At a public meeting in January more than 100 Lake Hawea residents expressed their opposition to having chlorine in their water supply.
A pressure group called Hawea Stand for Pure Water was formed last year. Spokeswoman Jen Rumore said the community was ready to do all it could to stop chlorination of the town's water supply.
She hoped the Wanaka ward councillors would listen to their concerns. Hawea Community Association chairman Paul Cunningham echoed her concerns.
"I don't think there will be anything new we haven't heard before, but people are very strongly against it and they need to be heard."
Council chief engineer Ulrich Glasner said yesterday a letter from Medical Officer of Health Dr Keith Reid, sent last September, was "clear guidance" the council should consider chlorination after last year's Havelock North water contamination crisis left 5000 people ill and was linked to three deaths.
There is already space for chlorination equipment in places like Arthurs Point, Arrowtown and Lake Hawea. In other areas, like Luggate and Glenorchy, small buildings might have to be constructed, he said.
Water supplies are mainly tested for E.coli and the parasites giardia and cryptosporidium.
A drinking water standards compliance report for Queenstown Lakes supplies, released late last year, showed Lake Hawea had four "transgressions" of E.coli levels in the 12 months to June 30 last year.
The same report showed multiple "turbidity" failures at Kelvin Heights, Two Mile, Wanaka's Beacon Point supply and Wanaka "Western".
In 2012, a norovirus outbreak in Cardrona, caused by sewage contamination of drinking water, caused at least 53 cases of diarrhoea, vomiting and nausea.
Dr Reid's September 5 letter to council chief executive Mike Theelen, released by the council to the ODT, warns the Havelock North incident had "clearly altered" the political and public tolerance of failures to ensure drinking water was safe and chlorination "may need to be reconsidered".
"This may mean that improvement measures identified in water safety plans but not yet implemented may need to be accelerated."
Dr Reid, of Dunedin, does not have the power to order councils to chlorinate.
Yesterday he welcomed what he called the council's precautionary approach.
He said it meant: "You can turn on the tap and know every day, 24 hours a day, that your water is protected from bacterial and viral contamination."
"You could imagine, if there was a large-scale outbreak, the impact that that would have on the tourist industry in Queenstown."
He did not think Queenstown's hospital could cope with an outbreak the size of Havelock North's.Arrowtown Village Association chairman Russell Heckler said the community had been disappointed when it was announced the water supply would be chlorinated over the 2016-17 summer.
But he had heard no complaints about it.
"I must admit the level of chlorine they've got in it must be reasonably low."
The annual plan will be adopted in late June.
