By Dale Maharidge
Mr. Maharidge is a professor at Columbia University’s Graduate School of Journalism.
- March 20, 2023
It’s difficult to fathom how the Colorado River could possibly carve the mile-deep chasm that is the Grand Canyon. But if one thinks of the river as a flume of liquid sandpaper rubbing the land over millions of years, it begins to make sense. “The finest workers in stone are not copper or steel tools,” Henry David Thoreau wrote, “but the gentle touches of air and water working at their leisure with a liberal allowance of time.”
In 1963, humans stopped time, when the brand new Glen Canyon Dam on the Utah-Arizona border cut off the reddish sediment that naturally eroded the Grand Canyon. Today the river runs vodka clear from the base of the dam.
But the silt never ceased arriving in Lake Powell, the reservoir above the dam. Each day on average for the past 60 years, the equivalent of 61 supersize Mississippi River barge-loads of sand and mud have been deposited there. The total accumulation would bury the length of Manhattan to a depth of 126 feet — close to the height of a 12-story building.
For years this mud was hidden beneath Lake Powell’s blue waters. Now, as climate change and overuse of the Colorado have drawn the reservoir down to record lows, the silt is exposed — forming “mud glaciers.” And because of a gradient created when the lake level falls, the giant mud blobs are moving at a rate of 100 feet or more per day toward the dam.
These advancing mud blobs pose existential threats to the water supply of the Southwest: One day they could form a constipating plug that blocks Glen Canyon, preventing the water from flowing downriver. They could also someday endanger the structural integrity of the dam.
Asked about the dangers that the sediment posed, Floyd Dominy, the commissioner of the U.S. Bureau of Reclamation in 1963, later quipped, “We will let people in the future worry about it.”
Now the future is here. With Lake Powell just 23 percent full, and Lake Mead, outside of Las Vegas, at 28 percent capacity, it’s time to stop trying to “save” Lake Powell. It should be abandoned and its water stored in Lake Mead.
Yet the Bureau of Reclamation, the federal agency in charge of managing water in the West, is desperately trying to keep the reservoir because it wants to keep the dam’s electricity-generating turbines working. If the water level drops another 30 feet from the present elevation, the turbines will become useless.
The bureau recently issued ideas to create new outlets for lake water at lower elevations in the dam so it can keep producing power and delivering water to users in the Southwest, Mexico and California. But there’s only one modification that would actually solve the sediment problem: boring two tunnels at the base of the dam, one at grade level with the riverbed. That would kill the reservoir but allow sediment to pass downstream. The bureau said this option had been discussed, but “not further considered.”
The bureau is scheduled to continue meeting with water managers, tribes and others with an interest in Colorado River water starting this spring, before selecting a plan later this year. Those with a stake in the river’s future should demand the bureau put that lowest tunnel back in play and allow the Colorado to run free in Glen Canyon again for the security of the water supply. The other options could leave the lake more than 200 feet below the already low levels, allowing the mud glaciers to continue advancing.
There’s another good reason to say goodbye to Lake Powell. As it has shrunk, various side canyons of Glen Canyon are no longer underwater and willows and cottonwoods are sprouting on their banks. Narrow and twisting slickrock tributary canyons — with grottos, soaring amphitheaters and hidden passages — are reappearing, like the images in “The Place No One Knew,” a Sierra Club book featuring Eliot Porter’s requiem photographs of pre-dam Glen Canyon.
That Glen Canyon, a thriving place of beauty and life, is the one I want back.
In 1969, when I was in the seventh grade in suburban Cleveland a nun gave me Porter’s book. It haunted me. In 1976 I took a Greyhound to Utah and went on a monthlong vision quest, backpacking parallel with the new reservoir, still 40 vertical feet from full. I witnessed remnants of some of the Eden-like canyons photographed by Porter before they were submerged.
In 1983, I camped on the shore of the lake next to the late Dave Foreman, a co-founder of Earth First! He’d come to protest the 20th anniversary celebration of the dam. We spent the night drinking from a case of beer. Two years earlier, Earth First! activists unfurled a 300-foot sheet of plastic over the face of the dam, simulating a crack. The lake seemed very permanent. It was brimming full.
Thus it was shocking in 2005 when I drove to an overlook and saw the water gone from the upper reaches of Lake Powell. (Little snow had fallen that winter in the mountains to feed the lake.) I then did something I never thought possible in my lifetime: I swam the Colorado in upper Glen Canyon. Because the lake had shrunk, it was at a spot that had been some 100 feet underwater for decades now exposed again to sunlight.
After crossing a vast mud flat, I bobbed downstream and then slipped and fell in muck on the way back to my clothes. It wasn’t a pleasant experience. Yet the swim had to be done. The lake soon re-flooded the site after a wet winter.
One thought on “Nobody wants to talk about the mud of the Colorado River ~ NYT”
Hello Robert, I’ve mentioned silt before. It, along with evaporation, is a shallowing process for the reservoir reducing its mean depth. The key to the “tipping point” of runaway evaporation is the mean depth of the reservoir (volume/surface area). Now the upper reaches are breaking into small “pools” hastening the process.
As Powell dries up (it will get a bit of a reprieve this very moist winter) from evaporation (the top), silt is working at the other end (the bottom).
I call that wall collapse in the video, The Creation of an Eddy. Dominy is dead. His pet project kept him in excellent bourbon to the end leaving a lot of folks in dire straights. He didn’t care then and can’t now. Reclamation is running around like a headless chicken (and you know what happens next).