India's Expanding Horizon: Desalination Beyond Chennai

 India's Expanding Horizon: Desalination Beyond Chennai

While Chennai has notably led India's municipal desalination efforts, the grim realities of climate change, erratic monsoons, and burgeoning urban populations are compelling other coastal cities and regions across the nation to turn to the sea. The last two decades have witnessed a burgeoning interest and concrete plans for desalination projects across India, transforming it from a niche solution to a critical component of national water security. This shift signifies a broader strategic acknowledgment that conventional freshwater sources are increasingly insufficient to meet the demands of a developing nation.

The Emerging Desalination Map of India: Key Cities and States

Beyond Chennai, several other states and major urban centers are either actively pursuing or already operating desalination plants, showcasing a diverse adoption of the technology:

1. Mumbai, Maharashtra: The Megacity's Coastal Lifeline
• Project: The Brihanmumbai Municipal Corporation (BMC) is moving ahead with plans for a significant desalination plant in Manori, a northern suburb of Mumbai. This project has seen multiple tenders and re-tenders, highlighting the complexities of such large-scale urban infrastructure.
• Capacity: The proposed plant is designed for 200 Million Litres per Day (MLD) in its first phase, with a future provision to expand to 400 MLD.
• Technology: It will utilize Seawater Reverse Osmosis (SWRO), the most common and energy-efficient method for large-scale desalination. The design includes advanced features like underground tunnels for seawater intake (2.5 km offshore) and brine outfall, minimizing surface disruption.
• Capex: The estimated cost for the 200 MLD plant is over ₹3,000 crore (approx. US$360 million), reflecting the substantial investment required for such a facility. The BMC has earmarked an initial allocation of ₹100 crore in its 2025 budget.
• Opex: While specific Opex figures for Manori are not public yet, it's expected to be a significant component of the overall cost, driven primarily by energy consumption and maintenance for a plant of this scale.
• Impact: Mumbai, currently relying on a network of seven lakes that often face strain during monsoons, has a daily water deficit of approximately 300 MLD against a demand of 4,250 MLD. This plant aims to bridge that gap, providing a much-needed, drought-resilient source, particularly crucial in a city where demand is projected to exceed 6,500 MLD by 2041. "Manori isn't just about water; it's about making Mumbai resilient against climate shocks," emphasized a BMC official.
• Historical Context: The idea was first mooted in 2007 but gained momentum in 2020. The project was inspired by Israel's success in desalination, with the BMC signing an MoU with an Israeli firm for a detailed project report in 2021.
2. Gujarat: Industrial Powerhouse and Emerging Municipal Player
• Status: Gujarat has a strong presence of industrial desalination plants and is rapidly expanding into municipal desalination. It boasts the longest coastline in India (1600 km), making desalination a natural fit.
• Key Projects & Technologies:
• Jamnagar (Reliance & Nayara Energy): Large-scale thermal (Multi-Effect Distillation - MED) and RO plants primarily serve the massive oil refineries, providing process water. For instance, the Nayara Energy (formerly Essar) refinery at Jamnagar has multiple MED units with a combined capacity of 65,000 m³/day (65 MLD). These projects, dating back to 2006, showcase large-scale industrial desalination expertise.
• Dahej Desalination Plant: Developed by Gujarat Industrial Development Corporation (GIDC), this 100 MLD SWRO plant is operational and crucial for the Dahej PCPIR (Petroleum, Chemicals and Petrochemicals Investment Region), providing water for industrial units. Its project cost, including 10 years of O&M, was approximately ₹1741.73 crore (around US$210 million).
• Upcoming Municipal Plants: Gujarat has ambitious plans to establish municipal desalination plants in various coastal areas. Proposals include:
• Jodiya coast (Jamnagar district): A 100 MLD RO plant.
• Bhavnagar: Proposed 70 MLD capacity.
• Gir Somnath: Proposed 30 MLD capacity.
• Other locations like Dwarka, Kutch, and Pipavav are also being considered.
• Innovation: Gujarat is exploring the integration of solar-powered desalination and the Public-Private Partnership (PPP) model to enhance economic and environmental feasibility. "Gujarat is leveraging its vast coastline and industrial acumen to secure its water future," stated a state government spokesperson.
• Impact: Salinity intrusion affects 1200-1500 villages in 50 coastal talukas of Gujarat. Desalination aims to address this critical issue, supporting both industrial expansion and agricultural irrigation in these affected regions. Gujarat currently accounts for over 40% of India's desalination plants, with a capacity of over 360 MLD, and aims to reach 1500 MLD by 2030.
3. Lakshadweep Islands: Lifeline for Island Communities
• Status: Operational and expanding.
• Projects: The National Institute of Ocean Technology (NIOT) in Chennai has been instrumental in deploying Low-Temperature Thermal Desalination (LTTD) plants across several islands in the Union Territory of Lakshadweep.
• Capacity: Individual plants typically have a capacity of 100,000 litres (0.1 MLD) or 150,000 litres (0.15 MLD) per day. Three plants were initially established in Kavaratti, Minicoy, and Agatti. Based on their success, 6 more LTTD plants are being established at Amini, Androth, Chetlet, Kadmat, Kalpeni, and Kiltan.
• Technology: LTTD is an indigenous, environmentally friendly technology that exploits the temperature difference between warm surface seawater and colder deep-sea water to produce fresh water. It does not require chemical pre- or post-treatment, minimizing pollution. "For our islands, LTTD is a quiet revolution, delivering life-giving water without harming the fragile ecosystem," remarked a local administrator.
• Impact: These small-scale, decentralized plants are vital for providing potable water to isolated island communities that have virtually no other perennial freshwater sources. They ensure basic survival and public health.
• Challenges: Currently, these plants are often powered by diesel generator sets, leading to a carbon footprint. Efforts are underway to make the process more emission-free.
4. Andhra Pradesh: Visakhapatnam's Future Horizon
• Status: Proposed and under planning.
• Project: A 100 MLD SWRO desalination plant has been proposed for Visakhapatnam (Vizag), a major port city on the eastern coast. The proposed location is Pudimadaka, about 45 km south of Vizag.
• Technology: Expected to be SWRO, the prevalent technology for large-scale municipal plants.
• Capex: Proposed investment is in the range of US$110-120 million.
• Innovation: Interestingly, Visakhapatnam is also at the forefront of a unique project: India's first desalination-based hydrogen plant. The Indian Institute of Petroleum and Energy (IIPE), in collaboration with NTPC, is executing a project to produce green hydrogen using distilled water from an existing NTPC desalination plant at Simhadri. This highlights a convergence of water security with emerging green energy goals.
• Impact: Vizag, like other coastal cities, faces growing water demand due to industrialization and population growth. This plant would provide a reliable source to meet future needs and reduce pressure on traditional sources.
5. Thoothukudi, Tamil Nadu:
• Status: Operational (industrial) and proposed (municipal).
• Existing: The Tuticorin Thermal Power Station (TANGEDCO) has had a 10 MLD RO-based desalination plant operational within its campus since at least 2015 to meet its raw water requirements. This demonstrates industrial-scale desalination in the city.
• Proposed: The Tamil Nadu government has announced plans and is in the tendering phase for a larger, dedicated 60 MLD municipal desalination plant in Thoothukudi, serving the city's potable water needs. There is also an RFQ out for a smaller 5 MLD SWRO plant for V.O. Chidambaranar Port Authority.
• Impact: Thoothukudi, another significant port city in Tamil Nadu, is grappling with increasing water demand from its industrial base and urban population. This municipal plant will be crucial in diversifying its water sources.

