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<br />001450
<br />
<br />-18-
<br />
<br />.'
<br />
<br />Colorado says that export diversions of existing enterprises in Colorado,
<br />as they are now constructed and will function in a year of normal climate.
<br />will average 135,000 acre 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, 19~. A comparll.ble figure for existing
<br />exportations in Utah under normal conditions appears to be 79,000 acre feet,
<br />making a to~al for the Upper Basin of 214,000 acre feet annually.
<br />
<br />34. Together, the existing depletions in the Upper Basin. resulting
<br />from water consumption incident to the irrigation of Lands within the na-
<br />tural basin and from export diversions for use outside the natural basin,
<br />exclusive of allowances for projects authorized but not constructed and
<br />enterprises not yet completed, as estimated by Colorado engineers for the
<br />average year of drouth cycles and normal periods, may be summarized as
<br />follows,
<br />
<br />.
<br />
<br />Drouth Cyc Ie
<br />
<br />Normal Period
<br />
<br />Irrigation Consumption in Upper Basin
<br />
<br />1.812.000
<br />
<br />2.013,000
<br />
<br />Export Diversions out of Natural Basin
<br />
<br />168 ,000
<br />
<br />214,000
<br />
<br />Total Existing Upper Basin Depletions
<br />
<br />1.980,000
<br />
<br />2. 2Z1 .000 *
<br />
<br />* The comparable figure derived from the Report may
<br />approximate 2,129.000 acre ,feet.
<br />
<br />.
<br />
<br />35. In the Lower Basin, the Report includes depletions within the
<br />natural basin with exportations for use outside the natural basin, the
<br />sum of the two together with evaporation losses from main-stem reservoirs
<br />being 4.497.000 acre feet annually. Total consumption inCident to the
<br />irrigation of 890,200 acres of lend wi thin the natural basin (in Arizona,
<br />Nevada, New Mexico and Utah) is estimated in the Report at 1,591,000 acre
<br />feet annually; diversions from the River for the irrigation <:if 4(,0.900
<br />acres of land in California are estimated at 2,193,000 acre feet annually;
<br />and evaporation los, es from main-stem reservoirs are estimated at 713,000
<br />acre feet armually. Independent estimates by Colorado engineers indicate
<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 irri gable lands of' existing enterprises that 'have not
<br />been irrigated up to the present time. Export diversions for use outside
<br />the natural basin below Lee Ferry are given in the Report at 2.193,000
<br />acre feet annually, and are estimated from diversion data by Colorado en-
<br />gineers at 2,700,000 acre feet armually. Evaporation losses from main-
<br />stem resenoirs appear in the Report as 713,000 acre feet annually, and
<br />are estimated by ColoradO engineers (from streamflow records) at 800,000
<br />aore feet annually. Since the estimates of its engineers, with respect
<br />to existing depletions in the Lower Basin, are substantially greater than
<br />the estimates appearing in the Report, ColoradO suggests that the BureaU
<br />of Reclemation re-examine its ca;Lculations; and, in the event the revised
<br />estimates are not materially increased, that the detailed information
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