Galli's-Dykstra Feasibility and Repair Project
The Galli’s and Dykstra levees (two levees) are in the City of Auburn along the left bank of the Green River and provide flood risk reduction benefits to residential and commercial areas of Auburn and unincorporated King County. The need for the project is based on concerns about potential low areas along the levees. At the request of the City of Auburn, in 2019, King County, as service provider to the King County Flood Control District, initiated a feasibility study to evaluate the existing levee heights and stability to ensure the levees function as designed and provide a uniform level of flood risk reduction to the area.
Feasibility studies identified three areas along the top of the levee where corrective action is needed to address low spots. The area farthest north (Area A) extends from the pedestrian bridge at Dykstra Park, (just south of Brannon Park) to adjacent multi-family buildings to the south. The other two locations (Area B and Area C) are farther to the south and adjacent to approximately 15 single-family homes.
The design of levee improvements for the three low areas is currently underway. Levee improvements will include raising the height of the levee to provide uniform flood risk reduction through the project area. Construction is scheduled for spring 2021.
The Galli’s-Dykstra Feasibility and Repair Project will evaluate and address low areas that compromise the level of flood risk reduction provided by the levee system.
When completed, this levee will provide uniform flood risk reduction to the homes in the neighborhood and commercial areas in Auburn. New riparian plantings between the river and levee where space is available will improve conditions for salmon and other species.
The Galli’s and Dykstra levees are part of a series of 28 miles of levees and revetments along the Lower Green River that extend from Highway 18 through Auburn, Kent and Tukwila. The levees help reduce the risk and impacts of flooding to residential, commercial, industrial development and agricultural lands throughout the Lower Green River.
In 2019 King County in partnership with the US Army Corps of Engineers completed the Green River System-Wide Improvement Framework (SWIF). The Green River SWIF includes a suite of actions including: (1) near term repairs focused on specific levee deficiencies, (2) capital projects to address slope stability concerns, levee inspection items and increase overall levee performance, (3) programmatic activities to ensure effective operation and maintenance of flood facilities, and (4) interim risk reduction measures. Regional considerations related to capital project design, repairs, levee operation and maintenance, including the management of vegetation, is also included as part of the SWIF and supporting appendices. One of the interim risk reduction measures identified in the SWIF was to find, evaluate and correct discrete locations where low spots exist along the levees.
Final design is underway with construction planned for spring 2021. The design will ensure stable levee height increases to provide uniform flood risk reduction for containment of floods up to 12,000 cubic feet per second (e.g. 1% annual chance exceedance or 100-year flood) through the project area.
Planned improvements include removing existing grass from the top of the levee and adding compacted fill material to correct low spots so that the height of the levee is uniform through the 1.3-mile-long Galli’s and Dykstra levees. The project also includes replacing grass along the levee crest and replacing any disturbed landscaping adjacent to the levee. New riparian planting of native shrubs and trees where space is available will be included between the river and the levee to improve conditions for salmon and other species.The images below provide an overview of the planned repairs in each of the three low areas identified as the focus of this project as well as construction access. Area A is located just south of the pedestrian bridge at Dykstra Park and extends south for approximately 1,000 feet in length. This area will require a levee height increase of up to 2.75 feet. Construction access for Area A will be off of 22nd St NE and Riverview Drive NE.
Area B is further to the south and is approximately 600 feet in length. Area B will require a levee height increase of up to 1 foot. Construction access for Area B will be through a King County-owned parcel.
Area C is the furthest south of the three low spots and is approximately 400 feet in length. Area C will require a levee height increase of up to 1 foot. Construction access for area C will be through an existing easement.
Residents were notified about the project by mail in September 2019. Outreach has been ongoing with residents and property owners near the three low areas to gather their input and address questions about the about the planned improvements. Additional outreach will take place as the construction schedule is developed.
To provide input on the project or if you have concerns or questions, please contact Jay Young. Project Manager, King County River and Floodplain Management. You can also sign up for updates and announcements about this project.
Potential schedule delays may occur depending on guidelines and restrictions related to COVID-19.
|Planning and alternatives selection||July 2019 - August 2020|
|Preliminary design (30 percent) Area A||Late Summer 2020|
|Final design and permits||September - December 2020|
|SEPA review||Summer - Fall 2020|
|Construction||August - October 2021|
About the King County Flood Control District
The King County Flood Control District is a special purpose government created to provide funding and policy oversight for flood protection projects and programs in King County. The Flood Control District’s Board is composed of the members of the King County Council. The Water and Land Resources Division of the King County Department of Natural Resources and Parks develops and implements the approved flood protection projects and programs. Information is available at kingcountyfloodcontrol.org.
For more information about the Galli's-Dykstra Feasibility and Repair Project, please contact Jay Young, Project Manager, King County River and Floodplain Management Section, Water and Land Resources Division, Department of Natural Resources and Parks.
Stay in touch
- Flood services and information
- System-Wide Improvement Framework (SWIF)
- Lower Green River Flood Hazard Management Plan
- WRIA 9 Salmon Recovery
- Army Corps of Engineers Levee Rehabilitation and Inspection Program