Elodea, also known as Canadian waterweed, is an aquatic plant that is native to North America and is now found in many parts of the world. It is often considered a nuisance because it can grow quickly and form dense mats that can interfere with recreational activities and harm wildlife habitats. In addition, it can also outcompete native plants, leading to a decline in biodiversity. Elodea was first identified in Devils Lake in 2019. Since then, Elodea growth has exploded in Devils Lake. Multiple in water vegetation management options exist but not all options work for all water bodies. Given the mixed use of Devils Lake the options below were identified as being the most appropriate methods to manage the nuisance aquatic vegetation growth for our basin.

Chemical control: Herbicides can be used to kill elodea, but they must be used carefully to avoid harming other aquatic plants or animals. After an initial pilot project involving small control areas in Devils Lake it was determined chemical control was not an effective method large scale vegetation control for our water body. However, some success has been found using the chemical herbicide “Dibrox”.

Mechanical removal: This can be done by hand or with special tools, such as rakes or harvesters. It’s important to remove all of the plant material, including roots and fragments, to prevent regrowth. In 2021 the Devils Lake Water Improvement District leased and began operating an aquatic harvesting boat. 

Biocontrol: Some species of fish and insects feed on elodea and can help control its spread. Sterile grass carp have been an effective in water vegetation management tool for Devils Lake in the recent past. In June of 2023, 5,000 grass carp were added into the lake. DLWID will perform an annual survey to measure the effectiveness of the grass carp.