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<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, 3 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 />h)'clraulic criteria. <br /> <br />Table 1: Data <br /> <br />Party X-See Date Q 250%-40% Summer (3/3) Winter (2/3) <br />USFS #1 6/18/2003 0.45 1.1 - 0.2 3.0(1) 0.71 <br />USFS #2 6/18/2003 1.48 3.7 - 0.6 3.2 1.1 <br />USFS #3 6/18/2003 1.36 3.4 - 0.5 4.5\') 3.6\') <br /> <br />USFS = United States Forest Service 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 spring/summer flow recommendation, which meets 3 of 3 criteria (x-section 2 and 3), and is <br />within the accuracy range of the R2CROSS model, is 3.2 cfs (See Table 1). The winter flow <br />recommendation, which meets 2 of 3 criteria (x-section 1 and 2), and is within the accuracy <br />range of the R2CROSS model, is 1.0 cfs (See Table 1). It is our belief that recommendations <br />that fall outside of the accuracy range of the model, over 250% of the measured discharge or <br />under 40% of the measured discharge may not give an accurate estimate of the necessary <br />instream flow required. <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 West Hubbard Creek near Ragged Mountain, CO (ID #09130600), which <br />has a drainage area of 7.4 square miles (See Gage Summary in Appendix C). The total drainage <br />area of the Dyke Creek Drainage is approximately 4.7 square miles. The period of record for <br />this gage was 1955-1965, the period of record used by staff in their analysis was 1955-1965, or <br />10 years of record. Table 2 below displays the estimated stream flow of Dyke Creek, in terms of <br />a percentage of exceedence. <br /> <br />-4- <br />