Cistern

On properties with no well and no connection to a city water main, a house cannot draw water on demand, so it stores a reserve in a cistern, a big storage tank, and draws from that. A pump pressurizes the water from the cistern into the home's plumbing, the same way a well pump would. Cisterns can be buried (below frost-free desert ground) or set above grade, and residential sizes commonly run from a few thousand gallons up to 10,000 gallons or more.

In the Phoenix metro, cisterns are most associated with hauled-water areas. Rio Verde Foothills is the well-known case: many homes there have no well and no pipe to a utility, so a water-hauling truck periodically fills a cistern, and the household lives off that stored water until the next delivery. The cistern size is sized to the household's usage and how often a truck can come, with bigger tanks meaning fewer deliveries.

The cistern choice has consequences beyond storage. Lenders care about it. A home that depends on hauled water into a cistern can be harder to finance, and federal programs are cautious: HUD's individual-water-systems guidance treats cistern and hauled-water supplies as a special case for FHA-insured loans, which is why buyers in these areas confirm their financing path early.

For example, a Rio Verde owner without a well might install a 10,000-gallon buried cistern, contract with a water hauler, and budget for both the tank and recurring delivery costs as part of the true cost of living on that lot.

If you are building where there is no well or main, the cistern is core infrastructure, not an add-on. Size it for real usage and delivery frequency, plan the pump and pressurization with the plumber, and verify how the stored-water supply affects both your loan and your insurance.