Backflow Prevention in Victoria: What Every Melbourne Property Owner Should Know
Backflow is the unwanted reversal of water flow in a plumbing system. In a Melbourne kitchen, garden or commercial site, contaminated water can be pushed back into the drinking supply if there is no protection device in place. Backflow prevention is one of the most important things a licensed plumber does on your property.
Why Backflow Happens
Backflow occurs when pressure drops in the mains, a hose is left submerged in a bucket, a garden sprayer is connected to a tap, or a commercial system creates suction. Without a check valve or testable device, dirty water can siphon back into the household supply. Yarra Valley Water at https://www.yvw.com.au/ and South East Water at https://southeastwater.com.au/ require devices on most non residential connections and many residential ones.
What Devices Look Like
The simplest is a dual check valve, fitted at the meter on most new Melbourne homes. Higher risk sites use testable devices such as a Reduced Pressure Zone Device or a Double Check Valve, installed in an accessible box. The Plumbing Code of Australia and AS/NZS 3500 explain hazard ratings. Standards Australia at https://www.standards.org.au/ publishes the full standard.
Who Has to Test Them
Testable devices must be tested every 12 months by a licensed plumber endorsed in backflow. The plumber lodges a test report with the water authority. The Victorian Building Authority register at https://www.vba.vic.gov.au/ shows which plumbers hold the backflow endorsement.
Common Melbourne Triggers
Pools and spas, rainwater tanks connected to mains top up, irrigation systems, dental and medical practices, cafes with steam ovens, and any premises with chemical dosing. Even a long hose left in a swimming pool can be enough to trigger an event without backflow protection.
Related Reading on Newton Plumbing
See The Plumbing Regulations 2018 Explained, AS/NZS 3500 in Plain English, What Is a Certificate of Compliance, and Rainwater Tank Plumbing for related compliance topics every Melbourne homeowner should know.
FAQ
Do I need backflow on a normal house? Many homes already have a dual check valve at the meter. If you have a pool, rainwater tank with mains top up or commercial activity at home, you may need a testable device.
How much does annual testing cost? Usually between $130 and $220 for a standard residential device.
What if my device fails the test? It must be repaired or replaced within the timeframe set by the water authority, often 30 days.
Can I install one myself? No. Backflow installation and testing requires a licensed plumber with a backflow endorsement.
Phone Newton Plumbing - +61 414 951 362. Newton Huang Licenced Plumber, Licence #107733.