Grand Canyon advocates are celebrating a decision by federal water managers to unleash a three-day pulse of high water from Glen Canyon Dam to rebuild beaches and improve environmental conditions on the Colorado River. The high-flow experience is scheduled to start Monday.
Environmentalists, river runners and others had sought such a flood release, outlined under the dam’s adaptive management program, for years. Healthy monsoon rains had pushed tons of sand into the river, but had also gouged the beaches and sandbars that create natural backwaters and campsites for river trips. Opening the dam’s floodgates before the fresh sediment gradually washed downstream could push the sand up to form new beaches...