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<br />~ <br />~ <br />.. <br /> <br />^, <br />" <br /> <br />Pg. 201, C. 1, P. 4. Since reproduction is not needed to sustain <br />the trout population but is desired to sustain the trout fishery <br />quality (i.e., the recreation quality), we suggest dividing the <br />matrix into those two elements and comparing the importance of the <br />alternatives. The percent of redds suggested as unaffected by <br />flows is a meaningless figure unless you relate it to the affect on <br />the population. Sustaining the population without stocking may <br />require only 5% successful redds if management continues to require <br />catch-and-release or minimal bag limits. <br /> <br />Pg. 201, C. 10, P. 1. The suggestion that the aquatic food base <br />will be improved with this alternative is speculative. There is at <br />least equal evidence supporting the opposite result (e.g., reduced <br />growth rate, reduced sloughing, lowered nutrient loads, etc.) in <br />areas downstream of Lee's Ferry. This native over-simplifies the <br />issue and thereby misleads as to the actual impacts. <br /> <br />'.~ <br /> <br />> <br /> <br />:"', <br /> <br />~'.. <br /> <br />Pg. 203, C. 1, P. 3. Bioloay - Expect to lose young humpback chub <br />downstream to Lake Mead with these high flows but this should not <br />hurt the population, according to W. Minckley. Young trout would <br />be washed downstream but stocking would compensate for these <br />losses. <br /> <br />. 2~ <br /> <br />l1. <br />t <br />.~-~ <br />:,'i:: <br /> <br />:~. <br /> <br />Pg. 203, C. 2, P. 1. Your suggestion of impacts to Cladophora <br />implies problems upstream of Lee's Ferry which is 15 miles below <br />the dam. Good growth of Cladophora occurs at least to the LCR <br />which is 75 miles below the dam. This suggests the impacted area, <br />if any, is less than 20% of the Cladophora-rich area (15 miles of <br />75 total) and the impact is about 5% (Wetted perimeter of 387 vs. <br />405). We conclude, if your numbers are correct, the overall loss <br />of Cladophora to the 75 miles of principal aquatic food base is <br />about 1 percent (5% of 20%) if minimal flows are reduced from 8000 <br />cfs to 3000 cfs. If this is a reasonable conclusion from your <br />data, then we may conclude impacts to the aquatic food base are <br />minimal. In any event, why has the DEIS not attempted to provide <br />the reader with an assessment of overall loss of Cladophora as a <br />percent of total Cladophora available? <br /> <br />Pg. 203, C. 2, P. 2. The referenced studies fail to discuss the <br />differences between their test data and the real world data in <br />order to rectify the obvious differences between what we all see <br />and their tests. <br /> <br />.,1 <br />" <br />"I <br />.::1 <br />.:,.., <br /> <br />, <br /> <br />:~:: <br /> <br />',".: <br />~~ <br />"{( <br /> <br />Your attempt to develop a proportional difference between no action <br />and the alternative may be incorrect. The DEIS should recognize <br />that higher peaks will create bank storage at higher elevations <br />which will contribute water over a longer time period and thereby <br />wet Cladophora for a different. period than would lower peaks. <br /> <br />Pg. 204, Table IV-9. This chart does not give the wetted perimeter <br />at the LCR. The entire reach from the dam to the LCR is considered <br />prime Cladophora habitat due to clearer water. You could provide <br /> <br />31 <br />