Water resources are critical for economic growth, and essential for ecology. In India, water resources are under tremendous pressure. Water demand is continuously rising, and with high population growth, the per capita water availability is decreasing over time. It is likely to touch the water scarce situation (about 1000 cubic meter per capita) in the coming years. The total water demand in India is projected to increase from 813 BCM (Billion Cubic Meters) in 2010 to 1093 BCM in 2025, and further to 1447 BCM in 2050 (TERI, Sept 2024).
By 2050, the expected water demand is likely to exceed the water availability. Of these demands, industry water demand is estimated as 17 BCM in 2010, 38 BCM in 2025 and 193 BCM in 2050. India faces complex challenges in managing its water resources, requiring efficient management to address water scarcity, pollution and unsustainable extraction practices.
Of all the industrial water demand, water consumption in thermal power plants is the highest, about 87.87 per cent, Engineering at 5.05 per cent, Paper & Pulp at 2.26 per cent, Textiles at 2.07 per cent, Steel at 1.29 per cent, Sugar at 0.49 per cent, Fertilisers at 0.18 per cent, and others at 0.78 per cent. India lost about 4 terawatt-hours of thermal power due to water shortage in 2016, cancelling out more than 20 per cent of growth in total electricity generation from 2015. Compared to international standards, the water use by Indian industry is very high. It consumes 2 to 3.5 tonnes more water per unit of production.
The industrial water productivity (in US$/cum) in India is about 7.5 while in Thailand it is 95.6, in Sweden 92.2, in Brazil 35, in Argentina 30, and in Norway 23.4. Thus, there is a huge scope for using less water per unit of production in India through efficient water management in industries. UNEP 2014 report estimated that without water efficiency improvement, global water demand will exceed the available water supplies by about 40 per cent by 2030. It is, thus, essential to enhance water conservation in industry, through recycle and reuse, etc., addressing the recent concept of having a “circular economy”. For the thermal power plants in India, the average water conservation is 80 m3/MWH as against the global norm of <10 m3/MWH. For Textile sector, the average water consumption in India is 200-500 m3/ton cotton cloth compared to the global norm of <100 m3/ton cotton cloth. For the Pulp & Paper industry in India, the average water consumption for Wood based mills is 150-200 m3/ton as against the global norm of 50- 75 m3/ton. For Waste-paper based mills the average consumption in India is 75-100 m3/ton as against the international norm of 10-25 m3/ton. For an integrated Iron and Steel plant in India the average water consumption is 10-80 m3 per ton of finished product as against the global norm of 5-10 m3 per ton of finished product. Thus, there is enormous scope for saving water in Indian industry. There are certain regulatory norms with respect to water consumption in certain industries. For example, SWC (Specific Water Consumption) for new thermal power plants installed after 1.1.2017 is mandated not to exceed maximum of 3.0 m3/MWH, and all existing cooling tower-based Thermal power plants commissioned before 1.1.2017 shall reduce SWC upto a maximum of 3.5 m3/MWH. Further the plants should achieve Zero Waste Water discharge. These benchmarks are not followed in all power plants in India. The potential achievable benchmarks for select industrial sectors are estimated by TERI (Feb. 2024). For example, short term interventions for Thermal Power plants are recirculation (about 70 per cent) of water in ash handling systems; zero discharge; and increasing Cycle of Concentration (CoC) (up to 6) in cooling systems. The long term interventions are switching to dry ash handling system from wet ash handling; and shifting to dry cooling system from conventional wet cooling. A rough estimate shows that with short term interventions, water saving of about 10 million cum /yr can be achieved, and by converting all thermal power plants from ‘oncethrough open-loop’ to ‘closedcycle cooling system’ using recycled water, about 65,000 million litres per day of fresh water can be saved. By taking short term interventions Thermal Power plants (1000 to 2500 MW) can save water to the extent of 0.6- 3.5 m3/MW and with long term interventions the water saving will be to the extent of 1.6-4.9 m3/MW of water. For Paper and Pulp industries, short term interventions are reduction of nozzle size in paper machines and reusing at least 50 per cent of waste water; while long term interventions include reclamation of processed water along with approaching ZLD (Zero Liquid Discharge). RCF ba - sed mills with use of short-term interventions can save 2.8-3.1 m3/MT of water and by using long term interventions they can save 5.9-5.2 m3/MT of water. For textiles industries, the interventions for improving water use efficiency include recycling and reuse of waste water as well as replacement of the existing washing machines with highly efficient ‘Computer Integrated Machines’. Textile and integrated industry (cotton) can save water to the extent of 161 m3/MT, by using these interventions. For iron and steel industries, water saving interventions include switching to Coke Dry Quenching, and reusing and recycling waste water. Using these interventions, the industry can save water to the extent of 1.4-1.6 m3 /MT. There is a need to adopt further actions to enhance water conservation in Indian Industry. First, there should be achievable benchmarks for water saving interventions in each industry. These benchmarks sho - uld be framed by the Bureau of Water Use Efficiency (BWUE), of the Ministry of Jal Shakti. BWUE should be given legal status early by using the provisions of the existing regulatory framework. Second, the Water Regulatory Authority (WRA) is in position in four states, and the remaining states should position WRAs early. They should be given a mandate to ensure that the water saving benchmarks set by BWUE are implemented in all industries. Third, the Punjab WRA has introduced a new concept called Water Conservation Credits (WCC), an incentive mechanism for industries for water saving. Each cubic meter of water conserved by an industry in Punjab will earn one WCC which will entitle the unit to a rebate of Rs 2.50/-. Further, incentivisation linked to different levels of resource recovery and reuse, waste water treatment and recycling, ZLD from industries should also be introduced in all industries. Fourth, regular water audits should be the norm in every industry. Every three years, a third party audit should be conducted for each industrial sector. WRAs in states should monitor this activity. Data sharing to enhance water productivity and water use efficiency in industries should be introduced and placed in the public domain. Fifth, formal partnership with industry players, CSR foundations, leading NGOs, etc. should be established for adopting ‘One Water’ approach for enhancing efficiency of both supply side and demand side of water management. Sixth, a ‘Centre for Excellence’ should be set up by the National Water Mission, which should work closely with BWUE and WRAs for having professional input to policy makers on improving industrial water use efficiency in the coming years. (The writer is a Distinguished Fellow, TERI, New Delhi and a former Secretary, Ministry of Water Resources, Govt. of India.)