Public lakes are classic candidates for the “tragedy of the commons”: use by everybody, management by no one. In a state with many such lakes, only the care and concern of local communities can overcome this syndrome. This paper summarizes the legal basis and functional role of the institutions involved with lake management in Wisconsin. Within that context, the activities and finances of sanitary districts, lake districts, and lake associations are compared. Among 36 activities, lake districts are most active in 26, lake associations are most active in 9, and sanitary districts are most active only in the provision of public sewers. Among all lake organizations, monitoring activities are most common, followed by newsletter publishing, fish management, support for local ordinances, and weed harvesting. Sanitary districts and lake districts are primarily funded through their taxing powers, while lake associations depend on dues and fundraisers.