A month into the drawdown of Lake Weyauwega, things are progressing as expected.
“Water is down significantly and the upper reaches of the lake are now starting to channelize and headcut. Water clarity in the Waupaca River doesn’t look too bad downstream of the dam and I haven’t heard of any fish concerns,” said Scott Koehnke, who is a water management specialist in the Wisconsin Department of Natural Resources’ Shawano office.
The drawdown began on June 17. Plans call for the lake to be down for a year, to be followed by a long-term maintenance program.
Koehnke recently walked out on the exposed lake bed. He said it is firming up nicely and the emergent vegetation is starting to pop up.
“It should be noted,” he said, “that it can change from solid ground to squishy muck in a single step, so folks should use caution when venturing out near the water.”
In a short amount of time, the exposed lake bed will look like a green lawn covered with pioneering species like pinkweed, bidens and smartweed.
“We may see things like rice cutgrass and other emergents as well. This is a good thing for the system, as the roots of these plant species are bringing large amounts of oxygen into the sediment and assisting with the breakdown of organics and using up the stored nutrients. The cracking of the bed is also allowing for oxygen to get into the sediment to assist with the break down of organics. This is why it was so important to have the lake down during the growing season,” Koehnke said.
He said one thing that has become apparent is the lack of submergent habitat in the form of coarse woody debris, especially in the shallow littoral zone.
The exposed stumps across from the south boat landing are now visible, but the remainder of the lake bed is an aquatic desert nearly devoid of complex and diverse habitat, he said.
“Submergent habitat considerations will be something to consider as we move forward. Speaking of the south boat landing – looks like it could use a little TLC. Now would be a good time to fix up both landings,” he said.
As with all drawdown projects, the one thing that cannot be controlled is the weather.
Weather plays an important role in affecting the outcome of any drawdown. “So far, so good,” he said.