TOUTLE — The unpaved road to the Toutle River Sediment Retention Structure was blocked by fallen trees, so Sen. Maria Cantwell and a group led by the U.S. Army Corps of Engineers walked through the mix of rain and snow to the top.
Cantwell was in Toutle on a recent afternoon to discuss the future of controlling sediment from Mount St. Helens’ 1980 eruption with civic leaders from across Cowlitz County and the Corps, who manages the region’s sediment control. The local leaders met to ask Cantwell for federal support for regular monitoring of sediment throughout the Cowlitz River and for long-term plans to keep the sediment from damaging the Cowlitz and Columbia rivers.
The Corps plans to raise the sediment retention wall by 11 feet in 2023 to create more space to keep sediment out of the Cowlitz River.
“While we have the raising of this facility here in the works, we need something post that will also help this sediment problem from clogging up the river downstream,” Cantwell said.
Before the walk up to the sediment retention structure, Cantwell sat for a roundtable discussion with city leaders from Kelso, Longview and Castle Rock; officials from Cowlitz County, the Port of Longview and the Cowlitz-Wahkiakum Council of Governments; and the Corps’ project engineers from the Portland District.
Local governments already are looking ahead to 2035, when the current federal authorization for the Corps to manage the sediment impacts of Mount St. Helens is set to expire. Officials asked Cantwell to help secure the next long-term set of monitoring and improvements.
“It’s important to study it but the everyday citizen feels like we know what’s happening. They want a long-term plan to get some of that sediment out of the river,” Cowlitz County Commissioner John Jabusch said.
Cantwell told The Daily News she will look to secure congressional funding for long-term plans related to the sediment issues.
Local officials used the roundtable to share frustrations about the slow pace of improvements in recent years.
Multiple sand bars had appeared in the Cowlitz River near Castle Rock. The boat launches at Gerhart Gardens Park and Willow Grove Park have been hobbled by the sediment buildup on the north side of the Columbia River. Kelso City Manager Andy Hamilton said the city still is buying water from Longview because of sediment buildup in the Kelso well system.
Some leaders, most vocally Castle Rock mayor Paul Helenburg, questioned whether the short-term benefit from raising the retention structure was the best approach given the ongoing problems.
“You’re spending a lot of money to build log structures and stuff like that that could be used elsewhere to take care of the silt problem,” Helenburg said.
All the public entities who were part of the roundtable talks at Fire Mountain Grill are members of the Spirit Lake-Toutle/Cowlitz River System Collaborative. The collaborative was formed in recent months to allow for easier discussions and agreements among the local stakeholders about the future of the water systems impacted by the 1980 eruption.
Cowlitz-Wahkiakum Council of Governments Executive Director Bill Fashing is the chairman of the Collaborative. Fashing said while the groups have not had immediate impacts on the river system, they will be able to coordinate requests for congressional and federal funding in the future.
“The Corps can’t always go to you and say we need more money for this,” Fashing said during the roundtable. “So I think it’s incumbent on us, as locals, to make sure we’re helping the Corps members address all of the long-term issues.”
Sediment studies have not been regularly performed in the region since 2015. Cowlitz County, Castle Rock and the diking districts combined resources to pay for a study in 2019. Federal funds for a survey were provided in 2020.
Cantwell and Rep. Jamie Herrera Beutler, R-Battle Ground, helped secure $918,000 to the Corps this year for monitoring and studying sediment along the Lower Cowlitz River.
Raised retention, Spirit Lake gate work
The Sediment Retention Structure on the North Toutle River was built in 1989 to catch sediment and reduce the flood risk for the cities downstream along the Toutle and Cowlitz rivers.
In 2012, the top of the structure was raised by 7 feet as debris filled the basin more quickly than expected. Sediment and debris filled the basin within two years.
Liza Wells, deputy district engineer for the Army Corps of Engineers’ Portland district, said the upcoming raise was put in the works after the Corps’ 2018 report on long-term sediment management. One of the biggest recommendations of that report was to raise the crest two times before 2035.
“That’s going to allow the water surface behind the structure to raise and add more capacity for sediment to drop out upstream,” Wells said.
Wells said if the Corps finishes drawing plans and is able to fund construction this year, the work on the retention structure will be done in the summer of 2023.
Another piece of the post-eruption improvement work is coming later this year. Wells told the roundtable improvements to the intake gate for Spirit Lake, which stabilizes the water levels for the lake, hopefully will be completed later this year. The gate project is overseen by the U.S. Forest Service.