1
|
General
|
|
|
|
|
Project name
|
Betan Karnali PROR Hydroelectric Project
|
|
Location
|
Surkhet District, Karnali Province & Achham District, Sudurpashchim Province
|
|
Co-ordinates of the Project area
|
28o50’57” N to 28o 56’04” N latitude,
|
|
|
81o11’43” E to 81o 24’42” E longitude
|
|
Nearest highway
|
Karnali highway
|
|
Nearest airport
|
Surkhet airport- 94.25 km from project site
|
|
|
Nepalgunj airport – 200.25 km from project site
|
|
River
|
Karnali
|
|
Climate
|
Moderate
|
|
Type of project
|
Peaking Run-of-River (PRoR)
|
2
|
Organization
|
|
Developer
|
Betan Karnali Sanchayakarta Hydropower Company Ltd.
|
|
Consultant
|
NEA Engineering Company Ltd.
|
3
|
Hydrology
|
|
Catchment area
|
22,511.25 km2
|
|
Mean annual flow
|
553.92 m3/s
|
|
Maximum average monthly discharge
|
1609.55 m3/s
|
|
Minimum average monthly discharge
|
134.80 m3/s
|
|
1 in 100 years flood (Q100)
|
8,530.00 m3/s
|
|
1 in 1000 years flood (Q1000)
|
11,548.00 m3/s
|
|
1 in 10,000 years flood (Q10,000)
|
14,560.00 m3/s
|
|
Probable maximum flood (QPMF)
|
22,604.00 m3/s
|
4
|
Reservoir
|
|
Gross storage volume
|
161.69 Mm3
|
|
Live storage volume
|
36.19 Mm3
|
|
Surface area at FSL
|
5.42 km2
|
|
Length of reservoir at FSL
|
21.93 km
|
|
Full supply level
|
473.30 masl
|
|
Monsoon operating level
|
470.00 masl
|
|
Minimum drawdown level
|
466.00 masl
|
5
|
River Diversion Works
|
|
Diversion discharge
|
2,400.00 m3/s
|
|
Number of tunnels
|
2 Nos.
|
|
Size and shape
|
9.80 m diameter horseshoe
|
|
Length
|
584.40 m & 727.10 m
|
|
Inlet and outlet level
|
400 masl & 394 masl (Diversion tunnel-1)
400.50 masl and 393.50 masl (Diversion tunnel-2)
|
|
Lining
|
Reinforced concrete lining
|
|
U/S cofferdam
|
|
|
Type & location (axis)
|
RCC (Permanent), 162.00 m u/s from dam axis
|
|
Height
|
40.96 m from existing riverbed
|
|
Crest Level
|
434.32 masl
|
|
D/S cofferdam
|
|
|
Type & location (axis)
|
Embankment dam, 306.00 m d/s from dam axis
|
|
Height
|
16.50 m from existing riverbed
|
|
Crest level
|
406.00 masl
|
6
|
Dam
|
|
Type of dam
|
Roller Compacted Concrete (RCC)
|
|
Location of dam
|
Approx. 2.00 km D/S from Malumela
|
|
Dam crest length
|
172.75 m
|
|
Dam height
|
90.00 m from riverbed
|
|
Dam height
|
140.00 m from foundation bed
|
|
Top width
|
10.00 m
|
|
Dam top elevation
|
480.00 masl
|
7
|
Spillway
|
A
|
Main Spillway
|
|
|
Type
|
Ogee and gated
|
|
Crest elevation
|
462.00 masl
|
|
Number and size of gates
|
6 nos, 11 m x 12 m (W X H)
|
|
Energy dissipation
|
Flip bucket
|
B
|
Sluice Spillway
|
|
|
Type
|
Sluice
|
|
Crest elevation
|
418.00 masl
|
|
Number and Size
|
6 nos, 7 m x 8 m (W X H)
|
C
|
Auxiliary Spillway
|
|
|
Type
|
Ogee and gated
|
|
Crest elevation
|
469.00 masl
|
|
Number and Size
|
1 no, 8 m x 5 m
|
|
Energy dissipation
|
Flip bucket
|
8
|
Intake
|
A
|
Main Power Intake
|
|
|
Type of intake
|
Side intake
|
|
Number and size of trashrack
|
9 nos., 5.90 m x 17.20 m (W X H))
|
|
Number and size of intake gate
|
3 nos., 8 m x 8 m (W X H)
|
|
Dry season design discharge
|
536.00 m3/s
|
|
Wet Season design discharge
|
551.33 m3/s
|
|
Invert level
|
450.00 masl
|
|
Deck level
|
480.00 masl
|
|
Trashrack
|
Inclined at 75⁰ to horizontal
|
B
|
Intake for Dam Toe Powerhouse
|
|
|
Type of intake
|
Embedded in dam
|
|
Number and size of trashrack
|
2 nos, 2.60 m wide up to dam deck level
|
|
Number and size of intake gates
|
2 nos, 1.6 m x 2 m
|
|
Invert level
|
460 masl
|
|
Design discharge
|
13.48 m3/s
|
|
Trashrack
|
Vertical
|
9
|
Headrace Tunnel
|
|
Number
|
3 nos.
