Himshila Power Company Limited

Gasali Khola Hydro Power Project

Gasali Khola Small Hydroelectric Project is situated at Khaniyabas Gaunpalika, Dhading District, Bagmati Province about 115 Km northwest of Kathmandu, and 45 Km northwest from Dhading Besi, the district headquarters of the Dhading District. Gasali Khola Hydroelectric Project (GKHEP) with proposed installed capacity of 4.5 MW is a run-off river scheme in Dhading district of Bagmati Province. HPCL has completed Feasibility Study on April 2018 and Initial Environmental Examination (IEE) on September 2019 considering installed capacity 4.5MW. Power Purchase Agreement (PPA) with Nepal Electricity Authority (NEA) for the project is also concluded on Shrawan 2080 (Aug, 2023).

Project Details

Project NameGasali Khola Hydropower Project
LocationKhaniyabas Rural Municipality (Ward No. 2), Dhading
ProvinceBagmati
Latitude28° 04′ 28″ N – 28° 05′ 30″ N
Longitude85° 00′ 38″ E – 85° 02′ 30″ E
Type of SchemeRun of River
Installed Capacity4.5 MW
Gross Head309 m
Rated Design Head300.8 m

 

Hydrology

Gasali Catchment Area40.40 km²
Agthali Catchment Area1.29 km²
100-Year Design Flood (Gasali)81.93 m³/s
100-Year Design Flood (Agthali)9.46 m³/s
Design Discharge (Total)1.77 m³/s
– From Gasali1.72 m³/s
– From Agthali0.05 m³/s
Mean Annual Discharge3.63 m³/s
Riparian Release54 lps

 

Headworks

Diversion StructureConcrete overflow weir with undersluice
Length of Weir18.0 m
Weir Crest ElevationEL 1204.00 masl
Height of Weir3.0 m from bed level
Undersluice2.25 m × 3.0 m (1 No.)
Undersluice Sill Level1201 masl
Intake TypeSide Intake
Intake Opening Size2.4 m × 1.2 m (2 Nos.)
Intake Sill Level1202.9 masl

 

Agthali Headwork

Diversion StructureConcrete overflow weir
Length of Weir7.0 m
Weir Crest ElevationEL 1210.00 masl
Height of Weir4.0 m from bed level
Intake TypeSide Intake
Intake Opening Size1.0 m × 0.5 m (1 No.)
Intake Sill Level1209.5 masl

 

Gravel Trap

GasaliRectangular RCC5 mm6.8 m × 1.5 m
AgthaliRectangular RCC5 mm3.3 m × 1.0 m

 

Approach Canal

TypeRCC Rectangular
Size (B × H)1.0 m × 1.3 m

 

Desander

TypeDufour, Double Bay
Particle Size to be Settled0.20 mm
SizeEach bay: 26.0 m × 4.2 m (L × B)

 

Headrace Pipe


Gasali Headrace Pipe

Total Length2264 m
TypeMS Pipe (Buried & Exposed)
Diameter1.2 m
Thickness6 mm

 

Agthali Headrace Pipe

Total Length70 m
TypeHDPE Pipe (Buried & Exposed)
Diameter200 mm (PN 12.5)

 

Surge Tank

TypeRestricted Orifice
Size1.8 m diameter
Thickness12 mm
Height14.4 m

 

Penstock Pipe

Total Length484 m
TypeMS Pipe (Buried & Exposed)
Diameter1.1 m
Thickness8 mm – 18 mm (varied)

 

Powerhouse

TypeSurface
Dimensions (L × B × H)27.7 m × 16.9 m × 14.23 m
Powerhouse Floor LevelEL 895.5 m
Turbine Centerline LevelEL 892.4 m

 

Tailrace

TypeRCC Box Canal
Size2.0 m wide × 1.5 m high
Length36 m
Tailrace Water LevelEL 895.0 m

 

Turbine

Type2 Nos. Horizontal Pelton
Rated Discharge (Each)0.885 m³/s
Rated Output (Each)2.25 MW
Rated Efficiency91%

 

Generator

Type2 Nos. Synchronous Brushless, 3Ø AC
Rated Voltage6.6 kV
Power Factor0.85
LayoutHorizontal
Synchronous Speed750 rpm
Rated Efficiency97%
Rated Output2.65 MVA
Rated Frequency50 Hz

 

Power Transformer

Type1 No. 3-Phase Step-Up Transformer
Frequency50 Hz
Rated Capacity5350 kVA
Voltage Ratio33 kV / 6.6 kV
Rated Efficiency99%

 

Transmission & Interconnection

Transmission Line Length3.5 km
RoutePowerhouse to Jharlang Substation
Circuit TypeSingle Circuit
Voltage Level33 kV
ConductorACSR “Dog”
Pole TypeSteel Tubular (11 m & 13 m height)

 

Power & Energy

Installed Capacity4.5 MW
Contract Energy (After Loss & Outage)26.51 GWh
Wet Saleable Energy18.52 GWh
Dry Saleable Energy7.98 GWh

 

Construction Period

Construction Period2.0 Years

 

Financial Indicators

Total Project Cost959.109 Million NRs (With IDC)
Benefit–Cost Ratio (B/C)1.37
Internal Rate of Return (IRR)14.13%
Return on Equity (RoE)17.24%
Cost per MW21.31 Crore NRs
Minimum DSCR1.29
Simple Payback Period6.6 Years