#By Dr. R B Chaudhary
Tamil Nadu is grappling with a severe water crisis in 2025, driven by a combination of depleted groundwater, dried-up reservoirs, erratic monsoons, and rapid urbanization. With a per capita water availability of just 750 cubic meters—far below the national average of 1,544 cubic meters—the state faces a critical challenge to its water security.
The situation is particularly dire in Chennai, where 11 million residents strain an outdated water infrastructure, leading to a projected water supply-demand gap of 466 million liters per day (MLD) by 2030. Compounding the issue, 70% of the state’s water is contaminated, disproportionately affecting low-income communities that spend ₹500–1,000 monthly on private water tankers.
Farmers are skipping sowing seasons, and industries face disruptions, threatening the state’s agricultural and economic stability. While recent rains and initiatives like desalination plants and rainwater harvesting offer hope, persistent challenges such as water body encroachment, high desalination costs, and the ongoing Cauvery dispute could push Tamil Nadu toward a “Day Zero” scenario by 2030 without urgent reforms.
The Water Resources Department (WRD) of Tamil Nadu reported in May 2025 that 13 districts, including Chennai, Thanjavur, Kancheepuram, and Tiruvallur, have experienced a significant decline in groundwater levels compared to the previous year. Thanjavur, a key agricultural delta district, saw its groundwater level drop by 2.51 meters, from 1.9 meters in May 2024 to 4.41 meters in May 2025, despite ample monsoon rainfall and increased water releases from Karnataka into the Cauvery River.
This decline is primarily attributed to over-extraction for water-intensive crops like turmeric, betel vine, banana, and vegetables. The Central Ground Water Board (CGWB) estimates Tamil Nadu’s annual groundwater recharge at 21.51 billion cubic meters (BCM), with extractable resources at 19.46 BCM. However, the state extracts 14.45 BCM annually, pushing aquifers toward depletion. Overexploitation, coupled with erratic monsoons influenced by climate change, has left 10 out of 90 reservoirs nearly empty, with Veeranam Lake recording zero million cubic feet (mcft) of water in April 2024.
Urbanization has exacerbated the crisis, particularly in Chennai, where 2,400 acres of water bodies have been lost to encroachment and development. The state has seen 7,828 tanks encroached upon, reducing natural recharge capacity. Chennai’s four main reservoirs—Puzhal, Cholavaram, Chembarambakkam, and Poondi—are critically low, with some completely dry, forcing reliance on private tankers and desalination plants. The 2019 “Day Zero” crisis, when Chennai’s reservoirs ran dry, serves as a stark reminder of the city’s vulnerability. Poor urban planning and inadequate maintenance of rainwater harvesting systems have further hindered groundwater recharge, while contaminated water sources—70% of which fail quality standards—pose health risks, particularly in low-income areas.
Recent assessments paint a grim picture. The NITI Aayog’s Composite Water Management Index highlights that nearly 600 million people in India, including many in Tamil Nadu, face high to extreme water stress. The Central Water Commission (CWC) classified water levels in the Cauvery basin as deficient in April 2024, with Veeranam Lake’s storage dropping from 687.40 mcft in April 2023 to zero in 2024. The CGWB’s 2023 report notes that Tamil Nadu’s groundwater extraction rate is unsustainable, with coastal regions like Chennai facing saline intrusion due to over-pumping. A 2021 study published in Frontiers projects that by 2050, Tamil Nadu’s water demand for irrigation, domestic, livestock, and industrial use will reach 61.28 BCM, far exceeding the available 47.6 BCM of surface and groundwater.
Urbanization has reduced Chennai’s water bodies from 60 in 1893 to just 28 in 2017, shrinking their area from 12.6 square kilometers to 3.2 square kilometers. This loss, combined with the disappearance of 2,400 acres of lakes and reservoirs in Chennai, Kancheepuram, and Tiruvallur, has crippled the region’s ability to store rainwater and recharge aquifers. The state’s dependence on the Northeast monsoon, which was 50% deficient in 2023, and the Southwest monsoon, with a 5.6% rainfall shortfall in 2023, underscores the impact of climate change. Erratic rainfall patterns and rising temperatures have increased evaporation, further depleting reservoirs and groundwater.
