Tulsi Lake, Freshwater lake in Borivali, India

Tulsi Lake is a freshwater body within Sanjay Gandhi National Park near Borivali, surrounded by dense deciduous forests that line its banks. The water serves as a key supply source for southern Mumbai through an extensive pipeline network.

The lake was constructed between 1872 and 1897 to supply drinking water to Mumbai's growing population. This infrastructure became an essential step in securing the city's water needs during the colonial period.

Tulsi Lake sits inside Sanjay Gandhi National Park, where the catchment slopes carry undisturbed mixed moist deciduous forest. The lake and its catchment are protected by the Brihanmumbai Municipal Corporation and the park authority. Because the lake lies within the park, the park's wildlife applies here too, and a Crocodile Park was set up so visitors can view mugger crocodiles of different sizes.

Entry permits must be obtained from the Sanjay Gandhi National Park authorities before visiting. By road the lake lies 32 km north of Mumbai, about 6 km from Borivli East station on the Western Railways and near the Western Express Highway; Sahar International Airport is roughly 20 km away.

Tulsi Lake was created by damming the Tasso River and diverting its flow to nearby Vihar Lake. Its 676-hectare catchment in the Powai-Kanheri hills drains into the lake, and during the monsoon the overflow runs on into Powai Lake and then the Mithi River. Marsh crocodiles live in the lake but are hard to spot, so the park set up a crocodile park where reptiles of different sizes can be seen.