Rainwater is a free water supply that constantly renews.
Having a rainwater supply:
- reduces demand on mains water supplies and stormwater
- provides you with an emergency supply
- provides an independent supply for watering the garden in times of drought
- reduces costs for users on a metered water supply.
Whether you want to use the collected water for indoor or outdoor use will determine the size and type of set up you will need.
It’s important that the water going into your rainwater tank is as clean as possible. To help with this you can install leaf guards and first-flush diverters on the downpipe leading to your rainwater tank.
Collecting and using rainwater – Smarter Homes
Water tanks can also help make you more resilient in the event of an emergency.
Civil Defence recommends storing a minimum of twenty litres per person, per day for drinking, cooking and hygiene.
WREMO - Store emergency water
Wellington City Council sells 200L emergency water tank kits that homeowners can install.
Water tanks and water containers
Tanks for stormwater retention
Rainwater tanks that are installed to reduce the amount of stormwater runoff during rain events are designed to be empty when it is not raining and then to fill up and release the collected stormwater slowly. For more information see Wellington Water - Stormwater neutrality.
Building and resource consents for water tanks
NZ Building Act allows for tanks up to 35,000 litres and supported directly on the ground to be installed without building consent. Tanks supported on a structure have limits on size before they need a consent. Installing a rainwater tank on top of a building and/or connecting it to the building's water supply will require consent.
Schedule One of the Building Act lists situations where tanks do not require building consent.
If you're planning to connect a rainwater tank to your building’s water system, you will need a building consent and a registered plumber to carry out this work for you.
If you want to use collected water for drinking, you’ll need to have the water treated or purified as part of this process.
Email our Building Compliance and Consents team if you’re unsure about requirements: firstname.lastname@example.org
As water tanks are considered a structure, factors like site coverage and building recession planes apply to them. You will need to keep in mind the rules and standards specific to your property.
Smaller tanks up to 2,000 liters are unlikely to trigger a consent, but it is the owner's responsibility to confirm any requirements for consents or permits have been met.
You can check the specific restrictions in your area through our online district plan ePlan.
If you’re unsure check with our Planning Team:
Phone 04 801 3590