What New York Can Do to Protect Itself From Future Storms
Continued from previous page
While no one could have predicted the unique meteorological phenomenon that was Sandy, the terrible scenarios that played out as the storm batteredthe New York City region should have sounded eerily familiar to Mayor Bloomberg, utility companies, and city, state, and federal agencies. The inundated coastline and desperate evacuees, the flooded roads, tunnels, and subways — they’d seen them all in computer models and PowerPoint presentations about the future impacts of climate change, and they had discussed them in interagency meetings with oceanographers, geologists, and climate scientists.
The problem was that what they were seeing was not supposed to be happening now — not for perhaps another 20 years when, they’d been told, rising sea levels due to climate change would turn the storm surges of ordinary nor’easters or low-category hurricanes into devastating tidal torrents.
It wasn’t as if they’d been derelict in starting to plan. New York City and its agencies had consulted an elite group of government and university scientists, economists, and risk management specialists to study how climate change would affect the city. In 2008, the New York Panel on Climate Change concluded that given steadily rising seas, today’s 1-in-100-year flood could occur once every 35 to 55 years by 2050, and once every 15 to 30 years by 2080. The panel also concluded that atmospheric changes would likely increase the intensity of storms and bring more rain to the region.
With the science in hand, the city formed a Climate Change Adaptation Task Force to determine how best to adapt infrastructure to withstand the effects of future climate challenges. The task force recommended a gradual approach to protecting the city’s assets: improve shoreline land management; consider building new wetlands out into the harbor to better absorb the power of storm surges; and build higher seawalls, jetties, and dykes to protect subway entrances, highway tunnels, and power stations. To keep the costs manageable, these changes would be made gradually. The cost would be in the tens of millions of dollars a year, but given time, New York would become the very model of a “climate-resilient” city that protected its people and its critical infrastructure.
But what recent storms have shown, including Hurricane Irene last year, is that it may be time to consider solutions more in scale with the risks. A decade ago, Bowman’s Storm Surge Research Group at the state university at Stony Brook conceived a system of large barriers and sea walls that would protect the city’s most vulnerable shorelines from storm surges. One would stand by the Whitestone Bridge on the upper East River, another by the eastern entrance to Jamaica Bay, and a third — and most ambitious — would be capable of sealing off the lower harbor and stretch from Brooklyn to Staten Island parallel to the Verrazano Narrows bridge.
Had such a system been in place, says Bowman, it would have stopped Sandy’s storm surge from reaching the city. And though it would have cost some $13 billion, it would have been cheaper than the current estimated damages from Sandy.
These are not untested technologies. Storm surge barriers have protected the Netherlands for centuries, with the most recent built to withstand a 1-in-10,000 year flooding event. Rotterdam began to work on its storm barriers after more than 1,800 people died in a 1953 flood. (The system of dikes, dams, and storm surge barriers is now a major tourist attraction.) St. Petersburg, Russia, last year completed a 15-mile sea surge barrier across the Gulf of Finland. Begun in 1978, it is designed to protect the city from tidal surges up to 16 feet.
Venice is building its own storm surge barriers, and London has a North Sea storm barrier. Examples of storm surge barriers already exist just north of New York City, where they protect the cities of Providence, R.I.; Stamford, Conn.; and New Bedford, Mass. As Sandy’s tidal surge increased, Providence shut the gates on its 3,000-foot long Fox Point Hurricane Barrier. The barrier, said a U.S. Army Corps of Engineers spokesman, “performed flawlessly.”