Nearly a year after a devastating accident claimed eight lives, the Telangana government has announced the resumption of work on the ambitious Srisailam Left Bank Canal (SLBC) tunnel project. The state's Irrigation Department will employ advanced tunnelling techniques to complete the remaining stretch, prioritizing safety and efficiency.
A Tragic Setback and a New Beginning
The project came to a grinding halt on February 22, 2025, when a section of the tunnel roof collapsed. The accident trapped eight workers, including engineers, all of whom were later declared dead. Following the tragedy, a Tunnel Boring Machine (TBM) became stuck at the Devarkonda outlet. Irrigation Minister N Uttam Kumar Reddy stated that the debris from the collapse has now been completely cleared.
However, in a significant shift, the government has decided to abandon the stuck TBM. Citing site-specific geological challenges, authorities will now use more sophisticated tunnelling methods to finish the project. "Work will restart, using ‘advanced tunnelling methodology’, which is both safe and efficient," Minister Reddy affirmed on Sunday.
World-Record Ambition and Critical Purpose
The SLBC tunnel is a key component of the Alimineti Madhava Reddy Project, initiated in 1983. Once completed, the 44-kilometre conduit will be the longest tunnel in the world excavated without intermediate shafts. It originates from the left bank of the Srisailam reservoir and is designed to serve a dual purpose: irrigating 3,00,000 acres in drought-prone areas of Telangana and supplying drinking water to fluoride-affected villages, particularly in Nalgonda district.
Chief Minister A Revanth Reddy has emphasized the project's importance, calling it a "lifeline" for the region and setting a strict deadline for its completion: December 9, 2027. To date, excavation of 13.94 km from the Srisailam inlet side and 20.4 km from the Devarkonda outlet side has been finished. This leaves approximately 9.8 km remaining to be excavated.
Advanced Safety and Morale-Boosting Measures
The state government is leaving nothing to chance for the renewed construction drive. A comprehensive helicopter-borne VTEM Plus Magnetic Geophysical Survey was conducted by scientists from the National Geophysical Research Institute (NGRI). This survey provided critical data on subsurface rock conditions, enabling the planning of an advance warning system for unstable rock zones.
3D monitoring systems will also be deployed, allowing engineers to install support structures based on real-time geological forecasts. To accelerate progress, operations will run 24/7 in three shifts. In a move to boost worker morale, the government has announced a 25% salary hike for all employees below the rank of executive engineer. "This will help towards getting workers to help resume the project," Minister Uttam Kumar Reddy said. Work will proceed simultaneously from both ends of the tunnel to meet the ambitious deadline.
