5/20/17 – Those swans are not real swans on some ponds in Beaver Dam. Director of Facilities Ritchie Piltz says the public is reporting swan sightings in city detention ponds. Piltz says the swans are decoys intended to deter geese from landing on the ponds. The city’s Stormwater Utility with the help from the Department of Public Works set a pair of swan decoys in the detention ponds on Corporate Drive and on Beichl Avenue. Piltz says goose droppings are a highly concentrated form of phosphorus, which is a chemical that is harmful to aquatic life. The ponds are mandated by the state to filter out debris and other impurities from rainwater before entering rivers and streams.