The U.S. Army Corps of Engineers will host a community meeting in Great Neck on Oct. 24 to discuss a proposed floodgate at Throgs Neck to prevent flooding in New York City during severe storms.
Officials in Nassau County have expressed concern that the project could result in worse flooding on the North Shore.
The meeting will be held from 5 to 8 p.m at the Inn at Great Neck at 30 Cuttermill Road. The Corps of Engineers will discuss tasks in a floodgate study underway since the release of an interrim report in February.
A key task that will be discussed, according to a news release from the Corps, is processing preliminary data obtained from hydrodynamic modeling which identifies possible induced flooding extents and considers measure to minimize the impact.
The new meeting date comes after the Corps canceled a Sept. 10 meeting at the Sands Point Preserve because modeling was not finished, according to Sarah Deonarine, executive director of the Manhasset Bay Protection Committee.
The federal agency is considering installing a floodgate that would span the length of the Throgs Neck Bridge and reach depths of 80 feet, which could result in a rise in sea level in the coastal communities of Nassau County’s North Shore.
A meeting with the agency has been being postponed for months, dating back to May, Deonarine said.
Michael Embrich with the Army Corps of Engineers said that the agency hasn’t postponed any meetings that we been scheduled in regard to the study.
“We are in the very early phases of this study with many more public meetings to come, he said. “We look forward to interacting with the public and garnering as much feedback, data, and insight as possible.”
The Corps of Engineers hosted eight community meetings in various locations throughout the study area in March and April, none of which were on Long Island.
More than that, Deonarine said, local groups have been pushing for a later start time because it is hard for people to get there on time after work. The Sept. 10 meeting was scheduled for 6 p.m., which organizers still feared was too early, she said.
Embrich said that the meeting will go on until 8 p.m. “and we will stay as long as it takes to address everyone’s concerns.”
This isn’t the first time the agency has forgotten about Long Island communities, Deonarine said. North Shore organizations did not hear about the proposed floodgates until about a year ago and had to push for an extension in the public comment period in order to have a public meeting, she said. The public comment period, originally supposed to end in July, was extended until November in order to consider the concerns of Long Islanders.
She said protection committees across Long Island, including the Manhasset Bay Protection Committee and Hempstead Harbor Protection Committee, wrote letters seeking an extension.
Five alternatives to address coastal storm flooding have been proposed by the Corps. Two of the five alternatives, Alternative 2 and Alternative 3A, involve the potential Throgs Neck floodgate in the southeastern Bronx where the East River meets Long Island Sound.
The engineers’ report shows that the potential Throgs Neck floodgate would not prevent flooding in Nassau County’s North Shore communities but instead protect Manhattan.
The Long Island Sound becomes increasingly narrow west toward Manhattan with coast-to-coast distances of less than two miles at points in Port Washington and Great Neck. A rise in sea level as a result of the floodgates could significantly increase flooding in North Shore communities.
The Army Corps of Engineers said in the report that preliminary models have shown that proposed alternatives 2 and 3A may induce flooding in the western Long Island Sound and the New York Bight Apex.
Deonarine said it is important for the meeting with the Corps of Engineers to have a big turnout when it does happen so that the agency “knows we are paying attention outside of the barriers.”
“We hope to be able to bring the federal government, state government, local governments and the community together to discuss this possible project,” said Peter Forman, commissioner of the Port Washington-Manhasset Office of Emergency Management and a Sands Point trustee. “Many are very concerned with the impact that a one-mile-long, massive floodgate and wall would have on the local communities in the western Long Island Sound where the waterway narrows from its widest width of 20 miles out east to as little as 1 mile here.”
“The blocked hurricane-driven waters will have to spill somewhere,” he said.
He said as he understands it, the Army Corps of Engineers is working on further revisions to the published concept plans which the Port Washington-Manhasset Office of Emergency Management looks forward to reviewing.
According to the report, 72 percent of all concerns raised to the Army Corps of Engineers by the community have addressed induced flooding. Many were concerned about possible induced flooding from two directions when the gates are closed: from behind the gates as water accumulates behind the barrier and from outside the gates as the storm surge reflects off the barrier and into the areas adjacent.
The Army Corps of Engineers’ response to the concerns of induced flooding was that it will be further reviewed during the feasibility study and would require mitigation before the project was permitted. Some possible solutions the Corps suggested were the installation of a pump to reduce a rise in sea level and floodgates to reduce damage by flooding.
The report states that 76 percent of community submissions to the Army Corps of Engineers were in regards to the environmental impact of the floodgates on the Long Island Sound’s wildlife and ecology. Long Island Sound is home to hundreds of water species, many of which migrate up and down the estuary and could potentially be restricted by the floodgates.
However, if the selected plan was found to have an unacceptable environmental impact, it could not go forward, according to the Corps’ response in the interim report.
Alternative 2 is projected to address coastal storm surge in 94.7 percent of the study area, which comprises coastal areas in the New York-New Jersey harbor region. Alternative 3 is expected to impact coastal storm flooding in 58 percent of the study area. Neither will address coastal flooding east of the Throgs Neck Bridge.
Deonarine said that the floodgates will make the impact of storms like Hurricane Sandy in 2012 much worse.
“I understand we need to protect Manhattan,” she said, “but not at the expense of communities outside the barrier.”
She said there wouldn’t be too much of an effect from the gates when they are opened, but when closed areas that experience flooding could see a rise in floods.
However, the permanent infrastructure of the floodgates could disrupt habitats, shift sediment flow and decrease dissolved oxygen levels, she said.
The public comment period was closed in May despite the lack of a meeting on Long Island.
The interim report was released by the Army Corps of Engineers in February, and the tentative selection of one of the alternatives is expected by January 2020.
“We need everybody to be aware of this,” Deonarine said. “Not just elected officials, but the public should pay attention because this affects their wellbeing and their lives.”