Water managers in the Colorado River system are preparing a spring push of additional flows that officials describe as necessary to keep hydropower operating at drought-depleted Lake Powell, even as that water could mean losses downstream.
In eastern Utah, officials expect canyons and river areas to churn with huge volumes of water this spring—at times comparable to “50,000 toilets flushing constantly at the same time”—as the Bureau of Reclamation tries to rebuild Powell after what it described as the driest winter on record. The additional water would come from upstream operations at Flaming Gorge Reservoir on the Green River in Wyoming and Utah, which officials intend to draw down to support electricity generation for households across much of the West.
Lake Powell, held back by Glen Canyon Dam, supplies carbon-free electricity to more than 350,000 homes, according to the report. But the reservoir has been left badly depleted by the prolonged drought, and the plan focuses on preventing Lake Powell from falling too low to operate the dam’s generators.
Officials said the operating target matters because Glen Canyon Dam’s turbines require enough water to avoid air entering the system and damaging equipment, which is why the Bureau of Reclamation is coordinating releases and reservoir levels rather than reducing generation abruptly. With no relief from weather, Flaming Gorge could fall as much as 27 feet (8 meters) a year from now, the report said, leaving some businesses and recreation areas facing a longer, harder wait for reservoir access.
At Buckboard Marina near Flaming Gorge, owners Tony and Jen Valdez said they are watching expected declines tied to the releases. Jen Valdez said, “Of course we’re concerned,” and added that it “will probably get to a point where we’ll need to be more concerned.” The report said a Flaming Gorge decline of about 10 feet (3 meters) by late summer would mean an ever-longer drive to reach the water’s edge to launch boats.
The operational effort is also expected to carry wider costs across the Colorado River basin because system reservoirs compete for limited supply. U.S. Bureau of Reclamation officials said keeping more water than usual from flowing out of Lake Powell on the Arizona-Utah line would be part of the approach. Downstream, Lake Mead near Las Vegas is described as on track to resemble lows from four years ago, when boats and human remains had been exposed.
Electricity providers that rely on hydropower also face uncertainty about what happens if generation falls further. The report said 155 customers receive hydropower electricity from Glen Canyon Dam and other federal generators, and that none relies on hydropower alone. Leslie James, executive director of the nonprofit Colorado River Energy Distributors Association, said federal customers and contractual obligations mean that if hydropower from Glen Canyon is reduced to zero or a low amount, the Western Area Power Administration would likely need to seek power elsewhere at higher cost and with less renewable generation.
James pointed to how replacing federal hydropower with market purchases has contributed to rate increases in recent years. The report cited Emily Brandt, energy resource manager for Heber Light & Power southeast of Salt Lake City, saying the utility has seen increases for the past five years and that the latest increase was 13%.
Alongside power and costs, the report said the strategy could bring environmental tradeoffs tied to water temperature, fish habitat, and invasive species pressures. It cited a concern that warm surface water from Lake Powell could encourage the spread of smallmouth bass, an invasive fish that competes with a threatened native species, the humpback chub. The report said groups including the Grand Canyon Trust urge water managers to mix in deeper, cooler water to keep the Grand Canyon inhospitable to smallmouth bass.
The report also described the hydrology constraints behind the plan, noting that increasing evaporation and rising demand—especially for irrigation—have left Lake Powell at 3,526 feet (1,075 meters) above sea level, or about 23% of full capacity. It said that to keep generating power, Lake Powell cannot fall below 3,490 feet (1,200 meters), the level at which Glen Canyon Dam’s water intakes for electricity generators operate, and that this threshold has never been reached since the dam was completed in 1963 and Lake Powell was filled to full capacity in 1980.
In 2022, the Bureau of Reclamation released an unprecedented 500,000 acre-feet (617 million cubic meters) of water from Flaming Gorge to raise Lake Powell, the report said. It said the latest releases to maintain Powell’s power generation could eventually total double that amount, even as the plan to hold back 1.5 million acre-feet (1.85 billion cubic meters) in Lake Powell would reduce electricity generation at Hoover Dam and contribute to lower Lake Mead levels.
The report also laid out that some of the strongest Flaming Gorge releases in the days and weeks ahead will be calibrated to help native fish in the Green River, a tributary of the Colorado River. Eventually, it said, Flaming Gorge could dip from 83% full to an estimated 59% full, and that the 2022 releases were followed by a wet winter that eased water worries temporarily.
For the Valdez family, that memory of weather relief is part of why they are watching for future improvement. Valdez said, “We kind of got saved by Mother Nature,” and expressed optimism that wet weather could return, saying, “Hopefully we can expand into doing some other things,” adding that “it’s going to come back eventually.”