OCR Text |
Show -16- reduce the consumptive use of water applied in irrigation, the next step was to introduce this summer index of precipitation into our equation. After many trials it was found that the use of summer precipitation for the four months of May through August, the usual irrigation season, as combined from the three stations in the lower area of the Green River Valley, that is, Sage, Eden and Green River, could be utilized with good effect. The sum of the precipitation quantities less than one inch during each month of the season at each of these stations, precipitation equal to and less than one inch, equal to and less than one and one half inches, equal to and less than two inches, and, finally, the total precipitation for each of these four months at each of these three stations, were all found to give an index which could be combined with an average irrigation depletion factor to adjust the observed historic outflow to virgin flow conditions. Actual depletion of stream flow will vary from year to year with variations in summer precipitation. In Appendix B, "Consumptive Use of Water Rates in the Upper Colorado River Basin" of the Final Report of the Engineering Advisory Committee to the Upper Colorado River Compact Commission summer precipitation was used only as an average quantity. In our investigations it has been treated as an independent variable. While it was believed earlier that variations in water supply, as used in the Debler formula adopted by the U. S. Bureau of Reclamation in its studies of water supply of the Colorado River Storage Project would improve our coefficient, |
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] : California exhibits. |