Plan looks to remove Clark Fork River dam, improve fish passage

Martin Kidston

(Missoula Current) Trout Unlimited is looking to a federal grant to reconstruct a century-old diversion dam on the Clark Fork River to improve the passage of fish, improve irrigation and enhance boater safety.

And Missoula County is backing the effort.

Commissioners this week signed a letter of support for Trout Unlimited's application with the Bureau of Reclamation seeking roughly $3 million to rehabilitate the Grass Valley French Ditch – a large diversion that still spans the Clark Fork River.

“The project is going to reconstruct the diversion, install a state-of-the-art fish screen to improve fish passage, install safety for boaters navigating this reach of the Clark Fork, and improve water management and ensure the ditch company can continue to deliver that reliable irrigation to agricultural users,” said Jennifer Zaso, the county's open lands manager. “It's a multi-benefit investment project.”

The Grass Valley French Ditch Company provides irrigation to roughly 2,500 acres in the valley's western reaches. The infrastructure provides reliable water feeding the area's agricultural lands.

But for more than a century, the concrete diversion dam and irrigation ditch have hindered fish passage. The dam also serves as an impassable barrier to boaters traveling down the Clark Fork River toward its confluence with the Bitterroot River.

“If they get the money, it would remove that and a person could boat down all the way to Kelly Island,” said Commissioner Josh Slotnick. “It would be better for the river with that fish passage and it would be better for irrigators in that there's a state-of-the-art ditch. It's 100 years old and can't really be modulated like this could be.”

According to Trout Unlimited, the improvements represent a plan developed by a range of interests including agricultural producers, conservation organizations, recreation and natural
resource professionals.

“By improving connectivity for native fisheries, maintaining cold, clean water and supporting the long-term viability of irrigated agriculture, this project advances shared community values and provides lasting public benefits,” the county wrote in support of the grant request.