How Mumbai neglected its groundwater – only to become dependent on it

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07-07-2025

In April, Mumbai's municipal corporation invoked the Disaster Management Act, 2005, to manage a crisis sparked by a strike by the city's water tanker association.
Many Mumbai residents, living both in buildings and informal slums, institutions and businesses, routinely depend on tankers for water – a fact that became even more apparent when the association's members went off the road to protest against a slew of new regulations.
To meet the challenge, the municipality issued a notification requisitioning private tankers, their drivers, cleaners and wells and borewells across the city.
The association withdrew the strike after five days, but the respite it offers does not address the core problem: that Mumbai's water supply is unequal, inefficient and inadequately planned, ignoring locally available groundwater resources.
In fact, Mumbai has access to sufficient water reserves. It is building wastewater treatment plants to boost its supply of non-potable water – even though that is what tankers primarily provide.
The commercial capital's reliance on tankers is a man-made crisis that reflects the misplaced priorities of its administrators.
Policy neglect of groundwater
The immediate trigger for the tanker strike in April was a set of regulatory conditions introduced by the Central Ground Water Authority in 2020.
As part of the new regulations, all borewell owners, if they wanted to continue their tanker operations, were required to obtain a permit and a no-objection certificate, fulfilling the conditions laid down by the ground water authority.
Mumbai's water tankers obtain their supply from wells and borewells, tapping into the city's aquifers. The city has significant groundwater reserves that have been used for decades, mainly for non-potable purposes.
Despite this long-standing reality, the city's water supply department has persistently ignored groundwater when making policy. This neglect can be attributed largely to the historical dependence on surface water sourced from distant reservoirs, coupled with institutional inertia within the water supply department – an entity predominantly staffed by civil engineers, who typically lack the capacity or expertise required for effective groundwater management.
There has been no acknowledgement of the city's groundwater in all the calculations of Mumbai's water demand and supply – in the Master Plan for Water Supply of Mumbai (1999), the White Paper on Water Supply of Mumbai (2009) or the Regional Plan for the Mumbai Metropolitan Region (2021).
Planning has proceeded under the assumption that groundwater does not exist in Mumbai. In 1994, a committee chaired by expert engineer MA Chitale had pointed out that though Mumbai's groundwater was limited, it could play an important role in the city's future water supply.
The committee had been tasked with planning future water resources for the city and suggesting improvements to the then-existing water supply system. It had specifically recommended that groundwater sources should be developed scientifically for non-potable use and that a dedicated geohydrological unit should be set up within the municipal administration to plan and manage groundwater resources.
The Chitale Committee's recommendations for new dams and desalination projects were taken aboard but the advice on groundwater management was forgotten.
Is limited regulation the solution?
The Central Ground Water Authority, established under the Environment (Protection) Act, 1986, aims to regulate groundwater usage primarily to conserve its level and quality across the country. As a part of this regulatory process, the authority has issued guidelines for tanker operators.
Since the Central Ground Water Authority lacks its own enforcement machinery, Mumbai's municipal corporation has been rigorously enforcing tanker-related regulations: requiring tanker operators and borewell owners to install digital water flow metres, maintain daily records of groundwater extraction, adhere to water quality standards prescribed by the Bureau of Indian standards and ensure the ownership of a 200-square-metre land around groundwater sources.
But Mumbai's municipal corporation itself has done nothing to study or understand the city's groundwater situation or act on the recommendations of the Chitale committee.
Regulating groundwater and the tanker system is vital but this demands a broader perspective: what is the purpose of such regulation and who will it serve? Will it be citizen-centric and environment-friendly?
Will regulation be limited to issuing permits and no-objection certificates and creating a new revenue stream for the groundwater authority, or will it truly conserve groundwater?
The municipal corporation and groundwater authority must articulate how conservation objectives will be achieved. They must also specify how, during periods of water shortage, tanker services will be made available to all citizens fairly and affordably. Otherwise, regulation risks becoming a bureaucratic exercise, disconnected from the real needs of residents.
If the municipal corporation is serious about regulating groundwater use, it must move decisively in that direction: identifying types of groundwater aquifers within the city and their characteristics, demarcating recharge and discharge zones of groundwater, setting up a mechanism to monitor groundwater levels, quality and rate of extraction, and preparing an aquifer management plan.
Establishing a dedicated geohydrological unit within the municipality's water supply division, as suggested by the Chitale Committee, would be a crucial first step.
The mismanagement of groundwater is just one part of the inequitable and inefficient piped water supply in Mumbai.
Mumbai's urban water supply
The crisis triggered by the tanker strike points to deeper and systemic problems of water governance in Mumbai.
According to the Regional Plan for Mumbai Metropolitan Region released in 2021, the city is supplied with 252 litres per capita per day for domestic use alone – enough to meet the needs of the entire population.
Non-domestic water use accounts for only around 10% of the city's total water supply. Yet, large sections of Mumbai's residents depend on private water tankers.
On the ground, the disparity is stark.
Nearly half the city's population lives in slums, where the entitled supply is just 100 litres per capita per day. Many in non-notified slums are disconnected from the formal water network. With enough water allocated to residents, at least on paper, why does the city still face acute shortages and an ever-growing reliance on tankers?
The real issue, then, is not scarcity, but inequity and inefficiency in water distribution due to shortfall in coverage and insufficient pressure and hours of water supply.
Gargai dam and desalination project
Taking advantage of the tanker strike crisis, the Maharashtra government on April 17 hastily approved the long-pending Gargai dam project, with a capacity of 440 million litres per day and cost estimated at a staggering Rs 3,105 crore. Moreover, Mumbai's municipal corporation recently completed the long-standing tendering process for a 200 MLD desalination plant, with an estimated cost of around Rs 3,200 crore.
But Mumbai does not need this dam and desalination project.
The municipal corporation is already investing nearly Rs 26,000 crore to build seven wastewater treatment plants that are expected to supply 2,464 million litres per day after secondary treatment – of this, 1,232 million litres per day will be suitable even for drinking purposes after tertiary treatment.
Three of these plants – at Ghatkopar, Bhandup and Versova – with a combined capacity of 732 million litres per day, are slated to be operational next year, with the rest by 2028. Even if this treated water is primarily allocated for non-potable uses, Mumbai will still have access to surplus water within the next three years.
In light of this, the municipal administration must urgently shift focus from building the new dam and desalination project to fixing water distribution inefficiencies and managing groundwater resources more intelligently.
Groundwater ownership
Another concern that must also be addressed is that under current laws, groundwater ownership is linked to land ownership: whoever owns the land owns the water beneath it.
This legal framework allows private landowners to sell groundwater, often resulting in over-extraction and profiteering. While the government and other public agencies invest in groundwater recharge and conservation efforts, private well and borewell owners reap the benefits without any obligation to contribute to groundwater conservation.
This is particularly evident in Mumbai and other Indian cities, where water shortages have created a thriving private tanker economy.
If groundwater is truly a commons, urgent legal reform is needed to separate groundwater ownership from land ownership. Only then can genuine groundwater conservation efforts succeed, both in urban and rural India.