A cistern water system stores the water needed for a household in a large container that can be filled either from a water truck or by rainwater. Cistern systems are common in areas that are outside of municipal water service and have unreliable well water. A 2,000-gallon cistern can supply a household of four people with water for several months if they are frugal with their water usage.

Cisterns can provide a backup or a primary water supply.

Types of Cisterns

Traditional cisterns can still be seen in many older houses and are usually large concrete basins that are built into the basement. A cistern that measures 8 feet wide by 12 feet long by 5 feet high can hold over 2,000 gallons. More modern cisterns are made of plastic and are self contained, allowing them to be placed in a basement or attic or buried under the ground. Some cisterns are placed on towers to provide water pressure.


A cistern water system can be used on its own in a situation where there is no water available. Cisterns are also commonly used as backups for well water systems. Households with dug wells in dry areas commonly run out of water in the dry months of summer and use cisterns to get them through until fall when the water table rises again. Cisterns are also used for livestock and agriculture, and may be located in the middle of a pasture where they store water from the rainy season to get animals through the dry season.


Uncovered cisterns can be a drowning hazard for small rodents, whose decomposing bodies may threaten the health of drinking water. If a cistern sustains damage or a leak, water can flood the basement or room where the cistern is located. Cisterns that use hard water can develop mineral deposits in the pipes that run to or from them over time. Cisterns in basements that experience temperature swings can contribute to moisture problems in the basement that can lead to rot or mildew in the joists and flooring.


Cistern water systems are independent of problems with municipal water systems. Cisterns can help people get through dry periods without having to import water or even leave their residence due to lack of water. In places where water is expensive, a rainwater-fed cistern system can save a lot of money.