Roesiger Invasive Plant Control Project

newburstgold50_png Public Hearing Continued for on Roesiger Annual Aquatic Plant Service Charge

Public Hearing for Proposed Roesiger Aquatic Plant Service Charge - is set to continue on Wednesday, November 23rd at 9:00 AM during the General Legislative Session

Attend in person or online via Zoom

In Person:

8th Floor Henry M. Jackson Room

Drewel Building (Administration East)

3000 Rockefeller Avenue

Everett, Washington 98201


Zoom Webinar Link:

Dial in: (253) 215 8782 or (301) 715 8592

Meeting ID: 948 4685 0772

In the first public hearing on Oct. 27, Snohomish County Council introduced an amendment to the proposed service charges on properties around Lake Roesiger for the purpose of controlling invasive aquatic plants in the lake. This amendment would add a separate service charge category for undeveloped lake front parcels of $120 per parcel. An undeveloped parcel is considered any lot not defined as developed under SCC 25.10.050. The online interactive map has been updated to reflect the change. 

Due to this amendment, the public comment period has been extended to Wednesday, November 23rd at 9:00 AM during the General Legislative Session. The meeting can be attended either in person or online via Zoom. Lake Roesiger residents may provide comment at the November 23rd meeting or by email at

If the amended ordinance is approved, the annual service charges beginning in 2023 are provided in the table below.

Rate Category

Annual Service Charge

Lake Front - Developed

$170.00 per parcel of real developed property abutting the shoreline of Lake Roesiger

Lake Front - Undeveloped

$120.00 per parcel of undeveloped real property abutting the shoreline of Lake Roesiger

Shared Lakefront

$35.00 per parcel of real property with an undivided ownership interest in lake front real property used for common beach access

Off Lake

$20.00 per parcel of developed real property within the Lake Roesiger basin that is not lakefront or shared

Proposed Service Charge Background

In 2021, your community and Snohomish County developed a plan to prevent and reduce harmful invasive plants at Lake Roesiger, including Eurasian watermilfoil, fragrant waterlily, slender arrowhead, yellow flag iris, purple loosestrife and knotweed. The plan was approved by 70% of lake area residents in an online survey.

Volunteers from the Lake Roesiger Community and Boat Club developed a proposal to fund the plan using 1) WA State grants, 2) Snohomish County contributions, and 3) an aquatic plant charge paid by Roesiger area residents. The proposed charge is described in the FAQ document and on the interactive map. If your parcel is affected by the proposed fee, you received a letter in the mail.

The Community Club has requested Snohomish County Council representatives for Lake Roesiger, Nate Nehring and Sam Low, introduce an ordinance to the full County Council to establish the proposed charge in Snohomish County Code. The ordinance would require approval via the formal County Council process to be adopted. 

View the August 25, 2022 public meeting recording  and presentation to learn about the charge, how it would be used at Lake Roesiger and listen to community feedback.

Roesiger Control Plan is Final

Snohomish County Surface Water Management and the Lake Roesiger Community and Boat Club partnered together to develop an Integrated Aquatic Vegetation Management Plan (IAVMP) for Lake Roesiger. The plan focuses on long-term control of key invasive plants and was developed with in-depth community engagement. 

In fall 2021, the plan was approved by 64% of all voters which included lake users that do not live near the lake. Approval was 70% among lake area residents and 74% among Lake Roesiger Community and Boat Club members. The Washington Department of Ecology approved the plan in February of 2022.

Read below to see the history of the plan development and all related draft documents, meetings, etc. 

Overview of Roesiger IAVMP Plan Elements 

Overview of Roesiger Aquatic Plant Management Plan Elements

Next Steps

The Lake Roesiger Community and Boat Club Board opted to have the County not apply for an implementation grant in 2021. Instead the Board chose to form a funding committee to ensure there is sustainable long-term funding before pursuing grants. Grant applications are due each year in November or December. To stay up-to-date or contact the the Roesiger Community and Boat Club, please visit their website

The Issue

Lake Roesiger 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, Lake Roesiger is also home to a few non-native, invasive plants. 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. 

