Public water supplies must meet the New Zealand Drinking Water Standards. The public health implications of contaminated water necessitate the protection of Christchurch’s drinking water.

What this means for our district

  • The secure supply of safe drinking water is maintained in sufficient quantities to provide for the community's reasonable needs
  • Water quality in aquifers is protected from the effects of land use
  • Communities demonstrate a commitment to water conservation, promoting water quality

How we are contributing

Temporary chlorination is currently being used to safeguard our drinking water while the necessary remedial work is undertaken. All efforts are being taken to complete the work as soon as possible to allow for the chlorination of our drinking water to end.

How you can help

The remedial work on wellheads will require certain pump stations to be closed off from the water supply network as work progresses in the area. If the community is able to conserve its water use across the city, this may enable several sites to be worked on at the same time while still maintaining an adequate water supply, which may reduce the time in which chlorination is required.

How we are doing

Status What do we want to achieve? What has happened?
Mixed
result
Indeterminate Result

Satisfaction with the overall quality of the water supply in Christchurch

Since 2005, around 90 per cent of residents have been satisfied with the overall quality of the water supply. However, in 2018 this declined to 79 per cent. Further information.

Mixed
result
Mixed Results

Protozoa and bacteriological compliance

100 per cent of the city's population receive water supplied by zones which comply with the NZ drinking standard for bacteriological compliance. Further information.

Positive result
PositiveResult

Groundwater quality

Groundwater quality in Christchurch is generally very good and the majority of samples meet the NZ drinking water standards without treatment. Further information.

Mixed
result
Indeterminate Result
Water supply abstraction and abstraction per person

Abstraction and per person abstraction rates declined after the earthquakes. In the last couple of years they have returned to levels similar to before the earthquakes. Further information.

Satisfaction with the overall quality of the water supply in Christchurch

Before the earthquakes, residents' overall satisfaction with the water supply was consistently over 90 per cent satisfied or very satisfied with the taste, pressure and appearance of the Council's water supply.

Since the earthquakes, this decreased slightly to 84 per cent satisfaction in 2014, before increasing to at least 90 per cent in 2016 and 2017. However in 2018, with the discussion about chlorinating the water supply, satisfaction fell to 79 per cent.

The 2018 survey was conducted before the introduction of chlorine to the city's water supply, so we would expect the impact of cholorination on the satisfaction to be more apparent in the 2019 survey results.

Protozoa and bacteriological compliance

Christchurch's water supplies have consistently met New Zealand drinking water standards for microbiological compliance, with 100 per cent of the water supplied to residents coming from complying zones since 2015.

Protozoan compliance since the earthquakes show that at least 75 per cent of water supplied to the city's population has complied with the drinking water standards. This proportion has declined slightly since 2012. 

Groundwater quality

Environment Canterbury reported(external link) that groundwater quality is generally very good and the majority of samples meet New Zealand drinking water standards without treatment. The best water quality occurs across the northern area, thanks to seepage of clean water from the Waimakariri River into the aquifer.

Groundwater quality in the south is still good, but the water contains more dissolved substances picked up during infiltration through the soil at the land surface.

Some areas near the estuary and old coastal swamps have low dissolved oxygen, which causes naturally poorer groundwater quality.

Environment Canterbury found very little evidence of changing groundwater quality in Christchurch over the last ten years. Four wells showed increasing concentrations of three or four monitoring parameters that could signal a slight long-term decline in quality near the groundwater table to the west and south west of the city. A fifth well with a definite declining trend is down gradient of known point source discharges of contaminants.

Two wells showed continuing improved groundwater quality in the Woolston-Heathcote groundwater management zones. The improvement is probably a result of better management of abstraction and discharges to ground than in previous decades. 

Water supply abstraction and abstraction per person

Total water abstracted from the aquifers for the Council's water supplies have fluctuated, but averaged around 52 million cubic metres per year in the 10 years to the earthquakes. 

After the earthquakes, abstraction declined to around 46 million cubic metres from 2012 to 2014. Consumption has since increased to 55.4 million cubic metres in the year to June 2017.

Per person abstraction before the earthquakes averaged 411 litres per person per year. After the earthquakes, this declined to 359 litres per person.

It has since increased back to 410 litres per person in the year to June 2017. Much of the variation between years in consumption of water is likely to be the result of differences in the weather, and how much gardens get watered.