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<br />Results show a historical balance in total sediment transport, and the balance <br />is maintained for the historical record adjusted to reflect present conditions <br />in the basin (the baseline condition). Using the Juniper Project as an example <br />of a project which changes flow distributions and frequency for power <br />11eerlodge eneration, the budget showed an accumulation trend or aggradation within the <br />Park to Mathers Hole reach. <br />,-Results also show that a minimum hydrograph can not be quantified in volume or <br />single peaks alone, but rather the frequency and duration of peak flows in <br />relation to the baseflows are important. If baseflows are increased, then peak <br />-flows may not be reduced as much if an equilibrium is to be maintained. This <br />`is because the baseflows tend to accumulate sediment within the reach, while <br />;peak flows transport the accumulation out. Results of the sediment budget are <br />,in agreement with field observations of sediment accumulation during the later <br />,summer through winter months and a reduction in accumulation during the peak <br />'flow periods. <br />An equilibrium in transport does not preclude changes in localized deposition <br />of sediment in pools, bars, beaches, and backwater areas. Increased deposition <br />of sediment combined with reduced flow levels may encourage vegetative <br />stabilization. Effects of changing sediment loads are also not limited to the <br />Yampa Canyon area. Changes in total sediment yield will also affect the Green <br />River. <br />Additional analyses are needed to further quantify the 'minimum streamflow <br />hydrographs'. Time limitations precluded addressing these items. A list of <br />recommendations follow: <br />RECOMMENDATIONS <br />1) Obtain the field data collected by O'Brien at Mathers Hole, specifically <br />the discharge measurements and sediment measurements. <br />2) Investigate whether other forms of a power curve provide a better fit of <br />data at Mathers Hole. Bias correction based on the Mathers Hole <br />measurements should also be done. Utilize appropriate bedload curves and <br />preform additional runs. A sensitivity analysis of rating curve shifts, <br />either from bias correction or changing sediment regimes, should be <br />preformed. <br />3) A more accurate extension of the Service baseline conditions to water years <br />1986 is needed. These are high flow years and the peak daily flows were <br />critical in maintaining the sediment balance in the reach as flows were <br />reduced, depleted and/or redistributed.