Town Testing New "Cliff Stabilizers" To Combat Erosion

Over the past three years, Madaket Beach has lost 19 feet of coastal bank due to erosion. The intersection of Ames Avenue and Madaket Road is now perilously close to the shore, and the town is considering the possibility that continued erosion could cut off the only public access to Smith's Point in the near future.

Those are among the reasons why the staff members of the town's Natural Resources Department were on their hands and knees Tuesday, installing a grid of green, honeycomb-shaped devices and planting beach grass within them. 

The new technology is called a "Cliff Stabilizer" and the town has launched a pilot program to install the devices at Madaket Beach and Dionis Beach to assist with dune planting. Leah Hill, the town's coastal resilience coordinator, has spearheaded the project and recently secured approval from the Conservation Commission to move forward with the two installations.

Each Cliff Stabilizer contains "cubbies" which are intended to shelter plugs, seedlings, and seeds from erosive forces, affording them the stability and time to grow root systems into the sediments. Once the roots of the beach grass become established, the devices are intended to be removed.

The Natural Resources Department told the Conservation Commission it will collect data including elevations, plant density and mortality, and erosion rates of the coastal bank before, during, and after the pilot project.

"The intersection of Madaket Road and Ames Avenue is about 45 ft from the edge of the bank to the edge of the intersection," Hill wrote in the notice of intent to the Conservation Commission. "If that intersection is lost due to erosion, the result would be an isolation risk to all Smith’s Point residents plus the broader Nantucket community who recreate there. In addition, emergency services would not have access to this neighborhood. The Town has received many letters from concerned citizens from Smith’s Point urging us to take action to preserve the longevity of this critical intersection. The goal of the pilot project is to evaluate new technologies for passive dune restoration in both a high and low-erosion area."

While it's not the massive expansion of the geotube project the town is pursuing with the Sconset Beach Preservation Fund on the east end of the island, the members of the Natural Resources Department hope that the pilot project can prove the concept works, and install the technology at other sites around the island.

The Cliff Stabilizers were developed by Coastal Technologies, based in Long Island, NY.