27 Oct 2015

Dredge W.A. Thompson and early dredging

In 1930 the 9-foot draft channel was legislated by Congress to increase commerce on the river. The U.S. Army Corps of Engineers began construction of the series of 29 locks and dams between St. Louis and Minneapolis, creating a stairway of water for river traffic. Since the river is constantly shifting its load of sand and sediment and tributaries along the way contribute more it is necessary to remove the material from the bottom of the channel to prevent a closure to navigation. This process of underwater excavation is called dredging.