A mudslide triggered by heavy rainfall in Coquitlam, B.C., has left several residents displaced and searching for answers, with some pointing to major construction projects on the slope above as a possible factor.

The slide came down Thursday in the 1900 block of Pipeline Road, near the Coquitlam River, after days of heavy rain from an unusually long atmospheric river. Eight people had to be airlifted out.

Jeannie Dmytronetz, who has lived in the area for about 40 years, said she was on Vancouver Island when she got a call early Friday morning about the slide.

“We just raced out, grabbed the first ferry that we could, and got home,” she said.

Her home was spared major damage, but she said her driveway and nearby properties, including her in-laws’, were hit hard.

At 90 and 89 years old, she said the couple is now unsure if they feel safe returning.

“They’ve built that house that was their forever home, retirement home,” she said. “It’s not just an inconvenience, it’s devastating.”

Dmytronetz, who is now staying in a motel with her family, says this is the third slide on the same hillside in the past decade.

“The first time wasn’t so bad, the second time was worse, and this time it’s been devastating.”

She believes multiple factors may be at play, including work tied to transmission towers built by B.C. Hydro on Eagle Mountain.

“When they twinned the big transmission towers, there was a lot of work done up on the slope up there,” the Coquitlam resident said. 

“There’s a lot of clear cutting of vegetation because they’ve had to clear cut to put in the towers,” Dmytronetz said.

Fortis B.C. is also adding 50 kilometres of new gas pipeline between Coquitlam and Squamish and construction work is ongoing at Eagle Mountain. 

B.C. Hydro said it has “no indication” that its infrastructure or past construction activity on Eagle Mountain contributed to the slide.

“The region has experienced significant rainfall and extreme weather of this scale is known to increase the likelihood of slope instability,” it said in a statement to CBC News.

The utility said it is working with the City of Coquitlam and will conduct further assessments if needed.

Metro Vancouver is also building a 12-kilometre Coquitlam Water Main along Pipeline Road to meet growing demand for drinking water. It said construction sites for that project were not impacted by the mudslide.

Too early to say what contributed to slide: city

The Metro Vancouver Regional District noted that between 2019 and 2021 crews did some work in the area to stabilize the slope. 

“It involved installing pilings and concrete barriers to stabilize the slope and roadway to protect the utilities underneath, as well as improve the road condition and access.” 

According to the City of Coquitlam, the situation is now stable, with cleanup underway, but it’s too early to say what may have caused the mudslide.

The city said it is continuing to assess the geological and hydrological conditions that contributed to the slide.

Dmytronetz acknowledges that the cause is not certain but wants to see a thorough investigation into it.

“I can’t say for sure that it is their fault. They can’t say for sure it’s not their fault. It has to be fully investigated.”

Development on steep slopes can increase risks

John Clague, an emeritus professor of earth sciences at Simon Fraser University, says clearing trees on slopes can heighten risks of slides during periods of heavy rain.

“When you remove vegetation, you increase runoff. If you increase runoff, in potentially unstable situations you can trigger these debris flows,” he said.

Clague noted events like this are not uncommon.

In 2024, a landslide in Lions Bay, resulted in the deaths of two long-time residents Barbara and David Enns and led to a lawsuit against the province, the Village of Lions Bay and a local resident. 

The lawsuit claims that Enns’ neighbour, Steven Vestergaard, illegally built roads and a reservoir above the couple’s home on Crown land, and the construction led to the slide.

None of the claims have been proven in court.

“It’s inherently not a good thing to develop steep slopes … you increase the likelihood of debris flows occurring with tragic, tragic outcomes,” said Clague.  

For residents like Dmytronetz, the focus now is on what comes next for her family, particularly her elderly in-laws.

“Unless they know that up above has been remediated properly, they won’t be able to go back and feel secure,” she said.