Mumbai is accustomed to rain, but this monsoon, repeated spells of heavy rainfall have once again exposed the city’s vulnerability. A landslide in Ghatkopar claimed seven lives on August 12, while several parts of Mumbai and its extended suburbs have faced waterlogging, power cuts, disrupted connectivity and essential services.
The disruption is not simply a story of an unforgiving monsoon. It is also about how Mumbai has been built — over natural spaces, along crowded slopes and with increasingly less room for water to drain away. The question is whether the city’s infrastructure and planning can keep pace with a changing rainfall pattern and relentless urbanisation.
Timeline
1912: Mumbai records 838 mm (33 inches) of rain in 24 hours. It remains the city’s single-day rainfall record for decades.
July 26, 2005: Mumbai receives 944 mm (37 inches) in 24 hours. A high tide prevents floodwater from draining into the sea, bringing the city to a standstill. More than 1,000 people die in Maharashtra. Several animals, mostly buffalo, are also killed. About 4,000 cabs, 900 BEST buses and 37,000 autorickshaws are destroyed, while around 10,000 trucks and tempos are forced off the roads. Homes, particularly in low-lying areas, vehicles and businesses are badly affected.
2005 onwards: The BMC steps up flood-mitigation work. Before the monsoon, nullahs are cleaned, rivers are desilted and flood-mitigation plans are implemented. During the monsoon, pumps are used in low-lying areas and automated flood gates are operated. Vasai-Virar and Nalasopara face five days of power disruption, along with problems with connectivity and essential services. Areas once known for agriculture and vegetable cultivation have seen extensive high-rise development. Landslides are also becoming common in the suburbs.
2026: The BMC prepares a Rs 13,000-crore flood-mitigation master plan with IIT Bombay and the National Disaster Management Authority. It proposes 33 strategically located pumping stations, compared with the existing 18 on the Mithi River. The BMC has also announced a Rs 20,730-crore climate budget for 2026-27.
Why is Mumbai becoming vulnerable during the monsoon?
Urban planners point to the way land has been used. Pankaj Joshi, Principal Director of Urban Central, Mumbai, says each inch of land is being converted into either a concrete road or a concrete building. As a result, there is little space left for rainwater to percolate.
When heavy rain comes, most of the water reaches the streets and has to recede through the drainage system. The problem becomes more difficult during high tide, when the sea cannot take the rainwater out. Water then accumulates in low-lying areas, affecting local train services and causing major traffic jams.
Is the amount of rain itself unusual for Mumbai?
Mumbai is a high-rainfall city. Its average annual rainfall is about 2,213 mm (87 inches) in South Mumbai’s Colaba and 2,502 mm (99 inches) in suburban Santacruz. Most of this comes during the southwest monsoon, over about 80 days.
For comparison:
• Delhi: 774 mm over 30 days
• Pune: 720 mm over 49 days
• Bengaluru: 986 mm over 60 days
• Chennai: 1,400 mm over 60 days
Mumbai therefore has a much larger amount of rainfall to handle than these cities, particularly during the monsoon.
Has the rainfall pattern changed?
According to Joshi, yes. Mumbai used to receive more regular rainfall, he says. The pattern is now more erratic. There can be one week of heavy rainfall followed by one or two weeks of a complete dry spell, giving the feeling of a hot summer.
There is also a delay in the arrival of the monsoon. Joshi says the BMC needs to study the changing monsoon pattern and climate change and incorporate these changes into its policies. He also says the civic body’s calendar needs to change accordingly.
What happened on July 26, 2005?
Mumbai received 944 mm of rain in 24 hours, or about 37 inches. The earlier single-day record was 838 mm, recorded in 1912. The flooding on July 26 was particularly severe because there was a high tide at sea, which prevented floodwater from draining into the sea.
More than 1,000 people died. Several animals, mostly buffalo, were also killed in Maharashtra. The flooding destroyed about 4,000 cabs, 900 BEST buses and 37,000 autorickshaws. Another 10,000 trucks and tempos were forced off the road.
