Lessons for U.S. From a Flood-Prone Land

Ilvy Njiokiktjien for The New York Times

The Netherlands has invested heavily in flood control projects like the Maeslantkering.

LELYSTAD, the Netherlands — Entrusted with ensuring that the central Netherlands never suffers a calamity like the one visited on New York by Hurricane Sandy, Willem van Dijk, guardian of the dikes in Flevoland, a Dutch province that is more than 12 feet below sea level, sends out 11 men each morning to combat a grave menace to the world’s most advanced network of storm defenses.

Their mission is to kill muskrats. Using metal cages and spring traps baited with carrots, Flevoland’s rodent hunters provide a low-tech but vital service in an elaborate and highly effective Dutch defensive system that includes flood-control techniques first developed in the Middle Ages and futuristic steel structures that, operated by computers, move to block storm surges when water levels rise too high.

In recent days, the Netherlands’ peerless expertise and centuries of experience in battling water have been widely hailed in the United States as offering lessons for how New York and other cities might better protect people and property from flooding. Dutch engineering companies are already pitching projects to fortify Manhattan against storms, stressing that the Netherlands has experience with a coastline and cluster of river estuaries that resemble New York’s, and pose similar flooding risks. But Dutch officials and hydrology experts who have examined the contrasting systems of the two countries say that replicating Dutch successes in the United States would require a radical reshaping of the American approach to vulnerable coastal areas and disaster prevention.

The New York Times

Much of the Dutch population lives below sea level.

The Dutch “way of thinking is completely different from the U.S.,” where disaster relief generally takes precedence over disaster avoidance, said Wim Kuijken, the Dutch government’s senior official for overall water control policy. “The U.S. is excellent at disaster management,” but “working to avoid disaster is completely different from working after a disaster.” The Netherlands does not have hurricanes but does have ferocious storms that hurtle in from the northwest, funneled toward the Dutch coast across the North Sea. Centuries of living so close to the edge have cultivated a keen awareness of the consequences of flooding and the imperative to prevent them in a country where two-thirds of the population, including most residents of Amsterdam, Rotterdam and The Hague, live on flood-prone land, much of it below sea level. “We know that if things go wrong, we pay for decades,” said Mr. Kuijken, who holds the post of delta commissioner. As a result, he said, the Netherlands has been able to mobilize enormous resources to anticipate and minimize the risk of flooding.

For most of their history, the Dutch held back water in land that began as a large peat swamp by creating an elaborate mosaic of dikes, which, strung together today, would stretch for nearly 50,000 miles. After serious floods in 1916 and 1953, however, it was decided that constantly building, raising and reinforcing dikes was no longer feasible, particularly in densely populated areas. This led to a series of huge dam projects to seal off flood-prone river estuaries and inlets from the sea, which shortened the coastline and sharply reduced the land area exposed to storm surges. On waterways that could not be sealed because of heavy shipping traffic, like the estuary leading to Rotterdam’s port, movable barriers were erected instead.

In response to the 1953 floods, which killed more than 1,800 people, the state laid down strict rules, ordering that flood defenses be made strong enough to resist a storm so severe that, according to computer projections, it would occur only once every 10,000 years. If a dike breaks in Flevoland, an area nearly three times the size of Manhattan and made up entirely of land reclaimed from the sea, it would take just 48 hours for the entire province to be submerged in water, Mr. Van Dijk said. He is responsible for dike maintenance in the province, which includes killing the muskrats that weaken the levees by burrowing deep into them to create nesting chambers. “We either kill the rats or the water kills us,” said Peter Glas, president of the Dutch Association of Regional Water Authorities, known as Waterschappen, or water boards in Dutch, elected local bodies that trace their roots to the 13th century and are empowered to levy taxes.

