Shark River Inlet, New Jersey, Entrance Shoaling: Report 2, Analysis With Coastal Modeling System

Abstract

Abstract : This report, the second in a series, documents a numerical modeling study performed with the Coastal Modeling System (CMS), supported by field data collection, to quantify alternative plans to reduce navigation channel maintenance cost, at Shark River Inlet, NJ. Since about year 2000, channel maintenance dredging requirements at the inlet have increased. Although Shark River Inlet possesses a small back bay, the current through the inlet is strong because of the small width between jetties. In the past century, this coast was sand deficient. With recent beach nourishment projects placed as part of a federal erosion-control program, the longshore sand transport potential along the coast is being met, allowing an ebb-tidal delta to form at the entrance. This delta is expected to increase in volume over the next two decades to reach about 0.92 x 10(6) m(3). Therefore, the dredging maintenance strategy must transition to one similar to those at other small tidal inlets along the Atlantic Ocean coasts of New Jersey and New York. This study concluded that 30-m channel wideners, a type of advance maintenance, will increase the time required between scheduled maintenance dredging. Other alternatives evaluated were extension of the north jetty to reach the same effective length as the south jetty, and a channel oriented to the northeast, which appears to be the direction of the natural channel under the present jetty configuration. The CMS proved to be a powerful tool for evaluating alternatives for maintaining the navigation channel in the short term and long term.