Homes, mainly in low-lying areas, were damaged. Vehicles and businesses were also affected.
Why does even affluent Juhu flood?
Juhu is one of Mumbai’s better-known and more affluent neighbourhoods, yet heavy rain can still leave parts of it submerged. Amitabh Bachchan’s residence has itself been affected during heavy spells, including rainfall of around 200 mm.
The episode illustrates a wider problem: even areas with expensive real estate and established infrastructure are not immune when large volumes of rainwater cannot be drained away quickly.
What has happened to Mumbai’s natural spaces?
Urban planner Shirish Patel has argued that a city has to evolve in itself to remain livable and vibrant. He has cited London, which was developed on the banks of the Thames. In the 19th century, the river was among the filthiest and most polluted rivers. The city’s planners cleaned the river and developed the city around its legacy and strength.
Mumbai, Patel’s argument goes, has not always treated its own geography in the same way. It is an island city formed by linking seven separate islands. Its culverts, rivers, open spaces and bay areas are necessary parts of the city’s functioning. Over time, many of these spaces have been affected as more high-rises and commercial and residential complexes have been built.
What does all the concrete mean for rainwater?
Joshi says there is simply less land where rainwater can go into the ground. When the rain falls heavily, it comes onto the streets and has to be carried away. This becomes particularly difficult when high tide prevents the water from flowing into the sea.
Concretisation also affects trees. Joshi points out that the area around trees is increasingly covered with concrete, choking the trees and weakening them. During strong winds in the rainy season, trees with loosened roots can fall, damaging vehicles and sometimes killing people.
Why is Nalasopara particularly vulnerable?
Nalasopara and the wider Vasai-Virar area were once agricultural areas. Joshi points out that Nalasopara has a long history and was known for its fresh vegetables, which were supplied to Mumbai.
During the Portuguese period, small bungalows known as wadis were developed, with large backyards where vegetables could be grown and open spaces where people could play. Much of that land has since been developed into a large township with high-rise buildings.
What was missing when the area was developed?
According to Joshi, a proper stormwater drainage system was not developed alongside the construction. He contrasts this with Mumbai, where drainage infrastructure had been developed during British rule.
During heavy rainfall of around 650 mm, the region, now home to about two million people, was submerged. Vasai-Virar and Nalasopara were cut off from power supply, connectivity and essential services for five days.
Joshi describes the situation as one of the worst Nalasopara had faced in recent times. He calls it a man-made disaster because agricultural land was converted into residential and commercial development without adequate thought to drainage and the natural movement of water. The land was covered with concrete roads and service roads as well as buildings.
Where have Mumbai’s open spaces gone?
Architect Milind Samel says land in Mumbai has become so valuable that it has been exploited for commercial purposes. Earlier, buildings had open spaces around them, used for parking and gardening but also providing ground-level open areas.
Samel says that arrangement is disappearing. Developers now provide podium gardens and playgrounds on building rooftops, but these do not provide the same ground-level open space.
Cities need open and recreational grounds because they are their “breathing spaces”, Samel says. They provide places for water to recede, help filter the air and give children places to play. His view is that rulers and urban planners need to go back to the drawing board if they are serious about the future of their cities.
Is Mumbai’s development also uneven?
Pankaj Kapoor, MD of real estate tracking firm Liases Foras, says much of Mumbai’s development is elite-centric. Development is concentrated in South Mumbai, where there are better and wider roads and amenities.
A majority of the population, however, lives in the suburbs and has to travel for several hours to reach workplaces. Kapoor says that if policymakers and bureaucrats lived in the suburbs rather than in the town area, they would understand better what the common man goes through.
He believes that could help bring practical solutions. He also says Mumbai has increased its “virtual space” — the built-up capacity and intensity of development — without adequate supporting infrastructure such as roads and drainage.
