Naugarh Gad Small Hydroelectric Project is a run-off-river type project located in the Dethala VDC of Darchula District, Mahakali Zone, Far-Western Development Region. The project utilizes the discharge of Naugarh Gad river which is a major tributary of the Chameliya River. The project is accessible by road from Gokuleshwore on Mahakali Highway. The Project site is around 7 Km from Gokuleshwor. The latitude and longitude of the project area are 29°41′16&Prime to 29°43′30&Prime North and 80°36′15″ to 80°36′46″ East.

The installed Capacity of the Project is 8500 KW which is obtained from a head of 134 m and design discharge of 8.5 m3/sec. The headworks of the project is located near the confluence of Naugarh and Suke Khola about 4.5 Km upstream from the powerhouse at Dethala Village. Water is diverted by a 5 m high diversion weir to a 65 m long desander which filters out the sand particles. The water is then diverted to the 4500 m long buried steel penstock of 2.1 m diameter which carries the water to the powerhouse at Dethala Village.

The powerhouse consists of two units of 4250 KW Francis turbines connected to two units of 5500 KVA generators which generate the electricity. The power is evacuated 33KV, transmission line (5 KM) which is connected to the Balanch substation of Chameliya Hydroelectric Project, Nepal Electricity Authority.

The Project has started its commercial operation since 2nd Bhadra, 2072 B.S. (19th August, 2015)

Project Details
Project Name	: Naugarh Gad Hydroelectric Project
Development Region	: Far Western
Zone	: Mahakali
District	: Darchula
Intake Site	: Dhuligada VDC
Powerhouse Site	: Dethala VDC
Geographical Co-ordinates
Latitude	: 29°43’30” N to 29°41’15” N
Longitude	: 80°36’46” E to 80°36’15” E
General
Water Source	: Naugarh Gad
Nearest Town	: Gokuleshwor
Type of Scheme	: Run-of-river
Gross Head	: 137.0 m
Net Head	: 122.30 m
Installed Capacity	: 8,500 kW
Hydrology
Catchment Area	: 194 km2
Average Annual Precipitation	: 2192 mm/year
100 years Design Flood (HW)	: 323 m3/s
100 years Design Flood (PH)	: 753 m3/s
Minimum Monthly Flow	: 3.58 m3/s
Riparian Release Intake
Naugarh Gad	: 0.358 m3/s
Headworks
Diversion Structure	: Hard Stone Lined Gravity Free Flow Weir
Type of Weir	: Concrete gravity dam
Length of Weir	: 37.05 m
Weir Crest Elevation	: EL 870 msl
Height of Weir	: 3.50 m from U/s Apron
Undersluice	: 2 Vertical Sluice Gates
Crest of Sluice	: EL 866.70 msl
Size of Sluice Gate (b x h)	: 3.0 m x 2.6 m
Intake Type	: Side Intake
Size of Opening	: 2.50 x 1.40 – 4 nos
Crest Elevation of Intake	: EL 868.80 msl
Gravel Trap
Type	: Rectangular with Slide Slopes
No. of bays	: 2
Particle Size to be Settled	: 20 mm
Trap Efficiency	: 98 %
Size of Gravel Trap (LxBxH)	: 14.50 m x 7.50  x (2.85 m – 3.95 m)
Spilway Length	: 17.06 m
Bed Slope	: 1:10
Flushing Channel Size	: 2 Nos. of 1.2 m x 1.0 m Rectangular Closed
Desander
Type	: Double Dufour Double Chamber Continuos Flushing Type
Trap Efficiency	: 90%
Size of Each Chamber (LxBxH)	: 55.0 m x 7.50 m x (3.65m – 4.65m)
Bed Slope	: 1:50
FSL @ Desander end	: 869.80 msl
Flushing Channel Size	: 2 Nos. of 1.0 m Rectangular
Headrace Pipe
Type	: MS-Pipe beried Section
Total Length	: 3740.40 m
Pipe Material	: IS 2062-B
Thickness	: 8 mm to 16 mm
Diameter of Pipe	: 2.10 & 2.0, 10mm – 12mm Thickness
Surge Tank
Type	: Circular Cylinder, Concrete (RCC)
Number of Chamber	: 1
Dia of Tank	: 12.0m
Total Height of Tank	: 24.30 m
Invert Level of Tank	: 854.15 m
Static Level	: 870.00 m
Upper Surge Level	: 878.16 m
Down Surge Level	: 855.87 masl
Penstock Pipe
Type	: MS-Pipe Open Structure
Length	: 14m from T  to Surgetank and 633.8m from T to Powerhouse
Pipe Materialize	: IS 2062-B
Size of Pipe	:1.7m dia , 10mm thick (from T-ST) & 1.9m dia 12mm-22m (from T-PH)
Number of Anchor Blocks	: 13 Nos. Including T, Y, B and A
Number of Supports	: 80 Nos.
Powerhouse
Type	: Surface
PH Dimensions, main Building (l x b)	: 29.80 m x 9.50 m
Height of PH Building	: 9.50 from Plinth Level
PH Floor Level	: EL 732.50 m
Tailrace
Type	: Closed Rectangular RCC Canal
Length	: 146.60 m (Including Both Units)
Size (w x h)	: 3.0 m x 2.75 m
Tailrace Water Level	: El 733.0 m at Outlet
Slope	: 1:500
Turbine
Type of Turbine	: Francis
Number	: Two (2)
Shaft Arrangement	: Horizontal
Rated Discharge for each Turbine	: 4.15 m3/s
Rated head	: 122.30 m
Rated Output for each Unit	: 4500 kW
RPM	: 1000
Rated Efficiency	: 90 % (at 100% Discharge)
Generator
Type	: Synchronous brushless, 3Ø AC
No of Units	: 2
Rated Voltage	: 6.3 kVA
Power Factor	: 0.85
Layout	: Horizontal
Rated Efficiency	: 96%
Rated Output	: 5000 kVA
Rated Frequency	: 50 Hz.
Power Transformer
Type	: Step up Power Transformer
Rated Capacity	: 11000 kVA
Rated Efficiency	: 99%
No of Unit	: 1
Number of Phases	: 3 ph, 50 Hz
Types of Connection	: Star/Delta
Type of Cooling	: ONAN
Voltage Ratio	: 6.3 kV (LV Side) / 132 kV (HV Side)
Station Supply Transformer
Type	: Indoor and Outdoor Type
Rate Power Output	: 200 kVA
No of Unit	: 2
Type of Cooling	: ONAN
Voltage Ratio	: 6.3/0.4 kV
Connection / Vector Group	: Dyn11
Transmission & Interconnection
Power House – Balanch Substation	: 4.8 km
Type of Circuit	: 33 kV Single Circuit Line up to 132 kV Balanch S/S
Line Conductor	: ACSR “DOG” 150mm2
Transmission Voltage	: 33 kV
Proposed Interconnection Point	: Balanch 33/132 kV Substation
Power and Energy
Installed Capacity	: 8.50 MW
Total Gross Energy	: 53.64 GWh
Contract Energy after Outage & Loss	: 50.96 GWh
Wet Saleable Energy	: 40.40 GWh (79.27%)
Dry Saleable Energy	: 10.56 GWh (20.73%)
Project Financial Indicators
Base Cost of the Project	: 1339 Millions NRs(Without IDC)
Term Loan	: 98 Crores
Interest Rate	: 8.5%
PPA Rate	: 4.00 Wet and 7.00 Dry Season
Simple Payback Period	: 6.3 years
B/C Ratio	: 1.26
IRR	: 15.38%
EIRR	: 20.65%
Average DCBR	: 1.17