.53 39.43 39.47 39.45 7 39.31 39.34 33.7? 39.75 38.89 38.90 33.75 31.77 38.16 38.86 3).15 39.07 39.32 39.33 39.56 39.56 39.54 39.54 3 9.43 39.50 39.45 39.45 37.49 39.50 9 39.72 33.71 31.83 33.93 38.37 37.17 39.32 79.55 39.54 39.51 39.46 39.46 10 39.29 33.71 31.87 31.91 38.85 37.06 39.33 39.57 39.55 37.50 39.43 39.44 11 39 .30 33.74 31.84 33.39 38.8: 39.05 39.31 39.55 39.56 39.47 39.43 39.45 12 39.32 33.73 35.83 31.16 38.27 31.11 39.33 3 9 .57 39.56 39.49 39.49 13 39.30 33.72 38.83 31.12 38.33 31.13 39.33 39.59 39.56 39.50 39.47 14 39.28 33.75 38.56 31.33 38.84 31.12 39.43 39.57 39.53 39.49 39.47 15 39.25 33.75 32.83 31.32 38.1 4 39.12 39.4J 39.55 39.61 39.49 39.45 16 17 39.24 39.24 31.'6 33.76 38.91 38.89 '1 13 33.. 90 32./4 32.35 39.12 33.11 39.40 39.43 31.53 31.54 39.61 39.57 37.46 39.46 39.46 39.45 18 39.20 33.79 33.87 '3.91 38.84 39.11 39.43 39.56 39.57 39.46 39.47 19 39.19 38.78 38.84 31.19 38.37 37.12 39.43 39.58 39.60 39.45 39.43 20 39.19 33.'9 38.87 73.14 38.'36 39.12 39.43 39.55 39.61 39.43 39.49 21 22 39.15 39.11 38.32 38.32 38.90 33.90 33.15 31.36 38.85 38.37 37 -14 39.17 39.43 39.42 39.58 39.60 39.59 39.59 31.43 31.42 39.50 39.48 23 39.12 33.10 33.58 33.33 38.33 31.19 39.45 39.59 39.61 39.43 39 .49 24 39.14 33.30 31.87 31.31 38.93 39.19 39.49 39.54 39.62 39.42 39.50 25 39.10 33.14 38.17 33.30 38.83 39.11 39.47 39.52 39.62 39.42 39.53 26 27 39.08 39.11 33.35 33.85 38.91 38.91 35.33 31.33 38.53 33.92 39.19 37.19 39.46 39.45 3/.53 39.54 39.63 39.66 39.42 37.45 39.52 39.52 39.12 28 39.14 38.34 38.9.2 33.81 38.95 37.20 39.49 39.55 39.67 37.46 39.53 39.11 29 39.13 33.36 31.90 33.32 33.95 39.21 39.51 39.54 39.70 39.44 39.54 39.10 30 39.03 33.39 18.91 33.44 --- 37.25 39.54 39.52 39.67 39.43 39.52 39.13 31 39.07 --- 33.90 31.34 39.27 --- 39.51 39.45 39.49 LOW 39.40 39.04 38.92 33.97 38.95 37.27 39.54 39.60 39.70 39.70 39.54 HIGH 39.07 38. 71 38.83 33.10 38.81 33.96 39.23 39.51 39.50 39.33 39.44 DJFMAMJJASONDJFMAMJJASONDJFMAMJJAS 1981 1982 1983 1984 40 334 GROUND-WATER LEVELS RIO YAGUEZ AND RIO GRANDE DE ARASCO BASINS 181233067083201. Local number, 45. LOCATION.--Lat 18°12'33", long 67°08'32". Owner: Cervecerfa India, Inc. Name: Well 1, Mayaguez. AQUIFER.--Alluvium of Quaternary Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 12 in (30 cm), cased 0-82 ft (0-25.0 m). Depth 82 ft (25.0 m). DATUM.--Altitude of land-surface datum is about 23 ft (7.0 m) above mean sea level. Measuring point: Top of wood cover, 0.9 ft (0.27 m) above land-surface datum. REMARKS.--Observation well. Affected by nearby pumping. PERIOD OF RECORD.--1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 9.41 ft (2.87 m) below land-surface datum, Sept. 15, 1977; lowest measured, 29.97 ft (9.13 m) below land-surface datum, Jan. 20, 1966. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 13.50 Jan. 12 13.33 Apr. 5 14.51 July 11 14.17 Nov. 3 13.08 Feb. 8 13.39 May 3 15.00 Aug. 9 13.81 Dec. 7 13.51 Mar. 5 13.11 June 7 15.18 Sept. 12 13.45 181522067090901. Local number, 53. LOCATION.--Lat 18°15'22", long 67°09'09". Owner: P.R. Ports Authority. Name: Mayaguez Airport. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 8 in (20 cm), cased 0-114 ft (0-34.8 m), perforated 82-114 ft (25.0-34.8 m), open hole 114-353 ft (34.8-107.6 m). Depth 353 ft (107.6 m). DATUM.--Altitude of land-surface datum is about 20 ft (6.1 m) above mean sea level. Measuring point: Slot in pump base, 0.4 ft (0.12 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--October 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 0.96 ft (0.29 m) below land-surface datum, Oct. 5, 1978; lowest measured, 8.70 ft (2.65 m) below land-surface datum, Feb. 14, 1979. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATION Water Water Water Water Date level Date level Date level Date level Oct. 5 2.62 Jan. 12 3.97 Apr. 5 5.55 July 12 2.32 Nov. 3 2.07 Feb. 8 4.72 May 3 6.09 Aug. 9 2.42 Dec. 7 2.78 Mar. 5 4.68 June 7 3.04 Sept. 12 2.04 335 GROUND-WATER LEVELS RIO CULEBRINAS BASIN 182228067113301. Local number, 58. LOCATION.--Lat 18°22'38", long 67°11'33". Owner: P.R. Aqueduct and Sewer Authority. Name: Aguada. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled public supply artesian well, diameter 20 in (51 cm) to 12 in (30 cm), cased 20 in (51 cm) 0-40 ft 0-40 ft (0-12.2 m), 12 in (30 cm) 0-60 ft (0-18.3 m), perforated 40-60 ft (12.2-18.3 m). Depth 160 ft (48.8 m). DATUM.--Altitude of land-surface datum is about 30 ft (9.1 m) above mean sea level. Measuring point: Lower edge of 0.75 in (1.90 cm) pipe in pump base, 1.90 ft (0.58 m) above land-surface datum. REMARKS.--Observation well. Piezometric head measured for highest water level. PERIOD OF RECORD.--January 1960 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, +0.81 ft (+0.25 m) above land-surface datum, Sept. 12, 1975; lowest measured, 83.53 ft (25.46 m) below land-surface datum, Aug. 7, 1974. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 5 0.38 Jan. 12 2.49 Apr. 5 2.76 July 11 0.12 Nov. 3 0.70 Feb. 8 2.90 May 3 3.33 Aug. 9 1.24 Dec. 7 1.64 Mar. 5 2.13 June 6 1.55 Sept. 12 1.11 182018066593201. Local number, 83. LOCATION.--Lat 18°20'18", long 66°59'32". Owner: P.R. Water Resources Authority. Name: San Sebastian. AQUIFER.--Volcanic rock of Eocene Age. WELL CHARACTERISTICS.--Drilled observation well, diameter 6 in (15 cm). Depth 300 ft (91.4 m). DATUM.--Altitude of land-surface datum is about 230 ft (70.1 m) above mean sea level. Measuring point: Top of casing, 2.40 ft (0.73 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--May 1967 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 21.95 ft (6.69 m) below land-surface datum, Apr. 15, 1976; lowest measured, 40.20 ft (12.25 m) below land-surface datum, July 21, 1970. WATER LEVEL, IN FEET BELOW LAND-SURFACE. DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 4 27.90 Jan 11 29.72 Apr. 4 30.44 July 3 27.56 Nov. 3 27.85 Feb. 7 30.12 May 1 30.07 Aug. 8 29.20 Dec. 6 29.08 Mar. 1 30.18 June 5 27.96 Sept. 5 28.04 + Above land-surface datum. Surf ace- Water Records for U.S. Virgin Islands 338 86°05' 65°00' 55' 64°50' 18°24' 18°20' 18°22' 64°50' I ..s==7 .:: 7 CZ) 'c.: 2 ST. JOHN 2950 45' 64°40' 1 18°18' 1 17°45' 17°40' Figure 26.--Location of surface-water stations in the U.S. Virgin Islands. --- --- 339 ST. THOMAS, U.S. VIRGIN ISLANDS 50252000 BONNE RESOLUTION GUT AT BONNE RESOLUTION, ST. THOMAS, VI LOCATION.--Lat 18°21'57", long 64°57'34", Hydrologic Unit 21020001, on right bank near Hull Bay Road, 0.5 mi (0.8 km) upstream from Atlantic Ocean, and 2.5 mi (4.02 km) northwest of Fort Christian, Charlotte Amalie. DRAINAGE AREA.--0.49 sq mi (1.27 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--December 1962 to February 1967, March 1979 to April 1981, May 1982 to current year. GAGE.--Water-stage recorder and concrete control. Altitude of gage is 280 ft (85.3 m), from topographic map. December 1962 to February 1967 at site about 100 ft (30.5 m) downstream at different datum. March 1979 to April 1981 at site about 100 ft (30.5 m) upstream at different datum. REMARKS. - -Records poor. AVERAGE DISCHARGE.--6 years (1964-66, 1980, 1983-84), 0.21 cu ft/s (0.0059 cu m/s), 5.82 in/yr (147.8 mm/yr), 152 acre-ft/yr (0.187 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 1,650 cu ft/s (46.7 cu m/s) Apr. 18, 1983, gage height, 7.00 ft (2.134 m), from floodmarks, from rating curve extended above 1.0 cu ft/s (0.03 cu m/s) on basis of critical-depth analysis and slope-area measurement of peak flow; no flow at times in most years. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 50 cu ft/s (1.42 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. 4 0915 58 1.64 1.52 0.463 June 5 1800 *63 1.78 1.56 0.475 Feb. 9 0015 56 1.59 1.50 0.457 No flow parts or all of many days. DISCHARGE, IN CUBIC FEET PER SECOND. