Lac de Coiselet

Lac de Coiselet
Location	Ain/Jura
Coordinates	46°19′40″N 5°37′00″E / 46.32778°N 5.6166667°E / 46.32778; 5.6166667Coordinates: 46°19′40″N 5°37′00″E / 46.32778°N 5.6166667°E / 46.32778; 5.6166667
Lake type	reservoir
Primary inflows	Ain, Bienne
Basin countries	France
Max. length	6 km
Surface area	3.8 km²
Average depth	9.5 m
Max. depth	30 m

Lac de Coiselet is a reservoir on the border between the Ain and Jura departments in France. Its surface area is 3.8 km². The lake formed in 1970 after the Barrage de Coiselet was built at the confluence of the Ain and Bienne rivers.