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Invasive species rule – NR 40

The invasive species rule, Wis. Admin. Code NR 40, makes it illegal to possess, transport, transfer or introduce certain invasive species in Wisconsin without a permit. Everyone is responsible to comply with these regulations. What you need to do as an individual, business, or organization may vary depending on your type of work and activities. The regulated species list and the details of the rule are shown in the tabs below.

View the full text of the invasive species rule. You can also view and print a complete list of the regulated species or a list of plants only.

Learn more about invasive species threatening Wisconsin and methods of identification and control on the species factsheet pages.

What the rule does

View a quick summary of the invasive species rule.

The invasive species rule creates a comprehensive, science-based system with criteria to classify invasive species into two categories: "prohibited" and "restricted." With certain exceptions, the transport, possession, transfer and introduction of prohibited species is banned.

Restricted species are also subject to a ban on transport, transfer and introduction, but possession is allowed, except for fish and crayfish. The department may issue permits for research or public display of any listed invasive species. For species other than invasive fish and crayfish, permits may also be issued for other purposes. The rule also defines the terminology used.

Measures to allow fast action

The regulations are aimed at preventing new invasive species from getting to Wisconsin, and enabling quick action to control or eradicate those here but not yet established. With landowner permission or a judicial inspection warrant, DNR may inspect for, sample and control prohibited species only. People found responsible for a prohibited species' presence on a property they own, control or manage may be ordered to carry out approved control measures.

If a control order is not followed and DNR takes control measures, DNR may seek cost recovery. Control of restricted species is encouraged, but not required. Incidental or unknowing transport, possession, transfer or introduction of a listed invasive species without a permit is exempt if DNR determines that it was not due to the person's failure to take reasonable precautions.

Preventive measures

The rule also includes preventive measures that are not species-specific but instead address common pathways that may allow invasives to spread. These measures complement existing statutes and rules such as the VHS rules, for example, and include requirements to remove aquatic plants and animals and drain water from vehicles, boats, trailers and equipment upon removal from the water and to remove aquatic plants and animals from any vehicle, boat, trailer or equipment before placing it in any water of the state or transporting it on a highway.


Follow these general guidelines to comply with the invasive species law.

  • Become familiar with Chapter NR 40 and how the rule may impact your work.
  • Become familiar with the listed species and their regulated status for your county.

Follow the law

  • Don't buy, sell, transport or introduce invasive species without a permit.
  • Inspect boats, trailers, and equipment and remove invasive species.
  • Don't use regulated species in plantings or projects.
  • Don't move firewood.
  • To learn about what else you can do, visit our prevention page.

Take action


In 2001, the Wisconsin Legislature directed the Department of Natural Resources to establish a statewide program to control invasive species and to promulgate rules to identify, classify and control invasive species for the purposes of the program. By 2004, the Wisconsin Council on Invasive Species was formed to assist DNR with this task.

As a result, on Sept. 1, 2009, the DNR created Wisconsin's Invasive Species Identification, Classification and Control Rule, Chapter NR 40, Wis. Adm. Code. The rule helps citizens learn to identify and minimize the spread of plants, animals and diseases that can invade our lands and waters and cause significant damage.

  • Invasive species are non-native plants, animals and pathogens whose introduction causes or is likely to cause economic or environmental harm or harm to human health.
  • Invasive species can alter ecological relationships among native species and can affect ecosystem function and structure, the economic value of ecosystems and human health.
  • There are many non-native plants that are invasive in forests, grasslands, wetlands, lakes and rivers. They displace native species and disrupt wildlife habitats.
  • Invasive species threaten Wisconsin's traditions, environment and economy in every corner of our lands and waters.

Why the rule is needed

Without this rule, different invasive species groups are not treated consistently, making concerted action less likely. Federal and state laws provide regulations and resources for the early detection and quarantine of invertebrates and disease-causing organisms. State law limits the release of non-native fish and other vertebrates into the wild.

However, there are very few federal or state laws that relate to non-native plants. Local noxious weed ordinances are erratic and often uneven in their implementation. This rule allows the department to have more consistent authority and actions between the species groups and to provide one clear, statewide law that is reasonable and feasible.