Mr. Glas said he was dismayed by images on television of darkened, waterlogged buildings in Lower Manhattan, and wondered how the area would have fared if it “had a Dutch approach to the problem.” American society, he said, “is more dependent on self-protection and taking care of your own household,” attitudes that make it difficult to mobilize public attention and money to prevent disasters ahead of time. While his country has invested heavily in flood control, Mr. Kuijken, the delta commissioner, says this does not mean idly throwing around money but instead involves a careful cost-benefit calculation.

The Dutch government currently spends around $1.3 billion a year on water control, and local water boards spend hundreds of millions more to maintain dikes and canals, kill muskrats and pump water from “polderland” — former swamps, lakes and sea areas that have been ringed with levees and turned into towns and farmland. Capital investment on large construction projects has added billions to the total bill. The Delta Works, a construction program begun after the 1953 flood, cost around $13 billion and took more than four decades to complete. The Maeslantkering, a movable storm surge barrier near Rotterdam that is twice as long as the Eiffel Tower is tall, was finished in 1997 and, testing aside, has been used only once, in November 2007.

While Flevoland’s muskrat hunters were out looking for rodents this week, the heir to the Dutch throne, Prince Willem-Alexander, joined other officials in the provincial capital, Lelystad, to open the Water Management Center. The center, a new central control unit, is studded with computers flashing real-time data about water levels, wind strength and other potential threats to levees built to hold in check the North Sea, the Rhine River and three other major waterways that flow through the Netherlands. A day later, scores of Dutch scientists, engineers and executives in the country’s flood-control industry gathered in Rotterdam to mark “hydrology day” — and to swap ideas on how they might hawk Dutch expertise to New York. Bas Jonkman, professor of hydraulic engineering at Delft University of Technology, gave a presentation comparing flood disasters around the world — the Netherlands in 1953 to New Orleans in 2005, northern Japan after last year’s tsunami and Hurricane Sandy in New York. Since 1953, Dutch defenses have mostly held firm, though a near disaster in the early 1990s led to the evacuation of 250,000 people and almost as many cows and pigs.

Because of Dutch successes, Mr. Jonkman said in an interview, “we have to go abroad to see how flood management systems respond in extreme situations.” New York, he added, is particularly interesting because of its dense population and geographical similarities with the Netherlands. The Dutch response to New York’s events, he said, “would be to build big barriers,” but a better, cheaper answer may lie in “local solutions like flood-proof entrances” to subway stations and parking garages. “You need to be careful not to just copy Dutch solutions,” he added.

In the last century, these consisted largely of megaprojects. Flevoland is the result of a building blitz after the 1916 flood. A 20-mile-long dam sealed off the Zuiderzee, an extension of the North Sea, and turned its northern portion into a freshwater lake and the southern end into Flevoland. Mr. Kuijken said that Dutch thinking had shifted and now puts a priority on methods “to enlarge defenses in a natural way.” The state is investing in a plan called Room for Rivers, which aims to ease flooding by giving waterways space to move and even overflow. Last year, the country spent around $100 million to dump 706 million cubic feet of sand off the coast north of Rotterdam to promote the formation of protective sandbars.

For New York, Arcadis, a Dutch engineering consulting company, is proposing a movable barrier near the Verrazano-Narrows Bridge. But, said Mathijs van Ledden, who works for the Dutch company Royal HaskoningDHV, “the big challenge in the U.S. is how you get a big pot of money in place for an entire region.” Not everyone in the Netherlands shares the nation’s passion for eliminating risk. Residents in Uitdam, a small town in the north, recently protested plans by the local water board to raise the height of dikes, complaining that this would destroy their view of an adjacent lake. And in Flevoland, Mr. Van Dijk said he received regular complaints from animal rights activists that killing muskrats is cruel and unnecessary. Jacko Westerndorp, a muskrat hunter who cruises the province each day in a Ford Ranger loaded with carrots, waterproof gear and traps, has little time for such concerns: “We have to do this work. If the water comes, we all drown.”

Source: NY Times

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