Kolkata: Heavy rain and high tide battered this eastern metropolis and some districts of West Bengal, resulting in a flood-like situation across large swathes of land, officials said on Monday.
Incessant rain since Saturday submerged key traffic corridors and connectors in Kolkata, while inundating districts in the Gangetic Bengal.
A high tide in the Hooghly river under the New Moon's effect has compounded the problem.
Heavy rain is likely to persist during the day owing to the presence of a low pressure area over Gangetic Bengal and adjoining Jharkhand and associated upper air cyclonic circulation, according to the weather office.
It said "acute spells of rain or thundershowers" were likely till Tuesday.
"Heavy showers may also hit isolated places. Gusty winds will accompany the rains. A generally cloudy sky would be seen," a Met official said.
West Bengal Irrigation Minister Rajib Banerjee said the Damodar Valley Corporation (DVC) has released 18,000 cusecs of water from its dams following the rains in Jharkhand.
"We are in discussions with them. We have requested them to not release more water. Our preparations are in line with the forecast for the next two days (Tuesday and Wednesday)," he said.
"In some areas, the cumulative rainfall for the past four days (since Thursday) is 600 mm or more. No embankments were breached. We have made arrangements to increase the height of some of the embankments," he added.
In addition, Monday and Tuesday being peak high tide timings, officials are carefully assessing the water flow, Banerjee said.
The Hooghly and Baidyadhari rivers serve as outlets for accumulated rainwater in the city to drain out from a network of drains and canals.
Usually the lock gates are opened three hours before the peak of high tide to about two hours after the tide recedes.
"Today (Monday) and tomorrow (Tuesday) is the peak (high tide). After tomorrow, the water will start receding," he said.
"We are trying to stem the reservoir release but we can do so only up till the point the river can accept the released water. During this time, if the lock gates are opened, there is a risk of river water flooding the networks," he said.
High tide peak is around 1.57 pm on Monday with a height of 19.36 feet.
Over 30 wards in neighbouring Howrah and at least 10 in Kolkata were inundated.
The water level in several rivers in some districts, including West Midnapore's Shilabati river, that were flowing above the danger level on Sunday, has started to go down, officials said.
Incessant rain overnight caused waterlogging in Burdwan's Asansol, Hooghly's Baidyabati, besides West and East Midnapore, affecting thousands of people.
Fresh alerts were issued to fishermen in East Mindapore.
Kolkata received around 83 mm of rainfall till Monday morning, the Met Office said.
Stretches in Garia, Barasat, Chittaranjan Avenue, Ultadanga, Baguiati, Behala were waterlogged, leading to massive traffic snarls with rickshaws and auto-rickshaws refusing to ply.
An ambulance in Baguiati got stuck in the submerged area, prompting the patient to take an auto ride to the hospital.
Civic officials in Behala said they would have to evacuate several families if the water level does not recede. Residents of Behala were seen wading through knee-deep water.
A portion of an old residence in Harish Neogi Road here collapsed in the downpour. No one was injured, civic officials said.
In view of the deteriorating situation, control rooms have been set up at the state secretariat Nabanna, and leaves of all officials and employees of the Irrigation Department cancelled till October 31.