Skip to main content
U.S. flag

An official website of the United States government

Erosion along the banks of the Toutle River results in resedimentat...

Detailed Description

People living adjacent to streams and rivers that flow away from the volcano are continually impacted by the upstream erosion and downstream sedimentation of the large volume of material erupted in 1980. The decrease in carrying capacity in downstream channels increases the chance for flooding.