Westmount backyard caves into next-door infill site after heavy rain, highlighting tricky nature of infill construction

Last week's heavy rainfall is to blame for collapsing part of a Westmount resident's backyard, an infill builder says.

The Lalonde family's fence began to fall into the excavation next door the evening of June 15.

That day, which followed two days of lighter precipitation, saw 40 millimetres of rain, according to Environment and Climate Change Canada's Blatchford weather station. The station recorded 50 more millimetres of rain on Sunday and around 15 millimetres each of the next two days.

The wetter the ground became, the more caved in.

"It’s heartbreaking watching your oasis fall into a pit," Tammy Lalonde told CTV News Edmonton during an interview on Monday.

Her husband, Danny, added, "Even though some of these pieces [of ground] are still here, I guess the integrity of what's left behind is a question at this point."

NO MISTAKE: BUILDER

The owner of the family-run infill building company says his crews made no error, but that the situation was the result of a factor out of their control: the weather.

"We started the digging a week before the rain [was] even forecasted," Euro Design Master Builder's Voyin Vilimanovich told CTV News Edmonton.

"The bank was holding solid up to the point of it actually started to rain. So this is standard process in our infill industry. There wasn't anything done outside the scope of regular excavation practices."

He believes the ground didn't hold as well because the Lalondes had a garden on their side of the fence, which wouldn't have the same kind of bearing capacity as, for example, ground with grass.

City inspectors concluded rain "likely contributed" to the damage.

"Look at Edson," Vilimanovich said. "A little bit more in Edson, and you got floods. So unfortunately in this kind of situation when a lot of rain comes down, it does tend to compromise some stuff."

He added: "Twenty-five years that I've been building, this is the first time anything's happened to us in this kind of situation."

The Lalonde family say they're confident crews will be able to help restore their property after heavy rain caused part of their yard to collapse into a neighboring infill excavation. (CTV News Edmonton)

'DON'T KNOW IF WE COULD EVER PREVENT EVERY SCENARIO'

The Lalondes wondered if shoring the side of the excavation at the beginning would have helped and if more preventative measures should be mandated for infills.

But while Vilimanovich says he prioritizes safety and supports modernized bylaws, he is wary of the financial impact unspecific regulations would have on the industry.

CTV News Edmonton asked a city supervisor, whose safety codes department inspected the Lalonde property, about the feasibility of requiring more protective action.

"Any project starts with planning and this would be a component of that planning," Chad Rich noted, when asked about the Lalonde's caving backyard. "Although the weather is not predictable, it needs to be considered through that process. It's the responsibility of the owner and in this case, could be a builder or developer."

He said a more robust set of rules does not exist because sites can be affected by so many variables.

"I don’t know if we could ever prevent every scenario, but we can assist permit applicants with mitigating some of these potential scenarios," Rich said.

He said incidents like this one in Westmount are rare.

For all infill projects, the city advises the involved parties to communicate early and often about their plans and strategies.

According to Vilimanovich, Euro Design Master Builder hands out business cards to neighbours when it first gets to a site.

"It's really tough," the owner said. "Unfortunately, this is the kind of stuff we have to deal with in the infill industry. We're dealing with neighbours, we're dealing with bylaws, we're dealing with existing builds over there as well, and we gotta try to keep everyone happy."

THE FALLOUT

Vilimanovich acknowledged the damage to the Lalondes' backyard is "really unfortunate" and promised "to make them 100 per cent whole."

"We've been in constant communication with the neighbours. We were the first to identify the problem and contact the neighbours, as well."

He is the second generation to lead the family business and says he takes the company's reputation and role in the infill industry very seriously.

The company is covering the cost of fixing the damage and offered compensation to the Lalondes' tenant, whose separate patio and entrance were compromised.

The Lalondes remain supportive of infill housing.

"It’s beautification, and more living spaces for people desperately needed," Tammy said.

"There was no worry. We’ve watched them go up around us. The worry came in when we watched the excavation begin and the pieces start to crumble in."

Euro Design Master Builder is doing its best to save the plants that were in both yards, including some planted by the infill owner's grandmother.

The company's plan is to drive screw piles along the property line, shore the side up, then move dirt back in and backfill.

"We don’t know how our landscape will look at the end of this, but we have to have faith they’ll bring it back to what it was," Tammy commented.

With files from CTV News Edmonton's Sean McClune and Nicole Weisberg