AZ vs. CA:24 California Exhibits, Vol. XXIV; Miscellaneous

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PROBLEMS OF IMPERIAL VALLEY AND VICINITY. power resources predominate and irrigation interests are small. In general, where irrigation interests are practicable, they should be given preference over power interests, and this rule requires storage of water in Boulder Canyon, or below, for the use of the lower valleys. The States in the upper basin are therefore vitally interested in seeing that such development takes place before the natural resources are depleted by storage above for use in the lower valleys. Likewise the States containing the lower valleys are interested in having storage in the lower basin on account of the economies thereby obtained and the greater convenience and ease of control of a reservoir near the point of use. Incidentally it will have large power resources which are important in the development of the resources of the Southwest. Recognizing the importance of developing the Colorado Basin on broad lines in such a way as to realize the greatest benefits therefrom, the States of the Colorado River Basin took steps to organize a commission upon which each of the seven States interested is represented and on which the United States is also represented in order to work out and recommend to their respective States and to Congress such action as will bring about the best use of the water resources of this great river system, the largest, and most important river system lying entirely within the arid region. Fortunately, the investigations at Boulder Canyon have shown the feasibility of a high dam at that point, which if built would furnish storage as shown in the following table: Table No. 8.-Capacity Boulder Canyon Reservoir. [Computed from original plane-table sheets; scale, 2 inches equals 1 mile.] Contour elevations. Area. Capacity. Contour elevations. Area. Capacity. 700..... ........... Acres. A ere-feet. 1 1,100....................... Acres. 67,740 Acre-feet. 10,153,000 750 2 350 58 750 1 1,150 . 84 110 13,949,250 HK) 7,950 316 250 1,200...... 105, 100 18,679,500 850 . . 15,260 21 620 846,500 1,818 500 : 1,250......... 127.660 131 000 24, 498, .500 26 000 000 900 ' 1,260 950 29,160 39,690 53,160 3, OSS, 000 4,609,250 7,130, 500 1,280... 142,000 152,000 28,600,000 31,600,000 1,000....... i 1,300....... 1,050....... Note.-The canyon walls extend up to above the 2,000-foot contour, or about 700 feet higher than the last one for which capacity is calculated. PROGRESS OF INVESTIGATIONS. The preliminary report on the problems of Imperial Valley and vicinity, published in January, 1921, described the progress of investigations up to that date, and these have been continued up to the preparation of this report. Soil surveys under the direction of Prof. Charles F. Shaw have been prosecuted, and land classification based upon this examination has been made and shown upon maps. These subjects are treated in this report on subsequent pages. Borings have been prosecuted at the proposed dam site in Boulder Can von, and the cross section of the canyon has been fairly well worked out. A large amount of additional borings is, however, nee-