This is the first article in an ongoing monthly column from the Waseca Lakes Association to inform you on activities and water quality issues affecting Loon and Clear lakes in Waseca. The Waseca Lakes Association is a nonprofit 501©3 organization formed in 2000 and consists of area residents who are non-lake shore owners as well as lakeshore owners.

As stated in its charter, the purpose of Waseca Lakes Association shall be to improve and maintain the water quality of the Waseca lakes and adjoining watershed for all users. The group will be organized as a non-profit organization to promote involvement and input from all watershed residents, interested persons and organizations through communication, action, and education.

The current top priorities for our lakes are aquatic invasive species (AIS) management, storm water inflow, in lake phosphorus cycling, and education. This month we will cover AIS management: Clear Lake has two aquatic invasive weeds that affect water quality, curlyleaf pondweed (CLP), and Eurasian watermilfoil (EWM).

1. CLP germinates very early and outcompetes native plants. Its life cycle is such that it grows fast in the Spring and reaches the water surface forming dense mats by mid-June inhibiting native plants and recreational activities. At that point, the foliage dies back which can cause a loss of dissolved oxygen and a release of its nutrients, especially phosphorus, causing algae blooms. CLP reproduces and spreads through winter buds called turions which form new plants under the ice in late winter, allowing CLP to be the first nuisance plants to emerge in spring.

2. EWM is a later emerging invasive plant that forms dense mats and grows towards the waters surface. It establishes and reproduces through vegetatively when a fragment breaks off and roots in the lake sediment. The plant dies back in the fall, but the roots can survive the winter to grow again the following season.

The Waseca Lakes Association has sought to manage CLP with aquatic herbicide treatments in Clear Lake since 2013. Costs of treatment and DNR permitted acreage limits have limited the success of CLP management. EWM has become a problem only in recent years with a large bloom in 2021. These two weeds severely limited recreation use of the lake in 2021 and contributed to algae growth which reduces water clarity.

Plans for 2021 are to work with Waseca county who has purchased a used mechanical weed harvester from Lake Minnetonka. We are hoping to see a more immediate impact with mechanical removal, as DNR permitting allows to cover more acres than with aquatic herbicide treatments.

You can contact the Waseca Lakes Association and find more information at our website:

Duane Rathmann is a member of the Waseca Lakes Association

Recommended for you

Load comments