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Show APPENDIX I INFLOW-OUTFLOW METHOD During the earlier part of the past year, a major portion of the time and effort of the engineering department was spent upon studies of the inflow-outflow method; that is to say, in the development of formulas and procedures for the application of the inflow-outflow method as required by Article VI and by Article VIII (d) (6) of the Upper Colorado River Basin Compact. Substantial progress has been made. These investigations must, however, be continued and extended to include tributary areas in each state. The Green River Basin in Wyoming was chosen as the area for the initial investigation of means for determining the detailed procedures and formulas for the application of the inflow-outflow method for several reasons, among which is the fact that the gaging station at Linwood, Utah is practically on the state line between Wyoming and Utah and that a fairly long period of stream flow and climatological records is available in that Basin. The table of stream flow and an accompanying plate of the inflow-outflow manual in the First Annual Report of the Upper Colorado River Commission contains the data and indicates the results of the studies of the Engineering Advisory Committee as reported to the Upper Colorado River Compact Commission up to the time of the organization of the present Commission. The number of inflow index stations will be increased from the original 5 to 9 or more and the stream discharge records have been brought up to include the year 1950 for the present investigation. The relation between the inflow index and the outflow at the Wyoming-Utah state line is approximately given by the following relation hereinafter referred to as formula (D- ' Y = 2.524 X2 - 770 In this formula, X2 is the inflow index for the Wyoming basin of the Green River and Y is the corresponding theoretical outflow, the units being 1,000 acre feet per year. Plate 13 of the Manual (Appendix L, First Annual Report) shows considerable variation between the outflow for individual years and the theoretical outflow quantities indicated by the trend lines. At the time of the adoption of the inflow-outflow method, the best means of compensating for these variations, a few of which are extreme, was found to be by the adoption of 10 year averages for determining the inflow-outflow relationships. However, the Commission also requires the determination of stream discharges and depletions at state lines and at -59- |