Des Moines - The Iowa Department of Natural Resources (DNR), Polk County Conservation Board, City of Des Moines, Polk Soil & Water Conservation District, Natural Resources Conservation Service, Iowa Department of Agriculture and Land Stewardship – Division of Soil Conservation, and other partners started working in 2008 to improve habitat and water quality at Easter Lake on the southeast edge of Des Moines.
Over 200 best management practices (BMPs) have been installed on residential properties in the Easter Lake watershed. Practices installed include urban storm water management practices, ponds built around the lake to trap nutrients and sediment, and stabilizing the streambank along Yeader Creek. In-lake work includes deepening and stabilizing the shoreline, installing fish habitat, removing excess sediment, and building an in-lake silt pond. Additionally, a fish rearing pond was built near the lake, the outlet structure of the lake was updated to include a fish barrier to prevent undesirable fish from coming back into Easter Lake, and the gate-valve structure was replaced.
As the lake restoration project nears completion, one of the final steps is to remove Common Carp and Gizzard Shad from Easter Lake and the watershed. These species have detrimental impacts to aquatic vegetation, the fishery, and water quality.
The Iowa DNR plans to treat Easter Lake and its watershed next Tuesday, Nov. 20th(pending workable weather conditions) with rotenone, a botanical pesticide, which is the most effective management way to remove all of the fish from a waterbody or stream.
Private property owners next to treatable water will be notified about 24 hours before the treatment with hangers on their doors. Avoid human and pet contact with water in the treatment area until notified by a 2nd notification on your door. It will likely take 24 to 48 hours for the rotenone to dissolve in flowing streams. However, it could take days or weeks in ponds and the main lake. Treated public areas will be closed to public use until the area reopens for public access.
Rotenone is used world-wide and has been since the 1930s. It is a common tool that fisheries managers use for managing sport fish, improving water quality, and managing endangered species. Rotenone is a naturally occurring compound that comes from the roots of a tropical plant in the bean family. The Iowa DNR commonly uses the commercially available formulation, 5% Prenfish, which has been approved for fisheries management by the U.S. Environmental Protection Agency (EPA).
The EPA has concluded that the use of rotenone for fish control does not present a risk of unreasonable adverse effects to humans or the environment. The EPA certifies all pesticides based on use according to label directions, which the Iowa DNR is equipped to fulfill these obligations.
For more information about rotenone and a map of the treatment area go to https://easterlake.org/project-updates/fisheries-renovations-rotenone-treatment/