Masonville Dredged Material Containment Facility: Mitigation Design Including Shore Protection, Reef Creation, and Wetlands Restoration

As a component of the Masonville Dredged Material Containment Facility (DMCF) project, the Maryland Port Administration (MPA) was required to develop a compensatory mitigation package to offset impacts associated with filling approximately 53 hectares (130 acres) of open water in the Patapsco River, which is a major tributary to the Chesapeake Bay. The mitigation is a comprehensive package of inwater and upland projects totaling over $20 million. The majority of mitigation is located adjacent to the DMCF in the 29 hectares (71 acres) of open water and 22 hectares (54 acres) of uplands that comprise Masonville Cove. The projects serve to enhance existing resources and provide improved habitat and increased wildlife use of the area, in addition to remediating contamination from historical industrial usage and dumping. The project will also provide opportunities for community-based environmental education to promote stewardship of the Bay waters for the local citizens. The mitigation projects discussed in this paper include shoreline stabilization and erosion control, reef creation and substrate improvement, and creation and enhancement of tidal and non-tidal wetlands. Design development concepts for these projects are presented. Following construction of the mitigation projects within the Cove, the area will be placed into a conservation easement and opened as an urban wildlife conservation area, environmental education center and natural park. The size and location of the Cove within Baltimore City make it a unique site for wildlife habitat and opportunity for the public to connect with the natural environment. The area is also a designated habitat protection area in the City and is in the Critical Area Resource Conservation Area.