CHARLESTON — During high tides, waves sweep over the granite boulders at the base of Fort Sumter and slam into the landmark’s brick and mortar.
So the prospect of a deeper shipping channel with larger ships moving even closer to the fort has captured the attention of the National Park Service.
The agency recently shared its concerns with the U.S. Army Corps of Engineers, which is working on a multimillion-dollar environmental impact study for deepening Charleston Harbor from 45 to 50 feet.
Rick Dorrance, chief of resource management for the Fort Sumter National Monument, says there are more questions than answers at this point.
The questions include: Will the channel, now about 1,200 feet from the fort, be shifted any closer? Will the larger ships send larger waves in Sumter’s direction? And what might be done to address any problems?
“This thing is in its very nascent stage,” Dorrance says. “This is not going to get hot for some time.”
The fort currently is protected by hundreds of granite blocks that were placed around its base in 1971, but they’re not enough to keep waves from crashing against the fort during high tides. Some stones have shifted and some bricks show gashes 6 inches deep.
“Even if there’s no impact from the channel dredging, we have to do something eventually,” he says. “I would think within 10 years.”
The National Park Service currently is working with Clemson University on an engineering assessment of the fort’s condition.
“That will give us better information about how serious a problem we have out there,” Dorrance says. “The good news is there does not appear to be any instability of the man-made island (built between 1829 and 1839). The other good news is the masonry is holding up against this pounding remarkably well.”
Fort Sumter isn’t the only historic site that could be affected by the harbor deepening.
The State Historic Preservation Office also has met with the Army Corps and noted the potential impacts on archaeological sites, including shipwrecks and the submerged foundation of an old light station.
Castle Pinckney, Charleston Harbor’s other historic masonry fortification, also sits near the channel. Last year, the State Ports Authority sold Castle Pinckney to the Sons of Confederate Veterans Camp 1269, and the Sons are exploring conservation options for it.
Dorrance says the Park Service also wants information on whether the deepening would affect Fort Moultrie on Sullivan’s Island. But that fort currently has about 100 yards of beach between it and the water at high tide — more than when it was first built.
The Army Corps is expected to consider how all the harbor’s history will be affected and to the extent that there’s potential harm, what can be done to mitigate it.