The Bhutan We Think We Know

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FAQ

Why is Punatsangchhu-I delayed?

Geology. Punatsangchhu-I (1,200 MW) broke ground in 2008 with commissioning expected around 2016 — but in 2013 the right bank above the dam pit began to slide, and investigations kept finding shear zones the original surveys had missed. The Himalayan rock the dam is keyed into is still actively rising and shifting. Slope after slope has had to be re-engineered, commissioning has slipped past every revised target, and the project remains unfinished eighteen years on, with the budget up from a projected Nu 35 billion to roughly Nu 100 billion. Its sister project PHPA-II (1,020 MW) escaped the worst geology and was commissioned in December 2024 — itself seven years late.

The short version: the mountain would not hold. A slow toe-slide in 2013 on the right bank above the dam pit revealed rock far weaker than the surveys had read, and the active mountain-building that raised the Himalaya turned out to be still at work directly beneath the site. Since then the project’s history has been told in geology — shear zones, slope stabilisation, re-engineering — rather than in turbines.

The cost of the delay compounds in every direction: a budget roughly tripled, eighteen years without a unit generated — longer than China took to build a dam thirteen times larger — and an entire cohort of engineers who have spent most of a career on one unfinished plant (Paradox #3).

The full story of both dams — including why the “successful” sister, PHPA-II, ended up carrying 78% of the nation’s audit irregularities — is in The Punatsangchhu Problem, and what it means for the ten further projects Bhutan plans is the harder question underneath it.

Primary sources