Drew Brayshaw presents an online talk ‘Disaster in the Valley’ through FVRL on April 20. (Drew Brayshaw photo)

Drew Brayshaw presents an online talk ‘Disaster in the Valley’ through FVRL on April 20. (Drew Brayshaw photo)

‘Disaster in the Valley’ talk will focus on effects of atmospheric river storms

Virtual talk is by Drew Brayshaw, hydrologist, geoscientist with Statlu Environmental Consulting

Drew Brayshaw of Chilliwack has been thinking about water and landslides for more than 20 years.

As a hydrologist and geoscientist with Statlu Environmental Consulting, Brayshaw’s expertise has been been in high demand since a series of atmospheric rivers slammed parts of B.C. last November.

His formidable training, plus his penchant for hiking and ice climbing, have more than prepared him for his online talk, ‘Disaster in the Valley’ on April 20 at 6:30 p.m. through the Fraser Valley Regional Library.

Brayshaw conducts terrain-stability assessments, or natural-hazard assessments in his consulting work, and many other facets of environmental geoscience, but his upcoming talk will zero in on “floods, landslides and atmospheric rivers.”

About 15 minutes before the end of his hour-long talk will be reserved for a Q&A session.

He is putting out a gentle warning in advance in case anyone is still feeling super-stressed, or at risk of a PTSD reaction from the flood and slide disaster discussion, that they could be triggered by it.

“I don’t want anyone to be surprised,” Brayshaw said.

For those who think they can handle it, he’ll be showing a few photographs of the flooded Sumas Prairie, landslides in the Chilliwack River Valley, and other examples of devastation like the debris field on Highway 7.

One question he’ll tackle is why the back-to-back record rainstorms were so damaging.

“What is hard is that we only get a couple of days’ warning to see these things form,” he said, talking about the effort to observe the formation of the atmospheric rivers in advance, with their long, narrow bands carrying moisture vapour aloft.

RELATED: Forecasters warned of heavy rain coming weekend of Nov. 14

“There can be as much water in the sky as there is in the Nile, or the Amazon, or the Fraser River,” Brayshaw said.

The term ‘atmospheric river’ describes the type of Pacific storm where copious amounts of rain comes down from corridors of concentrated moisture. It’s a term coined in 1998 by MIT researchers, to describe the rivers-in-the-sky phenomenon, that can come from Hawaii, the subtropics, or parts of Asia.

One of the 2021 rainstorms was so intense it brought water over to the West Coast from Philippines, he noted.

“Around the second storm we were told, ‘These are going to be bad,’ but it wasn’t clear yet how bad as three atmospheric rivers were going to arrive.”

It was something else to see it all from the aerial vantage point of a helicopter.

“I thought, ‘Wow, there’s a lake,’” Brayshaw recounted about seeing a flooded-out Sumas Prairie for the first time from above.

In hindsight he’s become convinced the draining of Sumas Lake in the early 1920s was nothing short of an “environmental tragedy.”

“Sumas is a lake bed. And just because it was drained doesn’t mean it doesn’t want to be a lake again.”

To register to get the Zoom link, go to: https://bit.ly/3IWXfcb

RELATED: River Forecast Centre puts South Coast on flood watch

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