'Freeway for fish' helps threatened species recover

TRUCKEE RIVER, Nevada (NBC) – As strange as it sounds, a new “freeway for fish” is actually helping a threatened species recover.

It’s a species that, for decades, had disappeared. 120 years ago, Derby Dam was built on the Truckee River east of Reno.

Julie O’Shea with the Farmers Conservation Alliance explained, “Years later, we realized it cut off passage for the Lahontan cutthroat trout.”

The species could no longer swim upstream to spawn. It vanished. But in the late 1970s, a surprise discovery: someone a century ago had put a small population of the fish in a remote stream nearly 400 miles away.

The species had survived. And now, the Lahontan cutthroat trout’s remarkable return to the Truckee is being aided by — as Jack Worsley with the Bureau of Reclamation stated, “The biggest horizontal fish screen in the world.”

Vertical fish screens have been around for a long time. They keep fish from getting into irrigation canals and power plants. But they don’t work well, and they break a lot.

So, Dan Kleinsmith and his team along Oregon’s Hood River came up with a whole new concept: A horizontal screen.

Here’s how it works: Water diverted from a river passes over the metal screen. Fish stay above it, but water also passes through the screen, and off into the irrigation canal or pipeline free of fish and debris.

It seems simple, but the weir wall has to be just the right height to keep enough water above the screen for the fish and the taper wall at the perfect angle to keep the flow fast enough despite changing conditions, so the fish can swim out the end, and get routed back into the river.

It’s good for the fish and good for the farmers.

So when the federal government was trying to keep the threatened Lahontan cutthroat trout out of the Truckee irrigation canal in Nevada, someone said, “Why don’t you guys look into that?”

To bring the species back to the Truckee River, a fish passage had been built around the dam so they could once again spawn upstream.

Roger Peka, U.S. Fish & Wildlife Service, said, “The problem was for the juveniles or the adults to return back downstream without going into the canal.”

So, five of the horizontal fish screens were built where the Truckee canal breaks off from the river. It’s a big step for the fish that came back from the dead.