Katrina the Corps and Science

The story of the flooding of New Orleans is now full of Urban Myths mostly perpetrated by the Corps of Engineers. It was NOT A NATURAL DISASTER. It was an ENGINEERING FAILURE comparable to CHERNOBYL. The design of the levees was fatally flawed and the Corps is busily trying to hide that fact from the public. They have hired a public relations firm and lobbied to have a Geologist critic fired from LSU and have accused him of spreading miss information because he is not an engineer. The partial story is at NY Times If you want the full story, go to: http://levees.org/index. The short story is that Katrina, although a large and dangerous storm, was down graded to category three before landfall. The storm surge, although high, was not a record breaker and was LOWER THAN THE DESIGNED MAXIMUM storm surge height. The flaw in their design was a simple one in my theory. Civil Engineers are used to designing buildings and structures that sit vertically and are subject to gravitational forces. The Levees most of their life time just sit there and do the same. The exception came when the storm surge raised the level of water to a considerable height. The shape of the stress ellipsoid was changed suddenly as a significant horizontal force perpendicular to the Levee was introduced by the hydrostatic component from the filled canal. The design engineers had used the compressional strength of the soils and now suddenly the SHEAR STRENGTH of the soils became a critical factor. The result was classic slumping of the levee, i.e., the horizontal thrusting of the levee until it completely breached. The post mortem on the levee showed that the cement T-wall was not over topped and back eroded as the Corps now contends. Rather, the entire levee was thrust more than 45 feet to the side and then the wall fell over(See the Independent Engineering Report fig 2.3b) . This was a predictable response to the forces involved if one took the time to model the levee as it was subjected to the forces of the surge and if one used the appropriate physical constants. We in the Earth Sciences have encountered Engineers
who have a limited concept of stress and strain relationships in the presence of anisotropy (almost certainly a factor in the soils), abnormal fluid pressure (certainly a factor), and significant stresses that are not vertical. The storm surge raised the water level (hydrostatic head) by about 10 feet . This increased (abnormal) fluid pressure was transmitted via the porous canal bottoms into the soils that supported the levee. The increased pressure caused a decrease in the soil strength (both compressional and shearing). As a result, a predictable failure of the levee occurred. A structural Geologist would look at this from the standpoint of M. King Hubbert's classic paper, "THE ROLE OF FLUID PRESSURE IN MECHANICS OF OVER THRUST FAULTING ", and would draw similarities to the Thrust Faults of the Canadian and Montana Rockies. The Corps explanation was that the levees were over topped and eroded from behind and that this was a 500 year event. So now we are faced with a Corps that has ignored Geologic and Geophysical advice for decades and has hired a PR firm with Tax Payer money to fight the bad press. We are also faced with a professional society, the American Society of Civil Engineers (ACSE) that has taken $2MM from the Corps to study the failures and has come up with a rosy picture of the Corps and tried to make Katrina out to be a storm of all storms which will never happen again (see link conflict of interest) . A Geologist activist at LSU has been fired for speaking out and the Corps has continued to shed the blame(Geologist(s) Slandered). Some Corps members have resorted to childish name calling (reference). I call on the members of the Geo Science community to take heed and even join the fight if you will. Katrina was only one example of the Corps failures. Many years ago when I was a Grad Student, I took a Graduate level course in Ground Water Hydrology. Most of the course was a diatribe against the Corps and all of its screw-ups. The USGS has been ignored while the Corps has gotten the go ahead to screw-up again and again. Join the Fight!
This is an ongoing problem. The Corps has obviously had some revised modeling done and it must have caused some panic because they started a new testing program on the repaired flood walls (Reference). This is a point of critical importance to the City and its future because if the repaired flood wall cannot stand up to several feet of water, then the rainfall in the City cannot effectively and promptly be pumped out to the lake. This will mean that the City will flood every time it rains hard. We have already had newly rebuilt and refurbished homes in Lake View flooded by rain because the Corps hadn't gotten the pumps working right - but that's a different Corps screw-up with the pumps that didn't work. How long do the Citizens of NOLA have to endure this incompetence and the attempts to cover it up?