A building consent is required for medium and high hazard backflow preventers unless you have already applied for a building consent for other work.
To apply for a building consent for backflow preventers, please include in your application:
Form B-002C application [DOC
791KB] or [PDF
Backflow prevention device checksheet (Form B-052) [PDF
When backflow occurs, water (which may be contaminated) can flow in the opposite direction from residential or commercial premises back into the public water supply network or within your premises to drinking water outlets. Organisations who use chemicals on site are more at risk.
There are various devices used to protect against backflow, e.g. dual check devices, testable double check valves, air gaps and testable reduced pressure zone devices which are installed at the water connection. The type of device used would depend on the risk and consequences of backflow. These devices are added to the building's Compliance Schedule as they are part of the building's specified systems.
Refer to the Building consent schedule of fees.