Sea Level Rise and The Future of Georgia's Coast
by Ken Edelstein
Stately buildings in the Greek revival style line the Historic District in St. Marys, Georgia. Spanish moss grows like beards off the crooked limbs of old live oaks. Green and gold cord grass rumples over ageless marshes.
Time has given St. Marys its charm and character.
But now time confronts St. Marys and the rest of Georgia’s coast with a relentless adversary. Sea level rise could inundate a third of the land in the state’s Atlantic counties within a century. And the little city in Georgia’s southeast corner— optimistically listed as 10 feet above sea level — is expected to see its landscape change over the next few decades as much as it has since Spaniards first explored the area in the 1500s.
St. Marys is one of five communities that were subjects of the most ambitious Blueprints for Successful Communities projects yet. Some 40 Conservancy staffers, Georgia Tech faculty members, and their students engaged over three years in three separate studios that reviewed the physical and social impacts of sea-level rise in Georgia, projected economic repercussions, and roughly scoped out potential adaptations.
“There is going to be substantial impact, and very little is being done about it right now,” says Georgia Tech planning professor emeritus Larry Keating, who led the first of the three studios.
Community to Research
The Sea Level Rise Project is unique in ways other than its scope. For one thing, it was designed as a conversation starter in a dialogue likely to continue for decades. For another, it’s based on scientific findings: One may be able to build a community consensus over the kind of development desired in a community, but no charrette is going to change the physical fact that the sea level along Georgia’s coast is rising.
This was to be a research-based Blueprints, rather than a community-based project. So staff at the Conservancy, and faculty and students at Georgia Tech started by assembling data: How much has the sea risen already? How much is it expected to rise in the near future? What land uses sit at or below elevations that will soon be flooded?
Participants insist that they relied on conservative estimates from the University of Georgia’s Skidaway Institute for Oceanography. They avoided making broad assumptions about the potentially divisive issue of climate change. In general, they didn’t even account for the storm surges that could wreak havoc in coastal communities already made more vulnerable by overall sea level rise.
“The studio was set up to ask the straightforward question: What are the decisions that have to be made today to deal with sea level rise and the consequences over the next century?” says Georgia Tech Planning Professor Richard Dagenhart, who led the third studio, which focused on adaptation. “We very quickly realized that all the decisions are elastic: In other words, we don’t know exactly how much the levels will rise. So we ended up dealing with what would happen at one foot, three feet, seven feet and so forth.”
Retreat. Adapt. Defend.
Despite that measured approach, the findings were stunning. And the potential solutions for the five communities from the final studio — entitled “Community Adaptation and Design Solutions for Sea Level Rise” — may appear to be as radical as the problem.
Take Tybee Island. More than half of Georgia’s most popular beach destination is expected to be underwater within a century, leaving little dry ground beyond a narrow strip between the main road and the beach itself. The causeway leading from Savannah to the barrier island will have to be raised repeatedly over the next half century — that is, ifthe causeway’s deemed worth saving in the first place.
Among the options might be to replace land-based buildings with floating buildings, much like those Dagenhart has studied in the Netherlands. But if raising the causeway was deemed too expensive, would it even make sense to invest in more structures on Tybee?
Dagenhart notes that another coastal city, Darien, is relatively lucky. Like Savannah, it was settled by James Oglethorpe, who wisely sited both cities on mainland bluffs overlooking coastal rivers.
“Oglethorpe knew his stuff,” says Dawn Riley, one of three planning students who worked with Dagenhart on adaptation options for Darien. “When we looked at the sea-level projections, most of downtown was in a place that’s protected from a storm surge. The parts of Darien that were going to be affected were the places where there was newer development.”
The local folks Riley interviewed weren’t as skeptical about sea-level rise as she’d expected. When an outside developer built a condo development over the last few years right up on the water, residents weren’t just annoyed that it cut down on their own marsh access; many recognized it as a bad idea because it was in a vulnerable location.
“There’s such a connection to the natural environment around the coast,” Riley says. “People’s attitude surprised us. They are more dependent on the natural environment than most communities, and they’ve seen that things are changing. Preserving the marsh and keeping it healthy has always been important for jobs in Darien.”
The people of Darien two key challenges. First, they must protect the the marsh’s ecology. Not only does it serve as the nursery for Darien’s shrimp and jellyfish fisheries, but it also protects the coastal communities from devastating storm surges.
