Updated 7 October at 12:25pm: The boil water notice has now lifted.
What's happened?
On Saturday 4 October we received a single positive result for E. coli in the Rototuna Reservoir from Hamilton City Council, who provide water to Gordonton and Puketaha. With advice from Taumata Arowai and the Ministry of Health, a boil water notice was issued for those in the Rototuna supply zone. There have been no other positive tests at the site, and testing at other reservoirs has not detected E. coli. The notice applies to Waikato District residents in Gordonton and Puketaha.
If you live in the affected water supply zone, you must boil tap water before using it for drinking, cooking, or brushing teeth. More information, see a list of updates below.
Updates
12pm Tuesday 7 October 2025
The boil water notice has now lifted. All tests confirm Rototuna Reservoir water supply is safe to
drink and has returned to full compliance. The water is
safe to use. Businesses and residents need to take a few steps before they
return to normal use, including running all cold taps for five minutes,
disposing of ice and refreshing water in appliances.
For properties on supplied directly from the network (i.e. no water tank):
- Run all cold taps for five minutes
- Run clean water through appliances like coffee machines, water dispenser and ice machines
- Dispose of any ice
- Maintain water filters according to the manufacturer’s advice (if you have one)
- if you have a header tank for drinking water, empty and refill
- hot water tanks do not need to be refilled
For properties on trickle feed supply or a water storage tank
- You must take ONE of these steps before flushing taps or cleaning appliances.
- Drain your tank, rinse it with clean water and then refill it.
- Continue to boil water until the tank is completely refreshed.
- Disinfect the water in your tank using additive-free bleach. The amount of bleach to use depends on the product. For bleach with 5% chlorine, use 33ml per 500L of water.
Learn more about Household water supplies: the selection, operation and maintenance of individual household water supplies.
Page 34 includes the calculations for using 3% household bleach. The volume of bleach should be adjusted based on the concentration of the product and the volume of water in your tank.
If in doubt or your prefer a professional completes a review and provides a tank health inspection, there are many companies who can provide this service at a cost to you.
Water treatment devices can be
added to your system by a registered plumber.
2:25pm Monday 6 October 2025
The boil water notice remains in place for Gordonton and Puketaha until at least tomorrow, as three consecutive days of clear testing are required before a notice can be lifted.
1:10pm Sunday 5 October
4:40pm Saturday 4 October 2025
Hamilton City Council has issued a boil notice for the area after a single confirmed test result today showed the presence of E. coli in a water sample from the Rototuna reservoir. Only Gordonton and Puketaha, that have water supplied by Hamilton City Council, are impacted by this this event. The boil water notice will be in place until at least Tuesday, 7 October.
Affected Waikato District residents
Only residents supplied the Greenhill bulk supply point, being Gordonton and Puketaha are impacted by this event. These residents are on the on-demand supply and the rural trickle feed supply network and will also be required to boil water for as long as this notice is in effect.
The boil water notice includes these roads:
- Gordonton Rd
- Greenhill Rd
- Puketaha Rd
- Sainsbury Rd
- Graham Rd
- Boyd Rd
- Williamson Rd
- Ballard Rd
- Taylor Rd
- Telephone Rd (half way, does not extend to Holland Rd)
- Seddon Rd (half way down, does not extend on to Waverly Rd)
- Reid Rd
- Piako Rd
- Woodlands Rd
- College Rd Peach Rd
- Garfeild St
Residents are advised to boil water for:
- Personal use such as brushing teeth
- Drinking (including making of sachet juice/drinks)
- Making ice
- Food preparation
- Brushing teeth
- Preparing infant/toddler formula
Babies, young children, the elderly and people who have compromised immune systems may be at increased risk. If you have specific health concerns, contact Healthline 0800 611 116 for free advice, or your doctor.
