Delhi groundwater may run dry in 3-5 years: study

“History shows us civilizations have vanished once water is also gone. Water carries people and we need to wake up now and do something before it is too late,” Mrinal Kanti Sen, director of NGRI told TOI on Tuesday.

Staring at an acute crisis, NGRI has been asked by the Central Ground Water Board (CGWB) under the ministry of water resources to trace new aquifers using heliborne electromagnetic techniques in the states of Rajasthan , Tamil Nadu, Karnataka, Maharashtra, Bihar and Rajasthan.

“The government is concerned and we are gearing up to find new aquifers all over the country as this is the only way out,” says Sen.

In Hyderabad, despite a very good 2011 monsoon, water levels in places like Sanjeevareddy Nagar and Maredpally were at a depth of just about 18 metres; the situation in other observatory zones are equally bad.

Hydrogeologists at NGRI and government water board officials say that with cities turning into concrete jungles very little rain water is getting infiltrated into the earth for conversion into groundwater.

“In an ideal scenario, at least 16% of total rainfall must seep into the earth to get recharged as groundwater , but in cities such as Hyderabad, Delhi, Mumbai and Chennai barely half of it does. This is very alarming,” says Dr SN Rai, a top scientist at NGRI.

“It is going to go down further, and at this rate Hyderabad will the first to run dry in three years time. Delhi will be next and may run dry in three to five years. There is a bleak future in store for other metros,” adds Rai, also the vice president of International Association of Hydrogeologists. NGRI scientists say the scenario in Delhi, western Uttar Pradesh, Haryana and Rajasthan are very bad with groundwater in 20 out of 27 tehsils in Delhi receding rapidly.

A two-year CGWB study shows that groundwater use in Delhi was upto 12,569 hectare metres (HM) against an extremely poor recharge of 2,652- 4,172 hm per tehsil. Vasant Vihar, Hauz Khas, Chankayapuri , along with Karol Bagh, Kotwali, Kalakji, Rajouri Garden and Paharganj, are among the worst exploited areas, officials say. Rampant digging of bore wells and poor water recharge areas due to construction of buildings are the reasons, they offer.

In Mumbai, civic bodies are resorting to artificial rains as the city’s water collection and storage is nearly 30 percent deficient; water needs can be handled only till February 2013.

CGWB officials say they have plans to revive 8000-10 ,000 old wells and hundreds of ring wells instead of the current trend of bore wells which does not help in water recharge.The only bright spot in Mumbai is that water levels in the lakes are higher than what it was last time, scientists say. The scenario in the southern metro of Chennai isn’t happy either, with hydrogeologists saying that the already declining groundwater level has been contaminated due to over exploitation . In fact, CGWB says that 247 out of 451 water samples taken from all districts of Tamil Nadu showed high levels of chloride, fluoride and nitrate — all very harmful for humans.The situation looked dangerous in towns like Perambalur, Namakkal , Salem and Vellore, officials say. In some of the areas, officials are using air compressors instead of pumps to draw groundwater.

“If Hyderabad is the worst, Delhi, Mumbai and Chennai have huge water worries of their own. Unless local governments and people learn to conserve water and think about our next generation, it’s all downhill from here,” says Dr Rai.

Scientists say every big household in the city needs a minimum 3 x 10 feet pit to collect rain water from the roof and divert it to the pits for recharge . Ramesh Kumar, deputy director at the Andhra Pradesh groundwater department, says that indiscriminate digging of bore wells, and encroachment of lakes and water tanks are the prime culprits. The city has only 300-odd lakes remaining out of 900 plus in the late 1960s.

“As a result we are forced to get water from Nagarjunasagar, about 140 km away from the city, to meet water demand,” says Kumar. “Hyderabad will run dry and there is no doubt about it if this trend continues.”

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