The current lighthouse structure was originally built approximately 1200 feet from
the shoreline of the Atlantic Ocean. Over the years the Corp of Engineers have
undertaken several programs to aid navigation and to keep the Charleston harbor open
to increased shipping demands. Significantly, around the turn of the last century a pair of
Jetties were constructed, drastically changing the approach direction for ships entering
the Charleston harbor. In subsequent years the harbor began to experience accelerated
siltation. In an effort to prompt a natural flushing mechanism for the harbor, an opening
of several hundred yards across was accomplished near the shore intersection with the
South Jetty. This breach, known locally as “Dynamite Hole” partially met its intended
purpose, however the new flow of water began to rapidly scour the ocean face of Morris
Island, located directly South of the “hole”. Within a few short years, the beach of Morris
Island was eroded to such an extent that the MIL now sits surrounded by the sea.
The original lighthouse was designed so that the wooden piles would always be
below the existing water table of Morris Island. The theory being that the piles would not
rot or deteriorate as long as they were continually submerged. The scouring of the soil importantly, to water born parasites such as ship worms or tereda worms, as they are
locally known. The introduction of these organisms led to severe deterioration of the
original support piles. The deterioration of the lighthouse structure and foundation led to
the current effort to save the lighthouse from the harsh Atlantic environment. An
organization known as “Save the Light” bought the structure in 1999, and is spearheading
the effort to “Save the Light”.
Subjects: morris island lighthouse, dynamic hole, micropiles
Author: William L. Snow, Sr., William B. Wright, PE, & Will Snow, Jr., PE
Publisher: ISM, DFI, ADSC