Army Corps releases draft report for Nassau County Back Bays study

USACE Philadelphia District
Published Aug. 27, 2021
Image of report cover shows satellite image of Hurricane Sandy

Nassau County Back Bays Study Draft Report

The U.S. Army Corps of Engineers has announced the release of a draft report for the Nassau County Back Bays Coastal Storm Risk Management Study. The report outlines a ‘Tentatively Selected Plan’ framework, which includes the elevation of more than 14,000 residential structures and dry flood proofing of more than 2,500 industrial/commercial properties to reduce the risk of flood damages associated with storm surge. 

It’s important to note that the plan is subject to change. It has not yet been approved by higher authorities, including Congress, and has not been funded for implementation at the federal or state level. 

The Army Corps, in partnership with the New York State Department of Environmental Conservation and Nassau County, is conducting the feasibility study within the Nassau County Back Bays area.  The study area includes all the tidally influenced bays and estuaries hydraulically connected to the south shore of Nassau County on the Atlantic Ocean.  The objective of the study is to investigate problems and solutions to reduce damages from coastal storm-related flooding that affects population, critical infrastructure, critical facilities, property, and ecosystems. 

“The Nassau County Back Bays Study outlines important strategies to protect our South Shore from the next major coastal storm. We need to continue hardening our shorelines and floodproofing homes, businesses, and critical infrastructure in order to ensure our residents’ safety in the years ahead,” said Nassau County Executive Laura Curran.  “Thank you to Senator Schumer for fighting to make sure this study was funded to completion. I look forward to working with our representatives in Congress on the next steps.” 

“The draft Nassau County Back Bays Coastal Storm Risk Management Study report released today sustains our efforts to obtain community guidance on plans, programs, and projects to optimize coastal resiliency along Nassau County’s southern shore,” said New York State DEC Commissioner Basil Seggos.  “With our strong and collaborative partners—the U.S. Army Corps of Engineers, Nassau County, local governments, and community stakeholders—this draft report includes potential strategies to protect our coastal communities from severe storms and weather events driven by our changing climate.”        

“Thank you to New York State and Nassau County for their partnership on this critical study,” said USACE Philadelphia District Commander Lt. Col. Ramon Brigantti. “We look forward to receiving feedback from the public on the draft report and continuing to collaborate with stakeholders as the study moves forward.”

The study team prepared the draft Report to present findings, technical analyses, and outline a Tentatively Selected Plan. The document describes engineering, economic, social, and environmental analyses. The Tentatively Selected Plan includes the following conceptual features:

  • Elevation of approximately 14,183 residential structures
  • Dry flood proofing of approximately 2,667 industrial/commercial (non-residential) structures from the ground surface up to 3 feet above ground. Dry flood proofing involves sealing all areas from the ground level up to approximately 3 feet of a structure.  Dry flood proofing measures help make walls, doors, windows, and other openings resistant to penetration by storm surge waters.
  • Additionally, the study team is continuing to evaluate natural and nature-based features as well as potential localized floodwalls to protect critical infrastructure (such as power stations and wastewater treatment plants) to help communities recover faster and improve resilience.

USACE evaluated other flood risk management measures during the study, including storm surge barriers, cross bay barriers, floodwalls, and natural and nature-based features. Hydraulic modeling indicated that storm surge barriers and cross-bay barriers did not significantly reduce water levels and, in some cases, exacerbated flooding in certain areas. Modeling also showed the study area could experience $1 billion in average annual flood damages from 2030 to 2080 with no federal project in place.

The Army Corps will host virtual public meetings to discuss the report and answer questions in September and/or October 2021. To view the report or virtual public meeting instructions, visit

In accordance with the National Environmental Policy Act, the public, agencies, and stakeholders are invited to provide comments by October 18, 2021.

  • Submit comments by email:
  • Submit comments by mail: U.S. Army Corps of Engineers Planning Division, Wanamaker Building, 100 Penn Square E. Philadelphia PA 19107

Steve Rochette

Release no. 21-023