GLEN CANYON, Ariz. – Federal water managers with the Bureau of Reclamation are opening up the flood gates, so to speak, at an Arizona dam in the hopes of restoring sand dunes along parts of the Colorado River near the Grand Canyon.
On Monday morning, officials began letting water flow out of the Glen Canyon Dam at about four to five times the usual rate. This will essentially flood the Colorado River for 72 hours before they'll return the dam to normal flow.
The process, known as a High Flow Experiment release, aims to rebuild beaches and backwater habitats along the Colorado River, Grand Canyon National Park officials said.
"The experiment is designed to move accumulated sediment from the Paria River up onto beaches and sandbars in Marble Canyon and eastern Grand Canyon to restore the Colorado River corridor in eastern Grand Canyon National Park," officials with the National Park Service wrote.
The move will drop Lake Powell by about 4.5 feet and eventually add about 4 feet to Lake Mead by the end of May, according to FOX 5 Las Vegas. But overall the Lake Mead's total intake will remain the same this year as last year. Instead, the release is designed to create more sandbars suitable for camping while also bringing needed sand to protect archaeological sites around the eastern Grand Canyon.
"The idea is to try to mitigate that sand loss and keep things close to the way they were before the dam," said USGS Hydrologist Bob Tusso.
Officials determined hydrology conditions and high sediment loads were suitable for conducting the release. It's the first time it's been done since November 2018.
Some campsites along the river may be inaccessible this week due to higher water levels, and NPS officials warned river runners that the river may behave differently around rapids during the release. The BOR will begin drawing back the outflow Thursday morning, and river flows should be back to typical levels by Thursday night.