43 U.S.C. § 1521 — Central Arizona Project

For the purposes of furnishing irrigation water and municipal water supplies to the water-deficient areas of Arizona and western New Mexico through direct diversion or exchange of water, control of floods, conservation and development of fish and wildlife resources, enhancement of recreation opportunities, and for other purposes, the Secretary shall construct, operate, and maintain the Central Arizona Project, consisting of the following principal works: (1) a system of main conduits and canals, including a main canal and pumping plants (Hayden-Rhodes Aqueduct and pumping plants), for diverting and carrying water from Lake Havasu to Orme Dam or suitable alternative, which system may have a capacity of 3,000 cubic feet per second or whatever lesser capacity is found to be feasible: Provided, That any capacity in the Hayden-Rhodes Aqueduct in excess of 2,500 cubic feet per second shall be utilized for the conveyance of Colorado River water only when Lake Powell is full or releases of water are made from Lake Powell to prevent the reservoir from exceeding elevation 3,700 feet above mean sea level or when releases are made pursuant to the proviso in section 1552(a)(3) of this title: Provided further, That the costs of providing any capacity in excess of 2,500 cubic feet per second shall be repaid by those funds available to Arizona pursuant to the provision of section 1543(f) of this title, or by funds from sources other than the development fund; (2) Orme Dam and Reservoir and power pumping plant or suitable alternative; (3) Buttes Dam and Reservoir, which shall be so operated as not to prejudice the rights of any user in and to the waters of the Gila River as those rights are set forth in the decree entered by the United States District Court for the District of Arizona on June 29, 1935, in United States against Gila Valley Irrigation District and others (Globe Equity Numbered 59); (4) Hooker Dam and Reservoir or suitable alternative, which shall be constructed in such a manner as to give effect to the provisions of subsection (f) of section 1524 of this title; (5) Charleston Dam and Reservoir; (6) Tucson aqueducts and pumping plants; (7) Fannin-McFarland Aqueduct; (8) related canals, regulating facilities, hydroelectric powerplants, and electric transmission facilities required for the operation of said principal works; (9) related water distribution and drainage works; and (10) appurtenant works.

Article II(B)(3) of the decree of the Supreme Court of the United States in Arizona against California (376 U.S. 340) shall be so administered that in any year in which, as determined by the Secretary, there is insufficient main stream Colorado River water available for release to satisfy annual consumptive use of seven million five hundred thousand acre-feet in Arizona, California, and Nevada, diversions from the main stream for the Central Arizona Project shall be so limited as to assure the availability of water in quantities sufficient to provide for the aggregate annual consumptive use by holders of present perfected rights, by other users in the State of California served under existing contracts with the United States by diversion works heretofore constructed, and by other existing Federal reservations in that State, of four million four hundred thousand acre-feet of mainstream water, and by users of the same character in Arizona and Nevada. Water users in the State of Nevada shall not be required to bear shortages in any proportion greater than would have been imposed in the absence of this subsection. This subsection shall not affect the relative priorities, among themselves, of water users in Arizona, Nevada, and California which are senior to diversions for the Central Arizona Project, or amend any provisions of said decree.

The limitation stated in subsection (b) of this section shall not apply so long as the Secretary shall determine and proclaim that means are available and in operation which augment the water supply of the Colorado River system in such quantity as to make sufficient mainstream water available for release to satisfy annual consumptive use of seven million five hundred thousand acre-feet in Arizona, California, and Nevada.