...that Germany and Italy share a common river basin? You always thought that the Alps acted as a divide between the watersheds and that southern rivers flowed into the Po?
Indeed, the Alps are a huge watershed and the source of many major European rivers – Rhine, Po, Rhone – that all flow in different directions.
So with Germany north of the Alps and Italy south - which river basin could draw from both Germany and Italy?
Did you guess? It is the Danube. In fact, the Danube basin draws from 18 different countries including Italy.
The Danube originates in Germany in Donaueschingen and then flows through (or marks a border between) 9 different countries – Austria, Slovakia, Hungary, Croatia, Serbia, Romania, Bulgaria, Moldavia and Ukraine before ending in the Black Sea.
With a total length of 2857 km, it is the largest river in the EU and, after the Wolga, the second largest in geographical Europe. The total drainage basin is estimated at 801,463 km2.
Italy contributes to the Danube through the river Spöl, previously called Aqua Granda, an Italian and Swiss river that flows into the river Inn, a tributary of the Danube.
The Spöll is 28 km long and, following a treaty between Italy and Switzerland, contributes to an artificial lake, the Lago di Livigno. This reservoir has a capacity of 164 million cubic metres.
So, overall the Italian contribution to the Danube is indeed small and less than <0.1%. However, the highest point of the Danube drainage basin is the summit of Piz Bernina on the Italy–Switzerland border at 4,049 metres.
More info on the river Spöl can be found here.