Flathead Lake to Remain Below Full Pool this Summer
Warm and dry conditions have left the Flathead River Basin at low levels for the third year in a row, forcing Séliš Ksanka Ql'ispé Dam operators to keep the lake below its full pool of 2,893 feet
By Maggie Dresser
Following unseasonably warm and dry conditions, a fast spring runoff has left the Flathead River Basin at extremely low levels and will keep Flathead Lake below full pool this summer, according to Energy Keepers, Inc., which oversees hydroelectric operations on the largest freshwater lake west of the Mississippi.
The conditions forced Séliš Ksanka Ql’ispé (SKQ) Dam operators to aggressively fill Flathead Lake this spring while avoiding flood control limits as required by license minimums, Energy Keepers said in a Thursday press release.
According to current forecasts, Flathead Lake on June 19 will reach its maximum level for the year at 2,892.3 feet – just below a full pool of 2,893 feet. Lake levels will then begin to slowly recede, hitting 2,891.5 feet on July 12.
“These unprecedented dry conditions are not only taxing on resources, they are also extremely impactful to generation of electricity from the SKQ facility,” Energy Keepers, Inc. CEO Brian Lipscomb said.
The forecast marks the third year in a row of hot and dry conditions that have impacted Flathead Lake’s levels. The Flathead River Basin’s snow water equivalent (SWE) levels on June 5 was 72% of normal, according to U.S. Department of Agriculture (USDA) data.
“Fast snowmelt and earlier than normal runoff in the month of May rapidly decreased snowpack statewide. This potentially corresponds to less available water later in the summer,” Florence Miller, a hydrologist with the USDA’s Natural Resources Conservation Service (NRCS), said Thursday. Miller explained that water supply forecasts at the beginning of May were between 70% and 110% of normal streamflow for most of the state on May 1, to a range between 50% and 100% of streamflow forecasted on June 1.
According to the Northwest River Forecast Center, the water supply volume in 2023 was 64% of annual average while the water supply in 2024 was 74%.
Electricity generation will be 10%, or 393 gigawatt hours (GWh), below normal this year, which is enough electricity to power between 33,000 and 41,000 homes or a city the size of Missoula for a year.
To prepare for the diminished water supply, Energy Keepers, a corporation of the Confederated Salish and Kootenai Tribes (CSKT), this spring began coordinating with its partners and has implemented the license-required drought management plan, according to officials.
The U.S. Army Corps of Engineers on March 13 approved a deviation request to allow as much runoff as possible to be captured, bringing lake elevations to 3 feet from full pool on May 26. Minimum flows have been maintained ever since.
“Our goal was to coordinate actions to increase the chance of refill as early as possible while balancing needs for flood risk management,” said Leah Hamilton, a Northwestern Division Reservoir Control Center water regulator. “Every water year is different, and there is a lot of uncertainty in trying to accurately predict runoff several months into the future.”
Lakefront boat storage and dock access may be affected if water level forecasts come to fruition.