Historical Operation Data of 256 Reservoirs in Contiguous United States

Reservoir operations face persistent challenges due to increasing water demand, more frequent extreme events, and stricter environmental requirements. Historical operation records are crucial to investigating real-world reservoir operations, which integrate prescribed operation rules, empirical knowledge of operators, and regulatory response to extreme events. This dataset offers processed daily operation records—including inflow, outflow, and storage—for 256 major reservoirs across the Contiguous United States (CONUS) from 1990 to 2019. The reservoirs were selected from the dataset of Li et al. (2023), which includes 452 reservoirs, based on two criteria: (1) a minimum of 25 years of records (starting in 1990 and ending in 2014 or later), (2) less than 10% missing data during the study period. To enhance data quality, we remove the outliers of storage data with abnormal sudden storage changes even when inflows remain stable, and use linear interpolation to fill missing values, resulting in continuous daily records. Additionally, daily water surface elevation data are included for 217 of the 256 reservoirs. Related findings on changes in reservoir storage and operations are published in Chen and Cai (2025, Water Resources Research).