EARTH: Releasing a flood of controversy on the Colorado River

As the Colorado River winds through the Colorado Plateau's soft sedimentary strata, it picks up a tremendous amount of sediment. This sediment – which once left the river's waters so muddy that Spanish explorers christened it El Rio Colorado "the reddish river" – is a vital component to the unique ecosystems of the river. However, with the construction of the Hoover and Glen Canyon dams, which trap the sediment, the once-turbid waters have become a dazzling blue-green, signaling major changes with serious implications for the health of the river's native ecosystems.

In an attempt to study the impact the dams have on the geomorphology and biology of the Grand Canyon, scientists have been experimenting with high flow episodes – periodically flooding the dam to try to recreate its native environment. Could controlled flooding benefit native fish, sandbars and cultural sites that have been drastically altered by the dams' construction and 50 years of operation? Or is the Colorado River forever changed? Read the story online and find out at http://bit.ly/13BSDTd.

Read this story and more in the March issue of EARTH Magazine available online now. Discover how ancient minerals rode icebergs across the Atlantic; join Voyager on the magnetic highway to interstellar space; and meet the new candidate for oldest dinosaur all in this month's issue of EARTH.

Provided by American Geosciences Institute