“Year after year, it gradually went from wild to deteriorated,” said Mr. Berti, whose parents moved to Angola by the Bay, a private community in Lewes, Del., in 1977, where he now lives with his wife, Debbie.
But in 2023, an extensive restoration effort converted a half-mile of shoreline from barren to verdant. A perimeter of logs and rolls of coconut husk held new sand in place. Lush beds of spartina, commonly known as cordgrass, grew, inviting wading birds and blue crabs.
Together, these elements have created a living shoreline, a nature-based way of stabilizing the coast, to absorb energy from the waves and protect the land from washing away.
Mr. Berti had never seen the waterfront like this before. “The change has just been spectacular,” he said.
Before
After
The U.S. government counts at least 150 living shorelines nationwide, with East Coast states like Maryland, South Carolina and Florida remediating thousands of feet of tidal areas. Thanks to the efforts of the Delaware Living Shorelines Committee, a state-supported working group, Delaware has led the charge for years. (...)
“The living component is key,” said Alison Rogerson, an environmental scientist for the state’s natural resources department and chair of the living shoreline committee.
The natural materials, she said, provide a permeable buffer. As waves pass through, they leave the mud and sand they were carrying on the side of the barrier closer to the shore. This sediment builds up over time, creating a stable surface for plants. As the plants grow, their roots reinforce the barrier by holding everything in place. The goal is not necessarily return the land to how it was before, but to create new, stronger habitat.
More traditional rigid structures, like concrete sea walls, steel bulkheads and piles of stone known as riprap, can provide instant protection but inevitably get weaker over time. Bulkheads can also backfire by eroding at the base or trapping floodwaters from storms. And because hardened structures are designed to deflect energy, not absorb it, they can actually worsen erosion in nearby areas.
Though living shorelines need initial care while they start to grow, scientists have found they can outperform rigid structures in storms and can repair themselves naturally. And as sea levels rise, living shorelines naturally inch inland with the coastline, providing continuous protection, whereas sea walls have to be rebuilt.
When the engineers leave after creating a gray rigid structure, like a sea wall, “that’s the strongest that structure is ever going to be, and at some point, it will fail,” said David Burdick, an associate professor of coastal ecology at the University of New Hampshire. “When we install living shorelines, it’s the weakest it’s going to be. And it will get stronger over time.”
And just as coastal areas come in all shapes and sizes, so do living shorelines. In other places that the committee has supported projects, like Angola by the Bay and the Delaware Botanical Garden, brackish water meant that oysters wouldn’t grow. Instead, the private community opted for large timber logs while the botanical garden built a unique crisscross fence from dead tree branches found on site. (...)
Sometimes, an area’s waves and wind are too powerful for a living shoreline to survive on its own, Mr. Janiec said. In these situations, a hybrid approach that combines hard structures can create a protected zone for plants and oysters to grow. And these don’t need to be traditional sea walls or riprap. Scientists can also use concrete reef structures and oyster castles to break up waves while allowing wildlife to thrive.
Gregg Moore, an associate professor of coastal restoration at the University of New Hampshire, said homeowners often choose rigid structures because they don’t act on erosion until the situation is urgent. When it comes to a person’s home, “you can’t blame somebody for wanting to put whatever they think is the fastest, most permanent solution possible,” he said. (...)
“Living shorelines are easier than people think, but they take a little time,” Mrs. Allread said. “You have to trust the process. Nature can do its own thing if you let it.”
by Sachi Kitajima Mulkey, NY Times | Read more:
Images: Erin Schaff
[ed. Streambank and coastal restoration/rehabilitation using bioengineering techniques has been standard practice in Alaska for decades (in fact, my former gf wrote the book on it - literally). I myself received a grant to rehabilitate 12 state park public use sites on the Kenai River (see here and here) that were heavily damaged and eroding from constant foot traffic and boat wakes. Won a National Coastal America Award for innovation. As noted here, most people want a quick fix, but this is a better, long-term solution.]
