The Willamette Water Supply Program is a partnership between the Tualatin Valley Water District, the City of Hillsboro and the City of Beaverton to develop the mid-Willamette River at Wilsonville as an additional water supply source.

Washington County


TVWD has enough water for today—but needs to take steps today so there will be enough water to meet future demands for people and jobs. The District’s portfolio of drinking water sources already includes the Tualatin/Trask watersheds, water purchased from Portland’s Bull Run supply, and an aquifer storage and recovery (ASR) well. All of these supplies will continue to supply water for the foreseeable future, but projections show the District’s population will increase by 82,000 people by 2042.

Learn more here.


The City of Hillsboro is looking ahead to secure an additional safe and reliable source of drinking water for the City’s future. The Tualatin watershed will continue to be Hillsboro’s primary water source, but in the next 25-50 years the City anticipates the need for twice the amount of water currently available.

Learn more here.


City of Beaverton residents and businesses will benefit from this partnership due to:

  • Resiliency – The Willamette Water Supply System will provide seismic resiliency and a separate source of drinking water with separate transmission pipeline and water storage facilities.
  • Proximity – The pipeline will be constructed near logical City of Beaverton system connection points and high growth areas like South Cooper Mountain.
  • Partnership – Washington County public agencies already coordinate and leverage joint opportunities. Joining the Willamette Water Supply Program is one more opportunity for agencies to collaborate better. Sharing four main water supply sources (Willamette River, Clackamas River, Bull Run Watershed, and Tualatin River) of high-quality drinking water is beneficial for the entire region.
  • Timing – To successfully plan for water supply availability – agencies must look decades ahead and forecast future demands. The City of Beaverton anticipates that their current water supply will be sufficient through 2045 and ownership in the WWSS supports planned growth.

Learn more here.


  • Tualatin Valley Water District
  • Hillsboro
  • Beaverton
  • Tualatin
  • Tigard
  • Sherwood
  • Wilsonville
  • Washington County