Aquatic Plant Management

Aquatic Plant Harvest on Lake Monona

Aquatic plant management in the Yahara lakes

Aquatic plant management in the Yahara lakes falls under the jurisdiction of the Wisconsin Department of Natural Resources (WDNR). The WDNR reviews, maintains, and enforces all permitting requests for the control or removal of aquatic vegetation in Wisconsin.

Additionally, the Dane County Land & Water Resources Department follows its own WDNR-approved aquatic plant management plans relevant to each lake. The department operates 11 mechanical harvesters from approximately mid-May to mid-August. Read more about the Dane County Aquatic Plant Management Program.

Aquatic Plant Harvesting on Lake Waubesa
Dane County’s aquatic plant harvester on Lake Waubesa

Can I remove aquatic plants in front of my shoreline property?

Waterfront (“riparian”) property owners may (without a permit) remove detached, floating aquatic plant debris and algae that accumulate on the shoreline. Dane County even has designated pier pickup times to collect and compost plants removed by property owners. Check out this link for an updated collection schedule.

Harvested algae and aquatic plants must be removed from the water and disposed of properly. TIP: Harvested aquatic plants and algae make great composting material!

Coontail, as seen in the photo, is eaten by waterfowl, turtles, snails, and carp. It also provides hiding places for many small organisms. It is a nuisance because it can be transported to other bodies of water by clinging to boats and occasionally aggregates along shorelines.

WDNR permitting requirements

If you feel the need to remove rooted aquatic plants, we recommend reviewing the WI DNR permitting requirements. There are a number of nuances regarding invasive species and harvesting techniques. Under Wisconsin state law, a permit is not required for riparian owners using manual or hand-held mechanical devices designed for cutting or mowing vegetation if the following conditions are met:

  1. Removal of native plants is limited to a single area with a maximum width of no more than 30 feet measured along the shoreline provided that any piers, boatlifts, swimrafts and other recreational and water use devices are located within that 30−foot wide zone, and may not be in a new area or additional to an area where plants are controlled by another method; or 
  1. Removal of non-native or invasive aquatic plants as designated under s. NR 109.07 when performed in a manner that does not harm the native aquatic plant community; or
  1. Removal of dislodged aquatic plants that drift onshore and accumulate along the waterfront.
  1. The targeted area is not located in a sensitive area as defined by the department under s. NR 107.05 (3) (i) 1., or in an area known to contain threatened or endangered resources or floating bogs.
  1. Does not interfere with the rights of other riparian owners.

Chapter NR 109 of Wisconsin state law establishes all procedures and requirements related to aquatic plant management.

Myriophyllum spicatum - Paul Skawinski Aquatic Plants of the Upper Midwest
Eurasian watermilfoil
Courtesy Paul Skawinski, Aquatic Plants of the Upper Midwest

Should I remove aquatic plants?

It’s important to recognize that aquatic plants are a critical component of healthy lake ecosystems, and that it’s typically the non-native and invasive varieties like Eurasian watermilfoil that cause problems. In other words, being selective in what species you target is important. Those who strive for the complete removal of aquatic vegetation in front of their lakefront homes may be removing vital habitat and causing more harm to the lake than they might realize. For example, regularly disturbed lake beds are magnets for aggressively colonizing species like Eurasian watermilfoil, the main target of Dane County’s weed-harvesting efforts.

Read more about some of the more commonly found aquatic plants and invasive weeds.