Uncertainty Around Future Of Mumbai’s Last Green Lung

• The Brihanmumbai Municipal Corporation’s draft zonal master plan for the Eco-Sensitive Zone of Sanjay Gandhi National Park has raised concerns among citizens, environmentalists, and tribal communities.
• The plan was released only in English with a 30-day window for objections, excluding many Marathi-speaking and tribal residents.
• Experts warn that the proposed plan could further fragment Mumbai’s green lung. Tribal groups fear displacement and erasure of their rights.

The Brihanmumbai Municipal Corporation (BMC) recently released a draft plan that could reshape the future of the green belt surrounding the Sanjay Gandhi National Park (SGNP), sparking objections from citizens, environmentalists, and tribal communities that live along the park’s edges.

While the draft claims to conserve SGNP’s eco-sensitive buffer, many argue it repackages real estate, commercial, and tourism projects as “regulated” growth, directly threatening Mumbai’s last green lung. SGNP is an expanse of hills, lakes, streams, and forests that supports leopards, deer, and a vast variety of flora and fauna. It spreads over 100 sq. km. over Mumbai and Thane districts.

This Draft Zonal Master Plan (ZMP) for the park’s Eco-Sensitive Zone (ESZ), was prepared by private firm Tandon Urban Solutions and made public on September 10, with a month’s window for suggestions and objections.

The Ministry of Environment, Forest, and Climate Change issued a notification on December 5, 2016, defining the Eco-Sensitive Zone (ESZ) around Sanjay Gandhi National Park (SGNP). Following this, the Government of Maharashtra delineated and published the ESZ boundaries. In 2022, the Supreme Court further directed that every national park and wildlife sanctuary in the country must have a mandatory eco-sensitive zone. Now, nine years after the first notification, the BMC developed a plan for this ecologically fragile area.

However, it was released only in English, with a 30-day window to respond, limiting participation, specially from the local residents who would be most impacted by the plan.

Adding to the complexity, the draft overlaps with existing planning documents. An activist Amrita Bhattacharjee, who works with tribal communities in Aarey Milk Colony, adjacent to the national park, explains, “The Development Plan (DP) 2034 under the MRTP Act 1966 for the urban local bodies already exists, which also covers the area of ESZ of SGNP. This means that for us to analyse this zonal draft plan, we have to cross-check the ESZ mapping in this draft with the one in DP 2034. This is a tedious job.” Given this, environmentalists, tribal communities, and activists had asked for more time, from 60-120 days, to properly review and submit their suggestions. The initial public notice also lacked contact details, forcing many to send printed letters instead of online submissions.

Applicants also faced an exhausting run-around between municipal offices. While the SGNP’s ESZ plan is being executed by the BMC, the park itself spreads beyond Mumbai district to parts of Thane and Palghar district which have their own municipal corporations.

Yeoor-based activist Nishant Bangera says the Thane municipal authority refused to accept objection letters, redirecting his team member to the BMC office. “The BMC combines the applications that are similar in text or multiple letters submitted by one person into one objection letter, which unjustly affects their petition counts,” he says.

While a BMC official reports 1,500 applications, the citizen-led Save SGNP campaign has over 30,000 petition signatures. Aarey tribal gram sabhas have also demanded the release of the draft in Marathi and an extended review period.

Bigger concerns

The zonal plan divides the Eco-Sensitive Zone (ESZ) surrounding Sanjay Gandhi National Park (SGNP) into three parts: ESZ-1 (Settlement Zone), ESZ-2 (Regulated Development Zone), and ESZ-3 (Ecologically Fragile Zone), based on a vulnerability index that assigns scores to each area within the ESZ.

The ESZ covers an area of almost 60 square kilometres, which has been divided into three zones, each with a list of permitted activities. The vulnerability index factors in parameters such as human-animal interactions, flood-prone areas, soil quality, and the presence of flora and fauna, etc.

Under this framework, ESZ-1 largely aligns with the existing Development Plan 2034, allowing for full-scale development, including residential, commercial, institutional, and industrial projects. Crucially, all activities permitted in ESZ-1 are also allowed in ESZ-2, unless specifically prohibited — raising concern since ESZ-2 areas score higher on ecological vulnerability.

Urban conservationist and associate professor at Kamla Raheja Vidyanidhi Institute for Architecture and Environmental Studies, Shweta Wagh points to a fundamental flaw: “There are no clear guidelines on how critical ecosystems and habitats in ESZ-1 and ESZ-2 will be conserved. Some areas in Aarey have also been zoned as ESZ-1, which permits high-intensity development. These are important catchments and hydrological zones. Any construction there will affect groundwater percolation and increase flood risks downstream. The proposed zoning is based on a faulty analysis that undermines the ecological sensitivity of the buffer zone.”

