Bangalore is located at an altitude of 3,000 feet on the ridge of three tributaries Arkavathi, North and South Pennar to river Cauvery. The city is located in hard rock area where recharge of ground water is difficult. That is why tanks were built to facilitate the recharge of ground water since third century B.C. Numerous tanks have been constructed historically to harvest rain water from the catchment. In this system of tanks called ‘Chain Tanks’ the surplus from a tank always flowed into tanks of succeeding sizes in the down stream. The termination of the chain, each chain gave rise to a stream through a huge tank. There were several tanks in and around Bangalore. Two major tributaries, North and South Pennar of Cauvery were sourced from these tanks.

Once, 481 tanks and lakes of various sizes existed within Bangalore, as per one estimation. One of the studies says that if these 481 tanks in Bangalore were conserved, they could have met more than 30 per cent of the present water demand of the city. It is a marvelous experience to travel on the ring road (dotted with lakes and water bodies) linking Old Madras Main Road and Hyderabad Highway. But the water of these tanks is no more potable due to letting of sewage. However, the state authorities have been taking care to preserve them. Hebbal lake is being conserved now.

According to the state official sources, potable water drawn from the rivers (presently river Cauvery water is being inadequately supplied ) to Bangalore is ten times costlier than the water drawn from tanks around the city. However, the tanks that existed in and around Bangalore have now been transformed into colonies and other public utility places like Kempe Gowda Bus-station and Kanteerava Stadium. Even if some of the lakes are being protected by the state government, they remain just ornamental or lung spaces to Bangalore like the Sankey Tank and are no more supplying potable water.

Hence India’s fastest growing city, Bangalore, has no option but to depend on Cauvery water and few nearby water tanks like Thippagondanahalli Reservoir. The severity of the city’s water scarcity has made both the government and people including Non Governmental Organisations (like Environment and Health Foundation, India) to realise the importance of conserving the remaining water tanks, ponds and lakes in and around Bangalore. In addition to that, Bangaloreans have now began to search for new ways like rain water harvesting from rooftops, treating the sewage water (for non-potable purposes like gardening) to solve the water scarcity.

The State Forest Department, on its part, has been involved in saving the lakes in and around the city. The Narsipur Lake near Vidyaranyapura and another tank near Krishnarajapura have been conserved and developed as picnic centers with greenery around, by the State Forest Department. There are still few lakes in the suburbs of Bangalore, which need the attention of the state authorities, such as the city suburb tanks at Yelahanka and Jakkur and other water bodies. Otherwise, some of these tanks may be encroached upon.

Years Percentage growth of population

Population growth in Bangalore between 1941 and 1981.

Bangalore experienced 90.24 per cent growth in population between 1941 and 1951. Between 1951 and 1961 a growth of 53.85 per cent and between 1971 and 1981 Bangalore witnessed a growth of 76.17 per cent. And the growth of city’s population has now crossed 60 lakhs. Given this population explosion, water being supplied by the Bangalore Water Supply and Sewerage Board is inadequate. Since 1896, the city planners have been bringing potable water to the city from sources away from the city than utilizing the locally available tanks water. When the 40 kms away Thippagondanahalli tank water also became inadequate for the city, the city authorities began to draw water from Cuavery from late 1970s, but scarcity of water still exists due to over population. Now the government is constructing the fourth stage of Cauvery.

Source: Seminar on ‘Rain water harvesting for Bangalore’ organized by Environment and Health Foundation (India)

Address: #7, 8th Main Road, 3rd Phase, 2nd Stage, Domlur, Bangalore-560 071.
Phone: 5308137/5543397.

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