A cistern is an underground, watertight storage chamber for collecting and holding rainwater or other fresh water. Cisterns have been used for thousands of years in areas with limited rainfall and are gaining renewed interest today for water conservation.
How it works
A cistern collects rainwater via the roof:
- Collection — rainwater flows through gutters and downpipes into the cistern
- Filtering — a filter catches leaves and coarse debris
- Storage — the water is kept cool and dark, which prevents algae growth
- Extraction — a pump delivers the water to the points of use
Application
Cisterns are used both historically and in modern building:
- Historic buildings — beneath churches, monasteries and manor houses
- Dry climates — in the Mediterranean and Middle East
- Modern homes — as rainwater harvesting for toilet flushing and garden irrigation
- Sustainable building — part of water-saving building concepts
- Agriculture — storing irrigation water
Materials
Historic cisterns were built of brick or stone and lined with waterproof render. Modern cisterns are typically:
- Concrete or plastic tanks
- Prefabricated polyethylene reservoirs
- Masonry with a waterproof coating
Related terms
- Water storage
- Rainwater harvesting
- Drainage
- Cellar
- Sustainable building
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