ENVIS Centre, Ministry of Environment & Forest, Govt. of India

Printed Date: Saturday, October 24, 2020

Latest News


Rain can't restore water table, experts worried

Experts are worried that many parts of the capital have reached a point of no return in terms of losing groundwater. At several places in south Delhi, it may take years to replenish this water but if and only if there is an immediate end to further extraction. For the last few years, Central Ground Water Board has been seeing no improvement in water level in the wells under its watch even after the monsoon season. TOI has accessed post-monsoon and pre-monsoon data of the wells. CGWB officials say it is a sign of how critical groundwater levels are in the city. CGWB has just completed recording the water levels (pre-monsoon) in its 120 wells and found these to be between three and 75 metres below ground level (mbgl).


The levels were similar in November 2013 and January 2014, which shows that the post-monsoon levels are no better. When compared to 2007 data, water levels in most south Delhi wells have fallen by more than a metre. "We are not seeing much change in depth of water post-monsoon. We are also noticing a steady decline in depth of wells in south Delhi and Ridge area which can be clearly attributed to unsustainable extraction," says a CGWB official. Wells located near Yamuna floodplains are in the safe zone because of the river in their vicinity but those in south and southwest Delhi are in critical condition with groundwater levels at 40-72mbgl. "As soon as we start digging below 40 metres, we are entering a danger zone.


If we go below 50 metres it's an emergency situation. Because after that we have very little exploitable water left and replenishing the aquifer is going to take years. It's like a disease. If not controlled now will lead to severe complications," says Shashank Shekhar, assistant professor, department of earth sciences, DU. In his recent study on 'groundwater management in Delhi', Shekhar found the rate of decline in water levels is as high as 1.7-2m/year in some areas of south and southwest Delhi. In fact, CGWB's groundwater year book of 2012-13 stated that a fall of more than 2m had been noticed in some areas between August 2011 and August 2012.


A comparison of pre-monsoon water levels in 2012 with August 2012 revealed there is rise in the water level in almost the entire country except in Delhi, Punjab, Haryana, Rajasthan, Gujarat, Karnataka and Tamil Nadu. Pace of recharge is far slower than the pace of depletion. Vikram Soni, water expert and professor at Jamia Millia University, said, "The water table can be recharged by a metre every year if there is no withdrawal. As soon as we go beyond 30 metres we have to harvest water. It is important that we stop withdrawing when we are about to reach half the depth of the aquifer." He added, "We are running out of time. Delhi needs to act now to deal with this crisis". The Delhi environment department has directed people and establishments to voluntarily disclose if they have borewells or tubewells. About 500 people have submitted data on their borewells, but the total number of users could be more than 4.5 lakhs.


Times of India, Delhi, Thursday 5th June 2014