Portland’s water mains that cross the Willamette River are more than 50 years old and will probably not survive a major earthquake. The Willamette River Crossing Project, which will build an earthquake-resilient water line under the Willamette River, is part of the Water Bureau’s investment in preparedness. The improvements we’re making will enhance our water system’s resilience and reduce future risks, ensuring safe and abundant water for generations to come.
The Water Bureau has worked for the past several decades to increase the number of water supply facilities that can withstand earthquakes. Reservoirs at Kelly Butte, Powell Butte, and Washington Park all meet seismic standards. The Willamette River Crossing is the next step in strengthening our system to make it more resistant to earthquakes. The new pipe is critical for bringing water to the west side of town.
- Learn more about the project by viewing our pre-construction online open house.
As part of the Water Bureau’s Capital Improvement Program, this project is funded by revenue bond proceeds paid back with the utility ratepayers’ fund. This means current and future ratepayers contribute to the project.
Construction work hours are expected to be 7 a.m. to 5 p.m., Monday through Friday. However, some future work will take place overnight, between 5 p.m. and 7 a.m. We will coordinate any overnight hours with affected property owners, businesses, tenants, and transportation agencies.
Work schedules can change for many reasons, including weather, traffic, and problems with tools, machines, or supplies. Sometimes we need to stop between different types of work and start again later.
Work on this project will take place on both the east and west sides of the river. There will be construction in locations where we:
- install pipe in trenches,
- connect to the existing water system, and
- build shafts to send tunneling machines underground.
The project will use three different tunneling technologies to install pipe underground, in addition to installing pipe in trenches closer to the road surface.
- Trench work: Between Southeast 3rd and Southeast 10th Avenues, we will replace pipes close to the road surface. We will cut a trench into the road surface and install pipe in the trench. This is much like the standard work we do replacing water mains across the city, except the pipe is bigger and will require a wider trench.
- Direct steerable pipe: We will launch a direct pipe tunnel boring machine from a shaft near Water Avenue between PCC and OMSI. The machine will drill under the river from east to west from this location, and the dirt removed for installing the pipe will be collected and removed at this location. Our contractor plans to use a former electrical transformer site for much of this work.
- Jack and Bore: We will use a different tunneling technology called Jack and Bore to install a pipe under the railroad from west to east at this location.
- Montgomery shaft: The direct pipe tunnel boring machine will travel under the river from east to west, and arrive in a shaft, or deep hole, in South Waterfront Park on the west side of the river. This shaft will be 30 feet in diameter and 100 feet deep. Two sections of pipe will be welded together at an angle at the bottom of this shaft. Once the pipe is installed, the contractor will fill in the shaft and restore the park.
- Microtunnel: Crews will launch a microtunnel machine from the large shaft in South Waterfront Park to a smaller and shallower shaft in S Harbor Drive.
- Trench work: At Harbor Drive, we will install the pipe in a trench closer to the road surface and connect it to the water system near SW Naito Parkway.
Project timeline and phases
The project has two distinct but overlapping phases: exploration/design and construction. For example, during the design phase, we have used construction equipment to gather information to inform the design of the pipeline. The project is currently in the design phase.
Tunneling and underground work is challenging, especially in an urban environment. We have known this from the beginning, so we built an exploratory phase, including a geotechnical probe, into our design process. This has allowed us the flexibility to be responsive and adapt to new information as we go along. As we have collected additional information through our exploration process, we have been able to develop a more detailed and data-informed understanding of the problems we need to solve to bring a pipe under the river. Making these adjustments took time but were essential to meeting our goal of bringing water to west side of the river after an earthquake.
We expect to wrap up design and begin procuring permits in summer 2022. Construction is anticipated to begin in fall 2022.
Design phase 1: Pre-construction activities (2019 to 2020)
- Soil sampling: On the east and west sides of the river, crews dug in the street, sidewalk, and public right-of-way to find the exact locations of underground utilities and assess conditions at the site.
- Geotechnical investigation: We needed to know what’s underground before going “full bore.” Drilling a geotechnical probe helped us identify the types of soil and rock deep underground. A 12-inch-diameter probe drilled a pilot hole from the parking lot on the west side toward the east. The computerized drill bit sent information to the surface about what it encountered. This process helped us understand the next steps we needed to take.
- West-side connection: Several years ago, the Water Bureau installed a large water pipe called the “Westside Header” on the west side of the Willamette River. This 5,000-foot-long water pipe received water from the east side of the river, then carried that water to the pipe system along the west side of the river. During winter 2020/2021, crews added a connection to the Westside Header to get it ready for the new Willamette River Crossing.
Design phase 1A: More investigation (January 2021 to September 2021)
- Additional vertical soil sampling: Through the geotechnical probe, we discovered that the soil along our proposed route couldn’t be drilled with the technology we were hoping to use. We did more vertical borings in the area to better understand the soil conditions underground. This additional geotechnical exploration and analysis took about six months and led to changes in our construction plan.
Design phase 1B: Fine-tuning our design (October 2021 to February 2022)
- Revising the plan to address changes: Based on information gathered from the geotechnical probe in 2020 and additional testing in the spring of 2021, we learned that we needed to change the path the pipe takes across the river and use direct steerable pipe instead of horizontal directional drilling. Our contractor is fine-tuning the design so that we can begin construction in fall 2022.
- Community consultation: Our outreach team consulted with area residents and business owners to learn how to mitigate construction impacts. The contractor is used the information collected during this phase to develop noise, traffic control, safety and business access plans that will help us be better neighbors during construction.
Design phase 1C: Refining the design (March to June 2022)
The contractor has submitted a draft of their plans, considered to be 60% complete. We are reviewing the plans to make sure they meet the parameters we set out at the beginning of the project. In addition to reviewing very technical information about how to construct the project, we will also review the contractor’s plans for limiting construction impacts on the people who live and work nearby. During this phase, we will share draft construction mitigation strategies that were informed by input over the past few months and begin preparing materials to share about what happens next.