Lake Edward Conservation Club

Treatment of Curly Leaf Pondweed in Lake Edward 2022-2024

Objective of Treating Curly Leaf Pondweed:  Experts have told the Lake Edward Conservation Club (LECC) that curly leaf pondweed (CLP) will continue to spread in Lake Edward over time unless the lake association can treat small CLP areas now. Currently, CLP is not dense or widespread enough to substantially interfere with fishing and water contact sports, which are high priority to neighbors that live on the lake and in surrounding areas. Our objective is to hold CLP to a manageable number of acres so that the 32 kinds of native species identified in Lake Edward remain healthy and help fend off the spread of CLP.  Another problem is that CLP dies off and decomposes exactly when the resulting nutrient releases support algal blooms on the lake, decreasing water clarity.   With that in mind, controlling CLP at this time contributes to conservation of future water clarity, fishing and water contact sports as is desired by all the lake neighbors and government managers.

Licensed Treatment Contractor: The LECC board has contracted with Mr. Ron Duy of Central Minnesota Aquatics, Inc to begin a 3-year chemical treatment of CLP in 2022.  The 2023 project for which we seek donations will be the second year of treatment.  We had intended to begin in previous years, but the weather did not cooperate. Success of chemical treatment requires that CLP is the only plant species active so that the chemical works only on CLP and not the 32 valuable native species.  That is supposed to happen at water temperatures below 60 F.  Without favorable conditions, the MN DNR will not issue the necessary permit, nor does LECC wish to waste valuable funding. Until favorable conditions occurred in 2022, the winter conditions and spring weather triggered growth of native plants and CLP simultaneously, which doesn't work for aquatic herbicides.  A 3-year treatment plan is desirable because CLP produces seed-like structures called "turions" which drop into the sediment and sprout later under favorable natural conditions. During three favorable treatment years, we want as many turions to sprout as possible. Then the process is to kill the CLP plants with approved aquatic herbicide before the CLP has a chance to produce new crops of turions. The plan is to meaningfully reduce net turion numbers in the sediment for 3 years.  Using the process of treating three years close to one another reduces the chances of spread of CLP beds to undesirable size and density, prohibitively expensive to treat. 

Our Plan: We have received a lot of technical assistance from the MN DNR, our contractor and others. The LECC board has decided to continue chemical treatment in one key area at the north end of Lake Edward where 40 acres of CLP was mapped in 2021 and 16 acres was treated with herbicide in 2022.  For our DNR permit application in 2022, Mr. Duy identified a 16-acre area that the DNR permitted treatment, for which the LECC paid $20,450.  LECC used $2,300 from previous GiveMN donations, a $6,400 MN DNR grant and most of $12,400 donations from lake neighbors. We expect to have similar costs in 2023 and currently have $5,500 identified in reserves. So our goal is at least $15,000 more for the 2023 project. LECC will again request a grant from the MN DNR for 2023. The 2023 CLP survey and map by our contractor will cost at least an additional $1,000 whether or not the DNR permits the second chemical treatment in 2023.   Past LECC board members indicate that LECC conducted helpful herbicide treatments of CLP historically in hot spots in the SW corner of Lake Edward.  We may need to address this area sometime in the future, depending on future CLP survey results.