Water History: Colorado River Again Makes Its Way Toward the Sea

Observers of the Colorado River are watching as a beautiful if rare experiment plays out with the river once again tracing its historic course toward the Sea of Cortez (Gulf of California), something that has happened only infrequently in more than a half-century.

The event has pushed water into the bone-dry Colorado River delta in Mexico, an area that was lush with flora and fauna during the eons before major dams were built on the river. The “pulse flow” of water from Morelos Dam near the international border was made possible by an agreement between the United States and Mexico, with the fervent advocacy of many environmental and conservation groups.

The idea is to mimic the historic spring flooding from Rocky Mountain snowmelt and study its impact on the delta’s current arid ecology. Under the agreement known as Minute 319, the water for the pulse was released from Lake Mead through Hoover Dam. It traveled some 320 river miles downsteam to Morelos Dam, where water is normally diverted into the Mexicali region for crop irrigation.

But when the gates were opened to the dry riverbed, the flow was off on a 70-mile course to the river’s historic mouth at the sea. Whether it will actually reach the sea hasn’t been determined, but no one is diminishing the power of the experiment.

The Los Angeles Times reported that the river was running, faster, deeper and wider than expected in the first days of the release, which began March 23. Osprey, egrets and even a beaver had been spotted.

Jennifer Pitt, Colorado River program director for the Environmental Defense Fund in Boulder, has worked on the project since 1999.

“Not withstanding the fact that I started talking about the pulse flow of water 15 years ago, spoken and written about it countless times, I was nonetheless astounded, overwhelmed and speechless when I saw the water appear in the river,” Pitt told Rocky Mountain PBS I-News. “It’s almost like we conjured a river back into being.”

Reaction to the river was emotionally intense, she said, as people flocked to it all along its course. What had been wasteland was suddenly beach front.

The pulse flow was part of a more elaborate agreement that the two country’s signed as a five-year pilot project in 2012, which calls for water sharing in shortages, among other provisions. The pulse is a one-time event under the agreement.

The High Country News in Paonia published a gallery of photos and an essay from New York-based photographer John Trotter, who has documented the Colorado River from many perspectives for more than 13 years. The photos capture the impact of the river’s flow on, among others, children who live along the ancient course who’ve never before seen it filled with water.

Trotter also described the river flow to Nevada Public Radio.

The river will continue to run until mid-month, with its impact being closely monitored by conservationists, scientists and others. National Geographic, which over the decades has closely monitored the drying of the delta, also reported on the historic flow.

The Colorado River compact goes back to 1922, when the four upper basin states – Colorado, Utah, New Mexico and Wyoming – joined with the three lower basin states – Arizona, Nevada and California – to divvy up the river’s water. Mexico gained a formal allotment in a 1944 treaty.

The Colorado, whose pristine origins are high on the Western Slope in Rocky Mountain National Park, has been called one of the most over-subscribed rivers in the world.

“It was a long time coming and a big moment of celebration among my colleagues on both sides of the border,” Pitt said. “There’s no guarantee we can ever do this again. But because of this, so many people got to see our vision of what it could be. We don’t need that much water all the time to keep it healthy, but we gave people a vision of what it can do, the impact that it can have.”


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