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<br />. <br /> <br />. <br /> <br />. <br /> <br />Table 1: Data <br /> <br />Party Date Q 250%-40% Summer (3/3) Winter (2/3) <br />DOW/CWCB 10/09/96 1.16 2.9- 0.5 0.9 0.6 <br /> <br />BLM = Bureau of Land Management DOW = Division of Wildlife CWCB = Colorado Water Conservation Board <br />(1) Predicted flow outside of the accuracy range of Manning's Equation. ? = Crileria never met in R2CROSS Staging Table. <br /> <br />Biologic Flow Recommendations <br />The CDOW recommended a 0.9 cfs summer flow and a 0.6 cfs winter flow based on the October <br />9th, 1996, data collection efforts. <br /> <br />Staff reviewed the data collected by the CDOW. The summer flow recommendation, which <br />meets 3 of 3 criteria and is within the accuracy range of the R2CROSS model is 0.9 cfs. The <br />winter flow recommendation which meets 2 of 3 criteria falls and is within the accuracy range of <br />the R2CROSS model is 0.6 cfs (See Table 1). <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 or historically operated <br />streamflow gages for this reach. The closest gage CWCB staff found was the gage located on the <br />San Miguel River 9 miles north of the Groundhog Gulch drainage. The hydro graph below was <br />derived from data collected by the USGS stream gage for the San Miguel River near Telluride, <br />CO (ID #09171200), which has a drainage area of 42.8 square miles. The drainage area of <br />Groundhog Gulch is approximately 2.1 square miles. Staff used a basin apportionment method <br />to estimate stream flows for Groundhog Gulch (See Gage Summary in Appendix C). The period <br />ofrecord for this gage was 1959 to 1965, the period ofrecord used by staff in their analysis was <br />1959 - 1965, or six years of record. Table 2 below displays the estimated flow of Groundhog <br />Gulch, in terms of a percentage of exceedence. <br /> <br />Table 2: <br /> <br />Estimated Groundhog Gulch Stream Flow <br />Exceedences J F b M h <br />1% <br />5% <br />10% <br />20% <br />50% <br />80% <br />90% <br />95% <br />99% <br /> <br />'1 <br /> <br />s <br /> <br />o <br /> <br />anuary e ruary arc Apn Mav June Julv AUllust eptember ctober November December <br />0.90 1.00 2.52 5.21 20.18 23.36 20.80 10.26 4.62 2.41 1.67 1.15 <br />0.85 0.95 1.53 4.49 17.41 20.70 17.88 6.02 3.64 1.98 1.45 1.00 <br />0.80 0.95 1.17 3.89 11.91 17.96 13.41 4.70 3.24 1.90 1.40 0.95 <br />0.80 0.90 1.00 3.04 9.22 15.46 10.04 3.79 2.79 1.65 1.30 0.90 <br />0.75 0.75 0.80 1.75 5.94 11.57 4.84 2.54 1.85 1.35 1.10 0.85 <br />0.70 0.70 0.70 1.10 3.49 6.58 2.74 1.95 1.35 1.15 1.00 0.80 <br />0.65 0.70 0.70 0.80 2.17 5.79 2.22 1.65 1.30 1.10 0.95 0.80 <br />0.65 0.70 0.70 0.80 1.81 4.99 2.01 1.45 1.25 1.10 0.95 0.65 <br />0.65 0.70 0.60 0.79 1.45 4.02 1.63 US 1.20 1.05 0.90 0.65 <br /> <br />- 4- <br />