Pacific Southwest Water Plan August 1963

Document: "Pacific Southwest Water Plan- Corrected to 8/19" Chapter III, August 19, 1964, page 2Water Use--There are six major diversions from the mainstream of the Lower Colorado River. These measured diversions and uses are summarized for the period of 1958-62 on table 6. 1. Lake Mead Diversions--Diversions from Lake Mead to Boulder City and the Las Vegas-Henderson area began in 1936 and 1942, respectively. 2. Colorado River Aqueduct--Diversion began in 1941 for service to the Metropolitan Water District of Southern California. 3. Colorado River Indian Reservation Canal--During the period 1870-1942, diversions in this vicinity were made by gravity and pumping. Since 1942 all diversions have been made at Headgate Rock Dam. The present service area is the Colorado River Indian Reservation in Arizona. 4. Palo-Verde Canal--The Palo-Verde Irrigation District in California formed in 1925 succeeded earlier diverters. 5. Gila Gravity Main Canal--Diversion began in 1943. The service area includes the Yuma Mesa and the Wellton-Mohawk Division of the Gila Project, and Yuma Auxiliary Division of the Yuma Project, Arizona. 6. All-American Canal--Diversion began in 1940. Service area includes Yuma, Coachella, and Immperial Valleys, California. Diversions from the All-American Canal through the Yuma Main Canal serve the Valley Division of the Yuma Project, Arizona, and the city of Yuma. Returns to the Colorado River through Pilot Knob Wasteway also serve Mexico. Unmeasured beneficial uses of water along the mainstream of the Colorado River include the Willow Beach National Fish Hatchery, Havasu and Imperial Wildlife Refuges, Lake Mead Recreational Area, Parker-Davis Project, Cocopah Indian Reservation in Arizona, and unauthorized diversions. Reservoir and Channel Losses--Numerous studies have been conducted to determine the channel losses along the Colorado River. Gross evaporation losses along the mainstream vary from 60 to over 86 inches annually. The estimated annual net evaporation of the mainstream reservoirs for the period 1957-1961 are: Lake Mead - 834,000 acre-feet; Lake Mohave - 175,000 acre-feet; Lake Havasu - 160,000 acre-feet; Head Gate Rock Reservoir - 2,000 acre-feet; and Imperial and Laguna Reservoirs - 34,000 acre-feet. III-2Epson Perfection 4870 Photo, 400 dpi, 8 bit, 1,085,960 byte