Bureau of Reclamation Mandates Colorado River Water Reductions for Arizona and Nevada

BOULDER CITY, NV — The United States Bureau of Reclamation released its definitive August 24-Month Study for the Colorado River Basin, establishing operational guidelines for Lake Mead and Lake Powell and declaring a Tier 2a Shortage condition for calendar year 2027.

Protecting Critical Reservoir Elevations and Hydropower Turbines

The federal determination mandates mandatory water consumption reductions totaling 613,000 acre-feet across the Lower Colorado River Basin. Arizona’s municipal and agricultural allocation will be reduced by 592,000 acre-feet (21% of its annual basic apportionment), while Nevada will reduce intake by 25,000 acre-feet (8%), and the Republic of Mexico will reduce delivery by 80,000 acre-feet under Minute 323 treaty protocols. The cuts prevent Lake Mead from declining below elevation 1,025 feet, protecting hydropower generation at Hoover Dam.

Reclamation Commissioner Camille Calimlim Touton affirmed that prolonged aridification requires coordinated basin-wide conservation across all seven basin states.

Municipal Water Authorities and Agricultural Response

Southern Nevada Water Authority (SNWA) confirmed that extensive indoor water recycling and ornamental grass bans ensure Las Vegas will meet water reduction targets without municipal rationing.

Central Arizona Project (CAP) agriculture districts prepared additional fallowing acreage under federal System Conservation funding.

Operating Year Timeline

Tier 2a mandatory water reduction schedules take legal operational effect on January 1, 2027.