Hurricane Gets Credit for Surprising Accumulation of Sand on Nearby Ocean Beaches

Beaches from Sagaponack to Water Mill have gained sand over the past five years.

Against all expectations, the amount of sand in a six-mile stretch of ocean beach between Town Line Road in Sagaponack and Flying Point Road in Water Mill has continued to increase over the years since a $26-million beach nourishment project was undertaken in 2013 by oceanfront property owners and the Town of Southampton.

“The bottom line is we have in excess of 100 percent of the material we placed five years ago,” the project’s coastal consultant Aram Terchunian of First Coastal Corp told the Southampton Town Board at a work session on June 13 at which he presented the results of a five-year assessment of the project.

“We were thinking we were going to lose something on the order of 5 percent a year,” he said, with the gradual loss through natural erosion of the 25 million cubic yards of sand that was pumped from the ocean floor onto the formerly narrow beach. “Instead we haven’t lost anything.”

He said the “wider, dry sandy beach is a source blowing sand into the dune,” which has added two cubic yards of sand for each linear foot of dune over five years.  That means “over 175,000 cubic yards of sand has accreted into the dune by blowing off the beach,” he said.

Ironically, Mr. Terchunian attributed the surprising result to Hurricane Sandy in 2012, which further gouged an already narrowed and storm-battered beach. Sandy’s 30-foot also waves stirred up sand from a normally undisturbed area of sea bottom well offshore, about 30 to 34 feet below the surface, shifting sand into shallower water, where normal wave action could bring it onto the beach.

“That bump is material,” he said, and without a similar storm event that replenishes that offshore source of sand, the beach is now beginning to lose sand and will continue to lose 5 percent of the total each year. That means the beach won’t be back to its “pre-nourishment” levels until 20 years from now, he noted.

The beach is monitored “to keep track of how much sand is in the sandbox,” Mr. Terchunian said, that is bounded by the crest of the dune line on the north, a depth of about 20 feet of water offshore to the south, and between Town Line Road on the east and Flying Point Road on the west. Annual monitoring is required “to make sure the project is working according to specs,” Mr. Terchunian said, and to qualify for a reimbursement of up to 87.5 percent of the cost of re-nourishing the beach in the event of a major storm and a presidentially declared disaster.

To gauge the amount of sand on the beach, Mr. Terchunian explained that GPS measurements are taken at varying levels every 500 feet between Town Line and Flying Point roads, from the dune out to 30 feet of water.

After the Town Board cleared the way with formal resolutions in 2010 to allow it, oceanfront property owners in Sagaponack, Bridgehampton and Water Mill voted 65 to 49 in a 2013 referendum to raise $24 million to replenish their eroded beachfront with sand pumped from offshore.

The project will encompass six miles of contiguous shoreline, including 141 properties, five of which are beaches owned by Southampton Town. The town added $1.5 million to the funding for the project.The Southampton Town Board’s five members serve as commissioners of both erosion control districts and issued the $24-million bond to finance the project, which is being repaid by homeowners and the town over a 10-year period.

Mr. Terchunian praised then-Supervisor Anna Throne Holst and the Town Board at the time — only one member of which, Christine Scalera, still sits on the board — and the homeowners for what he called “a visionary project” that he noted recently was “recognized as one of the top four restored beaches in America by the American Shore and Beach Preservation Association.”

Among the homeowners, he singled out as “spark plugs” who went door to door to convince their neighbors to support the plan: Alan Stillman, Barbara Slifka, Jeff Lignelli, David Letterman and Michael Cooper. “They really rolled up their sleeves and it’s a credit to them.”

There are a few properties west of the Mecox Bay cut with less sand than they had before the nourishment project, an anomaly Mr. Terchunian said was associated with the opening of the cut and the movement of sand into the inlet, where it shoals and fills in. He noted chief town environmental analyst Martin Shea will soon release a management plan for the bay that will address that and other issues.