Professor Vikram Gandhi’s Immersive Field Course (IFC) “Development while Decarbonizing: India’s Path to Net-Zero" delved into the critical aspect of decarbonization and sustainability goals amid India's rapid development. The course presented an opportunity for students to advance their knowledge of sustainability efforts, decarbonization, and net zero in the context of a broader development agenda. The class culminated in a series of site visits in January 2025 in Mumbai and Bangalore and this is one of 9 student essays that highlights their reflections on uncovering sustainable solutions across the country.
Few cities exemplify the complexities of urban growth as vividly as Mumbai. With its dense population of over 20 million and economic significance, the city is a powerhouse in a country expected to become the world’s fourth largest economy by 2026. Yet, in the midst of its growth, the city grapples with profound challenges—rising temperatures, volatile weather patterns, and a growing strain on its infrastructure. In its effort to address climate related risks, the Brihanmumbai Municipal Corporation (BMC) launched The Mumbai Climate Action Plan (MCAP) a comprehensive strategy to achieve net-zero emissions by 2050 while enhancing urban resilience. This forward-looking strategy underscores the city’s resolve to adapt to the changing climate while balancing the needs of its people and industries. During our trip to India, we had the opportunity to tour two sites aimed at securing the city’s water systems for a more sustainable future.
Setting the Context: The Mumbai Climate Action Plan (MCAP)
The Mumbai Climate Action Plan (MCAP) identifies six focus areas for mitigation and adaptation: energy, mobility, waste management, air quality, urban greening, and water resource management. Water resource management stands out as a critical priority, aiming to enhance water-use efficiency, implement sustainable flood management, and safeguard natural water bodies to mitigate climate-related stresses.
Approximately 31% of the 102.24 billion rupees allocated by the BMC for climate-relevant initiatives is dedicated to flood resilience and water resource management, highlighting the importance of water security in the city’s climate strategy. However, despite this focus, water management remains one of the least-funded sectors under public-private partnerships. Unlike energy and transport, which attract significantly higher private investment, water management is often overlooked due to its limited profitability. Key barriers include political resistance to raising tariffs on a public good, pervasive water theft, and fragmented governance and regulatory frameworks.
These challenges underscore the necessity of private intervention. Local utilities will require innovative financing mechanisms and technical assistance. Our site visits offer valuable insights into Mumbai’s ongoing water management initiatives, showcasing the city’s efforts to overcome systemic challenges.
Water Treatment Plant Visit
During our visit to the city’s water treatment plant, we were struck by the scale and complexity of Mumbai’s water management system. The facility currently processes 2,800 mega liters of water per day, supplied by seven water sources. The city plans to add three new surface water dams by 2041 for a cumulative yield of 7,064 mega liters per day. The BMC is also seeking bids for a desalination project to produce 200 mega liters of potable water daily, with potential to double the capacity to 400 mega liters in the future. The current plant manages water distribution through an extensive network of 7,500 kilometers of pipelines across primary, secondary, and tertiary networks. One notable insight was the use of conveyance tunnels, which handle 40% of the city’s water supply, ensuring efficient distribution to residential and commercial buildings.
In addition to this robust infrastructure, Mumbai is actively pursuing sustainable water management practices. Initiatives include recycling and reusing treated sewage water, with plans to make it potable to supply new residential complexes. However, infrastructure challenges persist. While the water exiting the treatment facility is potable, contamination occurs during distribution due to aging pipelines and poor water storage in older buildings, many dating back to the 1950s. This highlights the urgent need for upgrades to infrastructure to ensure water quality reaches end-users.
Colaba Sewage Treatment Plant Visit
At the sewage treatment facility, the scale of operations was equally impressive. Serving approximately 300,000 residents, the plant converts sludge into resources for electricity generation, showcasing a circular approach to waste management. Operated in partnership with Suez, a private contractor, the plant uses advanced treatment processes to treat wastewater for tertiary purposes, with ongoing projects to make this water potable.
Despite these efforts, significant barriers remain. Energy costs account for 60% of the facility’s expenses, underlining the need for more energy-efficient technologies. Additionally, stormwater and sewage water are treated separately, but the city must address the challenge of integrating these systems in areas vulnerable to flooding.
Barriers to Adaptation and Mitigation
Mumbai faces several systemic challenges in its water and waste management systems:
- Infrastructure Gaps: Aging pipelines and limited retrofitting in older buildings result in water contamination post-treatment, undermining the benefits of advanced facilities.
- Energy Intensity: High energy consumption in sewage treatment facilities raises costs and environmental impacts, highlighting the need for renewable energy integration.
- Access Inequities: Informal settlements often lack access to centralized water and waste infrastructure, leaving vulnerable populations reliant on unsafe alternatives.
- Environmental Degradation: The need for extensive water retreatment reflects a broader neglect of water bodies and public spaces, underscoring the importance of holistic environmental stewardship.
Solutions and Future Considerations
To bridge these gaps, Mumbai must continue prioritizing infrastructure modernization and sustainable innovations. Expanding the use of recycled sewage water for potable purposes can significantly improve quality of life for residents, provided infrastructure upgrades are implemented to ensure quality at the point of use. Improving energy efficiency at treatment plants, such as adopting renewable energy or advanced sludge-to-electricity technologies, can lower costs while reducing emissions.
Equity must also be central to adaptation efforts. Extending infrastructure to informal settlements can enhance public health outcomes and ensure more inclusive access to services. Additionally, testing wastewater for infectious diseases could provide valuable data for tracking public health trends, offering a dual benefit of environmental and epidemiological resilience. Finally, strengthening public-private partnerships, like the collaboration with Suez, can drive innovation and accountability in implementing solutions at scale.
Mumbai’s water management systems exemplify both the potential and challenges of urban adaptation in a rapidly growing, climate-vulnerable city. By combining technological advancements, inclusive policies, and environmental stewardship, the city can create a sustainable model for urban resilience that other global cities can emulate.