Lake Oswego Water Treatment Plant

Facility Description

The City of Lake Oswego has operated a drinking water treatment plant in West Linn’s Robinwood neighborhood since 1968. The Lake Oswego Tigard Water Partnership plans to upgrade and expand the treatment plant, located between Kenthorpe Way and Mapleton Drive, to meet current and future drinking water needs. The upgraded plant will supply Lake Oswego and Tigard, and will continue to serve as West Linn’s sole source of emergency and backup water supply.

History of the Water Treatment Plant

Built in 1968, Lake Oswego’s water treatment plant was originally located in unincorporated Clackamas County. The area was later annexed by West Linn. Through its 44-year history the plant has earned a reputation as a good neighbor. The City of West Linn has approved land use applications for upgrades and expansions three times since the plant was built.

It is not uncommon for wastewater and water treatment plants to be located in residential areas. South Fork Water Board’s treatment plant – jointly owned by West Linn and Oregon City – is located in Oregon City’s Park Place neighborhood. Extensive upgrading, expansion and treatment modifications have occurred there over the past several years to serve the two communities.

Water Treatment Plant – Good Neighbor Plan

Lake Oswego Tigard Water Partnership began discussions with the Robinwood Neighborhood Association in early 2010, sharing details of the water treatment plant expansion, listening to suggestions, and finding ways for the upgraded water plant to continue to be a good neighbor. Two years later, the Partnership has met with Robinwood neighbors more than 20 times, developing a Good Neighbor Plan (pdf, 308 kb) that contains the Partnership’s commitments for design–construction–operations of the new facility. Neighborhood input played a big role in design concepts with the addition of numerous plant layout changes and amenities requested by neighbors.

How to Get Involved

  • Click here for upcoming meeting dates.
  • Sign up to receive email notices.  Mark the ‘Water Treatment Plant' as your interest.
  • Click here to contact us by email.
  • Call the Water Hotline (503) 697-6502.

Additional Information

You can find regular updates on the Work Underway page.

Field Updates

Friday - December 19, 2014

Water Treatment Plant Construction Update

backfilled clearwell

brick veneer

Utility work on Kenthorpe Way

Portland General Electric (PGE) is installing the alternative electrical feed to the water treatment plant on Kenthorpe Way. For more information, please contact PGE’s Project Manager, Chris Jewett at: or 503-672-5481.

Finished water pump station and clearwell – south and center of site

Work continues on the structural support, electrical fixtures, roof joists and mechanical piping for the finished water pump station.

Coating is being applied to the exterior of the clearwell. Once a section is complete, the area around the outside of the clearwell will be backfilled. This is expected to take several weeks to complete and, at times, will require the use of the large vibratory compactor to compress the fill and gravel. Neighbors located close to the site and south of the site on Mapleton Drive can expect an increase in vibration during the fill placement and compaction of the clearwell.


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Friday - December 12, 2014

West Linn Pipeline Construction Update

An example of the type of work being performed at night along Highway 43.

Crews in Lake Oswego are currently working near Cherry Lane.

Highway 43 construction began this week in West Linn

Preliminary pipeline construction activities (saw-cutting asphalt and equipment mobilization) began on Monday, Dec. 8 at night on Highway 43 in West Linn near Mapleton Drive. On Sunday, Dec. 14, crews expect to begin nighttime pipe installation starting at the intersection of Mapleton Drive, working north along Highway 43 towards Lake Oswego. Schedules are subject to change.

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Friday - December 5, 2014

Highway 43 Pipeline Construction in West Linn - 48-hr Construction Notice

Starting Monday, Dec. 8, preliminary pipeline construction activities (including saw-cutting asphalt and equipment mobilization) will begin at night on Highway 43 in West Linn, near Mapleton Drive. On Sunday, Dec. 14, crews expect to begin installing pipe at night starting at the intersection of Mapleton Drive, working north along Highway 43 towards Lake Oswego. Schedules are subject to change.

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