Photograph by Mark C. Olsen, USAF/AP

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Seaside Heights, New Jersey's boardwalk amusement park the day after superstorm Sandy's landfall.

Photograph by Mark C. Olsen, USAF/AP

After Sandy: The Future of Boardwalks

In age of extreme weather, should they be rebuilt, redesigned, defended by dunes?

Part of our weekly "In Focus" seriesstepping back, looking closer.

The sound of flip-flops flapping will bring you there instantly. So will the rumble of bicycles over wooden slats, the cry of a seagull, the smell of taffy and French fries, and the sight of bumper cars and a Ferris wheel. A whiff, a glimpse, a sound and you are swept back to a warm evening on a beach boardwalk during an idyllic summer.

For many Americans, that evocative boardwalk is on the Jersey Shore.

Or was. Superstorm Sandy did not pause for nostalgia as she barreled up the New Jersey coast on October 29. She dumped Seaside Heights' Star Jet roller coaster into the ocean and shattered the 17-block-long boardwalk. In other coastal communities, she blasted boardwalk shards onto roads and yards or buried them under sand and sea.

After a disaster like Sandy, the cry to rebuild goes up quickly. "As a kid who was born and raised in this state and who spent a lot of time over my life­—both my childhood and my adult life—at the Jersey Shore," Governor Chris Christie told reporters October 31, "no question in my mind we'll rebuild it."

But the prospect of rising sea levels and increasingly intense storms raises the question of whether boardwalks should be rebuilt. And if the answer is yes, is there a better way to build them?

Solutions exist, but none are cheap. "We know how to do it," said Bob Bea, professor emeritus at the University of California, Berkeley's School of Civil and Environmental Engineering. But, he added, we need to change how we think about boardwalks.

The first boardwalk built in the United States was a temporary structure. Two local businessmen, weary of sand being tracked into their establishments, convinced the city council of Atlantic City to create a boardwalk in 1870. The boards were attached to frames, hauled in by mules, lined up on the beach for the summer, and hauled away when the season ended and the threat of storms began.

These days, boardwalks are built to last year-round. But hurricanes are making that difficult.

After Hurricane Irene damaged Belmar's boardwalk south of Asbury Park in 2011, the structure was rebuilt with composite lumber, in the hope that the walkway would endure for decades. It lasted just until Sandy came along.

Boardwalks to Go Back to the Future?

Replacing boardwalks is expensive. The mayor of Point Pleasant Beach estimates that restoring that town's mile-long (1.6-kilometer-long) boardwalk will cost four million dollars. That's a significant amount for a small town, but the Jersey Shore, with its iconic boardwalks, is the primary lure for the state's $38 billion tourist industry. (See our top ten boardwalks.)

"If you started today and looked at the coast [you might say] maybe we shouldn't develop here," said Larry Ragonese, press director of the New Jersey Department of Environmental Protection, "but you can't take back history, and you can't take back time."

You can, however, resurrect the original concept of a boardwalk as temporary.

Daniel Cox, a professor of civil engineering at Oregon State University, suggests thinking of boardwalks as sacrificial infrastructure: "design components intended to fail so that the whole [structure] doesn't go."

Boardwalks could be built more like concrete bridge piers, said Stewart Farrell, the director and founder of the Richard Stockton Coastal Research Center in Galloway, New Jersey, with "decking anchored to the concrete support structure. Even if [the decking] is pulled off [by a storm], you could drop [new planks] back in place."

Beyond the Boardwalk

It also helps to create a barrier between the boardwalk and the ocean.

Take a lesson from Atlantic City. "If you had walked down Atlantic City's boardwalk prior to a few weeks ago," said Thomas Herrington, associate professor of ocean engineering at the Stevens Institute of Technology in Hoboken, "you wouldn't have seen the ocean." You would have seen a nearly 15-foot-tall (4.6-meter-tall) dune, which shielded the city's boardwalk and casinos from the brunt of the storm. (Portions of the boardwalk in a residential area without the benefit of a dune were destroyed.) The dune is the result of a multimillion-dollar effort by the U.S. Army Corps of Engineers.

"The boardwalk experience is changing in New Jersey," Herrington said. "Towns with wide beaches and no dune lost everything." But after a storm, dunes may need to be rebuilt, just like other forms of infrastructure.

A more dramatic solution would be to push the promenade far above the sand. Scheveningen, a beach resort in the Netherlands, built a boardwalk of steel and concrete a hundred feet (31 meters) above sea level, because the North Sea waves can crest as high as 98 feet (30 meters) at the shoreline.

"That's actually a good thing from the standpoint of amusement rides," Bea said. "You get treated to things on the high side." (The resort is currently undergoing a massive remodel, which will significantly expand the width of the beach while also lowering the height of the boulevard, as it is called, to 40 feet [12 meters].)

It's hard to imagine boardwalks towering over the Jersey Shore, but then it can be hard to imagine—and to remember—the havoc that a storm can wreak.

"The big challenge," said Robert Kates, presidential professor of sustainability science at the University of Maine, "is to create another vision of how to use the shore"—a vision that will still leave some room for nostalgia.

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Kate Andries contributed reporting to this story.