The fire and ambulance services office (Amt für Feuerwehr und Rettungsdienst) is responsible for local civil protection in the city of Bonn. This includes protecting the general public in tense situations or defence matters (civil defence) for which the government is responsible, as well as dealing with large-scale emergencies (peacetime civil protection) on behalf of the state. In addition to the professional and volunteer fire departments, these tasks are performed by a series of organisations (with mainly voluntary helpers) as well as the Federal Agency for Technical Relief (Technisches Hilfswerk) and, under certain conditions, also the army and police force.
Contacts can be found here.
What to do in case of floods and heavy rains in Bonn?
Especially in summer, the warm and sunny days may occasionally bring thunderstorms and heavy rains, causing not only the Rhine river, but especially small streams to flood almost instantly. The attached pdf-file contains useful information on what to do and whom to contact in case of floods in Bonn. One of these things that are hopefully never needed, but good to have at hand, just in case...