The Central Arizona Project
Arizonans long dreamed of importing Colorado River water to central Arizona. However, only after the U.S. Supreme Court in 1963 confirmed the state's 2.8 million acre-foot allocation (1 a-f=326,000 gal.) of water did Congress authorize the U.S. Bureau of Reclamation to construct the Central Arizona Project (CAP). Construction began in 1973, with initial water deliveries in 1985. The CAP was declared substantially complete in 1993.
The CAP is capable of delivering up to 1.5 million a-f of Colorado River water annually to cities, irrigation districts and tribes in the central and southern counties of Maricopa, Pima, and Pinal. This water supports new growth, replaces current groundwater use to reduce overdraft, and provides surplus water for groundwater recharge (see Groundwater). The CAP also includes electric power generation, flood control, and recreation.
The CAP's $3.4 billion conveyance system is a 336-mile long series of canals, tunnels, siphons and pipelines, stretching from the Colorado River near Parker to the San Xavier Indian Reservation southwest of Tucson. Water is lifted as much as 2,900 feet by 14 pumping plants powered principally by the coal-fired Navajo Generating Station. New Waddell Dam provides seasonal storage, and modifications to Roosevelt Dam increase reservoir capacity.
The Central Arizona Water Conservation District (CAWCD) operates the CAP and repays the federal government for construction costs. Revenue sources include water sales, power sales and surcharges and property taxes.
Issues Summary