Groups work to improve fish habitat in Sun River

Rich Boyle is an angler who lives on the banks of the Sun River.

"That's one of the premier blue ribbon fly-fishing streams in the west," Boyle said. "I don't want to advertise it too much."

Boyle is also a farmer.

"This is very, very productive ground," he said.

As a farmer and an angler and the manager of the Fort Shaw Irrigation District, Boyle has a unique perspective on the Sun River. He understands the pressures placed on the river by agriculture, but also knows the river's importance to him and his neighbors.

Boyle, along with other partners, are working to balance agricultural needs along the Sun River with fish habitat.

The Fort Shaw Irrigation system was built in the early 1900s to supply water to settlers who wanted to farm the valley.

"All these old ditches were built with horses and scrappers," Boyle said.

The Sun River also supplies water for the Greenfield Irrigation District.

That use of the river's water has caused the river and its fishery to be stressed for about 100 years, said Laura Ziemer, senior counsel and water policy adviser for Trout Unlimited.

For the past 20 years, a partnership that includes landowners, the two irrigation districts, Trout Unlimited and others has been working to restore the Sun River.

When Alan Rollo, coordinator of the Sun River Watershed Group, first came to Montana, it was common for the Sun River to be completely dry below the irrigation diversion, he said. There was no mandate to keep water in the Sun River. It could all be removed for agriculture.

Today there is still no mandate to keep water in the river. Legally the Sun River could be drained dry for irrigation, Ziemer said. However, the Sun River Watershed Group and other partners are working to make sure that doesn't happen.

For the past five years, the group and the irrigation districts have been working to improve irrigation systems to make them more efficient. That allows more water to be left in the river.

The flow restoration goals for the Sun River are based on a determination by Montana Fish, Wildlife and Parks that a flow of 130 cubic feet per second is the minimum flow needed for a fair fishery.

"Not a great fishery but a fair fishery," Rollo said.

With flows of at least 130 cfs, the river's primary riffles are covered in water and continue to offer fish habitat. If those riffles go dry, fish suffer, Ziemer said.

"With a system as complex as the Sun River, it takes a lot of communication and management to keep that water in the system," Ziemer said.

The Fort Shaw Irrigation District has installed new pipelines, gravity-fed pipelines and new canals, all of which have made the system more efficient.

"I can leave 50 (cfs) more water in the river now with no problem," Boyle said.

An agreement prevents others with water rights from using water left in the river by other water users, he said.

The Sun River Watershed Group also is working to clean up the Sun River and its tributaries.

The group has removed car bodies from the river banks and some 400 tons of trash from a four-mile stretch of the Sun River.

They've also been able to reduce the sediment load coming from Muddy Creek by about 80 percent by improving the riparian area along the creek.

"That is enabling the lower Sun River to become a little bit cleaner," Rollo said.

This past summer was the first time that the river stayed above 100 cfs for almost the entire irrigating season. It dipped below 100 only once.

"That's unprecedented for the Sun River," Ziemer said.

2012 was a similar year in terms of precipitation and snow pack, and the river was often below 100 cfs in July, August and September.

Water temperatures also have stayed cooler as flows have been higher this year.

"It's the chronic dewatering of the Sun River that has created these exacerbated temperature problems," Ziemer said.

No new information on fish numbers is available since flows have increased on the Sun. However, Ziemer hopes to see major increases in fish populations.

The last count showed about 50 fish per mile in the lower Sun River. Ideally, there would be 400 to 500 fish per mile, she said.

Ziemer hopes to see a tenfold increase in fish numbers as flows increase.

Fish can handle the short dips in stream flows like the one seen this summer.

"The fish, they can live with this," she said.

Brown and rainbow trout can be found in the Sun River. However, arctic grayling are native to the river system. Currently, arctic grayling are found only in the main irrigation canal and not in the river. The fish found their way there through the years when the canal had water while the river was dry.

Down the road, the native fish may be re-introduced.

"We may actually return arctic grayling in the Sun River," Ziemer said.

Reach Tribune staff writer Erin Madison at 406-791-1466 or emadison@greatfallstribune.com. Follow her on Twitter @GFTrib_EMadison.