Canterbury’s drinking water
Canterbury has some of the best drinking water in the world, but no water supply is completely without risk.
Water can be contaminated by bacteria, viruses, nitrate, metals and other chemicals. Some contaminants occur naturally, while others come from human activities. If you’re on a reticulated supply, your local council or water supplier will assess those risks and make sure your drinking water is safe. If you have your own well, the responsibility rests with you.
Who helps ensure our water is safe to drink?
Local councils are responsible for the supply, distribution, treatment and safe supply of drinking water.
Environment Canterbury’s role is to monitor and test our drinking water and protect it at its source.
The Ministry of Health appoints drinking water assessors who are employed by the Canterbury District Health Board to oversee the impact of water quality on health.
People with private drinking wells are responsible for ensuring their supply is safe.
- Make sure you know where your well is and that it’s in good condition
- Ensure your well head is secure and clear of any debris and fenced off from animals
- Regularly test your water by taking a sample and sending it to a lab for analysis (at your own cost)
- Check the historical use of the land to understand the contamination risks
Check out this private well information sheet for more information and tips.
Find out more about drinking water safety.
Christchurch’s drinking water
Around three-quarters of Christchurch’s groundwater comes from the Waimakariri River to the north of the city. The rest comes from rainfall to the west and north of the city. The water from the river and rainfall seeps into the gravels and flows towards the city at up to 25 metres per day.
Downstream of this point, some of the water in the river begins to flow into the gravels of the plains, topping up the aquifers on which Christchurch depends for its drinking water.
Environment Canterbury owns a significant amount of land in this area. The land is managed to ensure it is used for appropriate purposes that won’t have an adverse impact on Christchurch’s groundwater.
Flowing through the gravels at about 25m a day, groundwater takes a few years to reach the zone from which Christchurch takes its drinking water.
Christchurch’s groundwater supply is famously pure at its source but the most serious threat to groundwater quality is development (industrial, agricultural and commercial) over the zone.
Christchurch’s drinking water is protected by rules in the Canterbury Land & Water Regional Plan which controls land-use to minimize the risk of contamination. Much of the area is used for very low intensity stock grazing and recreational parks.