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Hempstead planting beach grass to save the dunes

Town of Hempstead worker Michael Ryan knelt in the sand on a recent frigid day and placed a fistful of beach grass in an 8-inch-deep hole.

He scooped up more sand, rolled it between gloved fingers to break up the clumps, then tamped it down around the stalks. Then he moved on to the next hole about 18 inches over, one of dozens stretching in a line down the town beach at Point Lookout.

For decades, Hempstead has planted beach grass along the shoreline to build up dunes and prevent sand from being carried away by wind or water. It's a common strategy used along the Atlantic coast to protect low-lying buildings and roads from tidal flooding and storm surges.

"We did this just around the bend last year," said Ryan, a worker with the town's Department of Conservation and Waterways. He pointed east, to a series of rolling dunes dotted with vegetation that stand between the beach and Ocean Boulevard. "They took very well. They're still standing."

This winter, the town plans to combat coastal erosion by sowing three acres of beach grass west of Point Lookout. Hempstead spent $5,500 on plants; labor will be done by volunteers and employees in the Department of Conservation and Waterways.

Recent storms have narrowed Point Lookout beaches by 50 to 70 feet, the town estimates. That puts the infrastructure behind them in danger, said Ron Masters, Hempstead's commissioner of conservation and waterways.

Many homes vulnerable

There are 800 homes in Point Lookout, and probably another 500 in Lido Beach, Masters said. Lido Boulevard, the main artery just north of the town beach here, is the only evacuation route on this side of Long Beach island.

The beach by Point Lookout is particularly vulnerable because the Jones Inlet steals sand that would ordinarily flow west along the shoreline, said Jay Tanski, a coastal specialist at New York Sea Grant. Some gets sucked into the bay; some washes offshore, forming a shoal visible at low tide.

The grass is going in atop sand that was dredged from Jones Beach Inlet and pumped onto the beach in March 2008.

"Before the 2008 project, water was running up the beach," Masters said. "The dune was getting scarped from continuous nor'easters."

The hope is that the 50,000 stands of beach grass planted this winter will anchor that borrowed sand and build up the fledgling dune.

Known scientifically as Ammophila breviligulata, beach grass is a native plant found from Maine to North Carolina. It grows quickly and thrives in arid, nutrient-poor conditions.

"It has a deep root system, so it can go down and tap the water table," said Denise Seliskar, a research scientist at the University of Delaware who specializes in intertidal plants. "It doesn't necessarily like to have its roots in salt water, but the tops of the plants can handle some salt spray."

Those deep roots extend several feet down, forming dense structures that knit belowground and spread horizontally, stabilizing dunes. The plants reach 2 to 3 feet tall and continue to grow even when buried by heavy deposits of sand. The grasses help increase dune height by capturing sand as it blows past.

"It works like a snow fence," Seliskar said. "They cause the wind to slow down, and the sand drops out of the air and forms a dune."

Transplanting in fall, winter

Experts say the best time to plant is between October and April, except when the soil is frozen. Cool temperatures and wet weather let the transplants gain a foothold before being exposed to the heat and relative lack of water in summer, Seliskar said.

The town had hoped to rally volunteers for a planting in December, but the event was canceled after the Dec. 19-20 blizzard dumped 2 feet of snow on Long Island. Masters said the town would put out another call when the weather thaws.

"Down by us we can see the effects of how good this beach grass is," Mark Dirolf, president of the Lido Beach Civic Association, said at a recent event to publicize the plantings. "During the last storms, it really has saved our dunes and protected our area."

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