Invasive Species

Invasive species are organisms including plants, animals, bacteria and fungi that are not native.  These species can be harmful to their new environments. In fact, invasive species are capable of causing extinctions of native plants and animals, reducing biodiversity, competing for resources with native organisms, and altering habitats. Invasive species can have enormous economic impacts and fundamentally alter ecosystems. 

Lake Ballinger Invasive Plants

Invasive aquatic species have been identified in Lake Ballinger. The City of Mountlake Terrace was awarded a 5 year Ecology permit to use herbicides in Lake Ballinger during the summer of 2019 to control Eurasian Water Milfoil, Fragrant Water Lily, and Curly Leaf Pondweed in Lake Ballinger.

Invasive Eurasian water milfoil

Eurasian Milfoil

Eurasian Milfoil is not native to Washington State but has been imported for use as an ornamental plant. It forms dense mats that shade out other aquatic plants, degrades water quality, inhibits water flow and impacts recreation. Learn more here.

Citizens and staff from Mountlake Terrace and Edmonds are working together to control a severe milfoil infestation in Lake Ballinger. If you would like to be involved in this effort, please contact Laura Reed, Stormwater Program Manager, at 425-744-6226. For more information on how control milfoil, please see the WDFW publication "Rules for Aquatic Plant Removal and Control (PDF)."

Fragrant Water Lily

Invasive Fragrant Water Lily

Invasive Fragrant Water Lily Vs. Native Yellow Pond Lily

On Lake Ballinger, Fragrant Water Lily has taken hold in many areas around the shore. Fragrant Water Lily is not native to Washington State but has been imported for use as an ornamental in backyard ponds and is now found in many of the shallow lakes in the area. It has overtaken native Yellow Pond Lily in many areas around the lake. Learn more here.

Native Yellow Pond Lily

Native Yellow Pond Lily
  1. Why now?
  2. Why is it a problem?
  3. What's the goal of the treatment?
  4. What has been done so far?

Dense mats of aquatic weeds now cover 80-90% of the nearshore area of Lake Ballinger.  A June 2018 plant survey of the lake showed that nearly 18 acres of Lake Ballinger are covered with a mixture of Eurasian water milfoil (a Class B noxious weed), Fragrant water lily (a Class C noxious weed), and Curly leaf pondweed (a Class C noxious weed.)

Remember:  always check boats and fishing gear when you enter or leave the lake; remove all plant fragments and toss them in the trash.


Concerns or questions?  Please contact:  Laura Reed, City of Mountlake Terrace, Project Manager at lreed@ci.mlt.wa.us (425) 744-6226.


Additional Resources

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