Central Otago lakes and rivers remained generally suitable for swimming, after another successful summer monitoring programme.

The Otago Regional Council ran three water-based programmes, covering water quality monitoring, freshwater pest education and engagement and a boatie watercraft safety campaign.

The separate summer programmes all registered positive levels of public engagement and understanding around the educational aspects of water health, personal boat safety and aquatic pest controls.

Water Quality scientist, Helen Trotter, said the summer recreational water quality monitoring programme, which ran from December to March, incorporated weekly testing.

“Water quality was generally suitable for swimming across Otago during summer- even if the weather was less than ideal at times,” she said.

 In total the programme collected and analysed more than 450 water samples from over 30 sites.

She said high bacteria counts at levels unsuitable for swimming were detected at 10 sites during the summer, representing about 3 per cent of all samples collected.

“For most sites this meant a single occurrence which was typically associated with rainfall in the surrounding catchment, immediately prior to the sampling,” Helen said.

Toxic algae blooms were identified at three monitored sites; Butchers Dam near Alexandra, Lake Waihola south of Dunedin and Tomahawk Lagoon, on Dunedin’s coastal outskirts.

While no blooms were observed at the monitored river swim sites, toxic algae was confirmed at several other rivers sites across the region and were then listed on the ORC toxic algae notifications webpage, Helen said.

“In several cases, toxic algae observations were initially reported by members of the community which is a good sign people are engaging with the resources available on LAWA [Land, Air, Water Aotearoa], via the ORC website.”

“We encourage people to take an active interest in how to keep themselves, their pets and others in their communities safe,” she said.

During the off-season LAWA will display the long-term grade for monitored swim sites which indicates the general suitability of a site for swimming and other water-contact recreation.

During last summer two Central Otago-based ORC ambassadors surveyed 320 recreational water users, from a total 830 interactions with members of the public.

Manager environmental implementation Libby Caldwell said while there had been some “solid” areas of awareness around the Check, Clean, Dry (CCD) campaign, to keep watercraft free of pests, there remained room for improvement – between those who were ‘aware’ (238 people/ 74 per cent ) of CCD and those ‘unaware’ (82 people/ 26 per cent).

 “Checking, cleaning and drying watercraft to prevent the transfer of unwanted pests to new locations should be priority for watercraft users and swimmers. Some pests, both plant and animal, have the capacity to become easily established and cause devastation to waterways,” she said.

The Otago harbourmaster has had great engagement with Central Otago residents over summer. FILE SHOT

ORC harbourmaster Steve Rushbrook said the team had a good year out on the water, with great engagement with the public in Central Otago especially, over the holiday periods.

He said the number of incident reports had not been high and generally people appeared to be more conscious of being safe on the water.

“We’ve found only a very small percentage of people are not wearing their lifejackets and have to be reminded.”

Steve highlighted the team was still seeing quite a few vessels without identification on them.

He urged people to read the navigational bylaws around what was required; to display an identifying name or number on their vessel.

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