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<br />Biologic Flow Recommendation
<br />The summer flow recommendation, which met 3 of 3 criteria and is within the accuracy range of
<br />the R2CROSS model is 6.4 cfs (See Table I), The winter flow recommendation, which met 2 of
<br />3 criteria and is within the accuracy range of the R2CROSS model range is 4,1 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 hydrograph below was derived from data collected by the
<br />USGS stream gage for Smith Fork Gunnison River near Crawford, CO (ID #09128500), which
<br />has a drainage area of 42,8 square miles (See Gage Summary in Appendix C), The total
<br />drainage area of this segment of the South Fork of the Smith Fork Gunnison River is
<br />approximately 15,9 square miles, The period of record for this gage was 1935 to 1994, the
<br />period of record used by staff in their analysis was 1935 - 1994, or 60 years of record, Table 2
<br />below displays the estimated flow of South Fork Smith Fork Gunnison River at the gage, in
<br />terms of a percentage of exceedence,
<br />
<br />Table 2: Estimated Stream Flow in South Fork Smith Fork Gllllllison River
<br />Exeeedenees jan feb mar apr may jun jul aug sep oct nov Dee
<br />10/0 7,0 8,1 26,9 113.4 255,7 198,7 48,7 12,6 12.2 13,3 10.4 7.4
<br />50/0 4,8 5.2 15,5 84,5 158,5 127,5 26,3 8,7 8,5 10,0 7,0 5.2
<br />10% 3,5 4,1 11,8 66.2 132,8 101,8 21.1 7,0 7,0 7.4 5,6 4,1
<br />20% 3,0 3,5 7,0 44.4 107,7 65,1 15.2 5,6 5.2 5,6 4.4 3.4
<br />80% 1,9 2,0 2,8 8,9 34,0 18,5 4,8 2,7 2,1 2.4 2.4 2,0
<br />90% 1,8 1,9 2.4 5,9 26,6 13,0 3,6 2,1 1,8 2,1 2,1 1,9
<br />95% 1,7 1,7 2,1 5,0 19,6 9,6 2,8 1,6 1.4 1,9 2,0 1,8
<br />99% 1.4 1,6 1,9 3,3 8.4 6.2 2,0 1,0 1.1 1,5 1,7 1.4
<br />
<br />Estimated Stream Flow on South Fork Smith Fork
<br />
<br />20,0
<br />
<br />5,0
<br />
<br />15,0
<br />
<br />(/)
<br />U 10,0
<br />
<br />0,0
<br />
<br />jan
<br />
<br />feb mar apr may jun jul
<br />Month
<br />
<br />aug sep oct nov dec
<br />
<br />-4-
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