Comment permalink

High levels of E. coli, excess sediment and water quality issues are just some of the findings from a survey into three Wanaka waterways.

The Upper Clutha Lakes Trust and the Otago Fish & Game Council commissioned Wildlands Consultants to assess the effects of stormwater runoff from urban development in the town.

The survey focused on sediment quantity and quality and its effect on plant and animal life in Bullock Creek, Stoney Creek and Water Race Drain.

Ecologist Melanie Vermeulen sampled 20 sites across the three waterways over four days in September last year.

One interesting finding was that different sites along Bullock Creek had better water quality levels than others, Ms Vermeulen said.

"Everyone is proud of Bullock Creek because it is a community stream and aesthetically pleasing and so I think people assumed the water quality was very good.

"The Touchstone citizen science project had sampled water at the top of Bullock Creek and also at the bottom but the study that I did looked at several sites in between and it really showed how variable the sites are along the whole length of Bullock Creek."

Sediment had the biggest impact on fish life in the stream.

She had found sediment "still hanging around" where there had been breaches in the past from the nearby Meadowstone subdivision into Bullock Creek.

In her report, Ms Vermeulen recommended "it will be important to focus on improvement of sediment management during future subdivision developments".

The report was presented to stakeholders in Wanaka on Tuesday.

Results from the investigation may be used by the community to create a water management plan which included priorities for action to be implemented by the Queenstown Lakes District Council and the Otago Regional Council for future management of the catchment, she said.

kerrie.waterworth@odt.co.nz