Concerns About Effectiveness Of Building Seawalls
By Phil Gregory, WBGO News
January 22, 2013
Some New Jersey towns are considering building seawalls to provide protection from future storms. There are some concerns about how effective that might be.
New Jersey Sierra Club director Jeff Tittel says seawalls don’t work.
“When there are major storms instead of the water dispersing its energy over the dunes it ends up actually rising higher and then going either around the seawall or if the storm is high enough it will just go over it. It actually doesn’t make things safer. It’s a false sense of security.”
Environmentalists say the waves that crash against seawalls can lead to faster beach erosion.
Belmar Mayor Matt Doherty says a structure to help protect the town might still be worthwhile.
“When a storm surge comes it does scour away the sand, but we’d prefer to lose sand than losing a boardwalk and the houses that were taken in Sandy. It’s one thing to replenish sand. It’s much more difficult to rebuild a boardwalk and to rebuild homes.”
Jon Miller is a professor of coastal engineering as Stevens Institute of Technology. He says seawalls can be effective unless they’re too close to the water or the beach gets too narrow.
“There’s been a long history to people not wanting to put any structures on the oceanfront because it exacerbates erosion. The reality is that’s only true if the beach is narrow enough where the waves actually hit the structure on a regular basis.”
Stewart Farrell is director of the Coastal Research Center at Richard Stockton College. He does not believe constructing seawalls are worth the expense.
“If you’re going to deal with ocean waves you need a double sheeted wall with closely spaced pilings and several levels of whalers to tie it all together you’re looking at substantial money. Then you throw in concrete or rocks as a tow protection, you’re suddenly up in the ten thousand dollar a foot range.”