A Key Investment in Earthquake Preparedness for the Portland Region, the Washington Park Improvement Project Reaches Key Milestone

News Article
A man in an orange vest and yellow helmet working in the Washington Park reservoir

Yesterday marked an important milestone for a critical regional project that, when completed, will make Portland’s west side drinking water supply more resilient in the event of an earthquake. Even though we will continue pouring concrete for the reservoir walls, columns, and roof, this is a milestone worth noting!

Known as the Washington Park Improvement Project, the combined work of many is creating a seismically resilient reservoir—and crews poured the final section of its floor yesterday. Called “bottoming out” in the construction world, crews poured more than 1,000 cubic yards—or about a third of the volume an Olympic swimming pool—of concrete to cover the final section of the future reservoir’s floor.

A concrete pour into the Washington Park Reservoir at dawn while still dark out

“We’re proud to have committed crews always working on behalf of Portlanders, and today they started at three in the morning to beat bad weather and accomplish the goals for the day,” said Thomas Gilman, a construction manager for the project. “The previous reservoir was deteriorating and aging and wouldn’t last through an earthquake. Through this project, we’re proud to construct something that can provide peace-of-mind for Portlanders west of the Willamette River. As more and more people talk about the importance of protecting ourselves against the catastrophic impacts of the Big One, we’re working to do just that.”

Project at a Glance:
12.4 million gallons. 360,000 people.

Construction equipment inside of Washington Park
  • The future reservoir will store 12.4 million gallons of water for drinking and fire suppression and will be reinforced to resist landslides and earthquakes.
  • More than 360,000 people on the west side of the Willamette River will get water from the reservoir, including all downtown Portland businesses and residents, 20 schools, five hospital complexes, more than 60 parks, and the Oregon Zoo.
  • Project investment: $205 million, which includes planning, design, and construction cost    

Neighbors on Speed Dial: An Ongoing Community Conversation 

Throughout the design phases, the project team conducted stakeholder interviews, convened a Community Sounding Board, regularly briefed area neighbors and business groups, met with historic advocacy groups, and communicated with the Portland Historic Landmarks Commission. Ongoing community outreach includes sending mailers to neighbors, hosting an online virtual tour, attending neighborhood meetings, conducting outreach within the park, and convening partner meetings with Explore Washington Park. After gaining a clear understanding of the need for this project, there has been positive support for the public process and the design of the visible features of the project.

“I can see the crane from my home. I can walk down to the project and see the progress being made each day,” said Kathy Goeddel, a neighbor in the area. “It’s a really interesting and once-in-a-lifetime project, and the Water Bureau has worked really hard to gain feedback and apply that to the final plans. The communication has been superb.”

Click here for a video.

The More You Know

How many pours make a reservoir floor? And other quick facts.

The final floor pour used:

  • 1,000 cubic yards of concrete (100+ concrete trucks)
  • 80+ workers
  • 10+ hours

This project overall will use:

  • 3,000 truckloads of concrete
  • 35,000 truckloads of excavated and imported fill material moved on site
  • 7.4 million pounds of rebar

Creative Solutions for an Ancient Landslide

The Washington Park project site is on an ancient landslide. The Water Bureau has used various measures to reduce the effects of the landslide since the early 1900s. Building this new reservoir has required creative solutions to address the reality that this area is on a landslide site, including adding:

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

For more information on the Washington Park Improvement project, click here. To subscribe to the Washington Park newsletter, click here.