Fanno Creek Watershed

Photo shows a creek bed in a park setting with trees, plants, and a split-rail fence.
The Fanno Creek watershed spans more than 20,000 acres in the west and southwest of Portland. Encounter its diverse fish and wildlife on the Fanno Creek Trail and Greenway or several Portland parks.
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About the Fanno Creek Watershed

Fanno Creek starts at its headwaters in the West Hills of southwest Portland. The creek flows southwest for 15 miles through residential, commercial, and industrial lands. Then it enters the Tualatin River about nine miles above the Tualatin’s confluence with the Willamette River.

The watershed drains approximately 20,259 acres of land. The upper reaches of the watershed once were heavily wooded, and the lower portions were a mixture of woods and wet meadows. Today, it covers parts of west Portland, Beaverton, Tigard, Washington County, and Clackamas County. Within Portland, the primary land uses in the watershed are housing (mostly single-family homes), transportation (streets and roads), and parks and open space.  

The majority of the watershed is within the separated stormwater system. This means stormwater runoff from roads and other impervious surfaces flows into natural streams. As a result, the watershed has water quality concerns, including: 

  • Elevated stream temperatures. 
  • High levels of bacteria (E. coli). 
  • High levels of other urban pollutants. 

Although pollution is an issue, Fanno Creek does support fish, including coastal cutthroat trout. The creek’s tributary streams include Vermont, Woods, North, and South Ash creeks. These tributaries provide cool water and habitat for native fish and wildlife.  

How the Watershed Is Doing Today 

The most recent report card for the Fanno Creek watershed uses data collected from the 2023 Watershed Health Index. There is certainly room for improvement in the watershed. The most recent grades for Fanno Creek are: 

  • Hydrology – C
  • Water Quality – C
  • Habitat – B
  • Fish and Wildlife – D-

Review the Fanno Creek Watershed report card for more information.

Work We've Done to Improve Conditions

Past projects in the watershed have worked to decrease impervious surfaces and improve stormwater management, including:

  • Replacing the SW 45th Avenue culvert to improve stormwater flow, aquatic habitat, and fish passage. 
  • Enhancing a tributary stream in Dickinson Park, which removed a pipe, restored 68 feet of stream channel and created wetland and floodplain habitat next to the stream. Small, intact headwater streams like the one in Dickinson Park help to control flooding, recharge groundwater, trap sediments and pollution, recycle nutrients, and provide habitat.
  • At Albert Kelly Park, we daylighted Restoration Creek, taking it out of a pipe and returning it to the surface where it can flow naturally and provide habitat for birds and wildlife.

Find more information about past restoration projects in the Fanno Creek watershed on our restoration and monitoring map.

Work We're Doing to Improve Conditions

Our work in the watershed aims to improve the health by:

  • Decreasing impervious surfaces to reduce the amount and speed of runoff.
  • Treating stormwater runoff to prevent pollution and lower temperatures.
  • Replacing and repairing aging sewer pipes to prevent sewage releases to the environment to protect water quality.

Find information on all of our current projects that are working to protect and improve watershed health including stormwater improvements along SW Capitol Highway. Learn more about this project.

Important Fish and Wildlife 

Fish communities in Fanno Creek tend to have few species and low abundance due to culverts and urbanization. The native reticulate sculpin is by far the most common species, and cutthroat trout are found in some tributaries. Although Fanno has low numbers of fish, over 99 percent of the captured fish are native. 

Common and adaptable birds like robins, song sparrows, and crows are widespread in Fanno Creek watershed. Native species such as black-capped chickadees, spotted towhees, Bewick’s wrens, and the diminutive lesser goldfinch are also common in riparian zones. The common jay is Steller’s jay, with its bright blue plumaged, black crest, and loud presence. Colorful, red-breasted sapsuckers can sometimes be seen and heard drilling on deciduous tree trunks, while the band-tailed pigeon is occasionally seen in the canopy of larger patches of forest. 

Typical mammal sightings include raccoons, opossums, beavers, blacktail deer, coyote, and squirrels. 

How to Experience the Fanno Creek Watershed 

Streamside parks such as Albert Kelly, Gabriel, and Woods Memorial offer opportunities to explore Fanno Creek and its tributaries. The Fanno Creek Trail and Greenway is also a great way to experience bird and wildlife watching along the section of Fanno Creek in Beaverton. 

How to Get Involved 

  • Visit the Tualatin River Watershed Council for good information about getting involved in stewardship activities.
  • The Westside Watershed Resource Center inspires awareness and action on behalf of watershed health throughout Portland's westside. The center provides watershed resources including outreach and education, technical support and advice, a tool loan program, and project and partnership support. Learn more on the center's webpage.