we save rain water for the house plants.i have three 30 gallon drums in the basement that could be used if I filtered it.
the 55 gallon drum under the down spout has wire mesh to keep out big stuff and some goldfish eat the bugs.
water is not a problem here as a old historical spring that run all year long is at the end of our street.yes I would filter that for drinking water but the old timers around here don't.