Stricter building standards will change the bayfront after Sandy
Oceanfront homes cost a lot to build in New Jersey, and there’s a reason for that.
Yes, the cost of land is astronomical, but construction costs are also high. That’s because as the flood risks of living along the ocean became better understood, building codes were strengthened to require that houses be built to withstand the energy of battering waves during the most severe of storms.
For many wanting a slice of waterfront paradise, living along the bay was the more affordable option — one that came with a flood risk that has seemingly been forgotten over the years.
But in the wake of Hurricane Sandy, when bayfront properties were hit hardest by flooding, the question of how to protect these houses is getting increased attention. And as scientists and engineers kick around ideas on the best way to minimize risk, one thing is becoming increasingly clear: The look of South Jersey’s bayfront areas is likely to change considerably in coming years.
Engineers already have mastered a simple, if expensive, solution to protecting oceanfront property: Build a large enough sand dune with a wide enough beach, and the areas behind the structure can withstand hurricanes and storms.
“The bay is entirely a different story,” said Jeff Gebert, chief of the coastal planning section of the Army Corps of Engineers, Philadelphia district. “Unlike on the oceanfront where there is an expensive simple fix, we don’t even know if there is a simple, if expensive, fix on the bay side.”
At least twice as many homes line the bays as they do the ocean in South Jersey. But the low-to-the-ground ranchers and cape cods that are prevalent in these middle-class areas likely will become an endangered species as flood risks and post-Sandy building codes force new requirements upon property owners in order to rebuild or obtain affordable flood insurance.
“Clearly the construction standards are a huge part of (the future), said Mark Mauriello, a former commissioner of the state Department of Environmental Protection. “If you can build and rebuild homes that are higher, that can address possible wave action. That’s really important.”
Apart from building codes, some engineers, scientists and policy experts say it is also time to re-envision bayfront shorelines by restoring elements of the back bay ecosystem — such as salt marshes and oyster reefs — as a way to improve storm protection naturally.
That type of storm protection won’t necessarily keep the water out, but it will reduce the wave energy and the speed of a storm surge, said Thomas Herrington, a coastal engineering professor with the Stevens Institute of Technology.
By incorporating “living shorelines” along bayfront neighborhoods, carefully placed sand, rocks, grasses and even oyster reefs act essentially as speed bumps to storm-driven waves, said Danielle Kreeger, staff scientist with the Partnership for the Delaware Estuary, which has worked to develop pilot living-shoreline projects as part of a wider effort to help restore natural environments. The newly created habitat also improves water quality and increases the number of aquatic creatures living in the immediate area.
“What (living shorelines) do is they reduce the waves on top of that water. If a wave comes in and hits a bulkhead, it bounces back and up,” Kreeger said. “When a wave hits a natural vegetated edge or an oyster reef, it doesn’t bounce back. It absorbs it.”
Numerous studies over the years have developed a variety of formulas for how much wetland is needed to absorb or slow each foot of storm surge.
Old studies, including an Army Corps of Engineers paper from 1963, generally estimate that as much as 3 miles of marsh is required to reduce a storm surge by 1 foot. But other studies have found that the storm’s dynamics, as well as other geographical features and existing infrastructure, play a major role in how effective wetlands are at reducing the surges inland.
In other words, even if homeowners filled in several feet of shallow bay bottom in front of their bayfront homes with mud, mussels and grasses, it would not be enough to slow down the force from a 4-foot storm surge, the height of the surge in South Jersey during Sandy and possible in strong northeasters. But it could help reduce the damage, Herrington said.
Living shorelines are not new to the East Coast. Maryland has mandated since 2008 that property owners who want to build a bulkhead or seawall must meet certain criteria for a permit, including proving that a living shoreline is not viable for their property. Virginia’s legislature in 2011 passed a measure to encourage the use of living shorelines and streamline permits to develop them.
As part of a broader emergency order to help speed rebuilding efforts, New Jersey’s DEP last week announced it would streamline permits for living shoreline projects, making it easier for the projects to be built. State environmental advocates long have pushed for the measure, spokesman Larry Hajna said.
