9 Marine and Coastal Science

Thursday, 17 March 2005
1:00 PM - 4:00 PM

DELINEATING NORTH CAROLINA'S INLET HAZARD ZONES: REVAMPING THE STANDARDS

Paper number: 9-9
Program: Technical Sessions
Time: 3:40 PM – 4:00 PM

Authors

Abstract

Management issues related to tidal inlets have become a focus of concern for government agencies due to the need to better regulate development within poorly defined inlet hazard zones. Although North Carolina has been a leader in developing oceanfront management tools, the state’s current standards for these high hazard areas are woefully inadequate and are in need of revision. The current standards are primarily based on a statistical analysis of the movement of the inlet during the past 60 years and the adjacent oceanfront erosion rate. In all cases the width of the zone of the inlet’s influence, as currently defined, is too narrow. Regardless of the inlet’s stability index all are morphologically unstable, and have the capacity to promote significant shoreline change through complex linkages of the movement of the ebb channel and the attendant shape changes in the ebb-tidal delta.

Data indicate that inlets control the shoreline change patterns for 2 - 3km along the adjacent barriers and, as a consequence, all developed shorelines in southeastern North Carolina are experiencing chronic problems related to inlet-induced change. A significant portion of the inlet-related erosion hot-spots, that impact the 15 oceanfront communities in the area, lies outside the current hazard zone boundaries. The presentation provides an overview of inlet types, their influence on the adjacent barriers, management issues at exemplary sites and the parameters needed to better define specific hazard zones. Data derived from GIS based studies are presented for a number of distinctly different inlets within diverse coastal settings where inlet stability, shoreline change scenarios and man’s influence differ significantly.