CARTERS DAM
COOSAWATTEE RIVER, GEORGIA
PERTINENT DATA


MAIN DAM

GENERAL

  Dam site, miles above mouth of Coosawattee River                26.8
  Drainage area above dam site, square miles                       376


                   RESERVOIR
                   ---------

GENERAL

  Primary flood control pool elevation, ft. above msl             1,099
  Max. power pool elev. (wet season), ft. above msl               1,072
  Max. power pool elev. (dry season), ft. above msl               1,074
  Min. power pool elev., ft. above msl                            1,022
  Max. drawdown, feet                                                52
  Area of primary flood control pool, acres                       3,880
  Area of maximum power pool, acres                               3,220
  Area of minimum power pool, acres                               2,196
  Flood storage volume, acre-feet                                95,700
  Power storage volume, acre-feet                               134,900
  Dead storage volume, acre-feet                                242,200
  Maximum elevation of clearing, ft. above msl                    1,075


SPILLWAY DESIGN FLOOD

  Natural peak discharge at dam site, cfs                       194,200
  Peak inflow to full reservoir, cfs                            203,100
  Regulated peak outflow, cfs                                   199,200
  Regulated peak headwater, ft. above msl                       1,107.2


STANDARD PROJECT FLOOD

  Natural peak discharge at dam site, cfs                        97,600
  Natural peak stage at dam site, ft. above msl                   716.8
  Peak inflow to full reservoir, cfs                            102,000
  Regulated peak outflow, cfs                                    54,000
  Regulated peak headwater, ft. above msl                       1,106.5
  Regulated peak tailwater, ft. above msl                         707.0


NATURAL STREAM FLOW AT DAM SITE

  Period of continuous record                                 l937-l963*
  Average flow for period of record, cfs                            770
  Minimum mean monthly flow in period of record, cfs                210
  Minimum mean daily flow in period of record, cfs                  178
  Maximum mean monthly flow in period of record, cfs              2,210
  Maximum mean daily flow in period of record, cfs               12,400
  Maximum flow during period of continuous record
    (flood of April, 1938), cfs                                  26,700
  Peak stage for period of continuous record
    (flood of April 1938), ft. above msl                          685.9
  Floodway capacity for downstream reach,
    (dry season), cfs                                             3,200
  Floodway capacity for downstream reach,
    (wet season), cfs                                             5,000

  *Flows estimated by correlating Carters flow with
         Cartecay River near Ellijay, Georgia



                   MAIN DAM AND DIKES
                   ------------------

ROCKFILL DAM

  Top elevation, feet above msl                                 1,112.3
  Top width, feet                                                    40
  Length, feet                                                    2,053
  Maximum height, feet above foundation                             445
  Upstream slope                                               1 on 1.9
  Downstream slope                                             1 on 1.8
  Freeboard, top of dam above Spillway Design Flood, ft.            5.1

EARTHFILL SADDLE DIKES

  Top elevation, feet above msl                                 1,112.3
  Top width, feet                                                    30
  Number of dikes                                                     3
  Total length, feet                                                700
  Maximum height, feet                                               40
  Side slopes                                                  1 on 2.5
  Upstream slope protection                                 dumped rock
  Freeboard, top of dikes above Spillway Design Flood, ft.          5.1



                   EMERGENCY GATED SPILLWAY
                   ------------------------

GENERAL

  Total length, including end piers, ft.                            262
  Net length, ft.                                                   210
  Elevation of crest, ft. above msl                             1,070.0
  Type of gates                                                 tainter
  Number of gates                                                     5
  Length of gates, ft.                                               42
  Height of gates, ft.                                             36.5


                   DIVERSION TUNNEL
                   ----------------

GENERAL

  Length, ft.                                                     2,407
  Shape                                                       horseshoe
  Lining                                                           none
  Bottom width, ft.                                                  23
  Maximum height, ft.                                                23


                   EMERGENCY LOW-LEVEL SLUICE
                   --------------------------

GENERAL

  Number of sluices                                                   1
  Total length of tunnel, ft.                                     2,712


TUNNEL UPSTREAM OF GATE STRUCTURE

  Length of tunnel, ft.                                           1,198
  Shape                                                        circular
  Lining                                                       concrete
  Nominal diameter of excavated tunnel, ft.                        19.5
  Diameter of lined tunnel, ft.                                    16.5
  Invert elevation at upstream portal, ft. above msl                725


