By Steven Schauer, Deputy Executive Director
The King County Flood Control District (KCFCD) has been working diligently since its creation in 2007 to safeguard our communities from flooding. The KCFCD, in collaboration with King County as service provider, has spearheaded over 370 capital projects aimed at mitigating the risk of levee and revetment failures. These projects, along with the operation and maintenance of over 500 flood protection facilities, cover 118 linear miles and approximately 800 acres of land crucial for flood mitigation.
While the KCFCD’s weekly blog typically shares information about new and ongoing projects, each month, we will shine a spotlight on a completed project that is quietly doing its job to safeguard our community against the threat of flooding. The project we’re covering this month is the Cedar River Trail 5B Repair Project located near Maple Valley.
Protecting Infrastructure and Enhancing Habitat: The Cedar River Trail 5B Repair Project
In 2022, the KCFCD, together with King County as service provider, successfully completed the Cedar River Trail 5B Repair Project, ensuring the stability of a critical flood protection facility while maintaining ecological balance along the Cedar River. This project addressed significant flood damage sustained during the February 2020 flood event.
“The completion of the Cedar River Trail 5B Repair Project is a significant milestone for the safety and well-being of our community near Maple Valley,” said King County Flood Control District Executive Director Michelle Clark. “This project not only protects vital infrastructure, such as the Maple Valley Highway and regional utilities, but also preserves cherished recreational spaces like the Cedar River Trail. I want to thank everyone involved in bringing this project to fruition, ensuring that residents can continue to enjoy and rely on this area for years to come.”
Why the Repair Was Needed
The Cedar River Trail 5B (CRT5B) Revetment at River Mile 9.8 plays a vital role in protecting essential infrastructure, including:
- Maple Valley Highway (SR 169): A major transportation corridor.
- Cedar River Trail: A cherished recreational asset used year-round by walkers, joggers, and cyclists.
- Regional Fiber Optic Trunk Line and Natural Gas Pipelines: Critical utilities that sustain communication and energy needs.
Flood damage to the CRT5B Revetment had the potential to expand if left unaddressed, threatening these resources and causing loss of public property.
Key Project Actions
To repair up to 60 feet of the damaged revetment, the project employed large rock to stabilize the riverbank and included planting willow stakes and trees on the upper bank for added durability and ecological benefit. Approximately 11 trees were relocated during construction and carefully placed near the riverbank to serve as habitat for fish and wildlife.
While the primary goal was flood risk reduction, the project also integrated ecological mitigation measures, ensuring compliance with environmental permitting requirements.
Balancing Infrastructure and Ecology
The Cedar River, though a vital natural resource, has been significantly altered by human activities. Channel straightening and levee construction have increased water velocities and reduced habitat complexity, impacting species like Chinook salmon and steelhead, both listed as threatened under the Endangered Species Act.
This repair project, while focused on infrastructure stability, included efforts to support riverine ecology:
- Habitat Enhancement: Placed wood will increase habitat complexity and provide shading and refuge for aquatic species.
- Preservation of Recreation: The Cedar River Trail and nearby Belmondo Reach Natural Area remain accessible for recreational activities like floating, fishing, and hiking.
The project was designed and reviewed by a team of professional engineers, geologists, and ecologists to ensure adherence to best practices. The thoughtful placement of removed trees and the use of natural materials reflect a commitment to ecological stewardship alongside infrastructure protection.
A Model for Sustainable River Management
The Cedar River Trail 5B Repair Project exemplifies how the KCFCD works to protect communities and infrastructure from flood risks while fostering ecological resilience. By addressing immediate safety concerns and considering long-term environmental impacts, this project highlights our dedication to sustainable river management.
By combining innovative engineering with environmental stewardship, this project reflects the shared mission of the KCFCD and King County to reduce flood risks and enhance resilience across the county. Together, we will continue to prioritize projects that preserve and protect life and property, ensuring a safer and more sustainable future for all our communities.