The water from the Durance retained by the Serre-Ponçon dam in the Hautes-Alpes department is conveyed by a 155 mi (250 km) long canal, the first kilometers of which appear in this aerial shot. The canal joins the Étang de Berre at Saint-Chamas in the Bouches-du-Rhône department, successively operating fifteen hydroelectric power stations. Its role is essential since it also supplies drinking water to the inhabitants of the Southern Region and allows the irrigation of agricultural land. The canal also regulates the floods of the Durance and the economic activity on the lake of Serre-Ponçon.