Mid-Willamette Options

The largest river wholly within the state’s borders, the Willamette is an abundant resource. In fact, it is one of the few rivers with water available to be withdrawn in the critical summer months in Oregon, while still maintaining habitat for critical salmon and steelhead.
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Potential Sources Detail

Mid-Willamette Options

This option actually contains two alternatives for use of Willamette water near Wilsonville.  The first alternative for this water source would require a Willamette River water treatment plant near Wilsonville.  A 20-mile pipeline would also be built to carry treated water to Washington County residents.  The second alternative would only construct the 20-mile pipeline.  The pipe would carry non-treated water from the Wilsonville area to the existing JWC Water Treatment Plant for treatment.  In either case, drinking water providers would then work with Clean Water Services to meet its future flow restoration needs with water from Hagg Lake.

Water Quality

The Willamette River has proven an excellent  water source for some time.  Both the cities of Corvallis and Wilsonville have used Willamette River water as their community’s drinking water source for several years.


The study is developing cost estimates for this option. Results are expected in fall of 2011.


Both alternatives would include treatment options such as a conventional treatment plant with a potential ozone treatment technique.  A drinking water treatment plant in Wilsonville that currently treats Willamette River water for drinking is a conventional filtration treatment plant that also utilizes an ozone treatment technique.  The JWC Water Treatment Plant (WTP) is also a conventional filtration treatment plant and is currently conducting a pilot study to determine if additional ozone treatment is warranted.  The JWC WTP would need to be expanded to meet higher demands if Willamette River source water was piped there for treatment. 


The alternatives in this option contemplate a new surface water right.  Either alternative could also potentially use federally-stored water from the Willamette to augment supply.  Currently, stored water is not available to municipalities, however, municipalities in the Willamette Basin are currently working with USACE on  a program that allows municipalities to  contract for  stored water from the Willamette Basin dams. 

Treated water under this option would continue to be stored at the JWC Fern Hill Facility and throughout the system in agency-owned reservoirs.  Some of the water would also be injected and stored in aquifers during the winter.  The water would then be recovered and used during the summer.  

Regulatory Issues

The study has considered multiple regulatory issues and, to date, none of them present a barrier to the project.

Water Rights

Water for this project is relatively available under three scenarios:

New water right --The Oregon Water Resources Department (WRD), which is the agency that grants water rights, has determined that water is available in the Willamette River at this location to be taken out of the river for drinking water or other uses. Still unknown are what environmental actions WRD may require as part of the conditions for a new water right.

Obtain an existing water right -- It may be possible for Hillsboro to purchase an existing water right from a willing seller in the Willamette Valley. The City could then transfer that right downstream near Wilsonville to be used for Hillsboro’s future water supply. The study is currently evaluating if there are any opportunities that fall into this category.

Obtain a Willamette storage contract -- The U.S. Army Corps of Engineers (USACE) operates 13 dams in the Willamette basin that store 1.6 million acre feet of water. Currently a number of farmers in the Willamette Valley have contracts from the federal government to use that stored water once it is released from the dams. Municipalities are currently working with USACE on whether, in the future, a program can be developed for municipalities to similarly get a contract to use some of that water once it is released from the dams.

Land Use

Land use approvals for siting a new drinking water plant in the Wilsonville area would have to be obtained.  This may or may not be difficult depending on the exact location.  There is currently appropriate authority to expand the JWC Water Treatment Plant.  A pipeline can be sited by acquiring easements, using the public right of way, and utilizing the public utility facility siting statute.

Other Permitting

The permitting required for this alternative is still in the research phase.  All proper permits for the project will be obtained if this project option moves forward.  

Public Concerns

Hillsboro is currently analyzing public concerns, and will post information and FAQ’s as they become available.  If you have a concern you would like to see addressed, please click in the Green Box above and leave a comment.