What does Sanjay Ghadi’s five-hour commute show?
Mumbai deputy mayor and Shiv Sena corporator Sanjay Ghadi wrote to BMC chief Ashwini Joshi, requesting allotment of a bungalow near his workplace in South Mumbai. He said he was compelled to spend five hours commuting every day from his residence in Dahisar to the BMC headquarters in South Mumbai.
Ghadi said the daily commute was causing mental and physical distress and affecting his efficiency at work.
His complaint illustrates a wider problem: a large population lives in the suburbs while many workplaces remain concentrated in parts of South Mumbai, putting enormous pressure on transport infrastructure and forcing long daily commutes.
Why does Kapoor call Mumbai’s development a mismatch?
Kapoor says development in the city has not always been matched by infrastructure. He gives the example of the old textile mills. After the mills closed, their land was redeveloped into commercial complexes. Now, he says, too much commercial space has been created, resulting in a business problem.
Owners of these lands are now looking at developing them into residential buildings. For Kapoor, the changes show how the city is being developed without a consistent long-term plan.
He says the immediate intention often appears to be making money, while whether the development suits the city in the long term receives less attention. He describes Mumbai as having big-city development but says this does not necessarily make it a world-class city. His phrase is: “big cities, but they are dying cities.”
What does the BMC do to control flooding?
The BMC has two sets of flood-related measures. Before the monsoon, it cleans nullahs, desilts rivers and carries out work under its flood-mitigation plans.
During the monsoon, it uses water pumps, particularly in low-lying areas, to remove excess water. Automated flood gates are also used. The pumping stations are meant to remove excess rainwater from areas where water accumulates.
What is the Rs 13,000-crore flood-mitigation master plan?
The BMC’s plan has been developed jointly with IIT Bombay and the National Disaster Management Authority. The objective is to ensure that air, rail and road transport are not disrupted and to reduce the duration of waterlogging.
It proposes 33 strategically located pumping stations, compared with the existing 18 on the Mithi river. The BMC has separately announced a Rs 20,730-crore climate budget for 2026-27 to make Mumbai more climate-resilient.
Are pumping stations enough?
Joshi says they are a short-term solution. For the longer term, he proposes major holding tanks at several locations. The idea is to hold excess rainwater during high tide, when the sea cannot take the water, and release it during low tide.
He also says Mumbai should stop turning every inch of land into concrete. Open spaces should be retained wherever possible. The city’s rivers, many of which have been reduced to small nullahs, should be rejuvenated. As many open spaces as possible should be protected for future generations.
What does Milind Samel suggest for the city’s future?
Samel says urbanisation is increasing and the majority of the population is becoming concentrated in cities and their central parts. He believes this needs to be decentralised.
His question is why people in Mumbai should be forced to travel five or six hours every day and why business districts cannot be moved towards the northern wards instead of remaining concentrated in the south.
If more business activity moves northwards, he says, people’s travel time would fall. They would have more time to spend with their families and could face fewer mental and other problems associated with long travel. He also believes this could help stabilise housing prices, allowing people to buy homes or at least live in more livable places.
What is the broad issue the planners are pointing to?
The concerns raised by the planners go beyond flooding. There is less open land for rainwater to percolate. Natural waterways have been altered. More construction has taken place on land that was earlier agricultural. Drainage has not always kept pace with that construction. At the same time, jobs remain concentrated in parts of South Mumbai while a large population lives in the suburbs, creating long daily commutes.
The monsoon brings these weaknesses together in a highly visible way: waterlogging, traffic disruption, problems with local trains, fallen trees, power cuts and disruption of essential services.
The proposed measures — more pumping stations, holding tanks, protection of open spaces, river rejuvenation, changes to monsoon planning and decentralisation of business districts — address different parts of the problem.
For Mumbai, therefore, the challenge is not simply how to deal with more rain when it falls. It is how to build a city that leaves enough room for the water to go.