WORTH FIGHTING FOR Advocates for river try to balance competing interests
ON THE COLORADO RIVER – Megan Daubert cruises the Colorado River weekly to collect insects and help quantify the available fish food, part of an experiment led by the U.S. Geological Survey in the stretch of river below Glen Canyon Dam.
The young biologist visits sites every mile or so near the dam and Lees Ferry, where her crew has placed twin petri dishes Velcro-strapped back-to-back on a reed-thin post and coated with a gluey film to catch insects on the breeze. Some of the sites also have timer-activated traps that attract bugs in the hour after dusk and kill them when they fall in a dish of antifreeze.
The USGS is studying the low numbers of insects below the dam, a crack in the food chain that has altered the local ecosystem. Scientists believe the bugs can’t reproduce normally because of the river’s fluctuating water levels, driven by daily demands for electricity from the dam’s hydropower turbines.
As part of the experiment, the U.S. Bureau of Reclamation, which manages the dam, agreed to even out water flows on weekends, creating better conditions for water insects to lay eggs.
At one of her stops Daubert rolled a cigarette and thought out loud about why she never traps much more than midges and moths, or beetles that rarely enter the aquatic food chain.
Some colleagues on the Colorado’s upstream tributaries have found hundreds of caddisflies in their traps, she said.
“There’s a huge block on the river that’s definitely changed it,” she said, though the effect on insects isn’t certain.
“This river is freakin’ cold,” she said. She knows this firsthand, from the times she has to reach or hop overboard to rake vegetation out of the jet boat’s intakes. “But if you go to Tapeats Creek, that’s just as cold.”
Tapeats is full of the mayflies and other species that would fatten fish throughout Grand Canyon if they migrated up the Colorado. “They’re indicator species,” she said. Their absence indicates the native fishery’s limits.
As emblematic as humpback chubs have become for Grand Canyon conservation, a far broader web of wildlife relies on a healthy Colorado. From headwaters to delta, more than two-thirds of the species in lands drained by the river rely on it for at least part of their lives, said Jennifer Pitt, the Audubon Society’s Colorado River project director.
“Aquatic habitat and healthy riparian habitat is of enormous importance,” she said.
Equally important to conservation, though, is the Southwest’s water demand. Without adequate water in the reservoirs for human consumption, there’s little left for nature. That’s why groups including Audubon have pushed for an interstate agreement on water conservation.
“We will lose (wildlife) if we can’t fix the human equation at the same time,” Pitt said.
A trout fishery where there was none
Arizona’s trout anglers have their own fears for the river’s future — and a plan that some advocates fear could jeopardize chubs.
Brad Powell fishes Lees Ferry every year, catching and releasing iridescent trout that frequently land in the trophy size class. Some years are better than others, apparently owing to insect availability, and the Phoenix-area resident would like to see more stability in the population.
Unlike chubs, trout drive jobs for flyfishing guides and innkeepers in the Marble Canyon area.
“It’s the premier trout-fishing water in the state,” Powell said. “I don’t think a lot of people in this state know we have such a world-class resource up there.”
Powell leads regional fish conservation efforts for Trout Unlimited, which counts 2,000 members in Arizona. That makes it one of the largest sporting organizations in a state known more for its hot deserts than its cold waters.
“We’d like to figure out a way to have a sustainable trophy fishery,” he said, “not one that ebbs and flows every few years.”
He and biologists at Arizona Game and Fish think stocking more rainbows — altered to prevent their breeding — could help take pressure off the wild trout while also boosting the river’s reputation by increasing catch rates. Anglers currently average more than the hour of effort per fish caught that the state has set as a goal.
Those biologists met with guides and a few concerned environmentalists near Lees Ferry last winter to explain their plans. They would stock up to 16,000 trout a year whenever the area’s fishery needs a boost, and would expect most of those to be caught or otherwise die before the season’s end. Their statistical analysis suggested few of the stocked fish would drift downstream into the chub’s zone at the Little Colorado, and those that did would eat only 12 chubs over 20 years.
The extra fish, while not trophy size, would help restore some sizzle to a fishery whose attraction has waned since a population crash from an estimated 1.2 million trout in 2012 to 375,000 this year — a crash evidently brought on by insufficient insects for fish food.
