Hydrostatic pressure at Durgapur barrage threatens new causeway
The Statesman | 1 May 2025
Within hours of an inspection by the state irrigation minister, his department has halted trial traffic movement along the newly-constructed causeway across the Durgapur barrage on the Damodar river today.
Irrigation minister Dr Manas Bhunia, accompanied by senior engineers and officials, inspected the newly laid one-kilometre causeway yesterday. He instructed the engineers to explore multiple options before finalising the causeway as the sole alternative. Uncontrolled seepage of water over the riverbed road was reportedly causing difficulties for light vehicles.
Advertisement
The Rs 1.86 crore causeway has been constructed to divert vehicular movement from the Barrage’s carriageway, which is scheduled for a Rs 3.5 crore overhaul before 15 June.
The barrage’s carriageway, opened in 1955, handles an average daily load of 26,000 motor vehicles, according to an assessment by the Bankura district police.
Following the halt in traffic, Debashis Sengupta, chief engineer, irrigation, said: “After three days of trials, we had to suspend traffic to allow for a fresh, detailed investigation of the road to assess the impact of vehicle movement on the new construction, and to determine whether further engineering interventions are needed. We are scheduled to reopen it from Friday.”
When asked about the specific issues the causeway is facing, Sengupta replied: “Only continued seepage of water.”
While a National Green Tribunal verdict restricts road construction on riverbeds, in West Bengal, such roads may still be constructed provided they are carefully planned with proper soil engineering. These must account for the river’s natural flow, depth, potential erosion, and ecological balance. According to the public works department’s 2014 guidelines (Vol. III), a riverbed road “should use solid concrete blocks with minimum compressive strength, when tested, not less than 10.5 MPa (megapascal).” One megapascal is equivalent to one million pascals of pressure.
Sustained hydrostatic pressure, increasingly building in the stagnant waters of the Durgapur barrage’s pond, has caused continuous seepage, posing a growing threat to the newly-laid causeway. This, according to top irrigation engineers, warrants a fresh inspection. The water level in the barrage fluctuates between 28.5 and 30 feet, due to the combined discharge of 870 million cubic metres from the four upstream dams of the Damodar.
“The accumulated water constantly mounts pressure on the lock gates, resulting in seepage that can never be fully sealed without compromising the barrage’s structural safety,” said Sanjoy Majumdar, executive engineer, Damodar headworks, irrigation department.
The 692-metre-long barrage has 34 lock gates, along with a pair of underwater sluice gates. Excessive hydrostatic pressure at the gate bottoms had previously caused the collapse of two gates (Nos. 1 and 31) on 23 November, 2017 and 30 October, 2020, respectively, which led to the emptying of the pond.
“We cannot risk a repeat of such devastation. We must opt for a foolproof system that functions reliably,” said Dr Bhunia, the minister, adding: “We have very little time left to complete the renovation of the carriageway.”