The intertwined fate of Navi Mumbai’s Kolis and the Kasardi river

Editor's Note: The last two decades have been witness to the rapid and devastating march of unchecked urbanisation and climate change in India’s cities. Among the first victims of this change is freshwater and access to it—from rivers which sustained local ecosystems, to lakes and groundwater which quenched the thirst of residents. In this series, the Good Food Movement examines the everyday realities of neglect and pollution. It documents the vanishing and revival of water bodies, and community action that made a difference.

At 2 PM every afternoon, 53-year-old Gajanan Budhaji Kadke navigates a narrow, unpaved road in his autorickshaw. This hidden path, invisible from the Mumbai-Satara Highway unless one is specifically seeking the Roadpali fishermen at the Taloja and Kasardi river confluence, leads to his home. Past a handful of makeshift houses, standing at the very end is Kadke's dwelling; it bears a silent visual memory of his past–the fishing nets that were once essential to his livelihood, now hang idly like relics on his shed and the fence guarding it. What led this former fisherman to cast aside his nets and take up driving an auto-rickshaw?

The Kasardi or Kasadi river, spanning 20 km in Navi Mumbai, is more than just a water body—it’s a cultural and ecological cornerstone for Taloja’s (approx) 11,000 residents. Historically, the river was a fishing haven with nearly 45 fish varieties–including mackerel, shark, tilapia, bombay duck and other saltwater fish. The Koli community in areas such as Roadpali, Taloja, Kopara, and Navade have been traditionally dependent on the river and Panvel Creek for their livelihood.

However, steady contamination of the river has altered their very existence. Untreated industrial and domestic waste disposed in the Kasardi river has decimated fish populations, robbing the Koli community of their primary income source over the years.

“As children, we used to bathe and frolic in the river. Boats used to return full of fish, but now, you won’t be able to catch a single one.”

“A significant primary source of pollutants is the extensive old habitation directly discharging sewage into the Kasardi river. The Maharashtra Industrial Development Corporation (MIDC) has provided stormwater drainage outlets into the river. Beyond the MIDC area, new industries located on the banks of the river in nearby villages like Valap, Tondare, Pendhar and Diwale are also contributing to pollution,” says Dr Vikrant Hemant Bhalerao, Sub-regional Officer at the Maharashtra Pollution Control Board (MPCB), Taloja.

MIDC was established by Maharashtra state in 1962, leading to the quick acquisition of land in Navi Mumbai, which had been newly developed as a satellite town at the time, by the City and Industrial Development Corporation (CIDCO). CIDCO now reports 5,375 industrial plots and a total of 3,928 industries in the industrial belt along Navi Mumbai.  “In a few areas, there is a direct flow diversion of the Kasardi owing to illegal dumping and development by the industries located outside MIDC,” Dr Bhalerao explains.

The re-writing of a community livelihood

Dashrath Koli, now in his sixties, quit fishing 12 years ago after casting nets for three decades. “The arrival of the companies by the riverside led to chemicals leaching into the Kasardi. Over the years, it became increasingly difficult for us to catch fish, so I had to quit the profession. It completely ended our livelihood,” he says. Ever since, he’s spent his days at home in Kopara gaon, Kharghar. When asked if he considered pursuing other work, he rues, “Nobody is willing to hire a man above 60.” 

Koli’s story is resonant and familiar to many in the community. His household of six is reliant on his son's income from driving an auto rickshaw, as well as the earnings of his wife, Baby, who is a fishmonger. Baby buys catch from the Taloja fish market and sells it in Kopara gaon. She earns roughly Rs 500—and occasionally, Rs 800—per day. As she recalls childhood memories, Baby says, “I used to accompany my father to the riverside...it was possible to drink its water back then.”

Gajanan Kadke’s memories of the Kasardi are as clear as the river once was. “As children, we used to bathe and frolic in the river. Boats used to return full of fish, but now, you won’t be able to catch a single one.” A dip was observed in fishermen’s incomes over the past 15 years, when their monthly earnings amounted to only Rs 4,000–5,000—even when the city received heavy rainfall. Previously, they could easily earn Rs 10,000–Rs 15,000 per month. It was only the COVID-19 pandemic and subsequent shutting down of factories by the river that changed their fates: they were able to catch hundreds of kilos of fish in this period.

