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9. Removing the fill placed in the area of Riverwood Estates was not considered a feasible alternative with the existence of new structures in the area. I I I I I I I I I I I I I I I I I I I 6. Cross sections of the river channel were surveyed by the City and others in 1985 and 1986, to accurately measure the size and extent of the main channel at selected locations. 7. The study found that the fi 11 encroachment on the area of Riverwood Estates results in an increase of 0.1- to 0.5-feet in the FrS floodway profile. The profile rise effect extends a distance of 0.5- to 1.0-miles upstream of Riverwood Estates. 8. Widening the river by excavation of the east river bank, to obtain a main channel width of 250- to 300-feet, was considered and found to be a possible measure for mitigating the floodway encroachment. To implement this measure would require the further resolution of responsibility, ownership, cost, material disposal, permitting and other possible concerns, including tree removal. ~ 10. Considering the beneficial impact of the clearing of the river downstream and the resultant lowering of the calculated downstream water surface profile, would also serve as mitigation of the fill e nc roachment into the floodway at Ri verwood Estates. A water surface elevation of 0.4-feet lower than the FIS floodway elevation at Section 28.0, justified by the channel clearing and maintenance, provides this benefit. 11. Relocating the floodway through Riverwood Estates to follow the new west bank line, would be feasible, along with the river bank excavation effort or consideration of the channel clearing effort. Th e relocated fl oodway through Ri verwood Estates, as shown on Sheet 1, woul d resul tin a modest floodway profil e ri se for the river bank excavation condition and no resultant rise for the cleared and maintained channel condition. -19-