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Show PART XI PROJECTED WATER USE On-site depletion by 2020 on 2.1 million acres of irrigated cropland, incidental use on water-consuming noncropped areas and irrigation reservoir evaporation would total 3.29 million acre-feet annually. An increase of about 500,000 acres of new full supply crop- land would be developed between 1965 and 2020 to meet feed and food production projections. Of the 549,400 acres of presently short supply lands 421,100 acres would receive supplemental water to obtain full production. Irrigation consumptive use by 2020, including supplemental water, would total 2,707,000 acre-feet. Irrigation reservoir evaporation would be about 187,000 acre-feet. Incidental use is estimated to increase from the present 315,600 acre-feet (18.6 percent of consump- tive use) to about 400,000 acre-feet (14.8 percent of consumptive use) by 2020, which is an increase in irrigation efficiency of nearly four percent. Import Inflow to the region from the Great Basin to the Paria River would be the only import and will remain at the present level of 2,600 acre-feet annually. Export by Transmountain Diversions This plan envisions the export of 1.653 million acre-feet of water from the region by 2020. Wyoming's export of 185,000 acre-feet would be to the urban areas of Cheyenne-Laramie and to the North Platte and Bear Rivers systems. Colorado would export 883,000 acre- feet to the Fort Collins-Denver-Colorado Springs area for municipal, industrial and agricultural use, and to the Arkansas and Rio Grande systems. Utah would export 467,000 acre-feet to the Great Basin for municipal, industrial, and agricultural use. New Mexico would export 110,000 acre-feet to the Rio Grande by 1980 and an additional 7,500 acre-feet for municipal use at Gallup, located in the Lower Colorado Region. Main Stem Reservoir Evaporation Evaporation loss in 2020 from the five Main Stem regulating reservoirs (Lake Powell at 576,000 acre-feet, Flaming Gorge at 67,000 acre-feet, and three reservoirs in the Curecanti Unit at 17,000 acre- feet) for normal operating conditions would be 660,000 acre-feet. It should be noted, however, that these evaporation losses will be charged against the separate States only if curtailment of use is required in the Upper Colorado Region to make delivery at Lee Ferry under the Compact. 52 |