LAKE MANAGEMENT PLAN UPDATES
Below is an email communication LPPRD received from Andy Hudak (DNR) on March 8, 2024 regarding the 4th lake management plan draft submitted by Cason and Associates.
__________________________________________________________________________________________________________________________
From: Hudak, Andrew - DNR
Sent: Friday, March 8, 2024
Subject: Technical Review Team – Puckaway Management Plan Comments
Lake Puckaway P & R District:
The Water Resources Program has conducted a technical review of the draft APM plan submitted by Cason and Associates (4th draft). Please find attached, a list of questions and concerns that were identified during this technical review.
Overall, the plan lacks specificity and does not meet minimum Department standards for approval. Please reach out with any questions that you may have regarding our comments.
The Department will continue to work with you to develop a plan that will help guide informed decision making well into the future.
Sincerely,
Andy
__________________________________________________________________________________________________________________________
TO: Lake Puckaway P & R District
FROM: Water Resources – Technical Review
SUBJECT: Comments on Lake Puckaway, APM Plan – Draft 4
Introduction – the need for the plan update is multifold: old plan is over 5 years old, and the lake has flipped back to a clear-water plant dominated state. Not just because EWM has become prevalent.
Introduction: We don’t agree that the reason for Puckaway to flip back to a clear-water state is due to nutrients locked up in lakebed sediments which recently became available to plants. What evidence is there to support this claim?
Goals (page 7): It is not realistic to have a goal to drastically reduce EWM in a 5,000 lowland drainage lake. Despite the shear size of the lake, flow from the Fox River will greatly reduce herbicide contact exposure times.
Goals (page 7): In the above section it mentions that native plants, such as coontail, have also exhibited ‘explosive growth’. Three of the four goals specifically relate to EWM management; will the fourth goal to “mechanically harvest navigation lanes along the Southwest shore of Lake Puckaway” provide adequate recreational/nuisance relief to riparian’s if native plants grow to levels that require management?
Goals (Page 8). The long-term goal is to mechanically harvest more than the southwest shore of Lake Puckaway.
Page 10. The mentioned historical algal blooms were caused by harmful blue-green algae (BGA). This is important information to include in the management plan. Please offer a brief description of why BGA is dangerous and undesirable.
Mechanical harvesting – Mention the dates when harvesting was attempted. How big of an area was harvested?
Page 11. In-lake IPM strategies section only includes monitoring. While monitoring is one very important component of an IPM strategy, we suggest modifying the entire goals section to outline the thought process of an IPM strategy including monitoring and multiple strategies.
Page 12. ProcellaCOR year-of-treatment success criteria seems low (one acre at 50%, 10% of treatment area?). Moreover, what is the long-term success criteria for years 2-4 post treatment? We assume the amount of EWM present in years 2-4 would be higher than the 50-10? What data will be used assess if >50% of the water column (i.e., volume) is occupied by EWM?
Page 12: How were the 50% of the water column or greater than 10% of the management area created? What is the metric/standard to prompt control and what is the metric/standard for a successful control project.
Page 12. ProcellaCOR. At what confidence interval would significance be set?
Page 12. It does not seem appropriate that ‘failure’ is defined as “eradication of native aquatic plant species” as well as “no effect on EWM”.
Figure 3. There is a higher quality image available of the lakewide PI grid map: https://apps.dnr.wi.gov/lakes/plants/samplingmaps/SamplingMapDetail.aspx?wbic=158700
Page 15. Describe your procedure for conducting meander surveys. This seems very subjective and not repeatable.
Page 16. It is stated that “difference (in species richness between 2020 & 2022) is likely due to differences in observer sampling bias”. However, the same company (Onterra) did the surveys in all three years.
Page 19 & 20. Table 2 & 3 appear to be displaying the relative % frequency of occurrence (i.e., proportional frequency of species); it would be much more appropriate to display the littoral % frequency of occurrence here and throughout the report.
