Lake Minnetonka Conservation District

Eurasian Watermilfoil


Harvesting Program

Through cooperative efforts with the MN DNR, the 14 Lake Minnetonka communities and private citizens around the lake, the LMCD has been managing the growth of EWM on Lake Minnetonka since 1989. Permits to harvest curly-leaf pondweed (CLP) have been obtained since 2017 due to the increase in its presence. Generous donations were received from private residents around the lake for the initial purchase of harvesting equipment, which has been replaced in the 2000’s. The LMCD currently owns three paddlewheel harvesters and a transport barge that was purchased in 2003.  The three paddlewheel harvesters were purchased prior to the 2003, 2005 and 2012 seasons.

The harvesting season generally runs from mid-June through mid-August. The LMCD hires seasonal employees to perform the harvesting. The harvesters cut the EWM approximately three to six feet below the water surface and then removes it from the lake on to the harvester. EWM removed from the lake is disposed of at various compost sites located in the area.

Harvesting priorities are based upon impediment to boat navigation on the open water, with higher priority given to public navigation areas of the lake that are matted. The focus is to provide watercraft navigation from docks to open water. Although there are some areas of the lake with significant milfoil growth that is not aesthetically pleasing, the LMCD cannot harvest them unless they are impeding boat navigation in compliance with the permit that is obtained from the MN DNR for aquatic plant management.

A combination of clear-cutting and channel-cutting is utilized to address harvesting priorities depending on the location and density of docks in the area. Sometime tandem cutting is used or 180 degree skimming to minimize EWM fragments.  Other factors include weather and wind, and types of vegetation. Annually, areas that dictate the need for harvesting are cut once, with high growth areas harvested twice if time permits.