ENVIRONMENT

Chennai is on the southeast coast of India in the northeast of Tamil Nadu on a flat coastal plain known as the Eastern Coastal Plains. Its average elevation is around 6.7 metres (22 ft),[27] and its highest point is 60 m (200 ft).[28] The Marina Beach runs for 12 km along the shoreline of the city. Two rivers meander through Chennai, the Cooum River (or Koovam) through the centre and the Adyar River to the south. A third river, the Kortalaiyar, flows through the northern fringes of the city before draining into the sea at Ennore. Adyar and Cooum rivers are heavily polluted with effluents and waste from domestic and commercial sources. The state government periodically removes silt and pollution from the Adyar river, which is much less polluted than the Cooum. A protected estuary on the Adyar forms a natural habitat for several species of birds and animals.[29][30] The Buckingham Canal, 4 km (2.5 mi) inland, runs parallel to the coast, linking the two rivers. The Otteri Nullah, an east-west stream, runs through north Chennai and meets the Buckingham Canal at Basin Bridge. Several lakes of varying size are located on the western fringes of the city. Red Hills, Sholavaram and Chembarambakkam Lake supply Chennai with potable water. Groundwater sources are becoming brackish.[31]