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAT JUN JUL AUG SEP 1 .02 .03 .01 .02 .05 .02 .01 .04 .04 .02 .04 .02 2 .01 .03 2.1 .02 .05 .03 .00 .02 .05 .01 .03 .02 3 .01 .05 .09 .02 .05 .02 .01 .02 .05 .01 .01 .02 4 .02 10 .05 .03 .04 .03 .02 .03 .04 .02 .22 .02 5 .01 2.1 .03 .03 .05 .02 .01 .03 4.3 .02 .04 .02 6 .02 .23 .03 .05 .D5 .01 .02 .04 .59 .02 .02 .02 7 .01 .14 .02 .03 .05 .01 .02 .04 .09 .02 .01 .02 8 .02 .10 .03 .05 .51 .02 .03 .02 .04 .02 .01 .02 9 .01 .09 .03 .06 2.5 .02 .02 .02 .03 .02 .01 .01 10 .02 .06 .04 .05 .07 .02 .02 .02 .02 .02 .02 .01 11 .01 .05 .04 .05 .04 .02 .04 .02 .02 .03 .02 .01 12 .02 .06 .03 .07 .04 .03 .02 .02 .02 .01 .02 .03 13 .01 .05 .03 .03 .02 .02 .03 .04 .01 .01 .01 .02 14 .02 .07 .03 .04 .03 .02 .03 .05 .01 .01 .02 .01 15 .01 .06 .03 .03 .03 .02 .03 .02 .01 .01 .02 .01 16 .01 .05 .03 .05 .02 .02 .03 .02 .02 .01 .02 .02 17 .01 .06 .03 .02 .03 .01 .04 .02 .01 .01 .01 .02 18 .01 .05 .03 .02 .05 .01 .03 .02 .01 .01 .01 .03 19 .01 .05 .05 .02 .05 .01 .05 .01 .02 .01 .01 .03 20 .02 .05 .05 .03 .05 .01 .04 .02 .02 .01 .01 .03 21 .01 .05 .05 .04 .05 .01 .05 .03 .02 .01 .01 .12 22 .02 .05 .04 .03 .05 .01 .05 .02 .02 .01 .06 .03 23 .02 .06 .03 .03 .05 .01 .03 .05 .02 .01 .01 .03 24 .02 .05 .02 .03 .04 .01 .03 .02 .01 .01 .01 .06 25 .06 .05 .02 .03 .02 .01 .05 .02 .01 .01 .01 .04 26 .02 .05 .04 .02 .03 .01 .05 .02 .01 .01 .02 .02 27 .02 .05 .05 .02 .03 .01 .03 .01 .01 .01 .02 .04 28 .03 .05 .03 .02 .04 .01 .02 .03 .01 .01 .02 .05 29 .02 .05 .05 .02 .03 .01 .03 .03 .02 .01 .02 .04 30 .06 .03 .03 .04 --- .01 .03 .02 .02 .01 .02 .06 31 .02 .02 .05 .01 .06 --- .02 .02 --- TOTAL .58 13.87 3.16 1.05 4.12 .48 .87 .83 5.55 .42 .78 .88 MEAN .019 .46 .10 .034 .14 .015 .029 .027 .19 .014 .025 .029 MAX .06 10 2.1 .07 2.5 .03 .05 .06 4.3 .03 .22 .12 MIN .01 .03 .01 .02 .02 .01 .00 .01 .01 .01 .01 .01 CFSM .04 .94 .20 .07 .29 .03 .06 .06 .39 .03 .05 .06 IN. .04 1.05 .24 .08 .31 .04 .07 .06 .42 .03 .06 .07 AC-FT 1.2 28 6.3 2.1 8.2 1.0 1.7 1.6 11 .8 1.5 1.7 CAL YR 1983 TOTAL 246.57 MEAN .68 MAX 169 MIN .01 CFSM 1.39 IN 18.68 AC-FT 489 VTR YR 1984 TOTAL 32.59 MEAN .089 MAX 10 MIN .00 CFSM .18 IN 2.47 AC-FT 65 340 ST. THOMAS, U.S. VIRGIN ISLANDS 50252000 BONNE RESOLUTION GUT AT BONNE RESOLUTION, ST. THOMAS, VI--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--MARCH 1913 TO CURRENT YEAR WATER-UALITY DATA. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 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) OCT, 25 1028 .05 1252 24.5 MAY, 23 1642 .048 2141 22.5 NOV. 30 1704 .03 195' 23.5 JUL. 26 1213 .005 2160 28.0 JAN, 23 1331 .03 2163 24.5 AUG, 24 1117 .009 1900 26.0 APR. 04 1350 .017 2020 25.0 --- 341 ST. THOMAS, U.S. VIRGIN ISLANDS 50276000 TURPENTINE RUN AT MARIENDAL, ST. THOMAS, VI LOCATION.--Lat 18°19'48", long 64°52'58", Hydrologic Unit 21020001, on left bank, at Mariendal, 1.0 mi (1.6 km) upstream from mouth, and 3.3 mi (5.3 km) southeast of Fort Christian, Charlotte Amalie. DRAINAGE AREA.--2.97 sq mi (7.69 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to April 1969, October 1978 to September 1980, June 1982 to current year. GAGE.--Water-stage recorder. Altitude of gage is 40 ft (12.2 m), from topographic map. REMARKS.--Records poor. Since about 1975, low flow augmented by discharges from sewage plant. AVERAGE DISCHARGES.--9 years (1964-68, 1979-80, 1983-84), 1.04 cu ft/s (0.029 cu m/s), 4.76 in/yr (121 mm/yr), 753 acre-ft/yr (0.93 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 9,710 cu ft/s (275 cu m/s) Apr. 18, 1983, gage height, 11.09 ft (3.380 m), from floodmark, from rating curve extended above 500 cu ft/s (14.2 cu m/s) on basis of slope area measurement and step-backwater analysis; no flow many days from 1963 to 1969, and in 1984. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 100 cu ft/s (2.83 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) Nov. 4 0930 186 5.268 3.35 1.021 Sept. 17 2115 178 5.041 3.31 1.009 June 5 1715 *333 9.430 3.95 1.204 No flow part of each day Apr. 12, May 7, 11. DISCHARGE, IN CUBIC FEET PER SECOND, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .45 .33 .43 .26 .38 .17 .39 .11 .89 .25 .40 .11 2 .45 .35 10 .28 .38 .15 .28 .10 .96 .15 .44 .09 3 .45 1.3 .76 .24 .53 .25 .23 .09 1.2 .22 .34 .08 4 .45 45 .36 .27 .48 .17 .24 .15 .85 .29 4.9 .10 5 .53 16 .42 .30 .67 .18 .22 .13 37 .27 .20 .83 6 .33 3.6 .49 .36 .56 .19 .26 .13 14 .27 .14 .10 7 .45 1.8 .28 .46 .54 .20 .31 .07 6.8 .34 .11 .09 8 .45 1.4 .44 .36 .63 .19 .27 .11 1.4 .42 .10 .10 9 .45 3.2 .25 .32 2.6 .18 .23 .10 1.0 .27 .09 .16 10 .45 1.4 .27 .46 .57 .28 .16 .10 .82 .23 .08 .10 11 .38 1.2 .28 .32 .48 .25 .16 .10 .90 .30 .08 .09 12 .45 1.1 .36 .36 .51 .23 .13 .18 1.0 .24 .09 .30 13 .38 1.0 .26 .39 1.0 .22 .16 .22 .80 .21 .11 .12 14 .45 1.0 .26 2.0 .44 .18 .18 .13 .50 .24 .08 .11 15 1.2 1.0 .26 .36 .96 .20 .30 .17 .38 .27 .12 .10 16 .45 .91 .22 1.1 .51 .22 .21 .16 .36 .17 .09 .20 17 .45 .86 .24 .46 .44 .38 .19 .18 2.0 .21 .08 8.1 18 .33 .80 .24 .49 .46 .29 .21 .19 1.0 .19 .09 6.2 19 .33 .70 .23 .38 .45 .24 .24 .26 .50 .19 .08 .87 20 .33 .60 .27 .50 .42 .24 .34 .30 .30 .26 .08 .65 21 .33 .86 .24 .78 .34 .26 .44 .14 .20 .22 .11 .40 22 .38 .54 .27 .90 .35 .25 .32 .16 .16 .33 1.4 .30 23 .38 .60 .38 .63 .32 .21 .25 .20 .13 .23 .17 .20 24 .33 .50 .30 .51 .34 .24 .28 .34 .12 .23 .13 .17 25 .33 .43 .26 .62 .38 .24 .31 .34 .11 .21 .18 .20 26 .48 .40 1.1 .60 .34 .22 .37 .34 .10 .22 .20 .60 27 .33 .40 .29 .48 .27 .24 6.3 .52 .20 .18 .09 1.1 28 .40 .38 .30 .55 .26 .23 1.4 .48 .13 .24 .09 2.8 29 1.5 .60 .40 .45 .19 .24 .18 .33 .12 .24 .09 .70 30 .56 .23 .77 .42 --- .15 .11 .46 .25 .18 .1-1 2.5 31 .36 --- .34 .46 .23 1.3 --- .19 5.2 --- TOTAL 14.59 88.49 20.97 16.07 15.80 6.92 14.67 7.59 74.18 7.46 15.47 27.47 MEAN .47 2.95 .68 .52 .54 .22 .49 .24 2.47 .24 .50 .92 MAX 1.5 45 10 2.0 2.6 .38 6.3 1.3 37 .42 5.2 8.1 MIN .33 .23 .22 .24 .19 .15 .11 .07 .10 .15 .08 .08 CFSM .16 .99 .23 .18 .18 .07 .17 .08 .83 .08 .17 .31 IN. .18 1.11 .26 .20 .20 .09 .18 .10 .93 .09 .19 .34 AC-FT 29 176 42 32 31 14 29 15 147 15 31 54 CAL YR 1983 TOTAL 1593.94 MEAN 4.37 MAX 1000 MIN ..04 CFSM 1.47 IN 19.96 AC-FT 3160 WTR YR 1984 TOTAL 309.68 MEAN .85 MAX 45 MIN .07 CFSM .29 IN 3.88 AC-FT 614 342 ST. THOMAS, U.S. VIRGIN ISLANDS 50276000 TURPENTINE RUN AT MARIENDAL, ST. THOMAS, VI--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--MARCH 1983 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 DATE TIME STREAMFLOW, INSTANTANEOUS (CFS) SPECIFIC CON­ DUCTANCE (UMMOS) TEMPERA- TURE (DEG C) DATE TIME STREAMFLOWs INSTANTANEOUS (CFS) SPECIFIC CON- DUCTANCE (UMNOS) TEMPERA­ TORE (DEG C) OCT, 26 1320 NOV, 29 1210 JAN, 25 1000 APR, 04 1026 .61 2.0 .65 .14 2133 2179 750 2100 29.5 25.5 26.0 27.0 MAY, 23 1406 JUL, 26 1001 AUG, 24 0901 .33 .13 .03 2241 2130 1700 31.0 27.5 27.0 343 ST. JOHN, U.S. VIRGIN ISLANDS 50295000 GUINEA GUT AT BETHANY, ST. JOHN, VI LOCATION.--Lat. 18°19'55", long 64°46'50", Hydrologic Unit 21020001, 600 ft (183 m) southeast of Bethany Church, and 1.0 mi (1.6 km) east of Government House at Cruz Bay. DRAINAGE AREA.--0.37 sq mi (0.96 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to October 1967, September 1982 to current year. GAGE.--Water-stage recorder and concrete control. Altitude of gage is 260 ft (79.2 m), from topographic map. Prior to September 1982, at datum 1.00 ft (0.305 m) higher. REMARKS.--Records poor. AVERAGE DISCHARGE.--6 years(1964-67, 1983-84), 0.072 cu ft/s (0.002 cu m/s), 2.64 in/yr (67.1 mm/yr), 52.16 acre-ft/yr (0.064 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 946 cu ft/s (26.8 cu m/s) Apr. 18, 1983, gage height, 5.33 ft (1.625 m), from floodmark, from rating curve extended above 1.0 cu ft/s (0.028 cu m/s) on basis of step-backwater analysis and slope-area measurement of peak flow; no flow many days each year. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 10 cu ft/s (0.283 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. 4 0845 *136 3.85 2.93 0.893 Nov. 4 2330 14 0.40 2.10 0.640 No flow many days. DISCHARGE• IN CJBIC FEET PER SECOND. WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1 .01 .01 .01 .01 .01 .00 .00 .01 .00 .01 .01 .00 2 .01 .01 .02 .01 .01 .00 .00 .01 .00 .01 .01 .00 3 .01 .01 .01 .01 .00 .00 .00 .01 .00 .01 .01 .01 4 .03 13 .01 .01 .00 .01 .01 .00 .00 .01 .11 .01 5 .02 2.5 .01 .01 .01 .00 .01 .00 .01 .01 .00 .00 6 .02 .29 .01 .01 .01 .01 .01 .00 .12 .01 .00 .00 7 .03 .08 .00 .01 .01 .01 .01 .00 .02 .00 .00 .00 3 .03 .04 .01 .01 .01 .01 .01 .00 .01 .00 .00 .00 9 .01 .03 .01 .01 .01 .01 .01 .00 .01 .01 .00 .00 10 .01 .02 .01 .01 .01 .01 .01 .00 .01 .00 .00 .00 11 .01 .02 .01 .01 .01 .01 .01 .00 .01 .01 .00 .00 12 .03 .03 .01 .01 .01 .01 .01 .01 .01 .01 .01 .01 13 .03 .04 .01 .01 .01 .01 .01 .01 .01 .00 .00 .00 14 .01 .05 .01 .01 .01 .01 .01 .00 .01 .01 .00 .00 15 .02 .05 .01 .01 .01 .00 .01 .00 .01 .01 .00 .00 16 .02 .05 .01 .01 .00 .01 .01 .00 .01 .01 .00 .00 17 .02 .03 .01 .01 .00 .00 .01 .00 .01 .01 .00 .00 18 .02 .01 .01 .01 .00 .00 .01 .00 .01 .00 .01 .00 19 .02 .01 .01 .01 .00 .01 .01 .00 .01 .01 .01 .00 20 .01 .01 .01 .01 .00 .01 .01 .00 .01 .01 .00 .00 21 .02 .01 .01 .01 .00 .01 .01 .00 .01 .01 .01 .00 22 .02 .01 .01 .01 .00 .01 .00 .00 .01 .01 .00 .00 23 .02 .01 .01 .01 .01 .01 .00 .00 .01 .01 .00 .00 24 .01 .01 .01 .00 .00 .01 .00 .00 .01 .01 .00 .00 25 .00 .01 .01 .01 .00 .01 .00 .01 .01 .01 .00 .00 26 .01 .01 .01 .01 .00 .00 .00 .01 .01 .01 .00 .00 27 .01 .01 .01 .01 .00 .00 .01 .00 .01 .01 .00 .00 28 .01 .01 .01 .01 .00 .00 .01 .01 .01 .01 .00 .00 29 .01 .01 .01 .01 .00 .00 .01 .01 .01 .01 .00 .00 30 .01 .01 .01 .01 .00 .01 .01 .00 .01 .00 .00 31 .01 --- .01 .01 .00 --- .01 --- .01 .00 --- TOTAL .50 16.39 .31 .30 .14 .18 .22 .11 .37 .26 .18 .03 MEAN .016 .55 .010 .010 .005 .006 .007 .004 .012 .008 .006 .001 MAX .03 13 .02 .01 .01 .01 .01 .01 .12 .01 .11 .01 MIN .00 .01 .00 .00 .00 .00 .00 .00 .00 .00 .00 .00 CFSM .04 1.49 .03 .03 .01 .02 .02 .01 .03 .02 .02 .003 IN. .05 1.64 .03 .03 .01 .02 .02 .01 .04 .03 .02 .00 AC-FT 1.0 33 .6 .6 .3 .4 .4 .2 .7 .5 .4 .06 CAL YR 1983 TOTAL 142.93 MEAN .39 MAX 110 MIN .00 CFSM 1.05 IN 14.33 AC-FT 284 WTR YR 1984 TOTAL 18.99 MEAN .052 MAX 13 MIN .00 CFSM .14 IN 1.90 AC-FT 38 WATER QUALITY RECORDS PERIOD OF RECORD.