Water contamination events

A range of hazards and emergencies may contaminate your water supply and make it unsafe to drink or use.

This page contains broad advice on drinking water in an emergency. It will be updated in a water contamination event to provide specific details relating to the incident.

Boil water before consuming it

Until otherwise advised, people in affected by the water contamination event should boil all water for drinking, making up infant formula, preparing food and cleaning teeth.

How to boil water

Electric jugs with a cut-off switch can be used as long as they are full – allow the water to come to the boil and wait for it to switch off. Do not hold the switch down to increase the boiling time.

Water can also be placed a clean metal pan and brought to a rolling boil for one minute.

Boiled water should be covered and allowed to cool in the same container. The taste will improve if allowed to stand.

Find out more about using water when a boil water notice is in place from the Boil Water Advisory Fact Sheet (PDF, 268 KB) from Hawke’s Bay District Health Board.

Hand washing is important

Waterborne illnesses can’t be spread through the air but they can spread through contaminated water and food, or from contact with infected people, so hand washing is extremely important.

Wash your hands thoroughly by using plenty of soap, cleaning under fingernails, rinsing hands well and drying on a clean towel:

  • before and after preparing food
  • after going to the toilet or changing a baby’s nappy
  • after caring for people who are sick.


Children and older people are most at risk of dehydration and drinking fluids is very important. You will need to boil your tap water. See our advice above on boiling drinking water.

Signs of dehydration include:

  • little or no urine passed in the last 8 hours and the urine is dark and smelly
  • reduced saliva in their mouth, no tears, sunken eyes, sunken fontanelle in infants
  • dizziness, lethargy (no energy), floppiness, a rapid heart rate and breathing, cool hands and feet or grey cold skin
  • their skin doesn’t relax after being pinched.

Call Healthline 0800 611 116 or seek advice from a doctor if you want more information about the signs of dehydration.

Keeping up to date

Up-to-date information on the water contamination event will be available from the drinking water supplier. This is often the regional or district council. The local public health unit and district health board will also have advice on managing any health effects of the event.

Information will be available on both their corporate websites and official Facebook pages.

Call Healthline 24/7

Call Healthline on 0800 611 116 for free advice from our trained registered nurses. Healthline is here to help you 24 hours a day, 7 days a week.

Phone calls are free from within New Zealand – this includes calls from a mobile phone.

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