7/6/2009 3:23:00 PM Channel maintenance means heavy lifting
By David Schueller
Lake Minnetonka's channels might not have the mystique of islands or bays.
But the busy waterways don't have time to shed tears.
Channels are some of the few places on the lake that have traffic jams during hot summer boating days or winter sled weekends. They attract anglers and the occasional law-breaking bridge jumper.
The thankless job of making sure there isn't a Lake Minnetonka chain of lakes falls on Hennepin County.
Channel maintenance is a hard job - hard because keeping 33 channels navigable requires working with rocks on the shoreline, dredging and removing trees.
"We do a lot of work to make sure that they're not eroding into the lake," said Joel Settles, supervisor with the county.
Count in tasks like placing and removing buoys and picking up trash at 19 shore fishing areas, and you've got the county's Lake Improvement Program.
While the county has done such work for more than a century, the program was approved by the County Board in 1978 and it also covers Lake Independence and Lake Sarah.
The program, which does not include the many smaller channels on Lake Minnetonka, involves two tasks that some have tried to shy away from in recent years - dredging and rip-rapping.
Rip-rap is a rock barrier that protects against wave erosion.
Tony Brough, a senior environmentalist who manages the Lake Improvement Program, said that because rip-rap is installed in most channels, erosion has lessened. That means the county only needs to dredge on a spot-by-spot basis, unlike in the past, he said.
"Most of our dredging now isn't really channel wide. It's more of a spot here, a spot there," Brough said, adding that the county tries to maintain channels at a depth of six to eight feet so boaters don't hit bottom.
Softer solutions for stabilizing shoreline have been pushed by some groups. The city of Minnetonka nearly went as far as requiring shoreline buffers on private properties under some conditions, but backed away from the proposal.
Settles said the heavy erosion potential on some of Lake Minnetonka's channels means a plant buffer alone won't do the job.
And even if property owners would agree to have more yard taken up by native vegetation, the county wouldn't have the access to install it, Settles said.
"Even if it would hold up to the wave action, which in most times it won't, we wouldn't be able to install that," Settles said.
The county usually installs rip-rap via a barge and a temporary easement, paid for with a shoestring budget of about $30,000 a year, which means only about one or two projects are done each year.
For 2010, a rip-rap project is scheduled, probably at Seton Channel.
In 2009 the county installed rip-rap in the Frog Island channel near The Commons in Excelsior.
Settles said that project, which had been permitted by other agencies like the Minnehaha Creek Watershed District (MCWD) and the Department of Natural Resources, received an unusual complaint about the rip-rap - unusual because residents typically ask the county to rip-rap areas earlier than it plans.
"That resident did not agree that erosion was sufficiently severe to require rip-rap, and that the rip-rap was basically overkill. ... We just basically couldn't find common ground," Settles said.
Not far from Frog Island, the MCWD has been working on a demonstration project on an erosion-prone point at The Commons, where it planned to plant woody vegetation between rocks to hold the land in place. The city of Excelsior agreed to maintain the point once the vegetation is established.
In channels, rip-rap isn't the only hard solution used to protect the shore.
In 1938 a Works Progress Administration project - part of the stimulus plan of Franklin Delano Roosevelt - had laborers build the concrete walls of the Narrows channel.
"That was all done by hand," Brough said.
Sheet piles are also used, which form a metal wall that looks like corrugated cardboard.
At the fishing area north of Tanager Lake on Browns Bay, the county is allowing the MCWD to mix vegetation with rip-rap, and the county will manage the site afterwords.
Settles said the county supports the idea of more shoreline buffers. But they have to fit the site, he said, and in channels, there just isn't space for it.
"In most of these channels, if you drive through them, there's a channel, and there's a house, and a yard, and we don't really have the room," he said.
Sometimes, things growing on shore can even be dangerous.
Last month an ash tree fell into Forest Lake channel.
"Anything that's blocking the channel is a hazard," Brough said.
Often, hazards are reported by boaters who happen upon them in channels, which means more work for those who keep the channels clear.
"The first guy through it is gonna find it," Settles said.
Reader Comments
Posted: Thursday, July 09, 2009
Article comment by:
HJD
How can we remind homeowners to kepp the channels free of grass clippings, leaves etc from their property?