Environmentalists in the crowd wondered why the state would push back against a fish famine by boosting the population. State biologists said the stocked trout would be a temporary blip with little influence on the wild population’s diet, and guides said a higher catch rate was vital for rebuilding business.
Some regional Native American tribes, for whom the Little Colorado is sacred ground, remained skeptical — especially given that the National Park Service is proposing to kill trout in the same area to protect chubs.
Park officials are studying the possibility of electric shock or other methods to remove brown trout that are expanding their population in Lees Ferry. Browns are far more likely to eat fish than rainbows, and the idea is to stun all the fish but remove only the browns.
Grand Canyon National Park already has a program that has removed browns in this way from Bright Angel Creek, a trout spawning area deep in the park from which the agency feared a runaway population could devastate chubs.
Tribes historically have argued for conserving native species including chubs, while also opposing killings of non-natives except for human consumption.
“We spent years trying to get rid of trout out of that river,” said Michael Yeatts, an anthropologist for the Hopi Tribe. “All of the sudden we’re looking at putting the trout in?”
A new stocking program could lead to the deaths of both chubs and trout, he feared.
“Just let them be,” he said. Powell, the trout angler, opposes brown trout removals at Lees Ferry, at least until studies can prove that those trout are killing chubs. His concern isn’t for the browns, but how the stress of an electric shock may affect the rainbows that would remain in the river.
Park officials are considering more selective measures, such as paying anglers or tribal youths to catch and eat browns. The goal is to encourage people to use and enjoy the fish, and not to commercialize killing and indiscriminate disposal.
“We’re going to try to avoid the term ‘bounty,’ but rather use the term ‘restoration rewards,’ ” the National Park Service’s Colorado River program coordinator, Rob Billerbeck, told colleagues at an interagency dam management meeting last summer.
Randy Van Haverbeke, a U.S. Fish and Wildlife Service biologist, doesn’t advocate a wholesale trout slaughter when people enjoy catching trout.
“Let’s say you remove all the brown trout from Lees Ferry, if you could even do that,” he said. “Well, you’re not making friends for the chub.”
Instead, he worries most about the river’s temperatures. And, ironically, the more “natural” those temperatures get, the more he worries.
Smallmouth bass, despite their names, have bigger mouths than trout. They can latch onto chubs of any size, and do so at a rapacious rate in the warmer waters upstream of Lake Powell, where they and other alien predators dumped into the river at various times have established populations.
Flathead catfish pose similar threats in the warmer areas downstream of Grand Canyon.
So far, Van Haverbeke believes, the cooler waters coming out of Lake Powell have discouraged those species from entering the park. The drought that has warmed those waters has helped chubs, he said, but continued warming could invite new predators and a collapse.
“At this point the dam is almost acting to preserve the humpback chub in Grand Canyon,” he said.
His boss back in Flagstaff put that irony more bluntly. Glen Canyon Dam — the great destroyer of Colorado River fish habitat — may be the only hope for Grand Canyon chubs, Fish and Wildlife Service supervisory biologist Kirk Young said.
“I don’t think there would be chubs in there if the dam wasn’t there,” Young said.
Faced with the choice of an unnaturally cold river that chubs will have to tough out, or a historically more natural warm river, Young would prefer cold.
Toward that end he proposes new ideas for managing the dam. One would be to release water from two bypass tunnels that usually only operate when the reservoir gets so full that it’s dangerously close to overtopping, or when managers intentionally boost flows for environmental reasons.
Those tunnels are 100 feet deeper in Lake Powell’s cold depths. They would release colder water, but at a cost because that water wouldn’t flow through generators to produce electricity.
He suggests building new generators inside the tunnels. The Bureau of Reclamation estimates that would cost $469 million. Young argues that the project would generate money in power sales.
“We’re looking for the win-win,” Young said. “I think the payback would be pretty quick.”
If it worked it would be just one more human intervention in the river, but this time to preserve a piece of nature.
Bringing back the floods
Ecologically pure or not, the Grand Canyon remains a prize for whitewater enthusiasts who love wild places. They apply for private rafting permits and wait to hear whether they or their friends draw one.
“Man, it’s incredible,” rafter Steve Sanborn said while rowing an 18-foot inflatable raft and craning his neck to scan the towering granite gorge heading into Grand Canyon’s Phantom Ranch.
A trained stream ecologist and civil engineer from Knoxville, Tennessee, he was acutely aware of the unnaturally clear and cold water, the dam-controlled tides rising and falling nightly and the scrubby tamarisks choking out native vegetation on the banks.
