Memorandum on Substitution of Low Bridge Canyon Dam and Marble Canyon Dam for High Bridge Canyon Dam in the Plan for Central Arizona Project

Memorandum - Blue Envelope, From Dominy, to Stewart Udall, "Substitution of Low Bridge Canyon Dam and Marble Canyon Dam for High Bridge Canyon Dam in the Plan for Central Arizona Project," February 14, 1962, page 1UNITED STATES DEPARTMENT OF THE INTERIOR BUREAU OF RECLAMATION WASHINGTON 25, D. C. February 14, 1962 Memorandum - Blue Envelope To: Secretary of the Interior From: Commissioner of Reclamation Subject: Substitution of Low Bridge Canyon Dam and Marble Canyon Dam for High Bridge Canyon Dam in the Plan for Central Arizona Project We have made some very rough reconnaissance estimates of the effects on the potential Central Arizona Project of substituting a low Bridge Canyon Dam and a Marble Canyon Dam for a high Bridge Canyon Dam. The low Bridge Canyon Dam was assumed to be 94 feet lower in height than the high Bridge Canyon Dam. The reservoir would not encroach on the Grand Canyon National Park although it would extend into the National Monument. A comparison of the two installations follows: Low Bridge Canyon Plan ITEM Low Bridge Canyon Marble Canyon Low Bridge Canyon, Plus Marble Canyon High Bridge Canyon Plan Cost of Construction of Dam, Powerplant, Reservoir, and Associated Transmission System $400,000,000 $180,000,000 $580,000,000 $465,000,000 Installed Power Capacity in Kilowatts 1,250,000 375,000 1,625,000 1,500,000 Average Annual Salable Energy in Millions of Kilowatt-hours 4,871 3,550 Annual Commercial Power Revenues $29,000,000 $21,400,000 The total estimated cost of the Central Arizona Project with a high Bridge Canyon Dam is about $1,070,000,000. If the energy is sold at six mills per killowatt-hour, the project power investment could be repaid in 50 years with interest at 21/2 percent on the unamortized balance and a surplus of a little over $6,000,000 would accumulate in the last year of the payout period.Epson Perfection 4870 Photo, 400 dpi, 24 bit, 2,468,157 byte