This article, originally published Aug. 29 in The Salt Lake Tribune, is part of a special issue on the future of Lake Powell, looking at the reservoir as overallocation and severe drought dry the Colorado River. Find the whole project here.

REFLECTION CANYON — A yellow tape measure ran down a sandy, sagebrush-dotted bench, crossed a shallow stream where toads hopped through the shadows, and disappeared into a dense stand of willow.

Research ecologist Seth Arens was hidden in the bushes, shouting out the scientific names of plants to an assistant who sat in the shade of a young cottonwood tree with a pen and clipboard.

Sporobolus cryptandrus,” Arens said, using the Latin name for the native bunch grass commonly known as sand dropseed and noting the density of each species in one-meter plots along his tape measure.

“Oh, this is cool,” he said, interrupting himself. “There’s a little barrel cactus, about the size of my pinky finger.”

(Francisco Kjolseth | The Salt Lake Tribune) Research scientist Seth Arens tracks changes in vegetation and ecosystems occurring in the bed of Lake Powell in 2021.

The canyon could have been mistaken for a thousand places on the Colorado Plateau where a trickling stream runs between sculpted sandstone walls, but a 1970s-era can of Hamm’s beer eroding out of a nearby bank near an old fishing lure told a different story, as did the white ring of bleached rock on the cliffs.

The spot was inundated 40 years ago when Lake Powell first filled, backing up through Glen Canyon and over a hundred tributaries. The rising waters drowned waterfalls, box elder groves and thousands of cultural sites — ancestral Puebloan cliff dwellings, intricate rock art panels and Paleolithic hunting camps dating back over 12,000 years.

Over the top of the drowned canyons, millions of visitors flocked to Lake Powell, located in northern Arizona and stretching up into southern Utah, each year to houseboat, Jet Ski, fish and camp on the nation’s second-largest reservoir, which seemed to offer endless opportunities for exploration.

The reservoir began to recede in 2000 when the Colorado River basin entered what is known as the Millennium Drought, the driest period in the Southwest in at least 1,200 years. Last summer, it reached levels not seen since shortly after the Glen Canyon Dam was completed in 1963.

Low water has allowed the side canyons to spring back to life. Although Arens is still in the early stages of his multi-year project, some trends are already apparent.

“In general,” he said, “ecosystems are reestablishing much faster than I would have expected. In places where there is flowing water all or most of the year, the ecosystems are dominated by native plants rather than invasive plants.”

(Rick Egan | The Salt Lake Tribune) Moki Canyon in July. Low water has allowed the side canyons to spring back to life.

The ecological recovery is a bright spot amid a much larger crisis on the Colorado River, and it points to one possible future beyond Lake Powell, where the river runs free around a modified Glen Canyon Dam and into the Grand Canyon beyond. But there are other possibilities as well.

Perhaps Colorado River users — U.S. states, tribal nations, and Mexico — will rally to save the reservoir, radically reshaping water allocation systems to reduce overall use and stabilize lake levels. If warring water interests fail to follow either path, however, it appears likely Lake Powell will shrink to “dead pool,” where it will no longer perform its basic functions as a reservoir.

The ending isn’t written. But most observers, including water managers, states, cities and farmers, agree that without action, Lake Powell is heading toward catastrophe.

(Rick Egan | The Salt Lake Tribune) Boats moored in Bullfrog Marina in July, with water levels continually decreasing.

A broader crisis

The same low-water conditions that exposed the side canyons have left boat ramps perched and unusable in Lake Powell’s Bullfrog, Antelope Point and Wahweap marinas. The wonders emerging upstream are a threat to the reservoir-oriented economy that has grown around Lake Powell over the past 60 years.

In the wet years of the 1990s, the Dangling Rope Marina, located in the middle of the reservoir, sold more fuel than any other gas station in Utah. It closed last year.

Businesses owners told The Salt Lake Tribune they’re struggling to make ends meet with the record-low reservoir levels, and vacationers are canceling plans despite the fact that the reservoir still extends for 130 miles up the Colorado.

According to forecasts from the Bureau of Reclamation, Lake Powell could fall so low in the next two years that hydropower generation would stop, which could raise power rates significantly for the Navajo Nation and threaten funding for important environmental programs, including those that support endangered fish.

(Christopher Cherrington | The Salt Lake Tribune)

After years of projecting a recovery for Lake Powell, the level of alarm shown by the federal government reached new heights this year, with Bureau of Reclamation Commissioner Camille Touton repeatedly stating that the system is “approaching a tipping point.”

In June, for the first time ever, the Bureau of Reclamation threatened significant federal intervention if states could not agree to a plan to voluntarily cut water use by as much as 30% by next year in order to protect levels in Powell and Lake Mead near Las Vegas.

Climate change and 22 years of megadrought alone did not drain Lake Powell; the reservoir’s low levels are also the result of political agreements and decisions dating back over a century and are the result of water users’ failure to cut use to match water supply.

This year marks the hundredth anniversary of the Colorado River Compact of 1922, which divided the river’s water among the seven states in the basin — Utah, Colorado, Wyoming, New Mexico, Nevada, California and Arizona — and set the stage for a later treaty with Mexico.

