Tuesday, February 27, 2024

What does it mean that our shoreline is ‘hardening?’ It’s not good

Every year, the North Carolina coastline loses approximately 20 miles of the estuarine shoreline to vertical wall hardening through the installation of bulkheads and riprap, and local beaches are among the most hardened

(Author’s note: This is part one of a three-part series examining southeastern North Carolina’s hardened shoreline.)

SOUTHEASTERN, N.C.—Every year, the North Carolina coast is getting harder—and that’s not a good thing.

“We lose on average 26 miles a year to vertical wall hardening,” Ted Wilgis, a biologist for North Carolina Coastal Federation, said.

RELATED: Here’s how an artificial reef, oyster bed is being built near Carolina Beach 

Shorelines get “hardened” through the installation of bulkheads and the piles of large, loose rocks known as stone riprap. Bulkheads—vertical structures installed parallel to bodies of water—are common in areas where wave energy is high, like the Wilmington Riverwalk.

Designed to reduce erosion and protect property lines, bulkheads and riprap can have an invasive, jarring impact on natural wetland habitats, according to Wilgis.

“You’ve lost that gentle sloping interface that provides the nutrients, the habitat, the water quality, the natural energy-interchange between the land and the water,” Wilgis said.

In the absence of a natural shoreline to transfer wave energy, Wilgis said a hardened shoreline can create an unintended ripple effect.

“If your neighbor doesn’t have a bulkhead, it forces energy back into their line, forces them to install a bulkhead as well,” he said.

Southeastern North Carolina

Where tourism reigns and property values rise, natural shorelines are losing out to bulkheads.

In Wrightsville Beach, over 38 percent of the existing estuarine shoreline is consumed by bulkheads and riprap. That’s over six times the state average.

In Carolina Beach, hardened installments make up over 28 percent of the estuarine shoreline, according to a North Carolina Division of Coastal Management’s mapping project, updated in 2015.

The percentage of estuarine coastline, by mileage, that has been ‘hardened’ through bulkhead and riprap. The estuarine coastline mileage is not inclusive of oceanfront measurements. (Port City Daily/Johanna Ferebee)

North Carolina’s coastline is softer than the nation’s average. The most recent mapping research measures the United State’s shoreline is 14 percent hardened, while North Carolina’s is 6.3 percent.

In higher-density development areas, Wilgis said installing bulkheads and riprap is just what’s known.

“People want to be on the shoreline, which is understandable, but they want to harden the shoreline, landscape out to the edge of the bulkhead.”

Protecting property

Through sea level rise, extreme tides, increased boat traffic and other factors that contribute to erosion, coastal property owners are losing their land and money.

“They spend half a million dollars or more on property, they don’t want to lose an inch,” Hal Fogleman, owner of Allied Marine Contractors, said. 

Fogleman serves coastal property owners in southeastern, North Carolina. With a background in biology, Fogleman aims to steer clients toward bulkheads only when necessary.

“I’m aware of the argument on both sides, for and against bulkheads and living shorelines,” Fogleman said. “I think they both have their place.”

In high wave energy areas, he said alternative erosion techniques are not realistic if property owners want to protect their existing acreage. “These big yachts coming through on the waterway really do a lot of damage,” Fogleman said.

He said the Coastal Area Management Act prevents marine contractors and property owners from encroaching on existing wetlands.

“It’s not like we’re destroying marsh grass to put in a bulkhead,” Fogleman said. “Normally what we put in is a vinyl bulkhead, the way the CAMA rules work that’s got to be behind any marsh grass.”

Post-storm damage

Anne Deaton, a habitat assessment coordinator for the Division of Marine Fisheries, said bulkheads aren’t as strong as they look.

“A bulkhead, just looks,” Deaton said. “People think, ‘oh it will be strong.'” 

A 2012 University of North Carolina-Chapel Hill study found that over one-third of all bulkheads along the back-barrier shoreline in the Outer Banks were damaged or had collapsed completely. The study found no damage had incurred to a natural marsh sill, a living shoreline alternative to bulkheads. 

Bulkheads interfere with salt marsh function and inhibit upwards migration of shoreline habitats, thereby leading to the loss of habitats critical to fish production,” the study states.

Though CAMA prevents bulkheads from being installed on existing wetlands, Deaton said bulkheads behind vegetation can still cause damage. According to Deaton, when waves crash against the harsh, vertical wall, surrounding wetlands can get wiped out.

“It ends up having more wave energy when it hits that can scour out the wetlands that are in front of it,” Deaton said.

She said wetlands are the “big loser” with bulkheads. Between non-point source runoff pollution, higher wave energy, and unstable sediment, hardened shorelines can cause a slow burn.

“It’s death by a million cuts,” Deaton said. “We don’t understand the impacts that we all have, collectively.”

(Friday, part two: “3 days vs. 3 months? Regulatory structure makes it tougher to install living shoreline.”)


Johanna Ferebee can be reached at johanna@localvoicemedia.com or @j__ferebee on Twitter

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