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Show PART TV SUTURE DEMAND million acre-feet annually. Projected demands for irrigation will in- crease the annual depletions to about 3.294 million acre-feet by the year 2020. This is 50.5 percent of the total projected on-site depletion for all uses in the Upper Colorado Region. Table 28 includes projected ir- rigated land acreage and related water depletions for the target years 1980, 2000, and 2020. The 3.294 million-acre-foot water depletion for irrigation includes 2,707,000 acre-feet in irrigation consumptive use, 187,000 acre-feet in irrigation reservoir evaporation, and 400,000 acre- feet in incidental use on water-consuming noncropped areas. Table 28 - Projected on-site water depletions by irrigated incidental use, and irrigation reservoir evaporat land (new and ion- Framework supplemental), Plan 1980 2000 2020 Hydrologic Irrigated land (1,000 acres) Water depletions Irrigated land (1,000 acres) Water depletions Irrigated land (1,000 acres) Water depletions subregion and state , Supple-Total-' mental (1,000 ac.-ft. ) . Supple-Total±' mental (1,000 ac.-ft.) , Supple-Total-' mental (1,000 ac.-ft.) Green River Colorado Utah Wyoming 128.7 287-3 3^1-5 5.9 102.6 59.0 132.0 518.0 33^.0 130.3 284.6 379-5 13.1 102.6 85.0 139-0 516.0 407-0 13^.9 305.8 392.5 19.1 102.6 95.0 147.0 572.0 428.0 Subtotal 757-5 167.5 984.0 794.4 200.7 1,062.0 833.2 216.7 1 ,147.0 Upper Main Stem Colorado Utah 662.8 8.2 59.2 1,064.0 14.0 709.4 7-6 99.3 1,153.0 13.0 757-2 8.0 126.5 2.0 1 ,216.0 17.O Subtotal 671-0 59.2 1,078.0 717.0 99-3 1,166.0 765-2 128.5 1 ,233-0 San Juan-Colorado Arizona Colorado Hew Mexico Utah 10.0 211.7 104.2 39.2 -p-VJ1 00 VJl CD 7.0 283.0 245.0 56.0 9-h 247.8 139.2 46.4 53-8 5-5 7-0 8.0 341.0 329.0 76.0 9-h 259-8 174.2 80.3 55-8 5-5 14.6 9.0 36O.O 411.0 134.0 Subtotal 365-1 54.3 591.0 442.8 66-3 754.0 523.7 75-9 914.0 Region Arizona Colorado New Mexico Utah Wyoming 10.0 1,003.2 104.2 33^.7 3M.5 113.9 5-5 102.6 59.0 7.0 1,479.0 245.0 588.O 33^-0 1,087.5 139-2 338.6 379-5 166.2 5-5 109.6 85.O 8.0 1,633-0 329.0 605.0 407.0 9.4 1,151-9 174.2 39^.1 392.5 201.4 5.5 119.2 95-0 1 9.0 ,723.0 411.0 723.0 428.0 Total 1,793.6 281.0 2,653-0 1,954.2 366.3 2,982.0 2,122.1 421.1 3 ,294.0 1/ Total includes new and supplemental irrigated Projections land and idle land not irrigated 5 of Water Quality in an averag e year. The dilution effect of intervening streamflows immediately below ir- rigation projects plus the stabilization of base flows through reservoir operation will help maintain the overall quality for reuse of water for irrigation developments with the Upper Colorado Region. Development of the 587.4 million acres of potentially irrigable land and the effects of new stream depletions, however, will result in significantly larger in- creases in salinity concentrations of the Colorado River for reuse by ir- rigated agriculture in downstream areas of the Lower Colorado Region. Based on the GBERS level of development projected to 2020 and without an improvement program, the Water Quality, Pollution Control, and Health Fac- tors Work Group projected total dissolved solid concentrations of 750 mg./l. in the Green River at Green River, Utah (a 6l-percent increase over 1965); 1,300 mg./l. in the San Juan River near Bluff, Utah (a l84-percent increase); and 920 mg./l. in the Colorado River at Lees Ferry (a 57-percent increase). Data for these and other monitoring stations are shown in Tat)le 29. 73 |