Sandy-battered Shore sands provide weakened defense vs. flooding

The windy storm pelting the Jersey Shore right now poses more of a flood threat than it normally might.  Why? Hurricane Sandy weakened the defenses of coast and bay areas.

Jon Miller, a professor of coastal engineering at Stevens Institute of Technology, explains that the hurricane removed a lot of sand from the beaches,  and communities have been hard-pressed to replace all of it.

That leaves the oceanfront more vulnerable during the winter storm season.

“Communities are doing their best to get the sand back onto the beaches, and they’re screening it and typically piling it up into large piles where the sand dunes used to be,” Miller said. “hat sand is kind of the last line of defense and is more vulnerable than a natural dune would be. The real concern is whether that gets eroded or not in the nor’easters.”

Stewart Farrell is director of the Coastal Research Center at Richard Stockton College.  He says those big ridges of sand might not hold up in a really intense winter storm.

“That type of storm will probably cut through in a number of places,” Farrell said. “These ridges are discontinuous. Some of them are higher than others, and they are built with what was available not to any particular design that was uniform. They’re smaller. They’re lower. The sand is just a loose pile of material.”

Miller says the flooding situation at the Shore is just far more unpredictable post-Sandy.

“The water is just not going to move around the same way that it used to,” he said. “So there’s going to be perhaps more areas that used to be sheltered that are going to be more open and more subjected to some wave activity, and there will be other areas that are going to be more protected. It’s really going to depend on how the sand has moved and which specific areas it has moved into.”

Miller cites another concern:  All the sand that the storm surge from Sandy deposited into back bays will also make some bayside areas more prone to flooding.

Wednesday night’s storm is expected to dump up to an inch of precipitation on Shore communities, along with 30 m.p.h. winds.