U.S. Army Corps of Engineers reveals findings of Back Bays study

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The U.S. Army Corps of Engineers recently released a draft report for the Nassau County Coastal Storm Risk Management Study, which outlines a tentatively selected plan that includes East Rockaway and Lynbrook. It would include elevating more than 14,000 homes and flood-proofing more than 2,500 industrial and commercial properties across the South Shore to mitigate the risk of flood damage during storms.

Before moving forward, the plan must be approved by several authorities, including Congress, after engineers engage with the community to gather feedback on their ideas.

“This is a tentatively selected plan, and it’s part of the process where we release our findings and socialize with the public and stakeholders and affected constituents of the proposed plan,” said Scott Sanderson, a project manager for the Army Corps of Engineers who works in coastal planning in its Philadelphia District. “This is part of an ongoing process to get feedback on the findings and really evaluate the feelings on it and what revisions may need to be made as we go forward, or what refinements need to be made depending on the types of comments we get.”

The Army Corps, in partnership with the state’s Department of Environmental Conservation and the county, is conducting the feasibility study in Nassau’s Back Bays area, which includes all the tidal bays and estuaries connected to the South Shore. The study is investigating possible solutions to reduce damage from coastal storm flooding, which affects population, infrastructure, facilities, property and ecosystems, especially after Superstorm Sandy.

The study, begun in 2016, cost $6 million, half of which the DEC and federal programs funded. The estimated cost to elevate homes is $3.8 billion, funding for which has not been finalized because the plan is still tentative. Sanderson said the engineers hoped to finalize the study by June 2023, and noted raising homes is voluntary for homeowners and many may opt out, so a timeline is unknown at this time.

“The Nassau County Back Bays Study outlines important strategies to protect our South Shore from the next major coastal storm,” County Executive Laura Curran said in a statement. “We need to continue hardening our shorelines and flood-proofing homes, businesses and critical infrastructure in order to ensure our residents’ safety in the years ahead.”

The study team prepared the draft report to present findings and technical analyses and outline the plan. The document describes engineering, economic, social and environmental analyses, and includes:

 

Elevation of 14,183 homes across the county.

Flood-proofing 2,667 industrial or commercial structures from the ground up. Flood-proofing involves sealing all areas of a structure from the ground level up to about 3 feet. The measures would help make walls, doors, windows and other openings resistant to surge waters.

The study team will continue to evaluate natural features, as well as local floodwalls to protect critical infrastructure, such as power stations and wastewater treatment plants, including the Bay Park Water Reclamation Facility, to help communities recover faster and improve resilience.

According to Sanderson, the engineers evaluated other flood-risk management measures during the study, including storm-surge and cross-bay barriers, floodwalls and natural features, but hydraulic modeling indicated that storm-surge and cross-bay barriers did not significantly reduce water levels and, in some cases, exacerbated flooding in certain areas.

“It’s extremely important,” Sanderson said. “This particular study area was identified as a high-risk, vulnerable area, so this is a very important study, and the feedback from the public . . . it’s extremely important to get all that feedback over the next couple of months.”

The tentative plan has been lauded by elected officials, including State Sen. Todd Kaminsky, a Democrat from Long Beach.

“It’s been nine years since Superstorm Sandy, and South Shore communities need meaningful storm protection,” he said. “This study, while welcome, needs to become more than just paper and evolve into funding and real deliverables as soon as possible. This must go from concepts to actual, physical storm hardening — and that’s what matters as sea levels rise and storms intensify. Time is of the essence.”

The Army Corps will host public hearings to gather feedback on Sept. 29 and Oct. 6. To learn more, visit nap.usace.army.mil. Questions can also be submitted until Oct. 18 by email to PDPA-NAP@usace.army.mi.