A plan to protect downtown Charleston from hurricane surge no longer includes a large breakwater south of the city, and a wall to stop storm waves would be built closer to land.
The removal of the breakwater, a 4,000-foot line of granite that would have been placed parallel to The Battery sea wall in the Charleston Harbor, shaves $300 million from the total project cost. It also eliminates a visual obstruction that many had balked at.
But the updated project plan, presented to City Council in a Feb. 18 meeting by the Army Corps of Engineers, would still cost some $1.4 billion. Charleston has to say by this November whether it can pay 35 percent of the price, or about $500 million.
Other major changes could also make that price estimate change as more analysis is done:
- The wall's path would hew closer to high ground, especially in the Ashley River, to avoid slicing through marshes.
- A section of wall directly alongside the Citadel was removed completely, and segments on either side will tie into high ground instead.
- The tighter alignment adds several gates over major roads, including over Lockwood Drive and Morrison Drive.
- The project would be designed and built in four phases, with a section along Lockwood and the Medical District first.
The project, which would encircle most of the Charleston peninsula with about 8 miles of wall, would be the biggest flood management project in the Holy City to date. While the Corps is only focused on stopping the wall of ocean water from a hurricane, city leaders hope this barrier can also hold off more gradual sea-level rise.
Adjustments to the project come after public comment, but are also aimed at slimming down the total price for a better cost-benefit ratio. There are billions of dollars of unfunded Corps projects waiting for federal funding now, and a better balance of cost-to-damage reduction makes the project more competitive.
Not all questions about the project were answered during the meeting, including one burning concern: whether the wall will significantly affect communities across the harbor, and push floodwaters into other neighborhoods. That modeling is still ongoing.
The Corps also announced the feasibility study will now stretch to at least July 2022 instead of finishing this year. That's because project managers need to complete an Environmental Impact Statement, a more lengthy review of the work's environmental, cultural and socioeconomic effects.
As a result, another public meeting on the work will be held in March; an updated draft study will be released in August; and more public meetings, potentially in person, will be scheduled in September.
Consultants to the city who joined the presentation stressed that Charleston needs some kind of barrier at its perimeter over the long term.
The city predicts that there will be 2 to 3 feet of sea-level rise in the next 50 years. But on that point, the Corps slightly diverges: Its projections assume just 1.65 feet of ocean lift. The wall design is 3 feet above the High Battery, or 8 feet above the most minor tidal flooding level. It's meant to last through 2082.
"How are you going to stay there on that beautiful spit of land, how are you going to stay there as the water’s coming in?" asked David Waggonner, of Waggonner and Ball.
The design firm is leading a group of city consultants reviewing the Corps plan for Charleston. They continued to stress that a wall alignment farther out from the city would help the city avoid complicated gates across major roads and have other water-management benefits.
City Council members, receiving the most detailed presentation to date, had several questions. Councilmen Jason Sakran and William Dudley Gregorie asked about impacts to the Wagener Terrace neighborhood, including whether the wall would obstruct views and lower property values.
The Corps is in the middle of a viewshed study, and does not do analyses of how real estate values change, Project Manager Wes Wilson said.
Mayor John Tecklenburg added that "You’re going to retain property values out of the fact that it will be dry, as opposed to flooded."
Councilman Robert Mitchell also asked why the East Side of the city would see its wall built in the third of four phases, saying that part of the town "gets the (short) end of the stick every time." Mark Wilbert, Charleston's chief resilience officer, said that portion may be moved up in line, to the second spot.
The bigger picture
While Charleston has to commit to paying for this project by the end of the year, the bill wouldn't start to come due until 2023 at the earliest, Wilson said. That only happens if Congress decides to fund the next phase of design.
Councilman Keith Waring was already concerned about how the city will fund its share. Efforts to pay for school improvements and build the Ravenel Bridge also had large price tags, he said, but there were campaigns to fund them long in advance.
"It's going to take momentum like that to raise the city's match," Waring said.
But also top of mind was how the wall fits into Charleston's water-management plans. The city still has to contend with struggling drainage infrastructure, intense rains and development pressures, especially in its more suburban sections.
"There’s a long way to go between where we are today and coming up with an integrated solution" for all the city's flooding, Councilman Mike Seekings said.