Sea-Level Rise LogoTo combat rising waters and storm surge in Atlantic City, N.J., the U.S. Army Corps of Engineers is building a $34-million seawall-like project—the Absecon Inlet Coastal Storm Damage Reduction Structure. Breaking ground in 2015, the project is mostly funded by $24 million from the federal government. Further, the Corps is studying how to reduce flooding from the city’s back-bay area, which won’t be helped by the Absecon Inlet project.

Along the Jersey Shore, from Sandy Hook to Cape May, sea level has risen 16 in. in the past century, compared to the national average of only one foot. Thus, Sandy’s surge added even more water, causing the region to flood 27 sq miles more than it would have in 1880.

The Absecon project includes construction of seawall components along areas of the shoreline that currently have no protection; also, it will restore parts of the city’s famous boardwalk that Sandy destroyed. Had the seawall been in place during the storm, damage would have been greatly mitigated, notes Stephen Rochette, spokesman for the Corps of Engineers’ Philadelphia District. To determine the best way to complete the project, the Corps and contractor J. Fletcher Creamer & Son modeled “a myriad of storm scenarios and variables to determine how various alternatives—seawalls, dunes, submerged reefs, bulkheads, for example—fare when it comes to reducing damages to infrastructure,” Rochette says. This approach allowed the team to choose the most cost-effective plan.

“After Sandy, the Corps and its contractor modeled “a myriad of scenarios” to develop the most cost-effective storm defense.”

– Stephen Rochette, USACE

The project was planned based on a 50-year economic period. The seawall’s top will be 16.4 ft above the mean sea level. 

The seawall sections span 1,340 ft, from Oriental Avenue to Atlantic Avenue, as well as another 400-ft section between Madison Avenue and Melrose Avenue. The project’s scope includes construction of a large stone barricade of marine “mattresses” and jetty stones fronting a steel sheet-pile wall. While progress was delayed due to winter weather in 2015-16, the project is now on track to be complete later this year. 

How Engineers Are Preparing for Sea-Level Rise