Cañones del río Colorado, antes sumergidos, resurgen mientras los niveles del lago Powell caen por la sequía

GLEN CANYON, Utah — The tops of trees, dead since Lake Powell’s levels rose decades ago, poked through mud and ooze at the silent mouth of Davis Gulch, where the side canyon met the reservoir’s still waters. But just around a few bends in the sandstone walls, life began to appear.

First, a fuzz of inch-tall greenery. Then, knee-high cattails and primrose, followed shortly by small cottonwoods and willows, then by towering gambel oaks.

The silence of the canyon mouth was replaced by the soft rush of a creek, bird songs, and the constant cacophony of dragonflies and gnats.

Scattered throughout the canyon, an ecologist, bug scientists, birders and advocates for Glen Canyon were working to document the ecosystems emerging as Lake Powell’s water levels have dropped after decades of drought and water overuse. “Hiking the side canyons is like going through ecological time travel,” said Eric Balken, the executive director of the Glen Canyon Institute, a nonprofit dedicated to restoring the canyons inundated by Lake Powell, as he hiked up Davis Gulch.

The U.S. Bureau of Reclamation flooded Glen Canyon in the 1960s, converting an intricate network of canyons — carved by the Colorado River and its tributaries — into Lake Powell.

The massive reservoir functions as the water savings account for the Colorado River Basin, where the river serves as the lifeblood for millions of people and massive farming operations across seven states: Colorado, New Mexico, Utah, Wyoming, Arizona, Nevada and California. But years of water use that outpaced the Colorado River’s shrinking flows have, over the past two decades, sapped the reservoir’s water stores and created an existential crisis for water managers across the basin, home to 40 million people.

The falling water levels have also steadily revealed long-submerged canyonlands: red slot canyons, sandstone amphitheaters, waterfalls that tumble over slickrock cliffs. The reemerging landscapes provide a new opportunity to study life in Glen Canyon, which sits just upstream of the iconic Grand Canyon.

Little scientific work was completed in Glen Canyon before the federal government flooded it — an event seen by environmentalists then, and now, as an unmitigated ecological disaster, a paradise lost.

But for a new generation of advocates, regaining paradise seems possible as the reservoir’s shorelines recede, bringing more than 100,000 acres of rugged terrain out of the water. The Glen Canyon Institute and canyon activists for years have argued that Lake Powell should be drained and the Colorado River allowed to again flow freely through Glen Canyon.

Now, their argument is also bolstered by the fact that Lake Powell is emptying — whether Colorado River managers like it or not.

For those advocates, recent years have provided a rare chance to study life in the emerging canyonlands and to make their case to basin leaders who are contemplating the long-term future of Colorado River management. Basin leaders, including those from Colorado, will decide in the coming months how Lake Powell should be operated.

The impacts will have basinwide implications, including on hydropower, Grand Canyon recreation and ecosystems, Lake Powell recreation, and the amount of water in reservoirs up- and downstream. The decisions will determine the future of river management for years to come — and whether the reservoir’s levels rise and again inundate the canyons.

Balken has worked to coordinate and support research in the emerging canyons that examines what life looks like and what it could look like in the future. The goal, he said, is to show water managers and the general public the types of vibrant ecosystems that policymakers could permanently protect by lowering the reservoir levels.

“You can’t protect it if you don’t understand it,” Balken said.

The U.S. Bureau of Reclamation in 1963 closed the gates of the newly constructed Glen Canyon Dam and, for 17 years, water levels rose to create Lake Powell.

For the remainder of the 20th century, water levels stayed relatively stable — rising in the spring as snowmelt across the upper Colorado River Basin made its way to the reservoir, and then falling the rest of the year as water was sent downstream to cities and farm fields. The immensity of the body of water, which resembles an 186-mile vericose vein snaking across southern Utah, is difficult to comprehend or convey.

Three major tributaries meet what was the Colorado River at Lake Powell, and 127 named side canyons sprout from the main corridor, as do hundreds more without names.

The Glen Canyon Dam that created the reservoir is in northern Arizona, just over the state line. When full, Lake Powell’s shoreline spans 1,960 miles — the approximate driving distance from Denver to Boston.

