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.
Project timeline and phases
Timing has changed for implementation of the final phases of design and construction. The project is on pause for about a year, after which time we will complete the design and re-engage with the public about construction of the crossing. On this tentative schedule, construction would begin in fiscal year 2027-28.
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.