Christchurch’s water- what’s the story?
There’s plenty of water flowing under Christchurch which is available for community use as well as sourcing the city’s spring-fed streams. This page shows the key facts around the freshwater resource that sits under the city.
Christchurch’s water supply is well understood by scientists and is sustainably managed. As a community, we are committed to protecting this precious resource from overuse or contamination.
- If you’re interested in Cloud Ocean Water and its consent applications, visit our Water bottling - what's the story? page.
- If you’re interested in who does what to protect, monitor and supply visit our Christchurch’s drinking water page.
How much water does Christchurch have?
Around 375 million cubic metres flows beneath the city each year - that’s the same as 150,000 Olympic sized swimming pools.
While we measure water in cubic metres, a lot of people think about water in litres which makes the numbers huge. If we did this then the amount of water under Christchurch is 375,000,000,000 litres.
Where is this water?
There is water everywhere beneath the city, filling the pore spaces in the gravelly sediments under the ground. There is just one interconnected aquifer under the city – not a series of separate aquifers – and water flows through the sediments.
Users extract water through bores or wells – Christchurch City Council has nearly 150 bores throughout the city which supply water to houses and businesses through a network of pipes and supporting infrastructure.
How much water flows under Christchurch each year?
The system under Christchurch is in balance: water in = water out.
Around 375 million cubic metres of water flows in each year, it is made up of:
- 123 million cubic metres of rainfall onto the areas north and west of the city
- 252 million cubic metres of water that ‘leaks’ from the Waimakariri River and flows via shallow aquifers towards Christchurch.
How much water does Christchurch use, and what are the natural outflows?
Around 375 million cubic metres flows out of the Christchurch system - it is made up of:
- 208 million cubic metres that enters spring-fed streams such as the Heathcote and the Avon/Otakaro and flows to the estuary and the sea.
- 15 million cubic metres which flows underground to the sea or other springs.
- 152 million cubic metres allocated for Christchurch (but not all is used).
How much of the annual allocated water is used?
Around 152 million cubic metres is allocated on an annual basis - but not all that is allocated is used. Christchurch City Council, for instance, uses only around 70% of its allocation.
The top 20 industry users, which includes water bottling, mostly use significantly less than their allocated amount each year.
The allocations in Christchurch are:
- 57% to Christchurch City Council for community supplies.
- 38% allocated to industry.
- 7% allocated for water bottling.
No more water can be allocated except for community supplies (Christchurch City Council).
Industry or water bottlers are prohibited from applying for new consents to take water – but they can trade or transfer existing usage consents or apply for a variation to an existing consent.