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<br />accurate estimate of the necessary instream flow required. In these cases, CWCB staff relies
<br />upon the biological expertise of the cooperating agencies to develop a biologic instream flow
<br />recommendation.
<br />
<br />The BLM has indicated that this is a high priority stream segment to them. However, because
<br />the summer recommendation falls outside the accuracy range of the R2CROSS model, staff
<br />believes that more data needs to be collected to accurately predict the summer flow
<br />recommendation. Staff has consulted with the recommending agency and believes that it would
<br />be appropriate for the Board to file on a year-round flow of 1.5 cfs, if water was available (See
<br />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. The hydro graph below was derived from data collected by the
<br />USGS stream gage for Brush Creek near Eagle, CO (ill #09068000), which has a drainage area
<br />of 71.4 square miles (See Gage Summary in Appendix C). The total drainage area of the Salt
<br />Creek Drainage upstream of Kelly Creek is approximately 8.8 square miles. The period of
<br />record for this gage was 1950 - 1972, the period of record used by staff in their analysis was
<br />1950 - 1972, or 22 years of record. Table 2 below displays the estimated flow of Salt Creek
<br />upstream of Kelly Creek, in terms of a percentage of exceedence.
<br />
<br />Table 2: Salt Creek estimated flow upstream of Kelly Creek.
<br />Exceedences Jan Februa March '1 June Jul ust errtJer October NoverrtJer Decerrtler
<br />1% 2,96 2,71 3,08 10,94 30,87 53,44 40,02 13,00 7,94 6,58 4.49 3,33
<br />5% 2.83 2,46 2,83 5,55 21,57 35,13 19,72 9,12 6,29 5.05 3,82 3,08
<br />10% 2,71 2,46 259 4,44 17,50 31,18 17,25 7,39 5,79 4,56 3,57 2,96
<br />20% 2,46 2.34 2,34 3,70 13,56 25,88 1245 6,16 4,81 4,19 3,33 2,83
<br />50% 2,34 2,22 2,10 2,83 8,01 18,73 7,03 4,31 3,57 3,33 2,83 2,46
<br />80% 1,97 1,97 1,97 2,22 4,68 10,48 4,68 3,33 2.83 2,71 2,46 2,22
<br />00% 1,85 1,85 1,85 2,10 3,48 8,13 3,94 3,20 2,46 2,46 2,34 1,97
<br />95% 1.73 1,73 1,73 1,97 2,96 6,53 3,45 2,83 2,34 2,46 2,22 1.97
<br />99% 1.60 1,60 1,73 1,73 2,46 5,50 2.94 2,32 2,22 2,34 2,10 1.73
<br />
<br />Salt Creek Estimated Stream Flow
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