Colorado River in the Grand Canyon tops environment group's 'endangered rivers' list

The Colorado River in the Grand Canyon is the nation’s most threatened river in 2023, the nonprofit advocacy group American Rivers declared in an annual report released Tuesday.

It’s the second year in a row that the group has placed the Colorado atop its list, though last year’s designation applied to the entire river because of the region’s overuse of its water. This year, the group focused on how a drying climate and declining water stored in Lake Powell are harming ecological and cultural resources in the part of the river flowing through Grand Canyon National Park.

“In the last year, Grand Canyon has taken significant physical damage,” American Rivers spokesman Sinjin Eberle said.

One hit came in the form of a smallmouth bass invasion in the Lees Ferry stretch just upstream of the park. There, bass that likely slipped through Glen Canyon Dam’s hydropower turbines from Lake Powell, were found to have reproduced in the river, setting up a potential predation catastrophe for threatened humpback chubs in Grand Canyon. Scientists say low water levels in Lake Powell enabled this, by dropping the warm water bass species closer to the turbines, and also by letting warmer water pass through to the river below.

The threat to the canyon's river environment worsened when the U.S. Bureau of Reclamation held back more water than usual last year in an effort to preserve hydropower production capacity at the dam. But that threat would reach unprecedented levels if the reservoir were allowed to drop below the turbine intakes, leaving only bypass tunnels that weren’t designed for constant flow to keep the river moving. That would limit the government’s ability to flow enough water to protect the canyon.

Cultural and recreational resources also have suffered because the government has not released a restorative flood from the dam since 2018. Such floods pile up sand to form camping beaches and sandbars, and to cover and protect archaeological sites near the river.

Special report: As the Colorado River is stretched thin by drought, can the 100-year-old rules that divide it still work?

Other rivers on the endangered list

The other nine rivers on the group's 2023 endangered list are the Ohio in the Midwest; the Pearl in the South; the Snake in the Northwest; the Clark Fork in Montana; the Eel in California; the Lehigh in Pennsylvania; the Chilkat and Klehini in Alaska; the Rio Gallinas in New Mexico; and the Okefenokee Swamp in the Southeast.

American Rivers chooses its annual list based on both the urgency of risks to a waterway and on the potential for public advocacy to influence a pivotal decision within the next 12 months. In the Colorado River’s case, that decision will come from the Bureau of Reclamation about how to address the overuse of a water supply that a warming climate has reduced. Reclamation released a draft plan with alternate options for reducing water supplied to southwestern states.

It has also encouraged the states to negotiate their own plan but will choose a path after a 45-day public comment window that began on Friday.

Navajo Nation anthropologist Erik Stanfield joined American Rivers in asking water users and decision-makers to “treat Mother Earth as we would treat our own mothers."

“We cannot repay all of her gifts,” he said in a written statement, “but we can show her kindness, gratitude, and a willingness to sacrifice when she suffers.” The river, he said, is in “deep crisis” and needs shared sacrifice to heal.

This year’s water supply, from snow now melting in the Rocky Mountains, is healthier than it has been in years. That will help reduce the immediate worst case at Glen Canyon Dam, Eberle said. But it does not change the river’s long-term trajectory after more than two decades of drought.

“The abundant snowpack has obviously given us a reprieve for this year, anyway,” he said.

Report urges managers to work with tribes

The combination of overuse and warming temperatures has left less water for the environment as well as for people. As the government decides how to divide a shrunken river, the American Rivers report says, it must not put also protect this internationally renowned treasure. “We simply cannot allow the beloved Grand Canyon to become an ecological sacrifice zone as we work to solve the Colorado River basin’s ongoing water crisis.”

The report calls on dam managers to work closely with the tribes that place the river and the canyon central in their cultures.

“The Colorado River is in poor health,” said Jakob Maase, a Hopi cultural preservation officer who represents the tribe on Reclamation’s advisory panel for Glen Canyon Dam management. “Climate change and drought increasingly impact the health and ecosystem of the Colorado River and the Grand Canyon as a whole.

“The Hopi people have long been stewards of the Grand Canyon and Mother Earth. We hope that the agencies will listen and work with tribes on tackling these challenges.”

Brandon Loomis covers environmental and climate issues for The Arizona Republic and azcentral.com. Reach him at brandon.loomis@arizonarepublic.com or follow on Twitter @brandonloomis.

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at environment.azcentral.com and @azcenvironment on Facebook, Twitter and Instagram.

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This article originally appeared on Arizona Republic: Colorado River's Grand Canyon stretch called "most endandered river"