As water stress deepens, India asks thermal power plants to account for every drop

Persistent El Niño conditions, declining water availability and competition with drinking water and agriculture are putting a new spotlight on how much freshwater India’s thermal power plants consume
Water is running scarce. India’s thermal power plants are still wasting it
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India’s water stress is increasingly becoming a concern for its electricity system. The latest advisory dated September 2, 2026 from the Central Electricity Authority (CEA) asks thermal power stations to undertake comprehensive annual water audits, covering water use across their different systems and processes, identifying avoidable losses and improving recycling and reuse. The move comes as persistent El Nino conditions have raised concerns over below-normal monsoon rainfall, reduced river flows, reservoir inflows and groundwater availability. For thermal power plants, which depend heavily on freshwater for cooling and other processes, declining availability can quickly become an operational problem.

The concern is not simply that there may be less water available for industry. India’s National Water Policy prioritises drinking water and agriculture over industrial use, meaning power plants increasingly have to compete for a resource that is already under pressure. The National Water Mission has also set a target of improving water-use efficiency by 20 per cent by 2027. CEA’s advisory therefore places water efficiency within a larger question: how can a water-intensive electricity system continue operating when the reliability of its freshwater supply is becoming increasingly uncertain?

This vulnerability is not new. A 2021 study by Delhi-based think tank Centre for Science and Environment (CSE), which analysed water consumption data from about 75 per cent of India’s coal-based power capacity, found that 41 per cent of the surveyed capacity was not complying with the prescribed water-consumption norms. About 42 per cent was complying and 17 per cent was based on seawater and therefore exempt from the norms. Once seawater-based plants were excluded, almost half of the surveyed capacity was non-compliant.

The significance of this becomes clearer when the location of these plants is considered. CSE estimated that about 48 per cent of India’s existing coal-power fleet was located in water-scarce regions, while several studies indicated that more than 40 per cent was already located in areas of acute water stress. Plants in regions such as Nagpur and Chandrapur in Maharashtra, Raichur in Karnataka, Korba in Chhattisgarh and Barmer and Baran in Rajasthan have already faced water shortages. CSE documented instances where plants had to shut down or reduce electricity generation because of reduced or unavailable water. The problem can become particularly acute in summer, when electricity demand rises because of higher cooling needs, at the same time that water availability can come under greater pressure.

Problem not only how much water plants use

India has had water-consumption standards for thermal power plants since 2015. Freshwater-based plants with cooling towers are required to stay within a specific water-consumption limit of 3.5 or 3 cubic metres per megawatt-hour, depending on the category of plant. Older freshwater-based once-through cooling systems were also required to shift to cooling towers because they withdraw substantially more water. CSE noted that once-through systems could withdraw around 70–200 cubic metres per MWh, compared with the 3.5 cubic metres per MWh standard applicable after conversion to cooling towers.

Yet compliance has remained weak. The sector missed the December 2017 deadline for meeting the water norms, and no firm plant-specific deadlines followed. CSE found that even several years after the norms were introduced, a large proportion of coal-based capacity continued to exceed the prescribed limits. Among the 59 GW of non-complying capacity in its survey, about 65 per cent belonged to state-owned plants.

There is another problem that makes the scale of the issue difficult to establish: Measurement itself. Water consumption figures are largely self-reported by plants, while CSE found inconsistencies in reporting formats and a lack of third-party verification. In an RTI response, the Central Pollution Control Board said it did not maintain a record of the water-compliance status of individual plants, with the data held by State Pollution Control Boards instead. CSE consequently found a lack of transparency in the public availability of plant-level water consumption and compliance information.

This is where the new CEA advisory could be important. A water audit should not become another exercise in submitting consumption figures. It needs to establish a water balance for the entire plant , how much freshwater enters, where it is used, where it is lost, how much wastewater is generated and how much is recovered and reused. Without this level of accounting, a plant can technically report a water-consumption number without identifying the processes responsible for excessive use or the opportunities to reduce it.

Cooling only part of water problem

Cooling is the largest and most obvious part of the equation, but reducing the water footprint of a thermal power plant requires attention to several other systems. Cooling towers lose water through evaporation and blowdown. Ash handling, demineralisation plants, coal handling, domestic use and wastewater treatment also contribute to overall freshwater demand. The CSE study found examples of plants demonstrating that water can be circulated across different processes rather than repeatedly drawing fresh supplies. At some plants, cooling-tower blowdown has been reused for road washing, bottom-ash handling and sprinkling. At the Torangallu power plant in Karnataka, treated cooling-tower blowdown was recycled as cooling-tower makeup water, while the RO reject was used elsewhere in the industrial process.

This approach matters because water efficiency cannot be reduced to installing a single technology. It requires plants to identify every major water-consuming process and connect water streams wherever reuse is technically possible.

The newer generation of plants also has a stronger obligation: plants commissioned after 2016 were required to meet zero liquid discharge (ZLD) requirements. But CSE found that implementation of ZLD was not being adequately monitored, despite its importance in preventing wastewater discharge and maximising internal recycling.

The challenge is particularly significant because ZLD systems can be expensive and energy intensive. That makes monitoring and enforcement even more important. If compliance is left largely to self-reporting, plants have little incentive to make investments whose benefits may accrue primarily through reduced pressure on a common water resource.

Make audit a tool for accountability

The CEA’s annual water-audit advisory can be useful if it becomes the beginning of a stronger compliance system rather than an additional reporting requirement. Each audit should establish the plant’s actual water consumption, identify losses, map major wastewater streams, assess recycling and reuse, and specify measurable actions and timelines for reducing freshwater withdrawal. Plants that exceed the prescribed limits should have clear deadlines for correction, while repeated non-compliance should attract regulatory action.

The data also needs independent verification. This was one of the key gaps identified by CSE: Water consumption figures submitted by plants had not been systematically verified by regulators or independent agencies. The study recommended annual water audits and independent verification precisely because audits and water-balance studies can establish actual consumption and identify opportunities for conservation, recycling and reuse. There is also a strong case for prioritising the oldest and most water-intensive plants. CSE identified about 17 GW of freshwater-based once-through cooling capacity, much of it commissioned before 1999. For plants with little remaining operating life, investing heavily in retrofits may not make economic sense; decommissioning could be the more appropriate option. Plants expected to operate for longer, meanwhile, should be given firm timelines to shift to closed-loop cooling.

The urgency is ultimately about more than meeting an environmental standard. A thermal power plant without reliable water cannot reliably generate electricity. As water scarcity intensifies and competition among drinking water, agriculture, industry and ecosystems grows, plants that continue to consume freshwater inefficiently will face greater operational and social risks. CEA’s call for annual audits provides an opportunity to address that vulnerability , but only if the exercise moves beyond accounting for water to actually reducing the sector’s dependence on it. India’s thermal power sector has already had years to comply with water-use standards. The growing water stress means there is less justification for another cycle of reporting without action.

Down To Earth
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