Eurasian watermilfoil (EWM) was first discovered in Lake Minnetonka during the fall of 1987 in Excelsior Bay. Inspection of the Lake the following year found that EWM was widespread throughout Lake Minnetonka. This indicated that EWM was introduced into Lake Minnetonka years before it was reported.
Eurasian watermilfoil (Myriophyllum spicatum) is a submersed invasive aquatic plant that was inadvertently introduced to Minnesota. EWM can limit recreational activities on lakes by forming dense mats on the water surface, and alter aquatic ecosystems by displacing and out-competing native plants.
Recently, the LMCD has been involved in two programs concerning management EWM. These include:
The Lake Minnetonka Conservation District primarily uses mechanical harvesting to maintain recreational access for the public and riparian property owners. Mechanical harvesting is currently the most cost effective management option that the LMCD has to control EWM on a lakewide basis. The top five to six feet of the EWM plants are removed by the harvesters and this temporarily allows for problem-free boating and swimming.
Riparian lakeshore owners also have the ability to manage EWM and other invasive plants around their docks. For residents interested in chemical treatment or private mechanical harvesting, the MN DNR publishes the following lists of licensed Commercial Aquatic Pesticide Applicators and Licensed Mechanical Control Companies: