Environmentalists warn Grand Canyon could dry without dam fixes


The federal government must rapidly prepare plans to redesign Glen Canyon Dam’s plumbing to keep the Colorado River flowing through the Grand Canyon as the water levels behind the dam continue to fall, a coalition of environmental groups warned on Wednesday.

Lake Powell is just a quarter full, its surface now at 3,536 feet above sea level — 46 feet from the minimum level to produce hydropower — and falling after the early summer gush of snowmelt from the Rocky Mountains. Two more dry winters could push the reservoir past that point, according to forecasters, and ultimately dam managers may have to open bypass tunnels more than 100 feet deeper just to keep the river flowing.

If it comes to that, the river advocates and their new analysis caution, those tunnels will prove insufficient to release as much water as the Southwest counts on to pass through the Grand Canyon and restock Lake Mead each year.

“This system needs flexibility and it needs it now,” said Eric Balken, whose Glen Canyon Institute partnered with the Utah Rivers Council and the Great Basin Water Network on a new report urging action.

Grounded buoys sit on the shore at Wahweap Bay on Feb. 3, 2022, near Page. Lake Powell was at 26% of capacity, 168 feet below its full elevation of 3,700 feet above sea level at the time.

Lake Powell’s elevation has dropped more than 160 feet since it was essentially full at the turn of this century, and the pace has quickened in recent years. Dropping below what the outlets were designed to handle would jeopardize delivery of the water needed to irrigate farms and fully supply cities from Phoenix and Las Vegas to Los Angeles and Tijuana.

The groups’ quest is to persuade the U.S. Bureau of Reclamation, which manages the dam, to study how to keep the river flowing if, as their analysis suggests, climate change and overuse push the system to a breaking point in coming years. Their preferred alternatives are to either expand the capacity of the bypass tunnels or build new tunnels at the dam’s base to allow the river to flow even if Lake Powell empties.

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On their first premise — the need to act to prevent the loss of hydropower  — they’ll find agreement from many corners. The Bureau of Reclamation, the state of Arizona and the group representing the dam’s hydropower customers all say the region’s two decades of drought present an imminent threat to normal operations at Glen Canyon.

“Given the current uncertainties facing the Colorado River system, as well as the engineering uncertainties involving moving water through the existing infrastructure of Glen Canyon Dam with historically low levels, it would be prudent to thoroughly investigate all reasonable options for making changes to the infrastructure of the dam that enhance its capacity to move large volumes of water safely,” said Arizona Water Resources Director Tom Buschatzke.