The Willamette River Crossing project will deliver water to the west side of the river, even after an earthquake.
The pipes that carry water from the east to west side of the Willamette River are more than 50 years old and will probably not survive a major earthquake. An earthquake could leave Portland’s city core without reliable water for six months or more.
The Willamette River Crossing will deliver water to the west side of the river, even after an earthquake. Investment in this project makes sure that we can fight fires and provide water to critical facilities like hospitals. The project is key to our region’s ability to recover economically after an earthquake.
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 and Powell Butte on the east side, and the future reservoir at Washington Park on the west side, were all designed to meet current seismic standards. The Willamette River Crossing is the next step in strengthening our system to make it more resistant to earthquakes. The new pipe will be critical for bringing water to the west side of town.
The project budget is $88 million. 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.
Work schedules can change for many reasons, including weather and traffic, and problems with tools, machines, or supplies. Sometimes we need to stop between different types of work and start again later.
Construction work hours are expected to be 7:00 am to 5:00 pm, Monday through Saturday. However, some future work will take place overnight, between 6:00 pm and 6:00 am. We will coordinate overnight hours with affected property owners, businesses, tenants, and transportation agencies.
Much of the work will take place in parking lots on the east and west sides of the river, with some of the work taking place on surface streets (on Southeast Stephens and Southeast Harrison between Southeast 7th and 10th Avenues).
Project timeline and phases
The project has two distinct but overlapping phases: exploration/design and construction. For example, during the design phase, we may use construction equipment to gather information to inform the design of the pipeline. During construction, we will confirm the project design at each step, and we may revise the design based on what we discover about conditions under the river.
The project is currently in the exploration/design phase. Along with utility locates, site exploration, and soil testing, this phase included conducting a geotechnical probe. The probe provided essential information on how the geology beneath the river will impact construction. Conducting the geotechnical probe helped us determine the best tools to use for the future pipeline, and the best path across the river.
Design phase 1: Pre-construction activities (complete)
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. After completing exploration, we restored those streets and sidewalks with similar materials.
Preparing “Block J” (1720 SW Naito Parkway): Crews fenced off the parking lot at Southwest Naito Parkway between Harrison and Market to prepare for the geotechnical probe. They dug a 30-foot-deep hole in the parking lot, and placed the drill in the hole. The drill has since been removed, as the geotechnical probe is complete.
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 need to take.
Design phase 1A: More investigation (current)
By performing the geotechnical probe, we discovered that the soil along our proposed route couldn’t be drilled through with the technology we were hoping to use. We expect to do more vertical borings in the area to better understand the soil conditions underground. Doing this additional geotechnical exploration and analysis will take about six months. This geotechnical work will tell us whether we need to adjust the route or tunneling methods we plan to use.
We’re also continuing to prepare the areas where we will connect the new pipe.
Westside 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 receives water from the east side of the river, then carries that water to the pipe system along the west side of the river. During winter 2020/21, crews will add a connection to the Westside Header to get it ready for the new Willamette River Crossing.
Public impacts: Traffic will be temporarily diverted as crews dig a trench in Southwest Naito Parkway between Market and Harrison Streets.
Eastside connection: Just as the Willamette River Crossing pipe will need a connection to the Westside Header (mentioned above), it also will need a connection to the eastside water pipes that bring water toward downtown from the Powell Butte reservoirs. In winter 2021/2022, crews will survey the area and mark utilities in preparation to dig a trench where they will place the new water pipe.
Public impacts: There will be lane closures during this stage as we dig trenches along Southeast 7th Avenue between Stephens and Harrison, and on Southeast Harrison from Southeast 7th to 10th Avenues.
Eastside shaft: We will build a large-diameter shaft (hole) in a parking lot near Southeast Water Avenue and Clay Street, halfway between the east- and westside connections. We will use the shaft to begin digging a microtunnel to the east and a boring to the west.
Public impacts: The area will have increased truck traffic as we remove soil from the shaft.