No fish left behind: Trout Unlimited, FWP work to rescue fish in drying ditches
(Missoula Current) People walking along the Kim Williams Trail Monday might have heard a soft beeping rising from the ditch west of the Van Buren Street footbridge. If they’d stopped to listen, they might have heard occasional splashing followed by enthusiastic “yeah’s” and “wow’s.”
That’s the sound of Missoula’s fisheries professionals working to save fish - and being thrilled by the occasional large trout - that get stuck in the ditch once the irrigation season is over.
The beep emanates from the electrofishing gear that makes frightened fish easier to catch. Fortunately, the sound might also signal changes that could keep fish from ever being trapped again.
On Sunday and Monday, Bill Pfeiffer and Rob Roberts of Montana Trout Unlimited recruited a handful of volunteers to try to rescue fish stranded in some of the ditches that thread their way through Missoula. Local irrigation companies closed the ditch headgates on Friday, trapping any fish remaining in the ditches as the water slowly recedes.
As the Missoula area has become more urban, many residents are unaware of the irrigation ditches that parallel many streets, especially west of Reserve Street. Most of those ditches are part of the Missoula Ditch system, which has its headgate on the Clark Fork River near Van Buren Street.
Then there are two other “urban” headgates on the Clark Fork - Orchard Homes near Brennan’s Wave and Flynn-Lowney across from the McCormick Park boat ramp - that feed water into what have become urban ditches that water more lawns than crops. But they all strand fish in the fall.
“At 100 years old, these ditches literally built Missoula,” Roberts said. “Fast-forward 100 years, and times have changed. But some are still used for ag purposes. I think it’s fair to say if there’s a farmers market stand, there’s a good chance that they’re using this water.”
But no one is using the water now, so the ditches no longer flow. While stagnant water is still ankle- to knee-deep near the closed headgates, in the ditch miles from the headgate along Spurgin Road, the volunteers on Sunday found only a few shallow puddles harboring tiny pike minnows and sucker fry.
Other depressions in the ditch only recently dried up and still held dozens of tiny dead fish that had slowly suffocated. Roberts said a lot of juvenile fish end up in ditches because they seem safer.
“One of the things we lack, especially in the Clark Fork corridor with all this development and so few side channels, is juvenile habitat. So it’s no surprise that they’re seeking out ditches with calmer water,” Roberts said. “To them it’s a great idea. They just don’t know that they get three months of the party and then the lights go out.”
Montana Fish, Wildlife & Parks fisheries biologist Ladd Knotek has found the same thing for the past two decades as he’s tried to save what fish he can.
“Make no mistake - there are thousands upon thousands of fish in these ditches and they’re dying every year. Where we know we have concentrations of fish, we go and salvage them. We have only 200 to 300 catchable fish a mile in this reach - we gotta keep what we have,” Knotek said. “The solution is to work with the irrigators to screen the ditch. You can screen the fish without affecting the water - it’s just very expensive.”
And there’s the rub. Some irrigation companies are willing to do something to save fish, but fish screens cost between $1 million and $2 million to install, depending on size and the type of construction, Roberts said.
Yearly maintenance costs also have to be factored in. Most irrigation companies don’t have that kind of money - their revenue comes mainly from irrigator fees - so fish screens aren’t installed, and fish continue to die.
In other western states, irrigators don’t have that option. In Washington, Oregon and Idaho, where people are trying to save Pacific salmon runs, ditches have to have screens. So those states have programs, money and staff to install and maintain fish screens. But salmon runs don’t reach into Montana.
“We just had a regional screening conference in Missoula a few weeks ago, and we’re the only state without a dedicated staff and a regulatory approach,” Roberts said. “Montana is the only state that has an entirely voluntary approach for fish screens. You can’t walk up to an irrigation district and require them to install one. Yet, we’ve been successful.”
Roberts said about 100 fish screens have been installed in Montana over the past 20 to 30 years, mostly western Montana, and the Blackfoot watershed is home to about a third of those. One recent success was the fish screen installed on the Lolo Ditch. Roberts wants to add at least three more on the Clark Fork River in Missoula.
Trout Unlimited already has a pilot project started with the Grass Valley Ditch that flows northwest off the Clark Fork River near Kelly Island. The organization raised some money and hired an engineer to come up with some designs for the fish screen there, which should be complete this winter. Although more money is needed and plans can change, the hope is to have that fish screen installed by 2025, Roberts said.
“In the meantime, we’ll launch the same engineering and analysis process for the Missoula Ditch and move things incrementally along. It’s a pretty ambitious body of work, but you gotta start somewhere,” Roberts said. “That’s why we’re out here now. To get some information and drum up support. All three ditch companies are conceptually onboard with the idea of ‘Hey, if we can collaborate and do something that helps fisheries and it’s not going to be a huge burden on us financially, let’s do it.’ I think that’s something that’s evolved over time.”
While they work to raise awareness and money, Montana Trout Unlimited and FWP will continue to schedule fall events to scoop what fish they can out of the ditches and return them to the river. There are worse ways to spend a golden autumn afternoon than wading a sun-dappled ditch saving desperate longnose suckers, redside shiners, northern pikeminnow, hybrid rainbow-cutthroat trout and a crayfish or three.
“It’s still amazing to me what’s in there. That’s a large amount of biomass we’re putting in the river,” Roberts said. “To some people, maybe if they don’t see a ton of trout, they think maybe it's less of a priority. But even if you’re only trout-centric, trout eat other fish. And these are all native fish, they belong in this river system, so they’re just as important. Screening is about keeping all fish out of the ditch. No fish left behind.”
Contact reporter Laura Lundquist at firstname.lastname@example.org.