Monday's flooding was some of the worst in recent memory. Can Toronto handle the next big storm?
The floods that have swept through Toronto and Calgary recently may have been the worst we’ve seen in quite some time, but that doesn’t necessarily mean the next deluge won’t happen soon. Toronto’s flood-management and emergency officials say the City prepares for these things, and is capable of preventing the worst from happening under most circumstances.
“What we had yesterday is typical of the summer, and we deal with it every summer. The difference was we had a series of them on top of each other,” explained Laurian Farrell, the senior manager of flood-risk management for the Toronto and Region Conservation Authority (TRCA). “What we like to see is thunderstorms track across the city at a good pace. This one was slow, and sat over an area for a long period, and dumped water on top of itself, and it’s hard for the infrastructure to handle.”
According to Farrell, Monday’s storm “sat” over the Humber River, tracked across the city, and slowly made its way down the Don River. Over 120mm fell on the GTA, starting in the afternoon on Monday, July 8, but Farrell says we’ve had worse.
“There’s been a lot of talk about this being a storm of record, and it’s a bit of misnomer. At Pearson we recorded more rain, but [Hurricane] Hazel was focused over the Humber and there was way more rain [in that area]. This is not the biggest storm by any means. This is what we prepare for, and we still have capacity within our system to handle more.”
Hurricane Hazel devastated Toronto in 1954, causing 81 deaths and reportedly leaving 1,896 families homeless. Since then, emergency planning has been implemented and warning systems have been created to mitigate damage from severe weather.
Farrell says there are several key differences between here and Calgary, where recent flooding was far worse than what Toronto experienced this week. “Yes, we could have significant flooding here, and people live within the flood plains within the GTA,” she said. “But our nine watersheds here in the GTA are very small, and our rivers are very wide and contained. The scale of Calgary is different—the Bow River is massive compared to any river here.”
“There are different types of storms, and each type of storm requires a different response and a different lead-up time,” said Farrell. “Also, each watershed reacts differently. If we have a storm fall on the Humber River watershed, we would have more reaction time than if it fell on the Don River, which is highly urbanized.”
Toronto’s geography gives it some protection from major storms. “We are lucky to live in a very calm weather system, protected by the Niagara Escarpment and the great lakes,” explained Farrell.
“When a hurricane makes it up past the great lakes, like Hurricane Sandy, we have a bit of lead-up time. We can track hurricane progress, so we have time to figure out how big it will get by the time it gets to us.”
Even so, preparedness is key. “All of us have been glued to the news [about the Calgary floods],” said Allison Stuart, chief of Emergency Management Ontario, whom we interviewed prior to Monday’s flash floods in Toronto. “We’re looking at it from an emergency preparedness angle, sure, but on a whole other level each of us as individuals are thinking, ‘What if that were my basement, my house? If that happened here, how could I get it through it?’”
“We are never going to be able to think about every single possible event that could occur and be ready for it,” explained Stuart (again, she was speaking prior to Monday’s floods). “Here in Ontario, we’ve identified 39 hazards that we are susceptible to and then we looked at the risk. Yes, a space object can fall from the sky, but what is the likelihood of that event? We also encourage each community to personalize the list—like in Toronto, a chemical spill is much more likely than a forest fire—and make plans for the higher-risk events.”
Something else Toronto has that Calgary doesn’t is a large and populous waterfront, but, according to Farrell and others, flooding from the lake is not a concern. It’s the rivers that lead to Lake Ontario that have caused flooding in the past. (It’s too soon to say precisely what role Toronto’s rivers may have played in Monday’s flooding.)
Jennifer Smysnuik is the coordinator of emergency management for the City. In an interview conducted before Monday’s storm, she emphasized the role of individual preparedness in minimizing flood damage. “Events such as the flooding in Calgary reinforce the importance of some of our key preparedness messages,” she said. “These messages include the importance of having adequate homeowner/tenant insurance, the need for a grab-and-go kit in case you are forced to leave your home (including things such as key contact numbers, documentation, medications), and the creation of a family emergency plan, including plans for where you might be able to stay if forced to leave your home.”
Smysnuik says that with every event endured, the City improves its response planning. “We’re better prepared today than we were last year, and we’ll be even better prepared in future years,” she said.
The City’s Office of Emergency Management lists its top weather-related risks for the Toronto area as earthquakes, floods, tornadoes, high-speed winds, and winter storms.
According to Farrell, the TRCA flood-risk manager, one of the best things we have going for us here in Toronto is an unusually cautious planning regime. “After Hurricane Hazel in the ‘50s, the mindset shifted away from building right up close to the river,” she said. “We decided to give the river space to live, so there is no new development around the flood plains. This is unique. [Peers from all over the world] tell me, ‘I wish we could stop people from building in these places near the rivers and watersheds,’ and I tell them we can.”
Farrell suggests that people whose basements flooded during Monday’s storm call 311 and report it, because the City uses this information to decide where to conduct flood mitigation studies.