SR 161 - Unnamed Tributaries to Hylebos Creek - Fish Passage

Project overview

Three culverts carrying tributaries to Hylebos Creek near Federal Way that block fish passage will be replaced with new structures under SR 161 that restore natural stream conditions. This work builds on our commitment to remove fish barriers on streams that run under state highways.

Timeline

Spring 2021 - Fall 2026

Project status

Construction

Funding

$21.2 Million

What to expect

This project has been combined into a single contract with fish passage projects on I-90, SR 202 and SR 203. Construction on the combined project is scheduled to occur from early 2023 until early 2027. Work to relocate utilities running through the SR 161 work zones likely will begin in fall 2024, with major construction starting by mid-2025.

Replacing these three culverts on SR 161 is projected to take about a year. It will likely require closing one direction of SR 161 around-the-clock for up to six months, with traffic shifted to the opposite side of the highway and reduced to one lane in each direction. There may be up to four weekends of full highway closures. There also will be nightly lane closures.

More specific information about closures and when they will occur will be developed by the contractor and shared in advance with the public.

This map shows the locations of three culverts that carry tributaries under SR 161 to Hylebos Creek near Federal Way, WA.

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A map showing the locations of three culverts that will be replaced under SR 161 to Hylebos Creek near Federal Way, WA.

History and background

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 Replacing the outdated culverts with either bridges or fish-passable structures increases the likelihood of fish migration through Hylebos Creek and its tributaries.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.

Design work began in 2021. Guy F. Atkinson Construction was identified as submitting the Apparent Best Value proposal in fall 2023. Construction is scheduled to begin in spring 2023 with completion in 2026.

This project is being combined into a single contract with two other fish passage projects on I-90, SR 202 and SR 203. Construction is scheduled to occur from 2023-2027. Because of the multiple locations, we cannot specify at this time when the work will occur on SR 161.

Milestone

2021

Design

Spring 2022

Project advertisement

October 2022

Guy F. Atkinson Construction identified as submitting the Apparent Best Value proposal

Spring 2025

Construction tentatively scheduled to begin

Winter 2027

Complete tentatively scheduled for completion

For efficiency and cost savings, this project has been combined with the SR 202 Skunk Creek and SR 203 Unnamed Tributaries to Snoqualmie River, and the I-90 Sunset Creek fish passage projects. The estimated project cost total for the SR 161 unnamed tributaries to Hylebos Creek location is $21.2 million. The estimated project cost total for the three locations combined is $135 million.

This photo shows the existing 24 inch culvert between 28th Avenue South and Military Road South. — The concrete pipe that carries this tributary to Hylebos Creek under SR 161 is only 24-inches in diameter. Located between 28th Avenue South and Military Road South, it will be replaced with a new fish passage that has an opening of at least 31 feet.

This photo shows the existing 24 inch culvert at the intersection of SR 161 and 28th Avenue South near Federal Way — A 24-inch concrete pipe blocks fish passage on this tributary to Hylebos Creek. A new passage with an opening of at least 14 feet will replace it. This culvert is located under SR 161 at the intersection with 28th Avenue South.

This photo shows the existing 18-inch concrete pipe on SR 161 between South 370th and South 372nd streets — Fish can't get up this stream and through the pipe on this tributary located beneath SR 161 between South 370th and South 372nd Streets. The interior of the new fish passage will be at least 35 feet wide.

SR 161 - Unnamed Tributaries to Hylebos Creek - Fish Passage

Project overview

What to expect

History and background

New fish passages

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