Hanes: Brace yourselves for Thursday — destructive weather is now the norm

Montreal Gazette

21 hours ago

By
It wasn't a typhoon. It was just a regular old thunderstorm.
But when it barrelled through Montreal on Sunday after days of a heat wave, a record amount of rainfall poured from the skies, flooding basements and inundating underpasses.
Homeowners from Ahuntsic-Cartierville to St-Léonard found their belongings floating. An octogenarian had to be rescued from his nearly submerged vehicle by Montreal police.
And it could happen all over again on Thursday, weather forecasters have warned.
We've now reached the point where climate change has made what was once extraordinary ordinary. Severe weather isn't a once-a-decade or even once-a-year occurrence anymore. During our hot, humid summers, it has practically become a weekly phenomenon.
Last August, hurricane Debby, which had been downgraded to a post-tropical storm by the time it arrived, doused Montreal with up to 150 millimetres of rain in some parts of the region — a wet month's worth in a single day. It caused a record $2.5 billion in damages, according to the Insurance Bureau of Canada, surpassing the 1998 ice storm as Quebec's costliest event.
Montreal had a prelude to Debby's destruction last July, when the remnants of tropical storm Beryl drenched us with up to 100 millimetres of rain in some places.
Sunday's torrential rain brought 80 millimetres to Trudeau airport in less than an hour. Yet the fallout from this nameless thunderstorm was much the same.
On a St-Léonard street where water poured down sloping driveways, filling subterranean garages and basements, it's the second or even third year in a row residents have experienced this kind of flooding. Some unlucky folks had just finished renovations to recover from the previous deluge, only to now have to start all over again.
The mental and financial toll of dealing with this kind of damage can't be overestimated. Many will be out tens of thousands of dollars for work not covered by insurance. Premiums will rise. Their home values may sink due to the repeated flooding, which they would have to report on their seller's declaration.
Plus there's the trauma of having your possessions ruined, your home — your sanctuary — made inhospitable. More and more people are having to go through this rigmarole once. However, some are having to endure it multiple times.
The city is advising homeowners to protect their property. Some are installing sump pumps, ceramic tile or epoxy flooring that can be more easily cleaned up after water infiltration. But it costs money.
Tenants may have no choice in the matter if their landlords don't act. And those living in basement apartments can end up losing everything.
There's been talk of outlawing basement apartments or 'garden suites,' as partially below-grade condos are often called, due to the risk of water damage. But the housing crisis makes it impossible to scrap these units altogether.
The borough of St-Laurent has restricted the use of some basements for certain purposes in response to flooding. And there are new regulations for downward sloping driveways to avoid them funnelling rainwater into homes.
There's only so much residents can do to avoid infiltration of their dwellings. During last summer's storms, sewers backing up into people's homes was a primary cause of many flooded basements.
Despite hundreds of millions being invested in water infrastructure, deferred maintenance in decades past has set the city behind. Now it's hard to keep up with the repair backlog. And each major weather event weakens aging water mains, which can lead to breakages — or even geysers.
Now sponge parks and sponge streets that use naturalistic design to absorb runoff are all the rage. But it takes time — and money — to transform all the asphalt and concrete of the cityscape to mitigate the impact of climate change.
And it's not just water infrastructure that is stressed by heavy rainfall. Highways, parking lots and underpasses are also under strain.
Highway 40 came to a standstill in the West Island on Sunday because of pooling water.
Last summer, storms resulted in the temporary closure of the Île-aux-Tourtes Bridge and Highway 13.
The bottom line is we should expect more of the same — and more often. Destructive thunderstorms and diluvial rains are now the norm rather the exception.
Brace yourselves: The same conditions that preceded Sunday's deluge — a heat wave followed by a cold front — are brewing again for Thursday. The skies are expected to open.
Let's just hope it's not a disaster déjà vu.