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Backflow prevention

Backflow prevention

Backflow prevention devices reduce water supply contamination risk. 

What is backflow?

Backflow is a reversal of piped flow direction in a water system. It occurs when the supplied water pressure is lower than the internal plumbing system (back siphonage). Less pressure in the pipe may allow contaminated water from your property to be drawn back into the water supply system. This can be caused by:

  • a burst or ruptured water main
  • excessive demands during fire-fighting operations
  • other periods of high demand

Backflow incidents can also be caused by a cross-connection between your water supply and a contaminated source.

Do I need a backflow device?

All properties connected to a water supply from North East Water must be assessed to determine the risk of backflow. This assessment must be done by a suitably qualified and licensed plumber.

If your property is assessed to be a High or Medium hazard risk, then you need a device. If this is the case, you must arrange for the installation of an appropriate containment backflow prevention device. Such a device must be located at the water meter, or all meters if there is more than one and no connections are allowed to bypass the containment backflow prevention device.

If you already have a backflow prevention device installed within your property, a containment backflow prevention device is still required at the meter regardless of any installed zone or individual protection.

North East Water cannot guarantee the protection of the drinking water supply from backflow unless the site is contained by an appropriate device at the meter.

Who is responsible for backflow?

North East Water is responsible for assuring the delivery of safe drinking water to our community.  If you are a property owner, it is your responsibility to ensure that backflow does not occur at your property.

As a property owner, it is your responsibility to:

  • install a containment backflow prevention device
  • protect the drinking water supply within your property by installing a zone or individual protection system
  • engage an accredited backflow prevention plumber to assess, install, commission and test your devices
  • ensure your plumber installs the correct device for your property
  • have your device tested annually and engage a plumber to ensure it is working properly
  • make sure the backflow test report (for the containment device) is submitted to North East Water within 20 days from the date of test.

Backflow Test Certificate

If your property is tenanted, it is up to you as property owner to negotiate with the tenant regarding payment for the installation of the device and all ongoing maintenance.

A testable containment backflow prevention device must be tested every 12 months.

What device should I install?

If your property is assessed to be a High or Medium hazard risk, then you will need to install a Containment Backflow Prevention Device.

The following devices are required to be installed for each hazard rating:

Hazard Level Device Type
High Reduced Pressure Zone device (RPZD)
Registered Air Gap (RAG)
Medium Reduced Pressure Zone device (RPZD)
Registered Air Gap (RAG)

Examples for using the above devices:

  • Installations where the rain water tank is below ground and connected to toilet cisterns
  • Toilet douche spray/flexible hoses are present
  • Non-residential installations of grease interceptors and bin storage areas
  • Multi-story buildings (4 levels and greater)
  • Caravan Parks

The above guidelines will apply for the majority of installations. Should compliance with the above prove difficult for certain installations (due to pressure and/or flow reductions or other), we will perform an assessment of the owner’s proposed device installation and will provide a determination concerning required compliance on a case-by-case basis. 

Where an existing water service is being renewed, altered or relocated ‘between the main and the meter’ a backflow prevention containment device must be installed appropriate to the property’s hazard rating. 

Backflow Prevention Containment Policy

Backflow device application

Acquiring a new Commercial or Industrial Property?

If you are acquiring a new commercial or an industrial property, and a containment device is already present, you must enter into an agreement with North East Water. This confirms your understanding of responsibilities in respect to your ongoing connection to North East Water’s reticulated water services.

Example of Containment Backflow Prevention Device Agreement

If you are building a new commercial or industrial property, you must obtain our approval for the containment backflow prevention device that you intend to install at the property. 

Owners must apply and receive approval from North East Water before connecting to our drinking water system.

Backflow prevention application

Testing and reporting

If you have a testable backflow prevention device installed at the water meter you must have the device tested every 12 months.

Property owners are responsible for ensuring that the backflow test report (for the containment device) is submitted to North East Water within 20 days from the date of test. 

Backflow Test Certificate

Alternatively, copies of test results for containment backflow prevention devices may be sent to us via:


Mail: North East Water, Trade Waste, PO Box 863, Wodonga VIC 3689

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