New approach to killing invasive lake plants used in Eau ClaireA lake in Eau Claire is nearly free of invasive plants thanks to four years of treatments by the DNR and Army Corps of Engineers. It's a new approach that could be used throughout the state.
By: By Rich Kremer, Wisconsin Public Radio, Superior Telegram
(EAU CLAIRE) A lake in Eau Claire is nearly free of invasive plants thanks to four years of treatments by the DNR and Army Corps of Engineers. It's a new approach that could be used throughout the state.
The 150 acre Half Moon Lake is nestled near the heart of downtown Eau Claire. It used to draw tens of thousands of visitors each year until it became overrun with invasive plants like Eurasian Milfoil and Curly Leaf Pondweed. The plants were so thick it even forced the local water ski team to relocate. But the Army Corps of Engineers, Department of Natural Resources and city fought back with a combination of five yearly herbicide treatments and a single treatment of alum. Eau Claire Parks and Rec director Phil Feiber says the alum, which is a naturally occurring chemical that binds with phosphorus, was the key that has kept water clear of excess nutrients.
"The alum treatment last year, which was done after the third herbicide treatment, appears to be doing its job,” he said. “It has locked up the phosphorus that was in the water and kept it out of the water column."
Feiber says people are already returning to the lake.
"Towards the end of last year we saw people floating in inner tubes, we saw people swimming right off the causeway; we saw more and more use at the beach,” he said.
DNR lakes expert Buzz Sorge says Half Moon has come a long way. He says the treatment approach could be used at other lakes throughout Wisconsin.
"Where this is an applicable treatment for those lakes that have similar characteristics, yeah, this is the strategy you should use,” Sorge said.
Sorge says the caveat is that the treatments are expensive at around $300 an acre. The Half Moon Lake project is expected to cost around $500,000.