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<br />Table I: Data
<br />
<br />Party Date Q 250% -40% Summer (3/3) Winter (2/3)
<br />DOW 09/17/1980 45,1 112,8 - 18,0 11.1(1) 6,2(1)
<br />DOW 12/04/1987 19,2 47,9 - 7,7 10,3 4,8")
<br />DOW 12/04/1987 23,7 59,2 - 9,5 10,0 9,6
<br />DOW 12/04/1987 25,2 63,1-10,1 15,7 9,6(1)
<br />DOW 03/11/1993 11.5 28,7 - 4,6 12,9 4,9
<br />DOW 03/11/1993 12,3 30,7 - 4,9 6,8 2,8")
<br />DOW 03/11/1993 10,3 25,7-4,1 6,8 4,2
<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 recommendations, which met 3 of 3 criteria and are within the accuracy range
<br />of the R2CROSS model, range from 15,7 cfs to 6,8 cfs (See Table I), The winter flow
<br />recommendations, which met 2 of 3 criteria and are within the accuracy range of the R2CROSS
<br />model, range from 9,6 cfs to 4,2 cfs (See Table I), Averaging the six summer flow
<br />recommendations within range, results in a 10,5 cfs recommendation, Averaging the three
<br />winter flow recommendations within range, results in a 6,5 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, Staff found one historically operated streamflow gage located
<br />within this reach and approximately one mile upstream from the confluence with the South Fork
<br />San Miguel River. The hydrograph was derived from data collected by the USGS stream gage
<br />for the San Miguel River near Telluride, CO (ID #09171200), which has a drainage area of 42,8
<br />square miles (see below), The period of record for this gage was 1959 to 1965, the period of
<br />record used by staff in their analysis was 1959 - 1965, or seven years of record, Table 2 below
<br />displays the estimated flow of the San Miguel River, in terms of a percentage of exceedence,
<br />
<br />Table 2: Estimated Stream Flow in San l\1iguel River:
<br />Exeeedenee Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nav Dee
<br />10/0 18 20 50.56 104.4 404.6 468.4 416.9 205.6 92.6 48.28 33.4 23
<br />50/0 17 19 30.7 90 349 415 358.4 120.7 73 39.7 29 20
<br />10% 16 19 23.4 78 238.8 360 268.8 94.2 65 38 28 19
<br />20% 16 18 20 61 184.8 310 201.2 76 56 33 26 18
<br />80% 14 14 14 22 70 132 55 39 27 23 20 16
<br />90% 13 14 14 16 43.6 116 44.6 33 26 22 19 16
<br />95% 13 14 14 16 36.3 100 40.3 29 25 22 19 13
<br />99% 13 14 12 15.8 29 80.6 32.72 27 24 21 18 13
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