After the flooding during Hurricane Katrina in 2005, top brass with the U.S. Army Corps of Engineers conceded it had failed in its directive to protect New Orleans from hurricane storm surge. At the same time, the Corps also fingered New Orleans officials as playing a contributing role in the catastrophic flooding. The Corps claimed it originally wanted to install gates in the city's outfall (drainage) canals to prevent storm surge from entering the heart of the city, but were blocked by New Orleans agencies.
In a surprise recent development, Lt Gen Carl Strock, Corps Commander, has admitted he had no evidence when he made these incriminating statements about New Orleans agencies to the New York Times relating to the Katrina flooding.
Strock told reporter John Schwartz with the New York Times that the Corps was forced by local agencies to implement a "fallback plan of building flood walls in the canals," implying that gates were the superior protection option. Even though this claim was both historically and logically flawed, no one questioned the Commander in June of 2006. We wish to share the vetted facts about the spectacular failure of the outfall canals which flooded the portion of New Orleans with the most people, property and infrastructure.
In 1965, Hurricane Betsy demonstrated that a major hurricane could overtop the earthen levees of the 17th Street and the London Avenue Canals, and flood heavily settled residential and commercial areas of New Orleans. In response to Betsy, Congress directed the Corps of Engineers to work in consultation with the local Sewage and Water Board (SWB) and the Orleans Levee Board (OLB) to examine alternatives for providing hurricane protection at the outfall drainage canals.
The Corps offered two alternatives: 1) raise the height of the canal walls to prevent overtopping or 2) install gates at the canal's mouths to prevent storm surge from entering. In the 1980s, the higher walls plan was far more expensive than gates plan by a factor of three to five depending on the canal. The Corps indicated that both plans could reliably protect the area, but preferred the gates plan because it was much less expensive. The Corps felt the cheaper gates were consistent with its mandate to implement the "least-cost alternative for providing the authorized project purpose."
OLB meeting minutes during this time reveal that the engineering committee raised concerns about the Corps' preferred cheaper gates option. The OLB worried that once the gates were closed, rainwater could not be pumped out of the city. (We note that after Katrina, the Corps installed gates which, in fact, do include auxiliary pumps to handle rainwater.) The OLB brought their concerns to their Congressional Delegation and explained their preference for the high level plan which they believed was superior. Congress was convinced, and ordered the Corps to install the higher canal walls.
On August 29, 2005, the newly raised canal walls collapsed causing at least $27 billion in direct residential, commercial and public property damage in the city. This figure does not include indirect costs such as evacuation costs and lost wages, rents and profits.
Post-Katrina investigations revealed that the walls collapsed because the steel sheet pilings were too short and allowed dangerous water under seepage.
"The storm surge was still more than four feet below the tops of the flood walls at the time of the levee failures. Deeper sheet piles would likely have prevented these catastrophic failures", said Dr. Ray Seed, co-chair of an independent post-Katrina analysis underwritten by the U.S. National Science Foundation, in a letter to the author.
How could this happen? It seems that in 1985, the Corps of Engineers Division Headquarters initiated a Sheet Pile Test (a.k.a E-99 study) in the Atchafalaya Basin, a region with soils similar to those on New Orleans. The Corps improperly executed the study, and wrongly concluded that:
"...when foundation soils were poor, sheet pile penetration depth beyond a certain point would not significantly increase I-wall stability under the type of short-term loading conditions believed to characterize hurricane events...." - Hurricane Protection Decision Chronology
In other words, the Corps incorrectly determined that it only needed to drive sheet piles down to depths of seventeen feet instead of thirty-one to forty-six feet. The Corps believed that "sheet pile penetration beyond a certain depth would not improve wall stability and therefore was a wasteful expenditure." This switch by the Corp New Orleans District to significantly shorter sheet piles saved the District $100,000,000. But these cost savings came at the expense of engineering reliability, and led to flooding in the portion of the city with the highest concentration of people, property and infrastructure.
The Corps has an obligation to build its Congress-mandated flood protection competently. It is not logical to say that the local agencies should bear responsibility for the Corps' poorly built canal walls just because the Corps preferred the less expensive gates plan.
In January 2008, the U.S. District Court, Eastern District of Louisiana placed responsibility for the flood wall collapses and resulting flooding in downtown New Orleans squarely on the Army Corps of Engineers. However, the Corps of Engineers could not be found financially liable due to sovereign immunity established in the Flood Control Act of 1928.
"While the United States government is immune for legal liability for the defalcations alleged herein, it is not free, nor should it be, from posterity's judgment concerning its failure to accomplish what was its task...because of §702c, there is neither incentive, nor punishment to insure that our own government performs these tasks correctly," wrote Federal Judge Stanwood Duval.
In a fitting endnote, a recent response to a records request by the author reveals that the Corps of Engineers cannot produce any data to support its claims that New Orleans agencies are partly responsible for the failure of the canal flood walls. Subsequently, a reporter with the New Orleans Times Picayune contacted Lt Gen Strock, the Corps Commander who originally made the claim, and requested comment on the letter.
"Throughout our response to Katrina I emphasized how critical it was to be transparent and honest if we were to regain the trust of the public," Strock said. "I might have illustrated my description with things I had heard but not personally researched..."
Statements by senior Corps spokespersons in the months and years after Katrina, which have been oft-repeated in media, books and articles, have been injurious to the flooding victims because they may have alienated the nation's citizens. With Hurricane Isaac at our backdoor, Levees.Org will continue its mission to revise the initial inaccurate template until one day, the vetted truth about the worst civil engineering disaster in U.S. history becomes household knowledge.
This paper was written with assistance from H.J. Bosworth, Jr., lead researcher for Levees.org.
LeveesOrg was founded in November of 2005 by Sandy Rosenthal, 55, and her son Stan, then 15, while evacuated from New Orleans. They returned to the city and grew the organization to over 25,000 members with chapters in five states. Their mission is education that the Great Flood of 2005 was caused by the negligent acts of man, not the fury of a hurricane.