Cyclotella bodanica (better known as lake snow) has also recently been identified at low levels in Lake Hawea, but has not affected the Hawea water network.
Scientists have confirmed the algae does not present a health risk, but it can block up water filters on commercial premises and residential appliances such as dishwashers and washing machines.
Queenstown Lakes District Council is working with the Otago Regional Council and their scientific research partners to learn more about the algae, what causes it, why it has affected the lakes and what treatment options are available.
QLDC has yet to decide on treatment options but options include installing in-line filters throughout the water networks that take water from Lakes Wanaka and Wakatipu, moving from a lake intake to a bore water supply, or looking at expanding the filter system trialled at an intake in Lake Wanaka.
The issue was noteasily solved, QLDC chief engineer Ulrich Glasner said. “While we would prefer there to be no algae in our water supply, the fact of the matter is that it’s there and it is having an effect on our network, both in Wanaka and Queenstown.”
Mayor Jim Boult agreed, but said good data was needed before committing to a treatment option. “We’re working with the ORC to better understand the origins of the algae, but in the meantime we’re looking into all the available choices to treat our network. There are potential solutions both in the short term and further down the track, but they all involve a cost to ratepayers and as such we need detailed information to consider before we make any decisions.”
“Earlier this year, the Minister for the Environment, Nick Smith, announced the Freshwater Improvement Fund, a $100 million fund to support initiatives to clean up New Zealand’s fresh water. I’ve had initial discussions with the minister regarding this and he has indicated that water quality in our district’s lakes is high on his agenda, and research into the issue of lake algae would be likely to qualify for investment using this fund.”
More information about how to identify if you have a problem related to lake algae, and a flyer '‘Managing algae in your water supply'’ are available at www.qldc.govt.nz/services/water-services/lake-algae/
