The Mississippi Floods

The Mississippi Floods

One of the largest floods n the Mississippi was in the summer of 1993.

* The Mississippi River at St. Louis, Missouri, was above flood

stage for 144 days between April 1 and September 30, 1993.

* Approximately 3 billion cubic meters of water overflowed from the

river channel onto the floodplain downstream from St. Louis.

* All large Midwestern streams flooded including the Mississippi,

Missouri, Kansas, Illinois, Des Moines and Wisconsin rivers.

* Seventeen thousand square miles of land were covered by

floodwaters in a region covering all or parts of nine states

(North Dakota, South Dakota, Nebraska, Kansas, Missouri, Iowa,

Wisconsin, Minnesota, and Illinois).

[IMAGE] The Mississippi river basin had two parts to it the upper

basin and the lower basin. These two areas are located on the map

shown above but Flooding was confined to the Upper Mississippi because

the river channel widens considerably south of Thebes, and the Lower

Mississippi received lower than average inflow from tributaries.

The floods were caused by a weather system coming in from the Gulf of

Mexico. This front is shown in this diagram.

[IMAGE]

The Effects of The Floods were:

It was excellent for the farmers on the Mississippi flood plain. The

floodwater made the soils again rich and fertile. However there were a

variety of problems. In the Short term crop production dropped by up

to 10%, A Quarter of a million people were left without clean water

and 25,000 were actually evacuated. The floods also had economic

effects as The river could not be used by Ships, So power stations

which used the channel for transporting coal, had to plough into

reserve supplies, across Illinois and Iowa isolated building went

without power. |The transport problem cost almost $1 million per day

and lasted 2 months.

Flood Prevention

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