Rainfall the island. Yields to we Croix serves _ " _— yt 4 a = ¥ ————— eae pale rea : ith the | : : : ea THE VIRGIN ISLANDS : : B= oe iin: Min nie we . fe i eae r INTRODUCTION (Continued) Public-Water Supply : ie a Oy ESTIMATED ) WATER USE IN ST. CROIX, 5 Water is not an abundant aquifer in the central part of The public-water supply Ground water from the Thermoelectric power gener- system in St. well fields provided the ation by WAPA in St. Croix U.S. VIRGIN ISLANDS, staane 45 are low, seldom exceeding e: } B - about 30,000 peeeie ees Liem © Produc- during the study period re- - inc 1es per year, m st of which gallons per minute (UB p : ay records show quired about 36 Mgal/d = of » was ‘obta ned ‘from OCTOBER 1983 - SEPTEMBER 1985 — Ee ere ILS a ing the wiggi ap al Geological Survey, 1985). seawater. The water was used I lesalination plants. source at i sae yf tot r ; < for cooling of condensers. The water supply pe most private ees and Cosner, 1973). —— In 1985, the U.S. Geo= | homes. The Aegan of ie See Ole ye PN logical Survey, WRD (USGS) in Most of ae water te about Industrial Self-Supplied 7 f ter collected a _The bce ccaaa ci _ indicated By / f98 ae cooperation with the Water freshwater to he system are 0.72 Mgal/d (equivalent to 500 Petroleum refining and rum 5 Mgal/d. Gees: “eta r ine it Resources Research Center of located in Christiansted, where the water is pumped toward gallons per min te), are due to leaks in the distribution prods -ion are ie ee ee figurat bs princ st the College of the \ = x / Islands, conducted a general Frederiksted. Ground water is | system and unauthorized connec- city, ME ce 2 Sf ized water-use inventory in St. pumped into the distributi n tions. Gordan = re Croix. The inventory was system halfway between the two nee y z - conducted as a part of the towns. The distribution system There are two public 7 vigal/a of seawat ter cooling and desali seawater supply systems in St. aa age Freshwater produc- tf DEPARTMENT OF water-use program of the USGS covers about 14 square miles in cisterns ; 1983, Water management nd operates wader 4 combied Croix, one in Christiansted and peryeee | ory ncaa in the U.S. Virgin Islands. A and operates under a combina- agai earam oe es tion at th finer bout si sigs plan for the public water THE INTERIOR previous water use inventory tion of gravity and pumped ~ Fhe other in Frederiksted. pis en id eee rved a aes in each water geede can be obtained et se oC astor was conducted oe Sts Thomas pressure zones, (CH2M Hill Presently ; the eyecet in 3 district, 2) roof area of 1,000 from rainfall (fig. 9). srounc aed gen ally during 1984 (Torres and Southeast, 1983). one pene pis Ae Domestic oe i eS. Pe! yee ee d sy: av 60.07 Meare tee. su 7 their own “wat r rivate supply wells (Virgin ‘ system in st. Croix provided sted ‘system average 0.27 Mgal/d pp y : pr ieaice ae Org SC ee COTTON VALLEY Francois, D.C., Thompson, 7 deme 240 Gee ducioe Kia (Black, Crow, and Eidsness, needs from ground water, §_ Islands Depart nent of Con rva- i Francois, — ere ere See. WATER SOURCES eon dy = iar Se bean “ee Inc., 1976). The system is used rainwater collected from tion and C pura Affairs, a8 ae ee ove : a oo Wee vickereian te rooftops, or purchases from personal communication, 1985). zee? Water in St. Croix is A t 90 : id s a4 ter flushing of toilets at some of private water haulers. Esti- The remaining 0.05 Mgal/d was Rosz obtained principally from the ne ™ oo = F a san the Virgin Islands Housing mated water use for _ this pumped by commercial water = UNITED STATES sea, with smaller amounts from (1 gal/d) was from the ; 5 usin, : haulers. Several of these wells were visited during the study aquifers and rainfall catch- desalination plants operated by ius or a per capita usage of about _ iE I 0G CAI SU VEY ments. The total water used 40 gallons per day. period as a quality assurance a0 - ee VUNTE | ! & P y Pp aq y) no.4, pe “351. 362. ae during 1985 averaged about 72.4 measure. Ground water for » mil. gallons per day Ground water withdrawals domestic use is available in { ; Pict and Nees ay (Mga /d). Seawater use aver- for domestic self-supplied use nearly all parts of the island. i i cute Beane kl aged cena 70. 