The fading grandeur of the Glen Canyon Dam

Silt and erosion threaten to clog up the enduring structure.


It was 1973, and as I looked over the newly created Lake Powell from the top of Glen Canyon Dam, I wondered what the river had been like before. The narrow gorge now spreading out the Colorado River seemed far less interesting than the labyrinth I tried to imagine beneath the placid water.

Our tour guide noted, “Of course, the environmentalists think that saving that empty canyon is more important than providing basic services to millions of people.” One of my fellow Indian Health Service engineers chimed in: “Exactly where are the millions of people that will benefit from this project?” 

“Well,” our guide thought a minute, “Southern California, Phoenix and Tucson, I believe.”  

“What about the Navajo Reservation? Do they get any water or power?” 

“Well,” the guide answered, “I guess you could count the recreational benefits.” We all groaned.

Our guide tried again: “If it weren’t for Glen Canyon, Lake Mead would fill up with silt in about 10 years.”  

In 1964, the American Society of Civil Engineers voted Glen Canyon Dam the outstanding engineering achievement of the year.
Vicente Villamón, Flickr user

This quickened our interest, so he elaborated, “It’s not really official, but nearly two-thirds of the capacity of Lake Mead has been lost due to inordinately high siltation rates. This upstream dam will intercept the silt and minimize the capacity loss at Lake Mead, prolonging its useful life.” 

Again the voice from a fellow engineer from the back, “How long before Lake Powell fills up with silt?” Our guide shook his head. “Do you have any idea how big this reservoir is? It won’t be a problem in our lifetime, I’ll guarantee.”  

Six months later, I gazed out across the desolate landscape of the Navajo Reservation where dry washes — rivers of sand — showed where water had flowed after the frequent — and violent — summer rains. Erosion was the predominant surface feature, and the flat ground was only relieved by a low range of buttes to the north. 

My Navajo translator and I had come to see a Navajo resident who wanted us to run water to his house from higher up the wash. Years ago, his father had worked for the federal Civilian Conservation Corps on a pipeline that brought the water down to the surrounding flats, where they had cultivated fields. On a sand dune covered with greasewood, he kicked aside a layer of sand to reveal a broken concrete pipe fully 18 inches in diameter. It was hard to believe that at any time in the last 40 years this arid parcel of desert had been irrigated, but the pipeline could be traced through the sand, mute evidence of some decayed dream to turn the desert green. 

The pipe led through the bed of a wash upstream until it reached a spot where the wash was blocked by a large volcanic dike. The volcanic walls were more resistant to erosion by the wind and water, so they protruded above the sandy soil, where the wash formed a V-shaped breach in the dike. The bottom half of the breach had been filled by hand-placed stone, grouted in place. 

This dam was a work of art, silent testimony to whatever craftsmen had labored to haul and place each stone in a giant mosaic that soared nearly 60 feet above the floor of the wash. None of us spoke, but we admired the structure in silence for a few moments. 

Looking down from the top of that dam, I remembered the view from a similar angle at Glen Canyon Dam. While the Colorado River had coursed as a silver thread through steep canyon walls, the dry wash here meandered through squat hills out to the sheep-dotted desert flats. Sand had replaced the reservoir. It shouldn’t have been surprising. How could anyone hope to overcome the forces of nature that decreed this vast land a desert? 

I pictured Lake Powell, as low now as it has ever been, completely filled with silt, a sandy surface of greasewood and sagebrush. Where Anglos had once come to play in the lake, sheep would once again wander and browse.

No system of dams can capture and hold the Colorado River for long. How could we think that the dams we built a half-century ago were anything but temporary? The Bureau of Reclamation tour guide in 1973 seemed so confident about how long Glen Canyon Dam would endure, but I recall a scrawl of graffiti on a sandstone wall near a Lake Powell turnoff. It read: “NATURE BATS LAST.” 

Steve Tarlton is a contributor to Writers on the Range, the opinion service of High Country News. He is an environmental engineer who worked on the Navajo Indian Reservation from 1972 to 1974. He now lives in Golden, Colorado, and blogs at

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