A mitigation bank is a wetland and/or stream aquatic resource area that has been restored, established, enhanced, and/or preserved expressly for the purpose of providing compensatory mitigation under Section 404 of the Clean Water Act of 1972.
Restoration, establishment, and enhancement activities for streams and wetlands provide an uplift of ecosystem functions and services of the aquatic resource being improved within the mitigation bank. Preservation of streams and wetlands protects the existing functions of aquatic resources being preserved. Restoration, establishment, enhancement, and/or preservation within a mitigation bank are protected in perpetuity via legally required site protection and conservation.
Through these aquatic ecosystem uplift and preservation activities, the mitigation bank generates what law defines as “compensatory mitigation credits.” A mitigation bank’s permit requirements identify the specific ecological assessment techniques to assess the efficacy of the project to create and protect the designed level of desired ecosystem functions and services. Based on these assessment techniques, the mitigation banker can determine the number of credits that are available for sale from the mitigation bank to permittees seeking to obtain approval to discharge dredged or fill material for their project. Permittees seeking project approval within the mitigation bank’s approved service area—defined as the geographic area in which a given mitigation bank can compensate for permitted impacts—can then purchase credits to replace the loss of wetland and aquatic resource functions in the area as required by Section 404 of the Clean Water Act.