Middle Modi Hydroelectric Project (15 MW)

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    Middle-Modi-HeadworksMiddle Modi Hydroelectric Project (MMHP) is located about 40 km north-west of Pokhara in Kaski and Parbat Districts, Gandaki Zone of Western Development. The project lies in the Bhuktangle, Deupur and Tilhar VDCs of Parbat District and Salyan and Lumle VDCs of Kaski District. The headworks is located at Birethanti village. At present there is about 1.5km long earthen road access to the headworks area from Nayapul bazaar which is the nearest point with all year road access along the Pokhara – Baglung highway. The powerhouse lies opposite to the Pokhara – Baglung highway at the right bank of the Modi with waterway alignment located at the right bank of Modi Khola.

    This project is a simple Run-of-River scheme that utilizes the flow in Modi Khola. Modi Khola is one of the major tributaries of the Kaligandaki River of the Gandaki basin. The proposed project has installed capacity of 15MW, design discharge of 25m3/sec and net head of 70m. The diversion weir across the Modi Khola diverts the water into the side intake. A gravel trap of length 15m settles gravels coming through the six orifices of the intake and settling basin with four parallel settling chambers of length 166m settles sediment particles larger than 0.2mm and passes water into the headrace tunnel. The headrace tunnel of length 2840m of finished diameter of 3.6~4.4m and steel penstock pipe of diameter 3.2m and length 147m feed water to the two units of Vertical Axis Francis Turbines installed in the semi-surface powerhouse to generate 15MW power. The water will then be discharged back into the Modi Khola through 77m long concrete tailrace box culvert. A semi-underground surge tank is provisioned at the end of the headrace tunnel.

     

    The electricity generated from this plant will be connected to the National Grid at the Modi Khola Power Plant Sub Station at Patichaur through 4km long 132kV single circuit transmission line. The total net energy production will be 79.12GWh annually. Power Purchase Agreement was done on 21, Magsir,2069 with Nepal Electricity Authority with RCOD of 1, Aswin,2074.

     

    Salient Features

    Project Middle Modi Hydroelectric Project
    LOCATION
    Type of Project Run-of-River
    Village Development Committee Bhuktangle, Lumle, Deupur, Salyanand Tilhar VDCs
    Districts Kaski and Parbat
    Zone Gandaki and Dhaulagiri
    Development Region Western Development Region
    Headworks Area Bhuktangle/Birethanti village
    Powerhouse Area Dhaba, Just U/S of Modi HEP (NEA)
    River Modi Khola
    HYDROLOGY
    Catchment Area at Intake 488 km2
    Design Discharge 25 m3/s
    90% Annual Dependable Flow 7.31m3/s
    Compensation Flow 0.72m3/s
    FLOOD
    1 in 100 years Design Flood at Weir 972.9 m3/s
    1 in 200 years Design Flood at Weir 1084.5 m3/s
    ACCESS ROAD
    Access Road to HW Existing Nayapul – Birethanti Road
    Access Road to PH 700m from Pokhara-Baglung Highway
    DIVERSION WEIR
    Type of Weir Concrete Gravity with Uncontrolled Spillway
    Crest Length of Spillway 32m
    Weir Crest Level EL. 1014.5 masl
    Height of Weir 5 m from river bed
    Flood Level at 1 in 200 years Flood EL. 1021.85 masl
    Under-sluice gate 2 x 3m wide x 4m high
    Invert Level of Undersluice EL. 1010.20 masl
    INTAKE
    Type of Intake Side Intake, Orifice Type
    No. of Intake Openings Six (1.2m x 3m each)
    Invert Level of Sill EL. 1012.80 masl
    Design Flow 28.75 m3/s
    No. of Gates Six
    Gate Size 1.5m x 3m each
    GRAVEL TRAP
    Size 15m x 23~7m x 10m (L x B x H)
    Flushing Conduit 1m x 1.5m Box, 30m Length
    Top Level EL. 1019.7~1021.93 masl
    APPROACH BOX CULVERT
    Canal Type Double Box Culvert
    Length of Canal 83m
    Size of Canal 3.2m x 3.4m (H x W)
    SIDE SPILLWAY
    Length 27m
    Discharge Capacity 117.3 m3/sec
    Location At Side Wall of Combined Box Culvert
    SETTLING BASIN
    No. of Basins Two
    No. of Chambers Four
    Nominal Size of Trapped Particle 0.20mm
    Trap Efficiency 90%
    Transition Section 52m length
    Parallel Section Size 114m(L)x7m(W)x8.94~11.22m (H) each including bottom hopper
    Flushing Gates Four (1m x 1m)
    Outlet Orifice Submerged, 8 Nos, 1.25m x 2.5m
    HEADPOND
    Capacity 1200m3
    Size 28m (L) x 12m (W) x 2.5m (H)
    Side Spillway 22m Length
    Discharge Capacity 25 m3/sec
    Normal Water Level EL. 1013.41 masl
    HEADRACE TUNNEL
    Section Type Inverted-D
    Finish Diameter 3.6 ~4.4m
    Finish Area 12.02~15.21m2
    Length 2840m
    Support Fully Concrete Lined (160m) and Shotcrete Lining in Wall and Crown, Concrete Lining in Invert (2680m)
    SURGE TANK
    Type Surface and near HRT outlet portal
    Finish Diameter 9m
    Height 33.49m
    USWL EL. 1024.57 masl
    DSWL EL. 1000.18 masl
    PENSTOCK
    Material Steel
    Diameter 3.2m
    Length 147m
    Thickness 10, 12 and 16 mm
    POWERHOUSE
    Type Semi – Surface
    Dimension 30m (L) x 13.5m (W) x 24m (H)
    Turbine Axis Level EL. 938.30 masl
    Floor Level EL. 944.60 masl
    Tail Pond Level EL. 940.50 masl
    TAILRACE
    Type Concrete Box Culvert
    Length 77m
    Size 4m x 3.6m
    Outlet Tail water Level EL. 940.42 masl
    TURBINES
    Type of Turbine Francis (Vertical Axis)
    No. of Units Two
    Rated Net Head 69.78m
    Unit Discharge 12.50m3/s
    TRANSMISSION LINE
    Voltage 132kV
    Length 4km
    Connection NEA Sub-station at Patichaur, Parbat
    POWER AND ENERGY GENERATION
    Gross Head 72.91m
    Net Head 69.78m
    Installed Capacity 15MW
    Annual Net Energy 79.124GWh
    Dry Season Energy 12.198GWh
    Wet Season Energy 66.925GWh
    TARGET COMPLETION DATE: July 2014