This study, entitled, "What if Hurricane Ivan Had Not Missed New Orleans?", describes almost perfectly the current flood situation in New Orleans.  It goes on to say:

"In this hypothetical storm scenario, it is estimated that it would take nine weeks to pump the water out of the city, and only then could assessments begin to determine what buildings were habitable or salvageable. Sewer, water, and the extensive forced drainage pumping systems would be damaged. National authorities would be scrambling to build tent cities to house the hundreds of thousands of refugees unable to return to their homes and without other relocation options."
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I got this info from this thread on Slashdot.

Thats nine weeks if all pumps work.
I bet more than half would burnout within first few weeks.
Those pumps are like 80 years old.

Quoted: Thats nine weeks if all pumps work. I bet more than half would burnout within first few weeks. Those pumps are like 80 years old.

I believe they have installed some new pumps in the last couple of years… that may help… if the pumps are servicable, pumping stations are not underwater, and if they can power the pumps.

http://www.ar15.com/forums/topic.html?b=1&f=5&t=384452