Turning Back the Tide
As rising waters threaten coastal areas, communities are rethinking development and realizing that nature is their best first line of defense.
Out in the low country of Eastern North Carolina, inches matter. We’ve driven miles through Alligator River National Wildlife Refuge without ever ascending to heights as extreme as 10 feet above sea level. Having pulled onto a gravel track called Point Peter Road, we hop out of the pickup onto spongy peat to take in the ghost trees—bare silvery trunks, all that remains of former coastal forests killed by the intrusion of saltwater. “Inches are the difference between trees’ and plants’ living and dying,” says Christine Pickens, coastal restoration and adaptation specialist with The Nature Conservancy.
Water defines this landscape, whether it’s the wind tides of Pamlico Sound or the tannin-darkened fresh water of the pocosin bogs. But ditching and draining for forestry and agriculture changed the inland hydrology and allowed saltwater to penetrate miles inland, a dynamic exacerbated by intense hurricanes and sea-level rise. Salinization causes forests to turn to shrublands, shrublands to become marsh, and shoreline to erode into the sound—as much as 10 to 12 feet each year. The Conservancy has helped protect more than 450,000 acres on the Albemarle-Pamlico peninsula in the past several decades, but today great swaths of those protected lands are threatened, Pickens says.
Pickens has brought me to see three linked projects that demonstrate how the Conservancy is using the tools of conservation to encourage resilience: one studying the adaptive value of planting salt-tolerant vegetation, another restoring oyster reefs, and the last implementing different water management techniques. She points to research plots of salt meadow cord grass and young bald cypress, a comparatively salt-tolerant tree, being studied for their capacity to recover from extended brackish inundation. “Disturbance is part of the system,” says Pickens. “We’re working with the change.”
We drive on until the road runs right into the glinting waves of Pamlico Sound. Just off shore are artificial oyster reefs. In the past six years, five reef sites totaling approximately 2,000 linear feet have been built—another 1,400 linear feet will be in place by 2018—at points around Pamlico and Albemarle sounds to provide a physical block that reduces wave energy while also re-establishing the water-filtering shellfish.
Where possible, reefs are sited near large drainage ditches that are hot spots for erosion and also channel the saltwater inland. Smaller ditches are being plugged; water control structures and salinity-monitoring equipment are being installed in larger ones. “In wetlands, hydrology is the key to everything. Get that right and everything else follows,” says Pickens. The projects are demonstrating the power of nature-based approaches. “We can slow erosion and sometimes we can actually have marsh growth,” she adds.
The process of helping nature fend off the effects of climate is not unique to North Carolina. More and more, the Conservancy is engaging in this type of work. Climate adaptation is factoring into both traditional conservation projects and mitigation for developed areas.
At this point, many ecosystem at the edge of land and sea—whether it’s Pamlico Sound or Puget Sound—will be changing, and extraordinary weather events are becoming the norm. “We’re living in a changed and dynamic phase for the planet,” says Kacky Andrews, former director for TNC's North American conservation programs. “It’s going to be about how do you manage it, not how do you stop it. You can’t stop it.”
“Climate change is the number-one priority of the Conservancy because the science is telling us this is the biggest threat to accomplishing our mission,” Andrews says. “The effects of climate change aren’t in the distant future. They are beginning to happen now.” More than half of the U.S. population lives in the coastal zone, she notes, so huge numbers of people and structures are at risk.
Techniques the Conservancy has long practiced to protect and restore ecosystems—whether they are wetlands, oyster reefs, coral reefs or mangroves—can now be deployed to provide natural defenses. Healthy ecosystems are more resilient and better able to adapt to the effects of climate change. In some places, healthy marshes and mangroves have been able to accumulate enough sediment and biomass to keep up with sea-level rise. Intact floodplains can reduce property damage and help nature recover from even extreme flooding.
Along heavily developed coastlines, however, “green infrastructure” will not be enough, and just building higher seawalls or more levees is equally unrealistic: gray infrastructure erodes and requires maintenance. Andrews says, “It’s not green versus gray. It’s both/and.” Different communities and different countries will make different choices. The Conservancy’s goal is to make sure science- and nature-based solutions are part of the equation.
The Conservancy is scaling up its natural systems approach along the Gulf of Mexico, where communities are constantly dealing with shoreline erosion that is accelerating with sea-level rise and frequent hurricanes. The coastal ecosystems have been weakened by water quality issues stemming in part from inland agricultural runoff, which creates algal blooms that harm marine life. Addressing these problems means restoring natural coastal defenses like sea grasses and oyster beds on the local level. It also requires working with farmers far upstream in the watershed to reduce the fertilizer load entering the Mississippi River.
