Aquatic plants are an important part of a healthy lake ecosystem. They provide habitat and food sources for fish and wildlife, also contributing to the lake’s recreational value. Some aquatic plants are considered invasive (Aquatic Invasive Species AIS) and may cause problems. At other times, native vegetation may become a nuisance. People often consider these nuisance vegetation “weeds”. Visit the Lake Minnetonka Native and Invasive Species webpage to learn about the aquatics in Lake Minnetonka.
Certain regulations are in place to balance the need for a healthy lake, with the lakeshore owner’s safety and enjoyment of the lake. Whether you choose to hire a professional company, or perform the work yourself, there are some important items to know about vegetation management. Depending on the type of vegetation, the regulations and permits are managed by different MN DNR programs. Some information from the MN DNR website and links have been summarized for convenience. It provides guidance for lakeshore owners to manage aquatic vegetation in the dock use areas.
Aquatic vegetation can be managed by certain methods such as mechanical, chemical, and biological. There are advantages and limitations to each method. More information about vegetation management can be found in the Lake Minnetonka Vegetation & AIS Management Plan. We hope you find this summary and links to resources helpful. If you notice nuisance or suspicious aquatic animals or vegetation, please contact the LMCD. You can also report it HERE.
Hiring a Professional
If you are hiring a company to manage lake vegetation or other AIS, the company must be a permitted lake service provider (LSP) and have training in AIS. A list of permitted LSPs can be found on the MN DNR website.
Activities NOT Allowed
- Excavating the lake bottom for aquatic plant control. This may disturb sediment releasing phosphorus in the water column and negatively impact water quality.
- Improper use of hydraulic jets to disturb lake bottom, uproot plants, or create mats of vegetation or sediment berms.
- Destroying or preventing the growth of aquatic plants by using lake bottom barriers.
- Removing aquatic vegetation within posted fish-spawning areas.
- Removing aquatic plants from an undeveloped shoreline.
- Removing aquatic plants where they do not interfere with swimming, boating, or other recreation.
- Installation of fencing or other barriers in the water to obstruct vegetation or obstruct the flow of water.
Control Methods That REQUIRE a Permit
- Destruction of any emergent vegetation (for example, cattails and bulrushes).
- Cutting or pulling by hand, or by mechanical means, submerged vegetation in an area larger than 2,500 square feet.
- Applying herbicides, algaecides, pesticides, or other chemicals.
- Moving or removing a bog of any size that is free-floating or lodged in any area other than its place of origin in public waters.
- Transplanting aquatic plants into public waters.
- Use of automated aquatic plant control devices (such as the Crary WeedRoller).
- Physical removal of floating-leaf vegetation from an area larger than a channel 15 feet wide extending to open water.
- If the removal of loose or dead vegetation disturbs the shoreline, a permit from the Minnehaha Creek Watershed District may be required.
When a Permit Is NOT Required
- Mechanically maintaining a 15-foot wide channel from your shore or dock to open water. Any greater distance requires a permit from MN DNR.
- Maintaining or creating a swimming or boat-docking area and mechanically cutting or pulling submerged vegetation, such as Elodea under certain conditions:
- First, the area to be cleared must be no larger than 2,500 square feet.
- Second, the cleared area must not extend more than 50 feet along the shoreline or one-half the length of your shoreline, whichever is less. View the Temporary Structure Information webpage regarding swim platforms and buoy requirements.
You may contract with a licensed LSP to remove the vegetation, compost, or transport the vegetation to an approved site. Check city code requirements regarding composting. If you plan to dispose of the aquatic vegetation someplace other than on your property you will need to download the aquatic plant transport authorization form. This form allows you to transport the aquatic vegetation to a suitable location for disposal. Be sure the location will not result in the potential spread of AIS.
The same disposal requirements apply whether the vegetation to be disposed of is a direct result of your management efforts or if loose vegetation (i.e. cut by boat traffic) floats onto your shoreline.
Organizing Vegetation Control in Your Bay
Lakeshore owners may choose to work with a few neighbors to control vegetation or organize control for the whole bay. Some bays are organized and collect money for treatments on a voluntary basis or as part of an association. Libbs Lake Association has been organizing treatments and Harrisons Bay is in the process of organizing. Learn more about the Harrisons Bay Association activities to organize.
A couple of bays have chosen to organize and form a Lake Improvement District. Lake Improvement Districts (LID). Minnesota Statutes 103B.501 – 103B.581 allows local property owners to petition counties to create lake improvement districts in order to address specific concerns within a lake watershed that may not be addressed under normal governmental actions. Property owners in the district are taxed in order to raise the money for treatments. More information about LIDs is available at the MN DNR webpage. Current LIDs include St. Albans Bay and Carmens Bay.
Bay-wide and Large Area AIS Management and Prevention Funding Opportunities. Funding opportunities for AIS prevention and management vary each year. LMCD has created a new program to assist bays with organizing and funding for first-time whole bay or large area AIS management. Learn how your bay can organize and request funding and other potential funding resources.
Bay-Wide and Large Scale Treatment Permits
An Invasive Aquatic Plan Management Permit (IAPM) is required for large-scale bay treatments. The permitting process requires delineation surveys, field inspections, and signatures from lakeshore owners affected by the treatment. A summary of information is provided below. For additional information about bay-wide treatment and permits, visit the MN DNR IAPM webpage.
Cumulative Treatment Area
The littoral area is the surface area of a body of water where the depth is 15 feet or less and where most aquatic plants will grow. The littoral area is used to calculate the cumulative area in which aquatic plant management may occur. The following permit restrictions are intended to reduce risk of damage to native plants and impacts to water quality.
- Mechanical Removal: cannot exceed 50% of the littoral area
- Herbicide: cannot exceed 15% of the littoral area
- Mechanical and Herbicide Combined: cannot exceed 50% of the littoral area
- Biological: research being conducted, each request requires specific review and consideration
In some instances, the DNR may allow treatment of more than 15% of the littoral area with herbicides or more than 50% with mechanical removal under a variance and a permit. Consult with the DNR prior to considering this type of treatment. View requirements at IAPM webpage.
Bogs are essentially floating wetlands. Property owners are responsible for relocating a floating bog to an approved area if it becomes a nuisance. A permit is required from the MN DNR. More information about permits is available at the Aquatic Plant Management Program (APM) webpage. However, if a bog interferes with public navigation such as in a channel, please contact the LMCD office. If the bog is located in a Hennepin County monitored channel, the agency may relocate the bog and attach to the nearest suitable location.
Be a Good Neighbor- Prevent Safety Hazards and Nuisances
It is important to understand that you share the water with your neighbors and the public. If you are using chemicals as the control method, follow permit and manufacturer’s instructions regarding proper use and safety. If you cut or pull aquatic plants, be sure to properly dispose of them on land to prevent them from drifting onto your neighbor’s property or drifting back into the lake. If you install hydraulic jets or other electrical devices, make sure the power source and device meets all electrical code requirements and excessive noise is not produced. Visit the electric shock drowning webpage for more safety tips.