Ashburton people have voted against fluoridating the town’s water supply.
Fluoride was withdrawn in 2002 following a public campaign, but health officials were seeking to reinstate it, citing rising tooth decay rates.
More than 7000 residents took part in a binding referendum, and just under 55% voted against.
The three-week poll was open to 11,000 residents. Ashburton District Council electoral officer John Rollinson says the turnout is consistent with most local body issues in the town.
Mr Rollinson says the 725-vote margin against fluoridation is a good mandate.
He says the poll will be ratified by the council next month.