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