Posted: July 15, 2025

EWM treatment on Lake Riley today and on Duck Lake next week.

RPBCWD staff and consultants recently completed delineation surveys for Eurasian Watermilfoil (EWM) on selected lakes within the watershed district. The abundance of EWM on Riley, Duck, and Staring lakes was high enough to warrant herbicide treatment. Staring Lake, which has no shoreline residential properties, was treated last week.

The size of treatment areas is limited by the MN DNR and will be located in the areas of highest EWM density. Exact timing of treatments is determined the day before based on predicted weather conditions and contractor availability. Updates on timing will be posted at rpbcwd.org/AIS-control.

Staff have/will mail postcards to residents immediately adjacent to treatment areas, Click on a map below to see where treatments will be taking place:

• Lake Riley EWM treatment map
• Duck Lake EWM treatment map
• Staring Lake EWM treatment map

Did you know aquatic plants are protected?

Aquatic plants are essential to lake health and their management is regulated by the MN DNR. Learn more about aquatic plant regulations from the DNR. Also, check out our Aquatic Plant Protection handout.

Questions? Contact Josh Maxwell, Water Resources Manager at 952-607-6512 ext. 4 or jmaxwell@rpbcwd.org.