Salient Features

Sunkoshi Small Hydropower Project

Project Type Run-of-River
Installed Capacity 2.60 MW
Number of units 2
Gross head 124.50 m
Net energy 14.38 GWh
Catchment area 81.00 km²
Average annual flow 5.77 m³/s
Design discharge 2.7 m³/s
Minimum monthly flow 1.10 m³/s
Compensation flow 90.00 l/s
Project design floods  
20-years 130.00 m³/s
100-years 325.00 m³/s
500-years 460.00 m³/s
Weir length 36m
Weir crest level 952.50 m amsl
Weir height (Above river bed) 2.00 m
Weir discharge capacity 368.00 m³/s
Bottom orifice sill level 951.50 m amsl
Intake orifice size 1.50 m x 0.30 m (2 x 4 nos)
Design discharge including gravel flushing and sediment flushing 368.00 m³/s
Maximum intake capacity 8.00 m³/s
Intake culvert  
Total length 60.00 m
Canal slope 1 in 50
Size 1.29 x 2.20 m with 0.25 m freeboard at 100 years flood
Gravel trap  
Length (including transition) 18.40 m
Width 4.00 m
Settling length 20.00 m
Flushing discharge 0.80 m³/s
Flushing gate 1 no. size 0.60m x 0.75m
Particle size to be settled 5mm
Gravel flushing channel  
Type Rectangular with hard stone lining
Length 12.50 m
Width 1.00 m x 1.50 m
Slope 1:35
Pipe Crossing  
Truss bridge length 30.00 m
Pipe crossing 40 m long 1300 dia 6 mm thick MS pipe
Approach canal  
Length 220.00 m
Size 1.60 m x 1.50 m
Slope 1:530
Settling basin  
Length (including transition) 77.00 m
Settling chambers 2 nos., 4.50 m wide each
Settling length 45.00 m
Flushing discharge 1.08 m³/s
Particle size to be settled 0.2 mm
Particle trapping efficiency 90%
Sediment flushing gate size 2 nos. 0.6m x 0.6m
Sediment flushing channel  
Type Rectangular
Length 23.00 m
Size 1.20 m x 1.00 m
Slope 1:30
Size 10.00 m x 10.50 m x 5.60 m
Pressure Pipe  
Type Buried and exposed
Material GRP and mild steel
Total length 25.50 m
Internal diameter 1200mm and 1300mm
Type Surface
Size 18.00 m wide and 24.00 long
Turbine axis level 825.50 m amsl
Type Open canal structure
Length 43.00 m
Tail water level 819.00 m amsl
Turbine type Turgo
Model XJA – 60A/2 x14.5
Number of units 2 nos.
Rated capacity 1317 kW each
Efficiency 85%
Turbine inlet valve Gate valve
Powerhouse crane Overhead travelling crane
Capacity 10 tons
Model SFW 1250-10/ 1430
Rated Output 1250 kW each
Rated frequency 50 hz
Rated Current 143.2 A
Rated Voltage 6300 V
Power factor 0.8
Rated speed 750 rpm
Insulation Degree F/F
Main Transformer  
Model S93150-11/6.3
Rated Capacity 3150 kVA
Voltage 6.3 kV to 11 kV
Service Power Transformer  
Model S9-M-63/6kV
Rated Capacity 63 kVA
Excitation Transformer  
Model ZSJ-50/ 6 kVA
Rated capacity 50 kVA
Transmission line  
Line length 6.3km long, 11kV, single circuit
Switchyard 17 m x 15 m (approx.)
Design discharge 2.70 m³/s
Gross head 125.5 m
Net head at full flow 117.5 m
Installed capcity 2.6 MW
Total energy per year 14.38 GWh
Power evacuation At 11 kV Sunkoshi Substation, Phurketar, Lamosanghu, NEA HT switchboard 11 kV, 25 kA with copper Bus bar rated 2000 A consisting of incomer panel