--MARCH 1983 TO CURRENT YEAR WATER-QUALITY DATA, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 STREAMFLOW, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DUCTANCE TURE DATE TIME INSTANTANEOUS DUCTANCE TURE (CFS) (UMHOS) (DEG C) (CFS) (UNHOS) (DEG C) OCT, 27 0910 .006 2376 25.5 MAY, 15 1028 .002 2170 27.0 NOV, 30 0954 .007 2346 24.0 JUL, 25 1036 .007 2200 26.0 JAN. 24 0926 .004 2110 26.0 AUG, 25 0927 .002 2200 25.5 APR. 03 0943 .003 2100 23.5 344 ST. CROIX, U.S. VIRGIN ISLANDS 50345000 JOLLY HILL GUT AT JOLLY HILL, ST. CROIX, VI LOCATION.--Lat 17°44'00", long 64°51'47", Hydrologic Unit 21020002, on Mahogany Road at Jolly Hill, 1.8 mi (2.9 km) northeast of Frederiksted. DRAINAGE AREA.--2.10 sq mi (5.44 sq km). WATER-DISCHARGE RECORDS PERIOD OF RECORD.--January 1963 to December 1968. Monthly measurements, 1962, 69. October 1982 to current year. GAGE.--Water-stage recorder and V-notch concrete control. Altitude of gage is 140 ft (42.7 m) from topographic map. REMARKS.--Records poor. AVERAGE DISCHARGE.--7 years (1964-68, 1983-84), 0.027 cu ft/s (0.001 cu m/s), 0.17 in/yr (4.3 mm/yr), 19.6 acre-ft/yr (0.02 cu hm/yr). EXTREMES FOR PERIOD OF RECORD.--Maximum discharge, 223 cu ft/s (6.315 cu m/s) Dec. 12, 1965, gage height, 3.15 ft (0.96 m); no flow many days each year. EXTREMES FOR CURRENT YEAR.--Peak discharges above base of 25 cu ft/s (0.71 cu m/s) and maximum (*): Date Discharge Time (cu ft/s) (cu m/s) Gage height (ft) (m) Nov. 4 0945 *30 0.850 2.05 0.625 No flow many days. DISCHARGE, IN CUBIC FEET PER SECOND' WATER TEAR OCTOBER 1983 TO SEPTEMBER 1984 MEAN VALUES DAY OCT NOV DEC JAN FEB MAR APR MAT JUN JUL AUG SEP 1 .08 .03 .13 .07 .08 .04 .05 .02 .02 .00 .00 .00 2 .08 .03 .13 .07 .07 .03 .04 .02 .00 .00 .00 .00 3 .07 .03 .14 .07 .06 .03 .05 .02 .00 .00 .00 .00 4 .07 .81 .15 .07 .05 .03 .04 .01 .00 .00 .00 .00 5 .08 .20 .14 .07 .05 .04 .03 .01 .00 .00 .00 .00 6 .07 .12 .14 .09 .05 .04 .03 .01 .00 .00 .00 .00 7 .07 .11 .14 .11 .08 .03 .03 .03 .00 .00 .00 .00 8 .07 .12 .13 .09 .10 .04 .03 .03 .00 .00 .00 .00 9 .07 .12 .12 .09 .09 .05 .03 .02 .00 .00 .00 .00 10 .06 .14 .12 .10 .08 .05 .03 .01 .00 .00 .00 .00 11 .06 .14 .13 .09 .06 .04 .03 .01 .00 .00 .00 .00 12 .06 .15 .11 .08 .06 .04 .02 .01 .00 .00 .00 .00 13 .07 .15 .10 .08 .06 .04 .02 .00 .00 .00 .00 .00 14 .06 .15 .10 .08 .06 .07 .01 .00 .00 .00 .00 .00 15 .06 .15 .11 .07 .06 .04 .01 .00 .00 .00 .00 .00 16 .05 .15 .11 .07 .07 .07 .01 .00 .00 .00 .00 .00 17 .05 .15 .11 .07 .06 .04 .01 .00 .00 .00 .00 .00 18 .05 .14 .11 .07 .06 .05 .01 .00 .00 .00 .00 .00 19 .05 .17 .10 .07 .06 .06 .01 .00 .00 .00 .00 .00 20 .04 .16 .11 .07 .06 .05 .01 .00 .00 .00 .00 .00 21 .04 .15 .10 .06 .06 .06 .01 .00 .00 .00 .00 .00 22 .06 .14 .09 .06 .06 .05 .01 .00 .00 .00 .00 .00 23 .05 .14 .09 .06 .05 .05 .00 .00 .00 .00 .00 .00 24 .04 .14 .09 .06 .06 .05 .00 .00 .00 .00 .00 .00 25 .04 .14 .08 .07 .04 .05 .00 .00 .00 .00 .00 .00 26 .03 .15 .10 .05 .04 .05 .00 .00 .00 .00 .00 .00 27 .03 .13 .09 .05 .04 .05 .04 .00 .00 .00 .00 .00 28 .02 .13 .09 .05 .05 .05 .08 .00 .00 .00 .00 .00 29 .03 .13 .08 .05 .04 .05 .04 .00 .00 .00 .00 .00 30 .04 .13 .08 .05 --- .05 .04 .00 .00 .00 .00 .00 31 .04 --- .08 .06 .05 --- .00 --- .00 .00 --- TOTAL 1.69 4.60 3.40 2.20 1.76 1.44 .72 .20 .02 .00 .00 .00 MEAN .055 .15 .11 .071 .061 .046 .024 .006 .001 .000 .000 .000 MAX .08 .81 .15 .11 .10 .07 .08 .03 .02 .00 .00 .00 MIN .02 .03 .08 .05 .04 .03 .00 .00 .00 .00 .00 .00 CFSM .03 .07 .05 .03 .03 .02 .01 .003 .000 .000 .000 .000 IN. .03 .08 .06 .04 .03 .03 .01 .00 .00 .00 .00 .00 AC-FT 3.4 9.1 6.7 4.4 3.5 2.9 1.4 .4 .04 .00 .00 .00 CAL YR 1983 TOTAL 39.62 MEAN .11 MAX .81 MIN .00 CfSM .05 IN .70 AC-FT 79 NTR YR 1984 TOTAL 16.03 MEAN .044 MAX .81 MIN .00 CFSM .02 IN .28 AC-FT 32 345 ST. CROIX, U.S. VIRGIN ISLANDS 50345000 JOLLY HILL GUT AT JOLLY HILL, ST. CROIX, VI--Continued WATER QUALITY RECORDS PERIOD OF RECORD.--MARCM 1983 TO CURRENT YEAR MATER-QUALITY DATA, WATER YEAR OCTOBER 1985 TO SEPTEMBER 19841 STREAmFLOw, SPECIFIC CON- TEMPERA- STREAMFLOW, SPECIFIC CON- TEMPERA- DATE TIME INSTANTANEOUS DuCTANCE TuRE DATE TIME INSTANTANEOUS DUCTANCE TURF (CFS) (UMMOS) (OEG C) (CFS) (UMMOS) (DEG C) OCT, 25 1113 .05 1133 25.5 FEB, 27 1209 .04 1030 24.5 DEC, 06 1324 .14 1036 24.5 APR, 02 1121 .06 1030 25.0 JAN, 26 1435 .06 9890 24.0 MAY, 14 1226 .00 1030 27.5 Ground-Water Records for U.S. Virgin Islands 348 O 1 2 3 MILES O 1 2 3 4 KILOMETERS 0 2 3 MILES 1 0 1 2 3 4 KILOMETERS O 1 2 3 MILES I I H I I O 1 2 3 4 KILOMETERS Figure 27.--Location of ground-water stations in the U.S. Virgin Islands. 349 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174225064471900. Local number, 1. LOCATION.--Lat 17°42'25", long 64°47'19". Owner: Virgin Islands Government. Name: Fairplains 6 (FP6). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). DATUM.--Altitude of land-surface datum is about 20 ft (6.10 m) above mean sea level. Measuring point: Top of pump concrete base, 2.20 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumping. PERIOD OF RECORD.-- Water level: March 1982 to current year. Chemical analyses: June 20, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 15.64 ft (4.77 m) below land-surface datum, Mar. 25, 1982; lowest water level measured, a58.57 ft (17.9 m) below land-surface datum, June 20, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1981 TO SEPTEMBER 1983 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 a55.94 Feb. 27 27.91 May 14 18.10 July 24 a55.94 Dec. 6 a56.50 Apr. 2 26.92 June 25 a55.91 Aug. 22 a56.63 a Pumping. 350 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174225064472000. Local number, 2. LOCATION.--Lat 17°42'25", long 64°47'20". Owner: U.S. Government, Virgin Islands Government. Name: USGS-10, Fairplains 2 (FP2). AQUIFER: Alluvium and marl. WELL CHARACTERISTICS: Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). DATUM: Altitude of land-surface datum is about 20 ft (6.10 m) above mean sea level. Measuring point: Top of 0.5 in (0.01 m) hole at concrete base wall, 3.00 ft (0.91 m) above land-surface datum. REMARKS.--Observation recording well. Nearby pumping well. PERIOD OF RECORD.