Protect hydropower or threatened fish? Utah Republicans take sides in battle over Glen Canyon Dam.

Turning on the lights all across Utah — in Bountiful, Logan, Hurricane, Murray, St. George or Blanding — happens instantaneously.

But all of those cities receive some electrical power from hundreds of miles away, as water from the Colorado River system rushes through turbines inside Glen Canyon Dam on Lake Powell, producing affordable, carbon-free hydropower — enabling those lights to glow.

Climate change and chronic water overuse continue to constrict the mighty river’s flows, though, jeopardizing the dam’s ability to produce hydroelectric power. The lack of water has also created a slew of environmental problems in the Grand Canyon’s ecosystem, which sprawls below Glen Canyon Dam — most notably for an ancient, threatened fish species, the humpback chub, which is hunted by invasive smallmouth bass.

Under Biden last year, the U.S. Bureau of Reclamation finalized a decision that allows the dam to periodically release surges of water that bypass the machinery that generates power. These flows cool the river below the dam, which curbs smallmouth bass reproduction.

Utah Republicans and power providers say that decision has only further threatened the valuable energy source — and they hope to undo it.

“The Biden administration recklessly limited hydropower generation at this site and increased energy costs for millions of people in the surrounding areas,” said Sen. Mike Lee in a March statement, when he and Utah Sen. John Curtis introduced legislation that could lead to the decision’s undoing.

At the heart of the debate sits the struggling river that provides water to 40 million people, which has seen its flows fall by about 20% in the last quarter century. Lake Powell, the country’s second-largest reservoir, currently hovers at just one-third full, with little water expected to fill it as snow melts off the Rocky Mountains this summer.

“Climate change isn’t going anywhere, no matter how much you deny it, and that’s having a significant impact on hydropower generation throughout the West,” said Jen Pelz, a water advocate at the environmental nonprofit Grand Canyon Trust. “There needs to be an acknowledgement of that, and thinking, how can you replace that power?”

“The forecast for hydropower,” she continued, “is probably as dismal as for the humpback chub if we let smallmouth bass overtake the Grand Canyon.”

But an established population of the invasive fish in the Grand Canyon may be unavoidable, warns Jack Schmidt, a watershed sciences professor at Utah State University and director of its Center for Colorado River Studies, as the Colorado River’s dwindling flows threaten Lake Powell’s water levels.

“The issue before us in the long term,” he said, “is that there’s a certain inevitability that Powell is going to get really low at some point. Why not plan for that inevitability now?”

A source of ‘stable, low-cost electricity’

Since the first day of his second term, President Donald Trump has emphasized the need for American energy dominance, going as far as to declare “a national energy emergency.” The position makes the debate over whether to prioritize energy production or to protect native fish in one of the country’s most cherished landscapes even more consequential.

The Trump administration last week reversed a Biden-era decision intended to protect salmon runs and boost tribal engagement in the Pacific Northwest’s Columbia River Basin.

The previous move, said Interior Secretary Doug Burgum, “jeopardized four critical hydroelectric dams powering communities along the Snake River.”

“Now is not the time to shut down American energy,” Burgum added. “Instead, we’re keeping the lights on, costs low, and putting the American people first.”

Power providers in the American Southwest also say bypassing Glen Canyon Dam, no matter how compelling the reason, poses a major risk to energy users in Utah and across the West.

Eight generators within the 710-foot dam produce about 5,000 gigawatt-hours of hydroelectricity each year, distributed to Arizona, Colorado, Nebraska, Nevada, New Mexico, Utah and Wyoming, according to Reclamation.

“We are, across the board, experiencing upward pressure on energy pricing in the West and nationwide,” said Mike Squires, managing director of government affairs for Utah Associated Municipal Power Systems, or UAMPS.

The agency acts as a bridge between owners of power sources and municipalities across the West. The majority of its Utah members receive some power from Glen Canyon Dam, including cities like Bountiful, St. George and Logan.

“The value of the Glen Canyon Dam and the power we derive from it for our members is that it’s one we can largely dispatch,” Squires continued. “That, of course, depends on the hydrology of the year, but it’s largely something that’s available to us. It’s a valuable resource that provides a very strong financial case for our members, and we’re seeking every opportunity to keep energy costs as low as possible.”

