Georgia’s Vanishing Coast: With stronger storms, higher tides, and rising sea levels, how high will the water go?

By 2100, Tybee Island could be nearly submerged—what about Savannah and St. Marys?
Georgia's Vanishing Coast

Illustration by Zach Meyer

On October 5, 2016, 18 hours prior to Hurricane Matthew’s anticipated arrival in south Georgia, Jeff Adams received an ominous message in his inbox. Adams has a background in extreme climate events; he’s helped Kansans prepare for flash floods and Idahoans for mudslides. As director of community development for St. Marys, Georgia, Adams’s job was to guide the low-lying town as it planned for storm surges and higher seas.

Founded in the late 1700s, the town is laid out on a grid on the north bank of the St. Marys River, which separates Georgia from Florida and empties into the ocean a few miles downstream. The historic district, dotted with live oak trees and hazy with Spanish moss, forms a peninsula. The river meets it at the south, and to the east and west, it’s surrounded by vast expanses of flat, grassy salt marsh, which fill with water twice a day as the tides rise. A century-old hotel looks across St. Marys Street to an active marina, a waterfront park, and the dock for the ferry that brings visitors to Cumberland Island National Seashore.

The PDF that showed up in Adams’s inbox, from the National Hurricane Center, depicted a brightly colored map of the projected storm surge from Matthew—the strongest hurricane to blow through the Caribbean in a generation, which was maintaining a course about 30 miles off the Atlantic coast of Florida and vacillating between a category 3 and a category 4. On the map, most of downtown St. Marys was blanketed in yellow, indicating water levels greater than three feet, with halos of orange for flooding of six feet or more. Patches of red—nine feet of water or higher—ringed the peninsula and formed a straight line running through the center of downtown, a marshy, low-lying area.

Inside his windowless office on Osborne Street, just a few blocks from the water, Adams could immediately visualize the damage: “There’s very little that’s going to be above water if we get hit.”

Matthew wreaked havoc up and down the Georgia coast, but in the end, St. Marys escaped the direst predictions Adams had contemplated. Yet, the town was hardly in the clear. Adams realized that the map, with its bright shock of deep water in the town center, provided a vision of another future, one St. Marys is inexorably approaching. Simply put, it reveals what the town will look like someday—first at high tides, and then, eventually, under regular conditions—as sea levels continue to rise.

Recently, in a conference room next to his office in the St. Marys municipal building, Adams compared maps of rising sea levels to projections of the Hurricane Matthew storm surge. Turning to the rising sea levels map, he said: “We’re not looking at 50 years out. We’re looking at the next storm. It’s almost identical.” Three to six feet is the general range of sea level rise that scientists and city planners anticipate for the Georgia coast by the end of the century, a likelihood that towns like St. Marys are beginning to grapple with. “The historic area,” Adams said, “that’s pretty much gone at six feet.”

On the Georgia coast, which spans 100 miles between Savannah and St. Marys, two things have become apparent during the last decade: Climate change is coming, and it’s already here. Due to natural cycles in the global climate, the planet has been warming for centuries and the seas inching up; what’s more recently apparent is that, as humans release carbon into the atmosphere through the burning of fossil fuels, the rate of increase is accelerating. “We’re beginning to realize we were on a real slow linear trend, and over the last two or three decades, all the points are going above that line,” said Dr. Mark Risse, the director of the University of Georgia Marine Extension and Georgia Sea Grant. “We’re not on a linear path anymore.”

More flooding is afflicting the region, not just during extreme weather but, increasingly, during king tides—high tides that coincide with a full or new moon. These tides can cover the streets of St. Marys, Brunswick, or low-elevation parts of Savannah in otherwise fine weather conditions (the phenomenon is also called sunny-day flooding) with consequences that range from annoying to dangerous. The only road out to Tybee Island—a flat stretch between the Savannah River and the salt marsh—experienced tidal flooding a record 23 times in 2015. It’s projected that with just one foot of sea rise, it will be underwater 100 times annually.

“We’re not looking at 50 years out. We’re looking at the next storm.”