Prior to the order, rebuilding and restoring wetlands, especially in more developed areas, faced many regulatory hurdles due to strict rules under the Coastal Area Facility Review Act that equally protected shallow water habitat and salt marshes, Mauriello said.
The primary focus in the next few years needs to be raising houses and buildings well above flood levels, Herrington said, and engineers need to look at “softening the edges” in future projects.
But Mauriello said there’s also the concern that as sea levels continue to rise, wetlands won’t be able to move with conditions because of existing development, causing the grasses to drown.
There may also be the stark reality that, in the face of sea level rise, there may be areas where the flood risk is so high that homeowners and government at all levels may determine to abandon those properties and, instead, let nature take over, said Ken Miller, geology professor and sea level rise expert with Rutgers University.
Bays have naturally evolved to include a vast network of wetlands. These areas act as an ecological nursery for fish and wildlife and as giant sponges for storm surges and extreme high tides. However, as development along the bays became popular in the 1960s, so, too, did the filling in of these wetlands to create lagoon communities. And to maintain the line between the water and the land, bulkheads were installed and became the preferred aesthetic for residents.
But these two issues contribute to why protecting property along the bay is so complicated, Herrington said. The bulkheads and other hard structures can’t absorb wave energy during a storm, and the hard structures also create a bathtub effect — once the water reaches the top of the bulkhead, it spills over. Any low spot or break in the bulkhead is the proverbial hole in the dike.
This scenario played out in many bay communities during Sandy, including Brigantine. The highest bulkheads in Brigantine are 9 feet above mean low water, but Sandy’s surge was measured on the island at more than 10 feet, City Engineer Ed Stinson said.
But a bulkhead’s primary role is not flood control, it is to establish a line between the land and the water, Gebert said. Most bulkheads are privately owned and are built to different standards because ordinances vary from town to town. Older bulkheads were installed when there were no height requirements. Ordinances can dictate a minimum height, a maximum height, building material and whether a bulkhead is even required. “You’re dealing with a hodgepodge of construction types,” Gebert said.
Still, many towns with bay communities will look in the short term to existing techniques to protect their neighborhoods.
Brigantine, for example, may consider revising its bulkhead ordinance, Mayor Philip Guenther said. His city’s ordinance already is one of the strictest in the region, requiring the tops of new bulkheads to be at least 9 feet above mean low water. That ordinance, enacted in 1979, was designed with the idea that bringing bulkheads into compliance would be a process taking decades. Currently, only about half of the privately owned bulkheads in Brigantine meet the requirement, Stinson said.
The city also is considering strategically buying out select waterfront properties to strengthen its existing municipal infrastructure, Guenther said.
Following Sandy, Stinson, Guenther and other city officials are looking at where the hurricane’s floodwaters surged onto the island from the bay and trying to find fixes. One complicated spot is a boat ramp next to the Elks Lodge on Bayshore Avenue. The boat ramp acts almost as a channel sending floodwaters into a parking lot and on to low-lying Bayshore Avenue, which is a primary evacuation route for many residents living on the north end. An idea may be to create a type of flood gate that automatically closes when the water rises, Stinson said.
Living shoreline projects — either large or small — don’t seem to fit with the needs of the city, which has a highly urbanized bay shoreline, Stinson said. Oyster reefs, for example, could get in the way of boat traffic, and there already are expansive wetlands just across the channel from the island, he said.
Re-imagining the shoreline doesn’t mean that we look at it as it looks right now, said Tim Dillingham, executive director of the American Littoral Society.
“There’s a limited range of options because we’ve developed so densely and right up to the edge of the water so much along the coast that there isn’t a lot of maneuvering room,” Dillingham said. “We have to take a very long-term view of this. It didn’t take us a day to get into this situation, to build these communities, to overdevelop the coast in a way that makes us vulnerable, and we’re not going to get out of it in one day.”
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