If you’ve noticed some curious changes along the Squamish and Cheakamus rivers lately, you’re not alone.
New research from Simon Fraser University shows that heatwaves are shifting the timing of river flows, causing snow to melt earlier and extending low-flow periods in summer and fall.
By analyzing data from over 860 river basins, it seems these changes could affect water supplies, ecosystems, and tourism, especially in regions like B.C.’s west coast, including Squamish Valley and Paradise Valley.
Sam Anderson, a postdoctoral researcher at SFU, warns that these shifts could have wide-reaching impacts on everything from salmon populations to tourism and infrastructure.
In an interview with The Squamish Chief, Anderson said that “the connection between heatwaves and river flows” first caught his attention during the record-breaking heatwave of June 2021.
“Many rivers saw extreme floods, but others had very low flows. It got me thinking: What if this kind of heatwave had happened in the 1970s—or what if it happens in 2070?” he said.
Warmer winters, shrinking snowpacks
A predictable cycle of winter snowfall and spring melt is required to sustain the region’s rivers through the dry summer months.
But Anderson’s research shows that this cycle is breaking down as the region warms.
“A little bit of warming means more precipitation falls as rain instead of snow,” Anderson said.
“This eats away at the snowpack earlier in the year, reducing the amount of water available later in spring and summer.”
This shift could create serious problems for salmon that rely on cool, flowing rivers during their fall runs.
“If the snowpack melts too early, we’ll have lower water levels and warmer river temperatures by the time salmon need to migrate and spawn,” Anderson said.
The Cheakamus River, known for its salmon runs, may be especially vulnerable to these changes.
Anderson’s findings align with broader research showing that shrinking snowpacks across the Sea to Sky region are already affecting rivers.
The earlier snowmelt shortens the period when streams are fed by cold runoff, leaving them more prone to drying up just when water demand is highest—from both people and ecosystems.
“It’s during summer when municipal water use peaks, and it’s also when fish and plants need water the most to survive,” Anderson said.
Heatwaves + atmospheric rivers = A perfect storm
According to Anderson, extreme weather events tend to “cascade” into one another, making things worse.
In 2021, when a heatwave dried out the landscape in June, it was followed by heavy autumn rainstorms that caused flooding and landslides, for example.
“These overlapping events show how climate change amplifies risks,” Anderson said.
“When heatwaves dry out the land, it becomes more vulnerable to erosion and floods once the rains hit.”
Anderson warned that with climate change, atmospheric rivers are becoming warmer, delivering more rain and less snow—even at higher elevations.
“This amplifies flood risks in the fall and winter, while reducing flood risks in the spring melt season,” he said.
However, this shift creates new challenges for flood management. “Communities will need to prepare for more frequent fall and winter floods while still being ready for occasional spring floods when snowpacks remain high.”
Ripple effects on tourism and hydropower
Anderson also said that the changing behaviour of rivers could also affect Squamish’s tourism and energy sectors.
“Tourism activities like kayaking, rafting, and fishing all rely on predictable river flows,” Anderson said.
“When river levels fluctuate more unpredictably, tourism operators will need to adapt their schedules.”
Squamish also relies on several run-of-river hydroelectric facilities, including the Upper Mamquam and Cheakamus plants, which generate renewable energy for BC Hydro’s grid. However, shifting river flows due to climate change could disrupt these operations by reducing water availability during critical periods.
“If rivers dry up earlier in the season, it could disrupt energy production just when electricity demand is highest,” Anderson said.
The path forward
Anderson sees an opportunity for the community to take action. “Squamish is highly sensitive to even small temperature increases,” he said. “That’s daunting, but it also means that every bit of warming we prevent can make a big difference.”
“We need to understand whether heatwaves are becoming drier or wetter, and how these patterns will change in the future. That knowledge will be critical for managing water supplies effectively,” he said.
Anderson hopes his research will serve as both a warning and a call to action. “Heatwaves aren’t just temporary inconveniences—they’re events that reshape our rivers, our infrastructure, and our way of life,” he said.
For residents, that means advocating for climate solutions, supporting research efforts, and preparing for a future where river flows are less predictable.
“[It is] important for readers to advocate for climate solutions that prevent these impacts from accelerating,” Anderson said.
Bhagyashree Chatterjee is The Squamish Chief’s Indigenous affairs reporter. This reporting beat is made possible by the Local Journalism Initiative.
