Regional spotlight: Water security & desalination in India — what's different and why it matters

India faces a water crisis unlike any other major economy. With 18% of the world's population but only 4% of its freshwater resources, the country confronts structural water scarcity that threatens agricultural productivity, industrial output, and the livelihoods of hundreds of millions. The Central Water Commission reported in 2025 that 21 major Indian cities will face zero-day scenarios by 2030 without radical intervention, while NITI Aayog's composite water management index shows that 600 million people already experience high to extreme water stress. Desalination, long considered too expensive for developing economies, is rapidly emerging as a non-negotiable component of India's water security architecture. But what works in the Gulf States or Singapore does not translate directly to India. The regulatory environment, cost structures, energy mix, and social dynamics create a fundamentally different deployment landscape that demands its own analysis.

Why It Matters

India's water demand is projected to reach 1,180 billion cubic meters by 2050, roughly double the current sustainable supply of 695 billion cubic meters. Agriculture consumes approximately 80% of available freshwater, with groundwater depletion accelerating at 1-3 meters per year in key agricultural states including Punjab, Haryana, and Rajasthan. The World Bank estimates that water scarcity could reduce India's GDP growth by up to 6% by 2030 in the absence of adequate policy response.

Industrial water demand compounds the pressure. India's semiconductor fabrication ambitions under the India Semiconductor Mission require ultra-pure water at volumes of 10-15 million liters per day per facility. The textile and leather industries in Tamil Nadu and Gujarat consume 200-400 liters per kilogram of finished product. Thermal power generation, still dominant in India's energy mix, withdraws approximately 90% of industrial water allocations. These competing demands create zero-sum dynamics that desalination can help resolve by introducing new supply independent of rainfall and river systems.

The regulatory landscape differs substantially from Western and Gulf State frameworks. India lacks a unified national water law. Instead, water governance operates across state, municipal, and panchayat levels, creating fragmented authority that complicates large infrastructure projects. The 2024 amendment to the National Water Policy introduced desalination as a recognized supply augmentation strategy for the first time, but implementation guidelines remain under development. State-level variation is extreme: Tamil Nadu has an operational desalination policy framework with feed-in tariffs for treated water, while states like Maharashtra and Karnataka are still conducting feasibility studies.

Key Concepts

Reverse Osmosis (RO) Desalination dominates India's installed capacity, accounting for approximately 85% of operational plants. RO systems force seawater or brackish water through semi-permeable membranes at pressures of 55-80 bar, rejecting dissolved salts while allowing water molecules to pass. Indian installations typically achieve recovery rates of 40-45% for seawater and 70-85% for brackish water, compared to 45-50% in newer Gulf State facilities. The gap reflects India's older membrane inventory and lower operating pressures chosen to reduce energy consumption in a market where electricity costs substantially affect unit economics.

Brackish Water Desalination represents an underexploited opportunity in inland India. The Central Ground Water Board has mapped approximately 60% of Rajasthan, 40% of Gujarat, and portions of Andhra Pradesh, Telangana, and Haryana as having brackish groundwater with total dissolved solids between 1,500 and 10,000 mg/L. Treating brackish water requires 1-3 kWh per cubic meter, compared to 3.5-5.5 kWh for seawater, making it far more economically viable in regions with constrained grid capacity. Community-scale brackish water RO units serving 500-5,000 households have proliferated across Rajasthan and Gujarat, with over 2,400 installations operational as of 2025.

Thermal Desalination using multi-stage flash (MSF) or multi-effect distillation (MED) remains limited in India due to high energy requirements. However, co-location with thermal power plants and refineries offers waste heat utilization that can reduce primary energy input by 50-60%. The Reliance Jamnagar refinery complex operates India's largest thermal desalination facility at 170 million liters per day, using waste heat from refining operations. This co-location model is particularly relevant as India plans 27 GW of new coastal thermal capacity through 2030.

Solar-Powered Desalination is gaining traction as India's solar tariffs have fallen below INR 2.5 per kWh ($0.03/kWh). Pilot projects in Gujarat's Kutch district and Tamil Nadu's coastal villages have demonstrated solar-RO systems producing water at INR 40-60 per cubic meter ($0.48-0.72), competitive with tanker-delivered freshwater in water-scarce regions. The Indian Institute of Technology Madras has developed a solar thermal desalination system achieving 8-10 liters per square meter per day, targeting rural communities without grid connectivity.

India's Desalination Landscape: Current State

India's total installed desalination capacity reached approximately 1,900 million liters per day (MLD) in 2025, less than 3% of the Gulf Cooperation Council's combined capacity. Chennai alone accounts for nearly 40% of national capacity, reflecting Tamil Nadu's pioneering role. The distribution reveals stark regional disparities.

