Jerry Wendlandt finds himself on the water quite often during the summer months doing compliance checks on area lakes.

Wendlandt, the aquatic plant management specialist for the Glenwood DNR, issues permits to lakeshore owners. Aquatic plants are vital for keeping water clean and fish populations healthy, so it's Wendlandt's job to make sure people are abiding by the rules.

When it comes to the use of hydraulic jets on docks or boat lifts, there is no permit process. That's mainly due to the fact that their use is illegal when the intent is to move sediment or control aquatic vegetation. Despite that, Wendlandt is seeing them used for that almost every time he comes across them.

"I go out and look at the permits that I issue and see if people are abiding by the guidelines," Wendlandt said. "Last year during my compliance checks, I ran into a fair amount of hydraulic jets and over 90 percent of them were operated illegally."

Hydraulic jets, including products like HydroSweep, Aqua Blaster, Aqua Thruster and Aquasweep, can resemble a fan or trolling motor contained in a short tube. They create strong currents of moving water that can be mounted on docks and boat lifts. These products are often advertised to control or remove "muck" and "weeds" from a lake bottom; however, using hydraulic jets in this manner is not allowed in Minnesota.

A person may legally operate a hydraulic jet if it is placed high enough off the lake bed so that it doesn't move sediment or destroy rooted aquatic plants. It must be directed upward toward the water's surface, which can prevent dead vegetation and duckweed from collecting around docks and boat lifts.

Any displacement of sediment or removal of aquatic plants as a result of operating a hydraulic jet would be deemed a violation and may result in a fine. Wendlandt said the fine for operating them in this way varies by the county but the last one he saw was just shy of $300.

"We're starting to see them with more regularity," Wendlandt said of the jets' use on area lakes. "They kind of showed up on the scene in 2012 and now are increasing dramatically."

Wendlandt believes a lot of lakeshore owners don't realize what they're doing is illegal. He hears of people being told by vendors they don't need a permit to use them while looking into buying the jets. That sounds good on the surface, but the reason for that is because they are not legal for what many people are using them for.

"So we don't have a permit structuring process," Wendlandt said. "I believe there is some confusion there. People are told they don't need a permit, but they aren't being told that if they operate them with the intent to move sediment or control aquatic vegetation, their use is illegal."

Wendlandt has seen local cases where the hydraulic jets have created close to two feet of excavation on the lake bed.

That sediment and plant life goes somewhere once it is uprooted. Often times, it's onto the neighbor's property. It also has the potential to cover up fish spawning habitat.

Walleyes in particular need sand, gravel or rubble to naturally reproduce. Those types of areas are already limited in many area lakes.

"We afford those areas a lot more protection," Wendlandt said.