Summer swim monitoring has kicked off with good results across Otago, the Otago Regional Council (ORC) has reported.

Summer recreation water quality monitoring runs between December and the end of March every year.

The results of the past week’s monitoring were green across the board for Otago, indicating safe swimming conditions at 25 popular freshwater and coastal swimming spots around the region.

The results are made available through the Land, Air, Water Aotearoa (LAWA) “Can I Swim Here” tool.

Water in Lake Wānaka was found to be “generally safe for recreational activities”, but the regional council noted that bacterial contamination can occur, commonly after rainfall, as stormwater and rural run-off may contain human or animal effluent. 

‘Thumbs up’ for swimming in Lake Hāwea.

If the Matukituki River flows above 45 cumecs it generally indicates substantial rainfall has fallen in the catchment.

Results for Lake Hāwea also found the water was generally safe for recreational activities, with the same disclaimer about contamination after rain.

ORC water quality senior scientist Jason Augspurger said the results were a good reminder of the impact that weather can have on water quality.

“Rainfall is not the only factor in water quality, but it can be a big one. We’ve had a good few days without rain in Otago and we’re seeing that reflected in good water quality results throughout the region.

“Equally, this is a good reminder to avoid swimming for two to three days after heavy rainfall, as rain can wash contaminants off land and into waterways, which leads to water quality issues.”

Jason recommended prospective swimmers check the LAWA website before taking a dip.

“Whatever the weather, it always pays to check the ‘Can I Swim Here?’ tool on LAWA’s website, which collects water quality data for swimming from across the whole country, before deciding whether or not to swim.”

The other factor in swimming conditions is potentially toxic algae, he said.

“Potentially toxic algae thrive in warmer conditions, so it’s important to learn how to recognise these blooms in freshwater, and avoid swimming wherever you encounter them.”

Water quality results on LAWA will be updated weekly during the summer recreation season, and new signage at popular swimming spots directs people to the information here.

Learn more about potentially toxic algae here.

PHOTOS: Wanaka App