Bush admin knew levees could fail

Four days after Katrina, George W Bush said:

"I don't think anyone anticipated the breach of the levees."

However, videos obtained by the AP shows internal Bush administration briefings, including one in which Bush and DHS Secretary Michael Chertoff were told that the levees might breach:

In dramatic and sometimes agonizing terms, federal disaster officials warned President Bush and his homeland security chief before Hurricane Katrina struck that the storm could breach levees, put lives at risk in New Orleans' Superdome and overwhelm rescuers, according to confidential video footage.
Bush didn't ask a single question during the final briefing before Katrina struck on Aug. 29, but he assured soon-to-be-battered state officials: "We are fully prepared."
The footage - along with seven days of transcripts of briefings obtained by The Associated Press - show in excruciating detail that while federal officials anticipated the tragedy that unfolded in New Orleans and elsewhere along the Gulf Coast, they were fatally slow to realize they had not mustered enough resources to deal with the unprecedented disaster.
Linked by secure video, Bush expressed a confidence on Aug. 28 that starkly contrasted with the dire warnings his disaster chief and numerous federal, state and local officials provided during the four days before the storm...

Shown the tape, Ray Nagin says:

"I have kind of a sinking feeling right now in my gut. I mean, I was listening to what people were saying and I was believing them that they didn't know. So therefore it was an issue of a learning curve... From this tape it looks like everybody was fully aware."

However, DHS spokeshole Russ Knocke says:

"I'm not sure what is shocking about this video. There's really nothing new or insightful from it,"

There's some kind of video here, but I didn't watch it.
UPDATE: I should have watched the video. According to this, the AP report is wrong: Bush was warned the levees might overtop (water flowing over the top), not that they might breach (rupture). Since I still haven't watched the video, I'm forced to take his word for it, and something about breaching might be elsewhere on the tapes available.
UPDATE 2: Here's another video link. And, Dan Froomkin goes around the bend here, tying this latest example of Bush incompetence with his initial response to 9/11. Apparently Froomkin is one of those expecting Bush to immediately jump up and start barking orders, Harrison Ford style.
UPDATE 3: Democratic apostate Mickey Kaus says:

"Is the despised, self-parodying MSM intentionally glossing over this important difference in order to exaggerate the anti-Bush shock value of the video? I don't know--but I do know that the actual "topped" quote was hard to find in print, lending some of the stories an eerie, undocumented quality. Do reporters not print the quote because then they couldn't justify the charge that Bush lied about the "breach"? You make the call. I'm too paranoid at this point. P.P.S.: Shouldn't Bush's press operation, rather than Powerline and Patterico, be forcefully pointing all this out?"