Eurasian Water Milfoil in St. Croix River

Katelin and I were monitoring the St. Croix from the dam in St. Croix Falls to just south of Spangler’s picnic area today. There was Eurasian water milfoil (EWM) dotted everywhere in the littoral zone in depths ranging from 5’ to 1.5’ in depth. I wouldn’t say there are any “beds” per se but it will be one heck of a task to hand pull.


By the extent of the coverage I would say that EWM has been established for quite some time. I think we have a GPS point of the northern most area and took many readings going south to the dam. I’ve attached a photo and a map (didn’t have time to hit the Minnesota side although I am sure it in the bay-like areas) and I will press and mount specimens for the herbarium, right now on the WI surface water data viewer it appears that it is not documented as of yet.

 Jeremy Williamson
Water Quality Specialist
Aquatic Invasive Species Coordinator
Land & Water Resources Department
Polk County Wisconsin
100 Polk County Plaza, Suite 120
Balsam Lake, WI 54810
phone  715.485.8639
fax        715.485.8601