Second, they need to figure out what to do about newer sections of the city that sit low, right along the marshes. How can Darien, McIntosh County and the state more effectively discourage (and certainly not incentivize) waterfront development? Would Darien’s vital jellyfish industry still be viable if it moved off-land onto platforms floating in the marshes?
Those are pretty heavy questions, but they pale in comparison to questions facing the state’s second busiest port. Brunswick’s downtown is located on a low peninsula between coastal creeks and marshes. Dagenhart doesn’t mince words.
“Brunswick is sunk,” he declares, referring to the city center.
The Elephant in the Room
Tough-love, perhaps. But then again Sea Level Rise Project is meant to serve a different purpose from the typical Blueprints: It’s a wake-up call. Regardless of what one thinks about the causes, sea-level rise happening and communities along the coast would benefit by planning for it.
“The whole purpose of all of this is for us at the Conservancy to be able to have conversations with residents and leaders about something that they’re confronting,” says Katherine Moore, director of the Conservancy’s Sustainable Growth Program. “When our government bodies invest in infrastructure, they’re effectively encouraging development to happen around it. So now is absolutely the time for us to plan and to have that awareness so that we can direct investments away from areas that will be most vulnerable. It’s such a complex, far-reaching challenge.”
The same could be said for Sea Level Rise Project. Funded in phases by Home Depot Foundation, the Ray C. Anderson Foundation and the Gulfstream Aerospace Corp., it represents a new horizon for Blueprints. Moore says that’s appropriate given the scope of sea-level rise: “We felt like we needed to address the elephant in the room.”The topic is so far-reaching, in fact, that she expects it to fuel ongoing community-specific studios. In effect, the Sea Level Rise Project is growing into initiative in its own right, within the Conservancy’s Sustainable Growth Program. In a very basic way, however, the project is well within the Blueprints model.
“We found an issue and a gap, and we had a vehicle in Blueprints that had its special methods and its unique partners,” she says. “We thought it was a perfect role for us because our tradition as being a consensus builder and conversation starter.”
The studios concluded that, for the most part, structural answers — such as a building New Orleans-style levees — would be too expensive to justify in the less-than-densely populated areas that dominate Georgia’s coast. In addition, large structures could devastate the marshes that remain a key economic asset. On the other hand, Moore stresses, it’s not an “either-or” conversation: “The conclusion doesn’t have to be, ‘we have to run away from the coast,’ but ‘how do live with the water.’ ”
Living with the water may prove difficult for a city like Brunswick. But Dagenhart stresses that hard choices can turn into opportunities. Like downtown Brunswick, a low-lying section of Savannah sprawling east from downtown — another of the five communities reviewed by his adaptation studio – will be inundated by the end of the century.
“It will create the biggest basin on the Southeast coast,” Dagenhart says. “Why not adapt by doing a real estate project?” His suggestion: Instead of putting new land-based infrastructure in the “Gateway” area, Savannah should explore preparing the new basin to become a giant marina.
Down on other end of the coast, students came up with a fairly straightforward plan for that timeless part of St. Marys. They say the city has little choice but to move its historic district to higher land, and to build a new planned community around it.
“It will be a phased retreat over time,” Dagenhart says. “The city should actually purchase land at a higher elevation, develop a town center and incrementally move existing structures there.”
Johnny Aguilar, who focused as Dagenhart’s student on St. Marys, is now a architect and planner in Los Angeles. He views the studio that he was engaged in on the opposite coast with a tinge of sadness.
“One of the problems will be that everyone’s so overwhelmed that they don’t know how to deal with what first,” Aguilar says. “So how do you actually facilitate the easiest possible transition?”
He hopes that the studio at least outlined a viable future for St. Marys residents, along with steps the city could take to prepare for that future. Much of the city’s history will be lost, he acknowledged, but a carefully designed new center on higher ground, could at least retain part of what time built in St. Marys.
The studio suggested not moving one of those structures. The site of an old fort, which dates back to the 1700s, already sits in the marsh — no longer on true land. Over the next few decades, it’s expected to be washed over by higher tides and higher storm surges.
Dagenhart argues that there’s only one way to ensure that the fort site can be preserved in memory: Build the walls higher and higher around what is in effect a tiny, disappearing island.
“It’s going under,” he said. “It will be ghost, just a visual fixture to remind people where it was.”
This story appeared in the Georgia Conservancy's Summer 2015 issue of Panorama Magazine, celebrating 20 years of the Conservancy's Blueprints for Successful Communities Program.