7409 - Laserfiche WebLink

Home Browse Search

Chapter 6 Present and Future Development This section of the report summarizes the project depletions used by the Colorado River Simulation System (CRSS) to estimate the effects of depletions by water resources development at selected stations within the basin. Chapter 8 summarizes the results of the computer modeling. Table 3 presents a summary of the estimated depletion of water through the year 2010 for both the Upper and Lower Basins of the Colorado River. Depletions for 1990 were estimated in 1989 for preparing this report. The projections for the years 1990 through 2010 represent the best estimate by the Bureau of Reclamation of how water use will be developed over the next 20 years. The projections were made after consultation with individual States within the Colorado River Basin; however, the States do not necessarily concur with the projections adopted by Reclamation for planning purposes. UPPER BASIN DEPLETIONS Table 3 summarizes estimates of depletions due to water development in the Upper Colorado River Basin. Reclamation made these estimates in consultation with the water resource agencies of the Upper Basin States, and they have been . eviewed by the States. El timates of use in 1990 were developed by uplrlating depletions reported in the Upper Col<.'rad,o Region Comprehensive Framework Stud;;1I published in June 1971. Projections of water use beyond 1990 were developed from information supplied by State water resource agencies and from construction schedules of pro<<ts authorized for construction or already ,,",der construction. In table 3, the entry under each State labeled "Evaporation, Storage Units" represents that State's share of total evaporation from Flaming Gorge Reservoir, Lake Powell, and the Aspinall Unit Reservoirs which will be charged to that State when total Upper Basin water develop- ment is reached. This is provided for in Article V of the Upper Colorado River Basin Compact. The Upper Colorado River Basin Compact provides that the States of Arizona, Colorado, New Mexico, Utah, and Wyoming will share in the consumptive use of water available in the Upper Basin in the following proportions: Arizona, 50,000 acre-feet; Colorado, 51.75 percent of remainder; New Mexico, 11.25 percent of the remainder; Utah, 23.00 percent of the remainder; and Wyoming, 14.00 percent of the remainder. Arizona Miscellaneous Additional Depletions Consumptive uses due to irrigation and stockpond evaporation have increased by about 6,000 acre-feet since the Comprehensive Framework Study estimates were prepared. Municipal and domestic uses have increased by about 6,000 acre-feet. The Navajo Indian Nation and the city of Page, Arizona, are expected to use an additional 6,000 acre-feet for municipal purposes. Water for Page is reserved by The Reclamation Development Act of 1974, Public Law 93-493, which, among other actions, provided for the incorporation of the city. Navajo Powerplant Consumptive uses, according to records provided by the Navajo Generating Station, averaged 22,000 acre-feet over the 1980-85 period. The contract for sale of water out of Lake Powell allows for annual uses of up to 34,100 acre-feet;