Backflow prevention devices stop water flowing the wrong way. They're used to protect the public drinking-water supply and to protect people living or working inside buildings and properties.

Did you receive a letter from us regarding backflow prevention?

If you recently received a letter from us, following an assessment of your property, you may now need to either install a backflow prevention device or let us know of any existing backflow prevention devices that are already installed.

  • If you have an existing backflow prevention device, please let us know.
  • If you need to install a backflow prevention device you will need a building consent. Please complete an Application for a building consent for the installation of a backflow prevention device (Form B-009), available either as a Word [DOCX, 396 KB] document or PDF [PDF, 592 KB].

We have streamlined the building consent process for the installation of new backflow prevention devices only. There is a fixed fee of $430 (incl. GST). Please note that if any further information is required, there may be additional fees.

Note: The B-009 form is only to be used if you have received a letter from the Council to install a backflow prevention device. If you are installing a backflow prevention device as part of other building work you will need to apply for building consent in the normal manner as noted below using the Application for a building consent (Form B-002) form.

Installing a backflow prevention device

You need a building consent from us before you can install a backflow prevention device. But if you've already applied for a building consent for other work, you can include your device in the same application.

To apply for a building consent for a backflow prevention device, please complete and submit the following two forms: 

  1. Application for a building consent (Form B-002), available either as a Word Doc [DOCX, 425 KB] or PDF [PDF, 257 KB].
  2. Backflow prevention device check sheet [PDF, 96 KB] (Form B-052). 

Fees

We have streamlined the building consent process for the installation of new backflow prevention devices only. There is a fixed fee of $430 (incl. GST).  If any further information is required, there may be additional fees.

If there’s other additional building work to be undertaken please refer to the Building Consents fee schedule for more information.

Please note that the fixed fees and minimum application fees do not always cover all of the consent related costs of an application. For example, if the application does not contain all the required information.

About backflow prevention devices

A typical backflow prevention device for 'high risk' protection.

The property owner is responsible for the costs of installing, maintaining and testing any backflow prevention device. Costs for installation vary widely and depend on the:

  • degree of protection required (risk level)
  • size of the device
  • complexity of the installation

A registered plumber must install a backflow prevention device and all testing of the device must be carried out by an Independent Qualified Person (IQP) on backflow(external link)

Backflow prevention devices have to be tested immediately after installation to attain code compliance for the building consent. Devices must then be tested annually to ensure they are working correctly and providing protection.

Testing reports must be kept by the owner and a copy forwarded to Christchurch City Council to ensure the premise has a current Building Warrant of Fitness.

A backflow prevention device is a specified system which is added to a building's compliance schedule.

More information about backflow and backflow prevention.

Inspection and maintenance of a backflow prevention device

A backflow prevention device is a specified system. Specified systems need to be included on a compliance schedule.

A building warrant of fitness confirms that your specified system has been inspected and maintained as required. Please see our compliance schedule webpage for more information.

Questions and answers about backflow prevention

How do I know if I need a backflow prevention device?
All commercial and industrial properties, other than those with a backflow risk similar to a residential house, are required to have a backflow prevention device. If you recently received a letter from us asking you to install a backflow prevention device, then you need to apply for building consent and have one installed as soon as possible.

Do residential properties need backflow prevention?
Yes, if there are any 'high' or 'medium' backflow risk activities occurring on-site. This includes hairdressers, swimming pools, spa pools, and irrigation systems with underground controllers. A registered plumber can advise about your specific property.

Why do I need to install backflow prevention?
Backflow can cause water (and potentially chemicals and other contaminants) to be sucked or pushed back into the public drinking-water supply, potentially causing serious illness, injury or death. As a commercial or industrial property owner, you are legally responsible for preventing backflow from your property and for making sure you don't contaminate the public drinking-water supply.

I already have a device installed – what should I do?
If you recently received a letter from us but already have a backflow prevention device installed, then you need to let us know what devices are located on your property and the level of risk they protect against.

I own property but no building – do I still need a device?
If you don't intend to use water on your property, then you don't need to have a backflow prevention device installed. However, any use of water, even for irrigation, may mean you need a device. When applying for building consent to develop a property, backflow is considered as part of this application. If you don't need a water connection to your property, you can apply to have it removed.

I received a letter but my neighbour didn't – why?
It's possible they haven't yet received their letter from us, or their property wasn't deemed to be a risk to the water supply network.

Can I choose not to install a device?
As a commercial or industrial property owner, you are legally responsible for preventing backflow from your property and for making sure you don't contaminate the public drinking-water supply. If you don't meet these responsibilities, we may need to install a backflow prevention device at your cost.

Contact us

Phone 03 941 8999 or email backflowconsents@ccc.govt.nz.