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Upper Midwest Environmental Sciences Center

About the Upper Mississippi River System

(photos) about UMRS

In a Nation endowed with magnificent water resources, the Upper Mississippi River System is unparalleled. A 1,300-mile waterway linking five states to the Gulf Coast export markets, the River System supports a tremendous range of uses. Commercial navigation, recreation, and fish and wildlife all flourish on the Upper Mississippi. In addition, the region's more than 30 million residents rely on river water for public and industrial supplies, power plant cooling, wastewater assimilation, and other uses.

The Mississippi River is an integral part of the American heritage. It once served as our Nation's western border, and expansion beyond it was a key turning point in our history. Through his writings, Mark Twain made the Mississippi River a household word. In recent years, the river was the center of a national public policy debate and controversy involving reconstruction and expansion of Locks and Dam 26 (near St. Louis) at a cost of over $1 billion. The Great Flood of 1993 again brought the Mississippi River to national and international attention when multibillion-dollar economic damage was incurred.

The Mississippi River is more than just a river; it is a unique resource and the best example of a multi-purpose river in the United States. In 1986, Congress designated the Upper Mississippi River System (which consists of the Upper Mississippi and Illinois Rivers and several important tributaries) as both a nationally significant ecosystem and a nationally significant navigation system. It is the only inland river in the United States to have such a designation. Congress further recognized the system as producing a diversity of opportunities and experiences, and directed that it be administered and regulated in recognition of its many purposes. The National Research Council's Committee on Restoration of Aquatic Ecosystems recently targeted the Upper Mississippi River and the Illinois River for restoration as two of only three large river-floodplain ecosystems so designated.

Recreation opportunities on the Upper Mississippi River System are as varied as the river itself. Millions of people visit the area every year to participate in water activities, including boating, fishing, swimming, or simply enjoying the river's beauty. Annual recreational expenditures on the Upper Mississippi River System exceed $1.2 billion.

The river ecosystem is home to a diverse array of fish and wildlife that find habitat in its channels, backwaters, sloughs, wetlands, and adjacent uplands. The Mississippi Flyway is the migration corridor for 40% of North America's waterfowl and shorebirds. A 40-mile reach of the Upper Mississippi River has been characterized as the single most important inland area for migrating diving ducks in the United States. The Flyway is also an important migration corridor for raptors and neotropical songbirds. Portions of the River provide habitat for breeding and wintering birds, including the bald eagle. A total of 154 species of fish and 50 species of freshwater mussels have been recorded in the river system. The Illinois River once accounted for 10% of the Nation's inland river commercial fish harvest.

Five National Wildlife Refuges—the Upper Mississippi River National Wildlife and Fish Refuge, and the Mark Twain, Trempealeau, Minnesota Valley, and Illinois River National Wildlife Refuges—encompass over 300,000 acres of wooded islands, water, and wetlands along the river corridor.

The history of navigation on the Upper Mississippi River System goes back to the 1820's, when Congress authorized construction of a canal connecting Lake Michigan and the Illinois River and also authorized removal of snags and other obstructions in several reaches of the Mississippi River. Projects creating the current 9-foot navigation channel were authorized in the 1930's, and most were completed by 1940. Twenty-nine locks and dams on the Mississippi and eight on the Illinois replaced rapids and falls with a stairway of water for commercial and recreational traffic. More barge traffic than ever before now transports a wide variety of essential goods on the Upper Mississippi River System. From 2008–2011, an average of 61.3 million tons of cargo was shipped annually between Minneapolis and the mouth of the Missouri River. Food and farm products, petroleum products, and chemical products are the leading cargoes, with food and farm products accounting for approximately 40% of the total tonnage shipped (Institute for Water Resources 2011).

River modifications, control projects, and floodplain development have had wide-ranging effects on the natural processes—particularly hydrology—that drive and maintain the floodplain ecosystem. Sixty-six percent of the nearly 1,200,000 acres in the Upper Mississippi River floodplain are now used for crop and pastureland. These agriculture lands are isolated from the normal floodplain function by extensive levee systems. Although lock and dam construction originally created a significant increase in and diversity of habitat for fish and wildlife, sedimentation has since resulted in serious degradation. Present erosion rates in the basin exceed the rate of soil formation, resulting in a net increase of sediments entering the Mississippi River. The sediments fill in backwater areas and increase turbidity, carry excessive nutrients into the aquatic ecosystem, and bring in pesticides and other toxic chemicals. Continued sedimentation will degrade the quality of the habitat, reduce diversity, and result in a gradual aggradation of backwaters, leading to their transformation from aquatic to terrestrial habitat. The Mississippi River backwaters that presently provide fish and wildlife and plant production and nursery habitats may be lost to sedimentation and eutrophication within the next 50 to 100 years.

Institute for Water Resources.  2011. Waterborne Commerce of the United States, Part 2–Waterways and Harbors Gulf Coast, Mississippi River System and Antilles.  U.S. Army Corps of Engineers, IWR-WCUS-11-2

If you would like more information about the UMRS or the ongoing work of the UMESC in the UMRS, please write to:

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Upper Midwest Environmental Sciences Center

2630 Fanta Reed Road
La Crosse, WI 54603
Phone: (608) 783-6451


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