Mispillion Inlet

USACE DNREC team up on Mispillion Inlet navigational maintenance and habitat restoration project

Mispillion Inlet includes a harbor, navigation structures and a fragile yet vital beach habitat along the coast of Delaware. In 2009, the Corps and the Delaware Department of Natural Resources and Environmental Control (DNREC) collaborated to repair and maintain the navigational structures while restoring the beach habitat for horseshoe crabs and migrating shorebirds.

Mispillion Harbor is known for its high densities of horeshoe crabs in this region but also for the shorebirds that feed on them. A sandy beach at the mouth of the Mispillion River, which was created during the past construction of the breakwaters and jetties, provides habitat for the spawning crabs, and foraging birds. But the beach was severely eroding, and in 2008 DNREC officials began feasibility studies of restoration projects.

Shortly thereafter, a breach was discovered in the breakwater protecting Mispillion Harbor. The tidal flow through the breach was identified as the primary cause of the beach erosion. In response, the Corps Philadelphia District and DNREC initiated a joint repair and restoration project.

As the navigation channel was dredged for regular maintenance in September 2009, the sediment was deposited on the beach to mitigate the erosion and restore the habitat. Concurrently, a borrow site adjacent to the south jetty was identified and 25,000 yd3 of sand were pumped to the damaged breakwater. This sediment filled the breach that was accelerating the beach erosion.

This successful project demonstrated the Corps commitment to work with partner agencies to efficiently and effectively solve challenges in the coastal zone.


Reviewed 27 Sep 2016

Assateague Island

Assateague Island
Source: IAN Image Library

Beneficial Uses of Dredged Material

Habitat restoration and structural repairs are examples of the beneficial uses of dredged material. Combining such projects increases efficiency and meets multiple objectives, thereby demonstrating the Regional Sediment Management approach to coastal management.