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1983
Ground-Water Hydrology and Projected Effects of Ground-Water Withdrawals in the Sevier Desert, Utah
United States Geological Survey
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Recommended Citation United States Geological Survey, "Ground-Water Hydrology and Projected Effects of Ground-Water Withdrawals in the Sevier Desert, Utah" (1983). All U.S. Government Documents (Utah Regional Depository). Paper 151. https://digitalcommons.usu.edu/govdocs/151
This Report is brought to you for free and open access by the U.S. Government Documents (Utah Regional Depository) at DigitalCommons@USU. It has been accepted for inclusion in All U.S. Government Documents (Utah Regional Depository) by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. GlOUIID-IIATU RYDIOLOGY AJII) PROJECTED UIIlTED STATES DEI'AIlTl!EliT OF THE lIITElIOI
URCTS OF GIOUIiD-IIATU WlTHOlAWALS JAK!S G. WATT, Secretary
III THE SEVlD. OESUT, UTAH Dall •• L. Peck, Director
Iy Valter r. Bot. ••
O.S. GEOLOGICAL SUlVEY
OpeD-rile leport 83-688
Prepared iD cooperatioD. with the lJT4B DEPAIlTl!EliT OF IlATOlAL lBSOURCES,
DIVIS 1011 or WATU llGBTS
Dept. Seat
for additional infor.ation Copie. of tbi. report CAD be write to: be purcha.oc! fro.:
Diatrict Chi.f Opec-rile Service. Sec.tion O.S. Geological Sunrey Ve.tern • -ion Irancb 1016 .lclaiDi.tratioD BuildiDg "BoK 2542), 1 Center Salt Lak. City, Uteh 1745 Vut 1700 South Dener, Col. 80225 Salt Lake City, Utah 84104 [TalephoDe: • )3) 234-5888) 1983
3 COITEliTS COIITE1ITS--Cont i nued
Dilital-coaputer model in,--Cont inued Abltract ...... 9 Projected effec". of future ground-vater witbdravIl.--Continued IutZ'oductioD ...... 10 Ground_ater vitbdravala ooe-half tbe 1 g77-7 9 averaae hrpole, Icope, and aetbodl of inveltig&tioD ••••••••••••••••••••••• 10 rate ...... 40 he.,ioul atudie. Ind ackoovledpent...... 10 Cround-vater vitbdrawal. double the 1"7-79 average rate...... 44 Vell- and a~... ina-nuaberi", ayatea •••••••••••••••••••••••••••••••••• 11 Chanaes in location. of ground-vater withdraval. related to De.c.riptioD of tbe .tudy area ...... 13 the Interaountain Pover Project ...... 44 Ph,aioaraphy •••••••••••••••••••••••••••••••••••••••••••••••••• 13 S--.ar), and conclul ionl ...... 50 C;eololJ ••••••••••••••••••••••••••••••••••••••••••••••••••••••• 13 a.ferencel cited ...... 51 Cliaate ••••••••••••••••••••••••••••••••••••••••••••••••••••••• 13 'eletatioD ...... 15 W.USTUTIONS Surfacn vater ...... 15 C;ro""d_ater hydrology •••••••••••••••••••••••••••••••••••••••••••••••••• 17 [Plate ia in pocket I COlllolidated rocka ...... 17 UnconaoHdated baa in fill •••••••••••••••••••••••••••••••••••••••••• 18 Plate 1. Map of the Sevier De.ert, Utah, Iboving the potentiometric ..charee •••••••••••••••••••••••••••••••••••••••••••••••••••••• 21 .urface of the Iballow artelian aquifer and vater level • S•• pa,e froca atre...... 21 in tbe deep arteaian aquifer, !larch 1981. Seepa,e frow canall ...... 22 Seepage frOID relenoira ...... 23 rieure 1. Diaar_ ahoving vell- and aprine-nUlllberi", ayat ... uaed Seepaae frca uncon•• ed irrigation vater ...... 23 in Utah ••••••••••••• • ••••••••••••••••••••••••••••••••••••• 12 Sublurface inflow from conaolidate.d roclte along the aountain froDt ...... 23 2. !lap of Utah abowi", location of the atudy area •••••••••••••• 14 Precipitation on ba.alt outcropi ...... 23 Sub.urfaee inflow frena adjoining area ...... 24 3. Crapb .bowing eu.ulative departure fro. average anDual Mo.ment •••••••••••••••••••••••••••••••••••••••••••••••••••••• 24 pracipit.. tioD at Oak City, 1935-81 •••••••••••••••••••••••• 16 Diacharae ••••••••••••••••••••••••••••••••••••••••••••••••••••• 24 Clear Lake Sprinaa ••••••••••••••••••••.•••••••••••••••••• 25 4. Cenerali&ed geologic lectioD near L)'nndyl, Utab, IhoviDg S.epaae to the Sevier River ...... 25 litholoaJ and divilioUl of tbe ground..."ater re.ervoir 19 hapotranlpiratioQ ...... 25 Sub.urfaee outflow to IdjoiDina are...... 26 5. Ideali&ed ea.t-velt cro •• lection of the Sevier De.ert Valla •••••••••••••••••••••••••••••••••••••••••••••••••••• 26 .bovioa the elnentl of the ,round-vater aYlt ...... 20 aydraulic. propertiel ...... 28 Storage ••••••••••••••••••••••••••••••••••••••••••••••••••••••• 30 6.. Graph .hoving ground-vater vithdravall fro. the Sevier Vater quality ••..•••••.••...... ••••••••••••••••• ••••••••••• ••••• 30 Deurt, 1951-81 ••••••••••••••••••••••••••••••••••••••••••• 27 Cbaqe. in ITouDd-vlter cODdition., 1963-81 ...... 31 Ground-vatet' vithdraval. • ...... 31 7-9. !lapa ahowi",: Vater levell ...... 31 Vater quality •••••••••••••••••••••••••••••••••••••••••••••••••••••• 34 7. irleDie COQcentrat ionl in vater in the artelian Dieital-cOOlputer .odeliDa ••••••••••••••••••••••••••••••••••••••••••••••• 37 aquifera, 1 g7 ~81 ••••••••••••••••••••••••••••••••••••• 32 Ceneral delcription of aodel ...... 37 Projected effect. of future arouad.."ater withdrawal ...... 39 8. Area. of .ianifieant vater-level change in the Ihallow Cro\llld"""ater withdrawall equal to the 1 "7-7 9 Iverage rate .... . 40 arteaian aquifer, !larcb 1963 to !larcb 1981 •••••••••••• 33
9. Vater-level cbanae. in veIl. iD the deep artelian aq"ifer, !larch 1963 to !larch 1981 ••••••••••••••••••••• 35
4 ILLUSTUTIOII-Continu04 r.,. tABLES Pale riaur. 10. Crapha .bovina IIpeeific conductance of vater fro. •• lected vella co.pl~ted in tbe ,ballow Irteaian aquifer. table ).. Hydraulic coeff icieotl of arteliao aquiferl in the 19S8-80 • •••••••• •••• •••••••••••••••••••••••••••• ••••• •••• 36 S.... ier De.ert ...... 29
11-18. Kapa ahoving: 2. Steady-at.te (1952) and tranaient-atate (1980-81) ground .atel. budaetl for the Sevier Delert, computed by the 11. Projected vater-level decline. in the deep arttlila di,ita1 .odd, in .cre-feet per year ...... 38 .quifer for the period 1981-2000, ...... ing ground_.ter vitbdravala equal to tbe 1977-79 •••ra,e rate ...... 41
12. Projected vater-level declined in the .ballow .rteaian aquifer for tbe per iod 1981-2000, "'WIliu, ground-vater withdr.awal .. equal to tbe 1977-79 averaae rate ••••••••••••••••••••••••••••• 42
13. Projected vater-level cbangel in the deep Irteaian aquifer for the period 1981-2000, ."Wlling around_.ter vithdravalo one-half tbe 1977-79 nerl,1It rate ...... 43
14. Projected vlter-Ievel cbangea in the ,ba I 10'-· .rteai.n aquifer for tbe perid 1981-2000, •••uaiDI ground-vater withdrawal. one-b.lf tbe 1977-79 .verage r.te ••••••••••••••••••••••••••••• 4S
1'. Projected vater-level decline. in the deep arteaian .quifer for tbe period 1981-2000, ...... ing around_atn vitbdrav.la double the 1977-79 nerage rate ...... 46
16. Projected water-level decline. in the Ihallow arteaian .quifer for tbe perLo6 1981-2000, a.lUl:linl g:round-vater withdrawall double the 1977-79.verage r.te ...... 47
17 ...... Projected vater-level chaole. in the deep artelian aquifer relultinl fro-. cbanae~ in the location of around-vlter withdrawal I related to tbe Int.mountain Pover Project for tbe period 1981-2000 ...... 48
18. Projected v.ter-level chancea in the aballov art.aian aquifer relultioa frOil chanse. in the location of ITound-vater withdrawall related to tbe Intemountain Power Project for tba period 1981-2000 ...... 49
6 7 COllvu.S lOll FACTOiS AIID RELATED IlIFOillATIOH GROUND-WATER HYDROLOCY AND PROJECTED EFFECTS OF GROUND-WATER
Molt •• lu.. in thi, report are aiven in ioch-pound unit. folloved by WIIBDRAWALS III IBE SEVIER DESERT, UTAII ••tric unit.. The conver,ioD factorl are .bovn to four '1&oificlnt fiaure •• lit the tezt. ~ov~.er, tb~ metric . equivalent. Ire Ibovn only to the number of By Wol tor F. Holm .. ailDificlnt fllur.. COnl!ltent 1.1th the accuracy of tbe value io inch-pound aito. ABStRACT
To obtain Tbe principal ground-vater re.ervoir in the Sevier Delert ia the unconaolidated balin fill. The fill ha. been divided generally into aquifers acre 0.4047 aquare becto.eter (~2) and confining bedl, although tbere are no clearcut boundariel between tbese 0.004047 aq uare kilo.eter (kill ) unita--the primary aquifer. are tbe aballow .nd deep arteli.n Aquifers. acre-foot (acre-tt) 0.001233 cubic hecto.et§r (bal ) aechar,e to tbe ground-vater re.trvoir il by iof iltration of precipitation; 1233 cubic aeter (a ) lupa,e from Itreaml. canall, relervoirl, and uncoDsumed irrig.tion vater; and 3 cubic foot per aecond (tt /a) 0.02832 cubic aeter per aecond (al/a) lublurface inflow from consolidated rockl in mountain areaa .nd from adjoining cubicloot per day per foot 0.0929 cubic metes per d.,. per are... Dilcharge il by velll, 'pring', seepa,e to tbe Sevier River, (ft /d)/ft • aeter ( .. /d)/. ev.potranlpir.tion, .nd lublurf4ce outflow to .djoining are••• foot (ft) 0.3048 aeter (a) 2 Change a in ground'""Vater witbdrawala, water levela, and qu.lity of v.ter foot aquared per day (ft /d) 0.0929 aeter aquared per day (1I2/d) ,a11on per aiute (gal/_in) 0.06309 liter per aecond (L/a) occurred in the arteli.n aquifera of the Sevier Delert, Ut.h, during 1963-81- inch (in.) 25.40 .illiaeter (_) Grouud....",.ter withdraw.la increased from an average of 9,500 acre-feet (11.7 2.540 centiaeter (ca) ~ubic hectometers) per ye.r betveen 1951 .nd 1963 to an avera.ge of 27,500 aile (ai) 1.609 kiloaeter (b) acre-feet (3l.9 cubic hectometers) per year between 1964 and 1981. HOlt of aquare aile (ai 2) 2.590 aquare kiloaeter (kIII 2) the incre•• ed withdrawal was from the deep .rtesian .quifer.
Cb.nieal cODcentrationl are liven ooly io .etrie unit.. Che.ieal Water levela declined .1 much .1 1"9 feet (5.8 meters) in the deep conceDtr.ti~D ~. given in lIi~ligr ... per liter (maIL) or microgram. per liter arte,ian aquifer and.a much .1 13 feet (4.0) meter I in the shallow arte.i.n (al/~). Ml111~r... pe~ h.ter i,. unit expre •• ing tbe concentration of aquifer "'etveen 1963 and 1981. The declines probably .re due to iocrea.ee! cbeaJ.cal . conltl.tuent. 1n .olution a. veiabt <.illigr... ) of .olute per unit ground-water withdrawala for irrigation and municipal u'e. 'Y~l~. (11ter o~ vater). One tbou.and microarD' per liter i. equivalent to 1 a.t1111~" per llter. For concentration. Ie. I tban 7,000 mIlL, the nUlllerical Concentration. of dissolved conltituent8 in vater in tbe .hallow .rtelian •• loe 1. about the .ame a. for concentrationl in part. per aillion .. aquifer are increaling in .n area ne ... r Leamington and Lynndyl. Tbia ch.nge: probably ia the result of more mineralized water entering tbe ahallov artesia';) ,I.tiypal Geodetic Vertical.Datum of 1929 (NGVD of 1929): A geodetic aquifer from the a erlying vater-table aquifer. datua ~erlved frOil a leoeral adjustment of the fir.t-order level netl of both ~be tJ~1ted States and Canada, called HGY» of 1929, i. referred to a ••ea level Vater-level cbange. resulting from changea in recharge to .nd diacharge 1D tb11 report. frOID tbe .quifer. vere limulated u.ing a digital-computer model of the aquiff'r a,.tem. Cround'""Vater withdrawala for 20 years (1981-2000) were aimulated at one-half, one, and tvo tiaes the 1 CJ17-19 .verage r.te. Water-level declines of aore tban 80 feet (24 metera) were projected in the deep artesian aquifer with witbdravall tvice the 1 fJ17-7 9 average, declinea of core than 40 feet (12 aeter.) if withdraw.ll vere equal to the 1 tfl7-7 9 average, .nd decline. of more than 15 teet (4.6 meteu) if withdraw.1I were one-balf the 1977-79 average. Collputed v.ter-Ievel decline ••f ter 20 year. in the .hallow arte.ian aquifer were .ore than 50 feet (15 Gleterl) at two ti ..l el tbe 1977-79 aver.ge rate, aore than 15 feet (4.6 meteu) at the 1977-79 average, and Ie .. than 4 feet (1.2 aetera) at one-balf the 1977-79 .verage.
