Does sediment have any positive effects?
Sediment is an important component for some habitat types on the Mississippi River. For example shorebirds heavily utilize sand bars and mud flats created through sedimentation. Sedimentation has helped to literally bury some of the pollutants that once flowed downstream in high amounts from the Twin Cities Metropolitan area. These contaminated sediments settled in Lake Pepin and were consequently covered by silt carried by the river. This “burying” of contaminated sediments effectively improved the water quality of the river downstream from Lake Pepin. In addition, sand frequently drops out as a tributary meets the slower waters of the Mississippi River; Lake Pepin was formed by sand settling out at the mouth of the Chippewa River. The sand can also form a delta at the mouth of these tributaries which extends out into the river producing some of the richest wildlife habitat on the river.
