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Biological Data <br />The BLM has conducted field surveys of the fishery resources in this stream and have found a <br />natural environment that can be preserved. As reported in the letter from BLM to the CWCB <br />"Pauline Creek is a moderate gradient stream with large substrate and good vegetative cover. <br />Fishery surveys indicate that the creek supports a self - sustaining brook trout, rainbow trout, <br />brown trout, and white sucker fishery." The stream environment is presently in good condition <br />and provides suitable substrate, channel stability, water quality, and food supplies for salmonids. <br />However, the stream has a high number of pools and beaver ponds, so spawning locations are <br />limited. Accordingly, it is important to provide stream flows to maintain the limited amount of <br />spawning habitat and to maintain water exchange in pools during low flow periods." (See Fish <br />Survey in Appendix). <br />Field Survey Data <br />BLM staff used the R2Cross methodology to quantify the amount of water required to preserve <br />the natural environment to a reasonable degree. The R2Cross method requires that stream <br />discharge and channel profile data be collected in a riffle stream habitat type. Riffles are most <br />easily visualized as the stream habitat types that would dry up first should streamflow cease. <br />This type of hydraulic data collection consists of setting up a transect, surveying the stream <br />channel geometry, and measuring the stream discharge. The appendix contains copies of field <br />data collected for this proposed segment. <br />Biological Flow Recommendation <br />The CWCB staff relied upon the biological expertise of the cooperating agencies to interpret <br />output from the R2Cross data collected to develop the initial, biologic instream flow <br />recommendation. This initial recommendation is designed to address the unique biologic <br />requirements of each stream without regard to water availability. Three instream flow hydraulic <br />parameters, average depth, percent wetted perimeter, and average velocity are used to develop <br />biologic instream flow recommendations. The CDOW has determined that by maintaining these <br />three hydraulic parameters at adequate levels across riffle habitat types, aquatic habitat in pools <br />and runs will also be maintained for most life stages of fish and aquatic invertebrates (Nehring <br />1979; Espegren 1996). <br />For this segment of stream, 2 data sets were collected with the results shown in Table 1 below. <br />Table 1 shows who collected the data (Party), the date the data was collected (Date), the <br />measured discharge at the time of the survey (Q), the accuracy range of the predicted flows <br />based on Manning's Equation (240% and 40% of Q), the summer flow recommendation based <br />on meeting 3 of 3 hydraulic criteria and the winter flow recommendation based upon 2 of 3 <br />hydraulic criteria. <br />Table 1: Data <br />Party <br />Date <br />Q <br />250 % -40% <br />Summer (3/3) <br />Winter (2/3) <br />BLM <br />10/7/2005 <br />3.88 <br />9.7-1.6 <br />4.2 <br />NA <br />BLM <br />8/19/2004 <br />4.89 <br />12.2-2.0 <br />8.4 <br />NA <br />BLM = Bureau of Land Management llU W = olvisfon of Wildlife <br />