1.      Salient Features

1.      Location

Location                                                          Annapurna Rural Municipality - 04 Maygdi, Gandaki Province  

Type of Project                                               Run of River

Powerhouse Area                                            Baskot, Narchyang Annapurna Rural Municipality -04

River                                                               Ghalemdi Khola

Project Area                                                    Latitudes: 28°31’30”N and 28°32’30”N

                                                                        Longitudes: 83°40’30”E and 83°42’0”E


2.      Hydrology

Average Annual Precipitation                         1523mm

Catchment Area at intake site                         84.7 km2                            

Average flow                                                  4.05 m3/s

90% Firm flow                                                1.0 m3 /s

Design flow                                                    3.5 m3/s

Environmental flow                                        0.1m3/s

Design flood (1 in 100 years) at Intake site    219m3/s

Diversion flood (1 in 5 years)                         11.7m3/s

3.      Diversion Weir

Type of Weir                                                   Uncontrolled Concrete gravity structure

Spillway Length                                              20 m

Spillway Crest                                                 El 1781.0 m

Design Flood 1 in 100 years                           219m3/sec

Diversion flood 1 in 10 years                          139m3/sec

4.      Under sluice

Location                                                          At the right side of the weir

Section                                                            one gate 1.65m wide and 3.60m high

Bottom Level                                                  El 1777.70

5.      Intake

Location                                                          Immediately upstream from the under sluice at angle of 110° with the weir axis.

Invert Level                                                    EL 1779.50

Openings and size                                           Two openings each with 2.2m wide and 1.5m high separated by 0.8m wide pier

6.      Close Duct

Type                                                                  Rectangular RCC

Intake canal size                                               L=22.76m, B=2m, H=1.8m

Intake canal slope                                             1:450

7.      Gravel Trap

Width                                                                B=4.0m H=1.25m

Length                                                             10.0m

Gravel Flushing Gate                                      H=0.50m B=0.50m

Side Channel spillway                                    6.0m long

Bed Slope                                                       1:15


8.      Approach Canal

Type                                                                RCC

Length                                                             84 m;

Section                                                            Rectangular with 2.0m Wide and 1.25m high

9.      Desanding Basin

Type                                                                RCC Rectangular outdoor open surface type x 2 Basins

Particles size to be settled                               0.20mm

Size                                                                 L=40.0m, B=8.0m

Depth of Flow                                                3.50m at the start and 4.10 at the end

Length of basin                                               40.0m

Length of Inlet Transition                               10m

Length of Outlet Transition                            8m

Size of Flushing Duct                                     0.7m x 1.0m

10.  Headpond

Type                                                                Rectangular

Breadth and Height                                        4m x 4m

Length                                                             20m

11.  Headrace Tunnel

Length                                                             1580m

Shape                                                              Inverted D-Shaped

Size                                                                 2.0m wide and 2.2m high

Type of Lining                                                Concrete Lined;  Shotcrete Lined

Slope                                                               1:750 (up) and 1:750 (down)

12.  Surge Tank

Dia                                                                  4m

Height                                                             21m

Normal Water Level                                       EL 1779.50 m

13.  Penstock

Diameter of the pipe                                       1.0m and 0.70m after bifurcation

Length of the pipe                                          275 m up to bifurcations and then 7m

Type                                                                welded surface penstock

Pipe Material                                                   Mild steel conforming to IS 2062-B

No of Anchor Blocks                                      10 nos.

Thickness of the pipe                                      Ranges from 12mm to 18mm

14.  Powerhouse

Type                                                                Surface

Dimensions                                                     25.5 m x 10.5 m x 9.15 m                              

15.  Tailrace

Type                                                                Rectangular RCC

Size                                                                 1.8m x 1.2m

Length                                                             34 m                           

16.  Turbine

Number of Units                                             2

Type of Turbine                                              Francis

Shaft Arrangement                                         Horizontal

Rated discharge for each turbine                    1.75m3/s

Rated Head                                                     164.93 m

Rated Output for each unit                             2500kw (with allowance of 10% continuous overloading)

Rated Speed                                                   1000 RPM

Rated Efficiency                                             91.0%

17.  Generators

Type                                                                Synchronous, 3 phase, horizontal axis

No of Units                                                     2

Rated Voltage                                                 6.6 kV

Power factor                                                   0.85

Rated Output                                                  2 x 2.35MVA

Efficiency                                                       96 %

18.  Switchyard

Type                                                                Outdoor, conventional

Size                                                                 20m x 30m

Elevation of yard                                            1629m

19.  Transmission Line

Length                                                             3.2 km

Voltage                                                           33KV

Circuit                                                             single circuit with

Conductor                                                       ACSR DOG upto Dana Substation

20.  Power and Energy

Installed Capacity                                           5 MW

Firm Energy at Q 90%                                    11.68 GWh                                        

Average Annual Energy Output                     29.123 GWh

Dry Season Energy                                         4.86 GWh

Wet Season Energy                                         24.27 GWh