Mumbai’s Sinking Safeguards

As wetlands disappear beneath concrete, Mumbai’s resilience to floods and climate shocks is being severely undermined.

Every monsoon season, Mumbai falls into a similar pattern. The rain comes down hard, flooding streets, stopping trains, leaving neighbourhoods wet for days and officials playing catch-up. Heavy rains and climate change are often blamed for these disruptions, but an equally important, but far less talked about, factor is the decline of the city’s wetlands.

Threatened Ecosystems

Wetlands are among the most important natural assets of Mumbai, but also among the most threatened ecosystems. This interconnected web of mangroves, marshes, mudflats, salt pans and floodplains used to absorb excess rainwater, manage flooding, support biodiversity and protect coastal peoples from extreme weather events. Many of these natural buffers are already being eroded by increasing urbanisation, infrastructural growth and land reclamation.

The destruction of wet lands, with the growth of Mumbai, is more than an environmental issue. It is now a question of urban resilience, public safety and the long-term viability of the city.

No drainage system can be a substitute for the function of wetlands. They act like natural sponges in heavy rain, absorbing and storing excess water that they can release slowly. This diminishes and slows the amount of runoff that flows into rivers, drains and low-lying urban areas. This function is extremely important in a city like Mumbai which receives more than 2,000 mm of rains every year and is increasingly becoming prone to extreme weather events.

The July 2005 floods were a brutal reminder of the dangers of disturbing natural drainage systems. Over 900 mm of rain fell in less than 24 hours, killing hundreds and paralysing the city. The rain was an extraordinary amount, but scientists said decades of encroachment on wetlands, mangroves and floodplains had reduced Mumbai’s natural ability to absorb water. Nearly two decades later, the warning still holds true.

The population growth and economic significance of Mumbai have put enormous pressure on land resources. Wetlands are often perceived as unused or underutilized land, not as critical ecological infrastructure. They have therefore become easy targets for reclamation and development. There have been big changes over the years in some parts of the city that are rich in wetlands. Land in salt pan areas has been proposed for housing and development projects. Legislation has protected mangroves, but they have still been encroached upon. Roads and building and urban expansion have disrupted creeks and marshlands.

All those actions appear justified in their own right, but the cumulative effect is huge. Every wetland that is lost diminishes the city’s capacity to deal with heavy rain, rising sea levels and storm surges.

Wetlands disappearing anyway would be a problem. Climate change has made it only more acute. Scientific research suggests that heavy rainfall events are becoming more frequent and intense in many parts of India. Coastal cities such as Mumbai are also at increased risk from rising sea levels and cyclonic activity in the Arabian Sea. The increasing sea level and shrinking wetlands are a potentially dangerous combination. As climate-related threats become increasingly dire, natural coastal ecosystems that once provided protective barriers are disappearing.

This means that future floods may be worse, with more people affected and greater economic damage. The effects extend beyond infrastructure. Businesses, transit systems, schools and healthcare facilities are disrupted by flooding. The greatest burden is on informal settlements and low-income communities as they are more often located in vulnerable locations and have limited access to protective infrastructure.

Mumbai has a host of wildlife including fish, migratory birds and other species of wildlife in its mangroves and marshlands. They help local livelihoods by maintaining fisheries and other economic activities. Wetlands also improve water quality by filtering out pollutants and trapping sediments. They also help regulate local temperatures, which is useful for climate adaptation in a metropolis increasingly under heat stress.

Most importantly, they contain a lot of carbon. Mangroves are among the planet’s most effective carbon sinks and therefore valuable allies in the fight against climate change.

Incorrect Argument

The wetlands argument is often cast as a battle between development and environmental protection. This framing is incorrect. The question is not whether Mumbai should grow but how. Cities need housing, transportation infrastructure and economic opportunity. But considering wetlands as wasteland ignores the economic importance of the environmental services that they provide. Extreme weather events cause huge financial burdens such as flood damage, emergency response costs, infrastructure repairs, and productivity losses. Wetland protection is also often cheaper than using only constructed solutions to address flooding and climate threats.

Urban planners across the globe are increasingly recognising the importance of integrating nature-based solutions into city development strategies. Wetlands, mangroves and green spaces are viewed as critical infrastructure, not impediments to development. Mumbai could do with something similar.

Wetlands protection is not just an environmental issue. It is also a governance issue. Commonly, multiple organizations share responsibilities such as urban planning, environmental control, coastal management, and infrastructure development. Coordination gaps can lead to conflicting priorities and fragmented decisions.

Wetlands and mangroves are protected by law, but enforcement is uneven. If Mumbai is serious about preserving its remaining wetlands, it will need better collaboration between its institutions, better land use planning and tougher enforcement.

Mumbai stands at an inflection point in its urban development journey. The city is really investing in infrastructure and planning for growth. At the same time, climate change increases the risks associated with extreme weather events.

These two realities need to be dealt with together. The wetlands that exist in Mumbai are not wastelands but a natural infrastructure that helps make the city work. Protecting them should be seen as investing in resilience, not as a limitation of progress. For with every flood, we are reminded that climate problems cannot be met with concrete alone.

(The writer is a columnist and climate researcher with experience in political analysis, ESG research, and energy policy. Views personal.)