US Army Corps of Engineers
New York District

Nassau County Back Bays, NY

Nassau County Back Bays, NY Coastal Storm Risk Management Feasibility Study

The south shore of Nassau County is at increasing risk of natural hazards such as coastal erosion, coastal wave action, storm surge, flooding, and severe winds caused by coastal storms. This is largely due to the area’s geography, topography, and land use patterns. Many of the tidally influenced areas of Nassau County are at a low elevation, densely developed with residential and commercial infrastructure, and subject to flooding during high tides and storms. Much of the shoreline has been physically altered by people, creating a more stationary system than would normally exist in a barrier island and back bay system. This has resulted in changes to the natural sediment transport processes that has resulted in an impact on sensitive ecosystems and species that thrive in the area. These problems were highlighted by Hurricane Sandy, which made landfall in October 2012 and severely impacted the area. Over 1.3 million Nassau residents were affected by the storm. In response to the destruction caused by the storm, the U.S. Army Corps of Engineers (USACE) completed the North Atlantic Coast Comprehensive Study (NACCS). The NACCS January 2015 final report identified areas along the Atlantic Coast at high risk of coastal storm damage. The portion of southern Nassau County influenced by back bay flooding was identified as one of these high risk areas. The USACE New York District, New York State Department of Environmental Conservation (NYSDEC), and Nassau County have partnered to investigate ways to reduce coastal storm risk in this area. This includes communities in the Town of Hempstead and Town of Oyster Bay located within southern Nassau County, as well as the City of Long Beach, that front Hewlett Bay, Middle Bay, Jones Bay, South Oyster Bay, and connected creeks, channels, and minor waterbodies (the "Nassau County Back Bays"). An interagency agreement between the USACE, NYSDEC, and Nassau County was signed in October 2016 in order to begin the Nassau County Back Bays coastal storm risk management feasibility study.

The purpose of the Nassau County Back Bays feasibility study is to investigate potential ways to reduce the risk to people, critical infrastructure, and businesses caused by coastal storms such as Hurricane Sandy. The study team is investigating potential solutions that could reduce flood risk in ways that support the long‐term resilience and sustainability of communities and the environment, and that reduce the economic costs and risks associated with coastal storm damage. As of April 2017, the study team is working to scope out the study, and will start an analysis of potential risk reduction measures and alternative plans. The team will look into the feasibility of a number of measures, which includes but is not limited to storm surge barriers, bulkheads, floodwalls, levees, seawalls, shoreline stabilization, stormwater improvements, beach nourishment, living shorelines, wetland restoration, and the elevation, floodproofing, and/or relocation of structures.

In 2018, we completed important technical work that will inform the investigation of potential solutions to flooding. New information into hydrodynamics (the study of the movement of water), and an examination of who is at risk of flooding is now complete. A summary of this technical work and the plan selection process will be shared in a public report and during upcoming community meetings in 2019.


To learn more about the Nassau County Back Bays feasibility study, please visit the study fact sheet or email the study team at