--June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 21.80 ft (6.65 m) below land-surface datum, Jan. 3, 1984; lowest water level measured, 25.02 ft (7.63 m) below land-surface datum, Aug. 22, 1984. WATER LEVEL, IN FEET 8CLOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTA1EOUS OBSERVATIONS AT 1200 DAY OCT NOV DEC JAN FE9 MAR APR MAY JUN JUL AUG SEP 1 22.67 23.36 22.41 21.35 22.11 22.05 22.27 22.46 23.53 ?3.66 24.50 24.19 2 22.72 23.31 22.49 21.36 22.11 22.12 22.34 22.44 23.13 23.67 24.64 24.36 3 4 22.67 22.73 23.39 23.91 22.53 22.54 21.33 21.34 22.12 22.34 22.38 22.09 22.31 22.35 22.33 22..0 23.12 22.95 23.72 23.75 24.75 24.72 23.97 23.38 5 22.77 22.76 22.34 21.34 22.07 22.12 22.40 22.49 22.74 23.71 24.81 23.30 6 22.73 22.96 22.31 21.37 22.06 22.13 22.44 22.44 22.72 23.72 24.82 23.68 7 22.65 22.81 22.31 21.38 22.12 22.20 22.43 22.44 22.72 23.69 24.75 23.61 8 22.66 22.73 22.55 21.39 22.09 23.24 22.47 22.49 22.65 23.58 24.80 23.55 9 22.76 22.71 22.14 21.39 22.07 22.26 22.59 22.49 22.61 23.66 24.61 23.46 10 22.71 22.67 22.0o 21.39 22.35 22.20 22.45 22.55 22.61 23.32 24.75 23.40 11 22.79 22.77 21.97 21.39 22.05 22.29 22.44 22.54 22.63 23.51 24.85 23.32 12 23.03 22.63 21.94 21.90 22.19 22.34 22.45 22.55 22.62 23.75 24.87 23.26 13 23.14 22.55 21.95 21.99 22.13 22.36 22.47 22.58 22.63 23.96 24.91 23.22 14 23.22 22.57 21.91 22.04 22.13 22.36 22.52 22.56 22.60 24.06 24.72 23.21 15 23.03 22.72 21.94 22.03 22.15 22.37 22.53 22.58 22.62 24.15 24.75 23.18 16 23.05 22.72 21.93 22.37 22.15 22.32 22.45 22.39 22.64 24.06 24.73 23.15 17 23.03 22.61 21.94 22.02 22.05 22.32 22.44 23.12 22.63 24.09 24.74 23.12 18 23.07 22.55 21.94 21.98 22.07 22.30 22.51 22.99 22.64 24.28 24.73 23.12 19 23.20 22.29 21.89 22.01 22.05 22.28 22.56 23.23 22.58 24.37 24.73 23.08 20 23.11 22.19 21.91 22.02 22.07 22.25 22.56 23.24 23.05 24.43 24.77 23.02 21 23.19 22.16 21.89 22.01 22.09 22.24 22.51 23.36 23.24 24.48 24.91 22.96 22 23.25 22.11 21.93 22.00 22.04 22.24 22.47 23.35 23.30 24.52 25.00 22.88 23 23.25 22.35 21.94 22.32 21.45 22.21 22.47 23.44 23.42 24.56 24.98 22.89 24 23.27 22.01 21.94 22.03 21.93 22.28 22.47 23.48 23.52 24.55 24.77 22.38 25 23.25 21.99 21.90 22.33 22.01 22.32 22.49 23.48 23.61 24.64 24.76 22.86 26 23.26 22.00 21.90 22.36 22.04 22.26 22.46 23.49 23.65 24.68 24.59 22.32 27 23.22 21.89 21.83 22.03 22.06 22.31 22.43 23.50 23.69 24.71 24.54 22.79 28 23.22 21.85 21.90 22.07 22.04 22.26 22.48 23.53 23.69 24.73 24.79 22.41 29 23.25 22.31 21.87 22.08 22.07 22.29 22.4o 23.48 23.75 24.52 24.86 22.31 30 23.15 22.32 21.86 22.09 --- 22.28 22.47 23.55 23.68 24.32 24.90 22.76 31 23.32 --- 21.87 22.10 22.35 --- 23.58 --- 24.32 24.40 --- LOW 23.32 23.39 22.55 22.10 22.19 22.37 22.56 23.58 23.75 24.73 25.00 24.19 HIGH 22.65 21.85 21.86 21.83 21.93 22.05 22.31 22.38 22.53 23.51 24.40 22.76 WTR YR 1984 MEAN 22.88 LOW 25.00 HIGH 21.33 21 Li 0 D M 22 CD I-4( Lai CZ 1.41 L.-Z4 23 -J D > LI I -J Z < 24 25 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 351 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174243064475100. Local number, 3. LOCATION.--Lat 17°42'43", Long 64°47'51". Owner: U.S. Government, Virgin Islands Government. Name: Golden Grove-6 (PW6). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 8 in (0.20 m), cased 8 in (0.20 m). DATUM.--Altitude of land-surface datum is about 40 ft (12.2 m) above mean sea level. Measuring point: Upper edge of hole at 8 in (0.20 m) casing, 4.20 ft (1.28 m) above land-surface datum. REMARKS.--Observation well. Automatic Digital Recorder (ADR) installed on June 22, 1983. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 14.76 ft (4.50 m) below land-surface datum, March 25, 1982; lowest water level measured, 27.91 ft (8.51 m) below land-surface datum, Sept. 30, 1984. WATER LEVEL, /N FEET IELOU LAND-SURFACE OATUM, MATER YEAR OCTOBER 1983 TO SEPTEMEER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 DAY OCT NOV JEC JAN FE8 "SAP APR MAY JUN JUL AUG SEP 1 24.99 25.54 23.71 24.96 25.63 25.92 16.17 26.47 26.73 27.35 27.4J 77.67 2 25.02 25.55 23.75 24.09 25.63 25.93 26.20 26.48 25.71 27.37 27.41 27.68 3 25.04 25.57 23.79 25.02 25.69 25.94 26.23 26.49 26.69 27.10 27.41 27.69 4 25.06 25.58 23.84 22.35 e5.73 25.95 26.29 26.49 26.69 27.11 27.43 27.70 5 25.03 25.24 23.87 25.38 25.72 25.96 26.21 26.50 26.70 27.13 27.43 27.71 6 25.10 24.11 23.95 25.11 25.73 25.97 26.21 26.51 26.71 27.14 27.43 27.72 7 25.13 23.40 23.99 25.14 25.73 25.95 26.22 26.52 26.73 27.15 27.44 27.72 9 25.15 23.07 24.04 25.18 25.74 25.99 26.22 26.53 26.74 27.16 27.45 27.73 9 25.17 22.56 24.08 25.20 15.75 25.00 26.23 25.54 26.75 27.17 27.45 27.73 10 25.19 22.76 24.12 25.23 25.76 26.01 26.23 26.54 26.75 27.18 27.46 27.74 11 25.21 22.71 24.16 25.25 25.77 26.92 76.24 26.55 26.77 27.19 27.47 27.75 12 25.24 22.70 24.20 25.28 25.77 26.04 26.25 26.56 26.79 27.20 27.43 27.75 13 25.26 22.71 24.24 25.31 25.75 26.05 26.26 26.56 26.79 27.21 27.49 27.76 14 25.23 22.75 24.29 25.34 25.30 25.06 26.27 26.57 26.80 27.22 27.50 27.77 15 25.30 22.80 24.34 25.36 25.81 26.07 26.23 26.57 26.82 27.23 27.50 27.78 16 25.32 22.34 24.30 25.38 25.81 26.0P 20.21 26.57 26.83 27.24 27.51 27.79 17 25.34 22.89 24.43 25.41 25.82 2o.09 26.30 26.58 26.84 27.27 27.52 27.80 18 25.36 22.94 24.47 25.44 25.83 26.10 26.31 26.58 26.86 27.27 27.53 27.31 19 25.37 23.00 24.50 25.46 25.84 26.11 26.32 26.59 26.87 27.29 27.54 27.32 20 25.39 23.06 24.55 25.48 25.85 25.12 26.33 26.60 26.55 27.30 27.54 27.32 21 25.43 23.12 24.59 25.51 25.85 26.13 26.34 25.61 26.89 27.31 27.55 27.33 22 25.41 23.17 24.63 25.53 25.86 26.14 26.36 26.61 26.91 27.32 27.56 27.83 23 25.43 23.23 24.66 25.55 25.87 26.14 26.37 26.52 26.92 27.33 27.57 27.34 24 25.44 23.29 24.70 25.57 25.38 26.15 26.33 26.63 26.94 27.33 27.53 27.85 25 25.45 23.37 24.74 25.59 25.87 25.15 26.3? 26.65 26.95 27.34 27.60 27.86 26 25.46 23.43 24.77 25.60 25.39 25.15 26.41 26.66 26.96 27.35 27.60 27.87 27 25.45 23.48 24.81 25.62 25.90 26.16 26.42 26.67 26.98 27.35 27.61 27.87 28 25.49 23.54 24.84 25.63 25.91 26.16 26.43 26.68 27.00 27.36 27.63 27.88 29 25.50 23.60 24.97 25.64 25.91 23.16 26.44 26.69 27.02 27.37 27.64 27.89 30 25.51 23.66 24.91 25.65 --- 23.17 26.45 26.70 27.03 27.38 27.65 27.90 31 25.52 --- 24.94 25.66 23.17 --- 26.71 --- 27.39 27.66 --- LOW 25.52 25.58 24.94 25.56 25.91 26.17 26.45 26.71 27.03 27.39 27.66 27.90 HIGH 24.99 22.70 23.71 24.96 25.68 25.92 26.17 26.47 26.69 27.05 27.40 27.67 WTR YR 1984 MEAN 26.06 LOW 27.90 HIGH 22.70 22 0 -J CO < 24 LI 0 Li Li 0 Zrit .CC -J D > Li --I 0 26 LJ z< 28 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 352 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174245064475800. Local number, 4. LOCATION.--Lat 17°42'45", long 64°47'58". Owner: Virgin Islands Government. Name: Golden Grove - 1 (PW1). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m) 0-104 ft (0-31.70 m), perforated 64-104 ft (19.51-31.70 m). Depth 104 ft (31.70). DATUM.--Altitude of land-surface datum is about 40 ft (12.2 m) above mean sea level. Measuring point: lower edge of 1 in. (0.02 m) pipe at pump base, 3.40 ft (1.04 m) above land-surface datum. RENARKS.--Observation well. Lowest water level affected by pumping. PERIOD OF RECORD.-- Water level: January 1983 to current year. Chemical analyses: June 20, 1983 to current year. EXTREMES FOR PERIOD OF RECORD: Highest water level measured, 23.09 ft (7.04 m) below land-surface datum, May 18, 1983; lowest water level measured, a58.30 ft (17.77 m) below land-surface datum, September 27, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 a49.36 Feb. 27 26.64 May 14 28.46 July 24 a36.40 Dec. 6 26.38 Apr. 2 28.12 June 25 a58.30 Aug. 22 a32.47 Jan. 26 27.99 174336064523200. Local number, 5. LOCATION.--Lat 17°43'36", long 64°52'32". Owner: Virgin Islands Government. Name: Mahogany Road 3. AQIFER.--Alluvium of Quaternary age and volcanic rocks of Cretaceous age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m) 0-104 ft (0-31.70 0, perforated 64-104 ft (19.51-31.70 m). Depth 104 ft (31.70 m). DATUM.--Altitude of land-surface datum is 70 ft (21.3 m) above mean sea level. Measuring point: lower edge of 2 in. (0.05 m) pipe at pump base, 3.70 ft (1.13 m) above land-surface datum. Prior to December 1969, top of instrument platform, 2.57 ft (0.78 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by nearby pumpage. PERIOD OF RECORD.--May 1964 to December 1969, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 26.24 ft (8.00 m) below land-surface datum, Dec. 16, 1969; lowest water level measured, 74.31 ft (22.6 m) below land-surface datum, Mar. 29, 1965. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 59.75 Jan. 26 65.69 Apr. 2 68.53 Aug. 22 69.45 Dec. 6 62.10 Feb. 27 63.32 a Pumping. 353 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174308064484400. Local number, 6. LOCATION.--Lat 17°43'03", long 64°48'44". Owner: U.S. Government, Virgin Islands Government. Name: Adventure 28. AQUIFER.--Alluvium of Pleistocene age and marl of Oligocene age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 4 in (0.10 m), cased 4 in (0.10 m). DATUM.--Altitude of land-surface datum is about 80 ft (24.39 m) above mean sea level. Measuring point: Upper edge of hole at 4 in (0.10 m) casing, 2.00 ft (0.61 m) above land-surface datum. Prior June 20, 1983, top of 4 in (0.10 m) casing, 0.90 ft (0.27 m) above land-surface datum. REMARKS.--Observation well. Automatic Digital Recorder (ADR) installed on June 20, 1983. PERIOD OF RECORD.