In this article on Yahoo a man has built a temporary shelter that's 8'x9'. A 40' container could be made into 4 such shelters that would be much more water proof. There are lots of empty containers in the US thanks to our trade deficit with China and others. These containers could be made into permanent shelters later on.
To paraphrase Jefferson, "If the people wait for the government to build their housing they'll be drowning in the rain"