Nearly a decade later, the Portland Water Bureau is ready to unveil its completed Washington Park Reservoir Improvement Project this June.

For an unveiling of the yearslong restoration project, community members can save the date from 10 a.m. to 4 p.m. on Saturday, June 14, 4033 S.W. Canyon Road, Portland.

The newly renovated reservoir provides drinking water to 360,000 people in west Portland.

Elected officials will share project benefits and guests can stay for tours of the educational elements and historical features.

“This project helps cement Washington Park as one of the city’s crown jewel destinations. The park’s 3.5 million annual visitors from around the world will be able to experience the new public space,” Deputy City Administrator for Public Works Priya Dhanapal said in a news release. “The reservoir is a prime example of thoughtful planning, deliberate placemaking, and critical investments in the future of Portland.”

There will be a ribbon cutting, vendor booths, giveaways and more. A full schedule will later be announced.

New features include: two reflecting pools, a cascading water feature in the upper pool, restored walking paths, a wildlife habitat area and more.

Project background

The Portland Water Bureau and Oregon general contractor Hoffman Construction Company began the capital project in compliance with federal and state mandates to ensure a “healthy, resilient and secure water system,” according to the city’s website.

Two open reservoirs previously occupied the site, 2403 S.W. Jefferson St., along with two gate houses, a weir building, three pump houses, a generator house and associated underground piping.

These served as a gravity-fed drinking water system crafted more than 120 years ago in the 1890s, according to the city. It was an active system more than a hundred years before the recent construction project started.

Project timeline

Summer 2016: Construction for the project started in June 2016.

Winter 2020: The underground reservoir construction was completed. Crews started the process of connecting the reservoir to the rest of the water system.

Spring 2021: The reservoir was tested, sanitized and put into service.

Summer 2021: Soil was placed over the reservoir and around the site for future construction of reflecting pools, walkways and landscaping. Major construction paused from 2021 to 2023 to allow rocks atop the underground reservoir to settle. Small projects continued.

Summer 2023: The soil settled enough to start working on the reflecting pools and additional features.

June 2025: Construction of the reflecting pools, bioswale, walking paths and lowland wildlife area is completed. During the final construction phase, historical structures, including the gate houses, light fixtures and light poles are being restored.

What happens if an earthquake comes?

The new reservoir boasts the historic look and feel of the original reservoir, but is engineered with modern technology, according to the Portland Water Bureau, built to withstand seismic activity.

Washington Park is on an ancient landslide which extends from the Rose Garden down the hill to where the reservoir sits.

Here are some components used to help in the event of an earthquake:

• Heavy, 4-foot-thick concreate floors and walls, and 6 million pounds of rebar for seismic reinforcement.
• 176 piling embedded in stable bedrock to support the bottom of the reservoir.
• “State-of-the-art” compressible material that absorbs shock from earthquakes and landslide movement.

For more information, visit portland.gov.