| OCR Text |
Show recovered annually from the Gila River by phreatophyte control. The Early Action Program 1965 - 1980 is shown on the map following page 92. There are 9 reservoirs presently authorized or under construction in the Region totaling nearly 3.9 million acre-feet of capacity. The primary purpose of 6 of the reservoirs is conservation storage associ- ated with the Central Arizona and Dixie Projects. The remaining 3 would be primarily for flood control purposes. The 1965 to 198O land treatment and management program provides water yield improvement measures on about 175j000 acres of chaparral and coniferous forest lands to increase average annual water yield by about 30,000 acre-feet. Means to conserve and more efficiently utilize exist- ing water supplies are also included in the early action program. After implementation of the early action program, a water supply deficiency of about 1.5 million acre-feet will remain. Water Quality A Colorado River Basin Salinity control program is necessary to prevent further quality degradation of Colorado River water entering the Lower Colorado Basin. In the absence of controls, the concentra- tion of total dissolved solids at Lee Ferry is projected to increase from 586 milligrams per liter to 65O milligrams per liter during the 1965 to 1980 period, and at Imperial Dam, from 839 to 1,260 during the same time period. The early action water quality program provides facilities for additional treatment of municipal and industrial wastes in the Las Vegas Nevada, and Phoenix-Tucson, Arizona, areas. Provisions for reuse of reclaimed water are also provided. The Colorado River Basin salinity control program provides for the impoundment and evaporation of flows from LaVerkin Springs in Utah, which will prevent more than 100,000 tons of salt annually from reaching the Colorado River. Land Treatment and Management The land treatment and management program is needed to minimize irreversible losses of the land resources and to preserve the freedom of choice for future resource users. The program includes treatment of 19.3 million acres by 1980 at a total cost of about $205.7 million. Cropland-Measures such as diversions, levees and dikes, channel improvement, floodways, and streambank protection were considered for erosion, sediment, and runoff control on cropland. Necessary soil sur- veys are also included. These measures are primarily for protection of the land and improvements, but also help to maintain and/or improve the 91 |
