US Army Corps of Engineers
Philadelphia District & Marine Design Center

Delaware Coastal Storm Risk Management Program

Delaware Coastal Storm Risk Management Program Background

For more than 20 years, the U.S. Army Corps of Engineers Philadelphia District has worked in partnership with the Delaware Department of Natural Resources and Environmental Control (DNREC) on coastal storm risk management projects.  The District has constructed six coastal storm risk management projects along the coastline of Delaware (including Broadkill Beach on the Delaware Bay coastline). These projects are designed and built to reduce storm damages to infrastructure. Projects involve dredging sand from approved offshore borrow sites and pumping through a series of pipes onto the beach. The sand is then graded into a dune and berm design. Projects are periodically nourished with additional sand pending available funding. 

  • Broadkill Beach: initial construction in coordination with the Delaware River Deepening completed in 2016. Design includes 100 foot berm backed by a dune at elevation +16 feet. 
  • Lewes-Roosevelt Inlet: initial construction completed in 2004 with several nourishment/repair projects in subsequent years. Design includes a 100-foot berm backed by a dune at elevation +14 over a total project length of 1,400 feet at the northern/eastern end of Lewes. In January of 2016, the USACE Philadelphia District completed a repair/renourishment via truckfill.  
  • Rehoboth & Dewey: initial construction completed in 2006 with several nourishments/repair projects in subsequent years. Design includes 150-foot berm back by a dune at elevation +13.2 feet. The USACE Philadelphia District most recently renourished/repaired the project in 2016 and anticipates renourishing the project in the fall/winter of 2019/2020.   
  • Indian River Inlet Sand Bypass: The purpose of this project provides for construction of a sand bypassing beach plant, and operation of the plant for periodic nourishment of a feeder beach. 
  • Bethany & South Bethanyinitial construction completed in 2008 with several nourishments/repair projects in subsequent years. Design includes 150-foot berm back by a dune at elevation +16 feet.  The USACE Philadelphia District renourished/repaired the project in 2018. 
  • Fenwick Islandinitial construction completed in 2005 with several nourishments/repair projects in subsequent years. Design includes 200-foot berm back by a dune at elevation +17.7 feet. The USACE Philadelphia District renourished/repaired the project in 2018. 
  • Port Mahon: project was authorized by Congress in 1999, but has not been constructed. 

Dune System Animation During Potential Storm Event