Skip to Main Content View Text-Only

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

More Contact Info

About the Watershed

map of the Fanno Creek watershedThe Fanno Creek Watershed, located within the Tualatin River Basin, covers over 20,000 acres, with about 4,500 acres within Portland city limits. Fanno Creek flows west for about 15 miles from its headwaters in Hillsdale to its confluence with the Tualatin River near Durham.

Within Portland, the primary land use is single-family residential housing, with very limited parks and open space. The watershed contains steep slopes and mainly sandy clay loam soil. Streets, parking lots, and buildings contribute to the large impervious surface area.

The narrow riparian corridors commonly consist of native plant species like western red cedar, douglas fir, vine maple, and swordfern, as well as invasive species like English ivy. Biological communities are limited, however, steelhead and cutthroat trout are present in upper Fanno Creek.

Fanno Creek Tributaries

The watershed is divided into eight subwatersheds

Water Quality

Water quality in the Fanno Creek Watershed

Hydrology and Infrastructure

Where the rain goes


Fanno Creek Watershed habitat

Biological Communities

Wildlife in the Fanno Creek Watershed