New Delhi, Oct 18: Delhi’s ground water is rapidly depleting and water tables falling to extreme lows. This important resource is being drained to exhaustion and things are only getting worse with passing time. Delhi and National Capital Region (NCR) extract almost double the amount of groundwater than is recharged every year. This should ring the alarm bells loud for cities which largely depend on groundwater.
South and West Delhi and some adjoining areas are the worst hit, where the water tables have dropped as much as 10 meters to 20 meters in the past 10 years only. This badly hit area totals up to 264 square kilometers.
The falling water table is not the only bad news for Delhi. The quality of groundwater is also worsening. Fresh groundwater is available at depths ranging from 30m to 70m, below which water is brackish or saline.In a little better position than this, there are also some areas where division between fresh and saline water is at shallower depths of 20m to 25m.
Syed Azher, 32, a resident of Lajpat Nagar said, “I have been living here since 12 years. I use ground water in my house and its turning more and more saline each year. Two years back we had an extreme condition where the water started burning our eyes when we washed. It formed salt depositions in the overhead tank, so we bored the well deeper by 20 feet, now even at a depth of 120 feet we are getting saline water.”
Data compiled by the Central Groundwater Board of the Ministry of Water Resources shows there is no let-up. In 1983, fresh groundwater was available at a depth of 10m. By 2011 it had fallen to 40 meters, with the period between 2002 and 2011 registering the most precipitous drop of 8.75 meters.
“Water tables in urban areas are declining because of the reduction in recharge areas as a result of the construction of roads, buildings and pavements. The quality of water is deteriorating due to the mixing of sewerage water through unlined open drains, leakage from cesspits and septic drainage tanks, and contamination from industrial wastes,” said Sushil Gupta, chairman of CGWB, in a public dialogue held in Delhi in February
Delhi’s immediate neighbors are facing a similar situation. In the neighboring city of Faridabad, ground water fell at an average of 15 meters (approx) in the past decade. But, the situation in other cities is not as bad as the Delhi region. While the fall in Greater Mumbai was 6.77m during the same period water tables went up marginally in Chennai, Bangalore, Agra and Ahmedabad,
Recent studies by Dr Soni of Jamia Millia Islamia have shown that floodplains aquifer recharges even in absence of rain recharge and monsoon flows. It was found that recharge takes place from the river in response to pumping and from redistribution from river banks. This means that even large-scale withdrawal of water from floodplains may not be ecologically damaging provided it is scientifically managed.
- Touching new lows (thehindu.com)
- @USGS Report: ‘Groundwater Depletion in the United States (1900-2008)’ Plus More from @waltonwater (aquadoc.typepad.com)