Next time you keep your the tap running, think again. You may be causing irreparable damage to our revered National River Ganga. Whereas it is understood that every drop of water wasted is a dent to the limited water resources of the country, how excessive and inconsiderate use of this precious resource -- resulting in over-extraction of groundwater -- affects the Aviralta (or uninterrupted flow) of river Ganga is the aim of this article.?
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Groundwater is water stored underneath the surface of the earth that percolates through rocks and soil. The rocks in-between which groundwater is stored are called acquifers. Water moves through the gaps in the connected rocks that make them permeable. Heavy rains can cause the groundwater table to rise and conversely, continuous extraction of groundwater can cause the level to plummet significantly.?
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These acquifers, found in the Gangetic plains in Northern India, have significant storage spaces, and hence are a valuable source of fresh water supply. However, due to excessive groundwater extraction and low recharge rates, these acquifers are at the risk of irreversible over-extraction. Over-extraction of groundwater implies that the level of groundwater extraction is more than the annual groundwater recharge.?
Out of the total extracted groundwater, nearly 90 per cent is used for irrigation purposes followed by about 9 per cent for domestic use. 50 per cent of urban water requirements and 85 per cent of rural domestic water requirements are met by groundwater. The use of groundwater for irrigation picked up pace in the last two decades as more than 80 per cent of the net irrigated area gets groundwater. With ease in groundwater extraction technologies, the depth of wells has gone below beyond 400 feet from 30 feet in 1950s causing rapid decline in the water tables and deteriorating water quality. Whereas the use of groundwater for agricultural purposes results in higher crop yields, groundwater is also recharged from backflow from irrigational fields.
To prevent groundwater tables from dipping further, the Government of India is planning to make treated sewage water of irrigational quality, a sector that uses the maximum share of groundwater. Projects which have been approved under Namami Gange programme have a component of selling treated water for industrial purposes. In case of domestic use, however, not only is the water used inconsiderately (for every litre of water used about 80 per cent sewage is generated) thereby cutting the flow of water bodies, especially rivers, excess water use necessitates the cost of its treatment as well.??
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Groundwater discharge is a substantial component of the total flow of a stream. In many areas of the country, pumping wells capture groundwater that would otherwise discharge to connected streams, rivers, and other surface-water bodies thereby reducing their flow. The flow of groundwater to water bodies is vitally important to the hydrologic settings because it is responsible for keeping water in rivers during times of no rainfall.??
The issue of maintaining uninterrupted flow of water in the Ganges has become critical over past few years. There have been legal directions to ensure minimum environmental flow (e-flow) in the river. Environmental flow describes the quantity, timing, quality of water flows required to sustain freshwater and estuarine eco-systems and the human livelihoods. Put plainly, the more judicially we use water, the more it is available for required flow of the Ganges, which is critical for its well-being and ours.??
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To minimise the use of groundwater for irrigation, National Mission for Clean Ganga (NMCG) has signed MoUs with ministries to use treated sewage water for agriculture purposes. In the past about one year, 44 projects worth Rs. 7,547.87 have been approved by the Executive Committee of NMCG. These projects pertain to the creation of adequate sewage treatment capacities in Ganga basin States ¨C Uttarakhand (17), Uttar Pradesh (10), Bihar (11), Jharkhand (1), West Bengal (3) and Delhi (2). These projects will bridge the gap between treated and untreated sewage water, which will not only arrest the pollution in Ganga but would also decrease groundwater extraction for irrigation. A master plan of the water ministry to construct 1.11 crore rainwater harvesting and artificial recharge structures to harness 85 BCM of water has also been prepared. A Committee of Secretaries will soon be formed to look into the issue of over-extraction of groundwater.??
Currently, the Easement Act, 1882, provides every landowner with the right to collect and dispose of, within his own limits, all water under the land and on the surface. This makes it difficult to regulate the extraction of groundwater as it is owned by the person to whom the land belongs. Besides, water falls under the State list of the Constitution which implies that State legislative assemblies can make laws on the subject. In order to provide broad guidelines to state governments to frame their own laws relating to sustainable water usage, Ministry of Water Resources, River Development and Ganga Rejuvenation has circulated a Model Bill to all States/UTs to enable them to enact suitable groundwater legislation for its regulation and development which includes provision of rainwater harvesting. Draft guidelines for issuance of ¡®No Objection Certificate¡¯ for groundwater extraction have been issued recently by the ministry.? ?
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While the Government is sparing no effort to arrest over-extraction and ensure adequate replenishment of precious groundwater in the country which would eventually ensure adequate e-flow in the Ganges, the support of people in achieving the task is indispensable. By only refraining from using water in your households inconsiderately, one can contribute immensely to bring back the Aviralta of our river Ganga. Every drop of water saved in households will ultimately ensure that the Ganges flows like it used to, even in dry seasons. Put simply, the more water we leave for the Ganges, the more it would cleanse itself. Let us join hands with Namami Gange programme to bring back the mighty Ganges to its pristine glory.? ?
? Total annual availability of water in India is 1,869 billion cubic metres (BCM) out of which only 1,123 BCM is usable.?
? Total replenishable groundwater resource in the Ganga basin is 170.99 billion cubic metres (BCM)
? Ganga basin alone accounts for nearly 40 % of the country¡¯s total replenishable groundwater resource of the country which is 433 BCM.?
? Net ground water availability is 398 BCM. The annual groundwater draft (a reasonable release of discharge) is 245 BCM (as on 31st March 2017).??
? Out of total 6607 assessed units (blocks, mandals, districts), as many as 1071 units are ¡®over-exploited¡¯, 217 units are ¡®critical¡¯, 697 units are ¡®semi-critical¡¯ and 4530 as ¡®safe¡¯. Apart from these, there are 92 assessment units which were found to be completely saline.?
? Out of 820 assessed units (blocks) from 74 districts in Uttar Pradesh (Ganga basin state), 111 have been categorised as ¡®over-exploited¡¯, 68 as ¡®critical¡¯, 82 as ¡®semi-critical¡¯ and 559 as ¡®safe¡¯.? ??
? Out of 18 assessed units (blocks) in Uttarakhand (Ganga basin state) two have been categorised as ¡®critical¡¯, five as ¡®semi-critical¡¯ and 11 as safe. But, the net annual ground water availability has decreased in the state of Uttarakhand in 2011 by nearly 6 %.?
? Out of 271 assessed units (blocks) in West Bengal (Ganga basin state), 53 have been categorised as ¡®semi-critical¡¯ and one as ¡®critical¡¯.?
? Out of 27 assessed units (tehsils) in Union Territory of Delhi, 18 have been categorized as ¡®over-exploited¡¯, 2 as ¡®critical¡¯ 5 as ¡®semi-critical¡¯ and just 2 as ¡®safe¡¯.?
(The writer works with National Mission for Clean Ganga)