Geologically, an 'aquafact' is a boulder worn by running water that is too large to be rolled as a pebble, worn smooth on the upstream or seaward side and exposed top and with a sharp ridge on the downstream or landward side. These 'aquafacts' are simple facts to aid understanding of a range of issues about Christchurch and Canterbury water. 

Let's look at the (aqua)facts around Christchurch water

Our main urban area, Christchurch, is blessed with a plentiful supply of fresh clean drinking water. Environment Canterbury works with the community to help ensure we protect our fresh water now and for generations to come. People from across our region are working together as kaitiaki to protect and improve our water resources. 

Responsibility for water quality in Christchurch is held by three agencies.

All Canterbury city and district councils are involved with protecting our water via the Canterbury Water Management Strategy, but three agencies are directly responsible.

Environment Canterbury looks after the source of our drinking water (aquifers, rivers and lakes); local councils are responsible for the supply, distribution, treatment and safe supply of drinking water (the infrastructure) and the Ministry of Health through the Canterbury District Health Board monitors the impact of water quality on health. Watch the video for more information or read through our pages on Canterbury's drinking water.


Christchurch aquifers are replenished with 375 billion litres of water each year.

There is no risk of running out. Christchurch’s water supply is well understood by scientists and is sustainably managed. 123 billion litres of rainfall onto the areas north and west of the city, and 252 billion litres which ‘leaks’ from the Waimakariri River recharge the Christchurch aquifers each year. 

In total, that's about 375 billion litres or 150,000 Olympic swimming pools which flows through the Christchurch aquifers each year. What isn’t used ends up in the ocean.

The rules to protect our water are some of the strictest in New Zealand.

Nitrate levels are an indicator of water quality. Elevated levels can indicate the presence of compounds which may cause health issues. We know nitrate levels will increase over time due to poor land-use practices in the past.

Christchurch’s drinking water has about 1mg of nitrate per litre and strict rules are in place to keep our water at a safe level. The maximum national health level is 11.3mg per litre.

The Christchurch City Council currently uses only 70% of its 82 billion litre allocation.
We are not running out of water and not even close to using our current allocation. The City Council is allocated 82 billion litres of water each year for household supply and to keep our parks and gardens green. Right now, it uses about 70 percent of that allocation.
Water supply and recent water restrictions are not linked. They are to allow water network repairs to be completed sooner.
Water supply and recent water use restrictions are not linked. The restrictions(external link) are to allow the City Council to repair water infrastructure. The less water we use, the less water that will be travelling through the network, and the faster that work can be completed, allowing the City Council to stop chlorinating drinking water sooner. 
Chlorination is needed while the Christchurch City Council repair water infrastructure. 
There is nothing wrong with the water in Christchurch aquifers. But our city has old well heads which need replacing(external link). Until this is done the Christchurch City Council needs to chlorinate the supply(external link) to ensure safe drinking water is being delivered to your house.
No new consents to take water from Christchurch aquifers can be granted.
The City Council is the only organisation that can apply to take new water in Christchurch – and only for community supply. Consents can be transferred as long as new uses don’t have an increased environmental effect. For more information read the full story on consents.
Nitrate in waterways

General information about nitrate in waterways

  • National and local rules are in place to regulate nitrate in our freshwater
  • The National Policy Statement for Freshwater Management(external link) (NPSFM) requires that freshwater quality is at least maintained, or ideally improved
  • For drinking water, the New Zealand Drinking Water Standards set a Maximum Acceptable Level (MAV) of 50mg/l for nitrate, which is equivalent to 11.3 mg/l nitrate-nitrogen
  • If nitrate reach half that level (5.65 mg/l) in a community supply, additional monitoring must be undertaken.

Find out more about the Annual groundwater quality survey.

Environment Canterbury’s role in reducing nitrate

  • We put controls on land-use activities that could threaten water quality; for example, we control land-use to the west of Christchurch to protect the city’s drinking water supply; much of the area is used for very low intensity stock grazing and recreational parks
  • We have introduced some of the strictest rules(external link) in the country to help address water quality issues and, over time, deliver the improvements the community demands
  • This includes requiring farmers to operate within strict limits and adhere to industry agreed good management practice guidelines.
  • Higher risk farming types are now required to measure and manage nitrate leaching via a consent to farm. They are also required to have a Farm Environment Plan and their performance against this plan is graded by independent auditors as part of Environment Canterbury’s compliance programme
  • Many farmers are working hard(external link) to reduce their impact on the environment, such as fencing off water ways and planting along stream margins

We're fortunate to have plenty of water - Christchurch aquifers are replenished with 375 billion litres of water per year.

We now have the strictest limits in New Zealand to sustainably manage the use of our water.

Water allocation is an important and strategic issue. Decisions around water use need to both sustain the economy and protect our environment.

Responsibilty for water quality in Christchurch is held by three agencies; Environment Canterbury, the Christchurch City Council and Canterbury District Health Board.

Water diagram