Flathead Lake Data
September-2-2025_Lake-Data
The water supply forecasts and inflows did not change much this week. Project outflows will remain fairly stable. The project drafts to near 2891 ft by October 31 to mitigate the impacts of wave action on shoreline erosion. The range of forecast posts will start up again next spring.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
August-25-2025_Lake-Data
The water supply forecasts did not change much this week. The streamflow forecast for this week (subject to change) estimates that the lake will remain in the top 12 inches through August 28 and dip slightly below to near 1.2 ft below full pool on Labor Day.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
August-17-2025_Lake-Data
Please be aware the Flathead Lake USGS gauge has malfunctioned and the USGS has been notified. The streamflow forecast for this week (subject to change) estimates that the lake will remain in the top 12 inches through August 26 and dip slightly below to near 1.2 ft below full pool on Labor Day.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
August-11-2025_Lake-Data
The water supply forecasts did not change much this week. The streamflow forecast for this week (subject to change) estimates that the lake will remain in the top 12 inches through August 27 and dip slightly below to near 1.2 ft below full pool on Labor Day.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
July-29-2025_Lake-Data
Precipitation in July has been nearly 300% of normal. The streamflow forecast for this week (subject to change) estimates that the lake will remain in the top 12 inches through most of August.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
July-21-2025_Lake-Data
The streamflow forecast for this week (subject to change) estimates that the lake will remain in the top 12 inches through August 16 and in the top 18 inches for most of August.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
SKQ Drought Management Plan
Streamflow conditions in the Flathead Basin remain below normal and similar to 2023 and 2024 the project is being operated to increase the likelihood of meeting refill and minimum instream flow requirements (see SKQ’s drought management plan). January was incredibly dry in the basin and snowpack in the Northfork of the Flathead is low. However, there are still snow building months ahead.
Both weather and streamflows are highly uncertain. A warm and rainy event can rapidly increase streamflows in the spring, and similarly a cold and dry event can keep the streamflows quite low compared to normal. Temperatures, precipitation, and snowpack conditions such as density, all play a part in determining how high or low stream flows move as well as the timing of the runoff. If an early runoff is detected, EKI will coordinate flood risk management deviations with the USACE as needed to refill the lake.
SKQ project outflows and the Flathead Lake elevation are dependent on many variables including lake inflows, weather, the demand for electricity, and non-power constraints such as the downstream fishery and flood risk management needs.