The Miami metro area has become the poster child for sea-level rise. Neighborhoods predictably sink under what locals call king tides—the highest tides of each year. The Conservancy is partnering with the City of Miami, Miami-Dade County and University of Miami to pilot a green buffer along Wagner Creek, a tidal tributary of the Miami River. Though still in the predesign stage, the idea is to reconfigure a parking lot in a way that creates a new green space while maintaining current parking capacity and incorporating vegetated watercourses that absorb and filter water. Additionally, portions of the creek bank and the lot will be reworked to provide greater flood mitigation, stormwater water filtration and wildlife habitat. A greener, more welcoming space that also serves a necessary function in a city fighting flooding will demonstrate what can be done in countless other locations.
Even conservation projects that don’t focus on climate change have to take it into consideration. For instance, the Jamaica Bay Wildlife Refuge—part of Gateway National Park in the New York metropolitan area—was hit hard by Hurricane Sandy in 2012. Storm flooding and prolonged saltwater immersion killed many trees that were already competing against invasive vegetation. The Conservancy and four partners are restoring habitat for the roughly 325 species of birds that call the area home or pass through during their migration. “We are planting salt-tolerant coastal species like bayberry, marsh elder and pitch pine so that the next time it floods, there won’t be large die-offs,” explains Lauren Alleman, an urban ecologist with the Conservancy’s New York City program. This stretch of maritime forest is one of many examples of the city’s resilience following a devastating storm.
“Mastic Beach's climate bubble has burst,” says Maura Spery, the mayor of her small harbor town on Long Island. “I moved here to live on the water. It’s beautiful.” But there were trade-offs: She always kept waders in her car to deal with floodwater, maybe three times a year. “Now, I have to do it 12 times a year.”
Mastic Beach isn’t the Hamptons. It’s something even more extraordinary—affordable waterfront housing near New York City. Summer bungalows that were constructed on tiny lots before modern building codes have been expanded and winterized. Some have been newly raised on stilts by homeowners who never intend to leave. But for others, Hurricane Sandy was the moment they realized climate change was making their situation untenable. The solution has been to give risky properties back to nature.
“Climate adaptation isn’t a priority, it’s a necessity,” says Stuart Gruskin, the Conservancy’s chief conservation and external affairs officer for New York. More than a decade ago, the Conservancy embarked on a project to clean up water in the adjacent Great South Bay. As a proof-of-concept project, the organization arranged to buy a house that was built on marshland, its septic field leaching into the nearby water. The plan was to demolish the house and restore its land to a natural state.
When Hurricane Sandy struck in 2012, the storm carved an inlet through nearby Fire Island. The sea surged into neighborhoods, putting them six feet under water. In Mastic Beach, at least 60 homes were declared uninhabitable, and hundreds more were severely damaged. Sandy caused more than $67 billion in damage in an area spanning from North Carolina to Ohio to New Hampshire.
In the superstorm’s wake, Governor Andrew M. Cuomo created a commission to make recommendations on how to prepare New York for future storms and shocks. Mark Tercek, the Conservancy’s former CEO, was a member of the commission. Gruskin, who accompanied him to a meeting, described shocked silence after Tercek asked the group, “How can we responsibly do our jobs if we don’t acknowledge that there are some places where people shouldn’t live?”
Gruskin believes Tercek’s question led to the allocation of hundreds of millions of dollars for buyouts. “Strategic retreat was an enormous breakthrough,” he says. It created policy and funding to help willing sellers move out of high-risk areas. “Without political will and resources, it’s hard to come up with solutions,” he adds. “Post-Sandy, we ended up with a lot of money on the table and politicians who are willing to acknowledge we better do something about this.”
To date, 104 parcels in Mastic Beach are in various stages of being bought out by the town, county, state or federal government. Hundreds of houses have similarly been bought on Staten Island and in Brooklyn, Queens and other parts of Long Island, primarily with federal funds for Sandy recovery. New Jersey has used state and federal funds to acquire 543 properties as of January 2016. The pilot project home in Mastic Beach originally bought by the Conservancy has also been demolished, its property restored to marshland.
Spery admits many potential sellers in Mastic Beach have gotten frustrated trying to navigate the largely uncoordinated government buyback programs. But Gruskin remains optimistic about progress. “The whole idea of undevelopment—the idea of buying people out—is a relatively new approach to coastal resilience. Progress is incremental. Every step forward is a great step.”
