Bengaluru: With its lakes fast disappearing and little rainwater harvesting, Bengaluru’s groundwater table has been falling steadily over the years. But far from taking precautions, the city is going full steam ahead in exploiting groundwater through borewells and the like. Giving room for more concern now is a recent study by the Central Ground Water Board (CGWB) which says the city’s groundwater table is overexploited by nearly 176 per cent!
To blame is the haphazard urbanization, indiscriminate drilling of borewells and exponential growth in population and industrial units, it explains. All four taluks of Bengaluru district - Bengaluru North, South, East and Anekal- are guilty of overexploiting their groundwater resources, leaving little for future development, except in some pockets, the study warns.
The exploitation, it says, is greater in the outer peripheral areas of Bengaluru where there is no piped water supply from the Cauvery River than in its core areas.
“Water supply to the core area of about 220 sq km is met through surface water schemes of Cauvery. However, in the outer suburban area of 500 sq kms, the water requirement is mainly met from groundwater. As a result the exploitation is greater here,” it adds, regretting that rampant urbanisation and depletion in water level due to loss of green cover, tanks and lakes have further aggravated the problem.
“Urbanisation has exerted enormous pressure on lakes. Improper environmental planning has given room for establishment of new residential layouts without a proper sewerage system and even if such systems have been provided, they have not been connected to trunk sewers of the BWSSB.
The municipal effluents from such natural drains leading to tanks and lakes have deteriorated the quality of water,” the study deplores, noting that pollution from sewage is high in the western part of the city where all of it is let into the Vrishbahvathi river valley. A scientist with the CGWB, Dr K.R Suryanarayana, says the city’s groundwater is suffering both in terms of quality and quantity.
“The main problems affecting the groundwater are sewage and industrial pollution, high nitrate concentration and over exploitation,” he says, warning that we need to urgently replenish the groundwater for the city’s long term good.
