18 years
since groundbreaking at Punatsangchhu-I · still uncommissioned in 2026
The Eighteen-Year Project
A junior engineer who joined in 2008 has spent half her working life on a single incomplete dam. The country has spent a single project's worth of institutional attention across two decades.
The duration
One project, two decades, no electricity yet
Punatsangchhu-I broke ground in 2008. The dam is on the Punatsangchhu river in western Bhutan; the design output is 1,200 MW, roughly the same scale as the country’s already-commissioned Tala station. The build was financed under the bilateral Indian-rupee hydropower-debt framework — the same template that delivered Tala in nine years, Mangdechhu in six, and PHPA-II in fourteen.
Eighteen years later, in 2026, the station is still uncommissioned. The country’s audit ledger now carries the project as the single largest concentration of construction-procurement irregularity in any fiscal year on record.
The arithmetic of the delay
What 18 years has cost
≈ USD 1.6bn
approximate cumulative construction outlay against the original USD 1.2bn budget · cost overrun roughly 1.3×
≈ USD 2.5–3bn
modelled forward PV of foregone export-PPA revenue across the 18-year delay window
Nu 7.8bn
share of FY 2024/25 audit irregularities concentrated in the bilateral hydropower programme's other mega-project, PHPA-II
78%
of FY 2024/25 audit observations from one project (PHPA-II) · the rest of the country's institutional book has 22%
The cost is not only the missing electricity. It is the implicit cost of capital on the rupee-denominated bilateral debt that finances the build, the foregone export revenue at the PPA tariffs negotiated against an early-commissioning assumption, and the disproportionate share of institutional and audit attention absorbed by one project across two decades.
The geological story
Why the original schedule failed
The original 2008 design assumed conventional Himalayan hydro-construction geology. The site at Punatsangchhu sits within an active orogenic belt — the long-running tectonic accordion that produced the Himalayas in the first place — and the dam wall and adjacent slope ran into shear-zone and toe-slide problems that the pre-construction survey did not fully anticipate.
The most-cited inflection point is November 2013, when a toe-slide at the right-bank slope above the dam axis triggered a multi-year re-engineering programme. The project absorbed new ground-stabilisation work, a redesigned tunnel approach, additional foreign-consulting input, and a long sequence of stop-start construction periods.
The geology was not unknowable in 2008. It was undertested. The 2018 directive to complete a national-scale geological inventory — still being delivered in 2026 — is, in part, an institutional response to exactly this category of pre-construction-data gap.
2013
the toe-slide year · the project's first multi-year re-engineering window opened here
The comparators
How long peer projects took
Sira-Kvina · 4 years
Norway · 1,260 MW · Statkraft-led · 1967 → 1971 · roughly the same nameplate as PHPA-I
Mangdechhu · 6 years
Bhutan · 720 MW · same bilateral framework · 2013 → 2019
Baihetan · 9 years
China · 16,000 MW · CTGC · 2013 → 2022 · 13× PHPA-I's nameplate
Tala · 9 years
Bhutan · 1,020 MW · same bilateral framework · 1998 → 2007
Itaipu · 16 years
Brazil/Paraguay · 14,000 MW · the canonical long-build comparator · 1975 → 1991
Three Gorges · 17 years
China · 22,500 MW · the largest hydropower project in human history · 1993 → 2009
PHPA-I is now an outlier among outliers. The same bilateral construction framework that produced Mangdechhu in six years and Tala in nine has, on this site, run for eighteen.
The audit concentration
One sister project absorbs the compliance apparatus
The Royal Audit Authority’s FY 2024–25 Annual Audit Report recorded total construction-procurement irregularities of Nu 9,987 million — more than double the FY 2021/22 figure. The headline finding is the concentration, and it does not land on PHPA-I:
78%
of FY 2024/25 audit irregularities concentrated in PHPA-II — the sister mega-project, commissioned in late 2024 after a fourteen-year build
PHPA-I, still uncommissioned, will have its own audit reckoning when the project closes out. The current finding is that the bilateral hydropower programme’s other dam — built on the same rupee framework, by overlapping institutional teams — produced the single largest concentration of construction-procurement irregularity in any fiscal year on record.
The remaining 22% is spread across hundreds of smaller projects, agencies, and institutions across the country’s institutional book. The asymmetry is the structural finding. A single mega-project absorbs the audit apparatus’ attention in a way that compresses scrutiny on every other line item.
The Crown’s articulating function continues to operate on a forty-year horizon. The compliance apparatus that should monitor that horizon operates, today, on an annual cycle and a limited staff envelope. The gap shows up in the audit report.
The Tshering composite
An engineer who joined in 2008
A junior civil engineer joined the Punatsangchhu-I team in 2008. She was 24, fresh from CST or an Indian engineering institute. The project was her first major assignment.
Eighteen years later, in 2026, she is 42. She has greyed at the temples. She has raised children who are now in college themselves. She has watched two changes of government, three RMA Governors, the entire COVID pandemic, the lockdown of 2020–22, the global fuel-price spike, and the Royal launch of GMC. The project she joined as her first assignment is still not commissioned.
If it commissions in 2028, she will be 44. If she retires at 60, she will have spent almost half of her entire working career on one incomplete dam.
What follows
The second-order work the next decade requires
1
Complete the national geological inventory by 2027/28 · every future hydropower site referenced against integrated tectonic-stability data
2
Reform pre-construction risk-pricing on rupee bilateral debt · separate base-case from contingency from project-overrun lines explicitly
3
Expand RAA staffing to monitor multi-decade mega-projects in real time · not at the end-of-year audit window only
4
Commission PHPA-I and absorb the operational lesson into the next ten projects in the 13th FYP pipeline · 9,892 MW additional capacity to deliver
5
Publish a Punatsangchhu-I commissioning monograph · so the country's next forty years of hydropower work draws on what this project taught
The 13th FYP commits Bhutan to ten additional large hydropower projects totalling 9,892 MW: Nyera Amari, Kholongchu, Dorjilung, Bunakha, Wangchhu, Khomachhu, Dangchhu, Chamkharchhu-I, Sankosh, Kuri-Gongri. Plus the 1,800 MW Gongri-Jericho pumped-storage project under DPR.
Whether the country’s next forty years of hydropower work has absorbed the PHPA-I lesson is the question. The answer arrives one project at a time.