JOHN H. KERR PROJECT PERTINENT DATA Location of dam On Roanoke River, about 178.7 river miles above the mouth at latitude 36 35'56", longitude 78 18'06". It is in Mecklenburg County, Virginia; 20.3 miles downstream from Clarksville, Virginia; 18 miles upstream from the Virginia-North Carolina State line; 80 air miles from Richmond, Virginia. Purpose For reduction of flood damage in Lower Roanoke River, for generation of hydroelectric power, and for low water control for pollution abatement and conservation of fish and wildlife. Drainage areas Smith River at Philpott Dam . . . . . . . . . . 212 sq. miles Dan River at Clarksville, Virginia . . . . . 3,855 sq. miles Roanoke River at Clarksville, Virginia . . . 7,320 sq. miles Roanoke River at John H. Kerr Dam . . . . . . 7,800 sq. miles Roanoke River at Weldon, North Carolina . . . 8,445 sq. miles Roanoke River at mouth . . . . . . . . . . . 9,580 sq. miles Flows at damsite in Period Jan 1912-Dec 1981 Average. . . . . . . . . . . . . . . . . . . . . 7,641 c.f.s. Maximum (17 Aug 1940). . . . . . . . . . . . . .270,000 c.f.s. Minimum (21 Sept 1932) . . . . . . . . . . . . . . 467 c.f.s. Maximum Monthly (Aug 1940) . . . . . . . . . . . 36,980 c.f.s. Minimum Monthly (Sept 1968 ) . . . . . . . . . . . .439 c.f.s. Elevations. feet above mean sea level Top of dam . . . . . . . . . . . . . . . . . . . . . . . . 332 Flood plain (general elevation) . . . . . . . . . . . . . 212 Base of dam (approx.): Concrete portion lowest). . . . . . 188 Embankment (lowest) . . . . . . . . 287 Maximum surcharge elevation (Spillway Design Flood). . . . 326 Top of crest gates . . . . . . . . . . . . . . . . . . . . 320 Spillway crest . . . . . . . . . . . . . . . . . . . . . . 288 Top of power intakes . . . . . . . . . . . . . . . . . . . 265 Minimum elevation to which land has been purchased or flowage easements acquired . . . . . . . . . . . . . . . 320 Reservoir clearing limits: Upper . . . . . . . . . . . . . . . . . . . . . . . . . 302 Lower. . . . . . . . . . . . . . . . . . . . . . . . . . 267 Max.(29 Apr 1987) . . . . . . . . . . . . . . . . . . 319.61 Min.(3 Feb 1956) . . . . . . . . . . . . . . . . . . . 280.23 Tailwater elevation Max. level for Spillway Design Flood (800,000 c.f.s.). . . 265 Maximum design level for protection of powerhouse (460,000 c.f.s.) . . . . . . . . . . . . . . . . . . . 246 Normal operating level . . . . . . . . . . . . . . 199 to 209 Reservoir (excluding portion above Island Creek Dam) Counties Affected: State of Virginia. . . . . . . . Mecklenburg, Charlotte, Halifax State of North Carolina. . . . . . . . Granville, Vance, Warren Length at elev. 320: Roanoke River . . . . . . . . . . . . . . . . . . . 56 miles Dan River, above junction . . . . . . . . . . . . . 34 miles Length of shoreline at elev. 300 . . . . . . . . . . . 800 miles Maximum width at elev. 300 . . . . . . . . . . . . . . 2.0 miles Storage: Acre-Feet Inches Total volume at elev. 326 . . . . . . . . . 3,364,500 8.09 Uncontrolled flood storage (elev. 326 to elev. 320) . . . . . . . . . 594,500 1.43 Controlled flood storage (elev. 320 to elev. 300) . . . . . . . . . 1,281,400 3.08 Power drawdown (elev. 300 to elev. 268) . . 1,027,000 2.47 Volume at design minimum power pool (elev. 268) . . . . . . . . . . . . . . . . 461,600 1.11 Reservoir surface: At maximum flood-control pool (elev. 320). . . . 83,200 acres At maximum power pool (elev. 300). . . . . . . . 48,900 acres At minimum power pool (elev. 268). . . . . . . . 19,700 acres Original river area (below elev. 320). . . . . . 4,280 acres Dam Type and material. . . . Concrete gravity non-overflow sections; concrete gravity spillway section, gate controlled; concrete gravity power in- take section; earth wing and saddle dikes on right and left banks. Foundation . . . . . . . . . . . . . . . . . . . Granite gneiss Length: Right earth wing and saddle dike . . . . . . . . . . 9,030 ft. Non-overflow section on right bank . . . . . . . . . 629 ft. Spillway . . . . . . . . . . . . . . . . . . . . . . 1,092 ft. Intake to powerhouse . . . . . . . . . . . . . . . . 