A River in Decline

A River in Decline. . , Historically, the Mississippi River was a free-flowing river until the locks and dams were constructed in the 1930s to provide a 9-foot shipping channel. While critical to commerce, this project transformed the river. The locks and dams created reservoirs to keep the river from falling to its natural low levels. Many islands were submerged, and the river lost many of its wetlands and floodplains, important to its ability to filter and clean water., Even before the river's transformation by the locks and dams in the 1930s, many river cities used the Mississippi for sewage disposal. By 1900, the first "dead zone" on the Mississippi River was in Minneapolis and Saint Paul. The river was so depleted of oxygen and full of contaminants that few aquatic plants, fish, and animals could survive in its waters., After 1940, skipjack herring no longer migrated over the locks and dams, bald eagles rarely soared over the river, and once-abundant freshwater mussels were almost wiped out. Formerly lush river banks disappeared, and critical wildlife habitat was lost or destroyed. The river suffered from neglect and had a long road to recovery., At left, views of Saint Paul in 1889 and 2008, Exhibits funded through the generous support of: , CHS Foundation , The McKnight Foundation , The Mississippi River Fund of the National Park Service , Saint Paul Cultural STAR