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Show PROBLEMS OF IMPERIAL VALLEY AND VICINITY, 29 POWER DEVELOPMENT. 13. Preliminary 'studies have been made for power development based on two different reservoir capacities, viz, 26,500,000 acre-feet and 31,400,000 acre-feet. 14. The accompanying tabulation (Table No. 1) shovs a comparison of the power output and other related data for the two alternative reservoirs, based on different assumptions as to lands irrigated and to equated discharges for power development. 15. A comparison of the amount of firm power and irrigated acreage resulting from the various assumptions tabulated in connection with the 26,500,000 acre-foot reservoir leads to the conclusion that all lands in the United States and the lands under the All-American and Imperial canals in Mexico should be irrigated and that the power development should be based on the minimum irrigation discharge of 13,500 second-feet. This discharge with a minimum head of 360 feet will develop 486,000 turbine horsepower of firm power. If a 31,400,000 acre-foot reservoir is provided and the same lands irrigated the minimum discharge will be 14,300 second-feet, which, under a minimum head of 394 feet, will develop 563,000 horsepower of firm power. 3. The statements made in the paragraphs quoted above were based on a preliminary study of the Colorado River water supply by Engineer Harold Conkling in which it was assumed that a constant flow would be released from the reservoir for power development. A summary of Mr. Conkling's preliminary study is shown in Table No. 1 of the May 26 report. 4. Subsequent to the preparation of board report of May 26, 1921, further studies were made by Mr. Conkling which indicated that materially greater firm horsepower could be developed by a different reservoir operation whereby the amount of water released for power is varied inversely with the head. Under such operation of the reservoir, power water would be conserved at times of full reservoir and high head for use at times of low reservoir and small head. 5. Attached hereto you will find two plates prepared by Mr. Conkling showing the operation of Boulder Canyon reservoir of 31,400,000 acre-foot capacity as follows: Plate XII. Operation of Boulder Canyon Reservoir based on the development of 700,000 firm horsepower in connection with the irrigation of 1,505,000 acres in the lower valley. • Plate XII-A. Operation of Boulder Canyon Reservoir based on the development of 600,000 firm horsepower in connection with the irrigation of 2,020,000 acres in the lower valley. Both plates are based upon the assumption that the efficiency at the turbmes is 88 per cent and that the discharge at Boulder Canyon is 1,500 second-feet more than the recorded flow at Laguna Dam. 6. A review by members of this board of Mr. Conkling's later studies, including the plates attached hereto, leads to the following conclusions: (a) The diagram, Plate VI shown at page 20 of the director's report, correctly represents the available firm horsepower at tl^ie Boulder Canyon dam site. (&) This board concurs in the statements made on page 14 of the director's report relative to power development, as follows: It is estimated that the feasible irrigation projects in the lower basin comprise 2,020,000 acres, of which about 60 per cent is in the United States and 40 per cent in Mexico. The full development of the proposed projects in the upper basin will subtract substantially from the total water supply, but there will still be.left ample water to irrigate all the lands of the lower basin if it is conserved and regulated in a storage reservoir of ample capacity. The water can be used for power as drawn from the reservoir and the amount of power that can be developed with different amounts of storage capacity, and with different assumptions of irrigated land below is shown |
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Original book: [State of Arizona, complainant v. State of California, Palo Verde Irrigation District, Coachella Valley County Water District, Metropolitan Water District of Southern California, City of Los Angeles, California, City of San Diego, California, and County of San Diego, California, defendants, United States of America, State of Nevada, State of New Mexico, State of Utah, interveners] : |