(Chris Graythen ~ Associated Press)
Experts say the stronger levees and flood walls could funnel storm water into the cul-de-sac of the Industrial Canal, only 2 miles from Bourbon Street, and overwhelm the waterway's 12-foot-high concrete flood walls that shield some of the city's most cherished neighborhoods.
The only things separating Creole bungalows and St. Louis Cathedral from a hurricane's storm surge are those barriers, similar in design to the walls that broke during Katrina.
"A system is much like a chain. We have strengthened some of the lengths, and those areas are now better protected," said Robert Bea, a lead investigator of an independent National Science Foundation team that examined Katrina's levee failures.
"When the chain is challenged by high water again, it will break at those weak links, and they are now next to some of the oldest neighborhoods, including the French Quarter, Marigny, and all of those areas west of the cul-de-sac."
J. David Rogers, another engineer with the National Science Foundation team, concurred with Bea's assessment that the French Quarter may now be in more peril than before Katrina.
Officials from the Army Corps of Engineers knew the levee repairs would heighten the risk to the French Quarter. One commander even called it the system's "Achilles' heel."
To curb the danger, the corps reinforced the existing barriers. But engineers didn't have enough time or money to entirely replace the flood walls with higher, stronger ones.
Bea and other independent experts say those steps were insufficient.
"It wasn't, 'Get all the repairs done and then look at the rest of the system,"' said Ed Link, a University of Maryland engineer and a top adviser on the reconstruction work. "It was all being done in parallel."
The system, he said, is stronger now, but "it's misinformation to infer that it's an unintended consequence."
The possibility of a heightened risk came as a surprise to many residents of the French Quarter and districts such as New Marigny, where jazz great Jelly Roll Morton once lived.
"Is that what they're saying? Oh, boy, that's not good," said Nathan Chapman, president of Vieux CarrDe Property Owners, Residents and Associates Inc., an advocacy group that defends the quality of life in the French Quarter. "It's not on enough people's radar."
Adolph Bynum was unconvinced about the potential new threat to his restoration of an 1840 Creole cottage damaged by Katrina's winds in Treme, a charming neighborhood next to the French Quarter where plantation owners once housed their black mistresses.
"If the cottage floods or Treme floods, so will the French Quarter. If that happens, everything is flooded," Bynum said.
The city's oldest neighborhoods were settled long ago because they were the only dry ground in a wilderness of swamp. When Katrina struck, flooding only reached the outer limit of the French Quarter, creeping into places such as St. Louis Cemetery No. 1, the site of voodoo priestess Marie Laveau's tomb.
With their open-air markets, flamboyant artists, baroque churches and carefree lifestyle, the neighborhoods next to the Industrial Canal are some of the city's most prized real estate and give New Orleans its old-world soul.
"If we lose them, gosh, New Orleans would no longer be New Orleans," Chapman said.
As for the new threat posed by the Industrial Canal, corps officials argue that there are other low and weak spots along the channel that might be the first to go, taking pressure off of the section near the French Quarter.