🗞️ Why in News Construction on Bhutan’s 1,200 MW Punatsangchhu-I Hydroelectric Project resumed on April 10, 2026, after a seven-year halt caused by a slope failure in 2019. India’s Union Minister for Power, Manohar Lal, attended the concrete-pouring ceremony marking the resumption of work, underscoring the project’s centrality to India-Bhutan energy cooperation.
Project Specifications
| Parameter | Details |
|---|---|
| Installed capacity | 1,200 MW (6 × 200 MW underground turbines) |
| Dam height | 130 metres |
| Dam length | 239 metres |
| Dam type | Concrete gravity dam |
| River | Punatsangchhu River |
| Location | ~80 km east of Thimphu, Wangdue Phodrang District, Bhutan |
| Turbine arrangement | Underground powerhouse (6 Francis-type turbines) |
| Status (April 2026) | Physical completion: ~88% |
| Work halted | 2019 (slope failure) |
| Work resumed | April 10, 2026 |
Why Was the Project Halted?
In 2019, a major slope failure (landslide/geological instability on the dam abutment) forced a halt to all construction at Punatsangchhu-I. The right bank abutment — a critical structural support for the dam — showed signs of deep-seated geological movement.
Geological Challenge
- The Punatsangchhu River valley has complex geology — Himalayan geology with active tectonics and weak rock formations
- The slope failure forced engineers to redesign the dam’s abutment and drainage systems
- A modified design incorporating:
- Additional drainage tunnels and anchoring systems
- Revised dam profile to reduce load on the unstable slope
- International geological consultancy from European and Japanese experts
This is a common challenge in Himalayan hydropower: geological surveys conducted before construction often underestimate deep slope instability that manifests only during construction.
India’s Financing and Strategic Interest
Funding Structure
India finances the project under a grant + loan model standard for Bhutan hydro cooperation:
| Component | Details |
|---|---|
| Grant component | 40% of project cost (free of any repayment) |
| Loan component | 60% of project cost |
| Loan interest rate | 10% per annum |
| Repayment source | Power exports to India (electricity revenues service the loan) |
Strategic Logic
- All surplus power from Punatsangchhu-I will be exported to India — this is the cornerstone of the India-Bhutan energy relationship
- Bhutan’s hydro exports to India generate approximately 40–50% of Bhutan’s total government revenues
- For India: Bhutan provides clean, renewable, cross-border electricity that counts toward India’s renewable portfolio
India-Bhutan Hydropower Framework
Under successive agreements, India has been developing 10,000 MW of hydroelectric capacity in Bhutan by 2020 (a target that has slipped but continues). The framework covers:
- Operational: Tala (1,020 MW), Chukha (336 MW), Kurichu (60 MW)
- Under development/resumed: Punatsangchhu-I (1,200 MW), Punatsangchhu-II (1,020 MW), Mangdechhu (720 MW — operational 2019)
- Planned: Bunakha (180 MW), Chamkharchhu-I (670 MW)
India-Bhutan Relations — Energy as Cornerstone
India and Bhutan’s bilateral relationship is uniquely characterised by deep energy interdependence:
| Dimension | Details |
|---|---|
| Treaty basis | India-Bhutan Friendship Treaty (2007, revised from 1949) |
| Hydro cooperation | Established 1960s (Chukha project) |
| Revenue share | ~40–50% of Bhutan’s GDP contribution from hydro exports |
| India’s position | Only country with which Bhutan has a defence alignment |
| Open border | Free movement of people and goods (no passport/visa) |
| Indian rupee | Accepted alongside ngultrum in Bhutan (pegged 1:1) |
Why This Is Different from Other Regional Hydro Deals
India’s Bhutan model is distinct from deals with Nepal or Bangladesh:
- Bhutan cedes strategic autonomy (no military alliances without India’s knowledge) in exchange for economic security
- Indian PSUs (NHPC, SJVN) build, operate, and eventually hand over projects
- Power Purchase Agreements (PPAs) are long-term and guaranteed by India
Punatsangchhu-II — Nearby Sister Project
Punatsangchhu-I has a companion project: Punatsangchhu-II (1,020 MW), also on the Punatsangchhu River. It faces similar geological challenges and has also experienced delays. Both projects are often discussed together in UPSC context.
UPSC Relevance
| Paper | Angle |
|---|---|
| GS2 — International Relations | India-Bhutan bilateral; energy diplomacy; grant-loan model |
| GS2 — Governance | India’s cross-border energy cooperation framework |
| GS3 — Economy | Hydropower; renewable energy; transboundary river management |
| GS1 — Geography | Punatsangchhu River; Bhutan’s river systems; Himalayan geology |
| Interview | Should India use hydro financing as diplomatic leverage? Sustainable infrastructure in geologically fragile zones |
📌 Facts Corner
Punatsangchhu-I HEP: Capacity: 1,200 MW (6 × 200 MW underground turbines) | Dam: 130 m high, 239 m long (concrete gravity) | River: Punatsangchhu | Location: ~80 km east of Thimphu, Wangdue Phodrang | Halted: 2019 (slope failure/geological instability) | Resumed: April 10, 2026 | Physical completion: ~88% | Financial completion: ~93% | India funding: 40% grant + 60% loan @ 10% p.a. | All surplus power exported to India | India’s power minister at ceremony: Manohar Lal | Bhutan hydro revenues: ~40–50% of government revenues | GS2: India-Bhutan Relations; GS3: Economy, Hydropower
