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<br />"Fishery surveys indicate that the stream environment is presently in stable condition, and <br />supports a self-sustaining speckled dace and white sucker fishery. Channel stability, bank <br />stability, substrate, and food supplies are good for supporting a fishery. The primary limitations <br />in this stream are lack of cover in some reaches, occasionally high stream temperatures, <br />consistently low flows during the late summer and early fall. Accordingly, it is important to <br />protect stream flows if the continued existence of the fishery is to be assured" (See BLM Fish <br />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. 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. 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 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 /> <br />For this segment of stream, four data sets were collected with the results shown in Table 1 <br />below. 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 /> <br />Table I: Data <br />PartY Date Q 250%-40% Summer (3/3) Winter (2/3) <br />BLM 5/22/2002 2.26 5.6-0.9 3.7 3.0 <br />BLM 5/22/2002 1.83 4.4 - 0.7 6.3(1) 2.1 <br />BLM 6/04/2003 7.28 18.2 - 2.9 4.9 2.6(1) <br />BLM 6/04/2003 7.00 17.6-2.8 7.2 1.5\1T <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 R2CROSS Staging Table. <br /> <br />Biologic Flow Recommendation <br />The summer flow recommendations, which meet 3 of 3 criteria and are within the accuracy range <br />of the R2CROSS model range from 7.2 cfs and 3.7 cfs (See Table 1). Averaging the summer <br />flow recommendations within the accuracy range of the model results in a summer <br /> <br />- 3 - <br />