DNR cautions lake shore property owners about improper use of hydraulic jets.

The Minnesota Department of Natural Resources frequently receives questions about devices that generate water current to blast muck and plants away. They have various trade names, but the DNR refers to these devices generically as hydraulic jets. Even though you can buy one in Minnesota, they cannot be used in any way that disturbs the bottom of the lake or uproots plants.

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

Aquatic plants are important to lakes. They help maintain water clarity, prevent erosion, stabilize the bottom and provide habitat for fish and wildlife and are therefore protected under state law.

Specific regulations govern what situations require permits for aquatic plant removal. Regulations and a guide to aquatic plants can be found on the DNR website (mndnr.gov/ShorelandMgmt/Apg/Regulations.html). To apply for a permit, visit the DNR’s permitting and reporting system (mndnr.gov/MPARS).