Mumbai A recent analysis has revealed that while more than 35% of the city’s population is estimated to be living within 250 metres of known chronic flooding hotspots, less than half of the city’s population has easy access to flood shelters.
The results are as per an analysis of meteorological and civic data carried out by World Resources Institute (India), at the behest of the Brihanmumbai Municipal Corporation (BMC), that form a key chapter on urban flood risk in the Mumbai Climate Action Plan’s Vulnerability Assessment document, released earlier this year.
‘Urban flooding risk’ has been defined in the MCAP by analysing two parameters — extreme rainfall events (ERE) and flood risk. To assess the latter, chronic flooding spots as reported by the BMC were overlaid with the city’s stormwater drains network and flood shelters, to give a spatial variation of waterlogging across the city.
It was found that nearly 43% of Mumbai’s area (within BMC limits) houses 75.9% of the city’s population (per census 2011), which has access to a flood shelter within 1km walking distance.
The catch is that during periods of heavy rain — when flood shelters are most needed — only 46.5% of the population is able to access them easily. In Mumbai, as with other cities, flood shelters are repurposed from existing structures like public schools, hospitals, sports grounds, marketplaces, marriage halls, shelters for the homeless, and offices.
“The simple reason is that walkability and mobility reduce during flooding. So, in a truer sense, less than half the city’s population has easy access to a flood shelter. This analysis was carried out using remote sensing data, so the numbers should be taken as approximates,” said a researcher.
The BMC operates a total of 868 flood shelters in the city, with over half of them concentrated around Byculla, Girgaum Chowpatty and Grant Road. They are also located, albeit sparsely, to the north and northeast in Bandra, Ghatkopar, Andheri, Mulund and Borivali.
“Deonar, Mahul, Kandivali East, Saki Vihar Road in Powai, Four Bungalows in Andheri, and Versova are some of the underserved high-population density areas that do not have access to a flood shelter within 1 km,” the MCAP’s Vulnerability Assessment notes.
A major loophole in the city’s flood management plans, the MCAP points out, is that accessibility to flood shelters is lacking in those very wards where larger sections of the population are exposed to chronic waterlogging.
For example, in M/East Ward (Deonar, Mahul, Chembur, Trombay) — where an estimated 2,75,491 people live at risk of chronic flooding, where informal housing settlements are among the densest in Mumbai — only 13.3% of the population has easy access to a flood shelter during an extreme rain event, while in South Mumbai’s C/Ward — where 36,010 people are exposed to chronic flooding — 77.5% of the population has access to a flood shelter within 1km walking distance.
“We also found that 31% of the total area of informal housing settlements in Mumbai lies within 250 metres of a flooding hotspot, which is more than any other housing type. This only compounds the vulnerability of poorer sections of the population,” said the researcher cited above.
Pankaj Joshi, urban researcher and principal director, The Urban Centre, Mumbai, said these findings reflect a longstanding issue with regional development in the city.
“C Ward is one of Mumbai’s smallest, but it is chock-a-block with structures like municipal schools, hospitals, offices, marriage halls, sports grounds and so on, which can double up as flood shelters. In wards like M/East, population has grown by twice in the last two decades, but the area remains underserviced by critical infrastructure. This is reflected in the mapping of flood shelters,” Joshi said.