Mumbai

The alarming levels of India’s groundwater

Critical resource: According to Dr. Himanshu Kulkarni, groundwater supply is 80% to 95% of rural drinking water and 50% of urban drinking water.

Critical resource: According to Dr. Himanshu Kulkarni, groundwater supply is 80% to 95% of rural drinking water and 50% of urban drinking water.   | Photo Credit: File photo

Leading hydrogeology scientist explains how India’s dependence on groundwater could lead to a crisis if left unchecked

Mumbai: Groundwater is the world’s most extracted raw material, supplying and sustaining a range of human activity. Yet, because it is invisible and it’s supply often taken for granted, it is often inadequately acknowledged in policy and debates about the preservation of groundwater commons and aquifers. At best, it is usually shrouded in inaccessible scientific terminology.

In the third part of its Groundwater Lecture Series, the Columbia Global Centers in Mumbai recently hosted Himanshu Kulkarni, Founder Trustee and Executive Director of Advanced Centre for Water Resources Development and Management (ACWADAM). One of India’s leading scientists on hydrogeology and an advocate for groundwater management and governance, Dr. Kulkarni attempted to break down the numbers behind India’s dependence on groundwater and why it could lead to a crisis if left unchecked.

India, Dr. Kulkarni pointed out, is the country that extracts the most groundwater globally. “India is responsible for 25% of the global annual total of groundwater extracted. China and the US follow, but together they don’t account for as much as India extracts on its own.”

Steep rise

Referring to a 2005 study from the International Water Management Institute, he pointed out that India’s groundwater use went from about 7km³ in 1940 to about 270 km³ over the past decade. There was a particularly steep rise in the late 70s and 80s; while many would attribute that to the Green Revolution, Dr. Kulkarni says the numbers are evidence that there is a deeper story. “The Green Revolution was also linked with the building of big dams, which former prime minister Jawaharlal Nehru called the temples of modern India. Yet, I think the real revolution that happened in agriculture was by our small and marginal farmers and happened parallel to what the government talked off.”

Over-exploited reserves

India’s anomalous trajectory with groundwater has created a series of problems across several districts, particularly in the agriculture-heavy belts. With maps, Dr. Kulkarni explained that there is about 60% vulnerability in groundwater reserves across the country. Reserves are over-exploited or contaminated with chemicals like arsenic that occur at deeper levels of groundwater.

Using figures from Punjab alone, Dr. Kulkarni explained that all its districts showed a deficiency of billions of cubic meters; to reverse the trend only enough to restore groundwater to normal levels would take up to 30 years. He compared those figures with districts in Orissa, where groundwater tables are more healthy, but warned that there has been recent talk of taking the Green Revolution to parts of eastern India that could be ‘exploited’. “We have to ask, when there is talk of taking the green revolution to eastern India, if there is a strategy for doing this,” he said. We must also consider, he said that the eastern parts of the country are the ones that in recent years have seen a depletion of rainfall.

Reliable data lacking

Giving overall figures for India’s dependence on groundwater, Dr. Kulkarni said that groundwater supply is 80% to 95% of rural drinking water, 60% to 70% of water used in agriculture, and 50% of urban drinking water. It is lamentable, he said, that that there are no reliable data sets for the percentage of groundwater used by industry, which usually clubbed along with domestic water use.

Since drilling technology and hand pumps were introduced in India in response to the drought of 1972, Dr. Kulkarni said that it has proliferated as a business and reports now estimate that there are 40 million wells in India. By contrast, he said, there is almost no data on the number of perennial springs in India that supply fresh groundwater, and very little done to preserve them. His organisation, ACWADAM, is the only one to have quantified this, estimating that there are about two to three million perennial springs in the country.

Dr. Kulkarni pointed out that since 1950, the total share of groundwater in irrigation has nearly doubled, and that is used by 15% to 20% of all agricultural land. The situation, he said, calls for the urgent need for community-based groundwater management and an understanding of how to build and maintain the aquifers that hold and supply groundwater. “Unless a doomsday scenario is created I don’t think people will wake up.”

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Printable version | Feb 23, 2020 2:16:36 PM | https://www.thehindu.com/news/cities/mumbai/the-alarming-levels-of-indias-groundwater/article19253949.ece

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