The second stage of river diversion started yesterday

Dechen Dolkar 

The 1,020 MW Punatsangchhu-II Hydroelectric Project Authority (PHPA) crossed a vital milestone yesterday with the second stage of river diversion, bringing it closer to its commissioning.

The dam’s diversion tunnel, which was used to divert the river during the construction of the dam, was plugged in yesterday coinciding with the Foundation Day of the project. The dam is ready to store water.

A special ceremony was held at the project site to mark the occasion, which was attended by Minister of Economic Affairs, Loknath Sharma and Ambassador of India to Bhutan, Sudhakar Dalela.

Following the second stage river diversion, the plugging work of the diversion tunnel will be taken up by the project. Dam reservoir filling will start in April, 2023. The first diversion was done in May 2013.

The construction of the dam was completed earlier this month.

The Managing Director (MD) of the PHPA-II, Rajesh Kumar Chandel, said the milestone is a testament to the concerted efforts of project engineers, designers, management team, and everyone involved in different aspects of project construction activities.

“The project has managed to keep construction activities on track despite adversities such as geological surprises, flash floods and supply chain bottlenecks on account of the Covid-19 pandemic,” the MD said.

Lyonpo Loknath attended the plugging of the diversion tunnel yesterday

A 91-meter high concrete gravity dam with a storage capacity of 4.64 million cubic meters, an 8.51-km long Head Race Tunnel (HRT) and an underground Power House make the major components of the project that cost Nu 94.45B.

The MD said that the progress of the powerhouse is 84.20 percent, and 99 percent of the work is completed in HRT.

The project commissioning is targeted for October 2024.

Once commissioned, PHPA–II will generate 4,357 million units of electricity annually, increasing the power generation capacity in Bhutan by 43 percent over the present capacity. The project will help reduce 3.9 million tons of greenhouse gas emissions annually.

Officials said that the commissioning of PHPA–II will be a key milestone in the long-standing and mutually-beneficial collaboration between India and Bhutan in the hydro-power sector.  The commissioning of the project will lead to prosperity and energy security for the region.

“The project management team is fully committed to early commissioning of the project,” an official said.

The 1020MW PHPA-II is being implemented jointly by the government and the Government of India. The foundation stone of the Project was jointly laid by the then Prime Minister of Bhutan and the External Affairs Minister of India in 2010.