Erosion help may be near

Lower lake level proposed in fall

After decades of uncurbed erosion on Flathead Lake, a design has been developed to protect waterfowl production areas at the head of the Lake and PPL Montana proposes to lower the lake's elevation in the fall to reduce storm-driven erosion around the lake.

The proposal to draft the lake by a foot around Nov. 1 is a remarkable turnaround for the power company that operates Kerr Dam.

The drawdown is expected to reduce shoreline erosion around the lake and reduce damage to docks and other shoreline structures. It also will enhance the effectiveness of the gravel beach project proposed for the north shore, said project designer Mark Lorang of the University of Montana's Yellow Bay Biological Station.

"This is major. It's huge," Lorang said. "It will help everybody around the lake, not only for erosion, but also for seawalls and docks. We always get storms on the lake starting around Halloween. That's when they start coming in."

The only party that will not benefit from the lake drafting proposal is PPL Montana, Lorang noted.

Jon Jourdonnais, the power company's director of hydroelectric licensing and compliance, said PPL will forgo roughly $200,000 in annual power-production revenue as a result of the drawdown.

"I think the company looked at all the issues related to lake levels lakewide, including power generation and effects on the lower river, and saw an opportunity to provide a benefit to a lot of users," Jourdonnais said. "It's been a long process to work through all the issues and potential conflicts, but I think the company is pretty hopeful that the public will embrace this. And I think that it will, because this will do some great things."

Historically, Flathead Lake's elevation has averaged about 2892.2 feet on Nov. 1. The proposed one-foot elevation drop at that date will substantially curb erosion around the lake, he said.

The biological station has for years called for lowering the lake's elevation during the fall as the most effective way to curb shoreline erosion, which will in turn improve the lake's water quality.

Since Kerr Dam became operational in 1938, the north shoreline has receded more than a mile in places, Lorang said. And that translates to about 2,000 acres of land that has been washed away.

Since 1985, Lorang has called for the use of "dynamic equilibrium beaches" to curb erosion on the north shore, rather than traditional armored seawalls that can separate the lake from the wetlands behind the shoreline.

In the late 1990s, a U.S. Fish and Wildlife Service proposal to protect its waterfowl productions areas with seawalls was met with opposition from Lorang and others.

The idea was abandoned and the shoreline continued to recede - dramatically in some locations. Ten years ago, there were cottonwoods and cattails sheltering a pond at the interior of the waterfowl production area east of the river.

Now that pond is part of the lake.

Lorang's approach to shoreline protection was basically ignored until two years ago, when state Sen. Bob Keenan, R-Bigfork, used it to protect the badly eroding shoreline of his property at the head of the lake. A neighboring landowner followed suit last year.

Lorang's proposed design for the waterfowl production areas will involve an estimated 20,000 cubic yards of gravel, another 2,880 yards of cobble and 4,500 yards of additional fill material. The project will protect several sections of shoreline totaling about 8,000 linear feet.

Properly mixed, the various cobbles and gravels form an energy-absorbing beach that is shaped by wave action to provide increasingly effective erosion protection. The structures are not effective in many locations, but they are perfectly suited for the wave patterns that batter the north shore.

Lorang said people often are skeptical of their effectiveness because they involve loose materials rather than armored concrete. But they have proven effective in many locations, including shorelines at Yellow Bay and Blue Bay.

Jourdonnais said the project cost is estimated at roughly $1.3 million - far less than the $7 million discussed for shoreline protection designs in the late 1990s.

But the lake drawdown proposal will benefit the north shore project, he said.

"We won't need as rigorous of a design on the north shore that we would have if the lake was held up in the fall," he said. "The fall draft will provide greater certainty for its success."

The project will have to clear a series of regulatory and permitting hurdles, starting with the U.S. Fish and Wildlife Service.

"They will have to support the design and give us permission to go out and construct it," he said.

The Confederated Salish-Kootenai Tribes are co-licensees at Kerr Dam with PPL Montana. Jourdonnais said the tribal council already has reviewed and approved the company's proposals.

The project also will require approval from the U.S. Army Corps of Engineers, Flathead County, the Federal Energy Regulatory Commission and the Montana Department of Environmental Quality.

Despite all the bureaucratic scrutiny, Jourdonnais said he hopes the agencies have a "sense of urgency" to curb further shoreline erosion.

"They're going to need to be very helpful on the timeline," he said. "In the past, that has been somewhat of an issue."

PPL Montana plans to pay for the proposals, which are aimed at satisfying mitigation provisions in its 1998 relicensing agreement with the Federal Energy Regulatory Commission.

"If agencies want to do more than what we propose to do, that's where we will insist on cost sharing," Jourdonnais said.

Jourdonnais hopes the reviews and permitting can be complete by late 2007 so the project can be carried out when the lake is at its low elevation during the winter of 2007-08.

"It's actually going to do some things on the ground that people have been wanting to see happen for a long time," he said.

Reporter Jim Mann may be reached at 758-4407 or by e-mail at jmann@dailyinterlake.com