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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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Ash Creek Sewer Project

For several years, Environmental Services has worked to stop sewer overflows to South Ash Creek during wet weather. In 2006, the city installed a temporary bypass pipe on the surface near the creek to prevent overflows.

In late 2013, the city completed work on a project to repair portions of the Ash Creek sewer, remove the temporary pipe and install a permanent sewer line to improve sewer system reliability and stop wet weather overflows to South Ash Creek (see map).

map of Ash Creek sewer project

Construction Schedule

Construction is complete. Re-vegetation (see map) will begin in early 2014.

Post-Construction Re-vegetation

The Portland Watershed Management Plan identifies re-vegetation as a key strategy for protecting and improving watershed health. Environmental Services will remove invasive plant species and restore native trees, shrubs and ground cover in the city-owned area that will be disturbed by the sewer construction. Re-vegetation will include follow-up maintenance and ongoing invasive plant control using manual, mechanical and chemical methods.


The old Tualatin Hills Sanitary Sewer District built the Ash Creek sewer in the 1950s. The eight-inch diameter concrete pipe collects sewage from areas north and south of the creek, and from an area south of Interstate 5. It flows east to west and joins the Clean Water Services collection and treatment system west of the city line.

Although it is a sanitary-only sewer, a considerable amount of stormwater enters the pipe through joints and cracks. Because of that, the sewer is too small to handle wet weather flows.

For More Information

Contact Becky Tillson of Environmental Services at 503-823-2827.