To combat the lack of fish in the Kasardi, Koli fishermen have constructed small, man-made ponds to breed and catch fish across the city. These ponds are part of a traditional fishing practice, offering a localised ecosystem where fish can thrive and the community can ensure a steady supply. The ponds also help filter out pollutants and allow fish to spawn. In this area, the fishermen’s traditional fish ponds are supported by the Kasardi creek–which in itself is surrounded by spongy mangroves and mudflats. As a consequence, during high tide, the polluted water from the creek flows over, killing the fish being bred in the small ponds. The pond next to Kadke’s dwelling sometimes faces a similar fate. When the monsoon starts, the chemically infused water flows further into the river, polluting these ponds with toxic effluents and ultimately poisoning the aquatic life–before the eggs even mature.

Ultimately, financial strain pushed Kadke to switch professions. Beyond its impact on fishing, the Kasardi also limited Kadke’s ability to work in sand quarries. Diving into its toxic waters affected his esophagus, for which he had to undergo surgery twice.

The stark difference in the cost of living across five decades is hard for him to ignore. “My earnings from driving [an auto] are not sufficient to run the family, pay bills and meet our daily and health expenditures. On the other hand, our parents were able to build a home and the foundation for our future as fisherfolk solely by fishing,” he says. For the Kadkes, a home of their own remains a faraway dream in a city that is only becoming more expensive.

Also read: Bengaluru is fated to run out of water. When will the crisis hit?

Wading through murky waters

Presently, a significant chunk of the river–called Ganesh Ghat–is choked by water hyacinth, which can cut off oxygen supply for aquatic life, block water flow and increase sedimentation, along with algae formation. This is not all: the river changes colour as it meanders through various locations. It turns a caustic orange from the visible chemical effluents, plastic wrappers and clothes choking behind the MIDC area in Taloja, to a grassy green from the algae formation and solid waste dumping near Ganesh Ghat; and then a murky brown colour in some parts. The river has also turned milky white at times–due to the formation of chemical foam on its surface.

In fact, in 2017, an unusual concern made the rounds in Taloja: suddenly, the residents spotted a group of ‘blue-coloured’ dogs. The sight was bizarre enough to spark concern internationally, as well. The unusual coloration was initially attributed to the dogs wading in the heavily polluted Kasardi, where untreated industrial waste–including blue dye from a nearby detergent factory–was being dumped. It was also considered possible that they were exposed to dye directly at the factory site.

This is not all: the river changes colour as it meanders through various locations.

Beyond just the visual discoloration and waste dump, the river also emits a foul odour and being in its proximity can sometimes lead to irritation in the eyes.

Community and legal interventions

Said to be Mumbai’s earliest inhabitants, the Kolis sensed that change was imminent when the plan for expanding Mumbai—then Bombay—into the Thane district was initiated in the 1970s. Industries that processed chemicals, fish, pharmaceuticals as well as machinery factories, started developing rapidly and haphazardly around this expanded belt. Newer townships mushroomed. The first to bear witness to this silent devastation were the fish. Species like rawas, prawns, and pomfret that were once plentiful in the rivers and creeks along suburban Mumbai began to disappear.

In 2010, the Kasardi River was already affected by toxic effluents from the Taloja Industrial Belt. Studies revealed alarming levels of heavy metals—chromium, cadmium, lead—far exceeding safe limits, threatening aquatic life and the Kolis’ work. By 2013, the river was declared “unsuitable for fishing” with fish varieties plummeting from 45 to nearly none.

“Machli hai toh hum hai,” says Kadke. If the fish are here, then we are here. He reiterates that fishing is not merely a profession, but a pact between the Koli community and a river that has sustained them for generations. 

In 2016, activist Yogesh Pagade and Koli fishermen protested the inaction of the Maharashtra Pollution Control Board in the face of the Kasardi’s rapid degeneration. Even the Taloja Industries Association joined the fishing community to protest the release of untreated waste from the Common Effluent Treatment Plant (CETP) in Taloja that was polluting the river. Their water tests confirmed Biochemical Oxygen Demand (BOD) levels at 80 milligram per litre (mg/L), 13 times above safe limits, killing fish and mangroves. BOD determines the concentration of oxygen required for aquatic life to survive in the water. According to the Central Pollution Control Board (CPCB), BOD levels beyond 3 mg/L and 6 mg/L are unsuitable for human consumption and fish species respectively. The test also concluded high levels of chloride that is toxic for aquatic life and the vegetation.

