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flow-duration curve (curve B, fig. 8) was drawn with the altered discharge distribution. Annual streamflows represented by curves A and B were both 1.47 million acre-ft/yr. The annual total sediment load for scenario B was comput- ed with the flow-duration, sediment-transport-equation method previously de- scribed, and was found to be 1.89 million ton/yr, a 7-p~rcent reduction from the sediment load transported by the prevailing flow regime. SEDIMENT BUDGET AT DEERLODGE PARK Potential changes in channel morphology will depend principally on the temporal distribution of streamflow, and the degree to which the balance of sediment transport and supply is di srupted. A sediment budget analysi s has been used to predict gross changes in sediment storage of the Yampa River at Deerlodge Park if the prevailing streamflow or sediment supply are altered. A- sediment budget is the relation between sediment outflow (transport), sediment inflow (supply), and sediment storage in a particular river reach. Sediment budget analysis can be used as a planning tool to: \ (1) Estimate sediment surplus or deficit under the assumed streamflow frequency distribution, mean annual streamflow and sediment supply; and (2) identify levels of reduced streamflow a~d sed~ment supply that may result in negligible sediment surplus or deficit in the 1Deerlodge Park reach. By identifying annual sediment loads through Deerlodge 'Park, the analysis will quantify the amount of sediment estimated to enter the Yampa Canyon under assumed reduced streamflows. These data will be useful in ongoing studies of substrate and sediment transport in downstream canyon reaches. 11< Elements of the sediment budget at Deerlodge Park, stated in terms of annual sediment surplus or deficit, are presented in table 6. The scenarios in table 6 are based on hypothetical conditions resulting from altered streamflow a(1d(or) reduced sediment supply. Actual changes in the sediment budget will depend on several factors. Amounts of sediment supply are assumed in this illustration, but the actual volume of sediment supplied to Deerlodge Park will be influenced by the 10cc1tion of impoundments in the basin. The annual total sediment load (transport) is computed using an assumed average annua 1 streamflow, the correspondi ng fl ow-durati on curve, and the prevai 1i ng total sediment discharge versu 81' diSCharge relation. If streamflow and(or) sedi~ent pupply ar rastica ly reduced, however, indeterminant changes in tne re llat i on between e 1 ment di scharge and water di schargE! may occur over a period of years, thereby affecting estimates of sediment transport. Any reduction of annual streamflow probably will involve a reduction of the magnitude and duration of the highest discharges and possibly an increase in the duration of the lower discharges. To estimate the effect of reduced annual streamflow on sediment transport and the sediment budget at Deerlodge Park, the upper part of the 43-year flOW-duration curve (fig. 6) was arbitrar- ily reduced by six intervals. The resulting flow-duration curves are present- ed in figure 9, and they were used to compute annual sediment loads for the scenarios in table 6. These curves were arbitrarily derived and are presented only for the purpose of illustration. Annual streamflows were computed from the fl ow-durat i on curves by summi ng increments of di scharge as descri bed by Miller (1951). Reductions from the prevailing annual streamflow ranged from 9 24