Ottawa Public Health has issued a warning about the Rideau Canal. Test results of the murky water show toxic blue-green algae.

We are being ordered not to drink, swim, or even let our pets near the water. The test comes back after CTV Ottawa aired a story on the green hue on Tuesday.

Chris Piper didn't need test results to know there was something wrong with the Rideau Canal. He snapped several photos of a “Rio” green canal a week ago, wondering why the water looked so green.

“Something felt off,” says Piper today, alongside the canal, “It wasn’t normal. I hope now we get real answers.”

Even 4-year-old Nolan Tarrant wanted answers.

“Are there alligators in the water,” he asked his mother Tuesday, as he peered into the murky water.

After our story aired on Tuesday, the Ministry of the Environment and Climate Change got involved to test the water . It took until today to get those results back: that the blue green algae are the toxic one.

“Water samples collected by ministry staff near the Chateau Laurier hotel have confirmed a blue green algae bloom in the water, the specific algae is Anabaena. On Thursday (Sept 8th) evening the ministry also gathered additional samples to confirm the extent of the bloom. We expect to have those results next week,” Gary Wheeler with the Ministry wrote in an email. The Minstry informed Parks Canada and the City of Ottawa Public Health Unit. Ottawa Public Health has now issued some precautions for people using this popular waterway.

“The hazards are there and we want people to be aware,” says Martha Robinson with the Ottawa Public Health Environmental branch. Among their recommendations:

  • Don't eat any fish caught in the canal
  • Don't let your pets drink or swim in the water
  • And don't use the water for swimming, bathing or other recreational uses

“People who are using it recreationally, as long as they don't have too much of their body in it are not at risk,” says Robinson, “The real risk is from drinking it and eating fish that could be contaminated from it.”

Mooney's Bay remains open for now. Public Health says this area doesn't appear to be affected.

The Ministry of the Environment is still testing the levels of the toxins in the canal.

For Sue Heseltine and her husband Clint, tourists from Scotland out canoeing on the canal today, it was an interesting end to an otherwise lovely ride.

“I was trailing my fingers through the water,” says Sue, “I should wash them.”

“Well, they haven't dropped off yet,” teases her husband.

Public Health says this is the first time is has seen this blue-green algae in the downtown stretch of the Rideau. Chris Piper is hoping it's the last time.

“This is a very important tourist site, a UNESCO heritage site,” says Piper, “we have to take better care of it. We have to.”

Public Health says this toxin can cause a rash on your skin, make you feel itchy and sneezy. And, if you fall off your paddleboard and swallow a mouthful, it could cause an upset stomach.