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Ecological Effectiveness of Compensatory Mitigation

Each year more than 40,000 acres of wetlands are restored, established, enhanced, and preserved to compensate for the approximately 20,000 acres of losses permitted through the federal wetlands regulatory program. Nationwide, an estimated $2.9 billion is spent annually on these compensatory mitigation projects. However, it is not clear whether this significant investment in compensation yields projects that are effectively replacing lost wetlands.

Success of Wetland Mitigation Projects

State and regional studies on wetland compensatory mitigation suggest that a significant portion of compensation sites is failing to meet administrative and ecological performance standards. A National Wetlands Newsletter article, "Success of Wetland Mitigation Projects" (2008), provides a summary of ELI's review of the literature on the track record of compensatory mitigation projects in replacing lost aquatic resource functions and acres, as well as meeting administrative requirements.

A National Study

A national study of all three forms of mitigation – mitigation banking, in-lieu fee mitigation, and permittee-responsible mitigation – is needed to evaluate the ecological performance of compensatory mitigation and to allow for a comparison of these three mitigation mechanisms. There has been no consistent approach, methodology or effort at the national scale to assess the performance of mitigation, nor have essential study elements been described for comparing the three mitigation mechanisms.

ELI convened a panel of expert wetland scientists to develop a study design to assess the regulatory and ecological outcomes of the three compensatory mitigation mechanisms — mitigation banking, in-lieu fee mitigation, and permittee-responsible mitigation — in a manner that will enable comparisons of the three mechanisms nationwide. The final study design establishes a protocol for the on-going national assessment of mitigation sites.