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7 <br />on the upper Green River (live capacities of 1,364 and 4,625 million cubic meters, <br />respectively). There are numerous other small reservoirs in the Green River Drainage but <br />all are at least an order of magnitude smaller than Flaming Gorge, which has the capacity <br />to store twice the mean annual inflow of the Green River. Operation of Flaming Gorge <br />Dam has not reduced the mean annual discharge of the Green River; mean annual <br />discharge at the Greendale, UT stream gage (less than 2 km downstream from the dam) <br />was 59 m% before (1951-1962) and 62 m% after (1965-1999) closure of the dam. <br />However, based on data for the same time periods, the average magnitude of annual peak <br />flows decreased by about 54% (360 to 149 m%) at Greendale, UT and 22% (653 to 509 <br />In 3/S; pre-dam includes 1947-1962) 176 km downstream at Jensen, UT. Concomitant <br />with closure of the dam were changes in annual suspended sediment yield. Andrews <br />(1986) estimated annual suspended sediment yield was reduced from about 3.6 x 106 tons <br />to zero at Greendale and from 6.92 x 106 to 3.21 x 106 tons at Jensen, UT following <br />closure of the Flaming Gorge Dam <br />Changes in flow and sediment regime have altered the morphology of the Green <br />River. Reductions in peak flows and sediment load have resulted in a decrease in width <br />of the bankfull channel from 6% to 10% (Andrews 1986; Lyons and Pucherelli 1992) and <br />a reduction in effective discharge from 580 to 325 m3/s in the vicinity of the Jensen, UT <br />stream gage (Andrews 1986). Channel area has decreased due to the expansion of <br />islands, the formation of new islands, and the filling of side channels with sediment <br />(Lyons and Pucherelli 1992). Reduction in peak flows and decreases in channel area <br />have been followed by invasion of riparian vegetation down to the base flow channel <br />(Fisher et al. 1983). The effects of natural and man-made levees coupled with depletions