Eurasian watermilfoil

Eurasian Watermilfoil (EWM) is an invasive, non-native species present in Lake Johanna.


EWM was discovered in Lake Johanna on 6/13/2016 in 2 locations (SW corner and N side) by a Conservation Corps MN crew performing baseline AIS surveys for the MN DNR. Unfortunately, the DNR did not notify the LJIS.

On 10/13/2016 a neighbor notified the board that a sign announcing the presence of EWM was posted at the public access. We contacted an invasive species specialist at the DNR.

On 10/27/2016 the DNR visited the lake and “found a good amount of EWM widely distributed in areas around the lake." This map shows the details of their observations.

On 6/27/2017 Clarke conducted a survey looking for EWM and found moderate amounts. Read the report here.

On 9/17/2018 Blue Water Science conducted a survey looking for EWM but found none. Read the report here.

On 7/16/2019 The MN DNR and Rice Creek Watershed district surveyed the aquatic plants on the lake, paying particular attention to EWM. Read the preliminary findings in an email here.


Eurasian watermilfoil information from the Minnesota Aquatic Invasive Species Research Center.

Detailed information about how to identify Eurasian Watermilfoil and how it looks different than native Northern Watermilfoil.