The Bhutanese Leading the way.
Following the torrential rains and flooding on 5th October 2025, assessment and restoration works are ongoing at the Dagachu Hydropower Project, while operations have resumed at the Suchhu Hydropower Project after successful repairs.
According to the Ministry of Energy and Natural Resources (MoENR), the current assessment is complete in itself for Dagachu. However, movement of the affected slope remains active and slope protection work is still in progress. An initial, intensive on-site assessment was conducted by a team from Druk Green Consultancy between 9th and 11th October 2025.
The assessment found that the 5th October flood, with an estimated discharge of 1,200 cubic meters per second, far exceeding the plant’s 1-in-10,000-year design flood capacity of 859 m³/s, caused severe toe erosion of the slope beneath the Head Race Channel (HRC). This led to a landslide, classified as a geological issue. As a result, the plant has been shut down for assessment and requires significant ongoing repair and stabilisation work. The primary cause and extent of the damage have been clearly identified as a landslide triggered by flood-induced toe erosion.
A 3D survey of the HRC was carried out in October 2025, and the raw data were sent to the Hydropower Research & Development Center for detailed analysis using specialised software. Based on these findings, a rigorous continuous monitoring program is underway to track crack propagation and structural displacement. HRDC is currently taking measurements of vertical settlement and horizontal displacement twice a day to closely monitor the shifting slope.
Slope reinstatement works through the construction of a boulder barrier, gabion wall, and dynamic roller compacted backfill are in progress. Out of the planned 20 meters of slope restoration, 6 meters have already been completed. Once slope stabilization is fully ensured, the damaged portion of the Head Race Channel will be repaired.
However, the situation at the Suchhu Hydropower Project has largely stabilized following flood damage caused by the same torrential rains. The heavy rain caused structural damage to a small section of the Glass Reinforced Pipes that serve as the project’s water conductor system. After the damaged pipe was repaired, Suchhu was synchronised to the grid at 7:30 am on 28th October 2025.
The plant has now resumed operation and is currently generating around 9 MW against its installed capacity of 18 MW. This output is expected to reduce further due to a reduction in inflow. While power generation has resumed, the design and estimate for the access road, along with retaining walls, are still being prepared by the project.
In terms of long-term protection, apart from access roads, the plant structures at Suchhu are designed and built to withstand extreme weather events.
As of now, Dagachu remains under active slope stabilization and monitoring, while Suchhu has restored operations following successful repair works.
