Howrah remained waterlogged on Thursday, around 72 hours after the prolonged downpour that threw life out of gear across the city and its adjoining areas.

Environment activist Subhas Dutta on Thursday filed a public interest litigation in the high court seeking an order to the Howrah Municipal Corporation (HMC) to take "immediate steps" to solve the problem of waterlogging.

Civic sources said 20 of the 66 wards in Howrah were still under water on Thursday, with engineers attributing the problem to choked drains.

Among the flooded areas were Tikiapara, Salkia, Belilious Road, Panchanantala Road, East West Road, Belgachhia and Dasnagar. On many stretches, the water was knee deep.

Train services in the South Eastern Railway were affected for the third consecutive day on Thursday as the tracks between Howrah and Tikiapara were still under water.

The Howrah-Digha Tamralipta Express had to be cancelled, while the Howrah-Titlagarh Ispat Express started its journey from Santragachhi instead of Howrah. A railway official said as many as 30 suburban trains had to be cancelled.

The official held out the hope of the situation becoming normal on Friday.

As for Dutta's petition, court sources said it might come up for hearing next week before the division bench of acting Chief Justice Girish Chandra Gupta and Justice Arindam Sinha.

The petition stated that the 530-year-old city had been suffering from hygiene problems because of poor sewerage. The city, including the added areas, had more than 600km of open drains which have "never" been desilted, the petition said.

"The existing drainage and sewage systems cannot carry waste water even during the dry months. The question of carrying rainwater does not arise at all."

The petition also mentioned the disruption of train and other transport services because of waterlogging.

When asked why Howrah was still flooded, Dutta told Metro: "It's the responsibility of the civic body to clean and desilt the sewage channels and open drains. But it has completely failed to perform its duty."

Civic officials denied the allegation. "We regularly de-silt the drains," said Shyamal Mitra, the mayoral council member in charge of drainage.