Lac de Gravelle, Artificial lake in the Bois de Vincennes, Paris, France

Lac de Gravelle is an artificial lake in the 12th arrondissement of Paris that serves as a water reservoir for the city. It has an oval shape, is surrounded by quiet pathways, and is fed by Paris's non-potable water system designed for maintaining the area's waterways.

The lake was dug in the 1860s under Adolphe Alphand during the remodelling of the Bois de Vincennes into a park, since the sector had no water network. From 1866 to 1974 it was fed with Marne water pumped up from Saint-Maur-des-Fossés, about 40 metres below. The opening of the A4 motorway closed that station, and since 1974 Seine water has been pumped to the lake from the pont d'Austerlitz plant.

The lake's outflow is the 6.7 km Ruisseau de Gravelle, a stream that carries its water to Lac Daumesnil and Lac de Saint-Mandé; a second channel, the Rivière de Joinville, links it to Lac des Minimes. Visitors can follow these waterways through the woods.

The lake is freely accessible year-round with no time restrictions and can be reached on foot or by bicycle via Route Gravelle. Public transit access is simple by taking bus line 77 to the Plateau de Gravelle stop.

The lake is the highest of the four in the Bois de Vincennes, which is why water from the Seine is pumped up to it at the Pont d'Austerlitz plant before flowing down to the others. Its outlet toward Daumesnil and Saint-Mandé is the 6.7 km Ruisseau de Gravelle; the Minimes receives water through the Rivière de Joinville.