26 CFS Custom Design

Scott Ditch

Scott Ditch

This new system replaced an existing rotary drum screen that was out of compliance and had operation and maintenance issues.


The diversion runs at a fairly uniform flow throughout the irrigation season with seasonal loads of both sediment and organic debris. Bull Trout, Chinook Salmon, and Lower Columbia Steel head are all present in the Naches River at this location.

South Naches Irrigation District and WDFW chose the Farmers Screen for low operation and maintenance costs, as well as proven fish protection capabilities.

Project funding was provided by Bonneville Power Administration through the Yakama Nation Fisheries program. Civil and hydraulic engineering was provided by Paul Tappel of Fisheries Engineering, Inc. with input from all project partners. The Farmers Screen design and components were provided by FCA, while construction and screen installation was provided by WDFW’s Yakima Screen Shop. The Scott Ditch project was truly a collaborative effort to address a site which had been without a solution for over a decade.

This comprehensive project included the removal of an existing rotary drum screen, modification of an existing flow control/bypass structure, and construction of a new entry flume, horizontal fish screen, sediment control system, and fish return/by-pass structure. This new custom Farmers Screen system provides a maximum of 26 CFS screened water for South Naches Irrigation District while protecting Bull Trout, Chinook Salmon, and Lower Columbia Steelhead.

Oregon Public Broadcasting’s EarthFix reported on the project’s purpose and impact here.