Projects

South Fork North Fork Divide Creek Fish Passage

Project Description

The proposed project is located at the head of the South Fork Reservoir, a drinking water source for the residents of Butte. Currently, there is a healthy population of Westslope cutthroat trout (WCT) above the South Fork Reservoir; however, when fish migrate downstream and end up in the reservoir, there is no way the fish can migrate back upstream to spawn. The creek first outlets into the first settling pond and then cascades over a concrete weir structure. The creek is then diverted into a second settling pond by a steep and perched culvert. Water is then finally outled into the main South Fork Reservoir by a very undersized and extremely perched culvert. The combination of these three obstructions cause a complete barrier to fish passage and bifurcates the quality aquatic habitat upstream. Fish have nowhere to go downstream from the reservoir, as the water is piped directly to Butte’s Big Hole Water Treatment Plant.

This project proposes to replace all fish passage obstructions with passable step-pools and constructued stream channel to fully connect the upstream system to the reservoir. The project also will utilize an existing stream channel as a spawning site for migrating fish.

Project Goals

This project’s first and primary goal is to restore approximately 5 miles of upstream passage and stream connectivity for native WCT in the upper reaches of the South Fork North Fork Divide Creek, a tributary of the Big Hole River. This requires replacing the existing passage barriers with new fish passage channels to facilitate full-stream connectivity. Another goal of this project is to increase the fish populations in the upper reaches of the South Fork North Fork Divide Creek by constructing approximately 135 feet of a spawning channel in the project area.