Historically, most people had to fend for themselves when it came to supplying their homes with water. A well or a nearby stream did the job in most cases. A cistern held water for dry spells. The water wasn’t necessarily safe to drink, but boiling it into tea or soup rendered pathogens harmless. Adding grain and fermenting water into low alcohol beer accomplished the same goal.
With my own properties I tend to strive for pragmatic solutions at a reasonable price point. When I built a little vacation cottage in rural Hawaii there was no municipal water supply available and the property was too close to the beach for a well since the water would have been salty. So I attached a few tanks to the rain gutters. That gave me a 6,000 gallon supply of water that has never been exhausted in spite of periodic droughts. The water is run through a carbon filter and an ultraviolet zapper to eliminate bacteria, viruses, and impurities before it enters the house.
When I bought a modest fixer upper in Sonoma County the roof needed to be replaced. I chose a standing seam metal roof not only for its durability and ability to reflect summer heat off the house, but because it’s the cleanest surface for rain water catchment. I then installed a tank in the back garden and plumbed it to the rain gutters. This house has a private well, but California is earthquake country. It’s highly likely that in an emergency the power would go out and cause the electric well pump to fail. Having a ready supply of water on hand makes the property more resilient.
Here in San Francisco I have multiple water tanks tucked away in various spots. The configuration of the building and roof material don’t lend themselves to rainwater catchment so these tanks are filled with tap water delivered through a food grade garden hose. I calculate this is enough water to keep everyone in the building provisioned for about a month if we’re judicious. I feel more secure knowing this water is available.
My most recent property purchase is in an historic neighborhood in Cincinnati. Since Ohio has a winter season with hard freezes I’ll have to install the water tanks in the basement where the temperature is moderate throughout the year. The renovation of the building will include a new roof and I’ll be selecting a clean surface for rainwater catchment there as well. Ohio may not be subject to earthquakes or droughts like California, but it’s always best to have a Plan B. You never know. Back in 2014 the Elk River in West Virginia was contaminated by a chemical spill and 300,000 people in several cities were without water for a prolonged period of time. I think it’s sensible for everyone to have a parallel water system on hand regardless of the location or particulars.