Why Canada may not be ready for 'new reality' of flash flooding and severe storms

Nono Shen · The Canadian Press

· Posted: Jul 08, 2025 5:33 PM EDT | Last Updated: 1 hr ago

Ryan Ness of the Canadian Climate Institute says he's been pursuing the "terrible tragedy" of deadly flash flooding unfolding successful Texas, wherever much than 100 radical person died.

But he's besides disquieted Canada isn't doing capable to forestall specified disasters here, saying the state needs to put successful flood mapping, infrastructure and aboriginal informing systems.

"Luckily, determination are galore ways that we tin support ourselves, but we person to marque the effort," said Ness, the probe manager for adaptation astatine the argumentation probe organization.

"You know, archetypal of all, we person to recognize wherever the hazard is."

He said galore parts of Canada don't person flood maps, "so, it's hard to cognize wherever to support oregon wherever to nonstop warnings."

Flood informing systems are besides needed to assistance radical successful the way of flash floods "prepare oregon get away, if they can," portion semipermanent infrastructure upgrades are needed to support hazard zones.

"In immoderate cases, that means putting things successful the houses similar backflow valves that support sewers from backing up," helium said.

"Or it tin mean gathering flood walls on rivers to support flooding from happening. Or it tin mean making definite that metropolis readying doesn't let much caller lodging successful flood hazard zones."

WATCH | How flood warnings failed successful Texas:

The raging flash floods successful Texas — among the worst successful the United States successful decades — slammed into camps and homes on the Guadalupe River earlier daybreak Friday. Some survivors were recovered clinging to trees.

The catastrophe has enactment a absorption connected some the hazard of flash flooding arsenic good arsenic however to foretell oregon forestall it.

'Building the governmental will'

Jason Thistlethwaite, prof successful the School of Environment astatine the University of Waterloo, agrees with Ness connected the request to bounds improvement successful the high-risk areas, calling this the "biggest enactment of defence" successful Canada.

He said determination was a imaginable "conflict of interest" for municipal governments that could garner spot taxes from developments successful flood-risk zones.

But helium said determination had been "emerging signs" of leadership, citing the metropolis of Grand Forks, B.C., which is buying retired residents successful high-risk areas with the assistance of provincial and national funding, aft a devastating 2018 flood. 

"There are plentifulness of examples retired determination successful Canada astir however we bash this properly," helium said.

"It's truly conscionable a substance of getting the accusation retired and gathering the governmental volition and [having] upper-tier governments who are consenting to motion the cheques."

Flash flooding 'new reality'

Ness warned that clime alteration is making flash flooding worse, and galore Canadian cities, provinces and territories don't person laws successful spot to forestall improvement successful unsafe areas.

He called the accrued hazard of flash flooding and much terrible storms "the caller reality."

Flash floods person struck crossed Canada implicit the past year, including successful Coquitlam, B.C., wherever an atmospheric stream rainfall lawsuit triggered a mudslide that killed a teacher successful October, and successful Toronto, wherever torrential rainfall overwhelmed drainage past July and caused astir $990 cardinal successful insured losses. 

Jonathan Helmus, the manager of utilities for the City of Coquitlam, besides volunteers arsenic a scout person and runs an overnight campy for children.

He said seeing a campy overwhelmed by floodwaters successful Texas "hit particularly hard" for him. 

But Helmus said the ungraded and clime successful Texas are rather antithetic from B.C.'s

He noted that the flash flooding successful Texas was acceptable disconnected by astir 50 centimetres of rain, much than fractional the rainfall the country sees each year. 

"And their ungraded is rather dry, truthful it's hard for that h2o to get into the ground, which produces conditions similar what was seen determination — the flash flooding," said Helmus. 

Helmus noted flooding events successful 2021 and 2024 successful Coquitlam were linked to atmospheric rivers.

He said the metropolis has large diversion sewers, detention ponds, and basal augmentation tanks that could beryllium activated during important events to trim flooding risks.

Helmus said the metropolis besides has an integrated watershed absorption plan, allowing it to look astatine what's happening wrong the watershed and place wherever the flooding hazard is earlier immoderate improvement is allowed. 

"We bash person immoderate established floodplain areas wherever we say, if you're going to physique successful this area, we person a minimum flood operation level, and they person to physique supra that level," said Helmus. 

Ness said that successful hilly areas of B.C.'s Interior with accelerated h2o run-off, flash floods tin expanse distant people's homes with "very small warning." 

He said flash flooding tin beryllium made worse successful areas burned by wildfire, wherever ungraded that is nary longer held unneurotic by works beingness "is overmuch much apt to possibly crook into a mudslide oregon a landslide."

He said different hazard areas are successful Alberta successful the Front Ranges of the Rockies, featuring tons of stone and small absorbent soil.

"When it does rain, it tin travel downhill precise quickly. The municipality of Canmore [Alta.], for example, has identified this arsenic a large hazard and has a strategy to effort to woody with it," said Ness. Massive floods deed the municipality successful 2013.

In Montreal and Toronto, flash floods are usually owed to paved areas with nary ungraded to soak up dense rain, Ness said. 

"And the h2o rises precise rapidly successful rivers and streams that tally done those areas, and it besides rises precise rapidly successful sewers, and that's what backs up into people's basements astir often, and causes basement flooding," said Ness. 

He said Toronto has a multibillion-dollar strategy to amended tempest sewers. But it takes a agelong clip to find that overmuch funding, and the benignant of disruptive operation required isn't an casual fix. 

"That's different crushed to commencement making these investments arsenic soon arsenic possible, due to the fact that it is going to instrumentality immoderate time. But clime alteration isn't going to wait," said Ness. 

He said Canada needs to accommodate for flash flooding overmuch much quickly. 

"There are galore astute engineers and authorities officials who cognize what to do, but we request to enactment and put successful the projects to accommodate to this caller reality. Otherwise, we are not going to beryllium ready."