A Shared Pursuit: The Underlying Dynamics

The expansion of desalination across these diverse Indian locations reveals several overarching trends and shared challenges:

• Necessity as the Driver: For all these regions, desalination is driven by an acute and growing water deficit, often exacerbated by climate variability and over-reliance on dwindling groundwater or erratic monsoon-fed surface water. "The writing is on the wall: coastal India must look to the sea," remarked a water policy expert.
• Dominance of SWRO: For large-scale municipal and industrial applications, Seawater Reverse Osmosis (SWRO) is the preferred technology due to its efficiency and maturity, though niche applications like LTTD in islands also exist.
• High Costs and PPP Models: The substantial capital and operational costs necessitate innovative financing models, with Public-Private Partnerships (PPPs) being a common approach to distribute risks and leverage private expertise.
• Environmental Considerations: Concerns about energy consumption (leading to carbon emissions) and brine discharge are universal. Efforts are being made to incorporate energy recovery systems, explore renewable energy integration, and employ better brine dispersion techniques. However, continuous monitoring and research are critical.
• Integrated Water Management: While desalination is a powerful solution, it's increasingly viewed as one component of a broader integrated water management strategy that also includes rainwater harvesting, wastewater recycling, and aggressive conservation. "Desalination fills the critical gap, but it doesn't absolve us of our responsibility to conserve," reminded a grassroots environmental activist.

