The city of Hamburg in Germany introduced a stormwater fee in 2012 to provide an incentive for restoring ecosystems to provide more permeable surfaces, such as green roofs, and to recover some of its costs for sewage network renewal and wastewater management. More specifically, the city invests ca. €60 million per year for sewage network renewal and has spent ca. €263 million on wastewater management. Of this, 29.3% are costs for stormwater management and 70.7% are costs for sewage drainage and treatment. In practice, the stormwater fee works by charging a sliding fee according to the impermeable area of a property and the degree to which the property is connected to the sewage network. The Hamburg Department of Stormwater Management set up a common Hamburg-wide GIS-system integrating all the map data on individual properties necessary for stormwater planning and for computing the stormwtaer fee. The fee is embedded in a mix of mutually supporting instruments for stormwater management, on private and public property.