Representatives of California, Arizona and Nevada are urging the Trump administration to take a different approach in confronting the problems of the water-starved Colorado River.

As Trump’s appointees inherit the task of writing new rules for dealing with the river’s chronic water shortages, the three states are raising several concerns they want to see addressed. One of their top asks: consider fixing or overhauling Glen Canyon Dam.

The infrastructure problems at the dam in northern Arizona have come into focus over the last few years. If the levels of Lake Powell continue to decline and reach critically low levels, water could be released only through four 8-foot-wide steel tubes, potentially limiting how much could pass downstream to the three states and Mexico.

Last year, federal officials discovered damage inside those four tubes that could severely restrict water flow when reservoir levels are low, raising risks the Southwest could face major shortages that were previously unforeseen.

“It’s a better situation to have the dam actually function without tripping us up and forcing massive reductions,” said JB Hamby, California’s Colorado River commissioner. Making fixes to Glen Canyon Dam, he said, “would prevent the need for draconian reductions.”

Hamby and officials representing the governors of Arizona and Nevada presented their concerns in a letter to the Trump administration last month.

They urged Secretary of the Interior Doug Burgum to scrap a report the Biden administration released in November outlining options for new water management rules, arguing that it failed to consider their proposals and would violate the 1922 Colorado River Compact, the foundational agreement that apportions the water.

For one thing, they said, the federal Bureau of Reclamation, which manages the river’s dams, “must evaluate the impacts of infrastructure repairs, modifications and enhancements at Glen Canyon Dam” as part of its analysis of options.

The Colorado River provides water for cities from Denver to Los Angeles, 30 Native tribes and farmlands from the Rocky Mountains to northern Mexico. California relies on Colorado River water to supply farmlands in the Imperial Valley and the Coachella Valley, as well as cities from Palm Springs to San Diego.

The river’s water has long been overused and its reservoirs have declined dramatically since 2000. The average flow of the river has shrunk about 20% in that time, and while drought is partly to blame, scientists have estimated that roughly half the decline in flow has been caused by global warming driven by the burning of fossil fuels and rising levels of greenhouse gases.

The water level of Lake Powell, the nation’s second-largest reservoir, now stands at 34% of capacity. The reservoir’s surface is currently 71 feet above a threshold at which water could no longer flow through the dam’s main intakes and would instead have to move through the low-level bypass tubes — called the river outlet works.

The dam’s managers said last year that they had spotted deterioration in these bypass tubes, and federal officials have said they are analyzing options for fixes — but have been doing this on a separate track from the writing of new rules for sharing shortages.

The three states’ representatives said in their Feb. 13 letter that failing to consider these “infrastructure limitations” as part of the new rules would violate the law.

“The prior administration’s approach to protecting the Lake Powell outlet works by reducing releases from Lake Powell — rather than making infrastructure repairs and improvements — is shortsighted,” they wrote. They said this approach would harm the three states “by slashing the water available to our farmers, communities, and economies.”

Lake Powell has shimmered between Glen Canyon’s reddish sandstone walls along the Arizona-Utah border since the dam was completed in the 1960s.

But Glen Canyon Dam has been controversial since its inception, with environmentalists arguing the reservoir was unnecessary and destroyed the canyon’s pristine ecosystem. In recent years, advocates of river restoration have called for reengineering the dam and gradually draining Lake Powell to store the water downstream in Lake Mead near Las Vegas.

Hamby said the dam was “built in not a great way.” He likened it to a defective gas tank in a car that would stop working if it was less than half full.

“You’ve got a couple options. You could either constantly gas up your car or you could just stop driving,” Hamby said. “But a better option is, go get your car fixed.”

The push by California for the federal government to take a different approach is occurring alongside persistent disagreements that have left two camps at an impasse. On one side are the states in the river’s lower basin — California, Arizona and Nevada — which have been deadlocked in negotiations with the states in the river’s upper basin: Colorado, Utah, Wyoming and New Mexico.

Those on both sides say they are willing to continue trying to reach a deal on how to apportion cutbacks in water use after 2026, when the current rules expire.

In their letter, Hamby, Tom Buschatzke of Arizona and John Entsminger of Nevada suggested that the potential water-supply bottleneck at Glen Canyon Dam could be “avoided by some combination of straightforward engineering fixes, moving water to Lake Powell from upstream reservoirs when necessary, and temporary reductions in upper basin use.”

They said they would strongly support a “collaborative, consensus-driven approach,” but they also suggested that without a consensus, ongoing disputes among the Colorado River Basin’s seven states might end in court battles.

In response to questions about the states’ letter, a spokesperson for Bureau of Reclamation said in an email that the agency is “actively engaging in dialogue with the Colorado River Basin partners as we work toward long-term operational agreements for the river after 2026.”

The three states stressed in the letter that the 1922 Colorado River Compact requires the upper basin states to deliver an annual average of 7.5 million acre-feet to California, Arizona and Nevada over any 10-year period. If water deliveries were to decrease below that required minimum, that would enable the lower basin states to make a so-called compact call and require the upper basin states to cut their water usage.

The letter mentioned a potential compact call 23 times. It said this outcome is “reasonably foreseeable” in the coming years if the states don’t reach an agreement, and that the implications must be considered in the federal government’s review of alternatives.

“Ultimately, having a strong federal role to motivate people to come together and come to a compromise is essential,” Hamby said, “in order to get us to a place where we sustainably manage the river and don’t end up in litigation.”

Environmentalists said they agree with California, Arizona and Nevada.

“What the letter really is trying to do is force the Bureau of Reclamation to rebuild those bypass tubes so that they will pass enough water,” said Gary Wockner, executive director of the Colorado nonprofit group Save The World’s Rivers. “There needs to be an infrastructure solution that allows water to get through or around that dam in order for the Colorado River Compact to not be violated.”

During the Biden administration, federal officials said they were studying the possibility of overhauling the dam. They discussed proposals such as penetrating through the dam’s concrete to make new lower-level intakes, or tunneling a shaft around either side of the dam, among other options.

The Bureau of Reclamation announced in September that the agency was spending $8.9 million relining the bypass tubes, where the original coal-tar coating was “showing normal signs of wear and tear” after more than 60 years of use. The agency said this maintenance work, expected to take about a year, will not prevent the risk of additional “cavitation” when reservoir levels are low — which refers to the formation and collapse of air bubbles in flowing water, and which can pit and tear into metal, damaging infrastructure. The agency said it was “working on reducing that risk” by developing interim procedures and carrying out “additional analyses.”

But the three states indicated in their letter they believe the government must do more to address what they see as problems in the dam’s design.

“The reason that they wrote this letter is because they see a very serious water delivery risk at Glen Canyon Dam,” said Eric Balken, executive director of the nonprofit Glen Canyon Institute.

“The writing is on the wall that something has to be done sooner than later,” he said. “If we want to actually fix this river system for the long term, we have to have a thorough debate about how to reengineer Glen Canyon Dam.”