These glimpses of the future are becoming ever more vivid. Matthew was followed last September, less than a year later, by Hurricane Irma, whose outer winds lashed coastal Georgia with the force of a tropical storm. What’s remarkable about Irma is that it wasn’t an especially bad storm; it was just spectacularly ill-timed. Hitting around midday on a Monday, the storm coincided with a king tide, creating close to a five-foot surge in certain places and swells of up to 15 feet. River Street, Savannah’s popular tourist thoroughfare, ended up under several feet of water. Marshes overflowed onto the streets of Tybee.

The surge rose to 18 inches in downtown St. Marys, causing millions of dollars of damage from which the town is still recovering. The storm disabled the Cumberland Island ferry dock and sank or grounded 39 boats.

If the last decade’s increased tidal flooding initiated a conversation about the changing sea, the hurricane double-header of 2016 and 2017 added a couple of exclamation points. But while the effects of storms will be more severe with climate change, Georgia’s vulnerability to them isn’t new—to the surprise of residents of the coast, where a long period of calm had nurtured a belief that those things don’t happen here. Before Matthew hit in 2016, Georgia hadn’t experienced such a storm since the late 19th century. “In the last 50 years of the 1800s, we had more storms than we did in the next 115 years,” said Dr. Clark Alexander, a coastal geologist and the director of the Skidaway Institute of Oceanography.

Two punishing storms in the 1890s, in particular, changed the face of the coast both socially and physically. The evidence can be seen on Ossabaw, an uninhabited barrier island just south of Savannah. It was once home to a small community of formerly enslaved people, Gullah-Geechee farmers and fishermen, who were driven to the mainland by hurricanes in 1896 and 1898. They settled the marshside village of Pin Point. The 1898 hurricane was so powerful that it blew into place a long, high sand ridge that still exists on Ossabaw. The landscape was again reshaped by Hurricane Matthew, whose winds pushed the dunes all the way from Bradley Point, on the island’s north end, to a beach on the south, cutting 40 vertical feet of dune down to 10. Of course, on Ossabaw, it makes little difference which way the sands shift. Hardly anyone lives there. But elsewhere, the situation is more complicated.

Georgia's Vanishing Coast - flooding on Tybee Island
A Crab Shack employee maneuvers through the flooding on Tybee Island after Hurricane Matthew.

AP Photo/Stephen B. Morton

On St. Simons Island, Paula Eubanks walked along a wide beach she couldn’t recall from her youth; the sand has built up slowly over time. Eubanks, a St. Simons resident and a retired professor of art education, grew up in nearby Jesup. On Sundays, her family would make the hourlong drive to St. Simons or to Jekyll Island, where they swam or picnicked or caught crabs in the tidal streams. “St. Simons was quaint—little, wooden houses,” she said. “They weren’t air conditioned, and there were a lot of mosquitoes.”

As Eubanks made her way along East Beach, she dodged spring-breakers and surveyed how the land had changed. And how it was about to change. East Beach looks across a small inlet to the private community of Sea Island, the wealthiest zip code in Georgia. From the southernmost end of Sea Island projects a vanishingly narrow sand spit that’s been the subject of contention. After a legal battle with environmentalists, Sea Island recently got the go-ahead to construct a groin: a rock wall perpendicular to the shore that prevents sand from blowing or washing away, thereby preserving the tiny, sea-blasted strip for the construction of eight proposed homes. The empty lots, according to the Atlanta Journal-Constitution, are worth between $3.5 million and $5.5 million.

“There’s something about us as humans that makes us think we’re required to look at the water,” Eubanks said. “Water trumps all the other views. Everybody wants to live on the water. And I get it. I’m just like them.” Eubanks lives near the ocean and looks at the water with a photographer’s eye. She’s worked often as a collagist, scalpeling pieces of pictures apart and putting them back together (formerly by hand and more recently with Photoshop). These days, Eubanks is working on a series that imagines—or predicts—what the water will look like when it has invaded various places along the Georgia coast, mostly historic sites on islands like Cumberland and St. Simons.

