A teen who drowned in the Rangitikei River disappeared from a spot deemed unswimmable.
Police have recovered a body after the 16-year-old went missing on Sunday.
Horizons Regional Council had flagged on its website that swimming should be avoided at the bridge near Bulls because of E.coli.
The council monitors 81 popular swimming spots in the region.
About 40 per cent have E.Coli readings that make them a potential health hazard or unsuitable for swimming.
Council science and innovation manager Abby Matthews said it was disappointing more spots were not swimmable.
"We've got really hot, muggy weather, which encourages people to go out and enjoy the waterways."
She said low river flows allowed toxic algae to flourish.
Matthews said people were choosing to go to the beach instead of the river, or to not swim at all.
"That said, it is very hot and people are wanting to get out and about."
She said the drowning was a tragedy.
"We don't want anyone getting hurt, injured or killed in any of our waterways whether it's a beach or a river."
She urged people to read signs at swimming spots and to check the council's website.
Yesterday police said the body recovered from the river has yet to be formally identified.
The death would be referred to the coroner.