Page 21. Describe the differences between scattered, dominant, highly dominant and surface matted?
The term “dense beds, moderately dense, scattered and highly scattered” are used. How do these measures compare to dominant and other categories? Why are there multiple measures used for EWM populations?
Page 22. The 50-acre pilot project may have impacted EWM outside of the treatment area, but how these populations respond in 2024 & 2025 will provide a more complete assessment on if long-term control was achieved. To suggest that better results are expected from future ProcellaCOR treatments is premature.
Page 23. Why does Table 1 – Appendix L only show pre-treatment data and not post? We are assuming that this is pre-data as the title for the table is misleading. This table also appears to be displaying the relative % frequency of occurrence (i.e., proportional frequency of species); it would be more appropriate to display the littoral % frequency of occurrence.
Page 24. Comparisons between the 2022 PI and the 2023 Sub PI are not valid due to the very low sample size used in the comparison and shouldn’t be presented in this plan.
Under Herbicide Control, explain the differences between contact & systemic herbicides.
Page 27. Resolve minor discrepancy – last paragraph of section states 25ft navigation lanes, but 20ft is used in other parts of document and in Appendix D figures.
Page 28. Harvesting is being discussed under the heading of Manual Removal. Please offer a topic heading of Mechanical Removal.
The shortcomings of harvesting and manual removal are discussed. Please also discuss the limitations of herbicides. E.G., the cost of herbicide control of EWM on a 5,000-acre system.
Page 29. We disagree that there is “no doubt” that the EWM population will continue to worsen. It certainly could get worse, but the aquatic plant community is new and dynamic in Lake Puckaway with little resiliency. The system will continue to change, and we cannot be certain what exactly is going to happen.
Page 29. The strategy references using “ProcellaCOR to treat the worst areas of the lake.” How will the “worst areas” be determined from the meander survey? Is “the worst” different from “nuisance level” metric described in latter paragraph?
Page 30. The document states that in 2024, the goal is to harvest 51 acres along the south shore. Please have an appendix referenced or table that shows precisely where this 51-acre area is to be located.
How will these harvest areas be presented to the public for consideration and comment?
The criteria for EWM treatment success are less than 50% of the water column is occupied by EWM in greater than 50% of treatment polygons? This level of EWM regrowth is very high and does not seem to be worth the expense of an herbicide treatment. One should expect far less than a 50% reoccurrence of EWM two years post treatment.
Page 30. Document text indicates that herbicide treatment success will be longer lived without fragmentation of EWM from harvesting and boat traffic. Please explain that auto-fragmentation of EWM is an equal or more likely vector for EWM recolonization. Auto-fragmentation is a reproductive strategy that involved adventitious root systems forming at the leaf nodes etc… In other words, EWM will fragment without boat or harvesting disturbance.
Consider (continuous) numbering of the recommendations (instead of bullets) so it is easier for people to reference specific items.
Page 34. Include bullets and timelines for the aquatic plant surveys which are planned for in 2024 (and beyond).
Page 34. An AIS Large Scale Control Grant is listed. What are the activities anticipated to be included in the grant application?
Page 35. Include a NR109 permit in the timeline; a permit is needed prior to beginning 2024 harvesting.
Page 35. It would be best to have potential areas identified and mapped. Since additional data has been collected, potential treatment polygons should be able to be identified at this time. How will these treatment areas be presented to the public for consideration and comment?
The plan for herbicide use in 2024 and beyond lacks specificity. What is your adaptive management approach, also please reiterate the definition of efficacy here.
The same is true for harvesting (lack of specificity). Why hasn’t the proposed 51-acre area been spatially determined with a corresponding map? This map will be required for NR109 permitting and must be always present in the harvester.
Page 36. The text indicates that a DNR grant will be applied for/used to purchase an aquatic harvester. Note that purchase of a harvester is not an eligible item within the DNR Surface Water Grant program but is in the DNR Recreational Boating Facility program (Recreational Boating Facilities Grants | | Wisconsin DNR).