Background on Upper Mississippi River Basin

The Upper Mississippi River System is the only waterbody in the nation that has been recognized by Congress as "a nationally significant ecosystem and a nationally significant commercial navigation system." (Section 1103 of the Water Resources Development Act of 1986, P.L. 99-662)

The Upper Mississippi River Basin drains approximately 189,000 square miles, including large parts of the states of Illinois, Iowa, Minnesota, Missouri, and Wisconsin. Small portions of Indiana, Michigan, and South Dakota are also within the basin.

More than 30 million people live in the basin. Nearly 80 percent of the population lives in urban areas such as Minneapolis-St. Paul, Minnesota; St. Louis, Missouri; Chicago, Illinois; the Quad Cities, Illinois and Iowa; Des Moines, Iowa; La Crosse, Wisconsin; and Peoria, Illinois.

The basin has 30,700 miles of streams. There are 12 major tributaries to the Upper Mississippi River, including the Missouri, Illinois, Wisconsin, and Iowa Rivers. There are over 3,000 reservoirs in the basin. The flood storage volume of 40 million acre-feet would take over 3 months to flow past St. Louis at average discharges.

Over 60 percent of the basin is cropland or pasture. Major cash crops include corn and soybeans. In 2000, barges transported 122 million tons of commodities on the Upper Mississippi River, over half of which was grain for world export. Approximately 52 percent of the nation's corn and 41 percent of the nation's soybean exports are carried on the Upper Mississippi River System, which includes the Illinois River.

The average annual discharge on the Upper Mississippi River increases from 9,180 cubic feet per second (cfs) near St. Paul, Minnesota to 204,800 cfs at Thebes, Illinois. Flood control levees protect about 3 percent of the floodplain north of Rock Island, Illinois; 53 percent of the floodplain in the middle reach between Rock Island and St. Louis; and 83 percent of the floodplain south of St. Louis.

There are 3 national refuges along the Upper Mississippi River, totaling over 285,000 acres. They include the Upper Mississippi River National Wildlife and Fish Refuge, Trempealeau National Wildlife Refuge, and Mark Twain National Wildlife Refuge. The states manage another 140,000 acres of refuge lands along the river.

Recreational visits to the Upper Mississippi River region exceeded 11 million trips in 2000, more than most national parks, including Yellowstone. There are approximately 500 boat access points and marinas along the Upper Mississippi River between the headwaters in Minnesota and the confluence with the Ohio River in southern Illinois.

Over 7 billion gallons of water are withdrawn from surface water sources each day in the 60 counties that border the navigable Upper Mississippi River. Over 80 percent of this water is used as cooling water for energy production and thus returned to rivers and streams. There are 29 power plants that use water from the 1,300 mile long Upper Mississippi River. Approximately 278 facilities discharge wastewater to the Upper Mississippi River, including industrial facilities and municipal sewage treatment plants.

From St. Cloud, Minnesota in the north to Cape Girardeau, Missouri in the south, the Upper Mississippi River provides water to 23 public water suppliers serving a combined population of approximately 2.8 million people.