ECONOMIC VALUE OF BEACH AND DUNES SYSTEMS IN STORM PROTECTION, ISLE OF PALMS, SOUTH CAROLINA

As of 2013, 133.2 Million people lived in coastal shoreline counties, this comprises 42% of the total population of the United States and is rapidly growing. There has been a point of emphasis in mitigating these destructive forces in recent years. Luckily, the natural habitat of healthy, sandy, vegetated dunes can mitigate storm damage. There is a need to better understand the protective value of dunes and how the can be part of the coastal resilience strategy. While dunes play a significant part in the way our shorelines function, their survivability is precarious, particularly on developed barrier islands. On eroding coastlines, a natural process under sea level rise conditions, dunes shift landward during overwash events. Developed shorelines restrict this process, confining dunes to a narrow strip of land and exposing them to increased wave activity and scarping. With eminent domain laws, homeowners argued that dune construction diminished property values and thus asked for fair compensation. One specific case awarded the $375,000 in March 2012 for their easement.

As a response to cases like this one, the U.S. Army Corps of Engineers didn’t do many dune construction projects, instead using available sediment to focus on large berms, or long and flat beaches. As communities determine the amount of investment necessary to protect or rebuild their dunes, understanding the value they provide to their community will be paramount. Economic studies will also increase public awareness about their importance. This study focuses on Isle of Palms, South Carolina a well-documented island on the South Carolina shoreline with a typical, but varied, beach/dune system. The Wave Height Analysis for Flood Insurance Studies (WHAFIS) model is used to estimate wave crest elevations along representative transects using a one-dimensional model. This model is the basis for creating a better understanding of the protective value of Dunes in the region. The results of this study increase our understanding of dunes and their storm protection value as climate change and coastal development make scenario planning even more important in today’s decision making process.