After a dry start to the summer in the upper Chehalis River Basin, some observant locals are calling attention to record low water levels in the Chehalis River and its tributaries near Centralia and Chehalis.
The Chronicle first became aware of the low water levels in late June when the former chief of Lewis County Fire District 5 in Napavine, Gregg Peterson, posted to Facebook sharing with the community a photo of the Chehalis River at Grand Mound.
According to information he found on the United States Geological Survey (USGS) Water Dashboard, water flow was at less than 30% of normal flow at the time. Peterson said he called out the low water levels primarily out of concern for what it could mean for the state's fire season.
The Chehalis Basin Partnership, the Washington state Department of Fish and Wildlife and other groups concerned with water levels and fish health cited the same sensor in a recent news release, with their main concern being impacts to native fish populations.
Low water levels can mean pools and fish are cut off from the rest of the river. It also means the river is shallower and warms easier. Warm waters can stress or even kill many of the most vulnerable fish, such as salmon and trout.
While the two groups cite different concerns over the potential impacts of low water levels in the Chehalis Basin, they are sounding the same alarm, warning of the impacts of the dry, warm weather. While Peterson called out the low water levels at the end of June, including some moments of record lows, the Chehalis Basin Partnership has monitored the same sensor throughout the month of July and found the Chehalis River has been running near or below historic low water levels for the last two weeks.
According to Drought.gov, operated by the National Integrated Drought Information System together with the National Oceanic and Atmospheric Administration, which is largely responsible for predicting natural disasters, all of Lewis County is currently experiencing a drought with more than 70% — mostly east of Interstate 5 — seeing extreme drought conditions.
While no official fish deaths have been reported, Lee First, Twin Harbor Waterkeeper, reported a fish death downstream of Fort Borst Park last week.
On the fire front, Lewis County has seen a number of small fires crop up, and most of Western Washington has seen some amount of smoke wafting over from the Bear Gulch Fire in the southern part of Olympic National Park.
In the news release from local watershed coordinator Kirsten Harma, who facilitates the Chehalis Basin Partnership, she compares the average water flow this July to those of recent summers. According to Harma, the USGS monitoring gauge for the Chehalis River at Grand Mound, which measures water flow in cubic feet per second, recorded this July’s average flow at 140 cfs compared to 317 cfs in 2024, 193 cfs in 2023 and 487 cfs in 2022. According to the Chehalis Basin Partnership, it’s the lowest July average recorded since the record began in 1928.
Also contributing to the news release, water quality specialists with the Chehalis Tribe have tracked stream water temperatures well above the temperatures considered healthy and accommodating for native fish. While state law and officials call for water temperatures between 16 and 20 degrees celsius to keep salmon and other species healthy, recorded temperatures have been found as high as 22.8 C in the main stem of the Chehalis River as well as 21.5 C in the Newaukum River and 21.2 C in the Skookumchuck River at the end of July.
Harma added that since the Chehalis Basin has no year-round snow pack, the river relies on rain to keep water levels at normal amounts. Harma said it's the dry June and July that have set the county and the basin up for an unusually dry summer so far.
“The Chehalis Basin is a rain-dominated system, which means that when it doesn’t rain for a long period of time like this spring and summer, there will be less water in the streams and rivers,” Harma said. “Less water means less habitat, so the fish and wildlife that depend on streams right now are under a lot of stress. You can help keep conditions from getting worse for them in a few ways.”