GATE STRUCTURE

  Length of structure, ft.                                           62
  Number of water passages                                            2
  Invert elevation of water passages, ft. above msl                 723
  Number of gates per passage                                         2
  Total number of gates                                               4
  Type of gates                                                   slide
  Height of gates, ft.                                               10
  Width of gates, ft.                                                 5
  Type of operating machinery                                 hydraulic
  Nominal diameter of excavated shaft for combined
     emergency access and air vent, ft.                              10



TUNNEL DOWNSTREAM OF GATE STRUCTURE

  Length of tunnel, feet                                          1,452
  Shape                                                       horseshoe
  Lining                                                           none
  Bottom width, ft.                                                  22
  Maximum height, ft.                                                22
  Length of concrete splash apron, ft.                              200
  Invert elevation at downstream portal, ft. above msl              710



DOWNSTREAM CHANNEL

  Length, ft.                                                       640
  Maximum bottom width, ft.                                          50
  Side slopes:
    Sound rock                                                   4 on 1
    Weathered rock                                               1 on 1
    Overburden                                                   1 on 2
  Bottom elevation at downstream end of                             700



                   POWER INTAKE
                   ------------

GENERAL

  Number of intake structures                                         2

HEADRACE

  Length (approximate), ft.                                       1,600
  Width (minimum section), ft.                                      200
  Side slopes                                                    4 on 1
  Bottom elevation, ft. above msl                                 979.0


INTAKE STRUCTURES

  Top elevation, ft. above msl                                  1,112.5
  Width of each structure, ft.                                       94
  Length of base, ft. (excluding transition)                         51
  Maximum height, ft.                                             138.5
  Type of head gate                                             tractor
  Number of head gates, each structure                                2
  Height of gate, ft.                                              20.5
  Width of gate, ft.                                                 14
  Type of operation                                         fixed hoist
  Elevation of operating deck, ft. above msl                    1,112.5


PENSTOCKS

  Number                                                              4
  Length of conventional unit penstocks, ft.                        835
  Length of pump-turbine unit penstocks, ft.                        838
  Nominal diameter of excavated tunnel, ft.                          23
  Inside diameter of steel-lined penstock, ft.                       18
  Minimum thickness of concrete liner, inches                        30



                   POWER DATA
                   ----------

GENERAL

  Number of units                                                     4
  Capacity of each unit, kw                                     125,000
  Total installation, kw                                        500,000
  Dependable plant output during critical period, kw            500,000
  Operating head at maximum power pool, ft.                         396
  Minimum head at full drawdown, ft.                                324
  Maximum head loss at 115% generator rating, ft.                   4.8
  Maximum discharge per unit at 115% generator
           rating (conventional unit), cfs                        5,400
  Maximum discharge per unit at 115% generator
           rating (pump-turbine unit), cfs                        5,400
  Discharge each pump-turbine unit at 385 feet
           total head, cfs                                        3,765
  Maximum discharge at minimum power pool, elev. 1022,
           (estimated for 4 units), cfs                          20,900



GENERATING UNITS 1 AND 2 ONLY


  Speed-RPM                                                       163.6
  Spacing of units, center to center, ft.                            63
  Turbines
      Type-Francis, clockwise rotation
      Capacity, guaranteed
        at 345.0 ft. net head, HP, each                         172,000
        at 393.0 ft. net head, HP, each                         199,000
      Spiral cases -                                        plate steel
      Draft tubes -                                     concrete elbow,
                                               three discharge passages
  Generators
  Type -                           Vertical shaft, with combined thrust
                                 and guide bearing below rotor and with
                                    air enclosure for self-ventilation.

  Ratings
      Continuous at 60 C. rise -                            125,000 kW,
                                                            131,579 kVA

      Continuous capability at 1.15 rating -                143,750 kW,
                                                            151,316 kVA

      Power factor                                                 0.95
      Voltage, 60 hertz, 3-phase                                 13,800
      Short circuit ratio, not less than                          1.175
      Fly wheel effect (wK2 LBS-FT )                         95,700,000
      Ratio, Xq"/Xd", not more than                                1.35



GENERATOR/MOTOR UNITS 3 AND 4 ONLY

  Speed-RPM                                                         150
  Spacing of units, center to center, ft.                            63
  Pump/Turbines
      Type-Francis, clockwise rotation as
      turbine; counter-clockwise rotation
      as pump
      Capacity, guaranteed
        at 345.0 ft. net
          as a turbine                                          173,000
        at 376.0 ft. net
          as a turbine                                          209,000
        at 347 ft. total        eff                               87.6%
        at 383 ft. total        eff                               87.2%
      Spiral cases -                                        plate steel
      Draft tubes -                                     concrete elbow,
                                        three discharge/intake passages

