Great Flood of 1993

Great Mississippi and Missouri Rivers Flood of 1993

Flood waters inundated parts of Jefferson City, Missouri, and threatened the Missouri State Capitol during the "Great Flood of 1993".
Date	April – October 1993
Location	Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota, and Wisconsin
Deaths	32
Property damage	$15-20 billion

The Great Mississippi and Missouri Rivers Flood of 1993 (or "Great Flood of 1993") occurred in the American Midwest, along the Mississippi and Missouri rivers and their tributaries, from April to October 1993. The flood was among the most costly and devastating to ever occur in the United States, with $15 billion in damages. The hydrographic basin affected cover around 745 miles (1,199 km) in length and 435 miles (700 km) in width, totaling about 320,000 square miles (830,000 km²). Within this zone, the flooded area totaled around 30,000 square miles (78,000 km²) and was the worst such U.S. disaster since the Great Mississippi Flood of 1927, as measured by duration, area inundated, persons displaced, crop and property damage, and number of record river levels. In some categories, the 1993 flood even surpassed the 1927 flood, at the time the largest flood ever recorded on the Mississippi.

Well above average rainfall and below average temperatures beginning in the summer of 1992 resulted in above-normal soil moisture and reservoir levels in the Missouri and Upper Mississippi River basins. This weather pattern persisted throughout the following autumn. During the winter of 1992–93, the region experienced heavy snowfall. These conditions were followed by persistent spring weather patterns that produced storms over the same locations. Soils across much of the affected area were saturated by June 1, with additional rainfall all running off into streams and rivers, instead of soaking into the ground. These wet-weather conditions contrasted sharply with the droughts and heat waves experienced in the southeastern United States.

Storms, persistent and repetitive in nature during the late spring and summer, bombarded the Upper Midwest with voluminous rainfall. Portions of east-central Iowa received as much as 48 inches (120 cm) of rain between April 1 and August 31, 1993, and many areas across the central-northern plains had precipitation 400–750% above normal. 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.