FROM THE VICE PRESIDENT
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Vision is published annually by The University of Montana Office of the Vice President for Research and Development and University Relations. It is printed by UM Printing & Graphic Services.
PUBLISHER: Daniel J. Dwyer. MANAGING EDITOR AND GRAPHIC DESIGNER: Cary Shimek. PHOTOGRAPHER: Todd Goodrich. CONTRIBUTING EDITORS: Brianne Burrowes, Brenda Day, Judy Fredenberg, Joan Melcher, Rita Munzenrider, Patia Stephens and Alex Strickland. WEB DESIGN: Patia Stephens. EDITORIAL OFFICE: University Relations, Brantly Hall 330, Missoula, MT 59812, 406-243-5914. MANAGEMENT: Judy Fredenberg, Office of the Vice President for Research and Development, 116 Main Hall, Missoula, MT 59812, 406-243-6670.
University helps repair shore of Flathead Lake
By Vince Devlin
At a whopping 3 feet a year, the North Shore of Flathead Lake has been disappearing, swallowed by waves that pound relentlessly during the lake’s notorious storms.
It’s nothing a few hundred cement trucks and several million dollars couldn’t fix, but it has taken The University of Montana to come up with a solution that doesn’t produce a concrete ribbon along the shoreline. The University also helped broker an agreement among several parties sometimes at odds on other issues.
The solution? Help the lake heal itself.
The way? With gravel. Lots of gravel. Thousands of cubic yards of it.
And Christmas trees. Thousands of them.
Despite how enormous that makes the project sound, the UM assistant research professor spearheading it calls it a “minimalist” approach. It costs a fraction of what a traditional seawall would, and it’s a lot more natural.
“The gravel gives the waves something to do instead of eroding the land,” says Mark Lorang of UM’s Flathead Lake Biological Station. “The more the waves move the gravel around, the better the gravel gets at stopping the waves. It shuts the erosion down to glacial-like speeds.”
The gravel is for the lake shoreline near the mouth of the Flathead River, but the river poses a problem in and of itself. It does little good to protect the land along the lake if river currents still will erode it from the backside.
That’s where the Christmas trees come in.
Gravel along the riverbanks would simply wash away. But Lorang and his colleagues are using a technique they’ve had success with on the Sacramento-San Joaquin River Delta in California.
They’re piling discarded Christmas trees — called “bush bundles” — from Flathead Valley residents between untreated wooden posts they’ve driven into the riverbed. The bundles are then tamped down into a not-quite-solid mass along the riverbanks. During the next few years, sediment will be trapped behind the trees and build up, creating a riparian zone where plant and tree root systems will help thwart erosion.
The best part, Lorang says: The day will come when the trees have rotted away and any posts that haven’t followed suit will be removed. The gravel beaches on the North Shore will look like every other gravel beach on Flathead Lake. You really won’t know that anything’s been done.
But the land won’t be disappearing at the rate of 3 feet a year anymore.
It wasn’t always like this. The natural rise and fall of the lake level protected the shoreline. There was even a time when a delta extended a mile and a half into the lake where the Flathead River enters from the north near Bigfork.
UM’s association with the lake is nearly as old as the University itself. Professor Morton J. Elrod established the Flathead Lake Biological Station in 1899, just six years after the University was chartered, and Lorang says Elrod’s early research is invaluable to the work being done today.
“There’s a 100-year history of ecological work done by the biological station,” Lorang says. “The level of documentation is a gold mine.”
includes aerial photographs of the North Shore from the 1930s —
before Kerr Dam was commissioned on the southern outflow in 1938 —
showing the delta that once extended
The dam changed the lake. It held more water back for longer periods, creating the high-water erosion now prominent in the lake’s shallowest areas — the North Shore, Polson Bay and near Elmo.
In 1993 the Federal Energy Regulatory Commission ordered the now-defunct Montana Power Co., which then owned Kerr Dam, to repair the damage being done to the U.S. Fish and Wildlife Service-managed Flathead Waterfowl Production Area on the North Shore. When PPL Montana took over operation of the dam, responsibility fell to it.
That the area is taken care of is of great interest to the Confederated Salish and Kootenai Tribes, which have the option of buying the dam in 2015.
If you follow the political landscape in western Montana at all, you can see that brings to the table two entities — the U.S. Fish and Wildlife Service, and the tribes — that have been involved in a very public and heated battle over another issue, management of the nearby National Bison Range.
Add in that the only access to the eastern side of the river where much of the work must take place is a private landowner involved in a lawsuit with PPL Montana, and you might have a recipe for a stalemate when it comes to building beaches and restoring wetland habitat on the North Shore.
“I truly believe that without the University, this never would have happened,” Lorang says. “It took a neutral, non-biased party that’s interested in doing what’s best for the lake, as opposed to making a profit, to get PPL, the Fish and Wildlife Service, the tribes and private parties to make this leap of faith.”
And a leap of faith it is, Lorang says.
“People were skeptical,” he says. “Will gravel work? Will Christmas trees work? But we’ve all come together with one goal — to solve erosion.”
For Lorang, whose doctorate is in oceanography, it’s the perfect opportunity to put his skills to use inland. He focused on wave mechanics and sediment transport on beaches — particularly gravel beaches.
When the project is done by 2009, it will have taken 30,000 cubic yards of gravel from a glacial deposit in the mountains above nearby Woods Bay.
“We wanted to extract from areas where it would have the least environmental impact,” Lorang says.
The research professor is hesitant to estimate a final price tag, but says PPL Montana is $2 million into it so far — a lot of money, but nowhere near the cost of constructing seawalls, which was estimated at $8 million way back in 1993 and would no doubt be much more expensive now.
Of course, if you build a seawall, you’re done. Doing it this way, with gravel and Christmas trees, which Lorang calls a “soft solution,” will require monitoring in the years to come. UM students already have begun studying how fish will use the new habitats, researching what effects flowering rush — an invasive plant that likely will take hold in the riparian areas — may have, and doing bird counts in an area with three active eagle nests.
But they expect to establish 37 acres of new wetlands habitat, and by doing it UM’s way, Flathead Lake will have a chance to heal itself.
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