Backflow Prevention
Keeping water safe in our communities
Waipā District Council is committed to keeping our drinking water safe for our communities. That's why we are working with property owners to help prevent the risk of contaminants entering our water supplies.
What is backflow and how does it happen?
Backflow is one of the biggest risks to our public water supply. It occurs when water flows back into the network from a private property and, depending on the activity that occurs on the land, water entering the public supply in a backflow event could contain chemicals or contaminants.
Water pressure within the network ensures water is delivered to your property. If the water pressure changes, backflow can occur either by back-siphonage or decreases in pressure, which may allow contaminants and chemicals to flow into the water supply network.
Preventing backflow
We have developed a backflow prevention programme and is opting to manage the risk by requiring installation of backflow prevention devices where there is a medium or high risk of backflow occurring. We will work together with the public to locate, assess, and mitigate areas of risk at the boundaries of industrial, rural and commercial properties.
Backflow prevention devices are an effective tool for preventing backflow. Backflow prevention may be required where a risk of contamination is identified to the potable water network.
What are our legal responsibilities?
Under the Water Services Act 2021, we all have a duty to protect against the risk of backflow.
Our responsibility is to protect the public water supply network against the risk of backflow. We are required to determine when it is necessary for a backflow protection device to be used, maintain a register of the devices, ensure devices are tested at least annually, and have a Drinking Water Safety Plan in place. This is required under the Water Services Act 2021.
Your responsibilities as a property owner
You are legally responsible for ensuring activities you conduct don’t contaminate the public water supply.
If you carry out activities on your property which use substances that could enter the public water supply (and cause harm), and it is deemed this poses a risk to the water supply, it is your obligation to install backflow protection. Any costs associated with installation and operation of the protection are your responsibility.
It is also your duty to ensure the backflow device is maintained and tested each year.
Identified property owners have a responsibility to have adequate backflow prevention in place and/ or implement measures to prevent water from backflowing into the potable water supply. This is required under the Waipā District Council Water Supply Bylaw 2022.
Council policy on backflow prevention
- All points of supply must at all times have a backflow prevention device installed at the Council side of the point of supply as approved by Council.
- The type of backflow prevention device required will be determined by Council classifying the backflow risk of the applicable water supply system connection.
- All Backflow Prevention Devices must be supplied, installed and maintained by Council at the Customer's cost, unless otherwise agreed by Council, and thereafter will remain the property of Council.
- Council may, at any time test a backflow prevention device, at the customer's cost.
- The customer must notify the Council as soon as possible on becoming aware that a backflow prevention device may require repair or maintenance.
- Fire protection systems that include appropriate backflow prevention measures are generally not required to have additional backflow prevention, except in cases where the system is supplied by a non−potable source or a storage tank or fire pump that operates at a pressure in excess of Council's normal operating pressure.
Levels of risk
Council assigns one of three levels of risk, in terms of backflow, to each property in the district.
| Risk level | Device required | Hazard example |
| High risk | Testable Reduced Pressure Zone (RPZ) valve | High-risk hazards include equipment used for processing, handling, mixing, and measuring chemicals and other harmful substances. Including: any medical facilities (human/animal), bidets, clean in place vats food storage vessels, reticulated or recycled water (irrigation systems) using chemicals, livestock water supply cow shed washdowns, boilers and water-based heating systems, laboratories educational facilities, and swimming pools. |
| Medium risk | Testable Reduced Pressure Zone (RPZ) or testable double-check backflow valve | Medium-risk hazards include commercial and residential water uses other than general domestic use. Including: hairdresser’s sinks, commercial car washes/wash down areas without chemicals, untreated water tanks, residential and commercial swimming pools, spas and drinking fountains. |
| Low risk | Testable double-check backflow valve | Low-risk hazards including: drinking water fountains, ice makers, coffee machines, carbonated drink dispensers, hoses and taps, domestic irrigation systems, and parks drinking water fountains |
| Very low risk | Dual check valve | Very
low-risk hazards including domestic toilets, urinals, baths, and showers.
|
Do you require backflow prevention?
You will be required to install backflow prevention if the findings from your site visit conclude that your property poses a level of risk of backflow. This determination will be based on a number of factors, such as the activity conducted on your property, chemicals or equipment used and stored, or cross contamination risks.
Installing backflow prevention
A backflow prevention device not only protects your drinking water supply from contaminants, but it protects your neighbours and your community.
Reduced Pressure Zone (RPZ) Valves, Double Check Valves and managed air gaps are suitable forms of backflow protection.
Installation must be completed by a suitably qualified person and in accordance with Waipā District Council’s standards.
Where will the backflow device be installed?
Backflow devices are typically installed at the boundary of a property, either in-ground, or above ground in a cage or protective box. The way the device is installed will depend on the level of protection required. The device is installed at the boundary to protect the potable water supply from potential contamination from your property.
What happens after it is installed?
Backflow prevention devices require annual certification, which must be carried out by an Independently Qualified Person. Annual testing is needed to certify that the device remains functional and is operating as it should be. Annual certification is at the cost of the property owner. Council can arrange for the test to be carried out on the property owner’s behalf, at cost value.
When arranging your own certification, please email your test results to info@waipadc.govt.nz
How do I find an Independently Qualified Person (IQP)?
What if my land use activity changes?
If your land use activity changes and you think your level of backflow risk has changed, please contact Council to arrange a follow-up inspection to reassess your backflow risk.
