Twin torrents of water unleashed from a dam coursed through the Grand Canyon on Wednesday in a flood meant to mimic the natural ones that used to nourish the ecosystem by spreading sediment.
“This gives you a glimpse of what nature has been doing for millions of years, cutting through and creating this magnificent canyon,” Interior Secretary Dirk Kempthorne said after he pulled the lever releasing the water from Glen Canyon Dam, upstream from Grand Canyon National Park.
More than 300,000 gallons of water a second was being released from Lake Powell above the dam near the Arizona-Utah border. That’s enough water to fill the Empire State Building in 20 minutes, Kempthorne said. The water gushed from the dam into the Colorado River below, creating a churning, frothy pool that glided past the salmon-colored sandstone walls of the canyon.
The dam is releasing four to five times its usual flow during the three-day flooding. The water level in the canyon will rise only a few feet, but officials hope that will be enough to restore sandbars on the Colorado River downstream from the dam. Officials have flooded the canyon twice before, in 1996 and 2004.
Before the dam was built in 1963, the river was warm and muddy, and natural flooding built up sandbars that are essential to native plant and fish species. The river is now cool and clear, its sediment blocked by the dam.
The change helped speed the extinction of four fish species and push two others, including the endangered humpback chub, near the edge. Shrinking beaches have led to the loss of half the riverside camping sites in the canyon in the past decade.
Grand Canyon National Park Superintendent Steve Martin said manmade floods need to occur every time there’s enough sediment to do so.
PAGE, Ariz. — Online Watch video and browse a slide show of the flooding.
