Wednesday June 7, 2017
FISHBIO has helped install some large fish screens to prevent small fish from getting entrained in water diversions over the years, but sometimes we are reminded that fish screens come in all shapes and sizes. Last summer, one of our staff encountered this small rotating drum fish screen while traveling in Washington State. This custom-fabricated fish screen was placed at a junction where a small stream split off from the side channel of a larger creek, which is inhabited by endangered fish species (bull trout and steelhead). Before the improvements were made, a small diversion dam that directs water into the stream to irrigate the vineyard of Abeja Winery could have also inadvertently diverted endangered fish from the creek into the irrigation system.
With the help of a grant from the Snake River Salmon Recovery Funding Board, the fish screen was installed to allow irrigation water to be diverted while guiding fish back into the main creek. The rotating screen is designed to be self-cleaning: the water current moves a paddle wheel, which in turn rotates the porous drum screen, and the screen redirects fish and debris back into the larger creek. This example is a good reminder that even a small fish screen can involve considerable planning and coordination. The Walla Walla County Conservation District worked with Abeja’s owner, the property manager, and Washington Department of Fish and Wildlife to coordinate this project. With more than 3,000 Resource Conservation Districts throughout the country working with landowners to promote similar local conservation efforts, this is just one of many examples that shows how fish can benefit when everyone works together.