Rainwater tanks

South Australian building rules require new homes, extensions and alterations (with an area greater than 50m2), to be built with a rainwater tank no less than 1000 litres. The tank must:

  • be plumbed into the toilet;
  • to a water heater; or
  • to all cold-water outlets in the laundry, and the inlet and overflow must be fitted with mosquito proof screens.

In most cases for existing homes and/or businesses, development approval is not required to install a rainwater tank. Rainwater tanks that do need to be lodged on the PlanSA portal for development approval, are tanks exceeding 10m2 with a height of 4m (including the stand).

Rainwater tank capacity

This is dependent on what it will be used for, the size of your household and garden, your roof area, and annual rainfall within your area.

Adelaide’s mean annual rainfall varies from over 1100mm in the Adelaide Hills to around 400mm near the sea.

Types of rainwater tanks

There are several types of rainwater tanks to choose from, however they are generalised between these two:

  • Traditional stand-alone tanks (installed anywhere on property)
  • Modular tanks (installed against house)

Maintaining rainwater tanks

They are generally low maintenance, however, to ensure a consistent collection of good, clean rainwater, visit SA Health’s advice about rainwater and water quality.


Further information

SA Water | Be water wise – Calculate your home water use

SA Health | Rainwater

SA Health | Guidance on use  of rainwater tanks

SA Government | Rainwater tanks