Living shorelines: Along the N.C. coast, preparing for rising waters with natural remedies

A few miles north of the Surf City high-rise bridge on the mainland side of the Intracoastal Waterway, Richard Moore carefully planted a saltmarsh cordgrass plug in the shallow water just a few feet from the shoreline. 

A volunteer from Cisco’s sprawling operation in Research Triangle Park, Moore has worked on building and maintaining several living shorelines along the N.C. coast over the years.

“To see how it’s grown, changed and matured is fantastic,” he said on this muggy late August summer morning, ticking off all of the shellfish and other marine life he’s seen when he's returned to old projects. “It’s really rewarding.” 

Nearby, dozens of other volunteers from other groups, including the Marine Corps, planted more marsh grass and picked up trash as the wake from a passing Grady White lapped up against the shore of the N.C. Coastal Federation’s living classroom at Morris Landing. 

“These shoreline areas are where the land meets the sea, and they are very dynamic areas,” said Ted Wilgis, a coastal scientist with the federation, as he paused knee-deep in water after planting several cordgrass plugs. “And they're tougher than they look."

Adapting instead of defending

Americans have always been attracted to the sea. Initially, it was for sustenance and trade. But in a trend that has been increasing since World War II as the country became more wealthy and mobile, it has been for recreation and retirement. In Southeastern North Carolina, for example, the population of New Hanover, Brunswick and Pender counties between 1990 and 2020 more than doubled from nearly 201,000 to roughly 422,000, according to the U.S. Census Bureau.

Related:People are moving to NC from other states in droves. Where are they coming from, and why?

But as people and properties have crowded the coast, waterfront land has become more valuable. And as much of the shoreline has been “hardened” to protect if from erosion and create more “attractive” backyards, those coastal areas have become less flexible in responding to the environmental pressures a changing climate is increasingly placing on them.

Bulkheads, riprap and other armoring of shorelines is today a common sight along tidal creeks, estuaries and canals along the Tar Heel State's coastline. 

But a new, more flexible approach to shoreline management is gaining converts along the coast — helped in part by the looming challenges climate change promises to bring to coastal areas. Among the supporters are N.C. legislators, who have included $2 million to help promote living shorelines in the proposed state budget bill now working its way through the General Assembly.

This softer approach, which works best in low to moderate wave-energy areas, doesn't attempt to stop the added force brought to bear on coastal shorelines by higher tides and stronger storm surges. 

Instead, it tries to adapt with them.

Nature-based approach

Dr. Tracy Skrabal, a coastal scientist with the coastal federation and manager of the nonprofit environmental group's Southeast Regional Office in Wrightsville Beach, remembers initial wariness when she started promoting living shorelines in the 1990s. 

“I would say healthy, very healthy skepticism,” she said of the raised eyebrows she often received from property owners and local officials.

But as North Carolina's 20-year unlucky run with tropical weather systems repeatedly scoured many coastal areas and awareness grew about the impending impacts from sea-level rise, Skrabal said interest reached a "tipping point."

"But it's one thing to say it," Skrabal said of embracing a nature-based approach to protecting shorelines. "It's another thing to see it in your neighborhood."

The growing interest, and the hope of educating and bringing in more converts, is at the heart of the federation's efforts at Morris Landing. The 52-acre waterfront property in Holly Ridge, which has nearly 3,000 feet along the Intracoastal Waterway, consists of living shorelines made from different materials, including marsh grasses, limestone marl, oyster shells and wooden sills.

"We want to see how different materials, different structures respond to weather and environmental variables, and we want to be able to share and show that with researchers, marine contractors and other officials," Wilgis said.   

According to the National Oceanic and Atmospheric Administration (NOAA), benefits of living shorelines include purifying water, buffering floods, reducing erosion, storing carbon and creating habitat for a host of marine critters.

The move toward more natural coastline protection comes as officials focus more on resilience as they plan for how communities will adapt to climate change. Federal and local studies have found evidence that shorelines with intact natural coastal habitats not only see less damage, but bounce back more quickly from severe storms. 

