| OCR Text |
Show The framework program provides for the importation, prior to the year 2000, of 2.25 million acre-feet of desalted sea water to the Lower Colorado Region, including 1.80 million acre-feet of water to satisfy the national obligation to Mexico and O.**5 million acre-feet as a regional program. Lake Mead would provide seasonal regulatory storage for the imported water, thus allowing maximum use of the facilities, whereas alternative downstream reservoirs do not provide adequate storage. The water quality benefits achieved through mixing high quality desalted water with Colorado River water would be extensive, and by use of Lake Mead for storage, a portion of the increased costs could be recovered through increased power generation at Hoover and Davis Dams. If the initial water importation were in operation at year 2000, there would 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. It is recommended that between 2000 and 2020, addi- tional importation facilities provide about 1.9 million acre-feet annually, thereby reducing the Region* s annual deficiency by year 2020 to 0.17 million acre-feet. It is expected that some ground-water over- draft will continue throughout the study period, particularly in outlying basins remote from augmentation service areas. Additional facilities would be included to convey the successive stages of imported water from the Colorado River to the areas of need. Terminal regulatory reservoirs having a combined storage capacity of about 600,000 acre-feet would be required in the vicinities of the major demand centers. Such reservoirs also would provide about 14,000 surface acres for recreation opportunities and for fish and wildlife uses. Other facilities providing suitable water for multipurpose uses include tertiary treatment of 680,000 acre-feet annually of conven- tionally treated municipal and industrial waste water for reuse in Clark County, Nevada; and in Maricopa and Pima Counties, Arizona, the treatment of an additional 0.9 million acres of forest lands would increase annual water yield by 150,000 acre-feet. Augmentation of water supplies in the central Arizona area will 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 0.4 million acre-feet is provided to regulate flows for use in the upstream areas, largely in the Gila Subregion. See the following map, "Potential Water Resource Development Continuing Program, 1981-2020," for water resource development. |
