Incorporation of coarse-grained dredged material into marsh and shoreline restoration projects in coastal New Jersey

Abstract

Millions of cubic yards of sediment are dredged every year in coastal New Jersey for the operation and maintenance of an extensive marine transportation system stretching from the New Jersey Harbor south along the Atlantic Coast from Sandy Hook to Cape May and north up the Delaware River. Dredged material from these public and private projects has been managed using a variety of placement approaches and technologies, from open-water disposal to landfilling to construction materials. For the past several decades, the State of New Jersey has advocated for and implemented a policy of beneficial use of dredged material rather than its disposal. The New Jersey Department of Transportation’s Office of Maritime Resources (NJDOT/OMR) is the lead state agency for research and implementation of beneficial use statewide. NJDOT/ OMR is also responsible for the recovery of the 200-mile network of shallow-draft navigation channels along the Atlantic coast of New Jersey that was damaged by a series of severe coastal storms, most notably Superstorm Sandy in 2012. For the past decade, considerable effort has been made to develop methods that use clean dredged material from the Atlantic region to rebuild and improve coastal features such as marshes, dunes, and beaches, thereby retaining the sediment in the ecosystem. Although there have been a number of successful beneficial use projects, concerns remain about the long-term sustainability of the program due to high cost, timelines, scalability, habitat sensitivity, resiliency, aesthetics, and other factors. This paper explores some of these issues and proposes solutions. It focuses on the use of available coarse-grained material as a way to provide resiliency to these restored features while increasing scale and efficiency, protecting aesthetics, and providing increased habitat value.