AZ vs. CA:05 California Exhibits, Vol. V; Nos. 193-247

page 30

30 BOULDER CANYON PROJECT It is a great constructive improvement, not experimental, sound financially, well considered, shaped in the public interest, one the consummation of which will be a source alike of national pride and advantage. Report of the Secretary of the Interior Washington, January 21, 1928. Hon. Lawrence C. Phipps, Chairman Committee on Irrigation and Reclamation, United States Senate. My Dear Senator Phipps: I have your letter of December 15, transmitting with request for report, printed copies of S. 728 and S. 1274, bills to provide for the construction of works for the protection and development of the lower Colorado River Basin, for the approval of the Colorado River compact, and for other purposes. You invite attention to the fact that while these bills have identical titles, they differ in several important particulars, which have been fully considered. S. 728 is very similar in its general aspects to S. 18G8, Sixty-ninth Congress, H. R. 5773, Seventieth Congress, and other bills for this purpose upon which the department has heretofore reported. The dam and reservoir to be created presumably are essentially those described in the report of the Bureau of Reclamation dated February 28, 1924, which proposes the construction of a dam substantially 550 feet high and a reservoir to impound 26,000,000 acre-feet of water. The present bill provides for construction of a reservoir with capacity of not less than 20,000,000 acre-feet. I shall therefore consider this development as including three features: 1. A dam approximately 550 feet high creating a reservoir holding not less than 20,000,000 acre-feet of water. 2. Works for the generation of electric power. 3. An all-American canal starting at Laguna Dam and delivering water to the Imperial and Coachella Valley Canals. I. THE DAM AND RESERVOIR A dam 550 feet in height is necessary in order to provide a reservoir with sufficient capacity for effective flood control, to meet the needs of water for domestic purposes, and to satisfy irrigation requirements. The reservoir should be so constructed as to serve effectively the purpose intended for not less than 100 years, allowing for the large deposits of silt to be expected. It is these factors which determine the height of the dam. The reservoir should be regulated primarily to safeguard from the destructive effect of large floods the low-lying land in the valleys of Arizona and California, including the Imperial Valley with its present intensive development. Second only to flood protection is the need for an increased water supply for irrigation during periods of low flow. To meet these two needs, water levels in the reservoir would be raised during flood periods and lowered at other times, thus equalizing the discharge of the river below and securing a regulated flow for irrigation and power. The water sc impounded will be sold to cities requiring it for domestic and other municipal purposes and to irrigation districts to increase the water 6upply for irrigation in seasons of drought and to develop new areas. Water will be sold under the provisions df the reclamation law either for a complete or supplemental water supply. The height of the dam as fixed will not prevent the construction of the proposed dams at Diamond Creek or Bridge Canyon. 2. WORKS FOR THE GENERATION OF ELECTRIC POWER The dam if built to the height made necessary to serve the various purposes intended will afford an opportunity for the generation, at comparatively small additional expense, of a large amount of electric power which can be disposed of so us to Kf'n repay the cost of this development, make the project a financially solvent undertaking, and contribute greatly to the industrial progress and general prosperity of the Southwest.