The post-mortems continue on the New Orleans levees - and they're looking grimmer with each go-round. It's not that the list of design flaws, shoddy work, and snafus is growing longer - it's that, bit by bit, the government is slowly acknowledging the painful truth for the record.
The National Academy of Engineering and the National Research Council just came out with a critical review of the Army Corps of Engineers-run, draft 6,000-page report that came out in June. (See the Times-Picayune story here.) The Corps' original report was billed as the authoritative analysis of what happened. And it was impressive. Shortly after it came out, I spent some time at the Corps' Engineer Research and Development Center in Vicksburg, Mississippi, where a lot of the scientific work was done. It was fascinating. One team of engineers created models of the doomed floodwalls in Lucite boxes and spun them in a giant centrifuge to see what combination of forces would make them break. Another team spent weeks on the ground in New Orleans trying to reconstruct precisely which areas flooded when, taking data from stopped clocks, interviews, and other clues. Overall, they put an astonishingly detailed report together in record time.
But there were obvious problems from the get-go. The Corps, of course, was investigating itself, its central role in one of the biggest engineering failures in American history - the definition of a conflict of interest.
In March, Corps investigators announced that the now-famous floodwall collapses could not have been foreseen, sparking cries of foul from outside engineers. They pointed out that the Corps had run experiments on the same type of floodwall years before that showed the exact type of failure that doomed New Orleans.
Now the review has identified more problems. One of them was a sweeping, exculpatory sentence in the Corps report that said: "There was no evidence of government or contractor negligence or malfeasance." But as the NAE points out, the Corps was investigating the behavior of structures, not people - "there was no evidence" because the investigators weren't looking for it.
Another issue is the basic safety standards for levees and floodwalls. Independent engineers say they're too weak for critical structures protecting lives and property. The Corps report glossed over that concern. But the NAE suggests that "an urban levee designed to protect large numbers of people should have a higher factor of safety than one designed to protect farmland." Sounds self-evident, but the Corps was resisting the idea.
It's great that the record is being corrected - and that may help spark some changes. But I worry it will prove more useful to historians and engineering students than to the higher-ups in the Defense Department and White House -- not to mention Congress -- who have to make the decisions about protecting New Orleans and other exposed coastal areas. So far, there's little evidence that even cold facts will change the bureaucratic and political habits that led to the Katrina disaster.
John McQuaid is the co-author of Path of Destruction: The Devastation of New Orleans and the Coming Age of Superstorms.