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Lake Independence has a problem with too much water

  • Article by: Tom Meersman
  • Star Tribune
  • November 12, 2013 - 4:55 PM

Lake Independence has a problem that some would envy: too much water.

Shorelines at the popular west metro lake have been brim-full for much of the past 10 years, and consistently high since the early 1990s — too high for shoreline owners, cities and natural resource managers.

Put simply, said Brad Spencer, council member for the city of Independence, the lake is clogged.

“The outlet channel used to be a creek, and now it just disappears into a wetland,” said Spencer. “It’s completely congested.”

The outlet, Pioneer Creek, has filled in with cattails so thick and numerous that huge masses of vegetation are holding back water from the 851-acre lake, about 15 miles west of Minneapolis.

Crews are scheduled to begin work this week to remove the vegetation, and will use specialized equipment brought in from another state.

The high water has created worsening problems around the lake.

At YMCA Camp Ihduhapi along the lake’s northeast border, trees are falling into the water. Along private property, beaches are eroding, and rain and wind bring waves that lap onto lawns of some of the low-lying lakeshore lots. And at Baker Park’s beaches on the southern end of the lake, the high water is washing away soil, rocks and plants that are part of a recent $750,000 shoreline restoration by the Three Rivers Park District.

Things got so bad that Independence, Medina and the Pioneer Sarah Creek Watershed Management Commission were considering changes in 2011 to expand to the entire lake a no-wake zone imposed near shorelines. That would have required thousands of boaters to drive at very slow speeds that didn’t create any waves.

“There would have been no water skiing, jet-skiing, and the fishermen wouldn’t have been able to get from one end of the lake to the other in under half an hour or 45 minutes,” said John Barten, Three Rivers director of natural resources management.

“It would have a huge recreational impact that is unacceptable.”

Fed up with the problems, the park district, two cities and local watershed commission have joined forces to share the $58,000 cost of cleaning out the creek and freeing up the lake so its water levels can fluctuate normally.

Re-creating the creek

Craig Jochum, a water resources engineering consultant for Independence, said the project will remove vegetation along 2,600 feet of the channel between Independence Road and just north of Pagenkopf Road. About 800 to 1000 feet of the channel is totally blocked with cattails, he said, and the rest contains “plugs” of vegetation every 100 feet or so.

A feasibility report on the clean-out says the channel has a “very mucky” bottom and its water is two feet deep on average.

“It really isn’t a traditional creek,” Jochum said. “It’s a wetland complex with a channel carved within it. There’s no bank that you can stand on.”

Part of the problem is that hybrid cattails have become the predominant species in the outlet marsh. “They are very aggressive and can be considered invasive,” said Barten.

The clean-out project will probably take a couple of weeks, Jochum said, and will use an excavator similar to a backhoe, but with customized supports that float it. The workers will dislodge and remove the vegetation, he said, but they will not dredge the creek.

“We’re going to open up the channel about 10 feet wide and 3 feet deep,” said Spencer. “That should let the [lake] water flow through there, and then the lake association is going to do some maintenance in the future to make sure it doesn’t grow back in.”

Linked problems

John Conlin, who has lived on the lake for 28 years, said the clean-out is long overdue because the water has been “sky-high for most of the summer, most years” during the past decade. “You can go around the lake in June, July and August and see hundreds of mature trees literally sitting in standing water,” he said.

Conlin said the lake’s water quantity problems also are linked to its poor water ­quality. “All the erosion undoubtedly contributed to the phosphorus overload, which in turn causes the algae blooms we’ve seen pretty much all summer long over the years,” he said.

Jochum said citizens at public meetings have generally supported the clean-out, but some are fearful that the lake might lose too much water. That won’t happen, he said, because Independence has a small dam, or weir, at the outlet that will hold back the lake and not allow it to drain. The Minnesota Department of Natural Resources operates the weir and controls how low the lake levels can drop.

Dick Larson, a homeowner on the lake for the past seven years, agreed that re-creating the lake’s outlet is much needed and welcome. A five-inch rainstorm last May raised the lake levels more than a foot, he said, and washed away much of the protective rock and plants he had installed along his shoreline.

Besides being an expensive nuisance for lakeshore owners, he said, the greater concern is that pollutants from runoff are accumulating in the lake and making it less safe for children who swim there.

 

Tom Meersman • 612-673-7388

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