Indicators at a glance: Drinking-water quality

This section summarises the latest Environmental Health Indicators about drinking-water quality and health in New Zealand.


Water contaminated with pathogens may cause disease, particularly gastrointestinal diseases. 

Drinking-water supplies can be treated to remove pathogens and make the water safe to drink. The number of people on drinking-water supplies meeting the Drinking-water Standards for New Zealand is monitored annually.

Fluoride can also be added to water to help prevent tooth decay. In particular, children’s oral health can benefit from access to fluoridated water.

Indicator Key findings
Access to safe drinking-water
  • Most New Zealanders have access to safe drinking-water.
  • Among the 3.7 million New Zealanders on registered community supplies, most had access to bacteriologically compliant (96%) and protozoally compliant (83%) drinking-water in 2016-17.
Water-borne diseases related to drinking-water
  • There were over 9500 cases of campylobacteriosis, giardiasis and cryptosporidiosis notified in 2016.
  • Untreated water was a risk factor for 1930 notifications of campylobacteriosis, giardiasis and cryptosporidiosis in 2016.
Access to fluoridated water
  • 60% New Zealanders had access to fluoridated drinking-water in 2016-17 – about 2.3 million people.
  • Access to fluoridated water is mainly concentrated in cities.
Oral health of children
  • Children with fluoridated water supplies continued to have better oral health than those without fluoridated supplies.
  • In 2017, 61% of 5-year-olds and 66% of children in school-year 8 were caries-free. These were the highest caries-free percentages since at least 2000.
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