OCR Text |
Show Ill study, no probative evidence was presented to demonstrate that any of the assumptions were correct. First of all, both Erickson and Stetson based their predictions on the expected repetition of the succession of the annual virgin flows of the Colorado River at Lee Ferry during the period 1909-1956. It is highly unlikely that future yearly flows will even approximately repeat the 1909-1956 pattern. As previously noted, Hoover Dam may, to some extent, permit the translation of unequal yearly inflows into relatively equal yearly releases. But, because of the limits on its storage capacity, the large evaporation losses on stored water, demands of flood control and river regulation and other factors, Hoover Dam has limited utility in this regard. Unless the general pattern of supply conditions on which the studies were based repeats itself in the future, the studies cannot provide a useful guide to future supply. However, as I have pointed out, there is no evidence to indicate that the virgin flow during the period studied, even assuming its accuracy, will repeat itself in the future. A second and controlling assumption made in the Erickson and Stetson studies on which California relies is that the Upper Basin will deplete the virgin flow at Lee Ferry by between 6,500,000 and 6,800,000 acre-feet per annum. Yet there is nothing to indicate that the Upper Basin depletions, which have never exceeded 2,200,000 acre-feet per annum measured at Lee Ferry,40 will expand to anywhere near 6,500,000 acre-feet. Again, the witnesses assumed this amount of depletion on instruction from counsel; they did not express the opinion that it would occur. In sharp conflict with this assumption is the estimate expressed in 40The approximate Upper Basin depletion is shown by comparing the historic flow with the virgin flow figures at Lee Ferry in the tables printed at the end of this section. See also Ariz. Ex. 197. |
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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 |