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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

More Contact Info

SW Stephenson Roadside Swales

Project Background

Environmental Services is designing improvements to about 2,760 feet of ditches along SW Stephenson Street between SW 35th and SW Boones Ferry Road. Work will begin in spring 2015.

Ditches on SW Stephenson carry stormwater runoff from the street directly to Fanno Creek and its tributaries. The fast-moving water causes erosion and carries pollutants washed off streets.

This project will plant swales with a combination of grasses and low-growing plants. The vegetation will help protect the channel from erosion and may help reduce stormwater pollutants. As part of the project, the Portland Bureau of Transportation will add four-foot wide, paved shoulders.

SW Stephenson project map

Environmental Services is working with citizens and neighborhood groups on project plans including impacts to trees in the project areas.

The Fanno-Tryon Watershed Management Plan identified these improvements as a way to improve drainage and pedestrian safety and protect water quality. Over one-third of the roads in the watershed are paved and have no curbs. Ditches border most of them.

Tree trimming and removal

In preparation for the project, work crews will trim and remove some trees, shrubs and hedges in the public right-of-way. That work will start in late February to avoid bird nesting season. The city’s contractor will remove tree stumps and trim any additional trees necessary during construction.

Work crews will install plants in and around the new swales during the fall 2015 planting season.

Right-of-Way Markings

You may see crews in the area this winter marking the right-of-way lines, outlining the work areas and flagging trees that will be removed. Please leave the stakes, ribbons and other markings in place for use during construction.

Construction schedule and traffic controls

Construction is expected to begin this spring. There will be some lane closures, with flaggers directing traffic when necessary. The contractor will maintain access to homes and neighborhood streets. We will continue to be in touch as we get closer to construction.

For More Information

Contact Lisa Moscinski at 503-823-3663 or Lisa.Moscinski@portlandoregon.gov.