CALIFORNIA RESERVOIR REPORT

Last Updated: January 1, 2026

California's dam and reservoir system is currently experiencing a mix of conditions as we head into 2026, marked by both concern and relief. Recent storms have brought much-needed water to several reservoirs, which had been suffering from prolonged drought conditions. However, this influx has also raised concerns about flooding and the capacity of dams to manage the sudden increase in water levels. For instance, Lake Cachuma and Lake Hodges are being closely monitored ahead of storms to prevent potential overflow, while officials celebrate the relief the rains bring to the snowpack and water supply.

Analyzing the latest reservoir data, Lake Almanor, Antelope Lake, Lake San Antonio, and Berryessa show storage levels significantly above their average, indicating they have benefitted from the recent precipitation. Conversely, reservoirs like Bear and Beardsley Lake are below average, with Bear's storage at critically low levels. This disparity highlights the uneven impact of late-2025 and early-2026 storms across the state. The heavy rains and snowfall have also bolstered the vital snowpack, which California depends on for its summer water supply, although officials caution that additional snow accumulation is still needed. While the current situation eases some drought concerns, it also brings challenges such as managing increased water flows, potential flooding, and ecological impacts on wildlife, especially with the recent history of extreme weather events like wildfires and intense heatwaves. As the state navigates these complex conditions, continued monitoring and adaptive water management are essential to balance the benefits of increased water storage with the risks of sudden environmental changes.

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.