Simulated Floods Succeed in Restoring Colorado River Sandbars
A new study by the U.S. Geological Survey finds that a project to rebuild sandbars along the Colorado River in the Grand Canyon appears to be a success. As Arizona Public Radio’s Ryan Heinsius reports, officials say simulated floods have been effective in redistributing sand.
The study shows at least half of the monitored sandbars on the river increased in size during the experiments conducted annually for the last three years. During the high releases, federal water managers let out double or triple the water volume from Glen Canyon Dam for up to eight days at a time. They say the floods redistribute fine sediment and mud that make up the sandbars but is trapped upriver.
The sandbars serve as habitat for native and endangered fish, support key vegetation and provide campsites for hikers and river runners, but they’ve rapidly eroded since the dam’s construction in the 1960s.
If the controlled floods continue, officials say the long-term pattern of declining sandbars on the Colorado River could be reversed.