Massive rockfall forces evacuation of nine homes in Laval

A rocky embankment between certain residences on Lévesque Boulevard East and others on Bellevue Avenue in Saint-Vincent-de-Paul, has vulnerable areas that led to the evacuation of nine households. (Photo courtesy Courrier Laval)

On July 18, residents of 23 Bellevue Ave. in Saint-Vincent-de-Paul reported to the City of Laval that a rock weighing approximately one ton had fallen on their patio.

Nearly a month later, due to the risk of rockfalls, nine households in the area were evacuated.

A cliff separates the residences on Bellevue Avenue, on the banks of the Rivière des Prairies, from the above Lévesque Boulevard East.

After being notified that a large piece of rock fell from the cliff face, the city hired a construction engineering firm and a civil engineering company “to conduct an in-depth analysis of the stability of the [rock] slope in order to secure the areas at risk and recommend sustainable measures.”

“If it had fallen on the house, [my neighbour] wouldn’t have felt the rock coming... he would be dead today, I think,” said one of the Laval residents who evacuated his home on Aug. 15.

Evacuations

The discovery of the unstable rock pile led to the initial evacuation of three residences on Bellevue Avenue on July 27.

Two of those three households were able to return to their homes three days later, following the installation of a temporary fence securing the perimeter and the removal of unstable rock blocks.

Work continued and revealed “the presence of an anthropogenic retaining structure, approximately 25 metres long, with subsidence at the base,” meaning it was gradually caving in.

The structure consists of an “unconsolidated pile of rocks, simply stacked on top of each other.”

As a result, nine homes were evacuated as a precautionary measure on Aug. 15.

“These preventive evacuations will remain in effect until further notice,” said Marilaine Bolduc-Jacob, head of public affairs at the City of Laval’s communications and marketing department. “The site is being continuously assessed by teams of experts, and the decision to lift the evacuation will be made as soon as these teams deem that the measures taken are adequate to ensure the safety of the households concerned and the population.”

Imminent danger

According to a resident of one of the evacuated homes, the occupants had 30 minutes to leave.

Since then, some have been staying at the Comfort Inn hotel in Chomedey, while others have been taken in by family or friends.

“It’s as if we had an earthquake,” said a man living on Bellevue Avenue. “This is major. [...] I’ve been here for 20 years and I’ve never seen anything like it.”

Access to backyards and rooms at the rear of the homes is restricted for safety reasons.

Part of the rear of some homes on Lévesque Boulevard East has also been fenced off to limit traffic.

Traffic is permitted on both roads concerned, as there is no risk, according to the City of Laval.

Who should take action?

According to one evacuee, the city is considering installing a low wall behind a handful of houses as well as huge ropes to protect residents from possible landslides.

“Although the maintenance and safety of these properties is the responsibility of the owners, the city is taking preventive and exceptional measures to protect the safety of residents, pending action by the owners,” said the municipality, without specifying the measures taken or planned in the short, medium, or long term.

The owners affected by the evacuation say they believe the dangerous rock slope is the city’s responsibility, while the head of public affairs asserts that the cliff is located on private land.

“The city owns only a narrow strip of the slope in the area affected by the emergency work,” said Bolduc-Jacob. “All of the unstable areas that have been identified are located on private land.”

The interactive map of the Quebec Land Registry shows that part of the rocky slope is indeed located outside the property bounds of the evacuated houses on Lévesque Boulevard East and Bellevue Avenue.

According to one evacuee, the rock slide was caused in part by residents of Lévesque Boulevard East who had expanded their terraces beyond the permitted limits at the top of the cliff.

Because the “experts’ analysis is still ongoing,” the City of Laval was unable to confirm this information.

“The geotechnical study will include a stability analysis of the slope at 17 to 31A Bellevue Avenue, as well as recommendations for future work that will need to be carried out to secure the area,” concluded Bolduc-Jacob.

By Corinne Prince, Local Journalism Initiative, Courrier Laval.