The 720MW Mangdechhu Hydropower Project draws an inch closer to being commissioned.

The damn’s diversion tunnel, which was used to divert the river during the construction of the dam, will be plugged tomorrow. This means that the dam is ready to store water; reservoir filling will begin by lowering the floodgates.

While the sealing of the floodgate led to the delay in the January 10 deadline, project’s Managing director, A.K Mishra, said MHPA made history. The final cost of the project is Nu 49.83B.

The project cost as per the detailed project report (DPR) was around Nu 28.9B at 2008 price level, which was later revised to Nu 40.20B. The cost was again revised to Nu 42.81B at March 2015 price level. Early last year, the cost was revised again to Nu 52.7B at December 2017 price level.

The final cost per MW is around Nu 70M. This, A K Mishra said, was the lowest in the region and this is including the cost of building transmission stations and lines.

A K Mishra said that the project was completed in six and half years – time consumed in finding the solutions for sliding hill in Punatshngachhu project.

After plugging the diversion tunnel and filling the reservoir, the water will be conducted into the intake tunnel through desilting chamber and then to the headrace tunnel.  

He said that all the adit tunnels have been plugged and it is ready to receive water.

Officials said that it would take 15 days to fill the entire tunnel.

A K Mishra said that to save time the seepage water from the surface of the pressure shaft would to used to fill two pressure shafts. After filling the pressure and surge shafts with water, turbines in the powerhouse would be tested and power synchronized with the Indian grid.

He said that two units (capable of generating 360MW) would be commissioned next month. “By March 31, all four units would be commissioned,” he added.

Final touches on the two units are underway.

Tshering Dorji