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<br />. <br /> <br />Biologic Flow Recommendation <br />The summer flow recommendations, which met 3 of 3 criteria and are within the accuracy range <br />of the R2CROSS model range from 174 cfs to 56,6 cfs. Averaging the 20 summer flow <br />recommendations within range results in a 93-cfs recommendation (See Table 1). The winter <br />flow recommendations which met 2 of 3 criteria and are within the accuracy range of the <br />R2CROSS model range from 125 cfs to 30,8 cfs (See Table 1), Averaging the 20 winter flow <br />recommendations within range results in a 61-cfs recommendation, <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 the San Miguel River near Placerville, CO (ill #09172500), which has a <br />drainage area of 308 square miles (See Gage Summary in Appendix C), The period of record for <br />this gage was 1910 to 2000, the period ofrecord used by staff in their analysis was 1910 - 2000, <br />or 64 years of record. Table 2 below displays the flow of San Miguel River near Placerville, in <br />terms of a percentage of exceedence. <br /> <br />San Miguel River <br />Exceedences <br />1% <br />5% <br />10% <br />20% <br />50% <br />80% <br />90% <br />95% <br />99% <br /> <br />Januarv Februarv March Aori! Ma" June Julv Auaust Seotember October NOvember December <br />100 97 234,3 1000 1769 1875 1530 684 435,5 295,5 148 113 <br />90 87 127.8 632.5 1200 1460 1070 452,8 291,5 196 128 100 <br />80 82 108 465 991 1270 911 370 238 173 118 92 <br />74 73 a9 334 792 1100 674 298 185 144 104 83 <br />64 63 70 175 505 752 366,5 185 120 98 80 65 <br />50 50 57 101 310 464 192 118 88 75 65 55 <br />46 46 52 78 216,5 369 150 96 76 65 58 50 <br />42 44 49 67 173 299,5 124,8 as 69 61 53 48 <br />36 38 44 52,5 108.3 156 93.45 70.15 58,5 50 45 40 <br /> <br />. <br /> <br />San Miguel River Stream Flow <br /> <br />800.0 <br />700.0 <br />600.0 <br />500.0 <br />~ 400.0 <br />300.0 <br />200.0 <br />100.0 <br />.... .... .. .. .... ... '" ..- <br />0.0 <br /> <br /> <br />~1- ~ ~~ -S1~ ~ J- 't/1- v~ -S1VQ <5'~,() 00;- 1-0t, O~O <br /> <br />Month <br /> <br />. <br /> <br />Table 2 shows that the summer recommendation of 93 cfs is available at least 50% of the time <br />from May 1st to October 14th, Table 2 also shows that the winter flow recommendation of61 cfs <br />is available at least 50% of the time from October 15th to April 30th. <br />