What Happened
- Construction on Bhutan's 1,200 MW Punatsangchhu-I Hydroelectric Project has resumed after a seven-year halt (2019–2026) caused by severe geological challenges at the dam site, including recurring landslides and sinking of the right bank slope.
- The two governments reached an agreement in July 2025 on technical solutions for the geological issues, and the first concrete pour into the dam structure took place in early 2026.
- When complete (expected 2030), the project will add ~5,670 million units (MU) of power annually and boost Bhutan's total hydropower capacity by about 30% to nearly 4,700 MW.
Static Topic Bridges
India-Bhutan Hydropower Cooperation Framework
Hydropower is the foundation of the India-Bhutan special bilateral relationship. Bhutan's water-rich Himalayan rivers and India's capital, technical expertise, and energy demand create a natural complementarity. The two countries signed the Agreement on Cooperation in Hydroelectric Power in July 2006, which was followed by a Protocol in 2008 expanding joint targets from 5,000 MW to 10,000 MW by 2020. Projects are developed under an Inter-Governmental (IG) modality with grant and concessional loan components from India.
- Framework agreement: July 2006 (Agreement on Cooperation in Hydroelectric Power)
- 2008 Protocol: Expanded target from 5,000 MW to 10,000 MW by 2020
- Funding model: Grant + credit from Government of India to Royal Government of Bhutan
- Electricity export: Bhutan sells surplus power to India under Power Purchase Agreements (PPAs) managed by both governments
- Joint Vision on India-Bhutan Energy Partnership (JVoIBEP): Reconfirmed March 2024 to extend cooperation into new green energy and grid integration
Connection to this news: Punatsangchhu-I is a flagship IG-model project — its resumption after seven years signals the durability of the bilateral framework and India's continued willingness to provide technical and financial support for complex projects.
Punatsangchhu-I Hydroelectric Project: Technical Details
The Punatsangchhu-I Hydropower Project is a run-of-the-river scheme located in Wangdue Phodrang district, Bhutan, on the Punatsangchhu (Puna Tsang Chu / Sankosh) river. It is designed around a Reinforced Concrete Gravity Dam that will impound 4.6 million cubic metres of water to operate six turbines of 200 MW each.
- Installed capacity: 1,200 MW (6 × 200 MW)
- Type: Run-of-the-river (RoR) with limited storage
- Annual generation: ~5,670 million units (MU)
- Dam type: Reinforced Concrete Gravity Dam
- Dam reservoir storage: 4.6 million cubic metres
- Location: Wangdue Phodrang district, Bhutan
- Geological challenge: Recurring landslides and right bank slope instability at the dam site
- Project start: 2008; dam construction halted: 2019; resumed: 2026; expected completion: 2030
Connection to this news: The resumption of the dam construction — the most critical and delayed component — marks the physical turning point for a project whose other elements (headrace tunnel, powerhouse, transmission lines) were already largely complete.
Run-of-the-River Hydropower: Concept and Environmental Significance
A run-of-the-river (RoR) hydropower project generates electricity primarily from the natural flow of a river, without large storage reservoirs. Water is diverted to a powerhouse via a weir or small dam and a headrace tunnel, then released back to the river downstream. RoR projects have lower environmental impact than large reservoir-based hydro because they cause less inundation, reduced displacement, and minimal disruption to river sediment flow.
- RoR vs Reservoir Hydro: RoR = minimal storage, lower regulation; Reservoir = large impoundment, greater ecological impact
- Advantage: Lower displacement, less methane from submerged vegetation, smaller footprint
- Disadvantage: Power output depends on river flow; less flexible than reservoir hydro for peak demand management
- India–Bhutan projects: Mostly RoR (Chhukha, Tala, Punatsangchhu-II, Mangdechhu) — reflects environmental preference and Bhutan's limited flat terrain for large reservoirs
Connection to this news: Punatsangchhu-I's RoR design means the dam component is relatively smaller than a conventional hydro dam, making the geological challenges more tractable to engineering solutions once diagnosed.
Bhutan's Hydropower Economy and India Trade
Hydropower accounts for over 20% of Bhutan's GDP and over 40% of government revenue through electricity export earnings. India is Bhutan's sole power export destination, making the bilateral energy relationship the financial cornerstone of Bhutan's development. Bhutan's current hydropower capacity is approximately 3,600 MW, and Punatsangchhu-I's 1,200 MW addition would represent a ~33% increase.
- Bhutan's hydropower capacity (current): ~3,600 MW
- Expected new capacity (after P-I): ~4,700 MW (increase of ~30%)
- Hydropower's share in Bhutan's GDP: >20%
- Share in Bhutan's government revenue: >40% (electricity export income)
- Indian import of Bhutan power: Under bilateral PPAs; priced below Indian domestic generation costs — benefit to both
- Other major projects: Chhukha (336 MW, 1988), Tala (1,020 MW, 2006), Mangdechhu (720 MW, 2019), Punatsangchhu-II (1,020 MW, 2025 fully operational)
Connection to this news: Punatsangchhu-I's completion will significantly boost Bhutan's export earnings and reduce Bhutan's electricity trade deficit with India, strengthening the economic foundation of the bilateral relationship.
India-Bhutan Special Relationship
India and Bhutan maintain a unique Treaty of Friendship (1949, revised 2007), under which India provides security guarantees and development assistance while Bhutan maintains independence in external affairs. The relationship is characterised by absence of formal embassies (Bhutan has no formal diplomatic relations with the US or China) and deep economic interdependence. Hydropower is the most tangible economic expression of this partnership.
- Friendship Treaty: 1949 (signed), revised 2007 (Bhutan's foreign policy autonomy formally recognised)
- India as Bhutan's largest trade, development, and security partner
- Bhutan-China border: Long-standing disputes; India monitors boundary negotiations closely
- SAARC: Bhutan is a member; India-Bhutan also cooperate under BIMSTEC
- Bhutan's Five-Year Plans: Substantially funded by Indian grants and project assistance
Connection to this news: The resumption of P-I after seven years of geological impasse — requiring joint technical problem-solving — exemplifies the depth of institutional cooperation that distinguishes the India-Bhutan relationship from standard bilateral partnerships.
Key Facts & Data
- Punatsangchhu-I capacity: 1,200 MW (6 × 200 MW turbines)
- Annual generation target: ~5,670 million units (MU)
- Dam construction halt: 2019 (geological instability); Resumed: 2026
- Expected completion: 2030
- Location: Wangdue Phodrang, Bhutan; River: Punatsangchhu (Sankosh)
- Project type: Run-of-the-river; Dam type: Reinforced Concrete Gravity Dam
- Bhutan's total capacity after completion: ~4,700 MW (30% increase)
- India-Bhutan Hydropower Agreement: 2006; Protocol 2008 (target: 10,000 MW by 2020)
- Punatsangchhu-II (1,020 MW): Fully operational as of August 2025