CALIFORNIA RESERVOIR REPORT

Last Updated: December 29, 2025

California's dams and reservoirs are currently experiencing a mix of storage levels, with some recording higher than average storage and others facing deficits. Data as of December 29, 2025, shows that while Lake San Antonio is at an exceptionally high storage level of 270,863 acre-feet compared to its average of 132,675.92, other reservoirs like Donnell Lake are well below average, with a current storage of 4,792 acre-feet against a 4,844.66 average. These conditions reflect the impacts of recent weather events, including the Atmospheric River that brought significant rainfall to the region, affecting water inflows and storage dynamics. The clear and dry conditions forecasted by AccuWeather may provide a brief respite, but there's an anticipation of rain returning by New Year's, potentially influencing reservoir levels further.

Major reservoirs like Shasta Dam have seen a significant increase in storage, with current levels reaching 3,819,326 acre-feet, substantially higher than the average of 2,916,011.98, indicating a trend toward replenishment in some areas. Conversely, Oroville Dam's storage data is not provided, raising concerns about its status amidst corporate interests being blamed for driving the Colorado River to near-collapse, as reported by Liberation News. The state's water infrastructure is closely monitored, especially in the wake of extreme weather events such as the torrential rains and winds that have battered California, as showcased in recent atmospheric storm damage photographs. With the ongoing climate variability, the resilience and management of California's dams and reservoirs remain critical to addressing the state's water security challenges.

California has over 1,400 reservoirs and dams, which provide water for agriculture, industry, and households. Some of the major reservoirs in the state include Lake Oroville, Shasta Lake, and San Luis Reservoir. These reservoirs are fed by streams, rivers, and creeks such as the Feather River, Sacramento River, and San Joaquin River. The snowpack in the Sierra Nevada mountains is a crucial source of water for these reservoirs, as it melts during the spring and summer and fills the streams and rivers that flow into the reservoirs. However, drought conditions have been a major concern in recent years, with record low levels in some reservoirs. Seasonal trends show that reservoirs are typically at their lowest levels in the fall and winter, and reach their highest levels in the spring and summer. Overall, California’s reservoirs and dams play a vital role in managing the state’s water resources and ensuring a reliable water supply for its residents.

California has over 1,400 reservoirs and dams, which provide water for agriculture, industry, and households. Some of the major reservoirs in the state include Lake Oroville, Shasta Lake, and San Luis Reservoir. These reservoirs are fed by streams, rivers, and creeks such as the Feather River, Sacramento River, and San Joaquin River. The snowpack in the Sierra Nevada mountains is a crucial source of water for these reservoirs, as it melts during the spring and summer and fills the streams and rivers that flow into the reservoirs. However, drought conditions have been a major concern in recent years, with record low levels in some reservoirs. Seasonal trends show that reservoirs are typically at their lowest levels in the fall and winter, and reach their highest levels in the spring and summer. Overall, California’s reservoirs and dams play a vital role in managing the state’s water resources and ensuring a reliable water supply for its residents.