OCR Text |
Show The continuing water-quality program after I98O includes several waste water treatment plants and reuse facilities at or near the places of use. A desalting plant could be utilized in the lower Gila-Salt River drainage which would also aid the salt balance in the Gila Subregion, A desalting plant could also be utilized to treat effluents from the Las Vegas area. Optimum utilization of the water resources will require extensive treatment facilities to attain a high degree of water quality control. Augmentation of the Colorado River with high quality import water would have effects of major significance on improvement of the quality of this principal water source. Continuing studies of the Region's increasingly complex water quality problems are recommended. In addition, the land treatment and management program described in the following section would materially reduce the suspended sediment in the Region's surface water supply. Continued studies are proposed for the identification and solution to physical, engineering, legal, and institutional considerations necessary to implement a sound water quality program for the Region. Land Treatment and Management The land treatment and management program includes practices and measures which improve the quality, quantity, and timing of runoff; reduce erosion and sediment production; and improve the efficiency of use of most factors of production. The program represents a composite level which reconciles environmental protection and production objectives. To be effective, the program must harmonize with all water and related resource programs required to satisfy present and projected demands within the Region. Treatment would be included on nearly 20 million acres by I98O at an estimated cost of $278 million. From 1981 to 2020, an additional kk million acres would be treated at an estimated total cost of $85^ million. In most cases, the same acre will require treatment more than once during the study period because of development of improved methods, or the limited life of the measure or practice installed. Cropland--Measures such as diversions, levees and dikes, channel improvement, floodways, and streambank protection were considered for floodwater and erosion control on cropland. The program includes measures on about 573*000 acres of cropland between 1965 and I98O and 1.6 million acres during the I98I to 2020 period; About 52 percent of the program would be applied in the Lower Main Stem Subregion; 2 percent in the Little Colorado Subregion; and the remaining *+6 percent in the Gila Subregion. Rangeland-The land treatment and management program for rangeland was formulated to reduce erosion and sediment, control runoff, improve forage production, prevent and suppress wildfire, and associated programs. 18 |