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Show APPENDIX XII XII-35 schedules for both options should be projected to be matched on the Colorado River Simulation Model with varied projected hydrologic sequences and operating criteria to provide information on the extent and timing of potential future water shortages. 4. Investigations and activities to delineate the most appropriate means of augmenting the Colorado River as envisioned in the Colorado River Basin Project Act of 1968, should be given the highest priority. a. The weather modification program of the Bureau of Reclamation should be continued aggressively with emphasis on resolving remaining sociological, legal, and environmental problems. A demonstration program of several years' duration, as presently proposed under the weather modification program, should be initiated in the Upper Colorado River Basin as soon as practicable to verify the findings to date, particularly as to the magnitude of increases and results of the weather modification program in runoff. b. The ongoing geothermal desalting program of the Bureau of Reclamation on the East Mesa of Imperial Valley should be continued aggressively. c. Other means of augmentation such as the importation of surface water, directly or by exchange, should be investigated as early as such studies would be appropriate and justified. Lower Colorado River Main Stem Management. - The Colorado River from Lake Mead to its mouth has undergone more change in its physical characteristics and patterns of land and water use since completion of Hoover Dam in 1936 then any other major river in the Nation. These changes have created an urgent need for a comprehensive coordinated lower river water and related land management plan and operation. Prior to Hoover Dam, the lower river was uncontrolled, alternating between massive floods in the spring and early summer and meager flows in the late summer and fall, a traditional feast or famine situation. The area was sparsely populated and the river was little used except for limited irrigation diversion when water was available and diversion structures hadn't been destroyed by spring floods. It was an area more suited for wildlife than for human occupancy. Following construction of Hoover Dam and other major lower river regulatory and control structures, the character of the river and its uses changed radically. Today, the river is almost completely controlled. While still supporting important fish and wildlife populations, it has also become a center of intense human occupancy and activity. Recreation use of the river has burgeoned. More than 12 million people live within 4 hours driving time of the lower Colorado River and, during 1973, 8 million visitor-days of recreational use were recorded there. Urban and recreational home development along the main stem continues at an increasing pace. Much of the rapidly growing population growth in the area occurs along the river valley downstream from Davis Dam where the communities of Bullhead City, Havasu City, Parker, and Yuma in Arizona, and Blythe and Needles in California are located. Waste disposal associated with spreading population presents a water quality hazard. Several reaches of the river below Davis Dam still remain relatively undeveloped. These areas have some of the best fish habitat along the river and provide many thousands of man-days of fishing each year. Water and heavy vegetative growth throughout the bottomlands provide a favorable wildlife habitat, with animal life concentrated in and adjacent to thickets. Marshlands provide a habitat which is rare in the arid Southwest and support many species of resident and migratory wildlife. In addition to the numerous game and species, several endangered species depend upon these areas. The preservation of this favorable habitat and its abundant wildlife is 45 |