When she began making the series a couple of years ago, Eubanks did extensive reading on sea-level rise, poring over reports from the Intergovernmental Panel on Climate Change, the United Nations body that surveys climate research. She later consulted with a friend on St. Simons, a geologist named Jim Renner, to estimate the year at which water will reach the places it does in her artwork. Taking pictures recently at a historic fort in northeast Florida, Eubanks noted how high the water gets now. “I had to stand there and think: About how many feet is that from the floor of this fort? And how will the water get in?” The collages are quietly fantastical works, in which the past and the probable future crash together into what plausibly could be the present. In one piece, the door of a remaining slave cabin on Ossabaw Island opens out to the beach. “Of course, the beach is not right outside,” Eubanks said. “But I don’t think it’s going to take much for the beach to get there.”

The movement of the seas created the Georgia shore—its barrier islands and its marshes that disappear into the horizon. Oceans fall and rise on a natural cycle roughly every 20,000 years; the coastline used to reach Macon and Augusta. Over geologic time, this has created many beachfronts, the contours of which are visible in an aerial view of the uninhabited islands. You see successive ridges where each beach has been; islands like Ossabaw look like the back of a mossy seashell, a series of sandy ridges representing each time the shore settled into a new configuration.

But humans have thrown a couple of wrenches in the works. Further warming the climate with carbon emissions, we’ve, in essence, sped up the cycle. In the 20th century, the sea rose a little more than 3.2 millimeters a year, adding about one foot of water cumulatively, whereas experts who study the Georgia coast forecast at least three times that—one meter of rise—in the 21st century and possibly more. The uncertainty relates to how quickly the world can reduce its reliance on fossil fuels as well as to scientists’ developing understanding of the Antarctic ice sheet, whose collapse could raise average global sea levels 15 meters by 2500. That event would play out slowly in human years but transpire in an instant of geological time, and it would mean nothing less than a redrawing of the map of the planet. A 2017 flood resiliency report created for the town of St. Marys by Georgia Sea Grant cites broad scientific agreement on approximately 3.3 feet of rise in coastal Georgia, while acknowledging the possibility of twice that—6.6 feet—depending on the intermediate future of the ice caps.

Tybee graphicMeanwhile, we’ve placed buildings in—or otherwise gotten in the way of—the ecosystems that might absorb some of the water this warming will bring. Take Lewis Avenue, a pretty street of small homes on the backside of Tybee Island. “Lewis Avenue is the poster child for people in the wrong place,” said Paul Wolff, a former Tybee city councilman. When it was built out in the 1950s, nobody had any inkling of what was to come. The highest point on Tybee is Butler Avenue, the main commercial strip, which runs along an old sand ridge. Lewis Avenue is behind it, at lower elevation and between two marshes. “It’s an isthmus, basically,” Wolff said.

Fran Galloway moved to Lewis Avenue in 2009. Originally from Atlanta, she spent her career in television, working for CMT in Nashville for 13 years. She came to Tybee, semiretired, when it was still possible to believe in the overall placidity of the Georgia coast. She had lived in Savannah in the 1980s while working for WSAV and didn’t remember any particularly bad weather; researching the subject before returning in 2009, she learned the area hadn’t been hit by a hurricane in more than a century. Lewis Avenue is set back from the tourist hubbub that characterizes much of the island. Because so many of its houses are filled with homeowners rather than vacationers, it’s known at Halloween as “Trick or Treat Street” and draws costumers from as far away as Hilton Head. The houses on Lewis are mostly one-story, slab on grade, and built for working people. Galloway’s next-door neighbors have lived in their home for 49 years and “never got a drop” indoors, she said. Until the hurricanes.

Galloway lives across the street from a glimpse of her future: A neighbor’s house is being raised above the floodplain, stacked on wooden pilings that look like giant Jenga blocks. Galloway’s house has been flooded twice—first Matthew, then Irma. The first wasn’t bad, but in the second, the water reached four feet up the walls. Galloway didn’t evacuate during Irma. She went to another neighbor’s home and sat on the second-story porch, where she watched the water come running up both sides of the street—from both marshes. “It was so mesmerizing,” she said. Returning to her house, she found splash marks on the walls where the rising waters met.

