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Show projects which can assist in range stabilization is suggested. However such expansion should defi- nitely include provisions that would result in more desirable range management. Population pressure, with its attendant demand for farm homes, has resulted in an overdevelop- ment of the water resources of the Phoenix area of central Arizona. Irrigators first relied on surface waters of the Gila and Salt Rivers, but expansion of irrigated areas led next to pumping of ground waters for purposes of drainage, and finally to over- draft of the ground water supply for irrigation. Ground water levels are being continually lowered, and pumping lifts already have become so great that substantial acreages in this very rich valley have been abandoned. Ultimate abandonment of as much as 200,000 acres is indicated unless a new supply of irrigation water is brought into the area. This project is the principal rehabilitation work proposed. Other less expensive rehabilitation proj- ects also are pending in scattered localities. No action is possible on the Central Arizona Project until agreement is reached on division of waters in the lower basin. (See Problem A-1.) If water is made indisputably available for use in Arizona, first action should be a determination of the benefits as well as any adverse effects in terms of comprehensive basin development. (2) Land treatment measures (see Problem C-2).-Immediate attention should be given to the critical watershed situation, and a long-term program for the entire basin drafted and acted upon as rapidly as funds permit. (3) Addition to hydroelectric power facilities.- The Hoover Dam project has been one of the prin- cipal means by which the southern California- southern Arizona power market area has been able to meet its electric energy requirements during re- cent years. Normal load growth will require that this area, its oil and natural gas fuel supplies being seriously depleted, look to further hydroelectric power development on the lower Colorado River. Likewise expanding power loads in Utah, Colorado, and Wyoming focus attention on hydroelectric power possibilities in the upper basin. War emer- gency construction with the installation of 100,000 kilowatts of steam generating capacity in the Salt Lake City area was necessary despite the importa- tion to that area of a substantial amount of energy from Idaho and Montana. In addition, mineral resources of great size and variety in many basin localities are awaiting low-cost power for develop- ment. Because of the unquestioned present need for electric power, and because prospective consump- tive use of water in the upper basin may reduce capacities years hence, immediate construction on the best sites is highly desirable. (4) Enhancement of recreation values.-En- hancement of the great recreation values of the basin should be considered a coordinate purpose in water use, and they should be so considered in plan- ning an integrated program for highest beneficial use in the basin. (5) Knowledge of detailed relations among ele- ments of an integrated program.-Numerous small projects now divert water from the Upper Colo- rado River Basin and convey it by tunnels or trans- mountain canals to adjoining watersheds for irri- gation, domestic use, and power production. The Colorado-Big Thompson Project in Colorado and the Duchesne Tunnel of the Provo River Project in Utah are both under construction by the Bureau of Reclamation. There is a growing demand for more water from the Colorado River from water users in the adjacent North Platte, South Platte, Arkansas, Rio Grande, and Bonneville Basins. An ultimate diversion of 3 million acre-feet annually from the upper basin is physically possible, appar- ently at reasonable cost, but the exportation of this amount would substantially limit potential upper basin uses. Their effect on lower basin water qual- ity also is not known. The All-American Canal and the Colorado River Aqueduct are now exporting about 2 million acre- feet of water from the lower Colorado River for use in California. Potential expansion of these diversions to 5 million acre-feet is physically possible but would likewise conflict with potential uses with- in the basin. Preparation as soon as possible of a detailed study of interrelations of all projects from a basin com- prehensive multiple-purpose point of view is suggested. (6) Legal limitations on use.-That conflicts, real, apparent, and prospective, were present in the Colorado River Basin to the extent that basin-wide planning was inhibited was recognized in the Secre- tary of Interior's letter of July 19, 1947, to the President, by which he transmitted his report, The Colorado River. In that letter the Secretary said, "* * * due to the existing circumstances a comprehensive plan of development of the water resources of the Colorado River Basin cannot be formulated at this time." In the upper basin the "circumstances" to which 449 |
