As Mumbai braces for the monsoon, more than 300 landslide mitigation works remain incomplete across the city’s vulnerable hill slopes, raising concerns about the safety of nearly one lakh residents living in high risk zones.Data from the Brihanmumbai Municipal Corporation (BMC) shows that of the 749 landslide prevention works undertaken since 2023, only 440 have been completed. Work at 329 locations is either pending or yet to begin, despite repeated warnings from experts and a history of fatal landslide incidents in the city.The mitigation measures were recommended by the Geological Survey of India (GSI) in 2018 after a year long assessment of Mumbai’s landslide prone areas with adjoining human settlements.Landslides remain a recurring monsoon threat in Mumbai. According to BMC disaster management data, between 2021 and 2025, the city recorded 107 landslide incidents in which 31 people were killed and 25 injured.Mumbai currently has 249 identified landslide prone locations, including hillocks and ridges rising between 150 and 200 metres. Many of these slopes are either rocky and barren or covered with loose soil, making them vulnerable during heavy rainfall. Several are located on former quarry sites where excavation altered the natural terrain.The slopes are largely occupied by informal settlements inhabited by low income families and migrant workers. Official estimates suggest that nearly one lakh people live in these high risk areas.Work slows after initial pushOf Mumbai’s 249 landslide prone locations, 74 have been classified as dangerous and 46 as highly dangerous.The highest concentration is in the S ward covering Kanjurmarg and Vikhroli, which accounts for 116 vulnerable spots. Ghatkopar has 32 such locations, while Kurla has 17. Even affluent areas such as Malabar Hill have 15 landslide prone sites.To prevent rockfalls and debris from crashing onto settlements below, the GSI recommended construction of protective retaining walls along vulnerable slopes.Story continues below this adCivic records show that authorities initiated 749 mitigation works between 2023 and 2026. While 440 have been completed, 329 remain unfinished.The pace of execution has slowed significantly after the first year.In 2023-24, authorities initiated 302 works and completed 301. In 2024-25, 231 projects were sanctioned but only 113 were completed, while 117 remain pending. In 2025-26, 136 works were approved, but only 16 have been completed so far, with 88 still under construction.Funds and logistics emerge as hurdlesThe retaining wall projects are being implemented by the Slum Rehabilitation Authority (SRA) and the Public Works Department (PWD).Story continues below this adGovernment records show that more than Rs 400 crore was allocated between 2020 and 2023 for landslide mitigation works. However, officials said funding slowed thereafter, affecting the pace of execution.“Since there are too many agencies like BMC, SRA, Collector and PWD involved in the process, securing funds is not easy as it needs approval from multiple stages. Also, every year, BMC carries its own risk assessments as a result of which new vulnerable spots start to emerge annually making the list never ending,” an official told The Indian Express.Officials also pointed to continued encroachments on completed structures.“In many cases we have seen that the encroachers seal the weep holes in the walls due to which the percolated water can’t run out and the wall loses its strength and eventually collapses. These kinds of situations could only be averted through proper sensitisation campaigns,” the official said.A PWD official said difficult terrain and weather conditions continue to delay projects.Story continues below this ad“Another prime reason behind the slow pace is logistical challenges. One cannot carry heavy equipment like boulders and stone through the slope and during monsoon construction works need to be stopped entirely, so executing civil work in so many locations is a mammoth task therefore it requires time,” the official said.Fresh measures proposedAs an immediate precaution, civic authorities are setting up temporary shelters in BMC schools and community halls to accommodate residents from vulnerable areas during emergencies.Meanwhile, the district collector’s office has submitted a proposal worth Rs 195 crore to the state government for additional landslide prevention measures.Officials said the proposal goes beyond retaining walls and includes several recommendations prepared in consultation with IIT Bombay.Story continues below this ad“Some of the remedial measures would include installing high tensile wire net mesh on the rocks to prevent them from collapsing, increasing the vegetation to strengthen the soil surface and also finding out ways to make the surface stable. We have consulted with IIT Mumbai and based on their recommendations we have sent the proposal to the state government,” the official added.