Constructed Wetland

Natural wetlands are created geo-morphologically over time by natural systems evolution while constructed wetlands are designed.   Constructed wetlands (also referred to as treatment storm water wetlands) are constructed shallow marsh systems that are designed to both treat urban storm water and control runoff volumes.  As runoff flows through the wetland facility, water borne pollutant removal is achieved through settling, filtering, and uptake by marsh vegetation. Storm water wetlands temporarily store storm water runoff in shallow pools that support emergent and riparian vegetation. The perimeter may be planted with ornamental plants that provide food or shelter for wildlife.

Constructed wetlands are commonly used are large development projects such as golf courses, shopping centers, business parks and industrial sites.  These wetlands may be designed as part of an integrated drainage system built around lakes and ponds that may include detention areas, retention areas irrigation ponds or just low areas that collect and store storm water.

As a design water storage and or water treatment system, a constructed wetland must be properly sized, graded and planted with native wetland vegetation. Of these three functions, the planting is the most difficult to do under man made conditions.  For wetland vegetation to be successfully designed it must responds to water depth and competition from other plants and animals.