Concerns over riverbank erosion near downtown Missoula and the cost of bridging infrastructure east of Reserve Street could all be overcome if the city pulls together the funding needed to purchase the Flynn-Lowney Ditch and begin remediation work around it.

The city’s department of Public Works & Mobility earlier this year proposed funding the $1 million purchase using $725,000 from Transportation Impact and Water Development fees. An additional $265,000 was still needed from other sources such as grants, private donations and in-kind services.

Logan McInnis, deputy director of Public Works, said the project is now nearly fully covered, with contributions coming from a wide number of partners including Trout Unlimited and the Clark Fork Coalition.

This week, the Missoula Redevelopment Agency also joined the effort by contributing $57,000 to fund the permitting of water rights associated with the ditch's retirement.

“This is a multi-phased effort,” McInnis said. “Phase 1 is just getting the assets of the ditch company purchased. Phase 2 will be the removal of the ditch structure and reshaping the river to remove the hydraulic pressure along the south side of the (Clark Fork) river.

The ditch, owned by the Hellgate Valley Irrigation Co., takes in water at the head of Broadway Island near Silver Park and carries it west toward the greater Mullan area. It's there where the city and county are investing nearly $19 million to place the infrastructure needed to guide current and future development.

Buying the irrigation ditch would allow the city to decommission it, and city officials have said it would net nearly $2 million in savings for the Mullan BUILD project by reducing the cost of culverts and storm water drainage.

“A tremendous amount of expense was going to be needed to build the culverts and crossings as that ditch wanders through that land that's all ripe for development and will see development in the next couple years,” said MRA Director Ellen Buchanan. “A large portion of the purchase is a trade off for not having to spend that money as the area develops.”

The ditch is pictured in blue as it spreads across the Mullan area.
The ditch is pictured in blue as it spreads across the Mullan area.

While retiring the ditch could ease development costs in the Mullan area, it could also provide the city and the state an opportunity to address concerns with the Clark Fork River.

In recent years, the river has cut into the south bank to the point that it's now threatening vital infrastructure. Once the city owns the ditch, it can remove the diversion structure and make other improvements to the river where the ditch takes in water.

“The removal of that diversion structure is going to benefit fish habitat and water quality, and we get rid of the problem of fish getting trapped in the irrigation channel, which is a perpetual problem,” Buchanan said. “We believe this diversion is certainly a contributor to the bank erosion you're seeing on the south side. We're starting to worry about losing the trail and even having the stadium impacted if we don't get the bank stabilized. We're losing some pretty big chunks over there.”

The city has invested heavily in the area over the past decade, including the construction of Silver Park, trails, and a boat ramp on the south side of the river. It also purchased Broadway Island in 2011 for $25,000 and is working to transform the location into a public amenity.

The park initially opened to the public two years ago and covers roughly seven acres. Retiring the ditch could open new opportunities for the riverside park, Buchanan said.

“It gives us more flexibility with how we treat that side channel that is the ditch right now between the island and the north bank,” she said. “What if that became a controlled area where you could to teach kids to kayak? How do you make that an investment in the island? From my perspective, there's some pretty exciting things that could come out of this.”

A woman walks her dog on Broadway Island. The ditch is pictured to the right. (Missoula Current file)
A woman walks her dog on Broadway Island. The ditch is pictured to the right. (Missoula Current file)

While such ideas remain a work in progress, the city and its partners are working to complete the purchase of the ditch and prepare for the transfer the water rights. The purchase would provide funding to drill new wells for irrigators in the Mullan area.

McInnis said moving to wells has the support of longtime water users in the area.

“The active users will get new wells drilled and a water right will be put in their name,” he said. “The big irrigators are really supportive. They like the idea of turning on a well and pumping clean water and not worrying about having a ditch right, or mucking around in the river, putting jersey barriers and gravel and everything else out there. They'll have a more reliable water source.”

Retiring the ditch could also benefit wildlife habitat by keeping more water in the river to boost instream flows. According to the city, around 40 cubic feet per second of water would remain in the river. That could reduce fish loss and eliminate the need to alter the river channel to get the water to the ditch.

“Reducing loss of fish to ditches, improving instream flow and protecting river habitat are important objectives for Montana Fish, Wildlife and Parks,” Pat Saffel, the agency’s fisheries manager, said earlier this year. “Decommissioning the ditch achieves all these objectives completely and permanently.”