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<br />r <br />" <br />i\, <br />It <br />... <br />.~ <br /> <br />alternatives" (p. 166) have not been established and a technically <br />defensible non-use value survey is, at the very least, premature <br />and cannot be conducted in this uncertain scientific environment. <br />It remains to be seen whether the concept can be used in the future <br />with any predictive confidence. <br /> <br />" <br />-, <br /> <br />:.. <br /> <br />..~ <br />:~ <br /> <br />." <br /> <br />COMMON ELEMENTS OF THE PREFERRED ALTERNATIVE <br /> <br />A number of Common Elements were determined to be beneficial under <br />any operating scenario. We agree with some of these additions and <br />question the value of others. <br /> <br />AdaDtive Manaaement <br /> <br />Adaptive Management can provide the flexibility to assess the <br />impacts of operations on endangered fish and other resources but <br />this process should not be undermined at the onset by establishing <br />as the EIS Preferred Alternative a narrowly defined set of research <br />flows which forecloses, the opportunity for flexibility and may <br />delay action. Adaptive Management's strength is in its ability to <br />assimilate new information as it is developed and funnel it through <br />an assessment process toward a decision. As envisioned, this <br />process would not be encumbered by inflexibility or arbitrary <br />restrictions which could limit the ability to respond. <br /> <br />."'r:' <br />"~ <br />:t~; <br />':.r. <br />r.:,.: <br /> <br />',' <br /> <br />Flood Freauencv Reduction Measures <br /> <br />Reducing flood frequencies (i.e., flows >45,000 cfs) to one in 100 <br />years so as to create the opportunity for management of Habitat / <br />Beach Building Flows of 45,000 cfs further contradicts the natural <br />forces which produced and maintained historic riverine conditions. <br />Also, reducing capacity within Lake Powell to provide the needed <br />margin for flood waters is not as desirable an alternative as <br />providing additional capacity by raising the spillway elevation. <br /> <br />;'.': <br /> <br />'", <br />'" <br /> <br />," :~ <br /> <br />Habitat Buildina Flows lHBFl and Habitat Maintenance Flows lHMFl <br /> <br />The HBF proposal is common to all alternatives. It calls for flows <br />near 45,000 cfs to be released periodically (e.g., every 10 years) <br />for two weeks to redistribute sediment which has settled in the <br />river bottom. Also, HMF annual flows of about 30,000 cfs would be <br />released for two weeks to maintain backwaters and sand deposits. <br />Sediment would be resuspended by energy of the higher flows and <br />then deposited on the shore. This is intended to replace sand lost <br />from beaches and sand bars by its incessant move back into the <br />river from the shore due to water and wind erosion. <br /> <br />:2~. <br />.~'.:' <br />~! <br />,-)0,' <br />.., <br />".. , <br /> <br />9 <br />