Kolkata Metro: Why Bowbazar houses are cracking and what the future holds

The Kolkata Metro Rail Corporation (KMRC) will build 23 houses in the first phase for the affected residents of Bowbazar whose houses developed cracks during the East-West Metro construction. The agency has already invited tenders from firms, and the work may begin next February.

An expert committee from Jadavpur University (JU) has recommended the demolition of 45 houses after cracks appeared in many houses in central Kolkata’s Bowbazar. It is one of the oldest residential areas in the city and also known as a jewellery hub. All the buildings to be razed are nearly two centuries old.

The KMRC has already demolished 26 houses in Bowbazar for safety. Of these, 23 were pulled down in September 2019 and three in May this year. With the new lot of 45—if the recommendation is followed—the number will go up to 71.

The 16.5-km East-West corridor, which will connect Salt Lake Sector V with Howrah Maidan, will have a 10.8-km tunnel. A small section will run below the Hooghly—India’s first underwater metro tunnel. The corridor will intersect the existing north-south corridor at Esplanade, with the next stop at Sealdah. Bowbazar lies in this stretch.

The problem with Bowbazar

Problems with metro construction work in Bowbazar started on August 31, 2019, when several houses in Durga Pituri Lane developed cracks and parts of the buildings collapsed. Similar incidents were reported on May 11 and October 14 this year as well.

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The Kolkata Municipal Corporation (KMC) commissioned the JU expert committee, comprising retired and serving civil engineering professors, after the May incident. It was tasked with assessing the damage to buildings in Bowbazar and offer solutions.

Initially, the tunnel-boring machine was blamed for the cracks on the buildings. It was believed that the machine hit the aquifer—the underground layer of water-bearing rocks and sediments—which led the ground below to subside, and the houses to cave in or develop cracks as a result.

However, no major tunnelling work has been done since the September 2019 incidents. Yet, there have been five instances of buildings developing cracks due to Metro construction since then.

According to media reports, the JU panel’s report has cited archival materials, including British geographer James Rennell’s 1794 map of Bengal. The main problem could be that Bowbazar used to be a wetland. The area had a creek, and there is still an aquifer below Bowbazar. That means the soil is soft. According to the East India Company minutes, the British built a road here in 1709.

The plight of residents

Several residents of Durga Pithuri Lane have been shuttling between hotel rooms and their homes for three years now, ever since the first subsidence and cracks were reported in 2019. Since then, Metro authorities have thrice issued evacuation orders to the residents.

Chandeshwar Nath Jha, the MD of KMRC, told The Indian Express that nearly 1,000 people were displaced, but several families have returned after repairs. “We have set aside Rs 14 crore as compensation,” he said.

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Another 136 people joined them when 10 buildings on Madan Dutta Lane developed cracks as well in October. Metro officials were planning to move 400 more people as a safety measure.

Incidentally, Bowbazar was not part of the original route when the then UPA government sanctioned the project in 2008. The Bowbazar fiasco has now led to a political blame game, with the BJP-led Opposition in West Bengal alleging that the ruling Trinamool Congress had the route changed for the benefit of land developers, and the Trinamool Congress blaming the KMRC for “lapses.”

What the KMRC has already done

The KMRC has started fixing steel props to prevent the cracked buildings on Madan Dutta Lane from further deterioration and grouting their foundation to prevent further tilt or cave-in. Grouting involves pouring concrete mix under the foundations of the damaged houses.

However, several engineers have said that these measures may be too little too late. These should have been in place before the construction of the “cross passages” to link the two tunnels started.

“We want to repair some of the buildings on Madan Dutta Lane where minor cracks have appeared and ensure the residents return home at the earliest,” The Telegraph quoted N C Karmali, director, projects, KMRC, as saying.

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The KMRC earlier said that it would pay Rs 5 lakh to each house owner who cannot return home within 30 days from October 14. The owners of affected shops measuring less than 100 sq ft will get a compensation of Rs 1.5 lakh, while those measuring above 100 sq ft will get Rs 5 lakh.

“We will shortly begin the compensation process for the residents of Madan Dutta Lane who were displaced on October 14,” Karmali told The Print.

The future of East-West Metro and Bowbazar

The JU expert committee’s report suggests three ways to accommodate displaced residents and rebuild the affected Bowbazar neighbourhoods. One, the KMC and KMRC may develop a modern jewellery centre and residential high-rises to replace the two-century-old old houses, accordign to media reports. Two, they can rebuild the demolished houses, but that will not be cost-effective. The third option is a mix of high-rises and new two- to three-storey houses.

“Work inside the Metro tunnel cannot be put on hold for long. We want to start it as soon as the shifting of loose soil stops and the area has completely stabilised,” a KMRC official told The Telegraph.