Enhanced Wetland Inventory for Harpers Ferry National Historic Park

Tessel, Samantha; Lookingbill, Todd

The purpose of this report is to document, characterize, and delineate wetlands in Harpers Ferry National Historic Park (HAFE). Wetlands are considered transitional areas between terrestrial and aquatic ecosystems that support unique plant life adapted to inundated and anaerobic conditions for at least part of the growing season. Wetlands provide important ecosystem services such as excess nutrient removal, flood regulation, primary production and carbon storage, and are thus a primary conservation target (Keddy 2000). Encompassing approximately 3645 acres, HAFE contains over 10 linear miles of riparian and potential wetland habitats. The park is located at the confluence of the Potomac and Shenandoah Rivers in the Blue Ridge physiographic province. The wide range of riparian and terrestrial environments often found in association with deeply entrenched river systems creates a mosaic of habitats at HAFE that support a diverse flora and fauna. Wetland habitats within the Ridge and Valley and Blue Ridge physiographic provinces are clearly limited in extent. They, nonetheless, play a myriad of important roles, including maintaining water quality, flood mitigation and providing critical habitat for aquatic plant and animal species. Wetlands of the mountainous regions of the mid-Atlantic region are also known to harbor numerous Rare, Threatened and Endangered species not found elsewhere. Wetland sites within the park represent important ecological components of the park, as well as of the local and regional environments. It is imperative for HAFE to have an accurate and detailed inventory of these sites to ensure proper management and protection of wetland resources, and to comply with existing federal laws that regulate activities in or near these habitats (e.g., National Environmental Policy Act, Clean Water Act and the Rivers and Harbors Act). At present, HAFE relies upon the U.S. Fish & Wildlife Service's National Wetland Inventory (NWI) maps as their source for wetland resources found within the park. The maps have been produced at a large scale (1:24,000) and are based almost entirely upon aerial infrared imagery. Smaller wetlands, and those obscured by dense forest cover, can often be overlooked by the NWI mapping process. In addition, sites proposed by the NWI may not be supported by field observations. To provide a more accurate and detailed accounting of wetland resources, the University of Maryland Center for Environmental Science conducted an Enhanced Wetland Inventory of the park. Using digital information provided by HAFE and extensive ground truthing in the field, we generated wetland descriptions and an enhanced GIS map of the wetlands found in the park. Wetlands are defined here based on three criteria: hydrophytic vegetation, wetland hydrology, and hydric soils (US Army Corps of Engineers 1987). Accompanying the final report will be digital data from the mapping component of this project in ArcGIS shapefile format suitable for incorporation into the Park's GIS system.