Water Woes of Delhi and Shrinking Glaciers
- World Water Day
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Dr Adeeba Parveen
Though they seem apart, Delhi and the Himalayas have a close relationship. Delhi gets nearly 90% of its water from rivers fed by the glaciers in the Himalayas. Sadly, these glaciers are melting at an unprecedented rate, and in the future threaten the already challenged water system of cities like Delhi.
As a researcher in water resource management, I’ve always been interested in exploring ways to optimise, preserve, and internalise water in cities. But realising that the water we rely on is depleting made me rethink my entire approach and pushed me to examine the impact of glacial melting on Delhi. India’s bustling capital, Delhi is anticipated to be among the most affected if glaciers recede and water supplies dwindle.
Glaciers are the sensitive indicators of climate change, and their retreat is a strong sign of a warming planet. The world’s glaciers have lost an average of 272 billion tonnes of ice annually since 2000, with a significant increase in the past decade. This figure is approximately equivalent to the total water consumption of the world population over a 30-year period. One of the most concerning effects of this environmental shift is the melting of Himalayan glaciers, which supply water to millions of people across the Indian subcontinent. The meltwater from the Himalayas decides the availability of water in the downstream cities like Delhi.
The Melting Towers of Asia
The Himalayas, also known as the “Water Towers of Asia,” are among the most sensitive and vulnerable regions to climate change. These glaciers store approximately 12,000 km³ of freshwater and cover an area of 3 million hectares, making them the largest body of ice outside of the polar caps. Nearly 15,000 Himalayan glaciers, including the Gangotri glacier, the Bokhar Chu glacier, and the Chemangyungdung glacier, form a unique reservoir that supports perennial rivers like the Indus, Ganga, and Brahmaputra. These rivers bring life to millions of people in South Asian countries like India, Pakistan, Nepal, Bhutan, and Bangladesh. The Gangetic basin alone hosts 500 million individuals, approximately 10% of the total human population in the area.
However, the continuous warming of the earth has caused an increase in the rate of glacial melt. According to research conducted by the University of Leeds (2021), in recent decades, the Himalayan glaciers have experienced an ice loss at a rate ten times higher than the average rate over past centuries. They are shrinking at a faster rate than glaciers in other parts of the world and have been calculated to have lost around 40% of their area.
Loss of glaciers at such an alarming rate is concerning, particularly for countries like India, where the impacts of climate change are already evident. India’s glaciers, primarily located in the Himalayas, Karakoram, and the Tibetan Plateau, are essential sources of freshwater for many rivers. Rivers like the Ganga, Indus, Brahmaputra, and Yamuna, which provide water for millions of people, are fed by the meltwater from these glaciers. Glacial melting at such a pace, combined with erratic weather patterns, poses a significant threat to the water security of millions of people, particularly those living in urban centres like Delhi.
Overstretched Water Systems of Delhi
The National Capital Territory (NCT) of Delhi relies heavily on water supply from the Yamuna River, which originates in the Himalayas. The river has historically been a critical source of water for the city, providing drinking water, supporting agriculture, and fuelling industrial activities. However, rapid increases in population and urbanisation since the introduction of economic reforms in the 1990s have stretched Delhi’s available water supply (Figure 1 & 2).
Figure 1: Population growth in the NCT Delhi (1911-2011) (Source: District Census Handbook, Census of India, 2011)
Figure 2: Land Use and Land Cover (LULC) of the NCT Delhi (1980 & 2020) Source: Prepared by the author
Figure 3: Sources of Water in NCT Delhi (Source: Delhi Jal Board, GNCTD, 2021)
- Decreased Flow of River: As the glaciers retreat, they initially release large volumes of water into rivers. However, over time, this glacial meltwater decreases, leading to a reduction in the flow of rivers like the Yamuna, posing a serious threat to Delhi’s water supply future.
- Water Contamination: The water quality of rivers also gets influenced by the reduced flow of water. With less freshwater entering, the river’s ability to self-purify decreases, making it difficult for residents to access clean and safe water. For instance, Yamuna river is highly polluted and incapable of providing safe water for potable purposes.
- Declining Groundwater Levels: With surface water sources dwindling, Delhi’s reliance on groundwater increases. However, the situation with groundwater is no better. Delhi withdraws and uses more than the annual amount of available groundwater (0.29 BCM).[1] The unregulated and illegal extraction by the private water markets and locals has left the “rescue source,” groundwater, under stressed water level conditions. It means there is no to least fluctuation in water level between the pre- and post-monsoon seasons. This indicates that Delhi is running out of both surface water and underground water sources.
- Dependence on External Sources: Delhi imports a significant amount of water from three different sources (Yamuna River, Upper Ganga Canal, and Bhakra Storage) in neighbouring states. If the trend of retreating glaciers continues, the interstate water-sharing agreements could become a source of tension and conflict.
The water crisis in Delhi due to the rising water demand and its dropping availability (either by fluctuation in the river flow or over-abstraction of groundwater) is a complex issue and requires immediate attention and coordinated action.
The melting of glaciers is not just a distant environmental concern, it’s a growing crisis for cities across the world that depend on glacial-fed rivers for their water supply. As glaciers shrink, the once-reliable flow of water becomes unpredictable, threatening the livelihoods of millions in cities across the globe. The challenges are daunting, but not insurmountable. This issue is not limited to one region, it’s a global challenge that demands immediate action. The interconnectedness of climate change, glacial melt, and water scarcity means that cities must urgently improve water storage, increase water use efficiency, adopt sustainable water management practices and explore alternative solutions to secure their future water needs.
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