Urban development over the last several decades in the United States has greatly increased the amount of impervious surfaces, such as streets, rooftops, and parking lots in urban and suburban environs.  Rainwater does not soak into these areas like natural soils, but remains on the surface and runs overland towards lower areas, often accumulating pollutants along the way, such as motor oil, gasoline, heavy metals and nutrients.  Because rainwater cannot soak into the soil, impervious surfaces also generate greater volumes of water leading to increased frequency and depth of flooding.  To prevent flooding, drainage ditches have been constructed in such a way as to channel stormwater as far and as fast as possible away from developed areas, transporting pollutants many miles away to receiving rivers and bayous.

In order to remove pollutants from WHS stormwater runoff, the Environmental Protection Agency (EPA) and Louisiana Department of Environmental Quality (LDEQ) provided a grant to Louisiana State University (LSU) researchers to design and construct a wetland in the WHS detention pond.  The underlying premise was that as stormwater runoff from the surrounding landscape enters the constructed wetland, water velocity will slow, water residence time will increase, and downstream flooding and pollution transport will be decreased.  A meandering wetland channel was designed to be an aesthetically pleasing landscape feature as well as a functioning wetland filter, demonstrating the integration of landscape design with stormwater management and non-point source pollution mitigation.

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