Groundwater levels are falling at an alarming rate across the country, and Delhi fares worse than any other metro. Data presented by the Central Ground Water Board in January confirms this: the city's water table – the level below which the ground is saturated with water – has fallen from 20 feet in 1977 to as much as 214 feet in some areas in the south-east region of the Ridge forest area. This a little less than the height of the Qutub Minar.

The report also reveals that large parts of southwest Delhi, south Delhi and south-east Delhi are the worst affected areas. Experts say this is caused by millions of illegal borewells that are sucking the city dry.

Illegal borewells

An RTI query in July this year said there are 4.65 lakh borewells operating illegally in the city. Yet Delhi Jal Board officials privately admitted that this is only an estimate, and the actual figure could be much higher.

“Borewells installed inside homes are impossible to detect as we can’t inspect without an official search warrant and in company of the cops,” a senior Delhi Jal Board official said. “Most of these exist in densely populated areas in south-east Delhi.”

However, the Ministry of Environment and Forest is more concerned with the possibility of commercial exploitation than monitoring which households have installed these borewells.

In March, the National Green Tribunal indicted the Delhi Jal Board and the Delhi Pollution Control Committee for their lackadaisical efforts at catching and prosecuting users who illegally extract groundwater. The environment watchdog has also formed a panel to oversee the progress made by the Delhi Government’s agencies.

“Delhi is facing the highest decline of ground water level among all the metros in India,” Nitya Jacob, water programme director at the Centre of Science and Environment, said. “The main reason is that the city has got a huge built-up area and most areas do not get a supply of water. Consequently, groundwater is being over-exploited in densely populated areas. Commercial establishments and industrial units are also illegally extracting water.”

Farming, which is a water-intensive activity, is a major contributor to the depletion of rural groundwater levels. States like Punjab, West Bengal, Kerala, Karnataka, Meghalaya and Haryana have seen a dip of over 60% – simply in the last five years.

Of the states, Tamil Nadu is dealing with the greatest groundwater depletion, at 76%. Delhi has declined 62%.

Experts insist that immediate action needs to be taken before the situation gets out of hand. “In India, it is difficult to investigate and prosecute illegally extracted water sources,” Jacob said. “However, it is important to adopt proper usage of rain-water harvesting to replenish ground water lost. Both the central Government and state agencies need to initiate and prosecute rainwater harvesting projects immediately.”

A survey of wells

An analysis report of 10,219 wells across the country showed that 56% face an acute shortage of groundwater. The Central Ground Water Board’s report, filed in July, stated that a total of 5,699 wells are close to dry, as most of the groundwater in the area has been sucked out.

The annual per-capita availability of groundwater has depleted from 6,042 cubic metres in 1947 to 1,545 cubic metres in 2011. According to the Ministry of Water Resources, the annual per-capita availability of water is expected to further deplete to 1,340 by 2025 and 1,140 by 2050.

Future demand

Demand will only increase as the population continues to, and prosperity rises. It is estimated that the country would need 1,180 billion cubic meter of water annually by 2050. Currently, a total of 690 billion cubic meter of surface water is available and approximately 433 billion cubic meter of groundwater is extracted.

The country will not be able to meet its projected requirement unless it recharges its aquifers adequately and uses water more efficiently and judiciously.

The government has set up a body called National Bureau of Water Use Efficiency, under the National Water Commission, that will help in promoting the conservation of ground water.

Meanwhile, the Central Ground Water Board has partnered with the Indian Institute of Remote Sensing on a collaborative study assessing the impact of ground water extraction in the country. The study will be help identify those areas most affected by the over-exploitation of ground water.

In Delhi, state agencies last week formed five committees to comprehensively survey illegal borewells run by industrial units in Bawana and Narela.