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Water | Environment

Fish Screens Help Farmers, Save Fish

NACHES, Wash. – What looks like a long cement canal now sits alongside a small stream in central Washington. People peer down as the water flows through. This structure is a newly constructed fish screen – the first of it’s kind built in the state.

View Naches, Wash. in a larger map

Without fish screens, fish and debris can get into farmers’ irrigation pumps and pipes. That’s bad for the farmers and bad for the fish, said Les Perkins. He’s with Farmers Conservation Alliance, the company that helped develop this new fish screen.

“A fish can go down a canal and into a farmer’s fields. It can get caught at the end of a ditch, where it can’t get out,” Perkins said. “Ditches can be miles and miles long. So if a fish goes into a ditch, it’s unlikely it will turn around and get out. It typically will die there.”

Watch: Demonstrating new fish screens

Fish screens are more complex than screens on your windows. Mesh wire lays flat across a cement canal. Fish and debris flow quickly across the top and back into the stream. Irrigation water flows slowly through the mesh and into the farmer’s ditch.

Washington and Oregon require fish screens when water is being pumped out of streams, rivers and lakes. In Idaho, fish screens are mainly in place for anadromous salmon and steelhead, although some streams have screens to protect resident fish.

There are still hundreds to thousands of diversions in each state that don’t have fish screens. According to the Oregon Department of Fish and Wildlife, more than 98 percent of juvenile salmon survive fish screens, instead of winding up in pipes or ditches.

Bull trout, chinook salmon and lower Columbia steelhead all swim through this location off the Naches River.

FCA said, so far, this technology has opened up 177.61 river miles for fish passage, with 27 screens installed in Oregon, Idaho, Montana, Wyoming and, now, Washington. This fish screen will serve 85 landowners and 1,700 acres of farms.

old fish screen
The old fish screen that was replaced.
WDFW officials estimate it is at least 60 years old.

Typically fish screens look like a rotating mesh drum. Think of an old mill wheel. Fish and debris flip over the top. This type of screen was developed in Yakima, a few miles down the road from the new screen. As the drum turns, it moves fish back into streams and away from irrigation pipes. These types of fish screens have one main problem: moving parts.

Back in 1996, a flood rushed down Hood River. Farmers’ fish screens got swamped with silt, debris and fish. They decided to design a fish screen with no moving parts, hoping it would greatly improve maintenance and efficiency.

Dan Kleinsmith, the project manager for FCA, helped with that design.

“Any time you have a part that’s moving, it’s going to wear out eventually,” Kleinsmith said.

He said with the horizontal design, “If a big flood or something comes down, basically it’s just: shovel it off, clean it up and start it back up.”

Read: Fruit Growers Develop Innovative Screen To Keep Fish Out Of Irrigation Water

This design, known as the Farmers Screen, is like an extension of the stream. But it won’t work everywhere, Kleinsmith said. Streams must slope downhill and have room for the structure’s footprint, which takes up much more space than a typical screen.

“A lot of diversions need screening,” Kleinsmith said. “This is just one tool in the toolbox. There’s lots of technologies out there, and they all fit in one way or another.”

Michael Tobin is the district manager for the North Yakima Conservation District. He said the district works to protect fish and landowners.

“Every fish screen we can do, whether it’s a large one, like this particular screen, or an individual pump screen, they’re all equally important,” Tobin said. “They protect the resource. They enhance the community by having a good ecosystem balance. At the same time, economic considerations of maintaining agriculture are kept in place.”

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