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<br />sensitive cool water fishes, such as long-nose sucker. Channel stabili1y, bank stability, and <br />substrate are good for supporting a fish population. However, the fishery is limited by lack of <br />cover in some locations, and by occasional high temperamres and low stream flows. <br />Accordingly, it is important to provide stream flows iliat protect the limited amount of available <br />habitat if ilie continued existence of the fishery is to be assured" (See BLM Fish Survey in <br />Appendix B). <br /> <br />Field Survey Data <br /> <br />BLM staff used ilie R2Cross meiliodology to quantifY ilie amount of water required to preserve <br />ilie namral environment to a reasonable degree. The R2Cross method requires iliat stream <br />discharge and channel profile data be collected in a riffle stream habitat type. Riffles are most <br />easily visualized, as ilie stream habitat types iliat 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 ilie stream discharge. Appendix B contains copies of field <br />data collected for iliis proposed segment. <br /> <br />Biological Flow Recommendation <br /> <br />The CWCB staff relied upon the biological expertise of ilie cooperating agencies to interpret <br />output from ilie R2Cross data collected to develop the initial, biologic instream flow <br />recommendation. This initial recommendation is designed to address ilie unique biologic <br />requirements of each stream without regard to water availabili1y. Three instream flow hydraulic <br />parameters, average depili, percent wetted perimeter, and average veloci1y are used to develop <br />biologic instream flow recommendations. The CDOW has determined that maintaining iliese <br />iliree 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, two data sets were collected with ilie results shown in Table 1 below. <br />Table 1 shows who collected ilie data (Party), ilie date the data was collected (Date), the <br />measured discharge at ilie time of ilie 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 1: Data <br /> <br />Party Date Q 250%-40% Summer (3/3) Winter (2/3) <br />BLM 6/05/2003 1.94 4.7 - 0.8 5.1 (1) 1.5 <br />BLM 6/04/2003 2.11 5.1- 0.8 4.0 2.1 <br /> <br />ELM = Bureau of Land Management DOW = Division of Wildlife <br />(1) 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 recommendation, which meets 3 of 3 criteria and is wiiliin ilie accuracy range <br />of the R2CROSS model is 4.0 cfs (See Table 1). The winter flow recommendation, which meets <br />2 of 3 criteria, is 1.8 cfs. The winter recommendation is the result of averaging two modeling <br />runs iliat were within the accuracy range ofilie R2CROSS model (See Table 1). It is our belief <br />iliat recommendations that fall outside of the accuracy range of the model, over 250% of the <br /> <br />- 3 - <br />