Big Timber 2 Diversion Removal Suite

Project Narrative

A full fish passage barrier, the Big Timber 2 diversion, was removed and the site reclaimed through revegetation and bioengineering for bank stability. Removing the diversion opened 5.15 miles to fish passage, and protected 1.38 cfs of instream flow for 1.88 miles downstream to the mouth and confluence of the Lemhi River. While the final metrics of the Big Timber 2 Diversion Removal Suite were accomplished, a portion of the project was left on hold, and not all PCSRF awarded funds were utilized. As the Big Timber 2 diversion and ditch were no longer available, there was still a need to accommodate the claim for high water that the Big Timber 2 diversion had historically delivered. The original plan was to deliver the high flow to the current place of use, but from a new point of diversion on Big Timber Creek; however the water right had been abandoned through the Leadore Land Partners Conservation Easement of 2015. The Bonneville Power Administration is working through the implications of delivering the high water right in relation to the Leadore Land Partners Conservation Easement terms. The goal of this project is to address two limiting factors identified in NMFS, 2016 Proposed ESA Recovery Plan for Snake River Idaho Spring/Summer Chinook Salmon and Steelhead Populations. Specific limiting factors to the Lemhi River summer steelhead population and the Lemhi River spring Chinook Salmon population are stream flow and migration barriers.