The seven states in the river basin had a total population of 6.4 million in 1922. Today, 40 million people rely on Colorado River water between Wyoming and Tijuana.

The 30 tribal nations in the basin have been excluded from the vast majority of water negotiations over the past century. Though federal courts have repeatedly ruled tribes are entitled to around a quarter of the river’s average flow, many tribes have been unable to develop their water rights.

The compact’s structure has incentivized the Upper Basin states of Utah, Colorado, Wyoming and New Mexico — which in 1922 were promised far more water than they have ever used — to consider increasing their current allotment with projects like Utah’s Lake Powell Pipeline. In the Lower Basin, agricultural economies and sprawling urban areas in California, Arizona and Nevada have grown dependent on their historic water shares, adding contention as cutbacks are debated.

If the two basins fail to reach an agreement, they risk an uncertain judicial battle that could put the Colorado River Compact’s fate in the hands of the Supreme Court.

(Rick Egan | The Salt Lake Tribune) A buoy anchored far from the current water level at Hite Marina along the Colorado River.

Zombie pool

Looming over the complicated political negotiations is a relatively simple math problem. Unless the leading climate forecasts prove to be wrong and the river basin enters a sustained cycle of above-average snowfall, reducing water use is the only way to stop Lake Powell from dropping.

A team of researchers writing in the journal Science last month concluded water reductions of around 2 million acre-feet, or 15% of current use, could stabilize rapidly declining levels in lakes Powell and Mead, depending on weather patterns. But even that level of conservation would not be enough to refill Lake Powell.

These are mind-boggling quantities of water. Dig a one-foot deep pool on an acre of land, and it would require one acre-foot of water to fill it. To hold 25 million acre-feet, Lake Powell’s capacity when full, that same one-acre pool would have to be over 4,700 miles deep.

Lake Powell has already dropped 165 feet and is only 25% full. It only needs to fall another 43 feet from its current level of 3,533 to 3,490 feet in elevation for power generation to become impossible.

The topography under the lake, which contains far more storage capacity near the top, has caused the water level to drop more quickly the lower it gets.

(Christopher Cherrington | The Salt Lake Tribune)

Water currently pours out of Glen Canyon Dam’s power generators into the Grand Canyon, and the only lower set of outlets are at 3,370 feet in elevation. If Lake Powell falls to that point, a level known as dead pool, water releases could not be controlled but would flow out of the dam by gravity as it is filled by the San Juan and Colorado rivers upstream.

That’s a scenario that everyone — from environmentalists to water managers to Lake Powell visitors — want to avoid.

But would reaching dead pool spell the literal death of Lake Powell? Not exactly. A more accurate description of that scenario might be “zombie pool.”

At zombie pool, the reservoir would have ceased to fulfill nearly all of its intended functions — water storage, hydropower generation and even, to a large extent, recreation — but the Glen Canyon Dam would continue to impede the Colorado River.

The lake levels could fluctuate wildly between summer and winter months, by as much as 100 vertical feet, compounding management complications such as boat ramp access for visitors.

(Christopher Cherrington | The Salt Lake Tribune) At dead pool, Lake Powell would still back up over 100 miles, from the dam to upstream of Bullfrog Marina. This graphic — which shows Lake Powell’s footprint at dead pool, minimum power pool and full pool — was adapted from a map developed by Utah State University’s Center for Colorado River Studies.

Allowing Lake Powell to fall to dead pool would come with other costs. The reservoir would still back up for 100 miles, allowing the steady march of massive sediment plugs, which Mike DeHoff of the Returning Rapids Projects compares to “mud glaciers,” to push further into Glen Canyon. The majority of the reservoir is relatively free of sediment at this point, but the advancing mud could delay restoration efforts if the lake is ever drained.

This summer, nonnative smallmouth bass were discovered for the first time downstream of the Glen Canyon Dam. The fish, which biologists say pose a major threat to recovery programs for native fish like humpback chub in Grand Canyon National Park, were able to pass through the dam’s turbines because the warm surface of the reservoir is now closer to the hydropower intakes. The problem is expected to get worse with lower lake levels.

Fill Lake Powell

If letting Lake Powell’s level drop toward dead pool presents serious problems, then what would it take to save the reservoir?

Lake Powell attracted over 3 million visitors last year, many of whom spent multiple days in Glen Canyon National Recreation Area.

The BlueRibbon Coalition, a nonprofit that advocates for motorized users of public land, has joined with motorized users of Lake Powell to campaign for refilling the reservoir to 3,588 feet in elevation.

Ben Burr, the group’s executive director, said that’s the level at which most of the reservoir’s boat ramps and other amenities can be used, supporting over $400 million in direct economic activity each year and numerous local businesses.

(Rick Egan | The Salt Lake Tribune) A previously-submerged motorboat in South Fork Canyon.

But a recent report commissioned by the BlueRibbon Coalition on the plan points to a tough road ahead. Unless the Millennium Drought ends, the report shows that it will be necessary to cut Colorado River water use by up to 30%, pitting recreation at Lake Powell against farmers, cities and tribal nations.

