How Best to Dredge Montauk Harbor?

    The Army Corps of Engineers is seeking a decision from East Hampton Town about what tack to take for future dredging of Montauk Harbor and erosion control along the nearby western shore.
    At a town board meeting on Tuesday, Brian Frank, an environmental analyst at the Planning Department, laid out the options and their costs, estimates developed in 2010. Three alternatives had been presented by the Army Corps to the town board and to the public at two forums in June.
    The first, to maintain existing conditions at the Montauk inlet, would be fully paid for with federal funds. That plan would call for periodic dredging to maintain a 12-foot depth and 150-foot width in the channel, with a 50-foot wide “deposition basin,” which is an additional dug-out area to collect sand that would otherwise cause shoaling.    
    Under an “enhanced navigation” option, the channel would be deepened to 17 feet below sea level, and the deposition basin widened to 100 feet. A new area of dredging at the southeast end of the inlet would be included, and the spoil would be deposited on the West Lake Drive beach to the west of the inlet.
    Of a total projected cost of $26 million for that work, the town would be expected to pay $801,000.
    The third option would combine the “enhanced navigation” scenario with shoreline stabilization work to address the chronic erosion problems to the west of the channel, along the Soundview Drive beaches. Additional sand from Gin Beach would be deposited there, and three low-profile groins constructed to maintain it, perpendicular to the shore.
    That would create what qualifies under federal definitions as an “engineered beach,” meaning that, should a storm occur and an emergency be declared, the town would qualify for federal money to restore it.
    To complete that work would cost the town $1.5 million, out of a $41 million total. The state would pay $3.6 million, and federal money would cover the rest.
    However, to proceed with option three would also require the town to obtain access to beach and groin construction areas by purchasing land or easements, and to fulfill other federal requirements regarding public access to the area, which would become a public beach.
    “Construction of these groins requires access to these beaches, which we do not have,” Town Supervisor Bill Wilkinson pointed out.
    To achieve the required land access, he said, “would require nearly 100 percent participation [of] the property owners along that stretch,” Mr. Frank said. However, during a public comment period that ended in August, residents in the area said they were not only uninterested in participating, but objected to the idea. They expressed concerns about their property values, particularly the effect of establishing a public beach where the beach is now run privately by a property owners’ association.
    “I think we would be held up a long, long time, for a bunch of reasons, if we exercise option three,” Mr. Wilkinson said.
    Mr. Frank said that the three groins proposed would initially be made of geotextile tubes, and left in place for a trial period of 10 years so that their effect, down drift, could be observed. The groins’ size, height, orientation, and so on could be adapted before they would be permanently constructed out of stone or steel.
    Mr. Frank said both the Planning Department and the Natural Resources Department recommended the second option, which would “provide the best benefit to the town with the greatest flexibility.” Although the town’s staff is not opposed to the more comprehensive plan, “there are too many unanswered questions associated with that,” he said.
    “If there were a viable option for restoring a sandy beach west of the inlet, that’s obviously in everybody’s best interest,” Mr. Frank said, “for the property owners, for the public, for the environment.”
    “The fact of the matter is that Soundview, to Culloden Point, is 80 percent wrapped; it’s already been fortified on 80 percent of it,” Mr. Wilkinson said. Eventually, he said, “I think we need to wrap the other 20 percent of it — and plan for it.”
    Mr. Frank said that both the town code and the town’s local waterfront revitalization program plan “recognize that that’s an area where shore-hardening may be unavoidable.” But, said Councilman Peter Van Scoyoc, “It’s also a section of beach where the L.W.R.P. says there shouldn’t be any perpendicular structures.” Should the town want to proceed with option three, “that would have to be reconciled,” he said.
    “That’s part of the unknown with option three,” Mr. Frank acknowledged.
    Mr. Wilkinson suggested modifying the second, “enhanced navigation” option to include a project the town would carry out, removing sand from the east side of the inlet, at Gin Beach, and adding it to the dredged material that would be deposited to the west. That would also address the buildup of sand at the inlet’s east side, which contributes to shoaling in the navigational channel.
    Mr. Frank was asked to research whether the Army Corps would accept such a hybrid.
    One potential downside of choosing that option, Councilman Dominick Stanzione pointed out, is that “we lose our insurance” if the built-up beach is not designated an “engineered beach” by the Army Corps, thus qualifying it for federal funds should it be eroded by a storm. “If we rebuild  this beach, and we lose this beach, we’re back to square one,” he said.
    But, pointed out Councilwoman Theresa Quigley, if the effort entails only dumping sand, and not building groins, the town wouldn’t be wagering much, nor would it be responsible for rebuilding a huge project after a storm.
    Mr. Halsey said that in his opinion, the rebuilt beach under option two should qualify as an engineered beach, but said he would research that as well.
    Board members also said their decision should take into account a lawsuit that has been filed by Soundview Drive and Captain Kidd’s Path property owners against the town and the Army Corps over the impact of the existing groins marking the channel on their eroding shores.