Cbancel in locationl of ground-water withdr.w.la related to the Interaount.in Power Project would c.ule w.ter-Ievel declinel in tbe deep arteliaD aquifer of more tb.n 15 feet (4.6 meter.), but only am.ll cb.ogea in
8 9 •• ter l.vel. in tbe .ballov arte.ian aquifer after 20 year •• Tbe.e cbanle. Well- and Spring-Huaberinz Sy.tN ar. ia addition to cban&e. coaput.cl for 20 y.ar. of withdrawal. at tbe pre proj.ct 1977-79 vithdrawal rite. Tbe .y.tea of nuaberin& veil. and .pring. in Utah i. ba.ed on tbe cada.tra1 land-.uney .Yltea of tbe lI.S. Government. Tbe nu.ber, in addition DlnODOCTION to deailnatin.a tbe veIl or aprinl, de.cribe. it. polition in the land net. By the lllnd-.uney Iy.tea, tbe State il divided into four qUAdrant. by tbe Salt 'urpo.e. Scope. and "etbod. Lat. ba.e line and aeridiaa, and tbe.e quadrant. are deailnated by tbe oppercaae letter. A, B, C, and D, indicating tbe northelat, nortbvelt, Tbe 0.5. 'eololical Survey evaluated tbe &round-water re.ervoir of the aoutbveat, and .outhealt quadraota, re.pectively. Nuabera de.i,oatin& tbe Ini.r De.ert, Utab, durinl 1919-82, in cooperation witb the Utah Departaent tovalhip and range (in tbat order) follow tbe quadrant letter, Ind all tbree of .atural le.ource., Divi.ion of Water light.. Tbe objective. of the .tudy are eDcloled in parentbelel. Tbe number after the parentbe.e. indicatel tbe war. to add to tbe under.tandina of the area'. ,round-water hydrology. to a.ctioo, and ia folloved by tbree letter. iodicatina the quarter .ection, tbe det.raine chan,el in ground-vater condition•• ince tbe 1961-64 .tudy by Hover Clu.rter-quar~er l.tetion, and the quarter-quarter-qlJarter lection--&enerally 10 ane! r.ltil (1968), and to project tbe effectl on vater level. in tbe arte.ian acre. (4 b • .•J; tbe letter. a, b, c, and d indicate., relpectively, tbe aquifer. of potential future around~atar witbdraval •• DOrth.a.t. nortbve.t, loutbve.t. and .outhea.t qUlrter. of eacb .ubdiviaion. The waber .fter ~he letter. i. the leria1 number of tbe veil or .prioa vithin Infora.tioD collected and aetbodl uled LO collect it duriDI tbe .tudy the 10-acre (4-bll ) tract; tbe letter "s" precediog tbe .erial nu.ber denot~. incluel.e! di.cbar~e fro II veIl. and .prinll, vater level. in veIl., driller.' a apr inc. If' 4 veIl or .pring cannot be located vitbin I 10-acre (.-ba ) and ,eophy.ic.al log. of vell., water la.ple. wbich vere analyzed cbeaical1y, tract, one or two location letterl are u.ed and the lerill number i. o.itted. •• epa,e 101.e. froa or gain. to canall and Itrea.1 fro. a.a.ureaent. of Tbu. (C-12-6115blc-1 delignltel tbe tiut veil con.tructed or vi.ited in tbe .urface-vater flov, hydraulic propertiel of aquiferl from aquifer telt., and 8W~W~W~ lec. IS, T. 125., It. 6 W., Ind (C-2C-7)3d-S delilnlt .. I .pring cbaDI.a in area. of pbreatophyte growtb. .l diaital-computer .odel of tb. knovn only to be in tbe St" aec. J, T. 20 S., I. 7 W. the au.berine .y.te. i. around-vater .y.t •• val conltructed OD tbe ba.i. of tbil and other il1u.trated in fiaure 1. in.forwation.
Previou. Studie. and AckDovlednentl lAltboufh tbe bl.ie land unit, tbe let:tion, i. tbeoretical1y I .quare Pre'fiou. Itudie. of the ground-vlter hydrOlogy of the Sevier De.ert or aile (1.6 k. >. .af,y aectlonl are irregular. Such lectioD. are .ubdivided '0 •• "'pect of it include tho.e by Heiner (911), ""hon (952), Nehon Ind iDto 10-acre (4-hm ) tract., lenerally beginning at tbe lOuthea.t corner, and Tbo ... (953), Hover 0961, 1963, Ind 1967), Hover Ind Felti. (968), Blndy tb ••urp1u. or .bortage i. taken up in tbe tract I along tbe north and velt Ind otbeu (969), BI.er Ind Pitzer (978), Ind Bol... Ind Wilber, (1982). .ide. of tbe aeetion. 'r''fioully publi.bed co.pilation. of balic data for tbe Sevier Deaert include tbo.e by Hover and Felti. (964) Ind Eoriabt and Hol.e. (982). Otber diU on cbaa.a.e. in vater level. and around-vater vithdraval. in Utah are in a leriel of aonual around-vater reportl prepared by the U.s. Geological Survey, tbe .o.t recent being tblt by Appel and otbe .. (983). Hany of tbe conclu.ion. in tbi. report are ba.ed on the relulta of tbe di,it.l-coaputer aodel uaed in tbi. Itudy, but tbe detaill of it. delian, conltruction, and calibration are ,iun by Bol.e. (983). The 0.5. Depart •• nt of Agriculture (969) publi.bed I vater badlet for the Sevier liver baa in. Infor.atioD on leepale lo.ael fro. or ,aiD' to can. 1. and .treaa. in tb. area vere collected by Herbert and otb... (1982).
nia .tudy could DOt bave be eo coap1eted vithout tbe cooperation of local •• 11 ovnera, aDd per.onnel of irrilatioo coap.niel, .unicipalitiea. iodultrial ••ter u.er., utility coapanie., Ind the Utah Divi.ioD of Water light I. the ace••• to v.ll. aud data aranted by tb••• people il appreciated.
10 11 .: Delcription of the Study Area Trc.c:h wi~l\in • "Section Section. within. t.ev'I,!'Iip Phy.iosraphy
The Itudy are. encompa.lel approxim.te ly 2, lK)o .qu.re .. i leI (7,JOO km 2) of the Sevier De.ert in west-c.entral Utah (fig. 2). The .tudy area coincide. I t I I. . jr~·O'IS - witb the area .tudied hy Hover .nd Felti. 0968, pI. 1), excluding the Old b :"'--1--I I liver Bed .rea, .... t of tbe Keg Hountain., which drain. nortb toward Dugw.y I c: I 11 Valley (pl. 1) and then to the Great Salt Lake De.ert. The .tudy area i. I .' • bounded on tbe n..>rtb by tbe Welt Tintic, Sbeeprock. and leg Hountainl, and --~---i f~ -- , De.ert Mountain; on the ea.t by the Ea.t Tintic, eillon, and Canyon Kount.inl; on tbe louth by latitude Jgo N; on the .outhealt by Pavant V.lley; and on the • 011 ••• t by tbe DrUID Kountai D.I, Topaz Mountain, and the Hou.e aange (pl. 1) • 18 The Sevier Delert il • large balin .urrounded by .teep, rugged mountain. reaching altitudeo of ooore tban 9,700 feet (3,000 m). The topography III ,ener.lly Ilopel tC' the louthwelt toward tbe Sevier Lake play., a remnant of ancient Lake Bonneville. Other prominent topographic features of Lake Boneville include Ipit., bars, and other Ihoreline depositl. 30 Geology
31 Tbe rockl in the .tudy area range in age froa Precambrian to Holocene (Recent) (Mover and Feltis, 1968, pI. 2). Tbe lurrounding aountain. are coapo.ed of a variety of conlolidated ledimentary, metamorpbic, and igneoul roch (Stok.. [19641 and Hover and Felti. [1968, table 21).
The ba.in area ia underlain by depolitl con.isting primarily of .eaiconlolidated to unconsolidated lediments of Tertiary and Quaternary age, I but outcrop. of conlol;dated igneous rockl, primarily basalt flov., are , .cattered over tbe ba.in flov (Hover and Felti., 1968, pI. 2) and balalt and tuff are interbedded vitb the lediment.. The ba.in-fill lediments con.i.t of L___ _ unconsolidated cluy, .ilt, land, gravel, and boulders, and lemiconlolidated to rur LI.tt con.olidated conglomerates and fanglomerate. depo.ited io alluvial, " ...... S.1 t L..lla CI t)' \ lacultrioe, and at-Oli.n environment.. Additional information on the baa in fill depa.ito i. in reporto by Hover (1961 and 1963), Hover and Felti. (1968), I , Cilbert (1890), R'u.er and Pitzer (197 8, p. 3-3 to 3-6), and Holme. and Wilberg I , (982) • \' Climate T. 12 S., R. 6W.Y· I e The climate of tbe .tudy area range. frOD lemiarid on the ba.in floor to aubhuaid .t higher altitude. in tbe aurrounding mountain.. D.ytime teaper.turel on tbe balin floor during lummer month. may exceed 40°C and o I ainiau. temperature I during winter montha may be lesl tban -20 e. The mean I annual temperature at Deaeret ia about IOoC (National Oceanic and At.olpberic ',' Adainiatr&tioQ, 1982). _____ JI ..verase anDual precipit ation range. from le •• than 6 incbe. (152 IDm) on the h .. in floor to aore than 25 inch.. (635 m.) in the Sbeeprock and Canyon Figure 1 ,-Well- and spring-numbering system ~sed in Utah, Mountain. (Kover and Feltil, 196 8, pi. 4). The cumulative dep.rture fro.
