Duniway Park Sewer Improvement Project: Update
The Portland Bureau of Environmental Services is planning on replacing an old sewer pipe from the Marquam Trail shelter to the Lilac Garden in Duniway Park. The project will impact much of upper Duniway Park and its lilac garden, and will include changes to the bicycle and pedestrian paths adjacent to the park along Terwilliger Blvd. Work is scheduled to begin in 2027.
Duniway Park is next to the north end of Terwilliger Parkway, at the edge of Downtown Portland. It is located on an old land-fill that filled in Marquam Ravine, and at the bottom of all that is an aging sewer pipeline. BES originally planned to replace the sewer line from the hairpin turn on Sam Jackson Park Rd. (adjacent to the Marquam Trail shelter and trailhead) down through upper Duniway Park, but recent reductions to the scope of the project will leave the existing sewer line in place though most of Duniway Park.
However, there will still be impacts to the park for a boring shaft and a haul road, mostly in the west end of the park. The lilac garden will be heavily impacted, and plans are being made to transplant some of the impacted lilacs and to re-design and re-build the garden when the project is done.
Changes to the bike lanes and pedestrian path are also planned. The whole south-bound bike lane from Sheridan St. to the beginning of Sam Jackson Park Rd. will be widened and get a concrete separator. A new raised and widened north-bound bike lane will be placed in the park adjacent to a new widened pedestrian pathway. The combination of the 2 paths will remove grass and create a 10 to 14 ft. wide concrete strip in the park with a bright yellow separator. Some trees may have to be removed to accommodate the new pathways. The historic lamp posts will be preserved.
Construction is expected to begin in 2027 and finish in 2030. BES plans to update its project
website with this latest information soon:
https://www.portland.gov/bes/improvements/construction/sheridan-trunk-sewer-project-
duniway-park