Assam pipeline burst: Rescue work yet to begin due to high water pressure

A leakage from a burst pipeline carrying water to a hydro-power plant in Assam's Dima Hasao district. Photo: PTI File

Rescue operations to locate four persons who are trapped inside the pump house of a Neepco hydropower plant in Assam could not be started on Thursday (October 10), four days after a catastrophic pipeline burst due to continued heavy water pressure in it, officials said.

The authorities of North Eastern Electric Power Corporation (NEEPCO) expect that the water level at its pump house in the plant in Dima Hasao district will take another two to three days to recede, a Neepco official said on Thursday.

The rescue operation can be launched only after the water recedes to trace the three officials and a worker of the company who are trapped inside, he said. Experts from NHPC and BHEL have joined in the state-run company’s attempt to stop the extremely high volume water flow through the pipeline, Dima Hasao Deputy Commissioner Amitabh Rajkhowa told.

Teams of the National Disaster Response Force and State Disaster Response Force are camping at Kopili hydroelectric plant of Neepco at Umrangso, he said. “Three officials and a worker of Neepco, who were trapped inside, remain untraced and could not be rescued as the water level has not receded,” Rajkhowa said.

The district administration has deployed a team of the local disaster management authority led by an assistant commissioner to assist Neepco, he said. Neepco General Manager and head of Kopili Hydro Electric Project, Debotosh Bhattacharjee said “We are trying our best and hope the water level will recede in two to three days. Our priority is to rescue the trapped persons and to restore the system as soon as possible.”

Elaborating, he said the door of the tunnel will be closed as soon as the water pressure comes down and the rescue operation will be launched. A team each of SDRF and NDRF have been mobilised for emergency action.

The four Neepco employees went missing after a large portion of the hydroelectric plant, including its entire pump house area, was inundated due to a rupture in the pipeline that carries 12,000 litres of water per second in the early hours of Monday.

The four men have been identified, the official said adding a few others who were stuck at different locations of the project area had been rescued later in the day.

A high-level team from Delhi, including Neepco chairman and managing director Vinod Kumar Singh visited the plant site to assess the cause of the blast. He told reporters that acidity could have affected the pipeline.

Sources said that the water pipeline was repaired by in 2018 and the blast took place in the same portion. Large scale damage have been caused to the hydroelectric project due to the rupture. The water gushing out from the pipeline at high speed has not only submerged several office buildings but has also damaged more than 90% of the machineries of the project, the Neepco official said.

The water has also washed away the approach bridge of the plant. The local people are, however, not facing any difficulty as there is no habitation at the site, he said.

The official said that Neepco opened all the gates of the reservoir after the pipeline burst to release excess water and reduce the water pressure. “The inter-pipeline and the valve that burst used to supply water to the pump house of the project from its reservoir at Umrangso area in Dima Hasao district of Assam.”

“The massive pressure in the tunnel has created a water fountain which is rising up to several hundred feet into the sky, he said. The hydroelectric project on the Kopili river was the maiden venture of Neepco when it came into existence in 1976. The current total installed capacity of the project is 275 MW, the official added.