Courtesy of Chris Banks
A few years ago, a seriously degraded section of Pebble Creek — which had been straightened for irrigation purposes by a previous landowner — was restored to its natural condition through a team effort by several agencies, private interests and the current landowner.
This was a step forward, but it still did not address all of the problems for the stream in southeastern Idaho, near Bancroft.
Another project more recently focused on resolving a serious washout that destroyed a major irrigation ditch, dumping sediment into Pebble Creek.
Correcting the problem required consolidation of nine irrigation diversions — involving four landowners — into one central diversion that included a fish screen.
“Pebble Creek is the last remaining stronghold for Yellowstone cutthroat trout in the Portneuf River sub-basin,” said Chris Banks, project manager and owner of Conservation Basics LLC.
The landowners went to the Caribou Soil Conservation District asking for help after their irrigation ditch, which ran along a steep hill, washed out in 2011.
“This was not the first washout of this ditch. In fact, it had happened 17 times since the ditch was created,” Banks said. “However, this time it was a big one and it was estimated that nearly 100 tons of sediment washed down the hill, through a parking lot and into Pebble Creek.”
When the landowners approached the soil conservation district, it was obvious that something needed to be done, he said. Banks utilized his association with a group that calls itself the Portneuf River Project to bring more resources and expertise to the table.
“This irrigation ditch begins on Forest Service land, so bringing that agency into the project was essential, as certain protocols and rules would need to be followed. These included a cultural resources inspection and following (National Environmental Policy Act) guidelines,” Banks said.
“Louis Wasnewski, Forest Service hydrologist, has been incredible to work with, and his vast knowledge and skills bring a lot more than just a liaison for the Forest Service,” he said. “Louis has a great amount of experience in improving watersheds, and finding ways to save water, improve habitat and work with landowners at the same time.”
Other members of the project included the soil conservation district, Portneuf Soil and Water Conservation District, Caribou Conservancy Inc., South East Idaho Fly Fishers, Trout Unlimited, Idaho Department of Fish and Game, Idaho Department of Environmental Quality, Simplot, U.S. Fish and Wildlife Service, Sage Brush Steppe Regional Land Trust and Idaho State University.
“They have all donated money, time, resources and technical expertise,” Banks said.
The effort resulted in the conversion of an approximately 12,000-foot-long open ditch into a piped system, and the consolidation of all diversion points into one removed barriers for spawning Yellowstone cutthroat trout.
“The newly installed fish screen allows fish to travel safely back to the stream without being stranded in the irrigation system, while still providing adequate water to the landowners for irrigation,” Banks said.
“This project will also result in reduced landowners’ cost for pumping while improving habitat for the trout,” he said. It also removed the risk of a washout occurring again.
“We all feel this has been a great project,” he said.