Shore Towns Consider Sea Walls For Future Storms [AUDIO]
In an effort to protect shore communities from future storms, many are opting in favor of artificially constructed sea walls to act as a buffer.
While the premise of a large steel curtain may seem ideal in protecting against Sandy-like storm surges, environmentalists and coastal engineers say it’s not a cure-all.
Jon Miller, professor of coastal engineering at Steven Institute of Technology, believes sea walls can serve a means of protection but won’t work as the primary buffer against the ocean.
Sea Walls Can Accelerate Erosion
“What we’ve learned from some of the mistakes in the past is you can’t build them on a beach as the primary line of defense because otherwise it will accelerate the erosion [at the base of the wall]. ”
Environmental groups are claiming the walls actually speed up erosion and sand loss because the energy of the waves smacks up against the steel and is channeled upward and downward. Washing away the sand at the base of the wall.
However, Miller says, working in tandem with other factors, the walls are effective.
“If there is a wide beach in front of it and the sea wall itself serves as last line of defense or an emergency mechanism that becomes active in a big storm, then they can be pretty effective.”
Bay Head Using Sea Walls Effectively
The professor cites the Ocean County Borough of Bay Head as an example of a municipality that has utilized sea walls effectively.
“75% of that town was protected by a sea wall that dated back to the 1962 storm and to be honest with you I didn’t even know it was there and I’m sure residents didn’t know it was there because it was buried under the sand, there was a beach in front of it and a sand dune on top of it.”
He notes during Sandy, the wall was exposed and there was evidence it protected some of the homes behind it.
Belmar is considering construction of an engineered dune system involving 30 foot sheets of steel being driven 26 feet into the sand at the beach side of the boardwalk. Belmar Mayor Matt Doherty says those walls would then be covered with sand and dune grass.
Doherty says the 1.3 miles would create an “artificial bulkhead” that could act as a barrier against future storms.
Building Smarter After Sandy
“Simply putting dunes back the way we had them before doesn’t seem to make a lot of sense. After Sandy, we need to build smarter than we did in the past.”
The stability of the beach is vital when considering a sea wall according to Miller. Bay Head hasn’t needed any major replenishment projects, but notes it might not be ideal for all parts of the shore.
“If you build a sea wall on a beach that is already eroding at a fast rate, that’s when you really got to be concerned about it because you basically are going to have to provide some beach nourishment.”
Doherty notes as long as the storms are mild the artificial dune system wouldn’t need much upkeep. However, he says if a major storm does wash away most of the sand, paying to replenish the dunes is better than the alternative.
“We would much prefer to replenish sand than have to rebuild a boardwalk and pump millions of gallons of water out of our town.”
Belmar Waits for Funding
The mayor says the artificial dunes would go in conjunction with the borough’s 6.6 million modern boardwalk which is being built to FEMA specifications, as well as future beach replenishing and widening projects from the Army Corps of Engineers.
Early bids for Belmar’s proposed artificial dune system came in at $4.5 million from Sayreville-based Epic Construction (the same company building the borough’s boardwalk). However Doherty says while the boardwalk was built with the understanding that FEMA would reimburse the borough, the dune wall isn’t a certainty and they don’t want to move ahead before funding is secured.
‘It’s not prudent to start unless we have a solid source of funding.”
While sea walls can work with wide beaches and dunes to protect the seaward side of boardwalks, Miller says smart building codes, elevating structures, and good construction measures can determine what survives.