Willamette Water Supply Program

Water Transmission

willamette water supply yellow pipes on truck

Pipe Specifications:

134,700 feet of 30- to 66-inch C200 spiralweld steel pipe with cement mortar lining and polyurethane coating




Tualatin Valley Water District

Engineer Firm:

Various; Stantec (Program Manager)


Emery & Sons Construction Group, LLC; Kerr Contractors; Sundt Construction, Tapani Inc.; Kiewit Corporation; MEI Group; Hoffman-Fowler JV Construction Company

The Willamette Water Supply Program (WWSP) is a cooperative program between the Tualatin Valley Water District, City of Hillsboro, and City of Beaverton designed to provide an additional resilient water supply for the growing region. NWP has been awarded 22 contracts within the WWSP, supplying over 25 miles of the 30 miles of pipeline being constructed for the project. The majority of these contracts, consisting primarily of 48- and 66-inch spiralweld steel pipe with cement mortar lining and polyurethane coating, has been manufactured at our plant in nearby Portland. A portion of pipe for the program’s water treatment plant was supplied by our team in Tracy, California.

Owners of the project selected steel pipe due to its natural resilience during a seismic event. Much of the region served by the WWSP could be vulnerable to the damaging effects of a Cascadia Subduction Zone earthquake centered off the Oregon Coast. The system is engineered to better withstand natural disasters and the impacts of a large earthquake so that water service can be restored quickly to support emergency services and the community.

In addition to a new engineered steel pipeline, the program includes raw water intake modifications at the Willamette River and a new state-of-the-art water filtration plant in Sherwood, Oregon. From there, water will be pumped to a water storage tank and gravity-fed to additional storage and customers in the service areas. The program is scheduled to be complete in 2026.