I recall a couple years ago, the federal government sent a decommissioned aircraft carrier to house many of the homeless people in New York City. Sending such carriers/ships now to the New Orleans/Mississippi coastline seems like a good idea.
First, they run on their own generators, which will alleviate some of the power issues which arise from electricity shortages. similarly, they are designed with enough rooms, cots, clean water capacity and facilities to house thousands (if not tens of thousands) of individuals on each ship for periods of months at a time. The expected length of time for rebuilding the area's infrastructure will likely be at least that long. Furthermore, because these ships have been decomissioned, they are not of any pressing military need.
Just an idea by me.