Why the Wetlands of Mumbai Matter — And Why Their Protection is an Urban Imperative

Bombay is a city born out of wetlands. Long before it became a dense urban and financial centre, the region consisted of intertidal mudflats, mangrove forests, creeks, marshes, and low-lying floodplains. These wetlands shaped the city’s geography, regulated its water systems, and supported a complex web of life. Yet, as Mumbai expanded, these very ecosystems were systematically reclaimed, filled, and built over in the name of development.

Today, the consequences of this ecological erasure are increasingly visible. Frequent flooding, deteriorating water quality, rising urban heat, and loss of biodiversity are no longer abstract environmental concerns but everyday realities. Wetlands, often misunderstood as unusable or disease-prone land, are in fact among the most effective natural systems for maintaining environmental balance in a coastal megacity like Bombay.

Wetlands as Natural Flood Buffers

Mumbai’s annual monsoon flooding is often attributed to extreme rainfall. However, the deeper issue lies in the destruction of natural drainage systems. Wetlands function as sponges, absorbing excess rainwater and releasing it gradually, thereby preventing sudden surges into rivers and drains. Dr Aparna Phadke, a Professor at the University of Mumbai, notes, "These wetlands act as carbon sinks, and also as natural flood barriers". 

“Wetlands act as a major ecological support system, especially for a city like Mumbai. Since Mumbai experiences severe flooding during the monsoon, wetlands play an important role in absorbing excess rainwater and thereby reducing flood intensity,” says Tanishka Darade, who is currently pursuing her MA in Geography (2nd Year), specialising in Climate Change and Disaster Management.

The city’s coastal and low-lying geography further amplifies this dependence. As Tushar Dalvi, who completed his education inMSc LifeSciences (Environmental Biotechnology) from the University of Mumbai explains, “I think preserving Mumbai’s wetlands is important because of the geography of the city, they protect the city acting as a natural shield against floods and heavy rains. They act like sponges that absorb excess water.”

Mangroves form a critical part of this defence system. According to Sandesh Lad, founder of Let’s Go Outdoors, “Mumbai is blessed with one of the largest mangrove covers in the country for a highly developed city. Mangroves, an essential wetland ecosystem, function as Mumbai’s natural coast guard.” He adds that they act as a protective barrier against tidal movements and storms while significantly reducing erosion.

Ecological Balance and Biodiversity

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Wetlands are not barren or stagnant spaces; they are among the most productive ecosystems in nature. They support a wide range of plant and animal life and form the foundation of coastal and marine food chains. “Wetlands are rich in biodiversity, supporting diverse plant and animal life, including migratory birds,” saysDarade.

Bombay’s wetlands lie along major migratory routes, making them crucial resting and feeding grounds for birds. Sagar Paranjpe, wildlife filmmaker, zoologist and creator, highlights this vividly: “Wetlands in Mumbai aren’t just water bodies, they are a stage for nature to express its beauty. Thane Creek’s flamingos are a prime example of the beautiful biodiversity it supports.”

Sandesh Lad further explains the ecological richness of marshes and mangroves: “Marshes are nutrient-rich environments, creating ideal conditions for a wide variety of species, including fish, crustaceans, amphibians and birds. As a result, these ecosystems are exceptionally rich in biodiversity.”

Dr. Phadke states, "It is important to document these wetlands, register them with the guidance of the National Wetland Agency and be vigilant on the encroachment. She says, "We thoroughly documented the flora and the fauna along with water testing. Other than that, we conducted a bird-watching activity to create awareness amongst the youth. The involvement of the students made this a success."

Darade, who was also a part of this project, mentions, "The experience was extremely good. We identified and marked the flood line of the wetland and documented the surrounding flora and fauna. Interacting with experts on-site enhanced our understanding and provided valuable practical knowledge about wetland ecosystems and their importance."

Water Filtration and Environmental Health

Wetlands play a vital role in maintaining water quality by filtering pollutants and regulating sediment flow. They also function as natural water filters by trapping pollutants and improving overall water quality.  Elaborating on this process, Sagar Paranjpe explains, “In the case of heavy rains, they stop excess water runoff from entering rivers directly. They slow the pace of water flow, allowing the vegetation to ‘clean’ the water via absorption. They also allow silt and other sediment to settle before the water goes into the rivers or the sea, promoting a healthy ecosystem. While all of this happens, they actively recharge the groundwater.”

In a city where rivers often double as drains, the loss of this natural filtration system has serious consequences for public health and water security. Wetlands are frequently blamed for disease outbreaks, particularly due to stagnant water. However, ecologists argue that healthy wetlands maintain water movement and ecological balance.“Wetlands help keep our environment healthy and balanced. They clean our water, improve the air we breathe, and help cool the city,” says Tushar Dalvi. It is degraded and polluted wetlands—not protected ones—that pose risks. The destruction of wetlands often creates the very conditions they are accused of causing.

Wetland Protection in India and Mumbai

India has taken steps toward wetland conservation through the Wetlands (Conservation and Management) Rules, 2017, which restrict activities such as reclamation, construction, and waste dumping in notified wetlands. India is also a signatory to the Ramsar Convention, under which ecologically significant wetlands receive international recognition.

In Mumbai, initiatives such as the Thane Creek Flamingo Sanctuary’s Ramsar designation and the work of the Maharashtra Mangrove Cell have helped protect certain mangrove belts and intertidal zones. Mangroves in several areas have been granted forest status, offering legal protection. However, these measures remain limited in scope and uneven in enforcement.

The students of the Geography department, under the guidance of Dr. Aparna Phadke, mapped the wetlands of Mumbai

Gaps, Threats, and the Need for Action

Despite existing policies, wetlands in Mumbai continue to face threats from real estate pressure, infrastructure expansion, pollution, and encroachment. “The greatest threat to wetlands and mangroves today is unchecked greed,” says Sandesh Lad. “In the pursuit of profit, land is often acquired for luxury housing, commercial projects and recreational facilities, leading to the destruction of these sensitive ecosystems.”

He cites Navi Mumbai as an example, where proposals to convert wetlands into a golf course highlight the conflict between short-term economic gains and long-term environmental security.

Scientific research and monitoring remain essential. As Dalvi notes, “Currently, we are working on understanding ecology-rich intertidal zones of some regions of MMR, searching for various pollution indicators and changing dynamics of these delicate ecosystems. Also working with college students for capacity building to tackle environmental issues.”

Citizen Responsibility and Sustainable Engagement

Public participation plays a critical role in conservation. “As citizens, we can protect wetlands by being responsible and not polluting them. We can spread awareness, participate in citizen science initiatives, and support conservation efforts,” says Dalvi.

Lad emphasises experiential learning and responsible tourism. “We have been organising guided appreciation walks along the edges of mangroves and wetlands, enabling participants to observe biodiversity without disturbing the habitat,” he says, adding that non-motorised boat rides with local fishermen can foster deeper connections while aligning with initiatives like MISHTI.

“When people feel that these ecosystems are their own, their perspective and commitment to conservation changes profoundly,” he adds.