Hyderabad: Telangana Irrigation Minister N. Uttam Kumar Reddy on Monday said scientific precision will guide the completion of the Srisailam Left Bank Canal (SLBC) tunnel. He made this statement after launching a helicopter-borne electromagnetic survey to fast-track the remaining 9.8 kilometres of the 44-kilometre project.
Speaking at Mannevari Palli in Nagarkurnool district, the Minister joined Chief Minister A. Revanth Reddy, who flagged off the aerial survey using the Canadian-made VTEM Plus system. Sanctioned in 1983, the SLBC tunnel began construction in 2004 and is designed to irrigate 3 lakh acres and supply drinking water to 30 lakh people in Nalgonda and Mahabubnagar districts.
SLBC tunnel to follow scientific data for safe execution
According to Uttam Kumar Reddy, the National Geophysical Research Institute (NGRI) is leading the three-day survey. The system maps subsurface structures as deep as 1,000 metres. A transmitter loop, suspended below a helicopter, emits electromagnetic pulses to detect fault lines, water pockets and geological formations.
Engineers will process this data to build a 3D model of the terrain. This model will help them finalise the tunnel’s alignment, safety measures and drainage systems. “This marks a turning point. For the first time, we are relying on hard data instead of assumptions,” he said.
State deploys military engineers for tunnel work
To maintain high safety and engineering standards, the state government brought in military experts. Retired Lt. Gen. Harpal Singh now serves as an advisor, while Col. Parikshit Mehra—who previously led tunnelling projects at Rohtang Pass and under the Brahmaputra River—is heading on-site execution.
Col. Mehra explained that a tunnel driven from both ends without central access demands extreme accuracy. The VTEM Plus survey, he said, provides essential readings on rock strength and water flow, which are critical for accident-free excavation.
Gravity-fed system to cut irrigation costs by ₹500 crore
Once completed, the SLBC tunnel will deliver 30 TMC of water annually from the Srisailam reservoir through a gravity-based system. This approach will eliminate the need for electricity-intensive lift irrigation currently used under the MRP project. “The state can save nearly ₹500 crore each year on power alone,” Uttam Kumar Reddy noted.
He also said this project is key to restoring Telangana’s full Krishna river share. “Earlier governments gave away 512 TMC to Andhra Pradesh, leaving us with just 299 TMC. We must fix that imbalance,” he said.
SLBC tunnel to become a milestone in Telangana’s irrigation infrastructure
Describing it as one of Asia’s most complex tunnels, Uttam Kumar Reddy said the SLBC project combines modern technology with engineering expertise. Built without intermediate shafts, the tunnel now benefits from real-time data and high-level supervision. “Missing this chance would be a historic failure,” he warned.
The helicopter survey operates at 250 feet, while the sensor loop trails at around 120 feet. Scientists track and analyse data live during each flight. According to NGRI Director Dr. Prakash Garni, the survey will also help in groundwater and mineral resource planning across the state.