13 12 lU' 113: ___ _ 02' • -:----. EXPLANATION averaat anDual preClpltation at Oak City for 1935-81 i. ,bOVD in figure 3. .1 I ..... ~ STUDYAREA Pr,,~ipitation generally Val le .. than average during 1948-63 and 1972-77, and > ~ aore than average during 1935-47, 1964-71, and 1978-81. I .- Vegetation The moat comaou native plants io the mountain. of the .tudy area are juniper (Juniperus ~p.). pinyon piDe (Pinus llili!..>. Dougl.s fir (Pseudotauta TOO lIenzieaii) •• pruce (Pieia Ip.>. and quaking a.pen (populus tremuloides). CoalDon native plants on the b •• in floor include .agebruah (Artemeai. ap.), , re.aevood (Sarcobatus vermiculatus), s.lltgraal (Diatichlis spicat •. Y.Y'~ ~), rabbitbrush (Chrysothamnus nauseolus), and sbadlcale (Atriplex c.0afertifolia). Saltcedar (Tamarix gallica), a phreatophyte, probably ves iatrodu~ed into the area prior to 1950 (Hover and Feltis, 1968, p. 14), and ha. lince become eltablished along the Sevier River; .round Fool Creek lelervoirs; along major canall, ditcbes, and drains; and in lowland parts of tbe area. Hover and Felti. 0968, pl. 7) abow [he are .. of pbreatophyte ,rovth in 1963. Field checks made during tbi. study ahow nO .ignificant change in pbreatopbyte area. ainee 1963. . IrTigated crop. include alfalfa bay, alfalfa .eed, an1 grain with .ioor Dountl of corn and pasture. About 65,000 acre. (26,000 bm ) of cropland are under irrigation in tbe study area, eXCluding Tintic Valley (U.S. Department of Aariculture, 196 9, p. 26 afd 28). Tiati~ Valley vaa eatimated to bave fever thaa 1,000 a~r ... (400 bm ) of irriaated farm1aad. Surface Water the Sevier River i. the major atream in tbe area. The river enters the atudy area through Leamington Canyon, travel. loutbve.t acroas tbe aoutbel'Q part of tbe area, and dilcharge. into Sevier Lake playa during infrequent perioda of very high flov. Y'luring normal runoff years, tbe vater entering the Itudy area in tbe Sevier River ia completely diverted for irrigation and doe. Dot reach Sevier Lake playa. The average ~nflow to the study area in tbe Sevier River i. 162,980 a~re-feet (201 hOI ) per year (U.S. Departmeat of qriculture, 1969, p. 63). Several perennial, intermittent, and ephemeral strea.a originate in tbe Itudy area. Perennial Itreaml include Oak and Cherry Creeks, and Pole Creek (pueonial in lome reaches>. .ajor intermittent atream. include R.oad, Birch, Bop, aDd Fool Creek.; and .ajor ephemeral .tream. are Tanner Creek and Sva.ey Waab. Figu(e 2.-Location of the study area. 15 14 ·12 +lDD +!I +2110 Recorda fro. continuoul-recording gagiog .tatiolll vere used along vith +100 ~~ .Iti.at.a of annual rUDoff de rived from channel-geometry IDe •• urement. for pereanial, iDteraittent, and ephemeral Itreama (uliog tecbnique. of Hed.an and Ii I •• tner, 1977. and Field., 1975) to .Itimate runoff from are •• above an II -100 altitude of about 6,000 feet 0,830 .. ) iD the e .. terD aDd DortherD parta of ~~ -s: -2110 tbe .tudy area. Healurement. of runoff from represent:cive are •• or .Itimatel -!I liz ba.ed on cbanDel geometry vere related to drainage area, and the relationlhip I! -12 1935-81 """!IIlnnUlI ptlClpilition -JOD v •• uateS to •• timlte rUDoff from are •• with DO runoff record. or cbaoDel 12.42 inch .. (315 mml S- -15 -'flO leoaetry 1Ilea.urer.enta. The relult. indicate an annual runoff of about 11,01)0 -18 acse-feet (14 h .. ) fro .. the CanyoD IlouDtaiDI aDd about 15,600 acre-teet (19.2 ~ ~ -r§, boo ) froll the GilsoD aDd Sheeprock HountaiDs. The co .. biDed anDual rUDoff froll ~ 1 ~ ~ ~ all other area. on the aoutr and welt aide. of the .tudy area va. e.timated to be 8,000 acre-feet (9.9 hID ) per year. Figure 3 . -~umulal i ve depanure from average annual r>recipilalion al Oak City. 1935-81 . GROVND-WATER HYDROLOGY Cround vater in the Sevier De.ert i. pre.ent in both conlolidated rock. aDd UDconlO 1 ida ted ba. in fill. The pr incipal ground-vater re.ervoir in the Sevier Delert il the uncoa.lolidated balin fill, but conlolidated roekl in the .0Ulltailll and in lOme local are. I on the ba.in floor are important ,ouree' of vater. Conlol idated Rock. Conlolidated rock. yield vater to eprin,1 in the mount.ina and to a fev vella aloDa the .. araiOl of the basiD.· Th. laraeat kDOVD yield fro .. cODOolidated roclta ia at Clear Lake SpYiDga, (C-20-7)3d-S, v\ere the avera,e aDDual diacharge duriDg 1960-64 vaa 14,900 acre-feet (18.4 hID). Tbe apriDg • . dilcharge fro. baaalt of the PavaDt Flow of late Pliocene or early Pleiatocene a.e (Hover, 1967, p. E9). Other large apringa diachargiDg fro .. cODaolidated roclta are aak- r H~t SpriDga, (C-14-8)10dca-Sl, vith a di.charge of about 2,000 acre-feet (2.5 hID ) per year fro .. volcaDic rocka; aDd I'!j'iaD SpriDgI, (C-12- 5)16aca-Sl, which diachargea about 800 acre-f eet (J.O h .. ) per year fro.. the Salt Lake(?) PormatioD of Pliocene(?) age (Enright aDd Hol.. ea, 1982, table 2). VelIe completed in con.olidated rocks bave variable yield •. Conglomerat es of Tertiary age yield vate r to well. near Oak City, and the Salt Lake{ ~ ) For.atioD of PlioceDe(?) age yielda vater to a well iD TiDtic Valley (HOW H aDd Feltia, 1968, table 2). A deep oil-t eat hole iD aec. 23, T. 15 S., R.7 V. floved 800 to 1,200 ,allooo per lIiDute (50 to 76 L/a) of vater fro. fertiary aedi.eDu aDd volcaDica at a depth of about 10,000 f .. t (3,000 ») (Baa .. aDd Pitzer, 197 8, fif, o 6). Vella 80uth of the atudy area Dear Flovell iD 'a.. aDt Valley (27. .. i or 43 k .. aouth of Delta) obtaiD larae yielda fro .. fractured b ..clt aquife .. (Hower, 1965, table 8 aDd p. 40), aDd .. ight yield aublt.ntial ..ount. of vater to _~ e ll. in the Sevier Delert, altbough .o~e telt drilliD& viII be Decellary to verify thil pOI.ibility. 10 ceneral, conlolidated rockl cOUl i .tiog of cooclomerate of Tertiary ase yield vater to ••111 on the b.lin floor, and Pre-Ceno%oic ledi.eotary and metuorphic rockl ,.ield vater to apriDga iD the mountaina. 17 16 Unconsolidated 8asin Fill NorthuJt The principal aquifers of the Sevier Desert are within the unconsolidated balin fill, although in the extreme southeastern part of the area, basalt may METERS yield large quantities of water to ve1ls aa it does in the adjacent Pavant 'UT 11 'Valley (Hover, 1965, table 8). The uncon.olid~ted ba.in fill, .. identified in drillers' logo of well . (C-1S-S)33dcb-l and (C-16-S)9aaa-l (Enright and ~ Bolae., 1982, table. 1 and 5), i. at least 1,300 feet (396 II) thick and may be South_t I \Soo aa thick .. 2,140 feet (652 m) (Mower and Pelti., 1968, p. IS). ] j ; S j The ba.io fill generally consiatl of alluvial-fon and aeolian depolitl ;; j 1 ~ algna the edgel of the basin and fluvial depolitl of the Sevier River : : i i interbedded with lacustrine dep08it. of Lake Bonneville and prubably older ~ ~ ~ ~ ~ lakel io the center of the balia. The fluvial depolita become finer grained J ~: . : W".,'·,.oI.lIQulf., from the ealtern side of the baain tovard the velt and louthvelt. until Cortfln1ne • ol,ltbvelt of Delta, the fluvial depolitl caonot be dil tioguished froo the ..... 1400 fia.e-a-rained lacustrine depolitl. In general. the fluvial deposita consist of .and and gravel, and the lacultrine depolits conlil: of clay. lilt. land. and ,ra"el. Mover and Felti ~ (1968, p. 23) divided the ground-vater reservoir in mOlt of the Sevier Delert into upper and lover artelian aquifers, a lower per.eability zone (or confining bed) betveen them, and a vater-table aquifer, except along the vestern, eastern, and northea.tern margins of the basin fill . 1300 vhere there is only a single aquifer under vater-table condition •. In t hi. report, the upper and lower arte.ian aquiferl are termed the .hallow and deep arteaian aquifera, following the unge of Hower (1961 ond 1963) and Boll1e. and Wilberg (1982), and tbe basalt aquifer in tbe extreme loutbeaatern part of tbe atudy area i. included in the vater-table aquifer. A generalized geologic lection near Lynodyl, Utah (fig. 4) .hovi lithology ODd divisions of the around-vater reservoir; and an idealized ero •••eetion ea.t-welt aero •• the Sevier De.ert (fig. 5) IhoVI the various element. of the ground-water 'Yltem. 1200 At ao.t location_, there are tx? c1eareut boundariel between the aquifer. and confining beds. The eltimated thicknes. of the vater-table · aquif er in the center of tbe basin i. SO feet (15.2 m); but the voter-table aquifer near the .ountain frontl, where it includes beds that are latera1:y equivalent tu tho.e EXPLANATION of the arte.ian .quiferl, liIay be leveral hundred feet thick.. The vater-table aquifer in the center of the ba.in eonlilt. of predoainantly fine-grained c..... v .edilaent •. lAND 1100 tbe .hallow and deep artl.ian aquifer. are ea.ily identified near GRAVEL LY'DDdyl, but al tbe uncoDlolidated depo.itl become coar.er grained toward the CQNOU.. fIlATi Canyon Hountailll 00 the east, or become finer ITained tovard the cente'r of the """"bit .. PI",,",", b •• in near Delta, the leparation of tbe aquiferl becomel difficult (fig. 4...... Ifrom~kh and Kover and Peltia, 196 8, pl. 3). The thickne .. of tbe confining layer ... - ..__ IMid between tbe Iballow and deep artesian aquifers rangea from about 400 to 500 feet (120-150 a) nUr Lynndyl to about 100 to 17 S feet (30-53 .) near V...... rMion.1O Su,arville (Kower and Feith , 1968, p. 30). Tbe layer coalilto of bed. of 1 J f ,"'LII clay and .ilt with SOme .and and aravel. We.t of Sugarville, the .ediment. of I ! 1 I , KILO""•• ' the coofioin, bed may become more coar.e grained, and the aquifer. and Figure 4.-Generalized geologic section near Lynndyl, Utah, showing lithology and divisions of the ground-water reservoir (modifie 18 19 SoeSuR~lIG~ 11U~ FRo'" PfW/tAlr "IILLE! 11.,0 COI\ISjL IOATEl> ~oc.Ks 01= f'lOIJNTAltJ /fREAS DEE P ARTESlRAJ IUW'fE~ - - --- Figure 5.-ldealized east-west cross section of the Sevier Desert showing the elements of the ground-water system. confining bed may coalesce into a .ingle .omewhat fine-grained, artelian Hover and Felth 0968, p. 25-26) reported that the Sevier River is a aquifer. The confining bed may pinch out near the mountain front. where tbe a.jor .ource of recharge to the Sevier De.ert. Hore detailed recent studies entire gfound-vater re.ervoir i. under vater-table condition •. by Herbert and other a (1?82, p. 4-5) ahov that the SJvier. River in .1980 had a net ,.in of about 9 cub.c feet per aecond <0.25 .. 'a) .n a lect.on of the the deptb to water in tbe unconlolidated ba.in fill range. from .everal ~iver near Leamington, although tbe upper part of the reach Itudie! in ' hundred feet in the vater-table aquifer near the mountainl surrounding the Le •• inaton Canyon did have a 10 •• of 4 cubic feet per aecond (0.11 m ,.). b •• in to leveral feet above land surface in the artesian aquifers in tbe DuriDI period. of large ground-water withdrawal. and resulting water-level center of the balio. The altitude of vater levels i n the uncon.olidated ba.in decline., lome water from the Sevier River probably infiltrates the upper p.rt fill locally varin with depth. Hover and FelH. (j 968, p. 30) reported that of tbe Ifound-vater re.ervoir. in 1964 vater levels in the deep artesian aquifer ~ere about 20 to 30 feet (6.1-9.1 .. ) bigher than vater levels in the ahallov artesian aquifer along a Seepase froo canala.--Rechnrf,e from canal .eepage wal eltimated using the line atending through Delta and Sugarville near the center of the b•• io. The re.ulta of .eepage and infiltration studies. The U.S. Bureau of Reclamation dif~erence in vater level. relulted from 101. of bead a. vater from the deep (Pal .. er B. DeLone, vritten com .. un., Dece .. ber 8, 1970, and February 24, 1971) aquifer moved up,,-ard to the .hallow aquifer. No differences in vater level., conducted a .eepage: and infiltra.tion study on the Central Utah Canal betveen a bowever, vere ob.,erved between the .hallow and deep arte.ian aquifers in the point 100 feet (3,) .. ) downltream from the feeder canal turnout for Foo 1 Creek Lea.ington-Lynndyl-Oak City area on the eaatern side of the ba.in. Water leeervoir No.1 to a point 200 feet (61 .. ) aouth of State Highvay 26. Only level aea,urelDent. in Harch 1981 near Lynndyl .how vater level. in the .ballov 18.5 .. ilea (29.8 km) of the 28.4 miles (45.7 k .. ) of the canal that are witbin arteaian aquif er vere about 10 to 20 feet (3.0-6.1 .. ) bigher tban voter levela tbe atudy area (pI. 1) vere included in Delong', atudy. Tbe U.S. Geoloaical in tbe deep arteaian aquifer [Enright and Hol .... , 1982, table I, vella (C-15- Survey (Herbert and others, 1982) conducted seep!lge studies in 1980 on the S)33dcb-l and (C-15-5)33dcb-2). Part of the difference probably is cauled by Leamington and McIntyre C£nals, and on a section of the Central Utah Canal. puapiog from tbe deep arteaian aquifer that ha. lovered water level. in that The aection of the Central Utah Canal vas not previously .tudied by the Bureau aquifer more than in the Ihallow arte.ian aquifer. of leclagation and include. that part of the c.nal between the diversion on the Sevier River and the feeder canal turnout for Fool Creek Reservoir No. 1. iecharge Relult. of the .eepage and infiltration \tudies indicate an average Ie charge to tbe uncon.olidated ba.in fill il by leepage from .tream. .nnual 10 .. of .tout 12,000 acre-feet (14.8 b .. ) from tbe Central Utah a~d aloq the mountain front" canal. , re.ervoir., and from uncon.umed irrigation Hclntyre Caula. Thil figure con,ists of about 10,500 acre-feet 02.9 bm ) ,vater; lub.