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Show 109 It might be that over a short period of less than ten years Hoover Dam could be operated flexibly enough to translate the total inflow into an average yearly release. But it is most unlikely that this can be done over a longer period. And the fact is that it is almost as difficult to predict the average flow into Lake Mead for any ten year period as it is to predict the flow into the Lake for any particular year, for the average flows for ten year periods during the recorded history of the Colorado River have been as erratic and unpredictable as the yearly flows. For example, the ten-year cumulative flow at Lee Ferry for the period 1941-1950 was 130,473,700 acre-feet. Five years later, the cumulative flow for the period 1946-1955 was only 111,401,200 acre-feet." The difference in the average annual flow between the two periods is nearly 2,000,000 acre-feet. Even greater variations occur if ten or more consecutive years of record are used as a basis for averaging yearly supply. The following table illustrates the variations in flow depending upon the period selected. Colorado River at Lee Ferry88 Stream Flow in Acre-Feet Period 10 Team 1899-1908 144,870,000 1909-1918 165,873,700 1919-1928 153,616,500 1929-1938 117,328,400 1939-1948 121,532,800 1949-1958 116,555,900 SO Tears 310,743,700 270,944,900 238,088,700 30 Tear* 464,360,200 ¦ 355,417,100 "See note 14, p. 146, Part Two, infra. "Source: Ariz. Exs. 77B, table A, p. 25, 197; Calif. Ex. 5582A. Arizona Exhibit 77B is commonly called the White Book Supplement. It is a water supply study of the Lower Colorado River Basin by the Bureau of Reclamation, covering the period 1946-1951. The White Book itself (Ariz. Ex. 77) covered the period 1914-1945. |
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Original Report: State of Arizona, complainant v. State of California, Palo Verde Irrigation District, Imperial 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 |