--August 1973 to March 1974, discontinued. March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 24.90 ft (7.59 m) below land-surface datum, Mar. 25, 1982; lowest water level measured, 40.18 ft (12.25 m) below land-surface datum, Aug. 5, 1984. WATER LEVEL, IN FEET SELOW LAND-SURFACE DATUM, WATER YEAR OCTO8ER 1983 T3 SEPTEm8ER 1984 INSTANTANEOUS OESERVATTONS AT 1200 DAY OCT NOV DEC JAN Ff5 MAR APR mAY JUN JUL AUG SEP 1 34.41 34.22 35.87 16.73 37.76 37.95 35.37 35.37 73.88 37.25 35.31 43.16 2 34.40 34.22 15.89 36.31 37.77 35.95 35.34 35.38 36.13 37.35 37.43 40.16 3 4 34.40 34.40 32.48 27.46 35.90 35.93 35.38 35.96 37.73 37.33 33.80 35.58 35.33 35.32 3 5.38 35.38 36.14 35.33 3 7.41 3".47 33.65 38.73 40.16 40.17 5 34.40 27.38 35.96 35.00 37.85 35.53 35.3J 35.40 16.34 35.98 38.91 40.17 6 7 34.43 34.40 31.39 33.56 35.96 35.00 37.36 35.43 37.03 37.90 35.48 35.43 35.30 35.33 35.42 35.43 6.06 36.05 37.55 37.59 39.02 39.14 33.99 43.15 8 9 34.41 34.42 33.40 33.65 36.09 36.22 37.19 34.76 37.72 37.73 15.34 35.27 35.29 35.23 35.45 35.47 36.06 36.05 37.63 36.60 30.23 30.32 40.17 40.17 10 34.45 3 1.76 36.31 3'.22 37.69 35.19 35.23 35.50 36.05 37.67 39.41 40.03 11 34.45 33.33 36.42 37.32 37.75 35.13 35.23 35.52 32.63 37.71 39.49 39.93 12 13 34.43 34.48 34.51 34.09 36.4? 36.49 37.37 37.42 37.79 33.87 3). 06 35.30 35.23 35.23 35.55 35.56 35.9 36.17 37.75 37.73 39.56 39.62 38.93 33.93 14 15 34.49 34.50 34.94 35.14 36.48 36.41 37.45 37.48 37.91 37.95 35.95 35.91 35.2!! 35.23 35.58 35.53 36.25 36.23 37.31 37.33 39.70 39.76 33.93 33.93 16 34.54 35.33 36.34 37.50 37.97 35.36 35.23 15.59 36.23 37.56 39.82 38.93 17 18 19 34.50 34.43 34.46 35.47 35.61 35.70 36.24 36.17 36.16 37.52 37.55 17.57 37.97 37.92 37.50 35.82 35.76 35.70 35.23 35.29 35.29 35.60 35.62 35.64 36.23 34.84 36.20 37.83 37.91 36.94 39.37 39.93 39.93 38.93 36.65 39.64 20 33.55 35.74 36.15 3 7.59 37.85 35.68 35.29 35.65 36.22 37.97 40.03 39.70 21 34.31 35.77 36.15 37.60 17.95 35.65 35.31 35.70 36.23 37.99 40.07 39.56 22 34.36 35.77 36.17 77.61 38.0E 35.62 35.31 35.71 36.30 38.07 40.13 39.50 23 34.33 35.78 36.22 37.52 38.05 35.50 35.31 35.71 36.44 33.05 40.14 39.50 24 34.28 35.78 36.26 37.64 314 .08 35.57 35.33 35.77 36.57 33.09 40.14 39.50 25 34.29 15.78 36.31 37.66 38.08 35.53 35.33 35.93 36.69 38.11 40.14 39.53 26 34.27 35.81 36.36 37.57 37.76 35.47 35.35 36.10 36.78 33.14 40.14 39.56 27 34.27 35.81 36.40 17.54 37.64 35.46 35.35 36.18 36.80 33.15 40.15 39.58 2P 29 30 34.27 34.26 34.25 35.13 35.34 35.87 36.45 36.50 36.57 37.66 3 7.68 37.71 37.43 37.26 --- 35.43 35.42 35.41 35.35 35.35 35.36 36.21 36.21 36.21 36.84 37.03 37.17 38.17 38.19 33.21 40.15 40.15 40.16 39.60 39.63 39.65 31 34.22 --- 36.64 37.73 35.39 --- 35.21 --- 38.23 40.16 --- LOW HIGH 34.54 33.55 35.87 27.38 36.64 35.03 37.73 34.76 38.08 33.37 37.05 35.39 35.37 35.23 36.21 35.37 37.17 32.63 33.23 35.98 40.16 37.43 40.17 36.65 WTR YR 1934 MEAN 36.64 LOW 40.17 HIGH 27.38 26 3 0 0 30 mF 1- 4 L. 0 34 L > tr) Lai .1 0 Z < Q -J 38 42 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 354 GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174525064460600. Local number, 7. LOCATION.--Lat 17°45'25", long 64°46'06". Owner: Virgin Islands Government. Name: Concordia 14. AQUIFER.--Sand and gravel. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 85 ft (25.91 m). DATUM.--Altitude of land-surface datum is about 40 ft (12.2 m) above mean sea level. Measuring point: Top of 0.50 in (0.01 m) pipe on top of pump concrete base, 2.30 ft (0.70 m) above land-surface datum. REMARKS.--Observation well. Water level affected by pumpage. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 18.73 ft (5.71 m) below land-surface datum, June 25, 1984; lowest water level measured, 41.75 ft (12.73 m) below land-surface datum, Feb. 24, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 a39.16 Feb. 27 24.79 May 14 25.90 July 24 a35.20 Dec. 6 a32.68 Apr. 2 23.25 June 25 18.73 Aug. 22 a38.96 Jan. 27 23.87 174527064460100. Local number, 8. LOCATION.--Lat 17°45'27", long 64°46'01". Owner: Virgin Islands Government. Name: Concordia 1 (Main pump house). AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased. Depth 82 ft (25.0 m). DATUM.--Altitude of land-surface datum is about 40 ft (12.2 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.20 ft (0.67 m) above land-surface datum. REMARKS.--Observation well. Water levels affected by pumpage. PERIOD OF RECORD: Water level: March 1982 to current year. Chemical analyses: June 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 19.97 ft (6.09 m) below land-surface datum, Mar. 25, 1982; lowest water level measured, a28.39 ft (8.66 m) below land-surface datum, Dec. 8, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1981 TO SEPTEMBER 1983 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 27.82 Feb. 27 24.29 May 14 25.34 July 24 a24.70 Dec. 6 21.71 Apr. 2 24.64 June 25 a26.89 Aug. 22 26.52 Jan. 27 23.43 a Pumping. GROUND-WATER LEVELS ST. CROIX, U.S. VIRGIN ISLANDS 174532064460300. Local number, 9. LOCATION.--Lat 17°45'32", long 64°46'03". Owner: Virgin Islands Government. Name: Concordia 7. AQUIFER.--Limestone of Tertiary Age. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 0-81 ft (0-24.7 m). Depth 81 ft (24.7 m). DATUM.--Altitude of land-surface datum is 35 ft (10.7 m) above mean sea level. Measuring point: Hole in pump base, 2.20 ft (0.67 m) above land-surface datum. Previous to Mar. 25, 1982, hole in pump base 2.50 ft (0.76 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD: Water levels: June 1962 to October 1968, discontinued. March 1982 to current year. Chemical analysis: October 1964 to October 1967, discontinued. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 1.75 ft (0.53 m) below land-surface datum, May 11, 1966; lowest water level measured, 57.40 ft (17.5 m) below land-surface datum, Mar. 5, 1964. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1981 TO SEPTEMBER 1983 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 a43.37 Feb. 27 10.26 May 14 11.35 July 24 a21.82 Dec. 6 a27.79 Apr. 2 10.96 June 25 a28.34 Aug. 22 a20.48 Jan. 27 174329064454700. Local number, 10. LOCATION.--Lat 17°43'29", long 64°45'47". Owner: Virgin Islands Government. Name: Barren Spot 5 (PWD-5). AQUIFER.--Alluvium and marl. WELL CHARACTERISTICS.--Drilled production water-table well, diameter 6 in (0.15 m), cased 0-130 ft (0-39.63 m), perforated 71-130 ft (21.64-39.63 m). Depth 130 ft (39.63 m). DATUM.--Altitude of land-surface datum is about 75 ft (22.86 m) above mean sea level. Measuring point: Hole on top of pump base, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD: Water level: March 1982 to current year. Chemical analyses: June 22, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 61.86 ft (18.86 m) below land-surface datum, Mar. 26, 1982; lowest water level measured, a75.52 ft (23.02 m) below land-surface datum, Sept. 8, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1981 TO SEPTEMBER 1983 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 25 a70.50 Feb. 27 64.19 May 14 64.55 July 24 69.73 Dec. 6 64.29 Apr. 2 65.64 June 25 a68.93 Aug. 22 a73.77 Jan. 27 64.35 a Pumping. 355 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182050064580400. Local number, 1. LOCATION.--Lat 18°20'50", long 64°58'04". Owner: U.S. Government, Virgin Islands Government. Name: USGS-8 (Family well - Thatch Farm). AQUIFER.--Volcanic rocks of Cretaceous age. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 6 in (0.15 m) 0-25 ft (0-7.62 m), openhole 25-80 ft (7.62-24.4 m). Depth 80 ft (24.4 m). DATUM.--Altitude of land-surface datum is 80 ft (24.4 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.50 ft (0.76 m) above land-surface datum. Prior to Mar. 23, 1982, top of 6 in (0.15 m) casing, 1.30 ft (0.40 m) above land-surface datum. REMARKS.--Non-potable public-water supply and observation well. PERIOD OF RECORD: Water levels: October 1963 to August 1969, discontinued. March 1982 to current year. Chemical analyses: December 1963, discontinued. June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 5.29 ft (1.61 m) below land-surface datum, May 6, 1983; lowest water level measured, 56.44 ft (17.21 m) below land-surface datum, Aug. 24, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 26 26.34 Feb. 28 a32.73 May 23 a45.92 July 26 56.29 Nov. 30 26.07 Apr. 4 a43.45 June 29 a44.24 Aug. 24 56.44 Jan. 23 30.11 182138064543100. Local number, 2. LOCATION.--Lat 18°21'38", long 64°54'31". Owner: Mahogany Run Resort. Name: Mahogany #15. AQUIFER.--Fractured rocks. