Engin. Library TC 557 .A62 G68 A 5 1970 As the Nation's principal conservation agency, the Department of the Interior has basic responsibilities for water, fish, wildlife, mineral, land, park and recreational resources. Indian and Territorial affairs are other major concerns of America's "Department of Natural Resources." The Department works to assure the wisest choice in managing all our resources so each will make its full contribution to a better United States-now and in the future. Glen Canyon Dam, Powerplant, and Reservoir (Lake Powell) comprise one and the largest of the four units authorized by the Congress in 1956 for initial development under the Colorado River Storage project. The reservoir will contribute to the longtime regulatory storage needed to permit the upper basin States (Utah, Wyoming, Colorado, and New Mexico) to utilize their apportioned water under the terms of the 1922 Compact of the Colorado River. In addition to regulatory storage, the Colorado River Storage project and participating projects will provide electrical energy to a large area where it is urgently needed. Flood protection, sediment, retention, fish and wildlife conservation, and recreational opportunities are also provided. Approximately 95 percent of the costs of the Colorado River Storage project and participating projects are reimbursable and will be repaid by the water and power users. About 60 percent of such costs will be repaid with interest. Glen Canyon Dam Location: On the Colorado River in north-central Arizona, about 15 miles (24.1 kilometers) upstream from Lees Ferry and 12 river miles (19.3 kilometers) downstream from the Arizona-Utah State line. Type: Concrete arch Constructed: 1957-1964 Reservoir: Lake Powell Total capacity to top of active conservation level, elevation 3700.0 feet (1127.76 meters): 27,000,000 acrefeet (33,304,500,000 cubic meters) Active capacity: 20,876,000 acre-feet (25,750,546,000 cubic meters) Surface area: 161,390 acres (65,313 hectares) Maximum reservoir elevation: 3711 feet (1131.11 meters) Dam dimensions: Structural height: 710 feet (216.4 meters) Top width: 25 feet (7.62 meters) Maximum base width: 300 feet (91.44 meters) Crest length: 1,560 feet (457.49 meters) Crest elevation: 3715 feet (1323.32 meters) Volume: 4,901,000 cubic yards (3,747,059 cubic meters) Lowest point in dam foundation excavation: 3005 feet (915.9 meters) Spillways: One spillway in each dam abutment. Each spillway consists of an approach channel, intake structure, combination inclined and horizontal spillway tunnel, and deflection bucket. Each spillway has a concrete crest and concrete-lined circular tunnel through the dam abutments, controlled by two 40- by 52.5-foot (12.19- by 16.00-meter) radial gates. The spillway tunnels for the greater part of their length are 41 feet (12.5 meters) in diameter. The transition section downstream from the intake structure changes from a flat-arch-roof section 89 feet wide by 52 feet high (27.13 by 15.85 meters) to a circular section 48 feet 3 inches (14.71 meters) in diameter. From this point there is a further transition of the circular section to the 41-foot-diameter tunnel. The tunnels are designed to flow partially full, never more than 0.7 of the height. Length of left spillway tunnel: 1,870 feet (570 meters) Length of right spillway tunnel: 1,696 feet (517 meters) Elevation of top of all gates: 3700.0 feet (1127.76 meters) Crest elevation: 3648.0 feet (1111.91 meters) Capacity of each spillway: 138,000 cubic feet per second (3,907.75 cubic meters per second) with water surface at elevation 3711 feet (1131.11 meters) Penstocks: Eight 15-foot (4.57-meter) inside-diameter steel penstocks, each reducing to 14 feet (4.26 meters) inside-diameter within the dam, convey water to the turbines at centerline elevation 3140 feet (957.07 meters). Centerline elevation of the concrete bellmouth intake to each penstock is 3470 feet (1057.65 meters). A fixed-wheel