Marilyn Danks, Program Coordinator
500 Lafayette Road, Box 25
St Paul, MN 55155
The goals of the program are to ensure the safe winter operation of aeration systems and to ensure the appropriate use of aeration technology. In existence since 1974, the program has grown from issuing a few aeration permits annually to approximately 300 aeration permits statewide. The major use of aeration is to prevent the winterkill of fish, but in recent years the use of aeration has expanded to include shoreline protection, providing open water areas for captive waterfowl and, to some extent, water quality improvement.
The information below explains how lake aeration systems work, how they are used for lake management and how their use on public waters is regulated by the Department of Natural Resources (DNR). One lake problem that can be controlled quite successfully with aeration is the winterkill of fish. However, the effects of aeration on algal blooms and nutrient recycling are less predictable. There are important questions that need to be answered prior to pursuing lake aeration.
If, after reading this information, you feel that aeration has potential for the lake you are concerned about, please call or write your Area or Regional Fisheries Manager to discuss your ideas. He/she has important information regarding the lake and will be able to answer many of your questions.
A permit from the DNR is required to install and operate an aeration system in public waters. Public waters, generally, are water bodies which are 10 acres or larger in a rural area or 2.5 acres or larger in an incorporated area (i.e., within city limits). If you are unsure whether or not the lake is "public water", call your local DNR Office. Staff that work for the divisions of Fish and Wildlife or Ecological and Water Resources will be able to provide that information. A permit application and instructions on filling out the application are listed below.
The annual fee for an aeration permit was set by the 2003 Legislature at $250. The fee may be waived if specific criteria are met. Lakes that have public access and a management plan that recommends using aeration to reduce winterkill and promote angling opportunities, are likely to qualify. Aeration permits are renewed on an annual basis. A general liability insurance policy providing $500,000 combined single limit coverage may be required for winter operation, depending on shoreline ownership and public access.
The decision to operate an aeration system during the winter months should not be made hastily. The open water area created by aeration systems operated during the winter months is a serious public safety hazard. The primary concerns of the regulations that govern aeration system operation are public safety and ensuring appropriate application of aeration technology.