Could New Orleans be another Venice?

Is New Orleans destined to become the new American Venice, with permanently flooded streets?

That's one possible future for the devastated city, according to a Alan Zundel, a Brigham Young University civil engineer who has modeled the New Orleans situation.

Last week, Lake Pontchartrain spilled into the Crescent City when levees failed under storm surges generated by Hurricane Katrina. The city suffered immense damage, while estimates of the dead now number in the thousands.

But disaster may have been inevitable sooner or later, according to experts interviewed by the Deseret Morning News. New Orleans is below sea level and has been settling since long before the hurricane.

"Now the decision needs to be made as to where they rebuild," said Zundel, associate professor of civil engineering at BYU.

Should the city be rebuilt where it is? Should structures be on pontoons or fill? Should New Orleans be moved to the north, where it would be less vulnerable?

One possibility planners may consider, he said, is whether New Orleans should be turned into an American Venice "with canals everywhere."

According to Zundel, engineers in the New Orleans area have known for some time that if a Category 3 or larger hurricane "were to hit the city in any type of direct fashion, there would be wide-scale problems."

The main difficulty, he said, is that "the city is below sea level and settling very rapidly. . . . They don't even do surveys anymore (tracking the city's downward motion); they just install monitoring stations."

If a survey were carried out, it would be out of date in a year, he added.

"The whole city is on the Mississippi River delta," which is made of loose, poorly consolidated soil washed down the great river. But with levees to hold back the water, the river doesn't flow there anymore and no new soil is deposited on that part of the delta.

Soil under the city "continues to consolidate and settle." New Orleans is sinking as the loose material settles. New Orleans is now one of the few places in the United States, like Death Valley, that are below sea level.

"It keeps getting lower and lower, and the problem gets worse and worse," he said.

Normally, huge levees hold back the water from Lake Pontchartrain and the Gulf of Mexico. But if a storm should cause either to overtop a levee, "then the city becomes a swimming pool," Zundel said.