Toronto must adapt better to changing climate after 2nd major flooding event in 11 years, experts warn

Nicole Mortillaro · CBC News

· Posted: Jul 16, 2024 8:20 PM EDT | Last Updated: July 17

In 2013, Toronto was hit with a massive storm. In just 90 minutes, the city received 126 millimetres of rain.

Roads flooded, with drivers abandoning their cars, and stairs leading to subway stations became urban waterfalls. The Don Valley Parkway (DVP), the main north-south thoroughfare into the city, was closed as the adjacent Don River overran its banks, spilling onto the roadway. A GO Transit commuter train was stranded with 1,400 passengers on board. Nearly 300,000 residents were left without power.

And on Tuesday — 11 years and eight days after that historic flood — it’s déjà vu for the largest, most populous city in Canada. 

This time, the rain started in the morning around 9 a.m., catching many commuters off guard. It eased up for a bit until another, much more potent storm system moved in less than an hour later, lasting until the afternoon. Shortly after, power outages began to pop up across the city.

Once again, images and videos inundated social media: Toronto’s Union Station was flooded, as was the DVP and city streets; GO Transit halted service temporarily; cars were abandoned. 

Following the 2013 flood, talk abounded about how Toronto needed to better adapt, as climate change was likely to make these heavy rain events more frequent and more severe. And while it’s too early to attribute Tuesday’s rainfall to climate change, by all appearances, the city still seems unprepared for a major rainfall event.

As greenhouse gases continue to be pumped into our atmosphere, the effects of climate change will continue to be felt across Canada and the world.

“Climate change is not going anywhere.… These events are going to continue to increase in frequency and severity,” said Kathryn Bakos, managing director of finance and resilience at the University of Waterloo’s Intact Centre on Climate Adaptation.

“As temperatures continue to rise, you’re going to have more moisture in the system. So with more moisture and energy, you’re going to have bigger storms, larger precipitation events, with more water coming down over shorter periods of time,” she said, “so storms are going to come down with even greater force.

“And that’s exactly what we’re seeing all across the GTA and across Canada, as well.”

WATCH |Toronto’s Union Station floods due to heavy rain:

Union Station’s Bay Concourse Hall is dealing with flooding as a result of Tuesday’s torrential rainfall.

But it’s not just about climate change that’s exacerbating these events, she said. 

“Climate change isn’t the only driver in the system. You’re seeing aging municipal infrastructure, infrastructure that never incorporated adaptation,” she said. “It’s also not taking the increase the influx of people. We have more people utilizing the infrastructure.”

Need for more natural habitat

It’s also the concrete jungle effect, she noted.

Over time, Toronto has removed natural infrastructure like wetlands, grasslands and forested areas, which act like natural sponges. Instead, concrete roadways, driveways and buildings stand in their place. 

“The infrastructure that we have is designed really for the historical conditions, and these events have a very different nature,” Slobodan Simonovic, professor emeritus at Western University’s department of civil and environmental engineering told CBC News.

He said that pressure on governments and forethought into budgeting for these events is needed for the future.

WATCH | Is Toronto’s infrastructure built to withstand intense rain? This expert says no:

Slobodan Simonovic, professor emeritus of civil and environmental engineering at Western University, says many cities in Canada are woefully behind when it comes to infrastructure that can withstand flash floods.

“Climate change is real,” said Toronto Mayor Olivia Chow on Tuesday during a press scrum. “We are expecting almost a doubling of the number of severe rain storm days in 15 years. So we have to redouble our efforts to have mitigating actions, because we have to do more prevention work.”

Chow also noted that the city has provided more incentives to homeowners to prevent flooding in homes. 

She said the city has freed up $2 billion after the province uploaded the cost of the DVP and the Gardiner Expressway, which is being put toward Toronto’s aging transit system and roads. However, she noted the city is still $26 billion and more than 10 years behind in infrastructure work.

Bakos said the city has made some improvements.

“I think they’ve really recognized that they have a very big issue. Infrastructure improvements are being made, and I think they recognize that more needs to be done, as well.”

Yet it may be frustrating for commuters and residents who see the same areas flooded time and again, such as the DVP and Lake Shore Boulevard.

WATCH | Toronto directing funds to infrastructure, but still billions behind:

Toronto Mayor Olivia Chow says that because the city was able to upload maintenance of the Don Valley Parkway and the Gardiner Expressway to the province, it can now add $2 billion of funding toward the TTC, roadways, hydro, sewage management and other infrastructure projects. However, Chow says the city is still $26 billion and over 10 years behind in infrastructure work.

Adaptation is the key, Bakos said.

“Every dollar that you put into place for adaptation, on average, saves $3 to $8 in cost avoidance over a 10-year period. So it’s a more cost-effective strategy to become resilient and adapt to these extreme weather events now, rather than waiting in the future.”