Rainwater tanks
  • Last updated:
  • 06 Oct 2021

Installing a rainwater tank can save you water and money.

You can use rainwater outdoors for:

  • watering your garden
  • filling your pool
  • cleaning and
  • car washing.

You can connect your rainwater tank indoors for:

  • toilet flushing and
  • cold water in your washing machine.

Queensland Health recommend using town water where available for:

  • drinking
  • personal hygiene
  • dishwashing and
  • preparing food.


Before connecting a rainwater tank to internal plumbing, you need approval from council. If you are also on town water, you must install a backflow prevention device.

It is important to follow plumbing and building standards when installing the rainwater tank. This includes connecting to household fixtures and the stormwater system.

Tank overflow should be properly managed to prevent possible flooding and damage downstream.

If your rainwater tank is part of construction of a new house or building, it is assessed with the building and plumbing applications.

Refer to the following references in the Queensland Development Code (QDC):

  • MP 4.1 Sustainable buildings
  • MP 4.2 Rainwater tanks and other supplementary water supply systems
  • MP 4.3 Supplementary water sources - commercial buildings.

Pursuant to Building Regulation 2021, a building approval is not required where a rainwater tank is:

  • less than 10m² in area
  • less than 3.6m in diameter
  • less than 2.4m in height
  • less than 5.0m long and
  • is structurally suitable for its intended water volume and pressure.

Note: tanks not meeting all above criteria need a building permit from a private certifier.