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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

Tryon Creek Outfall Repair

Project Informationphoto of Tryon Creek outfall in need of repair

Environmental Services is designing a project to replace an outfall pipe that carries stormwater runoff from 24 acres in southwest Portland and from portions of Interstate 5. The 36-inch concrete pipe collects runoff near SW 35th Drive close to Barbur Boulevard and the freeway and discharges stormwater to Falling Creek, a Tryon Creek tributary.

Over the years, erosion has undercut the pipe where it drains to the creek. This project will replace the outfall pipe, stabilize slopes around and below the pipe, and replant the area with native vegetation.

Project Schedule

This project is scheduled for construction starting in late September and will last for several weeks.

Traffic Control

Much of the work on this project will take place down near Tryon Creek, off of the road. However, it will take a week or more for work crews to transport materials down to the creek, do some minor repair work up on the street and construct the new outfall down near the creek. During those days, flaggers will be present to help drivers negotiate lane closures. Drivers can expect minimal delays, note traffic control signs, and respect speed limits during construction.

Re-vegetation Work

Construction crews will not be removing any trees in the course of their work. They will be removing some smaller vegetation to allow for their materials and crews to access the creek. When the work near the creek is finished, construction crews will stabilize the slope. Re-vegetation staff are currently working on invasive species removal, and will be planting native species on about 1.5 acres within and outside of the work area this winter and next winter.

For More Information

With questions or for more information, please contact Becky Tillson at 503-823-2827 or To be added to an email update list, email Becky with “Tryon Outfall Project” in the subject line.