Rising lakes threaten cabins
An invasive plant species is causing more than an eyesore at one Minnesota lake.
Last year, the state Department of Natural Resources designated Polk County's Union Lake as infested waters because it has the non-native Eurasian watermilfoil weed. That means the more than $600,000 pump and outlet pipelines installed in 1999 had to be turned off to prevent the spread to other lakes and rivers.
Tuesday, members of the Union Lake/Lake Sarah Improvement District were at the Polk County Board of Commissioners meeting to begin the process needed to turn the pump into the Sand Hill River back on and prevent flood damage to cabins and boathouses.
The board made it clear that they're just a neutral party in the matter, but unanimously voted to start getting bids for a required screen system.
A few years ago, cabin owners on Union Lake and the neighboring Lake Sarah were hoping to open a natural outlet to help prevent flooding on the lakes. The area is similar to the Devils Lake Basin -- there's really nowhere for the water to escape right now, and a wet cycle has caused the lakes to continue rising.
The pump and pipelines already in place can drain between 8,000 and 10,000 gallons per minute, enough to lower the lakes by about an inch each week, according to district president Bryan Paradis. Sunny, dry weather evaporates another inch per week, he said.
But it can only be used until freeze-up each fall, and hasn't been used since the milfoil was discovered last year. A natural outlet would speed up the lake drop, but supporters faced problems getting approval in the past because it would affect several watershed districts and could lead to flooding problems in other areas.
The milfoil outbreak makes that even less likely, Paradis said. "I think that it was hard before, and it would be just about virtually impossible now."
The weed grows from the lake bottom up to the surface and can create a thick layer of plants. It's caused problems for visitors and residents on Union Lake, district member Jack Erickson said.
"It gets so thick it's almost like a carpet out there," he said. "People can't even drive their boats through it."
There's no easy solution to the problem either -- Paradis said the lake association needs to spend more than $10,000 each year to apply chemicals to keep it in check. If each cabin owner uses about $200 of chemical each year as well, the plants can't grow to the surface and cause as many problems.
"It's a costly thing," he said. "But people have realized that it's going to be there forever and we just have to try to hold it back as much as we can to make the lake usable."
The milfoil is an annoyance, but unless the pump can get a required screen system installed and be switched back on, residents could start to see flood damage to their properties.
"It's a piece of equipment out there that's useless unless we do something with it," he said.
Paradis said he would start the bidding process this week, which will take about four weeks. From there, the residents will know how much retrofitting the new screen system will actually cost.
Most of the construction could be done off-site and then moved into place, he said. He guessed that it might be two months before workers can start to install the screens at the lake, and said things will get done as soon as possible.
"The quicker we can get it going, the better off we'll be for next spring's runoff coming back in," he said.
Paradis didn't have a cost estimate yet, and said the Sand Hill River Watershed District has agreed to contribute some money -- but that hinges on Polk County's willingness to pick up part of the tab, too.
He said lake residents, district representatives and county officials will have a joint meeting after the bids are opened. Cabin owners paid for the pump's installation 10 years ago, and already have agreed to pay for some of the screen costs.
The rising lakes have eaten away shoreline and yards through erosion, Erickson said, and something needs to be done soon to get the water levels back down before a heavy rainfall proves disastrous. "People have already sandbagged a lot of areas there and if it gets any higher, it's going to be in their cabins," he said.