Um, no one.

Sorry to disappoint the moonbats and Mother Ship riders, but the flooding of New Orleans wasn’t a Republican conspiracy to kill black people. Via Paul at Wizbang, Bob Marshall of the New Orleans Time-Picayune penned a summary yesterday of the real reasons for the failure of the 17th Street Canal levee in New Orleans:

The floodwall on the 17th Street Canal levee was destined to fail long before it reached its maximum design load of 14 feet of water because the Army Corps of Engineers underestimated the weak soil layers 10 to 25 feet below the levee, the state’s forensic levee investigation team concluded in a report to be released this week.

That miscalculation was so obvious and fundamental, investigators said, they “could not fathom” how the design team of engineers from the corps, local firm Eustis Engineering and the national firm Modjeski and Masters could have missed what is being termed the costliest engineering mistake in American history.

The failure of the wall and other breaches in the city’s levee system flooded much of New Orleans when Hurricane Katrina slammed ashore Aug. 29, prompting investigations that have raised questions about the basic design and construction of the floodwalls.

“It’s simply beyond me,” said Billy Prochaska, a consulting engineer in the forensic group known as Team Louisiana. “This wasn’t a complicated problem. This is something the corps, Eustis, and Modjeski and Masters do all the time. Yet everyone missed it — everyone from the local offices all the way up to Washington.”

Team Louisiana, which consists of six LSU professors and three independent engineers, reached its conclusions by plugging soil strength data available to the corps into the engineering equations used to determine whether a wall is strong enough to withstand the force of rising water caused by a hurricane.

“Using the data we have available from the corps, we did our own calculations on how much water that design could take in these soils before failure,” said LSU professor Ivor van Heerden, a team member. “Our research shows it would fail at water levels between 11 and 12 feet — which is just what happened” in Katrina.

The screw-up, according to academic and professional investigators cited by Marshall, was that the sheet piling used to support the floodwalls was too short:

The corps has long claimed the sheet piling was driven to 17.5 feet deep, but Team Louisiana recently used sophisticated ground sonar to prove it was only 10 feet deep.

Van Heerden said Team Louisiana’s latest calculations prove investigators’ claims that a depth of 17 feet would have made little difference. He said the team ran the calculations for sheet piles at 17 feet and 16 feet deep, and the wall still would have failed at a load of 11 to 12 feet of water.

Investigators have been puzzled by the corps’ design since it was made public in news reports. They said it was obvious the weak soils in the former swampland upon which the canal and levee were built clearly called for sheet piles driven much deeper than the canal bottom. It was not a challenging engineering problem, investigators said.

Prochaska said a rule of thumb is that the length of sheet piling below a canal bottom should be two to three times longer than the length extending above the canal bottom.

“That’s if you have uniform soils, and we certainly don’t have that in the New Orleans area,” he said. “It kind of boggles the mind that they missed this, because it’s so basic, and there were so many qualified engineers working on this.”

According to records cited by Marshall, the Army Corps of Engineers reviewed and approved the flawed design plans.

In the immediate aftermath of Katrina, some liberals blamed levee failures on budget cuts supposedly pushed through by George W. Bush. But according to the Washington Post, reports of levee problems began to surface in the mid-1990s, before the floodwalls were even completed. The timeline is sketchy, but it looks like the flawed design plans were approved about two decades ago.

For the mathematically-challenged, that’s more than 10 years before Dubya was elected President.

* * *

In a separate article published November 19, Marshall reported that levee leaks were reported to the New Orleans Sewerage & Water Board a year ago. City officials neither took action nor bothered to report the leaks to the Army Corps of Engineers:

A year ago Beth LeBlanc and her neighbors on Bellaire Drive had a problem no one could seem to fix. Their yards, which swept to the base of the 17th Street Canal levee, kept filling with water. Then on Aug. 29, as Hurricane Katrina moved out of the area, that levee collapsed and tumbled into their homes, allowing Lake Pontchartrain and a world of misery to pour into the city.

Now the residents of Bellaire Drive have questions.

“We called Sewerage & Water Board, and one of their guys tested the water and said it was coming from the canal,” LeBlanc recalled. “They sent repair crews out. They tore up sidewalks and driveways. Things got better, but it never got dry.

“So I keep wondering why no one ever came out to ask about it. No one from the Corps of Engineers. No one from the Levee Board. Sewerage & Water Board never came back.”

The corps wonders as well.

“If someone had told us there was lake water on the outside of that levee — or any levee — it would have been a red flag to us, and we would have been out there, without question,” said Jerry Colletti, operations manager for completed works at the corps’ New Orleans office.

“We have nothing on that, nothing at all. That’s something we should have been told about.“

Ya think?

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