Putting knowledge to work to protect our coast

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Stewart Farrell, PhD, director the Richard Stockton Coastal Research Center in Port Republic, provided the following commentary on what the March 1962 storm means to us today as it relates to the subject of shore protection.

The lesson learned was that little perspective on what big storms could do was truly devastating when one happened. The dunes had been pushed down for a better view; the homes placed 25 feet from the high tide line. No regulations on building codes, site selection or damage avoidance.  This storm spawned the development of the National Flood Insurance Program.

 

The NFIP was begun in 1968, following other floods and storms, but the 1962 event and Hurricane Camille that trashed the Mississippi coast in the mid-1960s were the driving events pushing the Congress to enact the NFIP and create FEMA to oversee its implementation.

 

The Coastal Research Center has provided coastal managers with 25 years of data on how processes work and what to do when conflicts arise.

The major new contribution is the New Jersey Dune Vulnerability Assessment effort nearing statewide completion. This is a modeling effort to utilize past storm events, the existing dune parameters and the beach characteristics to predict the impacts of two-, five-, 10-, 20- and 50-year recurrence in specific storm events as defined by FEMA research in their mapping effort along the U.S. coastline. New technologies are going to give flood plain managers real time solutions for potential storm impacts so governing bodies can guide future development.

The introduction of digital LIDAR data (millions of 3-D elevation points taken from aircraft) and use of the tools in the geographical information systems software to manage map data gives us new tools to show flood plain managers what to expect during storms, sea level rise and evaluate the economic and societal impacts of future storms.

The 1962 storm is not unique. The 1992 storm had the potential, but moved away in just two high tides, not five. The December 1992 event followed the 1991 Halloween Storm (the Perfect Storm) and showed dramatically the impact of beach nourishment with an example in Ocean City. In 1991, prior to the beach fill project, they suffered $4 million in just boardwalk damages. Following the beach fill in the spring of 1992, the December event caused exactly zero damage to the boardwalk, so the city collected its part of the beach fill investment in the form of no boardwalk damage in less than eight months.

There has been no further damage to Ocean City infrastructure, public or private, since the start of shore protection in the form of beach restoration. It is a massive form of maintenance, just like painting the house you live in is maintenance to avoid costly weather damage over time.

New Jersey is first in the nation in terms of the percentage of the shoreline under beach project maintenance and in terms of the total value in federal dollars garnered for such activity in the country. We have just 127 miles of shoreline with more than 60 percent of the federal funding spent in this state. The New Jersey 1994 Coastal Protection Act put $15 million per year in a fund to leverage the federal dollars (later increased to $25 million per year). The feds put in 65 percent of the project cost; the state splits the 35 percent remainder with local jurisdictions (75 percent of it is state funding and 25 percent local). The net is that for every million dollars spent on a federal/state project, the local beach municipality spends just $87,500 in local tax money. There is no better shore protection project deal out there.

Increasing the shoreline width by 250 to 350 feet does wonders for reducing the wave damage, allows a decent dune width and elevation, which is the real wave barrier. And these things tend to last if they are built correctly and done in a large enough scale.

Each barrier island has at least one zone that is prone to erosion (we call them “hot spots”). The new concept being tested is to gather up sand that has moved to a zone on the island and continuously accumulates, and truck it back to the hot spot to extend the life expectancy of the initial big project.

We just completed a 64,000-cubic-yard project in the borough of Avalon and are awaiting permits to do 96,000 cubic yards between the borough of Wildwood Crest and the city of North Wildwood to restore Hurricane Irene beach and dune damage. These “back-passing” projects have two big cost advantages: very low cost to mobilize the project, and the sand is free.

Large, high-capacity trucks are used that haul 20 to 25 cubic yards in each haul, and are very content to be driven on the dry beach along the water line, with very low environmental impact. The sand is then graded into the desired beach shape or added to the dunes.

This does not replace big dredging projects, but acts to extend the time between major mobilization costs ($800,000 to $1.2 million for the first cubic yard) and doing annual maintenance with local funds following moderate storms or a bad winter.

 


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