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What the lowlands can teach the U.S. about warding off high water

October 29, 2013 at 12:00 AM EDT
Superstorm Sandy showed U.S. coastal cities the damage water can do -- a threat the Dutch have lived with for centuries. Their system of dams and dikes, locks and levees is keeping the Netherlands safe in a world with rising seas. Miles O'Brien reports on what Americans can learn from the Dutch model of flood management.
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GWEN IFILL: Now to the second installment of our look at what has and has not changed one year after superstorm Sandy blew ashore, taking 181 lives and damaging 650,000 homes.

Many of those affected are still trying to rebuild and to answer the question, are we doing enough to protect ourselves from floods?

In conjunction with NOVA, NewsHour science correspondent Miles O’Brien traveled to the Netherlands for one answer.

MILES O’BRIEN: The Netherlands, the name says it all, the lowlands, built on a swampy delta. Much of the country lies below sea level. American Tracy Metz is an author and water management expert living in Amsterdam.

TRACY METZ, water management expert: You really wonder why people settled here at all. This must have been such an uninhabitable, inhospitable place. It’s a very soggy delta.

MILES O’BRIEN: That’s what these are for. Windmills are essentially pumps.

PETER PAUL KLAPWIJK, miller: If the sails turn, the wheel will turn, and this will start spinning this wheel gets turned.

MILES O’BRIEN: A giant Archimedean screw lifts the water out of the floodplain.

Peter Paul Klapwijk is a miller near Rotterdam.

PETER PAUL KLAPWIJK: In 1450, when they were introduced, this enabled us to live in areas where before we couldn’t live.

MILES O’BRIEN: And then, of course, there are the dikes or levees, massive walls usually made of earth built to hold back floodwaters.

TRACY METZ: So, really, that’s what the Dutch have been doing for a long time is defending their country from the water. And defending also implies the feeling of the water as an enemy.

MILES O’BRIEN: In the winter of 1953, the enemy got the upper hand. A violent storm blew in from the North Sea. It was their Sandy and Katrina combined.

TRACY METZ: In one night, over 1,800 people lost their lives. Several hundred thousand lost their houses. About a million animals drowned.

JOS GELUK, engineer: My family knows what it is when your house is blown away by the water. And after that flood, we said, well, this may never happen again. And that was the reason for designing the delta program.

MILES O’BRIEN: Jos Geluk is an engineer for the delta program, or Delta Works, a massive flood control protection system launched in the wake of the ’53 flood.

In addition to a reinforced system of dams and dikes, locks and levees, the Dutch added what they hoped would be the ultimate weapons in water defense: enormous storm surge barriers across the mouths of rivers and estuaries. Protecting Rotterdam Harbor are two giant gates, together bigger than the Empire State Building, designed to swing shut if the North Sea threatens.

And bigger still, 50 miles southwest of Rotterdam, a five-and-a-half-mile-long storm surge barrier with 62 doors ready to close at the push of a button.

JOS GELUK: We designed on a chance of flooding of once in 4,000 years.

MILES O’BRIEN: If New York City wants to stay dry in a world with rising seas, should structures like these be a part of the plan?

JOS GELUK: I think more and more the Americans become aware of the threat of the water, and they will spend money on protecting against the water.

JEROEN AERTS, VU University Amsterdam: As a Dutchman, you are quite surprised to see a large city like New York, so many people exposed, and no levees, no protection at all, was astonishing to me.

MILES O’BRIEN: Jeroen Aerts is a professor of risk and water management in Amsterdam. Like many of his colleagues here, he is a big believer in big structures to keep the water out. He thinks New Yorkers should think about walling themselves off from future megastorms.

JEROEN AERTS: Don’t rule out yet the barriers, because sea level is going to rise very quickly. And you need a barrier.

MILES O’BRIEN: But with so many inlets to the sea to flow through, one barrier would never be enough to protect New York and New Jersey. The region would need to build an elaborate ring of strategically located barriers to fend off flooding from rising seas and worsening storms.

 

One scheme imagines a huge structure at the Verrazano-Narrows, which separates Staten Island and Brooklyn. The concept is a hybrid of two Dutch designs, the giant barrier with the gates and the huge swinging doors. Another idea is even more ambitious: a five-mile-long storm surge barrier that would span from Sandy Hook, New Jersey, to the Rockaway Peninsula in New York.

Engineer Jonathan Goldstick would love to build it, though he admits fortress New York would cost tens of billions of dollars.

JONATHAN GOLDSTICK, engineer: The cost-benefit analysis is tricky, but it’s a very good return, and it really keeps the water out.

MILES O’BRIEN: As sea levels continue rising, at some point in the future, even barriers like this won’t be high enough.

JONATHAN GOLDSTICK: What the barriers should do is provide us with a relatively short-term option for protection while we implement a plan that gets the city ready for future higher sea level rises. If I were king of New York, I would build it.

MILES O’BRIEN: But if billions are spent on colossal barriers, will New Yorkers be left with a false sense of security?

KLAUS JACOB, Lamont-Doherty Earth Observatory: It looks like, wow, this is an incredible benefit. But, essentially, we have delayed the problem.

MILES O’BRIEN: Klaus Jacob is with Columbia’s Lamont-Doherty Earth Observatory. Jacob worries the barriers might delay action on the crucial question of how and where to build in a manner that is more resilient.

And even in the short term, giant barrier cans cause huge problems. Just ask the Dutch. Behind the permanent seawalls, they created stagnant lakes that are plagued by noxious algae blooms. The doors on the giant storm surge barrier were added to address that problem, but even with the doors open the permanent barrier structures and manmade islands reduce the ebb and flow of tides by 30 percent. Precious little sediment flows in.

As a result, the estuary sandbars, wetlands and oyster beds are disappearing, taking with them the natural flood protection they used to provide.

TRACY METZ: This is one of the reasons that the Dutch are moving now towards a new approach to dealing with water and trying to intervene less.

MILES O’BRIEN: In addition to the ecological concerns, there was growing evidence that as the seas rise and the storms worsen, the flood-control system here may no longer be up to the job.

Hans Brouwer is an ecologist with a Dutch program called Room for the River. At the most flood-prone locations in the country, they ask property owners to leave, buying them out so the dikes could be moved inland. So when floodwaters come, they will flow on to empty land, without damaging homes or businesses.

HANS BROUWER, Room for the River: Now we were talking about giving back lands to the river system, and that was quite a step.

MILES O’BRIEN: It’s not just farmland making the room. In the city of Nijmegen, they are reshaping the landscape to make some space for the river wall, bulldozing a peninsula, leaving just a small island.

After many centuries of performing a sort of alchemy, turning water into land, the Dutch are facing the limits of their sorcery. Not everyone everywhere can be kept safe from the water. Is this the beginning of a tactical retreat?

TRACY METZ: The Dutch don’t see that as a retreat. They see it as a form of accommodation. Now we’re moving towards an approach in which water is seen as perhaps not a friend, but a frenemy, somewhere in between.

MILES O’BRIEN: Keeping their feet dry has always been a Dutch priority, but the key lesson they have learned over the years, simply fending off the water as if it were a mortal enemy is like tilting at windmills.