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<br />," <br /> <br />, <br /> <br />USFS Recommendation <br /> <br />. <br /> <br />The USFS instream flow recommendation is based on resource <br />requirements. Four flow levels were developed using data collected <br />at the USGS gage near piedra. These discharges were determined <br />using standard hydrologic techniques as follows3: <br /> <br />~l is the minimum value for the daily mean discharge over the <br />period of record. <br /> <br />Q~2 was derived from R2CROSS analysis customarily done by the <br />d~vision of wildlife uSing hydraulic criteria including <br />average depth, average velocity, and wetted perimeter. <br /> <br />QA is the average annual flow calculated from the period of <br />record. <br /> <br />Q1.5. was derived f~om Log Pearson analysis of the annual <br />ser~es over the per~od of record. <br /> <br />Table 1 displays the discharges associated with the recommended <br />flow levels at the lower wilderness boundary. <br /> <br />Table 1: Flow Amounts Determined by the USFS. <br /> <br />. <br /> <br /> FLOW LEVEL <br />QT., Q,..? Q" Q, ~ <br />55 cfs 100 cfs 308 cfs 1614 cfs <br /> <br />The USFS recommended flow claim would work in the following manner: <br /> <br />o if the actual streamflow is less than ~l' then the actual <br />streamflow would be claimed; <br /> <br />o if the actual streamflow is greater than or equal to QLl but <br />is less than ~2' than QLl would be claimed; <br /> <br />o if the actual streamflow is greater than or equal to ~2 but <br />less than QA' than ~2 would be claimed; <br /> <br />o if the actual streamflow is greater than or equal to QA but <br />less than Ql 5' than a percentage of the streamflow based on <br />the following formula would be claimed; <br /> <br />3 <br /> <br />As recommended in the USFS Instream Flow Needs Assessment <br />and Recommendations for the Proposed Piedra Wilderness <br />Report. <br /> <br />. <br />