The Eldon Mills Dam and Barney Reservoir are located at the headwaters of the North Fork Trask River in Oregon’s northern Coast Range.
The dam is composed of rock. It was originally completed in 1970 and expanded for capacity in 1999. Rainwater and snow melt is collected throughout the year in the reservoir, then released during summer months to meet customer’s water needs and enhance the flow and fish habitat in the Trask and Tualatin rivers.
The Barney Reservoir Joint Ownership Commission (BRJOC) owns and operates the dam and reservoir. The BRJOC’s partners include the Cities of Hillsboro, Forest Grove, and Beaverton, Tualatin Valley Water District, and Clean Water Services. The Hillsboro Water Department manages and staffs the BRJOC.
Annual Newsletter
To raise awareness and provide important updates about the Eldon S. Mills Dam and the Barney Reservoir, the BRJOC mails an annual newsletter to residents living directly downstream of the dam and reservoir. Access PDF copies of the newsletter:
Barney Reservoir Map
Access a map of the Barney Reservoir that includes prohibited activities and private land designations. 
Save the Date: Meet-and-Greet Event
- What: BRJOC staff will host a meet-and-greet event for residents living downstream of the dam. Please watch for an invite by mail closer to the event.
- When: Saturday, September 23, 2023 from 1 to 2:30 pm
- Where: Tillamook County Library, 1716 Third St. Tillamook, OR 97141
Stay in the Know
- Questions?
- Call: 503-615-6702
- Email: BarneyReservoir@Hillsboro-Oregon.gov
- Visit 150 East Main Street, Third Floor, Hillsboro, Oregon 97123
- Emergency Alerts: Sign up to be alerted about emergencies in Tillamook County by text or phone.