OCR Text |
Show The framework program provides for importing 2.25 million acre-feet of water annually to the Lower Colorado Region including 1.5 million acre-feet, plus 0.3 million acre-feet of associated losses, to satisfy the national obligation to Mexico, and 0.^5 million acre-feet as a regional program. Lake Mead would provide regulatory storage for the imported water thus allowing maximum use of the importation facilities. If the initial water importation were in operation at year 2000, there would still remain a regional annual water deficiency of about O.kk million acre-feet which would increase to about 2.1 million acre-feet annually by 2020. Between years 2000 and 2020, an additional augmentation in the amount of 1.9 million acre-feet annually is recommended. Under this plan, the Region's annual deficiency in year 2020 would be about 0.17 million acre-feet. Pumping from ground-water basins will still be required and it is expected that some ground-water overdraft will continue, particularly in outlying basins remote from augmentation service areas. Other means of providing suitable water for multipurpose uses, by year 2020, include the treatment of 0.68 million acre-feet annually of conventionally treated municipal and industrial waste water for reuse in Clark County, Nevada, and in Maricopa and Pima Counties, Arizona; and the treatment of 0.9 million acres of forest lands to increase annual water yield by 0.15 million acre-feet. Augmentation of water supplies in the central Arizona area could provide, through water exchanges, additional water for use in upstream areas for municipal, industrial, and mineral production needs, as well as for alleviating irrigation water deficiencies. Reservoir storage totaling 0.U million acre-feet is provided to regulate flows for use in the upstream areas, largely in the Gila Subregion. Water Quality High levels of dissolved mineral salts in surface and ground waters are the major water quality problem in the Region. The Colorado River Basin framework program for salinity improvement could remove about 2.3 million tons of salts annually by the year 2020, with about 2.2 million tons being included in the Upper Basin portion of the program. The early action salinity control program for the Colorado River Basin provides for the impoundment and evaporation of flows from LaVerkin Springs in Utah, which would remove more than 100,000 tons of salt annually. The program for Clark County, Nevada, consists of a plant for further treatment of secondary treated municipal and industrial wastes in the Las Vegas area. Facilities similar to that for Clark County and provisions for reuse of reclaimed water are also provided for further treatment of secondary treated municipal and industrial waste water occurring in the Phoenix and Tucson urban centers. 17 |