British Columbia

How to handle a flash flood when you're behind the wheel

With about 20 millimetres of rain in two hours in Vancouver on Sunday night, several motorists found themselves stranded in deep puddles. Here's some advice on how to avoid an expensive mechanic's bill if you have to drive through deep water.

Heavy rain left some of Vancouver's streets flooded Sunday night — and some cars stranded in deep water

A car splashes through a puddle in Vancouver after a torrential downpour Sunday night. (GP Mendoza/CBC)

The extremely heavy rain on Sunday night caught many drivers in Metro Vancouver off guard.

Within a couple of hours, about 20 millimetres had fallen, leaving deep puddles and flooding on some streets.

"There was damage to some vehicles," said Jerry Dobrovolny, general manager of engineering services with the City of Vancouver. "The water got so deep that it started to go up over the floorboards of the cars. Some of the cars got stuck."

City staff didn't note how many of the 128 overnight calls about flooding involved stranded vehicles or impassable roads, but a handful of cars did stall in the deep water Sunday night.

"I caution people, if you see a big puddle in the road, don't try driving through the middle of it. It seems like common sense, but a number of people got stuck through the night," said Dobrovolny.

A driver is forced to leave a BMW stalled in the middle of the street after heavy rain caused flooding on some Vancouver roads Sunday night. (GP Mendoza/CBC)

Avoiding the deep centre of a puddle — or just avoiding it completely — is good advice, of course. But what if it can't be avoided?

According to Brad Tremblay, service manager at Tremblay Motors, the best plan is to slow things down.

"People are going to naturally want to go fast to get through it. What that's going to do is create a wave, and the water will shoot up and it then has chance to go into your intake system and into your engine," said Tremblay.

According to Tremblay, some sports cars or modified vehicles will have very low air intakes near the front bumper — so, with those cars, standing water is especially risky.

Anyone who gets water in their engine could wind up with what's called hydrolock, which can completely ruin a motor, costing thousands to replace.

A driver braves some flooding on West 2nd Avenue in Vancouver. (GP Mendoza/CBC)

But Tremblay said a car stalled in a puddle doesn't mean a motorist is dealing with a worst-case-scenario. 

"If you go through a puddle and you go slow and the car does stall out, it doesn't necessarily mean your engine is in trouble. The ignition could be wet, so after you dry it out for a while — you get it towed to your shop — get it checked out," he said.

Another reason to take puddles very slowly, according to Tremblay, is that the force of the water could rip pieces of protective shielding off the bottom of a vehicle. They can be easily replaced, but who needs the bother?

If your vehicle stalls in deep water, you're advised to turn on your hazard lights and call a tow truck.