Lake Oswego Tigard Water Partnership

Partnership Overview

The cities of Tigard and Lake Oswego joined together in 2008 to share the costs of upgrading Lake Oswego’s water infrastructure and to provide high-quality drinking water year-round to both communities.

Lake Oswego's water supply facilities were undersized, aging and seismically weak. Tigard had long sought ownership in a secure, dependable water source and both cities wanted to keep water rates affordable for their residents. By sharing the cost of planning, designing and constructing a new supply system, each city secures its long term water supply needs at a cost neither could afford alone.

Project Overview

The Lake Oswego Tigard Water Partnership Project is complete and under budget. The nine-year project upgraded and increased system capacity to deliver high-quality drinking water from the Clackamas River to the communities of Lake Oswego and Tigard. Thank you to everyone in Lake Oswego and Tigard for supporting and investing in this project. An overview of the project can be found on the partnership website. You can also watch “A Legacy for Generations – the Lake Oswego Tigard Water Partnership Project”.

Construction started in spring 2013 and was completed in summer 2017, with the new system serving Clackamas River water to both Lake Oswego and Tigard starting in summer 2016.

The project involved upgrading and constructing five major facilities across four cities: a new river intake pump station on the Clackamas River in Gladstone, a water treatment plant in West Linn, a new 3.5 million gallon reservoir in Lake Oswego, a pump station in Tigard and more than 10 miles of large diameter pipeline serving as the backbone to the new water system.


Lake Oswego customers benefit by sharing water system improvement costs with Tigard, saving millions of dollars. Tigard customers also benefit by obtaining access to a high-quality water source and ownership in an advanced and reliable water supply system.

The new water supply system replaces aging, vulnerable, at-capacity infrastructure with a cutting-edge system designed to the highest seismic resiliency standards. The new system also enhances emergency water supply reliability regionally by providing access to Lake Oswego's and Tigard's combined storage as well as other supply sources.

Cost / Funding

The total cost for the project was $249 million, $5 million below the previous estimate of $254 million.

Funding sources for the Partnership project included bonds issued by Lake Oswego and Tigard to be repaid over the years by customers’ monthly water charges and SDCs (systems development charges). SDCs enable new connections to the system to pay for their respective share of capacity into the expanded system. Cities typically sell bonds to fund large capital projects. Both Lake Oswego and Tigard have increased water rates to repay the principal and interest on bonds, and to operate and maintain the joint water supply system.

More Information

To learn more, visit the Partnership website at

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