IMPACTS OF HURRICANE SANDY ON THE NEW JERSEY COASTLINE & HOW CAN WE RESPOND?

The eye of Hurricane Sandy made landfall between Cape May and Atlantic City on October 29, 2012. This was the first hurricane to make landfall in New Jersey since September 1903. During October 29 and the early morning of October 30, tide gauges recorded maximum storm surges of 13.3 feet above mean low water at Sandy Hook, 13.9 feet at the Battery in Lower Manhattan, 14.6 feet along the Kill van Kull on the north shore of Staten Island, but only 8.9 feet at Atlantic City and Cape May.

The Richard Stockton Coastal Research Center was tasked by the NJ State DEP to conduct post-Sandy beach surveys at the 105 survey sites between Sandy Hook and Cape May Point. Surveyed twice annually since 1986, the Sandy data would provide a clear picture of where dunes survived and how the beach performed along the many USACE project beaches as well as those not previously enhanced. Measurements of dune wave run-up ranged from 14.5 feet NAVD88 to 24.6 feet NAVD88 between Atlantic City and Long Branch in Monmouth County where damage was far worse. A NOAA-funded Dune Vulnerability Assessment underway since 2006 was examined throughout No. Ocean County and where the model showed dune survival under a FEMA 100-year storm event, the dunes did survive, and where the model showed dune failure under the 100-year storm conditions, the dune was erased. In addition on Long Beach Island, the difference in wave damage in a community where the USACE project had been completed (done in 3 stages in 2007, 2009, and 2012) was negligable (1/2 to 1/3 of the Federal-design dune was eroded accompanied by beach elevation and width losses) as contrasted with the complete overwash in the Holgate Beach section on LBI. Here the beach/dune system was transported across the width of the barrier island and deposited on land and into Barnegat Bay effectively moving this part of the island landward and slightly upward.

The New Jersey Geological and Water Survey (NJGWS) has identified approximately 350 million cubic yards of sand in approximately 30 offshore shoal features. NJGWS’ analysis of high-resolution marine seismic data and shallow sediment cores is an immediate resource for storm mitigation. This work will significantly bolster the State’s replenishment efforts, by having sand sources already identified and quantified.