Protecting NYCIn 2009, engineers predicted surge threats to N.Y.-N.J. and offered detailed mitigation measures

The leaders of the U.S. top engineering association, reflecting on the destruction inflicted by Superstorm Sandy, say that more than three years ago the association presented studies showing that a devastating storm surge in the region was all but inevitable.

The New York Times reports that the warnings were voiced at a conference in New York City convened by the American Society of Civil Engineers (ASCE). The Times notes that the ASCE’s findings are so respected that they are often written into building codes around the world.

Scientists from business, academia, and government attended the meeting and presented computer simulations of the storm-surge threat to NYC, and detailed engineering ideas and designs aiming to counter such surges.

Officials from the city’s Office of Emergency Management and the U.S. Army Corps of Engineers took an active part in the conference.

The Times notes that participants in the 30-31 March 2009 conference called on NYC officials seriously to consider whether to install surge barriers or tide gates in New York Harbor to protect the city. Their views and idea are contained in a book, titled Storm Surge Barriers to Protect New York City: Against the Deluge, scheduled for publication non 3 December.

Surge barriers and sea gates are large, costly, and time consuming engineering projects. Even if the federal, state, and city governments were to adopt these idea and start building in 2009, they would not have been ready to prevent to damage inflicted by Tropical Storm Irene last year or Superstorm Sandy.

Some of the participants in the 2009 seminar see parallels to alarms which were ignored before Hurricane Katrina struck New Orleans in 2005. “Scientists and engineers were saying years before Katrina happened, ‘Hey, it’s going to happen, folks. Stop putting your head in the sand,’ ” said Malcolm Bowman, a professor of oceanography at the State University at Stony Brook who spoke at the conference and is an editor of the proceedings.

“The same thing’s now happened here,” Bowman said.

He said the most workable plan would involve a roughly five-mile barrier from Sandy Hook, New Jersey, to the Rockaway Peninsula. A smaller barrier would stretch across the top of the East River to protect against surges from Long Island Sound.

East River barriers might rise from the ocean floor using hydraulics as a threat approached, and the larger barrier would require locks and sluiceways to allow ships and water to pass during ordinary times (see “Flood-proofing New York City with storm barriers,” HSNW 1 June 2009).

Mayor Michael Bloomberg has expressed doubt about such barriers and whether the benefits would outweigh the costs — well over $10 billion, by most estimates. Governor Andrew Cuomo has said in recent days that barriers were worth seriously examining.

The Times reports that engineers who were at the 2009 conference said that while the technology comes with many questions, it has already been deployed around the world, including in the Netherlands and on the Thames in London. Several American cities have versions of the structures, and a sea barrier surrounds St. Petersburg, Russia.

Dr. Jeroen Aerts, a researcher from the University of Amsterdam who was retained by NYC in 2009 to assess flood risks and protections, said he was asked by officials to look into barriers after Tropical Storm Irene.

Aerts said that he was still working on the research, but that the city should consider such a proposal. “Obviously, there’s a sense of urgency now,” he said.