News Tip: After Waters Recede, Next Step May Be To Raise Level of New Orleans

September 7, 2005

When civil engineers start planning for rebuilding New Orleans, there are few historical examples to guide them. Duke University engineering professor Henry Petroski says the closest example he can think of is the 1900 Galveston, Texas, hurricane which, like Katrina, left a city partially underwater.

To protect Galveston from a recurrence, engineers found a bold and challenging solution that Petroski said may be necessary to save New Orleans: they raised the entire city.

"There have been massive floods before, but few have covered such an extensive urban area as 21st- century New Orleans," said Petroski, an author of several books on engineering and society. "Galveston was devastated. What the engineers basically did was to raise it. Every low point of the city was higher than before, and some places were quite a bit higher, so if there was another flood the houses would be above it. In addition, they built a sea wall, but then they had backed this up so that the houses were higher if water did get through."

Petroski, a member of the National Academy of Engineering and chair of the American Society of Civil Engineers' History and Heritage Committee, said he doesn't know if engineers would consider something similar for New Orleans. "The challenges would be enormous. The city is so much larger than Galveston was in 1900. But, on the other hand, they have many more resources and tools that the Galveston engineers didn't have."

There are other examples for engineers to consider. To combat floods, the street level in Chicago was raised in 1856 to accommodate larger capacity storm sewers. Later, to keep waste water from running into Lake Michigan, from which the city drew its drinking water, engineers reversed the flow of the Chicago River.

"Engineers always feel more comfortable through redundancy," said Petroski, the Aleksandar S. Vesic Professor of Civil Engineering at Duke. "We like to have backup systems, sometimes to have backup systems of the backup systems."

In New Orleans, there are more immediate challenges for engineers, including the repair of broken levees and removal of water from the city. "These are difficult tasks, but this is the kind of thing engineers are supposed to do," he said. "We are expected to rise to the challenge."

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