Increase in silt & water halts tunnel rescue bid

Hyderabad: Efforts to rescue eight people — two engineers and six labourers— trapped in the Srisailam Left Bank Canal (SLBC) tunnel at Domalapenta in Telangana's Nagarkurnool district have come to a standstill after nearly three days of strenuous attempts. The situation, initially filled with hope, has become increasingly difficult due to rising water levels and shifting silt, making the operation riskier by the hour.
The eight people were trapped deep inside the tunnel when the roof caved in on Feb 22, while 52 others came out of the tunnel. By late evening some family members of the trapped people were also flown in by the authorities.
The state govt, initially considering vertical drilling and digging from the top of the tunnel, above 400 meters, has now abandoned that approach. Instead, the authorities have decided to continue efforts from within the tunnel to mitigate any potential harm to rescuers.
The increased water inflow and the sudden accumulation of silt have raised grave concerns about the structural integrity of the tunnel, forcing officials to reconsider their strategy.
Influx of water continues unabated
On Monday morning, rescue teams entered the tunnel to assess the situation, only to find that the silt had increased by about one meter, rising from five to six meters to over seven meters. The influx of water continued unabated, complicating the dewatering process.
Experts suspect that the fresh water surge could be due to either a sudden increase in activity at the collapsed roof or the onset of a new collapse—though they have been unable to confirm this theory immediately.
Officials further reported that the tunnel boring machine (TBM) had moved 500 meters, likely due to the rising water, and the conveyor belt used for material removal was also damaged.
In light of these developments, the National Highways and Infrastructure Development Corporation Limited (NHIDCL) urged the govt to slow down operations and proceed with utmost caution.
"We cannot afford to take risks at this point," they advised, urging the Telangana govt to observe the tunnel for any further signs of collapse while the water and silt gushed in.
580 personnel have been on standby near the site
State roads and buildings minister Komatireddy Venkat Reddy visited the site on Monday morning and convened a high-level review meeting with key officials from various disaster management agencies, including NDRF, SDRF, Army, Navy, Singareni, and private agencies. About 580 personnel have been on standby near the site, with seven operations carried out so far. There were discussions about bringing sniffer dogs to locate the missing workers, but the rising water and mud made it impossible for the dogs to reach the spot.
"We will continue our efforts," assured minister Komatireddy, while stressing the importance of involving outside experts. "Jaiprakash Associates and Robbins India have been instructed to bring in additional experts to assist us in the rescue operation," he added.
Meanwhile, a crucial recommendation came from Australian tunnel expert Chris Cooper, who strongly urged against using gas-cutters or any form of digging, emphasising that the area near the collapsed roof remained unstable.
"To gain a clearer picture of the terrain and soil conditions, the govt has sent coordinates and maps to institutions like the National Remote Sensing Centre, National Geophysical Research Institute, and Geological Survey of India for further analysis," a senior official said.
The rescue operation in the tunnel remains on hold as the authorities tread carefully, awaiting more information on how best to proceed without endangering additional lives.