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'. Rationale for fluctuation criteria during base flow each year was not explicit The intent apparently was for the Bureau of Reclamation to select a target flow between 1,800 - 1,100 cfs and not vary it more that:t 12.5%. The rationale for the 12.5% figure was not given. However, for perspective, flows in the North Fork of the Aathead River, Montana (an unregulated r!~er similar in size and water yield to the Yampa and Green Rivers), do not vary more than about 5% per day at baseflow and remain around 10% per day during spring runoff (see Figure 8 in Stanford and Hauer 1992). As noted above, this relationship should be examined quantitatively on the unregulated Yampa River to shore up the fluctuation criteria for Flaming Gorge Dam operations during the summer and for the duration of the baseflow period. However, it is quite clear that the current interim flow regime allows a great deal of fluctuation at baseflow. Indeed, due to Flaming Gorge operations, rapid and severe fluctuations were apparent in hydrographs obtained during late summer and winter, 1992, (Figures 10 and 12- 14) at the Jensen gauge on the Green River downstream from the Yampa confluence. These hydrographs were recorded after the interim flow criteria described above were supposedly implemented; yet, the fluctuations do not correspond to the criteria. I believe that even strict adherence to the recommended baseflow criteria of the interim flow agreement will not protect (and certainly not enhance) bioproduction and species diversity of food webs within the varial zone of the river (including backwaters and floodplain wetlands). Bioproduction in backwaters probably is virtually eliminated by one dewatering event, and some period of time (weeks to months) of more stable water levels may be required for recovery (my obsetvation). Moreover, the flow-backwater relationship of Pucherelli et al. (1990), upon which the baseflow recommendations were made, is valid only for current channel morphology and will likely change with onset of new peak flows. Additional research is needed to clarify these important flow - backwater food web relationships, but it must be linked to a more predictable baseflow regime from the dam. The ecological basis of the temperature criterion (Le., < 50C change at Jensen relative to Yampa River temperatures at the confluence) was not established for either the channel or the backwater environments. I argue in Section III above that temperature pattern in the channel and 58