Get Bureau Of Reclamation Scoping Letters Form

Colorado River 2007 Interim Guidelines Overview Arizona's annual water apportionment of 2.8 million acre-feet would be decreased by 320,000 acre-feet (about 11 percent) while Nevada's apportionment of 300,000 acre-feet would be cut by 13,000 acre-feet (about 3.7 percent).

In 2020 and 2021, the river operated in a “Tier Zero” status, requiring the State to forego 192,000 acre-feet of Arizona's 2.8-million acre-foot annual entitlement to Lake Mead. This reduction is coming entirely from the Central Arizona Project (CAP) system. Reclamation has declared a Tier 1 shortage for 2022.

Colorado River Storage Project Act of 1956 - Provides a comprehensive water resource development plan for the Upper Basin and authorized the construction of Glen Canyon, Flaming Gorge, Navajo and Curecanti dams as well as other participating projects, for multiple purposes.

The Colorado River Compact of 1922 divided the river into two basins: The Upper Basin (Colorado, New Mexico, Utah and Wyoming) and the Lower Basin (Arizona, California and Nevada), established the allotment for each basin and provided a framework for management of the river for years to come.

The Lower Colorado River Basin is in a Tier 2a shortage for 2023. This represents a 592,000 acre-foot reduction to Arizona's Colorado River supply, constituting 34% of Central Arizona Project's normal supply in an average year, 21% of Arizona's Colorado River supply and about 9% of Arizona's total water use.

The 500+ Plan relies upon financial contributions of “up to” $100 million from California, Nevada and Arizona to galvanize new water conservation efforts. The MOU contemplates that the federal government will match this amount, bringing total funds under the program to approximately $200 million.

In 1944, the Treaty with Mexico was signed to provide a set amount of water to Mexico from the Colorado River. The Treaty allocates Mexico 1.5 million-acre-feet each year, equally from the Upper and Lower Basins.