Why the Lower Colorado is America’s most endangered river

The Lower Colorado River, which runs from Lee’s Ferry, Arizona, to the Sea of Cortez in Mexico, provides drinking water for 1 in 10 Americans and irrigates 90 percent of the country’s winter vegetables. And, according to American Rivers, the country’s biggest river-advocacy group, it’s the most threatened river in the U.S.

American Rivers releases a list of the 10 most endangered rivers every year. They look at threats from dams, development, pollution and political action. In the past, they’ve stopped dams and mines on the listed rivers.

This year, a year that they say is a “critical year for rivers and clean water,” they picked the Lower Colorado, because so much of the U.S. is dependent on it for water and food, and because it’s over-allocated, dried up by climate change and at risk due to potential cuts to the federal agencies that manage and care for it, like the EPA and the Department of the Interior.

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“America’s Most Endangered River, the lower Colorado, provides drinking water for 30 million Americans, irrigates fields that grow 90 percent of the nation’s winter vegetables and slakes the thirst of growing cities including Los Angeles, San Diego, Las Vegas and Phoenix,” American Rivers claims. “But the water demands of Arizona, Nevada and California are outstripping supply, the impacts of climate change are becoming acute, and the river is at a breaking point.”

The Lower Colorado starts at Lee’s Ferry, at the outflow of Lake Powell, then winds through Arizona, Nevada, California and Mexico. Its water is piped out for agriculture in places like the Central Valley, and for cities across the Southwest. It’s so overused that it no longer makes it to its delta in the Sea of Cortez.

While rafting down the Grand Canyon, you see this view of the Colorado River from Nankoweap Trail; photo by Kara Hudgens

While rafting down the Grand Canyon, you see this view of the Colorado River from Nankoweap Trail. Photo: Courtesy of Kara Hudgens

Part of the problem is that there’s more demand than there is supply. When water rights in the river were divvied up in 1922, more water was allocated than actually exists in the river, and we’ve been steadily using up that water. Then there’s drought exacerbated by climate change. It’s been hot and dry across most of the Southwest, where the Colorado has been a major water source, for most of the last decade. That means we need more water and we get less of it.

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The Colorado, which has an estimated value of $900 billion, is carefully managed by a cadre of federal agencies, compacts and agreements. If those aren’t maintained, it could get dire quickly, which is why American Rivers is focusing on it now.

It’s an environmental and a political problem, and the two are now more intertwined than ever. “Americans must speak up and let their elected officials know that healthy rivers are essential to our families, our communities and our future. We must take care of the rivers that take care of us,” Bob Irvin, president of American Rivers, said in a report.

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Irvin says that it’s important for Americans who value clean water to tell Congress to protect the Colorado and the resources it provides. It’s going to take federal action and funding to keep it clean and running.

Concerned? Learn more about the Lower Colorado and the nine other rivers on the list and find out how you can help.