On whitewater, he became blissfully focused on the maze of rocks, waves and hydraulic hazards at hand, forgetting the human touch. “When it’s go time,” he said, “there’s only one thing in your brain.”
On flatwater stretches, though, the river’s health vexed him.
There’s no recovering a fully natural river at this point, he said, though he hoped people who visit the Canyon appreciate what’s left of the its natural components.
He could settle for “as natural as possible.”
Native fish and plants deserve a priority, he said, though the dam has its place because “everybody’s gotta drink.”
Recreation — including float trips like the one he enjoyed in May — helps people touch and understand water’s role in the environment, Sanborn said. It creates nature lovers at a time when nature everywhere is disappearing.
“We don’t have much wilderness left,” he said, “and what we have we’ve got to fight for.”
So what does he think the Canyon needs?
Looking over his shoulder at the tangles of thorny, invasive tamarisk, he imagined the pre-dam springtime
floods that sometimes scoured the Canyon and encouraged reseeding of native trees.
“You gotta get some high flows in here,” he said.
Six times since 1996 the Bureau of Reclamation has opened Glen Canyon Dam’s bypass tunnels to simulate a flood. The waters gushed midair below the dam before landing like giant firehose streams into the river, more than tripling the regulated flow to anywhere from 36,000 to 45,000 cubic feet per second for periods ranging from one day to one week.
The river typically flows at between 8,000 and 25,000 cubic feet per second through the Canyon.
When weather-dependent conditions are right, the agency may do it again.
The purpose is to restore a sliver of the environmental services that much larger floods once provided to Grand Canyon, and to let the many agencies and organizations with a stake in the Canyon study the effects.
So far the results have been mixed. As with so many things in Grand Canyon, the tally of benefits depends on one’s desired effects.
A primary goal, especially for the National Park Service, is to push sand in the river up onto the banks to rebuild beaches and sandbars. These are the places where boaters camp, and where native vegetation may re-establish within a root’s reach of steady water.
The problem is most of the sand that would naturally flow into the Canyon is instead piling up under the still waters of upper Lake Powell, backed up along with stored water behind the dam.
So dam managers wait for monsoon storms or other significant runoff to peel sediment out of southern Utah and push it through the Paria River to Lees Ferry, below the dam. It’s not the same as epic floods of old, which flowed two, three or more times higher than these experimental releases and carried sand from as far as Wyoming, but it’s enough to rebuild a beach.
And build it does, federal researchers have found.
For instance, a 2012 high-flow experiment more than doubled the size of some of the park’s beaches and sandbars, especially in the reaches closer to the dam. Researchers from the U.S. Geological Survey at the time watched 33 sandbars with remote cameras and noted 18 of them growing substantially, 12 remaining unchanged and three eroding.
After each such flood, they’ve also watched most of the gains eroded back into the river over the following year. Rising and falling “tides” that follow hydropower demand tend to eat into the banks, requiring renewed floods to rebuild them.
The problem lately has been a lack of sand, in part because drought has limited the flash floods that scour it out of tributary streams. The last high flow was in 2016. Dam managers will consider another only if the monsoon cooperates and reloads sand from the Paria.
Where larger beaches remain, their new sand loads tend to invite vegetation that crowds out camping areas. Much of it is tamarisk, said Jack Schmidt, a Utah State University scientist and former director of the Grand Canyon Research and Monitoring Center in Flagstaff.
Are these floods worth the trouble and cost?
Leslie James isn’t sure. The water that flows to raise the river comes through the bypass tunnels, missing a chance to generate the power that her organization, the Colorado River Energy Distributors Association, relies on to supply users across the West.
The revenue losses equal about $2 million each time, the Bureau of Reclamation estimates, and James must find power from some other source for customers.
“The jury is out” about whether the flows enhance beaches, she said. “Some win, some lose.”
Schmidt uses the same words: “The jury is out.”
But he sees evidence that continuing the experiments is worthwhile.
“There is a hint in the data and the latest studies that there is a slow progressive improvement in conditions,” he said. “So I would continue (the floods).”
Park officials have no doubts that the high flows should continue.
“We have a system that was inherently sediment-intensive,” Balsom said, “and with the trapping of so much in the reservoir, our system has become starved.”