Seth Arens has all the adventurous swagger of Indiana Jones. His long hair is tied up in a bun, tucked neatly under a wide brimmed hat. His skin bears the leathery tan of someone who has spent the whole summer under the desert sun.
But as Arens pushed his way through a taller-than-your-head thicket of unforgivingly dense grasses, he explained why he doesn鈥檛 carry a machete, betraying his differences from the whip-cracking tomb raider.
鈥淚 guess, as an ecologist, I can't quite bring myself to just hack down vegetation,鈥� Arens said.
Get top headlines and KUNC reporting directly to your mailbox each week when you subscribe to In The NoCo.
Arens is a scientist with Western Water Assessment and the Cooperative Institute for Research in Environmental Sciences, both environmental research groups headquartered at the University of Colorado Boulder.
He has spent weeks traversing the smooth, twisting red rock narrows of Glen Canyon in search of his own kind of treasure: never-before-collected data about plants.
Glen Canyon is perhaps best known for the reservoir that fills it. Lake Powell, the nation鈥檚 second-largest reservoir, has kept much of the canyon underwater since the 1960s and 70s. The 21st Century has changed that. Climate change and steady demand have brought its water levels to record lows, putting once-submerged reaches of the canyon above water for the first time in decades.
What happens next is still up in the air. Some environmental advocates want to see the reservoir drained so plants, animals, and geologic features can come back. Boaters and other recreators want to maintain the status quo 鈥� keep storing water in Lake Powell and sustain a tourism site that brings in millions of visitors each year.
In the snaking side canyons that were once under Lake Powell, Arens is methodically counting plants at different sites over the course of multiple years. He is creating a record of which species are taking root, and what might be lost if the reservoir were to rise again.
鈥淣ature has given us a second chance to reevaluate how we're going to manage this place,鈥� Arens said.
While the study is still underway, Arens said native species dominate the landscape alongside the area鈥檚 creeks. The same kinds of plants that lived in Glen Canyon before Lake Powell have taken root again 鈥� even after their habitats were drowned 鈥� filled in with towering piles of sediment deposits, and then shown the light of day once more.
鈥淚t turns out nature is doing a pretty good job by itself,鈥� Arens said, 鈥淥f coming back and establishing thriving ecosystems.鈥�
鈥極ld assumptions鈥� and new policies
The data produced by this study is going public during a pivotal time for the Colorado River and its major reservoirs.
Decisions made over the next two years will shape who gets how much water from the shrinking river, which supplies roughly 40 million people. Cities and farms from Wyoming to Mexico are all trying to make sure they get their fair shares, and environmental advocates are trying to make sure the region鈥檚 plants and animals aren鈥檛 an afterthought.
The current guidelines for managing the river expire in 2026. Right now, policymakers are working on a set of replacements. Eric Balken, director of the nonprofit Glen Canyon Institute, wants those new rules to factor in the wellbeing of plants around Lake Powell.
鈥淚f the old assumption was that we can store water in Glen Canyon because there's nothing there, that assumption is wrong,鈥� he said. 鈥淭here is a lot here. There is a serious ecological consequence to putting water in this reservoir, and we cannot ignore that anymore.鈥�
Balken鈥檚 group, which advocates for draining Lake Powell and storing its water elsewhere, provided some funding for the plant study being conducted by Seth Arens. Glen Canyon Institute is hoping it will provide data that proves the value of the canyon鈥檚 plant ecosystems to policymakers.
That鈥檚 extra important, Balken said, because federal water managers aren鈥檛 doing enough for Glen Canyon鈥檚 plants right now.
The Bureau of Reclamation, the federal agency that manages the West鈥檚 reservoirs, outlined its current strategy for river management in an October 2023 document called the 鈥淒raft Supplemental Environmental Impact Statement.鈥� Balken called that document鈥檚 assessment of Glen Canyon plants 鈥渄emonstrably false.鈥�
In short, an environment dominated by invasive plants that only stand to cause problems.
