Chinook Marsh Restoration Project
October 2023 - Snohomish County Surface Water Management (SWM) will host online and in person public events to share information and collect public input on proposed habitat restoration and infrastructure protection actions at Chinook Marsh.
Snohomish County is planning to restore publicly owned property between Ebey Slough and Fobes Hill. Formerly referred to as Diking District 6 (DD6), this approximately 430-acre property is now called Chinook Marsh.
Once restored, this tidal wetland will provide critical habitat for Endangered Species Act listed Chinook salmon. This project proposes to:
- Restore tidal habitat by reconnecting Ebey Slough to its natural floodplain
- Provide benefits to the public by upgrading flood protection for Home Acres Rd and properties near Swans Trail Slough
- Relocate a vital City of Everett drinking water transmission line to reduce flood and seismic hazards
Project History and Status
The majority of the former DD6 property was acquired in 1994 as part of a mediated agreement to conduct restoration work, provide open space, and ease flooding in the area. While a restoration plan was completed in 1996, implementation of a restoration project at the site did not progress for a variety of factors.
Upgrades to powerline structures by Puget Sound Energy ( YouTube Video see PSE video), new interest in and potential funding for relocation of the City’s water transmission line and updated science pointing to the importance of salmon habitat gains in this portion of the estuary have reenergized agency coordination and planning around this project. In 2020 the Washington Department of Fish and Wildlife led a multi-agency effort to prioritize actions to help move estuary restoration planning forward.
Starting in 2023, the County contracted Anchor QEA to begin assembling a strategic plan to ensure this new phase of project planning is built on a strong foundation. As plans are developed, information will be posted on this webpage. Please sign up for notifications to stay up to date on this important project.
Why is Restoration Needed at Chinook Marsh?
The Chinook Marsh property sits behind an aging and deteriorating levee that was constructed in the 1920’s to protect agricultural land. This levee has failed and been repaired during past flood events. Today the levee still cuts Ebey Slough off from its floodplain and constrains its ability to create and maintain fish and wildlife habitat.
As the tides ebb and flow in lower Snohomish River marshes, they provide slow, protective water and constant food supply for young Chinook and other salmon species that use these habitats to grow and adapt to the salty waters of Puget Sound. The loss of this “rearing” habitat is considered one of the primary factors limiting recovery of Chinook salmon. Restoration of tidally influenced habitat in the Snohomish River estuary has been identified as a priority for salmon recovery in the basin (Snohomish Basin Salmon Recovery Forum, 2005).
Recent restoration actions like those at https://www.qwuloolt.org/ Qwuloolt, https://snohomishcountywa.gov/1150/Smith-Island-Restoration-Project Smith Island, https://www.snohomishcountywa.gov/5417/Mid-Spencer-Island-Restoration-Project Mid-Spencer and https://www.portofeverett.com/environment/blue_heron_slough.php Blue Heron Slough have nearly doubled the amount of tidally inundated habitat available in the Snohomish River estuary, yet all of this newly available habitat is in the lowest extents of estuary. Rearing habitat remains severely lacking in areas more closely connected to the mainstem of the Snohomish River, where out-migrating juvenile salmon are concentrated.
Located less than a mile from where Ebey Slough diverges from the Snohomish River, restoration at the Chinook Marsh site will provide rearing habitat in an area where it is needed most. Restoration will increase available functional habitat, increase habitat complexity, improve habitat connectivity, and mitigate habitat fragmentation within the estuary system (Chamberlin, 2022).
The habitat restoration portion of the Chinook Marsh project is in the feasibility and conceptual design phase.
Snohomish County is currently working with a consultant to develop a strategic plan for the project, begin outreach and coordination with the public and a large group of stakeholders, begin data collection, conduct a feasibility analysis, and develop a conceptual design (2023-2024).
This work would be followed by the development of preliminary designs (2024-2025), final designs and permitting (2025-2026), and finally construction of the habitat restoration elements (2026-2028). This construction timeline could be expanded if construction of the habitat restoration elements needs to be phased due to funding limitations.