New Delhi, March 6, 2013- Delhi’s falling groundwater level has entered the danger zone. And things are only getting worse by the day.
In 1983, fresh groundwater was available at just a little below 33 feet. By 2011, this level had gone below 132 feet, with the most recent decade of 2002-2011 registering the sharpest fall of almost 29 feet.
Data compiled by the Central Groundwater Board of the Ministry of Water Resources shows there is no let-up.
The groundwater table across Delhi’s 1,484 sq km has declined from between 6 and 66 feet. Only three patches, accounting for a measly 18 square km, have not registered any significant drop in the groundwater level.
The worst-hit areas are South Delhi and parts of Southwest Delhi covering over 264 sq km where the water table has dropped by about 70 feet over the last 10 years.
In the remaining parts of South Delhi, Southwest and all West Delhi, the groundwater level has fallen between 13 and 33 feet) while the drop is between 6.6 and 13 feet in other parts – North, Northeast, East, and parts of Northwest and West Delhi.
“The groundwater situation in Delhi is quite scary. There is progressive lowering of groundwater levels due to pressures of urbanisation,” says Sushil Gupta, chairman of the board.
At this rate, the Capital could be faced with a permanent water crisis soon. The outstanding reason for Delhi’s dry nightmare-in-the-making is the lack of effective regulation on withdrawal of groundwater.
“The water table has been going down by an average of 3 feet every year for the past three decades. Yet there are no effective laws,” points out Dr Vikram Soni of Jamia Millia Islamia.
The falling water table is not the only bad news. The quality of groundwater too is deteriorating. Fresh groundwater is available at depths ranging from 10 feet to over 230 feet, below which water is brackish or saline.
And there are grey areas where the interface between fresh and saline water is at shallower depths of between 66 and 82 feet.
What you should worry about is that groundwater samples tested for quality have been found to contain nitrates, fluorides and heavy metals such as lead, cadmium and chromium.
The nitrate concentration in groundwater ranges from trace or very low levels at a few places in Delhi to 1,500 mg per litre – which is 33 times over the safety level of 45 mg per litre – at Tikri Kalan in West district.
In about 73.4 per cent of samples tested, nitrate was found above the safe drinking water limit. Nitrate pollution is mainly a result of overuse of fertilisers.
Fluoride, another contaminant, was present in almost all samples and its concentration varied from 0.07 mg per litre at Katlupur to 7.24 mg per litre at Khaira Kalan – both in North West district.
In 14.5 per cent samples, fluoride was more than the safe drinking water limit of 1.5 mg per litre. The presence of heavy metals was above permissible levels in sev-eral places in West, East and parts of Northwest and Northeast districts.
The situation in Delhi’s immediate neighbourhood is scarier. In Faridabad, for instance, the average fall in the groundwater table over the past decade was about 50 feet.
But the situation in other cities is not as bad as the Delhi region. Water tables have gone up marginally in Chennai, Bangalore, Agra and Ahmedabad, while the fall in Greater Mumbai was over 22 feet in the same period.
While over-exploitation is leading to a fall in water table, the root cause of pollution of groundwater, according to Gupta, is lack of adequate capacity to treat waste water generated in cities.
Metro cities and class I and II towns produce a total of 53,000 million litres per day (MLD), whereas the total treatment capacity is only 8,040 MLD. Untreated water accumulates in surface water bodies and cesspools, which ultimately water aquifers.
Delhi has recently been ranked the worst environmental performer in the country, according to the Environmental Performance Index (EPI) devised by the Planning Commission. One of the parameters was its very low score on the status of ground water and annual recharge.
The Central Ground Water Authority (CGWA) had notified three areas for regulation of ground water development and management – the Yamuna flood plain, apart from the South and South West districts of Delhi. Subsequently, the state government notified the whole of Delhi for regulation of groundwater.
This only means that new tubewells cannot be dug without permission. But in the absence of a comprehensive groundwater law, violation in notified areas is the rule rather an exception.
In one of the urgent steps to meet the crisis, the CGWA has directed all residential group housing societies, institutions, schools, hotels and industrial establishments falling in over-exploited and critical areas in the country to adopt rooftop rain water harvesting systems in their premises.
But, given the city’s huge needs and the extent of illegal exploitation of groundwater resources, this might not be quite enough.
