As predicted, southern Utah’s Lake Powell has fallen below a critical level that soon could threaten its ability to produce hydropower.
On Tuesday, the reservoir officially sank below a threshold of 3,525 feet, which can trigger mitigation efforts from Upper Colorado River Basin states like Utah, Colorado, Wyoming and New Mexico to ensure more water makes it downstream. Below 3,490 feet, the Glen Canyon Dam’s turbine won’t be able to pull enough water to generate electricity.
Glen Canyon Dam produces around 5 billion kilowatt-hours of hydroelectricity each year — enough to power about 450,000 households. That energy is distributed to places like Utah, Wyoming, Colorado, New Mexico, Arizona, Nevada and Nebraska.
The 3,525 baseline is meant to provide a 35-foot buffer response period per a 2019 Drought Contingency Plan Agreement among the Colorado River Basin states. But even at levels below that, equipment risks damage as turbines begin sucking air.
After an exceedingly dry winter, the U.S. Bureau of Reclamation warned earlier this month that Lake Powell would hit critical levels sometime in March. It sat at 3,525.08 feet Monday and dropped to 3,524.96 feet Tuesday.
The elevation marks a record, or historic, low since the Lake Powell reached its full pool of 3,700 feet in the 1980s. It could fall by another 2 to 3 feet before April.
The bureau forecasts that coming snowmelt will raise the reservoir back to 3,525 again by May.
“Reclamation is not planning to take further action to address this temporary dip below 3,525 feet because the spring runoff will resolve the deficit in the short term,” Reclamation Upper Colorado Basin Regional Director Wayne Pullan said in a March 4 news release. “However, our work is not done. Lake Powell is projected to drop below elevation 3,525 feet again later this year.”
Water managers have twice taken steps to bring Lake Powell to its target elevation in the past. In the summer of 2021, they channeled 160,000 acre-feet from Blue Mesa and Flaming Gorge reservoirs. From January to April of last year, they also stopped releasing water from Glen Canyon Dam to keep 350,000 acre-feet from flowing out of the lake downstream.