After a recent concern from a member of the community about algae and E.coli levels in the Hawea River, the Wanaka Sun asked Otago Regional Council (ORC) about the issue. Rachel Ozanne, an environmental resource scientist with ORC, got back to us.
“It'd be interesting to see how the river is after the recent flushing flows. This summer has been great - for us - and also great for algae growth. The quality of the river is really good, with low nutrient and bacteria concentrations.
“ORC has Schedule 15 limits (Regional Plan Water) for bacteria, nutrients and turbidity – the Hawea River at Camphill Bridge (pictured) easily meets these limits.
“The Hawea River, when compared to the grades set out in the National Objectives Framework, comes in the ‘A’ (top) band for water quality. In particular, when looking at bacteria levels, to obtain the ‘A’ band, the river must pass all four statistical tests.
“In addition, ORC monitors bacteria in Lake Hawea (at the Holiday park) over the summer period on a weekly basis. The water has very low concentrations of E.coli.
“We can safely say the water quality is great, but it seems that algae was rife this summer. This is likely to do with the extremely low stable flows, high temperature and therefore excellent growing conditions.
“I haven’t yet received the annual algae monitoring report from our consultant. It will be interesting to see if the report confirms that long green filamentous algae was more prolific than other years.”
Pictured: Hawea River. Photo: Nikki Heath / Wanaka Sun
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