Officials weigh cool water releases at Glen Canyon Dam

Federal officials are weighing a decision that would release cold water from the depths of Lake Powell through Arizona's Glen Canyon Dam this summer, a move aimed at protecting native fish but one that would significantly reduce hydropower generation and increase electricity costs for consumers. The Bureau of Reclamation is expected to announce its decision within weeks.

The proposal, known as a "cool mix flow," involves bypassing the dam's power turbines to send cold water from the bottom of the reservoir into the Colorado River below. This would cool the river, preventing nonnative smallmouth bass from spawning and threatening the federally protected humpback chub. However, because the deep, cold water cannot be used for power generation, the action would force utilities to purchase more expensive replacement energy.

The decision comes amid a severe water shortage. The Colorado River Basin recently recorded its worst snowpack on record, and Lake Powell, a critical reservoir, is only about two-thirds full. A record low inflow is expected this summer. These conditions are driving warm surface water from the reservoir through the dam's generators and downstream. Officials project...