Water quality is of key importance to man and nature. Flooding tends to reduce water
quality by introducing large amounts of eroded materials. By transforming low lying areas to
farm lands, man has removed much of the floodplain vegetation and wetland areas that act as
natural stilling ponds, sediment intercepts, hydraulic sponges, and erosion protection.
Compounding the problem, large quantities of chemicals are flushed into the surface water by
overland flows. Chemical loading and poor water quality can have long and short-termconsequences. Point sources for chemical introductions include inundated municipal and
industrial sites, including wastewater treatment plants, chemical processing and manufacturing
centers, and disposal or holding areas (Goolsby et al., 1993). The largest non-point pollution
source is runoff from agricultural land.
In the catastrophic Mississippi River basin flood of 1993, extremely large amounts of