|
|
Size and Shape
|
8.00 m diameter circular
|
|
Length
|
2017.26 m, 2011.15 m, 2017.39 m
|
|
Lining
|
450 to 300 mm thick concrete lining
|
|
Design velocity
|
3.56 m/s
|
|
Maximum velocity
|
3.66 m/s
|
10
|
Upstream Surge Shaft
|
|
Type
|
Restricted orifice
|
|
Number
|
3 nos
|
|
Diameter
|
24.00 m
|
|
Diameter of orifice
|
4.20 m
|
|
Height
|
37.70 m
|
11
|
Pressure Shaft and Pipes
|
A
|
Pressure shaft
|
|
|
Number
|
3 nos
|
|
Orientation
|
Vertical and horizontal
|
|
Diameter and length (concrete lined)
|
7.65 m circular pressure shaft of 109.80 m
|
|
Diameter and length (Steel lined)
|
7.65 m circular pressure shaft reducing to 7m before bifurcation of 42m
|
B
|
Bifurcated Pipes
|
|
|
Diameter and length
|
4.95 m circular bifurcating steel pipes of 79.36 and 72.74m of in each conveyance system
|
12
|
Penstock for Dam Toe Powerhouse
|
|
Type
|
Surface & steel
|
|
Number
|
2
|
|
Diameter
|
1.40 m
|
|
Length
|
100.87 m
|
13
|
Powerhouse
|
A
|
Main Powerhouse
|
|
|
Coordinate
|
81⁰14’48” E, 28⁰55’5” N
|
|
Type
|
Underground
|
|
Installed capacity
|
430.13 MW
|
|
Powerhouse size
|
202.00 x 23.50 x 54.48 (L X W X H)
|
|
Number and capacity of units
|
6 nos x 71.68 MW
|
|
Type of turbine
|
Francis, Vertical Axis
|
|
Normal tail water level
|
374.15 masl
|
|
Gross head
|
99.13 m
|
|
Net head at FSL
|
94.13 m
|
|
Net head at MOL
|
90.54 m
|
|
Machine floor level
|
380.21 masl
|
|
Generator floor level
|
375.61 masl
|
|
Turbine floor level
|
371.85 masl
|
|
Turbine centre line level
|
369.17 masl
|
B
|
Dam Toe Powerhouse
|
|
|
Type
|
Surface Toe of Dam
|
|
Installed capacity
|
8.77 MW
|
|
PH size
|
27.00 m X 15.60 m X 40.37 m (L X W X H)
|
|
Number and capacity of units
|
2 nos x 4.38 MW
|
|
Type of turbine
|
Francis, Vertical Axis
|
|
Normal tail water level
|
395 masl
|
|
Gross head
|
78.30 m
|
|
Rated net head
|
76.50 m
|
14
|
Tailrace Tunnel
|
|
Number
|
6 nos
|
|
Size and shape
|
6.5 m diameter concrete lined tunnel
|
|
Length
|
322.49 m, 312.26 m, 302.03 m, 291.80 m,
281.57 m and 271.35 m
|
15
|
Downstream Surge Shaft
|
|
|
Type
|
Restricted orifice
|
|
Number
|
1 (Chamber)
|
|
Orientation
|
Across and above 6 TRTs
|
|
Size
|
144 m x 15 m X 19.95 m (L X W X H)
|
|
Diameter of orifice
|
4.40 m
|
16
|
Tailrace Channel
|
|
Size and Shape
|
Trapezoidal Channel
|
|
Length
|
96.27 m at centreline
|
|
Average width
|
100 m
|
17
|
Energy
|
|
Wet season energy
|
1609.67 GWh/yr
|
|
Dry season peak energy
|
458.56 GWh/yr
|
|
Dry season off peak energy
|
230.82 GWh/yr
|
|
Dry season total energy
|
689.38 GWh/yr
|
|
Total annual energy
|
2299.05 GWh
|
18
|
Transmission Line
|
|
Substation
|
Bagmara Substation, Puchma
|
|
Connection length
|
5.00 km approx.
|
|
Voltage
|
400 kV
|