Domestic self-supply or shared domestic supply
Domestic supplies that serve 25 or fewer people don't need to register, but there are steps you can take to help ensure your water is safe to drink.
Key things you need to know as a provider of a domestic self-supply or shared domestic drinking water supply can be found on this page.
Is my supply a domestic self-supply or shared domestic supply?
A domestic self-supply is a drinking water supply that serves a single domestic dwelling or household unit.
A shared domestic supply is a drinking water supply that pipes water to any number of domestic dwellings and the total population does not exceed 25 people.
Meaning of domestic dwelling and household unit
Under the Water Services Act 2021outbound, a domestic dwelling means a building that is used as a single household unit, whether it is:
(a) tenanted on a long- or short-term basis; or
(b) occupied permanently or temporarily (for example, a holiday home).
Household unit has the meaning given to it by section 7 of the Building Act 2004outbound.
Examples
These examples are domestic self-supplies or shared domestic supplies:
- A single property with tenants on a lease that is supplied by a rainwater tank.
- A single holiday house that is supplied by a rainwater tank and is rented to tourists on a short-term basis.
These examples are not domestic self-supplies or shared domestic supplies:
- A multi-dwelling building (for example, multiple separate apartments contained in a single building) with more than 25 people that has its own bore water supply.
- A marae wharekai (dining hall) or community hall that has its own river water supply.
- A café building supplied by a rainwater tank.
Responsibilities under the Water Services Act 2021
Domestic self-supplies and shared domestic supplies have no specific responsibilities under the Water Services Act 2021. Unlike other types of supply, they are not required to register with us, prepare a drinking water safety plan or follow Drinking Water Quality Assurance Rules.
However, we recommend that you take steps to protect the health and wellbeing of the people who drink water from your supply (see below).
Some supplies serving a population of 25 or fewer do have responsibilities under the Act
The second set of examples above are situations where providers of a supply to 25 or fewer people do have specific responsibilities under the Act. In short, if your supply is not solely for domestic use and serves any kind of public, commercial or community facility (e.g. a café, marae, sports club or community hall) you have legal obligations under the Act.
To learn about those obligations and options for meeting them, see very small community supplies.
Keeping your water safe
Although domestic self-supplies and shared domestic supplies have no specific responsibilities under the Act, we recommend that you learn about the risks associated with your drinking water supply and manage them in the same way that a registered supplier would. This will help protect the health and wellbeing of the people served by your supply.
We recommend that you learn about:
- the physical, chemical and microbiological properties of your source water to understand what kind of treatment is needed to make it safe to drink
- end-point treatment of your drinking water, using cartridge filters, UV light and backflow prevention to make it safe to drink
- maintaining an end-point treatment system to ensure it always works effectively
- regularly sampling your water and using an accredited laboratory to test it for potentially harmful chemical and microbiological components.
To help, we’ve prepared three Acceptable Solutions – a legal term for readymade options that a supplier can use to ensure safe water is provided to their community. If you use an Acceptable Solution you’ll be applying the same safeguards to your drinking water supply that many registered suppliers do.
Learn about Acceptable Solutions here.
You might also like to view the information for a very small community supply for additional guidance on how to keep your water safe to drink.
If you’re unsure or have any questions about your supply, please contact us.
This webpage is intended as a guideline and summarises legal requirements but does not address every requirement under the Water Services Act. It is not intended to be definitive and is not legal advice. Drinking water suppliers are responsible for understanding and complying with their legislative duties. The Authority may review and revise this page over time. If you are using a printed copy, please check the website to make sure it is up to date.