CALIFORNIA RESERVOIR REPORT

Last Updated: December 31, 2025

California's reservoirs and dams have displayed mixed conditions as we enter 2026, with some reservoirs experiencing higher-than-average storage levels while others remain below expected capacities. A series of December storms has brought much-needed precipitation, positively impacting snowpack levels critical for the state's water supply. However, despite these gains, the overall snowpack remains below average, raising concerns about water supply sustainability if the accumulation does not continue to improve. Key reservoirs such as Lake San Antonio and New Bullards Bar are reporting storage levels significantly higher than their averages, indicating beneficial storm contributions, whereas others like Donnells are showing negative storage, highlighting the uneven distribution of recent rainfall and snowmelt.

Analyzing the latest data, Lake Havasu near Parker Dam and Bridgeport re near Bridgeport show slight deviations from average water surface elevations, whereas more pronounced differences are observed in the Independence Lake near Truckee and Stampede Reservoir near Boca, indicating higher water levels. Storage levels in major reservoirs such as Lake Almanor, Berryessa, and Trinity Lake have also seen considerable increases, suggesting enhanced water reserves. Conversely, places like Donnell Lake near Dardanelle and Beardsley Lake near Strawberry report lower than average water surface elevations, which could be concerning if the trend continues. The current conditions are primarily tied to the state's snowpack and river flows, which are pivotal factors for replenishing reservoirs. While recent storms have provided some relief, officials stress the need for continued snow accumulation to bolster California's water supplies for the year ahead. The data reflects a delicate balance in the state's water management system, where strategic planning and conservation remain crucial to address the variability in weather patterns and their impact on water resources.

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.