US hydropower generation is expected to recover in 2026, even as snow drought conditions in parts of the western US constrain water availability, according to the U.S. Energy Information Administration.
In its April Short-Term Energy Outlook, the agency forecasts output will rise by 5% to 259bn kWh, up from 245bn kWh in 2025. Despite the increase, generation will remain 1.8% below the 10-year average and account for around 6% of total US electricity supply.
Hydropower output continues to depend heavily on seasonal precipitation and snowpack levels. Snowpack acts as a natural reservoir, gradually releasing water into river systems. However, unusually warm winter temperatures across the western US have reduced snow accumulation and triggered early melting.
Although overall precipitation has been close to normal, a March heatwave accelerated snowmelt in California, the Southwest and parts of the Northwest. As a result, lower water availability is expected during the peak spring and summer generation period.
In the Northwest, which holds more than one-third of US hydropower capacity, generation is projected to reach 125bn kWh in 2026. This would mark a 17% increase from 2025, but still sit 4% below the long-term average. Earlier in the winter, a series of atmospheric rivers boosted output in December and January, though they also caused significant flooding.
In California, hydropower generation is forecast at 28.5bn kWh, down 6% from 2025 but 15% above the 10-year average. Reservoir levels remain relatively strong, with major sites above historical averages as of early April. However, snowpack levels are significantly below normal across the Sierra Nevada, and early melting has raised concerns about reduced inflows later in the year.
