News
12.03.2012
Venice on the Hudson?
New York considers massive floodgates to protect against storms.
Courtesy Arcadis

Hurricane Sandy has made it abundantly clear that addressing New York’s vulnerability to storm surges and rising sea levels is of paramount importance. Through the Mayor’s Office of Long Term Planning and Sustainability, the Bloomberg Administration has commissioned a study of major flood barrier infrastructure, with a draft report due in February.

“This hurricane has put everything upside down,” said Jeroen Aerts. Aerts, a professor of  environmental studies at the Free University of Amsterdam, spoke in a phone interview from Holland, where he has been working for the past few years on the draft report.

Aerts said that his instructions from the city were to do a cost-benefit analysis of two strategies. “One is looking at upgrading the current regulations—focusing more on building codes, zoning regulations, and flood insurance—as compared to developing levees and surge barriers,” he said.

Currently, Aerts and his team are analyzing two gate options. One, which would cost about $10 billion, involves a set of gates running between Sandy Hook and Breezy Point, and another in the East River in the area of Throgs Neck and the Whitestone Bridge. The second option, estimated to cost about $17 billion, involves three to four barriers that would cut off the Arthur Kill tidal strait between New Jersey and Staten Island, the Verrazano Narrows, the East River, and perhaps Jamaica Bay.

Determining whether or not gates are necessary may be one of the most critical decisions that elected officials make for the future of the New York City metropolitan region. Because of its low coastal settings and large population, New York is one of the areas most vulnerable to climate change in the United States.

Although Aerts’ report is not finished, Mayor Michael Bloomberg appears to be resistant to the idea of gates and levees. “I don’t know if there’s any kind of practical way to build barriers in the ocean, when you have an enormous harbor, like we do, and Long Island Sound,” the mayor said in a press conference in the aftermath of Sandy. “Even if you spent a fortune, it’s not clear to me you would get much value for it.” Governor Andrew Cuomo, however, has said such barriers might be necessary.

Some scientists, however, say that it is already clear that upgrading the city’s infrastructure to make it more resilient against future storms is not enough. “In a time of limited budget and economic stress, the mayor has done exactly the right thing, but you cannot flood-proof the city against a major catastrophe,” said Malcolm Bowman, a professor of Oceanography at State University of New York. “So there needs to be a longer-term plan that will weatherproof the city to a much higher degree.”

Bowman, who helped organize an American Society of Civil Engineers conference several years ago that warned of future devastating storms, said that floodgates could be designed to function as a roadway for vehicles and even trains going between New Jersey and Long Island.

“There is such a huge transportation bottleneck getting through New York City or Northern New Jersey,” Bowman said, adding, “I think that the gates could be hugely popular—there could even be a toll road there to pay for it.”

For his part, Aerts is reserving judgment. “I don’t have an opinion about floodgates,” he said, “What I can do is provide the relevant information on the basis of which you can make a decision.”

Alex Ulam