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Manmade barriers provide a level of protection

To the editor:

Once again, Seth Grossman reduces science to political chicanery, inviting readers with a heartwarming personal story before diving headfirst into his usual attorney-esque, irrelevant, throw-enough-spaghetti-on-the-wall line of argumentation. While this may sound harsh, let's revisit some of his comments.

He stated that "If a 6-year-old with a bucket and shovel knows that ocean waves quickly wash away piles of sand, why don't high-paid government 'experts' understand that?" It's not just government officials, but also geologists and geological engineers who specialize in coastal and oceanic geology, who would also be invalidated and mocked by Grossman’s comments. So is Grossman right?

It turns out that he is wrong. The upward slope, the beach berm, is a naturally occurring depositional feature that protects the beach, roughly analogous to how a levee protects a floodplain. Manmade structures such as groins, jetties and elongated dunes protect the beach or downbeach, much as enhanced levees provide additional protection. You may have noticed the erosional and depositional character (reduced somewhat by rip-rap) north and south of a groin/jetty, due to longshore drift, which almost looks a plot of the exponential function and its reflection. Manmade protections are not impervious to all weather conditions (think New Orleans and Hurricane Katrina) and are constructed in consideration of certain assumptions, but they provide a level of protection beyond the berms. The barrier island geology is constantly changing (as snapshot aerial photographs of Sandy Hook show) and, although there are naturally occurring preservation features (which acts much as natural selection does), if there is building to be done, it must be understood that the areas are vulnerable and additional protections must then be provided. After Katrina, we might recall debates of officials and private stakeholders ignoring prior warnings and even criticisms of habitation in certain parts of the city. With rising sea levels predicted for the East Coast, we may be facing similar problems.
Grossman goes on to the matter of the national press misreporting damages in the inlet area as representative of the entire city and the protective effectiveness of wide beaches in Wildwood, as well as seawalls and bulkheads in other barrier island communities – all of which I concur with him. However, it seems that he is attempting to rescue his earlier column, as none of these facts individually or collectively are supportive of his claim that the dunes have no protective effect and that their construction is purely political.

As another letter writer noted, Grossman initially wrote as if there were little damages or risks to life. If there is a political aspect present in this debate, it is that developers, owners and other benefactors (e.g., real estate attorneys) were either ignorant of or simply ignored risks that increased their assets and bankrolls. And now they want to pass the blame.
 
Jeff Lehman
Northfield


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