Laserfiche WebLink
<br />O[)i1;)~1 <br /> <br />Tilt' dl:pth 10 tilt' W:.ltl'r lal:lk is gt'nl:rJlly k~s than 100 f~d nul in some IOl"ali/eu art'as <br />it is :.is much ;JS 150 - :;00 fect. .'Iml sln'am valln.'s in the ct.'ntral and \~l'sll'rn pari of till.' <br />basin arc less than ~O fel."t aboVl.' the wah.'r l:.tole. Water tabk depths h..l\'l.' bl."l'n sh:adily <br />inc.:rca...ing in ,>uml' areas or the basin ....ilh Ill!.' illl.:rl'aseU withdr;.l\val and use of ~rollnJ watl'r <br />for irrigation. The alllount of ground watef In storage in till' basin bas bl'cn t'stimatt"u by Ihl' <br />Con:-.erv<.Jtinn and SUfWY Division of Itw University of :\ebr;lska na"t'J on h:sl holes drilleu <br />throughout the basin. Tills :.tn;Jlysis shows as much as (jO ft'l'l of watef In stor;I!!C in :.lquifl.'r,> <br />bcnt':Jth broad <lft'aS JdjJCl'nl to som!;" of till' Irihutarit's in the centr.il Jnl! nurthwl'sl parts of <br />the basin. Ilowevl'f. lllall}' of Ihe uplands in the IO....l'f parts of 11lL' basin arc underlain by <br />aquifers containing as Iillle a.. four feel of water. Again, il is emphasitt'd Ihat the amoullt of <br />water in slorag~' is not a dir~'l,:t indicalion of availability sim:l' spedne yield and trall"l11issibitity <br />of Ih~'s~' aquifers dt'lermine the amount of ground water that can be wilhdra....n. <br /> <br />GROUND WATER QUALITY <br /> <br /> <br />Ground wall,'r quality is not a probll'm in Illw.:11 of <br />th~' basin. !lowl'ver. some 1:!1"0Llnd wat~'r aquifers in Ih~' <br />Iowa central p:nt of Ihe ha..in nl'ar Wilbl'r and DeWit! <br />are highly mim'rali/~'d. This l.:ondilion is bl'liL'h'J 10 bl' <br />tlil' rt'sllil of Ihe n:ineralill'd wakr in Ihl' Ilalwl:l <br />s.andstolle moving up into till' s:lI1ds and graw]s abo....l'. In <br />addition, !!rotlnd w:Jtt'r of poorer qU:Jlily is gl.'llt'r:Jlly <br />found in art'as of lower transmissibilily. Wells in tllest' <br />arl':JS must pl'netralt' deeper aquifers which conl,lill lllorl' <br />highly minl'r:lli/ed w:lIl'rs in ordl'r 10 gl,'( sulTicil'nl <br />yields In a few in'\tanct's. iron. lllang:lllt"_l' ;Jnd nitral\.' <br />concl'nlrations :lfl' greall'r tlun Ill\' limib 01 till' lqh~ <br />Public I:ealth Service drinking W:Jtl'r stalllJards. In tilt' <br />arl';.l of tI'e basin bdow CH'te. !!rounJ w:I!l'r supplies may <br />bl,' more highly mineralileJ ;.lnd l'\Cl'l'd till' uppt'r Iimib <br />for SU]fatl'S. nitrJtc:. and tot31 dissolved solids set hy tht' <br />U. S. Puplic Ikallh Sl'rvk'~' as drinking watl'r standards. <br /> <br />The ground water in most of the basin is quite hi!!h in c:lll'iUIll c;.lrpOnall'. an indication of <br />hardnl':;'s. This dOl'S not constitute a health hJJ::lrJ bul iIH.lkah:s a f:H.'tor :llll'l."Iing "onll' of Ihe <br />lIses. Fi!!llfl' I ~ shows di~sol\"ed solids contt'nt of the Big BllIl' 1~:Jsin grollnd watl'r. <br /> <br />Salinity is nlt':.t'iured in Il'rms of conductivity or thl' ability of walt'r to carry an l'Il'l."Irk <br />curren!. Th~' highl'r Illl' S<llt conlt'nL till' !!rl'atl'r is tIll' w;.ltt'r's :lbilily to C:lrry :1 current. \\'atl'r <br />c1assilkd low or medium in salinily hat.ard can he used for irrigation on 1110s1 ,nib unles'i <br />inll'rnal dr:lin:lge b restril.'tl'd. <br /> <br />Rt'slllts of a nUIllPl'r of ~:atinilY h''\ls made throughout till' h:\sin arl' shown in Tablt, <br />-l.lI.:"l \losl uf till' wdts S<lmplcd yil'ldeJ watt'r whio.:h could b~' llSl'd wilhout salinity ha/ard~ <br />rl'sultinf!. Thl' majority of [hOSt' indkating some salinity ha/:ud could ht' conlrolh:J by W:ltl'r <br />n.anaVl'llll'nl ;.lnd leaching kchniqut's. PJ.rts of Salinl' and Lallc:J"ter (\wlllks arl' knOlAn to <br />haw high ..alinity ground waler. <br /> <br />;:6 <br />