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<br />March 19~1 - Sept. 1950; rer:"1:.dnd~r compu~cd bY' correlation with records of the
<br />North Platte .River at SutherVtnd and at North Platte.
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<br />North Pl;>,~te River- at North P_l0.ttc, NcbrasJ..:<.t:
<br />Record a\r,dI<lbl~ for entire stnd! period,
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<br />South Fbete River ne",-. Paxton, Ncbnska:
<br />Record ava'il;tble August 1939 - September 1950; remainder computed from SOClth
<br />Pl.:ttte at Jubsburg, .?'1d can.:1t diversion record.:'!.
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<br />South P12_tt,::, River near NOrth Platte, NebraskC'.:
<br />Record '?"/ai!ahle for entire sbdl period.
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<br />pl:Hte Rivf.'!' n~'?, Rr:dy, Nebraska:
<br />Record aVilil'tble: M?1 - Si?pt.. '1937; Met! - Sept. 1938; May - S~pt. 1939; Octob-
<br />er 19.10 - Se?~embcr 1950; remaindf!r computed from North and South Fhtte Riv-
<br />ers at North Pl.1.tte.
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<br />Platte P.iver nE'~r O'/edon:
<br />Record C'.'nllahle for entire 51:1.191 period.
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<br />In rrl.'l,king {he Pre3cnt Condition;} Study, tnP. Cornmitt~e aflslHnec1 that all p"""ler and irri-
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<br />g<ttion proj'O'ct,> ol,':r<\ting tod,~y hvJ b~cn in opf'ration since 1930, <lnd th"".t aU pr'e5~nt ditch and well
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<br />irrigation hact draw,""! uj,',on available water supplies dluing that pf'riod; in short, th..lt th~ 19:i1 de.".~lop~
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<br />ment h"lc? e,<.i3t,o;d contirHlou;:;J.y under the rn~teorologici1.1 conditlon~ that prevailed f.rom 1?31 to 1?50.
<br />inclusive. Wnf'rc n~ce33","ry. streamflow rCCOI'd.<; wc('e adjuste.d to refl€'ct this change in conditinos.
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<br />Since J930, thf' acreag~ under ditch irrigation in the basin .above O.".ert(>n h.-l.8 refnained
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<br />fairly constant except (or tn€:: land:'! on the Tri-Co'_lnty project which received initial irrigation a.bout
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<br />1941. The at"ea irrigated from. wells in the Platte Valley west o( Overton grew -[rom a few hundred
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<br />acres in 1930 to many thousands in 1950. The reservoirs of the Sutherland a.nd the Tri-County 5Y5-
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<br />terns were constructed a.nd placed 1n operation.
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<br />From its Present Conditions Study, the Committee found that the average annual flQW a.t
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<br />Overton would approximate 866, 000 acre~fee::t for the 1931 - 1950 period. In siY-teen of the twenty
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<br />years, or 80 percent of the time, it WQuld have exceeded 414,000 acre-feet. Flows for individual
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<br />years would have varied from about 360.000 acre-feet to 1,510,000 acre-feet, depending upon how
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<br />th..:: storage water in Lake McCona.ughy was utilized. Under the assumptions used in this study, at no
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<br />time during the period, including the dry Thirties, would the storage in Lake rvfcConaughy have been
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<br />less than 760.000 acre-tect, which is 40 percent of its capadty.
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<br />In making the Future Conditions Study, the Committee took into .consideration the present
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<br />devel:Jpm.cnts and those that !"t~a$onably may be expected in Colorado and Wyomir.g: und~"':r the existing
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<br />intt~rstatt-: compact on the South Platte River. the U. S. Supreme Court Decree on the North Platte
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<br />Riv~r. and in Nebra.ska under existing water appropriations. The Committee also considered pl'oba_
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<br />ble a.drlitioaal depIctions of the water supply through unrt:stricted expanfJion of well i'rrigation <'tbove
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<br />Overton, the cEft:ct on cal1allosscs ~nd return flows resulting from the work of scaling can2.ls now
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<br />under way or .conto::m.pla.t~d, and the probable recovery in the North atld South Platte. Rivers ol nOn~
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<br />evaporation losses from L"th~ McCon.-;ughy,'
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<br />From its Future Cnnditioll$ Study, the Cornmittec found that the average annual flow at
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<br />O\'t:r-ton would ilrnount to 6~8, 000 i'lC rc..(cet. with individual years varying bdwccn 210.000 acrt:-fcct
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<br />and 1,300,000 acrc-ft:d, dep~Z\I:ling U1!Otl now Kingsley stOt'OlgC water was utiliz-,cd. In sixteen of the
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<br />tw(~nty years, C'r 80 pcrCt'nt of the time, the aunual now at Overton WDul(! have excct~d~d 2.'>0,000
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<br />acre-feet. Minimum storage in L:\kc: McConi'<ughy under the 3ssumpt.ionH of this study would hilVC
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<br />been. 6921000 "ere_(cd.
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<br />Tho: det;dlcd ~om~),:'ltathHl3 illvulv~d in these StUdjc5. and rdlccti
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