Aquatic Plant Management Plan

2024 Aquatic Plant Management Plan 

The 2024 Aquatic Plant Management Plan (APMP) was approved by the WDNR and adopted by the Board of Commissioners of the Silver Lake Management District in March 2024.

The APMP includes the results of the comprehensive point-intercept survey of aquatic plants in Silver Lake.

  • Silver Lake is home to 28 different aquatic plant species, three of which are invasive species.
  • The most prolific species are, in order of magnitude, Chara or Muskgrass, Wild Celery, Native Pondweeds, Sago Pondweed, and Hybrid Water Milfoil (HWM).
  • Silver Lake has a high-quality plant community whose diversity metrics rank Silver Lake as one of the best in southeastern Wisconsin and in the top 25% of all other Wisconsin lakes.
  • Overall, the native aquatic plant community of Silver Lake is in excellent condition, and the study confirms that there have been no long-term effects on the aquatic plant community from the past decade of HWM treatment, including the whole-lake HWM treatment in 2015.

The APMP also identifies options for continued monitoring and treatment of the three invasive species found in Silver Lake.

  • Based on annual fall surveys, the densest areas of HWM will be considered for spring treatment in the continued effort to prevent the spread of HWM as occurred a decade ago.
  • The second invasive species, curly leaf pondweed, has been present for decades but only in low densities and does not require active management.
  • The third invasive species, starry stonewort, was identified in only one location in the 2023 survey.  Starry Stonewort is a relative newcomer to Wisconsin lakes and its presence in Silver Lake needs to be carefully monitored.

The 99 respondents to the APMP's Lake User Survey overwhelmingly supported continued treatment of invasive species, particularly HWM.  Respondents also ranked major concerns:  Invasive Species, Boating Safety and Enforcement, Lake Levels / Outlet Dam, and Water Quality.  The Board has adopted these concerns as the top priorities of the District going forward.

The process of updating the APMP started in 2022 and was completed in 1Q 2024 on schedule and under budget.  A WDNR Grant (max $7,929) and a $1,500 project grant from the Silver Lake Protection Association helped defray the budgeted $13,585 cost.  The comprehensive aquatic plant survey and the Lake User Survey were undertaken in August 2023.  The APMP was drafted in fall 2023 with public and WDNR review taking place in 1Q 2024.

Summary of Aquatic Management Plan Update - Watch Video

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In this video, I provide a brief review of the current aquatic management plan for invasive species and nuisance vegetation in our lake. I discuss the challenges we face, such as hybrid species and the spread of curlyleaf pondweed. I also highlight the importance of ongoing surveys and the need for a multi-year approach to maintain a healthy lake ecosystem. -- Jim Sharl