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 devices can be installed to eliminate the risk of contamination. Application and registration of a backflow prevention device is managed by your local council. For more information, please 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 dependent on the risk associated with the possible contamination.

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    Did You Know
  • Installing a water efficient 4 star rated showerhead will reduce the flow from 20 litres per minute to 9 litres per minute.