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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

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Fanno Creek Report Card

Photo of Fanno Creek

This is a summary of conditions in the Fanno Creek Watershed based on data from the 2015 Watershed Health Index. The scores are a snapshot of conditions across the entire watershed. Conditions can vary in smaller parts of the watershed.

Link to introduction page on the watershed report cards


Learn more about the Fanno Creek Watershed Program and Projects

Fanno Creek Hydrology Score: D

Hard surfaces like streets, rooftops and parking lots generate stormwater runoff during rainstorms. Runoff has a negative impact on the many small streams in this watershed. It can make stream banks unstable, cause erosion and deposit sediment in streambeds. Projects to improve stormwater management along Beaverton Hillsdale Highway and other streets will help improve hydrology, water quality, habitat and fish and wildlife scores.

Stream connectivity is poor because culverts and piped streams interfere with natural drainage. About 4.7 miles of Fanno Creek and its tributaries in Portland flow through pipes. The city works to bring portions of streams back to the surface when possible.


Fanno Creek
Hydrology Average Score

Hydrology score: 4.6


What is this?
Effective impervious area
Effective impervious area: 4.2
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Stream connectivity
Stream connectivity: 5.1

Fanno Creek Water Quality Score: C+

E. coli bacteria levels exceed water quality standards. Sources of E. coli include sewer leaks and animal waste.

Stormwater runoff is a significant cause of water quality problems in this watershed. Silt and sediment from roads, development and channel erosion contribute to high levels of total suspended solids (TSS). Copper from vehicle brake pads is a common pollutant in stormwater. Stream temperatures increase in summer and exceed water quality standards necessary for salmon rearing. Adding more green street planters and other ways for water to soak into the ground is one solution to reduce stream temperatures.

Projects to remove invasive plants, restore native vegetation and manage stormwater, like improvements planned along SW Hamilton Street, will help improve water quality scores.


Fanno Creek
Water Quality Average Score

Water quality score: 5.5


What is this? Ammonia-nitrogen Ammonia-nitrogen: 9.7
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Dissolved copper
Dissolved copper: 4.8
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Dissolved oxygen
Dissolved oxygen: 8.3
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E. coli
E. coli: 3.3
What is this? Temperature Temperature: 3.5
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Total mercury
Total mercury: 2.6
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Total phosphorus
Total phosphorus: 5.7
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Total suspended solids
Total suspended solids: 5.8

Fanno Creek Habitat Score: B-

Culverts in Fanno Creek limit stream accessibility for migratory fish. Some culverts, such as a section of the long culvert underneath Beaverton-Hillsdale Highway, are outside the Portland city limits. Portland continues to work on projects, like a planned culvert replacement at SW 45th Avenue, that improve fish passage and stream conditions.

The land along the most of the creek’s banks (riparian area) is narrow and vegetation cover is low. The stream lacks large wood and boulders, and a large amount of sand and silt covers the creek bed. The South Ash Creek Stream Enhancement project will improve in-stream habitat and repair and protect sewer infrastructure. Tree canopy overall is good and we will continue working to protect it with revegetation projects and invasive species management.


Fanno Creek
Habitat Average Score

Fanno Creek Habitat score: 5.7


What is this? Bank condition (hardening) Bank condition: 8.8
What is this? Floodplain condition Floodplain condition: 7.0 7.0
What is this? Large wood Large wood: 2.4
What is this? Riparian integrity Riparian integrity: 4.8
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Stream accessibility  Stream accessibility: 0.0 0.0
What is this? Substrate composition Substrate composition: 7.3  7.3
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Tree canopy
Tree canopy: 9.3

Fanno Creek Fish and Wildlife Score: D-

Cutthroat trout, at least 100 species of birds, and many other fish and wildlife species live in the Fanno Creek watershed. But the score for fish is low because there are only a few fish species and they are not abundant. Culverts and other barriers block access to fish habitat. Aquatic insects are limited by sediment in the stream.

Individual actions like improving backyard habitat, adding rain gardens and planting trees will help support fish and wildlife across the watershed and complement city infrastructure projects and natural area protection.


Fanno Creek 
Fish and Wildlife Average Score

Johnson Creek Fish and wildlife score: D-


What is this? Birds Birds: 3.3
What is this?
Fish: 0.5
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Macroinvertebrates: 3.9

For more information about what we measure and where these scores come from, visit the About Watershed Report Cards page.

See some of what Environmental Services is doing for healthy rivers and streams on the Explore Portland’s Watersheds map.