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 - May 22, 2015

Mapleton Drive Pipeline Construction: 48-hour notice

Crews have begun activities at the horizontal directional drilling (HDD) staging area (near Mary S. Young Park) to prepare for major pipe installation on Mapleton Drive. By mid-June, the remaining pieces of pipe will be installed at the site, the sound wall will be removed and the site restored.

Construction work to begin next week on Mapleton Drive

Starting Tuesday, May 26, crews expect to begin preparing a work pit (entry shaft) for the tunnel (auger bore) to be installed under Trillium Creek. An auger will be used to install piles and steel sheets to support the work pit, located on the road and gravel shoulder on Mapleton Drive, near the creek. The work pit will be excavated and the materials removed. In June, an auger bore machine will be placed inside the work pit to create a tunnel under Trillium Creek.

Read More

Friday - May 22, 2015

Mapleton Drive pipeline construction starts next week

Crews have begun activities at the horizontal directional drilling (HDD) staging area (near Mary S. Young Park) to prepare for major pipe installation on Mapleton Drive. By mid-June, the remaining pieces of pipe will be installed at the site, the sound wall will be removed and the site restored.

Read More

Thursday - May 21, 2015

Demolition work continues at the treatment plant

Placing rock and preparing the subgrade

Water Treatment Plant Construction Update

Sedimentation basin demolition – northwest of site

Demolition of the basins and alum room is progressing well, and the crushing of the stockpiled concrete started this week. Crushing the material on site for later reuse reduces truck traffic in the neighborhood.  

Over the last week or so, crews have needed to use the hydraulic hammer more frequently to break up the concrete in the base of the foundation. Unfortunately, this is a very noisy activity. Crews are aiming to be done with most of the demolition mid-next week, and are trying to use the concrete processors (jaws) as much as possible, which are not as noisy as the hammer. Demolition crews are working six day weeks (Monday through Saturday), and averaging 10-hour days, to help get the work finished sooner. We appreciate everyone’s patience during this noisy activity.

Read More