...Performance Evaluation Taskforce. In the months after Katrina, IPET analyzed storm forces and the engineered facilities responses of the New Orleans flood defenses. The IPET data were not faulted by the judge.
The plaintiff’s claims were based on a theory that Reach 2 levee began failing at about 6:30 a.m. on Aug. 30, about two hours before the peak of the surge arrived, because they had been compromised by years of erosion and settlement exacerbated by the Corps’ failure to armor them against wave action in MRGO. They argued it was the Corps’ failure to properly operate and maintain a navigation improvement that led to the flooding.
The Corps’ expert witnesses maintained, however, that the Reach 2 levees held until the surge began overtopping them at 7:30 a.m., and then they were rapidly cut down by erosion on the backside. They performed until they were overwhelmed, the experts claimed.
“The key to determining which theory is correct is grounded in one fact that this court finds unassailable—that is the timing of the peak surge in the MRGO,” the judge wrote. The judge cited one piece of hard evidence: a video from a surveillance camera that captured, at 8:35 a.m., water “forcefully” pouring over the 40 Arpent Levee, separated from the MRGO levees by a 32,000-acre polder called the Central Wetlands Unit. The parties did not dispute that the Arpent Levee could not have been overtopped until the Central Wetlands Unit had been filled. But Duval found the Corp experts’ modeling of how that happened “suspect.”
“The court finds that some of the Corps models are critically compromised by the use of input data that has been overly ‘scaled’ to obtain the results,” the judge wrote. For example, the Corp models shifted the storm track “some miles to the east of its actual track,” which changed the timing of the surge arrival. Experts who performed the modeling also used “scaled” surge and levee elevation data that Duval found suspect.
“The court finds that some of these models were manipulated to arrive at the conclusion that the peak surge occurred at 7:30 a.m., so that the Central Wetlands Unit would fill in time to overtop the 40 Arpent Levee at 8:30 a.m.,” Duval wrote. He concluded the levees failed prior to the surge arrival from weaknesses caused by poor maintenance and operation.
“It is the court’s opinion that the negligence of the Corps, in this instance by failing to maintain the MRGO properly, was not policy, but insouciance, myopia and shortsightedness,” Duval wrote.
