ORC Water Scientist Rachel Ozanne said that while water quality is generally good across Otago, wet and windy weather can impact water quality, which is why the general advice is to stay out of the water for two days after a big rainfall.

“Every Monday, our team wades out to take water samples in every corner of Otago, then sends them up to a laboratory in Christchurch to be analysed for nasties like E.coli, with those results automatically posted onto the LAWA website usually by Wednesday afternoon,” Mrs Ozanne said.

“Unfortunately for the first week of testing, it was right after the heavy rain we experienced over the weekend – demonstrating how rain can affect water quality.

“When rain falls, it falls on our rooftops, on our roads, into our gutters; the rain and all the contaminants it brings with it eventually enter waterways.

“That’s why it’s best to stay out of the water 48 hours after rainfall,” Mrs Ozanne said. “If you’re in doubt – if the water looks a bit murky or smelly – choose another spot to swim.”

ORC conducts its weekly monitoring between December and March (inclusive) with weekly results available online at the Land, Air, Water Aotearoa (LAWA) “Can I Swim Here?” website. The team will take fresh water samples for testing today with the results expected to be online by Wednesday afternoon.

Unlike previous seasons, the Otago Regional Council will not install temporary warning signs when bacteria levels are elevated. Instead, each swimming site has a permanent sign reminding users to check the latest results online before they swim.

Permanent water quality signs installed at Ōtokia Creek

A popular swimming area near Dunedin – Ōtokia Creek – experienced a particularly bad season of testing last summer (26% of samples had high bacteria concentrations requiring caution from prospective swimmers) and as a result has had new Ōtokia Creek specific signs installed asking the public to check the LAWA website to see the latest testing results before they swim.

ORC will keep a close eye on bacteria levels at the Creek again. To find the latest Ōtokia Creek results, click here.

The ocean at Brighton Beach is excluded from any warnings at Ōtokia Creek. ORC undertook testing at Brighton Beach at the same time the Creek was sampled last season, with 100% of the samples well within the safe limits for swimming, indicating the issue is upstream and any warning at Ōtokia Creek does not apply to Brighton Beach water.