Flood‐plain Delineation in Ice Jam Prone Regions

Abstract

Flood‐plain delineation in ice jam prone regions is in its infancy. A methodology is introduced for incorporating the risk of ice jams into flood‐plain delineations in northern regions of the U.S. The distribution of flood elevations is derived from the marginal probability distributions for ice cover and storm induced (non‐ice) flood elevations. An application indicates that incorporation of the hydraulics of an ice cover into flood‐plain delineations can result in substantial increases in the inundation levels which generally implies a significant increase in the lateral extent of flood‐plain boundaries. These results document the need to consider the probability of ice jam flood events in the computation of annual maximum flood elevation distributions and flood risk in ice jam prone regions.