Wednesday, May 22, 2024

Flathead Lake level drops prematurely

Hagadone News Network | June 29, 2023 12:05 AM

If people have noticed that the level of Flathead Lake appears to be dropping much sooner than normal, it’s not a figment of their imaginations. Instead, says Brian Lipscomb, CEO of Energy Keepers which operates the SKQ Dam, it’s a tangible result of a warming climate.

The lake level peaked at full pool June 12, and “immediately started to sag” says Lipscomb. It’s 9 inches below full pool now and, unless precipitation dramatically increases, is expected to be 18 inches below full pool in two weeks, by July 12.

According to Energy Keepers, without substantial precipitation or an increase in streamflows, the lowest level this summer is anticipated to be 1.8 feet below full pool. The lake typically sits close to full pool all summer long.

Lipscomb says Energy Keepers anticipated the drop in streamflows and worked with the Army Corp of Engineers to fill the lake in May when the snowmelt was at its peak. However, May’s warm wet weather brought a below-normal snowpack gushing out of the mountains, leaving just a trickle for June.

The streamflow average this month for northwest Montana’s basins was forecast at 40% of average and the forecast for July is 36% of average. And farther north, into Canada, the drying trends are even more extreme – contributing to the forest fires that have sent smoke tumbling across the border.

Lipscomb noted that the Kootenai sub-basin, which includes both the Flathead and Kootenai river drainages, is 70 percent of normal. Yet, last year it was considerably above average.

In the decade that he’s been at the helm of Energy Keepers, “the oscillation in cycles seems be getting more intense,” Lipscomb says, even as the La Nina and El Nino weather cycles become more extreme.

Last year was the third in a La Nina cycle, bringing above average precipitation to the Northern Rockies. This year marks the beginning of the hotter, drier El Nino cycle. In the Mission Valley, snow arrived in October and didn’t leave until April. However, the actual mountain snowpack was lower than usual in this region and left quickly.

In an attempt to fill the lake, Lipscomb says, Energy Keepers decreased outflows from the dam to the minimum streamflow allowed for the lower Flathead River at the beginning of June. But that doesn’t compensate for the lack of water coming in.

Hungry Horse Reservoir, which collects water from the South Fork of the Flathead River, “is several feet below full pool already,” he says.

Without a significant decrease in the carbon production that’s fueling rapid climate change, Lipscomb predicts hotter, dryer summers are ahead for the Flathead basin and across the West.

“I think this is our future – we’re just seeing the tip of it right now,” he says.

As to the immediate impacts of a lower lake level, Lipscomb anticipates that public boat ramps will remain viable through the summer. Boaters will need to be more vigilant close to shore and dock owners – especially those with boat lifts – need to keep a close eye on water levels.

“My advice to dock owners over time is to think about a different design that’s more flexible” and can better accommodate fluctuating water levels, he says.

The lower stream flows have already taken a toll on the dam’s ability to generate power. However, Lipscomb doesn’t anticipate any reduction in irrigation water for those farmers whose summer water supply is replenished by the Flathead River pumping station, which is located north of the dam.

As the summer progresses, he says, Energy Keepers and the Bureau of Reclamation, which operates Hungry Horse Dam, are apt to face “a lot of pressure to be moving water downstream for fish and other resources.”

To Lipscomb, that’s a sign of the times. “Over time the ability to have the lake as full as it is through summer is going to become more and more difficult.”

With the National Weather Service predicting a hot, dry summer ahead, he offers this glum advice: “Get out there and enjoy the lake now because it’s going to get more difficult and we’re going to be in a lot of smoke anyway.”