Construction continues on a Portland Water Bureau long term project to improve and updates the Washington Park reservoir at 2403 SW Jefferson Street. This project brings the city into compliance with federal and state mandates, seismically strengthens key water infrastructure on Portland’s west side. The improvements also help ensure a healthy, resilient, and secure water system.
A new 12.4-million gallon, seismically reinforced, below ground reservoir will be constructed in the same footprint of existing Reservoir 3 (the upper one) with a reflecting pool/water feature on top. The engineers preserved the historic drinking water function, and improved the reservoir to withstand ongoing landslide encroachment or other potentially catastrophic effects from a major earthquake.
Once completed, the upper reservoir will supply water to Portland’s west side and serve:
- 360,000 people
- All downtown businesses and residents
- Twenty schools
- Five hospital complexes
- Sixty parks
- Landmarks such as the Oregon Zoo
The existing Reservoir 4 (the lower one) is disconnected from the public drinking water system and will boast a lowland wildlife habitat area and bioswale. Additionally, a reflecting pool will be constructed in the basin.
Construction started September 12, 2016 and is anticipated to proceed through 2020. A pause is scheduled to occur from 2020 to 2022 to allow soils to settle for greater stability and resiliency. From 2022 to 2024, construction of interpretive features, including the two reflecting pools and surface features, will conclude the project.
July 2017 Accomplishments
- Reservoir 4 filling placement is intermittent and dependent on excavation shoring wall work. Begin installation of storm drain piping.
- Reservoir 3: Backfill and construction of the toe block continues.
- Work inside Gatehouse 4: Continue with piping, interior stairs and mid-level decking installation.
- Gatehouse 3: Abatement and removal of the wet well inside Gatehouse 3 will begin in August.
- Shoring wall construction along Sacajawea – Two shoring walls – one temporary and one permanent – are being built to protect the site from earth movement and allow for construction of the underground reservoir. The temporary wall has been completed and construction of the permanent wall has begun.
- Yard piping: Installation of waterline, storm and sanitary piping behind Pump Station 1 and Dam 3 will begin in August.
- Work inside Pump Station 3: Begin seismic upgrade work.
- Single large truck deliveries carrying materials for the construction of the permanent retaining wall will take place Monday mornings between 9 a.m. and 11 a.m. through the month of August.
- Yard Piping: Installation of waterline piping along Madison Trail has begun. This will cause a temporary closure of the trail.
- Erosion control at the site is ongoing.
Safety is Our Top Priority
The traffic control plan in place has been approved by the Portland Bureau of Transportation. The Water Bureau will be conducting evaluations and adjusting traffic flow as conditions require. The Water Bureau is working with Portland Parks & Recreation, Explore Washington Park, neighborhood associations, and the community to gather on-the-ground feedback and determine if changes are necessary. Please provide your traffic and signage feedback by phone, e-mail, or on the dedicated webpage.
Activity and Impacts
Until March 2018, major earthwork will occur along with the construction of shoring walls necessary for construction of the new underground reservoir. Work during this stage will cause temporary impacts to traffic, parking, and TriMet bus service.
Current to March 2018
Tour Buses, Free Park Shuttle
Traffic Flow Reversal
Multi-Use Shared Path
TriMet Bus Service