The Lac de Serre-Ponçon (French pronunciation: [lak də sɛʁ pɔ̃sɔ̃]), known in English as the Lake of Serre-Ponçon, is a reservoir on the border between the Hautes-Alpes and Alpes-de-Haute-Provence departments, in the Provence-Alpes-Côte d\'Azur region, Southeastern France, one of the largest in Western Europe. The lake gathers the waters of the Durance and the Ubaye rivers, flowing down through the Hautes-Alpes and the Alpes du Sud to the Rhône. The waters are dammed by the Barrage de Serre-Ponçon, a 123-metre high earth core dam.
As well as water control, sixteen hydroelectric plants use the water, with additional water control supporting; the lake provides irrigation to 1,500 square kilometres of land.
Its surface area is 28 km2 and max. depth 90 m.
