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Lake Powell is drying up, but parts of its ecology are thriving

Invasive species no longer have the upper hand in parts of Glen Canyon, according to ecologists and river rafters in the area.

HITE, Utah — Submerged human skeletons, preserved dinosaur tracks and sunken Nazi warships have all recently been uncovered as waters around the world continue to dry up.

The metaphor is easy: History is rising to the surface amid climate change. And the Southwest's megadrought is seeing the metaphor play out in real-time.

Lake Powell's sinking water levels are threatening thousands of human lives in Arizona. The crisis is causing water officials to try and find solutions fast, even proposing we just let the lake run dry. 

Nature, however, is more ... complicated. While human-made cities are dependent on the lake, photos show Glen Canyon's ecosystems are surviving – and even thriving – as the waters deplete.

RELATED: 'Life beyond Lake Powell': Experts weigh draining Arizona's iconic lake amid worsening megadrought

Editor's note for the above slider:

  • Left image: 2022 photo of Mille Crag Bend. Courtesy: Mike DeHoff.
  • Right image: 1961 photo of Mille Crag Bend. Courtesy: Returning Rapids Archive.

An unprecedented quick return after massive destruction

Called "the jewel of the Colorado River" by some, Lake Powell is known by others as the greatest environmental disaster in the West.

Countless ecosystems and Native American artifacts were drowned when humans decided to fill Glen Canyon with 325 billion gallons of water to create the lake in 1963.

The full extent of the damage is still unknown to officials today.

"The saddest thing is that [environmental surveys were] happening while the dam was being built and the reservoir was being filled," Mike DeHoff said. "The surveys done in Glen Canyon to figure out everything that would be affected by Lake Powell are outright apologetic about not being able to cover everything."

DeHoff is the principal investigator at the Returning Rapids Project, a team of Colorado River riders who have seen firsthand the return of many of the canyon's staples once thought drowned by Lake Powell, including rapids along the Colorado River and the northeastern end of Glen Canyon. The return has spurred the group to document the river and surrounding canyons' recovery as Lake Powell dwindles.

Editor's note for the above slider:

  • Left image: 2018 photo of Gypsum Canyon Rapid. Courtesy: Mike DeHoff.
  • Right image: 2021 photo of Gypsum Canyon Rapid. Courtesy: Mike DeHoff.

The wildlife that called Glen Canyon home before the lake was formed are now making their return, in some areas faster than most experts predicted.

"Going into Glen Canyon, I was startled at how quickly ecosystems are reestablishing," said Seth Arens, an ecologist at the Western Water Assessment in Utah. "There are places that have been out of water for only a couple of years that have a pretty remarkable gathering of plants and different animal species returning."

Desert ecosystems are usually known to grow very slowly since they're generally water-limited and have nutrient-poor soil. The filling, and subsequent drying up, of Lake Powell may have solved both those hurdles.

Some areas that used to be completely underwater now have streams running through them while areas that were previously slickrock now have a nutrient-rich soil source thanks to sediment buildup.

RELATED: 'Lowest point since 1967': Lake Powell's dry up captured by NASA satellite images

"The Colorado River flows very muddy...and what's changed with Lake Powell is that no matter what level the lake is at, any sediment that flows down the river immediately starts to accumulate when it hits the reservoir," Arens said. "This allows plants to grow in many locations where they couldn't have grown before because there wasn't any soil."

Another surprise for Arens came when he saw what was growing in the newfound soil.

Editor's note for the above slider:

  • Left image: 2018 photo of Gypsum Canyon Rapid. Courtesy: Mike DeHoff.
  • Right image: 2021 photo of Gypsum Canyon Rapid. Courtesy: Mike DeHoff.

Invasive 'scourge of many rivers' dying off as native species thrive

Another kind of ecological destruction took place in Glen Canyon before its ecosystem was drowned.

The tamarisk shrub blows in the breeze on the banks of the Colorado River just like any other leafy green plant. Its unassuming presence paints it as just another modest short tree.

The shrub, however, is a wolf in bush clothing. 

