Climate study shows drying of Cauvery to persist until 2050, even as other rivers swell
Cauvery faces potential “near-term decline” of about 3.5% of its waters between 2026 and 2050, even as its northern counterparts brace for floods; Godaveri-Cauvery link project may be a critical solution
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Context
A new climate study by IIT Gandhinagar researchers predicts a potential 3.5% decline in the Cauvery river's flow between 2026 and 2050, even as other major Indian rivers are expected to see increased flows due to climate change. This scientific projection intensifies the already contentious water-sharing dispute between and . The study suggests that this long-term drying trend could exacerbate water shortages, making future water-sharing agreements even more challenging.
UPSC Perspectives
Polity & Federalism
The projected decline in Cauvery's flow puts immense pressure on India's framework for resolving inter-state river water disputes. The constitutional mechanism for this is rooted in Article 262, which empowers Parliament to provide for the adjudication of such disputes and exclude the jurisdiction of all courts, including the . Acting on this, Parliament enacted the Inter-State River Water Disputes Act, 1956, which allows for the setting up of ad-hoc tribunals. The Cauvery dispute saw the creation of the in 1990, which gave its final award in 2007. This was later modified by a landmark judgment in 2018, which re-allocated water shares (404.25 TMC for Tamil Nadu, 284.75 TMC for Karnataka) and declared the Cauvery a "national asset," implying no single state has exclusive ownership. The new scientific evidence of decreasing flows will test the resilience of this very judgment and the principle of cooperative federalism, especially during deficit rainfall years, likely leading to more frequent legal and political confrontations.
Environmental & Geographical
The study highlights a critical geographical paradox of climate change in India: while overall warming may increase monsoon precipitation nationally, its regional distribution can be highly uneven. The research uses a 'constrained modelling' approach based on the latest global climate models ([CMIP6]), which corrects for biases by using historical river flow data. This refined method projects a grim future for the peninsular, rain-fed Cauvery, while snow-fed Himalayan rivers like the Ganga and Indus are projected to swell. This points to a growing North-South divide in water availability. Crucially, the study simulates naturalised flows, meaning it only accounts for climate-driven changes. The real-world situation is likely worse because it doesn't factor in human pressures like dam operations, rampant groundwater extraction, and increased demand for irrigation. The verdict of 2018 had already factored in Tamil Nadu's groundwater availability. A shrinking river will intensify reliance on groundwater, further stressing regional water security and ecological balance.
Governance & Economic
The forecast of a drier Cauvery basin forces a re-evaluation of long-term water management strategies and their economic consequences. The article mentions the [Godavari-Cauvery link project] as a potential supply-side solution, which aims to transfer surplus water from the Godavari basin to the deficit Cauvery basin. While such river interlinking projects are promoted as a panacea for water scarcity, they are fraught with challenges, including massive financial costs, significant environmental and ecological disruption, and complex inter-state negotiations for consensus. The economic stakes are incredibly high. The Cauvery delta is a vital agricultural hub for both and , and reduced water availability directly threatens food security and the livelihoods of millions dependent on agriculture. This necessitates a governance shift from merely augmenting supply to actively managing demand. Policy focus must shift towards promoting water-use efficiency through micro-irrigation (drip, sprinklers), advocating for less water-intensive cropping patterns, and implementing robust rainwater harvesting and water recycling programs at a large scale.