MALARI JHELUM H.E. PROJECT

  • Malari Jelam Hydroelectric Project is located on river Dhauliganga, a tributary of Alaknanda in Chamoli district of Uttarakhand. The dam site is approachable from Rishikesh by road via Rishikesh- Joshimath highway (National highway No.58) at a distance of 257 km and the proposed diversion site of the project is about 48.5km from Joshimath and the powerhouse site is 46.5 km. 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 117.0 m. As per the Viability Report, the proposed project involves construction of 27m high Barrage. The water conductor system consists of 2 nos. gated Power intake of size 4.0 m x 4.0 m each, 2 nos De-silting Chamber of size 200 m x 12 m x 13.6 m. The de-silting chambers converges, after a smooth transition to a 5.2m dia., 2.013 km long, horse shoe shaped, head race tunnel. The head race tunnel ends in a 12m dia. and 49m high  surge shaft. Further, one no. Pressure Shaft, 4.0m dia. is bifurcated into 2 nos. 2.30 m dia penstocks before entering into the machines in the underground machine hall of size 104.00 m x 20.5 m x 46.0 m. A Tail race tunnel of 7.0 m X 9.0 m D shape dia. and 181 m length, discharges the water back into the river.
     
    The project would afford an annual energy generation of 250.60 GWh in a 90% dependable year. The project is estimated to cost  ` 683.70 crores including IDC at July 2013 price level. The first year and levellised tariff from the project would be ` 6.40/ KWh and ` 5.56/ KWh respectively.
  • 1.    Project Location
     
    State                                                               Uttarakhand
    District                                                            Chamoli
    River                                                               Dhauliganga
    Site                                                                 Barrage site near Kosa Village
     
    2.    Hydrology
     
    Catchment area                                           1564 km2
    Area under snow                                         868  km2
    Rain fed area                                                696 km2
    Elevation of Snow Line                              4900 m a.s.I.
    Standard Project Flood                               1625 m3/s
     
    3.    Reservoir
     
    Maximum Water Level (M.W.L.)                 2838 m
    Full Reservoir Level (F.R.L.)                      2838 m
    Minimum Draw-down Level (M.D.D.L.)    2828.3 m
    Gross storage                                               0.88 million m3
    Live storage                                                  0.54 million m3
     
    4.    Barrage
     
    Latitude                                                          300 40’ 42.1” N
    Longitude                                                      790 51’ 57.5” E
    No. & size (W x H) of bays                          4 bays, 8.0 m x 6.0 m each
    Height of the barrage                                  27 m
    Spillway Crest Level                                    EL 2814 m
    Under Sluice Sill level                                EL 2813 m
    River Bed Level                                            EL 2813 m
    Top of barrage                                              EL 2840 m
                           
    5.    Barrage Gates
     
    Gate Type                                                      Radial
    No & size (W x H)                                         3 Nos., 8.0 m (W) x 6.0 m (H)
    Hoist Type                                                     Twin Hydraulic Cylinders
     
    6.    Under sluice Gate
     
    Gate Type                                                      Radial
    No & size (W x H)                                         1 No., 8.0 m (H) x 6.0 m (W)
    Hoist Type                                                     Twin Hydraulic Cylinders
    Stoplogs Type (common for barrage & Vertical Lift Slide type
    Under sluice gates No. & size                   1 No., 8.0 m x 8.40 m
    Hoist Type                                                     Gantry Crane using a lifting beam
     
    7.    Intake (On Right bank)
     
    Nos.                                                                Two
    Intake invert level                                         EL 2819.80 m
    Gate Type                                                      Vertical lift fixed wheel type
    Gate Size (W x H )                                       2 Nos., 4.0 m x 4.0 m
    Hoist Type                                                     Electrically operated Rope Drum                                                                          Hoist
    Type of Bulk Head Gates                           Vertical lift slide type
    Gate Size(W X H)                                         2 Nos., 4.0 m x 4.0 m
    Hoist Type                                                     Electrically operated Rope Drum   
                                                                            Hoist
     
    8.    Trash racks
     
    Type                                                               Fabricated steel panels
    Nos.                                                                8 Nos.
    Size of opening (W x H)                             3.0m x 6.8 m
    Size of trash rack panels (W x H)              3.0 m x 1.828 m
    Sill level                                                         2821.8 m
    Inclination of trash rack                              100 (with vertical)
    Clear opening between the bars              100 mm
     
     
    9.    Intake Ducts
     
    Nos.                                                                2
    Size of each duct (W x H)                           4.0 m x 4.0 m
    Length of each duct                                                15.28 m
     
    10. Feeder Tunnels
     
    Nos.                                                                2
    Size of each tunnel                                     4.0 m, D-shape
    Length                                                           693.9 m & 593.5 m
     
    11. De-sanding Chambers
     
    No. & Size (L x W x H)                                 2 Nos., 200m x 12.0 m x 13.6 m
    Size of particles to be removed                 > 0.2 mm
    Discharge for each chamber                     30.735 m3/s
    Flushing discharge for each chambers   6.15 m3/s
     
    12. Headrace Tunnel
     
    Design Discharge                                        61.47 cumec
    Shape                                                                        Modified Horseshoe
    Finished Size                                               5.2 m
    Length                                                           2013 m
    Thickness of lining                                      300 mm
     
    13. Surge shaft
     
    Type                                                               Restricted-orifice; Underground
    Diameter                                                        12.0 m
    Orifice Diameter                                           2.4 m
    HRT invert at surge shaft                           2794.5 m
    Surge Shaft Top                                           2861 m
    Total Height                                                  49 m
    Upsurge level                                               2855.5 m
    Down surge level                                         2810.5 m
     
    14. Pressure Shaft
     
    Number and Diameter                                1 Nos., 4.0 m
    Grade of Steel                                              ASTM A537, Class II
    Length of main Pressure Shaft                 120 m
     
    15. Branch Penstocks (Unit penstocks)
     
    Number and Diameter                                2 Nos., 2.30 m
    Grade of Steel                                              ASTM A537, Class II
     
    16. Powerhouse Complex
     
    Location                                                         underground, about 1 km upstream
                                                                      of Jelam reservoir.
    Dimensions (L x W x H)                              104 x 20.5 x 46m
     
    17. Turbine
     
    Installed Capacity                                        65 MW (2 X 32.5 MW)
    Turbine Type                                                            Vertical  Axis Francis
    Number of Units                                           2 Nos.
    Rated Discharge per Unit                           30.74 m3/s
    Rated net head                                            117 m
    Normal Tail Water level                               2712 m
     
    18. Generator
     
    Type                                                               Semi-umbrella
    Number                                                          2 Nos.
    Generator Frequency                                  50 +  5% Hz
    Power factor                                                  0.9
     
    19. Draft Tube Tunnel
     
    Nos. And Sizes (W x H)                              2 Nos., 7.0 m x 3.17 m
    Length of each tunnel                                70.0 m
     
    20. Tailrace Tunnel
     
    Length                                                           181 m
    Shape (W x H)                                              7.0 m x 9.00 m, D-shape
    Tailrace Outlet Gate type                            Vertical lift fixed wheel type
    Tailrace Gate Size (W x H)                         7.0 m x 6.0 m
    Hoist Type                                                     Rope Drum hoist
     
     
    21. Power Benefits
     
    90 % dependable energy                           250.60 MU
    50 % dependable energy                           300.16 MU
     
     




Updated on : 19/02/2018