Large stretches of Kolkata were flooded on Monday and water entered hundreds of homes in low-lying areas as the city received rain much beyond the capacity of its drainage system.
Records shared by the Kolkata Municipal Corporation (KMC) showed that 17 of their rainfall measuring sites recorded over 100mm rain between 10pm on Sunday and 2pm on Monday. Four of them recorded above 150mm of rain in the same period.
The bulk of the rain fell overnight. Seven sites recorded over 100mm between 10pm on Sunday and 6am on Monday.
A senior engineer of the civic body said that unlike some recent instances of heavy rain, the downpour from Sunday night was mostly uniform across the city, a reason why all corners of Kolkata got flooded.
Major roads such as Rashbehari Avenue, Southern Avenue, Camac Street, Park Street, CR Avenue and MG Road were waterlogged.
Many stretches were knee-deep under water.
“The sluice gates at the mouth of the drainage pipes that discharge water into the Hooghly were kept closed for over eight hours as the river’s water level rose above that of the pipes. That delayed the draining out of water,” said a KMC official.
The gates remained closed from 11pm on Sunday to 3am on Monday as the water in the Hooghly rose to 17.25ft. The gates were again closed between 10.30am and 3pm on Monday, when the water rose to 18.31ft.
In several housing complexes, residents were asked to remove their cars from the basement.
“The primary reason for the waterlogging is the very high volume of rain. Kolkata’s drainage system can handle up to 6mm in an hour. But several parts of the city received over 100mm rain in four or five hours. It is impossible to avert waterlogging in such a situation,” said the KMC engineer.
“We operated all 76 pumping stations in full capacity, yet the water could not be drained out from most places till Monday evening,” said the engineer.