Bangalore's lakes which had been a perennial source of water for the city for eons, now continue to vanish, worrying experts and citizens alike.Growing urbanisation and unbridled exploitation of these waterbodies are the main causes behind the grim condition of the city lakes.

A recent report prepared by the IISc and Bangalore University revealed the sorry condition of the lakes in the city. In 2002, Greater Bangalore housed 107 waterbodies. But a survey conducted in 2007 by IISc, which was released in 2008, revealed that the city is left with only 93 waterbodies. In fact, the city had 159 waterbodies in 1973 which came down to 147 in 1992.

In many places, waterbodies are used for washing, fishing and other household activities. The catchment areas are used as dumping sites for either municipal solid waste or construction debris. To make matters worse, many areas around the lakes have illegal construction work going on and a number of these buildings are being occupied by slum-dwellers who misuse the lake, said TV Ramachandra, professor at Centre for Ecological Sciences (CES), IISc.

Most lakes in Bangalore are polluted and are being encroached upon which causes them to flood during monsoons. There is a proposal made by the Bangalore Water Supply and Sewerage Board (BWSSB) to make use of the water from most of the lakes to meet the city's drinking water needs. But the high pollution levels of the lakes make it a risky affair.

"The lakes are full of solid waste, building debris, polythene, sewage, pesticides, fertilisers, polychlorobenzenes, polyhydroxy alkanoates, biphenyl compounds and heavy metals," said Uttam Kumar, student, IISC, department of CES and management studies.

According to BWSSB officials, the total water holding capacity of 80 lakes in Bangalore is 8000 mld and the present water availability is 600 mld. Ten lakes have been identified to pump water to the city in two phases. During the first phase, Nagawara (Hebbal), Kalkere (Raja Canal), Belandur (Kadabisanahalli), Kengeri (Mailsandra) and KR Pura (Vegaiahnakere) will pump 270 mld water to the city under JNNURM.

Doddabele, YM Chetty, Hulimavu, Pillarakatte, Agara, Puttenahalli and Madavara lakes will pump 170 mld treated water to Bangalore in the second phase. This will benefit residents of Hebbal, OMBR, Yelahanka, Hennur, Horamavu, Mahadevapura, Kengeri, RR Nagar, Yeshwanthpur, International airport area, HBR Layout, Sir MV Layout, Peenya and Hessarghatta localities, to name a few.