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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 will construct improvements to about 2,760 feet of ditches along SW Stephenson Street between SW 35th and SW Boones Ferry Road.

Ditches on SW Stephenson carry stormwater runoff from the street directly to Tryon 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

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.

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

Construction schedule and traffic controls

  • Construction on the SW Stephenson site is tentatively scheduled to begin the week of September 14, 2015. Our contractor’s schedule shows the work starting at SW 35th Avenue and SW Stephenson Street and moving east from that point. Once our contractor submits an overall schedule you will receive additional schedule details. There will be some lane closures, with flaggers directing traffic when necessary. The contractor will maintain access to homes and neighborhood streets.

What to Expect During Construction

  • Environmental Services and our contractor will be coordinating our work with Portland Public Schools and Stephenson Elementary.

  • Typical work hours will be 7:00 a.m. to 6:00 p.m. Monday through Friday. The contractor can also choose to work on Saturdays if necessary.

  • Traffic restriction will be in place, but local residents will have access to their property. You may experience delays.

  • There will be work in front of and adjacent to driveways. Our contractor will work with you to maintain access.

  • On-street parking in or near the work area will be prohibited during work hours.

  • Equipment and materials will be stored on nearby streets overnight.

  • A city construction inspector will be on-site during work hours, and may be able to assist you with construction concerns. Inspectors typically wear a green City of Portland safety vest and hard hat.

  • Let us know if you have concerns such as business operations, disability issues or medical deliveries.

For More Information

Contact Joe Annett at 503-823-2934 or To sign up for periodic email updates during construction, email Joe with "Stephenson Swales" in the subject line.

The City of Portland complies with all non-discrimination laws including Title VI (Civil Rights) and Title II (ADA). To request a translation, accommodation or additional information, please call 503-823-7740, or use City TTY 503-823-6868, or Oregon Relay Service: 711