01/30/2009
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–S&W–DEW [DRAFT]
Accreted Land Management Plan
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2253 [30 JANUARY 2009]
Town of Sullivan’s Island, SC
FIGURE 1.4. Representative profile of the AL study area showing the low-relief accreted land and vegetation cover that have
evolved seaward of houses during the past several decades. Note the profile scales (in feet) are greatly exaggerated in the
vertical. House and vegetation (not to scale) are stylized to help the reader interpret the cross-section. Along many South
Carolina beaches, “oceanfront” buildings would be situated close to the foredune (ie – ~1,500 ft seaward of the control line in
this example).
Following is a brief description of these jurisdictions and regulatory controls.
Development Control Lines
OCRM establishes jurisdictional lines along the open coast under the BMA of 1988 (amended
in 1990). Two lines are established:
Baseline: The approximate seaward dune crest (in the absence of shore-
protection structures) or the most landward shoreline (approximate seaward
vegetation line) during the past 40 years. The former applies to the ocean coast
away from inlets. The latter applies to inlet-influenced coasts such as Sullivan’s
Island.
Setback Line: A line measured landward of the baseline (a distance equal to
40 times the site-specific erosion rate) or a minimum of 20 ft landward of the
baseline along accreting shorelines.
Figure 1.5 illustrates the present baseline and setback line for Sullivan’s Island. Under the
BMA, jurisdictional lines are to be updated every ten years or so. The present lines were
established in 1999. As shown in Figure 1.5, the baseline and setback line pass through the
middle of the AL study area and are seaward of existing development parcels in Reach B and
Reach C by ~200–800 ft. The fact that the lines closely parallel each other (20 ft apart) con-
firms the official determination that Sullivan’s Island accreted during the past ~40 years.