561 ft. Non-overflow section on left bank. . . . . . . . . . 503 ft. Left earth wing and saddle dike . . . . . . . . . 10,220 ft. Total (rounded). . . . . . . . . . . . . . . . . . 22,035 ft. Maximum height: Concrete section . . . . . . . . . . . . . . . . . . 144 ft. Earth fill sections. . . . . . . . . . . . . . . . . 45 ft. Maximum width at base: Spillway section only. . . . . . . . . . . . . . . . 109 ft. Including bucket . . . . . . . . . . . . . . . . . . 146 ft. Crest gates: Type . . . . . . . . . . . . . . . . . . . . . . . . . Tainter Number . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Size (length by height). . . . . . . . . . . . . . 42 by 32 ft. Hoists . . . . . . . . . . . . . . . . . . . . . . . Individual Net length of spillway . . . . . . . . . . . . . . . . 924 ft. Capacity of spillway at elev. 326. . . . . . . . 800,000 c.f.s. Capacity of spillway at elev. 300. . . . . . . . 127,000 c.f.s. Sluices: Number . . . . . . . . . . . . Six 5-ft. 8-in. by 10-ft. inlets Sluice gates . . . Twelve (1 service and 1 emergency per outlet) slide gates hydraulically operated Capacity at elev. 300. . . . . . . . . . . . . . .l9,000 c.f.s. Spillway energy dissipator: Type . . . . . . . . . . . . . . . . . . . . . . Roller bucket Angle of bucket lip. . . . . . . . . . . . . . . . . 20 degrees Radius of bucket . . . . . . . . . . . . . . . . . . . . 40 ft. Elevation of bucket lip. . . . . . . . . . . . . 202 ft., m.s.l. Elevation of bucket invert . . . . . . . . . . . 195 ft., m.s.l. Power plant Power station Generating capacity: 6 units at 32,000 kw each. . . . . . . . . . . . . 192,000 kw 1 unit at 12,000 kw. . . . . . . . . . . . . . . . 12,000 kw 2 station service units at 1,000 kw each . . . . . 2,000 kw Principal dimensions: Powerhouse . . . 590 ft. long by 71 ft. wide by 142 ft. high Gates. . . . . . . 538 ft. long by 26 ft. wide by 29 ft. high Intakes: Number . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Gates . . . . . . . .Caterpillar type with individual hoists Penstocks: Number . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Type . . . . . . . . . . . . . . . . . . . Welded steel plate Dimensions: Penstocks to 32,000-kw units . . . . . . . 24-foot diameter Penstocks to 12,000-kw units . . . 15-foot, 6-inch diameter Penstocks to 1,000-kw units . . . 5-foot, 6-inch diameter Hydraulic turbines: Number . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Type . . . . . . . . . . . . . . . . . Francis Vertical Shaft Rated capacity of units: 6 units at 45,000 hp each at 90-ft. net head 1 unit at 17,000 hp each at 90-ft. net head 2 units at 1,600 hp each at 90-ft. net head Discharge at rated turbine capacity (90 ft. head) Discharge of 45,000 hp unit - 4,850 c.f.s. 6 units . . . . . . . . . . . 29,100 c.f.s. Discharge of 17,000 hp unit - 1,800 c.f.s. 1 unit. . . . . . . . . . . . 1,800 c.f.s. Discharge of 1,600 hp unit - 175 c.f.s. 2 units 350 c.f.s. Total Discharge. . . . . . . . . . . . . . . 31,250 c.f.s. Normal speed: 32,000 kw units. . . . . . . . . . . . . . . . .85.7 RPM 12,000 kw units. . . . . . . . . . . . . . . . 138.5 RPM 1,000 kw units. . . . . . . . . . . . . . . . 450.0 RPM Spacing of turbines: C to C of main power units . . . . . . . . . . . . . 70 ft. C to C of station service units. . . . . . . . . . . 20 ft. Draft tubes: Type . . . . ... . . . . . . . . . . . . . . . Concrete elbow Approximate throat diameter: For 45,000-hp units. . . . . . . . . . . . 17 feet 0 inches For 17,000-hp units. . . . . . . . . . . . 11 feet 6 inches For 1,600-hp units. . . . . . . . . . . . 3 feet 6 inches Horizontal length (center line of turbine to downstream face) . . . . . . . . . . . . . . . . . 60 ft. Net area at outlet opening (45,000-hp units) . . 846 sq. ft. Transformers: Type: 3 phase-60 cycle, forced oil, forced water. 13.2/115 KV Number and rating. . . . . . . . . . . . . . . 6-41,000 kva Number and rating. . . . . . . . . . . . . . . 1-15,000 kva Switchyard: Size . . . . . . 568 ft. long by 175 ft. wide by 90 ft. high Outgoing lines . . . . . . . . . . 6-110 KV-3 phase-60 cycle