By Steven Schauer, Deputy Executive Director and King County staff
Flooding and erosion along the South Fork Snoqualmie River have long been a concern, and unfortunately, a part of life, for the residents of the Circle River Ranch neighborhood. With the river’s unpredictable course and powerful flow, the risk of flood damage to homes and infrastructure in this area is significant. To address these risks, the King County Flood Control District (KCFCD), in collaboration with King County, launched the Circle River Ranch Flood Risk Reduction Project, a crucial initiative aimed at reducing the risk to the community and its surroundings.
“The Circle River Ranch Flood Risk Reduction Project is crucial in our ongoing efforts to protect this community from the devastating impacts of flooding,” said Michelle Clark, Executive Director, King County Flood Control District. “We are not only addressing immediate risks but also creating a safer and more resilient future for the residents of the Circle River Ranch neighborhood. This project is a testament to our commitment to Flood Control District’s vision of building a future to withstand flood risks where thriving King County communities and healthy ecosystems coexist in harmony with area rivers.”
Understanding the Challenge
The Circle River Ranch neighborhood, located on the right bank of the South Fork Snoqualmie River, just downstream from the City of North Bend, is home to 34 residences. Of these, 22 are in the FEMA-designated floodplain, 11 are within a moderate channel migration hazard area, nine are in a severe channel migration hazard area, and three homes are located within the FEMA floodway. This underscores the urgency of implementing effective flood risk reduction measures.
The existing Circle River Ranch Revetment, a structure designed to protect the riverbank from erosion, was damaged and is compromised in preventing channel migration. Without intervention, continued erosion could result in severe damage to homes, roads, and a private waterline, not to mention the disruption of natural habitats vital to local wildlife and indigenous communities.
The area boasts some of the healthiest aquatic and terrestrial habitats within the South Fork Snoqualmie corridor, making it a region of high importance to the Snoqualmie Indian Tribe and Tulalip Tribes. By incorporating input from interested parties into the selection of project alternatives, the KCFCD is committed to balancing flood risk reduction with the preservation of natural resources and cultural heritage.
The Path to a Solution
Recognizing the need for action, the KCFCD prioritized the Circle River Ranch Flood Risk Reduction Project as a near-term goal within the South Fork Snoqualmie River Capital Investment Strategy (CIS). The project commenced in October 2018, beginning with an extensive study of existing conditions conducted by King County as service provider to the KCFCD. Through rigorous analysis and community engagement, various alternatives to reduce flood risks were evaluated.
By Winter 2021, the District had selected a preferred alternative. This decision was guided by King County’s technical assessments and valuable public feedback, ensuring that the chosen solution would not only be effective but also aligned with the community’s needs and concerns.
The Selected Solution: A Buried Setback Revetment
The core of the selected alternative involves constructing a buried setback revetment to repair the damaged upstream portion of the existing revetment. This underground structure, composed of rock and wood, will be strategically built away from the river’s edge and covered with dirt. The revetment will remain buried until river erosion naturally exposes it, at which point it will function to limit further erosion and protect downstream properties.
This method is designed to provide long-term erosion protection, reduce the need for costly future repairs, and enhance the natural environment by promoting stability along the riverbank. Native plants will be added to the river’s edge to improve habitat for fish and wildlife, further supporting the ecological health of the area.
Community Engagement and Next Steps
From the outset, the Circle River Ranch community has been encouraged to participate in the project planning process. Residents were invited to provide their input to early conceptual plans throughout 2021 through various channels, including mailed notices, outdoor posters, and email alerts. Community input helped to inform the design and the choice of the selected alternative in Summer 2022. Continued outreach efforts ensured that residents remained informed as the project progressed.
Construction of the buried revetment is scheduled to begin on September 10, 2024. The project will adhere to noise guidelines for unincorporated King County, with work taking place Monday through Friday between 7:00 a.m. and 7:00 p.m. Residents can expect some noise from construction activities, but contractors are required to minimize dust and other disruptions to adjacent properties.
In addition to the revetment construction, King County, as service provider for the KCFCD, will offer to purchase at-risk homes from willing sellers, further reducing risks by moving people out of harm’s way. This holistic approach not only addresses the immediate threat of flooding but also provides a sustainable, long-term solution for the community.
Looking Ahead
The Circle River Ranch Flood Risk Reduction Project represents a significant step toward securing the safety and well-being of the community. As construction approaches, continued collaboration with residents and interested parties will be essential to ensuring the project’s success.
For more information about the project, please visit the project website. If you have any questions or concerns, feel free to contact King County at 206-263-2677 or email cbertolotto@nullkingcounty.gov.