Эдмонтон погрузился в исторические наводнения: штормы нанесли ущерб на 230 млн долларов и могут стать предвестником климатических катастроф для всех канадских городов

Post Malone had performed three songs at his July 25 tour stop at Edmonton’s Commonwealth Stadium when the wind started to pick up and the sky darkened. Moments later, a rainstorm erupted, sparking chaos as more than 30,000 fans sought shelter. A short distance away, winds approaching eighty-five kilometres per hour and sheets of sideways rain pummelled the city’s annual KDays exhibition, forcing families to shelter in place. Within an hour, the storm unleashed thirty millimetres of rain, causing torrents of water to run through low-lying neighbourhoods. On social media, footage quickly emerged of freeways and underpasses transformed into rivers and lakes, of iron manholes exploding into geysers, of stranded residents and flooded basements. This was just one of several storms that walloped Edmonton over the course of several weeks, each leaving behind it a trail of destruction. By the end of July, the typically sunny city had accumulated more than 580 millimetres of rain, putting it in the running for the wettest summer in history. At the time, Edmonton officials estimated that this summer’s storms could cost the city between $20–$30 million to clean up, while accumulating some $230 million in insured damages. Though shocking, what happened in Edmonton could be “a preview for every Canadian city,” according to Alireza Bayat, a professor of civil and environmental engineering at the University of Alberta, whose research focuses on underground infrastructure. Just a few days after the Edmonton floods, several communities in the Niagara region woke up to flooded homes and destroyed crops following a series of localized downpours that dumped up to 146 millimeters of rain. In early August, Quebec was hit with torrential storms, causing widespread flooding and landslides and triggering a state of emergency for a portion of the Laurentians. And on September 2, Toronto was hit with a massive “hundred-year” thunderstorm that triggered extensive flooding and power outages. Flooding has become the most common and costly climate disaster in Canada, according to the Canadian Climate Institute, affecting almost every region in the country and averaging nearly $800 million in insured damages each year. To make matters worse, Canadian cities—80 percent of which were at least partially built on floodplains—are aging and, in many cases, rely on infrastructure that was not built to withstand the deluges we see today. Over the past decade, municipalities across Canada have ramped up their flood mitigation efforts. Major cities, including Edmonton, Calgary, and Toronto, have invested hundreds of millions of dollars in projects designed to protect against extreme weather, building seawalls to brace against rising waters, engineering sophisticated drainage systems to divert floodwaters away from vulnerable communities, and expanding green spaces to absorb rainfall. Experts say these investments are beginning to pay off. Jennifer Drake, a professor of civil and environmental engineering at Carleton University and an expert on stormwater management and green infrastructure, says the country’s doing a good job of preventing “the worst outcomes associated with floods”—specifically, loss of life. “We have very good public policies in place to manage the floodplain and keep people from building in really dangerous areas,” she says. “And we have very strong flood prediction models and integrated strategies for managing emergency services.” But can any city truly adapt to our new climate reality? Is any community truly fortified against the impacts of flooding? It’s impossible to know, at least until the next tempest arrives. “There’s always a bigger storm,” Bayat warns. “And we cannot outbuild the sky.” Flooding is a natural process, but it’s exacerbated by urbanization. Building cities not only involves paving over green spaces with concrete, asphalt, and other impervious surfaces but also digging up or altering creeks or waterways. Together, these processes degrade an environment’s natural ability to absorb water and to direct its movement. Calgary’s spring 2013 floods are a catastrophic example of ravine flooding, in which snowmelt or heavy precipitation causes a river to spill over its banks. Heavy rain, combined with melting snowpack in the Rocky Mountains, triggered intense flooding in the region’s watersheds, including the Elbow and Bow Rivers. The flooding led to the deaths of five people and displaced over 100,000 residents. Following the Calgary floods, the Alberta government spent hundreds of millions of dollars to protect the city against future ravine flooding. In 2023, the city completed the Downtown Flood Barrier, a 1.39-kilometre structure consisting of steel sheet piles, earthen berms, and concrete. Last year, the city completed the Springbank Off-Stream Reservoir, a 3,700-acre network of flood mitigation infrastructure, including a massive dry reservoir designed to store flood water, located upstream of Calgary. Taken together, the new infrastructure provides the city with an estimated 70 percent reduction in flood risk exposure. “A lot can be learned from these types of crises,” says Drake. “When you go to Calgary now, its entire downtown has flood walls, and they’re beautifully integrated into public spaces. Unless you’re someone like me, you won’t even notice.” Another type of deluge is urban flooding, when intense rainfall overwhelms a city’s drainage infrastructure, and forces water to flow through the city. This is what happened in Edmonton: prior to the July 25 storm, the city had experienced weeks of unusually heavy rainfall, and most of the city’s green space was already saturated. The pipes filled up, then overflowed, causing runoff to cascade through low-lying parts of the city. Compared to ravine flooding, preventing urban flooding is difficult, and more complex. One strategy aims to keep rainfall from entering the drainage system. This involves building “green-blue infrastructure”—wetland parks, rain gardens, dry ponds, or vegetated rooftops—that can naturally absorb or store rainwater before it goes underground. Municipalities that adopt this model, which is popular in China, are sometimes referred to as “sponge cities.” A second strategy involves controlling what happens when a city’s pipes reach capacity and ensuring that any runoff ends up in controlled spaces rather than living rooms and basements. In Canada, cities rely on a mix of older and newer drainage systems. Some neighbourhoods, mostly those built in the early twentieth century, still rely on what is known as a “combined sewer,” an outdated system that uses just one pipe to transport both stormwater and domestic sewage. Neighbourhoods built around the mid-twentieth century typically used two separate pipes rather than one, creating extra capacity. Beginning in the 1980s, engineers and urban planners developed what’s known as a dual drainage system, which is capable of