Hyderabad: After resuming the Srisailam Left Bank Canal (SLBC) tunnelling works last week, officials have drilled about 20 metres from the Devarkonda side, where the work remained stalled for the past seven years.Irrigation minister N Uttam Kumar Reddy had directed the officials to take safety measures, as that remained paramount alongside adherence to schedules. He directed officials to ensure round-the-clock work with strict protocols. Breakthrough has been targeted by the end of next year (2027), with full commissioning expected by June 2028. This renewed push follows earlier decisions to shift from tunnel boring machine (TBM) methods —deemed unsuitable due to geological challenges — to safer, observation-based techniques.The minister reviewed the tunnelling works with irrigation department officials at the secretariat on Saturday, along with other issues such as mobilisation of manpower and equipment, and tentative completion timelines for both Tunnel-1 and Tunnel-II. The minister said that men and materials were mobilised to the site in a big way. Some seven excavation cycles were successfully completed from the Devarkonda end (outlet side). The works, which involved advanced tunnelling methods, were monitored closely using observational techniques that ensure safety through precise drilling protocols and the installation of extra supports.Uttam Kumar Reddy said that the implementation agency deployed specialised equipment to address anticipated ventilation challenges deep inside the tunnel, which is expected to accelerate the pace of excavation. Work from the inlet side will also commence soon, with preparations including a 20-metre open cut and additional safety installations already underway. The agency is importing electrical and more ventilation equipment to further enhance efficiency, with full operations likely ramping up in a fortnight.The 44-km SLBC tunnel — intended to irrigate drought-prone areas in Nalgonda and provide drinking water to fluoride-affected regions — has been under construction from both ends (inlet at Srisailam/Domalpenta and outlet at Devarkonda). Progress stalled following a tragic roof collapse on Feb 22, 2025, near the inlet-side end, halting operations.The govt also formed a dedicated division to monitor the project closely. The SLBC tunnel is a critical component of the state’s irrigation infrastructure, aimed at benefiting over three lakh acres, besides helping augment the drinking water sources in the region.
