A route has been determined for a 30-mile pipeline that would provide more than 300,000 residents and businesses in the city of Hillsboro and other west Portland suburbs with water from the Willamette River.
On Tuesday, the city of Hillsboro and the Tualatin Valley Water District revealed their proposal for the location of the major pipeline, which would run water from the Willamette River at Wilsonville, around the periphery of Tualatin, Tigard and Beaverton, and then out to Hillsboro.
A project of this size could cost around a billion dollars, and financing it may cause rates to increase for customers, said Todd Heidgerken, interim director for the Willamette Water Supply pipeline project. But in the long term, Hiedgerken expects the pipeline to add resiliency to the region’s water supply.
“One of the things we have realized over the last couple decades is the value in having multiple sources of supply,” he said.
According to Heidgerken, an expanded water portfolio can help stabilize costs and secure supply in times of drought and economic uncertainty. He says the new pipeline also will be more likely to withstand an earthquake.
The Willamette Water Supply is expecting Washington County to double its water needs by 2050.
Currently, the city of Hillsboro relies on water from a single source, the Joint Water Commission. In the winter, that water comes from the Tualatin River, but as the river dries up in the summer months, the commission looks to area reservoirs for supply. The TVWD relies on water from two sources; it buys its water from the city of Portland and is also a partner of the Joint Water Commission.
The new pipeline would require the existing water treatment facility in Willsonville to be significantly expanded to meet additional demand. Currently, the facility has the capacity to treat 15 million gallons per day, says Heidgerken, but ultimately they’d need to be able to treat well-over 100 million gallons to support customers in Hillsboro and TVWD areas.
Heidgerken says they are still in the initial phases of the project, and the proposed route could still see some changes as they look for opportunities to piggy-back on other road or utility construction projects. This summer, the Willamette Water Supply program plans to notify residents and businesses located within 500 feet of the proposed route.
Most of the pipeline construction is slated to to take place between 2020 and 2025.