Wetland Habitat Response to Low-Head Dam Removals in New England

The Gulf of Maine Council on the Environment’s Stream Barrier Removal Monitoring Guide presents detailed methodologies for monitoring physical characteristics specific to stream barrier removal in the Gulf of Maine watershed. The Guide recommends directly measuring and monitoring wetland and riparian plant community response to barrier removal.  Wetland functions and values represent an important component to the state and federal permitting processes.  Dewatering of these impounded areas can potentially restore critical wetland habitats and buffer zones and improve the functions and values of the wetland system.  Dam removal may also result in reduced wetland area and open up areas for colonization by invasive species.  Ultimately, alterations to wetland functions and values following dam removal may be difficult to predict due to uncertainty in post-removal soils, vegetation establishment, and hydrology.  Examples of wetland restoration of formally-impounded areas in New England and an evaluation of changes in wetland habitats and associated functions and values resulting from low-head dam removal are discussed.  Additional wetland and riparian habitat monitoring approaches are presented.