In essence, India's coastline is rapidly becoming a landscape of desalination plants, a testament to the nation's determination to secure its water future in the face of escalating challenges. Each plant, whether large or small, represents a step towards a more water-resilient India, a crucial adaptation in an era of climatic uncertainty.

Elsewhere in the World

Beyond the specific examples of Chennai, Mumbai, Gujarat, and the Lakshadweep Islands in India, and the highly advanced nations of Israel and Saudi Arabia, large-scale desalination projects are a growing phenomenon in many water-stressed regions globally. This expansion is driven by a combination of factors: rapid population growth, increasing industrial demand, diminishing conventional freshwater sources due to climate change and over-extraction, and advancements in desalination technology, particularly Reverse Osmosis (RO), which have made it more energy-efficient and economically viable.

Here's a look at other countries with significant ongoing or planned large desalination projects:

United Arab Emirates (UAE): A Desalination Giant

The UAE, particularly Abu Dhabi and Dubai, is a global leader in desalination, historically relying heavily on thermal processes (MSF, MED) due to abundant energy resources. However, like Qatar, there's a strong pivot towards RO for new capacity due to its higher efficiency and sustainability goals.

• Scale and Scope: The UAE has some of the world's largest operational desalination plants and continues to invest heavily. Desalinated water accounts for a substantial portion (over 40%) of its drinking water.
• Key Projects:
• Taweelah Desalination Plant (Abu Dhabi): When fully operational, this is set to be one of the world's largest RO desalination plants, with a capacity of 909,200 cubic meters per day (m³/day). It also includes a significant power generation component. Commissioned in phases, it began operations in 2022. "Taweelah underscores our commitment to future-proofing water supply through cutting-edge RO technology," stated an ADWEA official.
• Jebel Ali Desalination Plant (Dubai): This massive complex includes multiple units (e.g., M Station, M Station Extension) with a combined capacity of over 2,228,000 m³/day. While some units are older thermal plants, expansions often incorporate RO.
• Umm Al Quwain (UMM AL QWAIN) Desalination Plant: This independent water project (IWP) has a capacity of 681,900 m³/day, showcasing significant recent investment.
• Fujairah Desalination Plant: Another very large plant with a capacity of 1,045,361 m³/day.
• Innovation: The UAE is actively investing in R&D for next-generation desalination technologies, including combining RO with renewable energy sources like solar power to reduce its carbon footprint. The focus is on maximizing efficiency and minimizing environmental impact.

Australia: Battling the "Millennium Drought" Legacy

Australia, the driest inhabited continent, faced a severe "Millennium Drought" in the late 1990s and 2000s, which spurred significant investment in desalination as a drought-proofing measure for its major cities.

• Scale and Scope: Australia has several large-scale municipal desalination plants, primarily utilizing SWRO. While some plants were temporarily mothballed or run at reduced capacity after droughts broke, they remain critical strategic assets.
• Key Projects:
• Victorian Desalination Plant (Dalyston, Victoria): One of the largest in Australia, with a capacity of 410,000 m³/day. Completed in 2012, it provides a vital backup for Melbourne's water supply.
• Sydney Desalination Plant (Kurnell, New South Wales): Capacity of 250,000 m³/day, operating since 2010. It played a crucial role in providing water during recent dry periods.
• Perth Seawater Desalination Plant & Southern Seawater Desalination Plant (Western Australia): Perth was one of the first major Australian cities to heavily rely on desalination. The plants have a combined capacity of over 400,000 m³/day.
• Adelaide Desalination Plant (South Australia): Capacity of 300,000 m³/day, completed in 2012.
• Innovation: Australia has focused on incorporating renewable energy (often purchasing green power) to offset the energy demands of its plants. The plants are designed for flexibility, allowing them to scale production up or down based on water availability from other sources. "Desalination provides our cities with an essential insurance policy against future droughts," noted an Australian water utility CEO.

China: Addressing Regional Water Scarcity and Industrial Demand

While China has vast internal water resources, severe regional imbalances, pollution, and rapid industrialization and urbanization along its coast have led to increasing adoption of desalination, particularly in northern coastal areas.

