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<br />o <br /> <br />[ <br />[ <br />r <br /> <br />.. <br />L. <br />C <br />[ <br />I~ <br />!c <br />I[ <br />I. <br /> <br />I <br />C <br />lQ <br />w <br />I <br />\[ <br />\ <br />I~ <br /> <br />.. <br />11 <br /> <br />, <br />1 <br /> <br />L <br /> <br />the summer flow recommendation based upon meeting 3 of 3 hydraulic criteria and the winter <br />flow recommendation based upon 2 of 3 hydraulic criteria, <br /> <br />Table 1: Data <br /> <br />Party Date Q 250%-40% Summer (3/3) Winter (2/3) <br />BLM 4/28/97 2,01 5,0-0,8 1.8 1.3 <br />CWCB 4/16/99 1.04 ',6 -0.4 ? 0.3") <br /> <br />BLM. = Bureau of Land ManaQ:ement <br />(1) Predicted tlow outside of the accuracy range of Manning's Equation. <br /> <br />? = Criteria never met in R2CROSS Staging Table. <br /> <br />Biologic Flow Recommendations <br />The BLM recommended a 1.8 cfs summer flow and a 1.35 cfs winter flow based on their April <br />28'h. 1997, data collection effort. Staff reviewed the data collected by the BLM and decided to <br />collect an additional data sel. bringing the total number of data sets for review to two, The data <br />set collected by CWCB staff was not used in the analysis because the 3 of 3 criteria factor was <br />never met and the winter flow recommendation was outside of the accuracy range of the <br />R2CROSS model. The summer flow recommendations which met 3 of 3 criteria and are within <br />the accuracy range of the R2CROSS model is 1.8 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 is L3 cfs <br /> <br />Hydrologic Data <br /> <br />After receiving the cooperating agencies' 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 was derived from data collected by the USGS <br />stream gage for Fourmile Creek below Cripple Creek (10 #07096250), which has a drainage area <br />of 272 square miles (See Gage Summary in Appendix C), The period of record for this gage is <br />1992 to present, the period of record used by staff in their analysis was 1992-1997 or five years <br />of record, The estimated drainage area of Oil Creek is approximately 14 square miles, Table 2 <br />below displays the estimated flow of Oil Creek at the confluence with Fourmile Creek, in terms <br />of a percentage of exceedence, The orange shading highlights how often the summer flow has <br />been available and the blue shading highlights how often the winter flow has been available, <br /> <br />Table 2: Oil Creek at confluence with Fourmile Creek <br /> <br />1% <br />5% <br />10% <br />20"/0 <br />50% <br />80% <br />90% <br />95% <br />99% <br /> <br />Januarv Februarv March Anril Ma" June Julv Auaust Senlember October November December <br />1.21 0,80 0.69 3:37-- 17.73- '--'*9.16'- "5.14 3,84 ,. .2.....' -'4.08" .,....~ 4:09 '1 1.18 <br />0.93 0.72 0.57 3.09 10.05 7.88 4,43 2.37 1.80 1.49 1.36 0.98 <br />0.77 0.61 0.51 ,"-2.~2 8,03 8.38 4.09 2,03 1,39 1.39 0.93 0.88 <br />0.57 0.45 0.49 1.29 I 5.87 4,99 "_ 2,37_.__ . 1,60 1.24 1.08 0,88 0.57 <br />0,33 0.31 0.41 0,77 1,62 2.47. ~; 0,88 0,77 0.72 077 0,44 0,33 <br />0,28 0.21 0.30 0,50 0.72 0.82 0.62 0.51 0.47 0.47 0,38 0.28 <br />0.23 0,20 0.25 0,48 0.47 0.48 050 0.25 0,26 0.35 0,34 0_26 <br />0.21 0.19 0.24 0.42 0,34 0.40 0.39 0.21 0.23 0.28 0.31 0.24 <br />0.18 0.16 0,22 0,36 0.27 0.37 0.29 0.14 0.21 022 0.28 0.19 <br /> <br />Table 2 shows that the winter recommendation of 1.3 cfs (October 15th - April 14'h) is not <br />available December through March and is only available 10% of the time in April. Table 2 also <br />shows that the summer flow recommendation of 1.8 cfs (April 15th - October 14th) is available <br />10% of the time in April and August, 20% of the time in May and July, 50% of the time in June, <br />5% of the time in September and I % of the time in October. Based on the above water <br />availabilily analysis and the requiremem of the CWCB staff to balance the needs of mankind <br />with a reasonable preservation of the natural environment the recommended summer and winter <br />flows of 1.8 cfs and 1.3 cfs must be reduced further. Staff recommends that the proposed flow <br />recommendation be changed to 1.8 cfs (May 15 - June 30), 0,75 cfs (July I - October 14),0,3 <br />