Federal Decision Balances Hydropower and Native Fish Conservation on Colorado River

Federal officials announced they would not release cool water from one of the Colorado River’s key reservoirs this year, prioritizing hydropower production over endangered species protection. This decision comes amid concerns about reduced hydropower generation at Glen Canyon Dam in northern Arizona. The Colorado River’s shrinking resources due to overuse and climate change forced officials to choose between protecting the humpback chub, a threatened fish, and the cost of electricity for ratepayers.

The decision follows the worst snowpack recorded in the Colorado River Basin, which is vital to farmers, industries, wildlife, hydropower, and over 40 million people across seven U.S. states, tribal nations, and Mexico. It also comes after federal officials proposed measures to avoid a crisis following the inability of states reliant on the river to agree on long-term resource sharing. California, Nevada, and Arizona are set to take cuts under this proposal.

A ‘cool mix flow’ involves releasing cold water from deep within Lake Powell to cool the river downstream, but it results in decreased power generation as there are no turbines in the cold section. Now, Lake Powell is at about 23% capacity after decades of overuse, plus water evaporation due to rising average temperatures. Warm water near the surface flows through generators to the river below. This allows the sport-introduced smallmouth bass to spawn, threatening federally protected fish like the humpback chub.

Previous cool water releases in 2024 and 2025 successfully prevented smallmouth bass spawning. The river below the dam has reached temperatures of around 69°F (20.5°C). Recommendations for cold water releases are considered when daily temperatures exceed approximately 60°F (15.5°C) for three days consecutively, which has been regular for over a month. Wayne G. Pullan, regional director of the Upper Colorado Basin, stated that efforts will focus on rapid response removal actions, backwater adjustments, innovative tools evaluation, and advancement of robust structural solutions.

Matt Rice, director of the southwest region for the conservation group American Rivers, expressed disappointment despite understanding the decision was expected. He noted, ‘We’ve proven that cool mix flows are the most effective way to manage the smallmouth bass invasion in the Grand Canyon.’ Moreover, the rising temperatures pose a risk to the rainbow trout fishery. American Rivers encourages collaborative solutions that account for environmental protection and the needs of those relying on the river for energy.

Utilities purchasing hydropower from Glen Canyon Dam argued that releasing the cool water would have led them to incur additional costs for alternative, non-renewable energy sources, potentially raising electricity rates for consumers. Andy Colosimo, executive director of the Colorado River Energy Distributors Association, stated satisfaction with the decision, acknowledging the challenges faced on the river. ‘I think this was the right call, given the conditions that we’re all facing,’ he emphasized.

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