"Can Artificial Sand Dunes Save The Jersey Shore?"
CREDIT: Liz Van Steenburgh
On the morning after Superstorm Sandy slammed into the eastern seaboard, the New Jersey coast was paralyzed. Most people sat stunned, not sure just what had happened or what to do next. For some people, stranded in their homes by high water, there was nothing to do but sit and wait, hoping that help would come soon.
Stewart Farrell was one of the few on the move. As dawn broke over the storm-ravaged state, where 346,000 homes had been damaged or destroyed during the night, Farrell was getting ready to go to the beach.
Farrell is not a surfing fanatic hoping to catch the last of the storm’s wave action or a natural disaster tourist who enjoys taking pictures of destruction. He’s a scientist, and knowing the storm must have dramatically altered the coastline, he was getting ready to assess the performance of New Jersey beaches in the wake of a test no one thought they would be expected to endure.
“Sandy was many things,” said Farrell, director of the Richard Stockton College of New Jersey’s Coastal Research Center (CRC). “It was the destroyer of homes, the devastator of lives, and a giant laboratory experiment running in real time, testing the strength of the New Jersey coastline.”
The Jersey Shore has been routinely reinforced on a large scale since the 1980s. Of its 127 miles, 90 are developed and 55 percent of those, or about 53 miles, are routinely replenished by the Army Corps of Engineers. Over the past 25 years, 73.2 million cubic yards of sand have been dumped along the water’s edge to hold the shoreline against the Atlantic Ocean. In some areas, the local municipalities have used the sand to widen their beaches while other towns have built artificial dunes or some combination of the two.
Every year, twice a year, Farrell and his team survey 105 sites on the Jersey coasts, from Sandy Hook in the north to Cape May in the south. CRC has 27 years of mile-by-mile data on the shifting position of the shoreline, fluxes in sand volume and dune dynamics.
“Sandy showed us, without a doubt, what kind of configuration of dunes and width of beach worked best,” said Farrell, who spent the weeks from Halloween to Thanksgiving out on the shore at the survey sites, measuring the storm’s impact.
CREDIT: Glynnis Jones
The takeaway message from Farrell’s post-Sandy surveys was simple: dunes work and living on a unprotected coastline in Jersey does not. Despite this, however, dunes, which are essentially glorified piles of sand, are taking center stage in a battle over how to rebuild from the storm. These humble heaps of ground down rock and shell are fueling lawsuits, emptying federal pockets and, at the same time, are being heralded as a solution for coastal erosion.
The towns that weathered the storm the best, Harvey Cedars, Surf City and Brant Beach, all along Long Beach Island, had massive dune systems, 22 feet high, and set back from the high tide mark by an additional 300 feet. While the ocean claimed half of the beach here, and made off with at least one third of the total sand volume of the dunes, the dunes were never breached and the homes and businesses behind them were spared the brunt force of the storm.
On the other end of the spectrum were places like Mantoloking, which had no dune system. All 521 buildings on the island were either damaged or destroyed.
The lessons learned from Sandy are more subtle, however, than “build dunes,” which has been the dominant message from Gov. Chris Christie’s office in the months following the storm.
“Even towns with dunes had essentially no protection if the actual beach was narrow,” explained Farrell. “And if a public path was cut through the dunes at street level, or some homeowner had trampled down their own private path, forget about it. The dunes might just as well not have been there.”
Natural dunes are created by winds blowing off the ocean and take decades to form. As they build up gradually over time, plants take root in the dune at each year’s level, creating an intricate web of root systems that bind the sand together and hold it in place. Most natural dunes are wider and lower than artificial dunes — more like giant speed bumps than a wall — and form at least one hundred feet above the high tide mark.
Artificial dunes, on the other hand, occur wherever the town decides they need them, and consist of a core, usually rocks, sandbags or timber, that is covered over with sand to the desired height. Artificial dunes may have grass planted on top to mimic the beachy aesthetic, but unlike in a natural dune, the grass serves no structural purpose. The hard core of an artificial dune can actually work against it. When enough sand is eroded from the base of the dune and the rock or metal core is exposed, the energy of the wave action against the solid structure accelerates beach erosion.
This problem is at the center of a debate over a proposed four mile, $40 million sand dune intended to protect the recently rebuilt Route 35 on the thinnest, most vulnerable stretch of the upper Barnegat barrier beach peninsula. Sandy punched a new ocean inlet through this part of Mantoloking last September. The core of the dune would be an iron framework built to support a 16-foot dune.
It’s this iron curtain which has some experts worried.
“This is a situation asking for trouble. When that beach erodes and that wall is exposed, there will be trouble,” said Mark Mauriello, New Jersey’s former chief of the coastal division in the DEP.
Mauriello has been one of the few voices in New Jersey to warn that bigger piles of sand are not the answer. While he acknowledges the enormous protective role dunes played during Sandy, he points out that constantly replenishing beaches is not sustainable in the long-term.
“We can’t just rely on beach nourishment to solve all our problems,” said Mauriello. “It’s very expensive and very temporary. It needs have a complimentary program of acquisition to go along with it. So as we are pouring sand into the oceans to rebuild the beaches, we are also pulling back a little bit from the shoreline to create space for these beaches and dunes to sustain themselves over time.”
As Mauriello makes clear, the other big difference between a natural dune and an artificial dune is that natural dunes are free and artificial dunes come with the hefty price tag that is always associated with trying to maintain something Mother Nature would like to see gone. The 73.2 million cubic yards of sand that the Army Corps of Engineers has added to the Jersey Shore cost $556.8 million. The vast majority of this money comes from the federal government.
CREDIT: Glynnis Jones
“Municipalities pay $87,000 for every $1 million the federal government spends on these projects,” said Farrell. “That’s an incredible deal, at least for the people who live there, that is. Not so much for the rest of us.”
What no one is paying for is the protection of the 37 miles of unprotected coastline in the state. These stretches of shoreline, almost exclusively in parks and refuges, are doing what all of the New Jersey coast would like to do — retreating.
“The birds don’t give a damn,” said Farrell. “But if you live next to one of these areas, it doesn’t matter how much you’re protected out front, you’re going to get eaten away from the sides as that unprotected coastline moves back.”
The southern tip of Long Beach Island is the most noticeable example of undeveloped and thus unprotected beach retreat. The beach hear has moved back about eight hundred feet since CRC has been recording data.
The logistical nightmare of Mauriello’s proposed slow retreat from the shore is evidenced by the ongoing battle in New Jersey to force property owners to allow dune construction on their land.
While the complete devastation visited upon dune-less beach towns by Superstorm Sandy has convinced many, including the governor, that dunes are the way to go, over one thousand beach front property owners are still refusing to let dunes be constructed on their property. Many of these property owners say that their ocean view, and thus property value, would be severely impacted by a dune.
“These people are just being asked to accept having their ocean view obscured,” said Farrell. “Imagine what would happen if they were also told they had to move hundreds of yards away from the water.”
In a strange and precedent-setting case a Harvey Cedars couple who protested the building of that town’s dune back in 2010, were awarded $375,000 in compensation. Just last month, however, an appellate court ruled that the value of the protection afforded by the dunes more than compensated for the lost views or deflated property value. As a result, the couple’s award was reduced to $1.
Since the ruling, towns up and down the Jersey Shore with dune-opposed property owners have begun the process of acquiring the necessary strips of beachfront land through eminent domain.