National Weather Service United States Department of Commerce

The Great Flood of 1993

The size and impact of the Great Flood of 1993 was unprecedented and is considered the most costly and devastating flood to ravage the U.S. in modern history. The number of record river levels, the aerial extent, the number of persons displaced, amount of crop and property damage and its duration surpassed all earlier U.S. floods in modern times.

Uniquely extreme weather and hydrologic conditions led to the flood of 1993. The stage was set in 1992 with a wet fall which resulted in above normal soil moisture and reservoir levels in the Missouri and Upper Mississippi River basins.

These conditions were followed by persistent weather patterns that produced storms over the same locations. Their persistent, repetitive nature and aerial extent throughout the late spring and summer, bombarded the Upper Midwest with voluminous rainfall amounts. Some areas received more than 4 feet of rain during the period.

In the St. Louis National Weather Service (NWS) forecast area, encompassing eastern Missouri and southwest Illinois, 36 forecast points rose above flood stage, and 20 river stage records were broken. The 1993 flood broke record river levels set during the 1973 Mississippi and the 1951 Missouri River floods.

Over 1,000 flood warnings and statements, five times the normal, were issued to notify the public and need-to-know officials of river levels. In places like St. Louis Missouri, river levels were nearly 20 feet above flood stage and had never been this high in its 150 year history. The 52 foot St. Louis Flood wall, built to handle the volume of the 1844 flood, was able to keep the 1993 flood out with just over two feet to spare.

NASA imagery loop
Comparing NASA Imagery from 1991 to 1993
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