Fauntleroy Creek Culverts Replacement Project

Photo of spawning salmon in Fauntleroy Creek
Photo of spawning salmon in Fauntleroy Creek, courtesy of Whitney Fraser

Project Need

Promoting a healthy urban watershed in your neighborhood
Fauntleroy Creek is located in southwest Seattle and drains a 149-acre area (.23 square mile) - called the Fauntleroy Watershed - into the Puget Sound.

There are three culverts along Fauntleroy Creek. Two of the culverts are approximately 100 years old and in extremely poor structural condition. These culverts also do not meet state laws as they act as barriers for fish to pass into the upper channel of Fauntleroy Creek, which is a viable fish habitat. To reduce the risk of culvert failure, mitigate storm-related flooding, and restore fish passage, the culverts need to be fully replaced.

The third culvert, which is located under Fauntleroy Way and includes a fish ladder, was replaced in the late 1990's and is not part of this project.


The culverts are located at 45th Ave SW (near SW Wildwood Pl) and California Ave SW (near SW Brace Point Dr).

What's Happening Now?

The project is advancing through the Options Analysis Phase, and SPU has identified a recommended option for replacing the 45th Ave SW culvert. Options analysis will continue as the California Ave SW culvert design is evaluated further.
  • Options analysis kicked off in 2018 and will continue through early 2020
  • SPU is assessing the feasibility of design for recommended options and further refining cost estimates
  • SPU is working in close partnership with Fauntleroy Church to discuss options for the California Ave SW culvert (joint public/private ownership)
  • SPU is actively exploring grant opportunities to supplement project funding
SPU continues to investigate creek, drainage, sediment, utility, or other infrastructure issues within the Fauntleroy Creek drainage basin that may be addressed through this or other projects.

Community Benefits

The primary intent of the project is to prevent the risk of catastrophic failure of the roadway culverts and the associated potential impacts to health, public safety, and the environment. The project's goals and opportunities also include:

  • Reducing the risk of culvert failure
  • Improve creek resiliency to higher flows from anticipated climate change Restoring fish passage, which supports tribal treaty rights and SPU's commitment to racial and social justice
  • Considering community safety in culvert design
  • Enhancing the community's connection to the Fauntleroy watershed
  • Providing safer working conditions for maintenance crews

What Options are We Looking At?

For more information about the options SPU is considering, please review the Fall 2019 Community Outreach Display Boards.

Community Involvement

Over the past year, we have met with many community members and hosted briefings in the neighborhood to introduce the project and gather feedback. We are continuing to seek community input to inform the early design phase of the project and have been collaborating with Fauntleroy Church leadership to address design options, preferences, and potential partnership opportunities for the California Ave SW culvert.

If you are interested in receiving updates, please subscribe to the project email list.



Begin Options Analysis to identify and evaluate different culvert replacement options


  • Options Analysis phase initial outreach to residents and businesses
  • Continue Options Analysis to further assess the feasibility of design options and refine cost estimates
  • Continue collaboration with Fauntleroy Church to discuss options for the California Ave SW culvert (joint public/private ownership)
  • Explore grant opportunities to supplement project funding
  • Engage residents and businesses to update the community on project progress and opportunities
  • Develop criteria to evaluate the impacts and benefits of the options
  • Develop high level cost estimates
  • Economic analysis to determine the value for cost of each option
  • Recommend options to advance into design and/or for assessment of feasibility and cost refinement
  • Complete Geotechnical Investigations
  • Complete Land Surveying


  • Begin early design development for recommended options
  • Complete a third-party Value Engineering study to maximize functionality and minimize cost
  • Continue collaboration with Fauntleroy Church to discuss options for the California Ave SW culvert (joint public/private ownership)
  • Engage community members to solicit feedback on design and opportunities to reduce impacts


Existing culverts in poor structural condition
The 45th Avenue SW and California Avenue SW culverts, located along Fauntleroy Creek in West Seattle, are approximately 100 years old and in extremely deteriorated structural condition. The culverts have deformed pipes, with roots intruding into the pipe and portions of pipe missing. These conditions increase the risk of backups and flooding, and the need for emergency maintenance response. Repairing these culverts is not a viable strategy due to their age and condition. Instead, the culverts must be fully replaced to reduce risk of culvert failure and mitigate storm-related flooding.

Existing culverts are barriers to fish passage
The culverts at 45th Avenue SW and California Avenue SW also prevent fish passage in Fauntleroy Creek. While the middle and upper reaches of Fauntleroy Creek may not currently support a significant population of fish, stream conditions in these sections have been characterized as viable fish habitat by SPU fish biologists, independent consultants, and biologists from the Washington Department of Fish and Wildlife (WDFW). The Fauntleroy Creek watershed is in better condition than most of the City's urban streams with good water quality, a relatively high amount of forest canopy cover, the protection of City ownership for most of its area, and the incredible stewardship of property owners adjacent to the creek as well as community members who frequent the upper watershed trail system and park.
Based on stream surveys, nearly all of the mainstem of the creek, up into Fauntleroy Park was identified as "Type F" waters. This means fish-bearing or capable of supporting fish. New culverts on Type F waters need to be designed to meet state and federal requirements for fish passage. New culverts would be sized based WDFW Stream Crossing Guidelines to meet fish passage criteria, which will likely require a larger size for the culvert replacements.

Restoring fish passage is critical to support Tribal treaty rights
Many Tribal nations signed treaties in the 1800s which granted them perpetual rights to hunt and fish in their usual and accustomed areas. These treaties were based on a presumption that our government would be a caretaker and steward of these lands such that fish would remain plentiful.
Today fish are not plentiful in our urban creeks and hundreds of barriers prevent fish from getting access to available habitat. By restoring fish passage, SPU can support Tribal rights and start to make meaningful progress on this important race and social justice issue.