New Orleans levee committee uneasy with Corps of Engineers modeling

Published 15 November 2010

The Army Corps of Engineers uses complex computer models for hazard analysis calculations on which billions of dollars worth of repairs and improvements to the federal hurricane levee system are being based; the members of the regional levee commission want their own expert to scrutinize these computer models

Some regional levee commissioners responsible for storm-driven flood protection on the east bank want their own expert to scrutinize some of the complex hazard analysis calculations on which billions of dollars worth of repairs and improvements to the federal hurricane levee system are being based.

The Southeast Louisiana Flood Protection Authority East will be asked during its 18 November meeting to hire the specialist. The recommendation will come from the board’s Engineering Committee, whose members include all the levee commissioners who are engineers or specialists in related fields.

Engineering committee members are not challenging the validity of the hazard work and sophisticated computer modeling that was done in the years after Hurricane Katrina by an Army Corps of Engineers-led task force that also included engineers and scientists from academia and private industry.

Sheila Grissett writes in the Times-Picayune that in fact, they were told during a meeting on 4 November that different facets of the work already have been reviewed, at various levels and in a multiple venues, including a committee of the National Academies of Engineering. The commissioners, though, still want a bit more.

What I think is missing is that we don’t have a person able to … assure us that there’s not a problem,” said commissioner and geologist George Losonsky. “It would give me more comfort to have our own person down in the weeds.”

The discussion was triggered by former commissioner Stradford Goins, who visited last month’s authority meeting as a private citizen to recommend that the board hire someone to double-check the computer modeling.

The modeling used numeric assumptions to mimic what likely would occur during various storm scenarios, and Goins questioned a number of those assumptions.

Although Goins has repeatedly criticized a variety of corps decisions during his board tenure, he didn’t recommend a full-scale review of the modeling until last month.

Grissett writes that in response, the levee authority asked its engineering committee to consider Goins request as quickly as possible. On 4 November, the group did.

Committee chairman Tom Jackson agreed with other members that there is no need to double-check all aspects of the work, even if the authority had the money to pay for such a massive review. He said, though, that some additional review should be done to reassure the commission and the public.

If I was the public, I’d be alarmed that this was being brought up at this time,” he said.

Committee member and engineer-surveyor Steve Estopinal said the focus should be better to understand the residual risks of flooding that remain in the system, as well as doing a general review of the hazard analysis approach used and taking a close look at the specifics of the 152 theoretical storms that were analyzed. “But we shouldn’t try and re-invent the wheel,” he said.

Rickey Brouillette, chief engineer for the Office of Coastal Protection and Restoration and the state’s representative on the engineering committee, praised the corps’ modeling and hazard work. But he also likes the idea of yet another evaluation.

I personally think the job done was as good as could be done with the information available. The level of work and the quality of people doing the work was very good,” he said. “But peeking under the hood is good … It shows the people that we’re still involved.”

The committee will recommend that Bob Jacobsen with Taylor Engineering, a coastal engineering group familiar with much of the modeling and already doing work for the authority, be given this additional task. A feel will be negotiated if the full authority agrees to go forward and will be based on a scope of work not yet written.