Joint Water Commission

About 28% of water comes from the Joint Water Commission (JWC), which is jointly owned by TVWD and the Cities of Hillsboro, Beaverton and Forest Grove. The JWC source is comprised of water from Hagg Lake (Scoggins Reservoir) and the Barney Reservoir released into the upper portion of the Tualatin River. When flows are available, water from the Tualatin River is used. It is then withdrawn and filtered through the JWC water treatment plant. Chlorine and pH adjustments are added before leaving the plant.

Each owner has a different amount invested in different parts of the JWC system, with TVWD's portion consisting of storage in Barney Reservoir.