~rface inflow from con.olidated rocks of the mountain area.· .per year determined from the data of Palmer B. Delong (U .S. Bureau of precipitation on ba.alt outcropl; and lublurface inflov frolll adjoining area.: leclaaation, written commun.~ December 8, 1980, and February 24, 1971) and Ho.t of the recharge to the unconlolidated ba.in fill is to the vater-table about l,SOO acre-feet (1.8 bm ) per year baaed on the atudy of Herbert 3and aquifer near the mountain front. and it tben .ove. directly into tbe artelian otbera, 1982 [5 percent of annual diversion of 30,000 acre-feet (37 b .. »). .' aquifer.. the lar&e.t 10.le. occur near Oak City where infiltration rates of about 47 feet 04.3 .. ) per day vhen the canal vaa e .. pty and 7 feet (2.1 m) per day vhen Seepage from Itreaml.-Seepage .from .trealla i •• major aou:rce of recharge the canal vas full were aea.ured by the U.S . Bureau of Reclamation ulin& a to the unconlolidAted basin fill. Tbi. rech.rge: occurl .o.tly in the northern pipe driven about 8 to 12 incbes (203-305 mm) into tbe aand and gravel and ea~tern part. of the .tudy area, vhere .tream. originating in the underlying th~ C'!Dtral Utah Canal. The infiltration rate measured at tbi. • ounta1n. flow a cros. permeable alluvial-fan or aeolian depo.it. above an .ite va. more thl.n 10 time. greater thaD rates mea.ured at four other .ite • altitude of about 5,000 feet 0,500 .. ). Recharge fro ...trea .. a in tbe .outbern along the canal. and weltern part. of the .tudy Irea probably ia .mall becau.e of the .mall aDDual precipitation and re.ultant lack of Itr.amflow in tbeae area •• Seepage from canal. in the irrigated area. around Delta probably il • •• 11. Fine-grained deposita at or near the land .urface and an e,: ten'l'!'e 3 lecharge from Itreamflow i. eltimated to be about 27,000 acre-feet (33 program of canal lining that began in the 1960', probably limit recharge frOID ba ) per year. Tbi. repreaenu 78 percent of tbe available atrea .. flov canal aeepage in this area to •• mall amount. The .mall amount of recharge (excluding tbe Sevier River) estimated in the .tudy area from Itreamflov that doe. occur probably moves t~ drain. in the immediate vicinity of the record. and channel-geometry mea.urement. (.ee page 17). Tbe 78 percent canal •• fiaure .va. ,derived by a •• uming all tbe vater in .trea •• originatin8 in the aOUDta1cI 1n the northern and .aatern part. of the atudy area infiltrate . Soa. recharge by leepage fro. canall that collect the di.charge from before reachin8 tbe b •• in floor, and that evapotran.piration lo ~ ae. are drailll .ay occur northve.t of Delta, wbere the water levell in the upper part iNia,nificant in tbele northern and .a.tern upland bench area •• of ·tbe unconaolid.ted b.. in fill .. ay be lover than the bot to.. of the canala. Canal di.charge in tbi. area va. mealur!d and e.timated on July 30, 1981, to be about 6 cubic feet per aecond (0.17 .. ,.) (lIo&er Walker, Sevier River Water 21 22 ComGliaaioner, vritten commun., Augult 2, 1981). For the purpos e of thi. ..taated tbat about 1 inch (25.4 ... ) of preClpltation on the b.. alt flov near J report, it vaa estimated that 15 percent 01' about 700 acre-~eet <0.86 h.D. ) ~er P.va~~ Bu~te recbarge. tbe aquifer. Oaing ~bi . estimate, recharge from year of tbe flov in the canall recba~gea the unconlol1dated ba81n f1ll preClpltat10n on .bout 80,000 acrea (32,000 hID ) of b.. a1t in th) atudy area DOrtbvut of Delta. (Kover and Pettis, 1968, pl. 2) i. about .7,OOO acre-feet (8.6 b .. ) per year. rbi. a.auae. tbat all the bl.alt i. permeable and vater in it i. in hydraulic Seepage from reaervoirs.-Reservoir aeepa,.e rechargel .the unconlolidated connection with the re.t of the around-water Iy.tem. ba.in fill at Fool Creek Reservoirs Nos. 1 and 2, about 4 ll111e. (6.4 km) soutb of Lynndyl (pl. O. Seepage from the tvo re.eevoirs was estimated by the U.f. Ie charge frOID precipi tat i ,n in the remainder of the Sevier De.ert i. Department of Agriculture (196 9, p. 63) to be about 2,000 acr.e-feet (J.~ bm ) a.all. Kover and Fe1ti. (1968, p. 24-25) eati",ated Shat fro .. 1949-64 recbarge per year. Delta and Gunnison Bend Reservoirs along the Sev1er R1ver 1D tbe fr~. precipitation totaled 17,000 acre-feet (21 hID ) or 1,100 acre-feet (1.4 Itudy area are underlain by f in~-g~ained .edim.ent and any seepage from . them ba ) per year and occurred only in tbe winter and .pring of 1951-52 and 1961- probably return. to the river vltbln .. abort dlstance and doea not contr1bute 62 vben the December 1 to Harcb 31 precipitation exceeded 6 incbea Cl52 .... ). liln1ficant ~ount. of recharge. Durina year. of normal precipitation, recharge from precipitation with the exception of -tthat on ba.alt outcrop., i •••all. ' Seepage from unconsumed irrigation wa t er.-.-Kost of the aeepage. from uncon.umed irrigation vater occurs along the mountalQ front botween Leamlng~oD Sub.urface inflow from adjoinins Irea •• -Sublurface inflow frolll adjoining and Oak City, wbere : nfiltration rates in the sand and g~ a vel depolltl area. i. an ifDportant .ource of recharge along the loutbern and aouthea.tern probably are large. Hower and Felti. (196 8, p. 27-28) e SUma t.ed s eepage bordera of the Sevier Detert. Kover (196~, p. 54) eatimated tbe total lo •• e. in this area to be greater than ~ ! percent of the water dlverted for aubaurface flow fro!, Pavant Valley to the Sevier De.ert in 1959 to be 14,000 irrigation. Alauming a JO-percent lee page lOll, and ''In eltimated average acre-feet (17.3 b .. ). Later atudiu by Kover (1967, p. £27) indicate tbe annual application of about 12,000 acre-feet (14.8 bm ) of water from tbe .arlier eati.ate of aublurfa ce outflov from tbe four louthern ground-vater Central Utah C,oal (Roger Walker, verbal commun., Jan. 19,.1982), 5,.500 a~re 3 diatrict. of Pavant Valley va. low by about 30 percent. Aa.uming the tvo feet (6.8 hlD ) from Oak Creek (etticated f,roc U.S. Ceologlcal Survey g~gll:~ northern around-vater diltrict. were undere.timated by the .a.me percentage, atatioD recordl), 9,600 acre-feet 01.8 hm ) froc t~e He Intyre and Leaul1ngton tbe total flow fro .. Pavant Valley to tbe Sevier Detert during 1959 vould be Canal. (e.timated from data from thJ .eepage Itudlel by Hecbert and othera, about 18,000 acre-feet (22.2 bOl 3 ). Hover and Feltia (1968, p. 28) eati.ated 1982) and 2,400 acre-feet (3.0 bm ) fro .. ground-wa ter withdravah, tbe .ubaurface flow from the Beaver River v~lley (including inflov frOID the • lti1D~§e:d recharle from unconlumed irrigation vater i. about 9,000 acre-feet llilford area) to be 1,000 acre-feet 0.2 b::l ) per year • .(11 b .. ) per year. Movement In the irrilated farmland around Delta, wbere fine-grained depoaitl are at or near the surface, the leeplge 101les from unconsumed irri.glt.ion water Ground water in the uncoD.olidated ba.in fill in the Sevier De.ert probably are .mall. The unconsumed irrigati on water that does lnflltrate to lenerally lIlove. from recharge area. near the countaina on t he northea.t and tbe vater table probably movel Ihort dilta nce l and dilcharge • . to. a co.mplex ea.t toward di.charge &real in the ve.tern part of the .tudy area. Near tbe .y.tem of drain., and .Ome of this water ia rediverted for 1rr1gat100 ~n aoutb of Leamington Canyon, ground wa.ter GlOve. tovard and di.charge. to the lover lying landl. Ho . t O f; tbe drain vater, bovever, eventually ponda lD Seyier River, and in the loutheastern part of the .tudy area, ground water larae Wlvegetated areal and evaporatel .. lenerally move. weat or northvest from Pavant Va.l1ey tovard Clear Lake Sprin.g. (Kover, 1967, p. E15). Plate 1 .bov. the ~otentiometric .urface of the If vater levels vere to decline by an estimated 10 feet (3.g Gl) in the .ballov arte.i8n aquifer in March 1981, and tbe altitude of the potentiometric irrigated areas near Delta, an eltimated 10,000 acre-feet (12.3 bm ) per year aurface in the deep a.rte.ian aquifer at well. wbere water level. could be of vater migbt not be 1i.cbarged by drain. and would add to the total .u.ured. Sma.ll aoomalie. in the potentiometric lu,rface aear Delta are cauaed recharge .. by withdrawala of water for irrigation or municipal u'e. Data were Dot .yail.ble to conatruct a map .bowing the altitude of the potentio.etric Sub.urface inflow from consolidated rockl 'along the mountain fronta • __ aurface in the vater-table aq iter. . Kover and Felti. 096 8, p. 28) .uggeated tbat .ub.urf~ce inflow t~ tbe uncoDtolidated balin fill in the Sevier Delert from COololldated rock~ 10 t~e Ditcbarge .ountains may be an important lource of recharge. Data collected du.rul' th11 • tudJ were in.ufficient to calculate the amount of recharge from th1. lOurce. Ditcbarge fro. tbe uncon.olidated b.. in fill in tbe Sevier Detert i. fro • Clear take Spring., .eepage to the Sevier River , evapotranlpiration, Precipitation on baaalt outcropa.--Iecbarge by preci~itation on tbe .ub.urface flow to adjoiaio.a area., and wella. aquifer outcrop probably i. limited mainly to area. wbere blghly fractured ba.ait i. covered by thin depo.it. of .oil or aand. Kover (1967, p. !27) 23 24 Clear Lake Springa.--Mo.t of the ground water entering the Sevier Desert content of 1I0re tbat 10.000 .. gIL) (Enright and Hollie •• 1982. table 5. vells froll Pavant Valley diaeharges at Clear Lake Springa (Hover. 1961. p. £15). (C-15-1l32dcd-1 anc! (C-11-9)30aab-1j. SOlie phreatophyte. in these areas lIay be Hover (1961. p. E9) report~d an .verage diacbarge .t Clear Lake Spring. of tran.piring soil moi.ture derived from precipitation that i. perched or 14.900 .cre-feet (18.4 hm ) per year during 1960-64. Heuurellents of re.tained in landy soils and may not be withdrawing much water from the ground di.cb.rge during 1969-81 by the Ut.h Division of Wildlife auourc.. (Carl vater system. In addition, evapotranspiration r~te. may be lover than Lind, vrit~en cOlllmun., Aug. 19, 1982) show a var~ation io annual discharge e.tiaeted by .tover and FeIth: becau.e of the high .alinity of the vater. froll • lIaUIlUII of about 19.900 acre-feet (23 b. ) in 1914 to • lIinillulI of .. bout 13.00g .cre-feet 06 hm ) in 197 8. and .n average of .bout 16.000 .crc Recent e.ti~ate8 of evapotran'piration based on streamflow losses in the feet (20 hID ) per year. loutbeutern Uinta Basin of ealtern Utah (HolIIOl an.d Killball. 1983. p. 41) yield • rate of ~. 05 foot (0.015 II) per year froll Greosewood-covered alluvial . Seepage to the Sevier River.--Knowo di.charge from the unconlolidated valleYI with vegetation denlities (10 percent) and water quality similar to ba.in fill to tbe Sevier River occur. primarily near and up to about Smile. that of t he Sevier Desert. Based on this rate, the amount of ground-yater (8 km) below the mouth of Leamington Canyon where vater level. in the diacbarge by evapotranspiration froll 408.000 acres 065.000 bll ) of unconsolidated basin fill locally are bigber than tbe altitude of the Sevier pbreatophytel (~over and Felti •• 1968. table 7) lIay be as s .. all a. 20.000 River. Seepage .tudie. during 1980 .~owed a net gain of about 9 cubic feet .cre-feet (25 bll ) per year. per leeond (6.500 acre-ft/yr or 0.25 II .) (Herbert and otbera. 1982. p. 4-5). In tbe reacb of the river froll about 5 to about 9 lIilea (8 to about 14 kll) Sub.urface outflow to adjoining area • . --Discharge by 8ubsurface o_tflow below the moutb of Leamington Canyon 00 'gain. to or lo •• es from the river were to adjoining arellS probably occur. along the vestern boundary of the .tudy oblerved (Herbert and others. 1982. p. 5). The .eepage studies in 1980 were are.. An apparent ground-vater gradient toward the veat and northwest (pl. 1) conducted at the end of the irrig3tioo season when di.cbarge to the river indic.tes grounc!