They're back: Algae blooms forming again on Whistle Bend pond

Some residents of Whitehorse's Whistle Bend subdivision are renewing concerns about the artificial pond in their neighbourhood, as algae blooms have started forming there again — even after the territorial government spent almost $1 million to fix the problem several years ago.

Algae has appeared along the shore of the pond, making it look similar to what it was in 2016, when algae blanketed much of the water.

While the algae has not made the pond stink at this time, some residents worry it may start to give off a bad odour later in the season.

"The water's stagnant. It's just the algae keeps growing and there's tons of mosquitoes all around here, and we don't even want to use the park there," resident Kathleen Booth said Friday.

"It's a new pond. There's problems with these subdivision ponds all across Canada. I think they need to do some research, figure it out, the right way, or just cover it up, because there's tons of mosquitoes and the algae's just so thick that it's going to smell pretty bad this late summer."

Algae blooms — microscopic plants — flourish in freshwater that's rich in phosphorus and nitrogen. Fertilizers, soaps and sewage effluent are all sources of such nutrients.

The algae in the Whistle Bend pond has become a big topic of discussion on the neighbourhood's Facebook page.

Song Lin, who posted on the page, says it appears the fountain and aeration systems that are supposed to keep water moving in the pond have not been working this summer.

Lin said he also wonders if the pond is responsible for the swarm of mosquitoes in Whistle Bend this summer.

"I couldn't even send my kids there to go to the backyard to jump on the trampoline. They just don't want to go there," he said. "I went into my backyard for like literally less than two minutes, and I got six or seven bites right away."

But another Whistle Bend resident, Ken Andre, said he doesn't think the mosquitoes come from the pond.

"They're from across the street from the pond over there; there's standing water," he said. "In a year like this, where we've got a lot of rain, there's always going to be mosquitoes."

As for the algae in the pond, Andre said it doesn't bother him as long as it doesn't smell.

"And if there is no smell this year for some strange reason, I think algae's kind of a natural thing with water that doesn't move, so that's fine," he said.

The pond was built to be a "rain garden," a retention and evaporation pond for storm run-off in Whistle Bend.

After the algae blooms were detected in the pond in 2016, the territorial Department of Community Services spent more than $900,000 on changes to prevent the blooms from returning, including a new system for pumping water.

A City of Whitehorse official told CBC News that staff are looking into the new algae growth.