Hyderabad: Telangana has entered a new era of science-driven irrigation management with the launch of a helicopter-borne VTEM Plus electromagnetic survey for the SLBC project, aimed at fast-tracking the 44-kilometre Srisailam Left Bank Canal Tunnel-1.
Chief Minister A. Revanth Reddy, along with Ministers N. Uttam Kumar Reddy and Komatireddy Venkat Reddy, inaugurated the survey at Mannevaripally in Achampeta mandal of Nagarkurnool district. The Chief Minister personally reviewed the first sortie, signaling the government’s determination to complete the long-pending irrigation lifeline.
Irrigation Minister Uttam Kumar Reddy said the survey will provide precise geological data to help complete the remaining works safely within two years. The SLBC project was conceived to irrigate 3 lakh acres and supply drinking water to nearly 30 lakh people in Nalgonda and Mahabubnagar districts.
Originally sanctioned in 1983 and launched in 2004–05, the project cost has risen from Rs 2,000 crore to about Rs 4,000 crore. Of the 42-kilometre tunnel, 9.8 kilometres remain incomplete after a collapse earlier this year.
“The new survey marks a renewed scientific approach. Accurate subsurface mapping will guide safe and timely completion of the pending section,” the Minister said.
Survey to ensure safe, scientific SLBC project completion
The National Geophysical Research Institute (NGRI) is executing the survey using the Canadian-made VTEM Plus system. This advanced tool emits electromagnetic pulses deep into the earth, capturing reflections that identify variations in rock type, water flow, and mineral content up to 1,000 metres below the surface.
Each flight follows parallel paths across the entire alignment to produce 3D resistivity and conductivity maps. These findings will guide tunnel alignment, reinforcement, and drainage systems.
NGRI scientists will process the data in Hyderabad to create a detailed three-dimensional model of the SLBC corridor. “This combination of aerial precision and scientific analysis will ensure full safety in tunneling operations,” Uttam Kumar Reddy said.
When operational, the tunnel will draw over 30 TMC of water annually from the Srisailam reservoir, providing gravity-flow irrigation. The system will replace costly lift-irrigation setups and save about Rs 500 crore annually in electricity expenses.
To strengthen execution, the State government has enlisted expertise from the Indian Army’s Corps of Engineers. Retired Lt. Gen. Harpal Singh has been appointed advisor, and Col. Parikshit Mehra will supervise construction.
“Their experience in challenging terrains will ensure that global engineering standards guide Telangana’s irrigation projects,” the Minister said. The SLBC tunnel, driven from both ends without middle access, is considered among Asia’s most complex irrigation tunnels.
Col. Mehra explained that the VTEM Plus data will enable safe operations by detecting fault zones and predicting water inflows. NGRI Director Dr. Prakash Garni added that the findings will also support groundwater and mineral management.
Chief Minister Revanth Reddy emphasized that completing the SLBC is crucial to securing Telangana’s fair share of Krishna River water. Uttam Kumar Reddy reiterated that with leadership from Mahabubnagar and Nalgonda districts, the project must reach completion soon.
“The SLBC project unites science, governance, and engineering expertise. It will stand as a model of Telangana’s commitment to sustainable irrigation and self-reliance,” he said.
