OCR Text |
Show "With a storage capacity of 32.0 maf, as assumed by some, the limitation on the net depletion (beneficial consumptive use) in the States of the upper division, excluding evaporation from the reservoirs of the Upper Colorado River Storage Project, with a delivery at Lee Ferry of 7.5 maf per year would be about 5.6 maf per year, and would be 4.8 maf per year if the delivery at Lee Ferry were 8.25 maf per year. "Without importation of water, and such modifications in the required delivery of water at Lee Ferry as would be necessary for the Upper Basin to benefit from the importation of water, it is assumed that the total net beneficial consumptive use in the States of the upper division cannot be more than 5.6 maf per year, and might not be more than 4.8 maf per year. "The addition of more reservoir capacity than will be provided by the existing and authorized units of the Upper Colorado River Storage Project would not materially increase these depletions. The obvious means for enabling the States of the upper division to make a beneficial consumptive use of 7.5 maf per year allocated to them by the Colorado River Compact (less 50,000 af allocated to Arizona by the Upper Colorado River Compact), or even greater amounts, is the importation of water from areas of surplus. ''Lower Basin "What the actual future depletion will be in the States of the upper division of the Colorado River Basin is not known. The present studies were based on two future depletion schedules, one as estimated by the U. S. Department of Interior . . . and the other as estimated by the States of the upper division of the Colorado River Basin. The studies indicate plainly that the latter schedule of depletions cannot be attained with the available water supply. It is believed, therefore, that the true schedule of future depletions will lie somewhere between these two estimates. Releases from Lake Powell for the purpose of generating energy probably will be somewhere between 8.25 maf per year and 8.75 maf per year. These are in excess of that required by the Compact. "It is concluded from the results of the studies summarized in Tables No. 1 and 2 that shortages of water in the main stem of the Colorado River to supply 2.8 maf for beneficial consumptive use in Arizona, and up to 4.4 maf for beneficial consumptive use in California, and 0.3 maf of beneficial consumptive use in Nevada plus 1.5 maf to Mexico will amount to well over one million af by the year 2000. The shortage could materially exceed 1.5 maf by that 34 |