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Oak Ridge updates hydrologic data to help hydro operators

October 20, 2022

Lab addresses extreme weather, energy demand changes.

To help hydropower operators prepare for extreme weather events and climate-related shifts in seasonal energy demands, the U.S. Department of Energy’s Oak Ridge National Laboratory (ORNL) is providing new hydrologic data.

Federal researchers downscaled global climate projections and simulated future hydrologic conditions at 132 federal hydropower facilities across the United States. These stations account for about half of all U.S. hydropower capacity, and supplies public power utilities and rural electric cooperatives in 33 states.

The data are intended to inform water management plans based on reduced water availability as well as anticipated changes to operational schedules and seasonal water consumption. These models provide a state-by-state roadmap for long-term planning.

Using a suite of numerical models and statistical methods, ORNL researchers assessed each facility, simulating future streamflow, hydropower operations and reservoir evaporation. Based on the simulations, researchers also estimated future energy demand affected by changing climate conditions.

“The intensification of future extreme events, including both floods and droughts, is one of the most critical issues threatening the resilience of U.S. hydropower systems and infrastructure,” said Shih-Chieh Kao, ORNL’s water power program manager.

Another challenge for hydropower operations is the observed trend of an earlier start to snowpack meltoff in the western region. Earlier runoff may leave less water for hydropower generation during summer months, when energy demand grows.

Rising air temperatures lead to increased evaporation, which also strains the water supply for agricultural use and urban water utilities.


ORNL worked with DOE’s Water Power Technologies Office and other federal agencies including Pacific Northwest National Laboratory (PNNL), and Texas A&M University, building on two rounds of previous hydroclimate assessments conducted over the past 10 years. The study stems from regular updates to global climate projections from the Coupled Model Intercomparison Project.

To provide more assistance to hydropower stakeholders, DOE is extending its research to non-federal hydropower facilities where operators may not have access to or the resources to study and address climate challenges.

The study was directed by the SECURE Water Act of 2009 and supported by the Water Power Technologies Office in DOE’s Office of Energy Efficiency and Renewable Energy.