Modeling the suitability of wetland restoration potential at the watershed scale

Despite the fact that landscape level processes dominate wetland ecosystem development and sustainability, restoration decisions (including those for compensatory mitigation) are typically made on a project-by-project basis. Watershed planning designed to strategically restore wetlands has the potential to provide dramatic benefits by restoring ecosystem-level processes (functions) that maintain water resource integrity. We developed a GIS-based model to predict the suitability for wetland restoration for all locations in the Cuyahoga River watershed (2107 km2), in northeastern Ohio (U.S.A.). The model offers a useful tool to focus and set goals for wetland restoration efforts in a spatially explicit way. A two-phase approach was used: the first is to develop criteria, or environmental indicators, to identify the total population of sites suitable for wetland restoration. Locations are identified where restoration has a high likelihood of success and will be sustainable over the long term. Criteria used include hydric soils, land use, topography, stream order, and a saturation index based on slope and flow accumulation in each grid cell in the model. The second phase “filters” the total population of available sites in order to prioritize them according to their potential to contribute to water resource integrity once restored. We generated three versions of the suitability model depicting restoration potential. All versions rely on the same criteria but vary in how the factors were weighted or the hydrology criterion was calculated.