The MPCB responded in January 2017, ordering a 40% water supply cut to Taloja industries until online pollution monitoring was implemented. In fact, the Taloja CETP’s poor performance was rated the worst among Maharashtra’s 25 units—persisting due to overloaded capacity and unskilled labour. In November 2017, 10 CETP members were booked for releasing untreated waste, but the enforcement of norms faltered. Dr Bhalerao informs, "Since October 2024, the CETP has complied with the norms and guidelines set by the Ministry of Environment, Forest and Climate Change (MoEFCC) and MPCB.”

But the Koli community’s plight still prevailed–in fact, by 2018, it escalated. A 90% drop in fish catch forced many like Gajanan Kadke and Dashrath Koli to abandon fishing. This is when the National Green Tribunal (NGT) intervened, fining the CETP a collective Rs 15 crore for environmental damage and ordering for 371 polluting units to be closed. The case, challenged in the Supreme Court, remained sub-judice. In 2019, four factories shut down, but activist Arvind Mhatre–the complainant who brought the case to the NGT–criticised the MPCB’s lax oversight. Beyond just the chemical effluents, the river was also the victim of illegal debris dumping near the Taloja CETP in 2018.

In 2020, MIDC upgraded the CETP to treat 23 Million Litres per Day (MLD) of waste, yet untreated effluents persisted; locals reported health hazards from toxic fumes. Further, illegal tanker dumping worsened the crisis. In March 2023, IIT-Bombay submitted a report to MPCB regarding the restoration of the river, following the NGT’s 2019 orders. It highlighted the presence of chemicals in the river and warned of several health hazards if consumed. The report recommended construction of sewage and storm water drainage systems and diversion channels, asking industries by the river bank to treat their effluents, and coordination between agencies to prevent discharge of untreated waste. 

The effort continued into the next year. The NGT had given specific direction to the industry units on curbing pollution, but in vain. Their final recommendation to Mhatre was to approach the Supreme Court of India. In response, the apex court, on July 24, 2024, ordered the MPCB to submit a detailed affidavit within three weeks regarding the chemical pollution in the Kasardi caused by industrial effluents from approximately 900 factories in the Taloja MIDC industrial belt. 

According to the Water Quality Status Report of Maharashtra 2022-23, the BOD level of the Kasardi river stands at 30 mg/L, which is 10 times higher than the MPCB/CPCB's safer limit. In that year, samples of Kasardi river were not collected for seven months. 

Rejuvenation plans 

More recently, in May 2025, the Panvel Municipal Corporation (PMC) launched a rejuvenation project for the Kasardi river to combat severe pollution. Following the inspection on May 14, led by Additional Commissioner Ganesh Shete, authorities identified tankers illegally releasing chemicals at Ganesh Ghat in Navade and Tondare village, prompting immediate action. Shete has asked the CETP and MIDC to help process the chemical effluents already released into the river. 

With over Rs 17.4 crore in funding, the project includes constructing check dams and gabion walls, which are mesh baskets filled with stones or rocks; they prevent soil from being eroded away with flowing water. The project also aims at diverting contaminated water to the Common Effluent Treatment Plant, and installing solar-powered CCTV cameras for surveillance. 

“Machli hai toh hum hai,” says Kadke. If the fish are here, then we are here. He reiterates that fishing is not merely a profession, but a pact between the Koli community and a river that has sustained them for generations.

“After the rainy season, the water that flows into the Kasardi river is primarily sewage and water used to clean floors; it's not a continuous source of water as it is a rain-fed river. Removing pollutants is not the only answer; ensuring the continuous flow of water will help in the rejuvenation of the river,” says Dr Bhalerao.

Lately, there has been a lot of emphasis on the establishment of Sewage Treatment Plants (STPs) under several missions like Atal Mission for Rejuvenation and Urban Transformation or AMRUT, Swachh Bharat Mission, and Jal Jeevan Mission, because sewage water can be reutilised for other purposes if properly treated. “An important issue to be addressed beyond just industrial effluents is domestic sewage water, with dysfunctional or defunct STPs, or a few number of STPs; issues to be pondered upon by all authorities,” emphasises Dr Bhalerao.

He further adds, "We will be working on different aeration mechanisms along with building green bridges, which will actually increase the oxygen content in the water. It is also advised that apart from the rainy season, all the MIDC stormwater outlets to the Kasardi river will be completely blocked or diverted to the CETP. We are also planning to install CCTV cameras after every 250 metres. Few social miscreants are engaged in illegal discharge of industrial waste disposal in and around MIDC, for which local police and MIDC need to improve their vigilance.”

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Edited by Neerja Deodhar and Anushka Mukherjee

Produced by Nevin Thomas and Neerja Deodhar