नेपालको पानी जनताको लगानी, हरेक नेपाली विद्युतको शेयरधनी

Government of Nepal

Ministry of Energy, Water Resources and Irrigation

Janatako Jalavidhyut Karyakram

Janatako Jalavidhyut Karyakram

Ghunsa Khola

GKHEP, as proposed in the present study, has an installed capacity of 77.5 MW. GKHEP is designed as a SRoR scheme. Its headworks consists of an ungated weir with two under sluices, a side intake, and a pair of pressurized underground desilting chambers on the right bank of Ghunsa Khola at Lamatar. The GKHEP project area is located entirely in the Phaktanglung Rural Municipality of Taplejung District. It lies in the Himalaya region of Nepal. The electricity generated from the project will be evacuated through the Dhungesanghu substation.

Type Simple Run off the River
Latitude 27° 31' 46'' to 27° 34' 00'' N
Longitude 87° 48' 20'' to 87° 51' 38'' E
River Ghunsa Khola
Catchment area at intake site 726.75 km²
Design flood at intake (Q100) 880.00 m³/s
Flood at intake (Q10,000) 1442.00 m³/s
General Hydraulics
Gross head 432.00 m
Net head 425.55 m
Design flow Q43 21.28 m3/s
Upstream Pond Level 1947.0 m
C/L of Machine 1515.0 m
High Flood Level at Head works (Q100) 1951.50 m
River Diversion Arrangement
Monsoon flood (5 Year Return Period) 502 m³/s
Coffer Dam Type Rock fill Dam
Diversion Tunnel
Length 288.0 m
Type and Finished Size D- shaped, 6.5 m x 6.5 m with gate at inlet
Bed Slope 1 in 40
Diversion Weir
Type Un-gated weir and under sluice
Undersluice 2 Nos., 4.5 m (W) x 4.5 m (H), Radial Gated
Spillway Un-gated, 35 m wide
Type Well type side intake with trash rack
Size of opening 2 Nos., 3.1 m (W) x 3.1 m (H)
Trash rack opening 4 Nos., 3.5 m (W) x 3.5 m (H)
Connecting Tunnels
Shape D- Shaped
Size (width x height) 3.10 m x 3.10 m
Length 155.60 m (Connecting Tunnel #1)
112.80 m (Connecting Tunnel #2)
Desilting Chambers
Type Underground
Size (nos x length x width x height) 2 No - 62 m x 11.5 m x 14.65 m
Particle size to be removed 0.2 mm with > 90 % trapping efficiency
Silt Flushing Arrangement
Flushing operation mode Continuous
Silt Flushing Tunnel, SFT (Shape, Dia) D-Shape, 3.9 m x 3.9 m
Length of SFT 234.34m
Slope 1 in 50
Flushing Gate Chamber
Type &Size (Length x width x height) D-Shape, 13 m x 10.0 m x 15.5 m
Silt Flushing Gate
Bonnet type hydraulically operated (No. x width x height) 2.0 x 1.5 m x 2.0 m
Link Tunnels to HRT
Shape D- Shaped
Size (width x height) 3.90 m x 3.90 m
Length 88.79 m
Headrace Tunnel
Shape D- Shaped
Length 4319 m
Size (width x height) 3.90 m x 3.90 m
Lining Concrete
Flow Velocity 1.57 m/s
Bed Slope 1 in 160.0
Construction Adits
Number, Length 4 Nos.,A1=186m,A2=241m,A3=305m,A4=133m
Shape and Size (width x height) D- shaped, 4.5 m X 4.5 m
Surge Shaft
Type Simple Orifice, Concrete lined
Internal diameter 6.0 m
Height 56.4 m
PRESSURE SHAFT (Underground)
Type & Diameter Circular Steel Lined, 3.0 m
Length 626.3 m
Construction Adit 1 No, 4.5m D shape, 300 m long at El 1715m
Velocity at design discharge 3.01 m/s
Unit Penstock
No. of Unit Penstock 3
Total Length 35.78 m (Unit- 1 & 3)
30.00 m (Unit- 2)
Type and Diameter Circular Steel Lined, 1.70 m
Power House Cavern
Type Underground
Length x Width x Height 84.00 m x 16.0 m x 36.00 m
C/l of Turbine 1515.00 m
MIV Floor 1513.00 m
Turbine Floor 1516.50 m
Generator Floor 1520.85 m
Service Bay Floor 1525.40 m
Transformer and GIS Cavern
Type Underground
Length x Width x Height 80.00 m x 13.0 m x 25.50 m
Transformer Floor 1525.40 m
GIS Floor 1534.06 m
Main Access Tunnel (MAT)
Length 201.18 m
Type and Excavated Size D- shaped, 7.0 m x 7.0 m
Cable Cum Ventilation Tunnel (CVT)
Length 201.18 m
Type and Excavated Size D- shaped, 4.5 m x 4.5 m
Tailrace Tunnel & Outfall Structure
TRT Length 650.00 m
Type and Excavated Size D- shaped, 4.5 m x 4.5 m
Gate Size at outfall (Width x Height) 3.9 m x 3.9 m
Slope 0.493055556
Type of flow Free Flow
Velocity 2.63 m/s
Generation Plant
Turbine Type Pelton
Number 3
Rated Capacity 25.80 MW
Rated Net Head 425.55 m
Rated Discharge 7.09 m³/s
Speed 375 rpm
Number 3
Rated Capacity 29.2 MVA
Voltage 11 kV
Total Energy Output at Generator Terminals
At Normal Load 458.58 GWh
Transformer tYPE Single Phase
Number 9 + 1 spare

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