|
<br />1
<br />
<br />\
<br />
<br />e
<br />
<br />e
<br />
<br />e
<br />
<br />~f Q), the summer flow recommendation based upon meeting 3 of 3 hydraulic criteria and the
<br />winter flow recommendation based upon 2 of 3 hydraulic criteria,
<br />
<br />Table I: Data
<br />
<br />Party Date Q 250%-40% Summer (3/3) Winter (2/3)
<br />WWW/QR 11118/98 9,04 22,6 - 3.6 6,7 5,0
<br />DOW/wwW 4/15/99 8,33 20,8 - 3,3 8,7 1.5(1)
<br />BLM 4/17/96 13,95 34.9 - 5,6 13,0 4,5'1'
<br />DOWIWWW 4/16/99 9,08 22,7 - 3,6 2,5'" 1.9'"
<br />
<br />BLM = Bureau of Land Management DOW= Division of Wildlife WWW=WWWheeler OR = Queen of the River
<br />(I) Predicted flow outside of the accuracy range of Manning's .Equation. ? = Criteria never met in R2CROSS Staging Table.
<br />
<br />Biologic Flow Recommendations
<br />The BLM recommended a 13,0 cfs summer flow and a 4,5 cfs winter flow based on their April
<br />17th, 1996, data collection effort, An alternative flow recommendation, based on additional data
<br />collected by WWW/QR, of 5.25 cfs, April 1 through July 31 and 3,0 cfs, August I - March 31,
<br />was proposed by the City of Cripple Creek and Cripple Creek/Victor Mining Company, The
<br />WWW/QR flow recommendations were based on an adjustment of the CWCB/CDOW 1 ft/sec
<br />velocity criteria standard for summer flows down to 0,8 ft/sec (See WWW/QR Executive
<br />Summary), The CWCB tabled action on this flow recommendation until CWCB staff could
<br />review the additional data collected by WWW/QR and to collect additional data, if necessary,
<br />
<br />Staff reviewed the data collected by the BLM and WWW/QR and decided to collect two more
<br />data sets, bringing the total number of data sets to review to four. The summer flow
<br />recommendations which met 3 of 3 criteria and are within the accuracy range of the R2CROSS
<br />model fall between 13,0 and 6,7 cfs (See Table 1), Averaging the three summer flow
<br />recommendations gives a summer recommendation of9,5 cfs, The winter flow recommendation
<br />which met 2 of 3 criteria and was inside of the accuracy range of the R2CROSS model was 5,0
<br />cfs (See Table I),
<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 ofrecord used by staff in their analysis was 1992 - 1997, or five years
<br />of record, To estimate the flow of Fourmile Creek at Felch Creek and upstream of Wilson
<br />Creek, staff used the measured flow at the USGS gage and added the estimated inflow from the
<br />Carlton Tunnel, approximately 2,8 cfs, to all values and subtracted upstream in-priority
<br />diversions'Ii, Tables 2 and 3 below display the estimated flow of Fourmile Creek at the
<br />confluence with Felch and Wilson Creeks, in terms of a percentage of exceedence, The orange
<br />shading highlights how often the summer flow has been available and the blue shading highlights
<br />how often the winter flow has been available,
<br />
<br />(I) According to W,W, Wheeler, Engineers for Cripple Creek and Victor Gold Mine, the Carlton Tunnel is currently
<br />flowing at rates of 2,8 cfs to 3,5 cfs
<br />
|