Importance of the River
The Mississippi forms the backbone for a vast system of inland waterways. Connected to it are the Illinois Waterway, the navigable Missouri and Ohio rivers, and the Intracoastal Waterway. It forms most of a waterway linking the Great Lakes-St. Lawrence Seaway with the Gulf of Mexico. The river's 9-to 35-foot (2.7- to 10.7-m) minimum channel allows ocean vessels to reach Baton Rouge, Louisiana, and giant barges to travel as far as Minneapolis and St. Paul. Dredging is required to maintain the channel throughout the river's course. Above its junction with the Missouri, the river is made navigable by 26 locks and dams. Such facilities are unnecessary below St. Louis.
Cities along the banks, including such large ones as New Orleans, St. Louis, St. Paul, and Minneapolis, draw water from the river for home and industrial use. Hydroelectric power is produced in several localities, but the amount is relatively small since the amount of fall is so slight. The chief installations are at Keokuk, Iowa, and Minneapolis. The river is also extensively used for recreation.
The Mississippi brings many benefits to its valley, but it also brings destructive floods, especially in spring and winter. Since 1928 the number and severity of floods have been reduced by a large-scale federal flood-control program that includes dredging and straightening the channel and the building of levees, spillways, and reservoirs. Despite this flood-control program, torrential rains in 1993 resulted in massive floods throughout most of the upper Mississippi Valley, causing billions of dollars' worth of damage.