approximately from its source to the confluence with the Rhône. Departments and main towns crossed The river only runs through the towns of Briançon and Sisteron — built where the banks are very steep — the other towns are built on slopes close to the river: Hautes-Alpes Briançon Embrun Alpes-de-Haute-Provence Sisteron Château-Arnoux-Saint-Auban Vaucluse Pertuis Cadenet Cavaillon Bouches-du-Rhône left bank of the Durance. The Durance catchment area extends to three other departments: Var, Drôme and Alpes-Maritimes. The Durance is the longest river in Metropolitan France without a department named after it. Source to Serre-Ponçon The source of La Durance is on the northern slope of the , where the first small streams combine into a river. This runs near to Montgenèvre and then flows into the larger Clarée river, and then passes through Briançon before the Guisane joins it. It then continues south combining with the Gyronde — the Écrins glacial stream — at L'Argentière-la-Bessée. The confluence with the Guil occurs below Guillestre and Mont-Dauphin. The Durance then flows south-south-west and flows into the Lac de Serre-Ponçon just downstream of Embrun. The confluence with the Ubaye was flooded as the lake filled. Middle section: from Serre-Ponçon to Mirabeau The middle part of the Durance runs through a landscape that changes as the valley increasingly widens. The river itself becomes steeply banked by terraces, and carves a channel, sometimes a few metres deep, sometimes tens of metres deep. In its middle and lower reaches the Durance is affected by the Mediterranean climate: flooding after autumnal rains, with low water levels in summer. Just before the narrow gap in the mountains at Sisteron, the Durance joins Buëch and the . Water also flows in from the EDF Canal. Beyond Sisteron further rivers and streams join the Durance: Jabron, Vançon, Bléone near Les Mées and from the Asse (river) a few kilometres to the south of Oraison. The Verdon flows into the Durance near Cadarache. The valley widens still further into an alluvial plain several kilometres wide ( near Manosque). Here the river was diverted for the development of modern agriculture and the construction of the A51 motorway. There are several dams along the middle part of the Durance. In addition to main dam at Serre-Ponçon, there are dams at Espinasses, Sisteron, L'Escale and Cadarache. There are small canals whose primary purpose is to draw water from the river into the EDF Canal which