US Army Corps of Engineers
Philadelphia District & Marine Design Center Website

Nassau County Back Bays Coastal Storm Risk Management Study

The U.S. Army Corps of Engineers and study sponsors (New York State Department of Environmental Conservation and Nassau County) participated in a webinar with various elected officials in January 2021 to discuss aspects of the study and current findings. The Army Corps plans to host meetings with all stakeholders and a broad audience at a later date. The Study Team has conducted extensive engineering, economic, hydrologic, hydraulic, and environmental analyses and has evaluated numerous alternatives.

Currently, the Study Team is focused on non-structural alternatives (to include elevating and floodproofing structures), floodwalls in vulnerable areas, and alternatives to protect critical infrastructure (such as power stations and wastewater treatment plants) to help communities recover faster and improve resilience.

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 longā€term resilience and sustainability of communities and the environment, and that reduce the economic costs and risks associated with coastal storm damage. 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.

Potential Measures Under Consideration

Non-structural management measures are intended to reduce consequences flooding has on assets exposed to flood risk, as opposed to a structural measures that alter the characteristics or the probability of occurrence of flood risk. Elevating a structure is an example of a non-structural measure.
Natural and nature-based features such as living shorelines are potential solutions under consideration as part of the study. Natural coastal features take a variety of forms, including reefs, barrier islands, dunes, beaches, wetlands, and maritime forests.
Floodwalls are a measure under consideration as part of the study. Floodwalls are vertical structures constructed with steel or concrete that are used to reduce risk of flooding. Floodwalls are most commonly used where there is limited space for large flood protection measures.
Storm surge barriers consist of a series of movable gates that stay open under normal conditions to let navigation and flow pass but are closed when storm surges are predicted to exceed a specific water level. This is one of several measures under consideration as part of the study.
Bulkheads are vertical structures with the primary purpose of retaining land that adjoins a water body. Bulkheads, unlike floodwalls and levees, are generally constructed at or near the existing grade and flood risk management is of secondary importance.

Study Area Map


U.S. Army Corps of Engineers
Planning Division

100 Penn Square E.
Philadelphia, PA 19107

Video of June 27 2019 Public Meeting in Long Beach

Video of June 12 2019 Public Meeting in Freeport