A senior official of the North Eastern Electric Power Corporaton Ltd (Neepco) reached the Kopili hydro electric project site at Umrangsu in Assam’s Dima Hasao district from New Delhi on Tuesday to examine the pipeline blast site that caused extensive damage in the nearby areas on Monday.

Three Neepco staff and a contractual worker are still missing. Robert John, Prempal Balmiki, Joy Sing Tisso and Raju Reddy are suspected to have been trapped in the pumphouse.

“Our priority is to rescue the missing persons and restore the system as soon as possible,” Neepco general manager Debatosh Bhattacharjee said.

Water is being released from three gates of the dam to minimise damage.

The burst in the pipeline that carries water at 12,000 litres/sec from Neepco reservoir to the Kopili project site led to massive flooding, which damaged around 90 per cent of the machinery, and created a water fountain that rose several hundred feet into the sky.

“Our rescue team is on the standby. We are trying to bring down the water level in the reservoir and as soon as it recedes, we will start our rescue operation,” said Ricky Phukan, district project officer, District Disaster Management Authority, Dima Hasao.

Assam, Manipur, Meghalaya, Mizoram, Arunachal Pradesh, Nagaland and Tripura are the states set to benefit from the project.