But today, there are signs that the promise of the great dam has run its course.
Climate change is fundamentally altering the environment, making the West hotter and drier. There is less water to store, and few remaining good sites for new dams.
Many of the existing dams, meanwhile, have proven far less efficient—and less effective—than their champions had hoped. They have altered ecosystems and disrupted fisheries. They have left taxpayers saddled with debt.
And, in what is perhaps the most egregious failure for a system intended to conserve water, many of them lose hundreds of billions of gallons of precious water each year to evaporation and, sometimes, to leakage underground. These losses increasingly undercut the longstanding benefits of damming big rivers like the Colorado, and may now be making the West’s water crisis worse.
In no place is this lesson more acute than at Glen Canyon.
And yet even as these consequences come into focus, four states on the Colorado River are developing plans to build new dams and river diversions in an effort to seize a larger share of dwindling water supplies for themselves before that water flows downstream.
The projects, coupled with perhaps the most severe water shortages the region has ever seen, have reignited a debate about whether 20th-century solutions can address the challenges of a 21st-century drought, with a growing chorus of prominent former officials saying the plans fly in the face of a new climate reality.
“The Colorado River system is changing rapidly,” says Daniel Beard, a former commissioner of the U.S. Bureau of Reclamation, which oversees all of the federal government’s dams in the West. “We have a responsibility to reassess the fundamental precepts of how we have managed the river.”
That reassessment, Beard and others say, demands that even as new projects are debated, it’s time to decommission one of the grandest dams of them all, Glen Canyon.
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Glen Canyon Dam was erected as a political and environmental compromise, an evolution of the earliest water wars on the Colorado River.
In 1922, seven states—California, Arizona, Nevada, New Mexico, Utah, Colorado, and Wyoming—signed a compact agreement dividing the Colorado between them, and, later, with Mexico. The northern states agreed to send an annual quota of water downstream to California, Nevada, and Arizona, and the dam building began. But the faster those states grew the more water they used, and by mid-century, Colorado, Wyoming, and the rest of the upper basin feared it was only a matter of time before the south laid claim to the entire river. The northern states sought their own mega-dam—one which could give them control over the flow of the river and provide a gate through which they could mete out exactly how much of it was sent downstream. Their political jockeying in Congress eventually won the promise that the federal government would build more dams in the north too.