"I think they are a whole lot better than the alternative, which are often barren wastelands for the environment," said Dr. Larry Cahoon, a biological oceanographer at the University of North Carolina Wilmington.

He said rather than reflecting wave energy, living shorelines absorb and dissipate it more naturally without causing further damage to neighboring properties. That helps retain sediment, which in turn reduces erosion woes that can quickly buckle bulkheads and undermine other hardened structures.

Living shorelines also can move with the water, rolling inland as water levels rise. They also bounce back quickly, requiring little or no upkeep aside from removing trash and other debris that might harm the grasses and marine life or limit sunlight.

"You don't have to sacrifice environmental protection for property protection," Skrabal said. "Hardened structures are literally a line in the sand that offer very little, if any, flexibility."

Then there are the habitat advantages. The sea grasses and other natural structures used in living shorelines provide shelter and habitat for a host of marine life, from juvenile fish to crustaceans, and promote biodiversity, which creates a healthier ecosystem, Cahoon said.

"Across the board they are much better than what else we do," he said.  

Federal and state officials also have gotten on board in recent years, aiming to streamline the permitting process for living shorelines and engaging with groups like the coastal federation to host workshops for contractors and other marine professionals.

Economically viable?

Like any shoreline stabilization effort, designing and building a living shoreline isn't cheap and is often site-specific. But in general they come in as a little bit cheaper than a bulkhead or other hardened structure, Cahoon and Skrabal said.

Although factors from labor to access to materials to challenging locations can influence costs, NOAA states that a living shoreline costs anywhere from well less than $1,000 to $5,000 per linear foot to install, with maintenance fees generally less than $100 per foot per year.

That ease of maintenance is a clear advantage for living shorelines, Cahoon said.

“They tend not to require expensive replacement like that required with bulkheads, which when they fail, fail at the bottom," he said. “Definitely long term living shorelines are cheaper because maintenance is a lot less."

Skrabal said the $2 million in the proposed state budget, which seems to have bipartisan support, would be used to provide cost-share for living shoreline projects where other match sources don't cover all of the costs.

Looking at things differently

While the use of living shorelines is growing in popularity among residents in the mid- and northern sections of the North Carolina coast, private projects are still relatively uncommon in Southeastern North Carolina. Part of that is due to how much of the region's tidal creeks and canals have already been stabilized with bulkheads and other hardened structures, Skrabal said.

A map by the N.C. Division of Coastal Management of marsh sills constructed from 2000-18 found that two-thirds of them were found in just three of North Carolina's 20 coastal counties — Carteret, Dare and Hyde.

That's led local governments and other public entities to take the lead in promoting and building living shorelines in the state's southern coastal waters. Among the most recent living shorelines are a trio of projects in Topsail Beach on soundfront, lot-sized properties owned by the town. 

Town Manager Mike Rose said the balance between the human footprint and the natural resources is what draws people to the coast in the first place. When one overtakes the other, with consequences that can include increased shoreline erosion, declining water quality and nuisance flooding, it encourages the idea of at least contemplating new solutions.

“I think our board recognized that we have to look at things a little differently,” he said, noting Topsail Beach tapped some post-Hurricane Florence recovery and resiliency funds to cover the $30,000 cost of the living shoreline work.

With one project finished and work on the other two starting soon, Rose said residents have begun to notice and give feedback.

"Overall it's been positive, but there has been some concern about walking over the oyster shells," he said, since one of the living shoreline uses bags of oysters to provide structure. Officials have left an open space through the living shoreline to allow people, including kayakers, to still have access to the waterway.

"But there's a lot of interest, and people want to see how they work," Rose added.

Skrabal said that's a comment she's hearing a lot these days.

"People want to know will it work as well as a bulkhead," she said. "In most cases, that answer is clearly yes while also retaining access to the water."

Reporter Gareth McGrath can be reached at GMcGrath@Gannett.com or @GarethMcGrathSN on Twitter. This story was produced with financial support from 1Earth Fund and the Prentice Foundation. The USA TODAY Network maintains full editorial control of the work.