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<br />sideslopes of this interior channel were modeled at 1 :2.5 for the outside of the bend and 1: 1 0 <br />for the inside. The "n" value for the large channel was estimated at 0.060 and the interior <br />charmel was modeled using 0.035. This configuration would pass 3,000 cfs. A profile plot of <br />this area with the improved channel is shown in Plate 9 and a typical improved cross-section is <br />shown in Plate l4. <br /> <br />The sediment yield calculated for this configuration was 51,800 tonslyr with a mean <br />daily transport of l42 tons/day. This is somewhat less than the existing sediment transport <br />capacity for this subreach. This area showed a disturbingly high transport capacity in its <br />current state. This is due primarily to the extreme constriction at the downstream end and its <br />influence on channel morphology. <br /> <br />Problem Area 7. The improved channel for this sub-reach uses a 400 ft bottom-width <br />channel along the existing channel alignment with a slope of 0.00134 and 1:3 sideslopes, and a <br />slightly more sinuous interior channel with a 100 ft bottom width on a slope ofO.00l67. The <br />sideslopes of this interior channel were modeled at 1 :2.5 for the outside of the bend and l: 1 0 <br />for the inside. The "n" value for the large channel was estimated at 0.060 and the interior <br />channel was modeled using 0.035. This configuration would pass 3,000 cfs. A profile plot of <br />this area with the improved channel is shown in Plate 10 and a typical improved cross-section <br />is shown in Plate 15. <br /> <br />The sediment yield calculated for this configuration was 53,600 tonslyr with a mean <br />daily transport of l47 tons/day. This is approximately the same as the current condition, while <br />maintaining a higher conveyance capacity. <br /> <br />Table 4-1 summarizes the sediment yield values for the improved channel conditions in <br />all problem areas. Note that there is an increase in yield as we progress downstream. This <br />increase is fairly steady except for Problem Area 6. This is because the improved channel was <br />configured for the abnormally high current transport capacity. <br /> <br />Table 4-1. Improved channel yield summary, Channel Improvement alternative. <br />Problem Area Annual Yield (tons) Mean Daily Load (tons/day) <br /> <br />3 l5,500 <br />4 19,300 <br />5 29,600' <br />6 51,800 <br />7 53,600 <br />, Average of above- and below-diversion values. <br /> <br />43 <br />53 <br />81' <br />l42 <br />l47 <br /> <br />33 <br />