Researchers Examine Risks of Nooksack River Changing Course

A new study looks at the potential for the Whatcom County river to shift dramatically, as officials work to protect nearby communities from flooding.

Published on Feb. 26, 2026

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Researchers at the University of Washington and Western Washington University have begun a study funded by the National Science Foundation to examine the possibility of the Nooksack River in Whatcom County, Washington changing course, potentially reconnecting with the Fraser River in Canada. At the same time, local officials are working to manage the river and protect riverside communities from future flooding events.

Why it matters

The Nooksack River has a history of devastating floods, and officials are concerned about the potential for the river to dramatically shift course, which could have catastrophic impacts on nearby cities and towns. The research aims to better understand the risks and how to mitigate them, while local agencies are taking steps to manage the river and respond to flooding.

The details

The research team, led by Dr. Alexander Horner-Devine of the University of Washington and Dr. Alison Pfeiffer of Western Washington University, is using advanced modeling and technology to study the possibility of an 'avulsion' event, where the river changes course. They are examining whether such a shift would happen gradually or through a catastrophic event. Meanwhile, Whatcom County's Flood Planning & Mitigation Manager, Paula Harris, says the county has done work to maintain the river's bank line and prevent an avulsion, though the researchers have estimated a low probability of such an event during a 100-year flood. The researchers are working closely with local officials, providing their findings on a weekly basis to help inform the county's flood response efforts.

  • The NSF-funded study began in fall 2025 after a several-month funding delay.
  • The research team plans to continue their work over the next four years.

The players

Dr. Alexander Horner-Devine

A professor at the University of Washington who leads the research team studying the Nooksack River.

Dr. Alison Pfeiffer

A researcher at Western Washington University who is co-leading the study on the Nooksack River.

Paula Harris

Whatcom County's Flood Planning & Mitigation Manager, who is working with the researchers and overseeing the county's efforts to manage the Nooksack River.

Olivia Petralia

A student at Western Washington University who created a LIDAR map showing how the Nooksack River has moved significantly over the years.

Scott Anderson

A researcher with the United States Geological Survey who is studying the Nooksack River's geomorphology since the end of dredging in 1990.

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What they’re saying

“This actually grew out of a previous NSF-funded project. That previous project was looking at how the movement of sediment in rivers, broadly in the Pacific Northwest, can contribute to flooding.”

— Dr. Alexander Horner-Devine, Professor, University of Washington (MyBellinghamNow.com)

“The Nooksack is wild and weird, and I think that if people are confused about why flood managers can't just fix this problem, we should give them a little credit. They are dealing with an incredibly challenging and wily river and using traditional flood management tools is going to be potentially fraught here, just because the river channel itself is changing so rapidly and it's working with a landscape template that is very peculiar.”

— Dr. Alison Pfeiffer, Researcher, Western Washington University (MyBellinghamNow.com)

What’s next

The research team plans to continue their work over the next four years, providing weekly updates to local officials to help inform Whatcom County's flood response efforts.

The takeaway

The Nooksack River poses unique challenges for flood management due to its rapidly changing course and high sediment load, requiring innovative approaches and close collaboration between researchers and local authorities to protect nearby communities from potential catastrophic events.