SR 161 - Unnamed Tributaries to Hylebos Creek - Fish Passage

Project news

  • We will remove barriers to fish passage on three unnamed tributaries that feed East Fork Hylebos Creek near Federal Way.
  • This project is scheduled for construction from spring 2023 through fall 2024. 

Needs & benefits

Removing fish barriers can deliver impressive benefits, improving fish access for miles up and downstream.

The SR 161 Unnamed Tributaries to Hylebos Creek fish passage replacement project near Federal Way continues to build on our commitment to removing fish barriers on streams that run under state highways. Replacing the outdated culverts with either bridges or fish-passable structures increases the likelihood of fish migration through Hylebos Creek and its tributaries.

There are three culverts that run under SR 161/Enchanted Parkway South, to the south and east of Wild Waves Theme Park. These culverts carry unnamed tributaries under the highway to feed Hylebos Creek. These three culverts range from 18 to 24 inches in diameter. All of them are considered completely impassable to fish.

New fish passages

Replacing these culverts and rebuilding the streams will provide new habitat for the Coho, resident trout, steelhead, and searun cutthroat that use Hylebos Creek and nearby wetlands. Each culvert has a potential habitat gain ranging from 1,066 to more than 1,300 meters. These improvements and habitat gains will help restore fish runs and increase the population of these species.

This benefits commercial seafood operations, recreational fishers, and provides more food for our declining orca population. In addition, replacing these fish barriers helps us meet our obligation to remove barriers under the 2013 U.S. District Court injunction

Construction effect on highway traffic

Replacing these culverts will take up to two years. It will require closing one direction of SR 161 around-the-clock for several weekends. Traffic will be reduced to one lane in each direction using the opposite side of the highway during weekend work. There will also be nightly lane closures. Additional information will be available during construction.


2021: Design
Winter 2022: Advertise project
Summer 2022: Award contract to qualified design-builder
Spring 2023: Begin construction
Fall 2024: Complete construction


Financial Data for PIN 116103D
Funding Source Amount ($ in thousands)
2003 Gas Tax (Nickel Funding) $0
2005 Gas Tax (TPA) $0
Pre-Existing Funds (PEF) $0
CWA $24,479
Total $24,479


Kris Olsen

A map showing the locations of three blocked culverts under SR 161.