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Altitude of land-surface datum is 120 ft (36.6 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.20 ft (0.36 m) below land-surface datum. REMARKS.--Potable water supply. Observation well. Water level affected by nearby pumping well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 18.58 ft (5.66 m) below land-surface datum, July 20, 1983; lowest water level measured, 73.75 ft (22.48 m) below land-surface datum, July 26, 1984. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEARS OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Date Oct. 26 Nov. 30 Jan. 25 Water level 30.51 27.70 34.82 Date Feb. 28 Apr. 4 Water level 42.46 51.29 Date May 23 June 29 Water level 64.74 66.50 Date July 26 Aug. 24 Water level 73.65 69.68 182138064542500. Local number, 3. LOCATION.--Lat 18°21'38", long 64°54'25". Owner: Mahogany Run Resort. Name: Mahogany 16. AQUIFER.--Fractured rocks. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Altitude of land-surface datum is 130 ft (39.6 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.30 ft (0.40 m) below land-surface datum. REMARKS.--Water level affected by nearby pumping well. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 24.96 ft (7.61 m) below land-surface datum, Aug. 25, 1983; lowest water level measured, a68.20 ft (20.79 m) below land-surface datum, July 21, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 26 35.92 Feb. 28 45.30 May 23 53.03 July 26 55.75 Nov. 30 33.00 Apr. 4 48.67 June 29 50.05 Aug. 24 56.05 Jan. 25 38.73 a Pumping. 356 357 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN ISLANDS 182136064541900. Local number, 4. LOCATION.--lat 18°21'36", long 64°54'19". Owner: Mahogany Run Resort Name: Mahogany 17. AQUIFER.--Fractured rock. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 145 ft (44.21 m). DATUM.--Altitude of land-surface datum is 140 ft (42.7 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing at land-surface datum. REMARKS.--Potable water supply. Water level affected by nearby pumping. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 25.60 ft (7.80 m) below land-surface datum, July 20, 1983; lowest water level measured, a60.40 ft (18.41 m) below land-surface datum, Sept. 10, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 26 36.70 Feb. 28 40.92 May 23 44.12 July 26 44.03 Nov. 30 33.80 Apr. 4 42.07 June 29 43.48 Aug. 24 44.00 Jan. 25 38.22 182029064535200. Local number, 5. LOCATION.--Lat 18°20'29", long 64°53'52". Owner: Virgin Islands Government, V.I. Housing Authority. Name: Donoe 3. AQUIFER.--Volcanic rock undifferentiated. Fracture at 165 ft (50.3 m), from drilling log. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 0-20 ft (0-6.10 m), openhole 20-400 ft (6.10-122 m). Dept 400 ft (122 m). DATUM.--Altitude of land-surface datum is about 235 ft (71.6 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.30 ft (0.70 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD: Water levels: March 1982 to current year. Chemical analyses: July 1, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 71.44 ft (21.78 m) below land-surface datum, July 1, 1983; lowest water level measured, 88.37 ft (26.94 m) below land-surface datum, July 21, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 26 83.38 Feb. 28 78.04 May 23 85.63 July 26 86.63 Nov. 29 72.90 Apr. 4 81.58 June 29 85.04 Aug. 24 86.68 Jan. 25 78.10 a Pumping. 358 GROUND-WATER LEVELS ST. THOMAS, U.S. VIRGIN OSLANDS 182038064550300. Local number, 6. LOCATION.--Lat 18°20'38", long 64°55'03". Owner: U.S. Government, Virgin Islands Government. Name: Grade School 3. AQUIFER.--Volcanic breccia. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 70 ft (21.33 m). DATUM.--Altitude of land-surface datum is 60 ft (18.3 m) above mean sea level. Measuring point: Top of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.30 ft (0.40 m) above land-surface datum. Prior to June 27, 1983, top of 6 in (0.15 m) casing, 2.90 ft (0.88 m) above land-surface datum. REMARKS.--Observation well. Automatic Digital Recorder (ADR) was installed on June 27, 1983. PERIOD OF RECORD.--March 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 10.56 ft (3.22 m) below land-surface datum, July 9, 1983; lowest water level measured, 35.38 ft (10.79 m) below land-surface datum, July 21, 1982. WATER LEVEL, IN CET LAND-SURFACE DATUM, WATER YEAR OCTOBER 1933 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 DAY OCT NOV DEC JAN 1.E9 MAR APR MAY JUN JUL AUG SEP 1 22.03 23.97 22.05 27.55 24.51 25.31 25.08 25.65 26.49 24.25 23.45 25.22 2 22.13 24.03 22.10 27.59 24.56 25.30 25.24 25.88 25.37 24.44 23.17 24.56 3 22.23 24.38 20.97 23.79 24.79 25.28 25.53 26.00 26.13 24.60 22.71 24.23 4 22.42 24.00 10.5? 23.70 24.87 25.24 25.64 25.99 25.96 24.63 22.67 24.57 5 22.54 21.17 19.09 24.00 24.91 25.18 25.63 25.72 25.75 24.62 22.20 25.01 6 22.64 15.82 19.43 24.02 24.91 25.12 25.74 25.93 24.97 24.58 21.74 25.24 7 22.73 17.53 1 0.85 24.37 24.92 25.07 25.79 25.33 23.09 24.51 21.59 25.16 8 22.82 16.71 20.24 24.15 24.94 25.04 25.87 25.74 21.56 24.45 21.80 25.05 9 22.91 16.09 20.55 24.25 24.95 24.97 25.90 25.77 20.38 24.54 22.12 25.00 10 23.01 17.15 20.33 24.35 24.65 24.35 25.84 25.34 20.65 24.37 22.47 24.97 11 23.12 17.33 21.15 24.41 24.79 24.70 25.87 25.90 20.67 25.25 22.71 24.72 12 23.23 17.23 21.45 24.43 24.30 24.56 25.81 25.98 21.13 25.52 22.95 24.27 13 27.10 17.56 21.72 24.46 24.81 24.34 25.70 25.96 21.56 25.58 23.19 23.78 14 23.35 17.77 21.93 24.44 24.78 24.04 25.55 26.06 21.78 25.51 23.34 23.48 15 23.41 13.44 22.12 24.34 24.77 23.76 25.42 26.18 21.92 25.43 23.48 23.25 16 23.42 13.34 22.29 24.26 24.72 23.53 25.26 26.15 22.10 25.37 23.59 23.12 17 23.42 19.20 22.41 24.20 24.54 23.32 25.11 26.06 22.23 25.34 23.63 23.16 18 23.44 19.53 22.53 24.13 24.67 23.12 25.19 25.07 22.21 25.32 23.80 22.58 19 23.43 19.84 22.70 24.09 24.92 22.97 25.31 25.89 22.04 25.30 23.93 21.49 20 23.53 23.13 22./0 24.07 24.87 22.70 25.35 25.37 21.89 25.26 24.05 20.81 21 23.57 20.46 23.04 24.05 24.90 22.40 25.51 25.86 21.92 25.13 24.23 20.50 22 23.59 20.76 23.09 23.99 24.93 22.38 25.77 25.85 22.06 25.11 24.36 20.47 23 23.65 20.9F 23.15 23.02 24.99 22.44 25.97 25.54 22.34 25.04 24.25 20.72 24 23.72 21.17 23.22 23.03 25.01 22.70 26.05 25.30 22.76 25.00 24.07 21.00 25 23.73 21.34 23.33 23.99 25.04 23.29 26.09 25.79 23.28 24.99 24.01 21.30 26 23.84 21.47 23.49 24.07 25.09 23.38 26.12 25.78 23.65 25.04 24.04 21.61 27 23.92 21.52 23.60 24.15 25.15 24.41 26.03 25.96 23.83 24.99 24.08 21.89 28 23.97 21.73 23.59 24.24 25.22 24.75 25.52 26.27 23.94 24.89 24.19 22.25 29 24.01 21.81 23.60 24.32 25.29 24.86 25.12 26.53 24.07 24.49 24.53 22.63 30 24.02 21.90 23.64 24.45 --- 24.90 25.39 26.63 24.18 23.88 25.14 22.71 31 23.97 --- 23.65 24.55 24.96 --- 26.61 --- 23.58 25.37 --- LOW 24.02 24.08 23.65 24.55 25.29 25.31 26.12 26.53 26.49 25.58 25.37 25.24 HIGH 22.08 16.91 19.09 23.55 24.61 22.38 25.08 25.68 20.65 23.58 21.59 20.47 WTR YR 1984 MEAN 23.73 LOW 26.63 HIGH 15.91 10 3 Lan 1-WO4 16 U Z .ce > La I JO 22 28 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 359 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182010064472600. Local number, 1. LOCATION.--Lat 18°20'10", long 64°47'26". Owner: U.S. Government, National Park Services. Name: NPS-2 (Cruz Bay). AQUIFER: Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), 4 in (0.10 m), cased, 0-20 ft (0-6.10 m), open hole 20-99 ft (6.10-30.2 m). Depth 99 ft (30.2 m). DATUM: Altitude of land-surface datum is 60 ft (18.3 m) above mean sea level. Measuring point: Top of 4 in (0.10 m) casing, 4.10 ft (1.25 m) above old land-surface datum after 1.4 ft (0.43 m) land fill and 2.7 ft (0.82 m) casing extension occurred. Prior to June 29, 1983, top of 4 in (0.10 m) casing, 1.4 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. Lowest water level affected by pumping nearby well. PERIOD OF RECORD: Water levels: May 1964, discontinued. June 30, 1983 to current year. Chemical analyses: May 1964, discontinued. June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 5.39 ft (1.64 m) below land-surface datum, Aug. 24, 1983; lowest water level measured, 42.56 ft (12.98 m) below land-surface datum, Aug. 30, 1967. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 30.69 Feb. 29 27.07 May 15 33.50 July 25 33.24 Nov. 30 25.99 Apr. 3 27.42 June 27 27.74 Aug. 25 17.53 Jan. 24 23.74 182109064460300. Local number, 2. LOCATION.