Cyclone Fengal: Bridge opened in September washed away in floods in Tiruvannamalai

Two days after a newly inaugurated high-level bridge was washed away in Tiruvannamalai district amid heavy rains due to Cyclone Fengal, Tamil Nadu government officials on Thursday (December 5, 2024) said the structure was designed to withstand the discharge of only 54,417 cusecs of water.

Two days after a newly inaugurated high-level bridge was washed away in Tiruvannamalai district amid heavy rains due to Cyclone Fengal, Tamil Nadu government officials on Thursday (December 5, 2024) said the structure was designed to withstand the discharge of only 54,417 cusecs of water.

The bridge collapsed on Tuesday (December 3, 2024) after 1.68 lakh cusecs of water was released from Sathanur dam.

The structure was constructed across Thenpennai river between Agarampallipattu and Thondamanur village near Thandrampattu town in the district. Minister for Public Works E.V. Velu inaugurated the bridge, built at a cost of ₹15.90 crore under the NABARD scheme, on September 2 this year.

The 90-day-old bridge was 250 m long, 12 m wide, and 7 m high. “The new bridge was built based on data on floods that occurred in the river over the past 50 years. It was designed to withstand the discharge of 54,417 cusecs, but the discharge of excess rainwater into the river this time was more than three times that amount. This resulted in the collapse of the bridge,” a State Highways official said.

Officials said excess rainwater of over 1.68 lakh cusecs was released from Sathanur dam, about 24 km from the bridge on the upstream. The bridge was damaged due to the heavy inflow of water into the river due to continuous rains in the upstream areas. Excess rainwater overflowed onto the bridge, up to a height of 4 m.

The bridge had connected at least 20 farming villages downstream. Officials said water flow in the river has been slow over the past few days due to less rainfall in the upstream areas. “Repair work, including the removal of debris of the damaged structure, will be done once the flow of water becomes stable. Currently, the damaged bridge has been closed for traffic movement,” said the State Highways official.