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Plumbing and drainage

City of Gold Coast regulates and assesses residential and commercial plumbing and drainage to ensure compliance with legislation and minimise health and safety risk.

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Backflow devices

Backflow prevention is the term used to prevent the reverse flow of water from a potentially polluted or contaminated source into potable water supply.

Backflow is caused by cross connection. This is any point on a water system where a polluting substance may come in contact with drinking water. This may include any system piping that allows access to the drinking water supply, any connected auxiliary water supply, submerged inlets, by-pass arrangements, removable sections and temporary devices.

This is prevented by installing a backflow prevention device such as a one-way valve which prevents the contaminants from entering the drinking water supply. These are supplied in testable and non-testable types depending on the risk associated with the possible contamination. Testable devices require annual testing to ensure satisfactory operation.

Please note: Form 9 - Report on inspection and testing of backflow prevention devices, registered air gaps and registered break tank is available on the Department of Housing and Public Works website under the Plumbing and Drainage Act 2018.

The licensed plumber must submit the Form 9 to City of Gold Coast within 10 business days after inspecting or testing the device. The form can be emailed, posted or lodged in person at any of our customer service centres.

If you wish to post a Form 9, address it to:

Chief Executive Officer
City of Gold Coast
PO Box 5042

If you wish to email the Form 9, please email it to Plumbing&

For information, see the frequently asked questions below.

For any questions regarding backflow submission, please contact Plumbing and Drainage on 07 5667 5977.

Jump to key information
  • Why do I need to register my backflow device?

    State legislation requires all councils to keep and maintain a register of every testable backflow device within their boundaries.

  • What fees are associated with backflow registration and what are they used for?

     Please refer to the Register of fees and charges for the current backflow registration fees listed as:

    • Backflow Prevention Testable Device - Annual Registration Fees Class 1 & 10 Domestic
    • Backflow Prevention Testable Device - Annual Registration Fees Class 2 to 9 Commercial

    Fee invoices are issued in the third quarter of every year (approximately late August/September).

    The registration fees assist in:

    • maintaining the register (up to 50,000 letters can be issued per annum)
    • contacting contractors or owners who submit incorrect forms
    • investigation of untested devices by a backflow audit officer.
  • What are the servicing / testing requirements of a backflow device?

    Who can do this? Only a Queensland licensed plumber with a backflow endorsement on that licence can test the device. As the owner of a property, you are responsible to have the backflow device tested annually.

    How do they do it? The licensed plumber tests the device by using a finely calibrated instrument that ensure the device will shut down if a backflow scenario occurs.

    Why? If a device fails, the City's drinking water may be contaminated. This contaminated water could harm or cause death (imagine the contaminated water entering a day care centre's water supply).

    What if testing fails? If the test fails, the plumber must repair or replace the device immediately; it is a criminal offence to tamper with, or remove, a backflow prevention device without approval.

  • How do I update my registration details?

    Your plumber will update registration details in cases where a new device has been installed or replaced.


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