Drought conditions influence dam operations
Kerr Dam operators were able to raise Flathead Lake to its required level by June 15, but the lake could start dropping by up to a foot under a drought management plan.
The current flow below the dam is about 11,000 cubic feet per second and the lake elevation, as of July 2, was 2,892.25 feet. That level is 0.75 feet from full elevation of 2,893 feet — the required level that Flathead Lake must reach under the Federal Energy Regulatory Commission license.
Flathead Lake reached full pool of 2,893 feet above sea level June 15. Kerr Dam on the Flathead River near Polson is operated by NorthWestern Energy. The dam’s ownership will be transferred to the Confederated Salish and Kootenai Tribes in September.
Drought conditions however have not allowed NorthWestern to maintain full pool level. As a result, NorthWestern began implementing its drought management plan that it developed in 2002.
The first step in the plan is to reduce the lake elevation from June 15 to Sept. 1 from 2,893 feet to 2,892 feet. If after reducing the lake level, if flows into the lake are not adequate to maintain the new elevation, dam operators have two choices: They can increase flows into Flathead Lake from Hungry Horse Reservoir, or they can match the outflows of Kerr Dam to what the lake is receiving at the mouth of Flathead River near Bigfork.
The Bureau of Reclamation has increased outflows from Hungry Horse temporarily to support Kerr Dam operations. Depending upon flow conditions, NorthWestern will seek additional license variances as necessary throughout the summer to support a Flathead Lake elevation of at least 2,892 feet, NorthWestern representative Burch Larcombe said.
This is déjà vu all over again for Wayne Schile, a lakefront homeowner who started SHORE — an organization in 2001 to represent homeowners and businesses on Flathead Lake who are affected by the low lake levels.
SHORE worked with former Kerr Dam operators in 2001 and had a handshake agreement with them that the lake might drop, but no more than six inches. That agreement seems to have been forgotten about Schile said this week.
Schile worked with PPL, the former dam licensee, to obtain assurances that the lake during a drought wouldn’t drop more than six inches. Lower lake levels harm tourism-related businesses and property owners, Schile said.
“Why do anything that upsets the ability of these retailers in Polson and around the lake to operate a business?” he said.
“We get to a foot down, and people start losing propellers,” Schile said. “We don’t need to do that when the water is available.”
Schile recommends that NorthWestern take water that is stored in Hungry Horse Reservoir, upstream from Flathead Lake on the South Fork of the Flathead, and move that water into Flathead Lake. Unfortunately, he said, “We can’t force them to do it.”
Outflows from Kerr Dam this week are dropping significantly.
On June 30, Kerr Dam was releasing about 13,0000 cubic feet per second of water. On Tuesday, water releases were just under 8,000 cfs. Meanwhile, the South Fork of Flathead River through Hungry Horse Reservoir is averaging about 2,500 cfs.