SPIRIT LAKE, Iowa (KUOO) – The Iowa Great Lakes is feeling the heat of the summer vacation season.

Many Siouxlanders are traveling to Okoboji to have some fun on the water. But a seasonal nuisance has the potential to tangle up holiday plans.

That nuisance is curly leaf pond weed.

A representative from one of the lakes’ area protective associations says it was another successful year for curly leaf pond weed mitigation efforts.

Terry Wilts of the East Okoboji Lakes Improvement Corporation says the operation again this year consisted of a chemical treatment applied by a licensed firm approved by the Department of Natural Resources.

Wilts says the operations were expanded to include a portion of Lake Minnewashta where the invasive weed has been increasing its presence in recent years. He says they remain concerned, however, over growing evidence that more lake shore property owners are taking it upon themselves to chemically treat areas around their docks.

Not only does it pose a safety risk and is illegal, but Wilts says it also removes plants that are good for the lakes.

“You see a lot of homeowners taking those native plants out of there and yet when we go to fix shorelines, that shoreline is valuable as all get out and when you go to repair it, it’s expensive,” said Wilts. “And yet we want to take the very plant out that helps to protect our shorelines along with benefiting the fish with the oxygen and sucking up the nutrients out of the water and what not, so it’s one of those where if you can stand the look of it, natural lakes should look like that.”

The penalty for anyone caught illegally putting herbicide into the lake is a $1,000 fine.