State	Installed Capacity (MLD)	Technology	Primary Application
Tamil Nadu	730	Seawater RO	Municipal supply
Gujarat	420	Brackish/Seawater RO	Industrial + Municipal
Maharashtra	280	Seawater RO	Industrial
Andhra Pradesh	190	Brackish RO	Agricultural + Municipal
Rajasthan	160	Brackish RO	Community supply
Others	120	Mixed	Various

What's Working

Chennai's Multi-Plant Strategy

Chennai operates three seawater desalination plants at Minjur (100 MLD, commissioned 2010), Nemmeli (100 MLD, commissioned 2013), and Nemmeli Phase II (150 MLD, commissioned 2024), with a fourth 400 MLD facility under construction at Perur. The plants collectively supply approximately 25% of Chennai's municipal water demand. During the severe 2019 water crisis, when the city's four main reservoirs ran nearly dry, the Minjur and Nemmeli plants provided the only reliable piped water supply for over four million residents. Chennai Metro Water's experience demonstrates that desalination functions as drought insurance, providing value that extends beyond per-cubic-meter cost comparisons. The blended cost of desalinated water in Chennai's distribution network is INR 55-65 per cubic meter ($0.66-0.78), approximately 3x the subsidized municipal tariff but well below emergency tanker water costs of INR 200-400 per cubic meter.

Gujarat's Industrial Corridor Approach

Gujarat has adopted a different model, integrating desalination with industrial development corridors. The Dholera Special Investment Region, spanning 920 square kilometers, includes a 100 MLD desalination plant as core infrastructure, with treated water allocated to industrial users at commercial tariffs of INR 80-100 per cubic meter. This approach de-risks the economics by securing anchor industrial customers willing to pay above municipal tariffs. The Gujarat Industrial Development Corporation has replicated this model at Dahej and Mundra, where petrochemical and port operations provide base-load demand. Industrial users benefit from supply reliability, while the revenue cross-subsidizes municipal water allocation at concessional rates.

Community-Scale Brackish Water Treatment in Rajasthan

The Rajasthan government's Jal Swavlamban Abhiyan (Water Self-Reliance Campaign) has installed over 1,200 community-scale brackish water RO systems across Barmer, Jaisalmer, Jodhpur, and Bikaner districts since 2020. Each unit serves 200-1,000 households, treating groundwater with TDS levels of 2,000-8,000 mg/L to potable standards below 500 mg/L. Operating costs run INR 15-25 per cubic meter ($0.18-0.30), with solar hybrid configurations reducing energy costs by 40-60% compared to grid-only operation. The program has reached approximately 2.5 million rural residents who previously depended on irregular tanker deliveries or consumed brackish water with documented health consequences including fluorosis and kidney disease.

What's Not Working

Brine Disposal and Environmental Compliance

Indian desalination plants discharge brine concentrate with salinity levels 1.5-2x ambient seawater back into coastal waters, often with inadequate diffusion infrastructure. The National Green Tribunal's 2024 directive mandating environmental impact assessments for all new desalination projects above 50 MLD has increased compliance costs by 15-20% and extended project timelines by 12-18 months. The Chennai Minjur plant faced sustained protests from fishing communities citing reduced fish yields near the outfall zone. Zero-liquid discharge (ZLD) technologies exist but increase capital costs by 30-50% and energy consumption by 25-40%, making them economically prohibitive at current tariff structures. India has yet to develop comprehensive brine management standards comparable to Australia's or California's frameworks.

Energy Cost Volatility

Indian desalination economics remain highly sensitive to electricity tariffs, which vary from INR 3-8 per kWh ($0.036-0.096) across states and consumer categories. A seawater RO plant consuming 4 kWh per cubic meter faces operating energy costs of INR 12-32 per cubic meter depending on location and tariff category, a range that can shift project viability from clearly positive to marginal. States like Tamil Nadu offer concessional industrial tariffs for desalination, while others apply standard commercial rates. The absence of a national policy on electricity pricing for water infrastructure creates planning uncertainty for developers and investors.

Financing and Institutional Capacity

Large desalination projects require capital investments of INR 5-8 crore per MLD ($600,000-960,000 per MLD), putting a 200 MLD facility at INR 1,000-1,600 crore ($120-192 million). Indian municipal corporations typically lack the balance sheet capacity or creditworthiness to finance such projects directly. Public-private partnership (PPP) models have been used in Chennai and Gujarat, but standardized concession frameworks and payment security mechanisms remain underdeveloped. The Jal Jeevan Mission, India's flagship rural water program with a budget of INR 3.6 lakh crore ($43 billion), has allocated less than 2% of funds to desalination, favoring conventional surface water and groundwater schemes.

