Levee repairs have been underway ever since Katrina struck three years ago.
A leading U.C. civil engineer is warning the job isn't done and flooding could occur again.
"The possibility of significant flooding of any one, if not all three of the main basins is still there, and we could again have people up on roof tops if it goes badly," said Professor Raymond Seed.
Who can forget images of New Orleans residents stranded on rooftops by 11-foot high waters?
Professor Seed prepared an independent study of the levee failure for Congress.
One of his main concerns is that new steel pilings are not deep enough to prevent seepage under the levees.
"Some of the levees that have been built since Katrina, in our opinion, weren't built entirely to the standards we would have liked to have seen. That's being worked on, and further repairs are being made. But there's also incomplete work, work still in progress, so it's going to be a little dicey in terms of the level of preparation at the time of Gustav's arrival," said Professor Seed.
Robert Bea, in an interview last year, is already on his way to the Gulf. He's also a civil engineer familiar with the levees and oil facilities.
His concern- that the levee breaks will occur in different sections this time.
"You can expect to see breeching showing up not where it did last time but in these sections adjacent to where it occurred. So we're horribly exposed," said Professor Seed.
An elite team of urban search and rescue experts is leaving Oakland this afternoon for disaster duty.
Ben Ho was sent to Katrina and Rita. He hopes residents will need evacuation orders.
"Hopefully by having people listen to the warnings and get out of the way early, evacuate when the officials say to evacuate, that will lessen the impact that we will hav to pick up later as disaster workers," said Ben Ho.
Gustav is threatening the levees at a bad time.
Professor Seed tells us repairs of the Katrina damage from three years ago won't be completed for seven years.