Why Kolkata sank in just three hours of rain on Monday
Large parts of Kolkata resembled Venice on Monday evening because the heavy rainfall was accompanied by a high tide in the Hooghly river, leading to a crisis that Kolkata Municipal Corporation (KMC) employees manning the civic body’s pumping stations could not handle. Even the Kalighat residence of chief minister Mamata Banerjee, which is located right next to Adi Ganga, an old distributary of the Hooghly, was not spared by nature. Nabanna, the state secretariat that houses the CM’s office, was under ankle-deep water.
Though there was little or no downpour on Tuesday, Monday’s rainfall of around 110mm in just three hours and the high tide --- it raised the water level in the Hooghly which serves as the main outlet for Kolkata’s drainage system --- were enough to keep many parts of the city under water.
“The city received around 110mm of rainfall in three hours, which means hourly rainfall was 37mm. It was enough to drown the roads because our drainage system cannot handle more than 20mm of rain in one hour,” said Tarak Singh, member, Mayor-in-Council (Drainage) of the KMC.
Making matter worse was the high tide in the Hooghly on Monday evening --- the water level in the river swelled to 5.97 metres, said KMC officials. “We usually open the lock gates that allow drain water to enter the river or the canals when water level in the river is below 2.5 metres. Since the water level was so high all night we could open the lock gates even on Tuesday morning,” said a KMC engineer.
On Tuesday, parts of Strand Road, Central Avenue, College Street, Muktaram Babu Street (all in the north) and Camac Street, Bhowanipore, Park Circus, Harish Mukherjee Road, Garden Reach and Khidderpore remained under ankle-deep water. Uprooted trees added to the chaos --- traffic was slow, taking hours for a 5-km ride.
The scenario in neighbouring Howrah was even more gloomy. Residents in areas like Tikiapara had to wade through waist-deep dirty water to get food supplies. Water even entered the women and child ward of Satyabala Hospital in Salkia. Since the tracks in many placed were submerged, train movement was erratic. May long-distance trains were delayed.
“We have deployed around 800 staffers and kept all our 66 small pumping stations and the five big ones operational round the clock. The situation improved after the tide receded and we opened the lock-gates to drain the water out into the river,” said a KMC official.