Lac Brenet

Natural lake, reservoir in Vaud

46°40′23″N 6°19′24″E / 46.67306°N 6.32333°E / 46.67306; 6.32333Typenatural lake, reservoirPrimary outflowsundergroundMax. length1.5 km (0.93 mi)Max. width500 m (1,600 ft)Surface area0.80 km² (0.31 sq mi)Max. depth18 m (59 ft)Surface elevation1,002 m (3,287 ft) Map

Lac Brenet (French pronunciation: [lak bʁənɛ]) is a lake in the Vallée de Joux, canton of Vaud, Switzerland. It is located north of the Lac de Joux, only 200 metres away. Its elevation of 1002 metres is 2 metres below that of Lac de Joux.

The lake used to drain naturally underground and the water resurfaced at the source of the Orbe River. Today the lake is used as a reservoir of the hydroelectric plant at Vallorbe.