Future Streamflow Estimates for Tongue River to Enable Northern Cheyenne Data Driven Water Management and Planning
Atmospheric warming is driving:
- a shift in precipitation from snow to rain
- changing precipitation intensity and seasonality
- increasing atmospheric demand for moisture in mountain river watersheds across the western United States (Seager and others, 2015).
These changes will likely alter the timing and quantity of streamflow in rivers draining mountains. The Tongue River flows from the Bighorn mountains in north-central Wyoming into Montana to join the Yellowstone River at Miles City, Montana. The Tongue River is a minimally studied river that is important to Tribal water rights and management, fisheries, interstate water rights, irrigation, and reservoir operations. To better understand the current and future hydrology of the Tongue River watershed and its role in water use decision making, this project began in 2022.

Future hydrology estimates (2070-2099) will be extracted from an existing database containing two future climate scenarios and 32 different climate models. These data will be used in conjunction with a river system model and input from the Northern Cheyenne Nation and other project partners, such as the Tongue River Water Users Association, to produce estimates of future streamflow throughout the Tongue River watershed. Project partners will provide input on where future streamflow estimates will be produced and what forecast future climate ensemble members will be used. The river system model will include irrigation withdrawals and reservoir operations, ensuring future streamflow estimates to account for these processes. This project will use ensemble members to determine future streamflow estimates and will work with the Northern Cheyenne Nation and other project partners to ensure future climate ensemble members of interest are included.
References:
Seager, R., Hooks, A., Williams, A. P., Cook, B., Nakamura, J., & Henderson, N. (2015). Climatology, Variability, and Trends in the U.S. Vapor Pressure Deficit, an Important Fire-Related Meteorological Quantity, Journal of Applied Meteorology and Climatology, 54(6), 1121-1141. https://doi.org/10.1175/JAMC-D-14-0321.1
Below are partners associated with this project.
Atmospheric warming is driving:
- a shift in precipitation from snow to rain
- changing precipitation intensity and seasonality
- increasing atmospheric demand for moisture in mountain river watersheds across the western United States (Seager and others, 2015).
These changes will likely alter the timing and quantity of streamflow in rivers draining mountains. The Tongue River flows from the Bighorn mountains in north-central Wyoming into Montana to join the Yellowstone River at Miles City, Montana. The Tongue River is a minimally studied river that is important to Tribal water rights and management, fisheries, interstate water rights, irrigation, and reservoir operations. To better understand the current and future hydrology of the Tongue River watershed and its role in water use decision making, this project began in 2022.

Future hydrology estimates (2070-2099) will be extracted from an existing database containing two future climate scenarios and 32 different climate models. These data will be used in conjunction with a river system model and input from the Northern Cheyenne Nation and other project partners, such as the Tongue River Water Users Association, to produce estimates of future streamflow throughout the Tongue River watershed. Project partners will provide input on where future streamflow estimates will be produced and what forecast future climate ensemble members will be used. The river system model will include irrigation withdrawals and reservoir operations, ensuring future streamflow estimates to account for these processes. This project will use ensemble members to determine future streamflow estimates and will work with the Northern Cheyenne Nation and other project partners to ensure future climate ensemble members of interest are included.
References:
Seager, R., Hooks, A., Williams, A. P., Cook, B., Nakamura, J., & Henderson, N. (2015). Climatology, Variability, and Trends in the U.S. Vapor Pressure Deficit, an Important Fire-Related Meteorological Quantity, Journal of Applied Meteorology and Climatology, 54(6), 1121-1141. https://doi.org/10.1175/JAMC-D-14-0321.1
Below are partners associated with this project.