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Is Koshkonong project dredging up trouble?

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Neil Johnson
January 9, 2013

— The Rock-Koshkonong Lake District is ready for a dredge project it's trumpeting as a win-win for boating access and environmental habitat, but some state officials and state regulators say they aren't fully on board.

Plans and permits are in place for the lake district to begin work later this month dredging a boat access area in a bay off Lake Koshkonong's northeast shore. The dredged material would be moved south to bolster a thin shoreline that separates the backwaters of Mud Lake and Lake Koshkonong.

Meanwhile, officials said, the lake district is using the Indianford Dam to draw down the lake.

Lake District Chairman Brian Christianson has said the low water is ideal because it will allow the lake district to more easily move heavy machinery in and out of the dredge area.

The lake district estimates it will spend between $200,000 and $400,000 on the project.

Some lake residents and Wisconsin DNR officials are concerned about the timing of the project, and said the drawdown could put at risk animals that use shoreline shallows as winter habitat.

DNR and lake district officials said waters at the lake have fallen dramatically, in part because of the drought conditions last spring and summer but also because of the continued winter drawdown.

It has meant that some shoreline areas around the lake have dried up in recent weeks and have turned into frozen mudflats, residents and DNR officials say.

DNR biologist Kurt Welke told The Gazette some residents contacted the DNR with concerns the drawdown could have frozen and killed turtles, frogs, salamanders and some insects that use shallow-water shoreline areas of the lake as winter habitat.

Welke said that in late fall, cold-blooded animals dig into soupy shore areas where they're insulated by water against hard freezes. Once they dig in, they tend to stay put, even if receding water, low oxygen and low temperatures begin to put the animals at risk of freezing out.

"They go into a low-body state and don't tend to relocate," Welke said.

Welke acknowledged that low water at the lake put some wintering animals "potentially at risk," but he said the DNR does not have a clear indication that there have been any significant kills of wildlife because of the drawdown.

He said concerns by residents prompted a tour of the lakeshore by the DNR in mid-December. At that time, DNR fisheries technicians found a number of freshwater mussels in backwaters on the lake's south end with their shells popped open.

Welke said that can be a sign of stress on mussels, but he said he wasn't sure whether it was linked to water levels. He said the DNR's walkthrough came after the drawdown began but before the lake and its backwaters were frozen. Welke said that the DNR hasn't been back to survey the area since then.

A DNR biologist in charge of monitoring endangered species did not return repeated inquiries by The Gazette about whether any threatened species winter alongshore at the lake.

Welke said commercial fisherman have noticed no impact to fish. He indicated that winter conditions make it hard to determine what impact the drawdown might have had, but he said the time to mitigate risk to wildlife may already have passed.

"In a perfect, hindsight-20/20 world, these impacts would have been communicated before any drawdown," Welke said.

Still, the lake district isn't violating any rules with the drawdown or its dredge.

The DNR has had no authority to forestall the dredge because officials at the DNR's Waukesha office already have issued permits for the work to move ahead, said DNR engineer Sue Joseph.

Joseph said the agency also does not have the authority to stop the lake district's continued drawdown of the lake because water levels are within limits set by the DNR for winter months.

The DNR is in the midst of trying to implement new orders for lake levels which would set a new standard, requiring the lake district to keep water levels about six inches higher than they are right now.

The proposed standard is in part intended to protect animals that use shore areas to winter, DNR officials said.

Joseph said the new standard is not enforceable because it's tied up in a court fight over lake levels between the DNR and the lake district, and the case is pending a decision by the state Supreme Court.

"Legally, the lake district can do what they're doing. The DNR may like it (the water) higher, but they can do what they're doing," Joseph said.

Christianson said the lake district is working with adjacent townships to forge roads agreements to move the dredged materials with heavy equipment.

Christianson has said the lake district is poised to choose a contractor at a meeting Thursday, and the dredge could start as early as next week if the lake remains frozen.



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