Multi-pronged strategy needed to conserve groundwater

SK Sarkar

Distinguished Fellow, The Energy & Resources Institute

Although India accounts for about 17.5 per cent of the global population, only 4 per cent of the world’s water resources are available in the country. Human-induced climate change is creating water-stressed conditions in many regions of India. There is a declining availability of fresh water amid increasing demand. Out of India’s 766 districts, 256 are water-stressed.

According to the hydrological cycle, 1,999 billion cubic metres (bcm) of water resources are annually generated in India. Of this, the water that can be beneficially utilised is 1,126 bcm; 436 bcm comes from groundwater contribution and the remaining from surface water contribution. The first census report (2023) of water bodies revealed that out of 24.24 lakh of them, 72 per cent have a spread area of less than 5 hectares. About 1.6 per cent of the water bodies are encroached upon, primarily in rural areas.

A NITI Aayog report (2019) indicates that by 2030, India’s water demand will be twice the available supply. Groundwater meets about 62 per cent of the requirement in the case of irrigation, 85 per cent for rural water supply needs and 50 per cent for those of urban water supply. While groundwater is a replenishable resource, its availability varies as per the season and the region.

In 2023, the Central Ground Water Board (CGWB) assessed 6,553 monitoring wells and estimated the total annual groundwater recharge at 449 bcm, an increase from the 2022 estimate of 437 bcm. The annual extractable groundwater (considering allocation for natural discharge) was estimated at 407 bcm, higher than the 2022 estimate of 398 bcm. The annual groundwater extraction was 241 bcm, surpassing the 2022 estimate of 239 bcm. Overall, the average groundwater extraction in 2023 was 59.26 per cent, slightly lower than the 2022 estimate of 60.08 per cent.

In 2023, the states where the groundwater extraction was at least 50 per cent higher than the annual recharge included Delhi (99.13 per cent), Gujarat (51.68 per cent), Haryana (135.74 per cent) and Punjab (163.76 per cent). Last year, there was a notable imbalance between groundwater extraction and recharge in states like Haryana, Punjab and Rajasthan. Moreover, when compared to 2022, there was an increase of more than 1 bcm in groundwater recharge for states such as Gujarat, Karnataka, Telangana and West Bengal.

Out of 6,553 assessment units, 736 (11.23 per cent) are categorised as ‘overexploited’, which is a decrease compared to the 2022 figure of 14 per cent and the 2017 figure of 17 per cent. The ‘overexploited’ units are concentrated in Punjab, Haryana, Delhi and western UP, where there have been indiscriminate withdrawals of groundwater; western India (Rajasthan and Gujarat), where groundwater recharge is limited due to the arid climate; and southern states (Karnataka, Tamil Nadu, Telangana, Andhra Pradesh), where the groundwater availability is low due to the inherent characteristics of crystalline aquifers. In some areas, groundwater augmentation and conservation measures have improved due to government and private initiatives.

The annual increase in groundwater recharge in 2023 can be attributed to good rainfall, government interventions in conservation activities, the revival and rejuvenation of tanks and water bodies resulting in increased recharge from surface water resources, and surface water irrigation in various states. The decrease in groundwater recharge in Delhi and Punjab can be attributed to factors such as reduced recharge from rainfall, lining of unlined canals, decreased recharge from ponds and tanks and reduced extraction, along with a decrease in the irrigation draft.

Sustainable groundwater management involves managing both supply and demand. On the supply side, aquifer recharge of groundwater occurs through rivers, rainfall percolation and natural water bodies. However, the speed of groundwater recharge is slow from the last two sources; worse, rivers are shrinking due to mismanagement. Major rivers like Ganga, Narmada and Cauvery have experienced contraction, leading to a reduction in the recharge potential.

On the demand side, addressing groundwater management issues such as crop diversification, enhancing water use efficiency (WUE) and adopting better agronomic practices is crucial. A coordinated approach is necessary as different ministries oversee these aspects. Metered electricity supply and pricing can help reduce the demand and overextraction of groundwater.

Increasing WUE is a must for reducing groundwater demand for irrigation. Flood irrigation has a WUE of around 40 per cent, while micro-irrigation systems offer a higher WUE of about 80-95 per cent. Despite the potential for about 70 million hectares (mha) for micro-irrigation in India, only around 9 mha had been covered by 2018.

The institutional framework, such as the India Easements Act, 1882, poses a challenge to groundwater control. Section 7 (g) of the Act grants the landowner full control over the water beneath his/her property, often resulting in overexploitation. Legislative amendments are required to address such loopholes. The Supreme Court’s recommendation to designate groundwater as a common pool resource under the ‘Public Trust Doctrine’, with states as trustees, should be promptly adopted.

The Centre has formulated a Model Ground Water Bill aimed at regulating and developing groundwater. However, several states and UTs have not adopted it, and they should be provided incentives to do so.

The 1992 amendment to the Constitution introduced devolution of functions from the state to panchayats, encompassing minor irrigation, water management, watershed development, drinking water and the upkeep of community assets. However, in many states, panchayats have little role in groundwater management. Relevant state departments often retain control over groundwater irrigation management, citing a lack of technical knowledge and expertise among panchayats. This must be reconsidered, emphasising increased participation of the people in groundwater management. Panchayats should be given incentives for groundwater conservation and penalties should be imposed for failing to meet the targets. Water regulators may assume an overseeing role in ensuring sustainable groundwater management in the states and UTs.

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#Climate change #Environment #Groundwater