'Rain gardens' planned to reduce Winnipeg combined sewer overflows

Spills into Winnipeg's waterways could become less common thanks to new green infrastructure.

The city is in the midst of replacing its aging combined sewer network, which funnels storm water and household waste through the same pipes. During heavy rain and snow melt, the system sends water into the city's rivers.

To help with that, the city plans to use soil cells and other green infrastructure to trap and filter water before it enters the system.

"So rain gardens, these sorts of retention ideas," said Coun. Brian Mayes, the former chair of the water and waste committee.

"You're not just building more pipes, you're trying to do some projects that incorporate vegetation, or basically are more environmentally friendly."

Work to reduce sewer overflows is expected to take decades and cost billions of dollars.

The city has committed to spending 10 per cent of combined sewer funds on green infrastructure, water and waste department spokesperson Lisa Marquardson wrote in an email.

"To date, a significant portion of our investment in green infrastructure has been dedicated to designing innovative solutions," Marquardson wrote.

"These designs lay the groundwork for multiple contracts that will lead to construction in the coming years."

The city spent $192 million on combined sewer work between 2013 and 2023.

A pilot project saw the city using porous construction material in back lanes, but issues around maintenance and uncertainty about its effectiveness led city staff to recommend going in a different direction.

Soil cells were installed along Broadway earlier this summer, and more work is expected to be done along Leila Avenue as part of combined sewer separation work.

Mayes says the work has been a long time coming.

"We've been required since 2019 by the province to actually do something on this. And it's millions of dollars we should be spending. And I think we're slow to get going, but it's good that we are finally getting going. "

The city's work on separating combined sewers could take as long as 2095.