Vihar Lake is located near Vihar village on the Mithi River within the precincts of the Borivali National Park, also called the Sanjay Gandhi National Park, in North Mumbai. When built in 1860 (construction started in 1856), it was considered as the largest lake in Mumbai in the Salsette group of islands. It is hemmed between the Tulsi Lake and the Powai Lake(shown in map). It partly meets the drinking water needs of the South Mumbai region. It supplies only 3% of the Mumbai city’s water requirement, after filtration at Bhandup where the large water filtration plant is located.