Graphic Example

The Times Picayune has a great series of graphics showing what likely caused the levees to fail. In one instance, the levees failed because of dredging that was supposed to deepen the center channel but instead cut too close to the New Orleans side. The dredging undermined the levee, allowing additional seepage, which turned into a flood when the storm and storm surge hit.

This isn't going to stop the levees from being rebuilt, but we need a better understanding of why the levees failed - and more importantly - why the Army Corps of Engineers or the state's levee boards were unable to discover the inherent problems with the existing levees. These systemic problems are still there.

An internal review by the Army Corps of Engineers supports most of the criticisms leveled against the New Orleans area levee system by an independent team of engineers, including questions about soil strength, levee maintenance and whether the system was built as designed.

In a Dec. 5 interim report released Friday, the Interagency Performance Evaluation Task Force said its conclusions already have been passed on to engineers who are working to restore the levee system to its authorized protection level before it was overwhelmed by Hurricane Katrina, flooding more than 70 percent of the city.

Technorati: flood aid; hurricane katrina; katrina aid; hurricane rita; slidell; biloxi; gulfport; pascagoula; nagin; blanco; barbour; hurricane rita; hurricane wilma.