A flood-stage and discharge analysis was made for a 3.61 mile reach of Ninemile Creek between Amboy and Camillus. Water-surface profiles were developed for 50-year, 100-year, and September 26, 1975 flood discharges at Camillus for four different channel conditions: (1) with four culverts at Camillus bypass and a bridge at County Road 36 (present conditions); (2) with only the culverts removed; (3) with only County Road 36 bridge removed; and (4) with the culverts and County Road 36 bridge removed (preconstruction conditions) The 50- and 100-year flood discharges at the Camillus gaging station were determined to be 4,700 and 5,500 cubic feet per second, respectively, and the September 1975 flood discharge was measured to be 2,120 cubic feet per second. If the four culverts are removed, peak water-surface elevations at the gaging station in Camillus during the 50- and 100-year flood would be decreased by 0.7 and 0.3 foot, respectively, relative to those calculated for present conditions. If only County Road 36 bridge is removed, water-surface elevations during the 50- and 100-year flood would be decreased by 0.2 and 0.3 foot, respectively. If both structures are removed, water-surface elevations during the 50- and 10--year floods would be decreased y 0.8 and 0.6 foot, respectively. None of the channel variations would have altered the water-surface elevation at the gage using the September 1975 flood discharge.
