Experts: sea barrier in narrows could prevent surge
The vast destruction wreaked by the storm surge in New York could have been prevented with a sea barrier of the type that protects major cities in Europe, some scientists and engineers say.
“The time has come. The city is finally going to have to face this,” said oceanography professor Malcolm J. Bowman at Long Island’s Stony Brook University. He has warned for years of the potential for a catastrophic storm surge in New York and has advocated for a barrier.
Invited by Bowman and his colleague Douglas Hill, two European engineering firms have drawn up proposals for walling most of New York off from the sea, at a price just above $6 billion.
“With the kind of protection that has been considered so far, you cannot protect a multimillion-inhabitant city that runs part of the world economy,” said Piet Dircke, who has worked on the extensive system of sea barriers in the Netherlands with the Dutch engineering firm Arcadis.
His firm’s proposal is to build a barrier in the Narrows near the Verrazano Bridge between Brooklyn and Staten Island, shielding Upper New York Bay. It would be supplemented by two smaller barriers, one between Staten Island and New Jersey and the other on the East River.
Such a barrier would have protected Manhattan and much of Brooklyn and Staten Island from Sandy, but left southern Brooklyn and Kennedy Airport exposed.
Graeme Forsyth of CH2M Hill in Glasgow has worked on St. Petersburg’s barrier, which consists of 16 miles of levees and gates shielding the city, built on what was once a swamp, from the Baltic Sea and the river Neva.
The centerpiece of his firm’s early-stage proposal for New York is a levee-like barrier that would stretch five miles from the Rockaway peninsula in Queens on Long Island to the Sandy Hook promontory in New Jersey. The barrier would stop a surge of 30 feet, twice the height from Sandy. Gaps would allow ships, river water and tides through, but movable gates could close off all of New York Bay from the Atlantic when necessary.
The barrier would protect most of the city, with the exception of Rockaway itself. It would also shield parts of New Jersey.
Before the storm, Mayor Michael Bloomberg’s administration had said it was working to analyze natural risks and the effectiveness of various coast-protection techniques, including storm-surge barriers.
But officials had noted that barriers were only one of many ideas, and they have often emphasized more modest, immediate steps the city has taken, such as installing floodgates at sewage plants and raising the ground level while redeveloping a low-lying area in Queens.
Engineers know this approach as “resilience” — essentially, toughening the city piece by piece to make it soak up a surge without major damage. But the European engineering firms see this as unrealistic, given the vast amount of expensive infrastructure that underpins New York.
Robert Trentlyon, a New York community activist who has been advocating for storm-surge barriers, sees the one-two punch of Hurricane Irene in 2011 — which came within a foot of flooding subway stations in southern Manhattan — and Sandy as a sign that the time has come.
“Having had two storm surges within one year, and their both being major ones, I just find it very difficult to think the city could not go ahead and act,” the retired local newspaper publisher said by phone Sunday from his Chelsea apartment, which was left without power.