Restoring Dungeness River habitat for salmon

The Jamestown S’Klallam Tribe made strides this summer restoring much-needed salmon habitat in the Dungeness River.

The three biggest issues contributing to low salmon productivity have been decades of wood removal, ongoing irrigation withdrawals, and extensive manmade levees, dikes and bank revetments. These issues cut off floodplains and forests from the mainstem, increased water velocities and eliminated recruitment of large wood, said Hilton Turnbull, the tribe’s habitat biologist.

While the tribe has been working to address these problems for decades, 2022 was a year of significant progress, with four projects completed between May and October.

“Over time, logjams and large woody debris have been stripped from the Dungeness River,” Turnbull said. “Our projects are designed to get stable logjams back into the channel to create pools and retain spawning-size sediments and gravels, while also reconnecting off-channel habitat that isn’t currently available to salmon. We are also reconnecting floodplains and channel migration zones by removing levees, dikes and bank revetments.”

The Jamestown S’Klallam Tribe installed engineered logjams in the upper Dungeness River to reconnect the mainstem river with its floodplain and improve spawning and rearing habitat for salmon and bull trout. Photo: Jamestown S’Klallam Tribe

The project farthest upstream, the Phase III project at river mile 13, involved three days of helicopters placing logs, rootwads and rock anchors to create 11 engineered logjams in the upper watershed. The purpose was to reconnect the mainstem river with its floodplain and improve spawning and rearing habitat for salmon and bull trout.

Downstream at the Caldero project at river mile 9.5, the tribe installed four logjams in the main channel to slow the river’s velocity and constructed a 750-foot-long side channel replete with salmon habitat. 

“The lack of stable large wood in the Dungeness reduces productivity and hurts recovery efforts for federally listed salmon species, especially chinook,” Turnbull said. “Even low volume flood flows have been shown to reduce redd (salmon egg nest) survival.”

In 1961, at the current location of the Dungeness River Nature Center at river mile 5.8, a railroad company constructed a 350-foot-long dike to divert the river and block the eastern side of the floodplain. In 2022, the tribe removed the railroad dike and expanded the floodplain to its historical 1,000-foot width. The project also included installing new pedestrian bridges for the popular Olympic Discovery Trail that crosses the river, and adding 14 logjams for salmon habitat.

At River’s Edge, just a few miles from the river mouth, the tribe removed 1.8 miles of a U.S. Army Corps of Engineers levee built in 1964 that constricted river flows and damaged salmon habitat. The levee removal project reconnected approximately 140 acres of floodplain. To protect neighboring properties and the community of Dungeness, the tribe and Clallam County constructed nearly 2 miles of setback levees. The tribe also began planting native vegetation in the reconnected floodplain for a permanently conserved floodplain forest.

Getting all this done took time, perseverance and more importantly, collaborations with salmon stakeholders.

“Forming effective partnerships at every level is how these projects get done,” Turnbull said.

These projects included working with the state Department of Natural Resources, U.S. Forest Service, Clallam County, Clallam Conservation District, North Olympic Land Trust, North Olympic Salmon Coalition, the Dungeness River Nature Center, and private landowners, as well as a variety of funding sources, including Floodplains by Design, ORCA Pacific Salmon Treaty and Salmon Recovery Funding Board grants.

A dike was removed, floodplain expanded and a pedestrian bridge constructed at the Dungeness River Nature Center to improve salmon habitat. Story and photo: Tiffany Royal