An Integrated Hydroclimatic Assessment of Future Reservoir and Hydropower Operations in the U.S.

Journal Article · Tue Sep 16 00:00:00 EDT 2025 · Earth's Future

DOI:https://doi.org/10.1029/2025EF006203· OSTI ID:3002121

Bokhari, Hussain H. ^[1]; Corsi, Fabio ^[1]; Miara, Ariel ^[2]; Fekete, Balazs M. ^[1]; Gangrade, Sudershan ^[3]; Kao, Shih-Chieh ^[3]; Jackson, Nicole D. ^[4]; Vorosmarty, Charles J. ^[1]

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1. City Univ. of New York (CUNY), NY (United States)
2. National Renewable Energy Laboratory (NREL), Golden, CO (United States)
3. Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
4. Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)

The engineering of rivers by dams is a formative feature of human-nature systems and the interconnectivity of water, energy, and the climate. Sufficient and broad-based representations of dams in large-scale hydrological models prove essential to mapping their extensive regulation of river flow and biogeochemistry and gauging climate-linked provisions, including freshwater supply and hydropower. We present an integrated modeling framework to investigate future streamflow and hydropower generation in the Contiguous U.S. (1990–2075), leveraging an ensemble of six downscaled and bias-corrected General Circulation Models (GCMs) from the high-end SSP585 scenario of the CMIP6. To achieve this, we develop a reservoir operations and parameterization scheme for 1,384 dams in a high-resolution river network, including simulated hydropower generation for 326 dams. For the GCM ensemble mean, we simulate a widespread increase in regulated streamflow into the late-century (11% annual and 17% in winter for the dam median) with region-specific changes in summer streamflow that feature prominent declines in the Northwest (−7%). Mediation by reservoirs is shown to dampen intra-annual streamflow changes, delivering additional summer releases that partially mitigate declining flows. Total hydropower generation is projected to increase modestly (+3%), with boosted generation in the winter (+9%) and spring (+5%) offsetting declined summer generation (−3.4%), suggesting strong adaptation potential for hydropower in the future energy portfolio. Further analysis reveals that the choice of GCM, particularly in western regions, has significant bearing on projected streamflow and hydropower changes.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Energy Efficiency and Renewable Energy (EERE)
• Grant/Contract Number: AC05-00OR22725; AC36-08GO28308; NA0003525
• OSTI ID: 3002121
• Alternate ID(s): OSTI ID: 3011867
• Journal Information: Earth's Future, Journal Name: Earth's Future Journal Issue: 9 Vol. 13; ISSN 2328-4277
• Publisher: American Geophysical Union (AGU)
• Country of Publication: United States
• Language: English