Middle Fork Snoqualmie River Corridor Planning and Capital Investment Strategy
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Tuesday, Oct. 30, 2018
6:30 – 8:30 pm
North Bend Library, 115 E. 4th ST., North Bend
Join the King County project team for an open house and presentation about flood and channel migration risks and how to reduce those risks to people and property along the Middle Fork Snoqualmie River.
The Middle Fork Snoqualmie River corridor planning process, funded by the King County Flood Control District (external link), sets out to analyze flood and erosion risks and develop a long-range strategy for reducing those risks.
The upper Snoqualmie Valley has experienced several destructive floods in the last 20 years. These floods have posed risks to people, damaged homes and affected both the local and regional economy.
The study area encompasses five miles of the Middle Fork Snoqualmie River from the confluence with the North Fork Snoqualmie River upstream to Tanner at river mile 5.0.
The planning effort involves:
- Characterizing existing physical, biological, and social conditions in the corridor.
- Identifying the location, nature, and significance of flood and erosion risks and ecological conditions throughout the corridor.
- Developing potential solutions to flood risks in the river corridor.
- Partnering with tribes and stakeholders at key milestones throughout the planning process.
The outcome will be a draft Capital Investment Strategy proposing a sequence of coordinated projects to address the most critical flood and erosion risks to public safety.
Proposed actions are intended to:
- Reduce vulnerability to flood risks for residents.
- Protect public infrastructure.
- Minimize disruption to the regional economy as a result of flooding.
- Protect habitat and other community values.
- Engage residents, community groups, and resource agencies.
The Middle Fork Snoqualmie River Corridor planning process is guided by project goals and objectives adopted by the King County Flood Control District in July 2018.
Goal 1: Reduce risks from flood and channel migration hazards
- Mitigate risks associated with inundation and deep and fast flow hazards in consideration of future sediment aggradation and uncertainties due to climate change.
- Mitigate risks from channel migration and avulsion hazards predicted within the next 50 years in areas with homes and infrastructure.
Goal 2: Reduce long-term repetitive costs of flood hazard management
- Implement sustainable cost-effective floodplain management solutions.
- Reduce long-term costs of floodplain management.
Goal 3: Integrate sound and sustainable flood hazard management projects/practices that
benefit the natural environment to the degree practicable
- Protect and improve floodplain habitats and off-channel connectivity, when appropriate.
- Protect and improve instream aquatic habitat quality and quantity.
- Protect and improve riparian habitat quality and quantity.
Goal 4: Incorporate stakeholder and community input into the Corridor Planning process in
an equitably and socially just manner
- Incorporate stakeholder input into the Corridor Plan through community and stakeholder engagement from those affected by floodplain management actions.
- Strive to provide equitable flood risk reduction outcomes throughout the river corridor to the degree practicable.
The Middle Fork Snoqualmie River Corridor planning process aims to identify and prioritize a series of actions that reduce risk and are ecologically and financially sustainable over time.
Process and Timeline - Updated September 2018
- Spring - Summer 2018 - Characterize existing corridor conditions.
- Flood, geotechnical, channel migration hazards and risk.
- Aquatic and riparian habitat.
- Fall 2018 - Community outreach.
- Fall/winter 2018 - Identify problem areas and potential solutions.
- Winter 2019 - Draft Middle Fork Capital Investment Strategy (CIS).
- Late Spring 2019 - Update the Middle Fork CIS based on feedback.
- Summer 2019 - Flood Control District approval of the Middle Fork CIS.
Files are provided in Adobe Acrobat.
- Channel Migration in the Three Forks Area of the Snoqualmie River (PDF, 6MB)
- Geomorphic Assessment: Middle Fork Snoqualmie River, Tanner to Three Forks Natural Area, June 2013 (PDF, 34MB)
- Hydraulic Modeling and Analysis: Middle Fork Snoqualmie River, Tanner to Three Forks Natural Area, May 2016, updated May 2016 (PDF, 62.2MB)
- Ecological Resources Characterization: Middle Fork Snoqualmie River, Tanner to Three Forks Natural Area, September 2013 (PDF, 15MB)
- 2013 King County Flood Hazard Management Plan Update
- 2006 King County Flood Hazard Management Plan
- "So You Live Behind a Levee," American Society of Civil Engineers' brochure (external link)
For more information on the Middle Fork Snoqualmie River Corridor Management Plan, please contact Richelle Rose, Project Manager, Snoqualmie/South Fork Skykomish River Basins, King County River and Floodplain Management Section.