Redevelopment of the Opera Blocks, located in the southern corner of Portland's proposed new OMSI District near SE Tilikum Way, could add significant combined flows of sewage and stormwater into a public sewer mainline pipe that runs under the Union Pacific Railroad (UPRR) tracks near SE Division Street and SE Grand Avenue. The Opera Blocks Sewer Project will upsize the existing 12-inch-diameter sewer mainline pipe to 24 inches and replace it in a new alignment. The project will also construct a new sewer service lateral for the Oregon Rail Heritage Center's connection to the new mainline public sewer.
Project Area
The Opera Blocks Sewer Project is located at the Union Pacific Railroad tracks near SE Division Street and SE Grand Avenue, just east of the MLK viaduct.
What's Happening Now: Design Update
This project will upsize the existing 12-inch-diameter sewer mainline pipe to 24 inches and replace it in a new alignment.
The proposed scope of work includes the following construction activities:
- Jack and Bore 188 feet of 48-inch steel casing to install a 24-inch sewer mainline pipe.
- Construct one 72-inch maintenance hole at 2250 SE Water Avenue.
- Construct one shaft over the public sewer tunnel approximately 35 feet deep.
- Construct one 102-inch maintenance hole over the public sewer tunnel within the shaft.
- Re-route the existing sewer service lateral for the Oregon Rail Heritage Center to the new 72-inch maintenance hole.
- Fill, seal, and abandon several small-diameter public sewer mainline pipes that run parallel to the Union Pacific Railroad (UPRR) tracks.
- Coordinate with UPRR and the Oregon Rail Heritage Center for access and track and ground monitoring during construction.
Construction Methods
Engineers are planning to use the Jack and Bore construction method to upsize, replace, and relocate the public sewer mainline pipe. Jack and Bore is a trenchless method of sewer construction.
Crews dig a sending pit and a receiving pit to install a new sewer pipe. They place a jack and bore machine in the sending pit and cut a hole underground horizontally from the sending pit to the receiving pit, without disturbing the surface above. As the machine drills the hole with a thick steel casing, it also functions like a jack hammer to push the new sewer pipe in place.
Learn more details about the Jack and Bore construction method.
What to Expect
Read a brief guide on what you can expect during construction projects conducted by Environmental Services.
More details about the schedule and what to expect will be provided when crews are ready to construct the mainline sewer pipe.
We Want to Hear from You
Environmental Services will inform residents and businesses about project activities and respond to questions and concerns in a timely manner. The following resources will help you stay informed and report concerns:
- Project Webpage: Visit the project webpage for details and updates; use the shortcut portland.gov/bes/operablocks.
- Email Updates: To receive email or text message updates for this project, we encourage you to sign up now. Updates provided through our free GovDelivery subscription service are the best way to stay informed about what’s happening and what to expect. You can also sign up for bulletins on other projects and topics.
- Questions: Email city outreach staff or call 503-823-5753 and leave a message with your name, property address, email address, phone number, and project name (Opera Blocks).
- Sewer Emergency: In the event of a sewer backup or basement flooding, call the City Maintenance hotline immediately at 503-823-1700. It is staffed all hours and all days, 24/7.
Project Background
Redevelopment of the Opera Blocks will create a new neighborhood in Southeast Portland. The Oregon Museum of Science and Industry (OMSI) District will include approximately 3.4 million square feet of development, with a mix of institutional, commercial, retail, and residential space, including up to 1,200 units of housing, plus a sizable waterfront park. The master plan for the site spans approximately 10 city blocks from SE Clay Street to SE Caruthers Street, and from the Willamette River to Union Pacific Railroad (UPRR) tracks.
Visit OMSI’s District Development webpage.
This redevelopment could increase the likelihood of sewer backups, basement flooding, and street flooding in the area due to an undersized segment of 12‐inch-diameter public sewer mainline pipe that drains the combined sewer and stormwater system to the south. This pipe runs through 2250 SE Water Avenue (a lot owned by the City of Portland and the site of the Oregon Rail Heritage Museum) and underneath existing UPRR tracks all along the eastern edge of the MLK viaduct.
Upsizing, replacing, and relocating the existing public sewer mainline pipe will accommodate the redevelopment of the Opera Blocks and reduce the risks of sewer backups, basement flooding, and street flooding in the area.
Sign Up for Updates
Sign up for periodic email or text message updates for the Opera Blocks Sewer Project through our free GovDelivery subscription service. These updates are the best way to stay informed about what’s happening and what to expect. You can also sign up for bulletins on other projects and topics.
This project will help protect the health of the Willamette River Watershed.