Fraser Valley homeowners hit twice in four years by mudslide from heavy rains

In November 2021, Ken Lay’s Chilliwack home was hit by a debris flow that brought water, mud and rocks down onto his property.

Until then, Lay believed he and his wife were living in a paradise in their mountain home above the Fraser Valley.

While the mudslide blindsided them, when he was told by city officials in a conversation it was a one-in-100 year event, it brought some relief.

Lay said he remembers thinking how thankful he was it was a rare event and not likely to repeat anytime soon.

“Now, fast forward and it’s happened again,” said Lay.

His home and his neighbour’s remain under an evacuation order three weeks after they were hit by another debris flow that came off a gulley on the slopes below Elk Mountain, in the east side of the city.

Both times, the debris flows were triggered by so-called atmospheric rivers that carry huge plumes of moisture from tropical storms across the Pacific Ocean. The moisture is dumped in a short period of time when it hits landfall on B.C.’s west coast.

Lay said soil and rocks gave way above his property on Dec. 10, covering the road to his home, burying their water supply, and carried on to their neighbour’s property. He estimated there was tens of tonnes of mud and rocks that came down.

Lay said he is concerned that if this is now an uncontrollable debris slide area, a longer-term solution is needed, such as governments buying out the properties.

“I don’t think people want anything but to live somewhere safe,” he said.

Scientists have said that climate change is expected to increase the frequency and severity of atmospheric rivers that trigger floods, landslides and debris flows.

In a written response to Postmedia inquiries, City of Chilliwack officials did not response directly to questions about whether, given the debris flows of 2021 and 2025 and an expected increase in atmospheric rivers, these properties are safe to live in. Officials also did not respond to questions about whether the city was undertaking any further assessment of the landslide, debris flow and flood risks in this area to understand the effects to people and property.

Just to the west of the two properties, the city bought out 42 homes in 2010 because they were built on unstable ground over an ancient landslide site.

The city has also created a no-build zone around the site, but it does not include the area where Lay lives.

The city said it had retained the services of a geotechnical engineer during the recent storm event, who provided a geotechnical “review memo” identifying the public safety concerns at the two properties, but it would not release the document to Postmedia saying it contained private information.

Officials said in an email: “At this time, the city does not have any further information as to how long the order will be in effect and are waiting for the results of the assessments before determining whether any further action is required.”

The city also declined to release the geotechnical review to Lay, who had asked for it. Lay has filed a freedom of information request for the recent review as well as any geotechnical reports or reviews from the 2021 debris flow.

The city has told the two property owners they must hire their own geotechnical expert to complete a landslide assessment, provide a remediation plan and survey the remediation work.

Once the work has been completed, the qualified professional should provide a report to the city certifying that the slope stability hazards have been mitigated, the city said in a letter to Lay and his neighbour, Judy Decker.

In the letters, Doug Mossey, the City of Chilliwack’s manager of transportation and drainage, told the two property owners that an atmospheric river in southern B.C. on Dec. 10 and 11 resulted in a landslide that created slope instability, which appears to be on their properties.

Decker said water and mud reached her house, where it broke through her garage door, reached a wall that separates the house from the garage and got into the house.

She has been told by the city to also get a structural engineer to examine her house.

Decker noted the city did work after the first debris flow in 2021 above her property, installing culverts and an intake with a metal grate that was meant to alleviate flooding, but it did not appear to have any effect.

“My question to the city is, obviously the culvert system failed, was it plugged prior to this event, or was it plugged because of the event?” said Decker.

The City of Chilliwack did not respond to Postmedia’s questions about whether it had done any work to reduce the risk of flooding and debris flows to the properties, and if it had, why it did not work.

Decker bought her property 12 years ago, and Lay 14 years ago.

They both said there was no indication that the area was at risk of debris flows or flooding.

“I was very careful to make sure to investigate that this wasn’t listed as a slide zone or had any kind of issues that way,” said Decker.

In the letters to the two homeowners, city officials noted that “at the province’s discretion,” disaster financial assistance may become available for eligible British Columbians who were affected by flooding and landslides.

Nearby, in the Chilliwack River Valley, two properties that were deemed unsafe to live on due to increased landslide risk from the 2021 atmospheric river storms were ordered evacuated for the same reason earlier this month by the Fraser Valley Regional District.

The two homeowners, and several others, continue to suffer from a provincial decision not to provide disaster aid or buy out their homes, which have now been valued at just $2 by the province’s property assessor.

ghoekstra@postmedia.com

x.com/gordon_hoekstra

Related