Whanganui mayor Annette Main hopes Whanganui District Health Board will consult with the community if it gets to decide on fluoridating the city's water.
The Government announced this week that health boards rather than councils will decide on which water supplies are fluoridated.
"We've made it quite clear in Whanganui, and we've had referendums, that we don't want fluoride in our water and I would hope the DHB would consult with the community," Ms Main said. "Either way it should be a community decision and I'm just not positive that the same consultation would take place."
Ms Main said fluoridating town water only affected those in urban areas and said the Government should have also considered what could be done for rural communities.
And while she said it was a real health issue, she didn't know if water fluoridation was the most cost-effective way to deal with it.
"To be perfectly honest, I don't know how much water our children are drinking out of the tap."
It was interesting the council would still be required to pay for the cost of fluoridation despite the decision being out of its hands, Ms Main said.
Meanwhile, Whanganui District Health Board chairwoman Dot McKinnon was happy with the proposed change.
"I think it's probably a good move, she said. "I think they're probably in a better position to assess what the issues are."
But she wasn't sure if it would change Whanganui's fluoride status.
"It's a little way away down the track," she said.
"First of all, it's got to get through the House ... and of course we'll have a new board."
In a 2006 referendum in Whanganui, 74 per cent opposed fluoridation.
A review in 2014 of the health effects of fluoride commissioned by the Prime Minister's chief science adviser, Sir Peter Gluckman, and Royal Society of New Zealand president Sir David Skegg found there were no adverse effects of fluoridation of public water supplies.
Associate Health Minister Peter Dunne said the changes reflected that fluoridation was a health issue.
"Deciding which water supplies should be fluoridated aligns closely to DHBs' current responsibilities and expertise."
A bill is expected to be introduced to Parliament later this year.
Members of the public will have an opportunity to make submissions to the health select committee as it considers the bill.