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<br />.' <br /> <br />IFIM/PHABSIM and R2CROSS studies to support instream flow recommendations on highly <br />controversial streams; eg., the Blue River in Surnmit County. The flexibility of the IFIM also makes e <br />it a good tool for developing instream flow recommendations for fish species that depend on stream <br />habitats other than riffles and for developing recommendations for instream values other than fish. <br /> <br />Tennant (Montana) Method <br />The Tennant Method (Tennant 1976), also called the Montana Method, is an example of a <br />non-field, standard setting methodology where instream flow recommendations are based on <br />maintaining a predefmed percentage of mean annual flow (Table 3). Sixteen states routinely use the <br />Tennant Method to develop instream flow recommendations (Figure I). <br /> <br />Table 3. Instream flow regimens for fish, wildlife, recreation, and related environmental resources <br />(Tennant 1976). <br /> <br />Narrative Description of flows Recommended baseflow Recommended baseflow <br /> October - March April - September <br />Flushing or maximum 200% of average flow 200% of average flow <br />Optimum range 60%-100% of average flow 60%-100% of average flow <br />Outstanding 40% 60% <br />Excellent 30% 50% <br />Good 20% 40% <br />Fair or degrading 10% 30% <br />Poor or minimum 10% 10% <br />Severe degrading 0% - 10% of average flow 0% - 10% of average flow <br /> <br />e <br /> <br />The Tennant Method requires no field work. On gaged streams, estimates of mean annual <br />flow are easily obtained from historic gaging records. On ungaged streams, mean annual flow can <br />be estimated using accepted hydrologic techniques (Dunne and Leopold 1978; Kircher et al. 1985). <br /> <br />The Tennant Method may be an appropriate methodology for developing instream flow <br />recommendations on low priority stream segments or as a check on the reliability of R2CROSS- <br />based flow recommendations. The "Flushing or Maximum" category may also provide an estimate <br />of the channel maintenance or "out-of-bank" riparian flow requirements of a particular stream. <br /> <br />9 <br /> <br />e <br />