- Public Works
- 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 has a five-year Ecology permit (2019-2024) to use EPA- and Ecology-approved herbicides to control Eurasian watermilfoil, Fragrant water lily, and Curly leaf pondweed in Lake Ballinger. Approximately 50% of the lake will be treated for Eurasian watermilfoil May 4, 2021 using a herbicide approved for use in potable water (brand name ProcellaCOR.) There are no swimming or fishing restrictions required with the use of this herbicide, and all properties near the treatment area will be posted prior to the treatment to notify residents and park users.
Eurasian Watermilfoil 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 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
- Why act now?
- Why are these plants a problem?
- What's the goal of the treatment?
- What has been done so far?
While the herbicide treatment applied in July 2019 was successful in eliminating much of the Eurasian watermilfoil in Lake Ballinger, some plants have remained and re-established, particularly on the east side of the lake, which was not treated.
Lake residents and lake users have reported that the plants restrict movement and make it difficult to boat or fish. The decomposing plants smell unpleasant when they die off in the fall. There’s also a safety hazard; in other lakes, swimmers have become entangled in dense plant stands. Water quality in the lake has been impacted by the aggressive aquatic plant growth. Low oxygen levels can trigger increased phosphorus release from lake sediments. These conditions have in the past led to toxic algae blooms on Lake Ballinger.
The goal of this invasive control effort is to encourage a more balanced native plant community, improve overall lake water quality, and support recreational activities. The herbicide selected for this effort specifically targets Eurasian watermilfoil and does not harm native aquatic plants.
Since the spring of 2018, a steering committee composed of Lake Ballinger lakefront residents, lake users, the Nile Golf Course, an experienced limnologist, and city staff have been determining the best path forward to address the problem. They reviewed options, considered impacts, and decided on an adaptive management plan. The Lake Ballinger Integrated Aquatic Vegetation Plan (available on the Mountlake Terrace website) includes the use of placed burlap bags of sand for localized control on private property, and selective herbicides to combat the larger problem areas around the lake.
In July 2019, a qualified aquatic herbicide contractor treated approximately 9 acres of Eurasian water milfoil (50% of the shallow lake area) with Florpyrauxifen-benzyl, and in August and September of 2019, treat 25% of the non-native water lilies and pondweed with Fluridone. The work is being paid for by an Ecology grant. These selective herbicides were chosen by the steering committee in order to minimize risk to humans, wildlife, and to cause the least amount of restriction for swimming and fishing. Both herbicides have been approved by the EPA and the Washington Department of Ecology. Prior to herbicide treatment all lakefront property owners will be notified.
In June 2020, the annual aquatic weed survey completed on May 22, 2020 showed that the efforts to control Eurasian watermilfoil last summer were very effective. Only 2 small patches of Eurasian watermilfoil were found during survey, both on the north end of the lake near the Hall Creek inlet. For summer 2020, the steering committee for aquatic plant control in Lake Ballinger has decided on a combination of volunteer effort to physically remove fragrant water lilies and a small contract funded by the Ecology grant to have divers install biodegradable bottom barriers at the outlet of Lake Ballinger and other problem areas. The divers will also be able to hand-pull weeds when they find isolated patches. No herbicide application is planned for summer 2020 in Lake Ballinger.
On May 4th, 2021, a qualified and experienced aquatic herbicide contractor will treat Eurasian watermilfoil on the north, east, and southeastern sections of the lake with Florpyrauxifen-benzyl (brand name ProcellaCOR). The work is being paid for by an Ecology grant. This selective herbicide was chosen by the steering committee in order to minimize risk to humans, wildlife, and to cause the least amount of restriction for swimming and fishing. This herbicide is the same one that was used in Lake Ballinger July 2019, and has been approved by the EPA for use in potable water sources. Approximately 24 hours prior to herbicide application, all lakefront property will be posted with notification of the herbicide treatment.
See the Lake Ballinger Integrated Aquatic Vegetation Management Plan for more details.
Volunteer Invasive Species Removal
See how the Girl Scout Troop 44253 got involved with fragrant water lily removal at Lake Ballinger!
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 firstname.lastname@example.org or (425) 744-6226.
Lake Ballinger Integrated Aquatic Vegetation Management Plan
Rules for Aquatic Plant Removal and Control
Guidelines for burlap bottom barriers
Lake Ballinger Aquatic Weed Control Workshop (May 29, 2019)
Mountlake Terrace and Edmonds Lake Ballinger Aquatic Noxious Weed Control Interlocal Agreement