MONTANA RESERVOIR REPORT

Last Updated: December 28, 2025

Montana's dams and reservoirs are critical for water supply, recreation, and flood control. Among these, Flathead Lake at Polson, MT, is a significant reservoir whose water levels are closely monitored. As of the latest observation on December 28, 2025, the elevation of the reservoir water surface was at 2892 feet above datum, which is slightly above the average level of 2889.51 feet. This small increase suggests that the reservoir is holding more water than usual for this time of year. While this may not be cause for immediate concern, it is an abnormal condition that warrants attention. Factors like unusual weather patterns, variations in snowpack, and river flow can affect storage levels, and these factors are typically monitored by multiple data sources to ensure the accuracy of this information.

The above-normal water level at Flathead Lake could be indicative of various conditions in the region. A heavier than average snowpack melting into the rivers that feed the lake, increased precipitation, or reduced water usage downstream could all contribute to this rise in water level. It is also essential to consider that unusual climatic conditions, possibly influenced by broader patterns such as El Niño or La Niña, may be impacting snowpack and precipitation. The implications of these abnormal conditions can range from positive outcomes like improved water availability for the dry season to negative effects such as potential flooding if the levels continue to rise and exceed the dam's capacity. Continued monitoring and cross-referencing with other data sources will be crucial to manage the reservoir effectively and prepare for any required action to maintain safety and water balance in the region.

Montana has many reservoirs and dams that provide water for irrigation, hydropower, and recreation. Some notable reservoirs include Fort Peck Lake on the Missouri River, Hungry Horse Reservoir on the Flathead River, and Lake Koocanusa on the Kootenai River. These reservoirs receive water from various streams, rivers, and creeks in the surrounding areas, with snowpack and mountain melt contributing significantly to the water supply. The general hydrology of Montana is influenced by its mountainous terrain, with the western part of the state having a wetter climate and the eastern part being more arid. Record levels have been observed in recent years due to heavy snowfall and precipitation, but the state has also experienced drought conditions in some areas. Seasonal trends show that spring and early summer are the wettest times of the year, while late summer and fall are typically drier. Overall, reservoirs and dams play an important role in managing Montana's water resources and supporting various industries and recreational activities.

Montana has many reservoirs and dams that provide water for irrigation, hydropower, and recreation. Some notable reservoirs include Fort Peck Lake on the Missouri River, Hungry Horse Reservoir on the Flathead River, and Lake Koocanusa on the Kootenai River. These reservoirs receive water from various streams, rivers, and creeks in the surrounding areas, with snowpack and mountain melt contributing significantly to the water supply. The general hydrology of Montana is influenced by its mountainous terrain, with the western part of the state having a wetter climate and the eastern part being more arid. Record levels have been observed in recent years due to heavy snowfall and precipitation, but the state has also experienced drought conditions in some areas. Seasonal trends show that spring and early summer are the wettest times of the year, while late summer and fall are typically drier. Overall, reservoirs and dams play an important role in managing Montana's water resources and supporting various industries and recreational activities.