Bellandur Lake is a lake in the suburb of Bellandur in the southeast of the city of Bangalore and is the largest lake in the city. It is a part of Bellandur drainage system that drains the southern and the south-eastern parts of the city. The lake is a receptor from three chains of lakes upstream, and has a catchment area of about 148 square kilometres (37,000 acres). Water from this lake flows further east to the Varthur Lake, from where it flows down the plateau and eventually into the Pinakani river basin. It is currently highly polluted with sewage, and in May 2015 the foam covering the water surface caught fire and burned for hours.Bellandur Lake is a major water body which is located in one of the three main valleys of Bangalore. It forms a part of the Ponnaiyar River catchment, and water from Bellandur flows to Varthur Lake, ultimately joining the Pennar River. Currently, most of Bengaluru's treated and untreated sewage is released into Bellandur Lake, severely polluting it, resulting in a depletion of wildlife in and around the lake.