-water floy in thai direction: Rollles (1983. table 1) derived from .eepage frOID canal., reservoirs, end uncon.umed irrigation vater eni•• ted 8.800 acre-feet 00.9 hll ) per year of sublurface outflov to vould be greater tha'l at other times of the year. Therefore the 6,500 acre. adjoining area. west of the Sevier ne.ert. foot per year (8) bm ) figure may be more than the actual average .eepage to the river in this area. The eventual discharge point for the outflov il unknown, hut 801~e and Su... ion (1918. p. 13) eltillated tbat about 31.000 .cre-feet (38.2 ha ) per Dovnatream from the reach of the river .tudied by Herbert and other. year enters the Fish Spring. Flat area, northwest of Sevier Desert, by inflow (1982). little is known about .eepage to the Sevier River. Soutbvest of Delta froll Idjoining b •• ins; a .tudy by Stephens (1911. p. 21) also indic.ted the river flow. through An are. of ground-vater di.cba rge by lub.urface inflow to lule Valley, welt of the Sevier Desert. Both .rea. may evapotranspiration where the v.ter table i. at .hallow deptb.. In thi ••re. receive sub.urf.ce inflow from the Sevier Desert. Gatea and Kruer (1981, p. the river may al.o receive seepage locally from the ground-vater reservoir. 31-38) ,ullllarized the hydrology of we.t-centra1 Utab and di.cu.sed the .- con.iderable body of evidence that .ugge.t. flov in carbonate rocks between Evapotranapiration.--Di.charge by evapotran'piration va. e.timated by ba.in. northwest and southvelt of the Sevier Desert. They mentioned the Hover .nd Fe1t!s 0968. p. 52) to be betveen 135.000 .nd 115.000 .cre-feet po •• ibility of subsurface flow from the Sevier Deaert to baaiul to the velt, (}66 .nd 216 ha ) per year. The j"tillate by How.r .nd Feltis bc1udel 3.000 but becau.e they lacked vater-level .data and bccau.e they believed the Sevier to 8.000 acre-feet (3.1 to 9.9 hID ) per year of ev.potranspiration in tbe Old Lake playa vas the ultimate discharge poiot for ground water in the Sevier R.iver Bed, wbicb is not part of t he area of thil report. The averate De.ert, they concluded the flow va. not large. evapotranlpiration rate derived from the data of Hower and Felti. 096 a. table 7) .... betveen 0.30 anc! 0.39 foot (0.09 .nc! 0.12.) per year. Vel1 ••-Tbe p..timated witbdrawal froD veIl. io the .tudy area in 1981 va. 18.000 acre-feet (22.2 b1l 3) (Enrigbt .nd Hoi ..... 1982. t.ble 1). Are .. of Ie cent .tudi .. by Van By1ck ... a (1914. figl. 34-35) in Arizona indic.te •• jor ground-vater u.e include Leamington, Lynndyl, Oak City, Delta, and that both depth to vater and soil-vater .alinity have .ub.tantial effect. on Sugarville. Mo.t of the vater withdrawn is for irrigation or municipal use, ""potraolpiration rate. of .altcedar, and tbese effect. pre.umably apply to vitb •• aller quantities for indu.try, dome.tic, and .tock. usel. The 1951-81 .... potran.piration ..tao of otber phreatophytu. Kover Ind Feltil (196 8. p. crouod-vater withdrawal. in the Sevier Desert are Ihown in figure 6 • 52-59) did DOt . pecific.lly ba.e their e.timate. of evapotran'piration ratel aD depth to water and did not ioclude the effect of vater quality in their Ground-vater withdrawal. in a given year are related primarily to the ••thod. of eatim.tion. Data collected frOID teat hole. in the Sevier De.ert avail.bility of .urface vater. During yater years 1980 and 1981. the supply of indicate that vater levell in and near lome of the pbreatophyte area. mapped lurface vater from the Sevier River as me.lured at gaging .tation 10\24000 by Kover and Feltis in the northern and vestern part. of the .tudy area (196 8, (Sevier River near Lynndyl. Utah) v .. about 164.600 acre-feet (203 h .. ) per pl. 7) exceed 50 teet (15.2 II) (Enrigbt .nd Bolo.... 1982. table 1. weU. (C- year ••bout 21 percent .bove tbe 44-year average of 135.000 acre-feet (161 3 13-f»20acb-1 and (C-13-6)26b.c-1) Ind tbat .h.llow ground w.ter baa ••pecitic (ta ). Tbi. uce••• upply of .urface vater re.ulted in 8 reduced vi~hdrawal of conductance exceeding 20,000 aicromho. per centi.eter (or a di ••o1ved-.olid. &round v.ter in 1980-81-.n aver.ge of 15.500 acre-feet (19.1 bll ) per year 25 26 ill WI 70 1051-81 .... !uge .nnu.1wi ~drlwal ... SII ill 20,000 ",.. I ... (24.7 hm') (fi,. 6)1 one-t alf of tbe 1971-80 avera,e annual rate of 31.000 acre-feet 'II SII (J 8.2 bm ) (Bolae. and otbers. 1982. table 2). lnduatrial and municipal u ... !~ probably viII iocre•• e, irrigation u.e deerea.e., and dome.tic and .tock. uael ~~ 'Ill reaaiD unchanged in the future. -~ 3D i~0:'" Hydraulic properties I: 10 f' ! 10 i aydraulic coefficient. of the arteaian aquifera i n the uncon, ol i dated i b •• io fill in the Sevier De.ert vere reported by Nellon and Thoma. (1953 , t.ble 3). Hover and feit h 0968. table 8). Hover 0963. p. 2-4). and Hover 0961. p. C94). Additional value. of hydraulic coefficient. computed from teat da ta collected durin& this study are _bOWD in table I, lome of which Figurel. .-Ground·water withdrawals from the Sevier Desert, 1951-81 . differ froa previou.ly reported value. com.puted fro. data collected during palt teat. at ~ be .ame veIl.. The primary re•• on for these differencea is the aetbod. u.ed i n the analysis of the teat data. During this .tudy the Hantu.h modified metbod (Lohman. 1972. p. 32) and the ratio metbod (Neuman and Vither.poon, f 97 2) for determining hydraulic coefficient. of leaky confined aquifera vere u.ed for aquifer teats whe n enouc.h data vere available. Theae a.thod. generally give lower values of t ranl.i •• ivity and coef ficient of .torage than tbe Tbei. curve-matching procedure (Lohms.. 197 2. p. 34) • . The tran.mi •• ivity of the .hallow artesian aquife1· , a. eatimated fro. data of ~quifer t esta, range. from a high of about 47,000 feet aquared per day (4.400 .. /d) Kover and Felti •• 1968. table 8. veil (C-lS-S)2ddc-l) on the u.t .ide of t \e study area near Lynndyl, to • lov of about 3,600 feet .quared per day (340 m /d) in the central part of the ar~a vest of Sugarville (Nelson .nd Tho ..... 1953. table J. vell (C-16-8)l9ddd-l). The tranomiuivity of tbe d~ep artesian aquif er ranges from about 27.000 feet .quared Plr day (2.500 • /d) near Lynndyl to about 2.000 feet s quared per day (190 lD /d) 80uth of Delta (Hover a.d Feltis . 1968. table 8. vella (C-16-S118caa-l and (C-17- 6)28ecb-l]. The decre.,e in tranamilsivity in both aquifers from e.at to veat probably ia related to the depos i t i on of more permeable alluvial gravels and .and. in the eastern and central part of the study area compared with the depo.itioD of fine-grained alluvial and lacu.trine depoaits in its .outbve.tern and western parts (Kower and Felti ., 1968, p. 15). There i. no aajor change in thicknel. of the aquifer. related to this change in tran ••i •• ivity. Tbe hydraulic conductivity of the water-table aquifer i s .: .tiat.ted to r.n,e from .bout 1.000 feet (460 01) per day in the b ••• lt aquifer in the extre •••outhe •• tern part of the .tudy area (Hoille., 1983, p. 8) to about 1 foot (0.3 .. ) per day in the central part of t~e ba.in. The e.tim.te. of h1draulic conductivity in the central par t of the ba.in are ba.ed on '.acription. of •• terial in driller.' log. (Hover, 1978, p. 16 , and Enright .Dd Holme •• 1982. uble J). Tbe bydraulic conductivity of the vater-t.ble .. Aquifer generally i. greater Dear the mountain fronte and decre•• e. toward tbe cuter of the b•• in. Bolm ...n4 Wilber, (1982. p. 11) deterained the vertical hydraulic couductivity of the confining bed/etween the .hallow a~d deep art.lian .quifers near Lyn" ~ yl to be 6 ,,10- foot per day (l.8" 10- ./d). 110 teat. 27 28 --_. __ ... - _...... _--_ .. _------_ .. _----_ ... _----- _.. __ .. - .. _... . - --.. ------_._------ A'lulr .. r or Vrrli,. I hydraul.c 1\,.lh"d o r (lbo ...v I on conr i IIln bl·d Tnna.,uhil)' Stur.,~", conduci tV i I Y of anal)'ol or v II nr "I' II a (r COt't "'Iuar .. " eo.Cf id ~lI t cnnr,n.n,: bo·d rd ..... n .. '''' 1'''' p r day) Cf .. r 1'''' dfty) CC-I 5-")1 9, cc-I (C-I S-")7OcM-I d...,p orl~a inn J 2.700 I "nt,,"h OIodlClcd .. ' 1 hod (r-I >- ~) Xind-I "/luH"r (Lo"an, 1912. I" ) ); 2 bu-I Palo .!'thad CI: ..... ~n , ..ul 2101tc-1 W~l h('UFO"'" J 1112); 13dcb-1 nol.~1 nnd wi \I, .. rll (J 112 ) (C- lfo-') 9.>na-1 I r. " -I 19cbd-1 (C- I )-',)1 9ccc-I do. 17,900 Stroir.ht-lin ... llu·d (I",".n. 1912, p. 23) (C-IS-S) I od-7 c"nClnin~ b~d R"t io • thod (fI ...... n " .. d 26bo .. -2 b .. lv .... n d ...·p Wilhrropoon. 1972) ; 21dcc-2 lind a""lIov 1/01. I ond IIi Ibrrlt (19112) l1dcb-2 .. rl ... inn "quiCt'r (C-I'>-',)76tfrc - I unk""vn 21 . 300 Slrail:lal-I'''O' roe 1 I. .. " (1.<>".111 . 191 2. ". 7» u""oo,, .. Z4. ')(l(I l/ant,,"10 IIOdifi .. oJ a .·tho'! (1..,1.0 .. , 1972 . p. )71 (1" - 1 'i-'i)'1,lcb- I (1;- I S-S)3Jdcb-I d .. cp nrlroinn 11,000 IIqu If rr ( -I \ 10) I'lhcr-I (C- I 5-(,) I ll>cc-1 do. CI)S,400 ~dHi .. d 01,,, •• IIon"'I',il . I ?ccc-I brh. "chod (I"lf· l loK)uut:un (C-I S- ~ ) 11ddd-2 Pow .. r Pr"jrcr. 19/.1, p . I',) dOl . II, 'iOO ~ . rlllr.hl - I i nO' .clho,1 (t.olo."n, I 911 . I'. 7) I rftn- I 11'",,,"-1 do. 1.700 "' .. I t;,...... d .. I 'khd- I do. It. )0 lin • (.;-\1 - (,) 2"r. t-I ( .-Il- I,)l"ccc-I fin . I.O()O 0.• • ~------. - .. --- - _.. ----_ ... __ ...... -_ ... _------.. . 29 / vue .ade that yielded a value for the vertical hydraulic conductivity of the concentratioua vere in vater from veils perforated above 200 feet (61 m) in ..terial overlyina the .hallov artelian .quifer. the loutbveltern part of tbe .tudy area. where dislolved-solids concentrationl can exceed 10.000 milligraa. per liter • . Tbe.. larse concentration. prob.b1y The .tor'le coefficie.nt of the arte.ian aquifers estimated from aquifer re.ult fro. evapotran.piration wbich bal c~)Qcentrated .alt. in the vater-table 2 t ..to 5rangeo fro .. about 2 ,,10- (Hehon and Tho ..... 1953. table 3) to about 6 aquifer; or in tbe clle of VAter fro .. vell (C-20-12)laac-l. tbe large ." 10- (Hol.eo and Wilberg. 1982. table 2). The .pecific yield of the vater concentration of di.solved solid. may reflect the aovement of .batlov ground table aquifer i , ..ti .. ated to ranae fro .. about 0.27 near tbe .. ountain fronte "aUr fro .. Sevier Lake playa tovard tbe northveet (pl. 1). Tbe 1r rge to about 0.02 i " tbe center of tbe buin. Tbese value. are baaed on e.ti.. ate. concentration. of sodium (13.000 mg/L) and chloride (28.000 .. gIL) in thi. of .pedfic "ield f rom other atudieo tabulated by Jobp.on 0967. table 29) and '''ple, vhicb are product. of evaporation, seeu to support thi. contention.. ducriptioDO of .. " erial in drillero' log. (Enrigbt and Hol .. eo. 1982. t.ble 3). Extremely large concentrationa of arlenic have been found in vater frail '0 •• veil. in the Sevier Desert. The arsenic concentrationl in water ,ample. Storage froa the artesian aquifers are IboWD in figure 7. The largelt oblerved concentratiogl are in the louth-centr.l part of the .tudy .re. and may be tbe .aount of recoverable vater in .torage in the uneon,olidatfd b •• in related to the volcanic deposit. in the Black Rock De,ert. fill i. eoti.ated to be about 200 million acre-feet (250.0fO b .. ). Tbe e.ti•• te i. based on an area of 2,000 .quare mile. (5,180 km >. 'D average Concentrationl of nitrate plu. nitrite (reported in mglL a. N) in water oaturated tbickne .. of 1.000 feet (305 .. ). and an esti.. ated average 'pecific fro ••ome l.rge-dilcharge irrigation welll in the' Oak City-Fool Creek .rea yield of 0.15. Tbe eOCimate of .. t erated thickne .. i. bigher than tbe 77 5 unge fro .. about 4 to 22 milligram. per liter (Enright and Holmee. 1982. p. feet (236 .. ) reported by Hower .nd Felti. 0968. p. 36). Drillina .ince 1963 51. 53). These large concentrations Clay be th\! relult of downw ard le.k.ge of hi. indie.ted that 'Itur.ted depoe it. containing fresh vater extend to • depth uDconlumed irrigation water contaminated with lIaterial dillolved from of about 1.300 feet (400 Q) near Lynndyl (Holme. and Wilberg. 1982. table. 1 fertilizer, animal waite, or leptic-tank effluent. and S). TbuI, an average •• tur_ted thickness (including confining bed.) of 1.000 feet (305 .. ) v .....u .. ed. CHANGES IN GROUND-WATER CONDITIONS. 