Lake Powell heads toward record low after spring runoff fails to recover

Glen Canyon Dam sits 37 feet above hydropower turbine failure threshold

Lake Powell, the 185-mile reservoir straddling the Utah-Arizona border, currently holds about 5.6 million acre-feet of water, or roughly 23% of its capacity, according to data from the US Bureau of Reclamation. The reservoir fell below that level for a few months in the winter of 2023, but spring runoff that year carried it back up to 9.6 million acre-feet by June. This year, after a winter of historically low mountain snowpack and a record-breaking March heatwave across the Southwest, water levels barely rose in the spring. Even after supplemental releases from Flaming Gorge Reservoir upstream, Lake Powell ended June below the annual low it hit the month before, and it could keep dropping through the fall.

“Water management in the Colorado River system is starting to get terribly complicated,” said Jack Schmidt, director of Utah State University’s Center for Colorado River Studies. “What’s unique this year is that there was no recovery at all. What we expect to happen is that Lake Powell will go to unprecedented low conditions some time this fall.”

The low water level threatens the dam’s ability to generate hydroelectric power. Lake Powell stands at just 37 feet above the level at which its electricity-generating turbines would start to fail, according to the Guardian. The Glen Canyon power plant provides electricity for nearly 6 million households and businesses.

The failure to reach a long-term agreement on water sharing across the Colorado River system compounds the risk. Negotiators from the seven states with legal rights to the river — California, Nevada, Arizona, New Mexico, Colorado, Utah and Wyoming — have so far failed to agree on how to conserve the region’s most important surface water source. The Bureau of Reclamation could resolve the impasse by imposing its own plan for cuts as soon as next month.

Brad Udall, a water and climate research scientist at Colorado State University, said the fundamental problem is that too many users are drawing from a shrinking supply. “There are too many straws in the glass,” Udall said. “Rather than having an annual fight over who gets what, let’s remove some straws. One way to do that is the American way — let’s buy ‘em out.”

Udall said the Colorado River crisis may be the first time climate change is forcing a complete rethinking of the legal and policy framework governing a water source. “You see climate change impacts across the globe, like big floods, hurricanes — but people pick up the pieces and kind of go back to the way they were living before,” he said. “But here, because the flows are so low, we’re going to have to start buying out or cutting off water users, and the rules we have are completely inadequate to the task.”

Some Western cities are already taking steps to secure alternative water supplies. Phoenix, one of the most prominent cities whose users can no longer count on the Colorado River, is investing in recycling sewage effluent into drinking water. San Diego announced a plan last month to use surplus water from its desalination plant to strike a deal with Arizona and Nevada, allowing those states to buy some of San Diego’s unused Colorado River water rights.

Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, said cities have a range of tools they are starting to deploy. “Cities have a whole lot of tools that they’re going to deploy,” Porter said. “Because cities are going to be differentially impacted by the Colorado River shortage, they’ve developed a voluntary framework for helping each other out.”

The worst-case scenario — “dead pool,” in which the reservoir drops so low that gravity can no longer carry water downstream — is unlikely to occur, Schmidt said, because authorities would intercede with forced cuts and releases from Flaming Gorge. But experts expect Lakes Powell and Mead to remain largely depleted for the foreseeable future.

“In the 21st century, the ultimate cause of the problem is declining runoff,” Schmidt said. “There’s less water in the system. It’s caused by a warming climate, period.”

Porter said the only way to keep the situation from getting worse is to reduce consumption. “We have control over how bad it gets,” she said. “But the only thing we can do to keep it from getting bad is to take less water out.”