Trafton Floodplain Restoration
Snohomish County Department of Conservation and Natural Resources (DCNR) and the Stillaguamish Tribe are partnering on a floodplain restoration project at Trafton. This project is connected to a larger effort by the tribe to restore reach-scale river processes and salmon habitat on the lands they own at Trafton.
The project footprint will include work on both the tribe's and county’s property and will prioritize floodplain restoration and protecting the Whitehorse Trail, which runs adjacent to the project area, from future erosion and avulsion impacts.
Due to the dynamics of the North Fork Stillaguamish, there is risk to the Whitehorse Trail and the trestle bridge at the south end of the county’s property. Based on current predictions, it is inevitable impact will occur in the hay field between the river and the trail, threatening the future stability of the trail and bridge. The county and Stillaguamish Tribe partnering on this project offers a proactive approach to preserving the Whitehorse Trail and an exciting opportunity to increase salmon habitat and floodplain storage.
Thank you to everyone who participated in and provided feedback through our 3 public meetings and 3 online surveys! For a copy of the presentations and survey responses, please see “Documents” below.
The county and tribe have completed the conceptual design, where the team explored options for restoration. The potential project footprints ranged from working only on the tribe’s property at Trafton to expanding the restoration into part of Trafton Trailhead Park. Incorporating feedback from the public outreach process, consensus between the county, tribe, and the community was to maximize new side channel habitat, floodplain habitat, protection of the Whitehorse Trail, and recreation opportunities.
The team is now developing construction documents of the preferred design, working towards 60% design, and submitting for permits.
Grant Fundraising: 2023-2024
The Stillaguamish Tribe and Snohomish County are partnering on a large floodplain restoration project along two miles of the North Fork Stillaguamish River at Trafton. The project area is around 250 acres: 176 acres owned by the Tribe and around 70 acres of Trafton Trailhead Park, which is owned by the County.
While the Stillaguamish River supports a great diversity of animal species, much of the historic floodplain habitats of the area were cleared, drained, diked, and armored over the past 100 years. These changes have drastically reduced habitat for all species, especially salmonids and Chinook in particular.
The Tribe intends to restore reach-scale river processes, salmon habitat, and achieve their tribal vision for watershed recovery on the lands they own at Trafton.
The current pattern of the North Fork Stillaguamish River has potential to threaten the stability of the Whitehorse Trail and bridge adjacent to the restoration area. By partnering with the Tribe on this project the trail can be protected, and an additional 70 acres of floodplain can be restored.
This project also provides an opportunity for the County to partner with the Tribe and act on Executive Somers’ Puget Sound Salmon Safe Pledge. One of the actions within his pledge is to pursue habitat restoration on County-owned lands.
The design for the Preferred Alternative maximizes new side channel and floodplain habitat on both the tribe and the county's property as well as maximizing the protection of the Whitehorse Trail. This design includes:
- Activating the floodplain: removing rock and levee around the perimeter of the Tribe's property, and reconnecting the river to the project site as completely as possible
- New primary side channels (dark blue) and tertiary side channels (light blue) spread energy across the floodplain. The primary side channel alignment is extended onto the county's property, creating not only additional habitat but altering the energy of the river to better align with the trestle and protect the Whitehorse Trail
- Engineered log jams throughout, improving habitat for juvenile and adult salmonids and reducing flood velocity
- Floodplain roughness berms throughout, reducing flood velocities on site and in the North Fork
- Riparian plantings and weed control across the tribe's property, providing shade to cool water temperatures and to be a future source of wood for future log jams. Both outcomes improve instream habitat for salmonids
- New berm along the Whitehorse Trail, protecting the trail and keeping excavated soil on site
- Construction of a fisher trail near the trestle at the south end of the county's property, allowing for easier access to the river
- Construction of an interpretive trail near the Whitehorse Trail on the county's property, providing a place for trail users to learn about the project and larger salmon recovery efforts
- Trafton Floodplain Survey Responses Fall 2022 (PDF)
- Trafton Floodplain Restoration Meeting 1 Presentation (PDF)
- Trafton Floodplain Restoration Meeting 2 Presentation (PDF)
- Trafton Floodplain Restoration Project Survey Responses Winter 2022 (PDF)
- Trafton Floodplain Restoration Project Meeting 3 Presentation (PDF)
- Funding was awarded for preliminary design from the Salmon Recovery Funding Board.
- Funding was awarded for design, permitting and construction from a Pacific Salmon Treaty Orca Recovery Habitat grant.