Thursday, September 15, 2005

Katrina After Action Report (1)

The first question I've been analyzing for the AAR is why the levees broke - as opposed to being overtopped. Mark In Mexico has done the hard work here - read the whole piece - you may not agree with his political analysis (although I do), but his engineering research is perfect.

Overtopping was predictable under a set of circumstances that was not met. Levee failures - breaching, whatever - was not predicted except in cases where overtopping was so severe that scouring of the levee base would occur from the inside of the levee causing its collapse. That did not happen.