I was wondering something similar---how much water would be needed per person per day?

I have always heard "1 gallon per person per day." Given the heat in SoCal, that might not be enough, but taking Pete's "a couple of weeks" as an example, that would be 15 gallons (with a little left over), or 3 of those 5 gallon plastic water containers that sit on top of a water cooler. Storage of that much water does not seem to be that hard. Several people I know use these on a regular basis as they don't trust their well water for drinking/cooking. (I am lucky; my neighborhood is on County water--those just south of me---are not.)