Green River Basin Transit Loss Study

(2024 – 2025)

Precision has subcontracted with Follum Hydrologic Solutions to study the Green River Basin above Flaming Gorge Reservoir. As part of this comprehensive analysis, Precision is developing a suite of RiverWare© tools that will enable water managers to better understand and manage transit losses throughout this critical water supply system. This study serves two primary purposes:

• Study Transit Losses: Precision developed a RiverWare© tool to isolate transit losses in the system, informed by historical gage data and estimated consumptive use, evaporation, transpiration, and bank storage. This analysis provides essential data for understanding transit loss in this basin.

• Conserved Water Distribution: Precision designed a RiverWare© Model to distribute conserved water to Fontenelle Reservoir and eventually Flaming Gorge Reservoir while accurately accounting for both transit losses and evaporation along the route. The model allows conserved water to enter the basin at tributary and mainstem confluences, be stored and released through Fontenelle Reservoir, and ultimately arrive at Flaming Gorge Reservoir with appropriate accounting of losses along the way.

The final RiverWare© Model seeks to enable water managers to make more informed decisions about water conservation investments, understanding downstream impacts.