--Lat 18°21'09", long 64°46'03". Owner: U.S. Government, National Park Service. Name: NPS-5 (Trunk Bay). AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6 in (0.15 m), cased 0-12 ft (0-3.66 m), open hole 12-60 ft (3.66-18.3 m). Depth 60 ft (18.3 m). DATUM.--Altitude of land-surface datum is 60 ft (18.3 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 0.70 ft (0.21 m) above land-surface datum. Prior to Mar. 24, 1982 top of 6 in (0.15 m) casing, 1.00 ft (0.30 m) above land-surface datum. REMARKS.--Active water supply well for recreation facilities at Trunk Bay. PERIOD OF RECORD: Water levels: August 1964 to December 1969, discontinued. March 1982 to current year. Chemical analyses: July 1964 to June 1969, discontinued. June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 16.76 ft (5.11 m) below land-surface datum, June 3, 1969; lowest water level measured, a57.29 ft (17.47 m) below land-surface datum, Nov. 27, 1968. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 28.34 Feb. 29 30.96 May 15 a46.48 July 25 a48.34 Nov. 30 26.76 Apr. 3 37.84 June 27 a42.76 Aug. 25 35.75 Jan. 24 35.27 a Pumping. 360 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182116064451000. Local number, 3. LOCATION.--Lat 18°21'16", long 64°45'10". Owner: U.S. Government, National Park Service. Name: NPS-6 (Cinnamon Bay). AQUIFER.--Volcanic rocks of Cretaceous Age. WELL CHARACTERISTICS.--Drilled water-table production well, diameter 6-in (0.15 m), cased 0-51 ft (0-15.55 m), open hole 51-70 ft (15.55-21.34 m). Depth 70 ft (21.34 m). DATUM.--Altitude of land-surface datum is 60 ft (18.3 m) above mean sea level. Measuring point: Hole on 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. Prior to June 29, 1983, top of 6 in (0.15 m) casing at land-surface datum. REMARKS.--Abandoned as production well. Automatic Digital Recorder (ADR) installed on June 29, 1983. PERIOD OF RECORD: Water levels: August 1964 to December 1969, discontinued. March 1982 to current year. Chemical analyses: August 1964 to June 1969, discontinued. June 29, 1983. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 41.12 ft (12.54 m) below land-surface datum, Aug. 15, 1969; lowest water level measured, 63.15 ft (19.25 m) below land-surface datum, July 1, 1968. WATER LEVEL, IN EF ,ET LANO-SUREACE '?ATOM, MATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 DAY OCT NOV DEC JAN 5E2 MAR APR MAY JUN JUL AUG SEP 1 56.45 56.55 55.49 55.09 56.43 55. 75 56.84 56.80 57.14 57.61 57.92 57.88 2 56.45 55.54 55.54 55.02 56.44 55. 76 56.73 505.79 57. .7113 57.64 57.91 57.39 3 56.45 56.53 55.57 56.05 56.45 53. 73 56.71 57.08 57.90 57.91 4 56.44 56.43 55.62 56.35 56.46 56.67 56.67 56.81 57.09 57.57 57.89 57.91 5 56.41 55.04 55.6' 55.04 56.45 55.44 56.65 56.34 57.05 57.67 57.81 57.93 6 56.43 55.55 55.70 55.10 56.47 53.53 56.65 55.33 57.0J 57.65 57.73 57.93 7 56.40 54.73 55.74 55.33 36.53 56.63 56.67 55.95 56.76 57.63 57.66 57.93 8 56.43 5...25 55.75 55.05 56.52 55.65 56.72 56.99 56.95 57.64 57.60 57.93 9 56.41 53.94 55.79 55.99 56.53 56.59 56.77 57.02 58.95 57.69 57.56 57.15 10 56.44 53.79 55.81 55.1: 56.45 55.74 56.83 57.06 56.95 57.71 57.54 57.94 11 56.47 53.74 55.51 55.15 56.46 55.'6 56.31 57.33 56.96 57.74 57.54 57.39 12 56.41 53.76 55.82 55.18 56.44 55.78 56.81 57.10 57.00 57.74 57.54 57.79 13 56.53 53.34 55.84 55.21 56.43 55.76 56.31 57.11 57.04 57.75 57.56 57.72 14 56.55 53.97 55.87 55.24 56.43 55.74 56.79 57.13 57.03 57.77 57.59 57.68 15 56.55 54.09 55.E9 56.26 56.43 55. 73 56.77 57.15 57.13 57.78 57.62 57.65 16 56.55 54.22 55.91 55.27 56.44 51.73 56.77 57.18 57.15 57.78 57.64 57.64 17 56.56 54.33 55.94 55.26 56.45 55.71 56.77 57.20 57.19 57.81 57.65 57.63 18 56.55 54.45 55.96 55.25 56.47 55.66 56.79 57.22 57.24 57.53 57.63 57.61 19 56.55 54.58 55.99 55.24 56.49 55.62 56.83 57.24 57.26 57.36 57.71 57.60 20 56.55 54.69 56.02 55.25 56.5) 53.58 56.85 57.25 57.29 57.36 57.75 57.60 21 56.57 54.80 56.05 55.26 56.53 55.57 56.89 57.21 57.32 57.89 57.82 57.58 22 56.53 54.92 56.03 55.27 56.56 55.57 56.92 57.17 57.33 57.38 57.87 57.57 23 56.60 55.31 56.00 55.29 56.59 55.51 56.95 57.15 57.34 57.88 57.86 57.56 24 56.61 55.09 56.09 56.28 56.62 55.65 56.97 57.14 57.36 57.88 57.81 57.56 25 56.59 55.18 56.09 55.28 56.64 55.70 56.93 57.14 57.40 57.89 57.79 57.56 26 56.55 55.26 56.03 55.27 56.67 55.74 56.98 57.14 57.46 57.90 57.80 57.57 27 56.53 55.33 56.07 56.26 56.69 56.77 56.96 57.14 57.51 57.91 57.81 57.58 28 56.55 55.39 56.03 56.27 56.72 56.10 56.91 57.14 57.54 57.90 57.80 57.61 29 56.57 55.44 56.00 56.31 56.74 55.52 56.85 57.14 57.57 57.91 57.80 57.63 30 56.59 55.47 55.98 55.34 --- 55.83 56.83 57.15 57.59 57.91 57.83 57.63 31 56.57 --- 55.93 56.39 56.14 --- 57.17 --- 57.91 57.86 --- LOW 56.61 56.55 56.09 56.39 56.74 56.94 56.93 57.25 57.59 57.91 57.92 57.95 NIGH 56.40 53.74 55.49 55.99 56.43 56.57 56.65 56.79 56.95 57.61 57.54 57.56 WTR YR 1984 MEAN 56.76 LOW 57.95 NIGH 53.74 53 30 54 Lal CO p- < W 0 Ld Li 55 0 Z - I Lai > (/) 56 L.J - 1 0 Lai Z< i-a 57 3 58 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 361 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 181951064422100. Local number, 4. LOCATION.--Lat 18°19'51", long 64°42'21". Owner: U.S. Government, Virgin Islands Government. Name: USGS-15 (Calabash Boom). AQUIFER.--Volcanic rocks of Cretaceous age. WELL CHARACTERISTICS.--Drilled unused water-table well diameter 6 in (0.15 m), cased 0-61 ft (0-18.6 m), slotted 40-61 (12.2-18.6 m). Depth 62 ft (18.9 m). DATUM: Altitude of land-surface datum is 50 ft (15.2 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.10 ft (0.34 m) above land-surface datum. Previous to March 1982, top of 6 in. (0.15 m) casing, 1.40 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD: Water levels: September 1964 to December 1967, discontinued. March 1982 to current year. Chemical analyses: September 22, 1964, discontinued. June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured 39.55 ft (12.06 m) below land-surface datum, May 25, 1982; lowest water level measured, 44.55 ft (13.58 m) below land-surface datum, Mar. 22, 1965. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEARS OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Date level Date level Jan. 24 41.79 June 27 43.08 362 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182042064454500. Local number, 5. LOCATION.--Lat 18°20'42", long 64°45'45". Owner: Virgin Islands Government. Name: DPW-6. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 70 ft (21.3 m). DATUM.--Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.60 ft (0.49 m) above land-surface datum. Prior to June 28, 1983, top of 6 in (0.15 m) casing, 1.30 ft (0.40 m) above land-surface datum. REMARKS.--Observation well. Automatic Digital Recorder (ADR) installed on June 28, 1983. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 11.34 ft (3.46 m) below land-surface datum, Apr. 27, 1983; lowest water level measured, 21.88 ft (6.67 m) below land-surface datum, Sept. 30, 1984. WATER LEVEL, IN FEET .1ELCW LAND-SURFACE DATUM, WATER YEAR CCTOBER 1933 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1200 CAY OCT NOV DEC JAN FEE MAR APR MAY JUN JUL AUG SEP 1S.t7 14.07 15.45 lto.31 17.51 19.07 20.33 20.69 20.81 21.42 21.67 2 13.56 14.03 15.47 16.35 1'8 19.11 20.07 20.71 23.84 21.43 21.69 3 13.71 1 7.53 1^-.4 9 16.40 17.74 19.14 20.38 20.71 20.16 21.45 21.70 4 14.36 13.72 15.51 16.44 1 7.75 19.17 20.10 20.73 23.87 21.47 21.72 5 11.84 13.33 13.53 15.49 17.82 19.21 20.13 20.74 20.39 21.47 21.73 6 12.06 13.97 15.55 16.53 17.39 19.25 20.16 20.74 20.90 21.40 21.73 7 12.06 14.11 15.58 16.57 1 7.95 19.21 23.18 20.75 20.92 21.36 21.75 8 12.36 14.26 15.50 16.51 13.01 19.31 20.21 20.72 20.94 21.34 21.76 9 12.92 14.40 15.4? 16.66 13.35 19.34 20.23 20.69 20.96 21.34 21.77 10 12.57 14.54 13.64 16.70 13.11 19.37 20.26 20.66 20.97 21.35 21.77 11 12.33 14.62 15.55 16.74 13.17 19.41 20.28 20.64 20.99 21.17 21.73 12 12.81 14.74 15.67 16.71 13.22 19.45 23.29 20.63 21.01 21.39 21.79 13 12.77 14.85 1.69 16.83 13.28 19.49 20.31 20.63 21.04 21.42 21.79 14 12.79 14.97 15.71 16.89 13.32 19.52 20.34 20.63 21.06 21.44 21.79 15 12.31 15.05 15.73 16.92 11.35 19.57 20.38 20.63 21.09 21.47 21.79 16 18.32 12.31 15.12 15.'6 16.96 13.39 19.61 20.38 20.63 21.12 21.43 21.80 17 18.02 12.63 15.14 15.79 17.01 13.40 19.64 20.33 20.63 21.13 21.50 21.80 18 18.03 12.57 15.1? 