Great Flood of 1993

Great Flood of 1993
Name	Great Flood of 1993
Caption	Flooding on the Mississippi River in 1993
Date	April–October 1993
Locations	Midwestern United States, including Iowa, Missouri, Illinois, Minnesota, Wisconsin, Kansas, Nebraska
Type	Riverine flood
Fatalities	32–50+
Damages	~$15 billion (1993 USD)

Great Flood of 1993 The Great Flood of 1993 was a prolonged and devastating series of riverine floods across the Midwestern United States that inundated large sections of the Mississippi River and Missouri River basins from spring through autumn 1993. Exceptional precipitation linked to persistent storm systems overwhelmed levees, displaced communities, and strained federal and state agencies including the Federal Emergency Management Agency, United States Army Corps of Engineers, and regional authorities in states such as Iowa and Missouri. The event prompted major changes in floodplain management, levee policy, and hydrologic research at institutions like the United States Geological Survey and the National Oceanic and Atmospheric Administration.

Background and causes

Persistent upper-level atmospheric patterns associated with repeated slow-moving cyclones and frontal systems produced extreme precipitation across the Mississippi River Basin and tributaries such as the Des Moines River, Ohio River, and Arkansas River. Antecedent wetness followed heavy snowfall in states like Minnesota and Wisconsin and saturated soils during the preceding winters, creating high baseflow conditions recorded by the United States Geological Survey (USGS). Land-use practices—including agricultural drainage in the Corn Belt and levee construction along the Mississippi River and Missouri River—altered runoff characteristics monitored by the National Weather Service and influenced peak flows measured at gaging stations in St. Louis, Missouri, Kansas City, Missouri, and Burlington, Iowa. Climate drivers and teleconnections such as phases of the El Niño–Southern Oscillation and mid-latitude blocking patterns were investigated by NOAA and academic centers like University of Iowa and Iowa State University.

Chronology of the flood

Spring 1993 began with above-average precipitation recorded by the Climate Prediction Center and early river rises on the Missouri River tributaries. Major cresting occurred in late May and June at locations including St. Louis, Canton, Missouri, and Quincy, Illinois, while crests on the Mississippi River propagated downstream to Memphis, Tennessee and New Orleans, Louisiana in subsequent months. The Army Corps of Engineers and local levee districts reported sequential failures and overtopping along reaches of the Des Moines River near Des Moines, Iowa and along the Missouri River near Fulton, Missouri. A second wave of heavy rain in July and August produced renewed flooding on tributaries such as the Illinois River and Kaskaskia River, with prolonged inundation persisting into October in floodplains around Cairo, Illinois and the Bootheel, Missouri. Throughout the event, river stage data compiled by USGS and flood forecasts issued by the National Weather Service guided evacuations and operational decisions.

Impact and damage

The flood inundated extensive agricultural lands in the Corn Belt—affecting counties in Iowa, Missouri, Illinois, and Nebraska—destroying crops and farm infrastructure. Urban centers including St. Louis and Kansas City experienced transportation disruptions on the Interstate Highway System and closures of river ports used by the Army Corps of Engineers and private carriers. Critical facilities, such as ethanol plants, grain elevators, and railroad bridges operated by companies linked to the Burlington Northern Railroad and Union Pacific Railroad, suffered damage, while historic districts in river towns like Hannibal, Missouri and Muscatine, Iowa were flooded. Estimates from the Federal Emergency Management Agency and state agencies placed insured and uninsured losses in the billions, and fatalities were reported across impacted states.

Emergency response and recovery

Federal response involved coordination among FEMA, the US Army Corps of Engineers, the United States Coast Guard, and presidential disaster declarations issued under statutes administered by the Federal Emergency Management Agency. State governors in Iowa, Missouri, and Illinois mobilized National Guard units and worked with municipal authorities in cities such as St. Louis and Des Moines to conduct evacuations and sandbagging. Large-scale voluntary responses were mounted by non-governmental organizations including the American Red Cross, The Salvation Army, and faith-based groups tied to the United Methodist Church and local Catholic Charities. Recovery programs implemented by the Small Business Administration and the United States Department of Agriculture addressed infrastructure repair, farm loss payments, and community rebuilding, while litigation over levee failures involved levee districts and private landowners.

Environmental and ecological effects

Extended inundation altered floodplain ecology along the Mississippi River and tributaries like the Illinois River, redistributing sediments and nutrients documented by researchers at Iowa State University and University of Illinois Urbana–Champaign. Fish and wildlife populations—including species in the Upper Mississippi River National Wildlife and Fish Refuge and wetlands monitored by the U.S. Fish and Wildlife Service—experienced habitat loss and shifts in spawning patterns, while invasive species pathways involving the Great Lakes basin and river navigation channels came under scrutiny by the U.S. Fish and Wildlife Service and the Illinois Department of Natural Resources. Contamination events linked to flooded industrial sites prompted response by the Environmental Protection Agency and state environmental agencies, and restoration projects were later funded through federal and state environmental programs.

Economic and social consequences

Agricultural losses affected commodity markets monitored by the Chicago Board of Trade and government price support programs administered by the United States Department of Agriculture (USDA), with ripple effects in rural communities dependent on commodity processing facilities owned by firms linked to the Cargill and ADM (company). Urban economic impacts included port closures that affected shipping firms and industries tied to the Port of St. Louis, while insurance industry losses engaged the National Association of Insurance Commissioners and private carriers. Social consequences involved displacement of residents in counties across Iowa, Missouri, and Illinois, disruptions to schools such as those in the Des Moines Public Schools district, and long-term demographic shifts discussed by researchers at the Brookings Institution and regional universities.

Legacy and mitigation measures

The flood prompted policy and engineering changes including revisions to levee certification standards overseen by the US Army Corps of Engineers, expansion of floodplain mapping by the Federal Emergency Management Agency and National Flood Insurance Program, and investments in river management research at institutions like the USGS and NOAA. Communities adopted buyout programs administered by state emergency management agencies and the FEMA Hazard Mitigation Grant Program to move structures out of recurrent floodplains, while watershed-scale approaches promoted by the Natural Resources Conservation Service and academic centers gained prominence. The event remains a case study in hydrology, civil engineering, and emergency management taught at universities including the University of Iowa and University of Missouri, and it informed later responses to river floods in the United States.

Category:Floods in the United States Category:1993 natural disasters in the United States