DENVER— Conservation groups asked a federal appeals court today to reconsider a decision allowing Utah to divert tens of thousands of additional acre-feet of water each year from the Upper Colorado River Basin at the Green River below Utah’s Flaming Gorge Dam.

“Pretending climate change isn’t drying up the Colorado River will further harm the people and endangered species that depend on it,” said Taylor McKinnon, Southwest director at the Center for Biological Diversity. “The Bureau of Reclamation needs to take a hard look at the climate science before making any decisions about the Colorado River’s future. We’re hoping the appeals court reconsiders this critical water case and forces federal officials to face climate reality.”

The 2019 Bureau of Reclamation decision relied on water models that failed to consider climate change, drought or the over-allocation of Colorado River water. It ignored science projecting that climate warming will make the Colorado River system much drier than it has been in the last century.

Today’s petition asks the 10th U.S. Circuit Court of Appeals to reconsider its July ruling upholding the Bureau’s analysis. Conservation groups filed a March 2019 lawsuit challenging the Bureau’s environmental review greenlighting the Green River Water Rights Exchange Contract, and in August 2021 appealed a lower court ruling.

“July was the hottest ever on this planet, yet the Bureau continues to pretend that climate change isn’t going to get worse, we don’t have to worry about new water diversions of Colorado River water that doesn’t exist, and that snowpack runoff hasn't declined over the last two decades,” said Zachary Frankel, executive director of the Utah Rivers Council. “The Bureau is failing tens of millions of Americans by burying its head in the warming sands of climate denial.”

Four endangered fish may be harmed by changes to water flows and timing if the diversion and other pending water deals come to fruition. Changes to Flaming Gorge Dam operations necessary to accommodate the water contracts and drought-contingency planning could devastate endangered fish including Colorado pikeminnow, razorback sucker, humpback chub and bonytail chub, and other species.

"Lake Powell has lost 2.4 million acre-feet since 1991. That’s 800,000 acre-feet per decade," said John Weisheit of Living Rivers. "Just like the humbpack chub that has disappeared from Dinosaur National Park, the native fish of the lower basin are threatened by the river's declining flow. The Bureau of Reclamation must stop promising water that doesn’t exist and face the reality that every drop counts."

The Green River includes fragile riparian areas and wetlands, as well as breathtaking canyons popular with rafters. It winds through Browns Park National Wildlife Refuge, Dinosaur National Monument, Ouray National Wildlife Refuge and Canyonlands National Park before joining with the Colorado River.