Scott Namestnik
Wednesday, October 15, 2008 - 2:00-2:30
Mitigation wetlands are commonly created in an effort to offset impacts to natural wetlands that occur as a result of development. Creation of mitigation wetlands often happens in one of two ways: excavation within an upland, or restoration of hydrology to an area that had been converted to upland by being drained. In the latter case, the site was wetland historically and wetland soils and seed bank, as well as topographic conditions conducive to wetland development, often remain. It is therefore expected that wetland functions and values should return as water is returned to the system. Wetland restoration is generally preferred over excavation in uplands. Many journal articles report that mitigation is not fulfilling its purpose of no net loss of wetlands. Most of these articles, however, address only whether wetland mitigation efforts were undertaken; others address whether mitigation wetlands meet regulatory agency performance standards. This study investigated how existing mitigation wetlands compare to natural wetlands in terms of function and quality. Several existing mitigation wetlands were assessed using Ohio Rapid Assessment Method (ORAM). Mitigation wetlands investigated include sites meeting all regulatory agency performance standards, as well as sites not in regulatory compliance. For comparison, several naturally occurring wetlands similar in size and plant community to the assessed mitigation wetlands were scored using ORAM. Parameters compared include upland buffers and surrounding land use; hydrology; habitat alteration and development; special wetland communities; and vegetation, interspersion, and microtopography. Results demonstrate how mitigation wetlands compare in function and quality to naturally occurring wetlands.
Keywords: MITIGATION, WETLANDS, RESTORATION, FUNCTIONAL ASSESSMENT, ORAM