Myths vs. Reality

Myth: Desalination is too expensive for India

Reality: At INR 50-80 per cubic meter for seawater RO, desalinated water is more expensive than surface water treatment (INR 8-15) but comparable to or cheaper than tanker water delivery (INR 200-500), groundwater from declining aquifers requiring deeper borewells (INR 40-80), and inter-basin transfer schemes (INR 30-120 including capital amortization). The cost comparison depends entirely on the alternative supply being displaced.

Myth: India should focus on conservation rather than desalination

Reality: Conservation and desalination are complementary, not competing strategies. Even aggressive demand-side management achieving 20-30% reduction in agricultural water use through micro-irrigation and crop shifting cannot close the projected 480 billion cubic meter supply-demand gap. Desalination provides the supply-side augmentation necessary while conservation measures scale.

Myth: Desalination technology is standardized globally

Reality: Indian conditions require significant adaptation. Higher seawater temperatures (26-32 degrees C versus 15-22 degrees C in temperate regions) increase biofouling rates and reduce membrane performance by 10-15%. Seasonal monsoon turbidity spikes demand more robust pre-treatment. Coastal land acquisition faces regulatory and social constraints absent in Gulf State or Australian deployments. These factors increase Indian project costs by 15-25% compared to global benchmarks.

Action Checklist

• Assess regional water balance projections using Central Water Commission and state groundwater board data before evaluating desalination investments
• Evaluate brackish water desalination feasibility for inland applications where groundwater TDS exceeds 1,500 mg/L
• Model solar-hybrid configurations to reduce energy cost sensitivity, particularly in states with high commercial electricity tariffs
• Engage with state pollution control boards early on brine discharge permitting and environmental compliance requirements
• Structure PPP frameworks with payment security mechanisms including escrow accounts and state government guarantees
• Design modular plant architectures allowing phased capacity expansion to match demand growth and reduce upfront capital requirements
• Incorporate climate resilience into intake and outfall design, accounting for sea level rise projections and extreme weather frequency

FAQ

Q: What is the current cost of desalinated water in India compared to conventional sources? A: Seawater RO desalination produces water at INR 50-80 per cubic meter ($0.60-0.96), while brackish water RO achieves INR 15-30 per cubic meter ($0.18-0.36). Conventional surface water treatment costs INR 8-15 per cubic meter, but this comparison ignores the capital cost of new dams, canals, and pipeline infrastructure required to develop remaining surface water sources, which can bring lifecycle costs to INR 25-60 per cubic meter.

Q: How does India's energy mix affect desalination viability? A: India's grid carbon intensity of approximately 700-750 gCO2/kWh means grid-powered seawater desalination carries a carbon footprint of 2.5-4.0 kgCO2 per cubic meter. Solar-hybrid configurations can reduce this to 0.5-1.0 kgCO2 per cubic meter while simultaneously lowering energy costs. As India targets 500 GW of renewable capacity by 2030, grid-powered desalination emissions will decline proportionally.

Q: Which Indian states are most advanced in desalination policy? A: Tamil Nadu leads with operational plants, established tariff frameworks, and ongoing procurement for additional capacity. Gujarat follows with integrated industrial-municipal models. Andhra Pradesh and Maharashtra have active feasibility studies. Most other coastal states remain in early policy discussion stages.

Q: Can desalination address India's agricultural water crisis? A: Direct desalination for irrigation is economically unviable at current costs. However, desalination for municipal and industrial supply frees surface water and groundwater currently allocated to these sectors for agricultural reallocation. This indirect substitution effect is how desalination contributes to agricultural water security in water-stressed coastal regions.

Sources

• NITI Aayog. (2025). Composite Water Management Index: Third Assessment. New Delhi: Government of India.
• Central Water Commission. (2025). National Water Availability Assessment Report. New Delhi: Ministry of Jal Shakti.
• World Bank. (2024). India Water Sector Assessment: Bridging the Supply-Demand Gap. Washington, DC: World Bank Group.
• Chennai Metropolitan Water Supply and Sewerage Board. (2025). Annual Report 2024-25: Desalination Operations Review. Chennai: CMWSSB.
• Gujarat Industrial Development Corporation. (2025). Dholera SIR Infrastructure Status Report. Gandhinagar: GIDC.
• Central Ground Water Board. (2024). Dynamic Ground Water Resources of India: 2024 Assessment. New Delhi: Ministry of Jal Shakti.
• International Desalination Association. (2025). India Desalination Market Outlook. Topsfield, MA: IDA.
• Indian Institute of Technology Madras. (2025). Solar Thermal Desalination: Field Trial Results from Tamil Nadu Coastal Villages. Chennai: IIT Madras Department of Mechanical Engineering.