| OCR Text |
Show million acres now irrigated, much of it with an inadequate late season supply, development of the basin's land and water resources is little beyond the halfway mark toward ultimate potentialities. Ex- ploitation of the many mineral resources of the basin has barely begun. The great hydroelectric power possibilities of the river were first realized with com- pletion of Hoover Dam. With completion of all present and authorized construction, which will give the river system installed generating capacity of 2 million kilowatts, about a third of the basin's water power will be harnessed. Today within the natural boundary of the upper basin 1.3 million acres are being irrigated. Many of the larger irrigation projects have been under- taken with Federal assistance. The Bureau of Rec- lamation has constructed or is constructing nine projects within the upper basin involving 270,000 acres of irrigated lands, and four other projects which would export 400,000 acre-feet of water be- yond the natural boundary of the upper basin. Five projects under operation by the Bureau of Indian Affairs now irrigate about 93,000 acres within the upper basin. The estimated annual con- sumptive -use of upper basin water totals about 2.5 million acre-feet for existing projects and projects under construction in the upper basin. This in- cludes 650^,000 acre-feet annually of exported water. Within the lower basin there are presently irri- gated about 1.3 million acres of land. Total pres- ent use of 'water is estimated at about 5 million acre- feet annually which includes diversion by the Metropolitan Water District for municipal purposes in the Los Angeles and San Diego metropolitan areas. Under ultimate development the irrigated acreage ca.n be increased by about 300,000 acres. Substantial as is the present contribution of the basin to the national economy, a much greater con- tribution can be made when its existing problems are eliminated and its potentialities developed. The basin's million people are less than 1 percent of the Nation's total but they occupy 8 percent of the coun- try's land area. Paradoxically, however, popula- tion pressure in parts of the basin forces young people to migrate elsewhere for opportunities. The rate of development of the basin's water re- source must be considered in the light of both needs and potentialities. Among the aspects which must be considexed are: (1) Extension of irrigation water supply: (a) to expand present specialty-crop areas; (b) to permit better use of range land; and (c) to rehabilitate 448 existing irrigated areas, now expanded beyond their long-term water supply. (2) Land treatment measures. (3 ) Addition to hydroelectric power facilities. (4) Enhancement of recreational values. (5) Knowledge of the detailed relations among developments in an integrated program. (6) Legal limitations on use. Conclusions (1) Extension of irrigation water supply.-A stabilized and increased irrigation supply would permit a shift to more intensive types of farming in some sections, thus providing agricultural oppor- tunities for more people. The practical limit of water resources development by private enterprise has been reached in most of these areas. This is particularly illustrated in the upper basin, where intensive irrigation farming is carried on, notably in the Grand Valley area in Colorado and the Uinta Basin in Utah. Several Federal reclamation proj- ects provide a fairly adequate irrigation supply in some areas, but construction of additional projects is needed to supplement water supplies for inade- quately irrigated lands, permit more lands to be irrigated, and provide for substantial improvement in domestic water facilities. It is suggested that impartial technical determi- nation of national and regional need for additional production of predominant crops be made before submission of these projects for authorization. Inability to produce sufficient hay to winter-feed livestock has prevented best use of fine range land of Wyoming, Colorado, and northern Utah; and lack of winter feed in southern Utah, New" Mexico, and Arizona has increased the use of the range throughout the year, possibly because of the mild climate. Vast areas have been overgrazed with attendant erosion and destruction of range capacity. Specific examples of a lack of water to sustain existing communities and its effect on the range are found in the Virgin River and Little Colorado River Basins. In the Virgin River Basin, some- what isolated commercially and dependent almost exclusively upon an agricultural economy, the average area per irrigated farm is about 30 acres. To supplement his income the farmer has over- stocked the range, with the result that it has become denuded. Economic distress in the midst of usable land and water resources prevails. The same con- ditions hold in the Little Colorado River Basin. Early development of all economically feasible |
