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RECOMMENDATIONS The results and observations discussed in this report are broadly consistent with the recommendations given in previous reports, although the effects of some flow levels, such as the bankfull discharge, could not be assessed since these flows did not occur. Nonetheless, nothing observed over the course of this study suggests that the previous recommendations should be changed, therefore, the target flows discussed in earlier reports (Pitlick et al., 1999; Pitlick and Cress, 2000) are retained. The recommendations are are listed here as flow categories, with each category having an set of intended purposes, a target frequency and a target duration. If new information on the ecological or geomorphological effects of the recommended flows becomes available, and if there is a consensus among biologists and hydrologists that adjustments within the flow categories need to be made, the recommendations should be revised accordingly. A. Category: Flows > 621 cros (22,000 cfs) Purpose: Flows exceeding 621 cros (22,000 cfs) are required to overtop the floodplain on a widespread basis. Overbank flows entrain coarse particulate organic matter from the floodplain, thus providing nutrients for stimulating primary productivity. Flows that reach or exceed the bankfull discharge are likewise capable of mobilizing most of the framework particles forming the substrate (bed) of the river. Periodic mobilization of nearly all substrate particles is required to change channel morphology and maintain habitat complexity necessary for different ecological purposes. In addition, such flows should occur with sufficient frequency (see below) to maintain the mass balance of sediment through the critical reaches, so as to limit deposition in secondary channels and narrowing of the main channel. Duration: 5 days per year, averaged over a period of several years Frequency: One out of every three years 60