6 Mgal/d. : Ground was estimated at about 0.50 The principal aquifers and WATER RESOURCES ; a Mgal/d (58 percent of total their characteristics are shown Re miecansee eau on | DIVISION use). Of this amount, 0.45 in fig. 8. | 3 (1961-1980) : 0.49 Mgal/a iG. Sea ome ; Pes 6 Wee ~ EXPLANATION 7 7 ; Figure 3. ig aes eo SS AREA SERVED OPEN-FILE DATA © 1 2 3 KILOMETERS ie me — 2 ) 4 wisi indieicneg if a J \ 0 1 2 8 MILES DISTRICT ——- — —_—— es : REPORT 86 537 j | WATER USES a e - Figure 6. Area served by the freshwater distribution system and \ The principal uses of water (fig. age Seawater 0 on location of public supply well fields. | nae ir ceaeeer ry herr in St. Croix include thermo- used for fire emereene es an ae EXPLANATION ., 1975, A surve Prepared In cooperation with the - electric power generation, flushing of toilets in kinase AQuireR Bons Hee oe water pecaies of CARIBBEAN RESEARCH INSTITUTE t dedalin tion for domestic Christiansted and Frederiksted. PES Pann : Pa "eas Gil aol ae aah Ceo cee | pas ee ‘05| 102] ‘05 . Croix, U.S. Virgin RALI PAF ain Sig pee ale res 2S supply, public water supply, fo Ezz) baat 1s ee :- porit. cae 8607 | .25] .88| 3T Ailse|: a el eel ih eon ee as ee i ands: U.S. Geological COLLEGE OF THE VIRGIN ISLANDS public waste-water treatment, Ground water is used mainly 4 [___] COASTAL EMBAYMENT AQUIFER NOUR: <-> VAUUMS LESS ‘THAN 0.07 wgaa/a. me ee ; ) Survey Open-File Report, ST. THOMAS, U. 5. VIRGIN ISLANDS and domestic, commercial, and by domestic, commercial, and | 51 'p. industrial self supplied (fig. industrial self-supplied users, a Ee ‘ Figure 9. Monthly rainfall recovery and average annual yield by planning ie ‘ 4). Seawater is used for which are not connected to the On By lee aaesana ts as oS ee Miteea, 19 gerne seed: og Pa Se a ; district in St. Croix during October — to September 1984. Peebles, R.W., Pratt, A.E., 1987 cooling at thermoelectric power public water supply system ~~ WATER DISTRIBUTED ee ee a mS oe ae sees | large transient _ ee is ts sual stations) use about 0.15 Mgal/d supplied establishments and Islands, July 1983~June Rico and about 40 Bie sale popu ire ean i oul Liar eey el COOLING The author would like to of ground water. individual homes. — _Rainwater ae Zz ee of St. Thomas and. Si. Jehn services and facilities. le (36.00) acknowledge the — following collected from rooftops pro- Be ee (fig. 1) St. Croix has population and economic growth 50.4% Virgin Islafds — Government vided about 0.49 Mgal/d to Report 84-721, 1 ,pl. =i - re ep ees pe ; eee es snited in @ anne RAINFALL IN Agencies and private industry Nebel) earns Sah ss no) / experienced a dramatic increase of St. Croix has resulted in a © CATCHMENTS employees for their coopera- Public Waste-Water Treatment private homes, hotels, and U.S. Geeloeical § 1984, in its population over the last significant increase in the - : ae GROUND WATER 9.49 tion: The Virgin Islands Public ie pei 8 agen ir . industries. — ioe re itainie urvey, n its pop ro Baccus ND : Horie industries. National Water Summa 25 years, growing from about demand and supply of water pepgpers 1.29 ida eae Gears There is one public waste- U.S. Geological a. 15,000 inhabitants in 1960 to (fig. 2). 70.32 EXPLANATION Putten, The i water treatment facility in St. Freshwater production from Waeee-Sunp ly Paper 2250, CO - COMMERCIAL USE thortey= ve Croix (fig. 5f). serving both the desalination plants pp. 200-202. pee é Ce ae SUPPLY ks, The. vie a the Christiansted and Peeder ts averaged 3.5 Mgal/d in 1985, { : 67°00’ 66°30’ 66°00" ___ 65°30" 65°00" : “"IN- INDUSTRIAL USE ing Office - Mrs. Vena M. sted urban areas. Effluent with production about equally U.S. Geological Survey, 1985, -48°30'L A ; 4 T | T | — os e MS : ie ; oy is ap q Hess Prk as ae discharges were measured during split between WAPA and self- ; Nation: Water Summary, | ne a tee ocd 6a bia the study period. An average supplied industries. Only about Ground-Water Resources: ae , oe . = Inc. - Mr. Donald C. Nelthropp. discharge of 0.70 Mgal/d was 66 percent of the water pro-. U.S. Geological Survey UE ST. JOHN is : Pa le, Sot eg estimated for this period. duced by WAPA is accounted for. Water-Supply Paper 2275, abasic suas res Figure 4. Estimated water use by source and major use category in cine ee ee ee rena Se Pp. 409-414. St. Croix during 1985. : yea rite. [a8 naintenance Discharges from the local VIEQUES ond noe ed hore ae es waste-water t reatment P lant 18°00'T- ed Sa pea » aes a . : ge pee be = hate eee Lr oe were about 0.70 Mgal/d. ees A — Figure 5a. Thermoelectric-power generation. Figure 5b. Domestic withdrawals from public water supply. bees eo were about 0.70 Mgal/d CONVERSION TABLE ai eee ioe i ST. CROIX ; 102030 KILOMETERS 1 : : aaah = = 9.90 lowing factors may be used to Ns 1o 26 BO MILES | DESALINATION |, pound units of measurement nee | - ! COMMERCIAL X. =e Os FIRE oe to International System L — 1 SELF SUPPLIED |o \Q PROTECTION : Figure 1. Location of the U.S. Virgin Islands. 7 seawater \ ot Paes Cis dee 70.59 by SI unit 60F 3. y : wi K * war —__] as oem: au : a > : : 2 DESALINATION [= == inches (in.) 25.4 millimeters (mm) 2 50F a ; a Za Ie asians i ' — Ss miles (mi.) 1.609 kilometers (km) =z POPULATION, a Oe WATER * OES Ree : abe 2 cooheafhe. , 20 ; mnie ete 7 S Bec ces 0.0929 square meters = 26 Nese! sce a ost LOSSES square Pines 2.590 re ere, 23 er 2 RAINFALL IN | . users}222, eG eS seas Vol — f=