The Washington Post has a powerful news analysis piece on the future of New Orleans. That future is uncertain, of course, but the Post paints an incredibly sad picture that I don't have reason to question:

  First they have to pump the flooded city dry, and that will take a minimum of 30 days. Then they will have to flush the drinking water system, making sure they don't recycle the contaminants. Figure another month for that.
  The electricians will have to watch out for snakes in the water, wild animals and feral dogs. It will be a good idea to wear hip boots and take care of cuts and scrapes before the toxic slush turns them into festering sores. The power grid might be up in a few weeks, but many months will elapse before everybody's lights come back on.
  By that time, a lot of people won't care because they will have taken the insurance money and moved away — forever. Home rebuilding, as opposed to repairs, won't start for a year and will last for years after that.
  Even then, there may be nothing normal about New Orleans, because the floodwater, spiked with tons of contaminants ranging from heavy metals and hydrocarbons to industrial waste, human feces and the decayed remains of humans and animals, will linger nearby in the Gulf of Mexico for a decade.