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<br />Historical <br /> <br />Adjusted <br /> <br />N <br />1->0 <br />C() <br />CT; <br /> <br />San Juan at Bluff <br />Anim4s River at Cedar Hill <br />San Juan at Archuleta <br /> <br />1,505,050 AF <br />627,850 <br />891,670 <br /> <br />1,911,260 AF <br />797,300 <br />1,132,330 <br /> <br />For the Qpper Main Stem, three appraoches were used to obtain the <br />means for the different stations, For the Upper Gunnison stations, <br />1968 lev,l modified flows being used by the Bureau were assumed to <br />be suita~le and were used without further adjustment. For the <br />Gunnison;River at Grand Junction, the 1965 level depletion values for <br />the Dolotes, Gunnison, and main stem were adjusted for export values <br />and rece*t Reclamation projects. The remaining depletion was then <br />assumed ~o be proportional to flows. The total of the depletions thus <br />obtainedifor the Gunnison Basin was then used to adjust the longtime <br />period of data for the Gunnison River at Grand Junction. Concurrent <br />data for the 1942-1956 period were then used with the ratio procedure <br />to obtai~ a preliminary estimate for the Colorado River near Cameo <br />and the eunnison station. The difference between this Gunnison <br />estimateiand the above determined Gunnison estimate was then sub- <br />tracted from the preliminary Cameo estimate to obtain a final Cameo <br />station value. Estimates obtained for the stations follow: <br /> <br />Gunnison River at Blue Mesa <br />Gunnison River at Morrow Point <br />Gunnison River at Crystal <br />Gunnison River at Grand Junction <br />Colorado River nr Cameo <br />Colorado River nr Cisco <br /> <br />1,079,630 AF <br />1,144,200 <br />1,253,020 <br />1,820,700 <br />2,884,600 <br />5,230,800 <br /> <br />A stati04-by-station discussion of the data analysis results and <br />subsequent adjustments of the coefficients is provided in Appendix 1. <br /> <br />3.4 Adjustments to Lower Basin Flows <br /> <br />The seriis of storage developments in the Colorado River Basin have <br />greatly ~odified the streamflows and quality in the Lower Basin. <br />Beginnin~ with 1960 and in anticipation of the closure and filling of <br />Lake powell, the releases from Lake Mead were reduced to essentially <br />those required for downstream uses and the delivery to Mexico. In <br />recognition of these changes, two different periods of data were <br />utilized 'in developing the hydrologic data base. <br /> <br />For the 4rea above Lake Mead, data prior to closure of or unaffected <br />by Lake ~owell were used. Below Lake Mead, data for the period <br />1960-1968 were analyzed to obtain the modified flow and quality <br />values. 'Discussions of data analysis results and flow coefficient <br />adjustments are provided in Appendix 2, <br /> <br />23 <br /> <br />-(."- <br /> <br />