John Barry, author of Rising Tide, has an excellent op-ed today in USA Today:

Hurricane Katrina's devastation of New Orleans was not a natural disaster. It was a man-made disaster. But it wasn't man-made only because the levees built by the Army Corps of Engineers proved so flawed that, as the Corps itself said, they offered protection "in name only." It was man-made in a much larger sense, for even if the levees had kept New Orleans dry last year, eventually another hurricane would have ripped the city apart. That will still happen unless we do something....

...The most important step in rebuilding New Orleans is assuring residents and investors that it will be safe. The most important part of that is committing to build Category 5 hurricane protection. It isn't just New Orleans that needs it; the national economy needs it.

Read the whole thing. There is no feasible option that does not involve protecting New Orleans. The price tag is high, but actually laughably low when compared to the price everyone is paying for not having done it. And, as Barry notes, if Louisiana gets its fair share of the oil revenues like other states do, then the state can do it all by itself.