TEHRI DAM & HPP(STAGE-I)

  • TEHRI HYDRO POWER COMPLEX (2400 MW)

     INTRODUCTION :

    Tehri Hydro Power Complex (2400 MW), comprises the following components:
    1.      Tehri Dam & Hydro Power Plant (1000 MW)
    2.      Koteshwar Hydro Electric Project (400 MW) 
    3.      Tehri Pumped Storage Plant (PSP) (1000 MW)
    Govt. of India approved the implementation of Tehri Dam & HPP (1000 MW) in March, 1994 along with committed works of Koteshwar HEP and essential works of Tehri PSP, as Stage-I of Tehri Hydro Power Complex. All the four units of Tehri Power Station were commissioned in the year 2006-07. This project has become the landmark and pride of the Nation as a whole.
     
    Two Units of Koteshwar HEP were commissioned in Mar, 2011 and 3rd and 4th unit were commissioned in Jan, 2012 and Mar, 2012 respectively.
     
    The essential works of Tehri PSP have already been completed along with Tehri Dam & HPP Stage-I. Major works of the Project are being executed through a single EPC contract. Contract for EPC/Turnkey execution of the Project has been awarded to consortium of M/S Alstom Hydro France and Hindustan Construction Company on 23rd June-2011. Work on the project has commenced w.e.f 27th Jul,2011. 
     
    Benefits from the Tehri Hydro Power Complex
    ·         Addition to the installed generating capacity in the Northern Region 
    (1000 MW on completion of Tehri Stage-I)
     
    2400 MW
    • Annual energy availability (Peaking)
      (2797 MU on completion of Tehri Stage-I)
    5220 MU
    • Irrigation (additional)
    2.70 Lac.ha.
    • Stabilisation of existing irrigation
      (besides above)
    6.04 Lac.ha.
    • Additional Generation in downstream Projects
    200 MU
    • 300 Cusecs (162 million gallons per day) of drinking water for Delhi which will meet the requirements of about 40 lac people.
    • In addition, 200 Cusecs (108 million gallons per day) of drinking water for towns and villages of U.P. which will meet the requirement of 30 Lac people.
    • Flood Moderation
    ·         Integrated development of Garhwal region, including construction of a new hill station town with provision of all civic facilities; improved communication, education, health, tourism, development of horticultures, fisheries, and afforestation of the region.
     
     
    TEHRI  DAM & HPP (1000 MW) (Under Operation)  
    Tehri Dam & HPP (1000 MW) comprises a 260.5 M high Earth & Rockfill dam which is one of the highest dams of its type in the world, a Spillway System designed for PMF of 15540 cumecs and a drop of 220m, having one Chute Spillway and four Shaft Spillways and an underground Power House housing four Turbine/ Generator sets of 250 MW each, designed to operate with a head variation of 90 m.
    Project was commissioned in 2006-07 and all four machines of Tehri Power Station are under commercial operation. Besides providing much needed power to the Northern Grid, the command area is availing irrigation benefits from the Project and drinking water is being supplied to Delhi and UP.
     
    COMMISSIONING OF PROJECT
    All four units (Unit-IV, Unit-III, Unit-II & Unit-I) were synchronized with the Northern Grid in July’ 06, Oct’06, Jan’07 & Mar’07 and are in commercial operation w.e.f. 22nd Sep’06, 9th Nov’06, 30th March’07 & 9th July’ 07 respectively.
  • SALIENT FEATURES
     
    Nature of Scheme: Storage scheme
    Hydrology
    Normal Annual Rainfall     1016  to 2630 mm.
    Maximum recorded flood discharge    3800   Cumecs
    Adopted maximum flood for diversion during monsoon period  8120   Cumecs
    Probable maximum flood    15540  Cumecs
    Routed Flood   13248  Cumecs
    Reservoir
    Full Reservoir Level   (FRL) EL  830 m.
    Maximum Level during design flood (MFL)  EL   835 m
    Dead Storage Level  EL   740 m.
    Gross Storage  3540 MCM
    Dead Storage 925 MCM
    Live Storage  2615  MCM
    Water Spread at full Supply Level EL.830 m. 42 Sq.km.
    Water Spread at dead Storage Level EL.740 m.    18 Sq.km.

