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Construction of the 41.86 MW Super Lower Bagmati Hydropower Project, being developed on the Bagmati River, has gained momentum. Excavation of the project’s approximately 6.6-kilometre-long headrace tunnel - considered one of its most complex structures - is currently being carried out simultaneously from four working faces.

According to TAC Hydro Consultancy Pvt. Ltd., which is serving as the Technical Consultant on behalf of the project’s lead lender, Laxmi Sunrise Bank Limited, a recent site inspection found that construction activities are progressing in line with the approved schedule.

The company stated that the inspection assessed overall construction progress, quality of works, project performance, the condition of construction materials, and carried out technical verification of the Interim Payment Certificate (IPC) bills submitted by the contractor.

The inspection found that excavation of the headrace tunnel is continuing simultaneously from four locations. In the headworks area, all flood protection walls designed to safeguard the structures from flooding have been completed. Construction of two weir panels under the 94-metre-long ogee diversion weir has also been completed. In addition, construction of the intake, gravel trap, desander, and undersluice structures is progressing in parallel, according to TAC.

The Super Lower Bagmati Hydropower Project is spread across the districts of Makwanpur, Lalitpur, Kavrepalanchok, and Sindhuli in Bagmati Province. The project’s intake will be located at Huchitar in Bagmati Rural Municipality-7 of Makwanpur, while the powerhouse is being constructed at Bageri in Bagmati Rural Municipality-9.

The project is a run-of-river scheme. It will generate 41.86 MW of electricity by utilizing a gross head of 206.2 metres and a net head of 195.66 metres. Upon completion, the project is expected to add approximately 243.8 gigawatt-hours (GWh) of electricity annually to the national grid.

According to the project design, key structures include a 94-metre-long diversion weir on the river, four intake gates, a 20-metre-long gravel trap, two desanders equipped with hoppers, an 80.9-metre-long inverted siphon, a 6.59-kilometre-long pressurized headrace tunnel, a 50-metre-high surge shaft, and a 934-metre-long underground steel-lined pressure shaft.

Three vertical-axis Francis turbines, each with a capacity of 14.39 MW, will be installed at the powerhouse. The electricity generated at 11 kV will be stepped up to 132 kV through three 16.5 MVA transformers. It will then be connected to the national transmission system at the Chandranigahapur Substation in Rautahat via a 28-kilometre-long 132 kV single-circuit transmission line.

According to the developer, the project’s total cost, including interest during construction and financing costs, is estimated at Rs 8.63 billion. The cost per megawatt is estimated at approximately Rs 206.2 million. The construction period has been set at 48 months.

Technical studies indicate that the project has an Internal Rate of Return (IRR) of 14.03 percent, a Benefit-Cost Ratio (BCR) of 1.39, and a Debt Service Coverage Ratio (DSCR) of 1.45.

Why do banks carry out such technical monitoring?

As most large hydropower projects in Nepal are built with loans from banks and financial institutions, it is common practice for lenders to appoint independent technical consultants. These consultants regularly monitor whether construction activities are being carried out in accordance with the approved design, quality standards, and schedule. They also provide technical verification of the Interim Payment Certificate (IPC) bills submitted by contractors.

TAC Hydro Consultancy stated that it is performing this role for the Super Lower Bagmati Hydropower Project.

Super Lower Bagmati Hydropower Project at a Glance.

- Capacity: 41.86 MW

- River: Bagmati

- Project Type: Run-of-River (RoR)

- Annual Generation: 243.80 GWh

- Headrace Tunnel: 6.59 km

- Pressure Shaft: 934 meters

- Surge Shaft: 50 meters

- Turbines: Three vertical Francis turbines (14.39 MW each)

- Transmission Line: 132 kV, 28 km

- Grid Connection: Chandranigahapur 132 kV Substation

- Total Cost: Rs 8.6321 billion

- Construction Period: 48 months

jalasarokar