Before and after photos show restoration of aquatic vegetaton in Pool 5 of the Upper Mississippi River. Photos taken during drawdown in 2005 by Tim Schlagenhaft, Minnesota Department of Natural Resources

Water level management in Pool 5 of the Upper Mississippi River recently won an Honor Award and Design Team of the Year Award from the U.S. Army Corps of Engineers.  Pool-scale drawdowns in Pool 5 were conducted in 2005 and 2006 by the St. Paul District Corps of Engineers in cooperation with the Water Level Management Task Force.  The Task Force is an interagency partnership including the Corps, the U.S. Fish and Wildlife Service, the Minnesota Department of Natural Resources, Minnesota Pollution Control Agency, Wisconsin Department of Natural Resources, U.S. Geological Survey and the U.S. Coast Guard. 

A pool-scale drawdown involves a seasonal decrease in water levels at the navigation dam to mimic the low-flow cycle in the upstream reservoir that no longer occurs naturally.  In Pool 5, the drawdown was approximately 18 inches at the dam, exposing approximately 1,200 acres of riverbed.  Exposed areas quickly vegetated with aquatic plants, providing important habitat for fish and wildlife in the pool. Drawdowns are a low-cost way to improve large areas of shallow aquatic habitat that support fish and wildlife on the Upper Mississippi River.  In addition to improving aquatic vegetation, the project was also designed to maintain the federal 9-foot channel project for commercial navigation, minimize adverse effects on river recreation, and inform the public on the environmental benefits of drawdowns.  In 2007, drawdowns in Pools 5 and 8 received the Seven Wonders of Engineering award from the Minnesota Society of Professional Engineers.