The lake has three invasive species of concern in the lake basin - Eurasian watermilfoil, fragrant waterlily and narrow-leaved arrowhead. There are also three invasive species found on the lake shoreline - yellow flag iris, purple loosestrife and Japanese knotweed. See our aquatic plants page to learn more about the different types of plants and how to identify them. 
Fragrant Waterlily Patch and Flower

Fragrant waterlily

Introduced as an ornamental plant, it takes over shallow areas, limiting habitat and boating and speeds causes the lake to fill in faster.

Eurasian watermilfoil

Noxious weed, grows in hard to swim through mats and crowds out native plants. Can reduce oxygen in the water. Easily regrows from broken fragments.

Eurasian Watermilfoil Patch and Flower

Grass-Leaved Arrowhead

 Less researched, may displace natives plants and wildlife, can be a nuisance to swimmers. Found only in 5 lakes in the state, including Lake Roesiger.

Grass-leaved Arrowhead Patch and Flower

Yellow Flag Iris

Grows in dense clumps in shallow waters of lakes and streams. A piece of root can break off and grow a new plant. Resin from it can irritate the skin.  

Yellow Flag Iris Patch and Flower

Purple Loosestrife

Emerges from the water in dense stands, spreads rapidly. Crowds out plants that make for good nesting habitat. Could be mistaken for spiraea or fireweed 

Purple Loosestrife Patch and Flower

Past Efforts

Since 1998 Snohomish County controlled Eurasian watermilfoil in the lake through diver surveying and hand-pulling. These efforts were effective in keeping milfoil levels low with only small patches growing each year. Unfortunately, funding for this program was lost in 2017. The Community Club has raised funds to hire divers for some hand-pulling work in 2019 and 2021.

Over the years, some individuals have worked to control fragrant waterlilies in from of their properties. However, the problem has persisted and there was a growing desire to have a larger solution. In recent years, the Community Club has purchased tools for homeowners to do lily control on their property and obtained a larger permit for participating landowners to lay bottom barriers. While these efforts may provide relief in small areas, they are not addressing the large scale infestation.

The Integrated Aquatic Vegetation Management Plan

In 2020, the community approached the County for assistance in applying for a  Washington State Department of Ecology grant program to help fund invasive plant control. The program requires that an Integrated Aquatic Vegetation Management Plan first be developed before communities can obtain funds for control work. The County applied for and was awarded a grant beginning in July 2021. 

Plan Goal & Steps 

Roesiger Plan Timeline Of Actions

The project goal was to provide the community with a road map which will help native plants, ecosystem health, and lake recreation. The plan laid out all options with associated costs and benefits so the community could decide on the best path forward. 

Step 1

Map Invasive Species

In July 2021, County staff conducted a survey of the lake mapping all locations of identified invasive species as well as inventorying the native plant species. These maps were used to assist in the plan development and can be viewed online:

Step 2

Develop Draft Management Plan

Snohomish County contracted with Tetra Tech Inc. and ESA to develop the draft plan. Tetra Tech and ESA have extensive experience managing invasive aquatic plants including knowledge of the latest research in control technology. They also have experience working with local communities to facilitate development of  IAVMPs. 

Members of the Lake Roesiger Community and Boat Club were instrumental in developing the draft plan. The Club appointed a steering committee of 12 members with representation from each lake basin. The committee met twice to 1) provide input to Tetra Tech and ESA regarding the plan goals and 2) review the draft plan and develop recommendations for the full lake community. 

  • Steering Committee Meeting 1: August 9, 2021 - development of plan goals and control options. Watch the recorded meeting and view the presentation.
  • Steering Committee Meeting 2: Scheduled September 9, 2021 -  review draft management plan and develop recommendations. Watch the recorded meeting and view the presentation.
Step 3

Present Draft Plan to Community for Input

The plan was drafted and included four different scenarios for plant control. Tetra Tech  and ESA provided an online presentation to explain the plan and the potential management options. The entire lake community was invited via mail, email, and social media postings to view the presentation and the draft plan and provide feedback via an online survey. 

Finally, there was a lake-wide community on October 26th to review the plan feedback and discuss next steps.  Watch the recorded meeting.

Step 4

The community input was used to revise the plan and a final community vote approved the plan.