Residents of the Otago community of Lake Hawea are fighting against the permanent chlorination of their local water supply.
Queenstown Lakes District Council chlorinated water Arrowtown, Hawea and Glendhu Bay for the summer, on advice from the region's public health officials, after 5000 people fell ill in Havelock North from drinking bacteria-contaminated water last year.
Wanaka and Queenstown's water supplies are already chlorinated.
The temporary chlorination is in place until the end of March but the council will consult and vote this year on whether to permanently chlorinate the water.
"A lot of people, regardless of how they feel about chlorine, don't want it," said Lake Hawea resident Pip Harker.
"Because we've had the pleasure of not having it all this time it's a bit of a rude shock when it suddenly turns up."
More than 160 people have signed an online petition against the chlorination, citing reasons such as the smell and taste, and the council "going against the clear wishes of the community".
Ms Harker said the ultraviolet water treatment system, which households paid $5000 towards when it was put in place in 1987, was upgraded last April and there had been no E coli outbreaks since then.
A community meeting is planned for this Saturday with the council's chief engineer Ulrich Glasner.
Mr Glasner said the UV system would stay in place but chlorination was needed as well to eliminate the risk of water contamination.
A council spokesman will speak to residents at the meeting.
Any permanent chlorination measures will be decided by a council vote.