Interior finalized Colorado River operating rules for the 2027-2028 operating period, including cuts for Arizona, California, Nevada and Mexico.
Why it matters: The reductions affect farms, utilities and growth planning across the Southwest. They also set the operating terms for Lake Powell and Lake Mead as the basin remains in drought.
- The Interior Department said Friday it finalized Colorado River operating rules for 2027-2028.
- Arizona, California and Nevada will face a combined cut of 1.25 million acre-feet a year for two years starting in 2027, AP reported.
- Mexico will reduce its Colorado River intake by 250,000 acre-feet under a U.S.-Mexico treaty arrangement, according to AP.
- Colorado, Utah, Wyoming and New Mexico are not subject to the mandatory cuts announced so far.
The Interior Department said Friday it finalized new Colorado River operating rules for the 2027-2028 period, and the Bureau of Reclamation released the 24-Month Study that will guide operations under the plan. In plain terms, the study is the federal forecast used to help set how much water will move through the system over the next two years.
AP reported that Arizona, California and Nevada must reduce use by a combined 1.25 million acre-feet a year for two years beginning in 2027. An acre-foot is enough water to cover about an acre of land to a depth of one foot. AP also reported that Mexico will reduce its Colorado River intake by 250,000 acre-feet under a U.S.-Mexico treaty arrangement.
The Interior Department said the basin remains in prolonged drought and that long-term drought is reducing system storage and raising risks for water and power infrastructure serving more than 40 million people. Upstream basin states - Colorado, Utah, Wyoming and New Mexico - are not subject to the mandatory cuts announced so far.
Reclamation's final environmental impact statement says the new rules are part of a 10-year decision framework running through 2036. That framework is separate from the 2027-2028 operating period and is intended to guide longer-term planning for Lake Powell and Lake Mead.
California's chief Colorado River negotiator, JB Hamby, called the plan "a bridge, not a permanent solution". Arizona Department of Water Resources director Tom Buschatzke said it should "provide substantial stability for folks".
By the numbers
- 1.25 million acre-feet - Annual cut for Arizona, California and Nevada combined for two years starting in 2027, according to AP.
- 250,000 acre-feet - Mexico's reduction under a U.S.-Mexico treaty arrangement, according to AP.
- More than 40 million people - Interior says the drought risk affects water and power infrastructure serving this population.
Yes, but: The final rules cover the 2027-2028 operating period, but the longer-term 10-year framework still leaves future negotiations and planning unresolved.
What's next: The 2027-2028 operating period begins in 2027; the 10-year decision framework runs through 2036.