Punatsangchhu-I Hydroelectric Project
Why in News?
On April 9, 2026, the Indian and Bhutanese governments formally approved the construction of a barrage as a permanent solution to the recurrent landslides at the original dam site (right bank).
About
- Cost Escalation: The project cost has been revised to approximately ₹10,500 crore (Nu 105 billion) due to the technical redesign and decade-long delay.
- Prime Minister's Visit: The project was a key discussion point during PM Narendra Modi’s recent visit to Bhutan, where both nations reaffirmed their commitment to completing the "Jewel of Bhutan" by 2028-29.
- Energy Security: The project is seen as vital for Bhutan’s goal to double its GDP and for India’s transition to green energy.
Location and Geography
- River: Located on the Punatsangchhu River in Western Bhutan.
- District: Situated in the Wangdue Phodrang district.
- Partnership: It is a mega project under the Inter-Governmental (IG) Agreement signed between India and Bhutan in 2007.
Technical Specifications
- Capacity: Total installed capacity of 1,200 MW.
- Unit Configuration: Features 6 units of 200 MW each.
- Design Change: Originally designed as a 130-meter-high concrete gravity dam; it is now being adapted into a run-of-the-river project utilizing a barrage for water diversion.
- Underground Power House: One of the largest underground power stations in the region, which is already nearly 98% complete.
Strategic & Economic Significance
- Financing: Funded by the Government of India through a mix of grants (40%) and soft loans (60%).
- Nodal Agency: Executed by the Punatsangchhu-I Hydroelectric Project Authority (PHPA-I), comprising officials from both nations.
- Surplus Power: Most of the electricity generated will be exported to India, providing Bhutan with significant revenue in Indian Rupees.
- Regional Integration: A crucial link in the BBIN (Bangladesh, Bhutan, India, Nepal) energy cooperation framework.
Challenges and Delays
- Geological Instability: In July 2013, a massive landslide occurred on the right bank of the dam site. Despite multiple "remedial measures" over 12 years, the area remained unstable for a large dam.
- The "Barrage" Decision: Experts from the Central Water Commission (CWC) and WAPCOS (India) recommended the barrage as it is lighter and safer for the fragile Himalayan terrain.
Expected Benefits
- Carbon Offset: Will reduce millions of tonnes of carbon dioxide emissions annually.
- Economic Boom: Expected to significantly increase Bhutan's internal revenue once commissioned.
- Skill Transfer: Thousands of Bhutanese engineers and technicians have gained specialized experience in Himalayan tunnelling and hydro-technology.
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