CLIMATEWIRE | Climate adaptation comes in myriad shapes and sizes. In Westchester County, N.Y., it could take the form of bored-out concrete domes that look more like D-Day bunkers than green infrastructure.

The unusual shoreline structures — essentially half-spheres with port-sized holes — are turning up in tidal areas along the Atlantic Coast to help reduce the scouring effect of waves and storm surges on fragile marsh and shoreline habitat.

Westchester County hopes to deploy the structures known as “reef balls” as part of a Long Island Sound “living shoreline” project in Rye, N.Y. Storms and rising tides in the region’s coastal zones are threatening nearshore structures, including an iconic amusement park and the Edith G. Read Wildlife Sanctuary.

Officials say nearly 40 feet of the town’s shoreline has eroded since Superstorm Sandy slammed into the area in October 2012, a problem exacerbated by more recent storms like Hurricane Ida and king tides that rise ever closer to the shore.

Robert Doscher, an environmental planner with Westchester County, said reef balls can be as effective as seawalls, permanent breakwaters and other more expensive gray infrastructure at a fraction of the cost.

“It’s like a belt-and-suspenders type of approach,” Doscher told Westchester County’s Journal News. “It’s different layers that will break up the waves and help the shoreline stabilize.”

Placement of more than three dozen reef balls, each weighing between 1.5 and 2 tons, is expected next year at a cost of roughly $1.5 million, officials say, and is one of several elements of the living shoreline project at Rye. The balls will be visible above the water at low tide and disappear at high tide, officials said.

Reef balls aren’t new. The concept was pioneered decades ago to create artificial coral and oyster reefs in warm-water environments. The Florida-based Reef Ball Foundation has deployed balls of different sizes in coastal zones from the Hudson River and Tampa Bay to Malaysia and Indonesia, mostly for the purpose of restoring oyster beds.

Between 2014 and 2016, researchers from Sacred Heart University in Fairfield, Conn., and the University of Connecticut completed a pilot project to measure the effectiveness of placing more than 300 of the structures along an eroding shoreline at Stratford Point, Conn.

It worked. By breaking waves before they reached the shore, the balls reduced wave heights by half and lessened wave energy by an even greater factor, according to James O’Donnell, an oceanographer at UConn and director of the Connecticut Institute for Resilience and Climate Adaptation.

The balls will last between 10 to 15 years before weathering away. “They’re not like rocks that are going to stay there forever. The concrete will degrade when they’re exposed to the air," O’Donnell said in an interview.

In colder climates, the balls will deteriorate even faster due to freezing temperatures and ice buildup.

Sacred Heart professor and biologist Jennifer Mattei, who led the Connecticut project, said she was drawn to the idea of using reef balls because they are effective at capturing sediment and allowing fish and other marine life to pass through the holed structures.

"If you go out in these areas that have slightly rougher seas and try to plant a salt marsh, it just gets washed away," she said. “I wanted to make sure fish, horseshoe crab, even terrapins, can access the water and the beach without being blocked by a breakwater."

Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2022. E&E News provides essential news for energy and environment professionals.