Whanganui swimmers urged to check water quality before selecting swimming spots

Whanganui's beaches are generally considered safe for swimming in terms of water quality. Photo / NZME

With the summer holidays in full swing, it’s important to know which swimming spots in the Whanganui region have good water quality.

Horizons Regional Council is responsible for monitoring more than 80 bodies of water in its region and providing information on the potential health risks.

Horizons environmental monitoring scientist Ian Hurst said the sites were checked weekly - typically on Mondays or Tuesdays.

Each spot was checked for E. coli, enterococci and cyanobacteria. They were then graded as recommended by the Ministry of Health as well as Land, Air, Water Aotearoa (Lawa).

Hurst said the region was fortunate to have relatively safe water quality at its beaches.

“The beaches around Whanganui perform quite well and are swimmable 85-90%-plus of the time, he said.

“They out-perform some of the beaches around Auckland.”

However, Hurst recommended swimmers be more cautious at freshwater sites.

“The Whanganui River itself is around 50-70% swimmable and overall it has a long-term grade of poor, which is not great but is on par with what we see elsewhere in the region for that type of river.”

Last month samples taken from Lake Wiritoa and Lake Dudding provided evidence of toxic algae and in early December both lakes were declared unsafe for swimming. According to Lawa, the lakes were last sampled on December 23 and warnings remain in place. People are advised to avoid activities in or on the water, such as swimming, kayaking or water skiing. Potentially toxic algae can be harmful to humans and animals when touched or ingested.

Hurst highly discouraged swimming at Mowhanau, Ototoka and Kai Iwi streams because they had a history of poor water quality.

He also recommended not swimming in the Whanganui River at Mosquito Point as it was prone to unpredictable underwater currents that had resulted in drownings. Lawa’s website rates it “unsuitable” for swimming.

Hurst and research assistant Hannah Rowe had some rules of thumb for swimmers in the Whanganui region.

“Swim at beaches as they are usually pretty good. As for freshwater sites, try to swim after 72 hours of rainfall, don’t swim if you can’t see the bottom, check debris, odour and swim within your means,” Hurst said.

Rowe said there were Horizons signs present at most sites.

“A lot of them are personalised for that site. For Mowhanau, Ototoka and Kai Iwi’s streams, there are specific signs that warn you about the history of water quality,” she said.

“The signs give you our top tips on when or when not to swim as well as facts about that water quality.”

Hurst said swimming in unsafe spots could result in infection.

“Worst-case scenario for a human is that they get an infection which can lead to severe dehydration, diarrhoea, vomiting.

“I’m not aware of anything happening in our region that has led to anyone being severely sick; however, we have seen that in other parts of the country.”

Check the Lawa website lawa.org.nz for information on swimming spots.