Galloway’s house is in an initial batch for which Tybee Island is seeking a Federal Emergency Management Agency grant to lift above the floodplain. In her living room, the walls are stripped down to the studs, with insulation packed only into the top half of the frame. Contractors will drive steel beams through the midsection, so everything from four feet on down needs to be bare. Still, Galloway has reinstalled cupboards in the kitchen and plans to put up beadboard on the walls in the rest of the rooms—for her “mental health,” she said. (It’ll be easy to pop off when the time comes.) The house looks so comfortably lived-in now that there’s a sense of industrial chic about it; after a while, you can imagine the bare boards as an affectation rather than a disaster’s aftermath. It could be two years until Galloway’s house is lifted. That’s two hurricane seasons, at least, between now and when she will be safely out of the floodplain. The waiting has created its own vocabulary: “When I’m raised,” she said a couple of times. “I just don’t want to watch the Weather Channel,” Galloway said and laughed. “I’ll pray, and I’ll prepare, and that’s about all I can do. And just wait to be raised. If you’re not raised, you’re just going to have to deal with it all over again.”

In Georgia, Tybee Island has been on the front lines of climate change adaptation planning. In 2016, the city ratified a plan, created with assistance from Georgia Sea Grant, that involves placing tide gates on stormwater outfalls, protecting municipal wellheads from saltwater intrusion, and eventually raising Highway 80. St. Marys followed suit. Its own adaptation planning involves an upgraded municipal sewer system and various projects to help drain off some of the water that inundates the city. “What we’re trying to do is use low-impact or green infrastructure—permeable paving, rain gardens to collect the water—to absorb these inundations,” said Adams, the city planner.

In a coast-long congressional district represented by a Republican who says the science is unclear on fossil fuels and global warming, those advocating for adaptation planning have succeeded by focusing on effects rather than causes. But their success also shows how climate politics tend to get scrambled when the problem literally expresses itself in constituents’ backyards. Former councilman Wolff, whom a friend described as “a silver-haired environmentalist from the old days,” said, “We did our best to depoliticize the whole thing. We said, ‘look, we’re not going to argue about whether climate change is happening or whether we’re accelerating the process. We’re just here to talk about what we see, which is: The road’s underwater more often.’”

Planners agree it’s most productive to think incrementally. Tybee and St. Marys are both peering about a half-century into the future: the most practical time line, and one that stops short of the unimaginable. And later on? “Unless we build a bulkhead around the entire island, which would effectively destroy the beach, we’re just going to have to move inland,” Wolff said. “We will not have an option within 150, 200 years.”

People will have to move landward, and so will entire ecosystems. Higher oceans will push everything up. Saltwater will encroach into freshwater marshes, turning them to salt marshes and nudging the freshwater marshes themselves to higher ground—at least in a vision of the future in which the marshes have time and room to move.

South across the bridge from the small fishing town of Darien, near where the Altamaha River empties into the ocean, the wetlands scientist Christopher Craft has spent the last six years studying what happens when saltwater intrudes on fresh. When he launched SALTex in 2011—it stands for Seawater Addition Long-Term Experiment—Craft created a grid of experimental field plots in a freshwater marsh on the north bank of one of the Altamaha’s distributaries. Almost hidden by the tall marsh grass, a narrow plastic-lumber boardwalk runs alongside 30 2.5-meter plots, separated from one another by siding driven into the mud. Craft’s study site sits in the shadow of Interstate 95, across a dirt road from a series of duck impoundments. If you put on noise-blocking headphones, this would be a deeply peaceful scene; in early spring, the giant cutgrass dominating the ecosystem was a pale yellow-brown, and bony cypress trees on the riverbanks were draped in Spanish moss and just starting to leaf out.

SALTex is part of the University of Georgia Marine Institute’s Long-Term Ecological Research project, funded by the National Science Foundation and housed on nearby Sapelo Island. For four years, three or four times a week, research technician Dontrece Smith would wake at his home on Sapelo, take the ferry to the mainland, and fill a truck with seawater. Then, he would drive to the study site, dilute the saltwater in the truck with freshwater from the river—to mimic brackish conditions—and dump it into the study plots. The idea is to see what effect this would have on soil and plant life in the marsh.

