Ditch acquisition to keep more water in Clark Fork, lower infrastructure costs

The City of Missoula on Tuesday completed the purchase of the Flynn-Lowney Ditch, a move intended to simplify infrastructure work in the greater Mullan area and keep more water in the Clark Fork River.

The $990,000 purchase will enable to city to decommission the ditch and transfer water rights to wells for future irrigation. Unused water rights will be transferred back to the river to boost instream flows.

“This was a great collaboration with our partners,” said Jeremy Keene, director of the Department of Public Works and Mobility. “It really represents a project that appealed to a wide variety of interests.”

Earlier this year, the city negotiated an agreement with the Hellgate Valley Irrigation Co. to purchase the ditch. The City Council approved the purchase in October.

The $990,000 cost was paid for with $725,000 in Transportation Impact Fees and water development funds. The remaining balance of $265,000 was raised through grants, private donations and in-kind services.

Advocates of the acquisition said retiring the ditch could 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.”

The Flynn-Lowney Ditch runs throughout the Mullan area and would have required the installation of several large culverts to allow for street and utility construction as the multi-million BUILD project advances.

Installing the culverts would cost the project around $650,000 in additional funding, according to the city. By purchasing the ditch, the city now has the flexibility to decide how each ditch crossing should be handled to best accommodate Mullan-area infrastructure.

“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,” MRA Director Ellen Buchanan said in September. “A large portion of the purchase is a trade off for not having to spend that money as the area develops.”

Keene said the ditch easements will remain in place until the city formally releases them. The city intends to hold the easements to convey water, which may include carrying stormwater from adjacent roads or developments in the future.

Project partners included Montana Fish, Wildlife & Parks, Trout Unlimited, the Clark Fork Coalition, the Missoula Redevelopment Agency, Parks & Recreation, the Missoula Montana Airport, private landowners and irrigation company shareholders.