HEC-RAS Model for flood-inundation maps for Cayuga Inlet, Sixmile Creek, Cascadilla Creek, and Fall Creek at Ithaca, New York
Description
Flood profiles for the stream reaches were computed by combining a one-dimensional step-backwater model for the stream channels and a two-dimensional model for the overbank areas. The resulting hydraulic model was calibrated by using water-surface profiles from five observed storm events. The model was then used to compute 15 water-surface profiles for 5 flood frequencies (50- , 10- , 2- , 1- , and 0.2-percent annual exceedance probabilities, or 2- , 10- , 50- , 100- , and 500-year recurrence intervals) and 3 lake levels (representing average conditions, a 2-year-high condition, and a 100-year-high condition). The geographic information system flood-extent polygons, depth grids, and water surface elevation grids generated using this model are also available as part of this data release.