two more lakes of Bangalore have joined the list of polluted waterbodies. A socio-economic study conducted by the Indian Institute of Sciences ( iis ), Bangalore, in collaboration with the Union ministry of environment and forests shows that the Rachenahalli and Amurthahali lakes of the city have become polluted and are choked with weeds and other impurities. Rachenahalli's waters have become yellow while Amurthahali's waters have turned green and murky. The area of both the lakes has also declined during the past 20 years. Rajinikanth R and T V Ramachandra, both scientists at the Centre for Ecological Sciences ( ces ) of iis, say that pollutants from streets, sewage and industrial effluents are responsible for the condition of the lakes. An economic evaluation by the ces shows that people living around both these lakes are heavily dependent on them for their survival and daily consumption needs.