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Show Water Development Needs, Opportunities, and Programs Chapter 3 By national standards the Colorado Basin today is not a highly developed area, although it com- pares favorably with regions of similiar environ- ment in other parts of the world. Many important resource potentials remain for future exploitation. It is certain that the basin as a whole will always be one of extensive land use, and hence generally of sparse settlement. Nevertheless notable resource developments have taken place in the basin. One of the first important Federal hydroelectric projects was built here, and the longest interbasin diversion of water starts in this basin. Some of the most notable scenic res- ervations in the world, several associated with water, are within its limits. And in spite of the handicaps on full use of water brought about by the basin's political divisions, remarkable inge- nuity and resourcefulness have characterized occasional works, like those bringing water to some mining enterprises. In places the rewards have been great, in others the costs excessive, but every enterprise in the basin has depended above all else on water for its usefulness and its success. Irrigation Present Situation Irrigation has always been a prerequisite to in- tensive crop production in the Colorado River Basin. Archeological evidence indicates that farm- ing by irrigation as now practiced is a modern re- vival of an ancient agricultural development in the Gila and Salt River Valleys, where present canals are found to follow closely the route of an ancient canal system. During the eighteenth cen- tury, Spanish Jesuits who settled along the Santa Cruz River irrigated their land, but it was not until after 1850 that modern irrigation works were developed by the American pioneers. The Federal Government first attempted to re- claim arid lands on the Colorado River Indian Reservation in 1867; since then irrigation has con- tinued to expand steadily in both the upper and lower basins. Crop production in the Colorado River Basin is dependent almost wholly on irrigation. In 1946, 2,676,000 acres were under irrigation in the Colorado River watershed. Of this, 1,325,000 acres are in the upper basin and 1,351,000 acres in the lower basin. In addition 416,000 acres were irrigated in the Salton Sea Basin of southern Cal- ifornia with Colorado River water. Most of the irrigated lands have been developed by private enterprise. Nine projects involving some 270,000 acres of irrigated lands have been or are now being con- structed by the Bureau of Reclamation in the upper basin. None of these projects is large. Nearly all furnish water for some new lands and some supplemental water for previously irrigated lands. Four additional projects will export water beyond the boundary of the upper basin. At present over 200,000 acre-feet of water are being diverted annually outside the upper basin by transmountain diversions. When the largest of these projects now under construction-the Colo- rado-Big Thompson Project-is completed, an ad- ditional 300,000 acre-feet will be exported. The Bureau of Indian Affairs operates five proj- ects involving 93,000 acres of irrigated land on Indian reservations. Of the 20 projects in existence or under way in the lower basin, over half are for irrigation of Indian land, and one, the All-American Canal system, delivers waters to land in the Imperial 365 |