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The City of Portland, Oregon

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

MAILING ADDRESS: 1120 SW 5th Ave, Room 1000, Portland, OR 97204

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NW Thurman Sewer Reconstruction

Updated January 30, 2020Button. Click to sign up for email updates

Environmental Services has completed design of a project to reconstruct the public sewer system in NW Thurman Street and the Willamette Heights neighborhood. Sewer and stormwater improvements will increase the capacity of the 100-year-old sewer system, relieve basement sewer backups, and reduce street flooding.


The contractor advertise, bid, and selection process will continue through May 2020. Construction is anticipated to begin in June 2020 and will take a year and a half to complete. The project is expected to require two dry-weather seasons to complete construction - June 1 to November 30, 2020, and June 1 to November 30, 2021.


The map below illustrates where this project will construct sewer improvements. The primary construction method for each pipe segment is noted.

Project Map

By the Numbers

The NW Thurman Sewer Reconstruction Project is designed to accomplish the following sewer and stormwater improvements:

  • Relieve basement sewer backups at 31 properties;
  • Reduce the risk of street flooding at 16 locations based on the 25-year Design Storm;
  • Replace or repair 4,800 feet of public sewer mainline pipe, ranging in size from 8 inches to 14 inches in diameter;
  • Construct or replace 95 sewer service laterals that connect private sewer lines to the public sewer in the street; this will involve 1,500 feet of lateral sewer pipe;
  • Construct or replace 32 maintenance access holes, of which 1 (one) is a sedimentation manhole;
  • Replace 14 storm drain inlets and construct 280 feet of inlet lead pipe.

Construction Methods

Contractors will use open trench excavation and cured-in-place-pipe lining (CIPP) to construct sewer improvements. Of the 4,800 feet of mainline public sewer pipe to be replaced or repaired in this project, 4,200 feet will be constructed with the Open Trench Excavation method, and 600 feet will be repaired with the Cured-in-Place-Pipe Lining method. For details and photos of construction methods, click here.

This project will also include the following construction elements:

  • Abandon sewer pipes and maintenance access holes under the Balch Gulch Bridge and divert sewer and stormwater flows away from the bridge to the existing system at the intersection with NW 30th Avenue. The project will upsize the sewer line north on NW 31st Avenue and east on NW Vaughn Street to NW 30th to accommodate the flows from this diversion. This improvement will avoid compromising the integrity of retaining walls, a water line, the bridge abutment, and bridge pier supports, and improve future access to the system for maintenance.

  • Remove buried trolley track rails and ties to install new sewer pipes. After a construction contractor is selected in the spring of 2020, the contractor will propose the removal methods, a sequencing plan for construction activities, and a general schedule.

  • Extend the public sewer in NW Aspen Avenue just north of NW Savier Street to resolve nonconforming sewer connections. A segment just south of NW Belgrave Avenue is still being designed. It may be constructed as part of this project.

Anticipated Traffic Controls

Contractors will develop traffic control plans before construction begins, but you can expect the following traffic controls and impacts:

  • Traffic Delays: Expect traffic delays in and near the work zones.
  • Local Access: Access will always be maintained, but construction may temporarily block a driveway when crews are working in front of a house.
  • On-Street Parking Restrictions: Parking will be removed in and near work zones to create a safe work environment and to stage equipment and materials. The project team is exploring ways to minimize the impact of reduced parking in the area.
  • Lane Restrictions: At least one lane with two-way traffic on NW Thurman west of 31st will always be maintained, with flaggers during work hours to control traffic and assist pedestrians.
  • Cross-Street Closures: Work at intersections on NW Thurman may require temporary cross-street closures, with local access the next block up from the closure on that cross street.
  • Street Closure: Work in the intersection of NW Thurman and 31st may require a temporary street closure of NW Thurman. If closure is necessary, a signed detour will be in place, and work hours will be restricted.
  • Pedestrian Access: Crosswalks, sidewalks, and other pedestrian access will be maintained to the full extent possible. If closures are necessary, signage will indicate the alternate way for pedestrians to proceed.
  • Equipment Storage: Equipment may be stored on streets overnight, except on the detour route.
  • Garbage Pickup: Access to garbage and recycling bins for haulers will always be maintained.
  • TriMet Impacts: The project team is working with TriMet on how necessary traffic controls and work zones will affect their service route and bus stops. TriMet will communicate any changes to their riders.

Sewer Extension in NW Aspen

This project will extend the public sewer in NW Aspen Avenue north of NW Savier Street to provide properties a new connection to the public sewer. Staff will reach out directly to property owners in the southern section of NW Aspen Avenue just north of NW Savier Street to obtain information that will help engineers determine sewer service connection locations for those properties.

The northern segment on NW Aspen Avenue just south of NW Belgrave Avenue was removed from the NW Thurman project to be designed separately. That design process continues.  Environmental Services continues to coordinate with the Bureau of Development Services and adjacent property owners as needed. Whether or not that extension can be constructed during the Thurman sewer reconstruction project is unknown at this time, but the project team is hopeful.

Coordination with Transportation

The Portland Bureau of Transportation (PBOT) is coordinating landslide recovery work on NW Thurman Street. Although PBOT has not completed their street restoration work, Environmental Services will still proceed with sewer construction. The alignment for the new sewer will be designed and constructed to avoid conflict with the PBOT restoration area. For questions about PBOT's landslide recovery work, please contact Geren Shankar at 503-823-4793.

As is standard with all sewer projects, Environmental Services will coordinate with PBOT on street permits, street restoration requirements, and safe traffic controls. Any pavement disturbed by this project will be restored per PBOT's guidelines.

Report Basement Backups

If your basement sewer backs up or your property or street floods, please report it immediately to the City's 24/7 Maintenance Operations hotline at 503-823-1700. They will log the issue in a tracking database, visit the location to investigate the issue, make emergency repairs where necessary, and use this information to help plan future improvements to the system. This information will also be used to improve the local surface drainage conditions where possible. Please report an issue as it is happening so responding crews can observe it. We also encourage you to call the hotline to report locations where there is a history of local surface drainage issues.

For More Information

If you would like more information about the project or have questions and concerns you’d like to discuss, please call or email:

Cheryl Kuck
Community Outreach
Phone: 503-823-7898

If you have a concern or question about a pipe repair near you, please be sure to include your name, property address, and project name (NW Thurman) in your voicemail and email so we can provide you more details about what to expect in front of your property. Also, please write "NW Thurman" in the subject line of your email. Click SIGN UP to sign up for periodic email updates.

Project Overview

Including the project description, map and schedule

Community Outreach

Check out current and previous communications about the project