Anyone who has ventured to the shore of Flathead Lake recently may have noticed that its level resembles that of midsummer. That’s an anomaly, says Brian Lipscomb, the head of Energy Keepers Inc., which manages the tribally owned Séliš Ksanka Ql̓ispé Dam. 

Typically by now, the lake would be five or six feet below its full pool of 2,893 feet.

According to Lipscomb, the culprit is December’s record-setting "atmospheric river." The weather phenomenon, which brought extensive flooding and wind damage across western Montana, also delivered  238% of the normal amount of precipitation to the Flathead Basin. The 9.41 inches of moisture mostly fell as rain on top of existing snow, which tends to quickly swell rivers and lakes.

“This sent inflows into Flathead Lake soaring to 300% of normal,” he said. The deluges also created “a unique challenge for water management” in the basin, and downstream as well, with record-setting conditions chronicled across the entire Columbia Basin.

To prevent downstream flooding, he said Energy Keepers coordinated closely with the U.S. Army Corps of Engineers and the U.S. Bureau of Reclamation. “By utilizing all available system flexibility, operators successfully held the Columbia River just below flood stage at the Port of Vancouver,” he said. 

This feat required dam managers to fill regional storage reservoirs – including Flathead Lake, Lake Roosevelt, Lake Pend Oreille, and Dworshak and Umatilla reservoirs – to near capacity.

Lipscomb says EKI and its federal partners have begun rapidly drafting these reservoirs to accommodate spring runoff. That’s already apparent. On Jan. 1, the lake was at 2,892.8 feet, and by Tuesday, it was at 2,892.5.

“Residents should anticipate Flathead Lake reaching its lowest level for the season by late March,” Lipscomb said, which in most years means 10 feet below full pool, or 2,883 feet.

However, the amount of snow that accumulates in the mountains will be an important factor. “The lowest level we end up with at the end of March will be driven by the amount of snowpack we end up with,” Lipscomb says.

Drafting the lake now better enables Energy Keepers to manage the repercussions of a wet spring. “By lowering the lake levels, we are creating the necessary capacity – or 'room' – to capture and control potential floodwaters if heavy precipitation continues,” he says.

Of course, predictions can be fickle. While the short-term forecast from the National Weather Service predicts warmer temperatures and below-normal precipitation across the West in the next two weeks, the three-month outlook shows above normal precipitation for Montana, paired with normal to below-normal temperatures. Hopefully that translates into a deeper snowpack, which bodes well for skiers and irrigators.

As the season continues, Energy Keepers will continue to monitor the outlook and adjust the dam releases accordingly.

“Water management is not a 'set it and forget it' process,” Lipscomb says. “We stay in a cycle of constant adjustment, tuning our operations to accommodate weather patterns and snowpack levels as they change. Our goal is to maintain maximum flexibility so that we are prepared for either a wet or a dry spring, ensuring both local and downstream safety.”