Backflow prevention


What is backflow prevention?

Backflow prevention is the term used to refer to the prevention of an unwanted reverse flow of water from a potentially polluted source into the drinking water supply.

Application and registration of a backflow prevention device

Backflow prevention is managed by your local council. For more information, contact:

Moreton Bay Regional Council

Sunshine Coast Council

Noosa Council

When does backflow occur?

Backflow occurs because a condition exists in a water supply system that will cause back-siphonage or back-pressure. Back-siphonage can occur on a property through a vacuum created in the water supply system.

An example of back-siphonage would be a pipeline breakage, undersized pipework or high withdrawal rates. Back-pressure can occur within properties when high pressure is generated downstream by pumps, thermal expansion or elevation.

Backflow prevention starts within a property boundary by isolating a possible contamination source from the town mains or storage tanks (rainwater tanks) from the tap or appliance.


Examples of potential source of contamination:

  • fire hose reels (FHR)
  • irrigation
  • swimming pools
  • vehicle-maintenance pits
  • ornamental ponds
  • air-conditioning towers
  • vehicle/bin-washing bays
  • chemical injection areas.

Examples of properties requiring backflow prevention:

  • motels and unit complexes
  • hotels
  • vehicle-repair workshops
  • shops
  • restaurants
  • caravan parks
  • medical and dental surgeries
  • car and plant-washing facilities
  • dry-cleaners and laundries
  • hospitals and funeral parlours
  • club houses for sports
  • schools
  • daycare centres and kindergartens
  • pest control and water-carrying vehicles
  • botanic gardens.

What is the safeguard to prevent a backflow occurrence?

A correctly selected backflow prevention device (one way valve) will eliminate any risk of contamination of the drinking water supply. Backflow devices are either testable or non-testable types with the selection dependant on the risk associated with the possible contamination.

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    Saving Tips
  • Bathroom Tip #1

    Save water in the bathroom by turning off the tap while cleaning your teeth or shaving, keeping showers to less than four minutes, fix leaking taps, toilets and showers immediately, and installing a water-efficient shower rose.