Mumbai: The landslide in Ghatkopar’s Ashok Nagar this Wednesday that claimed eight lives has again raised questions about why parts of Mumbai’s hillsides are increasingly vulnerable to slope failures during intense rainfall.The Mumbai Climate Action Plan (MCAP), released in 2022, had identified landslides, urban heat, flooding, coastal risks and air pollution as key climate-related threats to Mumbai. Its assessment warned that increasing extreme rainfall could heighten the risk of rainfall-induced landslides, particularly in vulnerable settlements located on or close to hill slopes.According to data sourced from BMC’s disaster management department cited in the MCAP, 249 locations across Mumbai were identified as prone to landslides. The plan stated that a large proportion of these vulnerable locations were concentrated along hill slopes and foothill regions, including areas around Sanjay Gandhi National Park, Ghatkopar and Malabar Hill. The assessment also highlighted the disproportionate vulnerability of informal settlements, with poor and temporarily built environments aggravating the risk.Architects, disaster response officials and activists pointed to a combination of factors for the reasons behind the increasing vulnerability —from unchecked construction and encroachment to deforestation, soil erosion and inadequate attention to the city’s natural geography.Architect and activist P K Das, who has been involved in multiple civic issues such as slums redevelopment, affordable housing and quality of public spaces, said continuing interference with Mumbai’s natural landscape—whether hills, slopes or mangroves—have made landslides inevitable. The city’s Development Plan (DP) has traditionally focused on how much construction can be accommodated on land, rather than protecting its geographical character. “The administration has to attend to climate change and start addressing the city’s geographical character and its landscape,” said Das, stressing on the need to identify and protect natural slopes, wetlands and other ecologically sensitive areas.Mumbai was originally characterised by numerous hills, many of which were subsequently cut or altered to make space for urban expansion. Das said retaining the natural slope is particularly important in hillocks where settlements or encroachments have come up. Criticising the lack of adequate attention to ecological considerations, such as hill slopes, in city planning, he said Mumbai’s geography should be treated as a critical component of urban planning rather than merely as land available for development.The MCAP had cited projections from the UN’s Intergovernmental Panel on Climate Change, which indicated that the risk of landslides in India was expected to increase. For Mumbai, the plan warned that projected trends in extreme rainfall meant landslides could become an increasingly serious threat unless adequate adaptation measures were undertaken.The plan outlined the broad measures needed to reduce the risk. These included low-cost nature-based solutions to address flood and landslide risks, improved forecasting and emergency response mechanisms, early evacuation of vulnerable communities and over the longer term, gradual rehabilitation of communities living in high-risk locations to safer areas.Former Mumbai fire brigade officer Rajendra Chaudhary, who spent nearly three decades responding to severe landslides, said soil erosion linked to changing rainfall patterns and climate change has contributed to slope instability. Deforestation can aggravate the problem, he said. In some areas, he said excavation and construction at the foothills could remove the natural support of the slope.RTI activist Anil Galgali said civic amenities such as toilets, water connections and electricity are provided to many informal settlements, allowing them to expand further.
