A three-tiered framework to select, prioritize, and evaluate potential wetland and stream mitigation banking sites

Abstract

Wetland and stream mitigation programs originated to offset the unavoidable impacts to wetlands and streams from activities related to development. Until recently, most mitigation in the United States and globally was done on a case-by-case basis, with site selection based on availability. Today, systematic programs that choose sites based on structural and ecological characteristics that give an indication of the feasibility of the site for wetland and stream mitigation banking are necessary. This paper outlines a three-level framework to select, prioritize, and evaluate potential wetland and stream mitigation banking sites. The framework was tested on three ten-digit hydrologic unit code watersheds in West Virginia that were in three different physiographic regions and near proposed future road construction projects. Level 1 included a Geographic Information System (GIS) based analysis of watersheds and appropriate spatial data. Level 2 was a field reconnaissance survey of sites using evaluation criteria weighted with the pairwise comparison Analytical Hierarchy Process. Level 3 was an on-site evaluation of the highly ranked sites to verify the modeling approach. Results showed successful selection of suitable sites for combined wetland and stream mitigation banking. We found the framework to be an efficient and non-subjective way to identify and prioritize wetland and stream mitigation banking sites and has direct applications for other states or regions.