Under a public-private partnership, this project restored critical ecological processes and enhanced flood resilience in the Marysville region across 150 acres of seasonally inundated riparian floodplain, 1.7 miles of perennial side channels and 6.1 miles of seasonally inundated side channels, alcoves and swales.

Completed under budget and ahead of schedule in November 2023, this multiyear in-stream project in an environmentally sensitive watershed required collaborative partnerships with industry, environmental organizations, nonprofits and public agencies.

The goal of the project was to restore the river channel and provide a sustainable ecosystem for years to come. To accomplish this, the project team had to recreate the design of the main channel and restore the river’s natural processes.

Work was restricted to April-October due to flood season restrictions. Meanwhile, the possibility of having to build and dismantle a bridge annually presented another challenge. The solution was a Bailey bridge—a portable, prefabricated truss bridge—that facilitated access to the middle training wall, enabling efficient material extraction and cost savings.

In 2023, wet weather delayed access to project areas, prompting redesigns and close coordination on material removal and habitat grading. Weekly onsite meetings ensured progress alignment and facilitated the coordination of work zones.

The team was able to remove a significant amount of material and successfully lowered water surface elevations by 3 feet for the 100-year flood event, enhancing flood resilience downstream and ensuring community safety.