Irrigation minister N. Uttam Kumar Reddy on Sunday said excavation of the Srisailam Left Bank Canal (SLBC) tunnel had crossed a major geological challenge and its toughest stretch, with a cumulative progress of 700 metres recorded over the past five to six months.
The project team reported excavation of about 450 metres from the outlet end and 250 metres from the inlet. The work included passage through a major shear zone amid geological, technical and logistical challenges. Uttam Kumar Reddy was speaking after reviewing the SLBC tunnel and other key irrigation projects with elected representatives and senior officials from the three districts of erstwhile Nalgonda.
The nearly 44-km main tunnel is about 79 per cent complete, with around 9.1 km of excavation remaining. Once completed, the project is designed to draw more than 30 tmc ft of water from the Srisailam reservoir to provide irrigation to drought-prone areas, primarily in the erstwhile Nalgonda district.
Col. Parikshit Mehra, an Indian Army tunnel expert spearheading the operations, said excavation at the inlet had deliberately been slowed during the initial months because of weak ground, rock bursts and the need to prevent another accident. The diversion around the point where the tunnel-boring machine had become stuck had taken the working face through particularly poor geological conditions.
The minister directed officials and the contractor to maintain progress through the difficult geological stretch while ensuring the safety of people working more than 20 km inside the tunnel. He sought deployment of additional equipment, improved excavation cycles and close safety monitoring to meet the June 2028 water-delivery target.
Uttam Kumar Reddy expressed hope that a breakthrough in Tunnel 1 could be achieved by May-June 2028. Concrete lining is being carried out on completed sections of the tunnel while excavation continues. This reduces the amount of lining work that will remain after the two ends of the tunnel meet.
He also directed officials to complete Tunnel 2, the balancing reservoir and associated components in time to ensure that unfinished infrastructure did not delay water delivery. Lining work on the 7.1-km Tunnel 2 has resumed after a prolonged interruption.
Public representatives, who attended the review meet, include MPs K. Raghuveer Reddy and Chamala Kiran Kumar Reddy; MLAs Mandula Samel, K. Jaiveer Reddy, Vemula Veeresham and Anil Kumar Reddy; MLC Shankar Naik; and officials such as irrigation secretary E. Sridhar; engineer-in-chief O.V. Ramesh Babu; and the collectors of Suryapet, Nalgonda, Yadadri-Bhongir and Mahabubabad participated in the meeting.