section_path: Geography
section_name: Geography
paragraph_text: Geography
  
  Mumbai is on a narrow peninsula on the southwest of Salsette Island, which lies between the Arabian Sea to the west, Thane Creek to the east and Vasai Creek to the north. Mumbai's suburban district occupies most of the island. Navi Mumbai is east of Thane Creek and Thane is north of Vasai Creek. Mumbai consists of two distinct regions: Mumbai City district and Mumbai Suburban district, which form two separate revenue districts of Maharashtra. The city district region is also commonly referred to as the Island City or South Mumbai. The total area of Mumbai is 603.4 square kilometres (233.0 sq mi). Of this, the island city spans 67.79 square kilometres (26.17 sq mi), while the suburban district spans 370 square kilometres (140 sq mi), together accounting for 437.71 square kilometres (169.00 sq mi) under the administration of Municipal Corporation of Greater Mumbai (MCGM). The remaining areas belong to various Defence establishments, the Mumbai Port Trust, the Atomic Energy Commission and the Borivali National Park, which are out of the jurisdiction of the MCGM. The Mumbai Metropolitan Region which includes portions of Thane, Palghar and Raigad districts in addition to Greater Mumbai, covers an area of 4,355 square kilometres (1,681 sq mi). Mumbai lies at the mouth of the Ulhas River on the western coast of India, in the coastal region known as the Konkan. It sits on Salsette Island (Sashti Island), which it partially shares with the Thane district. Mumbai is bounded by the Arabian Sea to the west. Many parts of the city lie just above sea level, with elevations ranging from 10 to 15 metres (33 to 49 ft); the city has an average elevation of 14 metres (46 ft). Northern Mumbai (Salsette) is hilly, and the highest point in the city is 450 metres (1,480 ft) at Salsette in the Powai – Kanheri ranges. The Sanjay Gandhi National Park (Borivali National Park) is located partly in the Mumbai suburban district, and partly in the Thane district, and it extends over an area of 103.09 square kilometres (39.80 sq mi).
  
  Apart from the Bhatsa Dam, there are six major lakes that supply water to the city: Vihar, Lower Vaitarna, Upper Vaitarna, Tulsi, Tansa and Powai. Tulsi Lake and Vihar Lake are located in Borivili National Park, within the city's limits. The supply from Powai lake, also within the city limits, is used only for agricultural and industrial purposes. Three small rivers, the Dahisar River, Poinsar (or Poisar) and Ohiwara (or Oshiwara) originate within the park, while the Mithi River originates from Tulsi Lake and gathers water overflowing from Vihar and Powai Lakes. The coastline of the city is indented with numerous creeks and bays, stretching from the Thane creek on theeastern to Madh Marve on the western front. The eastern coast of Salsette Island is covered with large mangrove swamps, rich in biodiversity, while the western coast is mostly sandy and rocky.
  
  Soil cover in the city region is predominantly sandy due to its proximity to the sea. In the suburbs, the soil cover is largely alluvial and loamy. The underlying rock of the region is composed of black Deccan basalt flows, and their acidic and basic variants dating back to the late Cretaceous and early Eocene eras. Mumbai sits on a seismically active zone owing to the presence of 23 fault lines in the vicinity. The area is classified as a Seismic Zone III region, which means an earthquake of up to magnitude 6.5 on the Richter magnitude scale may be expected.