Posted on February 15, 2022
A proposed sea wall designed to protect the Charleston peninsula from rising seas and storm surges is heading toward the next step of development, but local advocacy groups want alternatives weighed before a commitment is made.
The Charleston Water Coalition (CWC), a recently formed group of local leaders, environmental and preservation advocates, engineers, business owners and concerned citizens, has already been hard at work. It cites reports from Robinson Design Engineers (RDE), the Coastal Conservation League (CCL) and the Southern Environmental Law Center (SELC) that detail alternative plans and design alterations to the proposed wall that would increase the environmental and community resilience of the program.
“If we step back for a moment, and this is my approach and that of many others, we need a comprehensive and holistic water management plan that’s integrated,” said former city councilwoman and CWC spokesperson Marie Delcioppo. “How do all of these things fit together? How do they impact one another?
“When you look at it, this isn’t the flooding that we face so frequently,” she said. “We face more and more flooding from rising tides and rain, and this wall does not do anything to protect us from those.”
Storm surge is major threat
Dale Morris, the city’s chief resilience officer, said storm surge is the most serious threat facing the peninsula.
“Surge brings with it devastating water levels, devastating wave energy that kills people, and destroys businesses and houses with a lasting impact of more-than five years,” he said. “That’s what we’re talking about. It doesn’t mean dealing with surge and then we’re done, because we have to mitigate all flood risks — we have river risk, we have tidal risk and groundwater risk
… and then we have sea level rise.”
The 8.5-mile wall, proposed by the Army Corps of Engineers, would wrap around the perimeter of downtown Charleston, rising as high as 11 feet in some areas. While environmental experts have said the need for storm surge protection is important, they also say the ‘single-purpose’ design of the wall falls short of what the city needs.
“As has been suggested in the Dutch Dialogues, that perimeter protection must be multifunctional and beautiful, that any perimeter protection must be logical, practical and forward looking, and that alignments must take a multi-benefit approach,” Delcioppo told the City Paper. “To advance a no-regrets approach, and before any further steps are taken regarding this single-purpose linear wall, all options must be considered and agreed upon.”
But Morris, the primary author of the Dutch Dialogues, said all of those aspects are already being discussed with the Corps. The complex process used by the Corps has kept some of the finer details from being worked out. “We just aren’t there yet,” Morris said.
“The Corps of Engineers process is more complex in some ways, so we are working through those processes with them to see if we can design a structure that would mitigate the surge risk as quantified by the city’s own vulnerability analysis,” he said. “We are not proposing to build a structure in the middle of nowhere that wouldn’t matter. This is super valuable, super important, an iconic place for so many reasons.”
Broad examination wanted
Engineering firm RDE’s critical assessment of the sea wall outlines a number of concerns with the proposal, including luring area residents into a false sense of security when emergencies call for evacuation. Ponding of water behind the wall could also increase the duration and depth of flooding, the report reads.
“As active participants in the Dutch Dialogues, we acknowledge the need for a storm surge barrier,” reads a RDE report. “This particular manifestation of that proposed structure, however, contradicts the core principles of building resilient cities.”
The critical assessment and the “Beyond the Wall” report by the CCL and SELC both identify the chief of these principals as nature-based solutions to natural challenges, like flooding. Natural breakwaters that form habitats for oysters and marshland each serve as natural buffers between floodwaters and Lowcountry communities. But Morris said both elements are present in the ideas behind the current plan, and they would be discussed at greater length during the design phase.
“The report was built off things presented in the Dutch Dialogues,” said Jason Crowley, CCL’s director of communities and transportation. “It looked at other alternatives — like DesignWorks’ and Biohabitats’ recommendations they had put out with the “Imagine the Wall” report.
“It was just a bunch of local designers and engineers here in the Charleston area putting their resources together to take what the Corps was trying to do, apply more nature-based features and develop something that accomplishes both the Corps’ goal of a storm surge barrier, but also the city’s goal of multi-beneficial uses, one of the tenants of the Dutch Dialogues.”
Delcioppo said while a lot of the ideologies detailed in the Dutch Dialogues can sound emotional — like the idea of living with water — they’re also core to the Charleston identity.
“One of the biggest draws to the area and one of our biggest assets is water,” she said. “Whether it’s the rivers, the oceans or the marshes, there’s some sort of water element that’s close by. … Water knows where it wants to go. It wants to go where it’s always gone, and it’s going to find a way to go where it has always gone.”
