Army Corps calls for more flood protection on N.J. back bays

A massive, two-year Army Corps of Engineers study found more attention needs to be paid to back-bay flooding on New Jersey’s barrier islands.

Dunes on the Atlantic coast can be maintained in a “relatively robust” condition even with six feet of sea level rise on Long Beach Island, the sample barrier island studied in the report, the authors found.

Concern should focus instead on back bays, where inundation from sea level rise will be felt first.

“Although the dunes and the ocean front get lots of attention because those are the places where the boardwalks are and where lots of our tourism is focused, it’s really been more and more recognized post-Sandy that it’s the back-bay communities [where] we really have to focus our risk and hazard mitigation attention,” said Lisa Auermuller, who works with shore communities to develop resilience plans from the Rutgers-affiliated Jacques Cousteau Research Reserve in Tuckerton, N.J.

“Those are going to be the areas that are on the front line of seeing the most inundation effects,” Auermuller said.

The U.S. Army Corps of Engineers North Atlantic Coast Comprehensive Study Report documents a congressionally mandated two-year study that evaluated coastal storm and flood risk in the Northeast in the wake of Hurricane Sandy.

The report outlines a nine-step coastal storm risk management framework for state and local leaders to plan for resilience and outlines a variety of different ways communities can make themselves more resilient. 

“We did not select a plan, one plan for the entire Northeast, or for any specific area,” said the Army Corps’ Amy Guise. Instead, she called the work ahead on increasing flood preparedness a “shared opportunity” for community members and elected officials.

On barrier islands, the report called the need to provide defenses on the bayshore “relatively urgent,” as just one foot of sea level rise would cause regular flooding of well over half of the island at high tide.

Auermuller said that reflects conversations she is having with community leaders on the shore.

“It’s not just about the oceanfront anymore, there’s actually some really big issues that we have to focus on in the back bay, and they need to get the same level of attention that the more ocean side beaches are getting,” Auermuller said.

The report outlined a variety of options for reduing back-bay flooding: building flood defenses on the back bays, changing drainage systems to prevent water backing up during high tides, and elevating property and roads systems to limit flooding damage.

Other measures outlined included making natural infrastructure changes, such as developing salt marsh systems, building oyster reefs and planting submerged aquatic vegetation, like sea grass meadows, to buffer land from coastal flooding.