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 - January 30, 2015

Water Treatment Plant Construction Update

Placing fill on the east side of the clearwell, to prepare for compaction

The gravity thickener mechanism helps thickens river sediments removed during the treatment process.

Work occurring on site over the next few weeks includes: 

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

Crews are working on the structural decking and mechanical piping for the finished water pump station.

Exterior coatings are now complete for the clearwell. This week, crews began using the large vibratory compactor to compress the fill and gravel around the clearwell. Backfilling of the clearwell is expected to take several weeks to complete. 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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Thursday - January 22, 2015

West Linn Pipeline Construction Update

Highway 43 pipeline construction

Pipeline construction on Highway 43 in West Linn is progressing north at about 50-100 feet per night. Crews are currently installing pipe between Cedar Oak Drive and Walling Circle in West Linn (pictured above). Nighttime work hours are Sunday through Thursday, 8 p.m. – 5 a.m. During construction, in most areas, one lane will be open at a time, with flaggers guiding traffic in each direction.

A second crew continues to install pipe on Highway 43 in Lake Oswego at night, near Holy Names Drive. This crew is working south, and will soon be laying pipe within the West Linn city limits, near Arbor Drive.

Please drive with caution while traveling through these construction zones and be sure to follow the directions given by flaggers. Steel plates and temporary pavement patches are frequently present, which can leave the road rough and uneven—driving at slower speeds is recommended. These delays are temporary and we appreciate your patience during this time.

Open for Business!

The Lake Oswego Tigard Water Partnership is committed to supporting local businesses during night construction on Highway 43. While construction is under way, businesses remain open to serve the community and visitors. Through discount coupons, an online business directory, signage, videos, special ads and promotional items in the West Linn Tidings, the Partnership is striving to increase business exposure, attract customers and encourage neighbors to buy local. The Partnership has also produced special “Shop Local” shopping bags (pictured right) available for free at the West Linn Library as well as several business along Highway 43 in West Linn.

Check out these new business videos and learn more about your local businesses!

For more information, drop-in to a bi-monthly construction meeting at Burgerville (next meeting is Feb. 3 at 7:30 a.m.), follow @LOTWater on Twitter, sign up to our “water pipelines in West Linn” email list or call 503-697-6502.

Friday - January 16, 2015

Water Treatment Plant Construction Update

Steel frames for new roof

Building tented for coating

Work occurring on site over the next few weeks includes:

Ballasted flocculation – center of site

Mechanical equipment continues to be installed within the structure. Steel frames have been installed as part of the ballasted flocculation roof system (pictured right). Crews are now beginning to place insulation and roof panels.

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