Issue

Over the past two decades, South Carolina’s eight coastal counties have experienced rapid growth, mostly from residential development. This growth includes development of beachfront properties and lands along estuaries, rivers, and tidal creeks; the pressure to develop these properties is mounting. At the same time, many of these shorelines are experiencing erosion caused by natural forces such as barrier island migration, sea level rise, and coastal storms, as well as anthropogenic forces such as jetties and dams.

Process

South Carolina developed a Beachfront Vulnerability Index (BVI) to assess community exposure and susceptibility to losses from storm surge and erosion. The BVI identifies vulnerability to coastal hazards under present-day conditions (using historical data instead of predictive models) at the parcel level. Created with the assistance of a NOAA Coastal Fellow by the Department of Health and Environmental Control’s Office of Ocean and Coastal Resource Management (DHEC-OCRM), the BVI combines data on elevation (lidar), long-term erosion rates (DHEC), number of dunes present (DHEC), wave height (NOAA), tidal range (NOAA), a habitable structure’s proximity to an inlet (DHEC), and a habitable structure’s distance from the DHEC-OCRM lines of jurisdiction (setback line and baseline). These data were edited, reclassified, and standardized using ArcGIS. The standardized variables were then analyzed using the ArcGIS Weighted Overlay tool to establish a vulnerability score for each parcel along the South Carolina beachfront.

Impact

Planners will use results from the BVI in long-term planning efforts to address vulnerable areas along the beachfront. For example, BVI results will help identify vulnerable areas within a community, encouraging local planners to incorporate mitigation and adaptation strategies in their beachfront management plans. Also, South Carolina officials will use BVI findings to update the state’s beachfront management plan.