Glen Canyon Dam producing less hydropower means that the Western Area Power Administration, an agency under the Department of Energy that distributes the energy the dam produces, must look for other power sources to give to its customers, including UAMPS, Squires said.

That can mean turning toward more expensive and more emissions-heavy alternatives offered by the broader energy market, like natural gas or coal, to replace the power not produced by the dam, he added.

The Western Area Power Administration did not respond to requests for comment for this story.

Tracy Rees, a spokesperson for the Utah Office of Energy Development, said that it’s difficult to calculate exactly how much power Utah receives from Glen Canyon Dam. “Electricity is like a credit system,” she wrote in an email. “[You] put things in at one place and take them out at another place.”

The Utah Municipal Power Agency — which represents Provo, Spanish Fork, Salem, Nephi, Manti and Levan — also opposes bypassing Glen Canyon Dam’s penstocks. Reversing the July 2024 decision, the agency’s President and CEO Layne Burningham said in a statement, “safeguards the financial foundation that keeps hydropower costs low and infrastructure well-maintained. This is especially critical for municipal utilities that depend on stable, low-cost electricity.”

Another concern, Squires said, is that turning to other energy sources to replace hydropower will deplete the Upper Colorado River Basin Fund, which pays for the operation and maintenance of Colorado River infrastructure — including Glen Canyon Dam.

The money in the fund comes from the entities purchasing power from the dam. So, Squires said, when agencies like UAMPS aren’t getting power from the dam itself, “there’s a bit of a two-fold effect:” the Western Area Power Administration has to replace that power by getting it from another source, and if that other power source is more expensive than the dam’s hydropower, the Upper Colorado River Basin Fund takes a hit.

Reclamation estimated that the bypasses allowed in the July 2024 decision could cost the fund between $13 million and $200 million. Congress could appropriate more money to the fund, Squires said, “but that’s not an easy task.”

The Trump administration, with its energy dominance agenda, is expected to be more open than the previous administration to prioritizing hydropower at the dam, Squires said.

There are other ways to curb invasive species that don’t impact hydropower production, he said, like removing reproducing populations. Reclamation announced it successfully removed a smallmouth bass spawning site near Glen Canyon Dam in early June.

‘Certain things you can’t put a price tag on’

Prioritizing the dam’s power production risks the health of the Grand Canyon’s ecosystem, some environmentalists say.

Federal agencies have known about the potential for non-native smallmouth bass to travel below Glen Canyon Dam, where they could threaten the humpback chub, for years. Scientists discussed possible solutions, like putting a barrier in Lake Powell to catch the invasive fish, though none were implemented.

But when Lake Powell hit a record-low level in 2022, smallmouth bass were discovered in the Grand Canyon, having traveled through the dam. Those fish reproduced, increasing their numbers, as even more smallmouth bass made their way through the dam the next year.

That situation led Reclamation to recommend the release of cooler water through Glen Canyon Dam’s river outlet works — four 8-foot-wide steel pipes at the bottom of the dam below the hydropower-producing penstocks — in July 2024 to flush out smallmouth bass, which reproduce in warmer water.

Reclamation conducted those releases for the first time last summer and fall, “carefully balancing the need to cool the river with the need to generate hydropower,” a spokesperson said. “This was accomplished by turning off the cooler water bypass during hours of high electricity demand.”

The results were “promising,” the Reclamation spokesperson said. “No young smallmouth bass were found in the river below the dam during increased monitoring.”

The agency has not yet decided whether or not it will conduct another cool mix experiment this year.

Pelz, with Grand Canyon Trust, called the cool mix flows “an emergency experiment and a creative solution.” And though they resulted in lower hydropower production, “there are certain things you can’t put a price tag on,” she said.

“There are only so many awes in this world,” she said. “Seeing the humpback chub, this prehistoric fish that has been here for a very long time, is one of the highlights of the Grand Canyon. You can’t put a price tag on what happens when that population completely crashes.”

