Federal officials will not release cool water from Lake Powell this year, AP reports.
Why it matters: The decision underscores the tradeoff between protecting threatened fish and preserving hydropower in a stressed Colorado River system. It also comes as federal officials race to finalize new post-2026 operating rules for the basin.
- The Bureau of Reclamation will not release cool water from Glen Canyon Dam/Lake Powell this year, AP reported Thursday.
- Officials said the move was driven by 'significant hydropower generation concerns under already strained system conditions.'
- Cool-mix releases can send colder water downstream to disrupt smallmouth bass spawning and help protect the threatened humpback chub.
- Interior says it is moving forward on post-2026 Colorado River operating guidelines and aims to finalize them by Oct. 1, 2026.
Federal officials have decided not to use a cool-water release from Glen Canyon Dam this year, according to AP. The reservoir at issue is Lake Powell on the Colorado River in northern Arizona.
The Bureau of Reclamation said in an email obtained by AP that the decision was made because of 'significant hydropower generation concerns under already strained system conditions.' The reservoir operator has used cool-mix releases before to lower water temperatures below the dam, which can disrupt smallmouth bass spawning and protect the threatened humpback chub.
Reclamation has said the outlet works sit about 100 feet below the penstocks and can release cooler water downstream. In 2024, the agency said the cool-mix approach did not change the total amount of water released from Glen Canyon Dam, only where that water came from.
The decision lands amid worsening hydrology. Reclamation said Lake Powell's minimum probable inflow for the water year was forecast at 2.78 million acre-feet, or 29% of historical average, and warned the lake could fall below the 3,490-foot minimum power pool level by August 2026 without major intervention. AP said the move also follows the worst snowpack on record for the Colorado River Basin and a broader federal proposal to address the river crisis.
Separately, the Interior Department said it is moving forward with the NEPA process for post-2026 Colorado River operating guidelines and wants those rules finalized by Oct. 1, 2026. Reclamation said there is a need for 'extraordinary collaboration for 2027 and beyond.'
By the numbers
- 2.78 million acre-feet - Lake Powell's minimum probable inflow forecast for the water year
- 29% - share of historical average that forecast represents
- 3,490 feet - minimum power pool level Powell could fall below by August 2026
Yes, but: Reclamation has said cool-mix releases do not change total releases from Glen Canyon Dam, only where the water is drawn from - but officials said hydropower conditions make that option too risky this year.
What's next: Interior aims to finalize post-2026 Colorado River operating guidelines by Oct. 1, 2026.