Akaroa and Takamatua residents are being told to boil water before using it for drinking, cooking and cleaning teeth.
Residents in Akaroa (pictured) and Takamatua share the same contaminated water supply. Photo: Gary Webber/ 123rf
On Tuesday during a routine check, several small dead animals were found in a Banks Peninsula reservoir supplying water to the area, Christchurch City Council said.
The animals were removed immediately and testing had showed there was enough chlorine in the water to kill bacteria, but protozoa could survive.
The risk to people's health was believed to be low due, but there was a chance of developing gastro illnesses if water was not boiled, said Canterbury District Health Board medical officer of health Cheryl Brunton.
Anyone concerned about their health should call a doctor, Brunton said.
Residents could have to boil water for drinking, food preparation, dish washing, brushing teeth, and making ice for several weeks.
Tankers have carried clean water from Christchurch to Akaroa, so residents and local businesses can fill their own containers with clean water while the boil water notice is in effect.
The tankers are at Rue Brittan and at Beach Rd.
Council staff have delivered large water containers to many businesses in Akaroa, for filling at the tankers.
Pallets of bottled water were taken to Akaroa's hospital and resthome yesterday, and will be delivered to Akaroa Area School tomorrow.
Council staff are working on a way to bypass the reservoir, so it can be emptied and cleaned.
"Until that happens, the boil water notice will remain in place," said acting head of Three Waters Adam Twose.
"Bringing water to the boil is sufficient to kill bugs. If you can't boil your water then bottled water is the only other option."
The council has set up electronic roadside signs in the affected areas and texted alerts to residents' cell phones.