Overview
Rainwater that runs off from built-up or paved areas is considered wastewater, as is the wastewater that accumulates on a property.
In principle, the wastewater generated on a property must be handed over to the City of Bonn for disposal.
However, if the property owner can prove that it is possible to infiltrate the rainwater on their property in a way that is compatible with the common good, the City of Bonn can waive the transfer of the rainwater.
Compatibility with the common good means: the rainwater must be unpolluted, the soil must be sufficiently permeable, the groundwater must not be polluted and third parties must not be affected by the infiltration.
A hydrological report is required to prove the public welfare compatibility. A soil or subsoil report is not sufficient.
In areas for which a development plan, a project and development plan or a building law statute establishes buildability after January 1, 1996, the City of Bonn will have it examined how the precipitation water can be disposed of.
If decentralized infiltration is possible on the individual properties or in a central infiltration system, this is stipulated in the development plan, in the project and development plan or in the building regulations.
According to water law, the infiltration of rainwater constitutes the use of groundwater. It requires prior permission under water law from the Lower Environmental Authority of the City of Bonn.