Telangana’s Chief Minister A. Revanth Reddy, joined by Ministers Uttam Kumar Reddy and Komatireddy Venkat Reddy, recently oversaw the launch of a vital aerial electromagnetic survey for the Srisailam Left Bank Canal (SLBC) tunnel project. This marks a significant step towards the project’s completion.
This state-of-the-art heli-borne magnetic survey utilizes a specialized transmitter mounted on a helicopter to gather geological information up to an astonishing depth of 1,000 meters. Its primary goal is to pinpoint underground shear zones and crucial water flow patterns, both essential for the precise planning and safe execution of the SLBC tunnel construction.
To get a firsthand look at this innovative process, the Chief Minister and his accompanying ministers even flew parallel to the survey helicopter for several kilometers, observing the operation directly from the air.
Minister Uttam Reddy emphasized that Telangana is embarking on a new era of science-driven irrigation management with this advanced VTEM Plus electromagnetic survey. He stated that the precise underground data collected will enable the safe completion of the remaining tunnel works within two years, ultimately providing much-needed water to millions of residents in Nalgonda and Mahabubnagar districts.
Reddy elaborated on the survey’s methodology, highlighting that the National Geophysical Research Institute (NGRI) is deploying the cutting-edge, Canadian-made VTEM Plus system. This system can detect geological features up to 1,000 meters deep. It operates by suspending a large transmitter loop 100-150 feet below the helicopter, which sends electromagnetic pulses into the earth. Sophisticated sensors then capture the reflections, revealing intricate details about rock structure, subterranean water flow, and mineral composition.
“This data will empower us to accurately identify fault zones, shear planes, and hidden underground water pockets,” the Minister explained. The survey flights meticulously cover the entire 44-kilometer alignment in straight, parallel passes, with re-runs conducted for verification as needed. Over three days, this process will generate detailed 3D resistivity and conductivity maps, providing indispensable guidance for engineers in optimizing tunnel alignment, reinforcement, and drainage designs.
NGRI scientists in Hyderabad will meticulously process the collected field data using specialized software to create a comprehensive three-dimensional geological model of the SLBC corridor. He assured that “the blend of aerial precision and thorough scientific analysis will offer a complete understanding of subsurface conditions, thus guaranteeing the safety of all future tunneling operations.”
To further bolster technical oversight, the government has brought in seasoned engineers from the Indian Army’s Corps of Engineers. Lieutenant General Harpal Singh (retired), former Engineer-in-Chief of the Indian Army, has been appointed as an advisor, and Colonel Parikshit Mehra, renowned for his supervision of significant tunneling projects including those under the Brahmaputra River and at Rohtang Pass, has been assigned to oversee the project’s execution.