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

Thursday - February 11, 2016

Testing of the finished water pumps set to begin in late February!

Trucks deliver gravel for backfilling around the basin.

A large compactor compresses the gravel to backfill the excavated area around the basin.

Launders will be installed as part of the backwashing system.

WTP public tour.

Water Treatment Plant Construction Update

Information about onsite work is outlined below. Please note, schedules are subject to change.

Washwater recovery basin – northwest of site

Insulation is now installed and the major backfill is complete for the basin. Thank you to neighbors for your patience during this work. Hand rail is now being placed, along with electrical duct bank and slabs for the pumps in the south end of the basin.

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Friday - February 5, 2016

Major pipeline work on Mapleton Drive almost complete

Crews approach the intersection of Mapleton Drive and Highway 43

West Linn Pipeline Construction Update: Mapleton Drive

Major pipeline work on Mapleton Drive is almost complete! Pipe is currently being installed near the intersection of Mapleton Drive and Highway 43.

No work is planned on Mapleton Drive tomorrow, Saturday, February 6 – crews will be working over in Gladstone tomorrow night to repair some concrete panels on Highway 99E. Mapleton Drive work will resume on Monday, February 8, to install the remaining pieces of pipe at the intersection of Highway 43.

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Friday - January 29, 2016

Final remaining sticks of pipe to be installed on Mapleton Drive next week

Crews prepare to install a piece of pipe in the final block of Mapleton Drive.

West Linn Pipeline Construction Update: Mapleton Drive

Final remaining sticks of pipe to be installed on Mapleton Drive next week!

Pipe crews are expecting to install their final sticks of pipe on Mapleton Drive next week, near Highway 43!

Once the pipe is in place, crews will continue working between Highway 43 and Trillium Creek to install an air valve and vault near the corner of Highway 43 and Mapleton Drive, pressure test and disinfect the pipe, and make final connections to the system. This work is expected to continue through February. Crews will also begin restoration and final “punch list” activities on Mapleton Drive.

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