Thanks everyone! I had a "Duh!" moment today. While reading through your insights, a couple of lightbulbs turned on.

First - why not store tap water in all our water carriers? We've got a few of the big blue cubes and a gazillion nagalene and stainless water bottles stored in the house and garage. They might as well be in use at the same time as they're sitting collecting dust.

Then a second lightbulb - why not make use of all the potential carriers that come into the house as well? All the bottles with resealable lids are perfect candidates. pop, juice, wine and liquor bottles with screw-top lids are now going to be diverted from the recycling bin.

Good prep for us and good for the earth. So simple! I feel like a dope for not thinking about it sooner and wasting all that money buying bottled water. Duh!