Fish fans are trying anew to keep trout from going with the flow up irrigation ditches in the Bitterroot, then getting stranded when headgates are closed and the ditches dry up.
Trout Unlimited is working with the Bitterroot Conservation District, Montana Fish, Wildlife and Parks and the Bitterroot National Forest to expand and improve bull trout and native fish populations, while maintaining or even improving irrigation infrastructure for agricultural producers in the Bitterroot Valley.
“We were contacted by the Bitterroot Conservation District to basically do an inventory of diversions in the Upper Bitterroot,” said Christine Brissette, a restoration ecologist working with Trout Unlimited. “We were looking at the impacts to fish and the possible ways to reduce those impacts.”
Various agencies and groups have done similar surveys in the past, including in the Little Blackfoot drainage. That effort involved working with willing landowners to install fish screens in the ditches to keep the fish out, or in other places to create passages so fish can go around diversion structures.
“If they’re not able to move up to their spawning grounds, those populations will decline,” Brissette said. “They don’t spawn in ditches, but if they encounter a diversion structure that’s several feet high, they can’t make their way upstream; or juveniles making their way downstream can’t get past, or get sucked into the diversion and down the ditch. Then when the diversion is turned off the fish will die.”
She doesn’t have any information about how many fish die in the ditches, but in 2016 volunteers pulled 2,143 rainbow, cutthroat and brown trout out of the private Lolo-Maclay Ditch in one day, then returned them to Lolo Creek.
Chris Clancy, a fisheries biologist with Montana Fish, Wildlife and Parks, said one study he saw showed that more than 7,800 fish entered three ditches along Skalkaho Creek, and a survey off of Lost Horse turned up about 18,000 fish.
They worked with Daly Ditches in years past to install a handful of fish screens, but the federal funding used to pay for the effort dried up. It’s also not just simply putting a piece of mesh across the ditch’s entryway.
“They don’t just screen fish, but every bit of debris,” Clancy noted. “Two screens on a couple of ditches coming out of the river cost around $200,000 each.”
Still, when money became available for Brissette’s work, she jumped at the opportunity. Last summer, Brissette and others knocked on irrigators’ doors, seeking permission to study and take notes on their diversions.
“We were just making cold calls,” Brissette said. “That’s pretty time consuming, but it’s the foundation for building relationships with people we might work with in the future. We meet with them and talk about the issues.”
They inventoried 18 diversions on seven streams, with a focus on the Upper Bitterroot including the West Fork, the upper East Fork, Nez Perce Fork and some west-side streams. Of those, they identified seven high priority projects, mainly in the East and West Forks, where there are interested landowners and a high potential to positively impact native trout.
Bissette noted that the projects have to balance feasibility and biology as well as ensure that irrigators get all of their water rights fulfilled.
“The other conversation that we usually have is that it needs to be a win/win, and not just benefit the fish,” she said. “The irrigators are working hard and they don’t need more on their plates.”
She said they’ve had mixed reactions from irrigators; while overall people are welcoming, they’re concerned about the future of agriculture in the valley, and they’re stressed out. They just want to continue the way their parents and grandparents irrigated, and some previous efforts at installing fish screens ended with all sorts of debris clogging the intakes, lowering the water flows.
“I completely understand that,” Bissette said. “That’s not a successful project, in my mind, if you’re creating a new headache.”
John Crowley, manager of the Bitter Root Irrigation District, said he wasn’t familiar with this effort by Trout Unlimited, but he thinks the commissioners would be interested in listening. Crowley agrees that clogged fish screens are the top concern of irrigators, as well as maintenance of any structures that are installed.
And then there’s the cost.
“The board would be open to listen, but it’s hard to find money; we are struggling to find the dollars to repair or replace our infrastructure,” Crowley said. “The board has had Trout Unlimited in before and is receptive, but another concern is if the screen is not letting the proper amount of water through, that’s a hardship created for irrigators.”
Bissette said the cost is usually related to the amount of water to be screened, so a large canal will be expensive. That’s why they’re mainly looking at ditches with water rights of 1 to 5 cubic feet per second, which will cost much less.
Some of the local fish and water groups may be able to help, according to Dave Campbell, a former district ranger in the Bitterroot, and a member of the Bitterroot Trout Unlimited chapter. He knows first-hand about the importance of maintaining connectivity for the Bitterroot fishery, and the damage that can occur when waterways are dewatered.
“We know fish screens require maintenance, and that’s where our chapter could get involved; maybe have a work day and help clean the screens,” Campbell said. “We will participate wherever we can. It might be helping do the inventories; it might be helping with projects; and it might be finding matching funds.
“This is a place we can make a difference with our money and our support. We have to make sure the habitat is connected.”