Across the West, many rivers and watersheds are fragmented by old diversion dams and other irrigation infrastructure. That’s a big problem for trout, which need access to the full range of river habitat in order to thrive. For Trout Unlimited, upgrading these obsolete or inefficient irrigation systems offers a tremendous opportunity to restore rivers. With the help of Orvis funding, TU recently completed an exciting “reconnection” project on the Salt River in west-central Wyoming that should boost both the fish habitat and the fishing.
The Salt River is home to native Yellowstone cutthroat trout, as well as wild rainbows and browns. But they faced a big obstacle: an aging, solitary diversion dam imposed a two-foot-high vertical barrier to fish movement. While adult fish could likely clear the hurdle most of the year, smaller trout and other native species weren’t able to move upstream.
TU’s Jim Gregory, working with Wyoming Game and Fish and the Eastside Canal Company, saw a golden opportunity to retrofit the structure with a fish ladder and open up some 21 miles of mainstem river habitat. This fall, TU and its partners—including the Wyoming Wildlife and Natural Resource Trust and the U.S. Forest Service—constructed a rock-ramp type fish ladder on the southern side of the diversion structure that provides a low-velocity, low-gradient passageway using a design that is simple, stable, and low-maintenance. The completed ladder allows all native fish species to clear the diversion hurdle and access upstream tributaries—such as Willow Creek, Stump Creek, and Crow Creek—which provide critical spawning and rearing habitatfor native fish.
Sometimes, as on the Salt River, removing a single barrier can dramatically improve miles of habitat for fish. TU is working on dozens of these infrastructure upgrade projects that offer some of the best opportunities to restore rivers for wildlife. As far as we know, no one is making any new rivers, but this might be the next best thing.
For more information on the Orvis/TU Culvert Fund, visit the Orvis Commitment page.
Randy Scholfield is the Director of Communications/Western Water Project for Trout Unlimited.