In a sweeping indictment of corps stewardship, the report alleges that agency supervisors ignored increases in the threat level for their project, knowingly built levees and floodwalls lower than congressionally mandated, failed to detect or ignored glaring errors during the review process, underestimated the impact of the Mississippi River-Gulf Outlet on the city's defenses, and failed to properly maintain the system.
The report, [Team Louisiana Forensic Levee Investigation] conducted by Team Louisiana at the request of the Department of Transportation and Development, echoes many points made in other probes last year, including that of the Independent Levee Investigation Team, led by the University of California-Berkeley, and the interim report from the corps' own Independent Performance and Evaluation Team. But while those efforts focused largely on technical aspects of the structural failures, the LSU-based Team Louisiana sought to pinpoint the decisions that caused those failures.
"It's one thing to use modern, state-of-the-art computer modeling and determine what happened, and the other teams did a very good job of that," said Ivor van Heerden, a director of the LSU Hurricane Center who led Team Louisiana. "But the only way to really understand if mistakes were made was by relying entirely on using the (engineering) tools the corps would have used -- or should have used -- when they did their designs."
A spokesman for the corps' hurricane protection office in New Orleans said officials there have not yet seen the report and had no comment.
18-month effort
The 10-member investigative team, including seven Louisiana State University engineering and storm researchers and three private sector engineers, spent almost 18 months and $200,000 on the effort, including a $100,000 grant from its major backer, the state Department of Transportation and Development. Among the key findings:
-- By ignoring two increases in the severity of the Standard Project Hurricane -- the model storm the system was designed to thwart -- the corps knowingly failed its 1965 congressional charge to protect the city against "the most severe combination of meteorological conditions reasonably expected."
The original model was based on research through 1959. But the corps did nothing to strengthen the system in response to two increases in the projected strength of the model storm, in 1972 and 1979.
"The standard set by Congress in 1965 was very specific -- 'the most severe threat that could be expected,' " van Heerden said. "Our research shows very clearly that the standard was changed, but the corps just kept going about its business as if nothing happened."
Katrina, a Category 3 storm when it made landfall, fell far short of the expectation of the most severe hurricane.
-- In 1985, the head of the project ordered his staff to ignore an official reduction in the elevation of the land they were building on, which meant the corps finished levees and floodwalls it knew were as much as 2 feet lower than claimed. That decision helped turn Katrina from an inconvenience into a catastrophe.
"Had the walls been built as high as called for, the floodwalls in the Lower 9th Ward would have been overtopped for 1.5 hours, but instead water poured over them for 4.5 hours," van Heerden said.
He said the extra three hours resulted in deep trenching on the protected side of the floodwalls, contributing to the collapse that sent a wall of water roaring through the neighborhood, killing more than 100 people and displacing an entire sector of the city.
Below-design walls and levees contributed to many of the more than 50 breaches the system sustained during Katrina, the researchers said.
More findings
-- Applying the corps' own design manuals in use at the time, Team Louisiana found instances where the agency missed glaring engineering mistakes by subcontractors, which led to breaches including those on the 17th Street and London Avenue canals.
Also see:
In one instance, local firm Eustis Engineering botched a standard engineering formula in deciding that a thin layer of clay at the bottom of the London Avenue Canal could prevent water from seeping into highly porous sands below, the report said. During Katrina, water pushed through the clay, quickly traveling through the sand to the dry-land side of the sheet pilings, weakening the levee and leading to a catastrophic breach. Eustis Engineering has declined to comment in the past on the matter and could not be reached for comment Tuesday.
"Had the corps caught that error -- as it is supposed to -- and required the work to have been done properly, in all likelihood the design would have been changed, which could have prevented this failure," van Heerden said.
"We found several stances where (better) designs were originally proposed -- T-walls instead of I-walls -- and then changed for no apparent reason."
-- The corps failed to maintain the parts of the system properly, including keeping pace with subsidence. Moreover, the agency ignored advances in engineering knowledge and technology that could have prevented the flood.
The system "was managed like a circa 1965 flood-control museum," the report reads, pointing out that the corps made no improvements to account for well-known changes in elevations, sea-level rise or even gaps left in the system.
Paul Kemp, who was part of Team Louisiana as an LSU storm modeler, said he was "struck by the fact that the corps showed no sense of mission on this project, even though it was involved with it for more than 40 years."
Instead, the agency showed "absolute adherence" to obsolete standards -- a 1959 model for the Standard Project Hurricane. And yet the corps seemed willing, Kemp said, to make other wholesale changes midstream, such as abandoning a proposal to install floodgates at the canals in the mid-1980s, which might have stopped the Katrina surge that broke through their walls.
"It looked like no one was really in charge," he said.
Calls for 8-29 panel
The report also calls for the state and Congress to hold "8-29 Commissions" for a full investigation of the disaster, passage of a "Katrina Recovery Bill" to ensure coastal restoration and flood protection are fully financed by the federal government, and more transparency on the part of federal and state authorities when discussing flood protection plans.
"Citizens of New Orleans were never told by those with both knowledge and responsibility just how vulnerable they were to flooding, or the public safety compromises made in designing and building structures," the report states.
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Bob Marshall can be reached at rmarshall@timespicayune.com or (504) 826-3539.