1963-81 The •• ti•• te of vater in .torage va. made ",uming that vater level. viII Cbanae. in ground ""'Vater conditionl aince 1963 include iDcre.led ground be drawn down enough 10 that the artelian aquifer. are devatered, and that a vater withdrawall, declines in water levell, and deterioration of water ,Ipecific yield typical of vater-table conditionl viii govern tbe am ount of quality. ' vater relealed from Itorage, rather than an arte.ian coefficient of Itorage. Ko.t of tbi •• tored ground vater ia frelb. but 'Ome is of poor quality. Ground-Water Withdrawall e.peeiolly tbat in tbe vater-table aquifer in tbe central part of the .tudy area. Ground-vater v ithdrava la during thj 18-yeer period fro .. 1964 to 1981 ."eraged about 27.500 acre-feet (33.9 bm ) pel' year. almoet threj timeo the WATEIl QUALITY l3-year 1951 to 1963 average of About 9.600 acre-feet (11.8 b .. ) per year (fig. 6). MOlt of tbe inc rea led vithdrawals vere from tbe deep artelian The cbeaical quality of .... pIe. of vater collected fro .. vello and .prina' aquifer for i rrigation. in tbe Sevier i) elert i. reported in Enrigbt and HoI .... (1982. table 5). Di ••olved .olid. in Ipring vater ranged from 3.710 ailligram. per liter at (C- Since 1963, annual vi~bdravall from vell£ have been .. lov al 13,000 to 14-8HOdca-51 to Ie.. tb.n 100 ailligra... per liter .t .prina (C-16-3)8abd-Sl. 18000 acre-feet (16-22 h .. ) during yeara vhen .urface vater for irrigation "a·. plent iful (Iuch .. 1970. 1971. and 1980); and u bigb 81 40.000 to 49.500 In leoeral. the c ... o 'pringl dilcharging from ba.alt flovl of late Pliocene or 3 urly Plei.tocene age contained larger concentrationl of di.lolved solid. than acre-feet (49-61 h .. ) during yeara vben .urEace vater v .. in Ihort ,upply Iprinll di.charging fro. other con.olidated rocks or uncoololidated b.,'io (.ucb .. 1977. 1978. and 1979). fill. Data on 'pecific conductance of vater fro ...prina. (Enrigbt and Hol.. e •• 1982. table 2) indicate tbat vater dilchorsed fro ••lluviull of Quaternary 'ge Water Leyell ,eoerally had a lover di •• olved-Iolid. concentration than vater fro. cODlolid.ted rock •• Vater level. generally have declined in tbe area .ince 1963. Are .. of .ilnificant vater-level chonge in the .ballov orteaian aquifer during the 18- Di ..olved .olid. in vater fro .. velll rans~d froa about 200 .. illigra.. 1 per "ear period fro .. Harcb 1963 to Harcb 1981 are .hovn in figure 8. Ha"i.us liter for vell (C-16-5H9cbd-l to about 49.000 .. illigra... per liter for vell dec lin.. of 10 to 13 feet (3-4 .. ) occurred over leveral .quare .. il .. of tbe (C-20-12)la.c-1. Tbe •• alle.t concentration. vere in vater fro .. veIl. .tucly area about 4 ail .. (6 k .. ) v .. t of DelCO. Water-level chansee in the perforated d.eper thon sao feet Cl52 a) betveen Lynndyl and Delta. The lorgut part. of tbe Itudy area not .hovn in figure 8 vere Ie .. tban 5 feet (1.5 .. ). 30 31 E XPLAN ATION .8 LL FROM WHICH WATER SAMPLED FOR ARSENIC ANAL YSIS.-Numbor Is COOWOIl .. II00 10 mlcto or nlS PIn Iller ---IO-LINE OF EQU"L "RSENIC CONCENTRATlON.-ln ••, ... 1 It n,l.ble. Oatllod wh.,. app,ow. In", ... It. CI • • ___ bOUNDARY 01- STUD V AREA.- 001. end dasI lIklOW ""41 1\JgII d. ,Ito I. , • • ) . , I I . , • . I. ' _. I.' •. •• ,. r ...... ,C •• a",." ,. • • U I "," •• ,. 1: 1 • •••• ·-l..L-"TI-----" It tl l .. 1I111 Figure? .- Ar sellic cO Il c:~n llatiol1s in water in lhe artesian aquifers. 1979·81. T. 15 S. T. 17 S. EXPLANATION • OBseRVATION WELL --S_ - LINE OF eOUAL WATER·LEVEL CHANGE IN THE SHALLOW ARTESIAN AOUIFER MARCH 1963 TO MARCH 1981. IN FEET.-O.hed wh Ie .Wlo.lmale. InlofV41 h 6 I I. R. 7 W. OECLINE RISE 11 ..,1 llee,1 ~ I 1 I 1 tM1L.ES & I 5 r 1 KIL.OMElERS t] ()'6 D.... ()'6 ~ &-10 ~ I()'I3 FiOlire 8 . -Ar~s of $igniflllll wcJl ' I ItNt.! c;hdllye in Ihe shallow arte:.iilll ilQllilcr. March 19 310 Mm h 1981. Water-level cbanges in tbe deep artesian aquifer, as measured in 13 wells, sre sbovn in figure 9. W ter levels declined by as mucb as 19 feet (5.8 m) about 2 miles (3.2 k ) south of Delta. The vater-level declines in the deep artesian aquifer south of Delta probably are due to increased ground-vater withdravals for irrigation and municipal use. The vater-level declines in the .hallow artesian aquifer v st of Delta also may be related to increased grnund-vater vithdravals from the deep artesian aquifer. Lover levels in the ~eep aquifer either have caused downward leakage from the shallov to the deep artesian aquifer or less upvard leakage, vhich has in turn lowered water levels in the shallov aquifer. The area of greatest decline in the shallov aquifer does not coincide vitb the area in vhicb veIls completed in the deep aquifer shov large declines. This "1 be due mo.tly to a lack of data from both aquifers in the same area •• One veIl near Oak City had a vater-level ri.e of about 5 feet (1.5 m) (fig. 8). The water-level rise in this area m~y be related to a rise of up to 17.2 feet (5.24 m) in this area that occurred between Karch 1980 and tlarch 1981 and that vas caused by above average precipitation and a decrease in the withdrawal of ground vater for irrigation from March 1980 to Karch 1981 {Herbert and others, 1981, p. 10}. The decline in vater levels over most of the rea caused some of the veIl. reported as flowing in Karch 1964 to cease flowing by Karch 1981 (Kower and Feltis, 1964, pl. I, and Enright and Holmes, 1982, pl. 1). The area in vhich veIls flowed in 1981, however, is only slightly smaller than the area in vhich veIls floved in 1964. Water Ouality Bandy and others 096 9) documented th deterioration of ground-w ter quality in the shallow artesian aquifer in the Leamington-Lynndyl area of the Sevier Desert during 1958-6L Since 1968, quality of ground water has continued to deteriorate in the area near Leamington and Lynndyl, as illustrated in figure 10 by measurements of specific conductance of water from four veIls, and by increases in sodium and chloride ions in water from veIls (Enrigbt and Bolmes, 1982, table 5). At vell (C-15-4)8cba-l, the concentration of sodium and potassium (as Ha) in vater increased from 241 milligrams per liter in 1967 to 316 milligrams per liter in 1980, and the concentration of chloride increased from 665 milligrams per liter in 1967 to 690 milligrams per liter in 1980 (Enright anc! Holmes, 1982, p. 48-49). The actual area of deterioration probably includes veIls farther vest than those sbown by Bandy and others (1969, fig. 6), as snovn by increasing specific conductance in vater from vells (C-15-5)2ddc-l and (C-15-5H3bbc-l (fig. 10). The deterioration of vater quality in the area probably results from poor-quality water recharging the ground-vater system. Kuch of the recharge to the unconsoli~ated basin fill in the Leamington-Lynndyl area is froQ unconsumed irrigation vater, seepage from canals and reservoirs, and possibly some infiltrat: from the Sevier River during periods of large ground-vater . vithdrawals resulting vater-level declines. Tbis recharge has a 34 t. II I . 1 ~'\ .'; ~"! .' ,', ~':"" '.~ I . I • • 4 'J' I .1,1 I " ' • • .('j . ,t , /r"I •• ...... ,." . ,. ~ J(II.' 1/ . " 4. d ( f. I . .., I. EXPLANATION .-tJOBSERVATION WI:LL-Numblr II _Itl·lewl I Ie (i) J or decline: 1-I,In I ...,. Meidl 1963 '0 Mwc:h 1981. o !- ri;;~~~~~:;~~~--~~~~~=i~::t-~~::~;;.~::~ BOUNOARY OF STUDY AREA.-Dou and dash" ,. .. I . ~- 11 I show dOlllni191 di\ de. 1./ , r'''';' I I .. • • It I . t . I' I . t . ' I. •. • ...... •••• r, •• •• •. ,." ,,1. 1' ,., .• , It .,LI • St • • •••• • t : , • •. ••• , II UI" '" Figure 9,,,WdlCr level dldllges ill wells in Ihe deep arte!:iall aquifer, March 1963 10 March 1981. relatively llrae c.oncentration of d ",.olved mineral. (Bandy and other., 1969. p. D-231). Deterioration of vater qua : ity probably viII continue in the future under pre.ent hydrologic. conditioDs. DIGlTAL-(;OHPUTFll HODEL INC General Description of Hodel HI! (C-15-4)8cba-l Tbe digital-com puter mode l described by Holmes (1983) vat used to lZIIJ ai.ulate potentiai future gfound-water vithdrawals and their effect. on water level., recbarse. and other form. of di. ch ~l ge. The model i. a tbree g- c"DII dimen.ionel finite-diff ereoce model developed by Trescott C1 '115), and Ir?dified ::> --- by Treacott and Larson (1976) and Tonk (1982). Tbe principal ground-vater in --- ...J BII re.ervoir of the Sevier Desert va. divided into .iz model J , erl. Nodes w o ~ around the boundary of the entire modeled area and aloo.& the Sev.l.er River were l&Il held at constant head during steady-.tate calibration. The model limulated ~ recharle from .tream. infiltration (this figure al.o include•• ublurface inflow N DII ~ from cODsolidated rock); sub s urfac.e inflow frOID adjoining areas; ex: ... precipitatioD; and seepage from canals, reservoirl, and uDcon8uaed irrigation w l&Il (C-lS-4 )l8daa-l vater. Simulated discharge included that to the Sevier River, Clear Lake w~ Spring., evapotranspiration, and sublurface outflow to adjoining areas. Holmes :E HI! (1983) give. detail s of the design, construction, and calibration of the i= lZIIJ z model. w DII o SteadY-ltate calibration of the model involved comparing computed vater ex: 1l1li w -- level. in the .hallow artesian aquifer to water-level measurement, in selected ... 1&111 9--- veIl. duriag the late winter and early spring of 1952. Transient-sta te :g --- calibra tion consisted of simulating two approximately JO-day aquifer t ests and 1'111 :I: co.paring computed water-level declines or recovery to observed values; and :E lZIIJ o .im.ulating ground-vater withdrawal s from 1952-81 and comparing the computed ex: o DII vater-level chanles for 1952-82 with observed water-level changea. The (C- lS-S)2ddc-l I'round-vater budgets for steady-etate ..:: onditions (1952) Gnd finel tranlient ~ 1l1li OCate condition. 0981-81) are shovn in table 2. -- Sub.urf ace inflow from Pavant Valley and tbe Be!Ver River valley compu ted --~- by tbe model is about 11,000 acre-feet (13.6 bm ) per year higher or 60 percent bigber than previously estimated (see pale 24). Data are insufficient --- -- to verify that model-computed v alues of inflow are an improvement over previous estimate •• Because mo.t of the inflow from Pavant Valley and the Beaver River valley il di.charged at Clear Lake Springe and nearby phreatopbyte areal before it reacbel t~e main arel of ground-vater v ithdrawals in the Sevier De.ert, and becaule vater levels along the lOuthern boundary of the modeled area are not significantly affected during tran.ient-Itate (C-lS-S) 13bbc-l .i.ulatioDs, the resulte of these .illulations probably are not dependent on . ~ the accuracy of tbe lub.urfsce inflow .imulated by the mo del along its ----- eouthern and louthesstern border. IZIII -~-- The total evapotranlpirati on computed b:, tbe model. 45,000 acre-feet (55.5 ba3 ) per year under Iteady-atate conditions , ia one-quarter to one 3 1l1li e--- -:.- third of tbe previous estimate of 131,000 to 166,000 acre-feet (162-205 bm ) per year (not including evapotranapiration in the Old River Bed area) by Kover Figure 10.-Specific conductance of water from selected wells completed in the shallow artesia n aquifer. 1958-80. 37 36 Table 2.--Steady-state (1952) and transient-state (1960-81) ground-water budgets for the Sevier Desert, computed by the digital model, in acre-feet per year TraDII ient state Steady (end of 19~ - Budget element atate 81 pumping (1952) period) Recharge Stream infiltration along mountain front. and aubsurf~ce inflow from consolidated rocks of the mountain areas Canyon Mountains 9,300 9,300 Sheeprock and Gilson Mountains 17,300 17 ,300 Subsurface inflow from adjoining areas Pavant Valley 26,800 26,800 Beaver River valley (including some from Milford area) 3,400 3,400 Sevier Lake area (including Cricket Hount ins) 3,700 3,700 Precipitation on basalt outcrops 7,000 7,000 Seepage from canals, reservoirs, and unconsumed irrigation water Central Utah Canal 11,900 11,900 Canals west of Sugarville 700 700 Fool Creek Reservoirs 2,800 2,800 Unconsumed irrigation water on eastern boundary 8,600 8,600 Total (rounded) 92,000 (1) 92,000 Diacharge Seepage to Sevier River 18,500 3,600 Clear Lake Springs 19,500 19,300 Evapotranspiration 45,000 42,300 Subaurface outflow to adjoining areas on vestern boundary 8,800 8,800 VeIls o 13,600 Total (rounded) 92,000 (1) 88,000 IThe different:e between recharge nd disch rge for the transient-state &round-vater budget is becauae part of the recharge (about 4,000 acre-feet per year) ia going into ground-vater storage becauae the amount of vater pumped fro. vella decreased between 1977-79 and 198)-81, resulting in riaes in vater leveh. 