New York City flood protection won't be easy

By Adam Geller

Associated Press

Published: Monday, Nov. 26 2012 12:00 a.m. MST

A 16-foot-wide prototype was tested in the Washington, D.C., Metro system in 2008, with highly pressurized smoke proving its ability to seal off a tunnel with irregular contours, said Ever Barbero, a professor of aerospace and mechanical engineering at West Virginia who developed the plug. Barbero said plugs, which could be made to varying sizes, could also be used to seal highway tunnels like the ones that flooded in New York.

After New York was hit by Sandy, "I told my co-workers we have our work cut out for us for the next 20 years," Barbero said.

The subway system would be a particular challenge, requiring flood gates, plugs or some other closure at thousands of vulnerable openings.

"A technology like this might be useful to plug certain points but it certainly is not an end-all, be-all answer to everything," said Dave Cadogan, director of engineering for Frederica, Del.-based ILC Dover, which has a contract to manufacturer the plugs. He and Barbero estimate they are still a couple of years away from marketing the plugs, with ones similar to the prototype likely to sell initially for about $400,000.

— ELECTRIC GRID: With Sandy pounding the coast, New York power supplier Con Edison preemptively shut down three networks serving parts of lower Manhattan and Brooklyn to prevent damage to equipment. But widespread outages were prolonged after a 14-foot surge inundated the utility's 13th Street substation, swamped critical gear located just over 11 feet above sea level, and caused an explosion. Also, above-ground lines in New Jersey and New York were taken down by falling trees.

Moving or shielding key components of the electrical distribution system would alleviate such problems, but that will be more challenging in New York then in other areas of the country, said Carol J. Friedland, a civil engineer at Louisiana State University who has studied wind and flood damage.

After hurricanes Katrina, Rita and Ike hit the Gulf Coast, some utilities elevated substations above the flood line. SLEMCO, a cooperative serving Southwest Louisiana, rebuilt three substations, raising them 13 feet above sea level, at a cost of $6.6 million. But all three substations were in a rural area, where a shortage of space, a premium on river views and construction noise are not at issue.

"As long as you have sky above, you should be able to go up. Now whether the neighbors would appreciate it, now that's a horse of a different color. That's where I think you all would have issues" in New York's dense neighborhoods. "It all comes down to what is your priority," said Mary Laurent, the Louisiana utility's communications director.

The protection afforded by elevation was demonstrated at Con Edison's World Trade Center substation. Sandy's surge infiltrated the substation, located in the base of an office tower, but never reached the critical equipment 12 feet above sea level, the company said. That enabled the utility to maintain power for the Battery Park City neighborhood even as the water rose.

Moving more power lines below ground would offer protection from storm damage, said Roger Anderson, a Columbia University research scientist specializing in smart electrical systems. But it is very expensive. A 2009 report by the Edison Electric Institute estimated installing lines underground in urban areas could cost up to $23 million per mile, five times the cost of lines above ground.

Anderson, a proponent of undergrounding, said that in the meantime comparatively small changes in infrastructure — including installation of hand pumps at gas stations that normally rely on electricity to bring fuel up from underground tanks and the use of rubber seals on electrical relay boxes that may be exposed to water — could improve the region's storm resilience.

The region's utilities might also do more to break their distribution networks into more localized "microgrids," letting them limit outages to smaller areas, said Bill Zarakas of The Brattle Group, a Cambridge, Mass.-based economic consulting firm specializing in the electric power and utility industries.

"Humans are not good at seeing the future if it hasn't yet happened to you, and once they see that, there's some easy solutions," Anderson said.

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