At full capacity, it holds about 25 million acre-feet of water — 26 times the capacity of Colorado’s largest reservoir, Blue Mesa Reservoir in Gunnison County. An acre-foot of water is approximately enough to cover a football field in water and is generally considered the annual water use of two to four families.

At full pool, the reservoir’s contents would fill the Empire State Building more than 33,000 times and could cover the entire state of Kentucky in a foot of water.

But the reservoir is not full, has not been full since 1999 and is unlikely to become full in the near future without extreme intervention from basin water managers. As of Tuesday, the reservoir was at 24% of capacity, and its water level was 172 feet lower than it would be if it were full.

Across the reservoir, sandstone arches that used to be submerged are now large enough to drive a boat through. Historic cultural sites from Indigenous groups that have inhabited the area for centuries are reemerging, though wiped of any artifacts.

The lower water levels were obvious as Balken led a caravan of two pontoon boats up the reservoir’s main channel on May 11. Halls Crossing Marina felt like a construction site as work crews made daily changes to adapt to the falling water levels.

Except for those in Balken’s group, the campground above the marina was empty on a lovely spring Sunday evening. A bright white stripe of bleached sandstone around the canyon walls, called the bathtub ring, marks where the water used to rise.

Balken and the only other two full-time staff members at the Glen Canyon Institute were leading the first formal trip of the organization’s Community Science Initiative (and allowed a Denver Post reporter and photographer to tag along). The program aims to survey the flora and fauna and aid established scientists in their research in the reemerging canyons.

The boats were loaded with tents, emergency oars, containers of gasoline, cameras, and 50 Mason jars for insect collection — along with two birders, two aquatic ecologists from Western Colorado University, a documentarian, and an ecologist who for years has helped compile the most expansive accounting of the vegetation in the canyons’ emerging landscapes.

Over the next three days, the group would bushwhack miles up side canyons looking for birds, beavers, bugs and more. For some, like the birders, it was their first foray into Glen Canyon’s reaches.

Others had been in the canyons multiple times over the years. Dawn Kish, a former Grand Canyon river guide and current documentarian of reemerging Glen Canyon, has spent hundreds of hours exploring the canyons and recreating photos taken before the dam gates closed.

The folds of the canyons continue to draw her in, she said. Documenting the canyons — and sharing them with the larger world — is the most important work she’s done in her life, she said.

Environmentalists for years have said one reason the Bureau of Reclamation was able to flood Glen Canyon with little public pushback is that so few knew the place. “This should never happen again, but I know that it could.

So we just have to keep fighting and telling people about it,” Kish said. “I think that’s what happened in the ’50s — people didn’t know about it.

Just before noon the following day, Susan Washko squatted over a white plastic tub beside the stream that runs through Fiftymile Canyon. “We’ve got some mayflies here, some midges,” she said, sifting her hands through the bucket and plucking out rocks.

It was the fourth stream sample of the second day of the trip for Washko, a researcher with Western Colorado University, and graduate student Ashlynn Mixon. The pair are compiling a survey of the aquatic bugs in the reemerging canyons and how those underwater worlds are changing as time passes.

They also collected samples from above the high-water line, where the reservoir did not reshape the landscape.

Over the coming year, Mixon will identify the insects found in their samples and the duo will eventually author a report for the National Park Service, which manages Glen Canyon National Recreation Area. In addition to mayflies and midges, they’ve found soliderflies in seeps on canyon walls, damselflies and several beetles, including Washko’s favorite — the sunburst diving beetle.

The black and yellow beetles create a bubble of air under their wings as they dive underwater so they can stay submerged longer, like a scuba diver’s tank.

The pair decided to study the canyons — which are a six-hour drive from WCU in Gunnison — after reading about the recession of Powell and the canyons coming back to life. It piqued their interest, and they reached out to the Glen Canyon Institute for guidance on navigating the area.

There is no comprehensive survey of the aquatic insects living in the reemerging canyons, and studies from before Glen Canyon Dam are haphazard, Washko said. There’s also little monitoring on the land above the lake shoreline.

“Not a lot of folks have been working down here. There aren’t a lot of records,” she said.

It’s a point repeated by several scientists working in Glen Canyon and its tributaries — nobody really knows what’s down there. “It’s this unknown, unstudied place, and that makes it unknown and unvalued in management decisions,” said Seth Arens, a researcher involved in the efforts.