Water Quality in Rainwater Tanks

Harvesting water for use in the home is more popular than ever with the availability of a variety of new stand alone rainwater tanks and for the installation of water conservation devices.

New houses built in South Australia are now required to install a rainwater tank of at least 1000 litres. The tank must be plumbed into the toilet, or a water heater or to all cold water outlets in the laundry, and the inlet and overflow must be fitted with mosquito proof screens. The rainwater tanks must also be fitted with an overflow device that disposes of overflow from the tank in accordance with the requirements of the relevant authority.

The same rules apply to new extensions or alterations with an area greater than 50m2 that include a toilet, water heater or laundry cold water outlet.

In most cases, development approval is not required to install a rainwater tank on an existing home or business. Exceptions are tanks with a footprint area over 10m2 and 4 metres in height, (including any stand) which need Development Approval. 

Rainwater is generally safe to drink for most people providing the rainwater is clear, has little taste or smell and the system is well maintained. There are however health and maintenance considerations that you need to be aware of.


What size tank? 

The tank capacity you need depends on what you want to use it for, the size of your household and garden, your roof area and the annual rainfall. The Adelaide mean annual rainfall varies from over 1100mm in the Adelaide Hills to around 400mm near the sea.

It is a common misconception that a tank for garden watering is the best way to save water. While you can save a significant amount of water this way you will need a very large tank, and you can usually save more water by connecting a smaller tank to your toilets or washing machine which are used regularly all year round.


Further Information

For more information about types of tanks and the right size tank for you, download the Australian Government's PDF Borchure on Rain Tanks >

For more information contact Councils Environmental Health Section on 08 8563 8444.