Good water filtration and water in storage Ideally one could put in a cistern under the house and after it was filled you could draw your water from that... having it refilled from what ever source as you use it. So when the supply dissappears you have several thousand gallons of water on hand for use. Then 1/2 hour showers will be a thing of the past. My grandfather could take a full on shower in five minutes.... learned it in the navy. He said they would wash with sea water and rinse with fresh. Or something like that.
Learning to scrub plates with sand is an option up at the house I have never endiing supply.... LOL. Setting in the sun to heat up too. during the summer. UV is a natural disinfectant.
But storing for an emergency that may last a month is wayy different than water consumption for living self sufficiently.
For instance I have a 3000 gallon water tank for fire support. My livestock are watered by gravity from this tank.. I have had a leak a mere drip drain it of all water in a matter of about two weeks. When everything is going well That should last my animals about two months. That is just drinking and loss through evaporation. It takes my well ten days to fill that tank.
For example A family of four consumes 40,000 to 80,000 gallons of water per year. (moderate water conservation no gardening) Storing that much would be problematic. But if its safe to collect rain water You only need to have enough to last you till the next rainy season.
For instance 1000 square foot of roof during a 1 inch rain fall will collect 550 gallons of water. IN my case I got 3 total inches of rain last year My roof is 2500 square feet (550 x 2.5) x 3 = 4125 gallons per year.... enough to fill my water tank with extra. So I am very very dependant on my well.
Past poultry: Buff Brhama, EE, Barred rock, Wellsummer,
Bantam mixes, Araucana, Turkeys, & Guinea Fowl.
Future poultry: Guinea Fowl, Sumatra, Wellsummer, Muscovy
"A dream without a plan is just a wish" Katherine Paterson