Glen Canyon Dam

Length: 186 miles

Volume: 27 million acre feet at full pool originally. However, after 30 years the volume is only 25 million acre feet due to sedimentation. One half of volume is in the top 100 feet of the reservoir. Volume was to equal 2 years average flow of the river, but now it is less due to sedimentation.

Surface Area: 252 square miles; 161,000 acres, 1960 miles of shoreline.

Historic Floods  - in cubic feet per second (cfs)
Colorado River at Lees Ferry   July 7, 1884       300,000 cfs
                                               June 18, 1921    220,000 cfs
Colorado River at Grand Canyon      1862         500,000 cfs (estimated)

In addition, there is evidence of prehistoric floods as large as 1,000,000 cfs, possibly even greater.

Probable Maximum Floods into Glen Canyon,
Drainage Area 108,000 sqare miles

Type of Flood              Peak Flood (cfs)       Volume (acre feet)            Duration
Rain                                        417,000                      2,063,600              6 days
Snowmelt                                196,100                   28,460,200              Apr-Jul
Spring (Snowmelt + Rain)        196,100                   28,923,900             Apr-Jul

From Colorado River Basin Probable Maximum Floods, Hoover and Glen Canyon Dams, prepared by the United States Department of Interior, Bureau of Reclamation, September 1990

Reservoir Levels and Releases - Bureau of Reclamation Web Site

Glen Canyon Dam Statistics

Designer: Louis Puls
Chief Construction Engineer: Lem Wylie
General Contractor: Merritt Chapman & Scott
Dam Construction Cost: $145,000,000
Total Cost( including power plants, etc.): $272,000,000
Size: 5 million cubic yards / 10 million tons
West Diversion tunnel: 2780 feet long. 41 foot diameter. Plugged with 400 feet of concrete.
Maximum Power Generation: 1300 megawatts with full reservoir, although operating at full capacity was proven to seriously damage downstream riparian environment in Grand Canyon.New protocols now reduce operating capacity to between 500 and 800 megawatts annually.

Release Capacity
Each Penstock delivers max 1.3 million GPM.
Dam bypasses, 8 penstocks - 32,000 cubic feet per second (cfs)
4 outlet Tubes - 15,000 cfs
East Spillway - 138,000 cfs
West Spillway - 138,000 cfs
       Total possible spill: 323,000 CFS

 Dates

April 11, 1956 - Dam authorized.
Oct 1, 1956 - Project begins.
Oct. 15, 1956 - Ceremonial blast.
Feb. 11, 1959 - Cofferdam in place, river diverted.
June 17, 1960 - First bucket of concrete poured.
Jan 21, 1963 - First diversion tunnel closed (west).
March 13, 1963 - Second diversion tunnel closed.
Sept. 13, 1963 - Last bucket of concrete poured.
Sept 4, 1964 - First dynamo operates.
Feb 28, 1966 - Last generator completed.
June 22, 1980 - Lake first filled to 3700 feet.

Lake Powell

recreation

top