Thanks for the advice. I'm looking into both rainfall barrels and other storage. As they say in the army, "2 is one and 1 is none." In other words, have a backup plan; multiple plans are best.
As far as treating water, i've heard you can use bleach, but that can't be stored longer than 6 mo, so a better, long term option is to get the chemicals used in pools, which is basically chlorine. It can be stored indefinitely and you can use these to purify the water, and then filter it through a Berkey or similar before drinking.