Lake Annecy

Lake Annecy (French: Lac d'Annecy, French pronunciation: [lak dansi]) is a perialpine lake in Haute-Savoie in France. It is named after the city of Annecy, which marks the start of the Thiou, Lake Annecy's outflow river.[1][2]^: 958

Lake Annecy
Ferry service on Lake Annecy, with the Château de Menthon-Saint-Bernard in the background
Lake Annecy
Location	Haute-Savoie
Coordinates	45°51′N 6°10′E
Native name	Lac d'Annecy (French)
Primary inflows	Ire, Eau morte, Laudon, Bornette and Biolon
Primary outflows	Thiou
Catchment area	251 km2 (97 sq mi)
Basin countries	France
Max. length	14.6 km (9.1 mi)
Max. width	3.2 km (2.0 mi)
Surface area	27.59 km2 (10.65 sq mi)
Average depth	41 m (135 ft)
Max. depth	82 m (269 ft)
Water volume	1,124.5 million cubic metres (911,600 acre⋅ft)
Residence time	4 years
Surface elevation	446.97 m (1,466.4 ft)
Settlements	Annecy (see list)

It is the third-largest lake in France, after the Lac du Bourget and Lac de Grand-Lieu, if the French part of Lake Geneva, which is shared between Switzerland and France, is excluded. It is known as "Europe's cleanest lake" because of strict environmental regulations introduced in the 1960s. It is a popular tourist destination known for its swimming and water sports.

The lake was formed about 18,000 years ago, at the time the large alpine glaciers melted. It is fed by many small rivers from the surrounding mountains (Ire, Eau morte, Laudon, Bornette and Biolon) and a powerful underwater source, the Boubioz, at an 82-metre depth (269 ft).