Tamil Nadu is staring at a groundwater crisis, if one goes by the recent joint assessment of the Central Ground Water Board and Tamil Nadu’s water resources department.The assessment classified nine districts as ‘over-exploited’ or extracting more water than is replenished by rain each year.The replenishable, or dynamic groundwater resource represents fluctuating water levels assessed in observation wells during pre-monsoon and post-monsoon. Static resources lie beneath the dynamic resource and are meant to be a reserve. “As per the latest assessment of 2025, in TN, annual ground water recharge is 22.61 billion cubic meter (BCM) and annual extractable groundwater resource is 20.46 BCM. But the annual groundwater extraction in the state has been estimated as 15.04 BCM (about 73.5%),” said Union minister of state for Jal Shakti, Raj Bhushan Choudhary, in response to a query from AIADMK MP R Dharmar, in Rajya Sabha.The Jal Shakti Abhiyan dashboard claims `15,531cr has been spent on artificial recharge, rainwater harvesting and watershed development in Tamil Nadu over the past five years. Choudhary said 60% of the wells analyzed showed a rise in groundwater levels, but in Dindigul, Kanyakumari, Namakkal, Pudukottai, Sivaganga, Tuticorin and Tiruppur, more than half the analyzed wells showed depletion.“By extracting more than 100%, we are moving towards static resources, which we are not supposed to do. It should be kept as a reserve,” says S Raja, a retired hydrologist from the water resources department.Policy decisions such as establishing desalination plants and tertiary treatment reverse osmosis plants are being implemented to meet greater domestic and industrial needs. Rejuvenation of water bodies, rainwater harvesting, artificial recharge and watershed management activities augment groundwater resources.“There is no legal framework for regulation and monitoring, which has led to rampant extraction. Districts are becoming overexploited despite good monsoon years,” says B Shaktivel, a hydrologist who works with govt agencies. The TN Ground Water (Development and Management) Act, 2003, was repealed in 2013, and water managers are now placing their hopes on the recently passed comprehensive TN Water Resources (Regulation, Management and Augmentation) Bill, 2026, which awaits assent from Lok Bhavan.ZONES OF CONCERNOver-exploited districts | Salem, Tirupathur, Vellore, Chennai, Dindigul, Mayiladuthurai, Namakkal, Karur, ThanjavurCritical districts | Krishnagiri and Coimbatore, with extraction levels ranging between 90% and 100%Semi-critical districts | Dharmapuri, Tiruvannamalai, Tirupur, Villupuram, Trichy, Ranipet, Theni, Kallakurichi, Erode, Madurai, Tenkasi, with extraction between70% and 90%Krishnagiri and Coimbatore are categorized as ‘critical’ with extraction levels ranging between 90% and 100%. Districts with extraction below 70% are considered safe
