Eurasian Water Milfoil


Image courtesy of the Columbia Shuswap Regional District

Latin name:

Myriophyllum Spicatum L.

Native to:

Europe, Asia and North Africa

Regional Distribution:
Eurasian Water Milfoil was first introduced to the Columbia Shuswap Regional District in August 1981.  Since its introduction, Eurasian Water Milfoil has colonized throughout Shuswap Lake, Little Shuswap Lake, Mara Lake and the Shuswap River.  The largest infestation is located in the Salmon Arm Bay.


Eurasian Water Milfoil is a rooted aquatic plant colonizing lakes and rivers at depths from 0.5 m to 5 m.  The milfoil stem is slender and can grow up to 175 cm long, 4 to 5 leaves are arranged in whorls around the stem and are characterized by 12 to 21 leaflet pairs per leaf.  During the spring and summer months, rapid growth can create dense mats of surfacing milfoil adversely affecting recreational activities, flood control, drainage, water conservation facilities and fish spawning areas.


The Columbia Shuswap Regional District is actively controlling the Eurasian Water Milfoil with a state-of-the-art vessel used exclusively in the Shuswap for treating infested Milfoil sites. The treatment involves rototilling shorelines in autumn and early winter, when water temperatures are too cold for plant fragments to establish a new colony.

For lakes without Eurasian Water Milfoil, prevention is the best control. Clean, Drain and Dry your boat before launching into another water-body.

For more information visit the CSRD Milfoil Control Program. 

Fun facts:
Eurasian Water Milfoil spreads primarily by fragmentation in the summer months. Fragmenting pieces can spread rapidly through boating activities and natural water currents.  It only takes one small piece of Milfoil to start a new plant which can expand into a colony in a short period of time.