Source of the Danube
As early as 1847 the following definition can already be found in the "Universallexikon des Großherzogtums Baden" (Universal Lexicon of the Grand Duchy of Baden): “Danube, the biggest river of Germany, rises at the Martinskapelle in a wild and lonely area of the Black Forest, is called Brege at its origin and forms the river Danube in Donaueschingen where it is unified with the Brigach." (German original: „Donau, der größte Fluß Deutschlands, entspringt bei der Martinskapelle in einer wilden und einsamen Gegend des Schwarzwaldes, heißt am Anfang Brege… und bildet erst in Donaueschingen, wo sie sich mit der Brigach vereinigt, die Donau.“)
Inn (river)
In Passau the Inn finally enters the Danube (as does the river Ilz there). Although the Inn has a greater average flow than the Danube when they converge in Passau, and its watershed contains the Piz Bernina also the highest point in the Danube watershed, the Inn is considered a tributary of the Danube, which has a greater length, drains a larger surface area, and has a more consistent flow.
The Inn is the only river originating in Switzerland that ends in the Black Sea (via the Danube).Average monthly flow (m³/s) of the Inn in Passau
Years 1921/2006