Lake Powell Faces Sediment Crisis: ‘30,000 Dump Truck Loads’ per Day

Lake Powell, an iconic centerpiece of the Colorado River Basin and the second-largest reservoir in the United States, is facing an escalating crisis as decades of sediment buildup threaten its future.
Created in 1963 by constructing the Glen Canyon Dam, Lake Powell was intended to be a critical water storage reservoir for the arid western United States. Sixty-one years later, sedimentation has reduced the lake’s storage capacity by nearly 7 percent, with an estimated “30,000 dump truck loads of sediment” settling daily, according to the Glen Canyon Institute (GCI).
“The Colorado got its name from the color. Colorado means colored red in Spanish. That red color comes from suspended sediment floating down,” Davide Ippolito, a researcher with the nonprofit Returning Rapids, told the Deseret News.
“A lot of material is being transported. So when you have a lake at the bottom of that, the water stops moving, and that material, that sediment, just sinks to the bottom. And now we’re seeing, with the drought, all this exposed sediment that’s sunk to the bottom.”
This sediment buildup has triggered a cascade of impacts throughout the Colorado River ecosystem. Toxic heavy metals like arsenic and lead are trapped within these sediments rather than flowing out to sea.
As water levels drop as a result of prolonged drought, concentrations of these harmful materials increase, posing greater risks to fish, wildlife and people.
Downstream, beaches at the river’s mouth are eroding, as sand, meant to replenish coastal areas, remains trapped in Lake Powell and Lake Mead, another struggling reservoir further along the river.
Within the river channels, a process known as “aggradation”—the accumulation of sediment where the river slows—has caused sediment to build up upstream, reaching heights hundreds of feet above the current reservoir level and burying large stretches of the Colorado River and its tributaries.
With no immediate solution, sediment continues to pour into the lake.
On Friday, the National Park Service reported a landslide of about 300 to 350 meters of shoreline from the river’s left bank into the channel. The slide created new rapids at the entry point, with sediment and mud continuing to shift, altering river conditions along a three-mile stretch upstream.
Lake Powell’s immense size means sedimentation does not immediately threaten the Glen Canyon Dam itself. However, experts are pressing for proactive measures.
The GCI, advocating for restoring Glen Canyon and allowing a free-flowing Colorado River, warns on its website that “the longer we wait to address the temporary nature and ultimate risks of Glen Canyon Dam, the more costly it will become. The true and staggering costs of sedimentation will ultimately be borne by the next generation unless practical solutions are developed now.”
Newsweek reached out to the GCI for comment.
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