To put it mildly, it is not entirely unimportant: from here, the water flows southwards towards the Mediterranean, northwards to the North Sea and westwards to the English Channel and thus to the Atlantic. The plateau is considered a water castle; numerous important rivers have their source here, such as the Seine, the Marne and the Meuse.
And another body of water is of great importance: a canal, the 224-kilometre-long Canal entre Champagne et Bourgogne. It connects the Marne and Saône rivers, creating a continuous navigable link between the Atlantic and the Mediterranean. The canal, which was built in the second half of the 19th century, is the product of a great deal of engineering skill: 114 locks are needed to overcome the difference in altitude between the lower-lying rivers and the Plateau de Langres. At the apex, the canal even leads through a navigable tunnel of almost five kilometres, which passes under the watershed line.