    TECHNICAL FEATURES
    Diversion Tunnels
    Type    Horse shoe
    Left Bank  2 Nos. 11.0m dia, 1774 &1778 m long
    Right Bank 2 Nos. 11.0m dia, 1298 &1429 m long
    Diversion Flood Discharge  8120 Cumecs
    Dam
    Type  Earth and Rock fill dam
    Top Level     EL 839.5 m
    Height  260.5 m
    Width at riverbed   1125 m
    Width at top  25.5 m flared to 30.5 m at abutments 
     Length at Top  592m
    Slope 
    Upstream  1: 2.5  
    Downstream  1: 2  
    Spillways
    Chute Spillway:    
    Crest Level  EL 815.0 m
    Waterway                                                                   3 bays of 10.5 m width
    Design Discharge    5500 Cumecs
    Type & No. of Gates Radial Gates, 3 Nos
    Right Bank Shaft Spillway:  
    Type                                                                           Ungated  2 Nos
    Crest Level   EL 830.2 m
    Dia of Shaft   12.0 m
    Design Discharge  3850 Cumecs
    Left Bank Shaft Spillway:    
    Type  Gated 2 Nos
    Crest Level   EL 815.0 m
    Dia of Shaft  12.0 m
    Design Discharge 3650 Cumecs
    Type of Gates Radial gates
    Intermediate Level Outlet:   
    No. and size  One; 8.5 m dia
    Discharge capacity ( at EL. 830.0 m)  1100 Cumecs
    Intake Works:  
    Location  Left Bank of river Bhagirathi
    No & Type of Structure 2 Nos. Submerged Structure
    Crest Elevation EL 720 m.
    Head Race Tunnels:  
    Size and Number 8.5m. dia, 2 Nos, 
    Total Length 1634 m
    Penstocks:  
    Number and Size 4 Nos., 5.75 m. dia each
    Total Length 1040 m
    Power House
    Machine Hall:  
    Type  Underground
    Location Left Bank, under ground
    Number & Units 4 Nos, 250 MW each
    Size 197 m long, 22.0 m wide, 47.2m. high
    Head  Maximum 231.5 m ,
    Minimum 127.50 m ,
    Design     188.0 m.
    Transformer Hall:  
    Type Underground
    Size 161m.long X 18.5m.wide X 29.0m high
    Step-up Transformers:  
    Capacity 306 MVA
    Number  4
    Voltage Ratio 15.7/400 KV
    Switchyard:  
    Location and Type Indoor SF-6 Switchgear
    Tail Race Works:  
    Number and size of tail race tunnels 2 Nos. , 9.0 m. dia  each
    Length of Tunnels  862.5 m & 747.5 m
    Invert Level of Outlet EL. 598.0 m.
    Installed Capacity : 1000 MW (4x250 MW)
     
  • Benefits from the Tehri Hydro Power Complex
    ·         Addition to the installed generating capacity in the Northern Region 
    (1000 MW on completion of Tehri Stage-I)
     
    2400 MW
    • Annual energy availability (Peaking)
      (2797 MU on completion of Tehri Stage-I)
    5220 MU
    • Irrigation (additional)
    2.70 Lac.ha.
    • Stabilisation of existing irrigation
      (besides above)
    6.04 Lac.ha.
    • Additional Generation in downstream Projects
    200 MU
    • 300 Cusecs (162 million gallons per day) of drinking water for Delhi which will meet the requirements of about 40 lac people.
    • In addition, 200 Cusecs (108 million gallons per day) of drinking water for towns and villages of U.P. which will meet the requirement of 30 Lac people.
    • Flood Moderation
    ·         Integrated development of Garhwal region, including construction of a new hill station town with provision of all civic facilities; improved communication, education, health, tourism, development of horticultures, fisheries, and afforestation of the region.
     




Updated on : 24/04/2018