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<br />;JUl94'l
<br />
<br />steeper, especially in the eastern part of the study area, than the gradient from the river to the center of the study
<br />.
<br />area.
<br />
<br />Estimate of Ground-Water Storage
<br />
<br />The generalized water-table map (fig. 2) was used with information describing the elevation for the base of
<br />
<br />the local alluvial aquifer (Nelson and others 1989), and with an estimate of the specific-yieId/~f the aquifer to esti-
<br />
<br />/ \,.
<br />mate the amount of water stored in the aquifer (Watts and others, 1992). The difference.~twe~ the w:1Ityr-tabIe
<br /></<~/> \y'? ('-"""_:>~t-""''}
<br />surface and the base ofthe aquifer represents the volume ofthe aquifer. The specipc'Ylel~{,stiI}l~~d:.~"'O~20/in the
<br />\ ~"",,'/ (i "" 1 '%'v"
<br />
<br />study area, is the ratio of the volume of water that will drain, due to gravitaJiq,~'ltl t(}fc,~~/;!>(t\l~~~t#e of the
<br />'<(" ~'//'~) 'f /(",:~:",~,,"~)
<br />aquifer from which it is drained. To obtain the estimate of water con~~~~!~:t.i17 ~~l!.if~~~~.h9}qiiifer volume was
<br />"'\ \~ ,i J " \" ,-'~---
<br />multiplied by the estimated specific yield. These methods indicl\l<,\d an ~'st!~tea:'~~( ~<:fntent of about 40,000
<br />'\ \ j" i')" '"'''' ,.}'
<br />
<br />acre-feet; however the entire estimated water content of tb.e'~~1fe}\yOI!Jd~::~t~!ltbie to wells only under ideal
<br />(/ <'~: 4,,,,, _ " j/ /---~ L,,"\, '/
<br />.nditions. Further, under similar ideal conditions, o,nly..@e: "~tef cOlital..~e:ij'iJ~he aquifer that is above the eleva-
<br />\ ';;-') '""~! /" ~- ~,\---'
<br />
<br />tion of the Arkansas River would be able to P~{)~i~~~~~~;~~(~~c~tributions to the river.
<br />
<br />-,--",~:~-~:~~:~~"'~/ //,<, \'-~- :::' /'
<br />'\ ~ -",', ~_ -"jf ~\" ~
<br />i\ <i< "'<""'> ~v-
<br />/:>: .. ;~/ \:.7
<br />, -<>-
<br />Depth to Water //.'\", <oj
<br />,,,,,~,,"'-f'/ '
<br />;'"
<br />/"",,'\,\ {\:,.<';;</,,,<:'- f",,/ ,,/ /~:-
<br />The generalizeddeptht,e,."y!lter..{hitR (fig.3) indicates that, during the measurement period, water levels
<br />!:;~,:\7<_,\_)-~/ "\ -,::~~1"";}'~'~'/
<br />ranged from less'~l\.ri)5;fee~'b\(lo.W.'tI1~'~and surface to about 50 feet below the land surface. In general the range of
<br />,j ~, " /"
<br />\"" "'- '\'" ">..,, \",/,/
<br />depths to water weregrea:fest lnJ~'eastem one-half of the study area.
<br />/---'-:,'-''-.'\",,-'/'
<br />1'-",f''',''',___,''
<br />Water levels w'\(t~&~~ilow, within 5 feet of the land surface, in about 31 percent ofthe study area (table 2).
<br />
<br />
<br />'" -,,~,
<br />
<br />The area of shallow water levels is mostly in a zone that parallels the river (fig. 3). Water levels are relatively
<br />
<br />shallow, from 5 to 10 feet below the land surface, in about 20 percent of the study area. The area of relatively
<br />
<br />.hallow water levels is prominent in the western one-half of the study area where it is relatively wide compared to
<br />
<br />4
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