38 and Felti. (1968. table 7). Recent Itudies indicate the previoul average In the fir at three .illulatioD., vater-level-change map. vere prepared rat.. of evapotranspiration, 0.30 and 0.39 foot (0.09 and 0.12 m) per year, that repre.ent tbe difference betveen the computed water levell at the end of .a, be too large (aee page 25). Tbe model compute. evapotran'pirAtion in .acb ,iautation and the 1981 water levela. In the fourth ailZlulatioD, relation to depth to water, by a .. uming a. rate of about 0.3 foot (0.09 m) per vitbdravall .~mulated vere equal to tbe 1977-79 average rate plu. 5,400 acre yur vhen the water level il at the land lurface (tbia figure vaa deri ~d froID feet (6.7 hm ) at tbe lite of the Intermountain Po\Oer Project minu. the aodel calibration pro';e •• ) and a linear decreaae in tbe evapotranspiration witbdraval. from vella for vhich vater rigbt. have been purcba.ed by the rate until it i. zero at a depth to water of 30 feet (9.1 .). The average Project (Jerry Old., Utah Divi.ioD of Water Right., vritten commun .• Aug. 16, rate computed by tbe model i. 0.12 foot (0.04 .) per year over tbe area 1982). The vater-level change. computed for the fourth aimulation are only covered by pbreatopbytea. It i. likely tbat the total evapotranapiration tbo.e cauaed by chaoae. in the location. of vitbdravall .alociated with the coaputed oy the model is clo.er to the true value than the e.timate made by Intermountain Pover Project. including reductions in witldravala irom wella Kover and rei til. for wbich vater right. have been purchased by the Project. the digital model developed in thil Itudy hal lome limitatio~.. The Vater-level-change a,pl vere Dot prepared for tbe vater-table aquifer. li.plified bou,ndary conditionl do not automatically allow changel in inflov to Vater-level and other data for the vater-table aquifer vere inaufficient to or outflow from the modeled area due to change. in hydraulic gradienta; and de.ign and calibrate the mo del in terms of thi. aquifer, and projected levels recharge is on.tant for aU .iaulation. regardle •• of actual variation. in f o't' the vater table may not be reliable. In general. change a in water level. precipitation, .treamflow. reservoir .tage, and irrigation. In addition, in the vater table near the lI.ountain fronts vere about the .ame a. cban&e. in bead-dependent diacharge from the vater-table aquifer to drain. in the vater level. in the .hallow artesian aq·uifer, and in tbe center of tbe baail ~ irrigated area. around Delta va. not incorporated i nto the model becauae of cbangea in vater level. in the vater table vere le8~ than tbole in tbe aballow the lack of data on the vater-table aquifer and becaul e of the difficulty of arteli4n aquifer . • iaulatins the network of cloaely-spaced drain. uling the model grid with itl ainim ... node .pacing of 1 mile 0.61 km). If vater lovell in tbe water-table Cround-Vater Withdrawall Equal to aquifer vere to decline by 10 feet (3.0 m), an estimated 10,000 acre-feet 3 (12.3 hm ) per year of vater diacharged to drain. aigbt remain in the water the 1977-79 Average Rate table aquifer. but this potential ".ource" of vater cannot be accounted for by the .odel aa it i. prelently de.igned. Al.o. diacharge by aub.urface outflow Cround-vater vithdravala equal to the ' l W7-7 9 average rate over a perio~ to adjacent area. i. aa.umed to occur only in the vater-table aquifer. of 20 yeara 0981-2000) would cau.e vater-level declinel of more than 40 feet Deapite tbe.e limitationl, the model reproduced oblerved water-level cbangea (12 .. ) in the deep arte.ian aquifer near Lynndyl (fig. 11), and vater-level betveen 1952 and 1982 reasonably vell (Holmes, 1983, fig. 7), and .hould make declinel of 1Iore than 15 feet (4.6 11) in the ,hallow artesian aquifer near the .ati.f.ctory projections of the effects of future &round-water withdraw.ll on Fool Creek Reaesvoiro (fig. 12). Tbe 1977-79 average vitbdrawal oi 43,400 a:round-vater levela. acre-feet (54 bill ) per year i. tbe higheat 3-year average on r ecord (fig. 6), and tberf:fore, tbi. lillulation repreaenta tbe vorat pOlaible ca.e baaed on Proiected Effectl of Future Ground-Water Withdraval. previoul bi.tory. The aigital-coaputer model val used to project the effect. on vater At the end of the 20-year period. the Sevier liver viii no longer be a levela or future ground-water witbdrawala over a 20-year aLDulatioD period liDe of Det dilcharge, ~ ut i D.tead will be recbarging tbe §round-vate= vith water levela computed by the model for! 981 as a atart~g point. The reaervoi r at a net rate of about 8,900 acre-feet (11 hm ) per year. 1977-79 average !lithdrawal ra te of 43,400 acre-feet (53.5 hm ) per year and Evapotranlpiration allo vii i decre.a.e. due to declining water levell, to about tbe 1977-79 vell locationo vere uled as a atandard for all limulation.. About 39,800 acre-feet (49 b113 ) per year. 60 percent ~f the withdravals during 1977-79 vere from the deep arteaian aquifer and about 40 percent vere from the .ballow arte,ian aquifer. The Ground-Water Witbdraval. Ono-llalf following ground-vater withdrawal rate. vere aimulated for 20-y.ar perioda: (1) cround_ater vitbdravala approximately e~ua1 to the atandard 0977-79) the 1977-79 Average Rate a .. erage rate--43,400 acre-feet ( 53.5 bm ) per year; (2) ground-vat':!r vitbdrawals at approximately one-balf thr .tandard-2I,7oo acre-feet (27 b .. ) Ground-vater v itbdravala at one-half tbe 1977 -7 9 average rate for 20 per year; (3) around-vatsr withdrawal. at approxi.ately double the Itandard- 1UrI 0981-2000) would cau.e vater-level declinea of more than 15 feet (4.6 86,800 acre-feet 097 h. ) per year; and (4) ground_ater withdravala at the .) near Lynndyl and ri.ea of .ore than 5 feet 0.5 .. ) near Delta in the deep Itandard rate witb change. in the locationa of witbdraw.l •• a.ociated with th~ arteaian aquifer (fig. 13). Near Lynndyl, therefore, water lovela vill IDt.raount.in Pover Project includins reductiona in "ithdrawala froll veil. for continue to decline even if withdrawal. were only one-half the 1 W7-7 9 average vbicb water rightl bave been purcb ..ed by the Project. rate. Rear Delta, however. a reductioD in witbdrawal. vould allov vater Inell ia tbe deep arteaian aquifer to recover. Cround-vater withdraval at 39 40 EXPLANATION • Ct. -II- LINE OF EOUAL WATER·LEVEl DECLINE. IN feET. ··lnIlIV" 10 '" ' DEC LINE II .... ,. E=:i 0·10 ~ 1020 § 2030 ~ :l().410 ( ., Mure Ihen 40 1 .1 . t . I.u t. t .12 I. '.11 1 . . ... I. I. t I.•.••. t.J t . t. t t . t.S II •• -- --- UOUNDARV 0 STUDY AREA.- Ouls = ~ :;. '! : : . ·i~it: ~ :~ :t '''' h ... , lilt ... ~IrH,l~,I' .',' I •• oct ~lOI aI,ow d, '1aOi d i\loo • t II It Ill.. "'" Figure l1. - Pr ojected WdlCr level d lines in the deep artesian aquifer for Ihe period 1981 ·2000, asslllning gr ollnd-waler withdrawals eqll ,. "I. ,. EXPLANATION It• I . J .:....-$ -LINE OF EOUAL WATER·LEVEL OECLINE. IN FT.- In'''''''' I, 6 I ..t o CLINE (I " ~ O!l ~ !ll0 1 ... 1.1 ••• 1 . I •• I • I. , ", .• ~.... 1015 ,It It ~ .... , ... '.1. ''''011 •• 1 .. , .. , I . . 1 I 1 .'UI 1111 . .... I : ...... IU'II hThHrh'r 1..LI .L..1.-...,-----', Muro lI ..n Ib • • II It "U.""I ~ ---IWUNOARY Of STUDY AR A .- OoU lid ~I" show d1 IMgOl d l 100 Figure 12.- Projecled W I' --S - LINE OF EQUAL WA ~ £ R.LEVEL • CHANGE. IN FEET. -I,,,e,., 1 , 6 I I O~CLlNE (I II ~ Of> ~ &-10 ~ 101(; Mora Ihiln I!J .,' t ' III RISE •• a •. (I",.. , •• 11 • • • ••• • • ••••• ••••• •••• ff' ...... 1 I •••• ' I,. • " J. lUll ... . II • • • I •• · it .••• ,,)'" h'rhTlrh'rLI..I.1..1 .1..1 ___1----" Ob • • II It .1L'.III1. D 0 M ",Ih.... !) •• _ ---BOUNDARY 0 STUDY AH A.-Dots Figure 13.-Projocletl wiJlcr·levcl hanges in the de p artesian aquifer lind cia>.hos ,how dl "I""IID d , do tor Ihe period 1981 ·2000. assllming !.Irounc'l Wdl r wilh At the end of the 20-year perio~, discharge to the Sevier River will decrease from 3,~OO acre-feet (4.4 hm ) per year in 1981 (table 2) to 2,600 J acre-feet (3.2 luD ) per year in the year 2000. Evapotranspiration als~ will decrease from about 42,300 to about 41,800 acre-fee,t (52.1 to 51.5 hm ) per year. Ground-Vater Withdrawals Double the 1977-79 Average Rate Ground-water withdrawals at double the 1977-79 average rate for 20 years 0981-2000) would cause water-level declines of more than 80 feet (24 m) in the deep artesi~n aquifer near Lynndyl (fig. 15), and declines of more than 50 feet 05 m) in the shallow artesian aquifer near Oak City (fig. 16). At the end of the 20-year period, recharge to the grou~d-water reservoir from the Sevier River would be about 31,900 acre-feet (39 hm ) per year. Th~s is 23 percent of the 42-year average discharge of 134,000 acre-feet 065 hm ) per year at gaging station 10224000 (Sevier River near Lynndyl, Utah) located about 2.8 miles (4.5 km) southwest of Lynndyl, Utah. It is not known if the material beneath the streambed is permeable enough to transmit this much water to the ground-water reservoir, or if flow downstream from the gaging station, after diversion Cor irrigation, is sufficient to allow this mU§h seepage. Evapotranspiration also decreased to about 35,500 acre-feet (44 hm ) per year. Change. in the Location of Ground-Water Withdrawals Related to the Intermountain Power Project Change. in the location of ground-water withdrawals related to the Intermountain Power Project would cause water-level declines of more than 15 feet (4.6 m) at the site of the Intermountain Power Project and rises of more lban 5 feet (1.5 u) near Oasis in the deep artesian aquifer (fig. 17) over the 1981-2000 perio~. These changes are in addition to the changes computed auuming withdrawals at the 1977-79 average rate f or 20 years. The water level declines are due to withdrawalS of about 5,400 acre-feet (6.7 hm3) per year for the 20-year period from the deep artesian aquifer at the site of the Intermountain Power Project, and th~ rises are due to the reduction of withdrawals from wells for which water rights have been purchased by the Project and transferred to the Project site. Only amall changes in water levels were projected in the shallow artesian aquifer (fig. 18) due to changes in the locations of ground-water withdrawals related to the Intermountain Power Project. Changes in seepage to or from the 44 EXPLANATION I. I.I NE OF EOUA I. WATER I.EVEI. \I --+s-- I . CHANGE. IN FEET. or-CLIN r. II Itwl' I. ().4 J ••••~~ r;~~~~~::~~~~~~~~~~t:=+~~~~~;;;;:=::=l ~ HI E III . t It I' # 1'1 I " .: 05 ...... I J'. t . u • . • . II I . • • " I . ••••• • • ••• '. •• ,. tt •• 1. 1 . '."" 't" .. .. ,' I , . • I' J •• ILI. D. 1"" •• " I : '...... ",." I hhHrrn L'J..I..LI.J.I--'I~ ___ .J [] Motu Ih,," 5 • , " II In ..tlllI .. -- --9 UNOAnv Of STUDY AREA.- Ools ... .d u.nl"" show tltilllW(lOl dl\ du Figure 14.-ProlecwrJ w,llt~r I ~ ·'l.h·1n9~ III me l>hallow Dltesido aqllif r for the pf;riod 1981-2000. d!>Sl/Illill!) glOLJlld-Wdler withJra als one·lldlf the 197, 79 (JV rage rate. e)(PLANATION OF e~UAL WA Tf R·t eVEL DECLINE. IN I EEl. - Intllvel'" 20 'HI DECI.INE /I II ~ ~ ~ 2040 ~ 4060 ~ 6000 , •. • t . Mum 1114" 80 I.t . t . 1 .1) . .. I .t, _ . t .lt l . • . .• '. • . I t . t. ' t . mil I • ,,, 1I . I US II • • 'f •• •.•. ".'., 'C , I liw'. ' , - - 80UNDMlY OF STUDY AREA.-OoIJ St.t ••• , . loa ••.••• II J' " I nhil i I'rl u.J'c-....., _ _ --' .. - - • " II I II .. IIIIS . " cld/...-s st. d •• ·,,"'tJII tll\ ldo Figure 15 - P/lJjec l d wdle, lwei dl.'(.lrnes in Ihe ueep UI WSidll d Irlfer for Ih . pellod WEll 200 •• ' ~ lIll1ill!-l9'O .net·wal , wlllulrdw,lls double Ilrtl 1977 IU . 1'1 '1 __-/O __ LINE OF OUAI WATER ·LEVEL OECLIN . IN F T - Inlorv II, 10 Inl DECLINE (I II 0,0 1020 2030 , - t •• '.11 • . I . " • . ' .1 • . ~ •• • • ••••• 1.'1 • ••••• 3040 •••• 't ...... a.f." I,. • II I •• UI. It... • I" ': I ••• II I 1 J. II h'rh\+rtnJ-1I.JI.J1L...-T' ___ --'I lIm 4050 t • It It IIUlllti. 11m I n50 .. -- ---BOUNOARY a STUDY AREA - Doll Figu,e 16.-Projecled wdler·levc.1 d "ntIS in the shallOW artesian aquifel for the nd dasillil $how dl II naoe dl"ide period 1981·2000. assuming !lro IIld-w ler wilhdrawals double the 1977·79 Ie . ···?.~"";;"""rM'" ~~-U-Xl'11 • I _:"~ , t ':r X'LANATION • • J • • ---5 -_ LINE OF EQUAL WA ER·LEVEL CHANGE. IN FEET. -I"r.ml ls 6t.t DECLINE /I 1 J 0& 1>-10 ,....;. . 10 16 n .. . ~ ~ / t. I • . •. I.. • . t t . ' .111. ,."" . • • " " • • • • I . • • ••• Mo,tllh." 16 •.•••.•••.•.•••••••••••• , .• , I . • " J •• ,Lt' RISE l-Irh\MJrLL.LIJ..I--.--- --" II ... .. ,. .:51..... "J-'" I (I 1 J t , It ,. "L •• trUI ···" D 05 Figure 17.-Projected walel I vtll chany . ill the d p artesian aquif I resulting Mortt 11111" I) from changes in the I calion of W01lnd Weit.1 withdrawals related to lhe D Interm untaill Power PlOj I fOl the period 1981 ·2000. ---80UNOARY or STUDY AIIEA - 0011 ."d daJhes .how I1tll neoe d,v EXPLANATION CHANGE. IN fEET... lnllrvllls 1 100\ DECLINE (I II ) ~ CH -p- I.