Snoqualmie/South Fork Skykomish River Basin

Snoqualmie/South Fork Skykomish River Basin
Highlighted Area Above: Snoqualmie/South Fork Skykomish Basin

The King County Flood Control District invests resources in the Snoqualmie/South Fork Skykomish River Basin to protect public safety, the regional economy, and critical infrastructure.

For the purposes of the Flood District’s budgeting and planning, the Snoqualmie/South Fork Skykomish River Basin includes the Lower Snoqualmie River, Raging River, Snoqualmie River, South Fork Skykomish River, Tolt River, and Upper Snoqualmie River.

Information about individual rivers in the basin are available below.

Investments in the Basin

Capital Investment Strategy

A capital investment strategy (CIS) proposes a sequence of coordinated projects to address the most critical flood and erosion risks and to restore habitat along a specified stretch of river or within a river basin.

The strategy highlights near-term, medium-term, and long-term projects and actions that were identified during an assessment of key problem areas and potential solutions.

Capital investment strategies are directed by the Flood Control District, completed by King County, and eventually approved as policy guidance by the District’s Executive Committee.

Current Projects

Circle River Ranch (South Fork Snoqualmie)
This project evaluates actions to reduce long term risks from channel migration in the Circle River Ranch Neighborhood on the South Fork Snoqualmie River north of the City of North Bend. The project is scheduled for completion in 2024.

Record Office Revetment Repair
The design and construction of this repair project is led by the City of Snoqualmie and repairs 230 feet of damaged bank protection revetment, in order to restore protection of Park Avenue SE.

Reinig Road Revetment Repair
This project implements short-term risk reduction measures and permanent repairs of damages to three sections of the Reinig Road Revetment along Reinig Road located between River Mile 41.75 and River Mile 41.84 on the Snoqualmie River.

SR 203 Bridge Improvements Feasibility Study
This feasibility study evaluates the opportunities, costs, and benefits of providing increased flood water flow through the SR 203 Bridge and road as you approach the bridge. The study will look at modifications to the existing bridge and/or the addition of culverts or additional bridges north of the existing bridge to reduce flooding on SR 203.

South Fork Skykomish Repetitive Loss Mitigation
The repetitive loss program funds elevation or buyout of individual structures in the South Fork Skykomish Basin to eliminate the risk of flooding or erosion damage during future flood events.

Timberlane Village Revetment Repair
This project repairs a in Timberlane Village on the South Fork Skykomish River. The revetment is now in poor condition and if left unmodified, the large rocks could fall unexpectedly creating a hazard for people walking along the river and/or cause aquatic degradation.

Tolt River Level of Service Analysis
This project conducts a detailed technical analysis to optimize the levels of protection provided by new levee systems in the lower two miles of the Tolt River in order to maximize public safety. The project will also include technical analysis that will investigate project sequencing and the resulting flood effects, both downstream and upstream, that might result.

Tolt River Sediment Management Feasibility Study
This project conducts a sediment management feasibility study in order to determine sediment production estimates, evaluate permit and mitigation requirements and if warranted, develop and implement a sediment management plan.

Completed Projects

  • Lower Snoqualmie Valley Residential and Agricultural Flood Mitigation
  • McElhoe-Pearson Habitat Restoration
  • Shake Mill Left Bank Flood Risk Reduction Repair
  • Shake Mill Right Bank Flood Risk Reduction Repair
  • Sinnema Quaale Upper Revetment Analysis and Repair
  • SE 19th Way Road Protection Revetment Repair
  • South Fork Snoqualmie Levee Improvement
  • South Fork Snoqualmie River Corridor Planning
  • Snoqualmie River Hydraulic and Hydrologic Study
  • Tolt Pipeline Protection Project (Lower Snoqulamie)
  • Upper Snoqualmie Valley or River Residential Flood Mitigation