Davenport on the Hood River
80 CFS Custom Farmers Screen
This screen supplies water to multiple hydro-power generation facilities. The reliability of the Farmers Screen has allowed for increased hydro-power revenue for the District as well as a major decrease in operation and maintenance costs.
• Wide flow range
• High sediment load
• Endangered species present
The Davenport Farmers Screen was the first working prototype of the Farmers Screen and was overbuilt to allow for research and development to refine the design. This screen has an adjustable taper wall which allowed for valuable data to be gathered on the perfect angle and throat width. The attenuation bay was also built twice as wide as necessary to allow for an adjustable weir wall which again has provided very valuable data.
Full-scale tests were conducted in the spring of 2003. The tests included hydraulic tests, debris-loading tests, and biological tests to evaluate injury or mortality to Chinook and Steelhead fry and smolt. Kelts were also released over the screen for evaluation. Test evaluations included velocity and depth tests, as well as evaluation of scale loss, injury, and delayed mortality to fish. The results of the tests demonstrated that the horizontal flat plate screen does not cause injury or mortality when designed and operated in accordance with design parameters. In addition, the tests and continued operation of the screen have demonstrated that the debris loading has been reduced up to 95% with a corresponding decrease in operation and maintenance costs. When operating under proper hydraulic conditions, the screen requires little to no cleaning.