· .• ' § 1-2 ~ 23 ~ r'I / '.' .. t.... t. , •. Mo< Ihlln3 I.,. " •• •.•. •.•• _,fca' •• , •• , II .'UI Ie 11., • .... I.' ...... ~~~-TI ______-Jl RISE II II LOUII" It II Figure 18.- Projer.!ed wal I lev I dKlllfiCS III II e shallow all~ian aquifer rcsultlng D 01 from changes in thl:ll lion of !Jlolllldwaler withdrawals related to Ihe o ""han I InlermollllleJin P weI Projec l for Ille p dod 198 1 2OGv. .. -- ---OOU OARY 0 Sl UDY ALA.-Doli 01,,11 r"~lib ,how dlflr\DU'l dl' dI Sevier liver and discharge by evapotranlpiration cauled by changes io ground Cround-vater vithdr~val. have increased from a 1951 to 1963 average of "a~er witbduwala rdated to the Project would be Ie .. tban 500 acre-teet (0.6 9,~00 acre-feet (U.8 hm ) per year to an average of 27,500 acre-feet (33.9 ba ) per year. b. ) per yur frolll 1964 to 1981. During 1963-81, vater 1evell declined 19 feet (5.8111) in the deep arte.ian aquifer south of Delta and 10 to 13 feet SUHllARY AND CONCLUSIONS (3.0-4.0) in the ahallov artesian aquifer vest of Delta, probably becauae of increased ground""",ater withdrawal. for irrigation and municipal use. Cround vater in the Sevier Delert occurs in both con.olidated rockl and wconlolidated bosin fill. Consolidated rocks yield water to springl in the Cround-vatet quality in the shallow artesian aquifer in the Leamington .ountain. and to a few wella along the margins of tbe basin, and Lynndyl area bas cont inued to deteriorate since 196& The deterioration unconaolidsted basin-fill deposits yield vater to numerous wells on tbe b•• in probably i. the result of vater of poor quality (uncoDsumed irrigation vater, fl\>Or. seepage from canals and reservoirs. and possibly some infiltration from the Sevier River) recharging the unconsolidated basin fill in this area. The principal aquifers of the Sevier Desert are within the unconsolidated b .. in fill. The tbickne •• of the basin fill i. at le .. t 1,300 feet (396 111) A digital-computer model was used to project the effects of future and .ay be aa thick a8 2,140 feet (6 52 m) . The ground-vater reservoir in mos t grouud-vater .withdrawals OD vater level., recharge, and ii.charge. The 1977- of the Sevier De.ert has been divided into shallow and deep artesian aquiferl. 79 average wlthdrawal rate of 43,400 acre-feet (53. 5 hll ) over a silllulation a c:oufining bed between them, and a wate~-table aquifer . period of 20 years vas used as a standard. Maximum vater-level declines of up to 40 feet (12 m) vere projected if ground-water withdrawals are equal to the lecharge to the basin fill is from seepage from Itreams, canals, 1977-79 average rate, lIIaxilllulII decline. of up to 15 feet 0.5111) if ground re.ervoira, and of unconsumed irrigation voter; subsurface inflov froQ vater withdrawals are one-half the 1977-79 average rate, and maximum declines conloiidated rOCKS of the mountains; precipitation on baaalt outcrop.; and of up to 80 feet (24111) if ground-vater withdrawals are double the 1977-79 .ublurface inflow from ad joining areas. Ground water generally 1D0ves frolt average rate. Projected maximum water-level declines due to changea in the recharge areas near the 1D0untaina on the northeast and eaat toward di.charge location of ground-water withdrawal. related to the Intermountain Pover areal in the we l tern part of the study area. Discharge from the Project are 15 feot (1.5111). unconsolidated basin fill is from springs, aeepage to the Sevier River, evapotranspiration, subsurface flow to adjoining areaa, and wells. REFERENCES CITED , The transmissivity of arte.ian aquifers in the Sevier De.er t, e8tilD~ted Appel, C. L, and others, 1983, Ground-water condition. in Utah, .pring of from aquifer te.t., ranges from about 47,000 teet squared per day (4,400 111 /d) 1983: Utah Division of Water Resources Cooperative Investigations Report iD the .hallow artesian aquifer on the ealte{n side of the basin near Oak City 23, 97 p. t o about 2,000 teet squared per day Cl 56 111 /d) in the deep artes ian aquifer .o~\b of Delta. The storage coefficient of artelian aquifers range. fr~m 2 x Boike, E. L., and Sums ion, C. T .. 1978, Hydrologic reconnaissance of the Fiah 10 near the lite of the Intermountain Pover Project to 6.4 x 10- near Spring. Flat area, tooele, Juab, and Millard Counties, Utah: Utah Lynndyl. Department of Natural Resource .. Technical Publication 64, 30 p. The amount of recoverable vater in storage in the unconso lidated basi;t Enright, Michael: and 1I01mes, W. F., 1982, Selected ground-vater data, Sevier fill ia eatilllated to be about 200 lIIillion acre-feet (250,000 hmJ). Moat 0>' Desert, Uu'" 1935-82: U.S. Geological Survey Open-File Report 82-910 tbis stored ground vater is fre8h, but some is of poor quality. e'peciallv (duplicated as Utah Hydrologic-Data Report 37), 59 p . that in the water-table aquifer in the central part of tbe .tudy area. ~ Field., F. K., 1975, Estimating streamflow characteristics for streams in Utah The dis801ved solid. in .pring and well vater range. froll less than 100 uling selected channel-geometry parameters: U.S. Geological Survey _illigrams per liter ,to about 49,000 milligram. per liter. In general, the Vater-iesources Investigations 34-74. s.alleat concentrations vere in vater from 'pringl in the lIountains and from vella between Lynndyl and Delta perforated below 500 teet Cl52 11), and the Cal ~ I, J . S., and Kruer, S. A., 1981, Hydrologic reconnai •• ance of the largest concentrationl were frOID wells perforated above 200 feet (61 m) in the .outhern Great Salt Lake Delert and summary of the hydrology of west loutbve.tern part of tbe .tudy area. Water salDple. frOID .01De well. in the entral Utah: Utah Department of Natural Relources Technical Publication _outh-central part of tbe study area contained large concentrations of 71, 55 p. ar.enic, aDd vater .ample. froll .Ome large-yield irrigation weill in the Oak City-Fool Creek area contained large concentration. of nitrate plus nitrite. Gilbert, G. 1(., 1890, Lake Bonneville: U.S. Geological Survey Monograpb I, 438 p. 50 51 aa.. er, B. N., and Pitzer, A. G., 1978, Hydrology Report for the LynDdyl Site: Hover, R.o V. , 1963, Effects on the shallow artesian aquifer of withdrawing Report prepared by the Los Angeles DepartmeDt of Water aDd Pover for the vater from the deep artesian aquifer near Sug.rville. Millard County. InteraouDtaio Pover Project. Utab: Utah State EDgiDeer InformatioD Bulletin 10, 9 p. Bandy, A. B. , Kover, R. Wo, and Sandberg. C. W., 1969, Changes in chemical ___ 196 5, Ground-vater resources of Pavant Valley. Utllh : U.S. Geological quality of grouod vater in three areas in the Creat Ba.io. Utah, ~ Survey WDter-Supply Paper 17 94, 76 p. CeologicQl Survey Relearch, 1969: U.S. ecological Survey Professional Paper 65O-D, p. D22&-D234. ___ 1967. Causes of fluctuations in the rate of discharge of Clear L a~e Springs, ~Iillard County, Utah: U.S. Geological Survey Water-Supply Pape r Redman, E. R" and Ka.tner, W. H. , 1977, Streamflow cbaracteristics related to 1839-£,31 p. channel geometry in tbe Mi.80uri River Baaio: U.S. Geological Survey JourDal of Relearch, Vol. 5, No.3, p . 285-300. _ "__ 1978, Hydrology of tbe Beaver Valley area. Beaver County, Utah, with emphasis on ground vate Utah Department of Natural R"' sourees Technical Herbert, L.R'., and other., 1981 , Ground-vater conditione in Utah, spring of Publication 63. 90 p.o 1981: Utah Division of Water Resources Ct)operative InveltigatioDa Report 21, 75 p. Hower. R. W.o, and Feltis. R. D., 1964, C" ouod-vater data , Sevier Desert, Utah: U.S. Geological Survey open-fil O! report (duplicated as Utah Basic-Dati , " Herbert, L. R' I Cruff, R. W., and Holmes , W. F., 1982, Seepage study of the Report 9), 34 p. Sevier River and the Central Utah, Hclntyre, and Leamington Canal,s, Juab and l-lillard Counties, Utab: Utah Department of Natural Resourcea ___ 1968. Ground-water hydrology of the Sevier Desert . Utah: U.S TechDical PublicatioD 74, 43 p. Geological Survey Water-Supply Paper 1854, 75 p. Bolmea, W. r., 1983, Three-dimensional digital-computer model of the principal National Oceanic and Atmolpheric Admini s t r atioQ. Environmental Data and around-vater reservoir of the Sevier Desert, Utah: U.S. Ceo logical Infor101ation Service. 1982. Cl imatological data , annual luwmary, Utall. Survey Water-Resources Investigations Report 83-4179, p . 123. 1981: v. 83, DO. 13, 15 p. Holmes. w. r., and Kimball. B. A. , 1983, Ground-water in the southeastern Nellon, W. B•• 1952, Sevier Desert, Hillard County, in Thomas, H. E., tlel.o':'!. Uinta Basin. Utah and Colorado: U.s. Geological Survey Open-File Report V. B., Lofgren, B. E. , and Butler, R. G., Status of develoflQent of 83-217 (to be printed as a U.S. Geological Survey Water-Supply Paper>. .elected ground-vater busina in Utah: Utah State Engineer Technical PublicatioD 7, p. 63-66. Holme •• W. F., and Wilberg, D. E., 1982, Ret:ults of an aquifer test near Lynndyl, Utah: U. S. Geolological Survey OpeD-File Report 82-514, 17 p. Nellon, W. B., and Thomas. H. E.• 1953, Pumping from weIll on t he floor of the Sevier Desert, Utah: Transaction., American Geophysical Union, v. 34. Intermountain Power Project. 1981, Well drilling and teating report : City of DO. 1, p. 74-84. Loa Angeles Department of Wat rand Pover. 29 p. Neuman, S. P., ond Witherapoon, P. A•• 1912, Field determination of the Johnlon, A. I., 1967. Specific yield--compilation of specific yield. for hydraulic properties of leaky mUltiple aquifer systems: Water Resourc-! s various .. aterials: U.S. Geological Survey Water-Supply Paper l662-D, 74 Reaearcb, v. 8, DO. 5, p . 1284-1298. p . Stepbens. J. C. , 1977, Hydrologic reconnaissance of the Tule Va lley drainage Lohman, S. w.. 1972, Ground-vater hydraulica: U.S. Geological Survey baa in, Juab and Hillard Counties, Utah : Utah Department of Natural Profe .. ioDal Paper 708, 70 p. Resources Technical Publication 56, 37 p. Heinzer, O. E., 1911. Ground vater in Juab. Hillard. and Iron Counties, Utah: Stoltu, W. L., (ed.l, 1964, Geologic map of Utab: Salt Lalte City, Univeroity U. S. Geological Survey Water-Supply Paper 277, 162 p. of Utah. Hover, R.o W.o, 1961, Relation of the deep and Ihallov artesian aquifer. near Torat. L. J., 1 982, Modifications and corrections to the finite-difference Lynndyl, Utah, in Geological Survey Reaearcb, 1961: U.S. Geological .odel fO T simulation of three-dimensional ground-water flow: u.s. Survey ProfessioDal Paper 424-C, p. C94-C 97 • Geological Survey Water-Resource. Investigations 82-4025. 30 p., plus appendixe •• 52 53 Tre.cott, P. C., 1975, Documentation of finite-differen~ model for .i ulation of three-dimensional ground-vater flow: U.S. Geological Surv y Open-File Report 75-438, 32 p., plus appendixes. Tre.cott, P. C., and Larson, S. P., 1976, Documentation of finite-difference model for simulation of three-dimensional ground-water flow: U.S. Geological Survey Open-File Report 76-591 (supplement to U.S. Geological Survey Open-File Report 75-438), 21 p. u.s. Department of Agriculture, 1969, Water budget analysis, Sevier River basin, Utah, Appendix IV: 92 p. Van Bylckama , T. E. A., 1974, Water use by saltcedar as measured by th.l water budget method: U.S. Geological Survey Professional Paper 491-E, 30 p. Waddell, K. M., I1nd Fields, F. K., 1977, Model for evaluating the effects of di es on the water and salt balance of Great Salt Lake, Utah: Utah Geological and Hineral Survey Hater-Resources Bulletin 21, 54 p. 54 P'lllllld inc_'lion"'lh,,, UNITED STATtS DEPARTMENT OF THE INTER IOR STATE OF UTAH U S ~s...... ,~FW.R_'I3688 GEOLOGICAL SURVEY O£'ART.. £N T OF NATURAL RESOURCES '100,.1 IP.IJ .. ".. 1lI1'lAH.'1ON MSf.~V ... 't()tOW(llCOlM'l(TEO IN 'Hl 5H"'UOIfit' .~l(SIAH ... OUlflH OIS(~V"'TIONW(l____l ()QM'UTEO 01 _ _ . IN...... TH( OU'"' . ..._, IlSIAH.. , .....OUIH...... - _ __....~_01 _ ...... ,., .. , - ' _ _ -f'OI(H"OMn" I(:OOH ' OV~ Of THI PlAUOIfit' ... IIU$I_ ... OUIFlII.-so-. ..,,_ o< _ _ ... ___ ._ ... ~1Iy ... waI"._'.,.DooIood-._ ...... c.r- ..._____...... :IO_IoO ...... ___ _. __ oI _'...... N___ __· .- ...... ,bo. _ ...... "'_.-w.. ___. .- __. •• - -lOUNo.o."vOf STUOV ... .,l.... - ____ ...... _ S f: 1' 11:.' H L I Ii f: "N "_ ~ " __ .," _N, D .... , ' ... '.'_._~ " ... ,., ~~~<• • ••~• • , . ..~ • • • • -~ .... ~" ~• • " .. MP OF THE SEVIER DESERT. UTAH. SHOW ING rHE POT[HTlCllETR I( SURFACE OF THE SHAll lN ARTES IAN AQU IFER AND ~ATER LEVELS IN THE DEEP ARTESIAN A(JJ IFER. PW:CH 1981