The 720 MW Mangdechhu Hydroelectric Project, which was supposed to be commissioned by end of this month, got delayed by a month from the last deadline – November end.

This, the project’s managing director, AK Mishra, said was because of the unforeseen circumstances that came up after the management found a crack in the one end-arm of the flood gate that was manufactured in Mumbai.

“The whole thing was redone and it took a month, delaying the completion of the dam,” he said.

He, however, said that the project was in advanced stage of completion with overall progress of 98.99 percent as of October 31 this year.

MHPA is planning to start filling the water conductor system, the headrace tunnel (HRT) and pressure shafts from December 20 along with plugging of diversion tunnel.

The entire hydromechanic works, according to the managing director, is expected to end by December 18. Diversion tunnel would be plugged with concrete and raising the water level in reservoir would begin, he said.

According to data, Mangdechhu reveals a discharge of 100 cumecs (cubic meters per second) during monsoon. By mid-September, he said it drops to 58 cumecs, which is more manageable to control the water discharge in a channelised manner.

The only remaining task, he said, was to plug the two adit tunnels.

By December 30 or 31, the project is planning to spin one 180 MW unit in the power house or turbine. In January two units would be commissioned. In the following month the project aims to spin another two units in the powerhouse.

“Synchronisation with the Indian grid will take place in the first 10 days of January 2019,” AK Mishra said,

This is expected to consume about a month because it has to be done in parts.

Each unit of the powerhouse is capable of generating 180MW of power and the four units would together produce 720MW.

In terms of financial progress, the project achieved till October 31 is 93.98 percent with respect to third revised cost estimate under approval of Government of India. As on October 31, the project incurred an expenditure of Nu 46.1B.

Mangdechhu project is expected to export 3 billion units every year to India. The tariff is under discussion.

Meanwhile, the entire staff and officers of MHPA, including the managing director have volunteered to conduct a mass cleaning of the 13.5kms HRT to ensure clean water discharge into the generating units. “No stone or iron pieces should remain in the tunnel before we start filling the water for commissioning of the units,” AK Mishra said.


Tshering Dorji