As rivers across Western North America face climate change-driven record-breaking temperatures, Raincoast Conservation Foundation, in partnership with the Scw’exmx Tribal Council and nłeʔképmx Guardians from Citxw Nlaka’pamux Assembly, have released a groundbreaking study and map of “thermal refuges” in the Coldwater River.
The project identifies vital cold-water pockets where endangered salmon congregate to survive lethal summer heatwaves. These areas are known as “thermal refuges” by researchers. Using aerial thermal infrared imaging collected by a drone, researchers found that while the mainstem of the Coldwater River reached a staggering 27°C in the summer of 2024 – a temperature often lethal to salmon – certain groundwater-fed refuges remained up to 8°C cooler.
By identifying and mapping thermal refuges, the researchers hope to restore habitat and plant shade-providing trees to ensure that these areas are suitable for salmon. They also aim to better understand how to protect groundwater, which creates thermal refuges when it seeps into the river.