Mumbai's 7.2-Km Underground Tunnel to Bring Desalinated Water to the City

Created by: Ajjay Bhagyakar

Mumbai's Water Supply Gets a Future-Ready Upgrade

Mumbai is set to take a major step towards strengthening its long-term water security with a planned 7.2-km underground tunnel that will connect the city's first seawater desalination plant at Manori to the existing water distribution network.

The ambitious infrastructure project is designed to carry desalinated water towards Charkop and Mahavir Nagar in Kandivli, helping integrate a new, climate-resilient water source into Mumbai's existing supply system. The tunnel is part of a larger ₹4,077-crore desalination project being developed to address the city's growing water demand and reduce its dependence on rainfall-fed lakes.

How the 7.2-Km Tunnel Will Transport Water

A Deep Underground Engineering Project

The proposed tunnel will stretch approximately 4.6 km from Manori to MNP Udyan at Charkop, followed by another 2.6 km section to Mahavir Nagar, Mumbai 7 2-Km Underground Tunnel to Bring Desalinated Water to the City.

The tunnel will be constructed at an impressive depth of approximately 104 to 128 metres below ground level using two tunnel boring machines operating simultaneously from Manori and Mahavir Nagar, Mumbai's 7.2-Km Underground Tunnel to Bring Desalinated Water to the City.

The project also includes three deep shafts at Manori, Charkop and Mahavir Nagar, along with transmission mains, water storage tanks, valve chambers and advanced SCADA systems for monitoring and controlling the water supply network.

Desalination Plant to Start With 200 MLD Capacity

Future Capacity Planned at 400 MLD

The pumping station at Manori is being designed with an ultimate capacity of 400 million litres per day (MLD). However, the first phase of mechanical and electrical infrastructure will initially support 200 MLD, matching the first phase capacity of the desalination plant.

Once operational, the new system is expected to allow approximately 190 MLD of water currently supplied from Bhandup to be redistributed to other parts of Mumbai. This could particularly benefit the western suburbs by improving the overall efficiency and flexibility of the city's water distribution network.

Why Mumbai Needs an Alternative Water Source

Tackling the City's Water Supply Gap

Mumbai's water demand is estimated at around 4,600 MLD, while the current available supply is approximately 4,100 MLD, creating a significant gap between demand and supply.

The desalination project is therefore being positioned as an additional source of water for the city's rapidly growing population.

Unlike Mumbai's traditional reservoirs, which depend heavily on monsoon rainfall, seawater desalination can provide a more reliable source of water that is less directly affected by fluctuations in rainfall.

With climate change contributing to increasingly unpredictable weather patterns, diversifying Mumbai's water sources could become increasingly important for long-term urban resilience.

Construction Could Begin Soon

45-Month Timeline Planned Mumbai's 7.2-Km Underground Tunnel to Bring Desalinated Water to the City

The tunnel construction, along with associated infrastructure, has been proposed at a cost of approximately ₹2,241.3 crore, with the overall desalination project estimated at ₹4,077 crore.

The project is expected to take around 45 months to complete once construction begins. The civic administration has also issued a public notice inviting objections from citizens and property owners regarding the proposed tunnel alignment, forming part of the planning and approval process.

A New Chapter in Mumbai's Water Infrastructure

Building a More Climate-Resilient Mumbai

The 7.2-km Manori–Charkop–Mahavir Nagar tunnel represents more than an underground engineering project. It is part of Mumbai's broader effort to develop a more diversified and climate-resilient water supply system.

As the city's population, infrastructure and economic activity continue to expand, reliable access to water will become increasingly important. The combination of desalination, underground water transmission and improved distribution could help Mumbai prepare for future demand while reducing its vulnerability to unpredictable monsoons.

If implemented successfully, the project could mark a significant milestone in Mumbai's journey towards long-term water security, providing the city with an additional source of water while strengthening the resilience of its existing supply network.