The Colorado River flowing between sandstone cliffs. The sun is shining on the far cliffs.

The Colorado River Basin, located in the southwestern United States, occupies an area of approximately 250,000 square miles. The Colorado River is approximately 1,400 miles long and originates along the Continental Divide in Rocky Mountain National Park, Colorado, and ends where it meets the Gulf of California in Mexico. The Colorado River is a critical resource in the West, because seven basin states (Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming) depend on it for water supply, hydropower production, recreation, fish and wildlife habitat, and other benefits. Although agricultural uses depend on 70 percent of Colorado River water, between 35 and 40 million people rely on the same water for some, if not all, of their municipal needs. Moreover, the United States also has a delivery obligation to Mexico for some of the Colorado River waters pursuant to a 1944 Treaty with Mexico.


Post 2026 Colorado River Operations

Supplemental EIS for Near-term Colorado River Operations

Drought Response Operations Agreement

Lower Colorado River Basin System Conservation and Efficiency Program

Upper Colorado River Basin System Conservation and Efficiency Program

Operating under the 2007 Interim Guidelines

Review of the 2007 Interim Guidelines & 7.D. Report


Announcements


Current Activities

Reclamation released the Post-2026 Operational Guidelines and Strategies for Lake Powell and Lake Mead – Draft EIS for public download on January 9, 2026. During the 45-day public review and comment period on the Draft EIS, Reclamation hosted two public meetings and received over 18,000 submissions. Videos of the public meetings and the public comments can be viewed on the Draft EIS Public Review and Comment Process page.


Map of the Colorado River Basin

A map of the Colorado River Basin showing both the upper and lower basins.

Federally Recognized Tribes in the Colorado River Basin

A map of the Colorado River Basin showing the Federally Recognized Tribes within the Basin.
Last Updated: 7/22/26