HerHusband wrote:

We live in a rural area which means we have occasional power outages,
usually at the worst times. Unfortunately, when the power goes out,
so does our water supply. That means we can't wash up, flush the
toilets, or even get a drink of water when the power goes out. We're
building a new house that will have a wood stove as a means of backup
heating. We could even heat pans of water on the woodstove if we
needed to for bathing, dish washing, etc. But, we still need a supply
of water that will last a day or two.

I don't know if this would work, but it's something to think about.

I've wondered about putting a tank on the 2nd floor of the house. (Like a
water heater, but not hooked up to heat the water.) When the power goes off
and pressure goes down, ISTM the first floor toilet could get a few flushes,
gravity fed, from the 2nd floor storage tank.

I don't know about "water hammer" issues, though.

Any comments are welcome.

-- Mark