Project Overview

In 2010, the Spread Creek dam, an obsolete, crumbling diversion dam for irrigation located just outside of Grand Teton National Park on Bridger-Teton National Forest lands was removed by a partnership effort led by TU’s Wyoming Water Project, opening up over 50 miles of Spread Creek to migratory Snake River cutthroat trout for the first time in over 50 years. Since the dam was removed and replaced with a fish passage-friendly diversion structure and new water delivery system, project partners have documented successful fish movement through the project area – but have also discovered that native fish, including migratory Snake River fine-spotted cutthroat trout and bluehead suckers (a Wyoming Species of Greatest Conservation Need) are being entrained in the Spread Creek irrigation system. In addition, the Spread Creek channel in the project area has been highly unstable following dam removal, both laterally and vertically, which has caused continued damage and issues with maintaining water delivery during high flow events in the 2011, 2017 and 2018 irrigation seasons (and associated sedimentation, bank instability, and scouring). Phase 2 of the Spread Creek Fish Passage project is a large-scale collaborative effort that will prevent future losses of migratory cutthroat trout and other native fish by installing a fish screen on the Spread Creek irrigation system. It will also make much-needed improvements to stabilize the diversion structure and channel within the project area. The project’s completion will represent the culmination of over 10 years of effort by TU, project partners (including multiple years of support by the Jackson Hole One Fly), and water users to implement a win-win-win solution for fish, land management agencies, and irrigators.