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At cross section 3, the Beta movement parameter is much lower for the same range of discharges and approaches 0.021 at 19,000 cfs. The absolute minimum Beta parameter of 0.017 is reached at a discharge of approximately 11,000 cfs. Thus, a flushing flow for cross section 3 can not be determined with the present data but lies in the 10,000 to 20,000 cfs range. Although the predicted energy slopes from the WSP program are suspect above 12,000 cfs, the graphs show that a minimum flushing flow of 10,000 cfs is needed and may be as great as 20,000 cfs. Again, an additional high flow measurement and bed material samples should help define the appropriate flushing flow more accurately. \The hydrograph of a flushing flow may be defined in terms of its ~agnitude, duration and frequency. The magnitude of the flushing discharge using the Beta movement parameter method is 10,000 to 20,000 cfs, thus a peak flow greater than 10,000 cfs is required. The duration required to flush sand and fines from the cobbles as discussed previously is not long, a number of hours above the flushing discharge should be sufficient. The majority of material flushed from the bed will stay in suspension and be transported \ downstream at lower discharges as the flow declines. I c,- Since the sediment transport capacity of the stream far exceeds the available sediment supply, any sediment freed from the substrate is expected to be removed from the channel. above Lake Powell as long as flushing flows continue to occur. This is supported by sediment transport measurements that show an i~creased sediment load in the downstream direction. This also indicates that the current tributary sediment load is being absorbed within the present transport capacity of the stream. 7