Advanced VTEM Plus tech to guide SLBC project completion
Hyderabad: The Telangana government has adopted cutting-edge VTEM Plus electromagnetic survey technology to accelerate and safely complete the SLBC project—the Srisailam Left Bank Canal Tunnel-1. This helicopter-borne survey will deliver precise underground data essential for completing the 44-kilometre tunnel within two years.
Chief Minister A. Revanth Reddy, accompanied by Ministers N. Uttam Kumar Reddy and Komatireddy Venkat Reddy, inaugurated the survey at Mannevaripally in Achampeta mandal. The Chief Minister monitored the maiden sortie, underscoring his government’s resolve to end decades of delay.
Scientific mapping to redefine SLBC project execution
Irrigation Minister Uttam Kumar Reddy explained that the SLBC project, designed to irrigate 3 lakh acres and supply drinking water to 30 lakh people, represents a turning point in Telangana’s irrigation engineering.
The project, initially sanctioned in 1983 with an estimated cost of Rs 2,000 crore, now carries a sanctioned amount of about Rs 4,000 crore. Of the total 42-kilometre tunnel, 9.8 kilometres remain incomplete after a collapse earlier this year.
“This survey begins a new phase of science-led construction. The data will ensure safety, precision, and on-schedule completion,” said Uttam Kumar Reddy.
The National Geophysical Research Institute (NGRI) is leading the aerial survey using the Canadian VTEM Plus system. The helicopter flies at about 250 feet with a transmitter loop suspended below, sending electromagnetic pulses deep into the earth. The reflected signals reveal geological variations such as fault zones, rock strength, and water movement up to 1,000 metres deep.
Flights follow straight, parallel paths across the 44-kilometre corridor, ensuring uniform coverage. The survey will produce high-resolution 3D resistivity and conductivity models that engineers will use to design tunneling reinforcement and drainage strategies.
Processed at NGRI’s Hyderabad centre, the data will create a three-dimensional geological model for tunnel planning. “We are merging aerial precision with data science to make the SLBC project the safest and most efficient irrigation tunnel in India,” said the Minister.
Once operational, the tunnel will draw more than 30 TMC of water annually from the Srisailam reservoir. It will supply irrigation through gravity flow, replacing energy-intensive lift-irrigation systems and saving around Rs 500 crore in electricity expenses yearly.
For expert supervision, the government appointed retired Lt. Gen. Harpal Singh as technical advisor and Col. Parikshit Mehra to oversee the tunnel’s engineering operations. Both officers bring extensive experience from Himalayan and riverine tunneling projects.
Col. Mehra noted that the VTEM Plus survey ensures precision for twin-end tunneling without intermediate access. NGRI Director Dr. Prakash Garni said the technology will also enhance groundwater management and mineral exploration in Telangana.
Uttam Kumar Reddy added that this initiative reaffirms the government’s commitment to equitable Krishna River water use. “The SLBC project embodies Telangana’s scientific, sustainable, and equitable water policy,” he said.
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