With around 80% of Colorado River water going to agriculture, and nearly 80% of that water used to grow forage crops for livestock like alfalfa, farmers would have to bear the majority of water cuts.

Other options for conservation that have been pursued aggressively in cities like Las Vegas include the removal of lawns and incentives to plant more drought-tolerant landscaping, though residential conservation alone won’t be enough to reduce total water use by 30%.

Cuts, said Tanya Trujillo, the Department of Interior’s assistant secretary of water and science at an August press conference, will need to come from “all states and all sectors.”

The federal government had the chance to impose cuts on the states in mid-August, the deadline for states to agree to a voluntary plan, but they haven’t yet done so.

Let it go

There is another potential option that water managers could pursue that would grant greater flexibility in water management decisions: allow Lake Powell to drain and the Colorado River to once again flow freely through Glen Canyon.

A growing number of environmental groups, including Glen Canyon Institute, Utah Rivers Council, Save the Colorado, Living Rivers and the Great Basin Water Network, are calling on federal officials to study the feasibility of drilling new tunnels around the base of the Glen Canyon Dam to avoid a dead pool scenario.

When the dam was being built, two tunnels funneled the water around the construction site through the nearby sandstone cliffs, but those tunnels were filled with reinforced concrete when Lake Powell began to fill in 1963.

By drilling new tunnels through the cliffs, river advocates say water managers could decide how to use the 1.9 million acre-feet of water that would otherwise be trapped in a dead-pool Lake Powell.

Eric Balken, executive director of the Glen Canyon Institute, said that the dam could still be used as an emergency backup structure for flood control, but he advocates for sending Lake Powell’s water to the larger Lake Mead. If all of Lake Powell’s water were moved to Lake Mead today, the latter reservoir that supplies Las Vegas and generates more power than the Glen Canyon Dam, would still only be half full.

Adding bypass tubes at the base of the dam would not solve the bigger problem of water use outpacing supply in the Colorado River system, and it would require modifications to the water intake that supplies Page, Arizona, and the LeChee Chapter of the Navajo Nation.

But it would allow for greater flexibility and adaptability, Balken said, and would free water managers from having to make decisions based on the design of the Glen Canyon Dam.

The new tunnels would have an additional benefit, allowing for Glen Canyon — which the writer Wallace Stegner once said would have made a “superb national park” — to begin to recover.

Archeologists at the Museum of Northern Arizona have discovered that at least a quarter of the numerous cultural sites that were surveyed in Glen Canyon prior to the dam’s completion have been reexposed and still exist, KNAU reports.

And Arens’ ecology research in the tributary canyons provides a sense of what might happen on a larger scale if Lake Powell’s water is sent to Lake Mead.

“As we walk up one of these canyons,” he said, “we’re not only walking in space, but we’re also … essentially walking backward in time.”

(Francisco Kjolseth | The Salt Lake Tribune) Seth Arens’ tape measure marks a plant survey transect in Clearwater Canyon, one of the tributaries along the Colorado River that was once flooded by Lake Powell.

Elevations between 3,680 and the full-pool level of 3,700 feet have been exposed for 20 years, allowing native bees to return, cottonwoods to grow 50 feet in height and beavers to once again dam the perennial streams.

Arens said his plant study is a relatively basic survey and there are numerous opportunities for other scientists to study the changes taking place in Lake Powell.

With more research, Balken hopes land and water managers will better understand what would be lost ecologically if the reservoir were to refill — and what might be in store if the Colorado River was allowed to flow around the dam.

“For a long time, there was a thinking that Glen Canyon is lost forever and there’s no hope of getting it back,” Balken said. “I think this research can start to dispel that myth.”

“The moment of reckoning”

The Bureau of Reclamation said it is studying making potential modifications to the dam that could allow water to be pumped or released from below the dead pool elevation, but the findings are not anticipated to be available before 2024, according to bureau spokesperson Jennifer Erickson.

Lake Powell, meanwhile, is continuing to drop. The ramp at Bullfrog Marina is expected to close next month, leaving only one access point for trailers on the entire reservoir, and thousands of Lake Powell visitors have submitted comments to federal officials demanding action.

Will the seven states and two countries in the Colorado River basin make significant, long-term cuts to water use in an attempt to salvage the reservoir as a world-renowned recreational destination and as a producer of hydropower?

Will water users and officials decide the dam outlived its useful life? Could Glen Canyon — sometimes called “America’s lost national park” — once again emerge, initiating what could be among the largest acts of environmental restoration ever undertaken in the United States?

Or will the conflicting demands of millions of users and the complicated set of legal doctrines that govern the river make decisive action impossible, leaving Lake Powell in some greatly diminished form, all while wreaking havoc on water planning efforts and the environment?

The future of Lake Powell will be hashed out in board rooms, conference calls, Congressional hearings and possibly the courts over the next months and years.

“What has been a slow-motion train wreck for 20 years is accelerating,” John Entsminger, general manager of the Southern Nevada Water Authority, said in testimony before the U.S. Senate Committee in June, “and the moment of reckoning is near.”

(Rick Egan | The Salt Lake Tribune) Bullfrog Marina on Lake Powell in July.

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