OCR Text |
Show Colorado River Compact of 1922, is one and one-half million acre feet less than the average which was evidently given to the Commissioners at the time as the probable annual virgin discharge of the Colorado River at Lee Ferry, and it also seems evident that the Commissioners at that time believed 15,000.000 acre feet to be the "safe yield" of the river. However, the black line indicating the running average has been declining since the year 1929, which was a year of very high discharge. The average for the past sixty years is now 15,260,000 acre feet. Comparing the character of this curve for the first fifteen or twenty years with the character of the curve for the last fifteen or twenty years, it is noticeable that as each new year's record was added, it had less and less effect on the mean as compared with the addition of each year at the beginning of the total period. At the end of the first thirty years, each added year had twice the effect on the running average as that which occurs at the present time. The curve also shows that during the first ten years and during the last twenty-six years, the average flows have been less than the long-time mean. In other words, for a period of twenty-four years between these two periods of low flow, there was a nearly continuous period of higher than average flow. The thirty-six years of low flow constitute sixty percent of the total period of sixty years, while the twenty-four years of higher flow are forty percent of the total. Evidently, then, there is represented here a period of high flow between two periods of lower annual flows tending to show that periods of low discharge are at least one and a half times as long as the recorded period of high flow, and |
Source |
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] : |