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<br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />MITIGATION MEASURES <br /> <br /> <br />The previous section noted the added fill into the floodway has <br />resulted in an increase in the floodway profile of up to O.S-feet. <br />Two measures have been identified and evaluated that would mitigate <br />that impact and return the floodway profile to the 1976 or pre-fill <br />condition. These measures are: <br /> <br />1. Opposite river bank excavation <br />2. River channel clearing and maintenance <br /> <br />Each measure is discussed in the following paragraphs. <br /> <br />Opposite River Bank Excavation <br /> <br />The ca 1 cul ated ri se in the floodway profil e may be el imi nated, or <br />significantly reduced, by enlarging the river cross section. <br />Enlarging the river cross section can be done by removing the material <br />placed by the subdivider or excavating a comparable enlargement of the <br />river section along the opposite or left (east) river bank. <br /> <br />The HEC-2 model was used to calculate the area needed for excavation. <br />The cross sections were revised in size until the rise due to filling <br />was eliminated. <br /> <br />Sheet 1 shows the approximate 1 imits of excavation along the left <br />(east) bank which would mitigate the flood profile rise impacts of the <br />fill along the right (west) bank. The extent of the excavation in <br />Sections 29.5, 29.0, 28.8 and 28.4 is also shown in Figures 1, 2 and <br />3. <br /> <br />Figure 4 shows the excavated condition would lower the floodway <br />profil e (E) to the recomputed F I S floodway profil e conditi on (C). <br />Table 2 shows a comparison of elevations for the excavated condition. <br /> <br />-12- <br />