Stillaguamish Tribe reconnects river to Blue Slough

The mark of a successful restoration project is the presence of salmon in newly created habitat.

This spring, Stillaguamish Natural Resources staff found hundreds of chum in Blue Slough, along with dozens of chinook, coho and steelhead.

The side channel had been cut off from the river by railroad tracks in the 1930s. Restoring the habitat was proposed in the 1970s, and the tribe began the work in 2005. Logjams and fish-friendly culverts were installed, creating 3,000 feet of side channel habitat and finally reconnecting the slough to the North Fork Stillaguamish River last fall.

“This was the ultimate example of a ‘lessons learned’ project,” said Pat Stevenson, environmental manager for the tribe.

Not only did the project take years to get off the ground, but there were a few surprises during the work, including changes to the natural armoring of the stream bed, a flood that lowered the channel and an increase in groundwater caused by channel excavation.

Prior to the work, Blue Slough connected two large ponds on private property, but was cut off from the river.

“The channel was all ground water,” Stevenson said. “It didn’t have that river smell.” Salmon use an acute sense of smell to navigate back to their natal streams to spawn.

Now, the slough is connected to the river at both ends, where water can flow continuously, providing winter and summer rearing habitat for juvenile chinook salmon Lack of rearing habitat is a top cause for the severe decline of chinook in the Stillaguamish watershed.

For more information, contact: Pat Stevenson, environmental manager, Stillaguamish Tribe, 360-631-0946 or [email protected]; Kari Neumeyer, information officer, NWIFC, 360-424-8226 or [email protected].