Scott Williams swilliams@wolfrivermedia.com
The battle to save Shawano Lake from destructive plants growing underwater has kicked into high gear.
Aiming to clear the lake’s waters for better boating, fishing and swimming this summer, crews carried out large-scale herbicide treatments this week to combat weed infestation that has troubled the lake in recent years.
The effort spearheaded by the group called Shawano Area Waterways Management is funded by $200,000 from the state and another $235,000 in local donations.
Unlike past efforts targeting small sections of the lake, the current treatments are designed to dramatically reduce invasive weeds throughout virtually the entire 6,000-acre lake.
“You’ve got to do the whole lake,” said Ray Zuelke, a board member of the waterways management group. “We wanted to do something that was going to have a huge, positive ecological impact on the whole lake.”
Within a few weeks, organizers anticipate that recreational users of Shawano Lake will see water that is clearer and healthier for boat traffic, fish populations and more. The attack on invasive plants comes just as the summer tourism season is starting to draw crowds to the lake and its related attractions.
State Sen. Rob Cowles, R-Green Bay, who helped win state funding for the cleanup effort, said he was pleased to see state resources at work for such a vital public improvement in Shawano County.
“This is a very important tourism issue, along with quality-of-life,” Cowles said. “We want to have water that is nice and clean.”
Officials estimate that the herbicide treatments will eliminate 75 percent or more of the existing invasive plants, most notably the destructive Eurasian Water Milfoil, a type of seaweed that grows so large and thick that it can impede fish populations and snag motorboats trying to navigate.
Shawano Area Waterways Management, a private nonprofit association, has been working to monitor and control invasive plants that threaten water quality and disrupt healthy habitats for native plants and wildlife.
Representatives involved in the newest cleanup effort discussed their strategy Monday in a presentation to the Shawano Rotary Club.
Brenda Nordin, a lake biologist with the state Department of Natural Resources, told those in attendance that state officials have been monitoring Shawano Lake for many years to gauge the impact of destructive non-native plants, along with pollutants that have seeped into the water.
“There’s a whole lot of issues that are occurring,” Nordin said. “So we all have to do our part.”
In 2014, a herbicide treatment of limited areas of the lake showed good success against the unwanted weeds. So when the waterways management group requested state funding this year for a broader attack, state officials agreed to contribute $200,000 — the maximum amount available and one of the largest grants ever approved for such an effort anywhere in the state.
Zuelke’s group collected another $238,000 in local donations, after conducting a survey of lakefront property owners and finding strong support for an aggressive move to improve water quality.
“They wanted somebody to do something about it,” Zuelke told the Rotary Club.
The group enlisted the De Pere consulting firm of Onterra LLC to identify areas throughout the lake where Eurasian Water Milfoil and other invasive species were most dense. Then a California-based firm called Clean Waters Inc. deployed three boats on the lake to apply the herbicide, starting on Monday and intending to continue on Tuesday.
The boats were equipped with long hoses so that the herbicide was released deep underwater, close to the unwanted plants growing below.
The targeted zones ranged in size and combined for a total of 928 acres of the lake.
Officials said the herbicide, known as DMA 4, is the same product that was used in the earlier test on Shawano Lake, and has been used elsewhere in Wisconsin to combat invasive plant species. Nordin said the herbicide was being applied at levels that are safe for fish, native plants and people using the lake for normal recreational activities, including swimming and fishing.
Zuelke told the Rotary Club that support for the cleanup effort was widespread, especially considering the importance of water quality to tourism.
“Our lake is beautiful,” he said. “But like all lakes, it needs help.”