Fighting the Tide: Could Netherlands’ floodgates save Manhattan?
When it comes to preventing another Hurricane Sandy, no step is more controversial than the prospect of creating a storm surge barrier. The floodgates could stop the harbor from overwhelming Manhattan, but it could also cost tens of billions of dollars and leave those on the other side more vulnerable. As we continue our series from the Netherlands, Fighting the Tide, we look at how the Dutch have come to rely on their barriers and what we can learn. Josh Robin has more.
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NETHERLANDS -- Rotterdam Harbor is Europe's busiest. Keeping it that way are enormous movable flood gates. With the Meuse River liable to overflow, the Dutch say the nearly billion dollar price tag 16 years ago was well worth it
"The cost benefit analysis of prevention in this country is favorable, above waiting and seeing what happens and then cleaning up the mess," said Dutch Delta Commissioner Wim Kuijken.
Each arm is as long as the Eiffel Tower and each twice as heavy. Inside a museum, a model shows what happens when activated.
It takes two hours for the gates protecting the Port of Rotterdam to close. A computer does it automatically, gauging the rise in sea level. In the 16 years that the system has been in place, that's only happened once, back in 2007. As you can imagine, once the gates are closed, that's a lot of water pressure hitting them. We're told it's the equivalent of 70,000 cars.
It's a vaster system further south at what's called the Oosterscheldekering. The 62 steel doors line a causeway connecting two islands. When computers sense trouble, gates drop to the sea floor, stemming the kind of flood that killed nearly 2,000 people here 60 years ago. It would cost nearly $5 billion today.
Some are eyeing a similar span connecting New Jersey and the Rockaways. It's a given that it would be far pricier, perhaps running into the tens of billions. It may prevent Manhattan streets and subway tunnels from flooding. But an unintended consequence is that it would make it worse elsewhere.
"On the locations outside of the barrier system, the non-protected areas, obviously, those locations also have to be strengthened," said Jeroen Aerts of the University of Amsterdam.
Flooding expert Jeroen Aerts has been a consultant for New York City. He says no matter what's ultimately decided on the barriers, the city should lengthen and raise its beaches.
Aerts said, "Study all the storm surge barriers and later on install them. So you don't have to do everything at once. But you should consider all options."