The Catastrophe Wasn't Katrina
The evidence, by now, is overwhelming: Beautiful, decadent New Orleans wasn't doomed by Hurricane Katrina but by decades of human incompetence and neglect. As far as the drowned city is concerned, the greatest natural disaster in the nation's history would have been just a messy inconvenience if not for the fumbling hand of man.
The mortal threat to New Orleans, as Katrina plowed into the Gulf Coast, was not the powerful winds -- Mississippi took the brunt of those -- but the massive storm surge the hurricane generated. We now know that the levees, floodwalls and other barriers protecting the city were, for the most part, plenty tall enough and theoretically strong enough to keep the waters at bay. On paper, New Orleans should have ended up wet and wounded, but basically intact.
What happened instead was "the single most costly catastrophic failure of an engineered system in history," according to a report issued last week by the Independent Levee Investigation Team, a blue-ribbon panel led by experts from the University of California at Berkeley and funded by the National Science Foundation.
Some of the flood barriers were built using inadequate materials, the report says. Others were designed so poorly that they provided weak spots for the waters to exploit. Still others were left unfinished for lack of funds.
The Army Corps of Engineers, which was responsible for building the levees that failed, has not yet issued its own final report on the flood and likely will dispute some of the independent team's conclusions. But Secretary of Homeland Security Michael Chertoff remarked last week that "had it not been for what appear to be structural problems in the building of the levees, Katrina would have been a bad hurricane" but not an unparalleled catastrophe.
The report of the independent team, which was led by UC Berkeley engineering professor Raymond B. Seed, cites these examples of cause and effect:
Earthen levees stretching east from the city were built with "highly erodible sand" and other "lightweight" materials that could be found locally, rather than more "cohesive" clay soils that would have had to be trucked in. "When the storm surge arrived, massive portions of these levees eroded catastrophically," the report says. "The resulting carnage in St. Bernard Parish was devastating," with a "wall of water . . . pushing homes laterally, flipping cars like toys and leaving them leaning against buildings, and driving large shrimp boats deep into the heart of residential neighborhoods."
Floodwalls lining the east side of the Inner Harbor Navigation Canal, known to locals as the Industrial Canal, were not engineered to keep water from seeping beneath and undermining them. "The result was two massive breaches that devastated the adjacent Ninth Ward neighborhood, and then pushed east to meet with the floodwaters already rapidly approaching from the east from St. Bernard Parish."
Surging water pushed by the hurricane's winds from Lake Pontchartrain into the 17th Street and London Avenue drainage canals remained "well below the design levels, and well below the tops of the floodwalls." Nonetheless, the floodwalls suffered "catastrophic" failures; the designers apparently had not fully understood the weakness of the foundation soils on which the walls were built. So even though little if any water lapped over the walls, sudden breaches inundated central New Orleans -- residential neighborhoods, business districts, the streets around the Superdome.
The report notes that "no one group or organization had a monopoly on responsibility" for the disaster. Local, state and national government officials were rarely on the same page. In terms of pure engineering, there should have been independent review of some of the Corps of Engineers' assumptions and methods.
The most chilling sentence in the report is this one:
"A number of these same problems appear to be somewhat pervasive, and call into question the integrity and reliability of other sections of the flood protection system that did not fail during the event."
In other words, there are many miles of levees around New Orleans that were built with the same questionable design principles and materials that were used in the barriers that gave way. The Corps has patched the levee system so that it could probably prevent the last flood, but what about the next one?
Chertoff worries about a storm hitting next-door Jefferson Parish, which has seen its population swell with evacuees and reconstruction workers. He worries that with so many people living in flimsy trailers, even an approaching tropical storm might necessitate an evacuation. With New Orleans still crippled and the jury not yet back on whether it can ever fully recover from Katrina, no one wants to flip the calendar. Hurricane season officially begins on Thursday.