New Commission Takes on River Erosion

By Beacon Staff

The Flathead River is known for its beauty, its glacial history and great recreational opportunities. Among some riverfront landowners, it is also known for eating up large chunks of their land as the levels of Flathead Lake constantly change.

Erosion has caused enough consternation among landowners that an official commission was created in April in coordination with county and state officials to help deal with river and land matters.

The Flathead County River Commission is tackling several aspects that come with living near the water, including pollutants, riverbank stabilization and farming procedures.

County Commissioner Joe Brenneman said he helped create the FCRC because he thought it would be helpful to those most affected by area rivers. Members of the commission include four riverfront landowners, representatives from Fish, Wildlife and Parks and the Flathead Conservation District, as well as a county commissioner.

Recently, the FCRC began looking at various riverbank stabilization methods. Brenneman said the Flathead River is unique to many rivers in the state because Flathead Lake’s water levels are controlled, causing a ripple effect upstream.

“In the lower 22 miles of the river, since they keep Flathead Lake artificially high, it backs the water up the river,” Brenneman said. “As a result, that water doesn’t go down to where river banks have historically been and its kept up the level where it’s almost even with the ground.”

FWP representative Mark Deleray said waves from the wind and boats, the backup from dams and natural channel migration can cause erosion along the river’s edge.

“All those different forces are playing at different sites,” Deleray said.

For some landowners, this can mean slouching banks and losing land to 30-foot drop-offs. As part of an $18,000 grant from the Department of Environmental Quality, the FCRC is exploring different approaches to riverbank stabilization.

The Sept. 29 meeting was held on the banks of the Flathead River as a fall storm moved in. Commission members walked along banks, admiring the new trees and grass that landowner Rusby Seabaugh put in on his property 21 river miles up from the lake.

Seabaugh used various techniques, with different rock sizes, trees and fences to keep the ground from falling into the 30-foot depths of the river below. He also sloped his riverbanks and has an area of “coconut logs,” which are bundled coconut husks that willow trees can grow through.

“It does help, it’s really no question,” Seabaugh said.

Though he is now a member of the FCRC, Seabaugh started experimenting with stabilization techniques on his own.

The commission visited three sites, each with its own unique challenges. By communicating with landowners and studying what works and what does not, the FCRC hopes to provide more comprehensive information on battling erosion.

Riverbank stabilization has seen some drastic permutations in the last few decades. A popular method of the 1960s was called “Detroit Riprap,” meaning landowners lined the banks with old automobiles to act as soil anchors. The rusting steel bodies can still be seen on many rivers in Montana, including the Flathead.

Concrete was also a popular option in the past, but it was determined by the Department of Environmental Quality to be detrimental to the environment. The latest riprap evolution is using different trees, grasses and planting techniques to stabilize the riverbank.

There are other river issues the FCRC plans on covering. As part of the DEQ grant it received almost immediately after forming, the commission is charged with arranging a study on general practices regarding agricultural land in the Flathead valley, with special attention to river-side properties.

Brenneman said this means figuring out how much land is being used for farming and what is being grown, with potential to study fertilizers. Another task is to determine the total maximum daily load of dirt and pollutants the river can take while still safely meeting water quality standards.