Drought in large parts of the country is being blamed on paucity of rains. Indeed, that is the immediate cause of these troubles. But we have contributed much to the making of this disaster by over extraction of groundwater. Rains have been failing periodically from time immemorial but that did not lead to the kind of distress seen at present because our groundwater reserves were full and we could survive by extracting the same during droughts. We have extracted the water that was stored in these aquifers for ages in our anxiety to cultivate water guzzling crops like grapes, banana, red chillies and sugarcane which has led to lowering of the level of groundwater aquifers. The cushion that these storages provided in periods of drought has exhausted. Thus the present drought has assumed alarming proportions.
Farmers are paying huge electricity bills to pump out water from great depths. It is a race to the bottom. Every farmer has to deepen his bore well because his neighbour has done the same. The total amount of water extracted remains unchanged. It is determined by the amount of water that percolates into the earth every year during the monsoons.
Previously, rainwater was percolating 20 feet into the earth and getting extracted. Now it is percolating 500 feet into the earth and being extracted. The total amount of water that is extracted has remained unchanged. However, every farmer is spending more diesel and electricity to pump out the same quantity of water from greater depths. Also, harmful chemicals like arsenic that were lying dormant at lower depths are pumped out with water and are leading to a huge health crisis due to arsenic poisoning in West Bengal and Bihar.
Previously, rainwater was percolating to, say, 20 feet depth while the arsenic layer lay at, say, 100 feet depth. The water did not touch the arsenic. Now the water percolates to 500 feet depth. It passes through the layer of arsenic and absorbs this chemical. As a result, the water extracted from bore wells is poisonous and not fit for drinking. People are per force having to install purification appliances and incurring additional expenditures. Fluorides are causing similar health crises in Rajasthan.
The subject of water is within the powers of the State Government in our Constitution. The Union Government cannot directly intervene in this matter. However, it has advised the State Governments to enact laws that require that new bore wells will have to obtain a license. The intention is good but it will not help as the existing bore wells are already leading to ground water table’s depletion which will continue even if new bore wells are not installed. The correct way is to specify the maximum depth till which a pump can be placed in the bore well. Say, a depth of 200 feet is specified. Every farmer will then draw water only from 200 feet. Everyone will gain by spending less for extraction. But this requires strict implementation.
It is also necessary to remove the hidden subsidies that encourage water extraction. Some states are providing free electricity to farmers to encourage them to extract more water. Say the cost of electricity in irrigating a field is Rs 500. The additional crop yield from the irrigation is Rs 200. The farmer will not irrigate the field if he has to pay Rs 500 for the electricity. But he irrigates the field because the cost of electricity to be paid by him is zero. The country incurs a loss. We use electricity worth Rs 500 to produce crop worth Rs 200. It is necessary to eliminate all subsidies on water extraction; and impose additional charge for the extracted water. A corresponding increase in the support price of food grains should be made so that the farmer is not adversely affected.
We must also prohibit the cultivation of water guzzling crops in areas where ground water levels are depleting. Chilly is being grown in the deserts of Rajasthan, cotton in Gujarat and grapes in the dry areas of the Deccan Plateau. Rich farmers are making deep wells and extracting water. The Government must make an assessment of the available rainfall and expected percolation of groundwater in each block of the country. Then it must be assessed which crops can be cultivated in the available water. All other water guzzling crops must be banned. The supply of groundwater must be curtailed by specifying the maximum depth of a bore well. The demand for groundwater must be curtailed by banning water-guzzling crops that are not suitable for cultivation in the area.
The present policy is to make large reservoirs like Tungabhadra, Tehri and Bhakra and store water for providing irrigation in lean periods. Such storage leads to evaporation of 10 to 20 percent of the water. That is a net loss to the country. Moreover a huge waste of water takes place in the command areas. Canals bring plentiful water here. The farmers have no incentive to use the water carefully. These dams also lead to the reduction of irrigation in the downstream areas.
A stretch of about 150 kilometers from Hathnikund to Sonepat in Haryana has seen reduction in irrigation because water of the Yamuna River has been diverted at Hathnikund. The increase of irrigation in the command areas is at least partially nullified by the reduction of irrigation in such downstream stretches. The same water can be stored in underground aquifers. Water can be pushed into the earth in the monsoons by making “percolation wells.” Water can be diverted from the flooded rivers and stored in such aquifers. The water can be extracted by bore wells in the lean season. This will have three benefits. One, the evaporation loss will be prevented. Two, the farmer will use the water judiciously because he will have to pay for the electricity used in pumping the water. Three, the country will be saved from the huge environmental impacts of large reservoirs. The Hydrology Policy made by the Government is the first step towards the implementation of these measures.
Author was formerly Professor of Economics at IIM Bengaluru