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the bed elevation did not change were most commonly between 11 and 14 m3/s (400 to . 500 fe/s). The degree of scour in the thalweg varied by year and could be as much as 1 meter. Discharge records also show that the width of the channel near the Watson gage has widened slightly since the late 1960s (Fig. 25). Adjustments in channel are likely a response to the large flO"ods of 1983-84, which were the highest since the mid-1960s. The increases in channel widths took place between 1979 and 1985, and coincide with these flood events. No width data are available for dates earlier than 1968, when flood magnitudes were typically higher. Cross Sectional Resurveys Bed material at established cross-sections is predominantly sand and gravel, but ranges in size from silt and clay to small angular boulders. Banks and flood plain surfaces were predominantly comprised of fine-grained alluvium, while the bed was almost entirely comprised of coarse material. Changes in channel geometry that occurred between 1995 and 1997 were determined by resurveys of the cross-sections (Appendix). As expected, scour and fill is greatest where the bed is finest, but bed elevation changes oCCUlTed over gravel and cobble beds as well. Channel cross-sections with predominantly sand beds had the greatest change in bed elevation (Fig. 26). Evidence of bedforms was detected at 51 m3/s (1800 fels) at several cross-sections, and is indicated by hummocky uneven traces which did not exist at base-flow (Fig. 27). Slight aggradation of the bed in the coarsest cross-sections was evident at the higher discharge, which may indicate finer bedload moving over the top of less mobile coarse material 25