OCR Text |
Show -2- 21,430,000 acre-feet in 1929. A high estimated discharge of 24,000,000 acre-feet was shown for the year 1917. The gaging station at Lees Ferry was installed in 1921. Records of historic and virgin flows prior to that time are based on estimates and correlations, which may in some instances be of questionable accuracy. The hydro-graph of Report No. 22 shows that the maximum annual flow for some years may be three or four times as great as in years of the lowest flows. An average figure for yield of the Colorado River is difficult to agree upon because it depends on the period chosen for the basis of computation. A period may be chosen for which an average virgin flow is obtained that may be either greater or less than 15,000,000 acre-feet, the approximate average for the past 60 years. The following examples illustrate these facts: Period Date Acre-Feet 23 years 1931-1955 13,120,000 34 years 1922-1955 14,100,000 42 years 1914-1955 15,000,000 ¦ 60 years 1896-1955 15,260,000 Evidently from the above examples the computation of a reliable average will depend upon the purpose for which it is to be used. Among other things, Engineering Report No. 22 was intended to show that a single average figure may not give the best answers to all questions which may arise pertaining to the yield of a stream or provide the most reliable basis for every purpose that an average is intended to serve. |
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] : |