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<br />. Channel and floodplain morphology in time and space is not a simple flow-area <br />relationship and complex interactions not yet fully understood may emerge that will compromise <br />recovery of the fish. <br />. What is the tradeoff between propensity of endangered fish larvae to drift downstream and <br />the need for high flows to maintain connectivity between the channel and backwaters and wetlands? <br />. Can food webs re-establish in key low velocity habitats (backwaters) to the extent needed <br />to recover the fishes, given the windows pennitted or needed for hydropower operations? <br />. Can the endangered fishes expand their range and productivity given the downstream <br />extension of cold water environments caused by regulation, and is the locality of the transition zone <br />between cold and warm reaches likely to stay constant as reregulated flow regimes are . <br />implemented? <br />. Interactions with nonnative fishes may limit recovery of endangered fishes regardless of <br />flow provisions. <br />The report concludes with recommendations that couple management action <br />(implementation of interim flow regimes) with additional study to resolve the uncertainties <br />presented above. The suite of recommendations constitute an ecosystem approach to resolution of <br />flows needed to protect and enhance the endangered fishes of the Upper Colorado River Basin. In <br />essence, these recommendations constitute a new, holistic instream flow methodology. <br />. Implement interim flows that re-establish seasonality with spring peaks that approach the <br />amplitude and frequency of preregulation events and summer and winter baseflows with daily <br />changes (not daily volume) limited to near preregulation conditions (likely no more than about 5% <br />per day). <br />. Provide common understanding of water availability so that interim flows can be provided <br />in relation to precipitation and legal flow abstraction in each subbasin. <br />. Improve the standardized monitoring pro~ as a mechanism to evaluate effectiveness of <br />interim flows by adding a community ecology perspective. <br /> <br />ill <br /> <br />GI0012 <br />