Rainwater tank

Roof and water

Rainwater tank

Ancestralcistern · water butt · chultún (Maya) · tanque de lluvia (Spanish)

housing school farm public building

It is a container that stores rainwater coming from the roof for later use. It can be buried or above ground.

What it solves

It provides water in the dry season or when the supply fails and reduces the flow that rushes out to the street in a downpour. In the tropics it serves for irrigation, toilets and cleaning and, properly treated, for drinking.

Today

Divert the first flush from the roof, cover the tank and put mesh on every opening so mosquitoes cannot get in. An overflow to a rain garden is advisable.

Common mistake

Leaving the tank uncovered or without mesh, which becomes a mosquito breeding ground.

Tomorrow

A tank shared by several houses or by the neighborhood school stores water for supply cuts and for watering. Caring for it together, cleaning gutters and filters, matters as much as the tank.

Fact As a general rule, contamination of the harvested water is halved for every millimeter of initial rain that is diverted.

Where it comes from

  • 1Maya Mesoamerica and the Puuc hills, Yucatán, pre-Columbian period
    The chultún was a bottle-shaped underground chamber with a stucco apron that led the rain inside.
  • 2Minoan Myrtos Pyrgos, Crete, around 1700 BC
    Its cistern held more than 80 m³ of rainwater.
  • 3Al-Andalus Iberian Peninsula, Middle Ages
    The word aljibe comes from Andalusian Arabic and names the underground rainwater tank.
  • 4Venice Italy, for centuries
    Its collection wells provided drinking water in the middle of a brackish lagoon.

Masters

  • Glenn Murcutt Magney House, Bingie, Australia, 1984
    He gives the roof a valley shape to gather the rain and store it in a cistern for later use. Roof and tank are designed as a single system.
Sources

See also

Also in Roof and water

Diagrams and texts by LDB Arquitectura. They are shared under the CC BY 4.0 license, which allows them to be used and adapted with credit to the source.