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Installing a rainwater tank

New houses built in South Australia are required to install rainwater tanks of at least 1,000L.

This also applies to new extensions or alterations to a building with an area greater than 50m2 that includes a toilet, water heater, or laundry cold water outlet.

Rainwater tanks must be plumbed into the toilet, a water heater, or to all cold water outlets in the laundry. The inlet and overflow must be fitted with mosquito proof screens. They must also be fitted with an overflow device that disposes of overflow from the tank in accordance with the requirements of the relevant authority.

Do I need development approval to install a rainwater tank?

In most cases, development approval is not required to install a rainwater tank on an existing home or business, unless the rainwater tank is larger than 10m2 and/or is 4m in height. To understand what your next steps are find out if you need building approval through the PlanSA Portal.

Rainwater tank size

The tank capacity you'll need depends on what you want to use it for, the size of your household and garden, your roof area, and the annual rainfall in your region. South Australia's annual rainfall varies from over 1,100mm in the Adelaide Hills to around 400mm near the sea. Rainwater tanks come in various sizes, small and large and range from 1000L, 2000L, 3000L and more. Newer slimline rainwater tanks, also known as mini rainwater tanks, are the perfect space saving solution for the smaller yard. You can also find them in different materials such as steel, concrete or plastic rainwater tanks.

Work out what size tank is best for your household with the Department of Health calculation for determining the required size of tank to be installed

Water saving

It's a common misconception that a tank for watering your garden is the best way to save water. Although you can save a significant amount of water this way, you would need a very large tank to make a real water-saving difference. You can usually save more water by connecting a smaller tank to your toilets or your washing machine, which are used regularly all year round.

Water quality in rainwater tanks

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 such as microbiological and chemical hazards. 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.


The cost of installing a rainwater tank can depend on many factors including the size of the tank and the space in which the area you're installing the tank. Contact your local rainwater tank supplier for more information.

Information on cleaning your rainwater tank can be found at SA Health.

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