Indicators at a glance: Drinking-water quality

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

Summary

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
  • About 83% of New Zealanders (4.1 million) received water from registered drinking-water supplies
  • 76% of New Zealanders (3.1 million) on registered supplies received drinking water that met all bacteriological, protozoal and chemical requirements
  • Small drinking-water supplies were less likely to meet protozoal and bacteriological standards than larger supplies
  • 32 supplies issued permanent boil-water notices during the 2018–2019 reporting period, affecting 9,073 people
Water-borne diseases related to drinking-water
  • The age-standardised campylobacteriosis notification rate was 132 per 100,000 people in 2018 (6,463 notifications). This was approximately the equal lowest rate since reports began in 2001.
  • The age-standardised notification rate for cryptosporidiosis was 38 per 100,000 people in 2018 (1,551 notifications). This was approximately the equal highest with 2001.
  • The age-standardised notification rate for giardiasis was 31 per 100,000 people in 2018 (1,392 notifications). This has remained unchanged since 2015.
  • Notification rates for potentially waterborne diseases continued to be higher for children aged 0–4, people of European/Other, and people living in less deprived or rural areas.
Access to fluoridated water
  • 60% of New Zealanders on registered drinking-water supplies had access to fluoridated drinking-water, 2018. This proportion has remained relatively stable since 2014–2015.
  • People in major urban areas were more likely to have access to fluoridated drinking-water compared to other areas.
  • People in the South Island were less likely to have access to fluoridated drinking-water (18%) compared to people in the North Island (75%).
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.
Useful links Back to Top