FACT SHEEI' FOR GLEN CANYON DAM

What is Glen Canyon Dam? The key structure in the Colorado River Storage Project -- a mul.tiple-purpose reclamation project covering the Upper Colorado River Basin. Glen Canyon Dam is the largest of four main­ stream storage units authorized for construction as part of the Colorado River Storage Project. The others are the Fla.ming Gorge Dam on the Green River in Utah, the Navajo Dam on the San Juan River in New Mexico, and the Curecanti Unit on the Gunnison River in Colorado. The Curecanti Unit may involve 3 or 4 dams, but requires some further investigation which is now underway.

Location. The Glen Canyon Dam site is located on the main stem of the Colorado River in Arizon -- at a point 13 miles downstream from the Arizona-Utah State line, and 16 miles upstream from Lee Ferry. Lee Ferry is the dividing point on the Colorado River between the Upper and Lower Colorado River Basins.

Height. Glen Canyon Dam will be the second highest dam in the United States. Only Hoover Dam will be higher. It will rise 700 feet above bedrock and 58o feet above the normal level of the Colorado River.

Width. The crest length of the concrete gravity-arch dam will be 1,400 feet.

Volume. Glen Canyon Dam will exceed Hoover Dam in volume of concrete. Only Grand Coulee Dam in Washington and Shasta Dam in California will be larger. More than 5 million cubic yards of concrete will be placed in building Glen Canyon Dam. By comparison, Hoover Dam has 3-1/4 million cubic yards of concrete; Grand Coulee, 10-1/2 million; and Shasta 6-1/2 million.

Reservoir. A 26,000,000 acre-foot reservoir will be created by Glen canyon Dam. About 20,000,000 acre-feet of this total storage will be active or usable storage.

The Glen Canyon reservoir will be long, winding, and narrow. It will extend 186 miles up the Colorado River nearly to the mouth of the Green River. Storage water will be backed 71 miles up the San Juan River, a principal tributary entering the Colorado River from the east.

The surface area of the Glen Canyon Reservoir will be about 21'0 square miles. Powerplant. A single powerhouse will be built at Glen Canyon Dam. Seven generators, of 1.15,000 kilowatts capacity each, will be in­ stalled. Thus the total generating capacity of the Green Canyon powerplant wil.l be about 8oo,ooo kilowatts. This one powerplant at Glen Canyon Dam will produce nearly half o! the hydroelectric generation planned for the entire Colorado River Storage Project. J . Bedrock at Glen Canyon. Glen Canyon provides a very good site for the construction of a high concrete dam. The wa.11.s of the canyon stand nearly vertically for 650 feet above the Colorado River.

Massive, uniform sandstone provide the abutments for Glen Canyon Dam.

Diversion of River. Construction of one diversion tunnel begins on October 15. Two diversion tunnels about 45 feet in diameter will be drilled through the abutment rock around the dam site. A coffer dam (low earth dam) will be constructed upstream from the dam site to divert the entire flow of the Colorado River during construction of the Glen Canyon Dam. Likewise, a coffer dam downstream will keep the dam site free of river water backing into the construction area.

Construction Work. The Bureau of Reclamation plans to get work underway on Glen Canyon Dam as rapidly as is practicable. Construction of the main structure of the dam will probably be completed in 6 years.

1. Diversion Tunnel - The contract for drilling the right or west side diversion tunnel was awarded on October 2. The Mountain States Construction Company of Denver, Colorado, was awarded the job. Their bid price is $2,452,340, for the 2,768 foot tunnel which wil.l range from 44 to 47 feet in diameter.

2. Highway Bridge. A highway bridge must be built across Glen Canyon just below the dam site. The Bureau of Reclama­ tion wil.l issue bids for construction of this bridge in November or December of this year.

The bridge will be 1,028 feet long and will be a single arch standing 700 feet above the Colorado River at the bottom of the canyon. A ;0-·fcot roadway and two 4-foot walks will be provided by the bridge.

The construction of the bridge will permit a permanent "loop" highway to be constructed from U.S. Highway 89. This loop would extend from Bitter Springs, Arizona, on the south to Kanab, Utah, on the north -- a distance of 96 miles.

2 3. Dam and Powerplant. It is expected that the invitation for bids on the prime contract for the construction of Glen Canyon Dam and Powerplant will be issued early in 1957. Cost of Glen Canlon Dam. The total estimated cost of the Glen Canyon Storage Unit dam and related works) is $421 million.

This entire cost and applicable interest will be repaid within 50 years of completion of construction.