A British-Era Main Bursts at Tala: What Kolkata's Flood Says About Ageing Water Pipes

On the morning of Monday, 9 November, a 72-inch drinking water main carrying water from the Tala reservoir burst in north Kolkata. The pipe runs nearly 30 feet below the railway tracks under Tala Bridge. Within hours, Bonomali Sarkar Street, Ghoshpara, parts of Bidhan Sarani, Hatkhola and nearby lanes were under ankle- to knee-deep water. It entered homes and shops, submerged cars and flooded several Kali Puja pandals.

The Kolkata Municipal Corporation (KMC) warned that "a leakage has been detected at a major diameter of the city water supply pipeline" and that supply could be affected in areas including CR Avenue, Rajabazar, Park Circus, AJC Bose Road, College Street, Bidhan Sarani, Ballygunge and Kasba. Circular Railway services were suspended after water reached the tracks, and electricity was cut in the flooded localities as a precaution. Municipal Commissioner Smita Pandey said the corporation was working "on a war footing". Minister of State for Urban Development Umesh Rai said the pipe dated from the British era. Repairs were expected to take one to two days.

A century-old system doing a modern city's work

The Tala tank itself opened in 1911. It holds about 9.9 million imperial gallons (around 45 million litres) and stands 110 feet tall, and it is fed from the Palta water works upstream on the Hooghly. Many of the trunk mains that leave it are of a similar age. They were laid for a city a fraction of today's size, and they now sit under roads, rail lines and buildings that make them very hard to reach.

Kolkata is not unusual. Most large Indian cities still rely on a handful of very large trunk mains, many of them decades old, to move treated water from a few plants to many neighbourhoods. When one of them fails, two things happen at once: a flood where the pipe bursts, and a dry tap far away.

Why big mains fail

• Age and corrosion. Cast iron and steel pipes thin from the inside and outside over decades, and old joints loosen.
• Load from above. Heavy road and rail traffic over a buried pipe adds vibration and stress, especially where the soil is soft or waterlogged.
• Pressure surges. When a pump starts or stops suddenly, or a valve is shut fast, a pressure wave (water hammer) runs down the pipe and can split a weak section.
• Leaks that grow unseen. A small leak washes away the soil around the pipe, the support goes, and the pipe eventually cracks under its own weight. Many "sudden" bursts start years earlier.

What makes a water network resilient

1. Know your pipes. A map of every trunk main with its age, material and condition, and regular inspection of the oldest and most critical ones.
2. No single points of failure. Ring mains and cross-connections, so that when one main is shut, water can reach a neighbourhood from another direction.
3. Find leaks early. District metering, acoustic leak detection and pressure monitoring catch small leaks before they become bursts, and cut the water that is lost before it reaches anyone.
4. Control pressure surges with slow-closing valves, surge tanks and soft-start pumps.
5. Storage close to people. Neighbourhood reservoirs and building tanks that can carry a ward through a one- or two-day outage.
6. Drainage that can take a burst. The flood at Tala was as damaging as the supply cut. Streets with working drains, and green space and ponds that can absorb a sudden surge, recover faster.

What a housing society or building can do

A city's pipes are the city's job, but every building decides how badly a burst hurts it:

• Store at least one to two days of water. An underground sump plus overhead tank sized for two days of use turns a crisis into an inconvenience. Keep tanks clean, and follow the confined space safety steps whenever anyone has to go inside one.
• Have a second source. Rainwater from the roof, stored or recharged into the ground, and treated water from your STP for flushing and gardens mean fewer litres you need from the main.
• Fix your own leaks. The same logic applies inside a campus: meter each block, look for night flows, and repair leaking lines before they undermine a basement or a road.
• Keep the plot drained. A recharge pit at the low point of a plot or a revived pond nearby takes in water from a storm or a burst, instead of sending it into homes. The recharge pit calculator shows how much a pit can handle.

The same pressure in Gurugram

Gurugram's piped network is far newer than Kolkata's, but the city's thirst for water is outgrowing it, and much of the gap is filled from an aquifer already pumped at nearly twice its recharge (Gurugram groundwater). Every litre lost to a leak, or not captured from the roof, ends up being pumped from below. Borewell recharge and pond rejuvenation in Gurugram help close that gap. For a water audit of your society or campus, or to design storage, rainwater harvesting and reuse, talk to us. Companies can fund this kind of work through CSR water conservation.

Sources

• The burst, the areas affected, KMC's notice and the officials' statements: Millennium Post, 10 November 2026.
• Time of the burst, rail cancellations and repair estimate: Indian Opinion.
• The original report: The Telegraph India, "Pipe leaks flood Tallah, water supply to large parts of Calcutta faces disruption", 10 November 2026.
• Tala tank history and capacity: Wikipedia, Tala tank.