By Steven Schauer, Deputy Executive Director and King County Staff
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 Countyline Levee Setback Project near the city of Pacific.
Countyline Levee Setback Project – A Vital Step in Flood Control and Habitat Restoration
In the fall of 2017, the KCFCD, together with King County as service provider, successfully completed the Countyline Levee Setback Project. This ambitious effort, located on the boundary of King and Pierce counties, significantly reduced flood risks for more than 200 homes near the White River while also revitalizing crucial floodplain habitats for fish and wildlife.
“The completion of the Countyline Levee Setback Project is a significant achievement for both flood protection and environmental restoration in King County,” said Pete von Reichbauer, King County Flood Control District Supervisor, District 7. “This project not only safeguards hundreds of families from the dangers of flooding, but it also revitalizes critical habitat for our local fish and wildlife. It’s a testament to what we can accomplish when we prioritize both community safety and environmental sustainability.”
Project Background
The White River, transitioning from a steep canyon upstream of Auburn to the flat Sumner valley, has experienced ongoing sediment buildup near the city of Pacific. This sedimentation has gradually reduced the river’s flood carrying capacity, posing a persistent flood risk.
In January 2009, significant flooding affected over 100 homes and numerous businesses in Pacific, largely due to this sediment accumulation. The Countyline Levee Setback Project was designed to address these issues, and it included these project goals:
- Flood Risk Reduction: Enhance safety for residents in Pacific by reducing flood risks.
- Habitat Restoration: Restore natural river functions to improve habitats for fish listed under the Endangered Species Act.
- Cost-effective Solutions: Balance flood risk reduction with environmental restoration in a sustainable and economical manner.
Key Components
The project removed approximately 4,500 feet of an outdated levee, reconnecting the White River with 121 acres of its historical floodplain. This reconnection created additional room to store floodwater and sediment, while simultaneously providing off-channel aquatic habitat.
A new setback levee, stretching 6,000 feet, was constructed, fortified with a 5,780-foot-long bio-revetment made of wood and several engineered log jams. The combination of these features enhances flood protection while promoting natural river processes.
Benefits to the Community, Fish, and Wildlife
In addition to provide flood protection to residents of Pacific, the project has already yielded notable environmental benefits as well. New side channels have formed in the floodplain, offering year-round habitat for species such as Chinook and coho salmon as well as steelhead trout. Additionally, almost 60,000 native plants have been established throughout the floodplain, supporting a resurgence in local wildlife populations. Beavers, deer, waterfowl, and birds of prey are now frequent visitors to the improved habitat along the riverbanks.
Ongoing Monitoring
The KCFCD and King County continue to monitor the Countyline Levee Setback Project to assess its long-term impacts on flood risk reduction, river health, and habitat restoration. Early signs show the river is adjusting well, flood risks are being reduced, and crucial habitats are thriving, all as designed by the project.
For more detailed insights and updates, please refer to the year 3 and year 5 monitoring reports.
Reducing Future Flood Risk
The Countyline Levee Setback Project serves as a model for future flood risk management and ecological restoration efforts in the region. Through collaborative efforts, the KCFCD and King County are ensuring that both communities and ecosystems can thrive.
By creating space for both floodwater and sediment, the Countyline Levee Setback Project significantly reduces the risk of flooding in the area. The completion of the upcoming Pacific Right Bank Flood Protection Project will complement this effort, providing comprehensive flood risk reduction along both banks of the White River near the city of Pacific.