Upstream overview of the Eliot Creek dual Farmers Screen.
In the fall of 2006, a rain on snow event caused massive debris flows down the flanks of Mount Hood. One of the casualties of this event was the Eliot Creek diversion within the Middle Fork Irrigation District. This diversion is an important component to Middle Fork’s water delivery system. The project was constructed in the spring of 2007, and it was operating by June of 2007.
• Wide operating range
• Extremely high sediment load
• Unstable stream bed
During the winter of 2006/2007, Middle Fork met with all of the agency partners as well as FCA and Anderson Perry & Associates engineering. A conceptual design was created including a dual design Farmers Screen. The goal of the project was to get the diversion re-established, install a criteria screen that required minimal maintenance and had a wide operating range, to locate the screen in a relatively protected area, and to minimize sediment entering the irrigation system.
The project was constructed in the spring of 2007, and it was operating by June of 2007. The diversion was designed to minimize the amount of sediment and debris entering the system. Within the screen structure itself, vortex tubes were utilized to eliminate as much fine sediment as possible. The result is a dramatic improvement in operating efficiencies for Middle Fork Irrigation District and protection for any fish species present.
The water enters the diversion between two rock weirs in the main creek channel. The water flows down a diversion channel to a head-gate with a trash rack. Behind the head-gate, a pipe carries the water to a control box and then on to two flumes that carry water to the dual screens. During high flows, both screens are operational but during low flows, one screen is shut off and all water is sent to the other screen. The screened water enters a manifold that connects to a pipe that delivers the water to a ditch. The cleaning water falls off the end of the screens and into a plunge pool. The cleaning water, debris, and fish then return to Eliot Creek in an open return channel.