Ultimately, the waters destroyed more than 4,000 buildings.
Afterward, the Dutch - realizing that the disaster could have been much worse, since half the country, including Amsterdam and Rotterdam, lies below sea level - vowed never again.
After all, as Tjalle de Haan, a Dutch public works official, put it in an interview last week, "Here, if something goes wrong, 10 million people can be threatened."
So at a cost of some $8 billion over a quarter century, the nation erected a futuristic system of coastal defenses that is admired around the world today as one of the best barriers against the sea's fury - one that could withstand the kind of storm that happens only once in 10,000 years."
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Why are the Europeans so much more forward thinking about the inevtiable cyclical natural disasters than we in the United States are?
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London has built floodgates on the Thames River. Venice is doing the same on the Adriatic.
Japan is erecting superlevees. Even Bangladesh has built concrete shelters on stilts as emergency havens for flood victims.
Experts in the United States say the foreign projects are worth studying for inspiration about how to rebuild New Orleans once the deadly waters of Hurricane Katrina recede into history.
"They have something to teach us," said George Z. Voyiadjis, head of civil and environmental engineering at Louisiana State University. "We should capitalize on them for building the future here."
The Dutch erected a kind of forward defensive shield, drastically reducing the amount of vulnerable coastline. Mr. de Haan, director of the water branch of the Road and Hydraulic Engineering Institute of the Dutch Ministry of Transport, Public Works and Water Management, said the project had the effect of shortening the coast by more than 400 miles.
For New Orleans, experts say, a similar forward defense would seal off Lake Pontchartrain from the Gulf of Mexico. That step would eliminate a major conduit by which hurricanes drive storm surges to the city's edge - or, as in the case of Katrina, through the barriers.
The Dutch also increased the height of their dikes, which now loom as much as 40 feet above the churning sea. (In New Orleans, the tallest flood walls are about half that size.) The government also erected vast complexes of floodgates that close when the weather turns violent but remain open at other times, so saltwater can flow into estuaries, preserving their ecosystems and the livelihoods that depend on them.
The Netherlands maintains large teams of inspectors and maintenance crews that safeguard the sprawling complex, which is known as Delta Works. The annual maintenance bill is about $500 million. "It's not cheap," Mr. de Haan said. "But it's not so much in relation to the gross national product. So it's a kind of insurance."
