Since the returned was living (and eating) for six months on the other side of the flooded town, how did they get a constant supply of food and power for that area?
I think that we are supposed to assume that the military stepped in and took control of the town- thus providing food from the outside and setting up power again.
I do'nt think the returned did have power in their bit did they? As for the rest - hunting in the woods, and stockpiling bottled water and canned goods I guess - their houses were certainly full of both items - how they got the stockpiles I dunno; if I had to guess it would be when the military first arrived with tonnes of stuff and no real oversight as to who took what (and no belief in the dead coming back to life).
----------------- American money - In God We Trust British banknotes - Charles Darwin