Explainer: Protecting NJ Coastal Development with Beaches, Walls and Dunes
Shore communities consider structural safeguards to make themselves safer from future storms
Before it was permanently settled and developed, storms and coastal erosion were never much of a problem along the Jersey Shore. But all that changed with a building boom beginning in the mid-19th and early 20th century. Railroads from New York and Philadelphia brought hordes of vacationers, and it wasn’t long before a resort industry sprang up.
“The major goal was to build as near the ocean as possible, and very little consideration was given to natural coastal processes in the planning or layout of the resorts,” notes the, a document drafted by the state’s Department of Environmental Protection in 1981. “Thus, very early the stage was set for erosion to threaten buildings and, therefore, to be a major problem along the New Jersey coast,” it says.
And it’s not just gradual erosion of beachfronts that’s a concern. Environmentalists say poor planning decisions -- particularly over the past 50 years -- have led to the state’s coastline being much more vulnerable than it otherwise would be to major storms like Irene and Sandy. Though many of the underlying problems persist, coastal communities have come up with several manmade solutions to provide a certain degree of protection in the short term. Here are the three main approaches they generally consider.
Beach replenishment/nourishment: Despite the boardwalks, rides, and carnival games, the Jersey Shore just wouldn’t be the same without its top attraction: its beaches.
But periodically replacing the sand that is constantly eroded by the waves isn’t just a necessity for the shore’s $19 billion tourism industry. It’s also a matter of public safety. For example, Atlantic City’s wide beach was credited with helping spare its boardwalk and casinos from the sort of damage that hit many other coastal areas.
It’s a complicated and expensive task, though, and it’s only temporary. Typically, sand is taken from a nearby beach or sandbar, an inland quarry, or dredged from a “borrow site” at the bottom of the ocean about two miles offshore before being shipped or trucked to land and spread by bulldozers and other machinery.
The work is done by the state’s Bureau of Coastal Engineering, in conjunction with the Army Corps of Engineers. Nourished beaches usually last several years before they need to be replenished, but extreme storms like Sandy can cause them to erode much faster.
Tim Dillingham who runs the American Littoral Society -- a coastal conservation group based in Sandy Hook -- says that while beach nourishment is a “softer approach” to protecting the coast than more extreme measures like building sea walls, it still has some downsides. Among his concerns are the impact on crabs and other wildlife that get buried with beach fill and the biological effect on fish habitats from places where the sand is dredged.
From an environmental standpoint, he says, “the problem is not the natural movement of sand on and off the beaches, but the fact that we’re trying to hold a static line of development on a coastline which naturally wants to move.”
Dunes: Dunes work by providing a reservoir of sand that can be sacrificed to absorb some of the wave energy during a storm. But not all dunes are created equal. The amount of protection a dune provides is based on its size and shape (width is more important that height), and even the size of the grains of sand, since grains that are too small might erode or blow away more quickly. Strange as it may sound, experts say that every time a dune or a beach washes away, it’s getting harder and harder to find large enough quantities of “good quality sand” to replace it.
In addition, natural dunes or man-made dunes made to mimic natural ones -- by planting vegetation and allowing for multiple hills and valleys rather than simply a single dune line -- are much less prone to erosion than simply mounding piles of sand along the coast. But even though they provide a higher, longer-lasting degree of protection, natural-style dunes aren’t being considered in the state’s current plans to fortify its 127 miles of coast because they’d take a much bigger footprint to create and would probably not be feasible unless development was forced to move back farther from the water’s edge.
Sea walls: Manmade structures like the rock and concrete wall that runs the length of Sea Bright or the steel wall currently planned for Mantoloking may seem like a surefire way for a community to protect itself from the ferocity of the ocean, but they come with a large price tag, and they, too, have their shortfalls. One criticism is that the hard surfaces of sea walls tend to reflect back the energy of the waves, causing beaches to erode even faster than they otherwise would, leaving only deep water in their place. So environmentalists clarify that while sea walls protect development along the coast, they do so at the detriment of the coastline itself.
The other main concern is that waves that slam into sea walls have a tendency to run down the length of those walls until they reach the end, possibly exacerbating flooding in adjacent communities. So unless a wall was built along the entire coast, there would always be a neighboring town or city that might suffer the consequences.
Other perspectives: There’s also a fourth option worth mentioning -- a plan recently proposed by a team in the Rebuild by Design Competition to10 to 12 miles off the coasts of New York and New Jersey to provide storm protection for the existing barrier islands and the coast. Though the idea could probably work in theory, cost estimates for the project range from $10 to $12 billion, and the logistical engineering challenges are so enormous that it seems unlikely that the project could ever be built.
Though each of these approaches has its advantages, in the end, none of them are entirely permanent or without their challenges, and they certainly don’t come cheap.
When discussing structural measures to harden the coast, Dillingham says environmentalists are clear to draw a distinction between just who would benefit.
“The goal of all these public programs and all the spending of these millions of public dollars is about protecting that real estate that’s right along the edge of the coast,” he says. “That’s a different goal than to say, ‘We want to protect the coastline and the beach environment for its value in supporting offshore fisheries or providing a recreational resource for the public of New Jersey who doesn’t happen to be lucky enough to own waterfront property.’” Difficult as it may be, he believes the best solution in the long term would be for people to move away from the water’s edge.
“If there was no development in these coastal areas, we wouldn’t have a problem,” agrees Chris Sturm, Senior Policy Director at NJ Future, a “smart growth” advocacy group. “Storms could happen, and the natural systems would be damaged but recover. People wouldn’t be affected. Properties wouldn’t be damaged,” she says, “So in large part, it’s a land-use problem that we have.”