Event Title

The Japanese Gulch Fish Passage Story

Speaker

Ruth Park

Presentation Abstract

The City of Mukilteo, Washington, needed to address fish passage and habitat restoration on Japanese Gulch Creek. This project was the first in-lieu-fee mitigation project authorized and processed by the Washington State Department of Fish and Wildlife. Funding was provided via an agreement with Snohomish County Airport, which had needs for habitat mitigation credits for development around the airport. The original concept of the project was to address fish passage in a concrete junction box between two culverts. Existing streamflow was spread over a concrete apron in a very thin layer that was a severe impediment to upstream adult fish passage. However, there were additional passage barriers upstream that would limit access to usable habitat should this initial barrier to passage be removed. The approach was based on an overall assessment of the conditions in the lower part of the watershed. This allowed the team to place the proposed project elements into context and to assess fish passage challenges in several locations in the lower creek as well as habitat conditions in the stream. The Confluence team developed a design using field engineered baffles and boulders to address the passage barrier in the junction box for a fraction of the initial cost projected by the City. This freed up project budget to address another upstream passage barrier in the form of a perched culvert. The team developed a conceptual design to move the stream from its existing heavily engineered channel (three concrete weirs and a concrete flume) back to its historical channel, thus bypassing three additional passage barriers and opening up more than twice the length of channel and habitat for future fish use. The original engineering estimate for the single junction box replacement was $650,000 and the Confluence team delivered a solution for four passage barriers and restoration of historical channel for $375,000. A future phase will daylight the creek and create a pocket estuary to enhance the connection between the creek and Puget Sound, thus providing juvenile fish habitat for salmonids and other species using the shoreline.

Session Title

Session S-08D: Salmon Recovery: Implementation and Progress I

Conference Track

Species and Food Webs

Conference Name

Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)

Document Type

Event

Start Date

1-5-2014 5:00 PM

End Date

1-5-2014 6:30 PM

Location

Room 6C

Genre/Form

conference proceedings; presentations (communicative events)

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Subjects – Topical (LCSH)

Fishways--Washington (State)--Japanese Gulch Creek; Stream restoration--Washington (State)--Japanese Gulch Creek

Geographic Coverage

Salish Sea (B.C. and Wash.); Japanese Gulch Creek (Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

Text

Language

English

Format

application/pdf

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COinS
 
May 1st, 5:00 PM May 1st, 6:30 PM

The Japanese Gulch Fish Passage Story

Room 6C

The City of Mukilteo, Washington, needed to address fish passage and habitat restoration on Japanese Gulch Creek. This project was the first in-lieu-fee mitigation project authorized and processed by the Washington State Department of Fish and Wildlife. Funding was provided via an agreement with Snohomish County Airport, which had needs for habitat mitigation credits for development around the airport. The original concept of the project was to address fish passage in a concrete junction box between two culverts. Existing streamflow was spread over a concrete apron in a very thin layer that was a severe impediment to upstream adult fish passage. However, there were additional passage barriers upstream that would limit access to usable habitat should this initial barrier to passage be removed. The approach was based on an overall assessment of the conditions in the lower part of the watershed. This allowed the team to place the proposed project elements into context and to assess fish passage challenges in several locations in the lower creek as well as habitat conditions in the stream. The Confluence team developed a design using field engineered baffles and boulders to address the passage barrier in the junction box for a fraction of the initial cost projected by the City. This freed up project budget to address another upstream passage barrier in the form of a perched culvert. The team developed a conceptual design to move the stream from its existing heavily engineered channel (three concrete weirs and a concrete flume) back to its historical channel, thus bypassing three additional passage barriers and opening up more than twice the length of channel and habitat for future fish use. The original engineering estimate for the single junction box replacement was $650,000 and the Confluence team delivered a solution for four passage barriers and restoration of historical channel for $375,000. A future phase will daylight the creek and create a pocket estuary to enhance the connection between the creek and Puget Sound, thus providing juvenile fish habitat for salmonids and other species using the shoreline.