IDAHO RESERVOIR REPORT

Last Updated: January 1, 2026

In Idaho, recent observations of reservoir and dam conditions reveal that some water bodies are exhibiting abnormal storage levels for the period. Priest Lake, for instance, is showing a gage height of 1 foot when the average is 1.95 feet, indicating a lower-than-average water level. Similarly, Milner Lake at the Milner Dam, Salmon River Canal Co Reservoir near Rogerson, and Mud Lake near Terreton are all below their average gage heights, suggesting potential concerns related to water storage and management. On the other hand, Coeur d'Alene Lake is slightly above its average, which could be a sign of healthy inflow or reduced outflows.

Notably, the Salmon River Canal Co Reservoir stands out with a current gage height of 10 feet, which is significantly below the average of 23.73 feet. This stark difference could be attributed to factors such as lower than expected snowpack melt and/or reduced river flows, which in turn affect the reservoir's ability to replenish. Additionally, Little Wood Reservoir near Carey is storing 13,380 acre-feet of water, far below the average storage of 17,024 acre-feet, potentially impacting local water supply and ecosystem health. Investigating these discrepancies is essential for water resource management, especially considering how critical these reservoirs are for irrigation, domestic use, and ecological balance. It is also important to cross-reference with multiple data sources when possible to ensure the accuracy and reliability of the observed data. These abnormal conditions necessitate further monitoring and may demand adaptive water management strategies to mitigate their impacts on the communities and ecosystems that depend on these water resources.

Idaho has numerous reservoirs and dams that provide irrigation, hydropower, and recreational opportunities. Major reservoirs include Lucky Peak, Anderson Ranch, and American Falls. These reservoirs are fed by streams and rivers such as the Boise River, Snake River, and Portneuf River. The hydrology of the area is heavily influenced by snowfall in the surrounding mountains, particularly the Sawtooth and Rocky Mountains. Snowpack levels are closely monitored as they impact streamflow and reservoir levels. In recent years, drought conditions have led to lower snowpack levels and decreased reservoir levels. Record low levels have been seen in several reservoirs during drought years. Seasonal trends show higher reservoir levels during the spring and early summer due to snowmelt, with levels decreasing through the fall and winter. Overall, reservoirs and dams play a significant role in Idaho's water management and the state's economy.

Idaho has numerous reservoirs and dams that provide irrigation, hydropower, and recreational opportunities. Major reservoirs include Lucky Peak, Anderson Ranch, and American Falls. These reservoirs are fed by streams and rivers such as the Boise River, Snake River, and Portneuf River. The hydrology of the area is heavily influenced by snowfall in the surrounding mountains, particularly the Sawtooth and Rocky Mountains. Snowpack levels are closely monitored as they impact streamflow and reservoir levels. In recent years, drought conditions have led to lower snowpack levels and decreased reservoir levels. Record low levels have been seen in several reservoirs during drought years. Seasonal trends show higher reservoir levels during the spring and early summer due to snowmelt, with levels decreasing through the fall and winter. Overall, reservoirs and dams play a significant role in Idaho's water management and the state's economy.