For instance, the northern end of the Vihar Lake catchment, recognised as a natural area in the DP 2034, has now been marked as ESZ-2, where several construction activities are permitted. According to that plan, about half of the total ESZ has been opened to “promoted” and 42.8% to “regulated” activities as per the existing land use survey.

Environmentalists fear that allowing such development under the label of “regulated” activities will fragment existing ecosystems, forest patches, and lake catchments. “ESZs should not be opened up for development based on the same parameters that apply to the rest of the city,” Wagh adds. “One would need to only allow or emphasise uses that are compatible with conservation.”

ESZ-3, meanwhile, is designated for areas containing ecologically rich features whose preservation is of utmost importance.

Experts have also questioned the methodology behind the vulnerability mapping that guided this zoning. The biodiversity survey itself, as the draft admits, suffered from accuracy gaps due to “security and wildlife-related restrictions.”

Urban practitioner and adjunct associate professor at the School of Environment and Architecture, Abhijit Ekbote says, “The methodology is based on vulnerability, not sensitivity. Even the ecological assessment wasn’t conducted through ground-level studies, but rather largely through remote sensing. A more robust evaluation could have used the parameters and methods prescribed in the Pronab Sen Committee report (2000) on identifying ecologically sensitive areas.”

Concern around lives

For tribal residents who have lived in the Sanjay Gandhi National Park (SGNP) area for generations, the draft plan feels like an act of erasure. The communities say they were not informed about the plan until environmental activists brought it to their attention.

The draft identifies 43 padas or hamlet — 28 in the Mumbai Suburban District and 15 in the Thane District — of which 14 fall within the Eco-Sensitive Zone (ESZ) of BMC jurisdiction. However, it undercounts the tribal population, pegging it at 3,626, which is lower compared to the real count, say activists. Bhattacharjee says, “There are data discrepancies regarding the population of tribals across SGNP. The population figure mentioned for the 14 padas within the ESZ in BMC’s jurisdiction in the draft is still incorrect. The population is more than what is being said, and so are the tribal hamlets, i.e., 27 in just Goregaon’s Aarey Milk Colony.”

The list also contains several errors. For instance, Filter Pada, a non-tribal settlement, is included as a tribal padas, while genuine tribal hamlets such as Habale Pada, Navsacha Pada, Khadak Pada, Khambacha Pada, Ronacha Pada, and Patona Pada are missing.

Dinesh Habale, President of the Adivasi Hakk Samvardhan Samiti and a resident of Habale Pada, voices the community’s fear. “Not only our padas but also our agricultural lands fall within ESZ-2. In Habale Pada, we have nearly 500-1,000 fruit-bearing trees within the forest. The authorities call us encroachers, but when they cut these trees for so-called development, it is considered legal.” The draft also mentions the rehabilitation of tribal and slum dwellers who have encroached on public land.

In a letter to the BMC, the gram sabhas of all Aarey tribal padas have opposed new development, demanded immediate approval of their forest rights claims, sought village status for all 27 padas, and requested that the draft be released in Marathi with an extended period for submitting responses.

Under the Thane Municipal Corporation (TMC) jurisdiction, the report lists 11 slums but omits the presence of tribal settlements, known as padas. This pattern is also seen in the Mira-Bhayander and Vasai-Virar municipal corporations.

For the tribal communities, the stakes are linked to their lives. “Hamara astitva sankat mein hai (Our existence is in danger),” says Habale, adding that many tribal people are living in fear and mental distress. A mass protest is being planned by tribal groups from Aarey, Yeoor, and neighbouring areas once they receive a formal response to their letter.

Development vs conservation

The draft also talks about nature-based tourism, wellness centres, trekking routes, and sustainable villages. While new polluting industry set-ups are prohibited, the plan does not call for the removal of any existing polluting industries operating in the ESZ. This ambiguity raises concern that existing factories and workshops in Vasai and Thane could continue operating unchecked.

Ekbote warns that past developments have already set a dangerous precedent. “For the last 20–25 years, a large luxury real-estate project has been destroying the hills of SGNP and building on steep slopes. If this plan goes through, increased concretisation will cause huge surface run-offs and waterlogging downhill,” he says.

Bhattacharjee points out that flooding is already a recurring consequence of such unplanned construction. “Every year, the main road from Powai and Marol to Aarey floods due to the land-filling and construction of the Metro 3 car depot in the Mithi River’s catchment areas,” she says. Similarly, several streams in Yeoor that eventually connect to the river Chena are blocked due to construction activities, causing annual waterlogging, she adds.