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<br />Colorado says that export diversionscofexisting enterprises in Colorado,
<br />as they aTe now oonstructed and will funotion in a year of normal olimate,
<br />will average 135,000 aore feet annually; and that detailed estimates by
<br />individual projects appear in the Statement submitted by Colorado at the
<br />meeting held in Reno, Nevada, July 20, 1944. A cOOlparable figure for existing :
<br />exportations in Utah under normal oondi tions appears to be 79,000 /lcore feet, c,
<br />making a total for the Upper Basin of 214,000, aore feet annually.
<br />
<br />34. Together, the existing depletions in cthe Upper Basin, resulting
<br />from water oonsumption inoident to the irrigation of lands within thena_
<br />tural basin and from export diversions for use outside the natural baSin,
<br />exolusive of allowanoes for projeots authorized ,but not oonstructed and
<br />enterprises not yet oompleted, as estimated by Colorado engineers for the
<br />average year of drouth oyoles and normal periods, may be summarized as
<br />follows:
<br />
<br />Drouth Cycle Normal Period I
<br />
<br />Irrigation Oonsumption in Upper Basin
<br />
<br />1,812,000
<br />
<br />2,Ol~,ooO
<br />
<br />Export Diversions out of Natural Basin
<br />
<br />168,000
<br />1,980,000
<br />
<br />214,000
<br />2,227,000 *
<br />
<br />Total Existing Upper Be.sin Depletions'
<br />
<br />* The oomparable figure derived from the Report may
<br />approximate 2,129,000 acre feet.
<br />
<br />~5. In the Lower Basin, the Report inoludes depletions within the
<br />natural basin with exportations for use outside the natural basin, the
<br />sum of the two together with evaporation losses fran main-stem reservoirs
<br />being 4,497,000 acre feet annually. Total consumption incident to the
<br />irrigation of 890,200 acres: of land within the natural basin (in Arizona,
<br />Nevada, New Mexico aDd Utah) is estimated in the Report at 1,591,000 acre
<br />feet annually; diversions from the River for the irrigati on of 460,900
<br />acres of land in California are estimated at 2,19~,OOO acre feet annually;
<br />and evaporation losses from main-stem reservoirs are estimated at 713,000
<br />sore feet annually. Independent estimates by Colorado engineers: indioate
<br />that depletions of existing projects in the Lower Basin, under normal
<br />climatic conditions, will average 5,670,000 acre feet annually, exclusive
<br />of allowances for irrigable lands of existing enterprises that have Dot
<br />beeD irrigated up to the present time. Export diversions for use outside
<br />the natural basin below Lee Ferry are gi van in the Report e.t 2.19~,OOO
<br />aore feet annually, and are 'estimated from diversion data by Colorado en-
<br />gineers at 2,700,000 acre feet annually. Evaporation losses from main-
<br />stem reservoirs appear in the Report as 713,000 aore feet annually, and
<br />are estimated by Colorado engire ers (from streamflow reoords)e.t 800,000
<br />acre feet annually. Since the estimate~ of its engineers, with respeot
<br />to existing depletions in the Lrn~er Basin, are substantially greater than
<br />the estimateS' appearing in the Report, Colorado suggests; that the BUreau
<br />of Reclamation re-examine its caloulations; and, in the event the revised
<br />estimates are not nlaterially increased, that the detailed information
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