When you think of cities vulnerable to hurricanes, what comes
to mind first? For most of us, it’s still New Orleans—and perhaps some other
Gulf Coast cities like Biloxi or Galveston. Some scientists, though, are
focusing on New York, saying the city is particularly vulnerable, in part
because evacuating large numbers of people from it is so difficult. Their
solution? Giant floating barriers.
Although no one has formally proposed them, several companies have
floated potential designs, so to speak. As detailed in an AP article last week, one would locate barriers of a mile or so in length at a few strategic locations
to protect certain parts of the city. Another calls for a five-mile-long barrier
stretching from New Jersey to Queens. Still another involves a wall that would
lie flat on the bottom of the East River and pivot up to deflect a storm surge
when needed.
A Category 3 storm could cause serious flooding and damage to the city,
producing storm surges as high as 25 feet. A 1938 hurricane did damage in Long
Island, and a hurricane in 1821 flooded Manhattan. Some scientists believe that
the water level around the city will rise by a couple of feet in the next few
decades because of global warming, making the city more vulnerable to such
storms.
Movable flood barriers are used in
other parts of the world, including the Netherlands, which has the largest
system in existence, and London, where a 12-year project in the 1970s and ’80s
resulted the Thames Barrier to protect the city from high tides and storm
surges. As the article notes, though, there is some question how much protection
London’s system will offer against increasingly high tides.
Any such project would cost
billions of dollars, and although New York City isn’t seriously considering it
yet, one official called the idea “intriguing.” There is also the question of how such
barriers—which would have openings to allow boat traffic—would affect the
ecosystem of the New York Harbor.