A typical Reduced Pressure Zone Backflow Preventer for high-hazard protection
Homes and businesses use substances and liquids that could be a major threat to the health and wellbeing of our customers and visitors. For that reason, backflow prevention is assessed and identified according to the risk to the health of consumers.
In Christchurch City Council's district, the backflow risk arising from the activities on a premises is assessed and it is mandatory that an appropriate backflow prevention device is installed at the point of water supply.
All commercial and industrial properties are to have a minimum of medium-hazard protection at the boundary to protect the main water supply. The installation of this device is a condition of supply and is the responsibility of the property owner.
For homeowners, Christchurch City Council provides low-level protection at the point of connection to the public water supply. It does not protect water from hazards that can occur within the home.
Sometimes the level of protection provided at the water connection may not be enough, especially if certain activities, such as spa baths, swimming pools or dialysis machines, exist within the premises. Protection within the premise must be carried out to comply with clause G12 of the New Zealand Building Code.
| Hazard level | Definitions | Premises type | Protection required | What you can do |
| High risk | Potential to cause loss of life | Commercial / Industrial premises | Reduced Pressure Zone Device or Air-Gap |
Contact a plumber experienced in backflow protection for advice and arrange an assessment and installation. A building consent is required before installation can occur. |
| Medium risk | Potential to cause illness | Commercial / Industrial premises (minimum protection level for commercial / industrial premises) | Testable Double Check Device |
Contact a plumber experienced in backflow protection for advice and arrange for an assessment and installation. A building consent is required before installation can occur. |
| Low risk | Potential to cause discomfort | Domestic premises only | Dual Check Device installed in the meter at the property boundary |
The Council installs dual check devices at water supply connections to domestic premises. If you have areas within your premises that could cause risk to your drinking water (e.g. spa pool, dialysis machine), contact the Council or a plumber experienced in backflow protection for advice. |
Note: Water will not be provided until the backflow prevention device is installed and a commissioning test has been carried out. The device must be certified by a suitably qualified person and a certificate must be sent to Christchurch City Council for code compliance.