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<br />three hydraulic paramelers at adequate levels across rime habital-types. aquatic habitat in pools <br />and runs will also be maintained for most life stages of fish and aquatic invertebrates (Nehring <br />1979: Espegren 1996). <br /> <br />For (his segment of stream. one data sel was collected with the results shown in Table I below, <br />Table I shows v,"ho collected the data (Panv). (he date the data was collected (Date). the <br />measured discharge at the time of the survey (Q). the accuracy range of predicted nov.'s based on <br />r..lanning's Equation (2.m%- and 40% of Q). the summer flow recommendation based upon <br />meeting 3 of 3 hydraulic criteria and the winter now recommendation based upon :2 of 3 <br />hydraulic criteria. <br /> <br />Table ), Data <br /> <br />. <br />Party Date Q 250 % -.JO % Summer (3/3) Winler (2/3) <br />BLM 7/9/98 4.73 11.8 - 1.9 5.7 1.8'" <br /> <br />BLM " Bureau of Land ~l.m"l'"<'mem III PrC<Jl<"led llow OUhld~ of Ille an'Urac) rdnf"c ('( 'l:lnnlng < Equal"'n. <br />~" ("nlrna ne"cr ~l in Rl("ROSS Sl.:l~ln!! T dl>lc. <br /> <br />Biologic Flow Recommendations <br />The BLM recommcnded a 5.75. 1.5. 1.6 and 1.0 cfs summer now and a 1.3.0.7 and 0.5 cfs <br />winter flow based on their July 91h. 1998. data collection effort and their water availability <br />analysis. Staff has reviewed thc data collected by the BLM, The summer now recommendation, <br />which meets 3 of 3 criteria and is within the accuracy range of the R2CROSS model. is 5.7 cfs. <br />The winter Ilow recommendation. which meets 1 of 3 criteria but falls outside of the accuracy of <br />the R2CROSS model. is 1.8 cfs. CWCB staff believes recommendations that fall outside of the <br />accuracy of the model. below 40% of the measured discharge. may underestimate the required <br />winter flow. To determine the wintcr llow recommendation. staff looked at valid winter llow <br />recommendations for the stream segment located above Trapper Creek (1.3 cfs) and considercd <br />the lower accuracy limit of the R2CROSS model (1.9 cfs). After consulting with the Colorado <br />Division of Wildlife. staff believes 1.8 cfs will be sufficient to protect the natural environment to <br />a reasonable degree. <br /> <br />Hydrologic Data <br /> <br />After receiving the cooperating agencies' biologic recommendation. the C\VCB staff conducted <br />an evaluation of the stream hydrology to determine if water was physically available for an <br />instream flow appropriation. The hydrograph was derived from data collected by the USGS <br />stream gage for East Middle Fork Parachute Creek near Rio Blanco (ID #(9092850). which has a <br />drainage area of 22.1 square miles (see Gage Summary in Appendix C), The period of record for <br />this gage is 1976 to 1983. the period of record used by staff in their analysis was 1976-1983. or <br />sevcn years of record. The estimated drainage area of East Middle Fork Parachute Creek <br />upstream of Northwater and Trapper Creeks is approximately 20,6 square miles. The drainage <br />area upstream of Corral Gulch is 22.1 square miles, Tables 1 and 3 below display the estimated <br />flow of East Fork Parachute Creek at the confluence with :-':orthwalcr and Trapper Creeks and <br />Corral Gulch. in terms of a percentage of exceedence. The orange shading highlights how otien <br />the summer flow has hcen available and the blue shading highlights how often the wimer !low <br />recommendat ions have been available, <br />