Finished Water Pipeline

Facility Description

Finished water is pumped from the Water Treatment Plant in West Linn through a large pipeline to Lake Oswego and the Waluga Reservoir.  Like the raw water pipeline, most of this pipe is at least 45 years old. Some portions are even older.

The "finished" (treated) water pipe is the length of pipe that will carry treated water from the Water Treatment Plant in West Linn to customers in Lake Oswego and Tigard. For this project, the Treated Water Pipe must be rebuilt from the treatment plant, up Highway 43, through Lake Oswego to the Waluga Reservoir north of Waluga Park--almost seven miles of new pipe! The existing pipe size ranges from 18 inches to 27 inches. The new pipe will range from 36 inches to 42 inches.

Working with Neighbors

This major construction effort will impact West Linn and Lake Oswego and is starting soon. Partnership staff is working to share information about construction plans now. A schedule for construction is provided below. As construction begins for each section of the pipeline, the team will provide information so neighbors and travelers know what to expect during construction and road restoration.

Representatives from the Partnership have contacted all West Linn and Lake Oswego Neighborhood Associations along the pipe alignment to provide updates for residents. Summaries of these meetings are available on our Meetings page.

Would you like Partnership staff to visit your group or organization? We would appreciate the opportunity to talk about the project and help you anticipate what it will mean for your neighborhood. Email us or call  (503) 697-6502.

What to expect

The Lake Oswego Tigard Partnership selected Emery & Sons Construction Inc., a local company from Salem, for the first segment of project in Lake Oswego from 5th and Cabana to the Waluga Reservoir. The competitive selection process resulted in a bid lower than engineering estimates, saving the project $660,000.  Emery & Sons will soon determine where to begin construction of the 3.4 mile segment of pipeline and a schedule for construction.

Learn more about construction with this helpful handout,  (pdf file is 792 kb).

The Partnership will organize a "Meet the Contractor" event before construction begins, where neighbors can learn more about the specific  construction schedule and expected impacts. Invitations for those events will go to members of our email lists (sign up to receive email notifications of meetings and timely information), to neighborhood association chairs and neighbors near the construction areas.


There are three sections to the finished water pipeline. Preliminary design and construction schedules are different for each section. These schedules will be more accurate as design is completed and a contractor has been selected.


(Click for larger version of map)

  1. Water Treatment Plant (West Linn) to Oswego Lake (East Arm)
  2. Under Oswego Lake (East Arm and Lakewood Bay)
  3. Oswego Lake to Waluga Reservoir

Phase Anticipated Duration
Construction (Oswego Lake to Waluga Reservoir) Winter 2013/2014-Fall 2014
Construction (Under Oswego Lake) Winter 2014-Fall 2015
Construction (Treatment Plant to Oswego Lake)  Spring 2014-Spring 2015
I-5 to Bonita Pump Station Summer 2014-Spring 2015

Additional Information:

How to Get Involved

Look Ahead: 

You can find regular updates on the Work Underway page.

These tables are now sortable, so you can view them however you want.  This is a new feature we just added.

Field Updates

Tuesday - April 4, 2017

Paving & Traffic Notice: Oswego Village & State Street near Starbucks Wed. 4/5/17

Last December, emergency repair work was conducted on a broken sewer line and man hole located in the Oswego Village parking lot and a portion of State Street, near Starbucks and the 365 market. Throughout the winter, a temporary pavement patch has been in place over the repaired sewer line. Crews have been waiting for the weather to improve before conducting the final restoration and repaving work.

Tomorrow, Wednesday April 5, the final paving will take place between 7 a.m. – 4 p.m. within the Oswego Village parking lot. During this time, the access directly in front of Starbucks on State Street will be closed. Access to Starbucks and the 365 market will be available at the Oswego Village main traffic signal at State Street and Northshore Road. Pedestrian and customer access will be maintained at all times.

To complete the paving work, a single northbound lane will be closed on State Street, near Starbucks, between 9 a.m. – 3 p.m. Please watch for signage and expect some delays during this time.

Read More

Wednesday - September 28, 2016

Partnership Wins 2016 American Cultural Resources Association Industry Award

Partnership representatives Joel Komarek and Terry Buchholtz accept ACRA award from Duane Peter, ACRA president.

September 28, 2016

In the news...

LAKE OSWEGO, Ore. – The Lake Oswego Tigard Water Partnership recently won a 2016 American Cultural Resources Association (ACRA) Industry Award-Public Sector for outstanding commitment to protecting cultural resources, as part of construction of a $254 million water project.

The award was presented during a ceremony at the ACRA annual conference in Palm Springs, California on September 19.

Read More

Wednesday - May 25, 2016

Lake Oswego Pipeline Construction Update Night Work

Highway 43 – night work May 25th and 26th

Crews will be working at the intersection of Highway 43 and Laurel Street, and Highway 43 and Burnham Road this Wednesday and Thursday nights. Final pipe abandonment work will be conducted. Motorists should expect partial lane closures and anticipate delays. Temporary pavement patching will be placed and final paving of the area will occur in the next few weeks. Neighbors should expect an increase in noise for these two nights.

Nighttime work hours on Highway 43 are 8:00 p.m. – 5:00 a.m. Please drive with caution while traveling through the construction zones and be sure to follow the directions given by flaggers.

For more information about the project, please contact us or follow @lotwater on Twitter.