A non-toxic, naturally occurring algae has been getting into Wanaka's drinking water system, prompting council officers to try to find ways to remove it at the intakes.
The Wanaka Community Board was told by Queenstown Lakes district utilities general manager Mark Kunath yesterday the intake filters would be checked this month and screens would be fitted to the western water intake.
Staff had been waiting for lake levels to drop before doing the work.
While the screens would prevent coarse material and fish from entering the system, they would not necessarily prevent algae, Mr Kunath said.
Council staff have been fielding complaints about algae since February 2008. It has clogged up some household showers and basin plug holes and reduced water pressure.
The problem occurs more frequently in late summer and the affected householders have been told to consider installing filters and to clean them regularly.
There have also been concerns about whether the algae has any health effects, but water services manager Gary McGraw had it tested in 2008 and again this year and says it is not toxic.
Mr Kunath told the board he needed to find a cost-effective way of preventing algae from entering the drinking water system. One possibility was a system similar to that invented to prevent didymo getting into irrigation systems. Another was to use something similar to a vacuum cleaner, with fine gauze cloth bags.
Council staff were also checking a system used in Pukekohe, near Auckland, which had had an algae problem in the past.
Other research work was also being done, Mr Kunath said.
