Wetlands act as natural sponges that trap and slowly release
surface water over time. This ability to
store water in times of heavy rainfall means that wetlands can help prevent
flooding. A one acre wetland can typically
store about one million gallons of water, though the degree of flood control
depends on many factors such as the type of wetland and soil permeability.
Wetlands
along the Mississippi River once stored at
least 60 days of floodwater, but now only store 12 days because most have been
filled or drained.
(c) GRN
Coastal wetlands are particularly important in the Gulf
region because they can help reduce flooding from hurricane storm surges. Many of the coastal areas in the Gulf are in
flat or low-lying areas, which are particularly vulnerable to hurricanes and
tropical storms. It is estimated that
for every 3.4 miles of healthy coastal wetlands a storm surge must travel over,
the surge is diminished by one foot.
Preserving wetlands, in conjunction with other flood control
measures, often offers superior flood protection and costs less than a
conventional system of dikes, levees, floodways, and stormwater retention ponds. As the cost of flood insurance continues to
rise in coastal areas throughout the Gulf of Mexico,
it is important to preserve wetlands, which truly are the first line of defense
against flooding.
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