Lake Powell Loses 40,000 Acre-Feet of Water

Photo: Bernard Spragg/Flickr

The Colorado River is in trouble, and has been for decades. It’s overextended, and even with back-to-back stellar water years, it’s still in bad shape. That’s why the recent news about an accidental release of 40,000 acre-feet of water from the Upper Colorado River Basin is worrying, to say the least.

According to Jerd Smith of Fresh Water News, Bureau of Reclamation officials confirmed that an accidental 40,000 acre-feet of water was discharged from Lake Powell between 2021 and 2022. That was a time of critical water levels at Lake Powell that threatened the reservoir’s ability to generate power. To mitigate that, releases were sent upstream from Flaming Gorge and Blue Mesa reservoirs. As that water arrived, it had to be pushed through Powell into Lake Mead for power generation, and to balance the water levels between those two reservoirs. That’s when an extra 40,000 acre-feet of water left Powell, which means it officially left the Upper Colorado River Basin. And according to Smith’s reporting, there are no plans to restore that lost water to the Upper Basin.

“Under the 2007 Interim Guidelines, this was the first time Reclamation balanced the contents between lakes Powell and Mead in near real-time, working against quickly changing hydrology over the course of just a few months,” Alex Pivarnik, supervisory hydrologist with Reclamation’s Upper Colorado Basin Region, said in an emailed statement to Smith. “Getting it within 0.5% is pretty remarkable, given the circumstances,”

40,000 acre-feet is enough water to serve 80,000 houses for one to two years, according to Smith. So, while it’s not a massive amount of water in comparison to the entire Colorado River, it’s still a significant mistake.

This news comes as Upper and Lower Basin states are fighting over new operating rules for the Colorado River, as the current rules expire in 2026. Upper Basin states want a larger share of their water, while Lower Basin states, including California, are reluctant to give up their shares.