Caused by algae, the floating mucus (lake snot) has been present in Lake Wanaka since the early 2000s and had caused issues for recreational lake users, as well as local business.
Although not harmful to humans, lake snot clogged water filters used by both residents and businesses in Wanaka.
Fish and Cruise Lake Wanaka owner operator Alan Baxter said for the first time since he first noticed the algae in 2002 it had been present in the lake during the winter.
A large algal bloom near Stevensons Arm in June did not bode well for when the lake warmed during spring and summer, he said.
From an isolated area near Stevensons Arm in 2002, the snot had spread across almost the entire lake, Mr Baxter said.
During that time he had gone to both the councils with his concerns and samples of the snot but the problem was getting worse, and nothing seemed to be done.
He no longer told people the water from the lake was clean enough to drink.
Guardians of Lake Wanaka chairman Don Robertson said inaction by the Otago Regional and Queenstown Lakes District councils meant issues like lake snot would continue to be an issue if nothing was done.
A lake management plan would be the minimum the councils could do to address the water quality issues, but they did not seem interested, Dr Robertson said.
Last summer, the Caltex Wanaka had to clean its water filters two times a day. Owner Matt Davison said filters still needed to be cleaned about once a week up until the start of June but the snot had not been much of an issue for the past two months.
The problem had got worse in the past three years and repeated attempts to talk to the Queenstown Lakes Council had led to nothing, Mr Davison said.
He said he had given up hope that anything would be done.
Queenstown Lakes Council chief engineer Ulrich Glasner said a three-month trial of a water treatment system to remove the algae from water to reduce its impact on water filters had shown promising results.
The cost of running the system full-time was being investigated, Mr Glasner said.
Lake snot and the water quality in Lake Wanaka is set to be an issue in the local body elections.
All candidates for the Wanaka ward have said water quality in Lake Wanaka was one of the most pressing issues for the council.
Candidate Ross McRobie has already started the debate, releasing a press release on Monday, saying Lake Wanaka’s water quality would be one of his top priorities if elected.
A spokesman for the Otago Regional Council said a report on the lake snot would be released early next week.