gate upstream from each bellmouth controls the flow from the reservoir to the penstocks. Outlet works: Four 96-inch (2.44-meter) diameter steel pipes through the dam, terminating at the downstream end in a valve structure. Each outlet has a cast iron bellmouth intake, a 96-inch (2.44-meter) ring-follower gate for emergency closure, and a 96-inch (2.44-meter) hollow-jet valve at the outlet end for regulation. Elevation centerline all inlets: 3374.00 feet (1028.40 meters) Elevation centerline all outlets: 3175.00 feet (967.74 meters) Maximum capacity of all four pipes: 15,000 cubic feet per second (424.76 cubic meters per second) at reservoir elevation 3490 feet (1063.75 meters). Diversion tunnels: Left: 41-foot (12.50-meter) diameter, concrete lined, 3,011 feet (917.75 meters) long, invert elevation 3170.67 feet (966.42 meters); temporary outlet works consisting of three 7- by 10.5-foot (2.13- by 3.20-meter) outlets controlled by 7- by 10.5-foot (2.13 by 3.20-meter) slide gates in tandem. Right: 41-foot (12.50-meter) diameter, concrete lined, 2,749 feet (837.89 meters) long, invert elevation 3137.37 feet (956.27 meters). Used for riverflows from 0 to 15,000 cubic feet per second (424.76 cubic meters per second). Glen Canyon Powerplant Location: 400 feet (121.9 meters) downstream from the axis of the dam. Structure: Indoor type; structural-steel superstructure enclosed with concrete curtain walls; intermediate structure and substructure are reinforced concrete. The powerplant is L shaped with the longitudinal centerline of units perpendicular to the canyon walls. The service bay and machine shop bay form the bottom of the L and are parallel to the left canyon wall. That portion of the powerplant housing the 8 generating units is about 546 feet (166.42-meters) long and 127 feet 6 inches (38.86 meters) wide. That portion of the plant housing the service bay and machine shop bay is about 103 feet (31.39 meters) wide and about 230 feet (70.10 meters) long. Number of units: 8 Total installed capacity: 1,000,000 kv.-a. at *90-percent power factor. Generators: Vertical-shaft type; 125,000 kv.-a. at *90-percent power factor, 3 phase, 60 cycles, 13,800 volts, and 150 r.p.m. Turbines: Francis type, 155,500 h.p., 150 r.p.m., headof 450 feet (137.16 meters) Glen Canyon Bridge The bridge was constructed to serve as a vital link in the new highway to the remote damsite, extending between Flagstaff, Ariz., and Kanab, Utah, a distance of about 200 miles (320 kilometers). The bridge was also essential to the transportation of construction materials and equipment by truck to the damsite as there were no rail facilities near the dam. Location: On the Colorado River in Arizona near the Utah border (approximately 17 miles (27 kilometers) upstream from Lee Ferry and 12 river miles (19 kilometers) downstream from the Arizona-Utah State line). Name Change: In the authorization, appropriations, specifications, original drawings, etc., this bridge was identified as the Colorado River Bridge. However, in 1959 the bridge was officially named the Glen Canyon Bridge as an aid in obtaining a more precise location identification. Technical Information: Bridge type: Steel-arch type with a single span Height above river: Approximately 700 feet (213 meters) Length of bridge: 1,271 feet (387.4 meters) including abutments with an arch span of 1,028 feet (313.3 meters) Location: 865 feet (263.6 meters) downstream from axis of Glen Canyon Dam Elevation of bridge deck: 3828 feet (1166.8 meters) Bridge roadway: The concrete roadway is 30 feet (9.14 meters) wide with 4-foot (1.22-meter) sidewalks on each side. Approximate construction quantities: Structural steel: 7,837,000 pounds (3,555,000 kilograms) Reinforcing steel: 371,000 pounds (168,000 kilograms) Handrailings: 110,000 pounds (50,000 kilograms) Concrete for bridge abutments, skewbacks and deck: 2,550 cubic yards (1,950 cubic meters) Rerated 95 percent, see page 296. |