KARMOLI H.E. PROJECT

  • The Karmoli Hydro Project is located on river Jadhganga, a tributary of Bhagirithi in Uttarkashi district of Uttarakhand envisages utilization of the water of the river. The Project is approachable from Rishikesh by road (via Tehri-Uttarkashi- Gangotri highway) at a distance of 267km up to Bhaironghati and further 13 km to project site. The nearest rail head is Rishikesh and nearest airport is Jolly Grant, Dehradun.
     
    The Project is a run-of-river scheme, harnessing a head of about 450 m.As per Pre-feasibility studies, the proposed project involves construction of 56m high Concrete Dam after diversion of river by constructing a 5m dia. D-shaped Diversion Tunnel. The water conductor system consists of 1 no. gated Power intake of size 3.5m x 3.5m each, a De-silting Chamber of size 10m x 15m x 200m. The desilting chambers converges, after a smooth transition to 3.5m dia., 8.6 km long, horse shoe shaped, head race tunnel. The head race tunnel ends in a 8.0m dia and 120m high u/s surge shaft. Further, one no. Pressure Shaft, 2.8m dia. is bifurcated into 2 nos. 2.0 m dia penstocks before entering the machines in the underground machine hall of size 77.5m x 15.5m x 34m. A Tail race tunnel of 3.5m dia. and 600m length, discharges the water back into the river.
     
    The project with a proposed installed capacity of 140MW (2x70MW) would afford an annual energy generation of 621.31 GWh in 90% dependable year. As per Pre Feasibility Report, the project is estimated to cost Rs. 456.60 crores including IDC of Rs 62.98 crores at June,2003 price level. The first year and levellised tariff from the project would be Rs.1.30 / KWh and Rs.1.05/ KWh respectively.
     
     
  • SALIENT FEATURES
    LOCATION
    State                                                        Uttarkhand
    District                                                         Uttarkashi
    River                                                      Jadhganga
    Nearest Rail Head Rishikesh
    Nearest Airport Dehradun
    DAM SITE
    Location 700 m D/S of confluence of  Chorgad with Jadhganga river.
    Longitude                                                     78° 58' 5" E.
    Latitude                                                       31° 6' 4" N.
    HYDROLOGY
    Catchment Area at Dam site 1605 sq. km.
    Snow bound Catchment Area                      
    (Including area under glacier cover)
    977.0 sq. km
    Maximum average discharge at Dam site 139.8 cumec
    Minimum average discharge at Dam site 7.7 cumec
    Average annual runoff                       1489.8 Mcum
    Average monsoon runoff           1204.9 Mcum
    Average non-monsoon runoff         284.9 Mcum.  
    RESERVOIR
    Full Reservoir Level (FRL) El. 3268.5 m
    Maximum Water level (MWL) El. 3268.5 m
    Minimum Draw Down Level (MDDL) El. 3254 m.
    Gross Storage at FRL 1.953 MCM
    Live Storage 0.816 MCM
    Area under submergence at FRL 9.94 ha.


    TECHNICAL FEATURES
    DIVERSION TUNNEL
    Number 1
    Diameter                                                          5 m
    Length                                                         350 m
    Diversion Discharge (assumed) 80 cumec
    DAM
    Type                                                             Concrete Gravity
    Top Elevation of Dam EI .3271 m.
    Height of Dam 56 m.
    Deepest foundation level.   
    Length of dam at top  128 m
    River bed level EL 3225 m.
    SPILLWAY
    Design flood                                5905 cumec.
    Type Ogee
    Crest elevation EI. 3244.5 m.
    Number and size of Bays                                 4 of 12.5 m x 11.5 m (clear)
    Length of spillway  68 m
    Energy dissipation Trajectory bucket.
    INTAKE
    Invert Level EL 3246.5 m
    Number 1
    Size of Gate opening 3.5m x 3.5 m
    Trash rack 5 of 9 m x 5 m
    DESILTING CHAMBER
    Number 1
    Size 10 m x 15 m
    Length 200 m
    Design discharge 45 cumecs
    Particle size to be removed 0.2 mm & above.
    Silt Flushing discharge   8 cumec
    Silt Flushing Tunnel size 2 m dia.
    Silt Flushing Tunnel length 180 m.
    HEAD RACE TUNNEL
    Number 1
    Shape                                                         Horse shoe
    Diameter 3.5 m
    Length 8.6 km
    Design Discharge 37.0 Cumec
    SURGE SHAFT
    Number                                                       1
    Type                                                            Simple surge shaft
    Diameter  8 m
    Height                                                          120 m
    PRESSURE SHAFT
    Numbers  1 (Bifurcated into 2 of 2m dia.).
    Diameter 2.8 m
    Length 600m
     POWER HOUSE
    Type Underground
    Installed capacity 140 MW
    Number of Units 2 X 70 MW
    Power house cavern size (main) 77.5m X 15.5m X 34m
    Type of Turbines Francis Vertical Axis
    EL of Turbines El 2811.5m
    Rated Head 419.67 m
    Size of Transformer Hall 92m (L) X 13.5m(W) X 17.5m (H)
    DOWNSTREAM SURGE SHAFT
    Diameter 8.0 m
    Height 80 m
    TAIL RACE  TUNNEL
    Diameter 7.5 m dia.
    Shape D-shaped
    Length 600 m
    Design discharge 37 cumec
    Maximum TWL 2820 m
    Minimum TWL 2818 m Tail Race Outlet
    SWITCH YARD
    Gas Insulated Switchyard (GIS) on the floor above the transformer/s in P/H cavern.
    POWER GENERATED
    Installed Capacity 140 MW
    Annual Energy generation  
    (i)  90% dependable year 621.31 GWH
    (ii) Energy in 90% year at 95% availability 592.22 GWH
    CONSTRUCTION PERIOD 5 Years




Updated on : 19/02/2018