Bengaluru’s rainfall pattern should be studied before drawing up master plan for city, feel experts

Given the extent of flooding in Bengaluru after the recent rainfall, experts have begun questioning how the city would fare if the single-day maximum rainfall recorded in 1997, were to be broken anytime soon.

Ram Prasad, the co-founder of citizens’ collective Friends of Lakes, said: “The situation was not bad in 1998. Over the years, there has been an increase in the built-up area of the city and there have been topographical changes. The government should sit with the experts and the officials including the weather department and decide to what extent the elevation in infrastructure should be allowed so that we do not encounter the same scenario… The rainfall pattern should be seen before making the city’s master plan.”

An official from Bruhat Bengaluru Mahanagara Palike (BBMP) lakes department said: “There has been a massive increase in the number of people who have settled near the Bellandur-Varthur area. Since urbanisation has increased, concretisation ought to increase. The number of IT parks, apartments and migrant labourers has exponentially increased in the past one decade.”

A source within the India Meteorological Department (IMD) said they were in the process of compiling data on highest-ever rainfall recorded in a single day in the city. “It takes time to compile the data… October 1, 1997, was the day when the city received 180mm of rain. Almost a year later on September 12, 1998, the city recorded 177.6mm of rainfall… The city received 128.7mm of rain on August 15, 2017, and areas like Koramangala and Sarjapura got inundated,” he said.

Since June 1, the city has received 1,032mm of rainfall as against the average of 661mm. In 2017, Bengaluru recorded 949.7mm rainfall.

According to data shared by the IMD, Bengaluru recorded 364.2mm rainfall in August this year. Whereas it had received 387.1mm rain in August 1998. In August 2021, the city recorded only 98.3mm rain.

According to the Met department, Bengaluru received an annual rainfall (January-December) of 1,510.5mm in 2021, with the wettest month being October (363.3mm). The annual rainfall was 1,200mm in 2020, and over 900mm in 2019.