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<br />measured at Deerlodge Park was shown to be highly correlated with daily <br />discharges recorded at the Lily and Maybell gages. <br /> <br />A sediment budget analysis was conducted by the USGS (Elliott et al. 1984) <br />for the Deerlodge Park reach which was presented as a planning tool to determine <br />combinations of discharge and sediment supply that would minimize channel <br />adjustments. A matrix of flow and sediment reduction scenarios were analyzed by <br />reducing the sediment supply by a prescribed percentage. Comparing the sediment <br />supply and sediment transport capacity determined by the sediment rating curves <br />resulted in a sediment budget for the Deerlodge Park reach. The results were <br />intuitive; a large reduction in the assumed sediment load would promote channel <br />bed degradation and a large percent reduction in streamflow would initiate bed <br />aggradation. <br /> <br />There are two concerns regarding this type of analysis. First, the <br />relationship between streamflow and sediment load are more complicated than <br />presumed in the analysis because of the diverse areal distribution of sediment yield <br />and water between the Yampa River and Little Snake River watersheds and <br />second, because a reduction in stream flow may also be accompanied by a shift in <br />the rating curve. One flow scenario analyzed the potential effects of altering the <br />flows through Deerlodge Park by adjusting the historic flow duration curve to <br />reflect the percent changes in flow duration of the Green River computed at the <br />Jensen, Utah gage on the Green River following the construction of Flaming Gorge <br />Dam. The analysis indicated that the alteration in the flow duration curve with no <br />loss of annual flow volume would correspond to a surplus of sediment in the <br />Deerlodge Park sediment budget. At least a 10% reduction in the sediment load <br />would have to occur to create a deficit of sediment. This indicates that some <br />reduction in the sediment supply to the Deerlodge Park reach must have occurred <br />in the last thirty years as upstream flow depletions increased to 10%. The USGS <br /> <br />33 <br />