From its source, it joins the Danube, which river down to that point it equals in length and far exceeds in volume of water.
Of the Caudine Forks, and so beyond Telese joins the Volturno.
In the north of the department; the Oise, traversing the northwest, with its tributaries the Serre and the Aisne, the latter of which joins it beyond the limits of the department; and the Marne and the Ourcq in the south.
The Am, the, Sane (which rises in the Faucilles and in the lower part of its course skirting the regions of Bresse and Dombes, receives the Doubs and joins the Rhone at Lyons), the Ardche and the Gard are the affluents on the right; on the left it is joined by the Arve, the Isre, the Drme and the Durance.
The principal affluents are the AriCge, the Tarn with the Aveyron and the Agout, the Lot and the Dordogne, which descends from Mont Dore-lesBains, and joins the Garonne at Bec-dAmbez, to form the Gironde.