When the Glen Canyon Dam was completed in 1963 and Lake Powell began filling, it was a devastating blow to the river runners who’d traveled the winding canyons of that section of the Colorado River. The dam inundated not only the main canyon, but countless slot canyons and alcoves, an area writer Edward Abbey called “a portion of earth’s original paradise.”
Today, Lake Powell is perilously low. The water level has dropped more than 150 feet from its peak elevation of 3,700 feet above sea level and continues to decline. While the reservoir’s falling water storage is bad news for millions of people who rely on the dam’s hydroelectric power, it’s a fascinating turn of events for rafters and kayakers who would like to see the Colorado River return to its original channel.
The low water levels have exposed the lower sections of Cataract Canyon, which enters the northern end of Lake Powell, and its many side canyons that were once drowned beneath the reservoir. As the water in the lake declined, acres of silt and sediment were exposed. The prolonged low water levels allowed the Colorado River to carve through this mud, pushing it further downstream toward the dam and slowly bringing back the original riffles and rapids that run over heavy rock debris and bedrock beneath the deposited sediment.
The changes in the river have taken place over several years and have been closely watched by rafters and river guides who frequent Cataract Canyon.
“Every trip there’s something coming back, there’s a new rock poking out, there’s a new beach forming,” says Pete Lefebvre, a longtime OARS guide, who’s clocked over 100 trips in Cataract Canyon. “It has this level of suspense where I’m looking forward to the last 20 or 30 miles because I’m excited about seeing what’s changed.”
Cataract’s Notorious Rapids
Cataract Canyon is famous for, and named after, its steep and frothing rapids. Decades before the Glen Canyon Dam, Cataract Canyon earned the nickname, “The Graveyard of the Colorado” for the many boats lost to its currents. Huge flows and sudden descents create a series of rapids that is often considered the biggest whitewater in North America. Rapids in Cataract Canyon are numbered and the highlights are Big Drop 1, 2 and 3.
Lake Powell covered approximately 25 miles of Cataract Canyon and some of the Colorado’s largest rapids. As the water dropped, the rapids (Rapids 27-30) near Imperial Canyon were the first to reappear. The rapids came back with deep holes and powerful wave trains. Cat trips now got to finish with splashy runs down Short Rapid, The Chute, and Waterhole Canyon Rapid.
Downstream from Rapid 30, Gypsum Canyon Rapid was the next on deck to be exposed by the falling water levels. In 2018, a riffle started to appear and has progressed into a small rapid. High flows could continue to push sediment downstream, further developing the holes and waves.
The largest rapid buried by Lake Powell was Dark Canyon, one of the river’s most daunting rapids, according to historical accounts. With low water levels, a slight riffle is now starting to appear. But it’s unlikely Dark Canyon Rapid will come back with the same intensity that surveyors and boaters saw before Lake Powell.
Dark Canyon, a large side canyon off Cataract, has continued to deliver debris into the canyon, the same action that created the original rapid. The new debris has been deposited on top of the sediment and silt from the lake, creating layers of material that the river would have to carve through to recreate its original descent.
Tracking the Changes
A group of passionate Utah boaters, Mike Dehoff, Lefebvre, Meg Flynn and Chris Benson have teamed up to document the changes in the Colorado River as it enters Lake Powell. DeHoff named the organization Returning Rapids. Their website catalogs select spots on the river where rapids are reemerging from under the silt deposited by the still waters of the lake.
“We’re seeing a rate of return of about three to four feet per year,” says DeHoff, who’s been boating in Cataract Canyon for 30 years. “That’s what the river is carving out. It’s a slow process, but it is slowly coming back. And I think we’re going to continue to see that. ”
The Returning Rapids crew, led by Meg Flynn, who’s a trained librarian and DeHoff’s wife, spent hundreds of hours combing through historic photos and archived surveys of Cataract Canyon for images that show what the area drowned by Lake Powell could look like. These photographs help them determine how deep the deposited sediment could be and what’s underneath.
“People need to know what’s going on out there and no one else was stepping up to really try to communicate it to people,” DeHoff says.
Returning Rapids is now a program under the Glen Canyon Institute. The group plans on running two observation trips this year. They should have an idea about how much the river has changed this season by June or early July, depending on when flows peak, DeHoff says.
DeHoff hopes the work for Returning Rapids will get people to consider what the future could look like for Cataract Canyon.
“If we can get people thinking about it and help protect a place that’s very dear to us, why the heck not?,” he says.
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Photos: Dylan Silver, Justin Bailie, Returning Rapids