Backflow is the unintended and undesirable reverse flow of water or other liquids within the plumbing system of a property to the public mains supply. Backflow may be caused by back pressure, back siphonage or a combination of both. It can result in contaminants being drawn into the public drinking water system through a cross connection.
Backflow can occur when water pressure is not maintained. Water pressure can be affected when:
- There is a break in the water main which supplies the property
- Water is being pumped from the main supply during a fire
- Water is being used at a higher pressure on the property than the pressure supplied from the public water supply system
- Heavy water use downstream reduces water pressure upstream
The policies below outlines the requirements and customer obligations, for the installation of backflow prevention containment devices on all properties connected to the public water supply.