  Generator/Motors
      Type -                        Vertical shaft, with thrust-bearing
                                   above rotor and guide-bearings above
                                and below rotor, and with air enclosure
                                                  for self-ventilation.
      Ratings
        As a generator:
          Continuous at 60 C. rise -            125,000 kW, 131,579 kVA
          Continuous capability at
            1.15 rating                         143,750 kW, 151,316 kVA
          Power factor                                              .95
          Voltage, 60 hertz, 3-phase                             13,800
          Short circuit ratio not less than                       1.175
          Flywheel effect (Wk2), LBS-FT2                     90,000,000

        As a motor:
          Output, rated, horsepower                             185,000
          Power factor                                              .95
          Voltage, 60 hertz, 3-phase                             13,800
          Speed, RPM                                                150


                   POWERHOUSE
                   ----------

GENERAL

  Location - right bank about 200 feet below the
     downstream toe of the main dam and 700 feet
     northward from the river channel

  Size of building
       Length, feet including unloading bay                     361'-6"
       Width, feet (including draft tube deck)                  114'-3"
       Entrance wing ("L" shaped)


ELEVATIONS, FEET (MSL)
       Bottom of structure                                       603.20
       Low point of draft tube   (Units 1 & 2)                   620.00
                                 (Units 3 & 4)                   615.67
       Centerline of distributor (Units 1 & 2)                   658.00
                                 (Units 3 & 4)                   649.00
       Turbine room floor        (Units 1 & 2)                   676.00
       Generator room floor      (Units 1 & 2)                   691.00
                                 (Units 3 & 4)                   676.00
       Control room                                              691.00
       Erection floor                                            708.00
       Unloading floor                                           708.00
       Draft tube deck                                           708.00
       Crane runway rail                                         737.50
       Roof, high point                                          758.08
       Top of parapet                                            761.92

DRAFT TUBE GATES
       Type                                        Vertical lift, slide
       Number                                                         3
       Size, feet (approx.)                           13'-9" x 20'-l"
       Method of handling                                  Gantry crane
       Type                                        Vertical life, slide
       Number                                                         6
       Size, feet (approx.)                           13'-9" x 21'-8"
       Method of handling                                  Gantry crane





                   REREGULATION DAM
                   ----------------

GENERAL

        Dam site, miles above mouth of Coosawattee River             25
        Drainage area above dam site, square miles                  530
        Drainage area of reregulation dam only, square miles        154

RESERVOIR

        Maximum storage poo1 elevation, ft. above msl             698.0
        Maximum normal operating poo1 elevation, ft. above msl      696
        Minimum poo1 elevation, ft. above msl                     662.5
        Minimum normal operating pool elevation, ft. above msl      677
        Area at maximum storage pool, acres                         870
        Area at minimum pool, acres                                  50
        Usable storage, acre-feet                                17,210
        Dead storage, acre-feet                                     290
        Area acquired, acres                                      1,373
        Maximum elevation of clearing, ft. above msl              700.0
        Area cleared, acres                                         320

SPILLWAY

        Total length, including end piers, ft.                      208
        Net length, ft.                                             168
        Elevation of crest, ft. above msl                         662.5
        Number of piers, including end piers                          5
        Width of piers, ft.                                           8
        Type of gates                                           tainter
        Number of gates                                               4
        Length of gates, ft.                                         42
        Height of gates, ft.                                       36.5
        Elevation of top of gates in closed position, ft msl      699.0
        Elevation of low steel of gates in fully open, ft msl     699.0
        Elevation of trunnion, ft. above msl                      675.0
        Elevation of access bridge, ft. above msl                 717.0
        Elevation of stilling basin apron, ft. above msl          647.5
        Length of stilling basin, ft.                                40
        Height of end sill, ft.                                       4


EARTH DIKES

        Top elevation, ft. above msl                              703.0
        Length, ft.                                               2,855
        Top width of right dike, ft                                  32
        Top width of left dike, ft                                   12
        Side slopes                                              1 on 3
        Thickness of riprap, inches                                  24
        Thickness of filter material, inches                          9
        Thickness of dumped rock, inches                             60