LO-Tigard water plant expansion gains steam

by: VERN UYETAKE - Excavation has started at the Lake Oswego water treatment plant, which is located in West Linn, to make room for an expansion.The dump trucks have arrived in West Linn, making trips back and forth along Highway 43 to the Lake Oswego water treatment plant. It’s just one sign and one step in a 28-month project.

With a tight timeline and many components all moving in an orchestrated plan, the Lake Oswego-Tigard (LOT) Water Partnership treatment plant project is plowing along.

Lake Oswego has operated a water treatment plant since 1968. In cooperation with the city of Tigard, Lake Oswego is expanding the plant and running a new pipeline to address the future water needs of both cities.

The plant, which will hold up to 2 million stored gallons of water underground and handle up to 38 million gallons each day, also serves as an emergency backup water supply for West Linn.

by: VERN UYETAKE - The noise and vibrations from the filling of dump trucks at the Lake Oswego water treatment plant are concerns of neighbors in West Linn.Along with a new plant, the project involves the installation of a 4-foot-diameter pipeline from the Clackamas River through West Linn and into Lake Oswego. The pipeline, which will be broken into four construction phases, will extend 1.9 miles in West Linn, crossing through both residential and commercial areas.

With activity planned in Gladstone, West Linn, Lake Oswego and Tigard, if one component gets off track, others could be derailed.

Construction started this summer in Gladstone at the river intake pump station, which is located along the southerly bank of the Clackamas River. Officials built a cofferdam there, which will keep water out, for construction of a pump station.

Last week, the real work started at the plant. Excavation is being done on the west end of the site to make room for trailers for general contractors and subcontractors.

by: VERN UYETAKE - A wheel wash set up where dump trucks exit the water treatment plant construction site helps keep dirt off of city streets.Crews are also starting the excavation of the clearwell and demolition of a shed. The old clearwell (a reservoir for storing filtered water) is being dug down to 20 feet then filled back up with a couple feet of gravel.

In the next four to six weeks, workers will install about 1,000 reinforced pilings, separated by about 7 to 8 feet, under the new treatment plant. The pilings are needed because the water plant sits in a liquefaction zone; just 15 feet below the surface, the soil turns into a runny, muddy slew that resembles unset pudding. About 50 feet below that, the soil turns into a hard gravel.

The pilings will help secure the facility in case of a natural disaster.

LOT is also currently working with West Linn staff to coordinate the replacement of old, brittle water lines along Mapleton Drive and Kenthorpe Way. Though West Linn will be designing and replacing the pipe itself, LOT will share in the cost of the upgrades, according to Komarek. That work will start in December and should be finished by February.

In Lake Oswego, this week a preconstruction conference meeting was held for the pipeline from Fifth Street near the north side of Oswego Lake to the Waluga Reservoir. That work should start in early November.

by: VERN UYETAKE - Construction is underway at the water treatment plant in West Linn that Lake Oswego and Tigard are expanding.Though there is a lot of work going on, there are issues still unresolved revolving around settlements, appeals and agreements.

Although LOT has initiated the project, four appeals were filed in an attempt to stop the work.

WaterWatch, a river conservation group, filed an appeal, now at the State Court of Appeals, challenging Lake Oswego’s use of its full water rights of 38 million gallons of water a day from the Clackamas River. The appeal is set for oral arguments on Nov. 15.

A group of West Linn residents also filed three appeals to the Oregon Land Use Board of Appeals, alleging procedural and substantive errors in the city of West Linn’s process. The appeals were consolidated for review and will now go before LUBA for oral arguments Thursday in Salem. The board should then make a decision within two weeks as to whether the process was flawed.

There are several options for LUBA. It could uphold the council’s decision, overrule the decision, remand the decision back to the council for further action, dismiss the case or transfer the appeal to Circuit Court.

For more information about the project, visit

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