August 2017
D I G E S T
The Official Publication of the Kiawah Island Community Association
How the Shape of the Beach Impacts Boardwalk Design
Hurricane Matthew caused 30-50 feet of erosion from West Beach along Eugenia Avenue.
It’s no secret that Kiawah’s beach consistently ranks as the
top amenity the island offers, and access to this magnificent
amenity is a top priority.
When Hurricane Matthew made landfall in the Carolinas on
Oct. 8, 2016, Kiawah’s 10-miles of dunes protected the island
just as they should have. Yet the storm left the beach dramatically
altered. The primary dunes, and in some cases also the secondary
dunes, were lost to erosion ranging from 10’ to 220’, according
to the Town of Kiawah Island’s pre- and post-storm survey.
The photo above demonstrates 30-50 feet of erosion in West
Beach and along Eugenia Avenue. (See the town’s full report at
kiawahisland.org/post-hurricane-beach-report).
KICA owns and maintains 25 boardwalks, stretching from
Boardwalk #1 (Duneside Villas) all the way to Boardwalk #42,
located at the Ocean Course. Twenty-three of these boardwalks
were damaged or destroyed during the hurricane.
In the five years preceding the storm, KICA had rebuilt 22
of its boardwalks at a cost of approximately $1 million. At
that time, significant accretion of the beach resulted in a
dune profile suitable for ramps in almost all locations (not
all locations have always had ramps). A few of the 23 storm-
damaged boardwalks were able to be repaired quickly by KICA
personnel and immediately reopened. The rest presented unique
challenges due to the loss of the dunes, altered topography
and regulations. Design regulations are administered by three
agencies: the South Carolina Ocean and Coastal Resource
Management Division of the state’s Department of Health and
Environmental Control, the Town of Kiawah Island, and the
Kiawah Island Architectural Review Board. To comply with
regulations, boardwalks must meet the beach perpendicular to
the shore, must cross the primary dune with a clearance of two
feet, and cannot extend more than 10 feet on to the beach. The
sheering of the dunes (photo above, right) and post-storm beach
profile in many locations resulted in a dune line so steep that
to meet the two-foot clearance requirement over the dune and
not extend further than 10 feet on to the beach, ramps would
have to have extremely steep and unnavigable slopes. Thus
the loss of the dune system necessitated the use of steps rather
than ramps as a repair solution in numerous locations. This
approach was partially based on the post storm report issued
by the town’s beach consultant. In the Oct. 31, 2016 report to
the Town of Kiawah Island, Coastal Science and Engineering
stated the following regarding damaged boardwalks:
“Ideally, construction of extensions should be delayed until
the beach has had ample opportunity to recover and a new
foredune begins to build. If possible, simple steps leading
to the beach could be built near the escarpment until this
recovery occurs. At that point, more permanent walkovers
can be constructed. This will offer time for the natural dune
to begin to develop and will limit the need to reconstruct
steps or significant portions of the walkover.”
As the board considered reconstruction of its boardwalks in the
wake of the storm, it concluded
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