- Home
- Your Government
- Community & Business Services
- Surface Water Management
- Water Quality
- Lakes
- Sunday Lake Invasive Plant Control
Sunday Lake Invasive Plant Control
County assistance for Sunday Lake Fragrant Water Lily Control
The Sunday Lake Organization requested assistance from Snohomish County for invasive lily control. The County was able to secure funding and offered the organization assistance for efforts in 2022 and 2023. The assistance includes paying for and managing the invasive plant treatments.
Control Actions for 2023
The County has contracted with Aquatechnex, a licensed aquatic herbicide applicator, to perform 2 to 3 separate treatments for fragrant waterlily control. The treatments will take place between July 5 - September 30, 2023. The first treatment occurred the week of August 7.
The second treatment is scheduled for the week of September 11. The treatment will take 1 day and will be dependent on weather. The contractor will post shoreline properties within 400 feet of the treatment areas.
- View the Herbicide Notification Letter sent to shoreline residents
- View the Sunday Lake Fragrant Waterlily Treatment Area Map for planned treatment areas.
The Issue
Sunday Lake is home to an abundance of native plants. These beneficial plants are vital to keeping lakes healthy. They provide important food and habitat for aquatic life including fish, turtles, frogs waterfowl and other aquatic life. They also are important for us as they help to clean the lake by filtering pollution and prevent shoreline erosion.
Unfortunately, Sunday Lake is also home to a few non-native invasive plants including fragrant water lily and yellow flag iris. These plants can crowd out the beneficial native plants, harm lake ecology, and interfere with swimming, fishing and boating. So while it is important to keep native plants in the lake, it can be desirable to manage invasive plants to reduce their impacts. Learn more about how the different types of aquatic plants and how to identify them.
Invasive Lily Control Efforts at Sunday Lake
Over the years, residents have worked to control invasive fragrant waterlilies in front of their properties by hand-cutting, pulling out the roots and using an aquatic mower. However, the infestation continued to grow covering the majority of the lake. In 2018, a group of residents formed the Sunday Lake Organization to advocate for the long-term health of the lake and the initial goal of addressing the lilies.
With funding from local residents, the group obtained a state permit and contracted with a licensed aquatic herbicide applicator to treat the invasive lilies. Treatments have occurred each summer in 2019-2021. In 2022, The County took over the state permit and treated over 15 acres of lilies.
Multiple years of treatment are needed as only a portion of the lilies can be treated each year. These treatments have been highly successful and provided relief in many areas, yet continued work is needed to address the remaining problems.
Toxic Algae Alert
-
The following lakes are posted for an ongoing toxic algae bloom. Blooms look like green or blue surface scums or algae clumps. While posted, follow the guidelines on the WARNING sign.
Learn more about toxic algae.
Updated September 21, 2023.
- Gissberg Twin Lake North - blue-green clumps on the lake bottom near the shoreline and some large blue or black clumps floating in the lake. A sample was collected 9/18 - microcystin (a liver toxin) was present above 10 ppb (parts per billion), which exceeds the recreational guidance value of 8 ppb, set by the Washington Department of Health.
- Lake Cassidy - scum along the west shore and boat launch. A sample was collected 9/11 - microcystin (a liver toxin) was present at 4.58 ppb (parts per billion) but below recreational guidance value of 8 ppb, set by the Washington Department of Health.
- Lake Wagner - scum along the west shore and boat launch. A sample was collected 9/12 - no toxins present.
See full toxin results at www.nwtoxicalgae.org.
Resources
Invasive Plant BMP Fact Sheets from King County
Sign up to receive updates for Sunday Lake.
Contact Us
-
Marisa Burghdoff
Water Quality Specialist
Ph: 425-388-3204
Jen Oden
Water Quality Specialist
Ph: 425-262-2601
Dominick Leskiw
Water Quality Analyst
Ph: 425-312-0623
email us at lakes@snoco.org