Pelz said that Lake Powell’s low levels, the result of chronic overuse of the Colorado River’s water and the increasing strain of climate change, are also to blame for the proliferation of invasive species in the Grand Canyon — and the debate about bypassing Glen Canyon Dam’s hydropower infrastructure.

When the reservoir was fuller, the water toward the bottom of Lake Powell was colder. That cooler water could pass through the hydropower penstocks and travel downstream. But as Lake Powell’s levels have fallen, the warmer water that smallmouth bass need has gone through the penstocks, bringing the invasive fish with it.

Because of that, Pelz said that at least for the short term, water managers should prioritize keeping Lake Powell fuller. “Either more reductions must be made in water use so that there’s more water in the system, or more water could be potentially stored in Lake Powell,” she said.

Less water, less power

But Schmidt, the Utah State professor, said “if we keep having these strings of dry years, it’s going to be almost impossible to keep Powell from getting really low.”

The Colorado River’s average flows have fallen by roughly 20% since 2000, and power generation at Glen Canyon Dam and Hoover Dam, which creates Lake Mead on the state line between Arizona and Nevada, has fallen with it.

From 1990 to 2000, Glen Canyon Dam produced 4,600 gigawatt-hours of electricity on average each year, according to a 2023 Congressional Research Service report.

From 2000 to 2020, though, that average dropped to 3,800 gigawatt-hours — a 17% decrease, according to the report. When Lake Powell reached a record-low elevation in 2022, the dam produced just 2,590 gigawatt-hours of electricity, a 45% drop compared to the decade before 2000.

The amount of electricity produced at either Glen Canyon Dam or Hoover Dam is proportional to how much water rushes through each dam’s turbines as well as the pressure of the water in the reservoir behind it. That means whichever reservoir has more water in it produces more hydropower at its respective dam.

The seven states that depend on the Colorado River continue to hash out new guidelines for how the river and its reservoirs should operate after 2026, when current rules expire. Those guidelines, in part, will determine how water along the entire system is stored and divided up among the Upper and Lower Basin states.

The Upper Basin states (Colorado, New Mexico, Utah and Wyoming) pull their share of Colorado River water from the river itself, while the Lower Basin states (Arizona, California and Nevada) get their allocation from the water stored in Lake Mead.

While most of the hydropower produced at Glen Canyon Dam on Lake Powell mostly goes to Upper Basin states, electricity generated at Hoover Dam on Lake Mead serves just Lower Basin states, according to Reclamation.

“Power produced at Hoover and power produced at Glen go to two separate and distinct user groups,” Schmidt said. “The grid is not tied together well, so you have different winners and different losers.”

“Right now, we remain trapped in the mindset that Powell is ‘our’ reservoir,” he continued, referring to the Upper Basin states, “and Mead is ‘their’ reservoir.”

Earlier this year, the Lower Basin states wrote to Trump’s Interior Secretary Doug Burgum that they would like post-2026 operations to allow for more water to be released from Lake Powell downstream to Lake Mead.

If more water is released from Powell when the reservoir is extremely low, Schmidt said, “the release of non-native fish from Lake Powell into the Grand Canyon will be very hard to control.”

And while the Upper Basin states oppose that idea and want to prioritize water storage in Lake Powell, Schmidt said it’s likely that the reservoir’s elevations will decrease regardless.

“You’ve got the double-whammy of a drying climate and less runoff that will reduce inflows to Lake Powell. Additionally, if the Upper Basin continues to grow in its use, then more snowmelt is intercepted before it ever gets to Lake Powell,” he said. “Either way, Lake Powell will be lower and less power will be produced, because less power is produced when the reservoir is low. These are unavoidable truths of physics and geography.”

The cool mix experiments designed to deter smallmouth bass from establishing themselves in the Grand Canyon might be the best course of action in the short term, Schmidt continued. But multiple dry years across the West will lead to such low water levels at Lake Powell, he said, that invasive fish moving through Glen Canyon Dam could become “unstoppable.”

“We ought to be thinking much more in the long term,“ Schmidt continued, ”and ask the questions: ‘What is the desired future condition of the Grand Canyon ecosystem in a world in which non-native fish begin to significantly establish themselves? Should maintenance of the native fish community be the guiding focus on environmental management of the Colorado River in Grand Canyon?’”

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