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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

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

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General Description

Miller Creek flows northeastward from the West Hills into the Multnomah Channel south of the Sauvie Island Bridge near Fred’s Marina. Part of the subwatershed is within Forest Park at the northwest tip of Portland’s urban services boundary and the remainder is in private ownership, some of which is outside the city. The confluence area consists of some fill materials, and the stream channel was rerouted within the last few years to allow for expansion of the marina. The stream flows through a concrete box culvert beneath Highway 30 and another culvert beneath the railroad tracks immediately adjacent to the highway.

West of Highway 30, the stream gradient of the main stem of Miller Creek ranges from 15 to 30 percent. The tributaries have gradients ranging from 30 to 45 percent.

Staff from Portland’s Bureau of Planning visited the Miller Creek basin during low-flow conditions in August 1990 and noted that the creek banks were generally stable, though undercutting and erosion were evident at least one site on the south bank. The banks were well vegetated with shade averaging 70 percent. The substrate composed of 35 percent gravel (up to 6 inch diameter rock), 60 percent cobble (6 inch to 3 ft diameter), and 5 percent boulders (greater than 3 inches in diameter). Water flow was low (12-16 gallons per minute) in mid-August following 40 days without measurable rainfall. Stream types noted included riffles and pools ( City of Portland Bureau of Planning, 2001).

Click here for a summary of rainfall data.

Open Channel 28069.6
Stormwater Pipe or Culvert 444.5
Maps & Files

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