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<br />food availability, and water temperatures are generally good for salmon ids. However, low flows <br />are common in the late summer and fall and the stream occasionally experiences flash flooding. <br />(See BLM Fish Survey in Appendix B). <br /> <br />Field Survey Data <br /> <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. Rimes 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. Appendix B contains copies of field <br />data collected for this proposed segment. <br /> <br />Biological Flow Recommendation <br /> <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 maintaining these <br />three hydraulic parameters at adequate levels across rime 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 /> <br />For this segment of stream, two data sets were collected with the results shown in Table I 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 Equation (240% and 40% of Q), the summer flow recommendation based on <br />meeting 3 of 3 hydraulic criteria and the winter flow recommendation based upon 2 of 3 <br />hydraulic criteria. <br /> <br />Table 1: Data <br />Party <br />BLM <br /> <br />BLM <br /> <br />Date <br />6/7/01 <br />6/7/01 <br /> <br />Q <br />6.36 <br />5.98 <br /> <br />250%-40% <br />15.9 - 2.5 <br />14.9 - 2.4 <br /> <br />Summer (3/3) <br />17.3'" <br /> <br />13.1 <br /> <br />Winter (213) <br />10.7 <br />10.2 <br /> <br />BLM Bureau of Land Management DOW Division of Wildlife <br />(I) Predicted flow outside of the accuracy range of Manning's Equation. ? =: Criteria never met in RlCROSS Staging Table. <br /> <br />Biologic Flow Recommendation <br />The summer flow recommendation, which met 3 of 3 criteria and is within the accuracy range of <br />the R2CROSS model is 13.1 cfs (See Table 1). The winter flow recommendations which met 2 <br />of 3 criteria and are within the accuracy range of the R2CROSS model range from 10.7 cfs to <br />10.2 cfs (See Table 1). Averaging the two winter flow recommendations within range results in <br />a 10.5 cfs recommendation. <br /> <br />Hydrologic Data <br /> <br />After receiving the cooperating agency's biologic recommendation, the CWCB staff conducted <br />an evaluation of the stream hydrology to determine if water was physically available for an <br />instream flow appropriation. There are no currently operated streamflow gages for this reach <br />but a station was operated from 1942 to 1950 near Sams, Colorado. This gage was located <br />- 4 -. <br />