• Welcome to Betan Karnali Sanchayakarta Hydropower Company Limited

Salient Features

S. No

Parameters

Details

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

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

Sluice Spillway

 

 

Type

Sluice

 

Crest elevation

418.00 masl

 

Number and Size

6 nos, 7 m x 8 m (W X H)

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