The decision to add fluoride to drinking water should be made by the Government, not district health boards, the Christchurch City Council says.

The council is calling for national leadership on the issue, as a bill makes it way through Parliament proposing to take the decision to fluoridate away from councils and give it to district health boards (DHBs).

The bill states councils will still have to pay the cost of setting up and maintaining fluoridation, regardless of who makes the decision. In Christchurch, fluoridating the city’s water is estimated to cost $10.5 million initially and $500,000 annually. The bill passed its first reading and is now open for public comment.

Christchurch is New Zealand’s largest city without a fluoridated drinking water supply.

In a draft submission on the bill, council city services general manager David Adamson said the Director General of Health, not DHBs, should be tasked with making the decision on fluoridation.

“National leadership is required in relation to decisions on the fluoridation of drinking water.”

Adamson said it was not appropriate for the council to fund and implement a decision it did not make. The council believed the cost should rest solely with the decision maker.

“The council will need to pass on the costs to ratepayers without any control over the decision. This type of expense is usually planned for, and would be consulted on as part of the council’s long term plan.”

The decision maker must be responsible for the costs of implementing fluoridation given the benefits of the decision would be reduced dental and health costs for the Government, Adamson said in the draft submission.

The council wanted the decision maker to consult with councils and communities where it was considering fluoridation and seek comment on the proposal.

“Decisions related to fresh water are important to our council and the communities in our district and there is a great deal of community sensitivity to the issue of fluoridation in particular.”

Labour Party health spokeswoman Annette King said she agreed the Director General of Health should make the decision on fluoridation.

Moving the decision from local authorities to DHBs only moved the political pressure from one set of elected representatives to another, she said.

“All it does is shift the deck chairs.”

King did not agree that the decision maker should pay the full cost of fluoridation but believed the cost should be shared by the Government and local authorities.

Canterbury Medical Officer of Health Dr Alistair Humphrey said last week Christchurch was a “special case” and the costs of fluoridation would have to be carefully weighed against the benefits, which were significant.

Christchurch draws its water from 155 wells and has 55 pump stations.

The city’s water is entirely untreated, due to its high-quality source: water that falls as rain high in the Southern Alps, then flows down the Waimakariri River and seeps into aquifers beneath the city.

Mayor Lianne Dalziel said last year she opposed fluoridation due to the likely cost. Her predecessor, Sir Bob Parker, was also against it.

The Canterbury DHB has long supported fluoridation, signing a position statement in support in 2003.

The council will discuss the draft submission at its meeting on Thursday.