BENGALURU: A spell of intense thundershowers accompanied by squally winds and hail battered central Bengaluru for just over an hour on Wednesday evening, making it the wettest April day in the city’s recorded climatological history, according to the India Meteorological Department (IMD).
The downpour dumped more than 11 cm of rain, prompting experts to highlight both the sheer scale of the rainfall and the missed opportunity to conserve it in a city that spends heavily to source water from 300–400 km away.
Officials from the Greater Bengaluru Authority (GBA) said the heaviest rainfall was concentrated over the central city corporation areas, covering roughly 200 sq km. Based on preliminary assessments, hydrologists estimate that the city received between 20 and 22 million cubic metres of water—equivalent to about 0.75 tmcft.
To put that into perspective, the volume of rainwater could fill over 30,000 standard 25-metre swimming pools with a depth of 5–6 feet.
Experts noted that Bengaluru typically receives between 95 cm and 110 cm of rainfall annually. This means nearly 10% of its yearly rainfall fell in a single day—enough to meet the city’s water needs for around two weeks.
However, much of this water was lost as runoff. An IMD official pointed out that widespread concretisation across the city prevented rainwater from seeping into the ground, significantly limiting groundwater recharge.
“With paved and cemented surfaces dominating central Bengaluru, most of the rainwater simply drained away. While the downpour caused disruption, it was also a lost opportunity to harvest a massive volume of water,” a meteorologist said.
A lake conservation activist working with the GBA added that the city’s shrinking lake capacity has worsened the situation. Due to encroachment and sedimentation, the storage capacity of Bengaluru’s lakes has declined sharply—from around 5 tmcft in 1970 to just 1.5 tmcft in 2025.
“Based on the rainfall recorded, this single spell could have filled nearly two-thirds of the remaining lake storage capacity,” the activist said.
