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<br />supports a self-sustaining brook trout fishery. Channel and bank stability, availability of pool <br />habitat, vegetative cover, substrate, and water quality are excellent for salmonids. Because of <br />some natural stream barriers, the stream also has potential to provide habitat for Colorado River <br />Cutthroat Trout" (See Fish Surveys 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 CD OW 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, one data set was collected with the results shown in Table 1 below. <br />Table I 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 />I Partv <br />I BLM <br /> <br />Date <br />08/28/1996 <br /> <br />Q I <br />3.52 I <br /> <br />250%-40% <br />8.8 -1.4 <br /> <br />Summer (3/3) <br />2.4 <br /> <br />Winter (2/3) <br />2.1 <br /> <br />BLM 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 within the accuracy range <br />of the R2CROSS model is 2.4 cfs (See Table 1). The winter flow recommendation, which meets <br />2 of 3 criteria and is inside the accuracy range of the R2CROSS model is 2.1 cfs (See Table I). <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. The hydro graph below was derived from data collected by the <br />USGS stream gage for East Canyon Creek above New Castle, CO (ill #09085300), which has a <br />drainage area of 15.1 square miles (See Gage Summary in Appendix C). The total drainage area <br /> <br />- 3 - <br />