Central Arizona Project

The Central Arizona Project (CAP) is a 336 mi (541 km) diversion canal in Arizona in the United States. The aqueduct diverts water from the Colorado River from the Bill Williams Wildlife Refuge south portion of Lake Havasu near Parker into central and southern Arizona. The CAP is the second largest and expansive aqueduct system ever constructed in the United States. CAP is managed and operated by the Central Arizona Water Conservation District (CAWCD). It was shepherded through Congress by Carl Hayden.

The CAP delivers Colorado River water, either directly or by exchange, into central and Southern Arizona. The project was envisioned to provide water to nearly one million acres (405,000 hectares) of irrigated agricultural land areas in Maricopa, Pinal, and Pima counties, as well as municipal water for several Arizona communities, including the metropolitan areas of Phoenix and Tucson. Authorization also was included for development of facilities to deliver water to Catron, Hidalgo, and Grant counties in New Mexico, but these facilities have not been constructed because of cost considerations, a lack of demand for the water, lack of repayment capability by the users, and environmental constraints. In addition to its water supply benefits, the project also provides substantial benefits from flood control, outdoor recreation, fish and wildlife conservation, and sediment control. The project was subdivided, for administration and construction purposes, into the Granite Reef, Orme, Salt-Gila, Gila River, Tucson, Indian Distribution, and Colorado River divisions. During project construction, the Orme Division was re-formulated and renamed the Regulatory Storage Division. Upon completion, the Granite Reef Division was renamed the Hayden-Rhodes Aqueduct, and the Salt-Gila Division was renamed the Fannin-McFarland Aqueduct.

...
Wikipedia