The Bhutanese Leading the way.
The 126 MW Dagachhu Hydropower Plant is expected to lose about Nu 655 million (mn) in revenue by the end of April 2026 following a prolonged shutdown caused by severe flood damage in October 2025.
The plant has remained out of operation since 9th October 2025 after heavy monsoon rains triggered flooding that damaged several key components of the project.
The floods severely affected parts of the Water Conductor System (WCS), particularly the Head Race Channel (HRC) connecting the desilter to the Head Race Tunnel. The channel’s foundation was completely washed away.
The damaged Head Race Channel is now being replaced with a steel penstock, with the contract awarded to M/s BHSL, Jigmeling. The first batch of steel penstock is expected to arrive by mid-February 2026.
Reinstatement of the downhill slope using a boulder barrier and compacted backfill has been completed, while stabilisation of the uphill slope through soil nailing and shotcreting is currently underway.
The flood also washed away the road leading to the diversion weir and powerhouse. Although the road network has been temporarily restored, access remains limited. The slope at the 220 kV Pothead Yard was completely eroded, though its foundation remains intact. Slope reinstatement works are in progress.
At the dam site, the downstream gantry crane and tuff boom were swept away by the flood, and replacement works are ongoing. The cut-off wing wall at the dam and a portion of the fish ladder were also damaged and will be restored after completion of the Water Conductor System repairs.
According to the DG of the Department of Energy, Karma P. Dorji, the project is tentatively expected to resume operations by the end of April 2026.
The estimated revenue loss is calculated based on a tariff of Nu 3.535 per unit, with the shutdown classified as a force majeure event.
