Te utu me te mauri o te wai

The quality of water supplied by your rainwater tank must be fit for its intended purpose – the needs of a thirsty garden are clearly different from the drinking water standards needed for humans.

Rainwater for garden use

If the rainwater you collect is not intended for drinking (non-potable) you need to clearly label your rainwater tank with ‘Not for drinking’ signage.

Installing a rainwater tank for outdoor garden use only, may still require a consent depending on its size and location (e.g. do you need a structure to ‘house’ your rainwater tank). 

Tank rainwater not intended for drinking should not be consumed unless needed in an emergency.  If this happens you must boil the water before use and follow Ministry of Health guidelines.

Rainwater for drinking water

Any rainwater system must meet the requirements of the Building Code.  Collected rainwater that is piped into a house and/or connected to a mains supply will require a building consent. Apply for a building consent here.

To reduce health risks:

• use a registered plumber to install your rainwater tank
• make sure your roof and gutters are clean
• use filters and mesh guards
• if you plan to connect your rainwater tank to the main water supply you’ll also need to fit a backflow prevention device (to avoid contamination of the main supply).

There are a number of companies around the district that offer water testing if you suspect your rainwater tank water may be contaminated.  Most rainwater tank suppliers also stock water testing kits.

Information on maintaining the quality of your rainwater, can be found at the Ministry of Health’s HealthEd website or drinking water publications

Estimating your costs

Buying the rainwater tank

A rainwater tank can cost from less than $100 for a basic rain barrel, to over $3000 for a 3000 to 5000-litre tank (and more for bigger sizes), depending on the design and what it’s made of.

Installation costs

Once you decide on the size and type of rainwater tank that works best for you, contact retailers or a registered plumber for advice on installation costs and the best place to put it.

Other potential costs

• Using a registered plumber.
  This is recommended if you plan to connect to internal plumbing (for laundry use, toilet flushing, or drinking water).
• Consent costs (if applicable).
  Check here for building consent information.
• Other installations costs.
  For example, if a structure is needed to house your rainwater tank.