Rainwater harvesting systems

Rainwater means water discharged from non-trafficable roof areas within a development site. A rainwater tank is a tank designed for the capture and storage of rainwater collected from all site roof areas (including separate garages/sheds etc). Rainwater tanks include all purpose built rainwater storage devices that meet the relevant standards and criteria.

BASIX assesses rainwater based on:

  • Capacity of the rainwater tank you are installing in litres
  • Area of the roof catchment to be connected to the rainwater tank
  • Uses the water from rainwater tank will be allocated to
  • Diversion of overflow from your rainwater tank to another tank for collection and re-use

Uses of Rainwater

NSW Health supports the use of rainwater for: toilet flushing, washing clothes, hot water systems, garden watering, car washing, filling swimming pools, outdoor spas and ornamental ponds. See Alternative Water Use. Rainwater can be used for firefighting, however, the portion of a rainwater tank designated for firefighting is not counted as part of a BASIX rainwater tank.

NSW Health guidelines (http://www.health.nsw.gov.au/environment/water - NSW Health website) should be referred to when harvested water is being considered for all uses. NSW Health does not recommend the use of rainwater for drinking purposes where a reticulated potable water supply is available.

To maintain a good quality rainwater supply, a rainwater tank requires good design and installation, and a regular ongoing maintenance regime.

You should contact your local council and/or a professional rainwater tank retailer for further information regarding the design and installation of rainwater tanks in your area.

Individual rainwater tanks in multi unit dwellings may be used to supply water to common areas, to single dwellings, or to more than one dwelling. Multi unit developments may also select the option of a central water tank to collect and supply water to common area or the individual dwellings.


Further information: