Spread Creek Images: Left: The Spread Creek Diversion structure was a passage barrier. Middle: Demolition is in progress on the diversion structure. Right: The new Spread Creek Diversion structure during high water immediately following construction.
Spread Creek Fish Passage Improvement Project, Grand Teton National Park, WY
Grand Teton National Park operated a water diversion structure on the Buffalo Ranger District in Spread Creek. The diversion enabled water to be supplied to the Elk Ranch and the Lower Cunningham pasture areas within Grand Teton National Park. The Park decided to remove these structures in order to replace them with fish passage friendly structures. The project was necessary due to the deteriorating condition and mature age of the current diversion structure as well as being a safety hazard. In addition, there would be ecological benefits to installing structures that allow fish passage by restoring the connectivity to 65 miles of stream habitat above the existing structure. Native Snake River cutthroat trout and native non-game fish reconnected through this project for the first time since 1967. QCI worked in conjunction with Trout Unlimited, the US Forest Service and Grand Teton National Park to provide for improved fish passage at an existing concrete diversion structure on Spread Creek. The existing concrete diversion structure was approximately nine feet high and 120 feet long with a six foot head differential between the upstream and downstream sides. The project replaced the existing structure with a series of rock weirs designed to maintain a maximum irrigation delivery rate of 60 cubic feet per second. The project included the construction of a new headgate structure, measurement devices, and 1,100 linear feet of pipeline. A segment of the pipeline operates as an inverted siphon to facilitate an underground crossing of Spread Creek.
QCI conducted a full topographic survey, performed a water rights analysis, prepared design drawings and specifications, and provided construction staking and oversight. In the winter of 2011, the project was featured in the national magazine of Trout Unlimited.