SLBC tunnel work resumes from outlet (Devarakonda) side

HYDERABAD

Minister for Irrigation and Civil Supplies N. Uttam Kumar Reddy on Saturday announced that work on the Srisailam Left Bank Canal (SLBC) tunnel project had resumed last week and about 20 metres of tunnel was excavated during the past one week from the Devarakonda side, where the work remained stalled for the past seven years.

He reviewed the progress of the work with senior officials of the Irrigation Department on mobilisation of manpower, equipment and tentative completion timelines for both Tunnel-I and Tunnel-II. He interacted with the project officials on the safety protocols being observed at the work site and the measures initiated to address ventilation and dewatering issues at the workplace in the tunnels.

The Minister said men and materials were mobilised at the site in a big way and some seven excavation cycles were successfully completed from the Devarakonda end (outlet side). The work, which involves advanced tunnelling methods, was being monitored closely using observational techniques that ensure safety through exact drilling protocols and installation of extra supports. He noted that the implementation agency had deployed specialised equipment to address anticipated ventilation challenges deep inside the tunnel and it is expected to accelerate the pace of excavation. Work from the inlet side would also commence soon with preparations including a 20-metre open cut and additional safety installations already underway.

Stating that the agency was importing electrical and ventilation equipment to further enhance efficiency with full operations likely to be ramped up in a fortnight, Mr. Uttam Reddy said 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/Domalapenta and outlet at Devarakonda).

However, the progress was stalled following a tragic roof collapse on February 22 last year near the inlet side-end. The Minister stressed that safety remains paramount alongside adherence to schedules. He instructed the officials to ensure round-the-clock work with strict protocols.

Breakthrough is targeted by the end of next year (2027) with full commissioning expected by June 2028, the Minister said optimistically. 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.

A dedicated division was formed to monitor the project closely. The SLBC tunnel is a critical component of Telangana’s irrigation infrastructure aimed at benefiting over 3-lakh acres ayacut, besides helping augment the drinking water sources in the region.