The Cauvery water dispute between Tamil Nadu and Karnataka remains a significant hurdle. Despite the Supreme Court’s 2018 ruling, tensions flared in 2023 when Karnataka sought to adjust surplus inflows against future releases, citing 32% excess rainfall. Tamil Nadu’s insistence on strict adherence to the ruling highlights the need for better interstate water governance. Meanwhile, 75% of Himalayan glaciers, which feed some of India’s rivers, are retreating, adding long-term pressure on water availability.
Tamil Nadu has implemented several measures to address the crisis. Chennai’s three desalination plants, with a combined capacity of 48 million gallons per day (mgd), provide a critical alternative water source, though they supply only a fraction of the city’s 1,200 MLD demand. A new 150 MLD desalination plant in Ramanathapuram and a ₹2,423 crore Ring Main pipeline project, set to link seven major water sources by 2025, aim to ensure uninterrupted supply. Posts on X highlight optimism about the Ring Main system, which will enable 24/7 circulation of treated water through a 93-km looped pipeline.
Rainwater harvesting, mandated since 2003, has shown success when properly implemented. The Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) has achieved 10% wastewater reuse, with plans to scale up to 75% by 2024 through tertiary treatment plants. The WRD is constructing check dams and desilting ponds, canals, and lakes to enhance recharge, while the Atal Bhujal Yojana promotes community-led groundwater management in water-stressed districts. Farmers are being encouraged to adopt micro-irrigation and shift to less water-intensive crops like millets, supported by schemes like the National Food Security Mission.
Despite these efforts, Tamil Nadu faces significant hurdles. The high cost of desalination—₹45–50 per 1,000 liters compared to ₹3–5 charged to consumers—raises concerns about financial sustainability. Reject water disposal from desalination plants poses environmental risks, particularly in coastal ecosystems. Encroachment of water bodies remains a persistent issue, with slow progress in eviction and restoration efforts. The loss of wetlands, critical for flood mitigation and recharge, continues unabated, with 40% of India’s water bodies losing quality for aquatic survival.
The Cauvery dispute underscores the need for transparent data-sharing and basin-wide management. Without resolution, Tamil Nadu’s agricultural heartland, particularly the Cauvery delta, faces ongoing uncertainty. Climate change will intensify erratic monsoons and heatwaves, with the Indian Meteorological Department predicting further rainfall declines. By 2030, Chennai’s water gap could widen to 454 MLD, and 21 Indian cities, including Chennai, may exhaust groundwater entirely. India’s projected water demand of 1,093 BCM by 2025 and 1,447 BCM by 2050 far exceeds the available 1,121 BCM, threatening a 6% GDP loss by 2050.
To avert a “Day Zero” scenario, Tamil Nadu must adopt an integrated approach. Strengthening enforcement of rainwater harvesting laws and maintaining existing systems are critical. Restoring lost water bodies and wetlands, as demonstrated by Indore’s revival of 330 traditional water sources, can enhance recharge and urban resilience. Expanding wastewater recycling, as seen in Bengaluru’s plan to recycle 1 crore MLD of sewage, could reduce pressure on freshwater sources. Community-led initiatives, like the City of 1,000 Tanks project, which redirects rainwater to aquifers, offer scalable models.
Policy reforms should prioritize stricter groundwater regulations, such as limiting borewell drilling and reforming subsidized electricity policies that encourage over-extraction. Adopting Israel’s Shafdan facility model for wastewater recycling and China’s “sponge city” concept for urban water management could build resilience. Investments in climate-resilient infrastructure, like decentralized storage and AI-driven water monitoring, are essential. Public awareness campaigns and corporate partnerships, linked to schemes like Atal Bhujal Yojana, can mobilize resources and foster sustainable practices.
Tamil Nadu stands at a crossroads. Recent rains offer temporary relief, but without comprehensive reforms, the state risks a catastrophic water crisis. By prioritizing conservation, restoring ecosystems, and resolving interstate disputes, Tamil Nadu can secure its water future and set a model for sustainable water management in India.
(#Author is associated with Hindusthan Samachar as representative of Tamilnadu State)
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Hindusthan Samachar / Dr. R. B. Chaudhary
