'Times-Picayune': Corps Never Pursued Design Doubts on Levees

By: E&P Staff In a troubling exclusive, the Times-Picayune reported Friday that engineering mistakes that led to the levee failures, leading to the flooding of most of New Orleans during Hurricane Katrina, "were found and then dismissed in the Army Corps of Engineers' design review process in 1990."

Forensic engineers who studied documents obtained by the New Orleans paper, which had to evacuate in that flooding, show project engineers made a critical mistake in assessing soil strengths on the 17th Avenue Canal project, said one expert, Robert Bea, a University of California-Berkeley professor who is a member of the National Science Foundation team.

"Corps documents show the mistake of overly optimistic levee strength was detected by its Vicksburg, Miss., office, which directed local engineers to make changes," the newspaper's Bob Marshall writes. "But when the chief engineer in New Orleans replied that the results were based on 'engineering judgment,' his superiors dropped the issue."

Bea said the memo points could reveal a systemic problem that will show up during investigation into two other levees, the London Avenue and Industrial Canal levees, which also breached during the Aug. 29 storm.

"From all the data we have, from all the documents made available to us, that exchange highlights where the key mistake was made in the design process, and how it was allowed to stand," Bea said this week.

"The design engineers didn't account for the weak layers in that swamp, and the Vicksburg office picks that up in review. But the New Orleans office says it's our professional judgment this is OK. In our business, that's an acceptable answer. But it's an answer Vicksburg can disagree with -- but it didn't.

"And from the documents we have, the issue is never raised again. At least not until Katrina comes along."

The Times-Picayune also published on its Web site samples of the key documents.

Marshall observed: "Investigators have long suspected engineering mistakes were at the heart of the levee and floodwall breaches. Not only did the structures fail before they reached design capacity, but documents show the designs were not appropriate for the weak soils and the depth of the canals, investigators said. Yet discovering why skilled engineers at reputable firms came up with obviously faulty designs, and how those mistakes were missed in the corps' lengthy review process, has stumped investigators."