Park’s Colorado flow has ‘significant’ damage
By Brandon Loomis || The Arizona Republic
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 th e 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.
[RELATED] Before Western States Suck the Colorado River Dry, We Have One Last Chance to Act by Bruce Babbitt
[RELATED] Native leaders honor sacred spaces on Arizona rivers
[RELATED Would your Arizona city purchase Phoenix’s purified wastewater? Here’s what they’re saying
