clp sign image

Information about Curlyleaf Pondweed

Curlyleaf Pondweed (CLP) entered North America in the late 1800’s.  It likely came to Lake Osakis prior to the WW2.    Only two times in history can I find there were control measures taken.  In the 80’s a mechanical harvest was done, turned out to be a non-approved method by DNR because it just reseeds itself.  The current method (Aquathal K herbicide) used was done in 2007, 08, 09 on portions of the lake.  Aquathal K is specific to CLP and does not harm MN native plants.

CLP impacts the Lake in several ways, it supports an algae bloom, floating plants interrupt fishing by catching on your line, dead and decaying plants on the shorelines, decaying plant materials (muck) on the lake bottom, as well as interfering with native plant growth.  CLP life cycle makes all the above mentioned possible.  CLP starts to grow in the winter, yes under the ice.  It sets Seed and Turions in mid-summer then of course the plant dies off.  The management effort is to stop the plant growth before Seed Set or Turion development takes place.  Research indicates CLP Seed and Turions can survive 3-5 years, therefor once the presence is determining the recommendation is to monitor (survey) and treat at least for three consecutive years.



OLA President

Bruce Magnus

Curlyleaf Pondweed /Planning 2022            6/24/2021

Curlyleaf Pondweed (CLP) is an Aquatic Invasive Species (AIS) that has supported algae blooms and shoreline plant residue on Lake Osakis. The entire Lake Osakis has been surveyed to determine the locations of CLP. This survey was completed by Blue Water Science (see attached map). There are 367 acres identified to potentially obtain a DNR Permit in 2022 to apply. Aquathol K is the herbicide of choice for CLP management and pricing can be variable. A spring survey will also be required prior to DNR permitting. There are Aquatic Invasive Species (AIS) grants available from DNR and County AIS programs, the amounts available varies based on county demand.

The 2022 cost is estimated to be $547 per acre. If there is enough funding to spray all 367 acres the total cost will come to $200,749, before the grant money is applied (unknown amount at this time). It is recommended the areas be treated 3-5 consecutive years based on survey results each spring.

The Local County Commissioners and City of Osakis have been asked to consider creating a Lake Improvement District (LID). This would result in property assessments. Osakis Lake Association Fund raisers and Grants would contribute to decrease the 883-property owner’s cost. A public meeting is being planned for the near future to discuss the process for LID creation on Lake Osakis. The LID will be vital for us to fund the much-needed improvements to Lake Osakis making it more enjoyable for years to come.
To learn more about a LID use the following link

Kind Regards
Osakis Lake Association Board

clp survey map

The map shows the trail from the survey crew. The colored areas identify the potential CLP management areas for 2022.  Areas 13-17 are the result of the 2021 survey.  Areas 1-12 were surveyed in 2020. Areas 3, 5, 6, 7, 8, 10, 12 were treated in 2021.