323 km long, the Durance is the most important river of Provence and the second largest tributary of the Rhone, into which it flows southwest of Avignon. Both Alpine and Mediterranean, it has its source in the Hautes-Alpes, at an altitude of 2,300 meters, near the Montgenèvre pass and the Italian border. Its basin of nearly 14,200 km² covers more than half of the southern region (Provence-Alpes-Côte d'Azur).