OCR Text |
Show requirement is less. A major purpose of a water resources program in the basin, then, is the attain- ment of optimum use of water on forests and range lands through wise management of these land resources. Consistent with the pattern of water apportion- ment dictated by the Colorado River Compact, by the Upper Colorado River Basin Compact for the upper basin, and safely within the implications of the controversy over lower basin waters, full eco- nomical development of the irrigation potentialities within the basin is contemplated. In the upper basin particularly, exportable field crops must be subordinated to the forage crops to provide a proper balance between the range use and winter feeding capabilities. The native grass hay meadows must give way to improved grasses and legumes. Throughout the basin, care of the tillable land re- sources through improved irrigation practices, crop rotation, contour plowing, and other beneficial techniques must be fostered. Poor irrigation prac- tices, and particularly leaking canals and too long irrigation runs, must be corrected not only to con- serve water, but to conserve the lands themselves. Control of nonbeneficial vegetation must be gained. The problem is already a major one, especially in the lower basin, in that weed-trees and shrubs consume a significant part of the water re- sources and this consumption is increasing. Al- though these nonbeneficial plants help control sedimentation of reservoirs, they also create flood hazards and in time will create swampy conditions. Some of them are already taking over extensive areas of overgrazed range. Much more research on con- trol methods is indicated. Adequate control tech- niques must be developed as a matter of urgency, and applied as rapidly and thoroughly as appro- priations will permit. The major communities dependent upon the Colorado River system for municipal water sup- ply-the Los Angeles and San Diego metropolitan areas, Denver, Salt Lake City, Phoenix-have an- ticipated that dependency, have assured themselves so far as practicable of the availability of needed supplies, and have plans for necessary physical works prepared well in advance of their needs. While the cities have been foresighted as to their normal requirements, supplies for possible indus- trial expansion within the entire basin have not been surveyed in the light of changing circum- stances; that survey must be made and brought into the planning process. Hydroelectric Power There is immediate need for additional electric energy in the market area within and contiguous to the basin. To the extent economical, then, the hydroelectrical potential of the Colorado River system must be developed. There are significant economic advantages ob- tainable through the further development of the Colorado River hydroelectric potential. Both Arizona and southern California import fuels for thermal generation. A low-cost supply of these fuels is not likely to be permanent, and there al- ready have been instances when a temporary peak in oil prices placed thermal generation costs beyond the means of industry. Industry cannot establish itself upon the basis of conjectural energy costs. Industry also cannot establish itself in areas of short water supply. In essentially every hydro- electric opportunity in the Colorado River Basin there is parallel opportunity for water conservation. Within the provisions of the compact economical hydroelectric development in the basin thus can develop two of the elements essential to industry. The extraordinarily complex allocation of Colo- rado River system water will require more than ordinary regulation of that water to serve the system of water rights. Great as well as lesser reservoirs will be required for long-term supplement of de- ficient natural flows, and maintenance of regula- tory storage capacity against the encroachment of sediment requires dead storage capacity. Great reservoirs imply major dams, equated flows imply firm water supply, and dead storage implies that the regulated stream will always be discharged under pressure. These are the elements of a hydro- electric potential, and these elements are present at many or most of the water resources development potentials in the basin. Development of hydroelectric energy is compat- ible with the use of the water resources for other functions and is given preference in the Colorado River Compact. Through multiple use of the same facilities, the cost to each is reduced; thus the irri- gated agriculture economy can be enhanced by eco- nomical hydroelectric development at multiple-use sites. The objective of water resources development is an improved permanent economy, which is to say a generally high standard of living; hydroelectric energy can contribute to that high standard all those elements which abundant energy contributes to the home and industry. 453 |