Several articles about how the deepening of Charleston Harbor could adversely impact Folly Beach have appeared in The Post and Courier. In the interest of promoting a better understanding of the history and relationship between the harbor and Folly Beach, I would like to clarify some misinformation that has been presented.
The work of examining whether the proposed deepening could increase erosion rates on Folly Beach and elsewhere will be performed by the Corps of Engineers. Our coastlines are dynamic, and the answer to this question is complicated.
Previous studies by the Corps have shown that, while erosion was occurring at Folly Island prior to the stabilization of the navigation channel by the jetties around the turn of the 19th century, about 57 percent of the average erosion rate for Folly Island can be attributed to the navigation project, with the primary cause being the jetties. Mitigation for this impact is already in place in the form of adjusted cost sharing of the Folly Beach project.
Since the plan for deepening does not propose changes to the jetties, the proposed changes to the entrance channel, when viewed in perspective of both the historical changes and large expanse of the ocean, are expected to result in negligible changes to the waves and currents that transport sediment.
Despite these facts, the professionals at the Corps and its non-federal, cost-share partner, the South Carolina State Ports Authority, are committed to examining the potential for changes in erosion rates from the proposed plan more thoroughly during the next step of the process known as the Preconstruction Engineering and Design (PED) phase.
Additionally, sand management is complex and highly dependent on local conditions. Just because some other ports have been able to use their dredged material as a sand source for beach nourishment projects does not mean that is a solution for Folly Beach. Most of the material dredged from Charleston Harbor is not compatible with direct placement on a beach; instead, it is a mixture of sands, silts and clay.
As a part of our normal business, when we identify material that is suitable for beneficial use, we determine if it is feasible and cost-effective to place it on a beach or elsewhere.
The Corps looks forward to continuing its relationship with the City of Folly Beach, one which has seen close to $60 million in federal investment since 1993 when the initial shore protection project for Folly Beach was constructed. We are currently considering all the comments received on the draft Feasibility Report and Environmental Impact Statement (FR/EIS) that was released last October. Our final recommendation will be presented in the final FR/EIS that is expected to be released this fall.
John T. Litz
Lieutenant Colonel, U.S. Army
Commander and District Engineer
U.S. Corps of Engineers