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<br />~ <br /> <br />. <br /> <br />. <br /> <br />4 <br /> <br />Conclusions <br /> <br />Estlmatfon of Pb by computing Pgm from historical gage records <br />is an adequate approximatfon of channel-forming flows. For the <br />Cleopatra's Couch site, the pgm calculated by comblnfng upstream <br />gage records fs much less than a ffeld-estlmated Pb. For this <br />site, the approximation of Pb derived from stream shape and dis- <br />charge measurements exceeds the pgm because of the colluvial bed <br />material. However, the pgm approximates the optfmum combfnatfon <br />of transport capacity and flood frequency to maximfze the. total <br />sediment load. This fs demonstrated by close agreement of the <br />Pgm and an effectfve discharge based upon sedfment samplfng. <br /> <br />For the three PHABSIM sites located in alluvfal channels, the <br />pgm fs the recommended channel forming/maintenance flow. For <br />the PHABSIM sfte at Cleopatras Couch a wider range of flows fs <br />necessary to maintafn the existfng channel conditions. The <br />calculated Pgm of 13,100 cfs wfth ft's associated return <br />Interval and duration Is recommended along wfth the fleld- <br />measured Pb of 21,500 cfs and It's associated return Interval <br />and duration. This wfde range of flows Is required because of <br />the unique channel settfng of the lower Yampa River. <br />