handling larger storms. This system includes an underground network of sewers and basins that capture and drain away the water produced by everyday rainstorms and a sort of emergency component designed to handle runoff when there’s flooding. Made up of overland roadways or graded surfaces, this secondary system either holds water temporarily or it transports runoff toward places where it can be safely stored or absorbed, like a dry pond or park. But being better prepared isn’t just a matter of upgrading or replacing old infrastructure. According to Bayat, even the most sophisticated systems won’t be able to withstand a mega-storm like the one that hit Edmonton. Instead, cities must anticipate that their stormwater system will occasionally flood. The job of urban planners and engineers is to find ways to make current systems work better when that happens. A flood-adapted city, Bayat suggests, is one that makes use of various tools and strategies at its disposal but also one that invests in the “relentless maintenance” of its current system. “If the rain comes and a pipe is clogged, that’s not a capacity problem—that’s a maintenance problem,” he says. The City of Edmonton, along with its utility provider, Epcor, is currently in the sixth year of a twenty-year, $1.6-billion flood mitigation plan. Officials say they have already spent about $350 million installing dry ponds and other blue-green infrastructure and conducting maintenance work. Despite the chaos on July 25, Bayat believes that the system was, for the most part, working as intended, estimating that “80 percent to 90 percent” of the city was not impacted by flooding. He likens the storm to an exam, one that exposes the city’s outstanding weaknesses. “It’s about continuous measurement, and a continuous process of improvement—you collect the data, digest it, and try to be smarter for the next one.” In 2009, Toronto passed a bylaw making it mandatory for all new buildings with roofs larger than 2,000 square metres to have vegetated roofs, transforming unused urban space into green infrastructure that can absorb rainwater. The bylaw, the first of its kind in North America, was celebrated as a successful and innovative approach to mitigate against urban flooding. Last year, the Ontario government scrapped the bylaw, suggesting it imposed unnecessary costs on builders and slowed the pace of development. It’s a common story when it comes to climate change: though scientists or engineers understand what mitigation and adaptation efforts are needed, they are often deprioritized or overrun by competing interests. This problem is driven by a mix of economic and political factors, according to Jeff Birchall, a professor of urban and regional planning at the University of Alberta. Building wastewater infrastructure costs billions of dollars and requires coordinated funding between all levels of government. But while it’s easy to drum up public and political support for a recreation centre or a hockey arena, it’s far more difficult to muster the same energy for underground water pipes. “Maintenance isn’t interesting, and it’s not sexy,” Birchall says. “But people need to realize that climate change is here, and if you make investments before the impact occurs, it’s much cheaper.” A recent report by the Canadian Climate Institute estimated that Canada will have to pay more than $15 billion per year on average to maintain its public infrastructure if it fails to invest in climate adaptation. Investing roughly $4.1 billion to proactively adapt infrastructure, the report found, could save up to $8.6 billion per year. Meanwhile, the average Canadian homeowner’s annual insurance premium is more than $533 higher today than it was in 2008 due to climate-driven extreme weather events, according to a recent report by Environmental Defence. Understanding and communicating these costs, Birchall says, could spur community buy-in for major infrastructure projects, providing, in turn, a mandate for governments to take action. “We can do things,” Birchall says, noting with cautious optimism that the current federal government under Prime Minister Mark Carney is investing billions into large infrastructure projects, from pipelines to housing development funds, across the country. “This is something that hasn’t been done in Canada in a long time,” Birchall says, though he is uncertain whether these investments will, “in practice,” be enough to adequately strengthen communities against the climate crisis. Stephen Legault, an Alberta-based policy advocate with the group Environmental Defence, believes government investment in climate mitigating is nowhere near the scale it needs to be, especially if federal and provincial governments continue to drag their feet on reducing greenhouse gas emissions and transitioning to a green economy. Under Carney, the federal government has rolled back many of the climate protections and policies to reduce carbon introduced by the previous government. Since 2025, the Liberals have scrapped the consumer carbon tax, reversed the implementation of an oil and gas emissions cap, and paused the electric vehicle sales mandate. And in July, Carney, alongside Alberta premier Danielle Smith, announced the planned route for a new oil pipeline from Alberta to the West Coast. Touted by Carney as a “nation-building project,” the pipeline is expected to cost taxpayers around $40 billion. Mitigating climate disasters is a political problem that depends, in part, on how we allocate money for infrastructure, he says. “If we’re putting money into infrastructure that makes the problem worse, like pipelines, then the problems will get worse.” On July 24, just one day before the Edmonton storm, the City of Toronto opened an additional ten acres of Biidaasige Park, a sprawling public park located at the mouth of the Don River. The expansion was part of the city’s Port Lands Flood Protection Project, a massive effort to revitalize Toronto’s waterfront funded by a $1.4 billion investment shared across all three levels of government. “The Port Lands project is a world-leading example of forward thinking, climate-adaptive urban growth,” says Drake. Once a marsh, Toronto’s waterfront was converted into industrial land as the city was built up, which, in turn, contaminated much of the soil in the area. The Don River was essentially channelized, turning a long, meandering river into a straight line that takes a hard, right-angle turn at the mouth of Lake Ontario. Over the past decade, the PLFP project has sought to naturalize the Don, removing more than 2 million cubic metres of contaminated soil and rebuilding the valley that connects the river with Lake Ontario. Once completed, the PLFP will not only protect existing Toronto neighbourhoods from extreme flooding but will also unlock a massive swath of land for future development. Drake believes that large-scale revitalization efforts like these—which require just as much engineering prowess as building a pipeline—should also be celebrated as nation-building projects. “This is the way you want to build cities,” she says.