Summary
For a full week last month, the Colorado River surged through the Grand Canyon at nearly triple its average flow—a torrent not seen since Glen Canyon Dam was completed more than 30 years ago. The flood was a $1.5 million ecological experiment designed to test the idea that controlled floods are a means of rejuvenation for riverbank ecosystems. And early results are positive: The flood stirred up sediments and rebuilt beaches and sandbars, creating new habitats for the Grand Canyon's native fishes.