The Mississippi River Flood Of 1993
The Mississippi River begins at Lake Itasca in Minnesota and flows south more than 2,000 miles to the Gulf of Mexico.
Residents along its banks are not unfamiliar with great floods.
The severe flooding of the Mississippi Valley in 1927 is considered responsible for the implementation of the first effective flood control measures put forward by the US Weather Bureau (now the National Weather Service).
There has not been a flood in recent American history that was as devastating as the great flood that affected the upper and middle Mississippi Valley from late June to mid-August 1993. Record flooding affected the Mississippi River and most of its tributaries from Minnesota to Missouri.
The floods were caused by events which developed as early as the Fall of 1992. At that time, soil moisture levels in the central United States were already high. Winter rain and snow contributed to the nearly saturated soil conditions, so that spring precipitation and snowmelt - normally able to soak into the ground - could only run off into streams and rivers.
By June 1st of 1993, rivers were running high as a persistent upper level atmospheric pattern developed over the central US.
A trough at high levels of the atmosphere became established over the interior West. Meanwhile, southerly low level winds directed a rich flow of moist air from the Gulf of Mexico into the Midwest. Upper level disturbances riding eastward from the western trough encountered the moisture-laden air, spawning drenching thunderstorms.
Wave after wave of these storms rumbled across the already soaked Mississippi River basin from June through August. By the end of summer, some locations had received over 30 inches of rain - nearly 200% of normal.
Minnesota, Iowa, Illinois, and Missouri were hardest hit. At St. Louis, the river crested at 49.6 feet - over 19 feet above flood stage, and more than six feet above the old record set in 1973. The Mississippi remained over flood stage at St. Louis for over two months.
Farther, north, record flooding occurred on the Des Moines River, a tributary of the Mississippi. At one point flooding disabled a major water plant, and Des Moines, Iowa, a city of nearly 200,000 people, was without safe drinking water.
Transportation and industry along the Mississippi was disrupted for months. Damages to surface and river transportation in the region were the worst ever incurred in the United States.
Over 1,000 of the 1,300 levees designed to hold back flood waters failed, though major cities along the rivers, like St. Louis, were protected from flooding by massive flood walls.
Over 70,000 people were displaced by the floods. Nearly 50,000 homes were damaged or destroyed and 52 people died. Over 12,000 square miles of productive farmland were rendered useless. Damage was estimated between $15-20 billion.
Some historical flash floods include the Johnstown Flood of 1889, the Big Thompson Canyon Flood of 1976, and the Shadyside, Ohio Flood of 1990.