15.30 17.05 13.42 19.67 23.41 20.63 21.15 21.51 21.80 19 18.03 12.91 15.19 1 5.92 17.09 13.44 19.69 20.45 20.63 21.17 21.53 21.75 20 18.12 12.91 15.21 15.34 17.14 13.45 19.72 20.47 20.64 21.19 21.56 21.74 21 18.12 12.94 15.23 15.36 17.19 11.43 19.75 23.49 20.66 21.21 21.57 21.73 22 18.17 12.99 15.25 15.88 17.22 13.59 19.79 20.51 20.69 21.23 21.58 21.73 23 18.23 13.07 15.27 15.70 17.27 13.73 19.82 20.53 20.70 21.26 21.53 21.74 24 18.25 13.19 15.29 15.46 17.31 19.78 19.87 20.55 20.73 21.28 21.60 21.77 25 18.34 13.37 15.31 15.00 17.35 13.81 19.89 20.57 20.76 21.30 21.61 21.80 26 18.35 13.49 15.33 13.05 17.40 13.36 19.91 20.59 20.77 21.30 21.61 21.32 27 18.43 13.64 15.35 16.19 17.44 11.90 19.93 20.61 20.79 21.32 21.61 21.32 28 18.46 13.30 15.37 15.13 17.49 13.93 19.95 20.53 20.77 21.33 21.62 21.84 29 18.51 13.95 15.39 16.18 17.55 13.96 19.98 20.65 20.77 21.35 21.64 21.85 30 18.54 14.37 15.41 15.22 --- 14.01 20.00 23.66 20.80 21.37 21.65 21.57 31 18.58 --- 15.43 15.27 19.03 --- 20.68 --- 21.41 21.66 --- LOW 13.71 15.43 16.27 17.56 14.03 20.03 20.68 20.80 21.41 21.66 21.97 HIGH 11.34 13.68 15.45 16.31 17.61 19.07 20.03 20.63 20.81 21.34 21.67 10 3 0 13 Fa L.1 La Z 16 --I :3 Li > vl t.LJ I -J C1 Z Lai < 19 < 22 JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY JUN JUL AUG SEP 1983 1984 363 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182044064454600. Local number, 6. LOCATION.--Lat 18°20'44", long 64°45'46". Owner: Virgin Islands Government. Name: DPW-5. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 145 ft (44.2 m). DATUM.--Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.40 ft (0.43 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD: Water levels: September 1982 to current year. Chemical analyses: June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 36.71 ft (11.19 m) below land-surface datum, Sept. 9, 1983; lowest water level measured, a104.96 ft (32.0 m) below land-surface datum, May 19, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 a87.34 Feb. 29 69.70 May 15 43.48 July 25 44.29 Nov. 30 45.59 Apr. 3 42.82 June 27 43.69 Aug. 25 45.90 Jan. 24 41.76 182044064454800. Local number, 7. LOCATION.--Lat 18°20'44, long 64°45'48". Owner: Virgin Islands Government. Name: DPW-4 AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 60 ft (18.3 m). DATUM: Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 0.60 ft (0.18 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 25.36 ft (7.73 m) below land-surface datum, Sept. 9, 1982; lowest water level measured, 49.10 ft (14.97 m) below land-surface datum, Oct. 26, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 43.87 Feb. 29 45.44 May 15 32.54 July 25 33.15 Nov. 30 34.80 Apr. 3 32.00 June 27 32.59 Aug. 25 34.52 Jan. 24 31.15 182044064454900. Local number, 8. LOCATION.--Lat 18°20'44", long 64°45'49". Owner: Virgin Islands Government. Name: DPW-3. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 110 ft (33.5 m). DATUM.--Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 1.80 ft (0.55 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 20.93 ft (6.38 m) below land-surface datum, Sept. 9, 1982; lowest water level measured, a69.08 ft (21.06 m) below land-surface datum, Dec. 9, 1982. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 48.58 Feb. 29 26.20 May 15 27.98 July 25 28.52 Nov. 30 30.15 Apr. 3 29.38 June 27 27.98 Aug. 25 29.81 Jan. 24 26.66 a Pumping. 364 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 182044064455000. Local number, 9. LOCATION.--Lat 18°20'44", long 64°45'50". Owner: Virgin Islands Government. Name: DPW-2. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 65 ft (19.8 m). DATUM.--Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 32.84 ft (10.01 m) below land-surface datum, Sept. 9, 1982; lowest water level measured, 52.44 ft (15.99 m) below land-surface datum, May 19, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Water Water Date level Date level Date level Date level Oct. 27 Nov. 30 Jan. 24 51.03 39.39 37.33 Feb. 29 Apr. 3 37.72 41.29 May 15 June 27 38.94 38.66 July 25 Aug. 25 39.21 40.30 182044064455200. Local number, 10. LOCATION.--Lat 18°20'44", long 64°45'52". Owner: Virgin Islands Government. Name: DPW-1. AQUIFER.--Louisenhoj Formation. WELL CHARACTERISTICS.--Drilled public supply water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Sounded depth 60 ft (18.3 m). DATUM.--Altitude of land-surface datum is about 640 ft (195 m) above mean sea level. Measuring point: Top of 6 in (0.15 m) casing, 2.00 ft (0.61 m) above land-surface datum. REMARKS.--Observation well. PERIOD OF RECORD.--September 1982 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 32.03 ft (9.76 m) below land-surface datum, Sept. 9, 1983; lowest water level measured, a37.60 ft (a11.46 m) below land-surface datum, Dec. 9, 1983. WATER LEVEL, IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS Water Water Date level Date level Water Water Date level Date level July 25 35.27 Oct. 27 36.59 Feb. 29 33.69 May 15 35.10 Nov. 30 35.62 Apr. 3 36.83 June 27 34.90 Aug. 25 36.18 Jan. 24 33.93 a Pumping. 365 GROUND-WATER LEVELS ST. JOHN, U.S. VIRGIN ISLANDS 181956064464500. Local number, 11. LOCATION.--Lat 18°19'56", long 64°46'45". Owner: Virgin Islands Government. Name: Guinea Gut Well. AQUIFER.--Louisenhoj Formation (Donnelly, 1959). WELL CHARACTERISTICS.--Drilled unused water-table well, diameter 6 in (0.15 m), cased 6 in (0.15 m). Depth 85 ft (25.9 m). DATUM.--Altitude of land-surface datum is about 280 ft (85.36 m) above mean sea level. Measuring point: Bottom of 0.5 in (0.01 m) hole at 6 in (0.15 m) casing, 1.50 ft (0.46 m) above land-surface datum. Prior to June 28, 1983, top of 6 in (0.15 m) casing, 1.80 ft (0.55 m) above land-surface datum. REMARKS.--Observation well. Automatic Digital Recorder (ADR) installed on June 28, 1983. PERIOD OF RECORD: Water levels: March 1982 to current year. Chemical analyses: June 30, 1983 to current year. EXTREMES FOR PERIOD OF RECORD.--Highest water level measured, 3.34 ft (1.02 m) below land-surface datum, May 25, 1982; lowest water level measured, 20.05 ft (6.11 m) below land-surface datum, Sept. 11, 1984. WATER LEVEL. IN FEET BELOW LAND-SURFACE DATUM, WATER YEAR OCTOBER 1983 TO SEPTEMBER 1984 INSTANTANEOUS OBSERVATIONS AT 1230 DAY OCT NOV OEC JAN FES MAR APR MAY JUN JUL AUG SEP 1 8.31 11.23 6.39 6.92 8.03 9.52 12.35 15.34 17.45 17.79 19.72 19.77 2 3 8.43 8.52 11.34 11.45 6.03 5.80 6.95 7.31 8.09 8.12 /.62 9.70 12.46 12.62 15.40 15.47 17.51 17.56 17.86 17.92 19.75 19.78 19.31 19.35 4 8.31 8.10 5.92 7.03 8.23 0.77 12.71 15.55 17.60 1 7.98 19.70 19.88 5 8.43 5.41 6.01 7.10 8.34 9.38 12.83 15.63 17.54 18.05 19.44 19.41 6 8.57 5.08 6.05 7.24 8.35 9.99 12.95 15.70 16.98 19.12 19.25 19.92 7 8.68 4.94 6.09 7.39 8.36 13.13 13.07 15.79 16.55 18.19 19.13 19.94 8 8.79 4.98 6.16 7.46 8.34 10.25 13.19 15.37 16.42 18.26 19.06 19.98 9 8.91 4.99 6.24 7.53 8.33 13.37 13.27 15.95 16.36 13.33 19.03 20.01 10 9.02 5.01 6.30 7.50 8.11 10.48 13.33 16.04 16.36 13.40 19.02 20.00 11 9.07 5.03 6.31 7.39 8.15 10.59 13.49 16.13 16.37 13.47 19.04 20.01 12 13 9.21 9.30 5.04 5.05 6.31 6.41 7.26 7.31 8.22 8.22 1).69 10.81 13.61 13.72 16.21 16.27 16.42 16.47 18.51 18.57 19.07 19.11 20.02 19.96 14 9.39 5.09 6.50 7.23 8.22 13.91 13.82 16.34 16.53 18.63 19.17 19.97 15 9.49 5.15 6.56 7.19 8.19 1).99 13.93 16.33 16.60 13.69 19.21 19.93 16 9.52 5.19 6.56 6.95 8.12 11.07 14.05 16.39 16.67 18.75 19.26 19.95 17 9.60 5.22 6.60 5.91 8.23 11.10 14.17 16.47 16.73 18.81 19.31 19.99 18 9.74 5.27 6.53 6.94 8.34 11.15 14.27 16.55 16.80 18.88 19.38 19.83 19 9.77 5.34 6.62 7.02 8.46 11.25 14.39 16.62 16.87 18.94 19.44 19.66 20 9.37 5.36 6.69 7.12 3.54 11.19 14.47 16.70 16.94 19.00 19.52 19.61 21 10.00 5.44 6.75 7.25 8.63 11.27 14.57 16.77 17.00 19.06 19.60 19.60 22 10.04 5.49 6.79 7.29 8.74 11.37 14.64 16.85 17.07 19.12 19.67 19.64 23 10.20 5.53 6.31 7.41 8.84 11.46 14.75 16.91 17.15 19.18 19.55 --- 24 10.35 5.60 6.85 '.49 8.93 11.56 14.86 16.97 17.23 19.24 19.48 25 10.45 5.75 6.92 7.54 9.00 11.66 14.95 17.03 17.33 19.29 19.50 26 10.57 5.88 7.00 7.62 9.11 11.77 15.05 17.08 17.43 19.40 19.52 27 10.73 6.04 6.91 7.66 9.24 11.85 15.13 17.14 17.55 19.46 19.55 28 10.86 6.21 6.96 7.71 9.35 11.95 15.16 17.20 17.62 19.52 19.61 29 10.94 6.31 7.00 7.79 9.43 12.04 15.23 17.27 17.68 19.58 19.66 30 11.00 6.33 6.99 7.87 --- 12.16 15.27 17.33 17.73 19.63 19.70 31 11.11 --- 6.94 7.96 12.25 --- 17.39 --- 19.66 19.73 LOW 11.11 11.45 7.00 7.96 9.43 12.25 15.27 17.39 17.73 19.66 19.78 HIGH 8.31 4.94 5.80 6.91 8.03 9.52 12.35 15.34 16.36 17.79 19.02 4 0 -J X , CO 1- I- 10 la 04 W Z -cc > La 0 16 cez w 4 i-