MINONG– The drawdown of the Minong Flowage to replace the surface concrete that is peeling off has been postponed from this spring to August 1.
A second drawdown is planned later to get rid of as much Eurasian milfoil as possible.
The first drawdown is because the gunite – a wear shield over the face of the dam that the water flows over – is flaking off, said Frank Scalzo, Washburn County highway commissioner.
In 2013 the dam was added on to, and at that time the gunite was fine. What has prompted the delayering now is a mystery.
“What caused this all of a sudden, I really don’t know, but it’s fallen off and it needs to be repaired,” Scalzo said.
The 1,587-acre flowage with its 24 miles of shoreline spans a portion of the towns of Minong and Wascott. At its deepest it is 21 feet, though 14.5 percent is less than 3 feet. A dam built in 1937 for hydropower impounded water from the Totagatic River and from Cranberry Creek which flowed south from Cranberry Lake. A pair of boat landings and the Totagatic County Park are public access points.
The lake will be dropped a foot to repair the dam.
“In some areas, that’s pretty significant, especially in some of the bays,” Scalzo said. “It drops the water quite a bit. You’re dropping it a foot at the dam, but you take a bay that’s half a mile up the lake, you’re going to drop that significantly.”
The drawdown had been planned for last fall, but uncooperative weather – too much rain and too cold – caused its postponement until spring. Scalzo said he had been leaning toward drawing down before fish spawning, while DNR fish biologist Craig Roberts leaned toward after spawning, which usually occurs at the end of May to the beginning of June. In that scenario, the repairs would have started in the beginning or middle of June.
Then [reason for postponment til fall].
“The water level is going to be down for no more than two weeks to do these repairs,” Scalzo said. “Once we get that gunite off the face of the dam, we will do a further inspection to make sure there’s no other damage.”
The drawdown could even last less than the two weeks, and Scalzo expects the flowage’s recovery to be fairly quick, with water flowing from Colton Dam, Nelson Lake, and the backwaters of Gilmore Lake helping to refill it.
The county is responsible for six dams: Minong Flowage, Pokegema Lake, Spooner Lake Dam, Slim Creek Dam, Long Lake, and Birch Lake.
“Thank goodness, they’re all good,” Scalzo said. “All the dams get inspected every other year. The reports are great on all of our dams. Minor repairs and maintenance, that’s all we have to look forward to there.”
The flowage’s shoreline owners and visitors are not unfamiliar with drawdowns. The lake level was dropped 5.5 feet in 2013 to add on to the dam so it could stand up against a 100-year flood. Two-thirds of the dam is new.
That drawdown showed that much of the Euraisan milfoil, an invasive plant, would die over winter when stripped of its protective water cover, and plans are underway to use a deep drawdown to expose the plants and let freezing and desciation decimate them.
“Eurasian milfoil, you can freeze it and it’s done,” Scalzo said. “I don’t know that you’ll ever get it all. This is something you might have to look at and do it in another four or five years, when the milfoil comes back.”
The highway department has permission from the Department of Natural Resources to draw the lake down 5 feet in a bid to kill the Euarsian milfoil along the shoreline. The department has been working with the Minong Flowage Lake Association for the past year, trying to ensure that all of the stakeholders support it.
The majority do because they recognize the milfoil will degrade the lake and its uses, including fishing and swimming, Scalzo said.
“Washburn County has got quite an investment in that in the Totogatic Park up there, and they’re doing this big expansion. Are people going to want to come to a lake that’s full of milfoil? That’s something to look at. So I think the drawdown will be a good thing. This last winter would have been an ideal winter because we didn’t have snow in the beginning, so the frost would have really killed the milfoil.”
The DNR has studied the project to make sure it would not harm the fish or the habitat for other inhabitants such as the turtles and frogs, Scalzo said.
The process could start in September and run until the ice is out in the spring. Doing it before the ice is out could cause the ice around the stumps in the lake to float, pulling the stumps out with it.
An unknown, however, has stymied plans for now: It is unclear how the lowered water level would affect Renewable World Energies’ production of electrical power at the dam during that period – and who should pay for any reduced capability.
“Dropping the water level that far, we don’t know how much energy they’re going to be able to generate throughout the winter with the water down like that, because they’ll generate electricity all winter long,” Scalzo said. “But with a drawdown, and to maintain that drawdown, we don’t don’t know how much water we’re going to be able to allow to go through to generate electricity. So Renewable World Energies is going to want to be compensated for that loss of electricity, which they sell to Dahlberg Electric.”
The county will not be responsible for those losses, he said. “It’s going to have to be the lake association that’s going to have to do something.”
A guarantee that money would be available to cover the lost revenue would have to be in place before the county would proceed, Scalzo said.
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