U. S. Army Corps of Engineers - Mobile District

Flood Control

     Floods are the cause of the greatest and quickest changes in lake levels.
Heavy rains produce floods which can raise a lake level several feet overnight.
When floods are over it is important to get the lake ready to store the next flood
that may be coming along.

     Because of the release of flood waters, rivers below a flood control dam will
stay high and swift for many days after a large flood.  Downstream boaters in
Springtime need to be extra cautious since stored flood waters are  very cold
as well as swift and deep.

    When a flood event is occurring, releases from the dam are curtailed or
minimized until downstream conditions allow making greater releases or if the lake
reaches its capacity to hold flood waters.  Once conditions do allow resuming
releases, the releases are made in manner to evacuate the flood waters as quickly
as possible to prepare for the next potential flood event.

    Not all Corps projects are designed for flood control and no dam can prevent
every flood.  Some major floods will eventually exceed the flood capacity of a
dam.  Typically, in a major flood, the dam will help reduce the peak flow of a
flood and help reduce the amount of damages that may have occurred if the dam was
not there.
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