Figure 6. The Kiawah River makes a sharp bend behind the spit, just downdrift of the Beachwalker Park beach access path, shown
by the yellow arrow. (Photo by L. Sautter, 2014)
County Park beach access point. Excavated sands were used
to form a dike structure across the old inlet to encourage
tides to flow through the newly cut channel. The project was
a great success, as Kiawah maintained the majority of the
spit’s acreage, while Seabrook was able to receive the wealth
of sand that became available after the inlet’s relocation. In
1996 Coastal Science and Engineering conducted a second
breaching, as well as a third engineered breach in 2015
(Figure 6). Since the man-made breaches are located far
downdrift, the spit’s neck has remained unaffected.
In summary, Kiawah Island’s drumstick-shaped
geomorphology is the result of thousands of years of
sand accretion and progradation. Most of the island’s
sand has been delivered to its updrift, northeast end from
detached and migratory swash bars that originated from
the Stono Inlet ebb-tidal delta. Once these sand bodies
weld onto the shoreline, they provide for significant dune
and vegetated beach ridge construction along with the
seaward progradation of the shoreline, thereby constructing
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the broadest part of the island. Through the process of
longshore transport, sediments from this “meaty” end of
the drumstick have been distributed southwestward along
the central portion of the island toward its downdrift end.
The accreted extension of the island’s length takes the form
of a recurved spit (the drumstick’s “handle”), the growth
of which causes Captain Sams Inlet to migrate toward
Seabrook Island. In the last 30 years, the inlet has been
intentionally breached on three occasions to reduce the
continual attack of Seabrook Island’s shoreline from the
inlet’s downdrift migration. These engineered breaches
have been located well downdrift of the neck, which
today remains a fragile, narrow strip of land.
With the continued and plentiful supply of sand from
the Stono Inlet ebb-tidal delta, Kiawah is likely to continue
to prograde into the future. If, on the other hand, the rising
sea level is supplemented with increased storm and wave
energies, erosion may take a more significant role in
shaping the barrier island’s dynamic shoreline. NK
Naturally Kiawah