On the Caribbean Island of Grenada, adapting to sea-level rise means restoring the natural defenses—coral reefs and mangroves—that once buffered its shorelines. The reefs act as natural wave breaks, and the mangroves help harden shorelines against smaller waves. They also provide necessary habitat for marine life. But both were severely damaged by years of pollution and human use that included mining the reefs and cutting mangroves for firewood. More frequent and severe storms, including a devastating blow from Hurricane Ivan in 2004, further damaged these protective systems, says Nealla Frederick, the project manager in Grenada and a conservation planner for the Conservancy in the eastern Caribbean.
Last year, the Conservancy led local, national and international partners in a pilot project to install almost 100 feet of artificial reef in Grenville Bay. Small pieces of broken coral found on the surrounding seabed were attached to 270 steel baskets filled with rocks and concrete cinder blocks. The cages act as a defense against waves while providing a substrate for new coral. Monitoring indicates that the artificial coral reef is showing early signs of health—growing, crusting with algae, attracting fish. The aim is to expand the reef to 1,000 feet.
In the past two years, an experimental patch of 1,500 red mangrove seedlings was planted along Telescope Beach in Grenville Bay. Because of high wave energy, browsing by land animals and even some recent vandalism, however, most of the seedlings have died. “There is an area that is doing quite nicely because it is sheltered,” Frederick says. “Once we do the full reef buildout, that will provide the necessary protections.” The Grenada Fund for Conservation Inc., a local partner, has established a mangrove nursery, and community members who learned how to do mangrove restoration in the pilot project continue to work on a number of other restoration efforts around the island.
“Going in the water and ‘fixing’ the reef is relatively easy,” says Vera Agostini, director of science and conservation for the Conservancy’s Caribbean program. The real challenge, she says, is making sure such projects involve communities. A partnership with the Grenada Red Cross Society helped the Conservancy engage at the local level—using local materials for the reef restoration and a mangrove replanting project, and hiring local workers, who developed expertise in planning, construction, and marine life monitoring that will be useful for future projects as well as ongoing stewardship. And an alliance with the international Red Cross is expanding to other parts of the Caribbean.
In January 2009, western Washington was drenched by a tropical storm that dumped days of rain and melted the winter snowpack. Rivers on the west side of the Cascades reached flood levels. In the town of Orting, firetrucks with loudspeakers drove through the streets warning the 26,000 residents in the town and surrounding valley to evacuate before the Puyallup River topped its levees. It was one of the largest urban evacuations in the state’s history. Today, Pierce County residents hope that will never happen again.
Pierce County runs from the 14,410-foot peak of Mount Rainier to Puget Sound. That’s one of the greatest elevation changes of any county in the country. Its levee system, which constricted the river into a straightened channel, had been battered by floods since the 1990s. The county could not repair the levees as quickly as they were being damaged, says Hans Hunger, who oversees the county’s flood control efforts.
After the 2009 flood, a partnership between the Conservancy and the state of Washington made drastic changes in the basin. “We got the flood control folks, who historically relied on gray, engineered infrastructure, together with the conservation folks, who relied on protecting and restoring green infrastructure, to work together to build sustainable hybrid solutions,” says Bob Carey, director of the Conservancy’s Floodplains by Design program.
The partnership helped residents move out of harm’s way by buying properties that were inside the floodplain. The new levees were rebuilt well back from the old ones, on average tripling the width of the floodplain. The results were impressive. In 2014 the river flowed at almost the same rate as the devastating 2009 flood, but with the setback levees, nothing happened. The river ran, and the town stayed dry.
This and other Floodplains by Design projects offer ecological benefits beyond the benefits to communities and properties. For salmon, a river that races through a chute is the equivalent of a freeway—not an environment that is conducive to spawning or hatching. When the river is reconnected to its floodplains, the braids and side channels offer calmer conditions, more sources of food and, by connecting the river with adjacent wetlands, inflows of cooler and cleaner water.
The Floodplain by Design approach has spread across the state. Gordon White, shorelines manager for the state’s Department of Ecology, says, “We started to realize the infrastructure we were trying to build was not as good as what Mother Nature had built.”
Natural defenses are not a panacea, but they are a valuable tool. As the number and variety of partnerships grow, the Conservancy’s expertise is increasingly sought after. “The Nature Conservancy has been focused on protecting and restoring rich, dynamic, productive ecosystems that support a huge array of biodiversity,” Carey says. “These are exactly the same places and habitats that create these really effective natural defenses to what climate change is going to throw at us."