| OCR Text |
Show cant as a unit in the development proposed under the Mexican Water Treaty, which provides, among other things, for the distribution of the waters of the Colorado River between the United States and Mexico. Alamo and Painted Rock flood control basins would supply protection to about 175,000 acres of cultivated land in the United States and to several cities and towns. Other authorized flood control projects include Whitlow Ranch Dam and Reservoir on Queen Greek, a tributary of Gila River south of Phoenix, Ariz.; Mathews Canyon and Pine Canyon flood control basins, located on tributaries of Meadow Valley Wash in the Virgin River Basin in Nevada; and a diversion channel project for the protection of Tucson. Whitlow Ranch Dam and Reservoir would pro- vide 24,000 acre-feet of storage for sediment and flood control. Flood discharges from a drainage area of 143 square miles would be controlled. The protected area would be 84,000 acres in extent, of which 59,000 acres are rich irrigated lands. This area includes canal systems and several small com- munities. Mathews Canyon and Pine Canyon flood control basins would provide 14,100 acre-feet of storage for flood control and sediment. Protection would be given to Caliente, Nev., and to many miles of the transcontinental main line of the Union Pacific Railroad. Tucson diversion channel would protect the city and adjacent suburban areas from floods on Tucson Arroyo and other desert washes tributary to the Santa Cruz River. The Tucson metropolitan area is the second largest population center in the Colo- rado River Basin. Loss of life from floods has occurred in this area in recent years. Future Flood Control Requirements The Corps of Engineers has studied the problems and considered project proposals in all parts of the Colorado River Basin. Those which are most ac- tive and on which considerable engineering and economic planning have been accomplished are lo- cated in three different areas of the basin: western Colorado, southern Arizona, and southeastern California. The potential project in western Colorado would consist of channel improvements along Fortifica- tion Creek in the vicinity of Craig. The southern Arizona project proposals comprise Buttes Reser- voir, a multiple-purpose unit for flood control, irri- gation, and power, located on the Gila River above Florence; the Charleston Reservoir on the San Pedro near Tombstone for flood control, irrigation storage, and municipal water supply for Tucson; the Tucson aqueduct for conveyance of water from Charleston Reservoir to Tucson; and the Saf- ford Valley improvements, which would provide for a modification of existing irrigation facilities along the Gila River in the Safford Valley. The southeastern California project proposals are located in and adjacent to Imperial Valley. Al- though this area is not tributary to the Colorado River, the topography along the Colorado delta is such that overflow from the river in Mexico could discharge into Salton Sea in Imperial Valley. In addition to the above projects on which studies have been made, many local protection projects may be needed as growth and develop- ment of the basin advance. Consideration also is being given to including flood control storage in reservoirs that may be constructed in the basin pri- marily for other purposes. Planning of flood con- trol improvements must of necessity be carried on at the same time that plans for conservation and utilization of the water resources of the basin are definitely determined. Local needs for flood con- trol may be affected by provision for large upstream conservation storage, and the amount and cost of such storage will influence the planning of storage for flood control in multiple-purpose reservoirs. Water Supplies Surface water is used for public water supplies by less than two-fifths of the communities and by about one-fourth of the persons in the Colorado River Basin. Seventy communities serving 95,000 persons use surface water, 153 communities serving 233,000 persons use ground water, and 17 com- munities serving 96,000 persons use both surface and ground water. For those communities with water consumption records available, the average use of water per per- son is 400 gallons per day. This abnormally high water usage is accounted for by the extensive use of municipal water for irrigation of lawns and gardens and for air conditioning. The Colorado River Aqueduct takes water from the river primarily for domestic and industrial use by the Metropolitan Water District of southern California. This aqueduct, originating at Parker 375 |
