Salinity Problems in the Lower Colorado River Area

Document: State of California, Colorado River Board of California, "Salinity Problems in the Lower Colorado River Area," September, 1962, page 13SALINITY PROBLEMS-LOWER COLORADO RIVER 13 Aqueduct to serve supplemental water for municipal and industrial use to eight million people on the coastal plain of Southern California. Annual capacity of the aqueduct is 1,212,000 acre-feet. Return flow to the river is negligible. Palo Verde Irrigation District (120,500 acres) About 75,000 acres of the Palo Verde District are developed and under irrigation. The Palo Verde diversion dam is 118 miles above the northerly boundary. Drainage re-enters the river in a main drain at the lower end of the project, about 50 miles above Imperial Dam, and by unmeasured underground seepage. Imperial Irrigation District (1,000,000 acres) There are 745,000 net irrigable acres of land within the service area of the District in addition to cities, towns, etc. The net acreage irrigated increased from zero in 1900 to 141,030 in 1908 and 436,000 in 1961. By 1961 over 280,000 acres of farmland had been provided with underground tile drainage and about 1,400 miles of outlet drain ditches had been constructed. All the drainage return from Imperial Valley flows into Salton Sea, along with a recently increasing amount of drainage and domestic sewage from Mexicali Valley. Coachella Valley County Water District (137,900 acres) Water distribution facilities have been completed for 74,500 acres in Coachella Valley. About 50,000 acres are presently irrigated. An extensive tile and ditch drainage system has been constructed and all the return flows enter Salton Sea. Yuma Project, Reservation Division (25,000 acres) The California part of the Yuma Project is north of and across the Colorado River from Yuma, Arizona. About 16,000 acres are within the service area of the water distribution system. The irrigated area has been consistently about 10,000 acres since 1921. Water was first delivered in 1910, from Laguna Dam, and now is diverted at Imperial Dam via the All-American Canal. Drainage from the Division is discharged into the Colorado River by the Reservation Main Drain and the Araz Drain, which also collect seepage water from the All-American Canal. ARIZONA PROJECTS Colorado River Indian Reservation (100,000 acres) About a third of the gross area is under irrigation. Diversion is at Headgate Rock Dam, 160 miles above the boundary. Drainage returns to the river at the lower end of the area, 118 miles above Imperial Dam, and by unmeasured underground seepage. Yuma Project, Valley Division (50,000 acres) The area irrigated has been consistently more than 40,000 acres since 1918. Water is diverted at the California side of Imperial Dam and conveyed by the All-American Canal to the Yuma Main Canal which passes under the Colorado River in a siphon to the Arizona side, where it divides into the East and West Main Canals. Three spillways from the West Main Canal discharge into the limitrophe section of Colorado River, the reach between the upper and lower Mexican boundaries. Waste from the EastEpson Perfection 4870 Photo, 600 dpi, 8 bit, 4,298,079 byte