Yes, there it is, but for whatever reason, a search for "levees" didn't bring this up, and a repeat search after your post didn't get it either. Thanks, there's a little more detail on this post than what was in the paper.
Search is sometimes "on vacation". Try clicking on Katrina in the list across the top of the screen ... most of the LA/NOLA/HURRICANE/ETC. posts end up with someone or another adding Katrina as a keyword.