• Scale and Scope: China's desalination capacity is growing rapidly, though it's still relatively small compared to its total water demand. The focus is on addressing acute water shortages in specific coastal cities and providing process water for industrial zones.
• Key Projects:
• Tianjin Desalination Plant (Tianjin): One of China's largest, with an operational capacity of 200,000 m³/day, providing drinking water to a major industrial and port city.
• Many other plants are under construction or planned in provinces like Shandong, Hebei, Liaoning, and islands like Hainan. China has ambitious goals to reach 3 million cubic meters of freshwater daily by 2030.
• Innovation: China is investing heavily in R&D to improve desalination technologies, aiming for greater energy efficiency and cost reduction. They are also developing indigenous membrane manufacturing capabilities. "Desalination is a strategic tool for China to balance its economic growth with environmental sustainability," stated a Ministry of Water Resources official.

Spain: Europe's Desalination Leader

Spain, particularly its arid southern and southeastern regions and islands, has been a pioneer in desalination in Europe, especially for agricultural and municipal use.

• Scale and Scope: Spain is the largest desalination country in Europe, with numerous plants along its Mediterranean and Atlantic coasts and on its islands. Its experience dates back decades.
• Key Projects:
• Torrevieja Desalination Plant (Murcia): One of the largest in Europe, with a capacity of 240,000 m³/day, serving a highly agricultural and tourist region.
• Numerous other plants are spread across regions like Andalusia, Catalonia, and the Canary Islands.
• Innovation: Spain has been at the forefront of developing energy-efficient RO technologies and integrating renewable energy sources to power desalination plants, particularly in island settings. Its expertise in managing water resources in arid conditions, including extensive water transfer networks, is highly valued. "Our desalination plants are a testament to our ongoing fight against desertification," commented a Spanish water authority representative.

Algeria: A Major Player in North Africa

Algeria, facing increasing water stress due to climate change and population growth, has embarked on a massive desalination program to secure its water supply, particularly for its coastal cities.

• Scale and Scope: Algeria has rapidly expanded its desalination capacity and ranks among the top countries in the Mediterranean region for desalinated water production. Many large plants are being built.
• Key Projects:
• Magtaa Reverse Osmosis (RO) Desalination Plant (Oran): One of the largest in Africa, with a capacity of 500,000 m³/day.
• Numerous other plants with capacities of 100,000 to 200,000 m³/day are operational or under construction in locations like Beni Saf, Hamma, Cap Djinet, Tenes, Fouka, and Tipaza.
• Upcoming Projects: Algeria plans to build 7 new desalination plants between 2025 and 2030 in various wilayas, including Tlemcen, Mostaganem, and Tizi Ouzou.
• Impact: These projects are crucial for providing drinking water to Algerian cities, reducing reliance on conventional sources, and supporting industrial development.

United States: Addressing Regional Drought and Industrial Needs

While the U.S. has vast freshwater resources, localized water scarcity, particularly in arid states like California and Texas, has driven the development of large desalination projects.

• Scale and Scope: The U.S. has a growing number of desalination plants, though the overall proportion of desalinated water in the national supply is smaller compared to the Middle East. Projects tend to be concentrated in specific coastal regions.
• Key Projects:
• Carlsbad Desalination Plant (San Diego County, California): The largest seawater desalination plant in the Western Hemisphere, with a capacity of 189,000 m³/day. Operational since 2015, it provides about 10% of San Diego County's water. "Carlsbad is a critical step in diversifying our water portfolio," stated a San Diego water district official.
• Huntington Beach Desalination Plant (California): Proposed for a significant capacity, but has faced considerable regulatory and environmental challenges.
• Smaller plants exist in Florida, Texas, and other states for brackish water desalination or specialized industrial uses.
• Challenges: Desalination projects in the U.S. often face significant hurdles related to high costs, environmental permitting (especially concerning intake and brine discharge), and public opposition.

Other Notable Countries:

• Oman: A significant player in the GCC region, with large plants like Barka Desalination Plant, consistently investing in new capacity.
• Egypt: Building numerous desalination plants along its coasts to diversify water sources beyond the Nile River, including large projects like the Gabal El Zeit Desalination Plant.
• Chile & Peru: Desalination is increasingly vital for the mining industry in these arid South American countries, supporting vast operations in remote, water-scarce regions. Projects like the Escondida mining complex in Chile have their own large desalination plants.
• Malta & Cyprus: Small island nations in the Mediterranean that heavily rely on desalination for their freshwater supply due to limited natural resources.

The global landscape of desalination is rapidly expanding and diversifying. While the Middle East and North Africa remain the epicenters of large-scale desalination due to extreme aridity and energy resources, countries across all continents are recognizing its critical role in ensuring water security in an era of increasing water stress. The trend is firmly towards more energy-efficient RO technology, integration with renewable energy, and sophisticated brine management solutions.