Tamarisk roots have the ability to change the chemistry of the soil by extracting salt from it. This effectively suffocates every nearby native plant and cuts them off from much-needed nutrients.

Humans in the 19th century saw this survival mechanic as useful for their own purposes and introduced the shrub to the Colorado River in hopes of slowing erosion. Tamarisk has been on a killing spree ever since.

"It really became this kind of scourge of many rivers in the West that were just lined with the impenetrable walls of the plant," Arens said. 

Tamarisk's colonization effort continued for the next two centuries, becoming more rigorous when Lake Powell's water levels were high. But the bush's victims may be exacting their revenge as the lake's waters dry up.

"In these tributary canyons and along the main stem of the Colorado River, in places where Lake Powell was once there, the tamarisks are not establishing very well," Arens said. "There are some young, newer tamarisks that are popping up, but they're not dominating the system.

Editor's note for the above slider:

  • Left image: 1980 photo taken at Gypsum Canyon. Courtesy: Returning Rapids Archive.
  • Right image: 2020 photo taken at Gypsum Canyon. Courtesy: Returning Rapids Archive.

Native plant species are both the new dominators and return champions of the budding ecosystems. Arens sees the comeback as an act of recovery for Glen Canyon's wildlife, both from the suppression of tamarisk and the submergence of Lake Powell. 

The victory isn't just against tamarisk, but invasive plants as a whole. The vast majority of plants returning to the area are native, which is another surprise to ecologists given what history has shown in similarly disturbed ecosystems like Glen Canyon. 

The concept of "ecological succession" revolves around how species and habitats in an ecosystem change over time. Researchers are rarely able to study the earliest changes a budding ecosystem goes through, called "primary succession," because it often takes an extreme disturbance, like lava flow or melting glaciers, to kick the process into gear.

Lake Powell's draining, on the other hand, seems to be exactly the extreme disturbance Glen Canyon's ecosystem needed to hop into the primary succession phase of recovery.

"On the ground, we're seeing that natural forces can be a driving force of restoration in the river corridor, if given the chance," DeHoff said. "I am amazed at how fast the river can restore itself. If we take the time to really understand it, there are a lot of possibilities for us to have the resources we need."

What comes after this disturbance remains to be seen.

'It's just a change, neither good nor bad'

Arens describes Glen Canyon's ecosystems as "richer" due to Lake Powell's dry-up. He's also careful to not say whether the change is good or bad, because there's a good chance these new ecosystems can get washed away as quickly as they reappeared.

The sediment that's been built up on the river's banks is very loose and can get blown out if the river sees any more extreme changes in water levels.

These changes are what the river used to be known for.

"Before Glen Canyon Dam, the Colorado River fluctuated wildly with years of it flowing as high as 200,000 cubic feet per second in extreme flood years and then go down to 2,000 cubic feet per second during the summer months," Arens said. "There's a long-term question of whether these new plants are going to stabilize the soil and become a permanent fixture in the system, or are we going to get high flows on the river...and have a flash flood that blows this sediment out?".

He's already witnessed a drown-out when he saw an area get established with numerous willows and beaver dams, only to get whipped out by a massive flash flood the following year.

Editor's note for the above slider:

  • Left image: 1921 photo taken at the mouth of the Green River. Courtesy: Doc Marston Papers, Huntington Digital Library, Public domain.
  • Right image: 2021 photo taken at the mouth of the Green River. Courtesy: Chris Wilkowske Rowing, Steve Dundorf photo.

Regardless of how permanent the new ecosystems may be, Arens and DeHoff see them as another area of life worthy of consideration as humans move forward with deciding what to do with Lake Powell and the Southwest's worsening water crisis as a whole.

"I think there's as much opportunity as there is crisis," DeHoff said. "We've been mismanaging the Colorado River ever since the first dam went in, because we didn't consider the overall ecosystem in the Southwest. Now we can see it and understand what's going on, from that we can have a conversation of where we go from here."

Water Wars

Water levels are dwindling across the Southwest as the megadrought continues. Here's how Arizona and local communities are being affected.

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