Pine Lake August Update: Weed Treatment, Lake Safety & Recent Events
Dear Pine Lake Riparians, Neighborhood Association members, Pine Lake Marina and PLCC members,
We want to share several important updates regarding Pine Lake, including a change to our planned weed-management approach, several recent events around the lake, and a few timely safety reminders.
____________________________________________________________________
Weed Management Update
The good news from Progressive’s most recent lake survey is that no invasive aquatic plant species remained from the areas treated earlier this season. This is an important accomplishment and reflects the focus and progress that has been made in controlling invasive species in Pine Lake.
At the same time, Pine Lake is experiencing unusually heavy growth of native sago pondweed this summer. Progressive has advised us that Pine Lake is not alone; similar increased growth is being seen on a number of Michigan lakes this year.
In several areas of Pine Lake, the density of the sago pondweed has become significant enough to interfere with established boat lanes, access from docks to those boat lanes, kayaking, paddle boarding and other recreational use.
____________________________________________________________________
Why the Plan Is Changing
Our original plan was to address the excessive native vegetation through mechanical harvesting, and Pine Lake was scheduled with our harvesting contractor.
However, unusually heavy aquatic plant growth on other lakes has caused the harvesting projects ahead of Pine Lake to take substantially longer than anticipated. As a result, the contractor is unable to reach Pine Lake on our originally scheduled timeline and now anticipates that the earliest they could begin work here would be late August.
We were also advised that the exceptionally dense growth on Pine Lake would require significantly more harvester loads than anticipated and would likely increase the cost of the work.
Given the delay and the current conditions on the lake, Progressive recommended that the Board reconsider the planned harvest and instead pursue an additional, targeted herbicide treatment specifically designed to address the sago pondweed growth.
____________________________________________________________________
EGLE Approval Was Required and Received
Pine Lake’s normal treatment program does not allow this type of treatment after June 15 without an approved exception from the Michigan Department of Environment, Great Lakes, and Energy (EGLE).
Progressive and Savin submitted the required amendment, and EGLE has approved the exception, allowing the additional targeted treatment to proceed.
This is an important distinction. The upcoming treatment is not simply an extension of the earlier-season program; it required additional regulatory review and approval based on the conditions currently present in the lake.
____________________________________________________________________
A Different Treatment Formula for Sago Pondweed
The treatment approach is also being changed from the earlier-season treatment.
Progressive and Savin have recommended a different combination of herbicides intended to more specifically and effectively target sago pondweed. Using herbicides with different modes of action is also intended to improve effectiveness and reduce the likelihood of plants developing tolerance to a single treatment approach.
Just as importantly, the treatment strategy has been selected with the goal of preserving other desirable native vegetation where possible, including chara, which is an important part of Pine Lake’s ecosystem.
____________________________________________________________________
The Board Reviewed the Alternatives
The PLPOA Board met to review the available options and their implications for both recreational use and the long-term health of the lake.
As part of that review, we sought input from Progressive, Savin Lake Services and Dr. David Jude, our independent lake ecologist.
Dr. Jude supported the use of herbicides to control native plant beds where excessive growth is interfering with critical lake access, while also emphasizing the importance of preserving healthy native vegetation where treatment is not necessary.
Native aquatic plants are an important part of a healthy lake. They provide fish habitat, support organisms that serve as fish food, produce oxygen, help stabilize lake sediments and can make it more difficult for invasive plants to recolonize.
For that reason, our goal is not to eliminate native aquatic vegetation from Pine Lake.
____________________________________________________________________
A Targeted Treatment Approach
After reviewing the proposed treatment areas, the Board elected to proceed with treatment while limiting it to areas where excessive vegetation is materially interfering with lake access and recreation.
Treatment will be focused on:
Established boat lanes
Areas needed for boats to travel between docks and boat lanes
Areas where dense vegetation is significantly affecting kayaking, paddle boarding and similar recreational use.
Where native vegetation is not creating a meaningful access or recreational issue, our intent is to leave it in place.
Below is the updated treatment map which shows the areas planned for treatment.
For additional perspective, Pine Lake encompasses approximately 393 acres, while the final treatment footprint represents approximately 50 acres, or about 13% of the lake’s total surface area.
____________________________________________________________________
Cost of the Revised Approach
Cost was also an important consideration in the Board’s decision.
Based on the unusually dense plant growth this year, the estimated cost of the planned mechanical harvest had increased to more than $30,000. By comparison, the total cost of the upcoming targeted treatment will be $17,835.
While cost was not the only factor in the decision, the targeted treatment provides a more timely approach to addressing the current access and navigation issues at a materially lower cost than the delayed harvest.
The Board’s decision was based on the combination of timing, expected effectiveness, lake-health considerations and cost, rather than any one factor alone.
____________________________________________________________________
New Invasive Found: Starry Stonewort
As part of the most recent survey, Progressive also identified starry stonewort in one small area of the south bay. Starry stonewort has been found from time to time in Pine Lake, but this is a larger concentration than we have previously observed.
Starry stonewort is a non-native invasive aquatic macroalga that grows underwater and can form dense mats along the lake bottom. When established in larger beds, it can crowd out desirable native vegetation and interfere with boating, swimming and other recreational use.
The newly identified area will be included in the upcoming treatment. Addressing this localized occurrence early is consistent with our ongoing approach of identifying and controlling invasive species before they have an opportunity to become more widespread.
____________________________________________________________________
Treatment Scheduled for Tuesday August 18th, 2026
Savin Lake Services is currently planning to conduct the treatment Tuesday, August 18, subject to weather and other conditions that could affect the treatment schedule.
As always, shoreline areas associated with the treatment will be posted as required. Please review the posted notices for any applicable swimming, irrigation or other water-use restrictions.
We will send an additional communication if the treatment date changes or if there is other information riparians need to know before treatment occurs.
____________________________________________________________________
No Additional Weed-Control Activity Is Anticipated This Season
Based on the current survey results and the treatment plan now being implemented, we do not anticipate any additional weed-control activities on Pine Lake this season.
Because the upcoming treatment is intended to address the areas of dense sago pondweed that had been planned for harvesting, we do not currently expect a late-season harvest to be necessary.
In addition, Progressive’s most recent survey found no additional invasive aquatic species requiring treatment beyond the localized starry stonewort occurrence in the south bay being addressed as part of the upcoming treatment.
We will continue to monitor lake conditions, but based on what we know today, the upcoming treatment is expected to conclude the active weed-management work for the 2026 season.
____________________________________________________________________
Looking Ahead: Harvesting Remains an Important Part of Our Strategy
While the Board believes the targeted treatment planned for next week is the appropriate response to the conditions we are facing now, mechanical harvesting remains our preferred approach for managing excessive native vegetation later in the season when conditions and timing make it practical.
Harvesting provides an important benefit because it physically removes plant biomass from the lake rather than leaving that material to naturally decompose in the water.
It also gives us another tool for addressing late-season navigation and access issues without relying on an additional herbicide treatment that may require further regulatory review or an exception from EGLE — an approval that is not guaranteed each year.
Different conditions call for different management approaches, and this year is a good example of why flexibility matters.
Every season brings new challenges, and effective lake management requires both planning ahead and responding to the conditions actually present in the lake. The Board will continue working proactively with Progressive, Savin, Dr. Jude and our other partners to evaluate treatment options, harvesting schedules and lake conditions as early as possible each season.
At the same time, we need to remain willing to adjust when weather, plant growth, contractor availability or other circumstances differ from what was anticipated.
Our goal remains the same: use the least disruptive and most effective management approach available to maintain reasonable recreational access while protecting the long-term health of Pine Lake.
____________________________________________________________________