鈥淲hen I read that,鈥� Balken said, sitting near a patch of native willow plants feet from Lake Powell鈥檚 edge. 鈥淚 just thought, 鈥楬ad these people even been to Glen Canyon?鈥欌�� This place is a vibrant, burgeoning ecosystem.鈥�
Reclamation鈥檚 report mentions some native species that form 鈥渦nique ecosystems within the desert,鈥� but appears to conclude that rising reservoir levels 鈥� which are partially the result of the agency鈥檚 own management decisions 鈥� would ultimately be good for plant life around Lake Powell.
It highlights the presence of invasive plant species and says 鈥渁ny additional acreage of exposed shoreline around Lake Powell has the potential to be invaded by invasive plant species such as tamarisk and Russian thistle.鈥�
Balken and Arens argue the opposite, pointing to early survey findings that include widespread native plant life in areas that have been exposed by declining reservoir levels.
Reclamation declined to be interviewed for this story, but a spokeswoman for the agency wrote in an email to KUNC, 鈥淩eclamation鈥檚 consideration of impacts to vegetation are primarily for resources downstream of Glen Canyon Dam that are affected by dam releases.鈥�
The spokeswoman wrote that 鈥渕ost of the releases, even on the annual time scale, have negligible effects on lake levels and vegetation,鈥� and pointed to inflows, such as annual snowmelt, as having a bigger impact on water levels in the reservoir than Reclamation鈥檚 releases of water from Glen Canyon Dam.
Balken suspects that Reclamation lacks data about Glen Canyon鈥檚 plants and hopes that the ongoing study will fill in those gaps and help shape management plans going forward.
The National Parks Service, which manages recreation on Lake Powell and gathers some data about the surrounding environment, was not able to provide comment for this story in time for publication.
鈥楢 chance for survival鈥� around Lake Powell
While Arens鈥� study hasn鈥檛 produced any hard data yet, he is taking a mental tally of plants every time he trudges through the lush, winding creekbeds that channel spring-fed streams into Lake Powell.
These riverside ecosystems were shaped by their years spent underneath the reservoir, and little signs of that reality are everywhere.
Standing in the baking desert sun, Arens poked at a digital map on his phone screen while trying to find his next research site, and the map showed that he was standing underwater. Much of the canyon is lined with banks of sediment, sometimes more than a dozen feet tall, that were left behind by the still waters of Lake Powell. Those banks now provide heaps of soil for the roots of native plants.
Now that some of those areas have been left to grow for more than two decades, in some cases, they abound with life.
In one canyon, frogs and toads hop along the clear trickle just downstream of a beaver pond while birds flit in and out of tall, shady cottonwoods. In another, ferns sprout from crevices where water seeps onto a damp rock wall.
It鈥檚 a veritable oasis in the desert 鈥� the kind of cool, spring-fed Eden that populated the heat-induced daydreams of traversing the expanses of the Old West.
Katie Woodward, Arens鈥� research assistant, is finding inspiration in these canyons, too.
鈥淚t's very obvious that nature can take care of its own and turn a highly disturbed landscape, a landscape that was disturbed because of the follies of man, and change that into something that is diverse and productive,鈥� she said. 鈥淚 would have never believed how possible that was until I came down here.鈥�
The researchers hope their findings about that recovering landscape end up in front of policymakers, whose decisions could shape the future of Glen Canyon鈥檚 native ecosystems.
鈥淎s Glen Canyon resurfaces, there's an incredible moment for species that are feeling the pressures of both human-induced and naturally driven change on water resources in riparian areas in the west, to have a chance for survival in a future that feels really unknown and kind of scary.鈥�
Some of those unknowns might get settled soon, as the next rules for Colorado River management are likely to include new plans for storing water in Lake Powell. State water negotiators have projected optimism that policy meetings will result in a new agreement for water management before the 2026 deadline.
This story is part of ongoing coverage of the Colorado River, produced by KUNC and supported by the Walton Family Foundation. KUNC is solely responsible for its editorial coverage.
