Mumbai has been slow in adapting it’s infrastructure to tackle climate change
Mumbai’s record in adapting to climate change has been abysmalUpdated: Nov 10, 2019 23:41 IST
This year’s rain has broken a series of records. Monsoon set in after a two-week delay but more than made up for the deficit in the next few weeks.
The city received 1,464.8mm of rain in July, 83% more than the average of 799mm for the month. In the first five days of August, the city received 80% – 458mm – of the month’s average of 585.2mm.
On August 4, Mumbai surpassed its entire seasonal average of 2,317.2mm, after three major rain spells took the tally to 2,374.2 mm. There were more records as the rains progressed.
In the first four days of September, the city got 496.5mm rains, compared to the average rainfall of 327.1mm for the month. There were five major spells of heavy rain between June and September when the city received more than 200mm (377.2mm on July 1-2), each month.
Before the monsoon made a late withdrawal – on October 14 – the city got 3,695.6mm during the season.
During its official four-month monsoon that ended on September 30, the city received 3,670mm of rain, breaking an earlier record of 3,452mm, set in 1954. This was 66% (1,464.4mm) more than the seasonal average. In the 2018 monsoon, Mumbai recorded 2,239.6mm rain over four months, which was 77.6mm less than the season’s average.
The year’s latest record was made last week when the India Meteorological Department (IMD) said that the city had received its highest November rain. Mumbai received 109.3mm rain, an all-time high for the month, since 1901 when the IMD began recording rain data.
The rain this year was influenced by cyclones. Cyclone Vayu in June delayed the onset of the southwest monsoon but subsequently led to extremely heavy rain in June-July. Cyclone Hikka delayed the withdrawal of the season. Cyclones Kyarr and Maha between October and November created the November rain record. The IMD has called the two post-monsoon cyclones ‘an extremely rare weather event’.
An analysis of six climate studies, reported by this newspaper last week, said that the unusual weather over Mumbai this year, including unseasonal rains caused by two rare November cyclones, says that air pollution and the resultant warming of the seas could be strengthening post-monsoon cyclones in the Arabian Sea. The analysis was made by Climate Trends, a communications initiative on climate change.
A weather expert told this newspaper that the rise in sea-levels due to climate change and the rise of hitherto unknown weather systems like post-monsoon cyclones will make coastal cities like Mumbai vulnerable. Scientists have said that the extreme weather events witnessed for almost five months in Mumbai indicate a changing climate, necessitating the adopting of climate-resilient technology in urban infrastructure.
Mumbai’s record in adapting to climate change has been abysmal. One example is the BRIMSTOWAD (Brihanmumbai Storm Water Disposal System), a project conceived nearly two decades ago, to enhance the capacity of Mumbai’s rain channels.
The island city’s stormwater drains, built more than 80-90 years ago, were built to drain 25mm rain per hour during low tide. During periods of higher rain intensity and high tide, when the sea pushes flood water back into the city, there is flooding. BRIMSTOWAD plans to enhance the carrying capacity of the drains to 50mm.
However, most components of the project remain incomplete. Some of the pumping stations that could drain floodwaters in low-lying areas are not even in the planning stage, with land for the projects under litigation or taken over by slums.
The BRIMSTOWAD plan foresees two to three events of extreme rain in a season when railway and road networks are affected. But the 2019 monsoon has reported five such spells which managed to paralyse the city.