The breach in the Fire Island wilderness area has grown dramatically since superstorm Sandy, federal records show, potentially opening up some South Shore communities to flooding.
The area facing Great South Bay has more than doubled in width and the portion facing the Atlantic Ocean has grown by more than 10 times since the Oct. 29 storm cut through the barrier island.
"It's basically an inlet, it's not a breach anymore," Village of Patchogue Mayor Paul Pontieri said. "I think they should seriously look at closing it."
"When you allow breaches to remain and when you get into nor'easter season, you're starting to roll the dice," Suffolk Deputy County Executive Jon Schneider said. "It has a potential to blow a breach wide open and make it difficult to contain."
Schumer still is pushing to fill it in.
"To protect at-risk homeowners on the South Shore from yet another flood disaster, it is important to close the breach," he said in a statement. "Clearly, the longer we wait the more risk we have and the harder it gets."
The breach was one of three created on Fire Island when the Oct. 29 storm hit and the only one that has not been closed by the U.S. Army Corps of Engineers, which would need a request from the state Department of Environmental Conservation and a permit from Fire Island National Seashore.
The park service, which operates the Seashore, has said it would monitor the breach to see if it filled in naturally.
If there is evidence of a danger to the mainland, the breach would be closed, Seashore spokeswoman Paula Valentine said.
The DEC also is monitoring the breach and has not asked the Army Corps to close it, agency spokeswoman Emily DeSantis said.
"While the breach has grown recently, there is no indication that the breach has affected the tidal ranges," she said in an email. "This growth in the breach is typical for this time of year."
The north end of the breach was 276 feet wide at the beginning of November. By the end of February it had grown to 616 feet wide.
The south opening into the Atlantic measured 108 feet wide in early November and was 1,171 feet wide by the end of February. It grew by 558 feet between Feb. 20 and 28.
"That's a remarkable jump," said Charles N. Flagg, a research professor at Stony Brook University's School of Marine and Atmospheric Sciences, who has been studying the breach. "The thing has all of a sudden increased its width by 50 percent within a week."
And the expanse widened more in early March by about 130 feet, according to seashore documents.
"I didn't think it was going to get this big at all," Flagg said.
Initially, the east side of the breach would build up with sand as the west side eroded, but "it doesn't seem to be able to keep up at this point," he said.
Storms since Sandy have pummeled the shore, but in calm periods the width has narrowed, indicating the breach could narrow naturally during a prolonged calm-weather period, said Michael Bilecki, chief of natural resources management at the Seashore.
"We still don't see major increases in water level in Great South Bay, which is the main reason people have concerns," he said.
Environmentalists have supported the park service's position, saying the breach would flush out and improve water quality in Great South Bay, which has a history of declining clam populations and algal blooms.
The bay has shown an increase in salinity, meaning ocean water is flushing in and out and should help clean up the bay, he said.
Brookhaven Town Supervisor Ed Romaine said the town, where the opening is located, had not made a decision about the breach but would also monitor developments. Suffolk County intends to do the same, Schneider said.
Researchers and the national seashore officials have said they think the breach will close on its own. It's close to an area known as Old Inlet, where a breach long ago was located. Fire Island was last breached in the 1990s.
"The question is how fast will it close and how big will it get before closing," said Jay Tanski, a coastal processes and facilities specialist at New York Sea Grant. "There's uncertainty there . . . Is it going to be six days, six months, six years or 60 years."
Aram Terchunian, a coastal geologist with First Coastal Corp. in Westhampton Beach, said he favored closing the breach as soon as possible. One reason is because the bigger it gets, the more expensive it will be to close.
"You don't mess with breaches on barrier islands," he said. "They should have closed it right away."