Invasive Aquatic Plant Management (IAPM) Permits
Invasive aquatic plants are non-native plants that can potentially create recreational nuisances to lakes and reduce native plant diversity. In some instances, when invasive plants become too abundant, they can cause economic or environmental harm. The DNR’s goal of invasive plant management is to minimize harmful effects caused by invasive plants while also protecting the natural resources and their use in the State. Once an invasive species is established in a waterbody, eradication is an unrealistic goal. Plant management is complex, and reductions in invasive plants often require long-term and resource-intensive efforts. Discussing your management proposal(s) with a local Invasive Species Specialist is recommended as a first step.
Management of invasive aquatic plants that involves either mechanical removal of plants or application of herbicides to public waters requires a permit from the DNR. Permits may be issued to property owners, lake organizations and local governments.
Commonly managed aquatic plants are:
Apply for an IAPM permit through MPARS
You may apply for an IAPM permit online. You may also renew any previously issued IAPM permit(s). If you can't apply online, contact your local Invasive Species Specialist to request a paper application.
As part of your IAPM application, the following documents must be received before a permit is issued. You can upload these into MPARS at any time.
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. Additional information is available on the value of aquatic plants and 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
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.
Delineation Surveys and Field Inspections
Delineation surveys are used to map the distribution and density of aquatic invasive plants. They are useful in determining appropriate treatment area and size and in evaluating efficacy post-treatment. Surveys should be conducted on a seasonal basis. If you are considering invasive aquatic plant management, working with local governments, lake consultants or other partners may be helpful in determining the appropriate treatment area. Proposed treatment areas are usually dominated by invasive aquatic plants or areas of high recreational use.
A DNR field inspection is required for all proposed treatment areas prior to issuing a permit. A field inspection may be waived if the proposed treatment areas are delineated by a third party consultant or at the discretion of your local Invasive Species Specialist.
IAPM Permit Resources
- Surveyors of Aquatic Plants in Lakes
- Commercial Aquatic Pesticide Applicators
- Commercial Mechanical Control Companies
- Instruction for Posting Areas Treated with Pesticides in Public Waters
Grant money may be available to support aquatic invasive plant management.
Aquatic Plant Management Resources
- Aquatic Vegetation Reports
- DNR Aquatic Plant Management Program
- References on management of aquatic plants
- Wisconsin DNR and USACE - Small-scale herbicide treatments
- Herbicide treatments in Wisconsin lakes
- DNR Best Management Practices
Find your local Invasive Species Specialist.