Monday, November 14, 2005

Not just bigger, but smarter levees.

At last we're ready to take some advice from people who KNOW how to protect land below sea level.
New Orleans is clamoring for a bigger, stronger levee system that will prevent a repeat of the flooding caused by Hurricane Katrina. But Dutch engineers say that's not enough: It will also have to be a smarter levee system.

The Netherlands employs the latest in safety principles and digital technology to design for the long haul. New Orleans levees were outdated long before their target date for completion. The Maeslant barrier is designed to last at least a century. Another structure, the Eastern Scheldt barrier, is meant to last twice as long.

The Dutch say thinking ahead is the only option in designing flood defenses: Plan obsessively. Look at the big picture. If things change, adjust. Those are clich├ęs, perhaps, but they're based on hard-won experience from 1,000 years of fighting floods.

With New Orleans' short- and long-term security and rebuilding efforts hanging in the balance, the political pressure is intense to build Category 5 hurricane protection, and build it quickly. But Dutch engineers also caution it would be a mistake to rush forward and build without a clear strategy.

"The first question is, what do you want to protect, people or the marshes? Define your problem -- analyze the system that way. Which is the system? The sea, the river, the lake, the weather? Which problem do you want to solve?" said Tlaje de Haan, an engineer with the Netherlands' water and public works department who helped design the Eastern Scheldt barrier. "Don't go in a hurry to build something. This is an engineer's wish -- to go somewhere and just start building."

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