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 130 acres of open water in the Patapsco River, which is a major tributary to the Chesapeake Bay. The mitigation approved for the project is a comprehensive package of inwater and upland environmental restoration projects totaling over $20 million, primarily located adjacent to the DMCF in 90 acres of open water and 54 acres of uplands that comprise Masonville Cove. The projects serve to enhance the environment and provide improved habitat and increased wildlife use of the area, in addition to remediating contamination from historical industrial usage and dumping. The projects discussed in this paper include over 2 miles of shoreline restoration and stabilization using created fringe marshes with sandy beaches and living shorelines behind offshore rock breakwaters, 90 acres of reef creation and substrate improvement, 15 acres of creation and enhancement of tidal and non-tidal wetlands, and 30 acres of upland capping of contaminated soil. Design development concepts for these projects are presented along with reports on the completed construction that describe practical measures used to achieve the goals of the restoration.