Craft experimented with two treatments, one that he called a press (a year-round brackish assault) and the other a pulse (doses only in September and October). “I use the analogy of, a press is like somebody who smokes two packs a day,” he said. Craft speaks with an amiable North Carolina drawl and did his PhD work in salt-marsh restoration. “A pulse is like somebody who doesn’t smoke except when they go to the bar on Friday night.” The press treatments provide a glimpse of how the marsh will react to saltwater inundation as seas rise; the pulse plots model brief, receding hits, like a hurricane’s storm surge.

“I don’t think climate change is going to be this gradual kind of thing. It’s going to be punctuated.”

About a third of the remaining salt marsh on the U.S. East Coast is in Georgia, whose shoreline—including most of the barrier islands—is largely undeveloped. The islands are separated from the mainland by 368,000 acres of undulating marshes, which act as a nursery for shrimp and crab. Beyond their value to Georgia’s seafood industry, marshes provide a range of environmental benefits, including the ability to store carbon that would otherwise enter the atmosphere. “Wetlands on a per-area basis sequester more carbon than any kind of ecosystem,” Craft said. As seas rise, one question is whether the salt marshes will be able to migrate—whether their sentinel species, spartina alterniflora, will be able to establish itself upland before the ecosystem is drowned. “If you kill the fresh plants, and the brackish plants don’t get there fast enough, you could end up with open water,” Craft said.

In his experiment, he found that plants died in the plots subject to sustained brackish treatment—the press plots. No surprise there. He’s focusing on the less obvious effects, like the nitrogen and phosphorus that dying plants release into the water (which could cause downstream algae blooms) or the loss in soil elevation that occurs as the plants’ roots biodegrade. In Craft’s press plots, the root loss has caused the soil to fall two inches in four years—a condition that, in an uncontrolled site, would further invite the rising sea.

Most barrier islands are held in conservation of some sort, and the salt marshes are protected by the Georgia Department of Natural Resources. These physical assets provide a buffer between us and the rising sea. It’s hard to think of a scenario in which climate change will devastate coastal Georgia to the extent it will South Florida, where development extends all the way to the shoreline. Still, this world will shrink. Coastal planners are trying to balance the need to give the marsh room to move with the increasing demands that people are placing on the coast. By 2030, the population of Georgia’s coastal counties is projected to be 50 percent larger than it was in 2000, exacerbating the already considerable pressure on the ecosystem. People who live on waterfront or marshfront property, meanwhile, will be tempted to armor their shorelines against rising tide and increasing erosion. Hitting those walls, the marsh will drown. Charles McMillan, the coastal director of the Georgia Conservancy, said, “From an engineering standpoint, you can raise a road. But there’s a lot more difficult issues when you’re trying to defend an entire landscape.”

Given enough time, the marsh can adjust; it has for millennia, with the inward and outward movement of the shoreline. The extent to which it will be able to make the necessary adjustments in the face of new challenges—the sand-spit development, the coastline armoring, the ocean levels gone off their linear path—is “the million-dollar question,” said Jan Mackinnon, a biologist for the DNR’s Coastal Resources Division in Brunswick. “How exactly will things change? It’s been very impressive, all of the brain power that’s gone in to trying to figure that out. But at the same time, no one really knows.”

Alexander, the Skidaway Institute of Oceanography director, said the marsh’s future “depends on what you think about how far sea level’s going to rise. If you go to two meters by 2100, the marsh is toast.”

Craft’s SALTex sites received their last treatment of saltwater in December, but the experiment will continue for another several years. Now, Craft will focus on how the freshwater marshes recover—which species grow back, for instance, and how quickly. In the pulse plots (the “occasional smokers”), the real-world utility of this knowledge is obvious. Craft is studying how coastal ecosystems respond to changing climate conditions we’re already seeing: periods of drought, or storm surges that are becoming fiercer and more frequent—they push inland, they dump a bunch of saltwater, and then, they’re gone. What happens next? And how will the marsh bounce back if it happens again and again?

“I don’t think climate change is going to be this gradual kind of thing,” Craft said. “It’s going to be punctuated: You have a hurricane like Matthew. And then you get another one like Irma a year later. And maybe you get a third one in the next two years. Then, you’re going to start seeing effects.”

The 2018 hurricane season began June 1. The chances a major storm will hit the U.S. mainland this year, meteorologists figure, are better than average.

This article appears in our June 2018 issue.

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