BMC launches new Mumbai coastal risk study amid rising sea-level threat

The Brihanmumbai Municipal Corporation (BMC) has commissioned a fresh assessment of Mumbai’s vulnerability to rising sea levels, with the study covering the city’s entire 149-km coastline.

The assessment is the second such exercise undertaken by the civic body in five years and will examine how coastal development, land-use changes and changing climate patterns have altered Mumbai’s vulnerability.

The study will map vulnerable stretches along the shoreline and identify inhabited areas that could face risks from rising sea levels. The report is expected to be released next year.

The new exercise comes against the backdrop of major changes to Mumbai’s coastline over the past five years, including construction of the Coastal Road.

A senior civic official associated with the assessment said the changes made a fresh study necessary.

“Over the last five years, Mumbai’s shoreline has seen a massive transformation. The Coastal Road has come up along the western seafront, with more than 100 hectares of the Arabian Sea reclaimed. On the eastern side, salt pan lands have been identified for development. There has also been a change in the overall land-use pattern. Therefore, a fresh risk assessment was needed,” the official said.

Unlike a global assessment of sea-level rise, the BMC study will focus specifically on Mumbai. It will examine local factors contributing to coastal vulnerability, project future sea-level rise and identify populations living near the shoreline who could be at risk.

The exercise follows a recent United Nations report that found global sea levels rose by 5.9 mm in 2024. The report projected at least 0.5 metre of sea-level rise by 2100 even under aggressive emissions-reduction scenarios, while a worst-case scenario involving instability of the West Antarctic ice sheet could result in a rise of up to two metres.

Mumbai’s first Climate Action Plan, released in 2022, had identified coastal flooding, rising pollution, loss of green cover and increasing urban heat as key climate risks.

The 2022 plan had also projected that 80 per cent of Mumbai’s island city could be submerged by 2050.

The new BMC assessment will therefore provide an updated picture of areas and populations exposed to coastal risks, taking into account development and land-use changes since the earlier study.

The assessment is expected to provide the civic administration with updated information for planning measures to improve Mumbai’s resilience to sea-level rise and coastal flooding.