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The City of Portland, Oregon

Portland Water Bureau

From forest to faucet, we deliver the best drinking water in the world.

Customer Service: 503-823-7770


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Washington Park Reservoir Improvement Project

  • Project Updates Stay in the know about project progress! Sign up to receive emailed updates.

  • Upper Reservoir - Pump House View The new reservoir is engineered to withstand ongoing landslide encroachment and seismic events.

  • Serving Portland Since 1895 When completed, the new reservoir will provide service for at least another 100 years.

  • Lower Reservoir 4 - Downtown View A lowland wildlife habitat area, bio-swale, and reflecting pool will be constructed.

  • Supplying Water to Portland's West Side Serving more than 360,000 people, 20 schools, three hospital complexes, 60 parks, and major attractions.

  • Upper Reservoir 3 - Grand Staircase View The new reservoir, in the footprint of the historic Reservoir 3 (upper), features a reflecting pool at ground level.

  • Washington Park Reservoir Improvement Project A new 12.4-million gallon, seismically reinforced underground reservoir.

  • Lower Reservoir 4 - Powerhouse View Existing Reservoir 4 (lower) will be disconnected from the public drinking water system.

Take the Virtual Tour


Updated: February 12, 2020

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What's Happening Now 

We've come a long, long way in the construction of the new reservoir: from the beginning in 2016, when the old reservoir was still visible, to now. Crews are pouring concrete into the forms that make up the reservoir floor and walls and the reservoir outline is taking shape.

Crews have also begun installing the pipes inside the reservoir. The pipes arrive with their ends covered to keep them clean and are then lifted into place by crane. Later, crews connect them so that they can carry water.

Work on the Reservoir 4 site has started again. For the past year, the site has been primarily used as a staging area for materials, construction of rebar cages, and as a liquid nitrogen injection station for Reservoir 3 construction. In the area that was formerly Reservoir 4, crews are continuing work on a reinforced soil slope. They are layering rock, geotextile (plastic fabric), and engineered fill (a specialized mix of soils) to build up the hill. This will also provide drainage to prevent water from destabilizing the new slope and existing landslide. The combination of different materials allows crews to build a steeper hillside that will look similar to what was here before construction of the original reservoir in 1894.

To see photos of work performed over the past month, click HERE.

To see a map of the construction site, click HERE.

Watch a video showing how the elements of the new reservoir fit together within the footprint of the historic reservoir HERE.

Concrete Pour Dates

Dates are approximate and may change due to weather, material availability, or other factors. Work can begin as early as 3:30 a.m. on these dates.

Wall Sections: February 13 and 26

Columns: Friday each week in February, starting at 5:30 a.m.

Noise Permit extension (more information HERE)

Due to the size and volume of concrete needed, deliveries will begin in the early morning, in some cases as early as 2:30 am and will continue through the day, with new concrete trucks arriving approximately every 3 - 5 minutes. Concrete deliveries should be completed before 6 pm but on site work will continue beyond that time to complete the finishing work.

Did You Know?

We’re working to insure our water is safe and abundant for generations to come. Learn about the benefits to filtration HERE.

Project Overview

Including the project description, map and schedule

Community Outreach History

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Traffic Impacts

Beginning April 2, 2018