USGS: Gains from Grand Canyon flooding short-lived

FLAGSTAFF, Ariz. -- An experiment meant to mimic natural flooding in the Colorado River through the Grand Canyon proved beneficial, but scientists say the gains were short-lived.

A man-made flood sent torrents of water from Glen Canyon Dam on the Arizona-Utah line for 60 hours in 2008 in an effort to build up sandbars crucial for wildlife.

But U.S. Geological Survey researchers say the key to maintaining the sandbars is not simply manipulating the flows from the dam. They say the frequency and timing of the flows would have to exceed the erosion that occurs between them.

Interior Secretary Ken Salazar has called for more of the man-made floods through the Grand Canyon. The plan would be developed partly on the USGS reports released on Tuesday.