Posted on December 17, 2025
The flooding comes a month after feds declined request to dredge
Leaders around Cowlitz County said Friday that sediment from Mount St. Helens worsened flooding along the Cowlitz River and called on the U.S. Army Corps of Engineers to start dredging it — a request the Corps has long avoided.
Millions of tons of sediment from the 1980 eruption continue to flow into the Cowlitz each year from the Toutle River’s North Fork, raising its bed and making the Cowlitz more prone to floods, said Scott Neves, director of the Cowlitz County Department of Emergency Management.
“I can’t dump a 5-gallon bucket of sand in my bathtub and expect to have the same amount of water capacity in that bathtub,” he said.
Despite repeated requests — including one by local leaders in the fall — the Corps says it cannot dredge a tributary to a major river due to budget constraints, despite more local rain and floods expected this week.
“If we start doing one, then we have to do it for everybody,” said John Morgan, a spokesperson for the Army Corps of Engineers’ Portland District, “and then everybody’s going to want dredging.”
‘Not a realistic expectation’
After initial dredging of the Cowlitz in the 1980s, the last time the river was dredged was in 2008, Morgan said.
In 2024, local lobbying succeeded in gaining federal approval to dredge the Cowlitz near its mouth but only to keep the Columbia River’s 43-foot-deep federal navigation channel operational — a channel that moves tens of billions of dollars in goods each year.
While Morgan explained the impacts of sediment in the river similarly to the local officials, he said the Corps simply cannot afford to dredge because of the precedent it stands to create.
The agency currently maintains over 25,000 miles of waterways, as well as 400 ports and harbors across the country, costing an average of $1.7 billion a year. The agency was also hit with at least $1.5 billion in cuts earlier this year.
“It’s just not a realistic expectation,” Morgan said. “We really do have to limit how much we can do because it’s expensive. It’s a very expensive proposition.”
Recent requests
In October, Cowlitz County Commissioner Steve Rader and state Sen. Jeff Wilson, R-Longview — alongside more than a dozen other officials around the county including mayors, county commissioners and state representatives — sent the Corps a letter asking it to dredge from the mouth of the Toutle River, down the Cowlitz to the Columbia, among other requests.
The commander of the Portland District, Col. Larry Caswell, responded in November. That letter, obtained by The Daily News, said the agency was aware of sandbars in the river but that levees along the lower Cowlitz were up to legal standards. It did not address dredging on the Cowlitz.
Rader said he has discussed the issue with the offices of Sens. Patty Murray, D-Wash., Maria Cantwell, D-Wash., and Rep. Marie Gluesenkamp Perez, D-Skamania, and he is headed to Washington, D.C., in February to talk to the Corps about the issue.
Islands of sediment in the river
The problems caused by sediment in the river became clear by the morning after Mount St. Helens’ 1980 eruption when a ship ran aground in the Columbia’s deep water navigation channel, which sediment had filled from 32 feet deep to just 12 feet.
The blast sent about 1 million Olympic swimming pools worth of debris into the area around the North Fork Toutle River. That’s slowly eroded at a rate of about 6 million tons each year on average, according to the U.S. Geological Survey.
But the problem of sediment in the Cowlitz has only grown worse in recent years due to a delayed raise of the roughly 36-year-old dam that captures the sediment back on the North Fork Toutle River.
The structure has become less and less effective as it fills, switching from catching about 80 percent of passing sediment to allowing 80 percent to pass, a Corps spokesperson said in March.
Rader and Neves said they can see the river filling with sediment.
“If you just take a look at the river,” Neves said, “we have literal islands in the middle of the Cowlitz River that have never existed there, and they’ve been there so long that there are actually trees growing on them.”
‘Not enough room in the river’
Officials from local cities echo similar frustrations.
Chris Collins, Longview public works director and assistant city manager, said the area is more prone to catastrophic flooding due to the sediment.
“There’s just not enough room in the river,” he said.
Devin Mackin, Kelso public works manager, said the sediment has increased the chances of flooding by raising the water table.
“With the amount of sediment in there, it does raise with the groundwater table a little bit,” he said. “If the Army Corps did come through and remove some of that sediment, that would help that groundwater table to lower.”
And David Vorse, the longtime Castle Rock public works director, said the sediment is worsening flood conditions each year.
“We’re overdue,” Vorse said about major flooding, “and because we now have a capacity issue within the basin, when we get hit, it’s going to have more dramatic effects than we have seen in the past.”
The next flood
Cowlitz County and the rest of the Pacific Northwest are set to be slammed by another atmospheric river early this week, with local officials warning of more potential flooding.
“In my 44 years of being here,” Vorse said on Friday, “I don’t know that I can recall seeing 5-plus inches of rain in 24 hours.” Some places in the area saw as much as 19 inches of rain, according to the U.S. Forest Service on Friday.
And Vorse said the recent rain leaves the region particularly vulnerable to flooding from the next storm.
“Now, everything is pretty well saturated, so there’s no holding capacity in the ground,” he said. “So if we continue to get rains, it’s going to immediately get into the river, and that’s going to make the impacts more severe.”
